JPS6392093A - Manufacture of multilayer interconnection board - Google Patents

Abstract

(57) [Abstract] 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 multilayer wiring that can be used in precision electronic equipment such as computers, which requires increased integration of functional elements such as ICs and LSIs, and multilayer wiring boards. This invention relates to a method for manufacturing a board.

2. Description of the Related Art In general, the method for forming inner layer circuits for multilayer wiring boards is to form a saturation resist on a thin copper-clad laminate using screen printing or photography, and then spraying an etching solution.
Etching has been performed to form inner layer circuits.

Problems to be Solved by the Invention Since the above method uses a film for the inner layer during the circuit formation process, the dimensions may be distorted during storage or transportation due to the influence of temperature and humidity, causing inner layer short circuits. . Short circuits in inner layer circuits are almost impossible to correct and are a fatal defect for multilayer wiring boards. In addition, the etching solution uses cupric chloride and ferric chloride, and the film stripping solution uses alkaline solutions such as caustic soda and organic solvents, which pose problems in terms of handling hazards and pollution treatment. be.

The present invention eliminates the above-mentioned conventional drawbacks and provides a method for manufacturing a multilayer wiring board with stable processing accuracy and eliminating the risk of short circuits in inner layer circuits.

Means for Solving the Problems In order to solve the above problems, the present invention is a thin insulating substrate with metal foil pasted on one side, and the through-holes that need to be connected to the outer layer circuits are not drilled and are connected to the outer layer circuits. The most common method for forming the through-hole portion where insulation is required is to press with a mold or drill a hole larger than the through-hole hole using an NC drill to form the inner power supply circuit layer and rolled circuit layer.

Effect: By using the above method, the dimensions are not affected by temperature or humidity and the dimensions do not go out of order. There is no inner layer short circuit due to dimensional deviation of the inner layer circuit, and the yield of multilayer wiring boards with stable processing accuracy can be improved.

EXAMPLE Hereinafter, a method for manufacturing a four-layer multilayer wiring board, which is an example of the present invention, will be explained with reference to the drawings.

FIGS. 2 and 3 are cross-sectional views of an extremely thin Epoquine glass insulating material 1.2 with 35μ inner layer copper foils 3, 4 attached.

Figures 4 and 5 are the inner layer copper foil 3.4 of Figures 2 and 3 above.
It is a sectional view in which a hole larger than the thistle hole is drilled by pressing with a mold or by an NC drill in a through-hole portion that needs to be insulated from the outer layer conductor of the epoxy glass PR material 1.2 to which is pasted. 5'/'i is a through-hole part that needs to be insulated from the outer layer circuit, and 6 is a through-hole part that needs to be electrically conductive with the outer layer circuit.

FIG. 6 is a sectional view showing a laminated state of the insulating materials 1 and 2 which have been subjected to the above-mentioned hole processing. The inner layer circuits shown in FIGS. 4 and 5 are installed on the front and back sides as shown. 7
is an adhesive sheet for bonding the inner layer copper foil 3 and the outer layer copper foil 8. This adhesive sheet 7 is pressurized (15~5okg/c7J
), heated (approximately 170°C) for 1 hour (approximately 40 to 80 minutes) to flow and solidify, and the resin of the adhesive sheet 7 is used to fill the holes of the through-hole portions 6 that need to ensure insulation with the outer layer circuit. can be filled. 9 is a heating plate for lamination.

FIG. 7 is a diagram in which the holes formed in the through-hole portions 5, which need to ensure insulation from the outer layer circuit, are filled with the resin of the adhesive sheet 7 after lamination.

FIG. 8 is a cross-sectional view of the through-hole hole 10.

FIG. 9 is a sectional view showing through-hole plating 11 applied.

The through hole portion 5 can ensure insulation with the outer layer copper foil 8, and the through hole portion 4 can have electrical conductivity with the outer layer copper foil 8.

FIG. 10 is a cross-sectional view after mesochyresist printing 12 has been applied.

FIG. 11 is a cross-sectional view showing the etching resist plating 13 applied.

FIG. 1 is a cross-sectional view of a completed multilayer wiring board that has been peeled off and etched using caustic soda or the like, and circuit formation on the outer and inner layers has been completed.

Effects of the Invention As described above, the present invention is a method for manufacturing a multilayer wiring board, in which inner layer circuits are formed by pressing with a mold or by drilling holes with an NC drill, so film produced by screen printing or photography is used. It is possible to form inner layer circuits for multilayer wiring boards with stable dimensional accuracy without being affected by the environment such as temperature and humidity than with the method of forming inner layer circuits using a method of forming inner layer circuits. It can improve yield and contribute to highly reliable precision electronic equipment such as in the computer field. Processing of cupric chloride, ferric chloride, etc. 1. It does not require the use of membrane stripping liquids such as tender liquid, caustic powder, and organic solvents, and is advantageous in terms of pollution treatment, making it an industrial value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a multilayer wiring board obtained by an embodiment of the method for manufacturing a multilayer wiring board of the present invention, and FIGS. 2 to 11 are inner layer circuits of a four-layer multilayer wiring board of an embodiment of the invention. It is sectional drawing of each process in a formation method. 1.2... Ultra-thin Evokin glass insulation material, 3,4
...Inner layer copper foil, 5...Through-hole part that requires insulation from the outer layer circuit, 6...Through-hole part that requires conductivity from the outer layer circuit, 7... ...Adhesive sheet, 8...Outer layer copper foil, 9...Hot plate for lamination, 10...Through hole hole, 11...Through hole plating, 12... ... Mesochresist printing, 13... Etching resist plating. Name of agent: Patent attorney Toshio Nakao and one other person No. 9
Figure lθ

Claims (1)

[Claims] The through-holes that require continuity with the outer layer circuit of a thin insulating material with metal foil pasted on one side are not drilled, and the through-holes that require insulation from the outer layer circuit are pressed with a mold, NC drill, etc. A method for manufacturing a multilayer wiring board, in which a hole is made larger than the through-hole hole, the holes are laminated together with an outer layer metal foil via an adhesive sheet, through-hole holes are formed, through-hole plating is applied, and an outer layer circuit is formed.