JP2000031648A - Manufacturing method of multilayer printed wiring board - Google Patents

Abstract

(57) [Problem] To provide a method of manufacturing a multilayer printed wiring board capable of freely connecting between layers, reducing the diameter of connection lands, and reducing the weight and thickness of circuit devices. SOLUTION: In a film forming step, a film 132 is formed releasably on the lower surface of the laminated substrate 120, and in a hole making step, a through hole 142 is formed in the laminated substrate 120 on which the film 132 is formed.
To form Next, in the plating step, the through holes 142
Copper plating is applied to the laminated substrate 120 on which is formed, and the plating material is filled in the through holes 142. Then, in the peeling step, the film 132 is peeled off, so that the through holes 14 are removed.
The plating layer in the region corresponding to No. 2 is formed in a state where it is left as a protruding contact 160. After this, 2
The two substrates 110 and 120 are welded with a molten resin in a state where the contact 160 on the lower surface and the wiring pattern on the upper surface are overlapped,
In a wiring pattern forming step, the plating layer on the upper surface of the substrate 120 is etched to form a wiring pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a multilayer printed wiring board.

[0002]

2. Description of the Related Art Conventionally, a multilayer printed wiring board having, for example, a four-layer structure is manufactured as follows. First, a double-sided wiring board is formed. That is, a metal foil such as copper is formed on the upper and lower surfaces of the insulating substrate, and through holes are formed at predetermined locations so as to penetrate vertically. Then, plating is performed on the inner surface of the through hole and the upper and lower surfaces of the metal foil to form a metal layer that is vertically conductive. Then, the metal foil is etched to form a wiring pattern on the upper and lower surfaces of the insulating substrate, thereby forming a double-sided wiring board.

Next, prepregs are adhered to the upper and lower surfaces of the double-sided wiring board, metal foils are laminated again on the outer surfaces of the upper and lower prepregs, and a predetermined portion thereof is vertically penetrated by pressing or drilling. Forming a through hole. Thereafter, metal plating is performed to form a conductive layer on the inner surface of the through hole, and then upper and lower metal foils are etched to form an outer wiring pattern. Thus, a multilayer printed wiring board having a four-layer structure in which the internal wiring pattern and the external wiring pattern are connected at the plated portions of the through holes is completed.

[0004]

However, in the above-mentioned conventional manufacturing method, free design is difficult, and
Since the layers to be connected are defined, it is not possible to meet the needs for light, thin and small. Further, Fotopia as new technology, Rezapia, also in B ² it, connecting layer is defined, it is considered that there are limits to high density in Aribu.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a multilayer printed wiring board, which allows flexible interlayer connection, and is capable of reducing the diameter of connection lands and reducing the size and weight of circuit devices. .

[0006]

According to the present invention, in order to achieve the above object, a large number of laminated substrates are laminated, a wiring pattern is formed between the laminated substrates, and a through-hole formed in each laminated substrate is formed. In a method of manufacturing a multilayer printed wiring board for connecting each wiring pattern between layers, a film forming step of forming a peelable film on a first surface of the laminated substrate;
A hole forming step of forming the through hole in the laminated substrate on which the film is formed, a plating step of plating the laminated substrate on which the through hole is formed, filling a plating material in the through hole, and peeling the film. A peeling step of forming a plated layer in a region corresponding to the through hole as a protruding contact protruding from the first surface of the laminated substrate; A pattern forming step of forming a wiring pattern from a plating layer on the surface, and a laminating step of joining the respective laminated substrates in a state where the contacts of one laminated substrate and the wiring pattern of the other laminated substrate which are laminated on each other are superimposed. And characterized in that:

In the method of manufacturing a multilayer printed wiring board according to the present invention, in the film forming step, a film is formed on the first surface of the laminated substrate so as to be peelable. In the hole making step, the through hole is formed in the laminated substrate on which the film is formed. Further, in the plating step, plating is performed on the laminated substrate having the through-hole formed therein, and the through-hole is filled with a plating material. In the peeling step, the coating is peeled off to form a plating layer in a region corresponding to the through hole as a protruding contact.

In the pattern forming step, a wiring pattern is formed from the plating layer on the second surface of the laminated substrate, and in the laminating step, the contact of one laminated substrate and the wiring pattern of the other laminated substrate are laminated. Each of the laminated substrates is joined in a state where is overlapped. By the above steps,
By appropriately selecting the positions of the through-holes and the wiring patterns, a flexible interlayer connection is possible, and the diameter of the connection land can be reduced by the protruding contacts, and the wiring density can be easily increased. Accordingly, it is possible to cope with a reduction in the size and weight of circuit devices.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a multilayer printed wiring board according to the present invention will be described below. FIG.
2 (A) to 2 (E) are cross-sectional views showing respective manufacturing steps in a method for manufacturing a multilayer printed wiring board according to the present invention, and FIG.
FIG. 2 is a sectional view showing a specific example of a multilayer printed wiring board manufactured by the manufacturing method shown in FIG. 1.

In FIG. 2, a multilayer printed wiring board 100 of this embodiment has a base substrate 110 on the lowermost side of which a wiring pattern is formed by using a conventional method.
A plurality of laminated substrates 1 on the same substrate using the manufacturing method of the present invention.
The laminated structure is formed by 20A, 120B, 120C, and 120D. The base substrate 110 is formed, for example, by the following method. First, a metal foil such as copper is formed on the upper and lower surfaces of the insulating substrate, and through holes 114 penetrating vertically are formed at predetermined locations. Then, electroless plating is performed on the inner surface of the through hole 114 and the upper and lower surfaces of the metal foil to form a metal layer that is vertically conductive. Then, the metal foil is etched to form the wiring patterns 112 on the upper and lower surfaces of the insulating substrate.

Next, a method of forming a layer to be laminated on the base substrate 110 will be described. First, in a film forming step, a film is formed on the lower surface (first surface) of a predetermined laminated substrate so as to be peelable. Here, the laminated substrate has a welding layer made of a molten resin or the like on both surfaces, and for example,
An insulating core having a resin layer, a prepreg having a copper foil layer,
Alternatively, it is formed from a prepreg. Further, as the film, a film formed by applying and drying ink (paint) on the lower surface of the laminated substrate to form a film, or a film obtained by sticking an adhesive sheet (eg, resin) to the lower surface of the laminated substrate is used. .
Next, through holes are formed in the laminated substrate on which the above-described film is formed by a hole making step. The formation of the through hole is performed by a laser processing machine or a drill.

Then, the upper surface (the second substrate) is formed on the laminated substrate on which the film and the through hole are formed as described above by the plating process.
Side) or plating on both upper and lower sides. FIG. 1 (A)
The copper plating layer 150 is formed on the upper surface of the laminated substrate 120 by, for example, a panel plating operation using copper or the like. In FIG. 1A, a peelable film 132 is formed on the lower surface of the laminated substrate 120 in a state where the copper plating layer is not attached, and a through hole 142 is formed penetrating the laminated substrate 120 and the film 132. Have been. And
In the plating step, a part of the copper is filled in the through-hole 142 to form a rod-like portion 150A, and the tip of the rod-like portion 150A protrudes toward the lower surface of the laminated substrate 120.

On the other hand, FIG. 1B shows that the copper plating layers 150 and 152 are formed on the upper and lower surfaces of the laminated substrate 120 by, for example, a panel plating operation using copper. FIG.
In (B), a peelable film 134 is formed on the lower surface of the laminated substrate 120 with the copper plating layer 152 attached thereto, and a through hole 142 is formed to penetrate the laminated substrate 120 and the film 134. ing. Then, in the plating step, a part of the copper is
2 is formed as a rod-shaped portion 150A, and is continuous between the copper plating layers 150 and 152 on the upper and lower surfaces.

Next, as described above, the copper plating layer 15 is formed.
0, 152, the film 13
2, 134 are peeled off. Thus, in the laminated substrate 120 shown in FIG.
As shown in FIG. 1C, the copper (rod-like portion 150A) protruding from the through hole 142 to the lower surface side of the laminated substrate 120
Is formed as a protrusion-like contact 160 protruding by an amount corresponding to the thickness of the film 132. Similarly, in the laminated substrate 120 shown in FIG. 1B, the coating 134 is peeled off from the lower surface, and the copper plating layer 152 on the lower surface of the laminated substrate 120 is removed leaving a region corresponding to the through hole 142. As shown in (C), a copper plating layer (rod-like portion 1) corresponding to through hole 142
50A) is formed in a state of remaining as a protruding contact 160 protruding by an amount corresponding to the thickness of the film 134.

Then, as shown in FIG. 1D, the laminated substrate 120 on which the contact 160 is formed is superposed on the base substrate 110 described above, and the contact 160 of the laminated substrate 120 and the wiring pattern 112 of the base substrate 110 are The two substrates 110 and 120 are joined by a laminating step in a state where they are in contact with each other. In this method, the two substrates 110 and 120 are overlapped and pressed under pressure by a molding press or the like, and further heated, thereby melting the resin layers provided on the two substrates 110 and 120 and welding and fixing them. Next, as shown in FIG. 1E, a wiring pattern 170 is formed by etching or the like on the copper plating layer on the upper surface of the laminated substrate 120 in a pattern forming step. By repeating the above operation for a plurality of laminated substrates, a multilayer printed wiring board as shown in FIG. 2 can be formed.

As described above, in the method for manufacturing a multilayer printed wiring board according to the present embodiment, a multilayer printed wiring board is easily manufactured by a film forming step, a hole forming step, a plating step, a peeling step, a laminating step, and a pattern forming step. By appropriately selecting the positions of the through holes and the wiring patterns, it is possible to freely connect the layers, and the diameter of the connection land can be reduced by the protruding contacts, and the density of the wiring can be increased. It becomes easy and it is possible to cope with light and thin circuit devices. Note that the present invention is not limited to the above-described example. For example, a laminating step can be performed after the pattern forming step. Further, the working methods and materials used in the individual steps described in the above-described examples can be appropriately changed.

[0017]

As described above, in the method for manufacturing a multilayer printed wiring board according to the present invention, a film is provided on the first surface of the laminated substrate so as to be peelable, a through hole is formed, and the through hole is formed by a plating step. By filling the plating material and peeling the film, the plating layer in the region corresponding to the through hole is left as a protruding contact, and this is brought into contact with the wiring pattern of another substrate to join the two substrates. I did it. Therefore, by appropriately selecting the positions of the through holes and the wiring patterns, a flexible interlayer connection is possible.
In addition, the diameter of the connection land can be reduced by the protruding contact, the density of the wiring can be easily increased, and it is possible to cope with the reduction in the weight and thickness of the circuit device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing each manufacturing step in a method for manufacturing a multilayer printed wiring board according to the present invention.

FIG. 2 is a cross-sectional view showing a specific example of a multilayer printed wiring board manufactured by the method for manufacturing a multilayer printed wiring board according to the present invention.

[Explanation of symbols]

100 multilayer printed wiring board, 110 base substrate, 112, 170 wiring pattern, 114, 142
...... Through-hole, 120, 120A, 120B, 12
0C, 120D ... laminated substrate, 132, 134 ... film, 150, 152 ... copper plating layer, 160 ... projecting contact.

Claims (12)

[Claims] 1. A method of manufacturing a multilayer printed wiring board in which a large number of laminated substrates are laminated, a wiring pattern is formed between the laminated substrates, and each wiring pattern is connected between layers via through holes formed in each laminated substrate. In the above, a film forming step of forming a film releasably on a first surface of the laminated substrate, a hole forming step of forming the through hole in the laminated substrate on which the film is formed, and a laminated substrate formed with the through hole Plating on
A plating step of filling a plating material in the through-hole, and peeling off the film to form a plating layer in a region corresponding to the through-hole as a protruding contact protruding from the first surface of the laminated substrate. A peeling step of forming a wiring pattern in a state of being left; a pattern forming step of forming a wiring pattern from a plating layer on the second surface of the laminated substrate; and a contact of one laminated substrate and the other laminated substrate laminated together. A method for manufacturing a multilayer printed wiring board, comprising: a laminating step of joining respective laminated substrates in a state where a wiring pattern is superimposed. 2. The method according to claim 1, wherein the plating is performed on the second substrate.
2. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein plating is performed from a surface side of the multilayer substrate, the through hole is filled with a plating material, and further, the projection is protruded toward a first surface side of the laminated substrate. Method. 3. The plating step includes plating from both sides of the laminated substrate to fill the through hole with a plating material, and the peeling step includes plating the first surface of the laminated substrate with the through hole. 2. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein the region corresponding to the above is removed. 4. The laminated substrate has a welding layer on at least one surface, and in the laminating step, the laminated layers are pressed and heated to melt the welded layer and join the laminated substrates. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein 5. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein a base substrate on which a wiring pattern is formed is provided, and the laminated substrate is sequentially laminated on the wiring pattern of the base substrate. 6. The method according to claim 1, wherein the pattern forming step is performed after the laminating step. 7. The method according to claim 1, wherein the laminated substrate is formed of an insulating core having a resin layer. 8. The method according to claim 1, wherein the laminated substrate is made of a prepreg having a copper foil layer. 9. The method according to claim 1, wherein the laminated substrate is made of prepreg. 10. The method according to claim 1, wherein the coating is formed by applying a paint to the laminated substrate and drying the coating. 11. The film according to claim 1, wherein the film is formed by attaching a sheet to the laminated substrate.
A method for producing the multilayer printed wiring board according to the above. 12. The method according to claim 4, wherein the welding layer is formed of a welding resin.