JPS5821850A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the deterioration or damage in the characteristics of a silicon element and the breakage of the internal wire of a semiconductor device by providing a protective layer on the element, die pad and the internal wires, thereby eliminating the application of mechanical distortion of sealing resin directly to respective sections. CONSTITUTION:A protective layer is covered with a protective resin 6 on a silicon element 1, a die pad 2 and internal wires 4, and which are sealed with sealing resin 5 together with external lead terminal 3. The resin 6 empolys a resin having elastic modulus lower than the resin 5. In this manner, when the resin 5 is formed in the predetermined shape, the volumetric contraction strain produced at the hardening step can be absorbed by the resin 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin-sealed semiconductor device that prevents deterioration and destruction of characteristics of semiconductor elements and breakage of internal wiring.

Conventionally, resin sealing of semiconductor devices has been carried out as follows. That is, in FIG. 1, 1 is a silicon element (semiconductor element) on which a circuit pattern is formed, 2
3 is a substrate for holding and fixing the silicon element 1 (hereinafter referred to as die pad); 3 is an external lead conductor for connecting the wiring from the silicon element 10 circuit electrode; 4 is the external lead conductor 3 between the silicon element 10 circuit electrode and the external lead conductor 3; 5 is a sealing resin.

To resin-seal this resin-sealed semiconductor device, first, the silicon element 1 is brazed to the center of the die pad 2, and the circuit electrodes of the cliffed element 1 and the external lead conductor 3 are connected to the internal wiring 4.
The silicon element 1. Die pad 2. Internal wiring 4. This is carried out by sealing a required portion of the external lead conductor 3 with a sealing resin 5.

Since conventional resin-sealed semiconductor devices are manufactured through the steps described above, they have the following drawbacks.

First, during molding of the sealing resin 5, mechanical strain is applied to the silicon element 1 and the internal wiring 4 due to volumetric contraction as the sealing resin 5 hardens, generating excessive internal stress therein.

Second, due to the heat cycle during use of the device, the Cricon element 1. Die pad 2. Internal wiring 4. Due to the difference in linear expansion coefficients of the sealing resin 5 and the sealing resin 5, the sealing resin 5 in particular generates excessive thermal stress on the silicon element 1 and the internal wiring 4.

Due to the above-mentioned factors, there were disadvantages such as deterioration of the electrical characteristics of the silicon element 1, furthermore, destruction of the silicon element 1 and rupture of the internal wiring 4.

This invention was developed to eliminate the above-mentioned drawbacks, and the silicon element, die pad, and internal wiring are covered with a resin having a lower elastic modulus than the sealing resin to form a protective layer. The purpose is to provide highly reliable resin-sealed semiconductor devices by preventing mechanical strain from being directly applied to the sealing resin, thereby preventing deterioration and destruction of silicon elements and rupture of internal wiring. It is said that This invention will be explained below.

FIG. 2 is a sectional view of a resin-sealed semiconductor device showing an embodiment of the present invention. To explain this manufacturing process, first, silicon element 1. A protective layer is formed by coating the die pad 2 and the internal wiring 4 with a protective resin 6, and then resin-sealed with the same sealing resin 5 as shown in FIG. 1 to form a resin-sealed semiconductor device. Note that 3 is a conductor for external leads. As the protective resin 6, a resin having a lower elastic modulus than the sealing resin 5 is used.

The resin-sealed semiconductor device configured in this manner has the following advantages.

First, when molding the sealing resin 5 into a desired shape, the volumetric shrinkage strain that occurs during the curing process is absorbed by the protective resin 6, which has a lower elastic modulus than the sealing resin 5, and the silicon element 1 is Deterioration and destruction of characteristics and breakage of the internal wiring 4 can be prevented.

Second, when the device is subjected to a heat cycle, silicon elements 1. Die pad 2. Internal wiring 4. Thermal strain occurs due to the difference in the linear expansion coefficients of the sealing resin 5 and the sealing resin 5. In particular, the thermal strain of the sealing resin 5, which is a major cause of thermal stress on the silicon element 1 and the internal wiring 4, is It is absorbed by the protective resin 6, which has a lower elastic modulus than the resin 5, and can prevent characteristic deterioration and destruction of the silicon element 1 and breakage of internal wiring.

Thirdly, silicon element 1. Die pad 2. Since the internal wiring 4 is covered with the protective resin 6 and then sealed with the sealing resin 5, even if moisture gets into the sealing resin 5 from the outside, this protective resin 6 will prevent moisture from entering. It is possible to prevent the infiltration of the silicon element 1 and prevent deterioration of the characteristics of the silicon element 1.

FIG. 3 shows another embodiment of the present invention, in which a silicon element 1. Die pad 2. A protective metal seal 7 is applied to the internal wiring 4 to form a protective layer, and then the resin-sealed semiconductor device obtained by this method is also sealed with a sealing resin 5, as shown in FIG. The same effect as in the embodiment is achieved.

As explained in detail above, the resin-sealed semiconductor device according to the present invention has a protective layer for the silicon element, die pad, and internal wiring, so that the mechanical strain of the encapsulating resin is not directly applied to these. Therefore, it is possible to prevent the deterioration and destruction of the characteristics of the silicon element and the breakage of the internal wiring, and it is possible to obtain a highly reliable resin-sealed semiconductor device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a conventional resin-sealed semiconductor device, FIG. 2 is a cross-sectional view of a resin-sealed semiconductor device showing an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing an example of a conventional resin-sealed semiconductor device. 1 is a cross-sectional view of a resin-sealed semiconductor device showing an example. In the figure, 1 is a silicon element, 2 is a die pad, 3 is an external lead conductor, 4 is internal wiring, 5 is a sealing resin, 6 is a protective resin, and 7 is a protective metal seal. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent: Nobu Kuzuno (1 other person)

Claims (1)

[Claims] A semiconductor element, a protective layer formed on a substrate to which the semiconductor element is attached, and an internal wiring whose one end is connected to the semiconductor element, and a sealing resin formed in a desired shape on the protective layer. A resin-sealed semiconductor device comprising: