JPH10284837A - Manufacturing method of multilayer printed wiring board - Google Patents

Abstract

(57) [Summary] [Problem] To make it unnecessary to provide through holes in each layer,
Easier to manufacture. SOLUTION: An insulating layer 2 having a hole with respect to a core material 1 is provided.
6, 11 and 15 are sequentially laminated, and each time the insulating layers 2, 6, 11, and 15 are laminated, these holes 2a,
Conductive pastes 4, 7, 13, 1 on 6a, 11a, 15a
6, the core material 1 and the circuit pattern of each layer can be made conductive, so that it is not necessary to provide through holes in all layers as in the prior art. It is possible to prevent the circuit patterns 3, 8, 12, and 17 formed on the layers 11 and 15 from being affected by the through-holes, and the circuit patterns of each layer are not restricted, and the degree of freedom of the circuit patterns is accordingly reduced. Can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed wiring board, and more particularly to a method suitable for manufacturing a multilayer printed wiring board.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture a multilayer printed wiring board, for example, in the case of a six-layered wiring board, three sets of laminated boards are formed by laminating two adjacent layers in advance, and then one layer is formed. After forming the second set of laminates on top of the set of laminates, the last set of laminates is stacked on top of this, and a through-hole is formed through the whole to apply plating. The entire layers are electrically connected.

[0003]

By the way, in the conventional multilayer printed wiring board shown above, each set of laminated boards is formed, and these are sequentially superimposed, and then through holes are formed in each layer of the whole. So, depending on the specific tier,
When a through hole is provided, a circuit pattern formed on a layer may be affected, and therefore, not only is it difficult to manufacture a printed wiring board having more layers, but also each layer has a problem. However, there is a problem that the circuit pattern to be formed is limited.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to eliminate the need to provide a through hole in each of the entire layers, to prevent a specific layer from being affected by the through holes, and to realize a multilayer printed wiring board. An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board that can be easily manufactured.

[0005]

According to the present invention, there is provided a multilayer printed wiring board formed by laminating a plurality of insulating layers having a desired circuit pattern on a core material.
Laminating a first insulating layer provided with a hole in advance at a position where the conductive portion of the core material and the first circuit pattern are conducted; B)
Next, filling the hole of the first insulating layer with a first conductive paste that is conductive to the core material; and C) thereafter, the first circuit pattern that is conductive to the first conductive paste on the first insulating layer. Is formed into a desired shape; D) a lamination of an insulating layer provided with a hole on the first circuit pattern and the first insulating layer at a position capable of conducting with the first circuit pattern; The filling of the paste and the formation of a desired circuit pattern on the insulating layer are sequentially repeated a predetermined number of times, and the circuit patterns of the stacked layers are electrically connected to each other via the conductive paste.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In the multilayer printed wiring board according to the embodiment, a first insulating layer 2 is laminated on a core material 1 provided with a solid pattern serving as a power supply layer and a ground layer on both upper and lower surfaces thereof. A desired circuit pattern 3 is formed thereon.

In this case, the first insulating layer 2 is made of, for example, a sheet-like prepreg material, and has a hole 2a at a predetermined position thereof. When the first insulating layer 2 is laminated on the core material 1, the hole 2 a is filled with the conductive paste 4 to form a circuit pattern formed on the core material 1 and the first insulating layer 2. 3 is conducted. That is, the hole 2 a of the first insulating layer 2 is formed at a position where the core material 1 and the circuit pattern 3 are conducted. The conductive paste 4 preferably solidifies at room temperature when filled into the holes 2a. For example, a silver-based conductive paste is used as a dispersed conductive material composed of a conductive filler such as metal powder and a binder such as glass powder. I have. Although the conductive paste 4 is illustrated in a size projecting from the hole 2a, a small amount is actually buried when filling the hole 2a, and the first insulating layer is pressed by the pressure when the circuit pattern 3 is laminated. The copper foil of the core material 1 and the copper foil of the circuit pattern 3 are brought into contact with each other by the compression of the thickness 2.

The circuit pattern 3 is formed by, for example, laminating on the first insulating layer 2 so as to cover the entire surface, and then etching it with a desired pattern. The core material 1 has a hole filled with a conductive paste 5 for conducting with the conductive paste 4 filled in the hole 2 a of the first insulating layer 2.

After the circuit patterns 3 are formed on the first insulating layer 2, a sheet-like second insulating layer 6 made of the same material as that of the first insulating layer 2 is laminated thereon. Then, the conductive paste 7 is filled into the holes 6a provided in the insulating layer 6 in advance and solidified. The hole 6a in this case is
The second insulating layer 6 is formed at a position where the circuit pattern 3 of the first insulating layer 2 and the circuit pattern 8 formed on the second insulating layer 6 are conducted.

Thereafter, a desired circuit pattern 8 is also formed on the second insulating layer 6. This circuit pattern 8 is also formed in the same manner as the circuit pattern 3, and electronic components 9 are mounted at predetermined positions by soldering 10.

On the other hand, a hole 11a is also formed on the lower surface of the core material 1 in advance.
The third insulating layer 11 in which is formed is laminated. In this case, the holes 11a are also filled with a conductive paste 13 for making a circuit pattern 12 described later and the core material 1 conductive, and solidified. After a desired circuit pattern 14 is laminated on the third insulating layer 11 and formed by etching, a fourth insulating layer 15 is laminated on the circuit pattern 14 and the third insulating layer 11. You. A hole 15a is also provided in advance in the fourth insulating layer 15, and after the hole 15a is filled with the conductive paste 16, a desired circuit pattern 17 is formed on the fourth insulating layer 15 by etching. A multilayer printed wiring board is configured.

As described above, the insulating layers 2, 6, 11, and 15 each having a hole are sequentially laminated on the core material 1, and each time the insulating layers 2, 6, 11, 15 are laminated. By sequentially filling the holes 2a, 6a, 11a, and 15a with the conductive pastes 4, 7, 13, and 16, the core material 1 and the circuit patterns 3, 8, 12, and 17 of each layer can be electrically connected. It is not necessary to provide a through hole in each layer as in the technique, and therefore, the circuit patterns 3, 8, 12, and 17 formed on the insulating layers 2, 6, 11, and 15 are affected by the through hole. Can be prevented, and the circuit pattern of each layer is not restricted, so that the degree of freedom in designing the circuit pattern can be increased accordingly.

In addition, since no through hole is required, the area of the circuit pattern can be increased, so that connection between the circuit patterns of each layer is facilitated and the density can be increased. In addition, there is no possibility that a through-hole is formed in an important part of the core material 1.

Therefore, by sequentially repeating the lamination of the insulating layer, the filling of the conductive paste, and the formation of the circuit pattern,
Since the circuit pattern of each layer is not restricted and the area of the circuit pattern can be increased, a high-density multilayer printed wiring board can be easily and reliably manufactured. This makes it possible to solve the problem associated with the through-hole (VIA) at the time of manufacturing the wiring board.
VH). In the illustrated embodiment, the example in which the patterns of the power supply layer and the ground layer are provided on both sides of the core material 1 is shown, but the present invention is not limited to this.
The same effect can be obtained by applying the present invention to one having a pattern provided on only one side.

[0015]

As described above, according to the method of the present invention, by sequentially repeating the lamination of the insulating layer, the filling of the conductive paste, and the formation of the circuit pattern, the circuit pattern of each layer is not restricted. Since the configuration is such that the area of the circuit pattern can be increased, there is an effect that a higher-density multilayer printed wiring board can be easily and reliably manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of a method for manufacturing a multilayer printed wiring board according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Core material, 2, 6, 11, 15 ... Insulating layer, 2a, 6
a, 11a, 15a ... holes, 3, 8, 12, 17 ... circuit patterns, 4, 7, 13, 16 ... conductive paste.

Claims (1)

[Claims] 1. A multilayer printed wiring board formed by laminating a plurality of insulating layers having a desired circuit pattern on a core material, wherein: A) a conductive portion of the core material, a first circuit pattern, B) Then, a first insulating layer provided with a hole in advance at a position where B is conducted is laminated, B) Then, a hole of the first insulating layer is filled with a first conductive paste conducting to the core material, and C) Forming the first circuit pattern, which conducts with the first conductive paste, on a first insulating layer into a desired shape; and D) forming a first circuit pattern on the first circuit pattern and the first insulating layer. The lamination of the insulating layer having a hole at a position where conduction is possible, the filling of the hole with a conductive paste, and the formation of a desired circuit pattern on the insulating layer are sequentially repeated a predetermined number of times, and the circuit pattern of each layer laminated Are electrically connected to each other through the conductive paste. Method for manufacturing a multilayer printed wiring board according to symptoms.