Substrate Metal Layer Structure for Wire Bonding and Power Semiconductor Devices

Abstract

The present application provides a substrate metal layer structure for wire bonding and a power semiconductor device. The substrate metal layer structure sequentially includes: a substrate; a metal layer disposed on the upper surface of the substrate; and leads, which are arranged on the surface of the metal layer away from the substrate and form a wire bond with the metal layer; wherein the metal layer includes a plurality of sub-metal layers stacked, and the plurality of sub-metal layers The surface area decreases gradually from bottom to top. Through the metal layer structure of the substrate and the power semiconductor device, the failure rate of wire bonding can be successfully reduced, the stress of the metal layer is small, the process is simple to realize, the cost is low, and the reliability of the device is improved.

Description

technical field [0001] The present invention relates to the technical field of semiconductors, and more specifically, to a substrate metal layer structure for wire bonding and a power semiconductor device. Background technique [0002] At present, power semiconductor devices are gradually developing towards high power density and high heat dissipation capacity, which requires the metal layer and leads used inside the device to have the characteristics of high thermal conductivity and high current carrying capacity. In practice, aluminum materials are changed to copper materials. At the same time, thickening the lead wire can increase the current density of the device, thereby prolonging the service life of the device. But there are also some problems at the same time. Compared with aluminum, copper is harder, and wire bonding requires greater bonding force to achieve successful bonding. Similarly, using thicker wires for bonding also requires greater bonding force, and large...

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Problems solved by technology

But there are also some problems at the same time. Compared with aluminum, copper is harder, and wire bonding requires greater bonding force to achieve successful bonding. Similarly, using thicker wires for bonding also requires greater bonding force, and larger The bonding force is easy to cause damage to the substrate (usually a chip or a substrate), degrade or even fail the device performance, and usually need to add a thicker metal layer on the substrate surface, and a thicker metal layer will cause greater stress. Especially in a high temperature environment, it is easy to cause the substrate to bend, the metal layer to peel and even the bonding point to fall off, resulting in device failure, which seriously affects the reliability of the device and shortens the service life of the product

[0003] Among the existing invention patents at home and abroad, aluminum, copper, gold and other metals have been widely used in semiconductor wire bonding, and some patents mention the use of wire bonding pads, pads, metal balls and other methods to achieve wire bonding. Bonding, however most of this is applied to the lead frame in the package structure without modification to the metal layer

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