WO2018006819A1

WO2018006819A1 - Multi-layer ceramic printed circuit board and manufacturing method therefor

Info

Publication number: WO2018006819A1
Application number: PCT/CN2017/091822
Authority: WO
Inventors: 王锐勋; 王玉河
Original assignee: 深圳市微纳科学技术有限公司
Priority date: 2016-07-06
Filing date: 2017-07-05
Publication date: 2018-01-11
Also published as: CN106550534B; CN106550534A

Abstract

A multi-layer ceramic printed circuit board (50) comprises at least two ceramic base PCB boards (100) covering each other; the ceramic base PCB boards (100) comprise a ceramic base layer (110) for heat conduction and/or dissipation and electrical insulation, an intermediate layer (120) for printing an electronic circuit and/or laying a heat-conducting metal face and a cover layer (130) composed of an eutectic material having an eutectic melting property; and the ceramic base PCB boards(100) are fitted to one another face to face and heated, and are welded into the multi-layer ceramic printed circuit board (50) by means of the cover layer (130) thereon through eutectic melting. The cover layer (130) above the printed electronic circuit and/or the laid heat-conducting metal face realises mechanical and electrical connection between layers through eutectic melting covering. The structure and manufacturing process of the multi-layer ceramic printed circuit board (50) greatly improve the heat-conduction performance of the multi-layer ceramic printed circuit board (50). The ceramic base layer (110) has very good heat-conduction performance and insulating strength, so the multi-layer ceramic printed circuit board (50) has very good heat-conduction performance and is suitable for high efficiency and high heat flow density application scenarios.

Description

Multilayer ceramic printed circuit board and manufacturing method thereof

Technical field

The present invention relates to the field of semiconductor circuit packaging and application, and particularly relates to a multilayer ceramic printed circuit board used in a high power density semiconductor circuit device of power electronic technology and a manufacturing method thereof, in particular to a high temperature resistant, high heat conduction requirement, high voltage And multilayer ceramic printed circuit boards for high power density applications and methods of making same.

Background technique

The most common technology in the prior art is a printed circuit board made of synthetic resin, such as FR-4 epoxy glass cloth laminate, in which FR-4 is a code name of a flame retardant material, which means that the species The resin material can be self-extinguishing after it has undergone combustion. Although the FR in FR-4 can be understood as FRP, which is the abbreviation of fibre reinforced plastics, it is not a material name, but a material grade, so FR-4 is currently used in general circuit boards. There are many types of graded materials, but most are composites made with epoxy plus filler and fiberglass cloth. Epoxy glass cloth laminates have high mechanical strength at high temperatures and stable electrical properties at high humidity, but in some applications of high current, high voltage, high power semiconductor circuit devices, their stability, dielectric strength, thermal expansion coefficient and thermal conductivity. Still not good for ceramic-based circuit carriers. Especially in today's semiconductor circuit applications, due to the increased integration, high power density, high heat flux density requirements, high power density and high heat flux density are common for common package substrates and application substrates. Challenge, hard to handle. Moreover, the difference in thermal expansion between the carrier material and silicon is difficult to match. When manufacturing a multi-layer printed circuit board, the connection between the single-layer printed circuit boards is usually mechanically bonded by resin material bonding, but these resin materials do not have all the physical characteristics required by power electronics technology, and heat conduction. The coefficient is also low and is not suitable for high power density applications.

The prior art printed circuit board using a ceramic carrier board, the physicochemical stability of the base ceramic material, high heat resistance, high dielectric strength and low thermal expansion coefficient, especially the alumina ceramic-based circuit carrier in the electrically insulating portion The alumina ceramic which is quite close to the thermal expansion coefficient of the silicon material is used, so that the target of higher wiring density can be achieved when the through hole is formed. Therefore, the appearance of the ceramic substrate overcomes the disadvantage that the synthetic resin printed circuit board is difficult to overcome.

The prior art multilayer ceramic printed circuit board is usually produced by a ceramic blank firing method. First, the ceramic powder of the raw material, the synthetic resin, the organic solvent, and the like are mixed and prepared by a ball pulverizer until the mixed liquid forms a milky shape. Ceramic material; next, sheet forming, the ceramic material is formed into a green belt, and the wire is printed on the green belt by using a powder of metal tungsten W mixed with an organic carrier to form a wiring; using a ceramic green belt Easy to process, can be perforated at any position in the green belt, through the embedded inside the hole to achieve interlayer conduction of the multilayer board; then through co-firing, nickel plating, needle brazing, gold plating, etc. A series of steps are completed; finally, the conductors in the laminate and the ceramic are sintered simultaneously. The action is completed while the ceramic-based electronic circuit board is completed. In the whole process, the most important steps are the formation of green belt and the technology of simultaneous sintering. High-melting-point metals such as molybdenum Mu and tungsten W are formed on the plurality of ceramic blanks and through holes to form conductor metal patterns and highly conductive metals. Copper Cu is sintered together to form a multilayer ceramic circuit board. The sintering process of the multilayer ceramic circuit board is complicated, it is difficult to mass-produce and apply, and the process precision is poor, and the fine circuit cannot be made; the combination of the high melting point metal and the copper is poor, leaving a reliability hazard and the thermal conductivity is low.

Glossary:

Eutectic: refers to the phenomenon in which a eutectic fusion occurs at a relatively low temperature, and the eutectic is a fusion of all components at a temperature lower than the melting point of any one of the compositions. The eutectic material changes directly from solid to liquid without passing through the plastic phase, and is a liquid state that simultaneously produces two solid equilibrium reactions. Its melting temperature is called the eutectic temperature. The eutectic material has a specific freezing point. The basic characteristics of the eutectic material are: two different metals or semiconductors or non-metals can form a eutectic fusion material at a temperature ratio well below the respective melting temperatures; this is a eutectic The most significant difference between materials and other non-eutectic materials.

Eutectic soldering: eutectic soldering, also known as low-melting alloy soldering, uses eutectic principles to allow two different metals or semiconductors or nonmetals to form a eutectic fusion state at a temperature ratio well below their respective melting temperatures. Cooling forms a eutectic crystal that achieves eutectic bonding between the two weld faces.

For example, the most common eutectic soldering in microelectronic devices is to solder a silicon chip to a gold-plated base or leadframe, or "gold-silicon eutectic solder." As is well known, gold has a melting point of 1063 ° C and silicon has a higher melting point of 1414 ° C. However, if a combination of silicon of 2.85% by weight and gold of 97.15% is used, a eutectic alloy body having a melting point of 363 ° C can be formed. This is the theoretical basis of gold-silicon eutectic soldering. The welding process of gold-silicon eutectic welding means that the silicon chip is gently rubbed on the gold-plated base at a constant temperature (above 363 ° C) and a certain pressure, and the unstable oxide layer is wiped off. The contact surfaces are melted and a solid phase is formed by two solid phases. After cooling, when the temperature is lower than the 359 ° C of the eutectic point of gold and silicon, the crystal forms formed by the liquid phase are combined with each other to form a mechanical mixture of gold-silicon co-melt crystals, so that the silicon chip is firmly welded on the base and formed into a good Low resistance ohmic contact.

Silicon nitride: The English is Silicon nitride; Si ₃ N ₄ ceramic is a covalent bond compound, the basic structural unit is [SiN ₄ ] tetrahedron, the silicon atom is located in the center of the tetrahedron, and there are four nitrogen atoms around it. , respectively located at the four vertices of the tetrahedron, and then form a continuous and solid grid structure in three-dimensional space in the form of one atom for every three tetrahedrons. Many of the properties of silicon nitride are attributed to this structure. Si ₃ N _{4 has a} low thermal expansion coefficient and a high thermal conductivity, so its thermal shock resistance is excellent.

Aluminum nitride: Its English is Aluminum nitride, abbreviated as AIN; covalent bond compound, belonging to the hexagonal crystal system, the crystal structure of lead-zinc mineral type, white or grayish white. Aluminum nitride is an atomic lattice and is a diamond-like nitride. Stable to 2200 ° C. The room temperature strength is high, and the strength decreases slowly with the increase of temperature, the thermal conductivity is good, and the thermal expansion coefficient is small, which is a good thermal shock resistant material. It has strong ability to resist molten metal erosion. Aluminum nitride is also an electrical insulator with good dielectric properties. It is one of the preferred materials for ceramic circuit carriers.

Al2O3: also known as alumina, chemical symbol: Al ₂ O ₃ , pure alumina is a white amorphous powder, commonly known as alumina, density 3.9-4.0g/cm ³ , melting point 2050 ° C, boiling point 2980 ° C, insoluble Water, an amphoteric oxide, is soluble in inorganic acids and alkaline solutions. It is mainly composed of two types of α-type and γ-type, and can be industrially extracted from bauxite. In the crystal lattice of α-type alumina, the oxygen ions are hexagonally packed tightly, and the aluminum ions are symmetrically distributed in the octahedral coordination center surrounded by oxygen ions, and the lattice energy is large, so the melting point and boiling point are high. Α-type alumina is insoluble in water and acid, also known as aluminum oxide in industry. It is the basic raw material for making metal aluminum. It is also used in making various refractory bricks, refractory enamel, refractory tubes, high temperature resistant experimental instruments, and as an abrasive. , flame retardants, fillers, etc.; high-purity α-alumina is also the raw material for the production of artificial corundum, artificial ruby and sapphire; also used to produce the board base of modern large-scale integrated circuits.

Thermal conductivity: The physical quantity that characterizes the thermal conductivity of a material. The unit is W/m·K, which is written in Chinese per meter. The value is the unit temperature drop in the object, that is, the heat transferred by the unit area per unit time when the temperature difference between the two sides of the material of 1 m thick is 1 Kelvin.

The high thermal conductivity referred to in this document is a guide thermal coefficient greater than or equal to 2 W/m·K.

MOS is the abbreviation of English Complementary Metal-Oxide Semiconductor, meaning Chinese is a complementary metal oxide semiconductor.

The MOSFET is an abbreviation of English Metallic Oxide Semiconductor Field Effect Transistor, meaning Chinese metal oxide semiconductor field effect transistor.

IGBT is the abbreviation of English Insulated Gate Bipolar Transistor, Chinese meaning is insulated gate bipolar transistor.

The CPU is the abbreviation of English Central Processing Unit, meaning Chinese is the central processing unit.

The GPU is an abbreviation of Graphic Processing Unit in English, meaning Chinese is a graphics processor.

MPU is the abbreviation of English Micro Processor Unit, meaning Chinese is microprocessor.

IPM is the abbreviation of English Integrated Power Module, meaning Chinese is the integrated power module.

PCB is the abbreviation of Printed Circuit Board in English, meaning Chinese is printed or printed circuit board.

LED is the abbreviation of English Light Emitting Diode, Chinese means LED.

COB is the abbreviation of English Chip On Board. The Chinese meaning is the chip on board. The chip package on the chip is one of the bare chip placement technologies. The semiconductor chip is placed on the printed circuit board, and the electrical connection between the chip and the substrate is made with the wire bond. The method is implemented and covered with resin to ensure reliability.

COB light source: LED planar light source or integrated light source is also called COB light source through COB; currently COB light source is mainly used in indoor and outdoor lighting, such as indoor spotlights, downlights, ceiling lights, ceiling lamps, fluorescent lamps and lamp strips, outdoor Street lamps, high bay lights, floodlights, wall lights, luminous characters, etc.

In the traditional printed circuit, the circuit and the pattern are included: the circuit is used as a tool for conducting conduction between the original components, and a large copper surface is additionally designed as a grounding and power supply layer. The line and the drawing are made at the same time. A circuit and a pattern have been provided on the ceramic-based PCB board (100) of the present invention.

A dielectric layer included in a conventional printed circuit: used to maintain insulation between a circuit and layers, commonly referred to as a substrate; the substrate in the present invention is a ceramic.

The conventional hole in the printed circuit (Through hole/via) is usually a via hole to allow two or more layers to be electrically connected to each other, and the larger via hole is used as a component plug-in, and the non-conducting is also used. Holes (nPTH) are generally used as surface mount positioning for fixing screws during assembly; in the embodiment of the present invention, some ceramic-based PCB boards are provided with via holes, and some ceramic-based PCB boards may not be turned on. Holes, depending on the specific conditions of each ceramic-based PCB in a specific multilayer ceramic printed circuit board.

Solder resistant/Solder Mask included in traditional printed circuits: not all copper surfaces should be tinned, so areas that are not tinned will be printed with a layer of tin-free material. Usually epoxy resin) to avoid short circuits between lines that are not tinned. According to different processes, it is divided into green oil, red oil and blue oil. The solder resist ink may also be disposed on the topmost and bottommost ceramic-based PCB boards of the present invention; however, no layer is provided between the ceramic-based PCB boards disposed in the multilayer ceramic printed circuit board for two Adjacent ceramic-based PCB boards are fixedly coupled and used for insulating layers of interlayer printed circuit insulation. In the present invention, between the ceramic-based PCB boards in the multilayer ceramic printed circuit board, the eutectic melting of the eutectic cladding material is used to achieve the fixed connection between the layers, and the eutectic overlay layer and the printing are involved. The intermediate layers of the electronic circuit can be electrically connected.

The conventional printed circuit also involves Surface Finish: since the copper surface is easily oxidized in a general environment, it is impossible to apply tin (poor solderability), so it is protected on the copper surface to be tinned. The protection methods include spray coating (HASL), gold (ENIG), silver (Immersion Silver), tin (Immersion Tin), and organic solder resist (OSP). The methods have their own advantages and disadvantages, collectively referred to as surface treatment. The surface of the multilayer ceramic printed circuit board to which the present invention relates can be treated by a conventional surface treatment.

Summary of the invention

The technical problem to be solved by the present invention is to provide a multilayer ceramic printed circuit board with high thermal conductivity by avoiding the insufficiency of the prior art multilayer ceramic circuit board manufacturing process, the precision is poor, and the thermal conductivity is low.

The technical solution adopted by the present invention to solve the technical problem is a multilayer ceramic printed circuit board, including at least two a ceramic-based PCB board that is mutually overlapped; each of the ceramic-based PCB boards includes a ceramic base layer, an intermediate layer, and a cover layer; the ceramic base layer is used for heat conduction and/or heat dissipation and electrical insulation; The two surfaces of the base layer which are generally parallel to each other are respectively referred to as a base A surface and a base B surface, the intermediate layer is disposed on the surface of the substrate A, or the intermediate layer is disposed on the surface of the substrate B; The intermediate layer is used for printing electronic circuits and/or for laying a thermally conductive metal surface; the intermediate layer comprises an electronic circuit printing area for printing electronic circuits and/or a copper-clad area for laying a thermally conductive metal surface, the covering The copper region covers a large area in the intermediate layer to achieve heat conduction and heat dissipation; the cladding layer is a eutectic material layer having eutectic melting characteristics; the cladding layer is used for another of the other ceramic-based PCB boards The eutectic layer of the cladding layer is combined to realize heat conduction or heat conduction and electrical connection; the cladding layer comprises an overlay layer of the electronic circuit printing area and/or a cladding layer of the copper-clad area; the overlay layer of the electronic circuit printing area is uniform Printed electronic circuit covering the electronic circuit printing area a line and a node; the copper-clad laminate layer is evenly distributed on the heat-conducting metal surface of the copper-clad region; the ceramic-based PCB board is bonded to each other in opposite directions, and the cover is applied thereon The eutectic soldering is completed in combination to fuse the ceramic-based PCB boards into a multilayer ceramic printed circuit board having at least two layers.

The printed circuit and/or the thermally conductive metal surface of the two opposite intermediate layers of the ceramic-based PCB board need to be mirror-symmetrical to each other, or at least a majority of the printed electronic circuit and/or the thermally conductive metal surface. The pattern is mirror symmetrical; when the ceramic-based PCB board needs to be covered with two opposite intermediate layers, the printed circuit and/or the thermally conductive metal surface are asymmetric in pattern, and the asymmetric portion is printed on the electronic circuit and The surface on which the thermally conductive metal faces face should be a blank ceramic face, or the face opposite the printed portion of the asymmetrical portion of the printed circuit and/or the thermally conductive metal face is an island-shaped printed circuit pattern.

When the intermediate layer is disposed on both the base A side and the base B side of the ceramic base layer, the printed circuit and/or the thermally conductive metal surface on each of the intermediate layers passes through the metal on the ceramic base layer The holes are electrically coupled; the metal holes include solid metal holes that are filled through the metal pillars and metallized through holes that have been plated with metal.

The multi-layer ceramic printed circuit board comprises a three-layer ceramic printed circuit board; the three-layer ceramic printed circuit board is eutectic-fused with two ceramic-based PCB boards on both sides thereof by an intermediate ceramic-based PCB board Forming the intermediate layer on the base A side and the base B side of the ceramic base layer of the intermediate ceramic-based PCB board, and on the intermediate layer of the base A side and the base B side The cover layer is disposed on the upper intermediate layer to accommodate the case where another ceramic-based PCB board is respectively covered on the base A surface and the base B surface of the same ceramic-based PCB board.

The multilayer ceramic printed circuit board comprises a multilayer ceramic printed circuit board having a number of layers of four or more layers; the multilayer ceramic printed circuit board comprises at least four ceramic-based PCB boards, each of the ceramic-based PCB boards Forming a multilayer ceramic printed circuit board by eutectic fusion bonding between the respective cladding layers and the facing layers facing each other; the multilayer ceramic printing The number of layers of the circuit board corresponds to the number of the ceramic-based PCB boards.

The thermally conductive metal surface of the copper-clad region is electrically coupled to a local functional network of the printed circuit in the electronic circuit printed region, or the thermally conductive metal surface of the copper-clad region and the printed portion of the electronic circuit printed region The electronic circuit has an electrical connection as a whole.

An isolation region for electrical insulation is further disposed between the electronic circuit printed area and the copper-clad area, and the cover layer is not disposed on the isolation area.

The electronic circuit printed area includes a high power density component holding area for setting a high power density component, a control circuit area for setting a control circuit, and a power electronic circuit area for routing power electronic circuits.

The eutectic material coated on the two layers facing the eutectic bonding is Au-Sn gold tin alloy, Au-Si gold silicon eutectic material, Au-Ge gold bismuth alloy, Ag-Sn silver tin alloy, Any one of Sn-Bi tin antimony alloy, Sn-In tin indium alloy or Sn-Pb tin lead alloy.

Participating in the eutectic soldering of the two layers facing the cladding layer, wherein one of the eutectic materials covered by the overlay layer is Au-Sn gold tin alloy, Au-Si gold silicon eutectic material, Au-Ge gold bismuth alloy Any one of Ag-Sn silver tin alloy, Sn-Bi tin antimony alloy, Sn-In tin indium alloy or Sn-Pb tin-lead alloy; wherein the eutectic material coated by the other cladding layer is a single a layer of gold Au, tin Sn, silicon Si, silver Ag, germanium Ge, germanium Bi, indium In, nickel Ni, lithium Li, palladium Pd or aluminum Al; or another eutectic material coated by the other cladding layer It is a mixture of two or more kinds of gold Au, tin Sn, silicon Si, silver Ag, yGe, 铋Bi, indium In, nickel Ni, lithium Li, palladium Pd or aluminum Al. Layer structure.

Two of the two overlapping layers that participate in the eutectic soldering are uniformly and individually coated with a single layer or a plurality of layers of gold Au, tin Sn, silicon Si, silver Ag, germanium Ge, One of 元素Bi, indium In, palladium Pd or lead Pb element materials; two of the two layers of the eutectic bonding which are opposite to each other, and the surface eutectic materials for the fusion lamination are two The same material; the two materials are melt-clad to form Au-Sn gold-tin alloy, Au-Si gold-silicon eutectic layer, Au-Ge gold-bismuth alloy, Ag-Sn silver-tin alloy during eutectic soldering, Any of Sn-Bi tin antimony alloy, Sn-In tin indium alloy, and Sn-Pb tin-lead alloy.

The Au-Sn gold-tin alloy, in terms of mass percentage, contains gold Au 80.0% ± 2.0%, and the balance is tin Sn.

The Ag-Sn silver-tin alloy is 96.5%±2.0% by mass of tin, and the balance is silver Ag.

The Au-Ge gold-bismuth alloy, in terms of mass percentage, contains gold Au 88.0% ± 2.0%, and the rest is 锗Ge.

The Au-Si gold silicon eutectic material, in terms of mass percentage, contains gold Au 97.0% ± 2.0%, and the balance is silicon Si.

The cover layer has a thickness of from 2 micrometers to 100 micrometers.

The cover layer has a thickness of from 3 micrometers to 20 micrometers.

The material of the ceramic base layer is a high thermal conductive ceramic material having a thermal conductivity of 2 W/m·K or more; the ceramic material for forming the ceramic base layer comprises aluminum oxide, aluminum nitride, silicon nitride and ruthenium oxide; The ceramic base layer is one or a combination of two or more of the above three materials.

The ceramic base layer of the plurality of ceramic-based PCB boards which are mutually overlapped may be made of the same material; or the ceramic base layer of the plurality of ceramic-based PCB boards which are mutually overlapped may have different materials; different ceramics The materials used for the substrate are selected according to the thermal and insulating requirements of the different layers.

The technical solution adopted by the present invention to solve the technical problem may also be a method for the foregoing multilayer ceramic printed circuit board comprising the following steps: A1: electronic circuit printing on the intermediate layer of the ceramic-based PCB board Uniformly coating the eutectic material on each line and each node of the printed circuit of the region, and/or uniformly coating the eutectic material on the thermally conductive metal surface of the copper-clad region of the intermediate layer of the ceramic-based PCB board, Forming a cover layer on each line of the printed circuit of the intermediate layer and on each of the nodes and/or on the thermally conductive metal surface; before the covering of the cover layer, the intermediate layer of the ceramic-based PCB board is provided with printing An electronic circuit printing area having printed circuit lines and a copper-clad area for conducting heat conduction and heat dissipation for a large area of the intermediate layer;

A2: pressing the cladding layers of at least two ceramic-based PCB boards to each other, heating together to the eutectic temperature of the eutectic material used, performing eutectic fusion coating, and melting and laminating the ceramic-based PCB boards into an integrated a multilayer ceramic printed circuit board; when the number of the ceramic-based PCB boards is plural, each of the ceramic-based PCB boards is between the respective cladding layers and the facing layers thereof The eutectic fusion cladding forms a multilayer ceramic printed circuit board; the number of layers of the multilayer ceramic printed circuit board corresponds to the number of the ceramic-based PCB boards.

The technical effects of the invention are as follows: 1. The cover layer not only facilitates the mechanical connection and electrical connection between the layers of the multilayer ceramic printed circuit board by eutectic soldering, but also greatly improves the thermal conductivity of the electronic circuit printed area; 2. The copper-clad area of the intermediate layer and the clad layer on the copper-clad area further improve the thermal conductivity of the multilayer ceramic printed circuit board; 3. The ceramic base material of the ceramic-based PCB board is high in ceramic material The thermally conductive ceramic material has good thermal conductivity and dielectric strength; the multilayer ceramic printed circuit board of the present invention has superior thermal conductivity and is particularly suitable for applications with high power and high heat flux density.

DRAWINGS

1 is a schematic plan view of a preferred embodiment of a high thermal conductivity multilayer ceramic printed circuit board 10 of the present invention; in the top view, the intermediate layer 120 and the cover layer 130 are shown as the same area.

Figure 2 is a cross-sectional view taken along line A-A of Figure 1;

Figure 3 is a partially enlarged schematic view of a portion D of Figure 2;

Figure 4 is a partially enlarged schematic view of portion E of Figure 3;

Figure 5 is a schematic perspective view of the exploded state of the preferred embodiment I of Figure 1, in which some parts and partial faces are not visible;

6 is a top plan view of the base B surface 114 of the first -1 ceramic-based PCB board 221 for fabricating the double-layer ceramic printed circuit board 50 of FIG. 1;

Figure 7 is a top plan view of the base A face 112 of the first -1 ceramic-based PCB board 221 for making the double-layer ceramic printed circuit board 52 of Figure 1;

Figure 8 is a top plan view of the base B face 114 of the first -2 ceramic-based PCB board 222 for making the double-layer ceramic printed circuit board 52 of Figure 1;

Figure 9 is a top plan view of the base A face 112 of the first -2 ceramic-based PCB board 222 for making the double-layer ceramic printed circuit board 52 of Figure 1;

In the top view of FIGS. 6-9, the intermediate layer 120 and the overlay layer 130 are shown as the same area; the electronic circuit printed area overlay layer 138 and the electronic circuit printed area 128 are shown as The same area; the copper-clad area cladding layer 135 and the copper-clad area 125 are shown as the same area;

10 is a schematic top plan view of the electronic circuit printed area 128 of the preferred embodiment II of the high thermal conductivity multilayer ceramic printed circuit board 10 of the present invention;

11 is a schematic circuit diagram of a MOSFET full bridge module of a preferred embodiment III of the high thermal conductivity multilayer ceramic printed circuit board 10 of the present invention;

12 is a plan view of the base B surface 114 of the ceramic base layer 110 of the III-1 ceramic-based PCB board 231 of the double-layer ceramic printed circuit board 52 in the MOSFET full-bridge module application according to the preferred embodiment III of the present invention. Schematic; the solid crystal region in the figure is a high power density component fixing area 1283, the wire bonding area and the pad in the figure are the control circuit area 1285, and the area copper in the figure is the copper-clad area 125;

13 is a plan view of the base A surface 112 of the ceramic base layer 110 of the III-1 ceramic-based PCB board 231 of the double-layer ceramic printed circuit board 52 in the MOSFET full-bridge module application according to the preferred embodiment III of the present invention. schematic diagram;

14 is a plan view of the base A surface 112 of the ceramic base layer 110 of the III-2 ceramic-based PCB board 232 of the double-layer ceramic printed circuit board 52 in the MOSFET full-bridge module application according to the preferred embodiment III of the present invention. schematic diagram;

15 is a plan view of the base B surface 114 of the ceramic base layer 110 of the III-2 ceramic-based PCB board 232 of the double-layer ceramic printed circuit board 52 in the MOSFET full-bridge module application according to the preferred embodiment III of the present invention. schematic diagram;

16 is a schematic axial projection view of a preferred embodiment IV of the present invention, that is, a multi-channel COB-LED light source application substrate;

17 is a top plan view showing a preferred embodiment IV of the present invention, that is, a four-layer ceramic printed circuit board 54;

Figure 18 is an orthographic projection of the base A face 112 of the IV-1 ceramic-based PCB board 441 in a preferred embodiment IV of the present invention. Top view;

Figure 19 is a front plan view showing the base B surface 114 of the IV-1 ceramic-based PCB board 441 in a preferred embodiment IV of the present invention;

20 is a front plan view of a base A surface 112 of a ceramic base layer 110 of the IV-2 ceramic-based PCB board 442 in a preferred embodiment IV of the present invention;

Figure 21 is a front plan view showing the base B surface 114 of the ceramic base layer 110 of the IV-2 ceramic-based PCB board 442 in a preferred embodiment IV of the present invention;

Figure 22 is a front plan view showing the base A surface 112 of the ceramic base layer 110 of the IV-3 ceramic-based PCB board 443 in the preferred embodiment IV of the present invention;

Figure 23 is a front plan view showing the base B surface 114 of the ceramic base layer 110 of the IV-3 ceramic-based PCB board 443 in the preferred embodiment IV of the present invention;

Figure 24 is a front plan view showing the base A surface 112 of the ceramic base layer 110 of the IV-4 ceramic-based PCB board 444 in the preferred embodiment IV of the present invention;

Figure 25 is a front plan view showing the base B surface 114 of the ceramic base layer 110 of the IV-3 ceramic-based PCB board 444 in the preferred embodiment IV of the present invention;

Figure 26 is a front elevational, side elevational view of a preferred embodiment IV of the present invention, i.e., a four-layer ceramic printed circuit board 54;

Figure 27 is a partial enlarged view of the upper portion of Figure 26;

Figure 28 is a partially enlarged schematic view showing a portion H of Figure 27;

The I-1 ceramic base PCB board 221, the I-1 ceramic base PCB board 222, the III-1 ceramic base PCB board 231, the III-2 ceramic base PCB board 232, and the The IV-1 ceramic-based PCB board 441, the IV-2 ceramic-based PCB board 442, the IV-3 ceramic-based PCB board 443, and the IV-4 ceramic-based PCB board 444 are all ceramic-based PCB boards 100 in different embodiments. Specific embodiments, the numbers are only used for identification, and these numbers are not represented by any order and priority;

The solid crystal regions of the different LED chips, and the positive and negative electrode pads of the LEDs are shown in FIGS. 16 to 18; the via holes and the pads are shown in FIGS. 19 to 23; The area of copper to be covered in the holes, the area copper in FIGS. 19 to 25 is the copper-clad area 125.

detailed description

The contents of the present invention will be further described in detail below with reference to the accompanying drawings.

A multilayer ceramic printed circuit board 50 having a high thermal conductivity has a plurality of embodiments.

As shown in FIG. 1 to FIG. 9, Embodiment I, in the embodiment I, the multilayer ceramic printed circuit board 50 is a double-layer ceramic The porcelain printed circuit board 52. In this embodiment, the first-th ceramic-based PCB board 221 and the first-th ceramic-based PCB board 222 are eutectic and melt-molded to form a double-layer ceramic printed circuit board 52.

In the embodiment of the double-layer ceramic printed circuit board 52 shown in FIGS. 1 to 9, the double-layer ceramic printed circuit board 52 includes two ceramic-based PCB boards 100 which are mutually overlapped; each of the ceramic-based PCBs The board 100 includes a ceramic base layer 110, an intermediate layer 120, and a cover layer 130; the ceramic base layer 110 is used for heat conduction and/or heat dissipation and electrical insulation; respectively, the ceramic base layer 110 is mutually parallel on both surfaces Referred to as substrate A face 112 and substrate B face 114, said intermediate layer 120 is disposed on said substrate A face 112, or said intermediate layer 120 is disposed on said substrate B face 114; said intermediate layer 120 is for Printed electronic circuitry and/or a thermally conductive metal surface; the intermediate layer 120 includes an electronic circuit footprint 128 for printing electronic circuitry and/or a copper-clad zone 125 for routing a thermally conductive metal surface, the copper cladding The region 125 covers a large area in the intermediate layer to achieve heat conduction and heat dissipation; the cover layer 130 is a eutectic material layer having eutectic melting characteristics; the cover layer 130 is used for another ceramic-based PCB board 100 A cover layer 130 is eutectic bonded to achieve heat conduction; the cover layer 130 includes electrons a line printed area capping layer 138 and/or a copper clad area capping layer 135; the electronic circuit printed area capping layer 138 is evenly distributed over the lines of the printed circuit of the electronic circuit printing area 128 and The copper-clad laminate layer 135 is evenly distributed on the heat-conducting metal surface of the copper-clad region 125; the ceramic-based PCB board 100 is bonded to each other in the opposite direction, by means of the above The cladding layer 130 completes eutectic soldering, thereby fused each of the ceramic-based PCB boards 100 to a multilayer ceramic printed circuit board 50 having two layers.

The cover layer 130 can not only realize the interlayer connection of the multilayer ceramic printed circuit board 50 by eutectic soldering, but also improve the thermal conductivity of the electronic circuit printed area 128. The copper clad zone 125 and the clad layer 130 on the copper clad zone 125 further enhance the thermal conductivity of the multilayer ceramic printed circuit board 50.

Of course, the number of layers of the multilayer ceramic printed circuit board 50 may be other multilayer ceramic printed circuit boards greater than two, such as three-layer, four-layer, five-layer, and higher-layer multilayer ceramic printed circuit boards. A layer is added for each additional ceramic-based PCB board 100.

In some embodiments, the printed circuit and/or the thermally conductive metal surface of the two opposite intermediate layers of the ceramic-based PCB board 100 need to be mirror-symmetrical to each other, or at least a majority of the printed electronic The pattern of the line and/or the thermally conductive metal surface is mirror-symmetrical; when the pattern of the printed circuit and/or the thermally conductive metal surface of the two opposite intermediate layers of the ceramic-based PCB board 100 needs to be overlapped, The side where the electronic circuit and/or the thermally conductive metal face face each other should be a blank ceramic face.

In some embodiments, when the intermediate layer 120 is disposed on the base A surface 112 and the base B surface 114 of the ceramic base layer 110, printed circuit lines and/or heat conduction on each of the intermediate layers 120. The metal face is electrically coupled through a metal hole 118 in the ceramic base layer 110; the metal hole 118 includes a metal post such as a metal pin The solid metal holes and or the walls of the holes have been metallized through metallized through holes.

In some embodiments, the metal holes 118 have been metallized before the ceramic-based PCB board 100 is used to fabricate the multilayer ceramic printed circuit board 50, and each of the ceramic-based PCB boards 100 is laminated in two layers. After the ceramic printed circuit board 50, since the eutectic solder has good fluidity, the surface of the metallized via also participates in eutectic bonding to form a eutectic layer which is favorable for heat conduction. The metal hole 118 includes a solid metallized hole and a hollow metallized through hole. Of course, the solid metallized holes have better thermal conductivity than the hollow metallized through holes. Where some of the extremely high thermal conductivity requirements are required, the metal holes can be designed as solid metallized holes. In addition, positioning holes for mounting and positioning may be disposed on each of the ceramic-based PCB boards 100.

In some embodiments, the thermally conductive metal surface of the copper-clad region 125 is electrically coupled to a local functional network of printed circuit circuitry in the electronic circuit footprint 128, or the thermally conductive metal surface of the copper-clad region 125 The printed electronic circuits in the electronic circuit printed area 128 are integrally electrically coupled.

In some embodiments, the ceramic substrate layer 110 and the intermediate layer 120 are electrically insulated from each other. The thermally conductive metal surface of the copper-clad region 125 of the intermediate layer 120 and the cladding layer 130 are both electrically and mechanically coupled. Similarly, when the printed circuit of the electronic circuit printed area 128 of the intermediate layer 120 and the respective layers of the printed circuit are overlapped with the cover layer 130, the lines and nodes of the printed electronic circuit are overlapped with the nodes. There are both electrical and mechanical connections between layers 130. That is, the electronic circuit printed area cover layer 138 is evenly distributed on the lines and nodes of the printed circuit, and the printed circuit area 138 and the printed circuit line are melted on each line and each node. After the lamination, the electrical connection and the mechanical coupling are realized; the copper-clad laminate layer 135 is evenly distributed on the heat-conducting metal surface of the copper-clad region 125, and the copper-clad laminate layer 135 and the heat-conducting metal surface are melted. The electrical connection and the mechanical connection are realized after the combination.

In some embodiments, when the two ceramic-based PCB boards 100 are melt-clad by the respective cladding layers 130, a fused eutectic molten layer is formed; the eutectic molten layer is formed on the two ceramic-based PCB boards 100. The lines and nodes of the printed circuit are electrically and mechanically coupled by eutectic melting; likewise, the respective thermally conductive metal faces of the two ceramic-based PCB boards 100 are electrically and mechanically coupled by eutectic melting.

In some embodiments, whether there is electrical connection between each line and each node of the printed circuit of the ceramic-based PCB board 100 and the thermally conductive metal surface can be flexibly modified according to actual needs.

In some embodiments, the thermally conductive metal face of the copper-clad region 125 is integrally electrically coupled to a local circuit function network or the electronic circuit footprint 128 in the electronic circuit footprint 128. That is, the copper-clad region 125 may have electrical characteristics in addition to the functions of heat conduction and heat dissipation. For example, in some embodiments, the copper-clad region 125 can be coupled to a ground network in the electronic circuit footprint 128 to impart electrical characteristics to the copper-clad region 125 to be grounded. According to the electromagnetic compatibility design requirements of the electronic circuit, the copper-clad area 125 can also be connected to different electrical networks in the electronic circuit of the electronic circuit printing area 128 to achieve better circuit realization effects. In some applications, in order to achieve the shielding effect of the circuit, the The electronic circuitry of the electronic circuit footprint 128 and the thermally conductive metal surface of the copper-clad region 125 are fully electrically coupled to form a shield.

In some embodiments, an isolation region 127 for electrical insulation is disposed between the electronic circuit printed region 128 and the copper-clad region 125, and the cover layer 130 is not disposed on the isolation region 127.

In practical applications, the ratio of the electronic circuit printing area 128 and the copper-clad area 125 to the entire intermediate layer 120 can be arranged according to the actual heat conduction requirement. The main purpose of the copper-clad area 125 is to conduct heat, and thus heat conduction. Where high requirements are required, in addition to the electronic circuit footprint 128 and the necessary isolation regions 127, the remaining intermediate layer regions may be entirely covered to form a large area of copper regions 125 to improve thermal conductivity.

In some embodiments, the electronic circuit footprint 128 includes a high power density component mounting area 1283 for setting high power density components, a control circuit area 1285 for setting control circuitry, and power for routing power electronics. Electronic circuit area 1287.

In some embodiments, when the ceramic-based PCB board 100 is located at the topmost or bottommost layer of the multilayer ceramic printed circuit board 50, the outer surface of the intermediate layer 120 further includes a solid for attaching the chip components. Crystal area.

In some embodiments, the multilayer ceramic printed circuit board 50 includes a three-layer ceramic printed circuit board; the three-layer ceramic printed circuit board consists of an intermediate ceramic-based PCB board 100 and two ceramic-based PCBs The plate 100 is eutectic melt-clad; the intermediate layer 120 is disposed on the base A surface 112 and the base B surface 114 of the ceramic base layer 110 of the intermediate ceramic-based PCB board 100, and the substrate A is The cover layer 130 is disposed on the intermediate layer 120 of the 112 and the intermediate layer 120 on the base B surface 114 to accommodate the base A surface 112 and the base B surface 114 of the same ceramic substrate PCB 100. The case of replacing another ceramic-based PCB board 100 is repeated.

In some embodiments, the multilayer ceramic printed circuit board 50 includes a multilayer ceramic printed circuit board 50 having a layer number of four or more layers; the multilayer ceramic printed circuit board 50 includes at least four ceramic-based PCBs a multi-layer ceramic printed circuit board 50 is formed between each of the ceramic-based PCB boards 100 by means of a eutectic fusion between the respective cover layer 130 and the facing layer 130; The number of layers of the multilayer ceramic printed circuit board 50 corresponds to the number of the ceramic-based PCB boards 100.

In some embodiments, the eutectic material coated by the two layers facing the eutectic layer is Au-Sn gold tin alloy, Au-Si gold silicon eutectic material, Au-Ge gold bismuth alloy, Any of Ag-Sn silver tin alloy, Sn-Bi tin antimony alloy, Sn-In tin indium alloy or Sn-Pb tin lead alloy. The eutectic material can also be replaced with other materials having eutectic properties suitable for eutectic soldering. Various eutectic materials have different eutectic temperatures depending on the composition of their eutectic materials; the usual eutectic temperature ranges from 200 degrees Celsius to 400 degrees Celsius; and some eutectic materials have eutectic temperatures between 100 degrees Celsius and 200 degrees Celsius; There are also eutectic materials with eutectic temperatures ranging from 400 degrees Celsius to 800 degrees Celsius. Among them, some eutectic materials such as Au-Sn gold-tin alloy have a eutectic temperature between 300 and 330 degrees Celsius. The temperature can be 310 or 320 degrees Celsius.

In some embodiments, the eutectic material of the double-sided facing cladding layer 130 participating in the eutectic soldering, wherein the eutectic material covered by the cladding layer 130 is Au-Sn gold tin alloy, Au-Si gold silicon eutectic Any one of a material, an Au-Ge gold-niobium alloy, an Ag-Sn silver-tin alloy, a Sn-Bi tin-bismuth alloy, a Sn-In tin-indium alloy, or a Sn-Pb tin-lead alloy; and the other of the cladding layers 130-coated eutectic material is a single layer of gold Au, tin Sn, silicon Si, silver Ag, germanium Ge, germanium Bi, indium In, nickel Ni, lithium Li, palladium Pd or aluminum Al; or the other said The eutectic material coated by the cladding layer 130 is any one of gold Au, tin Sn, silicon Si, silver Ag, yGe, 铋Bi, indium In, nickel Ni, lithium Li, palladium Pd or aluminum Al. Or two or more alternately laid multi-layer structures. Moreover, in one of the cladding layers 130 participating in the eutectic fusion welding, the Au-Sn gold-tin alloy, the Au-Si gold-silicon eutectic material, the Au- Any one or two or more alternating layers of Ge gold alloy, Ag-Sn silver tin alloy, Sn-Bi tin antimony alloy, Sn-In tin indium alloy, Sn-Pb tin-lead alloy; In the cladding layer 130 for crystal fusion welding, gold Au, tin Sn, silicon Si, silver Ag, germanium Ge, germanium Bi, indium In, nickel Ni, lithium may be uniformly coated under the molten cladding soldering surface. Any one or two or more of alternating layers of Li, lead Pb, aluminum Al, palladium Pd, and aluminum Al. The above-mentioned single material participating in the eutectic fusion welding can be replaced with any conventional metal material or semiconductor material.

In some embodiments, the two facing layers 130 of the two sides facing each other in the eutectic soldering are uniformly and separately coated with a single layer or a plurality of layers of gold Au, tin Sn, silicon Si. a silver Ag, 锗Ge, 铋Bi, indium In, palladium Pd or lead Pb elemental material; two of the facing layers 130 participating in the eutectic welding, each of which is used for the surface of the fusion cladding The eutectic material is two different materials; the two materials are melt-clad to form Au-Sn gold-tin alloy, Au-Si gold-silicon eutectic layer, Au-Ge gold-bismuth alloy during eutectic soldering. Any of Ag-Sn silver tin alloy, Sn-Bi tin antimony alloy, Sn-In tin indium alloy, and Sn-Pb tin-lead alloy. That is, in the cladding welding surface of the two opposing cladding layers 130 participating in the eutectic fusion welding: one side is uniformly covered with a single layer or alternating layers of gold Au, tin Sn, silicon Si, silver Ag, 锗Ge , 铋Bi, indium In, palladium Pd or lead Pb; the other side is uniformly coated with a single layer or alternating layers of gold Au, tin Sn, silicon Si, silver Ag, 锗Ge, 铋Bi, indium In, palladium Pd or Lead Pb; one of the two bonding surfaces of the opposite cladding layers 130 is evenly coated with a material of type A, and the other side is uniformly covered with a material B, the material of the type A and the material of the type B In the case of eutectic soldering, Au-Sn gold-tin alloy, Au-Si gold-silicon eutectic material, Au-Ge gold-bismuth alloy, Ag-Sn silver-tin alloy, Sn-Bi tin-bismuth alloy, and Sn-In tin-indium are formed by lamination. Any of alloys, Sn-Pb tin-lead alloys.

In some embodiments, in the Au-Sn gold-tin alloy, the mass percentage of gold Au is 80.0%, and the mass percentage of tin Sn is 20.0%. The eutectic temperature was 280 ° C, that is, the melting point of the eutectic soldering was 280 ° C.

In some embodiments, in the Ag-Sn silver tin alloy, the mass percentage of silver Ag is 3.5%, and the mass percentage of tin Sn is 96.5%.

In some embodiments, in the Au-Ge gold-niobium alloy, the mass percentage of gold Au is 88.0%, and the mass percentage of yGe is 12.0%. The eutectic temperature was 356 ° C, that is, the melting point of the eutectic soldering was 356 ° C.

In some embodiments, in the Au-Si gold silicon eutectic material, the mass percentage of gold Au is 97.0%, and the mass percentage of silicon Si is 3.0%. The eutectic temperature was 370 ° C, that is, the melting point of the eutectic soldering was 370 ° C.

The eutectic material is in addition to the aforementioned Au-Sn gold tin alloy, Au-Si gold silicon eutectic material, Au-Ge gold bismuth alloy, Ag-Sn silver tin alloy, Sn-Bi tin antimony alloy, and Sn-In. In addition to the tin-indium alloy, it may be any other eutectic composite material having eutectic properties.

According to the application occasions and process design requirements of different ceramic PCB boards, it is possible to select a suitable eutectic material. For example, in applications with different temperature requirements, eutectic materials with different eutectic temperatures can be selected.

For example, in the application of the preferred Au-Sn gold-tin alloy Au80Sn20 and Au-Si gold-silicon eutectic material Au97Si3, the multilayer ceramic PCB board using the two eutectic materials can withstand higher temperatures and enable multiple layers. The application range of ceramic plates is further expanded. For example, the substrate after eutectic of Au-Si gold-silicon eutectic material can withstand a reflow process of up to 280 degrees.

When it is necessary to perform secondary welding or lamination on the end faces of different materials, it is possible to select a eutectic clad material with better co-melting properties with the secondary soldering clad material; for example, silver-containing solder Sn-Ag, which is easy to be coated with the plating layer. Silver end face bonding; gold-containing, indium-containing alloy solders are easily bonded to the gold-containing end faces of the plating.

In some embodiments, the ceramic base layer 110 is made of a highly thermally conductive ceramic material having a thermal conductivity of 2 W/m·K or more; the ceramic material for forming the ceramic base layer 110 includes aluminum oxide and aluminum nitride. And silicon nitride and cerium oxide, wherein the ceramic base layer 110 is a ceramic obtained by sintering one or a mixture of two or more of the above three materials. The thermal conductivity of the substrate of aluminum oxide or aluminum nitride is much higher than that of the conventional FR4 epoxy glass cloth laminate and other ceramic ceramic laminates; the substrate insulation of aluminum oxide or aluminum nitride The strength is also much higher than the insulation strength of the aluminum-based laminate.

In some embodiments, the ceramic base layer 110 of the plurality of ceramic-based PCB boards 100 that are overlapped with each other may be made of the same material; or the ceramic base layer 110 of the plurality of ceramic-based PCB boards 100 that are overlapped with each other The materials are different; the materials used for the different ceramic substrate layers 110 are selected according to the thermal and insulating requirements of the different layers.

The thickness of the cover layer 130 in the above various embodiments is 2 micrometers to 100 micrometers; in a typical application, the thickness of the overlay layer 130 is preferably set at 2 micrometers to 20 micrometers or 3 micrometers to 20 micrometers. Micron.

The method for manufacturing the foregoing multilayer ceramic printed circuit board includes the following steps, A1: uniforming on the lines and nodes of the printed circuit of the electronic circuit printed area 128 of the intermediate layer 120 of the ceramic-based PCB board 100 Covering eutectic material, And/or the thermally conductive metal surface of the copper-clad region 125 of the intermediate layer 120 of the ceramic-based PCB board 100 is uniformly coated with a eutectic material on the lines and nodes of the printed circuit of the intermediate layer 120 and/or Or forming a clad layer 130 on the surface of the thermally conductive metal; before the covering of the clad layer 130, the intermediate layer 120 of the ceramic-based PCB board 100 is provided with an electronic circuit printed area printed with printed circuit 128 and a heat-conducting metal surface for the heat conduction and heat dissipation of the intermediate layer covering a large area, that is, a copper-clad area 125;

A2: The bonding layers 130 of at least two ceramic-based PCB boards 100 are pressed together, heated together to the eutectic temperature of the eutectic material used, and eutectic fusion lamination is performed to fuse and bond the ceramic-based PCB boards 100. An integrated multilayer ceramic printed circuit board 50; when the number of the ceramic-based PCB boards 100 is plural, each of the ceramic-based PCB boards 100 is opposed to each other by the respective cover layer 130 The eutectic fusion cladding between the cladding layers 130 forms a multilayer ceramic printed circuit board 50; the number of layers of the multilayer ceramic printed circuit board 50 corresponds to the number of the ceramic-based PCB boards 100.

In the manufacturing method for manufacturing a multilayer ceramic printed circuit board, the temperature range of the eutectic soldering involved may be between 100 ° C and 800 ° C, and may also be between 200 ° C and 400 ° C. Generally, the preferred range is between 300 ° C and 330 ° C. The specific temperature may be 310 ° C or 320 ° C. Such a temperature range is compatible with existing PCB processes, and is suitable for large-scale production, avoiding the conventional multilayer ceramic printed circuit board 50 High temperature and complex process methods in the manufacturing process.

Therefore, the multilayer ceramic printed circuit board 50 of the present invention has good thermal conductivity, high thermal conductivity and dielectric strength, and is particularly suitable for packaging of power devices such as MOSFETs, IGBTs, and LEDs, and is also suitable for high power CPU/ The packaging of MPU/GPU integrated circuits, as well as the application of integrated power module IPM and optical engine power modules.

Figure 11 shows the circuit schematic of a full-bridge module of a MOSFET. Usually the full bridge module of the MOSFET is easy to implement, but the integrated control part usually requires another independent PCB board implementation. In this embodiment, since a multilayer ceramic circuit with high thermal conductivity is used, a complicated control circuit can also be realized on the same ceramic substrate. The MOSFET die is directly soldered to the ceramic board, and the control circuit is integrated with the MOSFET; even if necessary, the rectifying sections are integrated to greatly reduce the module size. Due to the high insulation properties and high thermal conductivity of the ceramic circuit of the present invention, the heat conduction heat sink of the MOSFET can be integrated to improve reliability.

In the application of a MOSFET full-bridge high-current motor drive module integrated with a control circuit, a multilayer ceramic printed circuit board as shown in FIGS. 12 to 15 is employed, and an embodiment of the multilayer ceramic printed circuit board is used. In the middle, two ceramic-based PCB boards 100 are used: a III-1 ceramic-based PCB board 231 and a III-2 ceramic-based PCB board 232, respectively, the III-1 ceramic-based PCB board 231 and the III-2 ceramic The base PCB board 232 is joined to form another double layer ceramic printed circuit board 52 by eutectic bonding.

As shown in FIG. 10, the electronic circuit printed area 128 includes a high power density for setting high power density components. A component fixing area 1283, a control circuit area 1285 for setting a control circuit, and a power electronic circuit area 1287 for setting a power electronic circuit. Specifically, in the application of the MOSFET full-bridge high-current motor driving module shown in FIGS. 12 to 15, the high power density component fixing area is a MOSFET bare crystal fixed area, and the power circuit is specifically a rectifying line. It should be noted that, in FIG. 10, only for the convenience of the partition description, the actual high power density component fixing area 1283, the control line area 1285, and the power electronic circuit area 1287 are widely divided, and the actual device characteristics are required. Make the layout.

16 to 28 show an application substrate of a high power density four-channel RGBW COB-LED light source in which four ceramic-based PCB boards 100 are melt-clad to form a four-layer ceramic. Printed circuit board 54; as shown in FIGS. 26 to 28, the four-layer ceramic printed circuit board 54 includes four ceramic-based PCB boards 100, which are respectively an IV-1 ceramic-based PCB board 441, and an IV-2 The ceramic-based PCB board 442, the IV-3 ceramic-based PCB board 443, and the IV-4 ceramic-based PCB board 444; the IV-2 ceramic-based PCB board 442 and the I-1 ceramic-based PCB board 221 and the The IV-3 ceramic-based PCB board 443 is eutectic-fused by the corresponding cladding layer 130, and the IV-3 ceramic-based PCB board 443 and the IV-4 ceramic-based PCB board 444 are also passed through the corresponding coating. The layer 130 is eutectic melt-clad to form the four-layer ceramic printed circuit board 54.

Typically, RGBW sources are used for stage lighting. Due to the requirement of light distribution at a small angle, it is desirable that the light-emitting surface be as small as possible and the power density be as large as possible. The existing method is to closely mount the RGBW chip LED on the PCB. Due to the complicated circuit, a multi-layer board is required to meet the requirements. The existing MCPCB-metal core printed circuit board can only be used as a double panel, which can not meet the wiring requirements, and the thermal conductivity is only 0.8W/m·K-3W/mk; other materials PCBs have a very low thermal conductivity (thermal conductivity <1 W/m·K), and the lifetime of the lamps used in such lamps is greatly reduced.

In this embodiment, the multi-layer ceramic circuit board of the present invention is utilized, and the inverted R, G, B, and W color LED chips are respectively soldered to corresponding positions on a 13.5 mm × 13.5 mm multilayer ceramic substrate, and the chip size is 45mil × 45mil (that is, 1.14 mm × 1.14 mm), the light-emitting surface is only 4.73 mm × 4.73 mm, which solves this problem well.

16 and 17 are respectively a schematic projection view and a top view of an application substrate of a four-channel RGBW COB-LED light source, and it is seen that four kinds of LED chips of red, green, blue and white are integrated on one application substrate, each of which The color LED chip has respective positive and negative electrode pads and respective die bonding pads, that is, solid crystal regions.

As shown in FIGS. 18 to 25, four ceramic-based PCB boards 100 are collectively provided with complete electronic circuits; and four ceramic-based PCB boards 100 are preferably made of an AlN ceramic-based circuit board having a thickness of 0.254 mm. The four ceramic-based PCB boards 100 are referred to as an IV-1 ceramic-based PCB board 441, an IV-2 ceramic-based PCB board 442, an IV-3 ceramic-based PCB board 443, and an IV-4 ceramic-based PCB board 444, respectively. Wherein the IV-1 ceramic-based PCB board 441, the IV-2 ceramic-based PCB board 442 And the IV-3 ceramic-based PCB board 443 is provided with metal holes 118 for electrical connection between the arranged electronic circuits on the respective ceramic-based PCB boards. The IV-4 ceramic-based PCB board 444 is disposed at the bottom layer, and no metal hole 118 is disposed thereon.

As shown in FIG. 18, the intermediate layer 120 disposed on the substrate A face 112 of the IV-1 ceramic-based PCB board 441 includes positive and negative electrode pads, LED solid crystal pads, and electronic circuits for electrical connection.

Figure 19 shows a base B surface 114 of the IV-1 ceramic-based PCB board 441; a base substrate A surface 112 and a base B surface 114 of the IV-2 ceramic-based PCB board 442 shown in Figures 20 and 21; The base substrate A face 112 and the base B face 114 of the IV-3 ceramic-based PCB board 443 shown in FIGS. 22 and 23; the base substrate A face 112 of the IV-4 ceramic-based PCB board 444 shown in FIG. The intermediate layer 120 disposed on each of the six faces includes an electronic circuit printing area 128 for printing electronic circuits, a copper-clad area 125 for covering the non-electronic circuit printing area, and for isolating the electronic circuit The printed area 128 and the isolation area 127 of the copper-clad area 125. The copper-clad area 125 is sometimes referred to as an area copper, and the heat transfer and heat dissipation performance is improved by a large area of copper.

The first layer 120 of the six faces shown in FIGS. 19 to 24 is further provided with the cover layer 130, that is, the cover layer 130 is located above the intermediate layer 120; the cover layer 130 is a uniform A layer of crystalline material. Each of the ceramic-based PCB boards 100 is laminated to form a multilayer ceramic printed circuit board 50 by eutectic soldering of the upper cladding layer 130. The material of the overlay layer 130 is preferably AuSn80 gold tin alloy, preferably 6 microns thick; if the other two facing layers 130 to be covered are facing each other, one side is a gold tin alloy layer, and the other side may be infiltrated. A good single metal such as gold.

The base B surface 114 of the ceramic base layer 110 of the IV-1 ceramic-based PCB board 441 shown in FIG. 19 is opposed to the base A surface 112 of the ceramic base layer 110 of the IV-2 ceramic-based PCB board 442 shown in FIG. Covering, the cladding joint between the two ceramic-based PCB boards is realized by the lamination layer 130.

Similarly, the base B face 114 of the ceramic base layer 110 of the IV-2 ceramic-based PCB board 442 shown in FIG. 21 is opposite to the base A of the ceramic base layer 110 of the IV-3 ceramic-based PCB board 443 shown in FIG. The surface 112 is laminated, and the cladding joint of the IV-2 ceramic-based PCB board 442 and the IV-3 ceramic-based PCB board 443 is realized by the cover layer 130.

Similarly, the base B face 114 of the ceramic base layer 110 of the IV-3 ceramic-based PCB board 443 shown in FIG. 23 is opposite to the base A of the ceramic base layer 110 of the IV-4 ceramic-based PCB board 444 shown in FIG. The face 112 is laminated, and the cover joint of the IV-3 ceramic-based PCB board 443 and the IV-4 ceramic-based PCB board 444 is realized by the cover layer 130.

In the fabrication of the above four-layer ceramic printed circuit board 54, four ceramic-based PCB boards 100 may be pressed together for eutectic soldering; or two ceramic-based PCB boards 100 may be first melted into two-layer ceramics. a printed circuit board; the two double-layer ceramic printed circuit boards produced are melt-clad or by means of through-holes on the ceramic-based PCB board 100 A four-layer ceramic printed circuit board 54 is obtained by riveting the metal rivets.

In the fabrication of the above three-layer ceramic printed circuit board 54, three ceramic-based PCB boards 100 may be pressed together for eutectic soldering; or two ceramic-based PCB boards 100 may be first melted into two-layer ceramics. A printed circuit board is obtained by re-melting a double-layer ceramic printed circuit board or riveting a ceramic-based PCB board 100 with a metal rivet to obtain a three-layer ceramic printed circuit board.

As shown in FIG. 25, the base B surface 114 of the ceramic base layer 110 of the IV-4 ceramic-based PCB board 444 is provided with only a copper-clad region 125 for covering the non-electronic circuit printed area, and a large area of copper is coated to improve The heat conduction and heat dissipation performance of the substrate can also be used for fixed welding of the light source. The copper-clad area 125 is used as a light source mounting fixing surface, and the surface treatment can be simply treated as copper oxide or copper-plated gold; of course, the copper-clad area 125 can also be covered with a cladding layer for eutectic fusion welding. 130, after the eutectic melting, the eutectic bonding with other components is realized.

In practical applications, the corresponding parts of each ceramic-based PCB board are accurately stacked together by positioning holes or other positioning methods, and heated to 300-320 ° C to heat up to reach Au-Sn80 eutectic temperature, each ceramic-based PCB The eutectic melting between the cladding layers 130 of the board welds each of the ceramic-based PCB boards into an integrated multilayer ceramic circuit board. In this case, the copper thickness is 2 ounces, the thermal conductivity of aluminum nitride ceramics is 170 W/m·K, the thermal conductivity of gold-tin alloy is 57 W/m·K, and the uncovered portion of the line gap is calculated. The theoretical thermal conductivity is >120 W/m· K, much higher than the thermal conductivity of other multilayer boards.

In the present invention, the term "covering" is also referred to as "composite" in other documents in the prior art; the term "joining" is sometimes used as "in other documents in the prior art". "Connected", but the meaning of "joining" in this document does not only mean "connected", but also "combined" in some occasions.

In the present invention, the cover layer not only facilitates the interlayer connection of the multilayer ceramic printed circuit board by eutectic soldering, but also improves the thermal conductivity of the electronic circuit printed area; the copper layer of the intermediate layer and the copper-clad area The upper cladding layer further improves the thermal conductivity of the multilayer ceramic printed circuit board; the ceramic base material of the ceramic base PCB is made of any of aluminum oxide, aluminum nitride, silicon nitride and tantalum oxide. One or more mixtures with good thermal conductivity and dielectric strength. The bonding layer on the electronic circuit printing area and the copper-clad area greatly improves the thermal conductivity of the multilayer ceramic printed circuit board while achieving interlayer connection; the ceramic base layer has good thermal conductivity and dielectric strength, The multilayer ceramic printed circuit board of the present invention has excellent thermal conductivity and is suitable for applications with high power and high heat flux density.

The above is only the embodiment of the present invention, and thus does not limit the scope of the patent of the present invention, and the equivalent structure or equivalent process transformation made by using the description of the invention and the contents of the drawings, or directly or indirectly applied to other related technical fields. The same is included in the scope of patent protection of the present invention.

Claims

A multilayer ceramic printed circuit board (50) comprising at least two ceramic-based PCB boards (100) that are mutually overlapped; each of the ceramic-based PCB boards (100) includes a ceramic base layer (110) and a laminate a layer (130); an intermediate layer (120) is further disposed between the ceramic substrate layer (110) and the cover layer (130);

The ceramic base layer (110) is used for heat conduction and/or heat dissipation and electrical insulation; the two surfaces of the ceramic base layer (110) which are generally parallel to each other are referred to as a base A face (112) and a base B face, respectively ( 114), the intermediate layer (120) is disposed on the substrate A surface (112), or the intermediate layer (120) is disposed on the substrate B surface (114);

The intermediate layer (120) is used for printing electronic circuits and/or for laying a thermally conductive metal surface; the intermediate layer (120) comprises an electronic circuit printing area (128) for printing electronic circuits and/or for routing a copper-clad region (125) of a thermally conductive metal surface, the copper-clad region (125) covering a large area in the intermediate layer to achieve heat conduction and heat dissipation;

The cover layer (130) is a eutectic material layer having eutectic melting characteristics; the cover layer (130) is used for another of the cover layers (130) of another ceramic-based PCB board (100) a eutectic fusion coating to achieve thermal conduction or thermal conduction and electrical connection; the cladding layer (130) comprising an electronic circuit printed region overlay layer (138) and/or a copper clad region cladding layer (135); The circuit printed area cover layer (138) is evenly distributed on the lines and nodes of the printed circuit of the electronic circuit printing area (128); the copper-clad area cover layer (135) is evenly distributed On the thermally conductive metal surface of the copper-clad region (125);

The ceramic-based PCB board (100) is laminated and heated to each other, and the eutectic fusion welding is completed by the cover layer (130) thereon, thereby fused and laminated the ceramic-based PCB boards (100). A multilayer ceramic printed circuit board (50) having at least two layers.
The multilayer ceramic printed circuit board according to claim 1, wherein

Each of the ceramic-based PCB boards (100) requires a pattern of printed electronic circuits and/or thermally conductive metal surfaces of the two opposing intermediate layers to be mirror-symmetrical to each other, or at least a majority of the printed electronic circuits and/or The pattern of the thermally conductive metal surface is mirror symmetrical;

When the ceramic-based PCB board (100) needs to be covered by the two opposite intermediate layers, the printed circuit and/or the thermally conductive metal surface are asymmetric in pattern, and the asymmetric portion is printed with electronic circuits and/or heat conduction. The face on which the metal faces face is a blank ceramic face, or the face that faces the asymmetrical portion of the printed circuit and/or the thermally conductive metal face is an island-shaped printed circuit pattern.
The multilayer ceramic printed circuit board according to claim 1, wherein

When the intermediate layer (120) is disposed on the base A surface (112) and the base B surface (114) of the ceramic base layer (110), the printed circuit on each of the intermediate layers (120) And/or a thermally conductive metal surface passing through the ceramic substrate layer (110) The metal hole (118) is electrically coupled; the metal hole (118) includes a solid metal hole that is filled through the metal pillar and a metallized through hole in which the hole wall has been plated with metal.
The multilayer ceramic printed circuit board according to claim 1, wherein

The multilayer ceramic printed circuit board (50) comprises a three-layer ceramic printed circuit board; the three-layer ceramic printed circuit board consists of two ceramic-based PCBs on the two sides of the ceramic-based PCB board (100) Plate (100) eutectic fusion lamination;

The intermediate layer (120) is disposed on the substrate A surface (112) and the substrate B surface (114) of the ceramic base layer (110) of the intermediate ceramic-based PCB board (100), and the substrate A is disposed on the substrate A The cover layer (130) is disposed on the intermediate layer (120) of the face (112) and the intermediate layer (120) of the base B face (114) to accommodate the same piece of the ceramic-based PCB board (100) The case where the other ceramic-based PCB board (100) is overlaid on the substrate A side (112) and the substrate B side (114), respectively.
The multilayer ceramic printed circuit board according to claim 1, wherein

The multilayer ceramic printed circuit board (50) comprises a multilayer ceramic printed circuit board (50) having a number of layers of four or more; the multilayer ceramic printed circuit board (50) includes at least four ceramics a base PCB board (100), each of which is fused by eutectic between the ceramic-based PCB boards (100) by means of the respective cladding layer (130) and the facing layer (130) A multilayer ceramic printed circuit board (50) is formed; the number of layers of the multilayer ceramic printed circuit board (50) corresponds to the number of the ceramic-based PCB boards (100).
The multilayer ceramic printed circuit board according to claim 1, wherein

The thermally conductive metal surface of the copper-clad region (125) is electrically coupled to a local functional network of the printed circuit in the electronic circuit printed region (128), or the thermally conductive metal surface of the copper-clad region (125) The printed electronic circuits in the electronic circuit printed area (128) are integrally electrically coupled.
The multilayer ceramic printed circuit board according to claim 1, wherein

An isolation region (127) for electrically insulating is disposed between the electronic circuit printing region (128) and the copper-clad region (125), and the cladding layer is not disposed on the isolation region (127) ( 130).
The multilayer ceramic printed circuit board according to claim 1, wherein

The electronic circuit printed area (128) includes a high power density component fixing area (1283) for setting a high power density component, a control circuit area (1285) for setting a control circuit, and power for deploying a power electronic circuit. Electronic circuit area (1287).
The multilayer ceramic printed circuit board according to claim 1, wherein

The eutectic material coated on the two-sided facing cladding layer (130) participating in the eutectic soldering is Au-Sn gold tin alloy, Au-Si gold silicon eutectic material, Au-Ge gold bismuth alloy, Ag-Sn silver. Any one of a tin alloy, a Sn-Bi tin antimony alloy, a Sn-In tin indium alloy, or a Sn-Pb tin-lead alloy.
The multilayer ceramic printed circuit board according to claim 1, wherein

Participating in the eutectic soldering of the two layers of the facing layer (130), wherein the eutectic material covered by the covering layer (130) is Au-Sn gold tin alloy, Au-Si gold silicon eutectic material, Any one of Au-Ge gold-niobium alloy, Ag-Sn silver-tin alloy, Sn-Bi tin-bismuth alloy, Sn-In tin-indium alloy or Sn-Pb tin-lead alloy;

The eutectic material coated by the other cladding layer (130) is a single layer of gold Au, tin Sn, silicon Si, silver Ag, yGe, 铋Bi, indium In, nickel Ni, lithium Li, palladium Pd. Or aluminum Al; or the eutectic material coated by the other cladding layer (130) is gold Au, tin Sn, silicon Si, silver Ag, germanium Ge, germanium Bi, indium In, nickel Ni, lithium Li, A single layer of two or more kinds of palladium Pd or aluminum Al materials may be alternately laid to form a multilayer structure.
The multilayer ceramic printed circuit board according to claim 1, wherein

Two of the two overlapping layers (130) participating in the eutectic soldering are separately coated with a single layer or a plurality of layers of gold Au, tin Sn, silicon Si, silver Ag, germanium. a material of Ge, 铋Bi, indium In, palladium Pd or lead Pb;

Two overlapping layers (130) of two sides facing each other in the eutectic soldering, wherein the surface eutectic materials for melting and laminating are two mutually different materials;

The two materials are melt-clad to form Au-Sn gold-tin alloy, Au-Si gold-silicon eutectic layer, Au-Ge gold-bismuth alloy, Ag-Sn silver-tin alloy, and Sn-Bi tin during eutectic soldering. Any of niobium alloy, Sn-In tin indium alloy, and Sn-Pb tin-lead alloy.
The multilayer ceramic printed circuit board according to claim 9, wherein

The Au-Sn gold-tin alloy, in terms of mass percentage, contains gold Au 80.0% ± 2.0%, and the balance is tin Sn.
The multilayer ceramic printed circuit board according to claim 9, wherein

The Ag-Sn silver-tin alloy is in a mass percentage, wherein the tin-containing Sn is 96.5%±2.0%, and the balance is silver Ag.
The multilayer ceramic printed circuit board according to claim 9, wherein

The Au-Ge gold-bismuth alloy, in terms of mass percentage, contains gold Au88.0%±2.0%, and the rest is 锗Ge.
The multilayer ceramic printed circuit board according to claim 9, wherein

The Au-Si gold silicon eutectic material, in terms of mass percentage, contains gold Au 97.0% ± 2.0%, and the rest is silicon Si.
The multilayer ceramic printed circuit board according to claim 1, wherein

The cover layer (130) has a thickness of from 2 micrometers to 100 micrometers.
The multilayer ceramic printed circuit board according to claim 1, wherein

The cover layer (130) has a thickness of from 3 micrometers to 20 micrometers.
The multilayer ceramic printed circuit board according to claim 1, wherein

The material of the ceramic base layer (110) is a high thermal conductive ceramic material having a thermal conductivity of 2 W/m·K or more; the ceramic material for forming the ceramic base layer (110) includes aluminum oxide, aluminum nitride, and nitrogen. Silicon and yttrium oxide; the ceramic base layer (110) is one or a combination of two or more of the above four materials.
The multilayer ceramic printed circuit board according to claim 1, wherein

The ceramic base layer (110) of the plurality of ceramic-based PCB boards (100) that are overlapped with each other may be made of the same material; or the ceramic base layer of the plurality of ceramic-based PCB boards (100) that are overlapped with each other ( 110) The materials are different; the materials used for the different ceramic base layers (110) are selected according to the heat conduction and insulation requirements of the different layers.
A method for manufacturing the multilayer ceramic printed circuit board according to any one of claims 1 to 19, comprising the steps of: A1: electronic circuit printing on the intermediate layer (120) of the ceramic-based PCB board (100) The eutectic material is uniformly distributed on each line and each node of the printed circuit of the zone (128), and/or the heat conduction of the copper-clad zone (125) of the intermediate layer (120) of the ceramic-based PCB board (100) Uniformly coating the eutectic material on the metal surface, forming a cladding layer (130) on each line and each node of the printed circuit of the intermediate layer (120) and/or on the thermally conductive metal surface;

Before the covering layer (130) is laid, the intermediate layer (120) of the ceramic-based PCB board (100) is provided with an electronic circuit printing area (128) for printed circuit and for the intermediate layer A large area covers a thermally conductive metal surface that conducts heat and heat, that is, a copper-clad area (125);

A2: pressing at least two cladding layers (130) of the ceramic-based PCB board (100) to each other, heating together to the eutectic temperature of the eutectic material used, and performing eutectic fusion coating to make each ceramic-based PCB board ( 100) fusion lamination is joined to form an integrated multilayer ceramic printed circuit board (50);

When the number of the ceramic-based PCB boards (100) exceeds two, each of the ceramic-based PCB boards (100) is supported by the respective cover layer (130) and the cover layer (130) facing thereto. The eutectic fusion cladding between the layers forms a multilayer ceramic printed circuit board (50); the number of layers of the multilayer ceramic printed circuit board (50) corresponds to the number of the ceramic-based PCB boards (100).