Published by Eric Bogatin on 14 May 2013
Dave, the Director of Signal Integrity Engineering at Molex, outline the process Molex uses in designing connectors for ultra high speed, where simultaneous mechanical and electrical requirements push the envelop of what is practical.
He outlined a five step process and walked through a few examples.
The first step is establish a few simple figures of merit or rules of thumb. For example, usually the design goal is at the Nyquist frequency of the application data rate. The specs for return loss are typically less than –12 dB and for near end cross talk, less than –40 dB.
The second step is generating concept mechanical and electrical models. These are the basis for stress-strain curves and initial electrical performance.
The third step is feedback from all the team- mold engineering, stamping, assembly tooling, plating and marketing. This cycle of concept design- multi-disciplinary review feedback and re-design, continues a few cycles until a near final design converges.
In the fourth step, the final design is released. This is the best approximation to what will deliver the performance, reliability and manufacturability requirements. When it costs more than $100k for a mold to test out a design, simulation analysis tools are leveraged to explore virtual prototypes, rather than using the build it and test it approach.
This means it’s important to have confidence in the analysis tools that they will accurately predict the measured performance of a part once built. A design of experiments (DOE) study of the virtual prototype is a key element. This identifies the most important design variables and where attention needs to be focused for robust manufacturing.
The fifth and final step is verifying the design and creating the deliverables. For many customers, the board design is just as important in determining the connector performance as the connector itself. Dave’s team provides engineering support to help customer optimize the board design based on the specific details of the connectors.
If you would like to hear the details of how Dave implements this process for the highest performing connectors in the Molex portfolio, you can watch the complete recording and download a copy of his slides on the www.beTheSignal.com web site.
While you are there, you can also watch the recording of Jeff Loyer’s presentation from March 7, 2013.
If you are in Longmont, join us for the live Front Range Signal Integrity Seminar Series. All these events are always free. I hope to see you there!