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US 8,012,886 B2Granted
Leadframe treatment for enhancing adhesion of encapsulant thereto
AssigneeASM Assembly Materials Ltd.
InventorsYiu Fai Kwan, Tat Chi Chan, Wai Chan, Chi Chung Lee
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Abstract
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.
Claims16
A method for treating a leadframe to enhance adhesion of molding compound to the leadframe, the method comprising the steps of:
- providing the leadframe comprising copper or copper alloy and having a surface;
- immersing the leadframe in a pre-dip comprising a topography modifier and an organic additive but without an oxidizing agent to prepare the leadframe before oxidizing the leadframe in an oxidation treatment bath;
- then
- oxidizing the leadframe in the oxidation treatment bath to form copper oxide on the surface of the leadframe;
- then
- dipping the leadframe in a complexing or chelating agent to enhance the purity of the copper oxide formed;
- and thereafter
- cleaning the leadframe with an acid to remove contaminants remaining on the leadframe.
5 more elements
Dependencies are inferred from the claim text.