Nickel-iron expansion contact for semiconductor die
AssigneeInternational Rectifier Corporation
InventorPeter R. Ewer
Life of this patent
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Abstract
A contact clip for the aluminum contact of a semiconductor device has a central nickel-iron body, preferably Nilo alloy 42, which is coated on top and bottom by a soft, but high conductivity metal such as gold, silver or copper. The nickel-iron body has a thickness of about 15 mils, and is about the thickness of the silicon die. The conductive layers have a thickness of about 5% to 20% of that of the nickel-iron core.
Claims25
A conductive contact clip for contacting the surface of a semiconductor die;
- said contact clip comprising a generally flat elongated body having a planar contact area;
- said elongated body having top and bottom surfaces and a central major thickness section of a first material having a thermal expansion coefficient which is approximately that of silicon and having top and bottom conductive layers at said top and bottom surfaces which each are of materials which have an electrical conductivity substantially greater than that of said first material and are each from about 5% to about 20% of the thickness of said first material.
In a power semiconductor device comprising a silicon die having at least one extended area aluminum contact on its surface to which contact can be made by wire bonding;
- a contact clip which is rigidly connected to said die and which makes low resistance contact to said aluminum contact;
- said contact clip comprising an elongated body having a planar contact area;
- said elongated body having top and bottom surfaces and a central major thickness section of a first material having a thermal expansion coefficient which is approximately that of silicon and having top and bottom conductive layers at said top and bottom surfaces which each are of materials which have an electrical conductivity substantially greater than that of said first material and are each from about 5% to about 20% of the thickness of said first material;
- said bottom contact layer being permanently and rigidly connected to at least a portion of said extended area aluminum contact.
Dependencies are inferred from the claim text.