JPH1120298A - Manufacturing method of printed wiring board - Google Patents

Abstract

(57) [Problem] To provide a method for manufacturing a printed wiring board which remarkably improves dimensional accuracy in a screen printing method and also improves quality and reliability. In order to achieve this object, the present invention provides a printing plate in which a print image is divided into a plurality of blocks, and a transfer image is formed in which a dimensional correction coefficient at a printing start side is relatively reduced along a printing direction. Is used for screen printing on a substrate having copper foil on both sides or one side. With the above method, a printed wiring board with improved dimensional accuracy can be obtained.

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 printed wiring board by screen printing.

[0002]

2. Description of the Related Art In recent years, printed wiring boards, which are widely used in various electronic devices and the like, have been required to have higher wiring density as electronic devices have become smaller and more multifunctional.

[0003] A conventional printed wiring board will be described below. In particular, in recent years, importance has been placed on improving the dimensional accuracy as the density of printed wiring boards increases.

FIG. 3 is a sectional view showing a conventional method of manufacturing a printed wiring board by screen printing, FIG. 4 is a view showing the dimensional accuracy of screen printing of a conventional printed wiring board, and FIG. FIG. 4 is a diagram illustrating a distortion state in printing.

In FIG. 3, reference numeral 11 denotes a printed wiring board;
Is a base material, 13 is copper foil, 14 is a plate frame, 15 is a squeegee,
16 is an ink, 17 is a screen. In FIG. 4, reference numeral 21 denotes the dimensional accuracy of the plate (blocks: G1 to L1).
In FIG. 5, reference numeral 22 denotes a conventional image dimensional accuracy after printing (blocks: G2 to L2).

First, copper foil 1 is applied to one or both sides of the base material 12.
3 and screen printing using a plate corrected to the same size coefficient (each block: G1 to L1) on a substrate cut to a predetermined size, thereby obtaining a land pattern, a solder resist, and a road map. Then, the printed wiring board 11 is obtained.

[0007]

However, at the time of screen printing of a printed wiring board by the above-mentioned conventional manufacturing method, distortion (22, G2) in each block as shown in FIG.
~ L2) are significantly different. In FIG. 4, printing start side G
After printing the blocks H1, I1 and I1, distortion occurs on the positive side in the X and Y directions as shown in the printing distortion states G2, H2 and I2 in FIG. 5, and the printing end sides J1, K1 and L1 in FIG. After printing the blocks, the printing distortion states J2, K2, L in FIG.
As shown in FIG. 2, distortion occurs in the X direction on the positive side and in the Y direction on the negative side. Also, blocks G2, I2, J on both sides of the print image of FIG.
2, L2 and the center blocks H2, K2 also have different distortion states. As described above, the conventional screen printing has a problem that the distortion at the time of printing is large, the dimensional accuracy is poor, and the matching is poor. As a method of solving such a problem, examination of printing conditions, examination of a plate, and the like have been performed. However, the above problem could not be solved.

The present invention solves the above-mentioned conventional problems and provides a method for manufacturing a printed wiring board which improves dimensional accuracy, significantly improves productivity and the yield of the manufacturing process, and improves the quality of electronic equipment. Aim.

[0009]

In order to achieve this object, the present invention provides a transfer image in which a print image is divided into a plurality of blocks, and a dimensional correction coefficient at a print start side is relatively small along a print direction. Is screen-printed on a screen or a substrate having a copper foil on one side using the plate on which is formed. With the above method, a printed wiring board with improved dimensional accuracy can be obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, there is provided a transfer image in which a print image is divided into a plurality of blocks, and a dimensional correction coefficient at a print start side is relatively small along a print direction. This is a method for manufacturing a printed wiring board for screen-printing on a printing material using the formed plate. By using this plate, the dimensional accuracy at the time of screen printing is remarkably improved (prevention of poor conformity), thereby achieving high density and high density. quality·
It has the effect of improving high reliability.

According to a second aspect of the present invention, in the block arranged perpendicular to the printing direction, the dimensional correction coefficient of the blocks on both sides is made relatively smaller than that of the central block. A method for manufacturing a printed wiring board according to claim 1, wherein the blocks on both sides of the block in which the printed image is arranged perpendicular to the printing direction using the method according to claim 1 with respect to the center block. This is a method for manufacturing a printed wiring board in which a dimensional correction coefficient is relatively reduced, and has an effect that high quality screen printing can be performed.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 show an embodiment of the present invention and are diagrams showing the shape of each block of a print image.

FIG. 1 shows an embodiment of the present invention, in which a print image is divided into a plurality of blocks, and the dimensional accuracy of a transferred image in which a dimensional correction coefficient at a printing start side is relatively reduced along the printing direction is reduced. FIG. 2 is a view showing distortion after screen printing using a plate on which a transfer image in which a print image is divided into a plurality of blocks is formed.

The screen printing method is the same as the method shown in FIG. 3, and in FIG.
12 is a substrate, 13 is copper foil, 14 is a plate frame, 15 is a squeegee, 16 is an ultraviolet-curable etching resist ink, 1
7 is a screen. In FIG. 1, 1 is the dimensional accuracy of the plate, A1, B1, C1, D1, E1, and F1 are the dimensional accuracy of each block. In FIG. 2, 2 is the dimensional accuracy of the image after printing.
A2, B2, C2, D2, E2, and F2 are diagrams showing the image dimensional accuracy of each block. First, a copper foil 13 is laminated on both sides of the base material 12, and a plate on which a transfer image having a dimensional coefficient of a different value for each block is formed on a substrate cut to a predetermined size, The pattern is formed by screen printing, and the printed wiring board 11 is obtained.

In the present invention, by dividing a print image into a plurality of blocks and using a plate on which transfer images having different values of the dimensional correction coefficients of the respective blocks are formed, it is possible to remarkably reduce dimensional conformity accuracy defects and obtain high quality. Can be manufactured.

When the dimensional accuracy (degree of dimensional matching) of screen printing (solder resist formation) of the printed wiring board manufactured by the method according to the present invention was confirmed, the Y direction on the printing start side in FIG. Blocks (A1, B
1, C1) is X: 0.999925, Y:
0.99850, block at the end of printing (D1, E
X is 0.99925, Y:
By changing it to 1.00005, it becomes possible to correct the distortion of the entire printed image by 0.1 mm or more in comparison with the conventional distortion in the Y direction. Further, the dimensional correction coefficients of the both end blocks (A1, C1) of FIG. 1 vertically arranged along the printing direction are X: 0.99945, Y: 0.99995,
The dimensional correction coefficient of (D1, F1) is X: 0.99905,
Y: changed to 1.00000, and the central block (B1)
X: 0.99925, Y: 0.998
50, the size correction coefficient of the central block (E1) is set to X: 0.
99925, Y: 1.00005 to make the distortion during printing less than 0.1 in the XY direction compared to the conventional one.
It is possible to correct the distortion of the entire print image by 1 mm or more. From the above results, high-precision, high-quality screen printing of a printed wiring board can be performed, and the dimensional accuracy (distortion amount: deviation) with respect to a printing substrate is about 1/2 of that in the related art.

In the embodiment of the present invention, distortion during screen printing can be reduced, and no occurrence of abnormal quality can be recognized.

In the embodiment of the present invention, the etching resist is of the ultraviolet curing type, but it is needless to say that the etching resist may be a thermosetting etching resist. Further, the same applies to the solder resist and the road map, and the same configuration as that of the present invention can be adopted.

[0019]

As described above, the present invention divides a print image into a plurality of blocks, and uses a plate on which a transfer image having a different dimensional correction coefficient for each block is formed.
The dimensional accuracy at the time of printing can be improved, and the quality is greatly improved. That is, it is possible to provide a printed wiring board by a screen printing method that significantly improves the dimensional accuracy (prevents poor matching) and improves the reliability of the electronic device.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating dimensional accuracy of a transferred image according to an embodiment of the present invention.

FIG. 2 is a diagram showing distortion after screen printing according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a method of manufacturing a printed wiring board by a screen printing method.

FIG. 4 is a diagram showing dimensional accuracy of conventional screen printing of a printed wiring board;

FIG. 5 is a diagram showing a problem (distorted state) in screen printing of a conventional printed wiring board.

[Explanation of symbols]

 Reference Signs List 1 dimensional accuracy 2 dimensional accuracy after screen printing 11 printed wiring board 12 base material 13 copper foil 14 plate frame 15 squeegee 16 ultraviolet curable etching resist ink 17 screen

Claims (2)

[Claims] 1. A print in which a print image is divided into a plurality of blocks, and screen printing is performed on a printing material using a plate on which a transfer image in which a dimensional correction coefficient at a printing start side is relatively reduced along a printing direction is formed. Manufacturing method of wiring board. 2. The method for manufacturing a printed wiring board according to claim 1, wherein, in the blocks arranged perpendicular to the printing direction, the dimensional correction coefficients of the blocks on both sides are relatively smaller than those of the central block.