JPS6226828A - Resin sealing device for semiconductor element - Google Patents

Abstract

PURPOSE:To make resin-sealing constantly assure of high quality by adjusting position, velocity and compression of a plunger by a method wherein the plunger is driven by an AC servo-motor to pour and force resin into a lead frame. CONSTITUTION:When an AC servo-motor 50 is driven, the driving force is transmitted to a ball screw 46 through the intermediary of a pair of level gears 50a, 49 and a nut 45 threaded by the ball screw 46 is shifted in free direction by the driving force of screw 46 to lower a plunger 43. Therefore the resin 41 located below the plunger 43 is poured on a lead frame located on the speci fied position of a bottom force 15. At this time, the AC servo-motor 50 is limited to the specified torque to be stopped turning as soon as the compression of plunger 48 reaches the specified value. In other words, the AC servo-motor 50 stops turning for resin sealing by maintaining the compression for specified time. Through these procedures, the resin sealing can constantly assure of high quality.

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 sealing device for the semiconductor element tree 1, there is one shown in FIG. 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 places the frame and semiconductor elements between the upper and lower molds. It is sealed with resin.

In the figure, l is the upper platen, 2 is the lower platen, and 8
4 is a tie bar provided between the upper platen 1 and the lower platen 2, and 4 is a movable platen.
6. 6 is a main hydraulic piston and an auxiliary hydraulic piston for driving the movable platen 4 upward, 8 is a mold fixed to the upper platen 1, and 9 is a mold for moving the movable platen 4.
．． This is a fixed lower mold. In this lower mold 9, as shown in FIG.
A tablet insertion hole 80 into which a tablet is inserted is provided.

Further, a plunger 82 is slidably disposed in the tablet insertion hole 80, using the hole 80 as a cylinder, and is driven by hydraulic pressure.

Further, 7 is a power unit consisting of a motor, a hydraulic tank, etc., and this is for supplying hydraulic pressure to each cylinder in which the main hydraulic piston 5 and the auxiliary hydraulic piston 6 are housed, a 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 and the mold is clamped, and in this state, the atomization plunger 82 is driven by hydraulic pressure to inject resin into the mold, and the lead frame and semiconductor element are bonded to the MBB.
F! Seal. 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]

However, in such a conventional device, the plunger S
2 is hydraulically driven, the plunger 82
It is not possible to accurately adjust the speed and pressure of the
There was a problem that stable resin sealing was not possible. The movable platen 4 is also hydraulically driven, so check for oil leaks.

Maintenance such as prevention and replacement of sealing members is very complicated, and since a power unit and the like are required, the device itself becomes large and costs increase.

This invention was made in view of the above points, and it is possible to control the pressing force of the plunger with very high precision, and also to easily control its position and speed.Moreover, maintenance is easy, and the entire device can be easily controlled. It is an object of the present invention to provide a resin sealing device for semiconductor elements that can be made small and inexpensive.

[Means for solving problems]

The resin sealing device for semiconductor elements according to the present invention is provided with an AC servo motor that drives a plunger that injects and presses resin.

[Effect]

In this invention, the plunger is driven and controlled by an AC servo motor, thereby easily and accurately controlling the pressing force position and speed of the plunger.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 2. In the figure, 10 is an upper platen, 11 is a lower platen, and 12 is the upper platen 10 and the lower platen 11.
A tie bar 18 is provided between the tie bars 12, 18 is a movable platen movably provided on the tie bar 12, and 16 is an AC servo motor for driving the movable platen 18. The rotational force of the AC servo motor 16 is not shown. A driving force conversion mechanism (this converts the thrust force, thereby moving the movable platen 13. 14 is an upper die fixed to the upper platen 10, and 15 is a drive force fixed to the movable platen 18. 40 is a tablet insertion hole formed in the platen 4 and the upper mold α◆ into which a sealing resin (tablet) 41 is inserted; 42 is a tablet insertion hole formed in the upper mold α◆ and inserted into the tablet insertion hole; A tablet insertion hole 48 communicates with the tablet insertion hole 40, a plunger 48 is slidably arranged in the tablet insertion hole 40, and 44 is a connecting rod fixed to the plunger 48 and has a female thread (44a). .

45 is a ball screw nut coupled to the connecting rod 44;
6 is a ball screw screwed into this nut 45, 47 is a pair of bearings that rotatably supports this ball screw 46, 48
is a bearing box that supports this bearing 47 and is connected to the upper platen 10. 49 is an AC servo motor having a bevel gear 50a that meshes with the bevel gear 49 of *gear and 5° angle connected to the upper end of the ball screw 46, and a rotating shaft 50b that connects the bevel gear 50a; 51 is a connection A locking key 62 that prevents rotation of the 4ill 144 is a keyway into which the key 51 is screwed. A bevel gear 48a is provided at the upper end of the ball screw 48. 44 is a key for preventing rotation of the connection shaft, 44a is a key groove through which the key 44 passes, and 50 is an AC servo motor for driving the plunger 42, the output shaft 50a of which is connected to the bevel gear 48a of the ball screw 48. A bevel gear 50b that meshes with is provided.

The next operation will be explained.

When the operation start switch is turned on, the AC servo motor 6 starts rotating, and its rotational force is converted into thrust through a driving force conversion mechanism (not shown), thereby causing the movable platen 18 to rise. Then, when the upper mold 14 and the lower mold 15 come into contact and a certain clamping pressure is reached, the AC servo motor 16 is servo-locked and the mold is clamped.

In this mold-clamped state, the lead frame and semiconductor element are sealed with resin. That is, when the AC servo motor 50 rotates, this rotational force is transmitted to the bevel gear pair 50a,
The rotation of the ball screw 46 causes the nut 45 screwed thereto to move in the free direction. That is, the plunger 48 descends. Therefore, the resin 41 located below is injected onto the lead frame placed at a predetermined position of the lower mold 15. At this time, A
Since a certain torque is limited on the C servo motor 50 side, when the pressing force of the plunger 48 reaches a predetermined pressure, the AC servo motor 50 stops rotating. Then, the rotation of the AC servo motor 50 is stopped, and from that point on, the pressing force is maintained for a certain period of time to perform resin sealing.

In the device of this embodiment, since the driving method of the plunger 48 is motorized, the pressing force of the plunger 48 can be controlled with extremely high precision. Furthermore, the position and speed of the plunger 48 can be controlled easily and with high precision, which was extremely difficult with conventional hydraulic drive systems, and high-quality resin sealing can always be performed.

Incidentally, since the AC servo motor 5o does not require brushes, it is easy to maintain, and has good heat resistance against input current during suppression, resulting in a long life. Further, the plunger 48 is arranged in series with the nut 46 of the bottle screw, and the pressing force of the ball screw 46 is applied to the plunger 48.
ζ
It is what it is.

In this embodiment, the plunger 48 and the like are provided on the upper platen, but the same effect can be obtained even if the plunger is provided on the movable platen side.

In addition, as the means for obtaining press pressure, we use an electric method instead of hydraulic pressure as in the past, so there is no need for a power unit, etc., and the entire device can be made very small and inexpensive.
Also, maintenance becomes very easy.

〔Effect of the invention〕

As described above, according to the resin sealing device for semiconductor elements according to the present invention, the plunger is driven by an AC servo motor to inject and press the initial Bw. This can be adjusted very easily and has the effect of always providing high quality resin sealing.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a resin sealing device for semiconductor devices according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing a plunger of the device and its driving device, and FIG. 8 is a conventional configuration diagram for semiconductor devices. FIG. 4 is an enlarged view of the plunger portion of the resin sealing device. 14... Upper mold, 15... Lower mold, 41... Resin, 4
8... Plunger, 50... AC servo motor. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In a semiconductor element resin sealing device for resin-sealing a semiconductor element onto a lead frame, a plunger is provided in the upper mold or the lower mold to inject and press the resin, and this plunger is driven. AC that provides the driving force for
A resin sealing device for semiconductor elements, characterized by comprising a servo motor.