Metal and Technology, Inc. We support the realization of social ecology through the utilization of technology that uniformly disperses carbon in non-ferrous metals.

Handa

1. Bismuth (Bi) Eutectic Soldering

Challenges with Conventional [Bismuth Eutectic Soldering]

Conventional Bismuth Eutectic Soldering has a low melting point among other strong points, however, the disadvantages stem from the degree of hardness being too high, the viscosity being too low causing cracks for form easily. Because of that, there was a problem with it being unusable so there were many demands for a higher viscosity. In an attempt to solve this problem, a method of adding a 1wt.% silver additive was adopted; however there is a problem with silver as an additive because the cost is too high. Also, another defect was discovered during the formation of a metal alloy block that conventional tin and bismuth eutectic soldering have differing elemental distribution depending on the positioning so variations in the strength can be seen through usage positioning.

The Characteristics of Highly Stable Bismuth Eutectic Soldering

At our company, we felt it was necessary to correct the above listed [Bismuth Eutectic Soldering]'s defects. In the manufacturing process, we discovered a manufacturing method in which we created a temporary bond between tin and copper, then fused that alloy with Bismuth, and compared it to conventional [Bismuth Eutectic Soldering], the viscosity was much higher, and the segregation is reduced by the positioning on a metal block. We are currently applying for a patent of this Bismuth Eutectic Soldering method in cooperation with The Shirogane Co. Ltd. Also, we are using the lead free soldering [Carbon Solder] with carbon additive technology our company is currently selling to develop a strong viscosity [Carbon Additive Bismuth Eutectic Solder].

2. Bismuth Eutectic Soldering Tension Test Results

Conventional Bismuth Eutectic Soldering Tension Test Results

The graph below display the results from a conventional Bismuth Eutectic Soldering tension test. 2 types of samples underwent the tension test, the variations in the [Pulling Strength (Mpa) ] can be understood.

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Highly Stable [Bismuth Eutectic Soldering] Tension Test Results

The graph below displays the results of a tension test conducted by our company testing the patent pending manufacturing method for creating [Highly Stable Bismuth Eutectic Soldering]. 3 types of samples underwent the tension test, the [Pulling Strength (Mpa) ] section compares conventional bismuth eutectic soldering and [Pulling Strength (Mpa) ] shows lower variations.

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