JP3147601B2 - 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, die bonding of semiconductor devices,
High melting point (260-400) used for semiconductor device assembly such as flip chip bonding and IC package sealing
° C) solder material, Sn, In, Sb, Bi
One or more species: 1 to 10%, with the balance being Pb
And a Pb alloy having a composition composed of unavoidable impurities.

[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 its use environment temperature is about 100 ° C., the high-temperature strength is not sufficient, so that the brazed portion is easily broken.

[0004]

Therefore, the present inventor focused on the above-mentioned conventional Pb alloy solder material in order to improve the high-temperature strength from the above-mentioned viewpoints, and as a result, as a result, the above-mentioned conventional Pb alloy solder material was obtained. Pd: 3 ~ as alloying component in alloy solder
When 12% by weight is alloyed, the resulting Pb alloy solder material has excellent high-temperature strength, and when this is used for assembling a highly integrated semiconductor device with high heat generation, the soldered portion is not affected even in practical use. The research results showed that it exhibited excellent high-temperature strength and no breakage was observed.

The present invention has been made on the basis of the above-mentioned research results, and in terms of weight% (hereinafter,% indicates weight%), Pd: 3 to 12%, Sn, In, Sb, Bi One or two or more thereof: 1 to 10%;
And a Pb alloy solder material for assembling a semiconductor device, which is composed of a Pb alloy having a composition comprising unavoidable impurities.

Next, the reason why the component composition of the Pb alloy constituting the Pb alloy solder material of the present invention is limited as described above will be described. a) Sn, In, Sb, and Bi These components have the effect of lowering the melting point and improving the solderability, but if the content is less than 1%, the desired effects cannot be obtained in the above-mentioned effects. If the content exceeds 10%, the high-temperature strength decreases, so the content is set to 1 to 10%. b) Pd The Pd component has the effect of improving the high-temperature strength as described above, but if its content is less than 3%, the desired excellent high-temperature strength cannot be secured, while its content is 12%. %
If the temperature exceeds the limit, the melting point rises and soldering becomes difficult. Therefore, 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 an ingot having a diameter of 50 mm × length: 150 mm was cast, and the ingot was width: 30 mm × thickness: 3 mm. The Pb alloy solder materials 1 to 10 of the present invention and the conventional Pb alloy solder materials 1 to 10 having a thickness of 70 μm were produced, respectively. Next, in order to evaluate the high-temperature strength of the various Pb alloy solder materials obtained as a result, a high-temperature shear test was performed under the following conditions. That is, a test piece having a size of 20 mm × 20 mm was cut out from the above Pb solder material, and the width: 20 mm × thickness: 10 mm ×
Length: Each end of two Ni plates having a dimension of 100 mm is overlapped with a 20 mm overlap margin with the test piece in between, and a load of 0.2 MPa is applied thereto in a reflow furnace in a nitrogen atmosphere. Soldering was performed by heating at the melting point of each solder material + 80 ° C for 3 minutes. For this soldered body, 150
A shear test was conducted at 10 ° C. at a tensile speed of 10 mm / min, and the shear strength was measured. 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 soldering parts 1 to 10 of the present invention have a soldering part formed by using the same as the soldering parts formed by using the conventional soldering materials 1 to 10. Thus, it is clear that it has excellent high-temperature strength. 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 secured for a long period of time.

Claims (1)

(57) [Claims] 1. Pd: 3 to 12% by weight, Sn, I
one or more of n, Sb and Bi: 1 to 10%,
A Pb alloy solder material for semiconductor device assembly excellent in high-temperature strength, characterized by having a composition comprising Pb and inevitable impurities.