Gold alloy wire for bonding wire having high initial bondability, high bonding reliability, high roundness of compression ball, high straightness, high resin flowability resistance, and low specific resistance

Abstract

There are provided a gold alloy wire for a bonding wire having high initial bonding ability, high bonding reliability, high roundness of a compression ball, high straightness, high resin flowability resistance, and low specific resistance. The gold alloy wire having high initial bonding ability, high bonding reliability, high roundness of a compression ball, high straightness, high resin flowability resistance, and low specific resistance contains one or more of Pt and Pd of 500 to less than 1000 ppm in total, Ir of 1 to 100 ppm, Ca of more than 30 to 100 ppm, Eu of more than 30 to 100 ppm, Be of 0.1 to 20 ppm, if necessary, one or more of La, Ba, Sr, and Bi of 30 to 100 ppm in total, if necessary, and a balance being Au and inevitable impurities.

Description

CROSS-REFERENCE TO PRIOR APPLICATION[0001]This is a U.S. National Phase Application under 35 U.S.C. §371 of International Patent Application No. PCT / JP2006 / 311525 filed Jun. 8, 2006, which claims the benefit of Japanese Patent Application No. 2005-173726 filed Jun. 14, 2005. Both of them are incorporated by reference herein. The International Application was published in Japanese on Dec. 21, 2006 as WO 2006 / 134825 A1 under PCT Article 21(2).TECHNICAL FIELD[0002]The present invention relates to a gold alloy wire for a bonding wire that is used to connect a chip electrode of a semiconductor element such as a transistor, LSI, or IC to an external lead part and has high initial bonding ability, high bonding reliability, high roundness of a compression ball, high straightness, high resin flowability resistance, and low specific resistance. In particular, the invention relates to a gold alloy wire for wire bonding that can be used in a wide temperature range from low temperature to high t...

AI Technical Summary

Benefits of technology

The patent text describes a new gold alloy wire for a bonding wire that has improved properties for high-temperature and high-frequency use in automobile ICs. The wire has a higher initial bonding ability, higher bonding reliability, higher roundness of a compression ball, higher straightness, higher resin flowability resistance, and lower specific resistance compared to existing wires. The new wire composition includes Pt, Pd, Ir, Ca, and Eu in specific amounts, which are more than those of high-purity gold. The new wire is more suitable for high-density integration of semiconductor devices and ensures long-term reliability in high-temperature and high-frequency environments.

Problems solved by technology

In addition, the decrease of bonding strength due to a ball bonding or the occurrence of bonding failures due to a rise of electrical resistance in the bonding interface has caused problems in an automobile IC for requiring a high reliability at the severe use environments of a high-temperature and a high frequency IC in which the operating temperature is increased.

In addition, the roundness of the compression balls is low at the ball bonding, a portion of the compression balls are protruded from the Al pad, and a short failure occurs by the contact of a neighboring compression ball.

However, when the diameter of the gold alloy wire is reduced, when the coiled gold alloy wire is extracted from a spool, a curling or meandering (curvature or bending) may easily occur in the gold alloy wire.

When the bonding is conducted by using the gold alloy wire in which the curling or meandering (curvature or bending) exists, since the neighboring bonding wire contacts and a short occurs, the bad semiconductor chips are produced to reduce the yield ratio.

When the straightness is insufficient, since the loop contacts to the neighboring loop and shorts out, the bad semiconductor devices are produce to reduce the yield ratio.