JPH0339749B2 - - Google Patents

Abstract

PURPOSE:To perform uniform emission of adhesive material, by allowing the auxiliary leaf spring fixed in an adhesive receiving box so that the free end thereof is positioned above a nozzle to cooperate with the emitting leaf spring moving along the inner peripheral surface of the receiving box. CONSTITUTION:When a rotary shaft rotates, an adhesive emitting leaf spring 22 is rotated along with said rotary shaft and moved while pressed to the inner peripheral surface of an adhesive receiving box 1. When said leaf spring 22 approaches an auxiliary leaf spring 24, a definite amount of an adhesive 6 is accumulated under the auxiliary leaf spring 24 and, when the emitting leaf spring 22 passes above a nozzle 7, the auxiliary leaf spring 24 is downwardly pressed by the spring force of said leaf spring 22. Therefore, the adhesive 6 accumulated under the auxiliary leaf spring 24 is emitted quantitatively from the adhesive emitting holes 7a of the nozzle 7 and, as a result, the adhesion of a pellet to a lead frame is well performed uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an adhesive applicator used for bonding two parts.

[Prior Art] For example, in pellet bonding of semiconductor devices, pellets are bonded onto a lead frame using a paste adhesive.

Conventionally, a dispenser has generally been used as an adhesive application device for applying paste-like adhesive. This structure is designed to fill a syringe with paste-like adhesive, send compressed air into the syringe, and discharge the adhesive from a nozzle. In this case, the discharge amount can be varied by adjusting the pressure of the compressed air and the time during which this pressure is applied. Further, the nozzle generally uses a syringe needle, and by changing the inner diameter of the syringe needle, the discharge area is changed to cope with differences in pellet size.

[Problems to be Solved by the Invention] Since a syringe needle is used as a nozzle, the adhesive is discharged in a round shape. For this reason, for example, when the pellet size increases to 3 mm or more, the adhesive is present only in the center part, and each corner part to which the pellet is glued is left blank, causing a problem in which pellet attachment failure occurs. Furthermore, if the diameter of the nozzle hole is increased, the amount of adhesive used will be too large, which is uneconomical, and the pellets may float and stick to the pellets at an angle, or the adhesive may bulge above the surface of the pellets. There is a problem that defects occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide an adhesive coating device that solves the above-mentioned conventional problems.

[Means for Solving the Problems] The structure of the present invention for solving the problems of the above-mentioned prior art will be explained with reference to FIGS. 1 to 4 corresponding to embodiments. An adhesive storage box 1 that stores a paste-like adhesive 6 has an adhesive storage section 1a formed in a cylindrical shape. A rotating shaft 18 driven from the outside is disposed at the center of the adhesive storage box 1. An adhesive discharge plate spring 22 is attached to the rotating shaft 18.
One end is fixed, and the leaf spring 2 for discharging adhesive
The other end of 2 is in close contact with the inner circumferential surface of the adhesive storage section 1a of the adhesive storage box 1 by spring force. The adhesive storage portion 1a is provided in the portion forming the inner circumferential surface of the adhesive storage box 1, which is in close contact with the other end of the adhesive discharge plate spring.
A nozzle 7 in which an adhesive discharge hole 7a for discharging the adhesive 6 is formed is provided. Further, an auxiliary leaf spring 24 is fixed to the adhesive storage portion 1a of the adhesive storage box 1.
The free end is below the rotating shaft 18 and the nozzle 7
It is located above.

[Operation] When the rotating shaft 18 rotates, the adhesive 6 moves while being pressed against the inner peripheral surface of the adhesive storage box 1 by the adhesive discharge plate spring 22. When the adhesive discharge leaf spring 22 approaches the auxiliary leaf spring 24, a certain amount of adhesive 6 is accumulated below the auxiliary leaf spring 24, and the adhesive discharge leaf spring 22 moves above the nozzle 7. When passing through, the auxiliary leaf spring 24 is pushed downward by the spring force of the adhesive discharge leaf spring 22, and the adhesive 6 accumulated below the auxiliary leaf spring 24 is used for adhesive discharge from the nozzle 7. A fixed amount of adhesive 6 is discharged from 7a.

[Example] An example of the present invention will be described below with reference to FIGS. 1 to 4. The adhesive storage box 1 includes a box body 2,
It consists of a transparent lid 4 attached to the box body 2 via an O-ring 3, and the box body 2 and the lid 4 are detachably attached with a known lock 5. The inside of the adhesive storage box 1 has an adhesive storage section 1a formed in a cylindrical shape, and a paste-like adhesive 6 is stored in the adhesive storage section 1a. Further, the adhesive storage box 1 is arranged so that the axis of the cylindrical adhesive storage portion 1a is horizontal,
A plurality of adhesive discharge holes 7 are provided on the lower surface of the adhesive storage box 1 (in the embodiment, the lower surface of the box body 2) forming the inner peripheral surface of the adhesive storage section 1a.
A rectangular nozzle mounting hole 2a is formed in which the nozzle 7 having a shape a is mounted therein. The nozzle 7 has a collar portion 7b formed on its outer periphery that contacts the lower surface of the box body 2, and a U-shaped nozzle mounting plate 9 that is attached to the box body 2 with screws 8.
It is inserted into the groove 9a of the box body 2 and detachably attached to the nozzle attachment hole 2a of the box body 2. Further, the lid 4 is formed with an adhesive replenishment hole 2b for replenishing the adhesive 6 into the adhesive storage portion 1a, and this hole 2b is closed with a screw 10.

The box body 2 is fixed with a screw 16 to a hollow fixed shaft 15 that moves up and down by a drive means (not shown). In addition, in order to position the box body 2 on the fixed shaft 15 so that the nozzle 7 faces downward, the fixed shaft 15
A positioning pin 17 is implanted in 5, and this pin 1
7, a positioning groove 2c is formed in the box body 2. The box body 2 is rotatably provided via a shield ring 19 and a bearing 20 so that a rotating shaft 18 is located at the center of the adhesive storage section 1a. A drive shaft 21 that is rotationally driven is connected thereto. One end of an adhesive discharge leaf spring 22 is fixed to one end of the rotating shaft 18 with a screw 23, and the other end of the adhesive discharge leaf spring 22 is fixed to the inside of the adhesive storage part 1a of the adhesive storage box 1. It adheres to the surrounding surface by its own spring force. Further, in the adhesive storage portion 1a of the adhesive storage box 1, one end of an auxiliary leaf spring 24 is located above the nozzle 7, and the other end of the auxiliary leaf spring 24 It is bent at right angles along the side surface of the adhesive storage section 1a, and this bent section 24a is fixed to the side surface of the adhesive storage section 1a.

In FIG. 1, reference numeral 30 indicates a lead frame, and reference numeral 31 indicates a guide rail for guiding the lead frame 30.

Next, the effect will be explained. When the drive shaft 21 is driven by a drive means (not shown), the rotating shaft 18 and the adhesive discharge plate spring 22 rotate in the direction of arrow A (see FIG. 2), and the adhesive 6 is transferred to the adhesive discharge plate spring 2.
2 along the inner circumferential surface of the adhesive storage section 1a. Then, the adhesive discharge plate spring 22
When it reaches the position shown in FIG. 3, a certain amount of adhesive 6 is accumulated below the auxiliary leaf spring 24. When the adhesive discharging leaf spring 22 rotates further from this state, the adhesive discharging leaf spring 22 pushes down the auxiliary leaf spring 24, thereby causing the adhesive 6 accumulated below the auxiliary leaf spring 24 to move downward. A fixed amount of adhesive 6 is discharged from the adhesive discharge hole 7a of the nozzle 7, and the adhesive 6 is applied onto the lead frame 30. Here, the adhesive discharged from the adhesive discharge hole 7a is
Although it hangs like a thread from the adhesive plate a, it is cut off when the auxiliary leaf spring 24 returns to its original position due to its elasticity, preventing hanging from the adhesive discharge hole 7a and ensuring good application.

Therefore, by forming a plurality of adhesive discharge holes 7a in the nozzle 7 in accordance with the application range (size and shape of pellets) on the lead frame 30, the adhesive surface of the pellets on the lead frame 30 is large. It is also applied uniformly over the entire surface of the adhesive.
Furthermore, if the adhesive area on the lead frame 30 changes due to product switching, the nozzle 7 can be easily removed from the box body 2 by loosening the screws 8 and removing the nozzle mounting plate 9. It can be easily replaced with a suitable nozzle 7. By immediately cleaning the nozzle 7 that has been removed from the box body 2, the adhesive 6 in the adhesive discharge hole 7a is prevented from solidifying, making maintenance management easy. Further, an auxiliary leaf spring 24 is provided above the nozzle 7, and the adhesive 6 is pushed out by the auxiliary leaf spring 24, so that the adhesive 6 is evenly distributed from the plurality of adhesive discharge holes 7a of the nozzle 7. being pushed out.

In the above embodiment, the nozzle 7 is formed to be replaceable, but the adhesive discharge hole 7a may be formed directly in the adhesive storage box 1.

[Effects of the Invention] As is clear from the above description, according to the present invention, the auxiliary leaf spring is fixed to the adhesive storage part of the adhesive storage box so that the free end is located above the nozzle. Therefore, the adhesive is uniformly discharged from the plurality of adhesive discharge holes of the nozzle.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the adhesive application device according to the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a side view of FIG.
The figure is an enlarged sectional view of the main part, and FIG. 4 is a bottom view of FIG. 3. 1: Adhesive storage box, 1a: Adhesive storage section, 6:
Adhesive, 7: Nozzle, 7a: Adhesive discharge hole, 1
8: Rotating shaft, 22: Plate spring for adhesive discharge, 24:
Auxiliary leaf spring.

Claims (1)

[Claims] 1. An adhesive storage box having a cylindrical adhesive storage section, a rotatable rotating shaft disposed at the center of the adhesive storage box, one end fixed to the rotating shaft, and the other end fixed to the rotating shaft. An adhesive discharging leaf spring that comes into close contact with the inner circumferential surface of the adhesive storage portion of the adhesive storage box by spring force, and the other end of this adhesive discharging leaf spring forms the inner peripheral surface of the adhesive storage box that comes into close contact with it. a nozzle with an adhesive discharge hole for discharging the adhesive in the adhesive storage box; one end of the nozzle is fixed to the adhesive storage part of the adhesive storage box; An adhesive application device comprising: an auxiliary leaf spring disposed below a rotating shaft and above the nozzle.