JPH0999268A - Liquid applying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to surely control the height of nozzle to an existing installation, etc., with high accuracy by interrupting the measurement by height sensors only during the time a liquid applying nozzle passes at least one point of the moving locus of the liquid applying nozzle with respect to a work. SOLUTION: The liquid applying nozzle is first lowered onto the point 16a in order to apply the liquid on the surface of the work W according to the prescribed locus 14. For example, a Z-axis actuator 7 is then controlled by an operation control section 13 of a control means 12 in accordance with the detection signals of the height sensors 11 to control the height of the liquid applying nozzle. In succession, the liquid applying nozzle is moved on the locus 14 while the liquid is applied on the work. The measurement operation of the height sensors 11 is interrupted by the operation control section 13 and the liquid applying nozzle is relatively moved while the height is maintained constant when the liquid applying nozzle arrives at the position 16c just before the existing installation 15. The measurement operation of the height sensors 11 is thereafter resumed when the liquid applying nozzle arrives at the pass point 16d of the existing installation 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for applying a liquid to a surface of a work while controlling the height of a liquid application nozzle, such as an electronic material in the form of liquid, paste or cream, adhesive, etc. Steady state of the liquid material, which is not affected by the warp or swell of itself on the work consisting of printed circuit board, ceramic plate, glass plate, etc. It enables coating.

[0002]

2. Description of the Related Art When a liquid material discharged from a liquid coating nozzle is constantly or intermittently coated on a work surface continuously or intermittently, the work is warped and the distance between the tip of the coating nozzle and the work surface is small. If it changes, the amount of coating liquid, the coating shape, etc. become unstable. Therefore, as disclosed in JP-A-2-52742, the interval between the tip of the coating nozzle and the work surface is adjusted within a predetermined range. However, it has been proposed to apply a liquid material. However, in this proposed technique, when there is an already disposed object, an existing coating film, etc. on the work surface, the height of the coating nozzle is not the work surface,
Since the amount of the coating liquid, the coating shape, and the like are changed by adjusting the surface of the already-arranged object as a reference, as already disclosed in JP-A-6-114313. A liquid application method has been proposed in which the height of the application nozzle is maintained at a value immediately before the measured value exceeds the threshold while the sensor measured value for an object or the like exceeds the threshold.

[0003]

However, in the latter prior art, since the height of the coating nozzle is controlled by the feedback control of the actual measurement value of the sensor, there is a recent demand for a higher working speed. If the relative speed between the workpiece and the coating nozzle is increased, due to the time lag of the feedback control and the like, for example, only after the coating nozzle reaches the middle position of the already installed object,
The nozzle height threshold control is performed, and as a result, there is an inconvenience that the nozzle is unnecessarily raised above the work surface. This is more serious when the relative speed is further increased, and there is also a problem that as the relative speed increases, it becomes gradually difficult to distinguish between the work warp and the like, and the already-arranged objects. On the other hand, when a large number of discontinuous liquid coatings are applied to the surface of the work using the above-mentioned conventional technique, intermittent height measurement is performed for each coating position, and the height of the coating nozzle is determined based on the measurement result. Since feedback control was necessary, there was a limit to improving work efficiency.

The present invention has been made as a result of studies aimed at solving such problems of the prior art, and the object of the present invention is to prevent warping, undulation, etc. of the work itself. Not only can it be handled with high accuracy, but if there is an already installed object, existing coating film, etc. on the surface of the work, the vertical displacement of the liquid application nozzle will not occur at the existing position of the already installed object, etc. A liquid coating method that can sufficiently prevent fluctuations in the coating liquid amount, coating shape, etc. during high-speed work by accurately interrupting
It is another object of the present invention to provide a liquid coating method which can enhance the efficiency of height measurement particularly when discontinuously coating a liquid on a large number of locations and greatly improve the work efficiency.

[0005]

According to the liquid application method of the present invention, at the time of applying a liquid to the surface of a work, in particular, at least in a pre-programmed relative movement locus of the liquid application nozzle in the horizontal plane with respect to the work. In one place, in other words, in the place where there is an existing object, etc., until the liquid application nozzle finishes passing therethrough, this is also based on the program in advance, and the measurement by the height sensor is interrupted and the actuator is stopped. After the inoperative state, and after passing through the specific portion, the height measurement is restarted and the actuator is reactivated by reversing the signal or the like.

According to another liquid application method of the present invention, in particular, the surface of the work is divided into a plurality of liquid application areas, and prior to application of the liquid to each of the liquid application areas, the liquid application area in the liquid application areas is divided. At least at one point, measure the height of the liquid application nozzle from the surface of the work, correct the height of the liquid application nozzle according to the measurement result, and keep the corrected nozzle height. The entire liquid application area is applied.

In this latter method, the height of the liquid application nozzle is preferably measured near the center of each liquid application area, and preferably the height is measured in each liquid application area. Perform at two or more locations.

[0008]

According to the former method of the present invention, at the time of programming the relative movement locus of the liquid application nozzle, at what position and over what distance in the locus the already-arranged object and the like already exist. Therefore, at each such location, by pre-programming that height measurement by the sensor is interrupted, regardless of the relative speed of the liquid application nozzle and the work, When the coating nozzle reaches the existing area of the already-arranged object, the ascending / descending movement of the coating nozzle is surely stopped. Then, the height of the coating nozzle from the work surface is maintained at the time of stopping the lifting motion until it passes through the existing area of the already arranged object, so that the work surface, and by extension, The application of the liquid material to the surface of the already-arranged object or the like is performed without unnecessary vertical displacement of the liquid application nozzle with respect to the work surface regardless of the application speed. Therefore, when the work itself warps or swells, the coating nozzle can be displaced up and down with high accuracy to make the coating liquid amount, coating shape, etc. sufficiently steady, and the coating nozzle already installed. Compared with the prior art in which the height of the coating nozzle is adjusted until the middle position is reached, liquid coating is performed on the work surface as if there are no existing arrangements, etc. With this, it is possible to always perform accurate liquid application for the desired amount, shape, etc.

In the latter method of the present invention, the height of the liquid application nozzle from the surface of the work is measured at at least one representative position in each liquid application region where there is no existing object. Then, the height of the coating nozzle is corrected according to the measurement result, and the state after the correction is maintained,
By applying the liquid material to all positions in the liquid application area, especially when performing a large number of discontinuous liquid applications, the height of the application nozzle is measured and the height is adjusted for each application position. It is possible to greatly improve the work efficiency of the liquid application work and to sufficiently speed up the work, as compared with the conventional technique for performing the above.

By the way, in this method, when the height of the liquid coating nozzle is measured near the center of the liquid coating area, especially when the height is measured only at one location, a typical coating area in the coating area is obtained. In other words, there is a high possibility that the average nozzle height can be obtained, and therefore, the nozzle height accuracy for each coating position in the coating region can be maintained sufficiently high.

Further, when the height is measured at two or more positions in the coating area and the nozzle height is corrected based on the average value thereof, the height accuracy is further improved. You can

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic line front view showing an embodiment of the present invention, in which 1 denotes a base frame. Here, a Y-axis actuator 2 is attached to the base frame 1, and the Y-axis actuator 2 can drive a Y-axis base 3 arranged on the base frame in a direction orthogonal to the plane of the drawing. The X-axis actuator 4 mounted on the device 3 drives the X-axis base 5 arranged on the Y-axis base in the lateral direction of the drawing. here,
On the X-axis base, for example, a plate-shaped work W can be positioned and mounted by negative pressure suction, magnetic suction, flapping, or the like.

Further, here, a Z-axis actuator 7, for example, a pulse motor is attached to the Z-axis frame 6, and by this pulse motor, the Z-axis base 8 and, by extension, the liquid application nozzle 10 attached together with the syringe 9 are required. If possible, move up and down. A height sensor 11 that is displaced up and down together with the coating nozzle 10 is attached to the Z-axis base 8, which is a syringe 9 as shown in the figure, and the height sensor 11 allows the tip of the coating nozzle 10 to move from the surface of the workpiece W. The height is preferably measured at a position slightly ahead of the application nozzle 10. That is, if a slight time lag in the elevation control of the coating nozzle 10 is taken into consideration, the nozzle 10
By measuring at a position slightly ahead of, it is possible to effectively absorb the influence of the time lag.

By the way, each actuator 2, 4, 7
Is connected to the control means 12, and is operated at a predetermined speed and for a predetermined time based on a command from the control means 12, and the height sensor 11 is also connected to the control means 12, and the height sensor While inputting the measurement result of, the height measurement stop and restart signals are received from the input.

FIG. 2 is a schematic front view illustrating another embodiment of the device. In this example, two Z-axis frames 6 are provided.
By attaching Z-axis actuators 7a, 7b, Z-axis bases 8a, 8b and syringes 9a, 9b, those syringes
The respective liquid application nozzles 10a, 10b and the height sensors 11a, 11b provided in 9a, 9b can be operated independently of each other, and here again, the respective actuators 2, 4, 7a, 7b Height sensors 11a, 11b are connected to the control means 12.

FIG. 3 shows the control means 12 of the device described above,
Among them, the operation control unit 13 of the Z-axis actuators 7, 7a, 7b
It is a block diagram showing the action of. Here, in this control means 12, in addition to the relative movement loci of the liquid application nozzles 10, 10a, 10b, the location of the sharp uneven portion such as an already-arranged object in the movement locus is programmed in advance. , Because of this, Y
Each of the axis actuator 2 and the X-axis actuator 4 is based on a command from the control means 12 and the Y-axis base 3
Each of the X-axis base 5 and the work W on the X-axis base is displaced in the horizontal plane according to the programmed movement locus, and the operation control unit 13 causes the relative movement of the coating nozzles 10, 10a, 10b. Inside, when it reaches the location of the programmed pre-arrangement etc., the height sensor
A measurement interruption signal is output to 11, 11a, 11b, and as a result, the Z-axis actuators 7, 7a, 7b are made inoperative, and the heights of the liquid application nozzles 10, 10a, 10b are set to those of the already installed objects. Maintain the height before reaching the existing location. On the other hand, the operation control unit 13, when the coating nozzles 10, 10a, 10b pass through the existing location of the programmed already installed object,
A measurement restart signal is output to the height sensors 11, 11a, 11b, and thereafter, the operation of the Z-axis actuators 7, 7a, 7b is controlled based on the measurement results from the height sensors 11, 11a, 11b.

The operation control here is based on, for example, the height of the liquid application nozzles 10, 10a, 10b from the work surface, which is determined in accordance with the conditions such as the liquid application width and the application amount. The measurement result by the height sensors 11, 11a, 11b is the reference value, more accurately, the operation control unit 13 determines whether the measurement value is larger or smaller than a certain area around the reference value. If the judgment result is biased to either the large or small side due to swell, etc.,
A correction signal is output from the operation control unit 13 to the Z-axis actuators 7, 7a, 7b to cause the operation of the Z-axis actuators 7, 7a, 7b, and thus the liquid application nozzles 10, 10a, 10b.
Is performed by matching or approaching the height of the reference value with the reference value, and as a result, sufficiently steady application of the liquid is realized.

FIG. 4 shows this on the surface of the work W,
FIG. 6 is a plan view showing a case where a liquid is applied according to a pre-programmed trajectory 14, and FIG. 5 is a flowchart in that case. It should be noted that reference numeral 15 in FIG. 4 denotes an existing object existing in the trajectory 14.

Here, for example, points 16a to 16b in the figure
When applying clockwise to the liquid application nozzle 10,
Lower 10a and 10b above point 16a. In this case,
When the coating nozzles 10, 10a, 10b are within the height control range,
The measurement results of the height sensors 11, 11a, 11b are input to the operation control unit 13, and the operation control unit 13 outputs a correction signal corresponding to the measurement result to the Z-axis actuators 7, 7a, 7b, and the actuator 7 , 7a, 7b are actuated to bring the application nozzles 10, 10a, 10b to or near the reference height. After that, the application of the liquid from the liquid application nozzles 10, 10a, 10b and the relative movement of the application nozzles 10, 10a, 10b with respect to the work W are started, and the application nozzles 10, 10a, 10a,
10b is moved on the locus 14 under the operation of the height sensors 11, 11a, 11b. And the coating nozzles 10, 10a, 10b
However, when it reaches the front position 16c of the already installed object 15, the height sensors 11, 11 are supplied from the operation control unit 13 based on the input program.
A measurement interruption signal is output to a and 11b, and those sensors 1
1, 11a, 11b interrupt the height measurement. Therefore, after this interruption, the Z axis actuators 7, 7a, 7b from the operation control unit 13
There is no correction signal output to the coating nozzles 10, and the heights of the coating nozzles 10, 10a, 10b are maintained as they were when the height measurement was interrupted.

In this way, when the coating nozzles 10, 10a, 10b relatively move while maintaining the nozzle height constant and reach the passing point 16d of the already installed object 15, the operation control unit 13 A measurement restart signal is output to the height sensors 11, 11a, 11b,
After that, a correction signal is output from the operation measuring unit 13 to the Z-axis actuators 7, 7a, 7b according to the measurement results of the height sensors 11, 11a, 11b, the nozzle height is corrected, and When the coating nozzles 10, 10a, 10b reach the point 16b, the coating of the liquid is stopped and the coating nozzles 10, 10a, 10b are moved up to their original positions, and the series of coating operations is completed.

In the case of applying the liquid as described above, regardless of the relative moving speed of the application nozzles 10, 10a, 10b, the application nozzle 1 can be used in the existing portion 15 regardless of the relative movement speed.
The vertical displacement of 0, 10a, 10b can be stopped accurately without a time lag, so compared with the conventional technology that feedback-controls the nozzle height based on the measurement result of the sensor,
It is possible to bring much higher accuracy in terms of coating amount, shape, etc.

FIG. 6 is a plan view illustrating another method for applying a liquid. Here, first, a plurality of liquid application areas 21 to 26 are partitioned on the surface of the work W, and then the height sensor
Under the action of 11, 11a, 11b, the height of the coating nozzles 10, 10a, 10b from the work surface at each of the representative measurement points 21a to 26a located in the respective coating areas, that is, substantially in the center thereof in the figure. In addition to measuring, the operation control unit 13 calculates the correction value of the nozzle height for the representative measurement points 21a to 26a, for example, the increase / decrease amount with respect to the reference descent amount of the coating nozzles 10, 10a, 10b based on the measurement results. And then remember. After that, the application nozzles 10, 10a, and 10b in the raised posture are moved to the area 21
The liquid is applied to the application point 21b by taking the correction value for the representative measurement point 21a into consideration, the liquid is applied to the application point 21b, and then the nozzles 10, 10a, 10b are raised. After that, the same descending, coating, and ascending steps are sequentially repeated for all other coating points 21c to 21i in the area 21.

By the way, the nozzle descent amount in this case is a constant value obtained by adding or subtracting the correction increasing / decreasing amount at the representative measurement point 21a to the preset reference descent amount at all the coating points 21b to 21i. After finishing the coating in one area 21 in this way, the nozzle is lowered to the coating point 22b in the adjacent area 22 in consideration of the correction value for the representative measurement point 22a. This is repeated for all the other application points 22c to 22i, and these operations are performed in all the other areas 23 to 26 to end the series of application operations. In the above description, the height measurement of all the representative measurement points 21a to 26a and the coating work is started after performing the correction value calculation in advance, but the height measurement and the coating are performed for each area. The work and the work can be performed sequentially.

When the liquid is applied as described above, it is not necessary to measure the height and correct the height at each point, so that the working efficiency can be greatly improved.

[0025]

According to the first method of the present invention, the interruption position information of the height measurement is pre-programmed and inputted, regardless of the relative movement speed of the liquid application nozzle, the existing object is not provided. It is possible to reliably control the nozzle height with respect to the workpieces with high accuracy, so that the coating work can be performed as if there are no existing objects on the surface of the workpiece, and the amount of liquid applied, the shape, etc. can be increased. It can be controlled with precision. Further, according to the second method, since it is sufficient to measure the typical nozzle height of each of the plurality of liquid application areas, the work efficiency can be greatly improved. In this latter method, when the height is measured near the center of the liquid application area, the finishing accuracy can be further improved. This means that at two or more positions within the application area. It is more remarkable when the height is measured.

[Brief description of drawings]

FIG. 1 is a schematic front view illustrating an embodiment of the present invention.

FIG. 2 is a schematic front view illustrating another embodiment of the present invention.

FIG. 3 is a block diagram showing the operation of the control means.

FIG. 4 is an explanatory diagram of an invented method.

5 is a flow chart of the method shown in FIG.

FIG. 6 is an explanatory diagram of another inventive method.

[Explanation of symbols]

 1 base frame 2 Y-axis actuator 3 Y-axis base 4 X-axis actuator 5 X-axis base 6 Z-axis frame 7, 7a, 7b Z-axis actuator 8, 8a, 8b Z-axis base 9, 9a, 9b Syringe 10, 10a, 10b Liquid application nozzle 11, 11a, 11b Height sensor 12 Control means 13 Operation control unit 14 Locus 15 Existing object 16a, 16b Point 16c Front position 16d Pass point 21 to 26 Liquid application area 21a to 26a Typical measurement point 21b to 21i Dispensing point W work

Claims (4)

[Claims] 1. A table on which a work is positioned and displaceable in a horizontal plane, a liquid application nozzle which is displaced up and down with respect to the table, and a height for measuring a distance from the tip of the liquid application nozzle to the surface of the work. Sensor and
Based on the measurement result of the height sensor, a liquid application device comprising a control means for outputting an up-and-down displacement signal of the liquid application nozzle, and an actuator for up-and-down displacement of the liquid application nozzle according to the signal from the control means, When applying liquid to the surface of the work, at least one position in the preset relative movement locus of the liquid application nozzle in the horizontal plane with respect to the work, until the liquid application nozzle passes the height sensor. A method for applying liquid, characterized in that the actuator is made inoperative by interrupting the measurement by. 2. A table for positioning and placing a work, which is displaceable in a horizontal plane, a liquid application nozzle which is displaced up and down with respect to the table, and a height for measuring the distance from the tip of the liquid application nozzle to the surface of the work. Sensor and
Based on the measurement result of the height sensor, a liquid application device comprising a control means for outputting an up-and-down displacement signal of the liquid application nozzle, and an actuator for up-and-down displacement of the liquid application nozzle according to the signal from the control means, When applying the liquid to the work surface, the work surface is divided into a plurality of liquid application areas, and prior to the application of the liquid to each of the liquid application areas, at least one position in the liquid application area, of the liquid application nozzle, The height from the work surface is measured, the height of the liquid application nozzle is corrected according to the measurement result, and the liquid application nozzle height is maintained while the liquid application nozzle height is maintained. A method of applying a liquid, which comprises: 3. The liquid coating method according to claim 2, wherein the height of the liquid coating nozzle from the surface of the work is measured near the center of each liquid coating region. 4. The liquid coating method according to claim 2, wherein the height of the liquid coating nozzle from the surface of the work is measured at two or more positions in each liquid coating region.