CN103379750B - Multilayer circuit board and preparation method thereof - Google Patents

Abstract

A method for manufacturing a multilayer circuit board, comprising the steps of: providing a plurality of copper foil substrates; making the copper foil layer of each copper foil substrate to form a conductive circuit layer to obtain a plurality of first circuit substrates; The two surfaces of the substrate are pasted with films; a through hole is formed in the film; a conductive material is formed in the through hole, and the conductive material and the conductive circuit layer are electrically connected to each other to obtain a second circuit substrate; stacking and pressing the second circuit board Two circuit substrates and the first circuit substrate, so that each second circuit substrate is located between two adjacent first circuit substrates, and there is only one second circuit substrate between adjacent two first circuit substrates, so that Get a multilayer circuit board. The invention also provides a multilayer circuit board prepared by the method.

Description

Multi-layer circuit board and its manufacturing method

technical field

The invention relates to the field of circuit board production, in particular to a multilayer circuit board and a production method thereof.

Background technique

Printed circuit boards have been widely used due to their advantages such as high assembly density. For the application of the circuit board, please refer to the literature Takahashi, A.Ooki, N.Nagai, A.Akahoshi, H.Mukoh, A.Wajima, M.Res.Lab, HighdensitymultilayerprintedcircuitboardforHITACM-880, IEEETrans.onComponents, Packaging, and ManufacturingTechnology, 1992, 15(4):1418-1425.

In the production process of multilayer circuit boards, the inner base half of the circuit board is usually produced first, and the adhesive layer and the conductive layer are laminated on both sides of the inner substrate to obtain a multilayer circuit board. However, the multi-layer circuit board manufactured in this way needs to be manufactured step by step from the inner layer to the outer layer, and the manufacturing process is very long. Moreover, every time a build-up is performed, there will be defective production, so that when the entire circuit board is produced, the probability of defective circuit board production is relatively high, resulting in a low yield rate of circuit board production.

Contents of the invention

Therefore, it is necessary to provide a multilayer circuit board and a manufacturing method thereof, so as to improve the efficiency and yield of the circuit board manufacturing.

A method for manufacturing a multilayer circuit board, comprising the steps of: providing 2N+1 copper foil substrates, each of which includes a first copper foil layer, a first insulating layer, and a second copper foil layer stacked in sequence, Where N is a natural number greater than or equal to 1; the first copper foil layer of each copper foil substrate is fabricated to form the first conductive circuit layer, and the second copper foil layer is fabricated to form the second conductive circuit layer, so that 2N+1 copper The foil substrate is made into 2N+1 first circuit substrates; N first circuit substrates are selected from the 2N+1 first circuit substrates, and the surface of the first conductive circuit layer in the N first circuit substrates is pasted A film, the first film has a first through hole, a second film is pasted on the surface of the second conductive circuit layer of the N first circuit substrates, the second film has a second through hole, and the The first through hole is filled with a first conductive material, the second through hole is filled with a second conductive material, the first conductive material is electrically connected to the first conductive circuit layer, and the second conductive material is connected to the second The conductive circuit layers are electrically connected to each other, so that the N first circuit substrates are made into N second circuit substrates; and the N second circuit substrates and N+1 first circuit substrates are stacked, so that each second The circuit substrate is located between two adjacent first circuit substrates, and there is only one second circuit substrate between the two adjacent first circuit substrates, and the N second circuit substrates and N+ 1 first circuit substrate to obtain a 4N+2-layer circuit board.

A method for manufacturing a multilayer circuit board, comprising the steps of: providing 2N-1 copper foil substrates, each of which includes a first copper foil layer, a first insulating layer, and a second copper foil layer stacked in sequence, Where N is a natural number greater than or equal to 2; the first copper foil layer of each copper foil substrate is fabricated to form the first conductive circuit layer, and the second copper foil layer is fabricated to form the second conductive circuit layer, so that 2N-1 copper The foil substrate is made into 2N-1 first circuit substrates; N first circuit substrates are selected from the 2N-1 first circuit substrates, and the surface of the first conductive circuit layer in the N first circuit substrates is pasted with the first A film, the first film has a first through hole, a second film is pasted on the surface of the second conductive circuit layer of the N first circuit substrates, the second film has a second through hole, and the The first through hole is filled with a first conductive material, the second through hole is filled with a second conductive material, the first conductive material is electrically connected to the first conductive circuit layer, and the second conductive material is connected to the second The conductive circuit layers are electrically connected to each other, so that the N first circuit substrates are made into N second circuit substrates; a first copper foil and a second copper foil are provided, between the first copper foil and the second copper foil stacking the N second circuit substrates and N-1 first circuit substrates, so that each first circuit substrate is located between two adjacent second circuit substrates, and between two adjacent second circuit substrates There is only one first circuit substrate between them, and the one first copper foil, N second circuit substrates, N-1 first circuit substrates and one second copper foil are pressed together at one time; and the first copper foil The foil is fabricated to form a third conductive circuit layer, and the second copper foil is fabricated to form a fourth conductive circuit layer, thereby obtaining a 4N-layer circuit board.

A multilayer circuit board is manufactured by the method for manufacturing the multilayer circuit board.

Compared with the prior art, the multi-layer circuit board manufacturing method provided by this technical solution simultaneously manufactures multiple circuit substrates, and then forms films on the surface of some circuit substrates by laminating, and forms through holes in the films and forms There are conductive materials. In this way, the circuit substrate with the film and the conductive material bonded and the circuit substrate without the film bonded are stacked as needed, so that a multilayer circuit board can be obtained by one-time lamination. Since a plurality of circuit boards can be manufactured at the same time, the time for making the circuit board can be shortened. Since each circuit substrate is manufactured separately, compared with the layer-by-layer stacking method in the prior art, the defective rate of circuit board manufacturing can be reduced.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a copper foil substrate provided by an embodiment of the technical solution.

Fig. 2 is a schematic cross-sectional view of the copper foil substrate provided by the embodiment of the technical solution after the first circuit substrate is formed.

FIG. 3 is a schematic cross-sectional view of two opposite surfaces of the first circuit substrate in FIG. 2 after a first film and a second film are bonded.

FIG. 4 is a schematic cross-sectional view of the first through hole formed in the first film and the second through hole formed in the second film in FIG. 3 .

5 is a schematic cross-sectional view of the second circuit substrate obtained after the first conductive material is formed in the first through hole and the second conductive material is formed in the second through hole in FIG. 4 .

6 is a schematic cross-sectional view of the stacked first copper foil, the second circuit substrate, the first circuit substrate, the second circuit substrate and the second copper foil.

FIG. 7 is a schematic cross-sectional view after forming a third conductive circuit layer in the first copper foil of FIG. 6 and forming a fourth conductive circuit layer in the second copper foil.

8 is a schematic cross-sectional view of the first solder resist layer formed on the third conductive circuit layer and the second solder resist layer formed on the fourth conductive circuit layer in FIG. 7 .

9 is a schematic cross-sectional view of a six-layer circuit board obtained by stacking the first circuit substrate, the second circuit substrate and the first circuit substrate according to the technical method.

Description of main component symbols

first circuit substrate 10

Second circuit substrate 20

First Film 40

first through hole 41

first conductive material 42

Second Film 50

Second through hole 51

Second conductive material 52

The first copper foil 60

The third conductive circuit layer 61

First solder mask 62

Second copper foil 70

The fourth conductive circuit layer 71

Second solder mask layer 72

Circuit board 100, 200

Copper foil substrate 110

The first copper foil layer 111

insulating layer 112

The second copper foil layer 113

Conductive hole 114

The first conductive circuit layer 115

The second conductive circuit layer 116

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

detailed description

Taking the manufacture of an eight-layer circuit board as an example below, the method for manufacturing the circuit board provided by the embodiment of the technical solution is described. The method for manufacturing the circuit board includes the following steps:

In the first step, referring to FIG. 1 , three double-sided copper foil substrates 110 are provided.

The double-sided copper foil substrate 110 includes a first copper foil layer 111 , an insulating layer 112 and a second copper foil layer 113 stacked in sequence. The copper foil substrate 110 may be a flexible copper foil substrate or a rigid copper foil substrate.

The second step, referring to Fig. 2, forms conductive holes 114 in each copper foil substrate 110, and makes the first copper foil layer 111 to form the first conductive circuit layer 115, and makes the second copper foil layer 113 to form the second The conductive circuit layer 116 , the first conductive circuit layer 115 and the second conductive circuit layer 116 are electrically connected to each other through the conductive hole 114 , thereby obtaining three first circuit substrates 10 .

The conductive hole 114 can be formed by the following method: First, a through hole is formed in the first copper foil layer 111 and the insulating layer 112 of each copper foil substrate 110 by laser ablation. Then, metal is electroplated inside the through hole by means of electroplating, so as to obtain the conductive hole 114 . Preferably, when electroplating is performed, the metal plated completely fills the vias.

The first conductive circuit layer 115 and the second conductive circuit layer 116 are formed by an image transfer process and an etching process.

In this embodiment, the first conductive circuit layer 115 and the second conductive circuit layer 116 in the three first circuit substrates 10 are set according to the actual circuit board to be manufactured, and the first conductive circuit layer 116 in each first circuit substrate 10 The arrangement of the circuit layer 115 and the second conductive circuit layer 116 may be the same or different.

The third step, please refer to Fig. 3 to Fig. 5, stick the first film 40 on the first conductive circuit layer 115 of the two first circuit substrates 10, and stick the second film 50 on the second conductive circuit layer 116 . A first through hole 41 is formed in the first film 40, part of the first conductive circuit layer 115 is exposed from the bottom of the first through hole 41, a second through hole 51 is formed in the second film 50, and part of the second conductive circuit layer 116 is exposed from the bottom of the first through hole 41. The bottom of the second through hole 51 is exposed. The first conductive material 42 is formed in the first through hole 41, and the second conductive material 52 is formed in the second through hole 51, so that the first conductive material 42, the first conductive circuit layer 115, the conductive hole 114, and the second conductive circuit The layer 116 and the second conductive material 52 are electrically connected to each other to obtain the second circuit substrate 20 .

In this embodiment, both the first film 40 and the second film 50 are prepreg films. The curing temperature of the first film 40 and the second film 50 should be greater than 150 degrees Celsius.

In this embodiment, both the first through hole 41 and the second through hole 51 are formed by laser ablation. The first through hole 41 only penetrates the first film 40 , and the second through hole 51 only penetrates the second film 50 .

In this embodiment, the first conductive material 42 is formed in the first through hole 41 by printing metal conductive paste, and the second conductive material 52 is formed in the second through hole 51 . The metal conductive paste may be a silver paste containing an organic solvent. Fill the silver paste containing the organic solvent in the first through hole 41 and the second through hole 51 by screen printing, and then bake the first circuit substrate 10 printed with the silver paste to volatilize the organic solvent , the silver paste is solidified to form the first conductive material 42 and the second conductive material 52 . In this embodiment, the temperature for baking the first circuit substrate 10 printed with silver paste is 90 degrees Celsius to 100 degrees Celsius. At this temperature, the properties of the first film 40 and the second film 50 will not be affected.

The fourth step, please refer to FIG. 6 , provides the first copper foil 60 and the second copper foil 70, and stacks and presses the first copper foil 60, a second circuit substrate 20, the first circuit substrate 10, and another first copper foil in sequence. The second circuit substrate 20 and the second copper foil 70 are integrated.

When stacking the first copper foil 60, the second circuit substrate 20, the first circuit substrate 10, the second circuit substrate 20, and the second copper foil 70, it should be ensured that the second circuit substrate 20, the first circuit substrate 10, and the second circuit Precise alignment between the substrates 20. In actual operation, in the process of stacking, alignment holes can be respectively provided in the second circuit substrate 20, the first circuit substrate 10, and the second circuit substrate 20. The fixture is aligned.

In this embodiment, since the opposite two surfaces of the second circuit substrate 20 have the first film 40 and the second film 50 respectively, during the pressing process, the first film 40 and the second film 50 are solidified and bonded to them. Adjacent copper foil or first circuit substrate 10, so that in one pressing process, the first copper foil 60, the second circuit substrate 20, the first circuit substrate 10, the second circuit substrate 20 and the second copper foil 70 into a whole. In addition, in this embodiment, the conductive holes 114 , 41 , 51 in the respective circuit boards 10 , 20 are sequentially aligned and conducted, forming the effect of a conductive hole. In other embodiments, the conductive holes 114 , 41 , 51 in the respective circuit substrates 10 , 20 may not be aligned with each other, and it is only necessary to enable mutual conduction between the respective circuit substrates 10 , 20 .

The fifth step, please refer to FIG. 7 , is to fabricate the first copper foil 60 to form the third conductive circuit layer 61 , and fabricate the second copper foil to form the fourth conductive circuit layer 71 .

The third conductive circuit layer 61 and the fourth conductive circuit layer 71 can be formed by an image transfer process and an etching process.

The sixth step, please refer to FIG. 8 , forms the first solder resist layer 62 on the surface of the third conductive circuit layer 61 , forms the second solder resist layer 72 on the surface of the fourth conductive circuit layer 71 , and obtains the multilayer circuit board 100 .

The first solder resist layer 62 and the second solder resist layer 72 can be formed by printing solder resist ink. The first solder resist layer 62 is used to protect the third conductive circuit layer 61 , and the second solder resist layer 72 is used to protect the fourth conductive circuit layer 71 .

It can be understood that the method for manufacturing a circuit board provided by the technical solution can also be applied to the manufacture of circuit boards with other layers. Please refer to Fig. 9, when making a six-layer circuit board, the first copper foil 60 and the second copper foil 70 may not be needed, and a second circuit substrate 20 is directly arranged between the two first circuit substrates 10, after a one-time After lamination, a six-layer circuit board 200 is obtained.

When it is used to make a circuit board with more layers, such as a twelve-layer circuit board, the second circuit substrate 20, the first circuit substrate 10, and the second circuit substrate 20 can be sequentially arranged between the first copper foil 60 and the second copper foil 70 Two circuit substrates 20 , the first circuit substrate 10 and the second circuit substrate 20 . It can be understood that, after the lamination, a step of forming a solder resist layer on the surface of the conductive circuit layer of the first circuit substrate 10 exposed from both sides after the lamination is also included.

It can be concluded from the above that when using the circuit board manufacturing method provided by this technical solution to make a 4N-layer circuit board (N is a natural number greater than or equal to 2), it can be arranged between the first copper foil 60 and the second copper foil 70. N second circuit substrates 20 and N−1 first circuit substrates 10 are obtained by disposing the first circuit substrates 10 between adjacent second circuit substrates 20 through one-time pressing. When adopting the manufacturing method of the circuit board provided by this technical solution to manufacture and manufacture a 4N+2-layer circuit board (N is a natural number greater than or equal to 1), the first copper foil 60 and the second copper foil 70 can be unnecessary, and only N +1 first circuit substrate 10 and N second circuit substrates 20, and each second circuit substrate 20 is arranged between adjacent first circuit substrates 10, and obtained after one-time pressing.

The multi-layer circuit board manufacturing method provided by the technical solution simultaneously manufactures a plurality of circuit substrates, and then forms a film on the surface of some circuit substrates by laminating, and forms a through hole and a conductive material in the film. In this way, the circuit substrate with the film and the conductive material bonded and the circuit substrate without the film bonded are stacked as needed, so that a multilayer circuit board can be obtained by one-time lamination. Since a plurality of circuit boards can be manufactured at the same time, the time for making the circuit board can be shortened. Since each circuit substrate is manufactured separately, compared with the layer-by-layer stacking method in the prior art, the defective rate of circuit board manufacturing can be reduced.

It can be understood that those skilled in the art can make various other corresponding changes and modifications according to the technical concept of the present invention, and all these changes and modifications should belong to the protection scope of the claims of the present invention.

Claims (11)

1. a manufacture method for multilayer circuit board, including step:

Thering is provided 2N+1 copper clad laminate, each described copper clad laminate to include the first copper foil layer, the first insulating barrier and the second copper foil layer stacked gradually, wherein N is the natural number be more than or equal to 1; The mode adopting laser ablation forms through hole in first copper foil layer and insulating barrier of each copper clad laminate, adopts the mode of plating in the internal electroplated metal of described through hole, makes the first copper foil layer and the insulating barrier interior formation conductive hole of each copper clad laminate; First copper foil layer of each copper clad laminate is made and forms the first conductive circuit layer, the second copper foil layer is made and forms the second conductive circuit layer, thus 2N+1 copper clad laminate being made 2N+1 the first circuit substrate;

2N+1 the first circuit substrate selects N number of first circuit substrate, fit the first film in the first conductive circuit layer surface in this N number of first circuit substrate, described first film has the first through hole, part the first conductive circuit layer is exposed from the first via bottoms, fit on the second conductive circuit layer surface of this N number of first circuit substrate the second film, described second film has the second through hole, part the second conductive circuit layer is exposed from the second via bottoms, and fill the first conductive material in described first through hole, the second conductive material is filled in described second through hole, described first conductive material and the first conductive circuit layer conduct mutually, described second conductive material and the second conductive circuit layer conduct mutually, thus this N number of first circuit substrate is made N number of second circuit substrate, and

Stacking described N number of second circuit substrate and N+1 the first circuit substrate, make each second circuit substrate between two adjacent the first circuit substrates, and only have a second circuit substrate between adjacent two the first circuit substrates, and N number of second circuit substrate described in one step press and N+1 the first circuit substrate, thus obtaining 4N+2 layer circuit board.

2. the manufacture method of multilayer circuit board as claimed in claim 1, it is characterised in that described first conductive material and the second conductive material are formed each through type metal conductive paste.

3. the manufacture method of multilayer circuit board as claimed in claim 2, it is characterised in that described metallic conduction cream is the silver slurry containing organic solvent, forms described first conductive material and the second conductive material includes step:

The described silver slurry containing organic solvent of printing in the first through hole and in the second through hole; And

N number of first circuit substrate printed after silver-colored slurry is toasted so that the organic solvent volatilization in silver slurry is thus solidifying silver slurry.

4. the manufacture method of multilayer circuit board as claimed in claim 1, it is characterized in that, before forming the first conductive circuit layer and the second conductive circuit layer, being additionally included in the first copper foil layer and the interior step forming conductive hole of insulating barrier of copper clad laminate, described first conductive circuit layer and the second conductive circuit layer are conducted mutually by described conductive hole; In 4N+2 layer circuit board, conductive hole, the first through hole and the second through hole are mutually aligned.

5. the manufacture method of multilayer circuit board as claimed in claim 1, it is characterized in that, described first through hole is formed by the mode of laser ablation after the first film fits in the first conductive circuit layer, and described second through hole is formed by the mode of laser ablation after the second film fits in the second conductive circuit layer.

6. a manufacture method for multilayer circuit board, including step:

Thering is provided 2N-1 copper clad laminate, each described copper clad laminate to include the first copper foil layer, the first insulating barrier and the second copper foil layer stacked gradually, wherein N is the natural number be more than or equal to 2; The mode adopting laser ablation forms through hole in first copper foil layer and insulating barrier of each copper clad laminate, adopts the mode of plating in the internal electroplated metal of described through hole, makes the first copper foil layer and the insulating barrier interior formation conductive hole of each copper clad laminate; First copper foil layer of each copper clad laminate is made and forms the first conductive circuit layer, the second copper foil layer is made and forms the second conductive circuit layer, thus 2N-1 copper clad laminate being made 2N-1 the first circuit substrate;

2N-1 the first circuit substrate selects N number of first circuit substrate, fit the first film in the first conductive circuit layer surface in this N number of first circuit substrate, described first film has the first through hole, part the first conductive circuit layer is exposed from the first via bottoms, fit on the second conductive circuit layer surface of this N number of first circuit substrate the second film, described second film has the second through hole, part the second conductive circuit layer is exposed from the second via bottoms, and fill the first conductive material in described first through hole, the second conductive material is filled in described second through hole, described first conductive material and the first conductive circuit layer conduct mutually, described second conductive material and the second conductive circuit layer conduct mutually, thus this N number of first circuit substrate is made N number of second circuit substrate,

One the first Copper Foil and second Copper Foil are provided, stacking described N number of second circuit substrate and N-1 the first circuit substrate between the first Copper Foil and the second Copper Foil, make each first circuit substrate between two adjacent second circuit substrates, and between adjacent two second circuit substrates, only have first circuit substrate, and one step press one the first Copper Foil, N number of second circuit substrate, N-1 the first circuit substrate and second Copper Foil;

Described first Copper Foil is made and forms the 3rd conductive circuit layer, described second Copper Foil is made and forms the 4th conductive circuit layer, thus obtaining 4N layer circuit board.

7. the manufacture method of multilayer circuit board as claimed in claim 6, it is characterised in that described first conductive material and the second conductive material are formed each through type metal conductive paste.

8. the manufacture method of multilayer circuit board as claimed in claim 6, it is characterised in that described metallic conduction cream is the silver slurry containing organic solvent, forms described first conductive material and the second conductive material includes step:

The described silver slurry containing organic solvent of printing in the first through hole and in the second through hole; And

N-1 after having printed silver-colored slurry the first circuit substrate is toasted so that the organic solvent volatilization in silver slurry is thus solidifying silver slurry.

9. the manufacture method of multilayer circuit board as claimed in claim 6, it is characterized in that, before forming the first conductive circuit layer and the second conductive circuit layer, being additionally included in the first copper foil layer and the interior step forming conductive hole of insulating barrier of copper clad laminate, described first conductive circuit layer and the second conductive circuit layer are conducted mutually by described conductive hole; In 4N layer circuit board, conductive hole, the first through hole and the second through hole are mutually aligned.

10. the manufacture method of multilayer circuit board as claimed in claim 6, it is characterized in that, described first through hole is formed by the mode of laser ablation after the first film fits in the first conductive circuit layer, and described second through hole is formed by the mode of laser ablation after the second film fits in the second conductive circuit layer.

11. a multilayer circuit board, it is characterised in that described multilayer circuit board adopts the manufacture method of the multilayer circuit board as according to any one of claim 1 to 10 to make.