Considerations for the use of plasma in pre-wire bond applications

Integrated circuits continue to shrink in size, and the associated decrease in size of the wire bond pad on both the die and substrate presents substantial challenges in the manufacturing process. To ensure high device reliability and minimize manufacturing costs, it is important to optimize the wire bonding process to ensure good bond strengths and yields. Poor bond strengths and low yields are often due to upstream contamination sources or the selection of materials in advanced packaging. Gas plasma technology can be used to clean pads prior to wire bonding to improve bond strengths and yields. Examples specific to epoxy bleed-out contamination and considerations regarding substrate material and device characteristics are discussed.