JPH01320165A - Screen printing machine - Google Patents

Abstract

PURPOSE:To make a cream solder, a thick-film circuit paste, and others printable on a circuit board to be printed and others with high accuracy by a method wherein a material to be printed is pressed from upward and fixed with flanges of a plurality of fixed rollers and movable rollers, each of which can abut against the edge of the material to be printed and has the flange capable of pressing on the upper surface of the material to be printed. CONSTITUTION:A left fixed roller 30 is previously raised and pressed toward a right movable roller 31. In this state, a material to be printed 16 is fed until it abuts on the roller 30 and then brought to a stop. After that, the material to be printed 16 is loaded on a holding board 19 and lifted until the upper surface of the material 16 is disposed to be approximately flush with the upper surfaces of protective boards 17a, 17b. Thereafter, a rear movable roller 28 is pressed toward a front fixed roller 25 and, simultaneously, the roller 31 is raised to be pressed toward the roller 30, thereby the material to be printed 16 is positioned. After the positioning, the rollers 25, 28, 30, and 31 are lowered from upward of the material to be printed 16, and the material to be printed 16 is pressed by flanges 26a-26d thereof and simultaneously attracted and fixed to the holding board 19.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention mainly relates to a screen printing machine that prints cream solder, paste for thick film circuits, etc. on printed circuit boards with high precision.

BACKGROUND OF THE INVENTION In recent years, screen printing machines have been used for mass production, such as printing cream solder on printed circuit boards on which electronic components are mounted, and fully automatic screen printing machines have become popular. Under these circumstances, various methods of holding printing substrates with high reliability are being studied.

Hereinafter, the above-mentioned conventional screen printing machine will be explained with reference to the drawings.

The conventional screen printing machine is
There is a device described in Publication No. 0-7399.

In the figure, 1 is the printing material, 2 is the stage on which the printing material 1 is placed and fixed, 3 is the plate, and 4 is the printing material 11! i - a transport link for transport; 6 is a cylinder that moves the stage 2 up and down; 6 is a protection plate that is pushed up by the push rod 7 as the stage 2 rises; The stage 2 of the printing material 1 that has been transported by the transport rail 4 is raised by the cylinder 6, and at the same time the protection plate 6 is also pushed up by the push rod 7, so that the upper surfaces of the printing material 1 and the protection plate 6 become flat. Screen printed in position.

In FIG. 3, a method for fixing the printing material 1 placed on the stage 2 is a method of adsorbing and fixing the printing material using negative pressure suction, as described in Japanese Patent Application Laid-Open No. 61-160252. .

However, with the above configuration, when printing is performed on the printed material 1a with the warp shown in FIGS. 4 and 6, the part with the warp is not fixed to the stage 2 by suction and printing is performed. Before starting printing, in order to adjust the viscosity of the paste printed on the printing material 1 and to minimize printing smearing, fading, etc. that occur when using fine print patterns, the bottom surface of the screen 3 and the printing material are Since a gap is provided between printed matter 1 or they are brought into contact with each other, in the case shown in Fig. 4, the gap Ca in the center and the gap C in the warped part are
Since b is different, if printing is performed in this state, the print pattern on the screen 3 and the print pattern on the printing material 1a will be out of sync, and the amount of printing will be uneven. In the worst case, bleeding, staining, etc. may occur. In the case of Fig. 6, the printing material 12
The sled part of L is pushing up screen 3,
In such a case, for example, the printing substrate 1a rotates in the direction indicated by the arrow or moves in the direction indicated by the arrow 2, causing a problem in which the pattern on the screen 3 and the pattern on the printing substrate 1 deviate from each other even before printing. It had a point.

Therefore, as another method, there is a screen printing machine as shown in FIG. 8 is a printing material, 9 is a conveyor rail that transports the printing material 8, 10 is a protection plate that has a collar 12 that protects the screen 11 when the entire screen is printed, and moves up and down, 13 is a holding pin that holds the printing material 8, and 14 is a lifting/lowering device. This is a possible table. The printing material 8 is transported by the transport rail 9, and at this time, the collar 12 of the protection plate 10 moves upward and escapes so as not to come into contact with the upper surface of the printing material 8. After positioning the printing material 8 at a predetermined position using a positioning device (not shown), the protection plate 10 is lowered, and the printing material 8 is pressed down by the collar 12 to fix the printing material 8, and then Printing is performed on the table 14 at a position where the top surface of the protection plate 10 is raised to near the bottom surface of the screen 11. Problems to be Solved by the Invention However, in the above configuration, as shown in FIGS. 7 and 8, , hold the edge of the printing material 8 with the width F dimension, and since there is a difference in the height-gG dimension between the upper surface of the protection plate 1o and the upper surface of the printing material 8, only the width H of the printing material 8 is held at the edge of the printing material 8. The problem was that printing was not possible. The area that cannot be printed is shown in the shaded area J in FIG.

In view of the above problems, the present invention provides a screen printer capable of printing cream solder, paste for thick film circuits, etc. onto printed circuit boards and the like with high precision.

Means for Solving the Problems In order to solve the above problems, the screen printing machine of the present invention includes a pair of protective plates facing each other to protect the screen plate during printing and supporting the substrate to be printed; A holding plate is provided between the protection plates to hold the printing material, and a holding plate is provided above, which is normally located at the bottom of the printing material.When positioning the printing material, the printing material is placed on the holding plate and the printing material is placed on the holding plate. a table that can be raised and lowered until its top surface is approximately at the same height as the top surface of the protection plate; and a plurality of fixings having tabs that can abut against the edge of the printing material and can be biased against the top surface of the printing material. A roller, a plurality of movable rollers that are located substantially opposite the fixed roller and have a collar that can be biased and brought into contact with the upper surface of the printing material, and that can be biased and brought into contact with the edge of the printing material. established,
It has a structure in which the fixed roller brim and the movable roller brim press and fix the printing material from above.

Function: With the above-described configuration, the present invention can reliably fix a warped printing material to the holding plate, so that the printing material does not shift from the screen pattern, and the amount of clearance between the lower surface of the screen, the printing material, and the upper surface is made uniform. Since the amount of paste printed can be made uniform everywhere on the printed material, it is possible to minimize printing smearing, fading, etc., and it also prevents the printed material from shifting from its fixed fixed position. In this way, it is possible to minimize the area of the unprintable material that occurs when the printing material is pressed down from above.Example: Hereinafter, a screen printing machine according to an embodiment of the present invention will be described.
This will be explained with reference to the drawings.

FIG. 1 is a schematic sectional view of a main part of a screen printing machine according to an embodiment of the present invention, and FIG. 2 is a schematic plan view taken in the direction of the arrow 2 in FIG.

In FIGS. 1 and 2, it is a positioning table for positioning a 15fi printing material 16. In FIG. 172L.

17b is a pair of protection plates provided oppositely to protect the screen 18 during printing and to support the edge of the printing material 16 conveyed from the L direction; 191d is a holding plate that holds the printing material 16; 20 is a holding plate Place cylinder 21 on top of cylinder 21.
When positioning the printing material 16, the printing material 16 is placed on the holding plate 19, and the upper surface of the printing material 16 is placed on the protective plates 17a, 17t.
) A table that rises and falls until it reaches a height that is approximately the same as the top of the table.
22i1'j guide post supports the table 20,
026, which is slidably fitted into the bushing 24 fixed to the base 23, is a front fixed roller that can come into contact with the front edge of the printing medium 16. move. Normally, the cylinder 29& is moved upward by the drive of the cylinder 27&, but the cylinder 29&
This is a rear movable roller that can be biased and brought into contact with the rear edge of the printing medium 16 by moving back and forth, and has a collar 26b at the top, and is moved up and down by the drive of a cylinder 27b. Rear fixed roller 28ii Normally, cylinder 27b moves up and down
is moved upward by the drive of the cylinder 29a, and is moved rearward by the drive of the cylinder 29a.

3o is a left-side fixed roller that comes into contact with the left edge of the printing medium 16 by the drive of a cylinder 29b that moves laterally, has a boxwood 26Of at the top, and moves up and down by the drive of a cylinder (not shown). Normally, the cylinder 29 is moved to the left by the + drive, and is moved below the bottom surface of the printing material 16 by the drive of a cylinder (not shown) that moves up and down.The cylinder 31 is driven by the cylinder 290 that moves left and right. , a right-side movable roller that biases and abuts against the right edge of the printing medium 16; the right-side movable roller 31, which has a collar 26d'ii at the top and moves up and down by the drive of a cylinder (not shown) that moves up and down, is a left-side movable roller; The positioning table 16 is provided at a position substantially opposite to the roller 30. After positioning the printing material 16, the positioning table 16 is operated by a driving source such as a cylinder (not shown) until the upper surface of the printing material 16 comes near the lower surface of the screen plate 1B. The protective plates 172L and 1b are fixed to the support column 32.

The operation of the screen printing machine configured as described above will be explained below with reference to FIGS. 1 and 2.

In FIG. 1, the left fixed roller 30f is raised and biased toward the right movable roller 31.

In this state, feed the printing material 16 from the direction of the arrow (
(The driving source is not shown) is brought into contact with the fixed roller on the left side and stopped. Thereafter, the printing material 16 is placed on the holding plate 19 and raised until the upper surface of the printing material is approximately at the same height as the upper surface of the protection plates 17 and 17b. Thereafter, the rear fixed roller 28 is urged toward the front fixed roller 25 side, and the front and rear edges of the printing medium 16 are sandwiched between the front fixed roller 25 and the rear movable roller 28, and at the same time, the right fixed roller 3
1 is raised and biased toward the left movable roller 30, and the left and right edges of the printing material 16 are held between the left fixed roller 30 and the right movable roller 31, thereby positioning the printing material 16. After positioning, the front fixed roller 26, the rear fixed roller 28, the left fixed roller 30, and the right fixed roller 31 are all lowered from above the printed material 16, and each collar 262L to 26d presses the printed material 16, and at the same time, Using negative pressure suction (not shown), the printing substrate 16
is suctioned and fixed to the holding plate 19.

Next, the printing material 16 is raised to near the lower surface of the screen plate 18 and a printing process begins. After printing, the operation is performed in the reverse order as described above, and the printing material 16 is sent to the next process (the driving source is not shown).0 As described above, according to this embodiment, the screen plate 18 is moved when the positioning table 16 is completely printed. A pair of protection plates 171L, 17 provided oppositely to protect and support the printing material 16
b, a holding plate 19 that holds the printing material 16, and a holding plate 1
9 is placed above the printing material 16, and is normally located below the printing material 16. During positioning, the printing material 16 is placed on the holding plate 19, so that the upper surface of the printing material 16 is approximately at the same height as the upper surface of the protection plates 17a and 17b. A table 20 that can be raised and lowered until it reaches the top; a front fixed roller 25 that can come into contact with the front edge of the printing medium 16 and has a boxwood 26A'i that can press against the upper surface of the printing medium 16; Located at a position substantially opposite to the roller 26,
A collar 26bi that can press against and come into contact with the upper surface of the printing material 16
a rear fixed roller 28 that can be biased and abutted against the rear edge of the printing medium 16; and a rear fixed roller 28 that is capable of abutting the left edge of the printing medium 16 and biased against the upper surface of the printing medium 16; possible boxwood 26
C'(5), and a boxwood 26d'j5 which is located substantially opposite the left fixed roller 30 and can press against the upper surface of the printing medium 16.
and a right side fixed roller 31 which can be biased and abutted against the right edge of the collar 26.

By pressing down the printing material 16 from above with 26b, 26C, and 26d, the entire printing material 16 having the warp 2 can be securely fixed to the holding plate 19, so that the printing material 16 does not shift from the printing pattern on the screen 18. In addition, since the amount of gap between the bottom surface of the screen plate 18 and the printing material 18 can be made uniform, the amount of paste (not shown) printed can be made uniform everywhere on the printing material 16, and printing smearing, fading, etc. can be minimized. The area that cannot be printed when the printed material 16 with warp is pressed from above to prevent it from shifting from the fixed fixed position is expressed as the area of the shaded area M shown in FIG. 2. In addition to the effects of the present invention that can be minimized, the present invention protects the screen plate during printing,
A pair of protective plates are provided facing each other to support the edges of the printed material, a retaining plate is provided between the pair of protective plates to hold the printed material, and a retaining plate is provided on top of the protective plate, and a protective plate is provided at the bottom of the printed material at all times. When positioning, place the printing material on the holding plate,
A table that can be raised and lowered until the top surface of the printing material is approximately at the same height as the top surface of the protection plate, and a plurality of flanges that can come into contact with the edge of the printing material and can be biased against the top surface of the printing material. a fixed roller, and a plurality of movable rollers that are located substantially opposite the fixed roller, have a collar that can be biased and brought into contact with the upper surface of the printing material, and that can be biased and brought into contact with the edge of the printing material. By pressing and fixing the printing material from above with the fixed roller brim and the movable roller brim, it is possible to securely fix the printing material to the printing material held by the warp, thereby eliminating misalignment between the screen plate printing pattern and the printing pattern of the printing material. prevent,
The gap between the bottom surface of the screen plate and the top surface of the printing material can be made completely uniform, minimizing printing smearing, blurring, etc., and also keeping the printing material with warpage upward so that it does not shift from the fixed fixed position. Since the unprintable area that occurs when pressing down can be minimized, printing can be performed with high precision and reliability.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of the main parts of a printing press for slurry 1 according to an embodiment of the present invention, Fig. 2 is a schematic plan view taken in the direction of the - arrow in Fig. 1, and Fig. 3 is a conventional screen printing machine. Figures 4 and 6 are schematic front views of the main parts, showing the state when the substrate is raised to a predetermined position on the bottom surface of the screen plate in Figure 3, and Figure 6 is a schematic front view of the main parts. FIG. 7 is a detailed view of the main parts of a conventional screen printing machine when the substrate is raised to a predetermined position on the lower surface of the screen plate in FIG. 6, and FIG. FIG. 3 is a schematic plan view of main parts. 16...Printed material, 17a, 17b...
...Protection board, 18...Screen version, 19.
...Holding plate, 20...Table, 26.
...Front fixed roller, 265-26d...
...Brim, 28... Rear movable roller, 30.
... Left side fixed roller 531 ... Right side movable roller. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 4 Figure 5

Claims (1)

[Claims] A vertically movable positioning table positions the printed material conveyed from one direction, raises the printed material to near the bottom surface of a screen plate provided directly above the positioning table, and applies printing paste to the printed material. In the screen printing machine for printing, the positioning table is arranged between a pair of protection plates provided oppositely to protect the screen plate during printing and to support an edge of the substrate to be printed, and a pair of protection plates. a holding plate for holding the printed material; and a holding plate provided above the holding plate, which is normally located below the printed material, and when positioning the printed material, the printed material is placed on the holding plate. , a table that can be raised and lowered until the top surface of the printing material is approximately at the same height as the top surface of the protection plate; and a collar that can come into contact with an edge of the printing material and biased against the top surface of the printing material. a plurality of fixed rollers having a plurality of fixed rollers, and a collar that is located substantially opposite to the fixed roller and can be biased and abutted against the upper surface of the printing substrate, and that is biased and abutted against the edge of the printing substrate. 1. A screen printing machine, comprising a plurality of movable rollers, and the printing material is pressed and fixed from above by the brim of the fixed roller and the brim of the movable roller.