JPH01118438A - Screen printing machine - Google Patents

Abstract

PURPOSE:To enable cream solder, paste for thick film circuit, or the like to be printed high precisely on a printed circuit board or the like, by providing a plurality of thin sheet pressing mechanism parts capable of being energized by abutting against an upper surface of the thin sheet. CONSTITUTION:A matter-to-be-printed pressing mechanism 8 which converts the arrow G direction motion of a rack bar 11 to rotary motion of a matter-to- be-printed pressing lever 14 which is fixed with journal onto a pinion 13 by a pin 12, is established on both sides of a printing table 5 almost normal to a conveyor rails 2a, 2b via the rack bar 11 and the pinion 13. The matter-to-be- printed pressing lever 14 shuts and opens by performing rotary motion in the arrow H direction via the rack bar 11 and the pinion 13. When matter-to-be printed 1 is fixed to the printing table 5 by adsorption, the matter to be printed pressing lever 14 is rotated from a position 14a indicated by an alternate long and short dash line, and presses an upper surface of the matter to be printed 1. After fixing by adsorption, the matter-to-be-printed pressing lever 14 is firstly returned to the position 14a and then, the printing table 5 is lifted to a position 5a.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention primarily relates to a screen printing machine for printing cream solder, paste for thick film circuits, etc. onto printed circuit boards with high precision.

BACKGROUND OF THE INVENTION In recent years, screen printing machines have become increasingly finer in printing, and in response to this trend, various improvements have been made to screen printing machines to print with high precision.

The conventional screen printing machine mentioned above will be explained below with reference to the drawings. FIG. 3 is a schematic diagram of a conventional screen printing machine. The printing material 1 is placed on conveyor rails 2a, 2
The paper is supported at both edges by the rollers 3a and 3b, and is transported by the drive of the transport bells 3a and 3b, and stops at a predetermined position below the screen 4 where the printing pattern on the screen 4 and the printing pattern on the printing medium 1 match. Thereafter, the printing material 1 is suctioned and fixed in the positioned state on the upper surface of a printing tape/L'5 connected to a vacuum device (not shown) or the like.

The printing tape (V5) on which the printing material 1 is placed reciprocates up and down in the direction of the arrow. When printing, raise the printing tape/I15 to a predetermined position on the lower surface of the screen 4 to the position of the printing tape/I15a indicated by the - dotted chain line, and move the squeegee 6 in the direction of arrow B to -7, paste 7 is printed on the printing substrate 1a.

Problems to be Solved by the Invention However, with the above configuration, when printing on the printed material 1b with warpage as shown in FIGS. 4 and 5, the warped portion is fixed to the printing table 5 by suction. Printing is performed without the

Before starting printing, the amount of paste printed on the substrate 1 was adjusted, and the bottom surface of the screen 4 and the substrate were In the case shown in FIG. 5, the gap Ca in the center and the gap Cb in the warped area are different, so if you print in that state, the screen 4 will be in contact with the screen 4. The print pattern and the print pattern on the printing medium 1a may be misaligned, or the amount of printing may become uneven. In the worst case, bleeding, staining, etc. may occur. In the case of FIG. 6, the warped portion of the printing material 1a is pushing up the screen 4, but in such a case, for example, the printing material 1a rotates in the direction of the arrow or moves in the direction of the arrow E. , there was a problem in that the pattern on the screen 4 and the pattern on the printing material 1a were misaligned even before printing.

In view of the above-mentioned problems, the present invention provides a screen printing machine capable of printing cream quick release, thick film circuit paste, etc. on printed circuit boards and the like with high precision.

Means for Solving the Problems In order to solve the above-mentioned problems, the screen printing machine of the present invention has a table on which a thin plate is placed and fixed by suction. It has a structure in which a plurality of thin plate holding mechanisms are provided which can be biased by contacting the upper surface of the plate.

Function: With the above-described configuration, the present invention can reliably adsorb and fix a warped thin plate to a table, so that the thin plate does not shift from the screen pattern, and the amount of gap between the bottom surface of the screen and the top surface of the thin plate is made uniform. As a result, the printing amount of paste can be made uniform everywhere on the thin plate, and print bleeding, fading, etc. can be minimized.

Example Below Regarding one embodiment of the present invention, components having the same functions as those of the conventional example are given the same reference numerals as those of the conventional example, and
This will be explained with reference to the drawings and FIG.

FIG. 1 is a front view of a printing material holding mechanism of a screen printing machine according to the present invention, and FIG. 2 is a sectional view taken along the line F--F of the printing material holding mechanism in FIG.

In FIGS. 1 and 2, the substrate holding mechanism 8 is provided on a side surface of the printing table 5 in a direction substantially perpendicular to the conveyor rails 2a and 2b (a side surface substantially opposite to the side surface in FIG. 1). be. A cylinder 10 is provided at the bottom of the main body 9 attached to the side surface of the printing table 6, and a rack rod 11 provided at the tip of the cylinder 10 slides in the direction of arrow G. A pinion 13 and a printing material pressing lever 14 are pivotally fixed to the pin 12. Through the rack rod 11 and pinion 13,
The substrate presser lever 14 rotates in the direction of arrow H to open and close. When suctioning and fixing the printing material 1 to the printing table 5, the printing material pressing lever 14 is rotated from the position 14a shown by the dashed line to press down the upper surface of the printing material 1. After suctioning and fixing, move the printing material presser lever 14 to 1.
After returning to position 4a, the printing table 5 is raised to position 6a.

As described above, according to this embodiment, the transport rail 2a.

A rack rod 11 is attached to both side surfaces of the printing table 5 in a direction substantially perpendicular to 2b via a rack rod 11 and a pinion 13.
By providing a printing material holding mechanism section 8 that rotates a printing material pressing lever 14 which is pivotally fixed to a pin 12 on a pinion 13 in order to move in the direction of arrow G, even printing materials with warp can be reliably suctioned and fixed. Since it is possible, print material 1
However, without deviation from the print pattern of screen 4,
In addition, since the amount of gap between the bottom surface of the screen 4 and the printing material 1 can be made uniform, the amount of paste 7 printed can be made uniform everywhere on the printing material 1, making it possible to minimize printing smearing, fading, etc. Become.

7 Effects of the Vane Invention As described above, the present invention provides a lifting section that can raise and lower a table on which a thin plate is placed and fixed by suction to a predetermined position on the lower surface of the screen, and a plurality of vanes that can be biased by contacting the upper surface of the thin plate. By providing the thin plate valve mechanism, it is possible to prevent misalignment between the screen printing pattern and the thin plate printing pattern, and to equalize the amount of gap between the bottom surface of the screen and the top surface of the thin plate, so the amount of paste printed can be uniform, and printing smudges can be prevented. , blurring, etc. can be minimized, making it possible to print with higher precision and reliability.

[Brief explanation of the drawing]

FIG. 1 is a front view of a printing material valve mechanism section of a screen printing machine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the printing material valve mechanism section in FIG. This figure is a schematic front view of a conventional screen printing machine, and FIGS. 4 and 6 are front views of the screen printing machine showing the state when the printing material is raised to a predetermined position below the screen. 1...Printing material, 6...Printing table, 8...Printing material control mechanism, 11...
...Rack rod, 13...Pinion, 14...
...Printing target lever. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (2)

[Claims] (1) Screen printing is performed on the upper surface of the thin plate held at a predetermined position by comprising a table on which a thin plate is placed and fixed by suction, and an elevating section that can raise and lower the table to a predetermined position on the lower surface of the screen. A screen printing machine, characterized in that the elevating section is provided with a thin plate holding mechanism that can be biased by contacting the upper surface of the thin plate. (2) The thin plate holding mechanism section is composed of a rack rod and a pinion, and is configured to convert linear reciprocating motion of the rack rod into rotational movement of a thin plate holding lever that is pivotally fixed to the pinion. The screen printing machine according to item 1.