JPH1015984A - Resin sealing apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the irregularity of an injection speed in relation to disturbance such as a temp change of operation oil, by providing an injection speed control means for comparing the actually measured speed detected by a detection means with a set speed to control a flow rate control means so as to obtain the set speed. SOLUTION: A resin is injected by driving a hydraulic pump to sent oil pressure to a cylinder 8 through an adjusting valve 11 to start a piston 8a. Subsequently, the ejection speed of the piston 8a is detected. In an ejection speed control part 10, an actually measured speed is compared with a set value and the flow rate of a proportional electromagnetic flow rate adjusting valve is determined so that the speed of the hydraulic cylinder 8 becomes the set value at a time of a next molding cycle. This control part 10 controls the opening degree of the adjusting valve 11 so as to obtain a determined flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin sealing device for electronic parts, and more particularly to a resin sealing device using a hydraulic cylinder for resin injection.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional resin sealing apparatus using a hydraulic cylinder for resin injection. In FIG. 3, 1 is an upper fixing plate, 2 is a lower fixing plate, 3 is a tie bar provided between both fixing plates 1 and 2, and 4 is a mold clamping cylinder 5 which guides the tie bar.
Is an upper die attached to the upper fixed plate 1, and 7 is a lower die attached to the slide plate 4. Reference numeral 8 denotes an injection cylinder for injecting the resin supplied to the lower mold 7 into the mold. The injection cylinder 8 includes a piston 8a for injecting the resin R into the mold.

[0003] Using the above resin sealing device, the lead frame and the resin R are supplied to the lower mold 7 and the mold clamping cylinder 5 is supplied.
After the upper mold 6 and the lower mold 7 are clamped by the
The resin R supplied to the lower mold 7 by the piston 8a is injected into the mold, and the semiconductor component is resin-sealed.

[0004]

Conventionally, in this resin sealing device, since a hydraulic cylinder is used for resin injection, the viscosity of the hydraulic oil changes according to the temperature change of the hydraulic oil, thereby setting the speed of the injection cylinder. When the flow rate of the flow rate control valve changes, the speed of the injection cylinder varies.

As for the flow control valve, a flow control valve with temperature compensation has been devised. However, even if such a control valve is used, the amount of temperature change of the hydraulic oil may be 20 ° C. or more, which exceeds the temperature compensation limit. Therefore, the problem that the injection cylinder speed varies can not be solved.

[0006] If the speed of the injection cylinder varies, the injection speed of the resin changes, which may cause a problem that the wires in the semiconductor device are cut or the resin is not sufficiently filled.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to minimize the variation in injection speed with respect to disturbance such as temperature change of hydraulic oil in a resin sealing device having a hydraulic injection cylinder. And

[0008]

In order to solve the above problems, according to the present invention, in a resin sealing device, a flow rate control means for controlling a flow rate of hydraulic oil in a hydraulic cylinder and an injection speed of the hydraulic cylinder are detected. A detection means and an emission speed control means for comparing the measured speed detected by the detection means with the set speed and controlling the flow rate control means so as to reach the set speed are provided.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an embodiment of a resin sealing device according to the present invention, 8 is a hydraulic cylinder for injection, 9 is a speed detector of the hydraulic cylinder 8 for injection, 10 is an injection speed control unit, and 11 is a proportional electromagnetic flow control valve. , 12 are hydraulic pumps. The ejection hydraulic cylinder 8 includes a piston 8a that injects the resin R supplied to the lower mold 7 illustrated in FIG. 3 into the molds 6 and 7, similarly to the sealing device illustrated in FIG.

The speed detector 9 detects the ejection speed of the cylinder 8 (the ejection speed of the piston 8a). For example, the speed detector 9 detects the amount of movement of the piston 8a using a potentiometer, a rotary encoder, etc. Then, calculate the speed. Alternatively, since the movement amount of the piston 8a is determined, the movement time from the start point to the end point may be measured, and the movement time may be used as corresponding to the speed of the piston 8a.

The injection speed control unit 10 is composed of, for example, a sequencer, a microcomputer, and the like. The control unit 10 determines the next flow rate based on the injection speed detected by the speed detector 9, and controls the regulating valve 11 so that the flow rate becomes the determined flow rate.

The proportional electromagnetic flow control valve 11 is a proportional control valve for performing flow control in proportion to an input signal, and includes an electromagnetic coil and a plunger, and moves the plunger by a current supplied to the electromagnetic coil to adjust the valve opening. adjust. Control unit 10
The opening degree of the regulating valve 11 is adjusted according to the speed of the piston 8a of the cylinder 8 in response to the command from That is, if the speed of the piston 8a is higher than the set value, the control valve 11 is controlled to reduce the flow rate, and if the speed of the piston 8 is lower than the set value, the flow rate is increased. The relationship between the flow rate of the regulating valve 11 and the emission speed of the cylinder 8 is obtained in advance through experiments, and the relationship is stored in the control unit 10.

Next, the operation of the above apparatus will be described with reference to the flowchart of FIG. The hydraulic pump 12 is driven to send a hydraulic pressure to the cylinder 8 via the regulating valve 11 to start the piston 8a to inject the resin (Step 201). Next, the output speed of the piston 8a is detected (Step 202).
The emission speed may be detected based on the movement time from the start point to the end point of the piston 8a as described above. The ejection speed control unit 10 compares the measured speed with the set value (step 203), and the hydraulic cylinder 8 during the next molding cycle.
The proportional electromagnetic flow regulating valve 11
Is determined (step 204). The control unit 10 controls the valve opening of the regulating valve 11 so as to achieve the determined flow rate (Step 205). The next resin injection is performed based on the set flow rate (step 201), and the same operation is repeated thereafter.

As described above, according to the above-described apparatus, since the regulating valve 11 is controlled so as to attain the set speed, it is possible to minimize the variation in the output speed due to the temperature change of the hydraulic oil. Further, in the above-mentioned resin sealing device, since the flow rate control means is controlled for the next molding cycle every time one molding cycle is completed, complicated control is not required,
Inexpensive and effective control for keeping the emission speed constant becomes possible.

[0015]

As described above, in the resin sealing device of the present invention, the speed of the injection hydraulic cylinder is detected, and the injection speed control section compares the set value of the injection speed with the actually measured speed to determine the set speed. Therefore, in the resin sealing device of the hydraulic servo system, it is possible to obtain the effect that the variation of the injection speed can be minimized at a low cost with respect to disturbance such as temperature change of the working oil.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating the operation of the apparatus of FIG. 1;

FIG. 3 is a diagram showing a conventional resin sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper fixed plate 2 Lower fixed plate 3 Tie bar 4 Slide plate 5 Mold clamping cylinder 6 Upper die 7 Lower die 8 Injection cylinder 8a Piston 9 Speed detector 10 Injection speed control unit 11 Proportional electromagnetic flow control valve 12 Hydraulic pump R Resin

Claims (4)

[Claims] 1. A resin sealing device using a hydraulic cylinder as a resin injection drive source for sealing an electronic component, a flow rate control means for controlling a flow rate of hydraulic oil in the hydraulic cylinder, and an injection speed of the hydraulic cylinder. A resin sealing device comprising: a detecting means for detecting; and an injection speed control means for controlling the flow rate control means so as to compare the measured speed detected by the detecting means with the set speed so as to reach the set speed. Stop device. 2. The resin sealing device according to claim 1, wherein said flow control means is a proportional electromagnetic flow control valve. 3. The resin sealing device according to claim 1, wherein the injection speed control means controls the flow rate control means every time one molding cycle is completed. 4. A resin encapsulation method for encapsulating an electronic component with a hydraulic cylinder using a hydraulic cylinder, wherein an emission speed of the resin is set, an actual injection speed of the hydraulic cylinder is detected, and the actually measured speed and the set speed are set. And controlling the flow rate of the working oil so as to reach a set speed.