LAUSR

Preferred orientation Cu6Sn5 prisms are usually formed on (001)Cu single crystal, making use of which can highly improve the packaging reliability of electronic devices. A practical method for morphology controlling of preferred orientation Cu6Sn5 was put forward preliminarily in this article based on temperature variation. The roof-type Cu6Sn5 prisms actually behaved as scallops of highly preferred orientation relationship with (001)Cu substrate in isothermal heating of reflow process and began to transform into prismatic roofs without grain number and orientation changing following it cooled down to solidification. This new phenomenon undiscovered before can pave the way for understanding the precise mechanism of roof-type Cu6Sn5 formation and provide a scientific viewpoint that orientation, size, and outline control of oriented Cu6Sn5 should be realized in different stages of reflow process. This is quite significant for manufacture of morphology-controllable solder interconnections in electronic industry.