Suggesting PCB/PWB pad geometries
Written by on 2/20/2009
With the arrival of lead free processing and RoHS, Pletronics ceased recommending pad designs for the crystals and oscillators.
Previously the whole electronics industry was using lead tin solder and Pletronics could make recommendations based on this consistent requirement. Today, we have many different processes, many different fluxes, many differing process temperatures.
Add to this complexity that there are concerns about the resulting chemistry of the solder joint. For example, our ceramic crystals and oscillators have gold plating on the nickel pads to assure solderability, for some end users there is concern about the resulting concentration of gold in the completed solder joint.
The end user has to make the decision on what makes their process perform reliably, while considering the Pletronics pads, the PCB/PWB pad size, any plating on the PCB/PWB and the thickness of the solder screens.
Pletronics does provide accurate package pad information on the datasheets to assist in determining the proper PCB/PWB design.