Lead frame

Abstract

The invention provides a lead frame which comprises a lead frame body. A bare copper area is arranged on the lead frame body, a brown oxidation area is arranged all around the bare copper area in a surrounding mode, a semi-etching area is arranged on the periphery of the brown oxidation area, the brown oxidation area is formed by covering the lead frame body with a layer of brown copper oxide, a layer of solder combined material is arranged on the bare copper area in a pressing mode through a pressing die head, a chip is welded to the solder combined material, the size of the bare copper area is the same as the size of the pressing die head and an aluminum wire is welded between the chip and the brown copper oxide. The lead frame further comprises a plurality of protruding pins. The lead frame has the advantages that after regional brown oxidation, the reliability of wire welding is improved, the product yield is improved and meanwhile, the service life of the product is prolonged.

Description

technical field [0001] The invention relates to a semiconductor package, in particular to a lead frame. Background technique [0002] As the chip carrier of integrated circuits, the lead frame is a key structural part that realizes the electrical connection between the lead-out end of the chip's internal circuit and the outer lead by means of bonding materials (copper wire, aluminum wire, etc.), forming an electrical circuit. The bridge function of the external wire connection, most of the semiconductor integrated blocks need to use the lead frame, which is an important basic material in the electronic information industry; while copper wire and aluminum wire are commonly used materials in the lead frame, copper wire heat conduction The performance of high efficiency and radiant heat is very high, but in the manufacturing process, such as in the wire bonding process, when the copper wire is exposed to the external environment, its surface is easily oxidized, thus causing dam...

AI Technical Summary

Problems solved by technology

[0002] As the chip carrier of integrated circuits, the lead frame is a key structural part that realizes the electrical connection between the lead-out end of the chip's internal circuit and the outer lead by means of bonding materials (copper wire, aluminum wire, etc.), forming an electrical circuit. The bridge function of the external wire connection, most of the semiconductor integrated blocks need to use the lead frame, which is an important basic material in the electronic information industry; while copper wire and aluminum wire are commonly used materials in the lead frame, copper wire heat conduction The performance of high efficiency and radiant heat is very high, but in the manufacturing process, such as in the wire bonding process, when the copper wire is exposed to the external environment, its surface is easily oxidized, thus causing damage to its reliability In other words, if the surface of the copper wire is oxidized, the resistance value of the copper wire will increase, the electrical properties will be damaged, and the welding strength will decrease; while in the prior art, the welding point using aluminum wire will often be oxidized, thereby generating CuO2, The CuO2 structure is loose and easy to fall off. After injection molding, it is not tightly combined with the resin, which will easily lead to delamination of the product and affect the life of the product.

[0003] The Chinese patent application number 02161113.0 discloses an invention patent titled "Semiconductor Package with Non-Oxidized Copper Wires", which discloses a semiconductor package with non-oxidized copper wires connecting semiconductor chips and pads. Layer coating solves the problem that copper wires are easily oxidized, thereby providing good electrical characteristics and reliability; but there are the following disadvantages in its patent: 1. The non-oxidized layer is made of metal materials palladium or platinum, while palladium or platinum All are rare elements, and the cost consumption is high; 2. The welding of semiconductors and pads is likely to cause the benefits of materials such as bonding materials, which is not convenient for later process operations

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