JPS6174343A - Transfer mold forming device for semiconductor resin sealing - Google Patents

Abstract

PURPOSE:To meet the stable forming requirements despite dispersion of resin amount by a method wherein multiple auxiliary exit cylinders to be independently reciprocated separating from a main exit cylinder are provided to be operated in variable combination with one another. CONSTITUTION:A cylinder plate 2 actuated by reciprocation of a main exit cylinder 1 is fixed to the cylinder 1. Multiple auxiliary exit cylinders 6 to be reciprocated separating from the cylinder 1 are assembled into an unit 5 and independently fixed to the cylinder plate 2. When metallic molded pots 10 are charged with tablets, b, c made of different amount of resin, plungers 9 are lifted by the cylinder 1l at even speed to fill the cavities 13, 14 with the resins b, c. Finally the main exit cylinder 1 stops lifting operation thereof leaving the cavities 13, 14 slightly unfilled to be completely filled with the resins b, c by means of independently lifting the cylinders 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a transfer molding machine for sealing semiconductors with resin.

The injection cylinder mechanism of the conventional transformer 7 amoling machine of this type is the first one. Second. It is shown in Figure 3.

In FIG. 1, an auxiliary injection cylinder is not provided, a cylinder plate 2 is attached to an injection cylinder 1, and a plurality of plungers 9 are attached to a fixed plate 3. It is fixed with screw 7. As the injection cylinder 1 rises, the tablet-shaped resin injected into multiple pots 10 in the mold is transferred to the cull part 11 of the mold by a plunger 9 fixed to the cylinder plate 2.
．． Flow through the gate 12 and into the lower mold cavity 13. It is injected into the shed cavity 14, held under pressure for a certain period of time, and formed into a foam. Since the plunger 9 is fixed, if there is variation in the weight of the resin put into each pot 10, the pressure of the injection cylinder 1 will be applied only to the cavity part with the highest number of droplets, and the pressure of the injection cylinder 1 will be applied to the other cavity parts. The resin is under pressurized and many unfilled areas a occur, causing molding defects. The set pressure of the injection cylinder 1 is set by the total value of the pressure required for each plunger 9, and it is important that the amount of fat in each is the same. However, although the resin is processed from powder into a tablet shape using a tab knot machine, it is difficult to make the weight uniform, resulting in considerable weight variations.

Furthermore, improving the machining accuracy also increases the cost, which poses a problem. Furthermore, chips and cracks occur due to handling, which causes weight variations.

In Fig. 2, the plunger 9 is not fixed and the spring 4 is at the set pressure.
Pressure is constantly applied upward. The structure is such that variations in the amount of resin are compensated for by the pressure of the spring 4. The spring 4 of the plunger 9, into which the largest amount of resin has been injected, is deflected to the maximum. Therefore, due to the difference in the amount of resin, there is a difference in the deflection force of each spring 4, and the pressure applied to the resin in each cavity is constant. First, it is difficult to obtain uniform molded products. or,
Due to the fatigue of the spring 4, the pressure of the seal panel changes and cannot be maintained uniformly for a long period of time, causing maintenance problems.

Figure 3 shows the main injection cylinder 1 and the auxiliary injection cylinder 6.
It is a mechanism that possesses the following. The auxiliary injection cylinder 6 is formed into a unit S and is fixed to the cylinder plate 2 by screws 7 or the like. The plunger 9 is connected to the cylinder 6 by a joint 8.

When resin is poured into the pot 10 in the mold, the unit 5
After the auxiliary injection cylinder 6 is raised and the molding pressure is maintained at the set value by hydraulic pressure, the main injection cylinder 1 is raised and the plunger 9 injects resin into the cavity in the mold. At this time, the set pressure of the main injection cylinder 1 is set higher than the pressure required for each plunger 9. In this method, the variation in the amount of each resin is eliminated by the plunger 9.
The pressurizing oil in the auxiliary injection cylinder 6 is caused to leak by the pressure received by the auxiliary injection cylinder 6, and the auxiliary injection cylinder 6 moves downward to equalize each pressure and compensate for the discrepancy Φ in the amount of resin. However, if the pressure exceeds the set pressure, the plunger 9
When pressurized to This causes problems in the production of high-quality molded products. Also, since the internal unit 5 of the auxiliary injection cylinder 6 is attached and fixed to the main injection cylinder 1, the convex pole needs to be replaced.

Maintenance etc. takes time and causes a decrease in productivity.

The present invention comprises a main injection cylinder that reciprocates hydraulically, and a plurality of auxiliary injection cylinders that are separated from the main injection cylinder and can reciprocate independently, and variably combine the operations of the cylinders. This solves the above drawbacks, ensures stable molding conditions that can accommodate variations in the amount of resin, and enables the production of high-quality molded products.
Variety exchange.

This is a transformer 7 amoling machine with improved productivity such as maintenance.

That is, the present invention includes a main injection cylinder that reciprocates using hydraulic pressure, and a plurality of auxiliary injection cylinders that are separated from the main injection cylinder and can reciprocate independently.
By variably combining the operations of the cylinders,
This is a transfer molding machine for semiconductor resin sealing that is compatible with any molding conditions and can produce stable molded products.

Next, regarding the embodiments of the present invention, Section 4. Fifth. This will be explained with reference to FIG.

FIG. 4 shows the configuration of the present invention and shows the state before operation.

The cylinder plate 2 is fixedly attached to the main injection cylinder 1 and operates together with the reciprocation of the main injection cylinder 1. The unit 5 incorporating multiple auxiliary injection cylinders 6 is separated from the main injection cylinder 1 and is independently attached and fixed, and only the multiple auxiliary injection cylinders 6 reciprocate. When tablets b and c having different amounts of resin are put into the pot 10 of the mold, the upper and lower molds are clamped by a clamping cylinder (not shown in the figure) of the molding machine as shown in FIG. FIG. 5 shows a view in which resin is injected into the mold by the main injection cylinder 1. When the main injection cylinder 1 is ejected and raised, the multiple auxiliary injection cylinders 6 are pushed up by the cylinder plate 2 and raised, and the injection cylinders 6 are injected into each bot 10 by the multiple plungers 9 connected by a joint 8. @B and the cull part 11. at a uniform speed. It is injected into the lower mold cavity 13 and the upper mold cavity 14 via the gate 12. At this time, the multiple auxiliary injection cylinders 6 do not perform their own lifting operation, but are lifted by the main injection cylinder 1. When resin is injected into the metal cavities 13 and 14 by the main injection cylinder 1, the ascending distance is set in consideration of the variation in the amount of resin with respect to the amount of resin injected into each bot. Therefore,
When resin is injected by the main injection cylinder 1, the ascent is stopped with an unfinished lateral portion a remaining in the mold cavity 13, 14. The main injection cylinder 1 is used to inject resin into most of the mold cavity, and does not pressurize and hold the injection layer. FIG. 6 shows a form forming diagram of final resin injection using multiple auxiliary injection cylinders 6 and pressurization maintained at a set pressure. When the main injection cylinder 7/goo 1, which has injected most of the resin into the mold cavity 13, 14, stops rising, the multiple auxiliary injection cylinders 6 installed in the unit 5 perform an upward movement on their own to fill the mold cavity. 13. Completely fill the inside of 14 with resin, increase the injection pressure to the set pressure, hold the pressure for a certain period of time, and form F+7. I commend you. At this time, as shown in FIG. 6, the upward distance of the auxiliary injection cylinder 6 differs depending on the variation in the amount of resin injected. Operation switching between the main injection cylinder 1 and the auxiliary injection cylinder 6 can be performed by control without stopping the flowing resin. In order to lower the forming layer to its origin, both the main injection cylinder 1 and the auxiliary injection cylinder 6 are lowered to the state shown in FIG. 4 by independent hydraulic circuits. In addition, by combining the control methods, injection molding operation of only the auxiliary injection cylinder 6, ejection and ejection of the molded product can be controlled.
The mold release operation, the plunger 9 replacement operation, etc. can be performed, and it can be used for various purposes.In addition, the unit 5 can be replaced from the mold mounting surface side, which improves the maintenance and replacement of the product 5F.

As explained above, the present invention has a main injection cylinder that reciprocates using hydraulic pressure, and a plurality of auxiliary injection cylinders that are separated from the main injection cylinder and can independently reciprocate, thereby reducing the variation in resin amount. It also ensures stable molding conditions and enables the production of high-quality molded products.
In addition, it has the effect of improving the physiological efficiency of product replacement maintenance, etc., and being able to respond to a wide range of automation of packaging.

[Brief explanation of drawings]

1 to 3 are diagrams showing the prior art, and FIGS. 4 to 6 are diagrams showing embodiments of the present invention. ■・・・・・・Main injection cylinder (injection cylinder),
2... Cylinder plate, 3... Fixed plate,
4...Spring, 5...Cylinder unit, 6...Auxiliary injection cylinder p"-17...
...Screw, 8...Fitting, 9...Plunger 10...---it, 11...Drawing cal m, 12... ...Mold gate, 13...
・Lower mold cavity, 14... Upper mold cavity,
a... unfinished side part, b... resin tablet, c... resin tablet.

Claims (1)

[Claims] It is equipped with a main injection cylinder that reciprocates using hydraulic pressure, and a number of auxiliary injection cylinders that are separated from the main injection cylinder and can reciprocate independently. By variably combining the operations of these cylinders, molding conditions can be adjusted. A transfer molding machine for semiconductor resin encapsulation, which is characterized by being able to change.