At the conclusion of our webinar, Low Layer Count PCBs – Why They Are Not All Created Equal, we had several questions submitted to our presenter, Ed McMahon, CEO at Epec. We have compiled these questions into a readable format on our blog.
Q&A From Our Live Webinar
Quick Links:
- What is the best way to determine if a fabricator is capable of doing what you need?
- How do you measure for over-etching as it will pass an electrical test?
- How do you specify if you want serial numbers or QR codes based on your PCBs?
Watch the Recording Below:
Question: What is the best way to determine if a fabricator is capable of doing what you need?
Answer: That's kind of a tricky question. Because, unfortunately, they'll just send you samples of a similar design. It's really difficult. Because it's awfully hard to know where that's being manufactured. Traditionally, a site visit is probably the best. But if you can't do that, pictures of what they have for equipment because that's really going to tell you what you want to know.
If they have LDI, if they have the right shows, you're going to be able to see that. And you'll be able to understand if they've made it. Because a lot of companies too often use maybe lower-technology equipment to try to make high-technology parts. And their yield is only 30%, but that's just part of what they do – make a whole lot of it and try to inspect their way to quality.
So, that's probably the best way to do it.
Question: How do you measure for over-etching as it will pass an electrical test?
Answer: That's very true. If you've got a 5-mil trace, and it gets over-etched, and it's down to 2.5, it's still going to pass the test. Now, there are a couple of things you can do. I mean, you can obviously do some sort of a high pod test where it wouldn't pass, but the more effective way to do that is what we see from some of our customers, and we recommend, is if there's an area you're concerned about on your circuit board, as part of your submission of your purchase order, we take that image of the board and circle the area that you would like measured.
And the factories like us, we have microscopes that we're able to measure with a computer the area that you want and say that you want five of these printed circuit boards tested and you want the picture, and you want the measurement to make sure that all of those areas are etched the correct amount. And that's fine.
Again, that's one way to do it. Make sure they pick out five of them. It’s really hard to do unless you have computerized equipment. You can do it obviously under a microscope, but if you're talking 3- and 4-mil lines and spaces, you can see with a loop, but it's really hard to measure when they're that small.
Question: How do you specify if you want serial numbers or QR codes based on your PCBs?
Answer: Well, there are a couple of ways to do that. One is that we have some customers that just give us a standard of what they want on everything, and we just use that, and then we put that on their circuit boards as we manufacture. And they have a whole serialization scheme that they use, so they give that to us. Others just do it by the actual board.
So, you can put a serial number on it that's got date code, part number, a whole lot of other stuff, but really, work with your fabricator because it's not that difficult to do. And once you come up with a scheme with each other, it makes it pretty easy. And our engineering team is comfortable with adding it on as we go forward. So, work with your fabricator. All of them are capable if they have the right technology to do that.
