JP2857075B2 - Semiconductor package manufacturing method, and film and mold used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a method of packaging a semiconductor device such as a chip-like LSI such as an LSI with a resin, there is a method by transfer molding. In this method, powder or tablet-shaped resin is heated and pressurized, melted, and then injected into a mold and solidified to form a package. According to this, resin injection into the mold is performed at a low speed. By doing so, it is possible to mass-produce semiconductor packages of a constant quality at a relatively low cost. For this reason, the above-described transfer molding method is most often used in sealing a semiconductor device with a resin.

[0003]

With the recent demand for lowering the price of semiconductor devices, a significant improvement in productivity is required in the field of resin sealing of semiconductor devices as described above. I have.

In this regard, in a conventional transfer molding method, a semiconductor package is molded by directly injecting a resin as a sealing material into a cavity of a mold with a semiconductor device set in the cavity. For this reason, the resin adheres to the mold and remains, and in order to remove the resin, it is necessary to appropriately interrupt the molding process and clean the mold.
Further, after the molding, in order to take out the semiconductor package from the mold, the package is released by projecting a predetermined amount of the eject pin provided on the mold toward the cavity side, so that the semiconductor device is ejected by projecting the eject pin. However, there is a problem in that the mold cost is high as much as the die must be provided and the eject pin must be provided.

SUMMARY OF THE INVENTION The present invention addresses such a problem and, when a semiconductor device is manufactured by sealing a semiconductor device with a resin, the releasability of the semiconductor package from the mold is greatly improved. This eliminates the need for the mold cleaning work conventionally required or can greatly reduce the number of times, and even if there is no 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 enables a semiconductor package to be easily released from a mold after molding, and that can achieve higher productivity than before.

[0006]

Means for Solving the Problems In order to achieve the above object, each invention of the present application is characterized in that a method for manufacturing a semiconductor package by sealing a semiconductor device with a resin is constituted as follows. I do.

That is, according to the first invention of the present application (the invention according to claim 1), when a semiconductor package is manufactured by sealing a semiconductor device with a resin, the semiconductor device and the sealing are mounted on a mold for molding a semiconductor package. After setting the material inserted between a pair of films, close the mold ,
With the device sandwiched between a pair of films, the mold cavity
It is positioned within and then pressurized and heated sealing material between the films, the sealing material into the mold cavity, semiconductor
A pair of films sandwiching the body device
By injecting while spreading toward the cavity side ,
The semiconductor device is sealed.

According to a second invention of the present application (an invention according to claim 2), when a semiconductor device is manufactured by sealing a semiconductor device with a resin,
After setting the semiconductor device in a state of being inserted between a pair of films, the mold is closed, and then a sealing material injection hole provided in advance in one of the pair of films and between the two films. The semiconductor device is sealed by injecting a sealing material and filling the mold cavity.

In these inventions, when a sealing material is injected into a mold cavity at the time of molding a semiconductor package, the film to be used must extend to a certain extent along the cavity surface without being broken by the injection pressure. However, other points are optional as long as the film can secure such elongation. Examples of such a film include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (P
S), polytetrafluoroethylene (PTFE), nylon and other materials. The thickness of the film is not limited as long as it has the above-mentioned performance, but generally, a film having a thickness of 6 μm to 1 mm can be used. Further, in order to improve the releasability from the sealing material, the film surface may be subjected to a release treatment.

According to the second aspect of the present invention, when a sealing material (resin) is poured into a pot (heating chamber) depending on a mold to be used, for example, an upper film portion in a runner portion of the mold is the same. Since it runs along the bottom surface side of the runner portion, there is a possibility that a problem that the sealing material enters into the gap between the film and the mold may occur slightly. In order to solve such a problem, in order to prevent the film portion located in the runner portion from being loosened along the bottom surface side of the runner portion in the vicinity of the sealing material injection hole in the mold, a heat resistant material having a certain degree of stiffness is used. The conductive material may be inserted so as to cross the runner portion, and the mold may be closed in that state. With this configuration, a gap serving as a passage of the sealing material can be ensured 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. Note that this kind of heat-resistant material may be attached to at least one of a pair of films sandwiching the semiconductor device in advance.

As the above-mentioned heat-resistant material, a material which does not significantly deform at a high temperature (150 to 200 ° C.) in the sealing step is used. Specifically, for example, a polyimide resin or an epoxy resin can be used. The shape of this kind of heat resistant material is arbitrary. Therefore, a heat-resistant material may be provided on each of the runner portions of the mold in such a manner as to linearly cross them, or a heat-resistant material may be set in a ring shape so as to surround the pot.

Further, if the mold strongly presses the heat-resistant material when the mold is closed, there is a possibility that the mold surface of the pressed portion may be damaged. In order to avoid damage, a mold having a concave portion having a shape corresponding to the shape of the heat-resistant material may be used at a position corresponding to the setting position of the heat-resistant material.

[0013]

According to the first aspect of the present invention, 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 injected into the cavity by heating and pressurizing, one of the dies (for example, 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 the semiconductor device is sealed with the sealing material in that state.

Further, according to the second aspect of the present invention, when the mold is closed, the semiconductor device is positioned in the cavity with the semiconductor device inserted between the pair of films, and in that state, the semiconductor device is previously placed on the pair of films. Since the sealing material is injected between the two films from the sealing material injection hole provided and filled into 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 the first and second aspects of the present invention, the semiconductor package can be formed without bringing the sealing material into direct contact with the cavity surface of the mold. Moreover, since the semiconductor package held between the films can be easily peeled off from the mold after the molding, the molded semiconductor package can be easily taken out from the mold without the eject pin. . This makes it possible to eliminate or reduce the cleaning work of the mold and eliminate the need for the eject pin 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 openable and closable dies 3, 4 attached to a transfer molding machine 2. These molds 3 and 4 are provided with heaters 5... 5 respectively, and are provided with a cavity 6 for molding a semiconductor package and a pot in which a resin (sealing resin) 7 as a sealing material is set. Section 8 and each runner section 9 for communicating the pot section 8 with the cavity 6.
And a gate portion 10 are formed. Then, after the molds 3 and 4 are heated to a predetermined temperature by the heater 5, the sealing resin 7 is set in the pot portion 8, for example, as shown in the figure, and the plunger 11 in the transfer molding machine 2 is in this state.
By pressurizing and plasticizing the sealing resin 7 and injecting it into the cavity 6 through each runner section 9 and gate section 10, a semiconductor package can be formed.

In the example shown in FIG. 1, the pot 8 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 8 and each runner 9. A heat resistant material 12 is provided. These heat-resistant materials 12 are disposed in a predetermined state, for example, as shown in FIG. 2 so as to cross each runner 9 located on the lower mold 4 and in the vicinity of the pot 8. 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 dies 3, 4 of the 28-pin SOJ auto mold open, a PTFE film ( (Thickness: 60 μm) 21 is laid. Next, this film 2
1, a semiconductor device 23 fixed on a lead frame 22 (in the illustrated example, a connection portion for electrically connecting the semiconductor device 23 and the lead frame 22 is omitted. The same applies to the following. ) And the sealing material 24 are set in a predetermined state, and a PTFE film (thickness: 60 μm) 25 is spread thereon. At this time, the semiconductor device 2
3 is in the cavity 6 when the upper and lower molds 3 and 4 are put together, and the potting material 8 is
Is set to a predetermined state so that each exists.

Next, in this state, the upper and lower dies 3, 4 are closed as shown in FIG. At this time, the semiconductor device 23 and the sealing material 24 are
1 are positioned inside the cavities 6 of the molds 3 and 4 and the pot portion 8 respectively.

In this state, the plunger 11 (see FIG. 1) is pushed down in the direction of the arrow shown in FIG. Is pressed through the upper film 25. In this way, after the sealing material 24 is plasticized, the sealing material 24 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 spread toward the outer cavity surface side to fill the periphery of the semiconductor device 23.

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

Next, as shown in FIG. 1D, the films 21 and 25 are peeled from the surface of the semiconductor package 26 taken out of the molds 3 and 4, and unnecessary molding portions 27 are cut. Remove. Thus, a semiconductor package 26 in which the semiconductor device 23 is sealed with the resin 24 ′ formed of the sealing material 24 as shown in FIG.

According to such a configuration, the semiconductor device 23 set in the cavity 6 includes the pair of films 21 and
The semiconductor device 23 is sealed by being heated and pressurized and filled in the cavity 6 with the sealing material 24 inserted between the molds 25 and 25, so that the sealing material 24 is The semiconductor package 26 can be formed without directly contacting the cavity surface of the semiconductor package 26. Therefore,
Since there is no or little, if any, contamination of the cavity surfaces of the molds 3 and 4 with the sealing material 24, the work of periodically cleaning the molds 3 and 4 can be greatly reduced.

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

First, as shown in FIG. 4A, with a pair of upper and lower molds 3, 4 substantially similar to the case of the first embodiment opened, PTFE is placed on the lower mold 4 among them. Film (thickness: 60 μm) 31 is laid, and then the film 3
The semiconductor device 33 fixed on the lead frame 32 is set at the same predetermined position as that of the first embodiment. In this embodiment, the pot portion 8 of the mold is further provided.
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 of the heat-resistant materials 42 is set on the lower die 4 so as to cross the runner 9 near the pot portion, similarly to the heat-resistant material 12 shown in FIGS. 1 and 2, for example. . After the film 31, the semiconductor device 33, and the heat-resistant material 42 are sequentially set on the lower mold 4, a hole 35a for injecting a sealing material is formed in advance only in a portion corresponding to the pot portion 8 thereon. P
A TFE film (thickness: 60 μm) 35 is laid.

Next, in this state, the upper and lower molds 3, 4 are closed as shown in FIG. And the hole 35a
The sealing material 34 is set in the mold pot portion 8 where
In this state, the sealing material 34 is pressurized 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 9.
At this time, the heat-resistant material 42 is composed of the upper and lower films 35,
Since the upper film 35 is provided so as to cross the runner portion 9 between the runner portions 31, the upper film 35 is prevented from dripping into the runner portion 9.
The sealing material 34 injected from a flows between the upper and lower films 35 and 31 in each runner portion 9. Thereby, it is possible to reliably prevent the sealing material 34 from entering the gaps between the upper and lower films 35, 31 and the dies 3, 4 located outside thereof.

After the cavity 6 is filled with the sealing material 34, the sealing material 34 is filled as in the first embodiment.
After the molds 3 and 4 are cured, the molds 3 and 4 are opened, and the packaged semiconductor device 33, that is, the semiconductor package 36 (see (D) in FIG. 3) is opened from the molds.
Each of the films 35 and 31 is taken out from the surface of the semiconductor package 36 as shown in FIG.
Is removed, and unnecessary molding portions 37 are further cut.
As a result, a semiconductor package 36 in which the semiconductor device 33 is sealed with the resin 34 'formed of the sealing material 34 as shown in FIG.

In the second embodiment as well, the release of the semiconductor package 36 from the mold 4 or 3 after molding is very easy because the above-described films 31 and 35 are used together. Further, even when the above-described molding operation was repeated 1,000 times, no stain was generated on the molds 3 and 4, and it was confirmed that excellent mold releasability was maintained. [Comparative Example] After setting a semiconductor device fixed on a lead frame by a conventional method in a lower mold of a 28-pin SOJ auto mold, the upper mold is closed, and then sealed in a cavity in a usual manner. A semiconductor package was formed by injecting a stopper material. In this way, molding was performed 1,000 times, but the releasability was slightly poor during the initial period (number of moldings: 1 to 12), and then became good. Required cleaning of the mold.

[0030]

As described above, according to the present invention, the sealing material is filled around the semiconductor device between the films in the cavity with the semiconductor device inserted between the pair of films. The semiconductor package can be molded without bringing the sealing material into direct contact with the cavity surface of the mold. Moreover, since the semiconductor package held between the films can be easily separated from the mold together with the film after molding, the molded semiconductor package can be easily taken out of the mold without the eject pin. . As a result, the number of times of cleaning of the mold can be reduced, and the need for the eject pin can be eliminated. As a result, continuous moldability can be greatly improved by reducing the interruption time of the molding process, and the cost of the mold can be reduced. The productivity can be greatly improved.

[Brief description of the 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 cut away.

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

FIG. 3 is a cross-sectional view showing 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, in which each step in the first embodiment of the present invention is shown;
(B) is a cross-sectional view showing a state in which the film and the like are set between the molds and the mold is closed, and (C) is a cross-sectional view showing a state in which a sealing material is filled into a cavity by pressing or the like. 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 sectional view showing a finally obtained semiconductor package.

FIG. 4 is a sectional view showing a state in which a semiconductor device and a heat-resistant material are inserted between a pair of films in a state in which a mold is opened, in which each step in a second embodiment of the present invention is shown; (B) is a sectional view showing a state in which the above-mentioned film or the like is set between the molds, the mold is closed, and then a sealing material is set in a pot portion of the mold. A cross-sectional view showing a state in which the sealing material is injected and filled into the cavity from the sealing material injection hole 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 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 part 12, 42 ... heat resistant material (42) ... heat-resistant material composed of polyimide film) 21, 25, 31, 35 ... film 35a ... holes for injecting sealing material 23, 33 ... semiconductor devices 26, 36 ... semiconductor package

Continuation of the front page (56) References JP-A-8-142116 (JP, A) JP-A-6-151515 (JP, A) JP-A-6-216180 (JP, A) JP-A-8-142109 (JP) JP-A 8-142105 (JP, A) JP-A 8-156014 (JP, A) JP-A 8-156008 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB Name) B29C 45/00-45/84 H01L 21/56 WPI (DIALOG)

Claims (6)

(57) [Claims] When a semiconductor package is manufactured by sealing a semiconductor device with a resin, the semiconductor device and a sealing material are set on a mold for molding a semiconductor package in a state of being inserted between a pair of films. Close the mold , semi-conductive
With the body device sandwiched between a pair of films, the mold cavity
And then pressurize and heat the sealing material between the films and place the sealing material in the mold cavity halfway.
A pair of films sandwiching the conductor device are placed in a mold outside
A method of manufacturing a semiconductor package, wherein the semiconductor device is sealed by injecting the semiconductor device while pushing the semiconductor device toward a cavity surface . 2. When a semiconductor package is manufactured by sealing a semiconductor device with a resin, the semiconductor device is set on a mold for molding a semiconductor package with the semiconductor device inserted between a pair of films. Closing, then injecting a sealing material between the two films from a sealing material injecting hole provided in advance in one of the pair of films and filling the mold cavity, thereby forming the semiconductor device. A method for manufacturing a semiconductor package, comprising sealing a semiconductor device. 3. In the vicinity of a sealing material injection hole in a mold for molding a semiconductor package, a sealing material injected into the cavity from the injection hole via a runner portion enters between the mold and the film. 3. The method according to claim 2, wherein a heat-resistant material is inserted so as to cross the runner portion, and the mold is closed in that state. 4. The method 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 of manufacturing a semiconductor package according to claim 2, wherein at least one of the two films has a runner portion from a sealing material injection hole in a semiconductor package molding die. A heat-resistant material that prevents a sealing material injected into the cavity through the mold and the film from passing through the runner portion near the injection hole when the film is set in the mold. A film which is stuck on a film. 6. A mold for molding a semiconductor package used in the method of manufacturing a semiconductor package according to claim 3, wherein the heat-resistant material is set to cross a runner portion of the mold. A mold having a concave portion having a shape corresponding to the shape provided so as to correspond to a set position of the heat-resistant material.