JP3998140B2 - Screen printing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screen printing method, and more particularly to a screen printing method capable of transferring pastes only to the vertices of convex portions of a printing substrate having a concavo-convex surface.
[0002]
In this specification, “pastes” refers to metal pastes called pastes, inks or functional pastes.
[0003]
[Prior art]
When pastes are transferred by screen printing to the top of a convex part of a printed circuit board with irregularities on the surface, if the height of the convex part is about 10 to 50 microns, the paste falls into the concave part as well as the convex part Will be printed on the entire surface.
[0004]
In such a case, it is conceivable to create a printing pattern and perform screen printing. However, when the width of the printing pattern to be screen printed is about 10 to 40 microns, it is not only difficult to create the pattern, but also temporarily. Even if the pattern can be created, the alignment is extremely difficult. As a result, the surface is uneven, the height of the convex portion is 10 to 50 microns, and the width of the convex portion is about 10 to 40 microns. In a printed circuit board in which a print pattern is configured in the range, pastes cannot be transferred only by the screen printing to the top of the convex portion.
[0005]
In the case of a printed circuit board with irregularities on the surface, if the configuration of the print pattern is within the above range, for example, in order to transfer pastes only to the convex vertex, screen printing with a print pattern created on the screen plate In other words, screen printing by so-called solid printing is more suitable.
[0006]
In the prior art, a printing method has not been developed in which pastes are transferred by screen printing only on the vertices of convex portions of a printed circuit board having irregularities on the surface.
[0007]
[Problems to be solved by the invention]
The subject of this invention is providing the screen printing method which transfers pastes only to the convex-part vertex of the printing board | substrate with an unevenness | corrugation on the surface by screen printing.
[0008]
[Means for Solving the Problems]
Means for solving the problem is to transfer pastes by screen printing only to the convex vertices of the printed circuit board having irregularities on the surface, and a plane or rotary screen not provided with a printing pattern, and an elastic force. An elastic roller, and the elastic roller is interposed between the flat surface or the rotary screen and the printed circuit board, and pastes on the flat surface or the rotary screen are once transferred to the entire surface of the elastic roller. The paste transferred to the elastic roller is transferred to the apex of the convex portion of the printed board while rotating the elastic roller.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the start of printing when printing is performed using a flat screen , FIG. 2 shows the end of printing by the same method, and FIG. 3 shows the transfer state of pastes. FIG. 4 shows the start of printing when printing is performed using a rotary screen .
[0010]
In the embodiment, pastes on a flat surface or a rotary screen are once transferred to an elastic roller, and the pastes are transferred to the apex of a convex portion of a printed circuit board having an uneven surface while rotating the elastic roller.
[0011]
1 to 3 show an apparatus for executing the first embodiment. In these drawings, reference numeral 10 denotes a body of a screen printing machine, which is provided with a squeegee holder 11, and a squeegee 12 is fixed to the squeegee holder 11. The squeegee holder 11 can move up and down with the squeegee 12. Reference numeral 13 denotes a flat screen provided directly below the squeegee 12, and is provided to be movable in the horizontal direction in the first embodiment. Reference numeral 14 denotes a horizontally movable table provided in the machine body 10 for detachably fixing the printed circuit board 15.
[0012]
16 is an elastic roller provided rotatably between the flat screen 13 and the print board 15, and rotates while contacting with both of the flat screen 13 and the print substrate 15. The elastic roller 16 is formed in such a size that the pastes 17 can be transferred to the entire surface of the printed board 15 by one rotation. The elastic roller 16 of the embodiment is made of rubber or soft resin and has elasticity.
[0013]
The printed board 15 of the embodiment is formed of metal or glass or the like, and has a concavo-convex pattern in which convex portions 15a and concave portions 15b are alternately repeated on the surface as shown in FIG. In the embodiment, the height of the convex portion 15a is about 10 to 50 microns, and the width is about 10 to 40 microns.
[0014]
The apparatus for executing the first embodiment has the above-described configuration, and the flat screen 13 does not have a printing pattern, and the screen printing is performed by so-called solid printing. In FIG. 1, the table 14 is positioned on the right side of the squeegee 12, and the flat screen 13 is positioned on the left side of the squeegee 12. Next, the printed board 15 is placed on the table 14, and the flat screen 13 is simultaneously moved to the right and the table 14 is simultaneously moved to the left. As a result, the pastes 17 on the flat screen 13 are transferred to the surface of the elastic roller 16 and then transferred to the apex of the convex portion 15 a of the print substrate 15 by the rotation of the elastic roller 16.
[0015]
Referring to FIG. 3, the pastes 17 discharged from the flat screen 13 are formed on the surface of the elastic roller 16 so as to have an accurate film thickness by screen printing transfer. The pastes 17 thus transferred are transferred only to the convex portions 15a of the printed circuit board 15, which are necessary parts on the printed circuit board 15, as the elastic roller 16 rotates.
[0016]
The left part of FIG. 3 schematically shows a state where the pastes 17 are partially transferred because the pastes 17 transferred to the entire surface of the elastic roller 16 are transferred to the convex portions 15a of the printed board 15. However, since the thickness of the paste transferred to the surface of the elastic roller 16 is thin and the thickness of the paste transferred to the convex portion 15a is also thin, the paste remains on the surface of the elastic roller 16 after transfer. Sometimes.
[0017]
Figure 4 shows an apparatus for performing the second embodiment, the structure of the screen is a cylindrical Russia over Tari screen 20, other configurations are the same as those of the first embodiment.
[0018]
In both the first and second embodiments, the pastes are not directly ejected from the screen , but once the pastes 17 are transferred to the elastic roller 16, the elastic roller 16 is rotated while the vertex of the convex portion of the printing substrate 15 is rotated. Since the film thickness of the pastes transferred to the surface of the elastic roller 16 can be controlled, the pastes 17 are transferred only to the convex vertices of the printing substrate 15 and do not enter the concaves.
[0019]
【The invention's effect】
In the present invention, when transferring pastes only to the vertices of convex portions of a printed circuit board having irregularities on the surface, the pastes on a flat surface or a rotary screen are transferred to the surface of the elastic roller by so-called solid printing. The pastes transferred to the elastic roller are transferred to the top of the convex portion while rotating the paste, and the pastes are applied only to the top of the convex portion even when the height and width of the convex pattern are very small. It can be transferred.
[Brief description of the drawings]
FIG. 1 is a side view showing the start of printing when screen printing is performed using a flat screen .
FIG. 2 is a side view showing the end of printing when screen printing is performed using a flat screen .
FIG. 3 is an enlarged sectional view showing a transfer state of pastes on a flat screen .
FIG. 4 is a side view showing the start of printing when screen printing is performed using a rotary screen .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Airframe 11 Squeegee holder 12 Squeegee 13 Flat screen 14 Table 15 Printed circuit board 16 Elastic roller 17 Pastes 20 Rotary screen

Claims (1)

Paste is transferred by screen printing only to the top of the convex part of the printed circuit board with irregularities on the surface, and has a flat or rotary screen that does not have a printing pattern, and an elastic roller that has elastic force. The elastic roller is interposed between the flat or rotary screen and the printed circuit board, and pastes on the flat or rotary screen are temporarily transferred to the entire surface of the elastic roller , and the elastic roller is rotated. A screen printing method, wherein the paste transferred to the elastic roller is transferred to the apex of the convex portion of the printing substrate.

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