Asm Assembly Materials Ltd.

Chi Chung Lee

Yiu Fai Kwan

Tat Chi Chan

Wai Ho Chan

Chun Ho Yau

A method is provided for treating a leadframe comprising copper or copper alloy to enhance adhesion of molding compound to it. The leadframe is oxidized in an oxidation treatment bath to form copper oxide on the surface of the leadframe. It is then dipped in a complexing or chelating agent to enhance the purity of the copper oxide formed. Thereafter, the leadframe is cleaned with an acid to remove any contaminants remaining on the leadframe.

Leadframe treatment for enhancing adhesion of encapsulant thereto

A process for producing a pre-plated leadframe that has enhanced adhesion by molding compound is provided, wherein a base leadframe material is first plated with multiple layers of metallic material. Thereafter, the plated base leadframe material is covered with a mask, so as to expose selected surfaces thereof at unmasked areas where enhanced adhesion of molding compound is desired. The said unmasked areas are plated with a layer of copper before removing the mask. Optionally, the layer of copper may further be oxidized to form a layer of specially controlled copper oxide.

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Hong Kong, China

Chi Chung Lee