WO2017107535A1

WO2017107535A1 - Rigid-flex board and preparation method therefor

Info

Publication number: WO2017107535A1
Application number: PCT/CN2016/096903
Authority: WO
Inventors: 林楚涛; 陈蓓; 乔书晓
Original assignee: 广州兴森快捷电路科技有限公司; 深圳市兴森快捷电路科技股份有限公司; 广州市兴森电子有限公司
Priority date: 2015-12-25
Filing date: 2016-08-26
Publication date: 2017-06-29
Also published as: CN105472874A

Abstract

A rigid-flex board, comprising a rigid-flex sub-board (100) and a first copper layer (200) and a second copper layer (300) respectively fixed on the upper and lower surfaces of the rigid-flex sub-board, wherein at least one layer of flowing-type prepreg (400) is arranged both between the rigid-flex sub-board and the first copper layer and between the rigid-flex sub-board and the second copper layer. By respectively arranging at least one layer of flowing-type prepreg between a rigid-flex sub-board and a first copper layer and between the rigid-flex sub-board and a second copper layer, a buried hole of the rigid-flex sub-board can be directly filled, thereby reducing a resin hole-plugging flow. In addition, a board surface of a pressed PCB board is high in smoothness and of good quality, and the manufacturing of a fine circuit with the line width/line distance being 3mil/3mil can be realized.

Description

Rigid-flexible bonding plate and preparation method thereof

Technical field

The invention relates to the technical field of printed circuit boards, in particular to a rigid-flex board and a preparation method thereof.

Background technique

With the development of electronic products in the direction of miniaturization and portability, the printed circuit boards required for them are also developing in a light, thin, short, and small direction. Among them, high-density interconnect (HDI) rigid-flexible printed circuit boards with high-density wiring, contacts and three-dimensional assembly are the best in this direction. In recent years, the market demand for HDI rigid-flex panels has grown by more than 20% per year, much larger than other types of printed circuit boards.

In order to avoid the glue that just flexes the flexible region of the bonding plate, the rigid flexible bonding plate is pressed by the non-flowing prepreg. When the non-flowing type prepreg is pressed, the fluidity is poor, and the flatness of the surface of the rigid-flexed plate is poor after pressing. When the outer layer is fabricated, the filming of the plate surface depression will greatly affect the quality of the fine-flexed plate.

Summary of the invention

Based on the above, the present invention overcomes the defects of the prior art, and provides a rigid-flex plate and a preparation method thereof, which realizes good flatness of the plate after pressing, reduces resin plug holes, and has simple structure and convenient processing.

The object of the invention is achieved in this way:

A rigid-flex bonding board comprising a rigid-flex bonding sub-board and a first copper layer and a second copper layer respectively fixed on the rigid-flex bonding sub-board and the lower surface, the rigid-flex bonding sub-board and the At least one flow type prepreg is disposed between the first copper layer, the rigid-flex bonder plate, and the second copper layer.

The following is a description of further technical solutions:

Further, the flow type prepreg has a TG value of 170 ° C or more.

Further, the flow-type prepreg has a thickness ranging from 30 to 100 μm after pressing.

Further, the rigid-flex bonding sub-board includes a first rigid plate, a non-flowing type prepreg, a flexible board, a non-flowing type prepreg, and a second rigid board which are laminated and fixed in order from top to bottom, and the rigid-flexible sub-board There is at least one conductive channel on the top.

Further, the upper and lower surfaces of the flexible board are each provided with a circuit pattern, and the conductive channel is electrically connected to the line pattern.

Further, a flexible area is disposed on the upper and lower sides of the flexible board, and the circuit pattern is provided with a cover film, and the cover film is located in the flexible area.

Further, the conductive channel has a diameter ranging from 75 to 150 μm.

Further, the first copper layer and the second copper layer have a thickness ranging from 12 to 35 μm.

The invention also provides a method for preparing a rigid-flex plate according to the above claims, which comprises the following steps:

The upper and lower sides of the flexible board are transferred through the film to produce a line pattern;

Laying a cover film at the flexible area at the line pattern;

Laminating the first rigid plate, the flexible plate and the second rigid plate in sequence to form a rigid-flex bond plate;

Forming a conductive channel by rigid-flexing the bond plate through drilling and hole metallization;

Making a line pattern of the rigid-flexed bondboard through the film transfer;

The first copper layer, the flow type prepreg, the rigid-flex bonder plate, the flow-type prepreg, and the second copper layer are sequentially laminated and pressed.

The pressed rigid rigid joint plate is laser drilled to the first laser blind hole and the second laser blind hole, and the rigid flexible joint plate is fabricated through mechanical drilling, hole metallization and other subsequent processes.

The beneficial effects of the invention are:

The rigid-flex board is provided with at least one layer of the flow type prepreg between the rigid-flex bonder board and the first copper layer, and the rigid-flex bonder board and the second copper layer, respectively. The hole can be directly filled into the buried hole of the rigid-flex bonding sub-board, thereby reducing the resin plugging process. In addition, the flatness of the PCB surface after pressing is high, the quality is good, and the line width/line spacing can be realized. It is made of 3mil/3mil fine lines.

Through the preparation method of the rigid-flexible bonding plate described above, respectively, the rigid-flex bonded sub-board and the first Providing at least one layer of the flow type prepreg between the copper layer and the rigid flexible bonding sub-board and the second copper layer, so as to directly fill the buried holes of the rigid-flex bonding sub-board, thereby reducing The resin plugging process, in addition, the flatness of the PCB surface after pressing, the quality is good, and the fine line with the line width/line spacing of 3 mil/3 mil can be realized.

DRAWINGS

1 is a schematic structural view of a rigid-flex plate according to an embodiment of the present invention;

2 is a schematic view showing the fabrication of a flexographic circuit pattern and a cover film according to an embodiment of the present invention;

3 is a schematic view showing the fabrication of a rigid-flex bonded sub-board according to an embodiment of the invention;

4 is a schematic diagram of fabrication of a conductive channel according to an embodiment of the invention;

5 to FIG. 6 are schematic views showing the lamination of the embodiment of the present invention;

FIG. 7 is a schematic view showing the fabrication of a rigid-flex plate according to an embodiment of the invention.

Description of the reference signs:

100, rigid-flex jointing sub-board, 120, first rigid board, 140, non-flowing prepreg, 160, flexible board, 162, flexible area, 164, circuit pattern, 180, second rigid board, 200, first copper Layer, 300, second copper layer, 400, flow prepreg, 500, conductive vias, 600, cover film.

detailed description

The embodiments of the present invention are described in detail below:

As shown in FIG. 1 , a rigid flexible bonding board includes a rigid flexible bonding sub-board 100 and a first copper layer 200 and a second copper layer 300 respectively fixed on the upper and lower surfaces of the rigid flexible bonding sub-board 100. At least one flow type prepreg 400 is disposed between the rigid-flex bonder board 100 and the first copper layer 200, the rigid-flex bonder board 100, and the second copper layer 300.

Wherein the rigid-flex bonding plate is provided with at least one layer between the rigid-flex bonding sub-board 100 and the first copper layer 200, and the rigid-flex bonding sub-board 100 and the second copper layer 300, respectively. The flow type prepreg 400 can directly fill the buried holes of the rigid-flex bonding daughter board 100, thereby reducing the resin plugging process. In addition, the board surface of the PCB board is high in flatness and good in quality after pressing. It can realize the production of fine lines with line width/line spacing of 3mil/3mil.

In addition, according to the processing requirements of different specifications of the plate, one or more of the flow type prepreg 400 may be disposed during the lamination process to ensure good plate-making quality and ensure high flatness of the plate.

The flow type prepreg 400 has a TG value of 170 ° C or more. Further, it is preferable that the flow type prepreg 400 has a TG value of 170 ° C or more so as to have good fluidity after being heated, and to ensure that the buried holes are filled and the reliability of the operation is improved. In other embodiments, flow stencil sheets of other sizes of TG values may also be employed, and are also within the scope of the present invention.

The thickness of the flow type prepreg 400 after pressing is in the range of 30 to 100 μm. Preferably, the thickness of the flow type prepreg after pressing is 30-100 μm, which can avoid the thickness being too small, resulting in low insulation performance, low reliability, or excessive thickness, resulting in pre-cured sheets when the laminate is pressed. The expansion and wrinkles greatly affect the quality of the panel.

The rigid-flex bonding sub-board 100 includes a first rigid plate 120, a non-flowing type prepreg 140, a flexible board 160, a non-flowing type prepreg 140, and a second rigid board 180 which are laminated and fixed in order from top to bottom. The bonding sub-board 100 is provided with at least one conductive via 500.

The rigid flexible bonding board 100 of the present invention is exemplified by the rigid flexible bonding board of the six-layer structure, that is, the rigid flexible bonding sub-board 100 includes a first rigid board 120 and a non-flowing type prepreg 140 which are laminated and fixed in order from top to bottom. a flexible board 160, a non-flowing type prepreg 140 and a second rigid board 180, and the upper and lower covering surfaces of the flexible board 160 are provided with a flexible region 162 for fabricating a flexible daughter board, and at the same time, the rigid flexible bonding daughter board At least one conductive channel 500 is provided on the 100, so that the rigid-flex plate is simpler and more compact, and at the same time, a higher quality of the plate can be ensured.

The upper and lower surfaces of the flexible board 160 are each provided with a line pattern 164, and the conductive path 500 is electrically connected to the line pattern 164. In addition, the circuit pattern 164 is formed on the upper and lower surfaces of the flexible board 160 and is electrically connected to the conductive path 500 to achieve normal electrical connection between the inner flexible board and the outer rigid board, and achieve good performance. Signal transmission effect. The specific production method is as follows:

Dry film exposure on the flexible board 160 to form a line pattern;

Forming the line pattern 164 by dry film exposure, acid etching;

The conductive vias 500 are formed at the drilled through holes by sinking copper.

The flexible plate 160 is provided with a flexible region 162 on the upper and lower sides thereof. The circuit pattern 164 is provided with a cover film 600, and the cover film 600 is located in the flexible region 162.

In addition, the cover film 600 is a polyimide film which has good flexibility and flexibility and can protect the inner layer of the flexible plate 160. In other embodiments, films of other materials may also be used.

The first copper layer 200 and the second copper layer 300 have a thickness ranging from 12 to 35 μm. Preferably, the thickness of the first copper layer 200 and the second copper layer 300 is designed to be 12 to 35 μm, which can ensure the reliability of work, avoid damage caused by being too thin during pressing, or cause poor insulation due to too late. And easy to wrinkle, affecting the surface quality of the board.

The conductive channel 500 has a diameter ranging from 75 to 150 μm. Wherein, the conductive channel 500 preferably has a diameter ranging from 75 to 150 μm, which can ensure a proper aspect ratio, and coordinate the overall ratio of the conductive via 500 and the rigid flexible bonded plate. The above range of sizes is not intended to limit the scope of protection, and in other embodiments, other ranges of values may be employed.

The upper and lower sides of the flexible board 160 are transferred by film transfer to form the line pattern 164;

The cover film 600 is pasted at the flexible pattern 162 at the line pattern 164;

The first rigid plate 120, the flexible plate 160, the second rigid plate 180 are sequentially laminated and then pressed to form the rigid-flex bond plate 100;

Forming the conductive channel 500 by drilling and hole metallization of the rigid-flex bond daughter board 100;

Forming the line pattern 164 of the rigid-flex bond daughter board 100 by film transfer;

The first copper layer 200, the flow-type prepreg 400, the rigid-flex bonder plate 100, the flow-type prepreg 400, and the second copper layer 300 are sequentially laminated and pressed.

The rigid flexible bonded sheets produced by the above-described preparation method pass between the rigid-flex bonded sub-board 100 and the first copper layer 200, and between the rigid-flex bonded sub-board 100 and the second copper layer 300, respectively. Providing at least one layer of the flow type prepreg 400, which can directly achieve the rigid-flexed bond board The buried hole of 100 is filled, thereby reducing the resin plugging process. In addition, the flatness of the PCB board after pressing is high, and the quality is good, and the fine line with the line width/line spacing of 3 mil/3 mil can be realized.

The cover film in the above step 2 specifically refers to a circuit pattern covering the flexible region 162 for protection, and in addition, the first laser blind hole and the second laser blind hole are fabricated. The specific drilling is performed with a CO ₂ laser because of its higher production efficiency, which is suitable for mass production of rigid-flex bonded circuit boards.

The technical features of the above-described embodiments may be arbitrarily combined. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be considered as the scope of this manual.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A rigid-flexible bonding plate, comprising: a rigid-flex bonding sub-board, and a first copper layer and a second copper layer respectively fixed on the rigid-flex bonding sub-board and the lower surface, the rigid-flexible bond At least one flow type prepreg is disposed between the plate and the first copper layer, the rigid flexible bond daughter plate, and the second copper layer.
The rigid-flex board according to claim 1, wherein the flow type prepreg has a TG value of 170 ° C or more.
The rigid-flex board according to claim 2, wherein the flow-type prepreg has a thickness ranging from 30 to 100 μm after pressing.
The rigid-flex board according to claim 1, wherein the rigid-flex bonder board comprises a first rigid board, a non-flowing type prepreg, a flexible board, and a non-flowing type prepreg which are laminated and fixed in order from top to bottom. And a second rigid plate, wherein the rigid flexible bond plate is provided with at least one conductive channel.
The rigid-flex board according to claim 4, wherein the upper and lower surfaces of the flexible board are provided with a circuit pattern, and the conductive path is electrically connected to the line pattern.
The rigid-flex board according to claim 5, wherein the flexible board is provided with a flexible area on the upper and lower sides, and the cover pattern is provided with a cover film, and the cover film is located at the scratch Within the sexual area.
The rigid-flex plate according to claim 4, wherein the conductive passage has a diameter ranging from 75 to 150 μm.
The rigid-flex plate according to claim 1, wherein the first copper layer and the second copper layer have a thickness ranging from 12 to 35 μm.
A method for preparing a rigid-flex plate according to any one of claims 1 to 8, comprising the steps of:

The upper and lower sides of the flexible board are transferred through the film to produce a line pattern;

Laying a cover film at the flexible area at the line pattern;

Laminating the first rigid plate, the flexible plate and the second rigid plate in sequence to form a rigid-flex bond plate;

Forming a conductive channel by rigid-flexing the bond plate through drilling and hole metallization;

Making a line pattern of the rigid-flexed bondboard through the film transfer;

The first copper layer, the flow type prepreg, the rigid-flex bonder plate, the flow-type prepreg, and the second copper layer are sequentially laminated and pressed.

The pressed rigid rigid joint plate is laser drilled to the first laser blind hole and the second laser blind hole, and the rigid flexible joint plate is fabricated through mechanical drilling, hole metallization and other subsequent processes.