JPH08156029A - Manufacture of semiconductor package, film used therefor, and its mold - Google Patents

Abstract

PURPOSE: To dispense with cleaning operation of a mold by improving releasability by a method wherein after setting a semiconductor device and a sealing material between a pair of films on a mold, the mold is closed, the sealing material between the films is pressurized, heated, and casted into the cavity to seal a semiconductor package. CONSTITUTION: A film 21 is land on a bottom force 4, and a semiconductor device 23 and a sealing material 24 are positioned inside a cabity 6 and a pot part 8 thereon respectively. Further, a film 25 is laid thereon, and the top and bottom forces 3, 4 are closed. Then, when the sealing material 24 is pressurized while it is heated, the sealing material flows into the cavity 6 through respective runner parts 9 in a state of being put between the films 21, 25, and fills a periphery of the semoconductor device 23 while pushing and expanding the films 25, 21. After hardening the sealing material 24 thus, a semiconductor package 26 is taken out, the films 21, 25 are peeled off from its surface, and an unnecessary molded part 27 is cut off. Consequently there is no fear of staining a surface of the cavity by contact with the sealing material 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor package by sealing a semiconductor device with resin.

[0002]

2. Description of the Related Art As a method of sealing a semiconductor device such as a chip-like LSI with a resin and packaging it, there is a method by transfer molding. In this method, powdered or tablet-shaped resin is heated and pressurized to melt it, then it is poured into a mold and solidified to be packaged. According to this, the resin can be injected into the mold at a low speed. By doing so, it is possible to mass-produce semiconductor packages of constant quality at a relatively low cost. For this reason, in the past, the above-mentioned transfer molding method has been most often used when sealing a semiconductor device with a resin.

[0003]

By the way, with the recent demand for cost reduction of semiconductor devices, significant improvement in productivity is required also in the field of resin encapsulation of semiconductor devices as described above. There is.

In this regard, in the conventional transfer molding method, a semiconductor package is molded by directly injecting a resin, which is a sealing material, into a cavity of a mold while the semiconductor device is set in the cavity. Therefore, the resin remains attached to the mold, and it is necessary to appropriately interrupt the molding process and clean the mold in order to remove it.
Further, after molding, in order to take out the semiconductor package from the mold, the eject pin provided on the mold is projected toward the cavity side by a predetermined amount to release the package, and therefore the eject pin protrudes from the semiconductor device. There was a problem that the mold cost was high as much as it had to be damaged and the eject pin had to be provided.

The present invention addresses such a problem, and when the semiconductor device is sealed with resin to manufacture a semiconductor package, the releasability of the semiconductor package from the mold is greatly improved. As a result, it is possible to eliminate the need for a mold cleaning operation that has been conventionally required or to significantly reduce the number of times, and even without the eject pin that damages the semiconductor device and increases the mold cost. It is an object of the present invention to provide a sealing technique that allows a semiconductor package to be easily released from a mold after molding, and further that achieves higher productivity than ever before.

[0006]

In order to achieve the above object, each invention of the present application is characterized in that in a method of manufacturing a semiconductor package by sealing a semiconductor device with a resin, the method is configured as follows. To do.

That is, according to the first invention of the present application (the invention according to claim 1), when a semiconductor device is encapsulated with resin to manufacture a semiconductor package, the semiconductor device and the encapsulation are placed on a semiconductor package molding die. After the material is set in a state of being inserted between a pair of films, the mold is closed, and then the sealing material between the films is pressurized and heated to be injected into the mold cavity, whereby the semiconductor device is manufactured. It is characterized by sealing.

A second invention of the present application (an invention according to claim 2) is that, when a semiconductor device is sealed with a resin to manufacture a semiconductor package, a semiconductor package molding die is provided with:
After the semiconductor device is set in a state of being inserted between a pair of films, the mold is closed, and then one of the pair of films is provided with a sealing material injection hole previously provided between the two films. The semiconductor device is sealed by injecting a sealing material and filling the mold cavity.

In these inventions, the film used is required to extend to some extent along the cavity surface without breaking due to the injection pressure when the sealing material is injected into the mold cavity during molding of the semiconductor package. However, other points are optional as long as the film can secure such elongation. Examples of such films include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (P
Examples of the film include S), polytetrafluoroethylene (PTFE) and nylon. The thickness of the film having the above-mentioned properties is arbitrary, but generally, a film having a thickness of 6 μm to 1 mm can be used. Further, in order to improve the releasability with the sealing material, the film surface may be subjected to a releasing treatment.

When practicing the second invention, depending on the mold used, when the sealing material (resin) is injected into the pot (heating chamber), for example, the upper film part in the runner part of the mold is the same. Since it runs along the bottom surface side of the runner portion, there may be a slight problem that the sealing material enters the gap between the film and the mold. In order to eliminate such a problem, in the vicinity of the sealing material injection hole in the mold, a certain amount of heat resistance is provided so that the film part located in the runner does not become loose along the bottom side of the runner part. The elastic material may be inserted across the runner portion, and the mold may be closed in that state. With this configuration, a gap that serves as a passage for the sealing material can be secured between the pair of films in the runner portion, so that the sealing material is prevented from entering between the film and the mold when the sealing material is injected. be able to. The heat-resistant material of this type may be previously attached to at least one of a pair of films sandwiching the semiconductor device.

As the above-mentioned heat resistant material, a material which does not largely deform at a high temperature (150 to 200 ° C.) in the sealing step is used. Specific examples include polyimide resin and epoxy resin. The shape of this type of heat resistant material is arbitrary. Therefore, the heat-resistant material may be provided on each runner portion of the mold in such a manner as to traverse them linearly, or the heat-resistant material may be set in a ring shape so as to surround the pot.

If the mold strongly presses the heat resistant material when the mold is closed, the mold surface of the pressing portion may be damaged. In order to avoid damage, a mold in which a recess having a shape corresponding to the shape of the heat resistant material is provided at a position corresponding to the set position of the heat resistant material may be used.

[0013]

According to the first invention of the present application, when the mold is closed, the semiconductor device is positioned in the cavity while being inserted between the pair of films. Therefore, in this state, when the sealing material inserted between the films is heated and pressurized to be injected into the cavity, the injection pressure causes one film in the cavity to correspond to one mold (for example, one film). On the cavity surface of the upper mold)
The other film is along the cavity surface of the corresponding other mold (for example, the lower mold), and in that state, the semiconductor device is sealed with the sealing material.

Further, according to the second invention of the present application, when the mold is closed, the semiconductor device is located in the cavity with the semiconductor device inserted between the pair of films, and in that state, the semiconductor device is previously attached to the pair of films. Since the sealing material is injected between the two films through the holes for injecting the sealing material and is filled in the cavity, the film in the cavity is also in a state along the corresponding cavity surface in this case as well. At the same time, the semiconductor device is sealed by the sealing material filled between the films.

Therefore, according to both the first and second inventions, the semiconductor package can be molded without directly contacting the sealing material with the cavity surface of the mold. Moreover, after molding, the semiconductor package held between the films together with the film can be easily peeled off from the mold, so that the molded semiconductor package can be easily taken out from the mold without the eject pin. . As a result, it is possible to eliminate or reduce the cleaning work of the mold and to eliminate the need for eject pins in the mold.

[0016]

Embodiments of the present invention will be described below. First, a semiconductor package manufacturing apparatus that can be used in the method of the present invention will be briefly described.

FIG. 1 shows an example of such a manufacturing apparatus. The semiconductor package manufacturing apparatus 1 has a pair of upper and lower molds 3 and 4 which are attached to a transfer molding machine 2 and which can be opened and closed. Each of the molds 3 and 4 is provided with a heater 5 ... 5 and a pot in which a semiconductor package molding cavity 6 and a resin (sealing resin) 7 as a sealing material are set. The portion 8 and each runner portion 9 that connects the pot portion 8 and the cavity 6 to each other.
And the gate part 10 is formed. Then, the molds 3 and 4 are heated to a predetermined temperature by the heater 5, and then the sealing resin 7 is set in the pot portion 8 as shown in the drawing, and in this state, the plunger 11 in the transfer molding machine 2 is set.
Thus, the sealing resin 7 is pressurized and plasticized, and is injected into the cavity 6 through each runner portion 9 and the gate portion 10, so that the semiconductor package can be molded.

Incidentally, in the example shown in FIG. 1, it is used in the second embodiment of the present invention in the vicinity of the sealing resin injection hole corresponding to the boundary between the pot portion 8 or the pot portion 8 and each runner portion 9. A heat resistant material 12 is provided. These heat-resistant materials 12 are arranged in a predetermined state so as to cross each runner portion 9 located on the lower die 4 and near the pot portion 8 as shown in FIG. 2, for example. This will be described later. [First Embodiment] Next, a first embodiment of the present invention will be described.

First, as shown in FIG. 3 (A), with the upper and lower molds 3 and 4 of the 28-pin SOJ automold opened, a PTFE film ( A thickness of 60 μm) 21 is laid. Then this film 2
1, the semiconductor device 23 fixed on the lead frame 22 (the example of the figure shows a state in which a connecting portion for electrically connecting the semiconductor device 23 and the lead frame 22 is omitted. The same applies hereinafter. ) And the sealing material 24 are set in a predetermined state, and a PTFE film (thickness 60 μm) 25 is also laid on it. At this time, the semiconductor device 2
3 is placed in the cavity 6 when the upper and lower molds 3 and 4 are combined, and the potting material 8 is used for the sealing material 24.
Set to a predetermined state so that they exist in each.

Next, in this state, the upper and lower molds 3 and 4 are closed as shown in FIG. At this time, the semiconductor device 23 and the sealing material 24 are separated from each other by the upper and lower films 25, 2.
It will be located inside the cavities 6 of the molds 3 and 4 and the pot portion 8 while being sandwiched between the molds 1.

Therefore, in this state, the plunger 11 (see FIG. 1) is pushed down in the direction of the arrow shown in FIG. 3C while heating the potting material 24 existing in the pot portion 8 to heat the potting material 24. Is pressed through the film 25 above it. By doing so, the sealing material 24 is plasticized and then flows into the cavity 6 through each runner portion 9 while being sandwiched between the films 25 and 21, and as shown in FIG. The upper and lower films 25 and 21 sandwiching the semiconductor device 23 in the cavity 6 are expanded toward the cavity surface side on the outside thereof to fill the periphery of the semiconductor device 23.

After the semiconductor device 23 is sealed by filling the sealing material 24 in this way, the molds 3 and 4 are opened after the sealing material 24 is cured, and the semiconductor packaged from the mold. Device 23, that is, semiconductor package 2
6 (see (D) in the figure) is taken out of the molds 3, 4. At this time, the semiconductor package 26 has a pair of upper and lower films 2.
Since it is formed in a state of being sandwiched between the molds 5 and 21, it can be easily taken out of the molds 3 and 4 by separating the films 25 and 21 from the mold 4 or 3.

Next, as shown in FIG. 3D, the films 21 and 25 are separated from the surface of the semiconductor package 26 taken out of the molds 3 and 4, and unnecessary molding portions 27 are cut. Remove. As a result, a semiconductor package 26 obtained by sealing the semiconductor device 23 with the resin 24 'formed of the sealing material 24 is obtained as shown in FIG.

According to such a configuration, the semiconductor device 23 set in the cavity 6 has the pair of films 21,
The semiconductor device 23 is sealed by heating and pressurizing the sealing material 24 to fill the cavity 6 with the sealing material 24 being inserted between the molds 25, 25. The semiconductor package 26 can be molded without directly contacting the cavity surface of the semiconductor package 26. Therefore,
There is no risk of the cavity surfaces of the molds 3 and 4 being contaminated with the sealing material 24, or even if there is little, it is possible to greatly reduce the work for cleaning the molds 3 and 4 on a regular basis.

After the molding by the molds 3 and 4, the semiconductor package 26 held between the pair of films 21 and 25 can be easily separated from the mold 4 or 3 together with the films 21 and 25. Therefore, the molded semiconductor package 26 can be easily taken out without the eject pin. Therefore, the eject pin can be eliminated from the die for molding the semiconductor package, and the die cost can be reduced accordingly. [Second Embodiment] Next, a second embodiment of the present invention will be described.

First, as shown in FIG. 4A, a pair of upper and lower molds 3 and 4 similar to the case of the first embodiment are opened, and PTFE is placed on the lower mold 4 among them. Made film (thickness 60 μm) 31 is spread, and then the film 3
The semiconductor device 33 fixed on the lead frame 32 is set on the first position at the same predetermined position as in the first embodiment. Further, in this embodiment, the mold pot portion 8 is further added.
A heat resistant material 42 made of a polyimide film (50 μm thick) is set in each runner portion 9 located in the vicinity of. At this time, each heat-resistant material 42 is set in such a state that it crosses the runner portion 9 near the pot portion on the lower mold 4, like the heat-resistant material 12 shown in FIGS. 1 and 2, for example. . In this way, the film 31, the semiconductor device 33 and the heat resistant material 42 are sequentially set on the lower mold 4, and then the hole 35a for injecting the sealing material is preliminarily formed only on the portion corresponding to the pot portion 8. P
A TFE film (thickness 60 μm) 35 is laid.

Next, in that state, the upper and lower molds 3 and 4 are closed as shown in FIG. Then, the hole 35a
Set the sealing material 34 in the mold pot portion 8 where is,
In this state, the sealing material 34 is pressed by a plunger (see FIG. 1) to fill the cavity 6 through the space between the upper and lower films 35 and 31 in each runner portion 9.
At this time, the heat resistant material 42 has the upper and lower films 35,
Since the film 35 on the upper side is provided so as to traverse the runner portion 9, it is possible to prevent the film 35 on the upper side from hanging down into the runner portion 9.
The sealing material 34 injected from a passes between the upper and lower films 35 and 31 in each runner portion 9. As a result, it is possible to reliably prevent the sealing material 34 from entering the space between the upper and lower films 35 and 31 and the molds 3 and 4 located outside thereof.

After the cavity 6 has been filled with the sealing material 34 in this manner, the sealing material 34 is the same as in the first embodiment.
After the mold is cured, the molds 3 and 4 are opened, and the packaged semiconductor device 33, that is, the semiconductor package 36 (see (D) in the same figure) is transferred to the films 35 and 3.
After taking out one by one, the films 35, 31 are removed from the surface of the semiconductor package 36 as shown in FIG.
Are peeled off, and unnecessary molding portions 37 are cut.
As a result, a semiconductor package 36 obtained by sealing the semiconductor device 33 with the resin 34 'formed of the sealing material 34 is obtained as shown in FIG.

Also in this second embodiment, since the semiconductor package 36 is released from the mold 4 or 3 after molding, the above-mentioned films 31 and 35 are extremely easy to release. Further, it was confirmed that even when the above-described molding operation was repeated 1000 times, the molds 3 and 4 were not contaminated and excellent mold releasability was maintained. [Comparative Example] A semiconductor device fixed on a lead frame was set in a lower mold of a 28-pin SOJ automold by a conventional method, then the upper mold was closed, and in that state, it was sealed in a cavity by a conventional method. A semiconductor package was molded by injecting a stop material. In this way, 1000 moldings were tried, but the mold releasability was a little bad during the initial period (molding times: 1 to 12 times), and then became good, but when it exceeded 400 times, it became defective, and after 620 times. Needed mold cleaning.

[0030]

As described above, according to the present invention, the sealing material is filled around the semiconductor device between the films in the cavity in the state where the semiconductor device is inserted between the pair of films. The semiconductor package can be molded without directly contacting the sealing material with the cavity surface of the mold. Moreover, since the semiconductor package held between the films after molding can be easily separated from the mold together with the film, the molded semiconductor package can be easily taken out from the mold without the eject pin. . As a result, it is possible to reduce the number of mold cleaning times and to eliminate the need for eject pins.As a result, the continuous processability is greatly improved and the mold cost is reduced due to the reduction in the interruption time of the molding process. It is possible to significantly improve productivity.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a semiconductor package manufacturing apparatus used in an embodiment of the present invention with a part thereof broken away.

FIG. 2 is a plan view showing a state where a lower die in the apparatus is viewed from above.

FIG. 3 is a sectional view showing each step in the first embodiment of the present invention, in which (A) shows a state in which a semiconductor device and a sealing material are inserted between a pair of films in a state where a mold is opened;
(B) is a cross-sectional view showing a state in which the film or the like is set between the molds and the molds are closed, and (C) is a cross-sectional view showing a state in which the sealing material is pressurized to fill the cavity. Figure,
(D) is a cross-sectional view showing a state in which the film is peeled from the surface of the semiconductor package taken out of the mold after molding.
(E) is a cross-sectional view showing a finally obtained semiconductor package.

FIG. 4 is a cross-sectional view showing each step in the second embodiment of the present invention, in which (A) shows a state in which a semiconductor device and a heat resistant material are inserted between a pair of films in a state where a mold is opened; (B) is a cross-sectional view showing a state in which the film or the like is set between the molds, the molds are closed, and then the sealing material is set in the pot portion of the same mold, (C) is a pressurization of the sealing material. A cross-sectional view showing a state in which the sealing material is injected and filled into the cavity from the hole for injecting the sealing material in the upper film, etc.
(D) is a cross-sectional view showing a state in which the film is peeled from the surface of the semiconductor package taken out of the mold after molding.
(E) is a cross-sectional view showing a finally obtained semiconductor package.

[Explanation of symbols]

3, 4 ... Mold for molding semiconductor package 6 ... Cavity 7, 24, 34 ... Sealing material (sealing resin) 9 ... Runner portion 12, 42 ... Heat resistant material (42 ... Heat-resistant material composed of polyimide film) 21, 25, 31, 35 ... Film 35a ... Hole for injecting sealing material 23, 33 ... Semiconductor device 26, 36 ... Semiconductor package

Claims (6)

[Claims] 1. When manufacturing a semiconductor package by sealing a semiconductor device with a resin, the semiconductor device and a sealing material are set in a state of being inserted between a pair of films on a semiconductor package molding die. A method for manufacturing a semiconductor package, which comprises closing the mold, and then pressurizing and heating a sealing material between the films to inject into the mold cavity to seal the semiconductor device. 2. When manufacturing a semiconductor package by sealing a semiconductor device with a resin, the semiconductor device is set on a mold for molding a semiconductor package in a state of being inserted between a pair of films, and then the mold is set. The semiconductor device is closed by injecting a sealing material between both films through a hole for injecting a sealing material provided in one of the pair of films in advance and filling the mold cavity. A method of manufacturing a semiconductor package, which comprises: 3. In the vicinity of the sealing material injection hole in the semiconductor package molding die, the sealing material injected into the cavity from the injection hole through the runner portion enters between the die and the film. The method for manufacturing a semiconductor package according to claim 2, wherein a heat-resistant material for preventing the above is inserted in a state of traversing the runner portion, and the mold is closed in that state. 4. The method of manufacturing a semiconductor package according to claim 3, wherein the heat resistant material is previously attached to at least one of the pair of films. 5. A pair of films used in the method for manufacturing a semiconductor package according to claim 2, wherein at least one of the films has a runner portion from a sealing material injection hole in a semiconductor package molding die. The heat-resistant material that prevents the encapsulating material injected into the cavity through the space between the mold and the film crosses the runner portion near the injection hole when the film is set in the mold. A film characterized by being attached to. 6. A mold for molding a semiconductor package used in the method for manufacturing a semiconductor package according to claim 3, wherein the heat-resistant material is set so as to cross a runner portion of the mold. A mold, wherein a recess having a shape corresponding to the shape is provided so as to correspond to a set position of the heat resistant material.