Thermo-mechanical reliability of the benzocyclobuten (BCB) film in a WLCSP process

Author

Lee, K.O. ; Yu, Jin ; Kim, J.Y. ; Park, I.S.

Author_Institution

Dept. of Mater. Sci. & Eng., Korea Adv. Inst. of Sci. & Technol., Daejon, South Korea

fYear

2001

fDate

2001

Firstpage

84

Lastpage

87

Abstract

A new WLCSP process which enables reliable fabrication of high-performance and low cost package has been developed based on the low dielectric passivation layer. The fabrication process can be reduced by using the newly developed photosensitive-BCB and a conventional photolithography process. However, cracks frequently nucleating on the BCB poses serious reliability issues. In order to prevent the crack generation, the stresses in the BCB layer were reduced by optimizing the relative thickness of the BCB and the underlying stress buffer layer(SBL), and by stabilizing the BCB microstructure with optimal photolithography processes. The microstructure of the BCB was investigated by measuring the molecular weight, the cross link element intensity and the glass transition temperature

Keywords

chip scale packaging; cracks; dielectric thin films; photolithography; reliability; WLCSP process; benzocyclobuten; cracks; cross link element intensity; dielectric passivation layer; glass transition temperature; low cost package; molecular weight; photolithography; relative thickness; stress buffer layer; thermo-mechanical reliability; wafer level chip scale package; Costs; Dielectrics; Fabrication; Lithography; Microstructure; Packaging; Passivation; Stress; Thermomechanical processes; Weight measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Materials and Packaging, 2001. EMAP 2001. Advances in

Conference_Location

Jeju Island

Print_ISBN

0-7803-7157-7

Type

conf

DOI

10.1109/EMAP.2001.983963

Filename

983963