JPS6124298A - Method of producing multilayer printed board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a multilayer printed board formed by laminating printed circuit boards having pattern wiring on one side, and in particular, to The present invention relates to a method for manufacturing a multilayer printed board in which connections can be easily made in a lamination process.

Printed boards, which are widely used in the construction of various electronic devices, are generally made of copper-clad insulating boards, regardless of their size, and are coated with a chemical etching resist to print the pattern and remove unnecessary parts. It is manufactured by forming pattern wiring through processing.

In recent years, in order to achieve high-density mounting of such printed boards,
Multilayer printed circuit boards having multiple layers of pattern wiring have come to be manufactured by a build-up method in which an insulating layer and a pattern wiring layer are further laminated on top of the above-mentioned pattern wiring.

However, multilayer printed boards manufactured by such a build-up method tend to be expensive, and there is a need for an inexpensive manufacturing method for multilayer printed boards with a number of laminated layers of 2 to 3 F@, which are particularly useful.

[Conventional technology]

Figures (a), (b), (e), (d), (e) and (f) in Figure 2 are side sectional views showing the schematic steps of the conventionally most widely used method for manufacturing multilayer printed boards in order of process. be.

(As shown in the figure, pattern wiring 4, 5 is formed between insulating substrates 1, 2.3, and a printed circuit board tM is provided with copper coating 6 on each surface of insulating substrate 1.3. , as shown in figure (b), the through hole 7 is machined, and then, as shown in figure (e), copper plating is applied to the copper clad υ6 and the inner periphery of the through hole 7. A layer 8 is formed, and then an etching resist 9 is applied to the entire surface of the copper plating layer 80 as shown in FIG. 3(d), and a pattern is baked.

After the pattern is baked, a development process is performed to remove the copper plating layer 8 and the copper cladding other than the pattern, thereby forming a pattern as shown in Fig. Ce). Finally, by chemically removing the etching resist 8, (f) the pattern wiring 11 and lands shown in the figure are formed, and the pattern wiring 4.5 between each layer is formed.
Suruho connected! A multilayer printed board is obtained in which the laminate 10 is formed.

[Problem that the invention seeks to solve]

In this way, in the production of multilayer printed circuit boards, when processing the through holes 7 for the through holes 10, the positions of the pattern wirings 4 and 5 formed in each layer are precisely aligned with each other so that the pattern wirings are not cut. In addition, after lamination, the steel plating layer 8 is formed and processed, and the process of forming and etching the steel plating layer 8 is performed, which increases the cost.

[Means for solving problems]

To address the above-mentioned problem, a stud made of a conductive material is formed at a predetermined location of one of the pattern wirings facing each other with the insulating substrate interposed therebetween, and a through hole into which the stud is inserted is formed in the other pattern wiring. This problem is solved by the manufacturing method according to the present invention, in which a conductive adhesive is screen printed on the tip of the stud inserted into the through hole.

[Effect]

That is, correct positioning of interconnection is achieved by inserting a stud provided in one pattern wiring into a through hole provided in another pattern wiring, and the conductive adhesive at the tip of the stud allows pattern wiring between each layer to be aligned. The interconnection is ensured.

Therefore, pattern wiring between each layer can be interconnected without providing through holes formed by the conventional process of forming a copper plating layer and etching process.

〔Example〕

The present invention will be explained in detail below with reference to an embodiment shown in FIG. In the figure, (a) is a cross-sectional view, + (bl) (b2
) (b3) (cl) (C2) (dl) (d2) The figures are cross-sectional views showing the steps of the manufacturing method in the order of steps. The same reference numerals indicate the same objects throughout the figures.

(IL) As shown in the figure, studs 25 of a conductive material are fixed to the pattern wiring 23 of the insulating substrate 22 whose surface is smoothed by a resin layer 24, while the pattern wiring 28 of the insulating substrate 27 is penetrated. A hole 29 is provided, and the stud 25 is inserted into the through hole 29 and loaded.

The substrate 27 mounted in this way is fixed to the substrate 22 and the adhesive 30, and the pattern wiring 23.
2.8 interconnection is performed.

Such a configuration can be manufactured by the following manufacturing process sequence. First, pattern wiring 23 was formed (b
l) On an insulating substrate 22 having a heat sink 21 made of aluminum or the like as shown in the figure (b2), a resin layer 24 is formed on the same surface as the pattern wiring 23 as shown in the figure by screen printing.

Next, studs 25 made of a conductive material are fixed to predetermined locations of the pattern wiring 23 as shown in FIG. 3B, thereby manufacturing the printed board 20.

On the other hand, a printed circuit board 26 is manufactured in which a through hole 29 is formed as shown in FIG. 2 (C2) in the patterned wiring 2B provided on the film-like insulating sheet 27 shown in FIG.

This printed board 20 has a stud 25 in a through hole 26.
9. (dl) As shown in the figure, it is loaded and fixed with adhesive 30, and the tip of one stud 25 is screened with conductive adhesive 31 as shown in (d2). Fixed by printing.

Therefore, by manufacturing in this way, it is possible to
The pattern wiring 23 and 28 between the laminated layers can be formed without providing the through hole 10! Multiple electrically connected printed circuit boards can be produced.

〔Effect of the invention〕

As explained above, the present invention has a method of stacking a plurality of printed boards each having pattern wiring on one side by aligning them with studs and through holes, and making electrical connections between the patterns using conductive paint. There is no need for such high-precision positioning, and there is no need for the steps of forming a copper plating layer after lamination and etching, and there is a great economic effect in that an inexpensive multilayer printed board can be obtained using simple external manufacturing equipment.

[Brief explanation of drawings]

FIG. 1 illustrates an embodiment of the method for manufacturing a multilayer printed board according to the present invention. (a) is a cross-sectional view, (bl) (b2) (
b3) (cl) (c2) (dl) (d2) The figure is a cross-sectional view showing the manufacturing process, and Figure 2 shows the manufacturing process of a conventional multilayer printed board (a) (b) (d) (e) a) The figure shows a cross-sectional view. In the figure, 1, 2, 3, 22 are insulating substrates, 4.5 is a pattern layer, 6 is a copper clad layer, 7, 29 are through holes, 8 is a plating layer, 9 is an etching resist, 10 is a through hole,
Reference numerals 11, 23, and 28 indicate pattern wiring, 20, 26 a printed board, 21 a heat sink, 27 an insulating sheet, 24 a resin layer 1, 25 a stud, 30 an adhesive, and 31 a conductive adhesive. (Y'l r~ ζ 云 V 5-7J 卜

Claims (1)

[Claims] A method for manufacturing a multilayer printed board formed by laminating a plurality of printed circuit boards having pattern wiring on one side of an insulating substrate, the method comprising: a conductive material at a predetermined location of one of the pattern wirings facing each other with the insulating substrate interposed therebetween; A through hole into which the stud is inserted is formed in the other pattern wiring, and a conductive adhesive is screen printed on the tip of the stud inserted into the through hole. Features: A method for manufacturing multilayer printed boards.