Aluminum ribbon for ultrasonic bonding

Abstract

There is provided an aluminum ribbon for ultrasonic bonding consisting of an aluminum alloy of >=99 mass% in purity, which includes the additive element and the balance composed of aluminum. This ribbon has an extremely thin tape structure obtained by rolling after multistage wire drawing, the average of the crystal grain diameter in the cross-section of the ribbon is 5 to 200 [mu]m, and a ratio of thickness to width of the ribbon is 1 / 2 to 1 / 20. Preferably, an aspect ratio (width direction / thickness direction) of the crystal grain diameter is 0.5 to 10, and a mirror finish is made with a surface roughness of Rz<or=2 [mu]m.

Description

technical field [0001] The present invention relates to an aluminum ribbon connected by ultrasonic welding to semiconductor devices, lead parts of substrates in electronic parts, and semiconductor packages. Background technique [0002] In the manufacturing process of semiconductor devices, a method of soldering using an electrical conductor in the shape of a strip with a rectangular cross section (hereinafter referred to as "tape") is widely used to electrically connect the connection electrodes on the semiconductor wafer and the outer leads on the semiconductor package. terminals. [0003] This method is the application of the ultrasonic wire welding method using aluminum wires, and applies loads and ultrasonic vibrations to the aluminum strips to shatter the 1nm-thick oxide film naturally formed on the aluminum strips, thereby exposing the metal atoms on the surface and increasing each other. A new surface in intimate contact that creates plastic flow and atomic bonding ...

AI Technical Summary

Problems solved by technology

Therefore, in the traditional method, such as changing the appearance shape of the welding strip, it is difficult to perform tens of thousands of cycles of welding under constant conditions, and it is difficult to obtain high and stable welding strength

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