Aluminum ribbon for ultrasonic bonding

Abstract

Provided is an aluminum ribbon for ultrasonic bonding which, even when used for bonding tens of thousands of times, can retain high bond strength and a certain level of bond strength. The aluminum ribbon for ultrasonic bonding comprises aluminum metal or an aluminum-based alloy, the aluminum having a purity of 99.99 mass% or higher. The aluminum ribbon has a nonionic surfactant having a molecular weight of 500 or less, the surfactant having been deposited through vaporization to dryness on a mirror surface of the ribbon in an amount of 100-1,000 [mu]g / m2 in terms of total organic-carbon amount.

Description

technical field [0001] The present invention relates to an aluminum strip used for connecting semiconductor element electrodes and lead portions on the substrate side by ultrasonic welding in electronic components and semiconductor packages. Background technique [0002] In the manufacture of semiconductor devices, it is widely used to electrically connect the connection electrodes (pads) provided on the semiconductor chip and the external terminals (leads) provided in the semiconductor package, and use strip-shaped aluminum conductors with a nearly rectangular cross section. Body (hereinafter referred to as "strip") welding method. This welding method utilizes a welding method of aluminum conductive wires, in which a cemented carbide tool is pressed against an aluminum strip overlaid on an electrode or a lead, and the load and the energy of ultrasonic vibration are applied to perform bonding. [0003] The effect of applying ultrasonic waves is as follows, through the expan...

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Problems solved by technology

[0021] However, in the case of aluminum strips used to connect semiconductor devices by ultrasonic welding, although the joining conditions using ultrasonic waves are different between the front surface and the rear surface, ultrasonic welding is automatically performed at a rate of several per second, so it is necessary to Even tens of thousands of times must be joined under the same conditions

[0022] In this way, in the conventional method of mechanically changing the outer shape of the aluminum strip, although the effect can be exerted initially, when the ultrasonic welding is continued tens of thousands of times, the joining conditions will not be maintained, and connection failures will frequently occur.

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