JPH0513623A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To solve the problem where a trade-off relation exists between molding resins, one desirable for improving voltage characteristics and another desirable for improving moisture resistance. CONSTITUTION:The first resin member 7 for improving voltage characteristics is placed in a pot, and the second resin member 8 for improving moisture resistance is put on the first resin member, on which a semiconductor chip is placed. Then, transfer molding is performed in such a manner that molding resin is applied from above the chip in the cavity 3 between the two resin members. As a result, the chip is enclosed by both the resin for improving voltage characteristics and the resin for improving moisture resistance, and thus a highly reliable device is realized owing to the respective properties of both resin. This device is fabricated in a single transfer molding process.

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 device in which a semiconductor element body is covered with two layers of resin having different properties and resin-encapsulated.

[0002]

2. Description of the Related Art A semiconductor device in which a semiconductor body is sealed with a resin such as an epoxy resin in order to obtain stable characteristics by shielding the semiconductor body from the outside atmosphere is well known. In that case, it is also known that the influence on the semiconductor body differs depending on the properties of the resin. For example, to improve the moisture resistance, it is preferable to add a phosphorus-based catalyst to an epoxy resin, and to improve the stability against voltage application, an epoxy resin to which an imidazole-based catalyst is added. However, if it is sealed with a resin suitable for improving moisture resistance, the voltage application characteristics will be poor,
It is known that there is a trade-off relationship that moisture resistance deteriorates if the resin is sealed with a resin suitable for improving the application characteristics. Therefore, the conventional resin-encapsulated semiconductor device uses a resin having an intermediate property. As another measure, there is a semiconductor device in which both resins are doubly coated. In that case, one resin is potted on the semiconductor body.
After (potting), the other resin was molded (cast), for example, transfer molded.

[0003]

However, since a double resin coating is applied, the method of potting and then casting requires two steps of potting and molding, which is troublesome and costly. There are drawbacks. That being said, if you want to transfer mold both resins, you have to prepare two types of molds,
After all, it is time-consuming and costly.

An object of the present invention is to manufacture a semiconductor device which solves the above-mentioned problems and does not cause trouble and cost increase when the semiconductor element body is sequentially coated with different resins to improve reliability. To provide a method.

[0005]

In order to achieve the above-mentioned object, according to the present invention, a semiconductor element is coated with a layer made of a first resin and a layer made of a second resin on the layer. In the method for manufacturing a semiconductor device, the semiconductor element body is arranged directly below the gate in the cavity of the mold, the first resin is on the side close to the injection port in the pot, and the second resin is on the side far from the injection port. The resin is stored and cast by the transfer molding method. Then, it is effective that the length of the runner from the pot to each cavity is uniform. Further, it is effective to accommodate a tablet formed by laminating a layer made of the first resin and a layer made of the second resin in the pot. Further, it is effective that the first resin is an epoxy resin added with an imidazole catalyst and the second resin is an epoxy resin added with a phosphorus catalyst.

[0006]

When the resin in the pot is pressurized, the first resin near the injection port is injected from the gate directly above the semiconductor body in the cavity, so that the first resin is supplied around the semiconductor body. After that, the second resin, which is located farther from the injection port in the pot, is injected into the cavity and filled around the first resin layer. In this way, a semiconductor device of a double resin mold in which the periphery of the semiconductor body is covered with the first resin and the periphery thereof is covered with the second resin can be manufactured by one transfer molding shot. .

[0007]

EXAMPLE FIG. 2 conceptually shows a transfer mold die used in an example of the present invention. In the figure, the runner 2 connected to the lower portion of the pot 1 has the same length and has the respective cavity 3
The gate 4 opens. A semiconductor chip 5 fixed to a metal substrate 6 is inserted into each cavity 3 as shown in FIG. 1, but the gate 4 is directly above the chip. FIG. 3 shows a tablet supplied to the pot 1 of this mold, and this tablet is one in which a layer of a first resin 7 and a layer of a second resin 8 are laminated. As the first resin 7, an epoxy resin added with an imidazole catalyst and a filler such as crystalline silica or fusible silica, for example, Shin-Etsu Chemical Co., Ltd. trade name KMC52
The second resin 8 such as 2, X-43-3029 is obtained by adding a phosphorus-based catalyst to an epoxy resin, for example, Shin-Etsu Chemical Co., Ltd.
Product names X-43-3039, X-43-3035 and the like are used.
The thickness ratio of the first resin 7 and the second resin 8 of the tablet is, for example, 15:85.

When transfer molding is performed by applying a pressure of 2.8 tons in this manner, the periphery of the chip 5 becomes a layer of the first resin 7 and the second resin 8 surrounds the periphery thereof as shown in FIG. To cover. Since the length of each runner 2 is uniform,
The first resin 7 and the second resin 8 are supplied into the respective cavities 3 in the same proportion, and each chip 5 is similarly coated with two layers of the resins 7 and 8. In the semiconductor device manufactured in this manner, since the semiconductor chip 5 is directly coated with the first resin 7 to which the imidazole-based catalyst is added, the characteristics of the semiconductor device are not deteriorated when a voltage is applied, and the semiconductor device is covered with phosphorus. Since the second resin 8 to which the system catalyst is added covers the second resin 8 to prevent moisture from entering from the outside, the moisture resistance is also excellent. The first resin 7 also has the advantage that it has good adhesion to the metal substrate 6.

The present invention is not limited to the above embodiments, and it goes without saying that the combination of resins, the shape of the mold and the like can be arbitrarily changed.

[0010]

According to the present invention, it is possible to perform transfer molding in which the semiconductor element body is doubly coated with the resin by one shot by inserting the different types of resins in the pot while stacking them. By combining the resins, for example, the voltage application characteristics of the semiconductor device can be improved and the moisture resistance can also be improved, and therefore it is extremely effective in manufacturing a highly demanded and highly reliable semiconductor device.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold cavity during transfer molding according to an embodiment of the present invention.

FIG. 2 is a conceptual plan view of a transfer mold die used in one embodiment of the present invention.

FIG. 3 is a perspective view of a resin tablet used in one embodiment of the present invention.

[Explanation of symbols]

1 pot 2 runners 3 cavities 4 gates 5 semiconductor chips 7 First resin 8 Second resin

Claims (4)

[Claims] 1. A method of manufacturing a semiconductor device in which a semiconductor body is covered with a layer made of a first resin and a layer made of a second resin on the layer, the method comprising: It is arranged directly below the gate in the cavity, the first resin is accommodated in the pot near the injection port, the second resin is accommodated in the side farther from the injection port, and the mold is cast by the transfer molding method. Manufacturing method of semiconductor device. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the runners extending from the pot to each cavity have a uniform length. 3. The method for manufacturing a semiconductor device according to claim 1, wherein a tablet formed by laminating a layer made of the first resin and a layer made of the second resin is housed in the pot. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the first resin is an epoxy resin containing an imidazole catalyst and the second resin is an epoxy resin containing a phosphorus catalyst. .