SMTA International Conference Proceedings

Reliable Soldering for High and Mixed Volume Selective Soldering Processes

Author: Gerjan Diepstraten
Company: Vitronics Soltec B.V.
Date Published: 9/28/2014   Conference: SMTA International

Abstract: Although the number of Through Hole (THT) connections the electronics assemblies is decreasing due to miniaturization, selective soldering is still a growing market. More and more Surface Mount Devices (SMD) technology is being used and reflow soldering is becoming the main stream solder method. Nevertheless there will remain components that require through hole connections for strength or because they simply can’t withstand the high temperatures of a lead-free reflow process.

Selective soldering is very effective method to solder the THT components. There are two mainstream selective solder applications: - Drag soldering (point to point) - Dip soldering (stamp)

Both applications have a dropjet flux device to apply very small amounts of flux on the areas that are soldered. Despite these small amounts the remaining flux residues might cause electro-migration if not de-activated completely during the assembly process. This drives engineers to implement different flux formulations to avoid claims. Special in the automotive applications there are examples in the field that bridges and corrosion are caused by the growth of dendrites due to flux residues in combination with temperature, humidity and a current. The solder joints can be much more reliable when an inert flux is used in combination with a controlled soldering process.

Key Words: 

Selective soldering, reliability, 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.


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

Phone +1 952.920.7682
Fax +1 952.926.1819