JPS6354237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a thick film circuit pattern using a drawing nozzle.

Conventional Structures and Problems Conventionally, as a method for forming thick film circuit patterns, screen printing has been widely used for mass production, while drawing methods are increasingly being used for trial production. In the case of prototyping, trial and error is repeated, and it would take too much time to design and produce a screen version each time, whereas with the drawing method, free patterns can be produced in a short time using computer control. This is because the development period can be shortened.

Now, in the conventional drawing method, as shown in FIG. There is a method in which the original film paste 3 is applied to the surface of the substrate 1 by moving the drawing nozzle 4 relative to the substrate 1, as shown in FIG. A method of applying thick film paste 3 in contact with the surface has been used. These methods have the effect of making the thickness of the thick film paste uniform. However, in either method, the stylus 5 or the drawing nozzle 4 is in contact with the substrate 1, so when the drawing nozzle 4 is relatively moved as shown in FIGS. Scratches 6 may occur in other circuit patterns such as, which may adversely affect the electrical characteristics after firing. Furthermore, a ceramic substrate is usually used for the substrate 1, but since ceramic is very hard, the stylus 5 and drawing nozzle 4 that are in contact with the substrate 1 will wear out, making it necessary to replace the drawing nozzle 4 frequently. . Furthermore, if the relative moving speed is increased, the stylus 5 and the drawing nozzle 4 will bend or break, making it difficult to improve the drawing speed. Due to these shortcomings, it was only suitable for prototype production, but completely unsuitable for mass production.

OBJECTS OF THE INVENTION In view of the above drawbacks, it is an object of the present invention to provide a method for forming thick film circuit patterns that can be drawn at high speed and with high reliability and is suitable for mass production.

Structure of the Invention The present invention enables the drawing nozzle that discharges the thick film paste to apply the thick film paste without contacting the board and while maintaining a certain distance from the board, thereby preventing damage to the circuit pattern. , it also has the unique effect of increasing movement speed.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 5 and 6 are a sectional view and a perspective view showing essential parts of drawing in an embodiment of the present invention. 7 in the diagram
1 is a drawing nozzle having a slit-shaped discharge port, 1 is a ceramic substrate, 2 is a conductor pattern, and 3 is a thick film paste. The slit nozzle 7 is fixed to a drawing head (not shown) that is driven up and down, and the drawing head is moved up and down according to the irregularities of the substrate 1 measured by the preparatory laser length measurement method, thereby drawing and drawing on the substrate 1. The thick film paste 3 is applied to a desired position while maintaining the distance to the nozzle 7 at 100 μm, and the distance between the substrate 1 on which the conductive pattern 2 is formed and the drawing nozzle 7 is preferably in the range of 10 μm to 200 μm, and is 10 μm or less. If the drawing nozzle 7 comes into contact with the substrate 1 due to equipment vibration, a stable coating thickness of 200 μm or more cannot be obtained.

As described above, in this embodiment, the unevenness of the substrate is measured in advance in a non-contact manner using the laser length measurement method, and the drawing head is moved up and down according to this measurement to adjust the distance between the substrate 1 and the drawing nozzle 7 so that they are in contact with each other. The conductor pattern 2 can be formed by applying the thick film paste 3 to a desired position while maintaining the conductor pattern 2 at a constant level without causing damage, and it has become possible to draw at a high speed of 400 mm/sec without damaging the conductor pattern 2.

In addition, although the method of measuring the unevenness of the substrate was shown in advance in the example, any non-contact method such as an optical length measurement method using a laser, a length measurement method using ultrasonic waves, a length measurement method using magnetism, etc. It is also possible to keep the distance between the substrate 1 and the drawing nozzle 7 constant by applying the method and simultaneously measuring the irregularities of the substrate and feeding the results back to the drawing head to drive the drawing head up and down.

Effects of the Invention As is clear from the above explanation, the present invention has a method of applying a thick film paste without causing contact between the substrate and the drawing nozzle and while maintaining a constant distance, thereby achieving high speed application without damaging the conductor pattern. (more than three times the conventional rate). Therefore, the present invention has paved the way for the drawing method, which conventionally had problems in terms of reliability and mass production and was only used for prototyping, to be used for mass production, and its practical effects are great. There is something.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts showing the conventional drawing method, Figure 2
The figure is a perspective view of FIG. 1, FIG. 3 is a sectional view of a main part showing another example of the conventional drawing method, FIG. 4 is a perspective view of FIG. 3, and FIG. 5 is a perspective view of an embodiment of the present invention. FIG. 6 is a sectional view of the main parts shown, and FIG. 6 is a perspective view of FIG. 1...Substrate, 2...Conductor pattern, 3...Thick film paste (resistance), 7...Drawing nozzle.

Claims (1)

[Claims] 1. Before applying the thick film paste, the unevenness of the surface of the substrate is measured in advance using a non-contact measurement method, and based on the results, the drawing nozzle is moved up and down to maintain a constant level without contact between the substrate and the tip of the drawing nozzle. A method for forming a thick film circuit pattern, in which a drawing nozzle is moved relative to the substrate while a distance is maintained, and a thick film paste is applied to the substrate.