JPH0671849A - Screen printing method - Google Patents

Abstract

PURPOSE:To permit maintaining the thickness of film of printing ink stably at a desired value at all times by a method wherein the strain of a squeegee is measured by a strain gauge and the pressure of the squeegee is controlled based on the result of measurement. CONSTITUTION:When a strain gauge 18 inputs the result of measurement, a microcomputer 20 operates a pressure applied on a squeegee rubber 16 and the angle theta of the rubber 16 based on the amount of measured strain. When the pressure is larger than a desired value and the angle theta is smaller than a desired value, the computer 20 controls a solenoid valve control circuit 24 so that the solenoid valve of a regulator 26 is closed whereby compressed air, outputted from the regulator 26, is weakened. Then, a force to push down a squeegee rubber retaining jig 12 in an air cylinder 14 is weakened whereby the pressure applied on the rubber 16 is reduced and the angle theta is increased. On the other hand, when the pressure applied on the rubber 16 is smaller than a desired value and the angle theta is larger than the desired value, the pressure impressed on the rubber 16 is increased and the angle 8 is decreased. According to this method, the thickness of film of the printing ink can be kept constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing method, and in particular, for example, a multilayer capacitor, a multilayer substrate, and L
The present invention relates to a screen printing method used for forming internal electrodes when manufacturing electronic components such as C composite components.

[0002]

2. Description of the Related Art As shown in FIG. 4, in a conventional screen printing apparatus 1, a squeegee rubber holding jig 5 is moved up and down by adjusting compressed air injected from an compressor 2 into an air cylinder 3 with a regulator 4. , Thereby adjusting the pressure applied to the squeegee rubber 6, and
The printed film thickness of was adjusted.

[0003]

In the conventional screen printing apparatus 1 as described above, the pressure applied to the squeegee rubber holding jig 5 can be controlled, but the squeegee rubber 6 on the printing surface is controlled.
The angle θ cannot be controlled. Therefore, for example, even if the squeegee rubber 6 deteriorates and the angle θ changes, the pressure of the squeegee rubber holding jig 5 remains constant, and therefore the film thickness of the printing ink 8 applied to the printing target 7 is always desired. It was difficult to obtain a film thickness.

Therefore, a main object of the present invention is to provide a screen printing method capable of maintaining a stable film thickness.

[0005]

SUMMARY OF THE INVENTION The present invention is a screen printing method in which the strain of a squeegee is measured by a strain gauge and the pressure of the squeegee is controlled based on the strain.

[0006]

The strain of the squeegee is measured by, for example, the change of the electric resistance of the strain gauges attached to the one main surface and the other main surface of the squeegee. Then, from the measurement result, for example, by a microcomputer, the pressure applied to the squeegee and the angle of the squeegee rubber with respect to the printing object are calculated, and the pressure is adjusted by, for example, compressed air injected into the air cylinder via the regulator, and as a result, Since the angle is adjusted, the film thickness of the printing ink applied to the printing object is always the desired film thickness.

[0007]

According to the present invention, since the film thickness of the printing ink can be stably maintained, a product of excellent quality can be manufactured. The above objects of the present invention, other objects,
Features and advantages will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A screen printing apparatus 10 of this embodiment shown in FIG. 1 includes a squeegee rubber holding jig 12 which is vertically moved by an air cylinder 14. A squeegee rubber 16 is attached to the tip of the squeegee rubber holding jig 12. Further, the one main surface and the other main surface of the squeegee rubber 16 have squeegee rubber 16
A strain gauge 18 for measuring the strain is attached. The strain amount of the squeegee rubber 16 measured by the change in the electrical resistance of the strain gauge 18 is input to the microcomputer 20 as can be seen from FIG.

On the other hand, since the relationship between the amount of strain and the pressure applied to the squeegee rubber 16 and the relationship between the amount of strain and the angle θ of the squeegee rubber 16 with respect to the material to be printed 22 are input to the microcomputer 20 in advance, the squeegee rubber 16 is calculated. The pressure applied to and the angle θ are calculated. Then, the electromagnetic valve control device 24 is driven by the microcomputer 20 based on the calculation result,
An electromagnetic valve (not shown) built in the regulator 26 is controlled. The compressed air output from the compressor 28 is adjusted by the regulator 26, so the compressed air having a predetermined pressure is output from the regulator 26. The air cylinder 14 is driven by the compressed air adjusted by the regulator 26, whereby the pressure applied to the squeegee rubber 16 is adjusted, and as a result, the angle θ of the squeegee rubber 16 is adjusted.

In operation, the squeegee rubber holding jig 12
Is driven, and the figure drawn on the screen 30 is printed on the substrate 2
When printing starts on 2, the squeegee rubber 16 is distorted. The strain gauge 18 measures this strain and inputs the measurement result to the microcomputer 20.
Calculates the pressure applied to the squeegee rubber 16 and the angle θ of the squeegee rubber 16 based on the strain amount. When the pressure is larger than the desired value and the angle θ is smaller than the desired value, the microcomputer 20 drives the electromagnetic valve control circuit 24 so that the electromagnetic valve of the regulator 26 is closed, thereby outputting the output from the regulator 26. The compressed air is weakened. When the compressed air weakens, the force that pushes down the squeegee rubber holding jig 12 in the air cylinder 14 weakens, so the pressure applied to the squeegee rubber 16 decreases and the angle θ increases. On the other hand, when the pressure applied to the squeegee rubber 16 is smaller than the desired value and the angle θ is larger than the desired value, the pressure applied to the squeegee rubber 16 increases due to the operation reverse to the above, and the angle θ decreases. By performing such an operation, the film thickness of the printing ink applied to the printing material 22 can be made constant.

The pressure control on the squeegee rubber 16 based on the measurement result of the strain gauge 18 may be adjusted before starting the printing process or may be performed each time during the printing process. Another embodiment of screen printing apparatus 10 shown in FIG.
Includes a strain gauge 18 similar to the screen printing apparatus 10 shown in FIG.
Two pieces are attached to each of the lengthwise ends of the one side surface and the other side surface. However, the structure of this embodiment is the same as the structure of the embodiment shown in FIG. 1 except for the position of the strain gauge 18, and therefore, a duplicate description will be omitted here.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of the embodiment of FIG.

FIG. 3 is an external view showing another embodiment of the present invention.

FIG. 4 is an external view showing a conventional technique.

[Explanation of symbols]

 10 ... Screen printing device 12 ... Squeegee rubber holding jig 14 ... Air cylinder 16 ... Squeegee rubber 18 ... Strain gauge 20 ... Microcomputer 24 ... Electromagnetic valve control device 26 ... Regulator 28 ... Compressor

Claims (1)

[Claims] 1. A screen printing method in which the strain of a squeegee is measured by a strain gauge and the pressure of the squeegee is controlled based on the strain.