V4 Parts Library Overview

[Nolan Johnson]

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.

[Roberto]

I downloaded PCB123 V4 right because I thought: " in 500.000 symbols, they certainly have the common ones I use". Unfortunately I cannot find any of the ST Microelectronics ARM processors. Specifically, I was looking for the following one: STM32F103T8 Can you help please? thanks, Roberto

[Sal Hernandez]

Since we cannot provide every part number out there we have included an excellent sampling of the various footprint patterns and symbols that you might use in your designs. You can use these parts as starting point and make your own parts. To begin I recommend checking our libraries to see if we have a footprint you can use. Go to the layout and select Design Edit Footprint. Here you will want to search for the package style required for the part you want to use. In your example there are several options VFQFPN, LQFP and BGA. Searching for QFP or BGA you should find some footprint that you can use as a starting point. You would then load the part and modify it to match the part you are using. If you dont want to modify the footprints that you find here you can just close this screen and go back to the layout. There select Design New footprint and start from scratch. Once you have created the footprint select the save icon then name your part and save it to your custom library. We have provided a footprint generator that will work with limited number of footprint types and works very well for QFP footprints. If you would like to give it a try select Insert Part Manage Parts Generate Footprint from either the layout or schematic.

You would use the same process for the symbol. Go to the schematic select Tools Symbol Editor. Start by maximizing the Symbol Editor so that you can see all of the available toolbar options. If you want to create your own symbol start here; if you want to edit an existing symbol select the open symbol icon. Symbols are more generic than the footprint. You could search for CHIP, BGA or QFP and find something you can work with. Load the symbol, edit and save. I recommend changing the symbol name and saving it in your own custom library. Close the Symbol Editor to back to the schematic. We have also provide a Symbol Generator you can give it a try by selecting Tools Manage Parts Generate Symbol. The tool does not give you the same freedom to create parts that you have in the Symbol Editor.

The final step is to pair the footprint and symbol in the manage parts tool. Select Tools Manage Parts. The link below will walk you through the parts creation process.

updated-pcb123-parts-creation-process-t181.html

[Sal Hernandez]

If you cannot find the part you need in our library then you will need to create your own. There are three steps to parts creation. Simply creating a symbol will create a part that you can place on your layout. Please review the forum post below. This will walk you through the parts creation process.

updated-pcb123-parts-creation-process-t181.html

Feel free to contact customer support if you have any questions.

[hsamuels]

I used the footprint generator (metric) to create a TQFP44 pattern as specified in this Microchip data sheet, pages 318-319: http://ww1.microchip.com/downloads/en/D ... 33030a.pdf

The silk screen part outline covers part of the inside of each pad - this clearly isn't right.

Also, pin 1 appears at the top left during the creation process, but it is at the bottom left when viewed in 'manage parts' and when placed on the layout. It's easy enough to rotate the part, but is that the intent?

[Sal Hernandez]

Thanks for your feedback. I will submit this to our developer. Any silkscreen covering a pads would be automatically clipped away from the pad.