JPH08108455A - Mold for sealing semiconductor resin - Google Patents

Abstract

PURPOSE: To reduce the damage to an internally mounted article (semiconductor element or bonding wire) at the time of the release of a molding from a mold. CONSTITUTION: An ejector pipe 13 is provided so as to communicate with at least either one of use cavities 8, 9 of upper and lower molds, for example, the cavity 8 of the upper mold 1. An opening and closing valve 14 is arranged to the opening part 13a of the ejector pipe 13 so as to be flush with the surface of the upper mold cavity. At the time of release, the opening and closing valve 4 is opened to apply water pressure or air pressure from the opening part 13a of the ejector pipe 13 to release a molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor resin encapsulating mold used for encapsulating a semiconductor chip mounted on a lead frame with a molding resin.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view showing a conventional semiconductor resin sealing mold. In the semiconductor resin sealing die shown in FIG. 7, 1 is an upper die, 2 is a lower die, 3 is a transfer pot, 4 is a plunger, 5 is a cull portion, 6 is a runner, 7 is a gate, 8 is a Upper mold cavity, 9 is lower mold cavity, 10
Is an upper ejector pin, and 11 is a lower ejector pin.

When the semiconductor element is actually resin-sealed,
Resin is injected into the cavities 8 and 9 with the upper mold 1 and the lower mold 2 clamped (clamped). Next, after hardening the resin filled in the cavities 8 and 9, the molded product is released from the mold as follows. First, as the lower mold 2 descends, the upper mold ejector pin 10 is projected to push out the molded product 12 from the upper mold cavity 8 as shown in FIG. 8, whereby the molded product 12 is released from the upper mold 1. Let Then, immediately before the lower mold 2 is completely lowered, as shown in the figure, the lower mold ejector pin 11 is projected to push up the molded product 12 from the lower mold cavity 9, whereby the lower mold 2 is molded. The product 12 is released. At this point, the molded product 12 can be easily taken out from the upper and lower molds 1 and 2.

[0004]

However, in the above-mentioned conventional mold for semiconductor resin encapsulation, the surface of the molded product 12 has a reason for manufacturing control (for example, which mold is used for molding is judged from the appearance). Each ejector pin 10, 11 in order to put an identification mark from
The resin was injected into the cavities 8 and 9 in a state where the tip portion of the above was projected from the cavity surface. Therefore, especially TQF
P (Thin Quad Flat Package)
And TSOP (Thin Small Outline)
In the case of molding a thin package such as a package), the resin thickness at the eject position is locally thinned, which may damage the semiconductor element to be sealed, the bonding wire, or the like. In addition, due to the assembling accuracy of the upper and lower molds 1 and 2, the protrusion amount of the ejector pins 10 and 11 from the surfaces of the cavities 8 and 9 varies by several tens of μm, which is a semiconductor element or a bonding wire that is an internal mounting object. It was also a factor to increase the damage to.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has at least one of upper and lower molds having a cavity corresponding to a molded product and a cavity of the upper and lower molds. An ejector tube provided in communication with the ejector tube, and an opening / closing valve provided at the opening of the ejector tube and flush with the cavity surface. The opening of the ejector tube with the opening / closing valve open. It is a semiconductor resin encapsulation mold for releasing a molded product by applying water pressure or air pressure from the mold.

[0006]

In the semiconductor resin encapsulating mold of the present invention, air pressure or water pressure is applied to the molded product from the opening of the ejector tube provided in communication with at least one of the upper and lower mold cavities. In addition, since the molded product is released from the mold, the resin thickness of the molded product at the eject position is ensured to be thicker than before.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of a semiconductor resin sealing die according to the present invention. In the semiconductor resin sealing mold shown in FIG. 1, 1 is an upper mold, 2 is a lower mold, 3 is a transfer pot serving as a supply port of a molding material (resin tablet), and 4 is a molding material moved under pressure. Plunger 5 for forming a molding material, a cull portion serving as a starting point for introducing the molding material, 6 a runner serving as a flow path of the molding material that has been softened by heating, 7 a gate serving as an injection port of the molding material, and 8 corresponding to a molded product A mold cavity, 9 is a lower mold cavity corresponding to the same molded product, and 11 is a lower mold ejector pin for releasing the molded product from the lower mold 2.

In the mold structure of the first embodiment, the upper mold 1 is provided with an ejector tube 13 as a characteristic part thereof. This ejector tube 13
It is used to apply water pressure or air pressure when releasing the molded product, and is provided so as to communicate with the upper mold cavity 8. Further, in the opening 13a of the ejector tube 13 communicating with the upper mold cavity 8, for example, an electromagnetically driven opening / closing valve 14 is provided.
Are arranged flush with the surface of the cavity 8. This opening / closing valve 14 closes the opening 13a of the ejector tube 13 so that the cavity 8 surface is flush when the resin is filled, and operates when the molded product is released from the mold, as indicated by the chain double-dashed line in the figure. As shown, the ejector tube 13 is opened and the opening 13a is opened.

When a semiconductor element is resin-sealed by using the mold of the first embodiment, first, with the upper mold 1 and the lower mold 2 separated from each other, a lead frame (element (Shown)
Is set in the lower mold 2, and then, as shown in FIG. 2A, the upper mold 1 and the lower mold 2 are aligned and clamped (clamp).
To do. Next, resin doublet (not shown) that will be the molding material
Is charged into the transfer pot 3 and heat is applied to the resin tablet from the mold to reduce the resin viscosity. Then, the plunger 4 is driven to inject the resin in the transfer pot 3 into the cavities 8 and 9 of the upper and lower molds 1 and 2 through the cull portion 5 → runner 6 → gate 7. At this time, the opening / closing valve 14 of the upper mold 1 is closed, and the opening 13a of the ejector tube 13 is closed.
Therefore, the resin does not flow into the ejector tube 13, and the upper surface of the molded product is formed smoothly following the upper mold cavity 8 surface.

Then, the cavities 8 and 9 of the upper mold 1 and the lower mold 2 are kept filled with the resin for several minutes, and when the resin is cured by this, the molded product is released from the mold as follows. Let First, at the same time when the lower mold 2 descends, as shown in FIG.
As shown in (b), the opening / closing valve 14 is opened and compressed air (or pressurized water) is supplied from the opening 13a of the ejector tube 13.
Squirt out. As a result, air pressure (or water pressure) is applied to the upper surface of the molded product 12, so this air pressure (or water pressure) is applied.
Thus, the molded product 12 is released from the upper mold 1. Then, immediately before the lower mold 2 is completely lowered, as shown in the figure, the lower mold ejector pin 11 is projected into the lower mold cavity 9 to push up the molded product 12, and the molded product 1 is pushed from the lower mold 2.
Release 2 from the mold. At this point, the molded product 12 can be easily taken out from the upper and lower molds 1 and 2.

As described above, in the first embodiment, after the resin filled in the cavities 8 and 9 is cured, the opening / closing valve 14 is operated at the same time when the mold is opened, and the ejector provided in the upper mold 1 is operated. Molded product 1 from opening 13a of pipe 13
Pneumatic (or water pressure) is applied to 2 to mold 12 from upper mold 1
Since the molded product 12 is released from the mold, the resin thickness of the molded product 12 at the eject position becomes thicker than in the conventional case, and the damage to the internal mounting object (semiconductor element, bonding wire, etc.) can be reduced accordingly. Further, in the first embodiment, since the molded product 12 is released by pneumatic pressure (or water pressure) without applying mechanical stress by the ejector pin, peeling of the resin generated at the interface with the internal mounting object,
It is also possible to effectively suppress cracks and the like.

FIG. 3 is a sectional view showing a second embodiment of a semiconductor resin sealing die according to the present invention. In the second embodiment, the same components as those in the first embodiment will be described with the same reference numerals. In the semiconductor resin sealing die shown in FIG. 3, 1 is an upper die, 2 is a lower die, 3 is a transfer pot, 4 is a plunger, 5 is a cull portion, 6 is a runner,
7 is a gate, 8 is an upper mold cavity, 9 is a lower mold cavity, 10 is an upper mold ejector pin, and 11 is a lower mold ejector pin.

Here, in the mold structure of the second embodiment, as a characteristic part thereof, a concave groove 15 corresponding to the tip shape of the upper mold ejector pin 10 is formed on the surface of the cavity 8 provided in the upper mold 1. Has been formed. The outer diameter of the tip portion of the upper die ejector pin 10 is set to be larger than that of other portions with a predetermined step, and the step surface generated by this is used as a reference surface to be fitted into the concave groove 15 of the cavity 8 so as to be retractable. Has been done. When the tip portion of the upper ejector pin 10 is fitted in the groove 15 as shown in the drawing, the tip end surface of the pin is flush with the surface of the cavity 8.

When a semiconductor element is resin-sealed by using the mold of the second embodiment, the upper mold 1 and the lower mold 2 are clamped by the same procedure as in the first embodiment, and further, After softening the resin tablet (molding material) put in the transfer pot 3, the plunger 4 is driven to inject the resin into the cavities 8 and 9 through the cull portion 5 → runner 6 → gate 7. At this time, since the tip portion of the upper die ejector pin 10 is fitted in the concave groove 15 on the surface of the cavity 8, the upper surface of the molded product is formed smoothly along the surface of the upper die cavity 8. .

After that, the cavities 8 and 9 of the upper mold 1 and the lower mold 2 are kept filled with the resin for several minutes, and when the resin is cured by this, the molded product is released as follows. Let First, at the same time when the lower mold 2 descends, as shown in FIG.
As shown in FIG. 3, the upper die ejector pin 10 fitted in the groove 15 is projected from the surface of the cavity 8 to push out the molded article 12, and the molded article 1 is released from the upper mold 1. Then, immediately before the lower mold 2 is completely lowered, as shown in the figure, the lower mold ejector pin 11 is projected from the lower mold cavity 9 to push up the molded product 12, and the molded product 12 is pushed from the lower mold 2. To release. At this point, the molded product 12 can be easily taken out from the upper and lower molds 1 and 2.

As described above, in the second embodiment, the tip portion of the upper die ejector pin 10 is provided with the concave groove 1 until the cavities 8 and 9 of the upper and lower dies 1 and 2 are filled with the resin.
5, the tip end surface of the pin is arranged flush with the cavity 8 surface, and at the same time when the mold is opened after resin curing, the upper mold ejector pin 10 is projected from the cavity 8 surface to form the molded product 12. Since the molded product 12 is released from the mold, the resin thickness of the molded product 12 at the eject position becomes thicker than in the conventional case as in the first embodiment, and the damage to the internal mount can be reduced accordingly.

In the first embodiment described above, the ejector tube 13 is provided only in the upper mold 1 to allow the opening / closing valve 1
Although the molded product 12 is released from the mold by air pressure or water pressure by the operation of No. 4, the present invention is not limited to this. For example, the ejector pipe 13 and the opening / closing valve 14 may be provided only in the lower mold 2. You may Further, as shown in FIG. 5, if the ejector hole 13 and the opening / closing valve 14 are provided in both the upper die 1 and the lower die 2, respectively, the resin thickness of the molded product 12 at the eject position can be further increased. Therefore, it is possible to further reduce the damage of the internal mounting object at the time of mold release.

Also in the second embodiment described above, the concave groove 15 is provided only on the cavity 8 surface of the upper mold 1 so that the tip surface of the ejector pin 10 is flush with the cavity 8 surface. The present invention is not limited to this, and for example, a groove 15 may be provided only in the lower mold 2 and the tip portion of the ejector pin 11 may be fitted into this. Further, as shown in FIG. 6, a groove 15 is provided in each of the upper mold 1 and the lower mold 2 so that the tip surfaces of the ejector pins 10 and 11 are flush with the cavities 8 and 9. , Ejector pins 10 and 1 at the time of mold release as shown
If 1 is made to project, the resin thickness of the molded product 12 at the eject position is secured to be much thicker as described above, so that it is possible to further reduce the damage to the internal mounting object at the time of mold release.

[0019]

As described above, according to the present invention,
Of the cavities of the upper and lower molds, air pressure or water pressure is applied to the molded product from the opening of the ejector pipe that is provided in communication with at least one of the cavities, so the resin thickness of the molded product at the eject position is The thickness can be ensured to be thicker than in the past, and the damage to the internal mounting object (semiconductor element, bonding wire, etc.) can be reduced accordingly. As a result, especially when a thin package such as TQFP or TSOP is resin-sealed, it is possible to obtain sufficient releasability while avoiding damage to the internal mounting object, so that the package can be made thinner. This will lead to quality improvement as a semiconductor product.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a semiconductor resin sealing die according to the present invention.

FIG. 2 is a cross-sectional view showing a released state in the first embodiment.

FIG. 3 is a sectional view showing a second embodiment of a semiconductor resin sealing die according to the present invention.

FIG. 4 is a sectional view showing a releasing state in a second embodiment.

FIG. 5 is a sectional view showing a modification of the first embodiment.

FIG. 6 is a sectional view showing a modification of the second embodiment.

FIG. 7 is a cross-sectional view showing a conventional semiconductor resin sealing die.

FIG. 8 is a cross-sectional view showing a releasing state in a conventional example.

[Explanation of symbols]

1 Upper Mold 2 Lower Mold 8 Upper Mold Cavity 9 Lower Mold Cavity 10 Upper Mold Ejector Pin 11 Lower Mold Ejector Pin 12 Molded Product 13 Ejector Pipe 13a Opening 14 Opening Valve 15 Recessed Groove

Claims (2)

[Claims] 1. An upper and lower molds having a cavity corresponding to a molded product, an ejector pipe provided in communication with at least one of the upper and lower mold cavities, and an opening of the ejector pipe. And an opening / closing valve provided flush with the cavity surface, and releasing the molded product by applying water pressure or air pressure from the opening of the ejector tube with the opening / closing valve opened. A semiconductor resin encapsulating mold characterized by: 2. An upper and lower molds having a cavity corresponding to a molded product, a concave groove formed on at least one cavity surface of the upper and lower mold cavities, and the cavity fitted into the concave groove. A mold for semiconductor resin encapsulation, comprising an ejector pin which is provided so as to be retractable from a surface and whose tip end surface is flush with the cavity surface while being fitted in the concave groove.