JP2637994B2 - Screen printing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing machine having an automatic positioning mechanism for a thin plate-shaped material to be printed.

2. Description of the Related Art In recent years, a screen printing machine has been applied to mass production such as printing cream solder on a printed circuit board on which electronic components are mounted, and a fully automatic screen printing machine has begun to spread. Under such circumstances, various methods of holding the printing material with high reliability have been studied.

For example, in the device described in Japanese Utility Model Publication No. 48-43454,
As shown in the figure, a printing material 2 is placed on a table 1 having a step having the same depth as the thickness of the printing material, and the side surface of the printing material 2 is pressed and fixed by a pusher 3 and a roller 4. However, such a direct moving type of table is not suitable for full automation because it is difficult to automatically supply and take out the printing material and the operation speed is slow. So, as another method,
As shown in the figure, there is a position described in JP-B-60-7399. Reference numeral 5 denotes a printing material, 6 denotes a stage on which the printing material 5 is placed and fixed, 7 denotes a plate, 8 denotes a transport link for transporting the printing material 5, 9 denotes a cylinder that moves the stage 6 up and down, and 10 denotes a thrust by raising the stage 6. The protection plate is pushed up by the rod 11. The printing material 5 conveyed by the conveyance link 8 is lifted by the cylinder 9 and the protection plate 10 is simultaneously pushed up by the push rod 11, and the printing material 5 and the protection plate 10 are flattened at the position where they are flat. Screen printed.

In FIG. 4, as a method of fixing the printing material 5 placed on the stage 6, there is a method of adsorbing and fixing the printing material using a negative pressure suction action as disclosed in Japanese Patent Application Laid-Open No. 160252/1986. .

Problems to be Solved by the Invention However, in the above-described configuration, for example, recent printed circuit boards have electronic components mounted on both front and rear surfaces with the aim of high-density mounting, and boards having a large number of through-holes. There has been a problem that the area for suction for fixing the substrate, which is the printing substrate, is reduced, and as a result, the suction fixing force is weakened, the substrate is displaced during printing, and normal printing cannot be performed. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a screen printing machine which has a small suction area for suction and fixation, and which accurately and accurately positions and fixes an automatically supplied printing medium.

Means for Solving the Problems In order to solve the above problems, a screen printing machine according to the present invention is a screen printing machine for printing cream solder via a printing plate on a printing material positioned at a predetermined printing position. A pair of rails that carry both ends of the printed material and transport them to a predetermined position, and a stage configured to be able to ascend to the printing position while holding the printed material transported by the pair of rails by negative pressure suction. And a guide plate having a hole enough to receive the print material when the print material held by the stage is raised to the print position, and provided on the inner side surface of the hole of the guide plate, and is located at the print position. A fixed roller which can be positioned and fixed so that the height of the upper end surface of the printing material and the upper end surface of the guide plate are the same; and And a movable roller slidable on the fixed roller side when positioning the printing medium.

According to the above-described configuration, the present invention employs the above-described configuration to transfer the automatically supplied printing medium to the inside of a hole provided in the guide plate after temporarily placing the printing medium on the stage, and to press the end surface of the printing medium with the fixed roller and the movable roller. As a result, accurate positioning can be performed and high-precision printing can be performed.

Embodiment The screen printing machine according to one embodiment of the present invention has been described above.
This will be described with reference to the drawings. FIG. 1 is a schematic sectional view of an essential part showing one embodiment of the present invention, in which 12 is a printing material, 13 is a printing material.
A belt that conveys 12 and is rotated by a motor (not shown). Reference numeral 14 denotes a rail for supporting the belt 13, and a pair of rails are provided so as to oppose the belt 13 at both ends of the printing material 12 so as to abut. Reference numeral 15 denotes a stage on which the printing material 12 is placed and fixed by suction, and a plurality of holes 16 for sucking the printing material 12 under negative pressure are provided through the upper surface. An end hole 17 of the hole 16 is connected to a negative pressure generating source (not shown) such as a vacuum pump. Further, the upper surface of the stage 15 is provided with a concave portion 18 except for the peripheral portion of the hole 16. This is to prevent the stage 15 from coming into contact with the electronic component when there is a projection such as an electronic component on the back surface of the print substrate 12, and to prevent a gap from being formed there and a reduction in the attraction force. 19
Moves the stage 15 up and down with an air cylinder. The guide post 20 supports the stage 15 and is slidably fitted on a bush 22 fixed to the base 21. The guide plate 23 is provided below the plate 24 by a support 25. The guide plate 23 is provided with a hole 25 that is slightly larger than the outer shape of the printing medium 12. A plurality of fixed rollers 26 are provided on two adjacent sides of the inner surface of the hole 25. The state is shown in FIG. In FIG. 2, reference numeral 27 denotes a movable roller and a fixed roller 26.
Is provided at a position opposed to. In FIG. 1, the fixed rollers 26 are attached to the tips of brackets 28 fixed to the lower portions of the guide plates 23 with pins 29, respectively. Movable roller 27
Is mounted with a pin 32 on the tip of a movable bracket 31 of a pressing mechanism 30 provided below the guide plate 23. Reference numeral 33 denotes an air cylinder in which the above-mentioned movable bracket 31 is slidably fitted to the tip of the plunger. A spring 35 always pushes the plunger 34 back in the direction opposite to the direction of the fixed roller 26. 36 is also a spring with plunger 34 and movable bracket 31
It is provided between. 37 is a compressed air supply port to the air cylinder 33.

The operation of the screen printer configured as described above will be described below with reference to FIGS.

In FIG. 1, when the printing material 12 conveyed by the belt 13 comes directly above the stage 15, it is detected by a photoelectric switch (not shown) provided around the rail 14, and the belt 13 temporarily stops. I do. Next, the stage 15 is raised by the air cylinder 19. At this time, the hole 16 is suctioned at a negative pressure through the end hole 17. The stage 15 is mounted on the printing medium 12 while being lifted, and is suction-fixed.
Up to the hole 25, and the print substrate 12 and guide plate 23
Rises to a position where the upper surface of the is almost the same height. Then, as shown in FIG. 2, by supplying compressed air to the air cylinder 33 of the pressing mechanism 30, the plunger 34 protrudes against the spring 35, and the movable bracket 31,
When the movable roller 27 pushes the end of the printing material 12 via the pin 32 and the other end contacts the fixed roller 26, the printing material 12 is pressed and fixed by the fixed roller 26 and the movable roller 27 and positioned. Next, after screen printing is performed on the surface of the printing medium 12, the operation is performed in the reverse order to the above, and the printing medium 12 is
The belt 13 is transported to the upper side, and is transported to the next process by rotating the belt 13 again.

As described above, according to the present embodiment, the guide plate 23 having the hole 25 slightly larger than the outer shape of the printing medium 12 and the plurality of fixed rollers 26 provided on two adjacent sides of the inner surface of the hole 25 are provided. A movable roller 27 slidable is provided at a position substantially opposed to the fixed roller 26, and the movable roller 27 is slid by a pressing mechanism 30 to press the end of the printing object 12 with the fixed roller 26 and the movable roller 27, and fixed. Since the positioning is performed, it is possible to perform accurate screen printing without the print substrate 12 being displaced during printing.

Effect of the Invention As described above, the present invention provides a pair of rails that carry both ends of a printed material and transport them to a predetermined position, while holding the printed material transported by the pair of rails by negative pressure suction. A stage configured to be able to ascend to a printing position, a guide plate having a hole formed therein to receive the object to be printed when the object held by the stage is elevated to the printing position, and a hole in the guide plate. A fixed roller that is provided on the inner surface of the printing medium and that can be positioned and fixed so that the height of the upper end surface of the printing material at the printing position is equal to the height of the upper end surface of the guide plate. A movable roller is provided in the direction away from the fixed roller and slidable on the fixed roller side when positioning the printing material, so that the area for suction for fixing the printing material is increased. Even if the number is small, it is possible to perform accurate screen printing without misalignment as well as accurate positioning of the printing medium during printing.

[Brief description of 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, FIG. 2 is a plan view of a main part of a guide plate, FIG. The figure is a sectional view of a main part of another conventional example. 12 ... substrate, 14 ... rail, 15 ... stage, 23 ...
… Guide plate, 24… plate, 25… hole, 26… fixed roller, 27… movable roller, 30… pressing mechanism.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Taniguchi 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-56-44656 (JP, A)

Claims (1)

(57) [Claims] 1. A screen printing machine for printing cream solder via a printing plate on a printing material positioned at a predetermined printing position, comprising a pair of rails for carrying both ends of the printing material and transporting the printing material to a predetermined position. A stage configured to be able to ascend to a printing position while holding the printing material conveyed by the pair of rails by negative pressure suction, and when the printing material held by the stage rises to the printing position. A guide plate formed with a hole enough to receive a printed material, and an upper surface of the printed material provided at an inner surface of the hole of the guide plate, and an upper surface of the printed material at the printing position and an upper surface of the guide plate having the same height. A fixed roller that can be positioned and fixed, and is located at a position substantially opposite to the fixed roller, always in a direction away from the fixed roller, and slides toward the fixed roller when positioning a printing target. Screen printing machine, characterized in that a capacity of the movable roller.