- Buyers Guide
As promised in my last post, I want to share with you some of the feedback I got through Linked In groups and from a dozen or so folks that recently attended a talk I gave at the Del Mar Electronics and Design show entitled How to Fall in Love with your PCB Supplier.
I don’t think most design engineers expect the fabrication of their boards to be something akin to playing the odds in Vegas. However, I hear them saying that they are often leery about the results they will get from their PCB supplier. Let me illustrate in the words of those whom I queried:
Linked In responses
The question I posed was: “What do you like and dislike in your dealings with a PCB supplier?” The following is a condensed list that combines the responses from 12 individuals from 3 different Linked In groups. Most respondents were PCB design engineers.
- I like it when a board supplier looks over my design and lets me know when there are potential problems, especially when I first began to design. A couple of times, they saved me from costly mistakes when their trained eye caught something I had missed.
- A good supplier can discern your design intentions, so if you make a careless mistake they will catch it.
- For me, a good PCB supplier should accept Gerber files only. Some conversion programs can cause problems.
- I would like a clear depiction of the PCB supplier’s technological roadmap with current capabilities and emerging capabilities for the future.
- I want them to review the design thoroughly and make sure they can produce it reliably.
- I like them to accept data from all the major ECAD vendors and be able to do sound conversions.
- I like them to support a good range of panel sizes and support building multiple prototypes on a single panel.
- I like them to publish their process limits so you can keep those limits in mind when designing.
- I need them to meet or exceed normal industry standards eg. IPC222A
- I like a board house that can comment on likely loading issues or shadowing limits.
- They need to support electrical test
- They must have reliable process control, including drill and router bit wear and management
- I really need them to be on time!
- I don’t like when they don’t monitor the debris levels in the chemical baths that contaminate the boards
- I don’t like it when they make assumptions up front, then just ship a board to you without asking for clarification.
- I hate sloppy routing!
- It is important to know what their expected yield is on a borderline capability. For example, they say they can make a 4 mil trace, but they have to run 100% overage to get the yield you require and then charge you for it!
- I want a good board supplier to be very clear about their process limits for all processes.
- They must have photo imagable solder resists at a bare minimum.
- I would like input on prepreg stack-up on boards over 6 layers. Many times using an alternative to what I specify can work better and save money.
- When a PCB supplier applies automatic DRCs, they will open the solder masks and change the clearances to suit their processes without checking with me first. This causes problems!
- I like netlist testing over standard electrical testing.
- I like to see a PCB supplier doing cross sections and periodic metallurgic tests to identify possible process deviations.
- I don’t like it when a PCB supplier just takes my design and makes it without asking any questions or bring concerns to me.
- I think a PCB supplier should be proactive and anticipate the needs of their customers.
- I’ve had a PCB supplier completely change my stack up without asking me, because it was easier for them to process. This was an RF board and it completely messed up the RF characteristics of the board.
- I don’t like it when they don’t read the fab drawing before they accept the order, then they want to make exceptions after they have my order.
- It seems no matter how carefully I try to work with a PCB supplier to fit into their DFM guidelines and be very clear about my requirements and design with their capabilities in mind….they always have a problem even after I have spent so much time being proactive in my design. It seems like their DFMs work for everybody except me!
A blog ought to be brief and this one isn’t! So, I will take a break here and leave you with one thing to note in the above comments. You see the items in red? Those issues are all related to communication! In fact, near 70% of the responses I got were related to communication issues.
Good communication in business relationships is as critical to communication in interpersonal relationships. When communication falls apart in either, the relationship falters. This brings me back to the shock I experienced after my 12- year-kid-raising hiatus from our industry—people have cut way back on meaningful communication!
Sorry to leave you hanging at this point, but I promise to post again soon. Next time I will share the comments of the people who attended my talk and we will explore this further. I look forward to hearing your thoughts and comments and until then, “may the odds be ever in your favor!”