JPH04352433A - Automatic transfer molding machine - Google Patents

Abstract

PURPOSE:To provide an automatic transfer molding machine which can improve productivity by sharply reducing the supply time of dummy lead frames. CONSTITUTION:A lead flame b, where a semiconductor element is bonded, is stored in a magazine 10, and a magazine unit 11, which integrates a plurality of magazines, is placed on the elevator base 30a of one stage of a multistage type elevator mechanism 30. A dummy magazine unit 19, which integrates dummy lead frames 18 consisting of only lead frames, is placed on the elevator base 30a of other stage, and the elevator mechanism lifts up the dummy magazine unit to the sending-out position, in case that a fraction of the number of sheets to be sent out comes out with the final sending-out operation to the magazine unit, and sends out lead frames of a number lacking with one operation.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transfer molding machine that automatically seals semiconductor devices with resin, and more particularly to shortening the time required to supply dummy lead frames.

0002

2. Description of the Related Art In a semiconductor device S as shown in FIG. 4, a semiconductor element a is supported on a lead frame b, and then the semiconductor element a and the lead frame b are bonded with a thin metal wire c. The bonding portion between the semiconductor element a and the lead frame b is sealed with, for example, epoxy resin. d is its molded resin outer shell, and a portion of the lead frame b protrudes from the molded resin outer shell d.

[0003] Japanese Unexamined Patent Publication No. 58-21344 or Japanese Utility Model Publication No. 1-42343 discloses a schematic structure of an automatic transfer molding machine for automatically finishing such a semiconductor device S as a product.

That is, a large number of resin tablets are stored, and the resin tablets are arranged and supplied one by one, with or without preheating as necessary. This supply destination is a magazine that stores semiconductor elements and lead frames in a bonded state.

[0005] The magazine is conveyed between the upper mold and the lower mold based on a feed signal, and a lead frame and a resin tablet with semiconductor elements bonded to the surface of the lower mold are fed and placed. .

As shown in FIG. 5, the lower mold 1 and the upper mold 2 are fitted and clamped, and the resin tablet 4 introduced into the resin injection hole 3 is heated and melted, and the plunger Pressurized by 5. The molten resin passes through a resin supply section 6 provided in the upper and lower molds 2, 1, a transfer line (runner) 7, and a gate 8, and is press-fitted into a cavity 9 in which the semiconductor element a is housed.

[0007] After such press-fitting, the upper and lower molds 2 and 1 are maintained in a tightened state until the resin hardens. After that, open the mold and take out the resin-sealed product.
By cutting unnecessary parts such as the resin supply part and the runner part, the semiconductor element a as shown in FIG.
A semiconductor device S is obtained in which the bonding portion between the semiconductor element a and the lead frame b is sealed with a molded resin shell d.

[0008]

By the way, in such an automatic transfer molding machine, the bonded semiconductor element a and the lead frame b are stored in a magazine 10 made of a rectangular plate as shown in FIG. be accommodated in. The magazines 10 themselves are stacked at narrow intervals in the vertical direction in a magazine unit 11 consisting of a housing with both ends open.

A lever-shaped magazine pusher, for example, protrudes from one open end of the magazine unit 11, and the magazines 10 are sequentially fed out. At this delivery position, the resin tablets 4 supplied from the alignment device are received and further conveyed between the upper mold 2 and the lower mold 1.

Conventionally, the supply section of the magazine 10 is as shown in FIG.
It is configured as shown in . That is, a large number of magazine units 11 each having the same shape and dimensions and accommodating a plurality of magazines 10 of the same number are arranged on a magazine stand 12 which is a stocker section. This magazine stand 1
A magazine pusher 13 is provided at one end of the magazine unit 2 to sequentially send out the magazine units 11.

An elevator mechanism 14 is provided on one side of the magazine stand 12 on the delivery side. The elevator stand 14a of the elevator mechanism 14 supports one magazine unit 11 to be delivered, and the magazine 10 accommodated therein is delivered at a predetermined position (position F).

A dummy magazine stand 15, which is a dummy stocker section, is located above the magazine stand 12.
are arranged in parallel, and below the magazine stand 12, an empty magazine stand 17 for accommodating an empty magazine 16 is arranged in parallel.

On the dummy magazine stand 15, a large number of dummy magazine units 19 are lined up in which dummy lead frames 18 consisting only of lead frames b to which the semiconductor elements a are not bonded are integrated, and are sequentially fed out by a magazine pusher 20. It is now possible to

By the way, normally, a plurality (2 to 8) of magazines 10 are supplied in one operation (one shot), and the lead frames b with these elements are sealed with resin at the same time. The number of magazines 10 required for one operation varies depending on the required specifications. Basically, one lot is set for one magazine unit 11.

On the other hand, since the number of magazines 10 accommodated in the magazine unit 11 is constant, in some cases, the number of magazines 10 remains as a fraction in the final operation. That is, a predetermined number of sheets is insufficient in one operation.

[0016] At this time, the elevator stand 1 is at the above F position.
After all the remaining fractional magazines 10 are sent out from the magazine unit 11 on the magazine unit 4a to empty them, the elevator mechanism 14 is driven to lower the elevator platform 14a in the direction B, stop at position E, and empty the magazines 10. The magazine unit 16 is released onto the empty magazine stand 17.

Next, the elevator platform 14a is raised in the C direction and stopped at the G position facing the dummy magazine stand 15. The magazine pusher 20 operates to send out the dummy magazine unit 19 to the elevator stand 14a, and the elevator stand 14a descends again in the D direction and returns to the F position, which is the predetermined delivery position. At this position, the insufficient number of dummy lead frames 18 are fed out in one operation. In other words, the specified number required for one operation will be available.

[0018] Then, the dummy magazine unit 19
If the dummy lead frame 18 remains, the elevator platform 14a is raised in the C direction and stopped again at the G position, and the dummy magazine unit 1 is placed on the dummy magazine stand 15.
Return 9. In addition, when all the dummy lead frames 18 have been sent out, the empty dummy magazine unit 16 is lowered in the B direction and released to the empty magazine stand 17. In this way, there are many operations to feed out the missing dummy lead frame 18 from the dummy magazine unit 19.
The elevator mechanism 14 is essential.

However, the dummy lead frame 18
The elevator mechanism 14 must be driven up and down as necessary to reciprocate the elevator platform 14a between the magazine stand 12 and the dummy magazine stand 15.
It takes an extremely long time to receive the regular magazine unit 11, that is, the time required to supply the dummy lead frame 18.

Conventionally, the time required for the above operation is approximately 50 seconds (actually measured value). This time has a very large negative effect on the manufacturability of the semiconductor device S, and there is a strong demand for shortening the dummy lead frame supply time.

The present invention has been made in view of the above circumstances, and provides an automatic transfer molding machine that can shorten operating time when a dummy lead frame is required and significantly improve productivity. The purpose is to

[0022]

[Means for Solving the Problems] The present invention supplies a resin tablet to a lead frame to which a semiconductor element is bonded, and melts the resin tablet by heating and pressurizing the semiconductor element and the bonding portion between the semiconductor element and the lead frame. In an automatic transfer molding machine for resin-sealing, a magazine is equipped with a lead frame to which the semiconductor element is bonded, a plurality of the magazines are accumulated in a magazine unit, a large number of the magazine units are housed in a stocker part, and the magazine units are sequentially fed out; The magazine unit sent out from this stocker section is supported on the elevator stand on one stage, and a predetermined number of lead frames with elements are fed out from this magazine unit for each resin sealing operation, and transferred to the elevator stand on the other stage. Equipped with a multi-stage elevator mechanism that supports a dummy magazine unit for accumulating dummy lead frames consisting only of lead frames,
The elevator mechanism drives the dummy magazine unit up and down to the delivery position when the final delivery operation for the magazine unit results in a fraction less than the predetermined number of magazines to be delivered, and the elevator mechanism drives the dummy magazine unit up and down to the delivery position to remove the insufficient number of dummy lead frames in one operation. This is an automatic transfer molding machine that is characterized by sending out.

[0023]

[Operation] The elevator mechanism is always driven up and down with a magazine unit supported on one stage and a dummy magazine unit supported on the other stage. Even if a fraction of the magazine is produced in one operation, the dummy lead frame can be immediately sent out from the dummy magazine unit, and no feeding time is required.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The automatic transfer molding machine is constructed as shown in FIG. That is, the molding machine main body A disposed in the clean room R has a rectangular planar shape, and is composed of a plurality (six) of units described below, two rows in the front-rear direction and three in the width direction.

At the far left end is the resin stocker section 21. This resin stocker section 21 accommodates means for storing a large number of resin tablets 4 as previously explained with reference to FIG. 5, and means for arranging the resin tablets 4 from this stocker in a line and sequentially supplying them one by one.

Depending on the capacity of the resin tablet 4,
It may be necessary to preheat the resin tablet 4 in the resin stocker section 21, and a corresponding transfer molding machine may be provided with a preheater section here.

An inloader section 22 is provided adjacent to the front side of the resin stocker section 10. This inloader section 2
2 accommodates a magazine supply section 23, which will be described later, and which supplies the magazine 10 previously explained with reference to FIG. The magazine 10 supplied from the magazine supply section 23 to the inloader section 22 receives the resin tablets 4 supplied from the resin stocker section 21.

Adjacent to the side of the inloader section 22,
The unit at the center of the front is the mold press section 24. The mold press section 24 includes the lower mold 2 which is hydraulically driven up and down and the fixed upper mold 1, as described above with reference to FIG.

A mold cleaner section 25 is provided on the back side of the mold press section 24. For example, a rotary brush body is accommodated in the mold cleaner section 25, and the rotary brush body protrudes into the mold press section 24 every time one operation in the mold press section 24 is completed. It is designed to clean the mating surfaces of the In addition, the mold press section 24
The unit at the front right end of the main body A, which is the side adjacent to the main body A, is the outloader section 26.

The outloader section 26 is equipped with a robot that takes out and carries in the semiconductor device S molded in the mold press section 24, and is also equipped with a cutter device that removes unnecessary parts such as runner sections. Next, the magazine supply section 23 will be explained based on FIG. 1.

[0032] As previously explained with reference to FIG. 6, a magazine unit 11 is equipped with a predetermined number of magazines 10...
are aligned on the magazine stand 12, which is a stocker section. This magazine stand 12 is provided with a magazine pusher 13, which sequentially sends out the magazine units 11 one by one. Magazine stand 12 above
An empty magazine stand 17 for receiving an empty magazine unit 16 is provided along the lower portion of the magazine.

An elevator mechanism 30 is provided on one side of the magazine stand 12, which is the direction in which the magazine unit 11 is sent out by the magazine pusher 13. The elevator mechanism 30 here includes two elevator stages 30a and 30b, upper and lower, and is driven up and down. The upper elevator stand 30a can face the magazine stand 12 and its upper part, and the lower elevator stand 30a can face the magazine stand 12 and its upper part.
b is magazine stand 12 and empty magazine stand 1
It is possible to face 7. And the upper elevator stand 30a
A dummy magazine unit 19 in which a dummy lead frame 18 consisting only of lead frames b is integrated is supported. The lower elevator stand 30b is equipped with magazine units 11 that are sequentially fed out from the magazine stand 12.
is supported.

Next, the operation of the automatic transfer molding machine constructed in this manner will be explained based on FIG. 2. A large number of resin tablets 4 are placed in the resin stocker section 21.
is input and stored. The resin tablets 4 are arranged in a line and delivered, and then delivered one by one to the inloader section 22 at predetermined intervals.

In the inloader section 22, the magazine 10 containing the lead frame b to which the semiconductor element a is bonded is supplied from the magazine unit 11 of the magazine supply section 23 as will be described later, and the magazine 10 is supplied from the resin stocker section 21. 4 resin tablets to be stored in magazine 1
Accept 0.

[0036] Then, the magazine 1 is
0 to the mold press section 24, the semiconductor element a, the lead frame b, and the resin tablet 4 are placed on the lower mold 1, and the resin tablet 4 is heated.

Drive the lower mold 1 upward to align it with the upper mold 2,
The heated resin tablet 4 is pressurized by a plunger 5. The resin tablet 4 is melted and guided from the runner 7 to the cavity 9 via the gate 8, and is press-fitted into the cavity 9.

Until the resin hardens, the upper and lower molds 2, 1
remains tightened. Then, the upper and lower molds 2, 1
By opening the mold, the semiconductor element a and the bonding part between the semiconductor element a and the lead frame b are sealed with resin, and the resin-sealed part as a semi-finished product in which the resin supply part 6 and the runner 7 part are integrally connected is formed. Becomes a body.

The robot is carried out from the outloader section 26 to the mold press section 24, takes out the resin-sealed body as a semi-finished product molded here, and returns to the outloader section 26. In the outloader section 26, a cutter device removes unnecessary parts such as the resin supply section 6 and the runner section 7. Therefore, a resin-sealed semiconductor device S as a finished product is obtained.

Next, the operation of the magazine supply section 23 will be explained based on FIG. 1. The lower elevator stand 30b of the elevator mechanism 30 is at a predetermined position (F position), and the magazine 10 is sent out from the magazine unit 11 supported here to the inloader section 22 by the required amount in one operation (one shot). .

[0041] When the number of magazines 10 required for one operation is sent out, and all the magazines 10 are sent out in a predetermined operation and become empty, the elevator mechanism 30 is driven downward in the direction A, and the lower elevator platform 30b is moved. Stop at E position,
Empty magazine unit 16 is released onto empty magazine stand 17. At this time, the upper elevator stand 30a is
It will be located in the position.

In this manner, the magazines 10 are supplied from the magazine supply section 23 to the inloader section 22, and different numbers of magazines 10 are supplied in one operation depending on the required specifications. On the other hand, since the number of magazines 10 accommodated in the magazine unit 11 is constant, the number of magazines 10 remaining after the final operation may be a fraction. The dummy lead frame 18 is used to cover the shortage in one operation.

That is, after a fractional number of magazines 10 are sent out from the magazine unit 11 to empty them, the elevator mechanism 30 is driven downward in the A direction to change the lower elevator stand 30b to the E position.

With this downward drive, the upper elevator 30a faces the F position, and feeds out the insufficient number of dummy lead frames 18 from the dummy magazine unit 19 supported here in one operation. That is, the number of lead frames b and dummy lead frames 18 required for one operation is provided. At the same time, the empty magazine unit 16 is discharged from the lower elevator stand 30b to the empty magazine stand 17.

[0045] Then, the elevator mechanism 30 is driven upward in the direction B again to support a new magazine unit 11 of another lot on the lower elevator stand 30b. The dummy magazine unit 19 supported by the upper elevator stand 30a has dummy lead frames 1 accumulated therein.
Unless all 8 are sent out, elevator platform 3 will remain as it is.
Supports 0a.

In the empty state, an operator can remove the empty dummy magazine unit 19 and replace it with a new dummy magazine unit 19 in which dummy lead frames 18 are integrated.

As a result, by adopting the configuration according to the present invention, the required time for supplying the dummy lead frame 18 can be shortened from about 50 seconds in the conventional method to about 15 seconds, leading to a significant improvement in productivity.

In the above embodiment, the dummy magazine unit 19 supported on the upper elevator stand 30a was replaced by the worker when it was empty, but the invention is not limited to this. As shown in FIG. 2, a dummy magazine stand 15 for aligning dummy magazine units 19 may be provided above the magazine stand 12, as in the conventional case.

[0049] In this case as well, the elevator mechanism 30 having the same structure as that previously explained with reference to FIG. 1 and performing the same magazine supply operation is provided as is. Therefore, there is no change in the fact that the supply time for the dummy lead frame 18 is extremely short.

[0050] Then, the empty magazine unit 16
The operation of discharging the empty magazine into the empty magazine stand 17 is as described above. Empty dummy magazine unit 19
In order to discharge the magazine to the empty magazine stand 17, it is possible to lower the upper elevator platform 30a so as to face the E position. Naturally, at this time, the lower elevator stand 30b will protrude below the E position.

[0051] Furthermore, the elevator mechanism 30 is not limited to one having upper and lower elevator stands 30a and 30b. By further increasing the number of stages and arranging an appropriate number of magazine stands 12 in parallel, the same effects as in the above embodiment can be obtained.

[0052]

[Effects of the Invention] As explained above, according to the present invention, an elevator mechanism having a plurality of elevator stands is arranged,
By always supporting a dummy magazine unit in which dummy lead frames are integrated on the elevator stand on one stage, the dummy lead frame supply time can be significantly shortened.
This has the effect of contributing to improved productivity.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a magazine supply section of an automatic transfer molding machine, showing one embodiment of the present invention.

FIG. 2 is a plan view of the automatic transfer molding machine of the same embodiment.

FIG. 3 is a schematic configuration diagram of a magazine supply section in another embodiment.

FIG. 4 is a partially cutaway perspective view of a completed semiconductor device.

FIG. 5 is a partially vertical side view of the mold press section.

FIG. 6 is a perspective view of the magazine unit.

FIG. 7 is a schematic configuration diagram of a conventional magazine supply section.

[Explanation of symbols]

a...Semiconductor element, b...Lead frame, 4...Resin tablet, 10...Magazine, 11...Magazine unit, 12
...Stocker part (magazine stand), 30b...(lower stage)
Elevator stand, 30a... (upper stage) Elevator stand, 18...
Dummy lead frame, 19... dummy magazine unit, 30... elevator mechanism.

Claims (1)

[Claims] 1. An automatic transfer molding machine that supplies a resin tablet to a lead frame to which a semiconductor element has been bonded, heats and pressurizes the resin tablet to melt it, and seals the semiconductor element and the bonding portion between the semiconductor element and the lead frame with resin. A magazine equipped with a lead frame to which the semiconductor element is bonded, a magazine unit that accumulates a plurality of the magazines, a stocker section that accommodates a large number of the magazine units and sequentially feeds out the magazines, and a magazine that is fed out from the stocker section. The unit is supported on the elevator stand on one stage, and a predetermined number of lead frames with the above-mentioned elements are fed out from this magazine unit for each resin sealing operation, and a dummy consisting only of lead frames is placed on the elevator stand on the other stage. The elevator mechanism is equipped with a multi-stage elevator mechanism in which a dummy magazine unit for accumulating lead frames is supported, and the elevator mechanism is configured to: An automatic transmission molding machine characterized in that the dummy magazine unit is moved up and down to a delivery position to send out the insufficient number of dummy lead frames in one operation.