JPS62195135A - Resin sealing device for semiconductor - Google Patents

Abstract

PURPOSE:To relax the dispersion of the weight of a resin and to make all the final pressures to be applied to the resin to a constant by a method wherein, after each subcylinder is made to inject almost uniformly the resin by about 90% by the injection main cylinder, each subcylinder performs the final injection independently of one another. CONSTITUTION:A cylinder head 13 is positioned just under a subcylinder unit 12 and can be vertically moved by an injection main cylinder 21. In brief, subcylinders 11 can be lifted up by making the cylinder head 13 ascend. A resin can be injected by the subcylinders 11 only, but as the internal resistances of the subcylinders 11 and plungers 3 are different from each other, the ascending speeds of all the plungers 3 are not always constant. Accordingly, the subcylinders 11 are lifted up to about 90% of the height by the injection main cylinder 21 and to the remaining about 10% of the height, the subcylinders 11 only are each made to ascend independently of one another.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an apparatus for resin molding a semiconductor integrated circuit element (hereinafter referred to as IC) mounted on a lead frame, and in particular, a resin molding apparatus employing a multi-plunger method. Regarding equipment.

[Prior Art] As shown in FIG. 2, a conventional multi-plunger type resin sealing device has several pots 2, 2, etc. inside a lower mold 1 fixed to a base 4 of a molding machine. The plungers 3 are arranged in parallel, and plungers 3 for injecting resin are located inside each plunger. A spring 9 is located directly below each plunger 3 and is housed in a groove 7 of the cylinder head 6. The cylinder head 6 can be moved up and down by the injection cylinder 5. When the cylinder head 6 goes up, the plunger 3 goes up via the spring 9, and when the injection cylinder goes down, the plunger 3 is moved up by the pawl 8 in the groove 7. The plunger 3 was pulled down by the brim at the lower end of the plunger 3 and lowered.

[Problems to be Solved by the Invention] The resin used in the multi-plunger system is mainly in the form of tablets, with a diameter of φ10 to φ18. Height is 10~
Extremely small at 25mm. In general, the limit for tablet manufacturing capacity is weight variation of ±4%. For example, if the diameter is φ13 and the weight is 50, the weight variation will be 5±0.2C1. Also, the inner diameter of pot 2 is φ1
4, the variation in the height of the cull remaining inside the bot 2 after being sealed is ±0.7 mm.

In other words, according to the conventional resin injection method, the pressure is applied to the plunger 3 in the order of the amount of resin, and the highest pressure is applied to the part with the most resin, and the lowest pressure is applied to the part with the least amount of resin. , uniform pressure cannot be obtained. As a result, sufficient pressure is not applied to the IC injected with resin at low pressure, resulting in problems such as a large number of internal voids, unfilling, and reduced reliability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor resin encapsulation device that uniformizes the reliability of semiconductor elements by encapsulating semiconductor elements arranged in parallel with resin under uniform pressure.

[Means for Solving the Problems] The present invention includes a plurality of resin storage bots arranged in parallel, a plurality of plungers that are fitted into each of the bots, and a single bot that simultaneously drives the plurality of plungers. A semiconductor resin comprising: a main injection cylinder; and a plurality of sub-cylinders that are individually connected between the main injection cylinder and the plunger and individually drive each plunger independently of the main injection cylinder. It is a sealing device.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention.

In Fig. 1, a lower die 1 of the mold is fixed to a base 4 of a molding machine, and five bots 2 are placed in a horizontal row inside the center of the lower die 1.
are located side by side at the same pitch, and each plunger 3 for injecting tablet-shaped resin is provided inside the bot 2. A sub-cylinder unit 12 of the present invention is provided below the bot 2 and the group of plungers 3, and is fixed to the base 4 of the molding machine. The upper surfaces of the sub-cylinder lower chambers 1 to 12 are the same as or slightly lower than the upper surface of the base 4 of the molding machine.

The sub-cylinder unit 12 is provided with a sub-cylinder 11 corresponding to each plunger 3, and the plunger 3 and the sub-cylinder 11 are connected by a plunger joint 10 fixed to the upper tip of the sub-cylinder 11. The structure allows the plunger 3 to be easily removed from the holder. Each sub-cylinder upper chamber 16 inside the sub-cylinder unit 12 communicates with an upper bypass 15, and each sub-cylinder lower chamber 17 communicates with a lower bypass 14.

Oil supply and discharge to each sub-cylinder lower chamber 17 is from pipe 19, and oil supply and discharge to each sub-cylinder upper chamber 16 is from pipe 1.
It will be held from 8.

In other words, if oil is supplied from the pipe 19 in the upward direction, the oil will fill the lower chamber 17 of each sub-cylinder, and the oil pressure will cause each sub-cylinder 11 to rise independently and move the plunger 3 connected to the sub-cylinder 11 upward. to rise to. At this time, the oil in each sub-cylinder upper chamber 16 is discharged in the B direction. Upper and lower chambers 1 of each sub-cylinder
6 and 17 are in communication, each plunger 3 rises, and finally the applied pressures t become equal in total. Further, when lowering the plunger 3, the plunger 3 can be lowered by supplying oil from the pipe 18 in the D direction and discharging the oil from the pipe 19 in the C direction. A hole 20 is provided in the upper part of the sub-cylinder unit 12, but when the sub-cylinder 11 is lowered after the plunger 3 is removed from the upper surface of the lower mold 1 to facilitate mold replacement, the plunger joint 1
0 enters the hole 20, and the upper surface of the plunger joint 10 is positioned lower than the base 4 of the molding machine.

A cylinder head 13 is located directly below the sub-cylinder unit 12 of the present invention, and can be moved up and down by the injection main cylinder 21. That is, by raising the cylinder head 13, the sub-cylinder 11 can be lifted up.

In one embodiment of the present invention, resin can be injected using only the sub-cylinder 11, but since the sub-cylinder 11 and the plunger 3 have different internal resistances, the rising speed of all the plungers 3 is not necessarily constant. , the injection main cylinder 21 reaches a height of about 90%, and the sub cylinder 1
1, and lower the remaining approximately 10% of the height to the sub cylinder 1.
1 is increased independently.

[Effects of the Invention] As explained above, according to the present invention, by indexing about 90% of the resin in each sub-cylinder with the injection main cylinder, a fairly uniform indexing can be obtained, and each sub-cylinder can index approximately 90% of the resin. By performing the final injection independently, variations in resin weight can be alleviated and the final pressure applied to the resin can all be made constant. Therefore, the present invention has the effect of solving the conventional problems and greatly improving reliability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing the structure of a conventional injection cylinder section. 1... Lower mold 2... Pot 3...
Plunger 4...Base 5...Injection cylinder 6...Cylinder head 7...Groove
8...Claw 9...Spring
10...Plunger joint 11...Sub cylinder 12...Sub cylinder unit 13...Cylinder head 14...Lower bypass 15...Upper bypass 16...Sub cylinder upper chamber 17...Sub Cylinder lower chamber 18...pipe 19
... Pipe 20 ... Hole 21 ... Injection main cylinder

Claims (1)

[Claims] (1) A plurality of resin storage pots arranged in parallel, a plurality of plungers fitted into each of the pots, a single injection main cylinder that simultaneously drives the plurality of plungers, and an injection main cylinder. 1. A semiconductor resin encapsulating device comprising: a plurality of sub-cylinders individually connected between each plunger and each sub-cylinder independently driving each plunger independently of an injection main cylinder.