JPH0356341Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is used, for example, in an apparatus for resin-sealing parts to be sealed such as semiconductor elements mounted on a lead frame. This invention relates to an improvement in a mold release device used for releasing molds from molds.

(Prior Art) As a device for sealing a semiconductor element with a resin material, a transfer molding device has conventionally been used.

As shown in FIG. 5, this device consists of an upper die plate C fixed to a fixed platen A via a spacer block B, and a lower die plate F fixed to a movable platen D via a spacer block E. An upper mold G and a lower mold H for resin-sealing a semiconductor element are provided oppositely to the two mold plates C and F. Then, the molds G and H are clamped by raising the lower mold H to the parting line (PL) surface and bringing the two mold surfaces into close contact. This is because when the semiconductor element on the lead frame fitted in the cavity I of both molds is sealed with a resin material during mold clamping, a part of the resin material is
This is to prevent it from penetrating into the parting line surface of H and adhering to the mold surface or the surface of the lead frame. In addition, spacer blocks B and B for both types G and H are also available.
The main purpose of E is to configure a space L for fitting ejector plates J and K installed in order to release the resin-sealed molded body.

(Problems to be Solved by the Invention) By the way, since the ejector plates J and K release the resin-sealed molded product by sliding the ejector pin M provided on the plate up and down, The above-mentioned space L needs to be wide enough to allow the ejector plates J and K to freely reciprocate up and down, and spacer blocks B and E are arranged around both type plates C and F. Also, since both types G and H are arranged in the center of both types plates C and F,
The clamping pressure of both molds acts as a force that curves and deforms the center portions of both mold plates C and F in opposite directions (toward the space L side).

Even if such an external force is applied to both mold plates C and F, there will be no problem if mold clamping of both molds G and H is performed reliably, but during actual resin molding, for example, Due to the curved deformation of both mold plates C and F, both molds G and H become eccentric, or a gap is created between the parting line (PL) surfaces of both molds, resulting in defective molding, or mold defects. There is a serious problem such as the occurrence of large amounts of resin burrs on surfaces etc.

In order to deal with the above-mentioned drawbacks of the conventional technology, the present invention provides a method for separating molded products (resin-sealed molded bodies) that can omit the above-mentioned space L, which was considered indispensable in the structure of the resin-sealing device. The purpose is to provide a molding device.

(Means for solving the problem) Mold release device 2 for resin-sealed molded body 19 according to the present invention
0 refers to the ejector pin 21 for mold release of the resin-sealed molded product 19, and the above-mentioned ejector pin 21 that moves forward in the mold release direction of the resin-sealed molded product 19 and back in the opposite direction. The ejector pin 21 consists of a reciprocating sliding mechanism 22 of an ejector pin 21, and a reciprocating member 27 of the ejector pin 21 in the reciprocating sliding mechanism is formed of a shape memory alloy (hereinafter simply referred to as SMA). Pressing body 25
and heating/cooling means 26 for the pressing body.

(Function) According to the configuration of the present invention, both type plates 5 and 10
Since the device 20 of the present invention can be tightly fitted into the mounting hole provided in the mounting hole, etc., the space L for mounting the ejector plates J and K can be omitted from the configuration of the conventional resin sealing device. can.

Furthermore, since the ejector pin 21 in the configuration of the present invention has its pressing body 25 made of SMA, it can be slid back and forth by heating or cooling the pressing body. Therefore, by utilizing the reciprocating sliding motion of the ejector pin 21, the forward motion for releasing the resin-sealed molded body 19 and the return motion of the ejector pin 21 to its original position are performed. It can be carried out.

(Example) Next, the present invention will be explained based on the example diagrams shown in FIGS. 1 to 4.

FIG. 1 shows a resin sealing apparatus for sealing and molding a semiconductor element with a resin material R. As shown in FIG.

This device includes a fixed platen 3 fixed to the upper end of the tie bar through a plurality of tie bars 2 erected on a base 1, and a heat insulating plate 4 and an upper mold plate 5 attached to the lower part of the fixed platen 3. A fixed upper die 6 is fixed to the base plate 1, and a movable platen 8 is fitted to the tie bar 2 and is movable up and down by a vertical movement mechanism 7 using oil, air pressure, etc. provided on the base 1. The movable lower mold 11 is fixed to the upper part of the movable platen 8 via a heat insulating plate 9 and a lower mold plate 10.

In addition, a plurality of pots 1 are provided in the center of the lower mold 11.
A plunger 13 for pressurizing the resin material is fitted into each pot 12, and both molds 6 and 11 are positioned around each pot 12.
A required number of cavities 14 are provided opposite to each other on the parting line (PL) surface, and each pot 12
A passage 15 for transferring molten resin material is provided between each of the holes and a predetermined cavity 14 in the vicinity thereof.

Note that the transfer passage 15 is connected to the cull 15 1 of the upper mold 6 which is arranged opposite to the pot 12 position of the lower mold 11 _.
When both molds 6 and 11 are clamped, the cull 15 ₁
It consists of a gate ₁₅₂ provided to communicate with the
Further, the gate 15 ₂ is communicated with the cavity 14 on the lower mold 11 side. Therefore, although the sealing device shown in FIG. 1 is a runnerless type and a multi-pot plunger type, it is also possible to use a runner type in which a runner is disposed between the cull ₁₅₁ and the gate ₁₅₂ , and a large-sized sealing device. A one-pot plunger type with a pot may also be used.

Further, each of the plungers 13 is configured to move up and down by a transfer cylinder 16. Further, the lead frame 17 to which the semiconductor element (not shown) is attached is set at the predetermined position of both the molds 6 and 11 at once via the loading frame 18, and after the semiconductor element is resin-sealed and molded, It is configured so that it can be taken out all at once from between the molds 6 and 11.

Resin sealing molding of a semiconductor element using the resin sealing apparatus described above is performed as follows.

First, both molds 6 and 11 are opened as shown in FIG.

Next, the lead frame 17 is set at a predetermined position on the lower mold 11 via the loading frame 18.

At this time, the semiconductor element on the lead frame is aligned with the position of the cavity 14 of the lower die 11.

Next, the resin material R is supplied into the pot 12 of the lower mold 11, and in this state, the movable platen 8 is moved by the vertical movement mechanism 7.
is raised to perform mold clamping to join the lower mold 11 and the upper mold 6 at the parting line (PL) surface.

Next, the resin material R in the pot 12 is heated by a heater (not shown), and the plunger 13 is moved upward by the transfer cylinder 16 to pressurize and melt it. Under pressure, molten resin material is injected and filled into the upper and lower cavities 14 through the transfer passage 15 formed between the two molds 6 and 11, thereby transferring the semiconductor element fitted into the upper and lower cavities 14. Seal with resin.

By the way, the lead frame 17 set between the two dies 6 and 11 and the resin-sealed molded body 19 of the semiconductor element fixed to the lead frame 17 are removed by a mold release device 20 provided on both the dies 6 and 11. Then, it is taken out between the molds 6 and 11.

As shown in enlarged views in FIGS. 2 and 3, this mold release device 20 includes an ejector pin 21 fitted into the upper and lower cavities 14, and
at a predetermined position in the mold release direction of the resin-sealed molded body 19 (that is, in the vertical direction between the molds 6 and 11),
It also includes a reciprocating sliding mechanism 22 for an ejector pin 21 that reciprocates to a predetermined position in the opposite direction.

Note that the mold release device 20 is a lead frame 17
Alternatively, the purpose is to extrude the resin-sealed molded body 19 fixed to the lead frame 17 between the molds 6 and 11.

Therefore, it is customary to arrange them facing each other in the upper mold 6 and the lower mold 11, but if the mold release action and effect is good, for example, they can be arranged alternately in both the molds 6 and 11. You can. Moreover, the resin-sealed molded body 19
In order to release the mold, it is necessary to link the above-mentioned upward movement of the loading frame 18 with the mold release action. However, the upward movement of the loading frame 18 has the same purpose as the mold release device 20 disposed on the lower mold 11 in the sense of pushing up the resin-sealed molded body 19 and the like from the lower mold 11. Therefore, although not shown, the upward movement of the loading frame 18 can be performed by a vertical reciprocating mechanism having the same structure as the mold release device 20 shown in FIGS. 2 and 3.

The mold release device 20 has an upper mold 6 and a lower mold 11.
There is a difference that the direction of action is upside down, but in other respects, substantially the same configuration can be adopted, so hereinafter, only the configuration disposed on the lower mold 11 side will be described.

The lower part of the ejector pin 21 is fitted into a heat insulating case 23 fitted to the lower die plate 10. Further, the reciprocating (up and down) sliding mechanism 22 of the ejector pin 21 moves the upper end surface of the ejector pin 21 to the inner bottom surface of the lower mold cavity 14 when the molds 6 and 11 are clamped (FIG. 2). An elastic member 24 for backward movement (downward movement) to the position, and a pressing body 25 for the ejector pin 21 formed of SMA.
and a reciprocating member 27 of the ejector pin 21 consisting of a heating/cooling means 26 for the pressing body 25;
It is composed of.

The heating/cooling means 26 also includes a heating medium member 26 ₁ that also serves as a stopper in the above-mentioned backward movement (downward movement) position of the ejector pin 21, and a heating or cooling fluid that is supplied and circulated to the heating medium member 26 ₁ . a fluid circulation path 26 ₂ , a fluid storage tank, a switching valve, a circulation pump that can select and supply either heating or cooling fluid to the fluid circulation path 26 ₂ , and the switching valve and pump. It is composed of automatic control mechanisms (not shown) such as

Therefore, according to the above configuration, when the cooling fluid is circulated through the fluid circulation path 26 ₂ prior to the mold clamping shown in _FIG . The elastic member 2 is cooled to a temperature and softened, and the elastic member 2 is
4, it deforms so as to contract downward. At this time, the heating medium member 26 ₁ also serves as a stopper on the downward movement side of the ejector pin 21, so that the downward movement position of the ejector pin 21 is constant, and its upper end surface is aligned with the cavity 1.
It is set to be substantially flush with the inner bottom surface of No. 4. Therefore, in the above state, the lower mold 1 described above
Setting the lead frame 17 to 1/resin material R
Resin molding can be performed by supplying, mold clamping, and injecting and filling molten resin material into the upper and lower cavities 14.

After resin sealing molding, in order to release the resin sealing molded body 19 from the mold, the fluid circulation path 26 ₂
What is necessary is to circulate a heating fluid therein. At this time,
The pressing body 25 is heated and hardened to a predetermined temperature via the heating medium member ₂₆₁ , and as shown in FIG.
Because its shape is restored, the ejector pin 2
1 is raised to release the resin-sealed molded body 19 from the cavity 14. Furthermore, as mentioned above,
By linking the releasing action of the resin-sealed molded body 19 with the lifting action of the loading frame 18, the loading frame 18, the lead frame 17 supported thereon, and the lead frame 17 are fixed to each other. The entire resin-sealed molded body 19 is placed above the lower mold 11 (that is, between the two molds 6 and 11).
can be taken out.

FIG. 4 shows a case where the pressing body 25 is formed as a coil spring ₂₅₁ .
In this case, a heating/cooling liquid may be used as the heating/cooling means 26, but it is preferable to use a gas such as hot air or cold air. Also,
Plate-shaped SMA in place of the above coil spring 25 ₁
It may also be formed as a leaf spring (not shown) using. The other configurations can be substantially the same as those of the first embodiment (FIGS. 2 and 3) described above, so the same constituent members are designated by the same reference numerals as in FIGS. 2 and 3. It is attached. In this embodiment as well, by cooling and heating the coil spring 25 ₁ , the spring 25 ₁
can be contracted and deformed and restored to shape, and therefore the same effects as those of the first embodiment can be obtained.

In addition, in the illustrated example, the ejector pin 21
The reciprocating sliding mechanism 22 of the ejector pin 21 is made of SMA and has a reciprocating pressing body 25, ₂₅₁ for reciprocating movement,
A case is shown in which the ejector pin 21 is constructed of a coil spring or the like and a reciprocating elastic member 24. Therefore, the pressing bodies 25, 25 ₁ are as follows:
The elastic member 24 has a unidirectional property that memorizes the shape of the ejector pin 21 when it is pressed (upward movement) shown in FIG _.
It acts as a bias spring to move the ejector pin 21 back (move downward) to its original position. In particular, in the mold release device 20 provided on the upper mold 6 side, the pressing bodies 25, 25 ₁ are the ejector pins 2
1 is moved downward, so if the pressing body is unidirectional, a bias spring is required to move the ejector pin 21 back (upward) using the elasticity of the elastic member 24. .

In this way, the reciprocating sliding mechanism 22 may be constructed from a combination of the unidirectional pressing bodies 25, ₂₅₁ and the elastic member 24 as a bias spring, but the reciprocating sliding movement of the ejector pin 21 In order to ensure performance or simplify the configuration, the following improvements may be made.

That is, the pressing bodies 25, 25 ₁ made of SMA are given a bidirectional shape memory effect that acts reversibly in response to temperature changes, and the pressing bodies 25, 25 1 are made of SMA.
5 ₁ and the ejector pin 21 may be connected by appropriate means. Therefore, in this case, a spring (elastic member 24) as a bias spring is unnecessary.

Further, the temperature at which the shape of the pressing bodies 25, ₂₅₁ described above is restored is, for example, about 30°C to 100°C.
For example, the deformation temperature is approximately
The temperature should be below 30℃, but these temperature settings are
It can be arbitrarily set to suit the shape of the cavity 14 surface, the mold release resistance or mold release speed for the resin-sealed molded body 19, or other molding conditions such as room temperature. Furthermore, when the molds 6 and 11 are opened, the mold release device 20 provided on the upper mold 6 side performs a mold release action that pushes out the cull 15 ₁ of the upper mold 6 and the resin molded body in the cavity 14 downward at approximately the same time. However, such setting and adjustment of the start timing of the mold release action between the molds 6 and 11 may be performed by the automatic control mechanism described above.

In addition, the pressing bodies 25, 25 ₁ and the elastic member 24
It is also possible to adopt a configuration (not shown) in which both are formed of SMA and heating/cooling means 26 are provided for each separately.

Further, when the mold release device 20 is installed in the sealing device, the ejector pin 21 may be provided at a position where it acts on the lead frame 17.

(Effects of the invention) The mold release device of the present invention can be fitted and installed into the mounting holes of both mold plates, etc. in the sealing device, so the space for installing the conventional ejector plate is substantially omitted. be able to. Therefore, the clamping action of both molds can be performed efficiently and reliably, and the strength and durability of both mold plates and the like can be improved due to the increased wall thickness.

In addition, in the resin sealing device equipped with the device of the present invention, by ensuring the above-mentioned mold clamping, the resin sealing molding of the object to be sealed can be reliably performed.
This not only improves the quality of the product, but also simplifies the overall configuration of the resin sealing device, which provides practical effects such as ease of handling.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway longitudinal sectional front view showing the main parts of a resin sealing device for a semiconductor element equipped with a device according to the present invention. FIGS. 2 and 3 are an enlarged longitudinal sectional front view, partially cut away, showing the first embodiment of the device of the present invention, and an enlarged longitudinal sectional front view, partially cut away, for explaining its operation. FIG. 4 is a partially cutaway longitudinal sectional front view showing a second embodiment of the device of the present invention. FIG. 5 is a schematic longitudinal sectional front view showing a configuration example of a conventional resin sealing device. Explanation of symbols, 1...Base, 2...Tie bar, 3
... fixed plate, 4 ... heat insulation plate, 5 ... upper mold plate, 6 ... upper mold, 7 ... vertical movement mechanism, 8 ... movable plate, 9 ... heat insulation plate, 10 ... lower mold plate, 11
... lower mold, 12 ... pot, 13 ... plunger, 14 ... cavity, 15 ... transfer passage,
15 ₁ ... Cal, 15 ₂ ... Gate, 16 ... Transfer cylinder, 17 ... Lead frame, 18 ... Loading frame, 19 ... Resin sealing molded body, 20 ... Mold release device, 21 ... ...Ejector pin, 22...Reciprocating sliding mechanism, 23...
Heat insulation case, 24... Elastic member, 25... Pressing body, 25 ₁ ... Pressing body (coil spring), 26
... Heating/cooling means, 26 ₁ ... Heat carrier member, 2
6 ₂ ... fluid circulation path, 27 ... reciprocating member, R ...
...Resin material.

Claims (1)

[Scope of utility model registration request] An ejector pin for releasing a resin-sealed molded product,
and a reciprocating sliding mechanism for the ejector pin that moves the ejector pin forward in the mold release direction of the resin-sealed molded body and back in the opposite direction, the ejector pin in the reciprocating sliding mechanism. 1. A mold release device for a resin-sealed molded article, wherein the reciprocating member is composed of a pressing body of an ejector pin made of a shape memory alloy, and heating/cooling means for the pressing body.