Experimental Discovery of High-Purity Tin

Since recent semiconductor devices are densified and of large capacity, there is considerable risk of a soft error occurring due to the influence of the α ray from materials in the vicinity of the semiconductor chip. In particular, there are strong demands for purifying the soldering material or tin to be used in the vicinity of semiconductor devices, as well as for the realization of materials with fewer α rays. Thus, an object of the present invention is to provide high purity tin or tin alloy and the manufacturing method of such high purity tin by reducing the α dose of tin so as to be adaptable as the foregoing material.

In order to achieve the foregoing object, the present invention provides high purity tin or tin alloy wherein the respective contents of U and Th as radioactive elements are 5 ppb or less, the respective contents of Pb and Bi that emit radiation α particles are 1 ppm or less, and the purity is 5N or higher (provided that this excludes the gas components of O, C, N, H, S and P). The present invention aims at eliminating as much as possible the influence of the α ray on semiconductor chips.
The high purity tin or tin alloy of the present invention is ultimately manufactured by being rolled and cut when needed as well as being dissolved and cast. It is desirable that the α ray count of such high purity tin is 0.001 cph/cm2 or less. The high purity tin or tin alloy of the present invention realizes the foregoing numerical value.

Read More: high-purity tin price