JPH08139119A - Production of semiconductor device and laminate employed therein - Google Patents

Abstract

PURPOSE: To obtain a method for efficiently producing a semiconductor device in which a bonding material is applied to the surface of a resin package. CONSTITUTION: The semiconductor device, where a bonding material is applied to the surface of a resin package sealing a semiconductor element, is produced by adsorbing a bonding material exhibiting mold releasing properties to package molding dies 2, 3, setting a semiconductor element 5 in the dies 2, 3, injecting a molding resin and bonding the bonding material 4 to the surface of the resin package.

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 device in which a material to be adhered is adhered to the surface of a resin package, and a laminate used for the method.

[0002]

2. Description of the Related Art A resin package of a semiconductor device is a semiconductor device such as an LSI that is sealed and packaged by a transfer molding method using resin (mainly epoxy resin). It is widely used as a consumer package because of its good quality and low cost.

Various characteristics such as moisture resistance have been conventionally required for this type of package, and such requirements are accompanied by the recent trend toward larger semiconductor element size and surface mounting of the package. Are becoming stronger and stronger.

In order to meet such requirements, a semiconductor device in which the surface of a resin package is covered with a metal foil has been proposed (Japanese Patent Application No. 5-111595, etc.). According to this,
Moisture absorption by the resin is prevented by the metal foil material existing on the surface of the package, and the metal foil material reinforces the package to reduce the thermal shock resistance, so that the generation of package cracks is prevented.

[0005]

By the way, in molding a package of the above semiconductor device having a moisture resistant material adhered to its surface, it is necessary to temporarily fix the moisture resistant material to a molding die. However, the metal foil used as a moisture resistant material so far has poor handling,
Due to lack of flexibility, it is difficult to perform sufficient temporary fixing even by using a method of adsorbing the metal foil to the mold.For this reason, the metal foil is attached to the molding surface of the mold through the temporary fixing adhesive layer. There is a problem that it is necessary to temporarily fix it, and it takes time accordingly. Further, if the production is continued, there is a problem that after the molded resin package is taken out from the mold, a part of the temporary fixing adhesive is deposited on the mold molding surface, which requires cleaning work of the mold molding surface. It was

The present invention addresses such a problem, and as a method of manufacturing a semiconductor device having the above-described structure in which a material to be adhered is adhered to the surface of a resin package, an adhesive for temporary fixing to a mold is used. It is an object of the present invention to realize a superior method that does not require temporary fixation of a material to be adhered via a layer, and also to provide a laminate suitable for carrying out the method.

[0007]

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention provides a semiconductor device in which a material to be adhered is adhered to the surface of a package formed by encapsulating a semiconductor element with a resin. At the time of manufacturing, the adhered material having releasability for the mold is adsorbed on the mold for package molding, and then the semiconductor element is set in the mold and the molding resin is injected. It is characterized in that the adhered material is adhered to the surface of the package by molding.

A thermosetting resin is used as the molding resin, in other words, a package resin for encapsulating a semiconductor element. For example, epoxy resin, phenol resin, urea resin, melamine resin, polyester resin, diallyl phthalate resin, polyphenylene. Examples include sulfide. Among these, it is preferable to use an epoxy resin. In that case, the epoxy resin curing agent, curing accelerator,
A conventionally known additive such as a filler is mixed and used as an epoxy resin composition.

As a material to be adhered which has releasability from the above-mentioned molding die, the temperature at the time of molding (usually 150 ° C to
250 ° C.), a material having substantially no adhesive force with respect to a mold, and having flexibility capable of being temporarily fixed to the mold by adsorption and moisture resistance. However, the conditions are not particularly limited. Specific examples include polycarbodiimide and polytetrafluoroethylene (PTFE). Among them, polycarbodiimide is particularly preferable because it has a low water vapor transmission rate and can more effectively prevent moisture absorption of the package resin. As the polycarbodiimide, a known polymer compound having a carbodiimide bond can be used. In particular, the carbodiimide before the crosslinking reaction of the carbodiimide by heating has high flexibility, and further, the resin package is molded and post-cured. Since it can be crosslinked at this time, it is preferable in that the heat resistance of the carbodiimide can be further improved. The thickness of the adhered material is preferably 1 μm to 500 μm,
A more preferable range is 10 μm to 100 μm.

Further, as the above-mentioned adhered material, it is also possible to use a laminate in which a resin layer having releasability from a molding die is laminated on a metal foil. In this case, the package resin is used. Moisture absorption of is prevented by the metal foil,
Since the flexibility is increased by laminating the resin layer on the metal foil, temporary fixing by adsorption becomes possible. Examples of metal foil materials used in this case include aluminum,
It is copper, stainless steel, or the like, and the thickness thereof is preferably 1 μm to 500 μm, and more preferably 10 μm to 100 μm. Further, the resin used in this case includes a temperature at the time of molding (usually 150 ° C to
The condition is not particularly limited as long as it is a material capable of withstanding 250 ° C.), has substantially no adhesiveness to the mold, and is flexible enough to be temporarily fixed to the mold by adsorption. Specifically, polycarbodiimide, polyetherimide, polyimide, polytetrafluoroethylene (PT
FE) and the like. Further, in order to improve the adhesion between the metal foil and the resin layer to be laminated, a known surface treatment such as silane coupling agent treatment, sputtering treatment, hydrofluoric acid treatment, etc. may be performed.

The term "adsorption" used in the method of the present invention means that the material to be adhered to the molding surface of the mold is obtained by sucking negative pressure (so-called vacuum) from the outside through a suction hole provided in the package molding die. To be closely attached (see Examples described later).

[0012]

According to the method of the present invention, the adhered material can be adhered to the surface of the package by injecting the resin into the mold while adsorbing the adhered material on the mold and molding. There is no need to temporarily fix the adhered material on the mold via the temporary fixing adhesive layer during molding. Therefore,
There is no stain on the mold due to the transfer residue of the temporary fixing adhesive. Moreover, since the adhered material having releasability from the mold is used, the resin package formed by adhering the adhered material to the surface can be easily released after molding.

Further, in the above-mentioned case, if the laminate of the present invention is used as the adhered material, the adhered material can be easily temporarily fixed on the mold by adsorption, and therefore a temporary fixing adhesive is used at the time of molding. Compared to temporarily fixing the adhered material on the mold, the work of setting the adhered material on the mold during molding can be facilitated and the time can be shortened, and waste such as adhesive layers can be eliminated. it can. In particular, in the laminate of the present invention, since the resin layer is laminated on the metal foil, the flexibility is increased as compared with the adhered material consisting of the metal foil only. Temporary fixation by adsorption is possible.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Example 1 First, as shown in FIG. 1, with the upper mold 2 and the lower mold 3 constituting the mold 1 for package molding opened, the mold 1 was placed at a predetermined position on each molding surface. On the other hand, a material to be adhered (in this embodiment, a polycarbodiimide resin having a thickness of 30 μm) 4 having releasability is positioned, and in that state,
By sucking the inside of each of the molds 2 and 3 from the outside through suction holes (not shown) provided in the upper mold 2 and the lower mold 3, the adhered material is adhered to the molding surface of each of the molds 2 and 3. Stick 4 together.

Next, while maintaining this adsorption state, as shown in FIG.
As shown in FIG. 3, a lead frame 6 in which the semiconductor element 5 is fixed at a predetermined position in advance is inserted between the upper mold 2 and the lower mold 3, and then, as shown in FIG.
Close. Then, in this state, a molding resin (not shown) is injected into the mold 1 and cured to mold the resin package 7 (see FIG. 4) formed by sealing the semiconductor element 5. After molding, the mold 1 is opened and the adhered material 4 is attached to the surface.
The resin package 7 to which was adhered was taken out from the mold 1. At this time, since the adhered material 4 has releasability from the mold 1, it could be easily peeled from the mold 1. Thus, as shown in FIG. 4, the semiconductor device 8 in which the adhered material 4 is adhered to the surface of the resin package 7 is obtained.

In the semiconductor device 8 obtained in this embodiment, since the adhered material 4 is made of polycarbodiimide resin having a low water vapor transmission rate, the adhered material 4 effectively absorbs moisture from the package resin. Will be prevented. [Embodiment 2] In this embodiment, as shown in FIG. 5, as a material to be adhered, a laminated body 14 in which a polycarbodiimide resin layer (thickness 50 μm) 14b is laminated on an aluminum foil (thickness 40 μm) 14a is used. This was fixed on the surface of the resin package in the same manner as in Example 1. However, when the adhered material (laminate) was temporarily fixed to the molding surface of the mold by adsorption, the polycarbodiimide resin layer 14b was set so as to contact the molding surface of the mold. By thus applying the polycarbodiimide resin layer having mold releasability to the mold to the mold molding surface, after molding the resin package, the polycarbodiimide resin layer side can be easily peeled off from the mold. No stain due to transfer residue was found on the mold. Example 3 As a material to be adhered, a polycarbodiimide resin layer (having a thickness of 5 μm) was formed on an aluminum foil (having a thickness of 40 μm).
0 μm) is used to form a laminate, which is used in Example 1.
It was fixed to the surface of the resin package in the same manner as in (1). When temporarily fixing the adhered material to the molding surface of the mold, unlike the case of Example 2, the aluminum foil surface was set so as to contact the mold side. Even when set in such a state, the flexibility of the adhered material is increased by laminating the polycarbodiimide resin layer on the aluminum foil, so that the adhered material can easily be temporarily adhered to the mold surface by adsorption. I was able to fix it. Further, since the aluminum foil surface is in contact with the molding surface, the aluminum foil side can be easily peeled from the mold after the resin package molding, and the mold after the peeling shows no stain. There wasn't.

[0017]

As described above, according to the present invention, in molding a resin package of a semiconductor device, when a material to be adhered is fixed to the surface of the package, the mold releasing property of the package molding die is improved. By using the adhered material that is provided, it is not necessary to temporarily fix the adhered material on the mold via the temporary fixing adhesive layer. Therefore, the mold due to the transfer residue of such temporary fixing adhesive layer There is no stain on. Further, since the adhered material can be temporarily fixed on the mold by adsorption, it is possible to reduce the time and effort required to set the adhered material on the mold during molding. As a result, as a method of manufacturing a semiconductor device in which the adhered material is fixed to the surface of the package in which the semiconductor element is sealed with resin, a method with higher mass productivity can be realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a material to be adhered is set on a mold in an embodiment of the method of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a lead frame for fixing a semiconductor element is inserted between upper and lower molds after setting the adhered material.

FIG. 3 is a sectional view showing a state before the resin is injected into the mold by closing the mold after inserting the lead frame.

FIG. 4 is a sectional view showing a semiconductor device finally obtained in the above embodiment.

FIG. 5 is a cross-sectional view showing the structure of a laminate used in another example of the present invention.

[Explanation of symbols]

 1, 2 and 3 ... Mold (2 ... Upper mold, 3 ... Lower mold) 4 ... Adhering material 5 ... Semiconductor element 7 ... Resin package 14 ... Laminated body 14a ... Metal foil (aluminum foil) 14b ... Resin layer (polycarbodiimide resin layer)

Claims (6)

[Claims] 1. A method of manufacturing a semiconductor device in which a material to be adhered is fixed to a surface of a package, which is formed by sealing a semiconductor element with a resin, and is released from a mold for molding a package. A semiconductor characterized in that a material to be adhered is fixed to the package surface by adsorbing a material to be adhered, then setting a semiconductor element in the mold, and then injecting a molding resin for molding. Device manufacturing method. 2. The method for manufacturing a semiconductor device according to claim 1, wherein the adhered material comprises polycarbodiimide or polytetrafluoroethylene. 3. The adhered material comprises a laminated body of a metal foil and a resin layer laminated on the metal foil and having releasability from a mold for molding a package. Manufacturing method of semiconductor device. 4. The method of manufacturing a semiconductor device according to claim 3, wherein the resin layer is made of any one of polycarbodiimide, polyetherimide, polyimide and polytetrafluoroethylene. 5. A laminate used as a material to be adhered in the method of manufacturing a semiconductor device according to claim 1,
A laminated body comprising a metal foil and a resin layer laminated on the metal foil and having releasability from a mold for molding a package. 6. The laminate according to claim 5, wherein the resin layer is made of any one of polycarbodiimide, polyetherimide, polyimide and polytetrafluoroethylene.