Surface Mount International Conference Proceedings


EFFECTS OF UNDERFILL MATERIALS AND ASSEMBLY PROCESSES ON MOISTURE SENSITIVITY OF FLIP CHIP ASSEMBLIES

Author: Craig Beddingfield
Company: Motorola
Date Published: 4/28/1997   Conference: Surface Mount International


Seika Machinery, Inc.

Abstract: Moisture ingression into microelectronic packaging is a major problem in the assembly, performance and reliability of electronic products. Flip Chip Ball Grid Array components on organic substrates are included in the list of packages which are sensitive to moisture-induced stresses. This paper will discuss the aspects of the evaluation of underfill materials and assembly processes and their effect on the moisture-induced stress sensitivity of these types of components. Studies addressing the moisture characterization and preconditioning of assemblies built with three different undertfill materials, three various cleaning processes and a variation of substrate baking will be presented. Evaluations include solder joint integrity of the IC bumps and adhesion strength of the undertfill to the die and substrate surfaces after assembly, preconditioning and autoclave stressing. The effects of the experimental variables on underfill-to-die/ substrate adhesion using C-SAM imaging and cross-sectioning methods will also be presented. Additionally, a contamination study of a typical flip chip assembly process and it’s contribution to package moisture sensitivity will be reviewed, showing the critical processes where contamination could be introduced. Key Words: flip chip, underfill, assembly, moisture, sensitivity



Members download articles for free:

Not a member yet?

What else do you get when you join SMTA? Read about all of the benefits that go along with membership.

Notice: Sharing of articles is restricted to just your immediate work group. Downloaded papers should not be stored on an external network or shared on the internet.


Back


SMTA Headquarters
6600 City West Parkway, Suite 300
Eden Prairie, MN 55344 USA

Phone +1 952.920.7682
Fax +1 952.926.1819