JPH081908A - Screen process printing apparatus - Google Patents

Abstract

PURPOSE:To prevent damages from occurring to screens and substrates to be processed by a method wherein operations of the entire printing apparatus are controlled, based on outputs from a position detecting means that detects positions in the vertical direction for substrate pressing parts. CONSTITUTION:A single or a plurality of substrate pressing parts 13 and 15 are provided to a fist clamping device 31 so that they can move in the first direction for bringing one end thereof into contact with one side of a substrate 2 and in the second direction that is contrary to the first direction. Elastic members 16 bring each one end of the substrate pressing parts 13 and 15 into pressure contact with one side of the substrate 2 with the corresponding substrate pressing part 13 or 15 energized when the substrate 2 is corrected to become flat. Furthermore, a position detecting means 32 detects positions of the substrate pressing parts 13 and 15 in the first and the second directions. The state of warping of the substrate 2 or the state of unevenness on the surface of the substrate 2 can be judged, based on outputs from the position detecting means 32. Operations of the entire apparatus 30 is controlled, based on outputs from the position detecting means 32, and damages can be prevented from occurring to the substrate 2 and a screen 22 to be used in the printing process.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology (FIG. 5) Problems to be Solved by the Invention (FIGS. 5 to 7) Means for Solving Problems (FIGS. 1 to 4) Actions (FIGS. 1 to 4) Embodiments (FIGS. 1 to 4) Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus, and is suitable for application to, for example, a cream solder printing apparatus that supplies cream solder by printing it at a predetermined position on a substrate.

[0003]

2. Description of the Related Art As one of conventional cream solder printing apparatuses, there is an apparatus configured as shown in FIG. In the cream solder printing apparatus 1 having such a configuration, the printed wiring board 2 to be processed, which has been input, is first placed at the printed wiring board holding position by the transport mechanism (not shown) such as a belt conveyor. Sequentially transported to 3.

In the printing table section 3, a printing base 6 having a concave cross section is arranged on a plate-shaped base 4 via a printing base vertical drive cylinder 5, and a clamp member 7 is provided on the upper end surface of the printing base 6. Are arranged. In this case, a plurality of back-up pins 8 are arranged in the concave portion 6A of the printing base 6, and the printed wiring board 2 from the conveying means is arranged.
When the back wiring pin 8 is supplied, the back-up pin 8 rises to bring its tip into contact with the lower surface of the printed wiring board 2 to horizontally support the printed wiring board 2.

At this time, a board warp holding portion 10 is arranged above the printed wiring board holding position of the printing table portion 3, and the board warp holding portion 10 is provided with the print table portion 3.
When the printed wiring board 2 is horizontally supported by the back-up pins 8, the printed wiring board 2 is sandwiched together with the back-up pins 8 by moving in the downward direction shown by the arrow a as shown in FIG. Actually, the substrate warp holding unit 10 has a plate-shaped substrate warp holding plate 12 in which a plurality of cylindrical bushes 11 are inserted, and each of the bushes 11 has a substrate warp holding shaft 13 which moves vertically. It is freely inserted.

In addition, each substrate warp holding shaft 13 has a
An E-ring 14 is attached to the upper end to prevent the bush 11 from slipping out, and a substrate retainer 15 is attached to the lower end.
Is attached. Further, a coil spring 16 is provided between the board warp pressing plate 12 and each board pressing member 15 so as to surround the corresponding board warping pressing shaft 13. Thus, as shown in FIG. 6, the tip end of each board pressing member 15 is printed. Each substrate retainer 15 can be pressed against the upper surface of the printed wiring board 2 in a state where the substrate warp retainer 10 is lowered so as to contact the wiring board 2.

Thus, in this cream solder printing apparatus 1, when the printed wiring board 2 is sandwiched between the printing table portion 3 and the substrate warp holding portion 10, the elasticity of the coil spring 16 is provided on the upper surface of the printed wiring board 2. A downward pressure corresponding to the force is applied, and thus the warp of the printed wiring board 2 is corrected by the pressure. In this state, the clamp member 7 is driven in the printing table portion 3 to pinch the periphery of the printed wiring board 2 to fix and hold the printed wiring board 2 in this state.

Further, in the printing table section 3, after the board warp holding section 10 is raised thereafter, the board warp holding section 10 is raised.
By moving the printed wiring board 2 to a predetermined position below the screen printing unit 20 (a position where the printing table unit 3 is represented by a broken line in FIG. 5) arranged at a position different from that of the screen printing unit 20. The frame 21 is moved to the lower side of the screen 22 which is held in a planar shape. Subsequently, in the printing table unit 3, the printing base vertical drive cylinder 5 is driven to raise the printing base 6 so that the upper surface of the printed wiring board 2 is brought into contact with the lower surface of the screen 22.

In this state, the screen printing unit 20
Then, the stage 24 of the stage unit 23 moves downward and the entire stage unit 23 descends. Further, in the screen printing section 20, after this, the stage section 23 sequentially moves in the horizontal direction. Thereby, in this cream solder printing apparatus 1, cream solder can be printed and supplied at a predetermined position on the processed surface of the printed wiring board 2.

[0010]

However, in the cream solder printing apparatus 1 having such a configuration, when the printed wiring board 2 to be processed has a very large warp, the warp correction by the board warp holding portion 10 is completely performed. There are things that cannot be done. In such a case, the printing table unit 3 proceeds to the subsequent printing process while the printed wiring board 2 is fixedly held while a part of the printed wiring board 2 is lifted, so that there is a problem that the printing position of the cream solder is displaced. .

Further, in the cream solder printing apparatus 1 having such a structure, the printed wiring board 2 to be processed is subjected to double-sided reflow processing, and the back-up pins 8 of the printing table portion 3 supporting the printed wiring board 2 are installed. When the printed wiring board 2 is not fixed because the tip end of the back-up pin 8 hits the electronic component 25 already mounted on the printed wiring board 2 as shown in FIG. There is a problem that the screen 22 of the screen printing unit 20 and the printed wiring board 2 itself are damaged. Further, in the cream solder printing apparatus 1 having such a configuration, the printed wiring board 2 to be processed is subjected to double-sided reflow processing, and the operator mistakenly uses the already mounted surface as a processing surface to the cream solder printing apparatus 1. The same accident could occur even when it was thrown in.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a screen printing apparatus capable of preventing damage to a substrate to be processed and a screen.

[0013]

In order to solve such a problem, in the present invention, the supplied substrate (2) to be processed.
After being corrected to a flat plate shape by sandwiching it with the first and second sandwiching means (31) and (3) from the one surface side and the other surface side of the substrate, respectively, the corrected substrate (2) is fixed and held,
In a screen printing apparatus for screen-printing an object to be printed on one surface side of a substrate (2), first sandwiching means (3
1) is a single or a plurality of substrate pressing portions (movably arranged in a first direction in which one end of the substrate (2) is brought into contact with one surface of the substrate (2) and a second direction opposite to the first direction. 13-15)
When the substrate (2) is corrected into a flat plate shape, one end of the substrate holding part (13-15) is urged to the one surface of the substrate (2) by urging the corresponding substrate holding part (13-15). The elastic member (16) to be brought into pressure contact with the substrate pressing portion (13 to 1)
The position detecting means (32) for detecting the position in the first and second directions of 5) is provided.

Further, in the present invention, the substrate pressing portion (1
3 to 15) are in contact with the shaft (13) arranged parallel to and movable in the first and second directions, and one surface of the substrate (2) attached to one end of the shaft (13). It is composed of a substrate holder (15) and a position detecting means (32).
Is a sensor (32) for detecting the position of the reference point set in advance in the shaft (13).

[0015]

By providing the position detecting means (32) for detecting the positions of the substrate pressing parts (13 to 15) in the first and second directions, the substrate (based on the output of the position detecting means (32) ( The warped state of 2) and the uneven state of the processed surface of the substrate (2) can be determined. Therefore, the position detecting means (3
By controlling the operation of the entire device (30) based on the output of 2), it is possible to prevent the screen (22) and the substrate (2) used in the subsequent screen printing process from being damaged. can do.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1 in which parts corresponding to those in FIG. 5 are designated by the same reference numerals, 30 denotes a cream solder printing apparatus to which the present invention is applied as a whole, and is provided on the board warp holding plate 12 of the board warp holding portion 31. Each board warp restraint shaft 13
The cream solder printing apparatus 1 has the same configuration as the cream solder printing apparatus 1 shown in FIG. In this case, each sensor 32 is slightly smaller than the upper end position of the corresponding board warp holding shaft 13 when the board warp holding portion 31 is at the preset lowermost position as shown in FIG. 2 by the sensor bracket 33. It is supported so as to be able to detect the presence or absence of the pressing shaft 13 at a high position, and the detection results are sequentially sent to the CPU (not shown) via the sensor cable 34.

The CPU obtains the vertical position information of each substrate warp holding shaft 13 based on the detection result of each sensor 32, and the upper end of any one of the substrate warp holding shafts 13 is determined based on the position information. If it is lower than the position detection height by the sensor 32, the subsequent cream solder printing process is continued, while if it is higher, each drive mechanism (not shown) of the printing table unit 3, substrate warp holding unit 31, and screen printing unit 20. ) By sending a control signal to the print table unit 3 and the substrate warp holding unit 3
1 and the operation of the screen printing unit 20 are stopped. As a result, in the cream solder printing apparatus 30, when the warp of the printed wiring board 2 to be processed cannot be corrected within the predetermined range by the substrate warp holding portion 31 due to some factor, and the printed wiring board 2 to be processed.
When the substance such as the electronic component 25 (FIG. 7) is present on the processed surface of the
Thus, the screen 22 of the screen printing unit 20 and the printed wiring board 2 itself to be processed can be prevented from being damaged.

In the above-described structure, in this cream solder printing apparatus 30, there is no foreign matter on the printed wiring board 2 to be processed, which is supplied to the printing table section 3, and the warp is predetermined by the board warp holding section 31. When it is corrected to within the range, the upper end of each board warp holding shaft 13 of the board warp holding portion 31 is lower than the height detection position of each corresponding sensor 32 as shown in FIG. Subsequent steps for 2 are continued.

On the other hand, for example, as shown in FIG. 3, the printed wiring board 2 to be processed is a printed wiring board for which double-sided reflow is performed with the electronic component 25 already mounted on one surface side, and the printed wiring board is still present. When 2 is supplied to the printing table section 3 such that the surface on which the electronic component 25 is mounted becomes the processed surface due to a set mistake or the like, a substrate corresponding to the electronic component 25 is provided in the warp correction process for the printed wiring board 2. Since the upper end of the warp hold-down shaft 13 is raised by the height of the electronic component 25, the upper end is higher than the height detection position of the corresponding sensor 32, and as a result, this printed wiring board 2 is controlled by the CPU. Subsequent steps are stopped.

Similarly, for example, as shown in FIG. 4, the printed wiring board 2 to be processed is a printed wiring board for double-sided reflow in which the electronic component 25 is already mounted on one surface side,
The printed wiring board 2 is the back-up pin 8 at this time.
Even when the printed wiring board 2 is warped due to a mistake in the setting position, the upper end of the substrate warp holding shaft 13 located at a position facing the warped portion of the printed wiring board 2 is not printed.
Since the upper end of the CPU 32 is higher than the height detection position of the corresponding sensor 32 as a result of the CPU warping,
The subsequent steps for the printed wiring board 2 are stopped by the control of.

Therefore, in this cream solder printing apparatus 30, the printed wiring board 2 to be processed is printed on the screen 22 of the screen printing unit 20 and the printed wiring board 2 as shown in FIGS. 3 and 4 in the subsequent cream solder printing step. Since the cream solder printing process is stopped when the wiring board 2 itself or the like may be damaged, it is possible to prevent the screen 22 and the printed wiring board 2 itself from being damaged.

According to the above configuration, the substrate warp holding portion 3
1. A sensor 32 for detecting the vertical position is provided corresponding to each of the substrate warp pressing shafts 13 of 1, and the interruption of the subsequent cream solder printing process is determined based on the detection result of each sensor 32. Therefore, when the printed wiring board 2 is in a state where the screen 22 of the screen printing unit 20 or the printed wiring board 2 itself may be damaged in the cream solder printing step, the cream solder printing step is stopped. Thus, it is possible to realize a screen printing apparatus capable of preventing damage to the printed wiring board 2 and the screen 22 to be processed.

In the above-mentioned embodiment, the case where the present invention is applied to the cream solder printing apparatus 30 has been described, but the present invention is not limited to this, and it is suitable to be applied to other screen printing apparatuses. It is something.

Further, in the above-mentioned embodiment, the case where the sensor 32 is applied as the detecting means for detecting the upper end position of each substrate warp holding shaft 13 of the substrate warp holding portion 31 has been described. Not limited to this, for example, one electrode is provided on the upper end of each substrate warp holding shaft 13 and the other electrode is provided above each substrate warp holding shaft 13, and each substrate is checked depending on whether one or the other electrode is in contact with each other. Warp control shaft 13
It is also possible to obtain position information in the up-and-down direction, and various other detection means can be applied as the detection means for detecting the up-and-down position of each substrate warp holding shaft 13 of the substrate warp holding portion 31. . Further, in the above-described embodiment, the case where the coil spring 16 is used as a means for giving the elastic force in the vertical direction to each substrate warp holding shaft 13 has been described, but the present invention is not limited to this.
Various elastic bodies such as rubber can be applied as a means for applying an elastic force in the vertical direction to each substrate warp pressing shaft 13.

Further, in the above embodiment, the substrate warp holding plate 12 and the bush 11 are used as holding means for holding the substrate warp holding shafts 13 so as to be vertically movable.
However, the present invention is not limited to this, and various other holding means can be applied.

Further, in the above embodiment, the sensor 3
The case where the position 2 of the board warp presser shaft 13 is detected by detecting the upper end position of the board warp presser shaft 13 has been described, but the present invention is not limited to this, and the present invention is not limited to this. A reference point may be set at a position other than the upper end of 13, and the sensor 32 may detect the reference point to detect the vertical position of the substrate warp pressing shaft 13.

[0028]

As described above, according to the present invention, the supplied substrate to be processed is flattened by being sandwiched by the first and second sandwiching means from the one surface side and the other surface side of the substrate, respectively. Then, in a screen printing apparatus for screen-printing an object to be printed on one surface side of the substrate after the straightened substrate is fixedly held, the first sandwiching means has a first direction in which one end of the first sandwiching means is brought into contact with the one surface of the substrate. A single or a plurality of substrate pressing portions movably arranged in the opposite second direction, and when the substrate is corrected into a flat plate shape, the corresponding substrate pressing portion is urged to urge the corresponding substrate pressing portion. An elastic member for pressing one end of the substrate against one surface of the substrate and a first member of the substrate pressing unit.
And the position detecting means for detecting the position in the second direction, it is possible to judge the warped state of the substrate and the uneven state of the processed surface of the substrate based on the output of the position detecting means. Therefore, by controlling the operation of the entire apparatus based on the output of the position detecting means, it is possible to realize a screen printing apparatus capable of preventing damage to the screen or the substrate itself in the subsequent screen printing process.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a partial section of a cream solder printing apparatus according to an embodiment of the present invention.

FIG. 2 is a side view partially showing a cross section of how the printed wiring board is warped.

FIG. 3 is a side view partially showing a cross section of how the printed wiring board is warped when an electronic component is present on a processed surface of the printed wiring board.

FIG. 4 is a side view partially showing a section of a warp correction of the printed wiring board when a back-up pin is installed incorrectly.

FIG. 5 is a schematic side view showing a conventional cream solder printing apparatus with a partial cross section.

6 is a side view showing a state of warping correction of a printed wiring board by the cream solder printing apparatus of FIG. 5 with a partial cross section.

FIG. 7 is a side view partially showing a section of a warp correction of the printed wiring board at the time of a mistake in installing the back-up pins in the cream solder printing apparatus of FIG.

[Explanation of symbols]

1, 30 ... Cream solder printing device, 2 ... Printed wiring board, 3 ... Printing table part, 7 ... Clamping member,
8: back-up pins, 10, 31: substrate warp retainer, 11: bush, 12: substrate warp retainer plate,
13 board warp hold down shaft, 15 ... board hold down, 1
6 ... Coil spring, 22 ... Screen, 32 ... Sensor.

Claims (2)

[Claims] 1. A substrate to be processed that is supplied is corrected into a flat plate shape by sandwiching the substrate from one surface side and the other surface side of the substrate by first and second sandwiching means, and the corrected substrate is fixed and held. After that, in the screen printing apparatus for screen-printing a printing object on the one surface side of the substrate, the first sandwiching means includes a first direction and a first direction in which one end of the first sandwiching means is brought into contact with the one surface of the substrate. And a plurality of substrate pressing portions arranged movably in a second direction opposite to the above direction, and by pressing the corresponding substrate pressing portion when correcting the substrate into the flat plate shape. An elastic member for pressing the one end portion of the substrate pressing portion against the one surface of the substrate, and a position detecting means for detecting a position of the substrate pressing portion in the first and second directions. When Screen printing device. 2. The substrate pressing portion is in contact with a shaft arranged parallel to and movable in the first and second directions and the one surface of the substrate attached to one end of the shaft. 2. The screen printing apparatus according to claim 1, wherein the screen printing apparatus comprises a substrate holder, and the position detecting means is a sensor that detects the position of a reference point preset in the shaft.