As Dave Hillman mentioned, many companies have been applying this technique for some time. It has been my experience that using this process nearly always requires some design changes if the card was not originally intended for the process. The papers cited by Dave touch on some of the design concerns. Some other issues you may want to consider: >> Will your solder paste flux "escape" from inside the joint to the surface? You may have to try different pastes than what you are currently using. >> Does your reflow process have sufficient thermal transfer capabilities to heat under the through hole component body and into the center of the PCB? We have been "sold" on convection reflow but vapor phase may work as well. >> Will you be able to provide enough solder paste to make an acceptable joint? There are many ways to accomplish this but there are also a number of constraints. >> Which side you process first may have to be considered relative to how and when you will insert the component. In all, we have been very pleased with the success of this technique and would like to encourage component suppliers to expand the availability of parts which can be used in this manner. I would like to hear from others using this process. Please feel free to contact me directly or post your comments to the TechNet. Bill Barthel Electronic Assembly Corp. [log in to unmask] (414) 751-3651