CN101594752A

CN101594752A - The manufacture method of multilayer circuit board

Info

Publication number: CN101594752A
Application number: CNA2008103017795A
Authority: CN
Inventors: 林明; 刘兴泽; 林承贤
Original assignee: Honsentech Co Ltd; Fukui Precision Component Shenzhen Co Ltd
Current assignee: Honsentech Co Ltd; Avary Holding Shenzhen Co Ltd
Priority date: 2008-05-26
Filing date: 2008-05-26
Publication date: 2009-12-02

Abstract

The present invention relates to a kind of manufacture method of multilayer circuit board.Described manufacture method may further comprise the steps: provide the surface to be formed with the circuit substrate of conducting wire layer; Precalculated position in the conducting wire of circuit substrate laminar surface forms electric conductor; The surface that is provided with the conducting wire at circuit substrate forms insulating barrier and makes electric conductor be embedded at insulating barrier, and goes out from insulating layer exposing; Form the external conducting wire that links to each other with electric conductor in surface of insulating layer.This method need not to make via, has solved prior art and has made the defective of thru-hole electroplating difficulty, and simplified the circuit board making operation greatly, has improved the circuit board making yield.

Description

The manufacture method of multilayer circuit board

Technical field

The present invention relates to the circuit board making technology, relate in particular to a kind of manufacture method of multilayer circuit board.

Background technology

Along with the development of electronic product toward miniaturization, high speed direction, circuit board also develops toward the multilayer circuit board direction from single face circuit board, double-sided PCB.Multilayer circuit board is meant the circuit board with multilayer conductive circuit, it has more wiring area, higher interconnect density, thereby be widely used, referring to document Takahashi, A.Ooki, N.Nagai, A.Akahoshi, H.Mukoh, A.Wajima, M.Res.Lab., High density multilayer printedcircuit board for HITAC M-880, IEEE Trans.on Components, Packaging, andManufacturing Technology, 1992,15 (4): 418-425.

Process for manufacturing circuit board generally includes steps such as exposure, development, etching, boring, plating.With the multilayer circuit board is example, and it adopts lay-up method to make, and particularly, may further comprise the steps: the first step forms the conducting wire with exposure, development, etch process in the copper-clad base plate surface; In second step, bore the through hole that connects copper-clad base plate in the precalculated position of conducting wire; The 3rd step formed the copper layer with electroplating technology in the through hole hole wall, thereby formed via, made inner plating; The 4th step was an outermost layer substrate with another copper-clad base plate, adopted pure glue that this outermost layer substrate is pressure bonded to inner plating; In the 5th step, form blind hole or through hole in the precalculated position of outermost layer substrate; In the 6th step, form the copper layer in blind hole or through hole hole wall with electroplating technology; The 7th step, adopt exposure, development, etch process to form the conducting wire in the outermost layer substrate surface, make the two-tier circuit plate, be internal substrate with this two-tier circuit plate, repeated for the 4th step to the 7th step, can make multilayer circuit board.

This shows, the manufacturing process of every layer of structure comprises that very complicated conducting wire makes in the production process of existing multilayer circuit board, steps such as the pressing that constantly repeats, exposure, development, etching, the labour intensity that makes multilayer circuit board make is bigger, and make efficiency is lower.And the production process of existing multilayer circuit board some technologic problems of also can deriving; as soft board size generation breathing in process for pressing; be difficult for accurately being controlled; deviation appears in regular meeting when causing the circuit contraposition between soft board layer and the layer, causes external conducting wire and the internal layer conducting wire can't conducting.And, being further to improve the utilance of substrate surface, via is made more and more forr a short time, and this makes more and more difficulty of operation that electroplating ventilating hole forms via, causes the yield of the circuit board that finally makes lower.

Therefore, be necessary to provide a kind of multilayer circuit board and preparation method thereof,, improve the circuit board yield to simplify the circuit board making operation.

Summary of the invention

To with embodiment the manufacture method that example illustrates a kind of multilayer circuit board below.

A kind of manufacture method of multilayer circuit board, it may further comprise the steps: provide the surface to be formed with the circuit substrate of conducting wire layer; Precalculated position in the conducting wire of circuit substrate laminar surface forms electric conductor; The surface that is provided with the conducting wire at circuit substrate forms insulating barrier and makes electric conductor be embedded at insulating barrier, and goes out from insulating layer exposing; Form the external conducting wire that links to each other with electric conductor in surface of insulating layer.

Compared with prior art, the manufacture method of the multilayer circuit board of the technical program need not made via, therefore, can effectively overcome the defective of the plating via hole wall difficulty that the making via brings in the prior art, and simplify the circuit board making operation greatly, improve the circuit board making yield.

Description of drawings

Fig. 1 is the structural representation of the circuit substrate that adopted of multilayer circuit board manufacturing method that the technical program embodiment provides.

Fig. 2 is the schematic diagram that forms electric conductor in circuit substrate shown in Figure 1.

Fig. 3 is the schematic diagram that forms insulating barrier in circuit substrate shown in Figure 2.

Fig. 4 is the schematic diagram that forms conductive metal layer in insulating barrier shown in Figure 3.

Fig. 5 is the schematic diagram that the conductive metal layer of etching circuit substrate shown in Figure 4 forms the conducting wire.

Embodiment

Be elaborated below with reference to the manufacture method of drawings and Examples to the multilayer circuit board of the technical program.

The manufacture method of described multilayer circuit board may further comprise the steps:

The first step: circuit substrate 10 is provided.

Circuit substrate 10 can be the single face circuit substrate of the common structure in this area, double-sided circuit substrate or Mulitilayer circuit board.See also Fig. 1, the circuit substrate 10 that present embodiment adopts is the double-sided circuit substrate, and it comprises insulated base material layer 11 and the conducting

wire layer

12,13 that is positioned at insulated base material layer 11 relative two surfaces.Certainly, as conducting mutually between the need conducting

wire layer

12,13, can adopt this area bore process commonly used to bore and connect conducting wire layer 12 in

circuit substrate

10,13 through hole adopts electroplating technology commonly used to make the through hole hole wall form conductive layer then, thereby forms via.

In second step, form electric conductor 20 in the precalculated position on

layer

12,13 surface, the conducting wire of circuit substrate 10.

See also Fig. 1 and Fig. 2, the electric conductor 20 that desire forms from conducting

wire layer

12,13 surface to away from conducting

wire layer

12,13 direction is extended, be the surface that electric conductor 20 protrudes from conducting

wire layer

12,13, it is used to conduct the conducting wire between the multilayer circuit board adjacent two layers.

Electric conductor 20 can adopt print process to be formed at described precalculated position.Particularly, print process is carried out according to the following steps: at first template such as web plate or steel plate are covered in conducting

wire layer

12,13 surface of circuit substrate 10, described template has a plurality of through holes, and described through hole is corresponding to the precalculated position of conducting

wire layer

12,13; Secondly, with the liquid thermosetting conductive materials as copper cream, silver paste or carbon paste printing to as described in the through hole; Once more, baking or the described conductive materials of ultraviolet light polymerization, making this conductive materials solidified forming is electric conductor 20; At last template is separated with circuit substrate 10, obtain being provided with the circuit substrate of electric conductor 20 thus.

Make precision for improving, electric conductor 20 can adopt ink-jet method to make.Particularly, can adopt following two kinds of methods to make.First kind, at first, injection apparatus and template are provided, described template is provided with the through hole on its relative two surfaces of a plurality of perforations, injection apparatus has injector head, the through hole that is used for seeing through template sprays liquid thermosetting conductive materials such as copper slurry, silver slurry to the precalculated position of the conducting wire of circuit substrate 10

layer

12,13; Secondly, adopt this area curing process commonly used such as the soft roasting or hard roasting liquid conductive materials that solidifies, liquid conductive materials is solidified; At last, force in template, it is separated with the conductive materials solidfied material, thereby form a plurality of electric conductors 20 in the precalculated position of conducting wire layer 12,13.Second kind, directly in the conducting wire of circuit substrate 10

layer

12,13 precalculated position forms electric conductor 20, promptly adopt the MEMS (micro electro mechanical system) that has the injector head of MEMS (micro electro mechanical system) and the position data of through hole is imported this injector head, under the condition of UV-irradiation or heated baking, utilize this injector head directly liquid conductive materials to be injected into the conducting wire layer 12 of circuit substrate then, 13 precalculated position, solidified forming is a plurality of electric conductors 20 when realizing that liquid conductive materials self-injection head is sprayed onto the precalculated position.

In the 3rd step, the surface that is provided with conducting

wire layer

12,13 at circuit substrate 10 forms insulating barrier 30 and makes electric conductor 20 be embedded at insulating barrier 30, and exposes from insulating barrier 30.

See also Fig. 2 and Fig. 3, at first liquid insulating material is filled between every adjacent two electric conductors 20 with conventional rubbing method in this area or ink-jet method.Under the influence of surface tension of liquid, liquid insulating material will be towards the direction diffusion near electric conductor 20, until soaking into electric conductor 20.For avoiding liquid insulating material to overflow, the thickness of the liquid insulating material of being filled is advisable with the height that is no more than electric conductor 20.The operation of described ink-jet method can be referring to step 2.The material of described liquid insulating material is the normal resin that adopts in this area, as in phenolic resins, epoxy resin, mylar, polyimides, Teflon, poly-thiamines, polymethyl methacrylate, Merlon, polyethylene terephthalate, the polyimides polyethylene terephthaldehyde ester copolymer one or more.

Behind the insulating material to be filled, need to adopt the conventional heat curing process in this area as baking or ultraviolet light polymerization with the liquid insulating material solidified forming, thereby form insulating barrier 30, and expose electric conductor 20.

In the 4th step, form the external conducting wire 50 that links to each other with electric conductor on insulating barrier 30 surfaces.

Before forming external conducting wire 50, can carry out preliminary treatment to the surface of insulating barrier 30, as flatten processing, to improve the interface binding power between follow-up external conducting wire 50 and the insulating barrier 30 and to guarantee the profile pattern of external conducting wire 50, thereby improve the making precision of external conducting wire 50, or remove the insulating material that may adhere to electric conductor 20 surfaces when forming insulating barrier 30 with rubbing method, to expose corresponding electric conductor 20, being convenient to follow-up external conducting wire realizes conducting with conducting

wire layer

12,13 by electric conductor 20.

The formation of external conducting wire 50 can be adopted directly and form by predetermined design pattern injection conductive materials with ink-jet method in the surface of insulating barrier 30, also can adopt the method for etching metal conductive layer to form.In the present embodiment, adopt the method for etching metal conductive layer to make external conducting wire.

See also Fig. 3 to Fig. 5, at first, need to form the conductive metal layer 40 that links to each other with electric conductor 20 in the surface of insulating barrier 30.Conductive metal layer 40 is formed at insulating barrier 30 surfaces with sedimentation, or directly adopts process for pressing that in type conductive metal foil such as Copper Foil, aluminium foil or goldleaf are pressure bonded to insulating barrier 30 surfaces to form.Described sedimentation comprises chemical vapour deposition technique, plasma enhanced chemical vapor deposition method, ion beam sputtering, magnetron sputtering method.

Secondly, etching conductive metal layer 40 to form the external conducting wire 50 that links to each other with electric conductor 20, makes circuit board 60 thus.As circuit substrate, repeating step two can be made the circuit board of more multi-layered number to step 4 with circuit board 60.

The manufacture method of the multilayer circuit board of the technical program need not made via, therefore, can effectively overcome the defective of the plating via hole wall difficulty that the making via brings in the prior art, and simplify the multilayer circuit board production process greatly, improve multilayer circuit board and make yield.

Claims

1. the manufacture method of a multilayer circuit board, it may further comprise the steps: provide the surface to be formed with the circuit substrate of conducting wire layer; Precalculated position in the conducting wire of circuit substrate laminar surface forms electric conductor; The surface that is provided with the conducting wire at circuit substrate forms insulating barrier and makes electric conductor be embedded at insulating barrier, and goes out from insulating layer exposing; Form the external conducting wire that links to each other with electric conductor in surface of insulating layer.

2. the manufacture method of multilayer circuit board as claimed in claim 1 is characterized in that, described electric conductor is the liquid thermosetting conductive materials, and it is formed at described precalculated position with print process or ink-jet method.

3. the manufacture method of multilayer circuit board as claimed in claim 1 is characterized in that, the formation of described insulating barrier comprises the step that liquid insulating material is filled in the zone of circuit substrate surface except that electric conductor with rubbing method or ink-jet method.

4. the manufacture method of multilayer circuit board as claimed in claim 1 is characterized in that, described external conducting wire is directly sprayed conductive materials in surface of insulating layer with ink-jet method and formed.

5. the manufacture method of multilayer circuit board as claimed in claim 1, it is characterized in that, the formation of described external conducting wire is included in surface of insulating layer and forms the conductive metal layer that links to each other with electric conductor, and the etching conductive metal layer forms the step of the external conducting wire that links to each other with electric conductor.

6. the manufacture method of multilayer circuit board as claimed in claim 5 is characterized in that, described conductive metal layer is formed at surface of insulating layer with sedimentation.

7. the manufacture method of multilayer circuit board as claimed in claim 5 is characterized in that, described conductive metal layer is formed at surface of insulating layer with process for pressing.

8. as the manufacture method of each described multilayer circuit board of claim 1 ~ 7, it is characterized in that described manufacture method also is included in and forms the step of solidifying electric conductor before the insulating barrier.

9. the manufacture method of multilayer circuit board as claimed in claim 8 is characterized in that, described manufacture method also is included in and forms the step of solidifying insulating barrier before the external conducting wire.

10. the manufacture method of multilayer circuit board as claimed in claim 9 is characterized in that, described manufacture method forms the step that insulating barrier is handled in the preceding leveling of external conducting wire after also being included in and forming insulating barrier.