WO2008007940A1 - Dissipative ceramic wire clamp - Google Patents
Dissipative ceramic wire clamp Download PDFInfo
- Publication number
- WO2008007940A1 WO2008007940A1 PCT/MY2007/000048 MY2007000048W WO2008007940A1 WO 2008007940 A1 WO2008007940 A1 WO 2008007940A1 MY 2007000048 W MY2007000048 W MY 2007000048W WO 2008007940 A1 WO2008007940 A1 WO 2008007940A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- clamp
- wire
- bonding
- dissipative
- wire bonding
- Prior art date
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 14
- 230000001052 transient effect Effects 0.000 claims abstract description 22
- 239000000463 material Substances 0.000 claims description 35
- 238000000034 method Methods 0.000 claims description 20
- 230000008569 process Effects 0.000 claims description 8
- 230000008901 benefit Effects 0.000 abstract description 4
- 230000005611 electricity Effects 0.000 abstract description 4
- 230000009467 reduction Effects 0.000 abstract description 4
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 230000003068 static effect Effects 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 239000004020 conductor Substances 0.000 description 4
- 239000012212 insulator Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 238000005524 ceramic coating Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 235000012431 wafers Nutrition 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/002—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating specially adapted for particular articles or work
- B23K20/004—Wire welding
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
- H01L24/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
- H01L24/85—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a wire connector
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- H01L2224/45001—Core members of the connector
- H01L2224/45099—Material
- H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
- H01L2224/45117—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 400°C and less than 950°C
- H01L2224/45124—Aluminium (Al) as principal constituent
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- H01L2224/45001—Core members of the connector
- H01L2224/45099—Material
- H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
- H01L2224/45138—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
- H01L2224/45144—Gold (Au) as principal constituent
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
- H01L2224/85—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a wire connector
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
- H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L24/42—Wire connectors; Manufacturing methods related thereto
- H01L24/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L24/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
- H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L24/42—Wire connectors; Manufacturing methods related thereto
- H01L24/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L24/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01013—Aluminum [Al]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01014—Silicon [Si]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01015—Phosphorus [P]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01029—Copper [Cu]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01033—Arsenic [As]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/0104—Zirconium [Zr]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01047—Silver [Ag]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01079—Gold [Au]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/01—Chemical elements
- H01L2924/01082—Lead [Pb]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/10—Details of semiconductor or other solid state devices to be connected
- H01L2924/11—Device type
- H01L2924/14—Integrated circuits
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/19—Details of hybrid assemblies other than the semiconductor or other solid state devices to be connected
- H01L2924/1901—Structure
- H01L2924/1904—Component type
- H01L2924/19043—Component type being a resistor
Definitions
- This invention relates to clamps for wire bonding machines. More particularly, the present invention relates to wire bond clamps for clamping fingers of lead frames in the proper position for bonding of ah electrical wire connection thereto.
- IC integrated circuits
- die attach pad at the center of a lead frame
- individual leads are connected with wire to individual bond pads on the IC.
- the wire is fed through a tubular bonding tool tip being, hold by a wire bond clamp. Thereafter, electrical connections are established between points on the IC component, the wire of the lead frame, the bonding tooi tips, and the wire bond clamp during the wire bonding process. .
- U.S. patent 5,616,257 to Harada discloses an electrode used in a wire bonding method and apparatus for applying an electric discharge to an end of a bonding wire so as to form a ball at the end of the bonding wire.
- the electrode is provided with an obliquely cut surface at one end so that the end of the electrode is in a semicircular shape, and an edge area of the . semicircular end surface is positioned to face upward and used" as an electric discharge part.
- the electrode can be covered by a ceramic material except for the semicircular end surface.
- U.S. patent 5,280,979 to PoIi discloses a tip for a vacuum pipette having improved electrostatic discharge properties is disclosed.
- the tip and the coupling sections of a known tip are separated both physically and electrically from one another.
- a large resistance then electrically couples the two sections together and a plastic insulator surrounds the resistance to physically couple the sections together.
- This construction forces all static discharges to flow through the resistor, thereby changing the static discharge from one large discharge to a series of small discharges, each small discharge being insufficient to damage the wafers.
- the tip is also coated with a thin ceramic coating, which acts as a barrier against ionic contamination from the material used to make the tip.
- This coating is also smoother and more abrasion resistant than the basic material, causing less contamination when used.
- the coating can have a controlled conductivity that improves the static discharge behavior of the tip.
- U.S patent 6,935,548 discloses methods for making and using dissipative ceramic bonding tool tips for wire bonding electrical connections to bonding pads on integrated circuit chips and packages.
- the method of using the dissipative ceramic bonding tool tip includes dissipating charge while bonding to avoid damaging delicate electronic devices by a sudden surge of accumulated charge.
- the method of making the tool tip includes affecting its conductivity so that it conducts electricity at a rate sufficient to prevent charge buildup, but not sufficient to overload the device being bonded.
- a resistance in the tip assembly itself should range from 5x10 4 or 10 5 to 10 12 ⁇ .
- the tips must also have specific mechanical properties to function satisfactorily. . ,
- the disadvantage of conventional wire bond clamps made of metals is that the transient current at wire ranged from 5 to 7 mAz-p, which is relatively higher than ESD control specification, i.e. less than 3 mAz-p. This is mainly due to the intermittent occurs between the wire and the wire bond clamp made of metal during electrical wire connections. In addition to that, resistance incurred while bonding is significantly low since the clamps are made of conductive materials, and can cause damage to the device bonded.
- the objective of the invention is to create a wire bonding machine assembly with the clamps made from a new material that can meet the ESD safety requirements.
- the new material should be characterized with low enough resistance that it is not an insulator, and yet high enough to prevent damaging device being bonded, like the IC chips.
- the purpose of the invention is thus to reduce the transient current at the wire bond machine during bonding process to less than 3 mAz-p, as well as to increase the resistance to avoid a build up of charge that could discharge to the device being bonded.
- the present invention relates to a device comprising a wire bond clamp having a dissipative material for use in wire bonding machines for clamping a plurality of fingers of at least one lead frame for electrical connection to at least one integrated circuit component.
- the present invention also relates to method of using a wire bond clamp, comprising: providing an electrically dissipative wire bond clamp; clamping lead frames that bond a material to a device; and allowing essentially low transient current and high resistance to dissipate to the device, wherein the transient current being low enough so as not to ' damage said device being bonded and the resistance being high enough to avoid a build up of charge that could discharge to the device being bonded and damage the device being bonded.
- the wire bonding clamps made -from a new material that can meet the ESD safety requirements.
- This new material is a dissipative material preferably 1 ceramic.
- the roost preferable embodiments include different types of ceramic such as Zirconia (Zirconium . dioxide). Alumina (Aluminium oxide), and silicon carbide.
- the present invention relates to wire bond clamp at the wire bonding machine. More particularly, the present invention relates to the wire bond clamp made with dissipative material.
- the invention shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings. However, it is to be understood that limiting the description to the preferred embodiments of the invention and to the drawings is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.
- dissipative materials used throughout the- specification refers to the materials have resistance to current flow that is greater than conductors, but less than insulators. In more particular, the dissipative materials allow charges to move slowly across their volume. While charges are placed in one spot on a dissipative object, it will flow around the object so that all parts of the object share the same charge. If " a charged dissipative material is grounded, charges will recombine at a slower rate until the object has no charge.
- a dissipative material shall have a surface resistance (in Ohms) ranges from 10 5 to 10 n .
- the goal of the invention is to create a wire bonding machine assembly with the clamps made from a new material that can meet the ESD safety requirements.
- Typical wire- bond clamp available on 1he " market today are made of a conductor, i.e. metal. Gold and aluminum, on the ' other hand, are the commonly used wire materials. In addition, copper and silver have also been used. Bonding of these wires to different pad materials produce rather high transient current in the range of 5 to 7 mAz-p. Thus, electrostatic discharge from the wire bond machine making contact with the bonding pad of the circuit, due to the transient current, can damage the IC component it is wiring.
- the static electric generated on the clamp can be attributed to the use of electromagnetic in operating the clamps, friction or touching of the clamps surface with other components (made of different materials) during bonding process, or generation of the pyroelectirc charges which may add to the contact electrification due to high temperature in the operating environment.
- the invention therefore discloses an improved wire bond clamp having a dissipative material for use in wire bond machines for clamping fingers of lead frame for electrical connection to integrated circuit (IC) component.
- the device comprises a wire bond clamp having an electrically dissipative ceramic for use in bonding machines for clamping fingers of lead frame for electrical connection to integrated circuit component.
- the bonding machines can be capillary wedge- type wire bonding machine or capillary ball-type wire bonding machine.
- the disclosed improved clamp comprises of improvement with a low transient current generation during the process of wire bonding process. In the most preferred embodiment, the transient current generated in the improved clamp is lower than 3mAz-p.
- Wedge bonding is named based on the shape of its bonding tool. In this technique, the wire is fed at an angle usually 30-60° from the horizontal bonding surface through a hole in the back of a bonding wedge. Although other connection technologies have gained popularity, wire bonding technique still maintains its competitive position due to the massive equipment infrastructure of wire, bonding: Wedge bonding technique can be used for both aluminum wire and gold wire bonding applications. The main advantage for gold wire wedge bonding is the possibility to avoid the need of hermetic packaging after bonding since the gold is inert and non-reactive. - ' '
- the method of using the wire bond clamp including providing an electrically dissipative wire bond clamp, which is used for clamping lead frames that bond a material to a device.
- the material and device comprise preferably metal wires and IC components, respectively.
- Low transient current and high resistance are then allowed to dissipate to the device, wherein the transient current is low enough, i.e. 2 to 2.5 mAz-p so as not to damage the device being bonded.
- the dissipative ceramic wire bond clamp affects the intermittent between the metal wires and the clamp and hence causes a high transient current reduction.
- the invention provides wire bonding machine with a transient current that meet the ESD control specifications during the electrical connection procedures on the IC components.
- the resistance is high enough, i.e. 4.0 x 10 6 ohm, which can avoid a build up of charge that could discharge to the device being bonded and damage the device being bonded.
- the resistance is significantly higher when compared to the one, i.e. 0.2 ohm, when the conventional metal wire bond clamp is used.
- the present invention provides electrically dissipative ceramic wire bond clamp for supporting electrical connections to bonding tool tips on electrical devices.
- the method of using the. present invention involves an added step of dissipating electrical charge at a resistance sufficiently high to prevent charge buildup, but not high enough to overload the device being bonded.
- the ordinary charge dissipation is avoided so as not to overload the circuit. Consequently, to avoid damaging delicate electronic devices by . any electrostatic discharge, the wire bond clamp is improved to dissipate the static electricity at "a transient current sufficiently low to prevent charge buildup. In other words, it is desirable for the wire bond clamp to discharge slowly.
- a resistance in the clamp assembly itself should range from about 3 x 10 6 to 5 x 10 6 ohms.
- the improved clamp shall contain dissipative material to reduce the transient current generation during the process of wire bonding.
- One embodiment of the present invention is to have the entire improved clamp made of dissipative materials.
- Another embodiment involves of coating the dissipative materials, onto the surface of the improved clamp which may actually made of other materials to prevent high transient current.
- part of the improved clamp instead of whole improve clamp made of the dissipative material especially parts whereby the improved clamp having contact with the wire or the apparatus to be bonded.
- wire bond clamp should conduct electricity at a rate sufficiently high to prevent charge buildup, but not high enough to overload the device being bonded. It has been determined that the wire bond machine using the invention in this embodiment has a tribocharge of zero voltage. The resistance should be low enough that the material is not an insulator that does not allow charge dissipation, and high enough that it is not a conductor allowing a current flow that is damaging to the device being bonded.
- Table 1 shows the tested result in reduction of transient current due to the use of the improved clamp compare to the conventional clamp using metal.
- the reduction in transient current generated can be lower to as much as 60%.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Wire Bonding (AREA)
Abstract
The present invention relates to a device comprising of dissipative ceramic wire bond clamp for clamping fingers of lead frame at wire bonding machines for electrical connection to integrated circuit component and packages. The advantage of using the dissipative wire bond clamp includes dissipating charge while bonding to avoid damaging delicate electronic devices with high transient current reduction. Further advantage of using the ceramic wire bond clamp includes increasing resistance while bonding so that it conducts electricity at a rate sufficient to prevent charge buildup, but not sufficient to overload the device being bonded.
Description
DISSIP ATIVE CERAMIC WIRE CLAMP
Field of Invention
This invention relates to clamps for wire bonding machines. More particularly, the present invention relates to wire bond clamps for clamping fingers of lead frames in the proper position for bonding of ah electrical wire connection thereto.
Background of Invention
In' fabricating a semiconductor device, integrated circuits (IC) components are typically attached to a die attach pad at the center of a lead frame, and individual leads are connected with wire to individual bond pads on the IC. The wire is fed through a tubular bonding tool tip being, hold by a wire bond clamp. Thereafter, electrical connections are established between points on the IC component, the wire of the lead frame, the bonding tooi tips, and the wire bond clamp during the wire bonding process. .
U.S. patent 5,616,257 to Harada discloses an electrode used in a wire bonding method and apparatus for applying an electric discharge to an end of a bonding wire so as to form a ball at the end of the bonding wire. The electrode is provided with an obliquely cut surface at one end so that the end of the electrode is in a semicircular shape, and an edge area of the . semicircular end surface is positioned to face upward and used" as an electric discharge part. The electrode can be covered by a ceramic material except for the semicircular end surface.
U.S. patent 5,280,979 to PoIi discloses a tip for a vacuum pipette having improved electrostatic discharge properties is disclosed. The tip and the coupling sections of a known tip are separated both physically and electrically from one another. A large resistance then electrically couples the two sections together and a plastic insulator surrounds the resistance to physically couple the sections together. This construction forces all static discharges to
flow through the resistor, thereby changing the static discharge from one large discharge to a series of small discharges, each small discharge being insufficient to damage the wafers. The tip is also coated with a thin ceramic coating, which acts as a barrier against ionic contamination from the material used to make the tip. This coating is also smoother and more abrasion resistant than the basic material, causing less contamination when used. Finally, the coating can have a controlled conductivity that improves the static discharge behavior of the tip.
U.S patent 6,935,548 discloses methods for making and using dissipative ceramic bonding tool tips for wire bonding electrical connections to bonding pads on integrated circuit chips and packages. The method of using the dissipative ceramic bonding tool tip includes dissipating charge while bonding to avoid damaging delicate electronic devices by a sudden surge of accumulated charge. The method of making the tool tip includes affecting its conductivity so that it conducts electricity at a rate sufficient to prevent charge buildup, but not sufficient to overload the device being bonded. For best results, a resistance in the tip assembly itself should range from 5x104 or 105 to 1012 Ω. In addition, the tips must also have specific mechanical properties to function satisfactorily. . ,
The disadvantage of conventional wire bond clamps made of metals is that the transient current at wire ranged from 5 to 7 mAz-p, which is relatively higher than ESD control specification, i.e. less than 3 mAz-p. This is mainly due to the intermittent occurs between the wire and the wire bond clamp made of metal during electrical wire connections. In addition to that, resistance incurred while bonding is significantly low since the clamps are made of conductive materials, and can cause damage to the device bonded.
The objective of the invention is to create a wire bonding machine assembly with the clamps made from a new material that can meet the ESD safety requirements. The new material should be characterized with low enough resistance that it is not an insulator, and yet high enough to prevent damaging device being bonded, like the IC chips. The purpose of the
invention is thus to reduce the transient current at the wire bond machine during bonding process to less than 3 mAz-p, as well as to increase the resistance to avoid a build up of charge that could discharge to the device being bonded.
Summary of the Invention
The present invention relates to a device comprising a wire bond clamp having a dissipative material for use in wire bonding machines for clamping a plurality of fingers of at least one lead frame for electrical connection to at least one integrated circuit component.
The present invention also relates to method of using a wire bond clamp, comprising: providing an electrically dissipative wire bond clamp; clamping lead frames that bond a material to a device; and allowing essentially low transient current and high resistance to dissipate to the device, wherein the transient current being low enough so as not to' damage said device being bonded and the resistance being high enough to avoid a build up of charge that could discharge to the device being bonded and damage the device being bonded. Preferably, the present invention the wire bonding clamps made -from a new material that can meet the ESD safety requirements. This new material is a dissipative material preferably1 ceramic. In more particular, the roost preferable embodiments include different types of ceramic such as Zirconia (Zirconium . dioxide). Alumina (Aluminium oxide), and silicon carbide.
Detail Description of the Invention
The present invention relates to wire bond clamp at the wire bonding machine. More particularly, the present invention relates to the wire bond clamp made with dissipative material. Hereinafter, the invention shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings. However, it is to be understood that limiting the description to the preferred embodiments of the invention and to the drawings is merely to facilitate discussion of the
present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.
The term "dissipative materials" used throughout the- specification refers to the materials have resistance to current flow that is greater than conductors, but less than insulators. In more particular, the dissipative materials allow charges to move slowly across their volume. While charges are placed in one spot on a dissipative object, it will flow around the object so that all parts of the object share the same charge. If "a charged dissipative material is grounded, charges will recombine at a slower rate until the object has no charge. A dissipative material shall have a surface resistance (in Ohms) ranges from 105 to 10n.
The goal of the invention is to create a wire bonding machine assembly with the clamps made from a new material that can meet the ESD safety requirements. Typical wire- bond clamp available on 1he "market today are made of a conductor, i.e. metal. Gold and aluminum, on the' other hand, are the commonly used wire materials. In addition, copper and silver have also been used. Bonding of these wires to different pad materials produce rather high transient current in the range of 5 to 7 mAz-p. Thus, electrostatic discharge from the wire bond machine making contact with the bonding pad of the circuit, due to the transient current, can damage the IC component it is wiring. The static electric generated on the clamp can be attributed to the use of electromagnetic in operating the clamps, friction or touching of the clamps surface with other components (made of different materials) during bonding process, or generation of the pyroelectirc charges which may add to the contact electrification due to high temperature in the operating environment.
The invention therefore discloses an improved wire bond clamp having a dissipative material for use in wire bond machines for clamping fingers of lead frame for electrical connection to integrated circuit (IC) component. In the preferred embodiment of the present invention, the device comprises a wire bond clamp having an electrically dissipative ceramic for use in bonding machines for clamping fingers of lead frame for electrical
connection to integrated circuit component. The bonding machines can be capillary wedge- type wire bonding machine or capillary ball-type wire bonding machine. The disclosed improved clamp comprises of improvement with a low transient current generation during the process of wire bonding process. In the most preferred embodiment, the transient current generated in the improved clamp is lower than 3mAz-p.
Wedge bonding is named based on the shape of its bonding tool. In this technique, the wire is fed at an angle usually 30-60° from the horizontal bonding surface through a hole in the back of a bonding wedge. Although other connection technologies have gained popularity, wire bonding technique still maintains its competitive position due to the massive equipment infrastructure of wire, bonding: Wedge bonding technique can be used for both aluminum wire and gold wire bonding applications. The main advantage for gold wire wedge bonding is the possibility to avoid the need of hermetic packaging after bonding since the gold is inert and non-reactive. - ' '
It is an advantage of the present invention to provide a dissipative wire bond clamp, which is durable and capable of providing uniform and ESD safe electrical connections between an IC component and a lead, frame at the wire bonding machine, It is important to note that the size and shape of said improved clamp are subjected to different modification under different requirement of different machines.
The method of using the wire bond clamp, including providing an electrically dissipative wire bond clamp, which is used for clamping lead frames that bond a material to a device. The material and device comprise preferably metal wires and IC components, respectively. Low transient current and high resistance are then allowed to dissipate to the device, wherein the transient current is low enough, i.e. 2 to 2.5 mAz-p so as not to damage the device being bonded. The dissipative ceramic wire bond clamp affects the intermittent between the metal wires and the clamp and hence causes a high transient current reduction. In other words, the invention provides wire bonding machine with a transient current that
meet the ESD control specifications during the electrical connection procedures on the IC components. On the other hand, the resistance is high enough, i.e. 4.0 x 106 ohm, which can avoid a build up of charge that could discharge to the device being bonded and damage the device being bonded. The resistance is significantly higher when compared to the one, i.e. 0.2 ohm, when the conventional metal wire bond clamp is used.
The present invention provides electrically dissipative ceramic wire bond clamp for supporting electrical connections to bonding tool tips on electrical devices. In accordance with principles of the present invention, the method of using the. present invention involves an added step of dissipating electrical charge at a resistance sufficiently high to prevent charge buildup, but not high enough to overload the device being bonded. The ordinary charge dissipation is avoided so as not to overload the circuit. Consequently, to avoid damaging delicate electronic devices by. any electrostatic discharge, the wire bond clamp is improved to dissipate the static electricity at "a transient current sufficiently low to prevent charge buildup. In other words, it is desirable for the wire bond clamp to discharge slowly. For best results, a resistance in the clamp assembly itself should range from about 3 x 106 to 5 x 106 ohms. As herein set forth before, the improved clamp shall contain dissipative material to reduce the transient current generation during the process of wire bonding. One embodiment of the present invention is to have the entire improved clamp made of dissipative materials. Another embodiment involves of coating the dissipative materials, onto the surface of the improved clamp which may actually made of other materials to prevent high transient current. It is also possible to have part of the improved clamp instead of whole improve clamp made of the dissipative material especially parts whereby the improved clamp having contact with the wire or the apparatus to be bonded.
In accordance with principles of the present invention, to avoid damaging delicate electronic devices by this electrostatic discharge, wire bond clamp should conduct electricity at a rate sufficiently high to prevent charge buildup, but not high enough to overload the device being bonded. It has been determined that the wire bond machine using the invention in this
embodiment has a tribocharge of zero voltage. The resistance should be low enough that the material is not an insulator that does not allow charge dissipation, and high enough that it is not a conductor allowing a current flow that is damaging to the device being bonded.
Table 1 shows the tested result in reduction of transient current due to the use of the improved clamp compare to the conventional clamp using metal. The reduction in transient current generated can be lower to as much as 60%.
Table 1
While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.
Claims
1. An improved wire bond clamp used in wire bonding machine characterized by having dissipative materials in making of said clamp to reduce transient current generated during the wire bonding process.
2. A clamp according to claim 1, wherein said dissipative materials are ceramic.
3. A clamp according to claim I5 wherein said wire bonding machine is capillary wedge-type wire bonding machine.
4. An improved wire bond clamp used in wire bonding machine characterized by having dissipative materials in making parts of said improved clamp to reduce transient current generated, during the wire bonding process, wherein said parts having contact with an apparatus to be bonded.' . .
5. A clamp according to claim 4, wherein said dissipative materials are ceramic.
6. A clamp according to claim 4, wherein said wire bonding machine is capillary wedge-type wire bonding machine.
7. A method of using an improved wire bond clamp characterized by having dissipative materials in making of said clamp, comprising the steps off providing an electrically dissipative wire bond clamp; clamping lead frames that bond a material to a device; and allowing essentially low transient current and high resistance to dissipate to the device, wherein the transient current being low enough so as not to damage said device being bonded and the resistance being high enough to avoid a build up of charge that could discharge to the device being bonded and damage the device being bonded.
8. A method according to claim 7, wherein said dissipatiye material is ceramic.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| MYPI20063275 | 2006-07-11 | ||
| MYPI20063275 | 2006-07-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2008007940A1 true WO2008007940A1 (en) | 2008-01-17 |
Family
ID=38923454
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/MY2007/000048 WO2008007940A1 (en) | 2006-07-11 | 2007-07-10 | Dissipative ceramic wire clamp |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2008007940A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001015545A (en) * | 1999-07-02 | 2001-01-19 | Shinkawa Ltd | Machine and method for wire bonding |
| JP2001189340A (en) * | 1999-12-28 | 2001-07-10 | Shinkawa Ltd | Wire-bonding method and device thereof |
| JP2004119639A (en) * | 2002-09-26 | 2004-04-15 | Shinkawa Ltd | Method and device for wire bonding method |
-
2007
- 2007-07-10 WO PCT/MY2007/000048 patent/WO2008007940A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001015545A (en) * | 1999-07-02 | 2001-01-19 | Shinkawa Ltd | Machine and method for wire bonding |
| JP2001189340A (en) * | 1999-12-28 | 2001-07-10 | Shinkawa Ltd | Wire-bonding method and device thereof |
| JP2004119639A (en) * | 2002-09-26 | 2004-04-15 | Shinkawa Ltd | Method and device for wire bonding method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100444371C (en) | Power Semiconductor Packaging | |
| TWI605012B (en) | Microdevice conversion system using a pivot mount | |
| US8310064B2 (en) | Semiconductor devices including voltage switchable materials for over-voltage protection | |
| US6354479B1 (en) | Dissipative ceramic bonding tip | |
| US20090008796A1 (en) | Copper on organic solderability preservative (osp) interconnect | |
| US20110075306A1 (en) | Local integration of non-linear sheet i integrated circuit packages for esd/eos protection | |
| JPH10507878A (en) | Method of forming contact pins and interconnects for a semiconductor die | |
| CN1286173C (en) | Circuit structure connecting pads and ESD protection circuit | |
| US6896170B2 (en) | Wire bonder for ball bonding insulated wire and method of using same | |
| US20080197172A1 (en) | Bonding Tool | |
| TWI234829B (en) | Method of connecting an integrated circuit to a substrate and corresponding circuit arrangement | |
| US20060049505A1 (en) | High density interconnect power and ground strap and method therefor | |
| US20060261132A1 (en) | Low range bonding tool | |
| US7032802B2 (en) | Bonding tool with resistance | |
| JPH06261448A (en) | Protector for communication equipment | |
| US11594500B2 (en) | Semiconductor package | |
| WO2008007940A1 (en) | Dissipative ceramic wire clamp | |
| CN114594293A (en) | Probe apparatus and method of assembling the same | |
| JP2006510201A (en) | High density package interconnect wire bond stripline and method thereof | |
| JP4007917B2 (en) | Semiconductor device and manufacturing method thereof | |
| TWI868864B (en) | Lead frame package and lead frame package assembly method | |
| KR100356928B1 (en) | A circuit board having protection against electrostatic discharge | |
| CN111641095B (en) | Vertical surface mount C-type USB connector | |
| JP2000216188A (en) | Wire bonding method, semiconductor device, circuit board, electronic device, and wire bonding device | |
| WO2007012187A1 (en) | System and method for assembling packaged integrated circuits using insulated wire bond |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 07768890 Country of ref document: EP Kind code of ref document: A1 |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| NENP | Non-entry into the national phase |
Ref country code: RU |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 07768890 Country of ref document: EP Kind code of ref document: A1 |