Bonding wire of gold (Au) alloy

Abstract

An ultrafine wire having a diameter of 20 [mu]m or less for ball bonding, with which bonding can be successively conducted hundreds of thousands of times. Ca, Mg, and La are incorporated as minor additive elements in a concentration of 5-50 mass ppm each into an alloy matrix obtained by incorporating one or more of Pd, Pt, and Cu that have a high purity of 3N or above, in a total concentration of 5-2 mass%, into gold that has a high purity of 5N or above. Alternatively, Be is further incorporated in a concentration of 1-20 ppm, and / or one or more of Ce, Y, and Eu are further incorporated in a total concentration of 1-30 mass ppm. Furthermore, the total concentration of these minor additive elements may be regulated to 100 ppm or less. Thus, the additive elements are inhibited from segregating in the surface of the melt ball, and deposits or oxides of the additive elements are inhibited from accumulating on the capillary tip during bonding and thereby increasing the sliding resistance of the wire during loop formation. Since the surface of the capillary tip is kept smooth, bonding failures in the wire bonding, such as neck damage and nonbonding, are inhibited from occurring and long-term continuous bonding is rendered possible.

Description

technical field [0001] The present invention relates to a gold (Au) alloy bonding wire for wire bonding of semiconductor elements used to connect electrodes (pads) on semiconductor integrated circuit elements and electrodes (external wires) connected to circuit wiring boards; more specifically , relates to a wire-drawn gold (Au) alloy bonding wire with a diameter of 20 μm or less that suppresses surface segregation of trace elements. Background technique [0002] Conventionally, gold (Au) alloy bonds made of high-purity gold with a purity of 99.99% by mass or more have been frequently used as wires with a wire diameter of about 25-35 μm that connect pads on semiconductor chips used in semiconductor devices and external wires. fit line. [0003] In general, among methods of connecting gold (Au) alloy bonding wires, a bonding method in combination with ultrasonic waves and heat pressing is mainly used for the first bonding. [0004] In this method, the tip of the wire expose...

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Problems solved by technology

[0021] This is a bond in which a predetermined amount of a second element such as Ca and a third element such as La are added to a gold alloy containing a first element group such as palladium (Pd) as described in paragraphs 0033-0034 of Patent Document 1. In the joint line, even if the cohesiveness is improved or the sphericity of the ball shape is increased, the problem still cannot be solved

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