Structures and methods to improve lead-free C4 interconnect reliability

US8198133B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Timothy H. Daubenspeck · Colchester, US
• Paul F. Fortier · Keyano, CA
• Jeffrey P. Gambino · Gresham, US
• Christopher D. Muzzy · Burlington, US
• David L. Questad · Hopewell Junction, US
• Wolfgang Sauter · Avon, US
• Timothy D. Sullivan · Batavia, US

Key dates

• Filing date: Jul 13, 2009
• Grant date: Jun 12, 2012
• Expiry date: Dec 1, 2029

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/3511
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Controlled collapse chip connection (C4) structures and methods of manufacture, and more specifically to structures and methods to improve lead-free C4 interconnect reliability. A structure includes a ball limited metallization (BLM) layer and a controlled collapse chip connection (C4) solder ball formed on the BLM layer. Additionally, the structure includes a final metal pad layer beneath the BLM layer and a cap layer beneath the final metal pad layer. Furthermore, the structure includes an air gap formed beneath the C4 solder ball between the final metal pad layer and one of the BLM layer and the cap layer.