JPH01105716A - Resin sealing device - Google Patents

Abstract

PURPOSE:To prevent plungers from pulsating by a method wherein a plurality of the plungers are integrally fixed to one another against their energizing forces by actuating a spring plate toward fixing direction by means of a driving part during the lowering of the plungers. CONSTITUTION:A plurality of plungers 1 are provided so as to be held by respective plunger holders 3, each of which is supported through a spring plate 4 by a plunger plate 5 and pushed down by means of each spring 6. At the lowering of the plunger plate 5 by means of a hydraulic cylinder, the spring plate 4 is actuated upwards integrally with the respective plunger holders 3, resulting in fixing the respective springs 6. Under the state as just mentioned above, the plunger plate 5 and the plungers 1 lower, resulting in making the lowering speeds of the plungers equal to the actuating speed of a hydraulic cylinder for lowering the plungers 1. At the lowering limit of the plungers 1, the pistons 11 of hydraulic cylinders 10 are lowered so as to bring the springs 6 into unfixed state in order to apply pouring pressures to the resin poured in a mold by means of the springs 6, resulting in making the pouring pressures of a plurality of the plungers 1 constant.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a multi-plunger type resin sealing device for semiconductors, electronic parts, etc. using thermosetting resin materials.

Prior Art A conventional resin sealing device is shown in FIG. 2o←God,
A plurality of plungers are provided, each of which fits into the bond 21. A plunger holder 22 is provided corresponding to the plunger 2o. A spring 23 is similarly provided corresponding to the plunger 20, and applies a constant injection pressure to each plunger 2°. 24 is a plunger plate, which is moved up and down by a hydraulic cylinder (not shown) or the like. 25 is a spring cover, which includes the plunger plate 24, the spring 23, and the spring cover 25, and the plunger 2
o and plunger holder 22 are fully supported. 26
is an upper mold, to which a pot 21 is fixed, and a mold 27 for half of the product to be formed is provided. 28 is the lower mold,
A -hl part 29 is provided corresponding to the pot 21, and the cull part 29 and the ricade part 3o communicate with a half mold 31 of the product to be molded, into which resin is injected. Upper mold 26. The pot 21 and the lower mold 28 are heated by a heater (not shown).

With this structure, the resin 32 is supplied into the pot 21 and heated and melted. Thereafter, the plunger plate 24 is lowered by a hydraulic cylinder or the like. The amount of resin 32 supplied to each pot 21 may vary slightly, and the spring 23 absorbs the variation in volume, and the lower limit, that is, the molding pressure generated when the injection of resin into the molds 27 and 31 is completed. Keep constant.

Problems to be Solved by the Invention However, in this method, when the resin 32 and the like become entangled in the fitting portion of the pot 21 and the plunger 20, and the plunger 1 receives resistance during the downward movement, the spring 23 completely deflects. , the power of the descending cylinder is likely to be concentrated on the plunger 20, which has received resistance. If this is repeated, the downward movement of the plunger 20 will pulsate, causing a problem in that the speed of the injected resin will change and bubbles will occur in the molded product. Means for Solving Secondary Problems □ In order to solve the above problems, the present invention includes a plurality of plungers for injecting molten resin into a mold, and a spring for applying injection pressure to each plunger. The resin sealing device is provided with a spring plate that integrally fixes the plurality of springs against a biasing force or releases the biasing force, and a drive unit that moves the spring plate in the fixing or releasing direction. It is characterized by

Operation According to the above structure, when the plunger moves downward, the spring plate is moved in the fixing direction by the driving section, and the plurality of springs are integrally fixed against the biasing force, so that when the plunger moves downward, the spring plate is moved in the fixing direction. Pulsation can be prevented even when resistance is encountered, and multiple plungers can be lowered at the same speed.

By operating the spring plate in the opening direction at the lower limit of the plunger to open the plurality of springs, the plurality of plungers can apply injection pressure by the springs to the resin in the mold.

Embodiment FIGS. 1 and 2 are cross-sectional views showing an embodiment of the present invention.
A plurality of plungers 1 are provided, each of which fits into the pot 2 at its lower limit. 3 is the plunger holder,
It is held by a plunger plate 6 via a spring plate 4. Reference numeral 6 denotes a spring, which is fixed to the plunger plate 5 by a spring cover 7 so as to apply a force that pushes the plunger holder 3 downward. The spring plate 4 is fixed to a push-up plate 9 via a connector 8. 1o is a hydraulic cylinder for operating the push-up plate 9, which is fixed to the spring cover 7;
The piston 11 is in contact with the push-up plate 9. The plunger plate 5 is connected to a hydraulic cylinder (not shown) via blocks 12 on both sides. The pot 2 is fixed to an upper mold 13, and the upper mold 13 is provided with a mold 14 for the upper half of the product to be molded. A lower mold 15 is provided with a cull portion 16, a gate portion 17, and a mold 18 for the lower half of the product to be molded, corresponding to the pot 2. The upper mold 13, the pot part 2, and the lower mold 16 are equipped with heaters (not shown).
is heated to a predetermined temperature.

The resin 19 is supplied into the heated pot 2 and melted. Next, the plunger plate 5 is lowered by the hydraulic cylinder. At this time, the push-up plate 9 is pushed up by the hydraulic cylinder 10.

That is, the spring plate 4 moves upward integrally with the plunger holder 3, and the spring 6 is fixed.

In this state, the plunger plate 5 and plunger 1 are lowered. That is, the descending speed of the plunger 1 is equal to the operating speed of the hydraulic cylinder for lowering the plunger 1. At the lower limit of the plunger 1, the piston 11 of the hydraulic cylinder 10 is lowered to release the spring e. That is, type 14.
Injection pressure is applied to the resin 19 injected into the resin 18 by the spring 6, and a constant pressure can be applied without variation in the injection pressure of the plurality of plungers 1.

Effects of the Invention By fixing the biasing force of the spring and keeping the descending speed of the plunger constant as described above, the speed at which the molten resin flows into the mold can be kept constant without causing pulsation of the plunger, and By controlling the descending speed, the inflow speed can be controlled, so there is no sudden change in the resin inflow speed, and the entrainment of air bubbles and the generation of voids can be suppressed. Therefore, in the case of four semiconductors, it is possible to prevent the bonding wire from falling or breaking.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an embodiment of the present invention, FIG. 2 is a front sectional view thereof, and FIG. 3 is a side sectional view of a conventional example. 1... Plunger, 4... Spring plate, 6... Spring, 10... Cylinder, 13... Upper mold, 15... ...Lower mold. Name of agent: Patent attorney Toshio Nakao and 1 other person
-Arashija Figure 1
4'1'X'1000-L body Toha half 2nd figure

Claims (1)

[Claims] In a resin sealing device equipped with a plurality of plungers for injecting molten resin into a mold and springs that apply injection pressure to each plunger, the plurality of springs are integrally connected against a biasing force. A resin sealing device comprising: a spring plate that fixes or releases the biasing force; and a drive unit that moves the spring plate in the fixing or releasing direction.