Who Selects the Design Data Format, and Why?

Estimated reading time: 2 minutes

For this issue on design data formats, I wanted some feedback from a PCB design bureau, so I spoke with Jen Kolar, VP of engineering at Monsoon Solutions in Bellevue, Washington. I asked Jen who decides on the design data format at Monsoon, and why. 

Andy Shaughnessy: Jen, who makes the decision at Monsoon about which design data format to use for a particular job? 

Jen Kolar: It varies. We were just talking about this as a design team. At Monsoon, our standard (which is documented for our designers to follow), unless stated otherwise by the customer, is to output both Gerbers and ODB++ (as a TGZ file). We are considering dropping Gerbers from our standard format because when both are sent to the fab vendor, it always results in a question about which one to use. It is also more prone to having a file accidentally left out. 

That said, when doing a really hot job, we might release copper first followed by silk later, and in that case, I expect most assemblers would prefer Gerbers and getting only the changed file vs. having to “trust” nothing else changed in the ODB++ package. 

Interestingly, I find many fab vendors default to Gerbers vs. ODB++ if they have both. I’ve also seen issues with ODB 8 vs. ODB 7 with many vendors, and that might be another reason they may prefer Gerbers. We have some customers who mandate what they want. Some customers want only ODB++ and will refuse to work with any fab or assembly vendor who won’t support it. This is not so much of an issue now, but it was several years ago, particularly with some assemblers.  

We have others who insist on Gerbers only, who also like to review them as PDFs. Many customers don’t really care, as long as they have something the fab vendor and assembler can use. We’ve never had anyone request IPC-2581 and we have never output it. Is that answer long-winded enough for you (she asked with a laugh)? 

Shaughnessy: That will work fine. So, what is the title of the person who usually makes this decision? 

Kolar: At Monsoon, it was once our COO, as he ran design. We now have one of our principal designers in a role to direct and document all design processes. It is all done with input from the whole team including me, as well as our director of manufacturing services, if there is a question of the impact on manufacturing. 

Shaughnessy: Sometimes I wonder if this whole “horse race” angle regarding Gerber vs. ODB++ vs. IPC-2581 is a little overblown. The systems seems to be working fine with three different formats. Are there any inherent downsides to having more than one format for design data transfer in the industry? 

Kolar: I don’t see an issue with having more than one format, other than the risk of translation errors. But, hey, it’s not a CAD tool if it doesn’t have errors. The convenience of ODB++ is awesome. But for some companies without ODB++ viewers, or for people who are not familiar with them, Gerbers are just simpler.  

Shaughnessy: This really helpful. Thanks for your time, Jen. 

Kolar: Sure. Thank you, Andy.

This conversation originally appeared in the October 2021 issue of Design007 Magazine.