JPH02268860A - High-viscosity fluid applying device - Google Patents

Abstract

PURPOSE:To prevent the damage of an object with the applying device of an adhesive agent, etc., to printed circuit boards, etc., by detecting the relative positions of an applying means and the object and controlling the clearance so as to have the side adequate for the application. CONSTITUTION:A height position detector 166 provided in an applying unit 24 is disposed with a laser light emitting body 100 in the direction inclining by theta deg. with the axial line of an applying nozzle 72 and emits laser light when an X-axis, Y-axis table moves a printed circuit board 168 so as to position the coating point thereof to right under the applying nozzle 72. The reflection pulses thereof are detected by a detecting element 104. The distance is determined by an arithmetic unit and the height of the applying nozzle 72 from the circuit board 168 is computed from this distance and the angle theta of inclination. The moving means is controlled in accordance with this height in such a manner that the clearance attains the adequate height. High viscosity fluid, such as adhesive agent or cream solder, is then applied from the applying nozzle 72. The application is thus efficiently executed without damaging the object.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an apparatus for applying a highly viscous fluid such as an adhesive or creamy solder to a material to be coated such as a printed circuit board, and in particular relates to ensuring coating clearance. be.

BACKGROUND OF THE INVENTION Apparatus for applying highly viscous fluids come in various forms. For example, in the coating device described in Japanese Patent Application Laid-Open No. 59-152689, a high viscosity fluid contained in a syringe is injected in predetermined amounts by supplying compressed air; In the coating device described in 1., a high viscosity fluid contained in a closed container is forced out by a pin and directly coated on a printed circuit board.

As described above, the highly viscous fluid can be applied in various ways, but in any case, it is common to provide a certain clearance between the application means such as a syringe and the object during application. This is because the highly viscous fluid cannot be applied satisfactorily to the object if the application means is in close contact with the object. Therefore, in the coating apparatus described in JP-A-1-56165, the coating means is provided with a stopper that extends toward the object, and the stopper is brought into contact with the object, so that there is a constant distance between the application means and the object. clearance.

Problems to be Solved by the Invention However, if the stopper is brought into contact with an object, there is a risk that the object may be damaged due to the impact caused by the contact. In addition, since the size of the clearance varies depending on the type of high viscosity fluid, viscosity, amount of application, etc., the stopper should be adjustable in position and the position should be adjusted each time the clearance size changes, or multiple stoppers should be used. It is necessary to provide different types and to replace each time the clearance is changed, and the adjustment or replacement work is troublesome, which impedes improvement in coating efficiency and increases the cost of the device.

The present invention has been made with the object of providing a high viscosity fluid coating device that can set the clearance between the coating means and the object to a size suitable for coating without using a stopper. .

Means for Solving the Problems In order to solve the above problems, the high viscosity fluid application device according to the present invention has the following features: (a) from a position separated by a certain clearance from the surface of the object; (b) moving means for moving at least one of the application means and the object to move them closer to or away from each other; (d) measuring means for measuring the position in the approach/separation direction;
and a movement control means for controlling the movement means so that the clearance has a size suitable for coating based on the measurement result of the measurement means.

The action and effect measuring means is configured to measure the position of the object in a non-contact manner using light, ultrasonic waves, or the like. For example, a light emitter emits light from a fixed position onto an object, the reflected light is received by a photoreceptor, and the height is detected based on the difference in the position of the light incident on the photoreceptor due to the difference in the position of the object. can do. It is also possible to apply ultrasonic waves to an object using an ultrasonic oscillator and detect the position based on the time it takes for the reflected waves to return to the oscillator. If the position of the object is known in this way, it is possible to find a position that is separated from the object by a clearance suitable for coating, and by moving the applicator and the object relative to that position, the coating can be applied without using a stopper. It is possible to position the means and the target object at a suitable position for coating, it is possible to apply high viscosity fluid without damaging the target object, and there is no need to adjust or replace the stopper position. The effects of cost reduction and coating efficiency improvement can be obtained.

EXAMPLE Hereinafter, a case will be described in detail based on the drawings, taking as an example a case in which the present invention is applied to an apparatus for applying adhesive to a location where an electronic component is fixed on a printed circuit board.

FIG. 2 is a diagram showing the entire mechanical section of the adhesive applicator,
In the figure, 10 is an X-axis table that moves in the X-axis direction within a horizontal plane. The X-axis table 10 is connected to a servo motor 11 (sixth
(see figure). Further, on the X-axis table 10, a Y-axis table 12 is provided which moves in a Y-axis direction perpendicular to the X-axis direction in a horizontal plane. The Y-axis table 12 is moved by having a nut 14 fixed thereon screwed onto a ball screw 16, and the ball screw 16 being rotated by a servo motor 18.

A pair of coating units 244 are attached to the side surfaces of the Y-axis table 12 parallel to the X-axis direction by brackets 26, respectively. The bracket 26 is the Y-axis table 12
The coating unit 24 is attached to the coating unit 24 so as to be movable up and down, and is raised and lowered by a lifting device 2 while holding the coating unit 24.

The bracket 26 is L-shaped as shown in FIG. 3, and the application unit 24 is attached to its horizontally extending arm 29, while the guide block 32 provided to the vertically extending arm 30 is attached to the Y-axis frame 12. It is slidably fitted into a guide rail 34 provided in the. A block 36 is attached to the side surface of the Y-axis table 12 in a downwardly extending position.1. Guide rail 3 in front of it
4 is attached so as to extend in the vertical direction, and the bracket 26 is vertically raised and lowered at a position below the Y-axis table 12. The lifting device 28 includes a rack 42 , a gear train that is housed in a gear housing 44 and includes a plurality of gears, and a servo motor 46 . rack 42
As shown in FIG. 3, a rod 48 is connected to the lower end of the rod 48, one end of a plate 50 is fixed to the rod 48 with a nut 52, and a bracket 26 is fixed to the other end of the plate 50. There is. Therefore, when the servo motor 46 is activated and the rack 42 is moved by rotation of the gear train, the bracket 26 is raised and lowered,
The coating unit 24 is moved toward and away from the printed circuit board that is transported in a horizontal state. The lifting device 28 constitutes a moving means. The rising end of the rack 42 is defined by a stopper (not shown) and is detected by a photoelectric switch 54 provided on the gear housing 44, and the servo motor 46 is switched based on the detection signal.

The coating unit 24 includes a syringe 60 and a discharge head 6.
2 is attached to the arm portion 30 by a holder 64. This coating unit 24 is the same as the coating unit described in the above-mentioned Japanese Patent Laid-Open No. 1-56165, and will be briefly described.

The holder 64 has a sleeve 68 having a large-diameter gear 66 formed at one end thereof, and the sleeve 68 is fitted to the arm portion 30 so as to be rotatable but immovable in the axial direction. A cylindrical member (not shown) is fitted into the sleeve 68 so as to be immovable relative to each other and immovable in the axial direction, and the discharge head 62 is prevented from rotating at the lower end of the cylindrical member protruding from the arm portion 30.
It is fixed with a cap nut 70. This discharge head 6
2 is equipped with one nozzle 72. The large-diameter gear 66 is a small-diameter gear 74 (see FIG. 2) that is rotatably arranged around an axis extending in the vertical direction between the pair of coating units 24.
The small diameter gear 74 is engaged with the servo motor 7.
6, the sleeve 68 is rotated and the ejection head 62 is rotated.

When using a discharge head equipped with two nozzles to apply adhesive to two points at a time, the discharge head is rotated when it is necessary to change the alignment direction of the two discharge pipes. -ing

Further, a holding member 80 is fixed to the upper surface of the large-diameter gear 66, and the ° syringe 60 is removably attached thereto. The syringe 60 includes a bottomed cylindrical member 82 whose opening is closed by a cap 84, and a piston is fitted inside the cylindrical member 82 in an airtight and slidable manner. A hose 86 connected to a compressed air supply source (not shown) is connected to the cap 84 by a connecting fitting 88. An electromagnetic directional switching valve 90 (see FIG. 6) is provided in the middle of the hose 86, and by switching the switching valve 90, the syringe 60 is selectively communicated with the compressed air supply source and the atmosphere. When the syringe 60 is attached to the holding member 80, it is airtightly connected to the passage inside the cylindrical member, and when compressed air is supplied to the syringe 60, the piston is lowered and the adhesive is applied to the tube. A predetermined amount is ejected through a shaped member, a passage formed in the ejection head 62, and a nozzle 72.

As shown in FIG. 2, a height detection device 9 as a measuring means for detecting the height of the printed circuit board by means of a bracket 94 is provided on the arm portion 30 extending in the vertical direction of the bracket 26.
6 is attached and is configured to move up and down together with the coating unit 24. This height detection device 96 detects the position of the printed circuit board by shining a laser beam onto the printed circuit board, and as shown in FIG. The device includes a laser light emitting body 100 that emits laser light, a light receiving lens 102 that collects reflected light from a printed circuit board, and a detection element 104 that receives the light collected by the light receiving lens 102. The light receiving lens 102 and the detection element 104 are provided to be inclined with respect to the optical axis of the laser light emitted from the laser emitter 100. Further, as shown in FIG. 5, the detection element 104 has two layers formed on the front surface and an n layer on the back surface of a high-resistance silicon substrate 106, and electrodes 108 and 110 for signal extraction are formed on both ends of the substrate. It has been established. When light enters the detection element I04, a current proportional to the intensity of the light is generated, which passes through the two layers and is extracted from the electrodes 108 and 110. The two layers are uniform resistance layers, and the current extracted from the electrodes 108, 110 is inversely proportional to the distance from the light incident point to each electrode.

The incident position of the light changes as the height of the printed circuit board 112, that is, the position of the top surface of the printed circuit board 112 in the vertical direction changes, as shown in FIG. The unevenness on the upper surface of the printed circuit board 112 occurs in a range of approximately 1000 μm, and the detection element 104 is capable of detecting height changes of up to 2000 μm. The flatness detection device 96 has an arithmetic unit II4, and the output of the detection element 104 is supplied to the arithmetic unit 114, where it is converted into a vertical distance in units of μ and output. This conversion is printed circuit board 1
The reflected light from 12 is transmitted to the electrodes 108 and 11 of the detection element 104.
This is done so that the output value becomes 1000 μm when the light enters an intermediate position between 0 and 0. Further, the coating unit 24 has an output value of 100 from the calculation device 114 with respect to the height detection device 96.
When the diameter is 0 μm, the tip of the nozzle 72 touches the printed circuit board 11.
It is attached to the bracket 30 so as to be located 200,011 m from the top surface of 2.

Furthermore, as shown in FIG. 2, this adhesive application device includes:
A camera 126 that reads reference marks provided on the printed circuit board is mounted on the Y-axis table 12 at a position adjacent to the coating unit 24. The camera 126 is the holding tube 1
The reference mark is provided with a lens held by a lens 27, and a light projector 128 provided at the bottom of the lens illuminates the reference mark during photographing. The reflected light from the reference mark illuminated by the projector 128 enters the lens, and an image corresponding to the outer shape of the reference mark is formed on the solid-state image sensor of the camera 126, and the image is converted into a binary signal and output. be done. The adhesive application position is set based on the reference mark, and the reference mark is read prior to applying the adhesive. Based on the read result, the amount of movement of the table 10.12 is corrected, so that the application unit 24 can be moved to the adhesive application position on the printed circuit board 112 with high precision.

Although not shown, a printed circuit board positioning and supporting device is provided below the adhesive application device, and the printed circuit board 112 is transported by the loading device and is coated with adhesive while being positioned and supported by the positioning and supporting device. Coating is performed, and after coating, the material is transported to the next process by a delivery device.

The adhesive application device configured as described above is controlled by a control device 130 shown in FIG.

The control device 130 includes a CPU 132. ROM134゜RA
It is mainly a microcomputer having an M 136 and a bus 138. An input interface 140 connected to bus 138 includes input devices 142 . The calculation device 114 of the height detection device 96 and the like are connected. Input bag W142 is the type of printed circuit board to which adhesive is applied,
This is for inputting the adhesive application position, the number of adhesive application locations, the size of the clearance provided between the nozzle 72 and the printed circuit board 112 during application, etc.

An output interface 146 is also connected to the bus 138 and connects servo motor drive circuits 148, 150, 152, 1
54,156. Electromagnetic directional valve control circuit 158. A servo motor 11 for driving the X-axis table, a servo motor 18 for driving the Y-axis table, and each servo motor 46 for the two lifting devices 28 are connected via the camera drive circuit 160, respectively. Discharge head rotation servo motor 76, electromagnetic directional control valve 90° camera 126. A printed circuit board carry-in device, a 9-position fire support device, a carry-out device, etc. are connected.

Further, as shown in FIG. 7, the RAM 136 contains flags,
A counter 2 table movement information memory, coating clearance memory, coating location number memory, coating unit lowering amount memory, etc. are provided together with the work area. Furthermore, R.O.
The M134 stores an adhesive application program shown in the flowchart of FIG. 8, and the CPU 32 controls adhesive application according to this program. below,
Application of adhesive will be explained based on this flowchart.

Step SL (hereinafter abbreviated as SL) is performed at the same time as the power is turned on to the device. The same applies to other steps.

), clear the counter and turn off the flag.

After initial settings including returning the X-axis and Y-axis tables 10.12 to their original positions are performed, the input device 142 is activated in S2.
The input data is stored in a predetermined memory. Data specifying the position on the printed circuit board 112 where the adhesive is to be applied is stored in the table movement data memory, and the number of application points N is stored in the application point number memory. The size of the clearance is stored in the coating clearance memory. The adhesive application positions are stored in the order of application, and the count number of the counter specifies the application position data to be read. When this input is completed and input completion data is input, the determination result in S3 becomes YES, and the reference mark is read in S4. Next, in S5, the count number C of the counter is incremented by 1, and then table movement data specifying the first adhesive application position is read out in S6, and the movement data is corrected in S7. In this coating device, the height of the printed circuit board 112 is detected at each coating position prior to applying adhesive to the printed circuit board 112. Since the laser emitter 1 is installed at a position that is shifted vertically and horizontally, the laser emitter 1
The movement data is corrected so that 00 is located just above the application position. At S8, the X-axis table 10. After the Y-axis table 12 is moved according to the corrected movement data, it is determined in S9 whether or not the flag is ON, but this flag is set to OFF in the initial setting.
Since the FF is set, the determination is No, and in S10, the height detection device 96 detects that the output value of the calculation device 114 is 100.
After being lowered to 0 μm, the amount of descent of the coating unit 24 at the first coating position is calculated in 311. When the output value of the arithmetic unit 114 becomes 1000 μ, the coating unit 24 determines that the bottom surface of the nozzle 72 is 20 μm from the top surface of the first coating position of the printed circuit board 112.
Since it is located 00 μm above, 2000 μm is added to the descending distance of the coating unit 24 at this time (this distance is obtained by multiplying the number of pulses of the servo motor 46 by the moving distance per pulse), and the coating clearance is The subtracted value is the descending distance of the coating unit 24 when applying adhesive to the first coating position, and the descending amount of the coating unit is determined by dividing this descending distance by the moving distance per pulse. This value is a value for lowering the coating unit 24 from the upper end position defined by the stopper until a predetermined clearance is generated between the lower surface of the nozzle 72 and the upper surface of the printed circuit board 112, and is the amount by which the coating unit is lowered. stored in memory.

Note that by setting the height of the first coating position to 1000 μm, even if the coating position is the highest or the lowest of all the coating positions on the printed circuit board 112, Since the heights of the other coating positions do not differ by more than 1000 μm from the height of the first coating position, they are all detected as positive values. Hereinafter, the height detection device 96 has a detection value of 10 at the first application position.
The coating unit 24 is moved horizontally while maintaining the height of 00 μm, detects the height of the other coating position, and lowers the coating unit 24 at the other coating position based on the amount of descent at the first coating position. The amount is calculated.

After the flag is turned on in S12, it is determined in S13 whether the count number C of the counter is equal to or greater than the number N of coating positions. It is determined whether or not the nozzle descending amount has been set for all positions on the printed circuit board where adhesive is applied, but this determination is NO and the program execution returns to S5. In S5, the count number of the counter is set to 2, and by executing steps 86 to S8, the detection device 96 is moved to the position where the adhesive is applied second. In this case, the determination in S9 is YES, the height detection device 96 detects the height of the printed circuit board 112 in 314, and the amount of descent of the coating unit is calculated in 315. Comparing the detection value of the height detection device 96 with 1000 μm,
If it is larger than 1000 μm, subtract the number of pulses of the servo motor 46 corresponding to the difference from the lowering amount calculated for the first coating position, and if it is smaller than 1000 μm, the number of pulses corresponding to the difference is subtracted from the lowering amount. In addition,
The amount of descent of the coating unit at the coating position whose height was detected in S14 is calculated. The amount of descent at the first coating position is the amount by which the nozzle 72 is positioned just across the coating clearance from the printed circuit board 112, and corresponds to the difference in height of the printed circuit board 112 for this amount of descent. The application unit 24 adjusts the number of pulses to
By lowering it, you can position it in a position suitable for coating. The calculated descending amount is stored in the second storage location of the coating unit descending amount memory in S15, and thereafter, in S5 to S9 until the descending amount is calculated for all coating positions. S13 to S15 are repeatedly executed.

If S13 is YES, the counter is set to 0 in S16, the X-axis table 10 and the Y-axis table 12 are returned to their original positions in 317, and then adhesive is applied. After the count number C of the counter is incremented by 1 in step 318, table movement data for moving the application unit 24 to the first adhesive application position and nozzle lowering amount data for that application position are read out in step S19. If the X-axis and Y-axis tables 10 and 12 are moved by a predetermined amount in S20 and the nozzle 72 is moved above the coating position, the coating unit 24 is moved in S21.
is lowered by a set amount. As a result, the clearance between the nozzle 72 and the upper surface of the printed circuit board 112 becomes a preset size, and the adhesive is always applied with a clearance suitable for its properties and application amount. Note that the amount of adhesive applied per location is determined in advance, and when changing the amount of adhesive applied depending on the type of printed circuit board, etc., it is changed by adjusting the pressure of compressed air. After applying the adhesive, if the application unit 24 is raised to the rising end position, it is determined in S22 whether or not the adhesive has been applied to all application positions, but this determination is NO. Thereafter, steps 318 to 322 are repeatedly executed until the determination in S22 becomes YES.

If the adhesive has been applied to all application positions on the printed circuit board 112, the determination at 322 becomes YES, and after the counter is set to O and the flag is turned off at S23, the X-axis is applied at 324.

The Y-axis table 10.12 is returned to its original position. Then, in S25, it is determined whether or not the printed circuit board is finished. This determination can be made in various ways, such as by sending end information from the printed circuit board transport device, or by attaching an end mark to the printed circuit board and reading it.

If the printed circuit board 112 is not completed, the program execution returns to S4, and the nozzle descending amount for each coating position is calculated and adhesive is applied to the next printed circuit board 112. If the printed circuit board 112 is completed, S25 becomes YES, and the program continues. execution ends.

As is clear from the above explanation, in this example,
Application unit lowering amount memory, SIo of ROM134, 3
11, 314 and the part that stores S15 and the CPU
The part that executes those steps of 132 is the height detection device 96. The nozzle lifting servo motor constitutes a measuring means for measuring the height of the printed circuit board 112, which is the object, together with the nozzle lifting servo motor 76, etc., and the part of the ROM 134 that stores S19 and S20 and the part of the CPU 132 that executes these steps are the nozzle lifting servo motor. Together with 76 and the like, it constitutes a movement control means.

In the above embodiment, the height of the printed circuit board was detected at every coating position and the amount of nozzle descent was calculated, but the upper surface of the printed circuit board is divided into multiple sections, and The detection position may be determined to detect the height of the printed circuit board, and for coating positions belonging to the same section, the coating unit 24 may be lowered by the amount of descent corresponding to the height of the printed circuit board determined for that section. In this case, it is assumed that the printed circuit board 164 is divided as shown in FIG. 9, for example. The dashed boundaries of each section are the X axis and Y axis.
It can be expressed by an expression of XY coordinates with the original position of axis table 10.12 as the origin, and the application position is expressed by the X coordinate and Y coordinate.
Since it is specified by coordinates, it is possible to know which division the application position belongs to from the application position and the boundary line formula.
When applying the adhesive, it is determined which section the application position belongs to, and the application unit 24 is lowered by the amount of descent calculated for that section to apply the adhesive.

By detecting the height of a plurality of coating locations one by one and calculating the amount of descent in this way, the time required to detect the height and calculate the amount of descent can be reduced, and the coating time can be shortened.

Further, in the above embodiment, the laser emitter 100 of the height detection device 96 was configured to emit light in a direction parallel to the axis of the nozzle 72, but the height detection device 166 shown in FIG. Then, the laser light emitting body 100 emits laser light in a direction oblique to the axis of the nozzle 72, and the X-axis and Y-axis tables 10°12 are set so that the application area of the printed circuit board 168 is located directly below the nozzle 72. It may be provided so that when it is moved, a laser beam is emitted toward the application position. In this case, the height detection device 166 detects the distance in the direction parallel to the laser beam emission direction of the printed circuit board 168, so the detected value is transferred to the laser light emitting body 100.
It is necessary to convert it into a vertical distance based on the inclination angle θ of . In this conversion, as shown in FIG. 11, the distance obtained based on the incidence of light on the detection element 104 is
, where X is the distance in the vertical direction, and is performed by the formula: X=αcosθ. The thin line indicates that the height of the intersection of the optical path of the laser beam and the axis of the nozzle 72 is at the height of the printed circuit board 168.
This is the case where the - dotted chain line and the two points ui
The lines indicate the case where the printed circuit board 168 is located above and below it. In this way, the height detection device 166
If provided, the X-axis can be used to detect the height of the coating position on the printed circuit board.

When moving the Y-axis table 10.12, table movement data for adhesive application can be used as is without being converted into movement data for detection.

Furthermore, the adhesive may be applied while detecting the height of the printed circuit board. In this case, it is possible to detect the height of the printed circuit board and apply the adhesive without stopping the movement of the X-axis and Y-axis tables 10.12, but the height of the printed circuit board is It is desirable to detect the movement of the Y-axis table 10.12 without stopping, and apply the adhesive while stopping. As shown in FIG. 12, a height detecting device 170 and a coating unit 172 are provided on an elevating member 174, and an X-Y table 1 supports the elevating member 174 via an elevating device.
76 is moved so that the height detection device 170 is located in front of the coating unit 172 in the moving direction indicated by the arrow in the figure. Further, the coating unit 172 is connected to the height detection device 17.
It is attached so that when the detected value of 0 becomes 1000 μm, the distance is 2000 μm from the printed circuit board 178.

When applying adhesive, first, the first application position (this application position is defined as a reference detection position) is applied.

The detection position may be set in advance on the printed circuit board.

), and move the height detection device 170 directly above the point (
The number of pulses A' required to lower the coating unit by the descending distance A to the position indicated by the dot-dashed line in the figure, and the number of pulses A' required to lower the coating unit by the descending distance A, and the number of pulses A' required to lower the coating unit 172 by a distance B from that position to the printed circuit board 178. On the other hand, the number of pulses B' required to achieve a state where the clearance C is separated is calculated. In this state, the coating unit 172 is moved to a position directly above the coating position, and the coating unit 172 is lowered by the number of pulses B' to coat the adhesive. After coating, return the coating unit 172 to a position lowered by a distance A from the upper end position,
Move toward the second application position. Then, when the height detection device 170 reaches the coating position, the height is detected and the amount of descent of the coating unit 172 is calculated. The height detection device 170 detects the height of the printed circuit board 178 based on the height at which the detected value is 1000 μm, and the amount of descent of the coating unit 172 is the number of pulses B' calculated for the first coating position. When the coating unit 172 reaches directly above the coating position, the movement is stopped and the coating unit 172 is lowered by the calculated lowering amount. , apply the adhesive.

By applying the adhesive while calculating the height of the printed circuit board 178 in this manner, the application device only needs to be moved once, and the application efficiency can be improved.

In addition, when the direction of a straight line connecting two application positions that are applied one after the other changes variously, the height detection device 1
It is desirable to provide a rotation device for rotating the elevating member 174 around the vertical axis so that the elevating member 70 and the coating unit 172 are aligned along each straight line. In this way, height detection and adhesive application can be performed efficiently while moving between a plurality of application positions with the shortest moving distance.

Further, the height detection device 170 and the coating unit 172 are raised and lowered by separate lifting devices, and the height detection device 170 has a detection value of 1 at the first coating position.
000 μm was obtained, and the coating unit 1 was moved.
72 may be raised and lowered between a rising end position and a coating position separated by a predetermined clearance with respect to the printed circuit board 178.

It is also possible to apply the adhesive while having the application unit trace the printed circuit board at a distance of a desired clearance. For example, as shown in FIG. 13, a height detection device 180 and a coating unit 182 are provided on one elevating member 184, and the height detection device 180 emits laser light as in the embodiment shown in FIG. The coating unit 182 is tilted so that the optical path of the body and the axis of the coating unit 182 intersect. Coating unit 18
2 is provided so that the distance between the intersection of the optical path of the laser beam and the axis of the coating unit 182 and the nozzle 186 of the coating unit 182 is close to the clearance C suitable for coating. Then, the coating unit 182 coats the printed circuit board 18.
The detected value S of the height detecting device 180 when a desired clearance C is separated from the height detecting device 8 is stored, and thereafter the height detecting device 180 is raised and lowered so that this detected value S is always obtained. As a result, as shown by the two-dot chain line in the figure, the application unit 182 always moves with a clearance C apart from the printed circuit board 188, and when it reaches the application position, it is necessary to apply the adhesive in the X-Y direction. table 1
The adhesive can be applied without stopping the machine 90, and the application efficiency can be further improved. Further, the height detection device 180 can always detect the height near the center of the application position, and can perform application with a highly accurate clearance.

Furthermore, both the detection of the height of the printed circuit board and the application of adhesive may be performed while the printed circuit board is not moving.

In this case as well, the height detection device is installed so that the laser optical path intersects with the axis of the coating unit, and the movement of the coating unit is stopped when it is positioned above the coating position, so that the detection value of the height detection device is set to a predetermined value. The coating unit is lowered until the clearance is obtained.

When applying adhesive to a printed circuit board, there are cases where parts such as lead wires and chips are already attached to the printed circuit board. It is necessary to move it to In this case, for example, the movement data of the coating unit may be created in advance to avoid pre-attached parts, or the coating unit may be moved while detecting the height, and if there are pre-attached parts, they may be moved at a certain level. You may try to cross it at intervals. In the latter case, the height detection device detects the height of a tiny point on the printed circuit board that is hit by the laser beam (laser irradiation point), whereas the coating unit is large, so , chip 194
is attached to the printed circuit board 196, and if the height detection device detects the height of the part that is removed from the chip 194, the nozzle 198 moves at a height that is a predetermined clearance away from the top surface of the printed circuit board 196. , chip 19
It will collide with 4. Therefore, as only the position of the laser irradiation point 200 is shown in FIG. 14, a plurality of height detection devices are provided in the direction perpendicular to the moving direction of the coating unit to reliably detect the pre-applied parts and avoid collisions. do.

In addition, when multiple application units are provided and adhesive is applied to multiple locations at the same time, one height detection device is installed for each application unit to typically detect the height of one location and set the amount of descent. You may also do so.

Furthermore, in the coating apparatus shown in FIGS. 1 to 9, 10 to 11, and 12, the amount of descent of the coating unit can be calculated without bringing the nozzle into contact with the printed circuit board. However, the nozzle may be brought into contact with the printed circuit board for calculation. In this case, a reference position is set on the printed circuit board, and the nozzle is lowered until it lightly touches the top surface of the printed circuit board.
At this time, the rotation start position of the servo motor for raising and lowering the nozzle is aligned with the position of the marker signal provided on the encoder, and the number of pulses from that position until the nozzle contacts the top surface of the printed circuit board is counted. The amount obtained by subtracting the number of pulses corresponding to the coating clearance from this number of pulses is the descending amount P of the coating unit at the reference position. Next, the coating unit is returned to the position before being lowered, the height detection device is moved to the reference position, and the height of the printed circuit board is measured. Let the measured value at this time be D. Then, the height detection device is sequentially moved to the coating position and the height of each position is measured, and the difference between this measured value and D is the descending distance of the coating unit at the reference position and the height of the coating unit at the coating position. The amount of descent of the coating unit at each coating position is calculated by adding or subtracting the number of pulses corresponding to the difference between the height measurement value and D to the amount of descent P at the reference position of the coating unit. be able to. Note that it is desirable that the nozzle be brought into contact with a portion of the printed circuit board supported by the positioning support device. Further, the calculation of the reference lowering amount based on the contact of the nozzle with the printed circuit board may be performed only for the first printed circuit board of the same type. Furthermore, if the nozzle is replaced, it is calculated at the time of replacement.

In addition, in each of the above embodiments, the printed circuit board is conveyed horizontally and the adhesive is applied to its upper surface. The coating device according to the present invention can also be used when conveying in the vertical direction and applying adhesive to the surface thereof.

Furthermore, in each of the above embodiments, the coating unit was moved in the horizontal direction and raised and lowered, but the printed circuit board was moved.

It may be moved up and down.

In addition to applying adhesive in spots, the present invention also applies to coating devices that apply adhesive in a linear manner, devices that apply high viscosity fluids such as cream solder in addition to adhesives, and applications other than printed circuit boards. It can be applied to devices that apply high viscosity fluid to objects.

Although not illustrated in detail, the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. FIG. 2 is a front view of an adhesive applicator according to an embodiment of the present invention, and FIG. 3 is a side view. FIG. 4 is a conceptual diagram of a height detection device provided in the coating device. FIG. 5 is a front view showing the detection element of the height detection device taken out. FIG. 6 is a block diagram showing the configuration of a control device that controls the coating device. FIG. 7 is a block diagram showing the configuration of the RAM of the computer that constitutes the main body of the control device, and FIG. 8 is a flowchart showing the adhesive application program stored in the ROM. FIG. 9 is a diagram illustrating another aspect of calculating the amount of descent of the application unit at the adhesive application position of the printed circuit board. FIG. 10 is a front view showing another aspect of the installation of the height detection device, and FIG. 11 is a diagram illustrating conversion of the distance detected by the height detection device into height. Figures 12, 13 and 14
Each figure is a diagram showing another height detection and application mode of the adhesive application device. 24: Application unit 28: Lifting device 96: Height detection device 112 Niblint board 130: Control device
164 Niblint board 166: Height detection device 168 Niblint board 170: Height detection device 172: Coating unit 174: Lifting member 178 Niblint board 18
0: Height detection device 182: Coating unit 184: Lifting member 188.196: Printed circuit board

Claims (1)

[Scope of Claims] Application means for applying a highly viscous fluid to the surface of an object from a position separated by a certain clearance from the surface of the object; and at least one of the application means and the object, and a moving means for moving the objects toward and away from each other; a measuring means for measuring the position of the object in the approaching and separating directions; A highly viscous fluid application device comprising: movement control means for controlling the movement means.