We've received a number of questions and comments on the new parts library in PCB123 V4, so we thought it would make sense to go into a little more detail on where the parts come from and how reliable we think the parts are. The parts library is a sourced directly from Accelerated Designs' Ultralib library (http://www.accelerated-designs.com
). The Ultralib, which is available for purchase from Accelerated Designs for other CAD tools as well, contains 1.5 million parts definitions. Based on market analysis work we performed here at Sunstone Printed Circuits
, we chose the 500,000 most-likely-to-be-used parts from the Ultralib for the V4 release.
Making use of a recognized industry leader as a source for our library parts is a good thing -- in that we're using an industrial-grade database for our reference -- but it does make it difficult for us to guarantee complete test coverage of all the parts. With a half-million parts, for example, if you could completely verify one part every five seconds, it would take five months to check all the parts. Even though we tested parts in house, as a practical matter we must rely on prior testing and prior use over at Accelerated Designs to ensure high quality parts. And this is one of the reasons we chose Accelerated Designs: their parts libraries have been proven out in the marketplace as useful and accurate. When we tested our copy of the V4 library prior to release, we used a statistical sampling method. In our testing, we found a very low number of parts with landing pattern issues - in the low-fractions-of-1% range.
Statistically speaking, then, the Ultralib was a compelling choice as a new parts library precisely because it has been reviewed and maintained actively for a number of years - making it much more reliable than having the PCB123 team manually create parts from scratch ourselves. Having said that, however, while the library is more than 99.6+% accurate, any specific wrongly-defined part is still 100% wrong. Here's what we do when a customer reports an issue with a part definition in the PCB123 libraries: 1. We compare the PCB123 part to the source part from Accelerated Designs. 2. If the problem is on the Sunstone side somehow, we fix the part. 3. If the problem is on the Accelerated Designs side somehow, we report the problem to Accelerated Designs. 4. The responsible development team fixes the problem(s) with the part. 5. The PCB123 team updates the parts server with the corrected parts information. And, don't hesitate to contact us to tell us which parts you searched for but didn't find. That information helps us to make priority choices about how to grow and develop the library in the future.