JPS60210896A - Method of producing both-side printed circuit 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] The present invention relates to a method for manufacturing a double-sided printed wiring board.

Conventionally, the saputrite tape method (copper through-hole method) is known as a method for manufacturing this type of double-sided printed wiring board. These methods for manufacturing double-sided printed wiring boards will be explained.

First, the above-mentioned copper through-hole method will be explained with reference to FIGS. 12 to 20. A laminated plate (5υ is cut into a regular shape in FIG. 12) with one side covered with copper (51a) is cut into a predetermined position on the laminated plate 6.
The through-holes are opened (No. 13), and the electroless plating Q is applied thickly to the holes 15a, etc. (Fig. 14) Next, a dry film 5 with conductive pattern patterns is applied to both sides of the laminate 6υ. (see Figure 15), then the first exposure and development process.
6) First, corrosion processing (etching processing) is performed to expose the exposed area (
Melt the copper (51a) (Fig. 17), form a conductive pattern (to) from this (Fig. 17), and then peel off the dry film 6a (Fig. 18).

After that, a green or similar turdare resist 157) is applied by printing or the like on both sides of the laminate 61), excluding the holes 52, etc. (Fig. 19).

After that, apply solder coat □□□ to the holes 62 etc.
Finally, a finished product is obtained by performing finishing processing, for example, external processing 1, surface cleaning, and application of a rust preventive agent.

However, in the case of the above-mentioned conventional method for manufacturing a double-sided printed wiring board, in the above process, a dry film with a thickness of about 55 microns in total is used. Therefore, due to the phenomenon of light refraction during exposure, a fine pattern of conductive parts cannot be formed, and therefore, there is a problem that a fine pattern of conductive parts cannot be formed.

The present invention aims to provide a method for manufacturing a double-sided printed wiring board that can eliminate these disadvantages.

Hereinafter, the present invention will be explained with reference to the attached drawings ζ shown in FIGS. 1 to 11.

1st step (Fig. 2) Cutting the laminate (1) covered with copper (1a) on both sides into a regular shape. 2nd step (Fig. 3) Both sides of the laminate (1) are coated with photosensitive function and corrosion protection. A functional photosensitive retention M film (2) is applied by dipping or the like.

For example, dippying is directed toward a novolac resin-based photoresist.

3rd process (Fig. 4)
Exposure and development using negative printing.

This forms a negative portion (3J).

Fourth step (Figure 5) The exposed part (4) is corroded. For example, a liquid of ferric chloride or cupric chloride is sprayed.

As a result, a conductive pattern (5) is formed.Fifth step (FIG. 6) The photosensitive maintenance film (2) is peeled off.

For example, O Step 6 (Figure 7) A hole (6) is made at a predetermined position in the laminate (11).

For example, a high speed drill machine is used.

7th step (Figure 8) Both sides of the am board (1) and hole 16) 4: Pretreatment (7
).

For example, a sensitizing material (baladium) is applied.

tA8 engineering! (FIG. 9) Solder resist (8) is applied to both sides of the laminate (1) except for the holes (61, etc.).

For example, printing with green epoxy thread ink, etc.
Application 0 Note that this solder resist (8) is one that can withstand electroless plating and solder coating.

9th process (Figure 10) The hole (6) * is electrolessly plated (9).

For example, use chemical copper plating.

After that, the terminal part (Y) is also plated.

10th process (11th prisoner) Private university (6) etc. is coated with solder (so-called solder) (11
Teru.

Eleventh Step Finishing is performed on the laminate (1). For example, external shape processing, terminal section alignment, final polishing, surface cleaning, rust preventive coating, etc. are performed. This completes the finished product.

As described above, the present invention forms negative parts (3) of the two conductive part patterns (5) on both sides of the laminate (1) by applying the photosensitive e-retaining film (21) and exposing and developing it, and
) is processed to form the conductive part pattern (5), so the photosensitive adhesive NP&(21) can be applied as extremely thin as 3 to 5 microns, so there is no problem of light refraction during photosensitive development. That's all, the fine conductive part pattern +51
can be formed.

In addition, since the hole (6) is processed two times after the photosensitive protective film (2) is applied and exposed and developed, the photosensitive protective film (2) penetrates into the hole (6). (It does not interfere with the application and exposure development of the second photosensitive retention film (2), and it also does not interfere with the electroless plating (9) of the hole +61. C: Double-sided printing. Before applying the solder resist (8), the wiring board can be manufactured. 6. Before applying the solder resist (8), the solder resist (8) is applied. Electroless plating (9) is applied only to the portion 6) and the terminal portion, and there is no shadow on the conductive portion pattern (5), which allows for efficient manufacturing.

As described above, the intended purpose can be fully achieved.

[Brief explanation of drawings]

1 to 11 are process explanatory diagrams of the present invention, and FIGS. 12 to 20 are process explanatory diagrams of a conventional example.・・Photosensitive protective film, (
3)...Negative part, (4)...Exposed part, (5)...
Conductive part pattern, (6)...hole, (7 doors/plating pre-treatment, (8)...solder resist, (93--electroless plating, box 11 solder coat. Date of April 4, 1980-person) Shinwa measurement 'Kyu Co., Ltd./Han

Claims (1)

[Claims] The first step is cutting a double-sided steel laminate into a regular shape, and the double-sided ζ photosensitive function and corrosion protection of the laminate! ! A second step of applying a functional photosensitive protective film, a third step of exposing and developing the conductive part pattern of the photosensitive protective film, a fourth step of etching the base part, and a fifth step of peeling off the photosensitive storage film; a sixth step of making holes at predetermined positions in the laminate; a seventh step of performing plating pretreatment on both sides of the laminate and the holes; and an eighth step of applying solder resist to both sides of the laminate except for terminals, etc., a ninth step of electroless plating the holes, etc., a tenth step of solder coating the holes, etc., and the laminate 6. ; A method for manufacturing a double-sided printed wiring board, comprising an eleventh step of performing finishing processing.