JPH04312966A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a sealed semiconductor device which has a simple electrode terminal and in which peeling of a soldered part of the terminal is prevented. CONSTITUTION:A through hole 9a in which one end of an electrode terminal 10 is passed, is formed with a suitable clearance in a case 9, the other end of the terminal 10 is electrically connected to a semiconductor chip 5 placed on a copper base plate 1 in the case 9, and the terminal 10 is held with predetermined clearances in vertical directions in the case 9. The terminal 10 is formed longitudinally movably in the case 9. Even if repetitive load is applied directly to the soldered part of an electrode terminal 4 in a heat cycle test, the load can be absorbed by a longitudinal movement and by holding with a silicone rubber 11.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to sealed semiconductor devices, particularly power module packages consisting of an outsert case, that is, a case in which electrode terminals are assembled. This is related to ji.

0002

2. Description of the Related Art FIG. 3 is a sectional view showing a semiconductor device constructed of a conventional outsert case. In this figure, 1 is a copper base plate that constitutes the base of the semiconductor device and also serves as a heat dissipator. 2 is fixed to the top surface of this copper base plate 1, and thick copper foil is covered on both sides. 3 is a resin outsert case fitted and fixed to the outer periphery of the copper base plate 1, 4 is an electrode terminal, and an S-shaped bent portion is formed at one end. 4a, and the pattern on the insulating substrate 2.
The other end is soldered to the outsert cable.
It is fixed to the fixing part 3a in a state of protruding from the upper surface of the base 3. 5 is a semiconductor chip bonded to the upper surface of the insulating substrate 2; 6 is an aluminum wire that connects the semiconductor chip 5 and the required circuit of the insulating substrate 2; 7 is the semiconductor chip 5, the aluminum wire 6, and an electrode. silicone gel for sealing the terminals 4 etc. inside the outsert case 3;
8 is injected into the upper part of this silicon gel 7, and the electrode terminal 4
This is an epoxy resin for resin-sealing the inside of the outsert case 3.

[0003] Next, reliability problems of power modules constructed with outsert cases will be discussed. Semiconductor products have a variety of uses, not just power modules. When it comes to packaging, the first priority is to fully bring out the characteristics of semiconductor devices and to ensure that they exhibit stable performance under the usage conditions. A power module composed of an outsert case, which is the object of the present invention, is as follows:
As a result of efforts to shorten manufacturing time, automate production, and achieve stable quality, this package is now the mainstream of power modules. The most important thing to pay attention to in terms of reliability is the power module package.
This is a part where solder is used to join parts, especially the solder joint part between the external electrode terminal 4 and the insulating board 2 with thick copper foil. This part functions as a contact point for extracting the current converted by the semiconductor device, and is a very important part. A heat cycle test is commonly used to evaluate the reliability of this part. In a heat cycle test, this solder joint is subjected to repeated alternating tension and compression (test temperature -40°C to 125°C). A problem with reliability occurs when a tensile load is applied, and at this time the load is applied to the electrode terminal 4 on the insulating substrate 2 to which it is
It works in the direction of trying to peel it off from the thick copper foil. The repeated loads applied to the solder joints are caused by warpage caused by the size of the package and the difference in coefficient of thermal expansion between the copper base plate 1 and the thick copper foil insulating substrate 2. In addition, because the expansion coefficient of the silicone gel 7 used as the sealant is one order of magnitude larger than the thermal expansion coefficient of the case material or epoxy resin 8, the outsert case 3 can be heated at high temperatures during heat cycles.
Since the electrode terminal 4 is fixed to the insulating substrate 2, a force is exerted to peel the electrode terminal 4 from the thick copper foil of the insulating substrate 2. Therefore, in order to absorb this repeated load and reduce the stress applied to the terminal soldering part, a part called "S-bent part" 4a which has a kind of spring effect is essential.

0004

[Problems to be Solved by the Invention] A power module package consisting of a conventional outsert case 3 is
With the above structure, it is necessary to provide the S vent 4a portion in the electrode terminal 4, which makes the shape of the electrode terminal 4 complicated and increases the cost. In addition, there were other problems such as the solder joints peeling off due to the expansion that occurs during the heat test.

The present invention has been made to solve the above-mentioned problems, and provides a sealed semiconductor device that can simplify the shape of electrode terminals and eliminate peeling of solder joints. The purpose is to

[0006]

[Means for Solving the Problems] In the sealed semiconductor device according to the present invention, the penetration portion of the electrode terminal of the outsert case is made larger than the outer shape of the electrode terminal, and the upper half of the inside of the case is made larger. An elastic material such as silicone rubber is used as the sealing material.

[0007]

[Operation] In the sealed semiconductor device of the present invention, the electrode terminal held by the elastic material in the outsert case can move in the longitudinal direction of the through-hole of the outsert case.

[0008]

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. In this figure, 1, 2, 5 to 7 are
Since the configuration is substantially the same as that of the conventional example, the explanation thereof will be omitted. 9
is a resin outsert case that is fitted and fixed to the outer edge of the copper base 1, and has a through hole 9a in the upper part. 10 is an electrode terminal having one end soldered to the pattern on the insulating substrate 2 and the other end protruding from the through hole 9a of the outsert case 9 without an S-bent portion; 11 is an electrode terminal connected to the silicon gel 7; Silicone rubber is injected into the upper part of the outer case 9 to seal the electrode terminal 10 inside the outsert case 9. Note that the through hole 9a is formed somewhat larger than the outer shape of the electrode terminal 10.

Next, the operation of the present invention will be explained with reference to FIG. FIG. 2 is a view seen from the direction of the arrow in FIG.
0 is held in the outsert case 9, and the electrode terminal 10 has a predetermined clearance for escape in both the vertical direction within the outsert case 9, that is, the downward clearance a, It is held with an upward clearance b. With this holding method, the electrode terminal 10 becomes free in the outsert case 9 while the electrode terminal 10 shown in FIG. 1 and the insulating substrate 2 with thick copper foil are soldered together. In the conventional semiconductor device shown in FIG. 3, after the silicon gel 7 is injected and lowered in this state, the electrode terminal 4 and the outsert case 3 are fixed with the epoxy resin 8, so the heat cycle test is not performed. In this case, repeated loads are applied directly to the solder joint. However, as in the present invention, the epoxy resin is changed to silicone rubber 11, and the through hole 9
By providing a, the electrode terminal 10 is made of silicone rubber 1.
1 can be freely moved in the longitudinal direction, and the force applied to the solder joint of the electrode terminal 10 due to thermal expansion can be eliminated.

In the present invention, silicone rubber 11 is used to hold the electrode terminal 10, but other materials may be used as long as they can elastically support the electrode terminal 10 and seal it.
The same effects as in the above embodiment are achieved.

[0011]

[Effects of the Invention] As explained above, according to the present invention,
An elastic material is enclosed in the outsert case to hold the electrode terminal, and the electrode terminal is configured to be movable in the longitudinal direction, so the S-bent part of the electrode terminal can be eliminated, reducing inductance. , and cost reduction can be achieved. In addition, there is no peeling of the solder joints, which has the effect of improving quality.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a sealed semiconductor device showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a state in which the electrode terminal in FIG. 1 is held.

FIG. 3 is a cross-sectional view showing an example of a conventional sealed semiconductor device.

[Explanation of symbols]

1 Copper base plate 2 Insulating substrate 5 Semiconductor chip 7 Silicon gel 9 Outsert case 9a Through hole 10 Electrode terminal 11 Silicone rubber

Claims (1)

[Claims] Claim 1: A base plate on which a semiconductor chip is mounted; a case fixed to the outer edge of the base plate; one end passing through the upper part of the case; an electrode terminal whose end is electrically connected to the semiconductor chip; a gel-like encapsulant that seals approximately the lower half of the inside of the case; and a solid encapsulant that seals approximately the upper half of the case. In the sealed semiconductor device configured, a through hole through which one end of the electrode terminal passes is formed in the case to be larger than the outer shape of the electrode terminal, and a through hole is formed in the sealing material in the upper half of the case. A sealed semiconductor device characterized by using an elastic material.