Recommendations for assembly house - 0201, fine pitch BGA - Page 1
Forum section: electronics / general

author: thirtyone
author_rank: Newbie
timestamp: October 02, 2019, 08:25:11 pm
content: Hi,I'm working on a fairly high density, space constrained design. Most of the components are 0201s and fine pitch BGA / WLCSP packages. I'm wondering if anyone has *personal* experience with a supplier they can recommend with a reasonably dense board with 0201s. The supplier can be in the US, China, or wherever, so long as if they can communicate with someone in the US and know what they're doing. Had some fairly bad experiences with two different seemingly good US vendors a few years back. They claimed they could do 0201, turns out they never had a customer who actually needed it, and they basically used us to test their assembly equipment and found out they couldn't actually do it reliably. Ended up using larger components after we realized the design didn't have to be so small.I have also recently contacted several well known Chinese assembly houses (including one I routinely use for larger designs) who claimed they can go down to 0201. I found out after contacting their engineering department that they actually can't or have low yields, and typically subcontract to another unnamed vendor. Would rather not name names here, partly because I'm sure the US vendors are better now, but I'd rather not go back to them.Point is, I'm interested in recommendations for board houses anyone has personally used for designs with many 0201s or smaller parts. If they do the boards as well, that probably makes the most sense. I'm expecting to need laser vias and generally multilayer HDI specs for the board. Space is absolutely critical here - we're actually planning on constraining the mechanical layout and design based on what the board house is capable of doing, so I really don't want to go down the rabbit hole with a supplier who isn't actually familiar with the limits of their process.Thanks!

author: marshallh
author_rank: Unknown
timestamp: October 04, 2019, 06:06:38 pm
content: I've used macrofab many times. If they say they can do 01005 placement then I'd take it at face value. That wasn't something they could do a year ago, must've upgraded the PnP.Macrofab is a good value for development prototypes (1-5 units) but does not scale well. That said, they are cheaper than the other US fab shops that charge eye-watering prices and only cater to ITAR.They sub out the PCBs. I was pretty impressed with the supplier's quality and rarely had problems. However, every single PCB vendor I've used has produced bad runs or boards that pass flying probe checks but fail after the first reflow cycle, and theirs is no exception. Typical failure rate is 2-4%.Assembly is usually ok, as it's automated... so as long as that is programmed right it's fine. With some exceptions.Lead time was pretty consistently about 5 weeks regardless of the website estimation (This is about on par with most fabs, just wish they'd be realistic)I've had probably a thousand boards built with Macrofab. In the end I decided to go back to china for both prototype and production, even with all the caveats.Problems encountered:1. Parts oriented backwards (this was back when their web UI sucked)2. Not enough paste applied causing parts to fall off the board3. Repeat orders with special notes not carried forward to subsequent orders, causing $10k boards to be scrapped and re-built, on their dollar4. A pcb batch with 20% failure rate5. Nearly entire batch where a BGA was soldered backwards, but they realized the mistake, and removed the BGA, cleaned and resoldered. But without reballing, so connections were all goneFinally I should qualify all this by saying Macrofab is constantly evolving and adding production capacity. There were (and probably still are) many growing pains, and they may well have resolved many of the issues they had by now. Some of these are issues you will encounter with many other fabs as well.