JPS60192353A - Sealing process of semiconductor device - Google Patents

Abstract

PURPOSE:To block the passage of water content permeating along a lead terminal led out of a semiconductor pellets or a loading substrate by a method wherein a major sheathing resin is provided with a hygroscopic resin layer. CONSTITUTION:A connection between a lead terminal 3 and a metallic wire 5 is locally covered with a hygroscopic phenol resin 9 while the whole body is further covered with sheathing epoxy resin 7 for protection. Besides, the part near a conductive channel 8 connected to semiconductor pellets 2 and a metallic wire 5 is locally covered with hygroscopic phenol resin 9 while the whole body is further covered with the external resin 7 protection. Moreover, multiple semiconductor pellets 2 placed on an insulating substrate 1a are entirely covered with a hygroscopic resin layer 9. Through these procedures, the whole permeating water content may be absorbed into the hygroscopic resin to prevent the water content from permeating into a semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a resin restraining method for covering semiconductor pellets with resin in order to protect the semiconductor pellets from the external environment.

Conventional technology Conventionally, semiconductor pellet encapsulation technology has been developed with the main focus on improving moisture resistance, and if the cost disadvantage is ignored,
Performance that is satisfactory to some extent can be obtained.

However, in resin sealing using commonly used epoxy resins, further improvement in moisture resistance is one of the keys to improving reliability.

The conventional resin sealing method, as shown in the cross-sectional view of Figure 1,
A semiconductor pellet 2 is placed on a metal substrate 1, a lead terminal 3 for external connection and the pellet are connected using a gold wire 5, etc., and in this state, the pellet is sealed using a resin 7 such as epoxy. was.

Alternatively, as shown in FIG. 2, the semiconductor pellet 2 is placed on the insulating substrate 1a, the conductive i88 on the insulating substrate and the electrode of the semiconductor pellet are connected with a gold wire 5, and then the semiconductor pellet 2 is placed on the insulating substrate 1a. The semiconductor pellet 2 was protected with a precoat 6, and the electrode of the semiconductor pellet 2 was led out from the side of the insulating substrate 1a via a conductive path 8 through a lead terminal 4, and the semiconductor pellet 2 was sealed using an exterior resin 7 such as epoxy.

However, these conventional sealing methods cannot completely prevent moisture from entering through gaps created at the interface between the lead terminal and the sealing resin, or between the entire bonding line and the sealing resin. Semiconductor pellets often become contaminated and fail, which has been considered a problem in resin encapsulation.

C.6 Purpose of the Invention An object of the present invention is to provide a resin sealing method that improves the moisture resistance disadvantage of conventional resin sealing.

20 Structure of the Invention According to the present invention, the main exterior resin layer has hygroscopicity so as to block the entry path of moisture that enters along the lead terminal pulled out from the semiconductor pellet or the mounting board. A method for sealing a semiconductor device in which a resin layer is provided is obtained.

E, Example Next, the present invention will be explained by examples.

FIG. 3 is a sectional view for explaining the first embodiment of the present invention. In Fig. 3, when comparing this with the conventional example shown in Fig. 1, the connection part of the lead terminal 3 with the gold wire 5 is locally wrapped with a hygroscopic resin, for example, a phenol resin 9, and the exterior is further covered. It is entirely covered and protected with epoxy resin 7.

FIG. 4 shows a second embodiment corresponding to the conventional example shown in FIG. Then, the entire exterior is covered with epoxy resin 7.

Similar to FIG. 3, FIG. 5 shows a third embodiment corresponding to the conventional example shown in FIG. 1. In FIG. 9, and then covered and protected as a whole with exterior epoxy resin 7.

FIG. 6 is a cross-sectional view for explaining the fourth embodiment. In this embodiment, a plurality of semiconductor pellets 2, 2. . . . In contrast, a moisture-absorbing resin #9 is provided on the substrate 1a, like an embankment, so as to surround all of them at once.

1. Effects of the Invention The sealing method of the present invention prevents moisture from entering along the lead terminal drawn out from the semiconductor pellet or the substrate on which the pellet is mounted, which corresponds to any of the above embodiments. A layer of water-absorbing resin is provided to block the moisture that enters through this infiltration path, and the water-absorbing AT fat absorbs all of the moisture, preventing moisture from flowing forward. Infiltration will be prevented and reliability will be improved.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of a resin-sealed semiconductor device for explaining a conventional sealing method, and FIG. 3 is a cross-sectional view of a resin-sealed semiconductor device. 4, 5 and 6 respectively show the first embodiment of the present invention.
Second. FIG. 7 is a cross-sectional view of a resin-sealed semiconductor device for explaining third and fourth examples. 1.1a... Semiconductor pellet mounting board, 2...
... Semiconductor bellet), 3.4 ... Lead terminal, 5 ... Gold wire, 6 ... Precoat,
7... Exterior epoxy resin, 8... Conductive path, 9... Resin with water absorbing properties.

Claims (1)

[Claims] When sealing the semiconductor pellet with resin, a hygroscopic resin is added in the main exterior resin layer so as to block the infiltration of moisture M from entering along the board on which the semiconductor pellet is mounted or the lead terminals. A method for sealing a semiconductor device, characterized by providing a layer.