JP3147602B2 - Pb alloy solder for semiconductor device assembly with excellent high temperature strength - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Pb alloy solder having a high melting point (260-400.degree. C.) and excellent high-temperature strength used for assembling semiconductor devices.

[0002]

2. Description of the Related Art Conventionally, high melting points (260 to 4) used for assembling semiconductor devices such as die bonding, flip chip bonding and IC package sealing of semiconductor elements (Si).
Pb-Sn alloy, Pb
Pb alloys such as -Ag alloy, Pb-Sn-Ag alloy and Pb-In alloy have been known.

[0003]

On the other hand, high integration of semiconductor devices in recent years is remarkable, and accordingly, heat generation of the semiconductor devices is also increased, and the soldering portions constituting the semiconductor devices are also placed in a high temperature environment. However, the above-mentioned conventional Pb alloy solder material has a problem that, when the use environment is about 100 ° C., the high-temperature strength is not sufficient, and the brazed portion is easily broken.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
In view of the above, research was conducted to develop a Pb alloy solder material that can be used particularly for highly integrated assembly of semiconductor devices. As a result, the solder material is expressed in terms of% by weight (hereinafter,% indicates% by weight). Pd: 3 to 12%, the remainder being Pb
And a Pb alloy composed of unavoidable impurities, the resulting Pb alloy solder material has excellent high-temperature strength. Therefore, when this is used for assembling a highly integrated semiconductor device with high heat generation, it can be used for practical use. The research results showed that the soldered part exhibited excellent high-temperature strength and no breakage was observed.

The present invention has been made on the basis of the above research results, and comprises a Pb alloy having a composition containing Pd: 3 to 12% and the balance consisting of Pb and unavoidable impurities. Is characterized by the following Pb alloy solder material for assembling semiconductor devices.

In the Pb alloy constituting the Pb alloy solder material of the present invention, it is an alloy component. The reason why the content of Pd is set to 3 to 12% is that if the content is less than 3%, the desired high-temperature strength cannot be ensured, while if the content exceeds 12%, the melting point becomes too high. Since the soldering becomes difficult, the content is set to 3 to 12%.

[0007]

Next, the Pb alloy solder material of the present invention will be specifically described with reference to examples. In a normal high-frequency melting furnace, a Pb alloy melt having the component composition shown in Table 1 was prepared and cast into an ingot of diameter: 50 mm × length: 150 mm, and the ingot was width: 30 mm × thickness: It was cold-extruded to 3 mm and cold-rolled to produce Pb alloy solder materials 1 to 4 of the present invention having a thickness of 70 μm and conventional Pb alloy solder materials 1 to 5 respectively. Next, the various Pb alloy solders obtained as a result were subjected to a high-temperature shear test under the following conditions in order to evaluate the high-temperature strength.
That is, a test piece having a size of 20 mm × 20 mm was cut out from the above Pb alloy solder material, and the width: 20 mm × thickness: 10 mm ×
Length: Each end of two Ni plates having dimensions of 100 mm is overlapped with a 20 mm overlap allowance with the test piece in between, and each is subjected to a reflow furnace in a nitrogen atmosphere while applying a load of 0.2 MPa. Soldering was performed by heating at the melting point of the solder material + 80 ° C for 3 minutes. About 150 ℃
A shear test was conducted at a tensile speed of 10 mm / min to measure the shear strength. The test results were taken as the average value of the five samples.

[0008]

[Table 1]

[0009]

According to the results shown in Table 1, the solder materials 1 to 4 of the present invention have the following advantages.
It is evident that it has superior high-temperature strength as compared with soldered portions formed using conventional solder materials 1 to 5. As described above, the Pb alloy solder material of the present invention has excellent high-temperature strength. Therefore, even when the Pb alloy solder material is used for assembling a highly integrated semiconductor device which generates heat at a high temperature, the brazed portion is broken in practical use. Therefore, high reliability can be ensured for a long period of time.

Claims (1)

(57) [Claims] (1) containing, by weight%, Pd: 3 to 12%;
A Pb alloy solder material for assembling semiconductor devices having excellent high-temperature strength, the balance being composed of Pb and unavoidable impurities.