JPS62190896A - Manufacture of printed wiring 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 Application of Nitojou] The present invention relates to a method of manufacturing a printed wiring board, and more particularly to a method of manufacturing a printed wiring board having both through holes and non-through holes.

[Conventional technology]

Conventionally, through holes have continuity between the upper and lower surfaces.

In order to manufacture a printed wiring board with a mixture of non-through holes without conduction, first, as shown in Part 2 (a), a printed wiring board (hereinafter referred to as a board) 1 with copper foil 2 coated on the front and back surfaces is prepared. hole 3
Next, the entire surface of the substrate 1 is plated to cover four 4-conductor layers, and a through hole 38 is formed (second hole (b)).
) Next, the through holes 3a are filled with resin paste 6, and after curing, the resin paste 6 that has adhered to the surface of the substrate 1 is removed, and then a part of the surface of the substrate 10 is filled as shown in FIG. 2(c). The etching resist layer 7 is deposited and shaped. Next, as shown in FIG. 2(d), the entire surface of the substrate 1 is etched and removed using the etching resist layer 7 as an etching mask, and then the etching resist layer 7 and the resin paste 6 are peeled off and removed as shown in FIG. 2(e). , desired circuit pattern 4
Form into &. Next, as shown in FIG. 2(f), a non-through hole 5ak NC hole is drilled on the rocky shore. Next, Figure 2 @
As shown in the figure, the solder resist 8 was completely printed and adhered, and finally the outer frame was processed to obtain a printed wiring board in which through-holes 3a and non-through-holes 5a coexisted.

[Problem that the invention seeks to solve]

In such a conventional printed wiring board manufacturing method.

If the through hole 3a and the non-through hole 5a were to be drilled at the same time, the conductive layer 4 would remain on the hole wall of the non-through hole 5a, so the non-through hole 5a' ( I-separate holes were made.This resulted in the following disadvantages.

(a) ICs, LSIs, resistors, and capacitors for printed wiring boards in recent years? Automatic mounting machines are used to mount parts, and the rate of their use is increasing year by year. In this case, the relative positional accuracy between the through hole 3a and the non-through hole 5a is ±50μ.
High accuracy is required, within m. On the other hand, when the through hole 3a and the non-through hole 5a are formed by separate drilling, the expansion and contraction of the substrate 1 during the manufacturing process and the drilling used when drilling the through hole 3a and the non-through hole 5a, respectively, are There is a drawback that the relative hole position accuracy between the through hole 3a and the non-through hole 5a deteriorates due to the relative positional deviation.

(b) Also, when drilling the hole 3, normally, the so-called stacked drilling is performed, in which two to three boards 1-3 are stacked on each rock per shaft, but when drilling the non-through hole 5, the drilling is carried out in a stacked manner. When all is done, through hole 3a and non-through hole 5
Since the relative positional accuracy with a is significantly deteriorated, overlapping holes are not drilled, and one hole is normally drilled per axis. As a result, work efficiency is significantly reduced, and the cost of materials used in conjunction with the work, such as backing plates, back-up materials, and drills, is also high.9% Therefore, it is difficult to manufacture inexpensive printed wiring boards. Hand 〇 [A means of all problems solved] The manufacturing method of the present invention is a hole for through holes and non -through holes on the front and back of the present invention on the front and back. A step of forming a through hole by plating the entire surface of the board and depositing a conductive layer on the inner wall surface of the hole and a copper foil surface, and a step of filling the through hole with K [fat paste]. After curing, a step of forming a resin mask on the entire center of the board, and drilling seven small front through holes with a diameter of 9 for non-through holes at the center of the holes for non-through holes. After that, the resin paste in the through hole is chemically dissolved and removed, and the resin mask? ]? a step of mechanically peeling off, a step of forming an etching resist layer on a part of the surface of the conductive layer, and a step of forming an etching resist layer on a part of the surface of the conductive layer;
Along with etching the electrical layer to form a circuit pattern,
A step of etching and removing the four layers in the hole for a non-through hole, and the resin paste and etching resist #
It consists of a complete removal step.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1(a) to (4).

First, as shown in Figure 1 (ml), the copper foil 2 is bonded to both the front and back surfaces of the nfC, f plate l, and the holes 3 for through holes and the holes 5'k for non-through holes are simultaneously drilled by a machine.Next Then, as shown in FIG. 1(b), electroless steel plating and electrolytic steel plating are applied to the substrate 1, a conductive layer 4 is applied, and a through hole 3a'i is formed on the wall of the hole 3.Next, as shown in FIG. (
As shown in C), an alkali-soluble solvent drying type resin base) 6 is placed in the through-hole 3a and the hole 5 for non-through-holes.
t-, using a roll coater (not shown), for example, at a temperature of 1o.

Dry and cure at ~120°C for 30-60 minutes. (The resin paste 6 used is of ultraviolet curable type, in order to harden the resin paste 6 to the inside.

Both sides of the substrate 1 are irradiated with ultraviolet light of 1 to 2 J/cm" and cured. Resin masks 9t-W are applied to the front and back surfaces of the substrate 10 as shown in FIG. 1(d). As shown in FIG. hole drilling 9
NC holes with a small diameter of 0.1 to 0.3 mm are formed by drilling 2 to 3 substrates per shaft in a stacked manner using a rock to form a hole 5' that passes seven holes through one front and back surface. Next, as shown in FIG.
Then, after spraying on the substrate 1 for 30 to 60 seconds to dissolve and remove the hole filler 6 attached to the hole wall of the hole 5', the 11th
Peel and remove the resin mask 9 on the front and back surfaces as shown in Figure 1).

Next, as shown in FIG. 1 (5), the resin paste 6 adhering to the stretched conductive layer 4 was removed by polishing with a puff, and then screen printing was performed as shown in FIG. 1 (1). Alternatively, the etching resist layer 7 is formed on a portion of the conductive layer 4 by a photoprinting method. Next, as in Section 111(j).

Etching resist layer 77 is used as an etching mask to completely remove the repaired portion of conductive layer 4 to form a desired circuit pattern, and at the same time, the copper-plated conductive layer 4 on the inner wall of hole 5 is also etched away to form non-through hole 5a'. (Formation. Next, as shown in FIG. 1 (2), an etching resist layer 7 is formed.
After peeling and removing the resin paste 6 by spraying it with a 2-4 weight sodium hydroxide aqueous solution at a temperature of 40-50°C for 2-4 minutes, the solder resist 8
was printed on the circuit pattern, and finally a predetermined outer frame was processed to obtain a printed wiring board in which non-through holes 5a and through holes 3a coexisted.

〔Effect of the invention〕

As is clear from the above description, the present invention has a first-order effect.

(1) Since it is possible to form an edge in simultaneous drilling of through holes, non-through holes, and holes, the relative hole position W consistency of both can be guaranteed, and a printed wiring board compatible with automatic mounting of n% components can be manufactured.

(IT) It is possible to improve work efficiency and reduce material costs, and to manufacture inexpensive printed wiring boards.

[Brief explanation of drawings]

FIGS. 1(a) to 1(t) are cross-sectional views illustrating an embodiment of the method for manufacturing a printed wiring board according to the present invention in the order of steps.
Figures (a) to (-c) are cross-sectional views illustrating a conventional printed wiring board manufacturing method step by step.
3...hole (for through hole), 3a...
...Through hole, 4...Conductive layer, 5...
...Hole (for non-through hole), 5a...Non through hole, 6...W fat paste. 7... Etching resist layer, 8...
Solder resist, 9...resin mask. treetop diagram

Claims (1)

[Claims] A process of simultaneously drilling holes for through holes and non-through holes on a board with copper foil bonded on both the front and back sides, and plating the entire surface of the board to form a conductive layer on the inner wall surface of the hole and the copper foil surface. a step of filling a resin paste into the hole in which a conductive layer is formed on the inner wall surface and curing it, and then a step of forming a resin mask on the entire front and back surfaces of the substrate; After drilling a front and back through hole with a smaller diameter than a hole for a non-through hole at the center position, a step of chemically dissolving and removing the resin paste in the through hole, and a step of mechanically peeling off the resin mask. , a step of forming an etching resist layer on a part of the surface of the conductive layer, and using this etching resist layer as an etching mask, etching the exposed conductive layer to form a circuit pattern, and also forming a conductive layer in the hole for a non-through hole. A method for manufacturing a printed wiring board, comprising the steps of etching away the layer and removing the resin paste and the etching resist layer.