JPH0376782B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resin sealing device for semiconductor elements for resin sealing semiconductor elements on lead frames.

[Conventional technology]

As a conventional resin sealing device for semiconductor elements, the fourth
I got what is shown in the figure. This uses hydraulic pressure to clamp an upper mold (hereinafter referred to as the upper mold) and a lower mold (hereinafter referred to as the lower mold), and the lead frame and semiconductor element placed between the upper mold and the lower mold. is sealed with resin.

In the figure, 1 is an upper platen, 2 is a lower platen, and 3 is the above-mentioned upper platen 1 and lower platen 2.
4 is a movable platen provided in between; 5 and 6 are main hydraulic pistons for driving the movable platen 4 upward;
An auxiliary hydraulic piston, 8 is an upper die fixed to the upper platen 1, and 9 is a lower die fixed to the movable platen 4. As shown in FIG. 5, this lower mold 9 has a plunger 32 connected to a cylinder 30 for injecting and pressing a sealing resin (tablet) 31.
It is slidably mounted on the shaft and is driven by hydraulic pressure. In addition, the cylinder 30
The upper part serves as a tablet insertion opening into which the resin 31 is inserted. A power unit 7 is composed of a motor, a hydraulic tank, etc., and is used to supply hydraulic pressure to each cylinder in which the main hydraulic piston 5 and the auxiliary hydraulic piston 6 are accommodated, to the plunger drive unit, etc.

To explain the general operation of the conventional apparatus having such a configuration, first, a lead frame and a semiconductor element are placed on the lower mold 9, and then the movable platen 4 is driven upward by hydraulic pressure, and the lower mold 9 is moved to the upper mold 8. to press. Then, the pressing force, that is, the press pressure, is maintained at a predetermined pressure to clamp the mold, and in this state, the plunger 32 is hydraulically driven to inject resin into the mold, and the lead frame and semiconductor element are sealed with resin. Stop. When the resin sealing is completed, the movable platen 4 is lowered, the upper mold 8 and the lower mold 9 are separated, and the resin-sealed lead frame is taken out.

[Problem that the invention seeks to solve]

In such conventional equipment, resin powder may get into the lower part of the cylinder, but the resin powder that gets into the lower part of the cylinder cannot be easily removed, and in order to remove it, the mold must be disassembled. There was a problem that I had to do. In addition, since the above conventional equipment uses a hydraulic drive system, inspection and prevention of oil leaks, replacement of seal members, etc.
The maintenance thereof is very complicated, and since a power unit and the like are required, the device itself becomes large and the cost increases.

This invention was made in view of this point, and easily removes resin powder that has entered the cylinder.
Moreover, it is an object of the present invention to provide a resin sealing device for a semiconductor element that can be reliably cleaned, is easy to maintain, and can be made small and inexpensive.

[Means for solving problems]

The resin sealing device for semiconductor elements according to the present invention includes:
An air supply port provided near the bottom of the cylinder that accommodates the plunger; a plunger driving means such as a motor that causes the plunger to protrude from the mold surface; A groove is provided to form a communication path extending from the supply port to the space above the cylinder.

[Effect]

In this invention, after resin sealing, the plunger is made to protrude from the mold surface, air is supplied into the cylinder from the bottom, and the resin powder inside the cylinder is passed through the groove provided on the side surface of the plunger to the outside of the upper part of the cylinder. Discharge into space.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of a resin sealing device for semiconductor elements according to an embodiment of the present invention, and in the figure, 1
0 is an upper platen, 11 is a lower platen, 12 is a tie bar provided between the upper platen 10 and the lower platen 11, 13 is a movable platen movably provided on this tie bar 12, and 16 is a drive for this movable platen 13. The rotational force of the AC servo motor 16 is converted into thrust by a driving force conversion mechanism (not shown), thereby moving the movable platen 13. 14 is the upper platen 10
The upper mold 15 is fixed to the movable platen 13.
The lower die is fixed to the

FIG. 2 is an enlarged view of the plunger portion provided on the lower mold 15. In the figure, 40 is a plunger for injecting and pressing resin, and 41 is a cylinder that accommodates this plunger 40. An air supply port 42 is provided on the lower side of the cylinder, and an external compressor is connected to the compressor via this air supply port 42. Air is supplied into the cylinder 41 from the cylinder 41 . 43 is a nut fixed to the plunger 40, 44 is screwed into this nut 43,
A ball screw rotatably supported by the lower mold 15, 4
5 is a bevel gear fixed to one end of the ball screw 44; 46 is a plunger drive shaft to which a bevel gear 47 that meshes with the bevel gear 45 of the ball screw 44 is fixed;
is adapted to receive driving force from a plunger motor 51 shown in FIG. 1 via a power transmission system 52. Further, a plurality of grooves 40 are provided on the side surface of the plunger 40 in the axial direction of the plunger 40.
a, 40b are formed (see Fig. 3), and when the plunger 40 is protruded from the mold surface, a communication path exits from the air supply port 42 to the space outside the cylinder through the grooves 40b, 40a. It is starting to form.

Next, the operation will be explained.

When the operation start switch is turned on, the AC servo motor 16 starts rotating, and its rotational force is converted into thrust through a driving force conversion mechanism (not shown), thereby causing the movable platen 13 to rise. Then, when the upper mold 14 and the lower mold 15 come into contact and a certain clamping pressure is reached, a servo lock is applied to the AC servo motor 16 to perform mold clamping.

In this mold-clamped state, the lead frame and semiconductor element are sealed with resin. That is,
When the plunger motor 51 rotates, this rotational force is transmitted to the plunger drive shaft 46 via the power transmission system 52.
It is further transmitted to the ball screw 44 via the bevel gears 47 and 45. This rotational force is converted into thrust by the ball screw 44 and nut 43, and the plunger 40 rises.
The resin placed on the top of the plunger 40 is injected into the mold under a predetermined pressure.

In this way, resin sealing of the lead frame and semiconductor element is completed, but in this resin sealing process, resin powder enters into the cylinder 41,
If operated for a long time, this will have a negative effect on the movement of the plunger 40. Therefore, after the operation for a predetermined period of time, the plunger 40 is made to protrude a certain amount from the surface of the lower mold 15 to be in the state shown by the dashed line in FIG. Supply air inside. At this time, a communication path is formed from the air supply port 42 to the outside space through the grooves 40b and 40a on the side surface of the plunger 40, and therefore, the resin powder in the cylinder 41 is supplied from the air supply port 42. The air is discharged to the outside through the communication path, and the inside of the cylinder 41 is cleaned.

In the device of this embodiment, the plunger 40
While forming grooves 40a and 40b on the side surfaces of
An air supply port 42 is provided below the cylinder 41, and the resin powder that has entered the cylinder 41 is discharged to the outside using air. Therefore, the inside of the cylinder 41 can be easily and reliably cleaned, compared to the conventional method. There is no need to disassemble and clean the mold, making maintenance extremely easy.

In addition, in this embodiment of the apparatus, the means for obtaining press pressure and the means for driving the plunger are not hydraulic as in the past, but are electrically operated, eliminating the need for a power unit, etc., making the entire apparatus extremely compact. And it can be done cheaply.

Note that in the above embodiment, a ball screw and a nut are used as means for applying thrust to the plunger, but other configurations such as a rack and nut may be used.
A mechanism using a pinion or the like may also be used.

〔Effect of the invention〕

As described above, according to the resin sealing device for semiconductor elements according to the present invention, after resin sealing, air is supplied from the bottom of the cylinder to remove resin powder that has entered the cylinder through the groove formed on the side surface of the plunger. Since the liquid is discharged into the space above the cylinder, the inside of the cylinder can be easily and reliably cleaned.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a resin sealing device for semiconductor elements according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the plunger portion thereof, and FIG.
4 is a line sectional view, FIG. 4 is a configuration diagram of a conventional resin sealing device for semiconductor elements, and FIG. 5 is an enlarged sectional view of a plunger portion thereof. 14... Upper die, 15... Lower die, 40... Plunger,
40a, 40b...Groove, 41...Cylinder, 42...Air supply port, 50...Compressor, 51...Plunger motor, 52...Power transmission system. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A semiconductor element resin sealing device for resin-sealing a semiconductor element on a lead frame, comprising: a plunger provided in a lower mold for injecting and pressing resin upward; an air supply port provided near the bottom of the housing cylinder; a plunger driving means for causing the plunger to protrude from a mating surface of the upper mold and the lower mold; and an air supply port provided in the axial direction on an outer peripheral side surface of the plunger, A resin sealing device for a semiconductor element, comprising: a groove that forms a communication path that communicates the air supply port with the space above the cylinder when the groove protrudes from the mating surface.