SMTA International Conference Proceedings


WETTING AND SPREADING STUDIES FOR LEAD FREE SOLDER AND FLUX MATERIALS IN FLIP CHIP PACKAGES

Authors: Jinlin Wang, Ph.D.
Company: Intel Corporation
Date Published: 10/11/2007   Conference: SMTA International


Abstract: Three solder wetting analysis methods will be discussed in this paper. The solder wetting balance test is a common method used for wettability evaluation. A solder spreading test was used for solder wetting analysis under different reflow conditions. Wetting angles of solder spheres after reflow were calculated by using analytical equations from the solder spreading diameter. The calculated wetting angles were compared with measured values. Values of contact angles calculated using analytical equations were consistent with measurements. For very low contact angles, it is challenging to measure it accurately. The wetting angle calculated from solder spreading provides a good estimate for low contact angles. The wetting properties for different solders, fluxes, and different surface finishes were also studied. A dynamic solder spreading test was also used to obtain the spreading diameter and dynamic contact angle. Our results showed that wetting force and wetting angle measurements can provide useful information about the performance of the solder and flux materials

Key words: solder wetting, solder spreading, contact angle, lead free solder, flux



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