CN103596382A

CN103596382A - Printed circuit board

Info

Publication number: CN103596382A
Application number: CN201310553608.2A
Authority: CN
Inventors: 张翠
Original assignee: LIYANG JIANGDA TECHNOLOGY TRANSFER CENTER Co Ltd
Current assignee: LIYANG JIANGDA TECHNOLOGY TRANSFER CENTER Co Ltd
Priority date: 2013-11-08
Filing date: 2013-11-08
Publication date: 2014-02-19

Abstract

The invention discloses a printed circuit board which comprises an insulating core layer (1), a metal tin layer (3), copper foil layers (2) and a plurality of copper-tin alloy columns. The metal tin layer (3) is embedded into the insulating core layer (1), the copper foil layers (2) are formed on the front face of the insulting core layer (1) and the back face of the insulating core layer (1) and the copper-tin alloy columns (4) are formed between the metal tin layer (3) and the copper foil layers (2). The printed circuit board can improve the bonding strength between the insulating core layer (1) and the copper foil layers (2), avoid disengaging of the insulating core layer and the copper foil layers, and therefore the reliability and the product yield of the printed circuit board are improved.

Description

A kind of printed circuit board (PCB)

Technical field

The invention belongs to circuit board technology field, particularly a kind of printed circuit board (PCB).

Background technology

Printed circuit board (PCB) is the carrier that electronic device connects, it is cheap for manufacturing cost, be commonly referred to PCB or PWB, be printed circuit board (PCB) or printed wiring board, its structure generally includes insulation sandwich layer, is formed on the copper foil layer on insulation sandwich layer two sides, according to the connection needs of subsequent electronics, can carry out patterning to copper foil layer, and in printed circuit board (PCB), form the interconnected pores such as through hole, blind hole.Electronic device can be formed on the two sides of printed circuit board (PCB) simultaneously, thereby improves integration density.

The substrate as PCB in the copper-clad plate (CCL) of insulation sandwich layer two sides stacking copper foil layer successively, copper-clad plate can be divided into glass/epoxy CCL, heat stable resin CCL, paper/phenol CCL, high frequency CCL, flexible CCL(polyimide film according to application), compound CCL etc.The most frequently used two-sided PCB or the multi-layer PCB manufactured of glass/epoxy CCL wherein.

First carry out chemical-copper-plating process and carry out the required thin conducting film of copper plating process to form.Carry out afterwards copper plating process and form copper foil layer.Form thus copper-clad plate.But the bond strength between copper foil layer and insulation sandwich layer may be low, thereby cause copper foil layer easily from insulation sandwich layer, to be peeled off, thereby make product there is major defect.In recent years, also once attempted to increase surface roughness by the alligatoring surface that sandwich layer contacts with copper foil layer of insulating, thereby improved the two bond strength.But its complex process, cost are higher, and the roughness of the coarse surface forming be there are certain requirements, thereby can realize the adhering object of enhancing.

Summary of the invention

In view of this, the present invention is directed to the problem of prior art, proposed a kind of printed circuit board (PCB).By the bond strength between the Copper Foil of this printed circuit board (PCB) and insulation sandwich layer is improved, can improve the reliability of printed circuit board (PCB), strengthen thus bond strength and improve product yield.

The printed circuit board (PCB) that the present invention proposes comprises:

Insulation sandwich layer (1);

Embed the inner metallic tin layer (3) of insulation sandwich layer (1);

Be formed on insulation sandwich layer (1) front and back on copper foil layer (2); And

Be formed on a plurality of signal bronze posts (4) between metallic tin layer (3) and copper foil layer (2).

Accompanying drawing explanation

Fig. 1 is the sectional view of the printed circuit board (PCB) that proposes of the present invention;

Fig. 2 is the sectional view of the printed circuit board (PCB) that proposes of the present invention before forming copper foil layer.

Embodiment

Embodiment 1

Below with reference to Fig. 1 and Fig. 2, describe structure and the manufacture method thereof of printed circuit board (PCB) of the present invention in detail.For clarity sake, the equal not drawn on scale of each structure shown in accompanying drawing, and the present invention is not limited to structure shown in figure.

As shown in fig. 1, printed circuit board (PCB) of the present invention comprises: insulation sandwich layer 1, embed insulation sandwich layer 1 inside metallic tin layer 3, be formed on the copper foil layer 2 on the front and back of insulation sandwich layer 1 and be formed on metallic tin layer 3 and copper foil layer 2 between a plurality of signal bronze posts 4.

The manufacture method of printed circuit board (PCB) of the present invention is below described.

First, provide metallic tin layer 3.Metallic tin is a kind of soft metal, and its fusing point is about 231 degrees Celsius.

Subsequently, metallic tin layer 3 is placed in to mould, to casting insulation material in mould, thereby form the insulation sandwich layer 1 that has wherein embedded metallic tin layer 3, the material of insulation sandwich layer is fire resistant resin material, for example polyflon (PTFE), organic siliconresin, novolac epoxy resin (EPN), polyimide resin etc.Insulation sandwich layer 1 should be high temperature resistant, and its fusion temperature or decomposition temperature should be greater than the fusing point of the metallic tin layer 3 wherein embedding.

Subsequently, utilize laser drill or etching to start to form until a plurality of through holes of metallic tin layer 3 from the front and back of insulation sandwich layer 1, the position of the corresponding through hole between a plurality of through holes is corresponding one by one, from the front of insulation sandwich layer 1, starts the position alignment that the position of each through hole of forming and the back side from insulation sandwich layer 1 start each through hole of forming.

Subsequently, as shown in Figure 2, in a plurality of through holes, form a plurality of signal bronze posts 4, each signal bronze post 4 that starts to form from the front of insulation sandwich layer 1 in a plurality of signal bronze posts 4 and the back side from insulation sandwich layer 1 start the position alignment of each signal bronze post 4 of forming.And said structure is heated, heating-up temperature makes 3 fusing of metallic tin layer but the softening decomposition of sandwich layer 1 that do not make to insulate, and temperature range is about 230 degrees Celsius-250 degrees Celsius, preferably 231 degrees Celsius, 235 degrees Celsius, 240 degrees Celsius, 246 degrees Celsius.This temperature range can the impact of the fire resistant resin material production in sandwich layer 1 on insulation, the chemical stability of the sandwich layer 1 that therefore can keep insulating.Because heating-up temperature makes 3 fusing of metallic tin layer, therefore the signal bronze post 4 forming in a plurality of through holes embeds in metallic tin layer 3, and the degree of depth that signal bronze post 4 embeds in metallic tin layer 3 is 20nm-40nm, preferably 25nm, 30nm, 35nm, 40nm, make the bond strength between signal bronze post 4 and metallic tin layer 3 strengthen thus.And a plurality of signal bronze posts 4 form the front and back that its top protrudes from insulation sandwich layer 1, thereby form a plurality of bulge-structures.The height that bulge-structure protrudes from the front and back of insulation sandwich layer 1 is 5nm-15nm, preferably 6nm, 8nm, 10nm, 13nm, 15nm.

Subsequently, utilize a plurality of bulge-structures as copper facing seed crystal structure, on the front and back of insulation sandwich layer 1, form the copper foil layer 2 that covers a plurality of bulge-structures completely.So far form printed circuit board (PCB) of the present invention.

So far, detailed explanation of foregoing description printed circuit board (PCB) of the present invention and manufacture method, the printed circuit board (PCB) making with respect to existing method, the printed circuit board (PCB) that the method that the present invention proposes makes can increase substantially the bond strength between copper foil layer 2 and insulation sandwich layer 1, thereby improves reliability and the product yield of whole printed circuit board (PCB).The embodiment describing is above only the preferred embodiments of the present invention, and it is not intended to limit the present invention.Those skilled in the art are not departing under the prerequisite of spirit of the present invention, can make any modification to the present invention, and protection scope of the present invention are limited to the appended claims.

Claims

1. a printed circuit board (PCB), comprising:

Insulation sandwich layer (1);

Embed the inner metallic tin layer (3) of insulation sandwich layer (1);

2. printed circuit board (PCB) according to claim 1, is characterised in that:

The material of sandwich layer (1) of wherein insulating is fire resistant resin material, for example polyflon (PTFE), organic siliconresin, novolac epoxy resin (EPN), polyimide resin etc.

3. printed circuit board (PCB) according to claim 2, is characterised in that:

Front from insulation sandwich layer (1) in a plurality of signal bronze posts (4) starts each signal bronze post (4) forming and the position alignment that starts each signal bronze post (4) of formation from the back side of insulation sandwich layer (1).

4. printed circuit board (PCB) according to claim 3, is characterised in that:

A plurality of signal bronze posts (4) embed in metallic tin layer (3), and the degree of depth that a plurality of signal bronze post (4) embeds in metallic tin layer (3) is 20nm-40nm.

5. printed circuit board (PCB) according to claim 4, is characterised in that:

A plurality of signal bronze posts (4) form the front and back that its top protrudes from insulation sandwich layer (1), thereby form a plurality of bulge-structures, and the height that a plurality of bulge-structures protrude from the front and back of insulation sandwich layer (1) is 5nm-15nm.