Flux free flip chip attach technology for BGA/CSP packages

Author

Furuno, M. ; Masuda, T. ; Doi, Kaznhide ; Nomura, Hiroshi

Author_Institution

Tamura Corp., Tokyo, Japan

fYear

1999

fDate

1999

Firstpage

408

Lastpage

414

Abstract

The solder flip chip attach without flux using plasma treatment has been developed in order to eliminate the flux residue cleaning process for manufacturing the BGA/CSP packages. The plasma treatment is composed of roughening the solder surface and improving the solder wettability. Argon gas added hydrogen (Ar+H₂) plasma has been very superior to argon plasma for etching/roughening the solder surface, therefore, a mixed gas plasma composed of carbon tetrafluoride and argon or oxygen(CF₄/Ar or CF₄/O₂) has modified the solder surface for good solderability without damage to the Si chip, the passivation film and the organic substrate because of the active solder surface. After the Si chip was mounted on the organic substrate with the solder bumps treated with plasma, the solder bumps were renewed at 230°C and underfilled. Package reliability has been demonstrated by the temperature cycle test (TCT) and temperature humidity bias test (THB) and this flux free flip chip attach technology with plasma treatment has been sufficiently verified such that it can be applied to packaging processes

Keywords

ball grid arrays; chip scale packaging; flip-chip devices; integrated circuit interconnections; microassembling; plasma materials processing; reflow soldering; sputter etching; 230 C; BGA packages; CF₄/Ar plasma; CF₄/O₂ plasma; CSP packages; Si; Si chip; carbon tetrafluoride; flux free flip chip attach technology; mixed gas plasma; organic substrate; package reliability; plasma treatment; solder bumps; solder surface roughening; solder wettability improvement; temperature cycle test; temperature humidity bias test; underfilling; Argon; Chip scale packaging; Flip chip; Plasma applications; Plasma materials processing; Plasma temperature; Rough surfaces; Substrates; Surface roughness; Surface treatment;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Components and Technology Conference, 1999. 1999 Proceedings. 49th

Conference_Location

San Diego, CA

ISSN

0569-5503

Print_ISBN

0-7803-5231-9

Type

conf

DOI

10.1109/ECTC.1999.776206

Filename

776206