JPH0289653A - Applicator of resistance paste for thermal head - Google Patents

Abstract

PURPOSE:To draw paste in specified height accurately at the center of a glazed section by providing a displacement sensor measuring the height of a substrate on an XY table and a means keeping the temperature of paste constant and a pressure means and furnishing a means vertically moving a syringe having a means detecting force applied to a nozzle. CONSTITUTION:The shaft 26 of a syringe 20 is held vertically movably and freely by a linear ball bush 28 fixed to a block 27, and force applied at the nose of a nose section 24 is measured by a load cell 31. A pressure port 33 applying air pressure in order to discharge paste 32 from the tip of a nozzle 21 is formed to the shaft 26, and a heat-insulating chamber 35 is installed to a paste holding section 25. An X table is retreated while the upper section of a substrate 13 is measured by displacement sensors 16, 17, and a Y table 6 is fed to l2 until the point K1 of a substrate chuck 14 coincides with the measuring point of a displacement sensor 18 when the center 41 of a glazed section 40 and the measuring point of the sensor 16 agree. The height of a paste applying start point K2 on the substrate 13 is measured by the sensor 18, and the position of the tip of the nozzle 21 is positioned in height higher than the height of the point K2 by DELTAh. Paste 32 begins to be discharged when the feed of the Y table 6 is brought to l2 while the surface of the substrate 13 is measured by the sensor 18 under the state.

Description

[Detailed description of the invention] [Fields of use outside of work] My brother Akira developed a thermal head using a drawing nozzle. Related to resistance paste coating equipment.

[Conventional technology]

As described in Japanese Unexamined Patent Publication No. 164598/1983, the conventional device allows the nozzle position to be moved to any position in the three-dimensional coordinates by a program, and paste is ejected from the tip of the nozzle onto the substrate to form fine circuits. It is something that forms.

Furthermore, in JP-A-59-11L587, a drawing nozzle for discharging paste is moved relative to the substrate, and the unevenness of the surface of the substrate is measured by a non-contact foot measurement method, and the results are The paste is applied to the substrate by feeding back to the drawing head that holds the nozzle while maintaining a constant distance from the substrate and the drawing nozzle to prevent light leakage.

[Problem to be solved by the invention]

In the conventional technique described above, the position of the paste on the substrate is determined by the state in which the substrate is set in the device. Therefore, if the application position on the substrate is determined in advance and this position varies depending on the state of the substrate set in the device, a pattern is formed at a predetermined position with a high n1 degree. It is not possible.

In the application of resistance paste for a thermal head, which is the object of the present invention, the substrate to be coated is rectangular, and a raised part (glaze part) with a small radius of curvature is formed linearly in the longitudinal direction on a part of the board. It is being The center of this glazed area ((it is necessary to apply paste with high precision. However, the position of this glazed area varies on the board, so with conventional equipment, it is not possible to just center the board. The base l-r accuracy was good at the position (but it was not possible to apply it.

In addition, in JP-A No. 59-111387, in a method in which the unevenness on the substrate is measured and the nozzle is applied from a trap at a constant interval on the substrate to apply paste,
No consideration is given to ensuring that the gap between the tips of the nozzles is precisely within a predetermined value.

The purpose of the present invention is to solve the above-mentioned problems, and to draw a paste of a predetermined height with high precision in the center of the glaze part on a substrate for a thermal head (resistance paste for a thermal head).
T! The purpose is to provide a picture mounting W.

[Means to solve the problem]

The above purpose is to provide means for fixing the substrate on the XYI doublet driven by an actuator, and
The force applied to the nozzle is the displacement sensor f6 set for measuring the height of the substrate, the means for keeping the paste temperature constant, the means for pressurizing the paste, and the force applied to the nozzle. This is achieved by comprising a syringe having means for dispensing and means for closing the syringe with an actuator.

[Effect]

By measuring the substrate fixed on the XY# table with a 2M displacement sensor, the position and direction of the glaze part is detected, and from this value, using the X# table, the center of the glaze part is set relative to the nozzle. Perform all alignments. Then, using the remaining centimeters and the means for detecting the force provided on the syringe, the distance between the nozzle tip and the substrate is adjusted to a predetermined distance, and the distance between the substrate and the substrate is adjusted using the Y table. While moving, measure the height of the board using this displacement centimeter, adjust the nozzle height to the irregularities of the board based on this signal, maintain the distance between the board and the nozzle tip at a predetermined value, and apply the paste. . By such an operation, it is possible to accurately apply paste to a predetermined height at the center of the glaze portion.

〔Example〕

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

In FIG. 1, 1 is a pedestal, and a Y base 2 is fixed on the pedestal 1. Y pace 2 has guide rail 6
A Y table 6 is attached which is guided by a pulse motor 4 and can be driven in the Y direction via a ball screw 5. Mounted on the Y table 6 is an X table 10 which is guided by a guide rail 7 and can be driven by a pulse motor 8 via a ball screw 9 in the X direction. On the X table 10, a pulse motor 11
A table 12 that rotates by a slight opening is attached.

On the θ table 12, there is a substrate chuck 14 for fixing the ceramic substrate 16 l)! , 1 rectangle. Further, a bracket 15 is fixed on the pedestal 1,
Displacement sensors f16, 17, and 18 for detecting the height above the board 16 are fixed to the bracket 15 at predetermined positions. Furthermore, a syringe 2° for applying resistance paste is attached to the bracket 15 and is driven by a pulse motor 19 to the upper blade.

FIG. 2 shows the sensor 1 attached to the bracket 15.
8 and syringe 20 are shown. A nozzle 21 is fixed to the tip of the syringe 2°. Also, syringe 2
0 is fixed to the bracket 22, and the bracket 22
is held by a guide rail 23 so as to be vertically movable. A ball screw 250 and a nact 24 for vertically driving the bracket 22 are fixed to the bracket 22, and the ball screw 26 is rotated by a pulse motor 19.

FIG. 6 shows a cross-sectional view of the syringe 20. Syringe 20
is composed of a tip portion 24, a paste holding portion 25, and a syringe shaft 26. The tip portion 24 is screwed and fixed to the paste holding portion 25 in a fixed manner. Further, the paste holding portion 25 is also screwed and fixed to the syringe shaft 26 so as to be removable.

The reason for this configuration is to replenish the paste 32 to the syringe 20 and to maintain the nozzle 24 to prevent paste clogging.

The syringe shaft 26 is held by a linear ball bush 28 fixed to the syringe block 27 so as to be able to move vertically. Further, a collar 29 is provided at the upper end of the syringe shaft 26, and a compression spring 60 between the syringe block 27 and the collar 29 causes the upper surface of the collar 29 to be pressed against a load cell 61 fixed to the syringe block 27. It is being Therefore, the force applied to the tip of the tip portion 24 is measured by the load cell 51. Here, the syringe block 27 is fixed to the bract 22. In addition, the 7-ring shaft 26VC is provided with a pressurizing port 66 that applies air pressure in order to discharge the paste 52 inside the syringe from the nozzle tip, and the tube 3
Air at a predetermined pressure is applied through 4. The paste holding section 25 is provided with a heat preservation chamber 65, and the heat preservation chamber 35
For precise control of a given temperature (controlled liquid or liquid).

Gas is flowed through a tube 38 connected to an inlet 66 and an outlet 37. This is because the viscosity of the paste 32 is greatly affected by the paste temperature.
This is to keep the temperature of the paste constant and to reduce changes in viscosity.

With the above configuration, the operation of the non-embodiment will be explained next.

First, the conditions for applying the resistive paste on the thermal head will be described. FIG. 4 shows the ceramic substrate 13 constituting the thermal head. The heat generating portion of the thermal head is a paste 62 applied to the raised glaze portion 40 on the ceramic substrate 16.

FIG. 5 shows an enlarged view of part A in FIG. 4. @W of the applied paste 32 is approximately 50011 m, and the height hp is approximately 20
It is μm. Here, a problem in terms of the performance of the thermal head is the variation in resistance value over the coating length. That is, it is necessary to suppress variations in the applied cross-sectional area of the resistance paste in the longitudinal direction. Further, the application position of the paste 32 is the center 4 of the raised glaze 40.
It should be applied around 1 and 1.

Furthermore, since the viscosity of the paste 52 is very high, as shown in FIG.
When the paste 32 is discharged and applied with a gap Δh (10 to 150 μm) relative to 6, the nozzle height and paste application cross-sectional area are proportional to each other in the small gap range (10 to 70 μm), as shown in Figure 7. do.

In this graph, for example, if the nozzle height jll is 20μ
In the case of m, if the nozzle height fluctuates by ±2 μm, the cross-sectional area of the paste fluctuates by about ±7% centering on the case where the nozzle height is 20 μm17). In terms of product performance, this variation value is -
The difference in the height of the ceramic substrate 15 and nozzle 21 while drawing the actual paste must be kept within 2.8.71 m. be.

Henceforth, in this example, the operation flow shown in Fig. 8 was used to perform the operation to satisfy the above-mentioned pace and application conditions.
I will explain.

First, the ceramic substrate 16 is sectioned onto the substrate chuck 14, and is positioned and fixed. (Positioning and fixing means are not shown) Here, the ceramic substrate is positioned by pressing the side surfaces 50 and 51 of the ceramic substrate 13 against predetermined positions of the substrate chuck. Here, it is considered that the glaze 40 on the ceramic substrate 13 is not formed sufficiently parallel to the side surface 51 and is inclined by θ degrees (approximately ±15 degrees). Therefore, first, the inclination of the glaze 40 must be corrected to make it parallel to the moving direction of the Y table 6 (the paste application direction).

Furthermore, with the ceramic substrate 13 positioned, the measurement points of the upper displacement inch 16 and 17 are 52 and 53. A straight line d connecting the measurement points 52 and 53 is parallel to the moving direction of the Y table 6, and the measurement point of the displacement sensor f18 and the tip of the nozzle 21 are located on the extension of this d line.

Next, from the displacement sensor f16, 17 K, the ceramic substrate 1
While measuring on lines e and f, the position of the glaze 40 on lines e and f is measured by moving the X table backward and scanning the measurement points of displacement sensors f16 and f17.

FIG. 10 shows the signals of the displacement sensors f16 and f17. In this graph, the horizontal axis represents the number of pulses when moving the X stage. Yf-Movement direction of pull 6 and glaze 4
To correct the slope I of 0, K is the displacement cm 16, 17
It is necessary to find the glaze position in the signal. The distance 1 between this i- and lines e and f
1 (set value) from K -= tan (1, I/1.
Find - from the relationship + ), and use this value to create Table 1.
2, the angle of the glaze 40 can be corrected.

Using the block diagram of FIG. 11, a concrete glaze 40
We will explain how to correct the angle.

First, the signals from the displacement sensors 16 and 17 are input to the comparators 60 and 61K, and are set to a set value 62.

When the displacement becomes larger than the set value 62, the comparator 6
0.61 is easy memo! Outputs a signal at +65.64. Here, the set value is set slightly higher than the surface of the ceramic substrate 15 other than the glaze 40. The latch memories 65 and 64 count the clock pulses from the pulse motor controller 65 that controls the movement of the X table 10 using the counter 66 based on the signals from the comparators 60 and 61. , when reversing is subtracted). That is, the latch memory 65.64 has line e
, f in the X direction of the starting point of the glaze 40 is stored as a counter value of 67.68. next,
By inputting the values of the latch memories 63 and 64 to the subtracter 69, the number of pulse motor drive pulses in the X direction corresponding to h can be obtained. Based on this value, 2
Using the set value 71 of 1, the number of pulses to be applied to the pulse motor 11 for rotating the I table, which is necessary for angle correction, is calculated. Then, by rotating the θ table 10, the glaze 400 angle is corrected using this value.

Next, in order to align the center 41 of the glaze 40 with the paste application position, the measurement points 52 of the displacement sensors 16 and 17 must be aligned with the center 41 of the glaze 40. For this purpose, next, the ceramic substrate 13 is advanced and the displacement sensor 16 measures the line e once again. At this time, the address of the starting point 73 of the glaze 40 is stored in the latch memory 63. The latch memory 74 stores an address 68 of the end point of the glaze 40. Therefore, the center position of the glaze 40 can be obtained by inputting the addresses of the latch memories 74 and 63 to the adder, further inputting them to the divider, and pressing the divide by 2 button. Input this value to the CPU 70, compare it with the value of the counter 66, and move the X table until the value of the counter 66 becomes equal to the address of the center of gravity value. From K, the center of the glaze 40 and the measurement point of the displacement sensor f16 can be matched.

Once the center 41 of the glaze 40 and the measurement point of the displacement sensor f16 are aligned, the Y table 6 is advanced until the second point of the substrate chuck 14 is aligned with the measurement point of the displacement sensor f18. Here, using FIGS. 12 and 15, we will explain how to position the nozzle tip at a height of 20 μm with respect to the top surface of the ceramic substrate 15, and how to position the nozzle tip with respect to the top surface of the ceramic substrate 13. A method of applying the paste while maintaining a height of 20μ will be explained.

FIG. 12(a) shows a state where one point on the substrate chuck 14 and the measurement point of the displacement sensor 18 are aligned. At this time, K
The height of one point is measured by displacement sensor f18, and this value is
K resect. Then, this value is read by a counter (1) 70 and placed in a shift register 71. Here, the number of words in the shift register 71 is 9, assuming that the distance from the displacement centimeter measurement point to the nozzle tip is 12 (set value).
This is the value obtained by dividing this 22 by the feed rate per pulse of the pulse motor for Y table feed. For example, f2=10. −
If the feed amount per pulse is 1 μ fathom, then W:
It becomes 1000#. Furthermore, the data in this shift register 71 is stored in the Y table feed pulse motor controller 7.
Shift in synchronization with the second clock cycle.

Next, as shown in FIG. 12(b) K, the Y table 6 is
Send to 22nd. Then, the Kt point and the position of the nozzle 21 coincide. At this time, the measurement point of the displacement sensor +18 coincides with the paste application start point 2 on the ceramic substrate 15. (The distance between the two points from point K+ is 22.) Now, lower the syringe 20 and set the nozzle tip at one point Km.
Teru. When the tip of the nozzle hits one point, force is applied to the load cell 51, and the value of the load cell 31 is amplified by the dynamic strain meter 75 and input to the comparator 74. The comparator 74 has a set value for the load applied to the load cell 51, which is used as a threshold value, and when this value is exceeded, the controller
The value of the counter (2) 75 is reset from the counter (2) 74.

The counter F2) 75 receives a clock signal of a pulse motor controller 76 for raising and lowering the syringe 20. Therefore, when the nozzle tip hits point K1, the value inside the counter is set to 9 and becomes 0.

At this time, displacement sensor +18 measures the height of point K2, counter (1) 70 contains the height of point K2, and this value is also stored in the first register of shift resin tough 1. Sent. In this state, C is stored in the shift register 21.
A shift command is given from the PTJ77 to shift the nine direction data. Then, the value of the flatness at point K2 is entered into the adder 78 and added to the set value 411 (height between the substrate and the nozzle). This output H and the counter (2
) internal data (distance fi between the nozzle and the substrate) H is calculated by the subtractor 79 as Δx = H - H, and then the CPU
77, the rotation direction and the value of the number of pulses (1) xi) are output to the pulse motor controller 76 according to the sign of 'CΔX. From this K, the nozzle tip position is positioned at a height of Δh from the height of point K2. In this state, the X table 6 is fed while measuring the surface of the ceramic substrate 130 using the displacement sensor fi8VC, and when the feed amount reaches A2, paste discharging is started. At this time, the shift command for the shift register 71 is based on a clock signal from the Y table controller 72. By applying pressure in this way,
The paste can be applied while the nozzle height is always maintained at a height of 4h from the surface of the ceramic substrate 130.

〔Effect of the invention〕

As described above, according to the cleaning method of the present invention, the paste can be accurately applied to the center of the glaze portion at a predetermined height.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is a partially enlarged perspective view of Fig. 1, Fig. 3 is a sectional view of a syringe, and Fig. 4 is a perspective view of a ceramic substrate coated with resistance paste. Figure 5 is an enlarged view of section A in Figure 4. Figure 6 is a cross-sectional view showing the state of paste discharge, Figure 7 is a relationship diagram between the nozzle height and the cross-sectional area of the applied paste, and Figure 8 is a diagram showing the relationship between the nozzle height and the applied paste cross-sectional area.
The figure is an operation flow diagram of this embodiment, and Fig. 9 shows a displacement of 16 centimeters.
, 17' and the fixed ceramic substrate! A perspective view showing the relationship, FIG. 10 is an explanatory diagram showing the output signal from the displacement sensor f16.17, FIG. 11 is a control block diagram for ceramic substrate alignment, FIG. 12 is an explanatory diagram of the operation for nozzle height adjustment, FIG. 13 is a control block diagram for nozzle height adjustment. 6...Y table 10...X table, 12...
-Tape/l/, 16, 17.18...displacement sensor? ,
20...Syringe, 21...Nozzle, 51...
Load cell, 32... Paste, 15... Ceramic substrate, 40... Glaze portion.

Claims (1)

[Claims] 1. A method for forming a resistor of a thermal head used for printing, etc. by discharging paste from the tip of a nozzle and applying it, a means for fixing a ceramic substrate having a direct raised portion on which a resistor is to be formed; A means for driving this fixing means in the XY directions by an actuator, three sets of displacement sensors for measuring the substrate height, a means for keeping the paste temperature constant, a means for pressurizing the paste, and a force applied to the nozzle. a syringe having means for detecting;
1. A resistance paste application device for a thermal head, comprising means for moving a syringe up and down by an actuator.