CN110913577A

CN110913577A - Stacking structure of six-layer rigid-flex board

Info

Publication number: CN110913577A
Application number: CN201911341871.9A
Authority: CN
Inventors: 李胜伦; 汪涛; 钱发树
Original assignee: Jiangsu Hongxin Huayin Circuit Technology Co Ltd
Current assignee: Jiangsu Hongxin Huayin Circuit Technology Co Ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-03-24

Abstract

The invention discloses a stacked structure of six layers of rigid-flexible combined boards, which comprises a rigid area and a flexible area; the middle parts of the rigid area and the flexible area are both flexible copper clad plates, and copper clad layers are attached to both sides of each flexible copper clad plate; the surface of the copper plating layer positioned in the rigid area is sequentially attached with a first polypropylene layer, a first copper layer, a second polypropylene layer and a second copper layer; the surface of the copper plating layer positioned in the flexible area is attached with a covering film layer, and the covering film layer comprises a polyvinyl chloride layer positioned in an inner layer and a polyimide layer positioned in an outer layer. The flexible copper clad laminate is used as the middle layer, and the conductive capability of the flexible copper clad laminate is improved on the surface of the flexible copper clad laminate through electroplating a copper clad laminate, so that the use requirement of a foundation (double layers) is met, and then the rigid area and the flexible area are respectively subjected to multi-layer design, so that the rigid-flexible combined laminate is lightened and thinned as far as possible under the condition of meeting the normal use capability of six layers of rigid-flexible combined laminates.

Description

Stacking structure of six-layer rigid-flex board

Technical Field

The invention relates to a stacking structure of a six-layer rigid-flexible combined board.

Background

The flexible circuit board and the rigid circuit board are combined together according to relevant process requirements through processes of pressing and the like, so that the flexible circuit board and the rigid circuit board form the circuit board with the FPC characteristic and the PCB characteristic, and the flexible circuit board has the advantages of light weight, small size, free bending, stretching, folding and the like in three-dimensional space.

The six-layer rigid-flex board is used as a multi-layer form in the rigid-flex board, is particularly widely applied to the field of mobile phone double-shooting wiring, and is particularly applied to the background of the era that a mobile phone pursues lightness and thinness. The total thickness requirement of the six-layer rigid-flexible board is increasingly strict. However, the conventional six-layer rigid-flex printed circuit board adopts a mode that inner-pressing extending copper foils are attached to two ends of an intermediate substrate as a base layer, the total thickness of the six-layer rigid-flex printed circuit board cannot be greatly limited, and when a rigid outer polypropylene film is thin, the insulation function between layers cannot be met.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a stacked structure of six-layer rigid-flexible combined boards.

A stacked structure of six-layer rigid-flexible combined boards comprises a rigid area and a flexible area;

the middle parts of the rigid area and the flexible area are both flexible copper clad plates, and copper clad layers are attached to both sides of each flexible copper clad plate;

the surface of the copper plating layer positioned in the rigid area is sequentially attached with a first polypropylene layer, a first copper layer, a second polypropylene layer and a second copper layer;

the surface of the copper plating layer positioned in the flexible area is attached with a covering film layer, and the covering film layer comprises a polyvinyl chloride layer positioned in an inner layer and a polyimide layer positioned in an outer layer.

Preferably, the flexible copper clad laminate comprises an inner polyimide layer, wherein inner copper layers are attached to two sides of the inner polyimide layer, the thickness of each inner copper layer is h1, the thickness of each inner polyimide layer is h2, and h2 is greater than 2h 1.

Preferably, the outer surfaces of the first copper layer and the second copper layer are both attached with an electric copper layer.

Preferably, the surface of the electric copper layer attached to the outer surface of the second copper layer is provided with a solder mask layer, and the solder mask layer is made of polysulfide rubber.

Preferably, the surface copper thickness of the copper layer is 25um +/-5 um, and the hole copper thickness is 12um +/-2 um.

Preferably, the thickness of the first polypropylene layer is d1, the thickness of the first copper layer is d2, the thickness of the second polypropylene layer is d3, the thickness of the second copper layer is d4, the d1 ═ d3, d2 ═ d4, and d1 ═ 3d 2. Taking the first copper layer 12um as an example, the first polypropylene layer is designed to be 55um, and the thickness of the polypropylene layer is approximately three times of that of the copper layer, plus a certain safety margin.

Preferably, the surface copper thickness of copper plating layer is 20um 5um, and hole copper thickness is 8um 2 um.

The inner copper layer, the first copper layer and the second copper layer are all made of red electrolytic flexible copper.

Has the advantages that:

the design that the flexible copper clad laminate is used as the middle layer is adopted, the conductive capability of the flexible copper clad laminate is improved through electroplating the copper clad laminate on the surface of the flexible copper clad laminate, so that the use requirement of a foundation (double layers) is met, then the rigid region and the flexible region are respectively subjected to multi-layer design, the rigid region is accurately designed in a ratio of 1:3 through the design of the first polypropylene layer, the first copper layer, the second polypropylene layer and the second copper layer, and certain safety margin is added, so that the total thickness of the whole soft and hard combined board is reduced as far as possible under the condition that the requirement of insulativity is met, and the six layers of soft and hard combined boards can be applied to the field with smaller space.

The surface of flexible layer is protected through covering the rete, and concrete polyvinyl chloride layer through the inlayer encapsulates the protection with being located outer polyimide layer to it, also can not destroy the ability of buckling of flexible layer through polyvinyl chloride layer and polyimide layer to guarantee the normal use of soft and hard combined plate.

Drawings

FIG. 1 is a schematic diagram of a six-layer rigid-flex board with designed blind holes and through holes;

Detailed Description

For the purpose of enhancing the understanding of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, which are only used for explaining the present invention and are not to be construed as limiting the scope of the present invention.

As shown in fig. 1, the six-layer rigid-flex board has a stacked structure, and there are seven design manners of the blind holes and one design manner of the through holes, so that the space wiring manner of the rigid-flex board can be greatly enriched through the blind holes and the through holes, and a relatively complex circuit connection can be designed in a very small space.

Specifically, the stacked structure of the six-layer rigid-flexible combined board comprises a rigid area and a flexible area; wherein the rigid region is provided with six layers, namely L1, L2, L3, L4, L5 and L6.

The flexible copper-clad plate comprises an inner polyimide layer, wherein inner copper layers are attached to two sides of the inner polyimide layer, the thickness of each inner copper layer is h1, the thickness of each inner polyimide layer is h2, and h2 is greater than 2h 1.

The surface of first copper layer, second copper layer all with the copper layer, the surface that attaches to the copper layer of second copper layer surface be equipped with the solder mask, the material of solder mask is polysulfide rubber.

Specifically, the surface copper thickness of the copper layer is 25um +/-5 um, and the hole copper thickness is 12um +/-2 um. The thickness on first polypropylene layer is 55um, the thickness on first copper layer is 12um, the thickness on second polypropylene layer is 55um, the thickness on second copper layer is 12um, the face copper thickness on copper-plated layer is 20um 5um, and hole copper thickness is 8um 2 um.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A stacked structure of six-layer rigid-flexible combined boards is characterized by comprising a rigid area and a flexible area;

2. The laminated structure of six-layer rigid-flex boards as claimed in claim 1, wherein the flexible copper clad laminate comprises an inner copper layer adhered to both sides of the inner polyimide layer, the thickness of the inner copper layer is h1, the thickness of the inner polyimide layer is h2, and h2>2h 1.

3. The laminated structure of six-layer rigid-flex boards as claimed in claim 1, wherein the outer surfaces of the first and second copper layers are attached with copper plating.

4. The laminated structure of a six-layer rigid-flex board as claimed in claim 3, wherein a solder resist layer is formed on the surface of the electro-copper layer attached to the outer surface of the second copper layer, and the solder resist layer is made of polysulfide rubber.

5. The laminated structure of a six-layer rigid-flex board as claimed in claim 3, wherein the surface copper thickness of the copper layer is 25um ± 5um, and the hole copper thickness is 12um ± 2 um.

6. The laminated structure of a six-layer rigid-flexible printed circuit board as claimed in claim 1, wherein the thickness of the first polypropylene layer is d1, the thickness of the first copper layer is d2, the thickness of the second polypropylene layer is d3, the thickness of the second copper layer is d4, d1 ═ d3, d2 ═ d4, and d1>3d 2.

7. The laminated structure of a six-layer rigid-flexible printed circuit board as claimed in claim 1, wherein the copper-plated layer has a surface copper thickness of 20um ± 5um and a hole copper thickness of 8um ± 2 um.