Surface Mount International Conference Proceedings


Author: Trent Thompson
Company: Motorola Semiconductor Product
Date Published: 9/10/1996   Conference: Surface Mount International

Abstract: This report summarizes evaluations performed to determine and improve the moisture sensitivity level and autoclave performance of the glob top ball grid array (GTBGA). Two “glob top” or liquid encapsulant with different CTES and rates of moisture absorption were considered. Results horn studies determining the optimal cure profile for the liquid encapsulant are included. The effects of using clean methods A or B at different positions in assembly to enhance encapsulant to die surface and solder resist/substrate adhesion are presented. Flag designs that reduce Cu surface area on the substrate for better die attach adhesion, the optimal substrate solder resist and die attach epoxy for this application are also discussed. These results aR benchmarked with the overmolded plastic ball grid area (PBGA) performance which is a JEDEC Level 5. The reliability test responses are the package peel test which evaluates die bond cohesive strength and encapsulant to solder resist adhesion; C-SAM (C-Mode Scanning Acoustic Microscopy) to inspect for delamination at various package interfaces and weight gain to determine package moisture absorption and reabsorption rates.

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.


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

Phone +1 952.920.7682
Fax +1 952.926.1819