Are you using EasyEDA, or at least running your design through EasyEDA and creating the Gerbers from it ? We found early on that sending the ones direct from Altium did have a few issues which importing into EasyEDA before sending them off solved.I think it's cheap in the sense of one-size-fits-all, no opportunity to tune the reflow profile to suit individual boards, limited feedback on the causes of low yields etc. Cheap not in the sense of low quality, but because it's engineered specifically to cut out cost by running everything through a streamlined automated process.
I don't mean to knock them for it at all - it's extremely good for what it is, but it doesn't give you a personalised product introduction process (for which you'd expect to pay 100x the price!).
I've never had anything from them which I would describe as outright bad quality, but I have had quite a lot of soldering failures of one sort or another, and I accept that as part of the cost of doing things this way. My impression is that their paste application isn't perfectly uniform (some boards come out with more or less paste on different runs of essentially the same design, or there's visibly less paste on one area of a board than another). But I certainly couldn't do any better - particularly with the constraint that they are just pasting a couple of panels off each stencil then throwing it away rather than ever getting into a regular flow.
Possibly some of my failures are my fault, though I've normally been using manufacturer's recommended footprints - and part of the problem is that even if it is my fault it's hard to discover in exactly what way that is the case, and if I tweak things to improve it, hard to know if my tweak worked or I just got lucky.
In many cases it's easy to touch up by hand the odd failed joint, but on these tiny packages that's just not possible. The other part that gave me problems was a 0.5mm pitch BGA - but I knew I was pushing the limits with that one, so unsurprised with some failures.
Also quite a few footprints in EasyEDA are not the same as the manufacturers - they've been optimised for their process, so now we import those the other way into Altium. For example capacitors and resistors of nominally the same size have very different footprints because of the way they absorb heat during reflow. If you just use a standard footprint for a component size then you will have problems. So certainly I accept you have to build your designs to their process, not tune their process to your design.
Was the BGA on a 6 layer or greater board ? Their 2 and 4 layer aren't really suitable for that spec as they don't have plugged vias so surprised they didn't reject the submission in the first case. But should have been fine if 6 or more.
I've never seen paste variations though. Did you take this up with your assigned engineering contact ? They are very helpful when you have problems so that future iterations or new designs don't have the same problem.
Statistics: Posted by MikeDB — Tue Jul 01, 2025 5:17 am