JPH10146558A - Adhesive coating method and coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the vertical motion of an application head and to enable high speed application by ejecting a supplied and pressurized adhesive from the end of the nozzle of the head and applying the adhesive between the junction electrodes of a circuit substrate without touching it. SOLUTION: A supplied and pressurized adhesive is ejected from the end of the nozzle 6 of an application head 4 which is moved horizontally with an X-moving robot 1 and positioned to a circuit substrate 5 on a Y-moving table 2 and applied between the junction electrodes of the substrate 5 without touching it. In this process, a cross-shaped part consisting of slits crossing at right angles is formed at the end opening of the nozzle 6, and a central slit crossing part is made to be an adhesive discharge opening. In this way, the head 4 can be positioned only by horizontal movement, and the vertical motion of the head 4 is prevented to enable high speed application.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying an adhesive for temporarily fixing an electronic component to a circuit board with an adhesive and mounting the same, and an apparatus for applying the adhesive.

[0002]

2. Description of the Related Art As one means of soldering electronic components on a circuit board, an adhesive is applied between bonding electrodes of the circuit board,
There is a flow soldering method in which after the components are mounted, they are heat-cured to temporarily fix them, and finally the molten solder is jetted to join them.

FIG. 6 is a perspective view showing the structure of a conventional adhesive applying apparatus used in the adhesive applying step. This adhesive coating apparatus has a positioning means composed of an X mobile robot 1 and a Y mobile table 2, and has an application head 4 on which a barrel 3 filled with adhesive is mounted. The tip of the barrel 3 has a nozzle 6 for extruding and applying an adhesive between the bonding electrodes of the circuit board 5. The robot stage 7 is installed on the apparatus main body 8, and the Y moving table 2 and the X moving robot 1 are incorporated via the robot stage 7.

[0004] Next, the operation will be briefly described. When an electrically controlled air valve (not shown) is opened and air is sent into the barrel 3, the air flows from the tip of the nozzle 6 attached to the tip of the barrel 3. The adhesive is extruded. The position where the adhesive is applied is determined by the X-moving robot 1 and the Y-moving table 2. After the XY movement, the application head 4 descends and the tip of the nozzle 6 comes into contact with the circuit board 5, and the adhesive is applied to the circuit board 5. It is applied in a state of being transferred to the substrate surface.

After applying the adhesive to the circuit board 5, the application head 4 immediately rises and starts positioning to the next point specified on the NC program. The circuit board 5 on which the application of the adhesive has been completed moves to the next electronic component mounting process, and is completed through the component mounting, adhesive curing, and soldering processes.

Here, the amount of the adhesive applied is determined by the nozzle hole diameter,
It can be changed by conditions such as the air pressure, the opening time of the air valve, and the temperature of the nozzle tip.

[0007]

However, in such a conventional adhesive coating apparatus, it is difficult to expect a further increase in the speed because the vertical operation time of the coating head is required. In addition, when the application head is lifted, the adhesive spreads in a thread form and is applied in a whisker form or scatters, thereby deteriorating the application accuracy. In addition, the adhesive is applied to the bonding electrodes of the circuit board, resulting in poor soldering. Cause.

[0008] In addition, viscosity characteristics and the like have been improved for adhesives in order to improve coating accuracy, but it has been difficult to increase the coating speed in terms of coating quality.

On the other hand, in order to eliminate the up-down operation time of the coating head and to increase the speed, a jet method has been devised in which an adhesive is sprayed from a nozzle and supplied to a circuit board in a non-contact manner. However, in the case of the non-contact method, the ejection direction tends to vary due to the deformation of the nozzle opening, the surface roughness of the inner wall surface of the nozzle, or the unevenness of the adhesive composition. Affects directly. This tendency further increases in proportion to the distance between the tip of the jetting nozzle and the substrate surface.

Furthermore, in the case of a normal circular nozzle, the flow of the adhesive is not constant due to the variation in the inner wall surface roughness, the shape of the discharge port, or the viscosity of the adhesive, which causes a variation in the jetting direction. This phenomenon is remarkable in the vicinity of the initial stage and the end of the low flow velocity injection.In addition, in the case of the adhesive having thixotropic property, the viscosity difference is increased by the flow velocity difference, and the dispersion of the injection direction is increased. Become.

SUMMARY OF THE INVENTION The present invention solves such a problem, and provides a method and an apparatus for applying an adhesive with high positional accuracy and stable application accuracy in supplying an adhesive to a circuit board in a non-contact manner. It is intended to do so.

[0012]

According to the present invention, in order to achieve the above object, a method of applying an adhesive is performed by moving a horizontal position together with an X moving robot on a circuit board on a Y moving table from a nozzle end of a coating head positioned. This is a method in which the supplied and pressurized adhesive is sprayed and applied in a non-contact manner between the bonding electrodes of the circuit board. The application head only moves in a horizontal direction, and can perform high-speed application without raising and lowering operations. Application with little variation in stringing, flying, and application position is possible.

Further, the adhesive applying apparatus of the present invention comprises a means for supplying an adhesive to a nozzle of a coating head which is horizontally moved and positioned together with an X-moving robot, and a means for supplying the adhesive supplied from the adhesive supplying means. An adhesive pressurizing means for applying a predetermined nozzle injection pressure, and a nozzle for injecting the adhesive between the bonding electrodes of the circuit board and applying the nozzle, and a tip end opening of the nozzle is formed by an orthogonal slit. The cross-shaped part is formed, the central slit crossing part is used as the ejection and discharge port of the adhesive, the cross-shaped part is formed as the projection, and the slit crossing part is formed as the circular hole. Variations in application position accuracy and application shape caused by the surface roughness of the inner wall surface or the non-uniformity of the adhesive composition can be eliminated, and highly stable application quality can be secured.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment) FIG. 1 is a perspective view showing the structure of an adhesive applying apparatus for carrying out the method of the present invention. I have. Here, the difference from the conventional example of FIG. 6 is that the nozzle 6 for spraying and applying the adhesive between the joining electrodes of the circuit board 5 in a non-contact manner is mounted on the coating head 4 and only the horizontal movement of the X mobile robot 1 is performed. As a result, it is positioned on the circuit board 5 on the Y moving table 2. Therefore, the coating head 4
Since there is no raising and lowering operation for applying the adhesive between the bonding electrodes of the circuit board 5 and it can be performed only by horizontal movement, high-speed application becomes possible.

FIG. 2 is a block diagram showing the construction of the barrel 3 in the coating head 4 shown in FIG. 1, and comprises an adhesive supply section 31 and a pressure section 32 for applying the adhesive to a predetermined pressure. Pressurizing section
The adhesive output from the nozzle 32 is sprayed from the nozzle 6 to the bonding electrode of the circuit board 5.

FIGS. 3 to 5 show examples of the shapes of the nozzles described with reference to FIGS. 1 and 2, wherein (1) is a plan view and (2) is a sectional view thereof.

First, in FIG. 3, an intersection (hereinafter referred to as a cross-shaped portion 63) at the center of the orthogonal slits 61 and 62 serves as an adhesive discharge port, and discharge does not occur from the peripheral slit portion. In addition, it plays the role of the wall of the flowing adhesive,
In addition to being affected by surface roughness and the like unlike metal, surface tension acts simultaneously in four directions, and the surface tension acts to correct the phenomenon of inclining in one direction and attempting to discharge.
A cross-hole shape in which the length a of the slits 61 and 62 in FIG. 3A is 1.0 mm, the width b of the slits 61 and 62 is 0.1 mm, and the depth c of the nozzle hole in FIG. When the distance between the tip of the nozzle and the circuit board 5 is 3.5 mm, and an adhesive having a viscosity of 24 Pa.s is used to apply the coating with a coating diameter of 1.0 mm, poor threading and jumping As a result of measuring the incidence, it was reduced to 45% compared to the conventional circular nozzle.

FIG. 4 shows a cross-shaped portion 63 of FIG. 3 which is formed in a protruding shape protruding by a dimension d to limit the amount of adhesive applied to the discharge port to the vicinity of the nozzle discharge port, thereby further stabilizing the effect of surface tension. is there.

FIG. 5 shows a slit 61 whose semicircle is orthogonal.
A nozzle provided with a circular hole 64 at the center where the slit intersects with 62, which corrects the inclination of the discharge by the surface tension of the adhesive accumulated in the slit when the adhesive is injected through the circular hole 64. It is.

[0021]

As described above, according to the present invention, the nozzle for spray coating in a non-contact manner is mounted on the coating head.
The positioning of the coating head only requires horizontal movement, and there is no raising / lowering operation of the coating head, and high-speed coating can be performed. Therefore, it is possible to provide an application method and an application apparatus for an adhesive with little variation in stringing, jumping, and application position.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an adhesive application device for carrying out a method of the present invention.

FIG. 2 is a configuration block diagram of a barrel in the coating head of FIG.

FIG. 3 is a plan view (1) and a cross-sectional view (2) showing one shape of a nozzle according to the embodiment of the present invention.

FIG. 4 is a plan view (1) and a sectional view (2) showing one shape of a nozzle according to the embodiment of the present invention.

FIG. 5 is a plan view (1) and a cross-sectional view (2) showing one shape of a nozzle according to the embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a conventional adhesive coating device.

[Explanation of symbols]

1 X moving robot, 2 Y moving table, 3 barrel, 4 coating head, 5 circuit board, 6 nozzle, 7 robot stage, 8 main body, 31 adhesive supply section, 32 adhesive Agent pressurizing section, 61, 62 ... slit, 63 ... slit intersection (cross-shaped part), 64 ... circular hole.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Naka 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. An adhesive supplied and pressed from a nozzle tip of a coating head positioned and moved horizontally with an X moving robot to a circuit board on a Y moving table, and is jetted between bonding electrodes of the circuit board. A method for applying an adhesive, wherein the adhesive is applied in a non-contact manner. 2. A means for supplying an adhesive to a nozzle of a coating head which is horizontally moved and positioned together with an X-moving robot, and an adhesive applying means for applying the adhesive supplied from the adhesive supplying means to a predetermined nozzle injection pressure. And a nozzle for spraying and applying the adhesive between the joining electrodes of the circuit board. 3. The bonding according to claim 2, wherein a cross-shaped portion formed by orthogonal slits is formed in the opening at the tip of the nozzle, and the central slit crossing portion is used as an ejection port for the adhesive. Agent application device. 4. An opening at the tip end of the nozzle forms a cross-shaped portion consisting of orthogonal slits, a central slit crossing portion is an ejection orifice of an adhesive, and the cross-shaped portion has a projection shape. 3. The apparatus for applying an adhesive according to claim 2, wherein: 5. An opening at a tip end of the nozzle forms a cross-shaped portion composed of orthogonal slits, a center slit intersection has a circular hole, and an adhesive is injected through the slit intersection having the circular hole. 3. The apparatus for applying an adhesive according to claim 2, wherein the apparatus is a discharge port.