JPH02202422A - Sealing device of resin - Google Patents

Abstract

PURPOSE:To constitute the above device so that reliability on a molded product is not spoiled, by a method wherein at the time of mold clamping, a material to be sealed is held within a mold so that the material does not abuts against an ejection mechanism and at the time of mold clamping, the material is ejected into a casting part of resin and the molded product is extruded from the casting part of the resin. CONSTITUTION:A material to be sealed is set onto a bottom force 2. In this instance, a knockout pin 8 is held already within a top force 1 with operation of a hydraulic press 20 and not ejected into a cavity 7. Then mold clamping is performed by raising the bottom force 2. Then casting of resin within the cavity 7 is performed. Then when a molded product is completed by performing molding cure of the resin, the bottom force 2 is lowered and mold breaking is started. Then since the knockout pin 8 is ejected into the cavity 7 with strong force and the molded product in the cavity 7 is pushed down strongly, the molded product in the cavity 7 is released smooth and arranged on the bottom force 2. Finally, the knockout pin 8 is held within the top force 1 and a procedure is performed until the knockout pin 8 arrives at a state where the same does not eject within the cavity 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin encapsulation device mainly used for resin encapsulation of semiconductors.

[Conventional technology]

4 to 7 are cross-sectional views showing the operation of the resin seal 1 by a conventional transfer molding device.

Hereinafter, the resin sealing operation will be explained with reference to these figures.

FIG. 4 shows the resin sealing material when it is not present.

In the figure, 1 is an upper mold, 2 is a lower mold that can be moved up and down by an h8 pressure press (not shown), and a material to be sealed 3 is set on the lower mold 2. The material to be sealed 3 is a semiconductor device, and is composed of a frame 3a, a semiconductor chip 3b, and an inner lead 3c.The material to be sealed 3 is, for example, an MP-3 as shown in FIG. There is an external transistor 30. Note that the MP-3 external transistor 30 shown in FIG. 8 is a molded product that has already been resin-sealed with the epoxy resin 11. Note that 12 is a mark caused by the knockout bottle, which will be described later.

The upper mold 1 is suspended from the return plate 4 via a spring attachment pin 5, and the normal position of the return plate 4 and the upper mold 1 is maintained by the elasticity of the spring 6 attached to the spring attachment pin 5. The relationship is fixed as shown in FIG. Further, a cavity 7 which is a resin injection part is provided in the lower part of the upper mold 1.

One knockout bin 8 is provided in a region corresponding to each cavity 7 from the lower surface of the return plate 4 downward. In addition, a return bin 9 that is longer than the thickness of the upper mold 1 extends downward from the lower surface of the return plate 4 where the upper mold 1 is not present (usually the lower surface of the return plate 4 corresponding to the four corners of the lower mold 2). It is provided.

In such a configuration, the resin sealing material 3 shown in FIG.
When setting the upper mold 1. The lower mold 2 is fixed together,
At this time, the knockout bin 8 is inserted into the cavity 7 of the upper mold 1.
protrudes inward.

Mold clamping is performed by raising the lower mold 2 from this state by driving a hydraulic press. Before this mold clamping is completed, the lower surface of the return bin 9 hits the lower mold 2, and thereafter, as the lower mold 2 rises, the return bin 9 also rises. Therefore, the return plate 4 and the knockout bin 8, which are mechanically interlocked with the return bin 9, also rise.

When the mold clamping is completed, the knockout bin 8 is raised to a state where it is almost housed in the upper mold 1, as shown in FIG.

Next, as shown in FIG. 6, the cavity 7 is filled with a heat-plasticized epoxy resin 11, and the mold is cured by heat and pressure to seal the material 3 to be sealed with the resin to produce a molded product.

After manufacturing the molded product, the hydraulic press is operated again, the lower mold 2 is lowered, and mold opening begins. As the lower mold 2 descends,
The return bin 9 also descends. The knockout bin 8 mechanically interlocked with the return bin 9 attempts to descend, and the restoring force of the spring 6 is also applied, so that the resin 11 in the cavity 7 is strongly pushed down. As a result, the molded product 15 in the cavity 7 is smoothly released from the mold and placed on the lower mold 2 as shown in FIG.

[Problem to be solved by the invention]

The conventional transfer molding device is constructed as described above, and the knockout bin 8 protruding into the cavity 7 is housed in the upper mold 1 as the lower mold 2 moves during mold clamping. Ta. In other words, the knockout bin 8 was completely housed in the upper mold when the mold clamping was completed.

Therefore, from the time the material to be sealed is set until the mold clamping is completed, the material to be sealed is deformed during manufacturing, the momentum of the material due to the @ movement that occurs when the hydraulic press is turned on and off, or the As shown in Fig. 9, there is a possibility that the knockout bottle 8, which is not yet completely housed in the upper mold 1, will hit the material to be sealed 3 due to warping of the material to be sealed due to the heat of the high temperature lower mold 2. Most likely.

When the knockout bottle 8 hits the material 3 to be sealed, phenomena such as destruction of the semiconductor chip 3b of the material 3 to be sealed and deformation of the inner leads 3C occur, which deteriorate the characteristics of the product. There was a problem that the performance was significantly reduced.

This invention was made to solve the above problems, and aims to provide a resin sealing device that does not impair the reliability of molded products.

[Means to solve the problem]

According to the present invention, the resin sealing device has a resin injection part, and a mold for forming a molded product by sealing a material to be sealed with resin during mold clamping in the resin injection part, and a mold for forming a molded product. an ejecting mechanism housed in a mold and capable of ejecting into the resin injection section; a first driving means for causing the molding die to perform mold opening and mold clamping operations; a second driving means operable independently of the ll device and causing the ejection mechanism to eject into the resin injection part and accommodate in the mold; and the first and second drives. When the molding die is clamped before forming a molded product, the ejecting mechanism is housed in the molding die so that the material to be sealed does not come into contact with the ejecting mechanism, and the ejecting mechanism is The molding apparatus further includes a control means for causing the ejecting mechanism to protrude into the resin injection part to extrude the molded product from the resin injection part when the molding die is separated from the mold after the product is formed.

[Effect]

The control means in this invention controls the first and second drive means, and when clamping the molding die before forming a molded product, the control means controls the ejection so that the material to be sealed does not come into contact with the ejection mechanism. A mechanism is housed in the molding die, and when the molding die is pressed after forming a molded product, the ejecting mechanism is caused to protrude into the resin injection part to push out the molded product from the resin injection part. , the protrusion mechanism does not come into contact with the material to be sealed during mold clamping before forming the molded product.

〔Example〕

FIG. 1 is a sectional view showing a transfer molding apparatus which is an embodiment of the present invention. As shown in the figure, the return plate 4 is raised and lowered by a second hydraulic press 20 via a return bin 9 which is shorter than the conventional one. This second hydraulic press 20 can be controlled independently of the first hydraulic press (not shown) that drives the lower mold 2. Note that the other configurations are the same as the conventional one, so explanations will be omitted.

FIG. 2 is a flowchart showing the resin sealing operation by the transfer molding apparatus shown in FIG. Note that the first hydraulic press and the second hydraulic press 20 are controlled by a control device (not shown).

First, in step S1, the material to be sealed 3 is set on the lower mold 2. At this time, the second hydraulic press 20
As a result of the operation, the knockout bin 8 is housed in the upper mold 1 and does not protrude into the cavity 7, as shown in FIG.

Next, in step S2, the lower mold 2 is raised and clamped by operating the first hydraulic press until completion of mold clamping is confirmed W1 by a pressure switch (not shown). At this point, the knockout bin 8 is already housed in the upper mold 1 due to the operation of the second hydraulic press 20, as shown in FIG. , as shown in FIG.
b.

The mold is clamped without hitting the inner lead 3C, and the warp is corrected upon completion of mold clamping.

Then, in step S3, resin is injected into the cavity 7. After the resin is injected, the injection pressure is detected by a pressure switch, and the pressure inside the cavity 7 is controlled to a constant pressure. Then, this management is released after the timer setting time has elapsed.

After that, after a certain period of time has elapsed and the resin hardens in the mold in the Ps-bitty 7 and the molded product is completed, in step S4 the π mold 2 is lowered by the first hydraulic press,
Start pattern listening. At the timing of this mold opening ltl 9M, the second hydraulic press 20 is operated and the return plate 4 is also lowered. Accordingly, a force is applied to the knockout bin 8, which is mechanically interlocked with the return plays 1 and 4, to try to lower it. Since the restoring force of the spring 6 is also added, the knockout bottle 8 is pushed into the cavity 7 with a strong force. As a result, the knockout bin 8 strongly pushes down the molded product in the cavity 7,
The molded product in the cavity 7 is smoothly released and placed on the lower mold 2.

After 1d, the second hydraulic press 20 is operated in step S5, and the return plate 4 is raised.

This elevation is continued until the knockout bin 8 mechanically interlocked with the return plate 4 is housed in the upper mold 1 and does not protrude into the hole 7.

In this way, the upper limit of the lower mold 2, the mold clamping by lowering, the mold opening operation, and the raising of the return plate 4.

■The operation of ejecting the knockout bin 8 into the cavity 7 due to falling and storing the knockout bin 8 into the upper mold 1 is performed by a separate drive device.
oil 1 mopress, second hydraulic press 20),
Since the control device controlled the knockout bin 8 to be ejected into the cavity 7 only when the mold is opened, there is no possibility that the material to be sealed 3 that has warped or the like will hit the knockout bin 8 in the cavity 7 when the mold is closed. .

As a result, a phenomenon that deteriorates the characteristics of the material to be sealed 3 during mold clamping does not occur, so that the reliability of the resin-sealed molded product is not impaired.

In this example, a semiconductor device was used as an example of the material to be sealed, but the present invention is not limited to this, and can be applied to any material to be sealed that may impair reliability if it hits a knockout bottle during mold clamping. .

(Effects of the Invention) As explained above, according to the present invention, the first and second driving means are controlled by the control means, and when the molding die is clamped before forming the molded product, the sealed The ejecting mechanism is housed in the molding die so that the material does not come into contact with the ejecting mechanism, and when the molding die is opened after forming the molded product, the ejecting mechanism is ejected into the resin injection part. Since the molded product is extruded from the resin injection part in this manner, the reliability of the molded product is not impaired.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a sectional view showing a transfer molding device according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the resin sealing operation of the transfer molding device shown in FIG. 1. Fig. 3 is a sectional view showing the effect of the transfer molding device shown in Fig. 1, Figs. FIG. 9 is a perspective view showing an example, and a sectional view showing problems of a conventional transfer molding device. In the figure, 1 is an upper mold, 2 is a lower mold, 3 is a material to be sealed,
4 is a return plate, 7 is a cavity, 8 is a knockout bin, and 20 is a second hydraulic press. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A molding die having a resin injection part, in which a material to be sealed is sealed with resin during mold clamping to form a molded product; a first ejecting mechanism that allows the mold to eject into the mold;
a second driving means that is operable independently of the first driving device and causes the ejecting mechanism to eject into the resin injection part and to be accommodated in the molding die; The first and second driving means are controlled, and when the mold is clamped before forming a molded product, the ejecting mechanism is moved into the mold so that the material to be sealed does not come into contact with the ejecting mechanism. and a control means for causing the ejecting mechanism to protrude into the resin injection part to push out the molded product from the resin injection part when the mold is opened after forming the molded product. Device.