defects in pcb manufacturing

Top picture: We're not wild about the 'poor registration,' the differing thickness of the solder mask, and the crud all over the board. But, then again, we don't have a basis for rejection. Bottom picture: No basis for rejection

Help us out, what don't you like about these boards?

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The top picture probably won't run. You have black soldermask dramatically misregistered and overlapping what look a lot like fids. Either your machines are going to pitch a fit and not find the fid or they're going to center on the soldermask outline. Neither is going to leave you with acceptable results.

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Hi, I see a huge solder mask shift on chip comp pads. This would result in mid-chip solder balls or solder beads. Overall, the solder mask workmanship is not acceptable. Mask is on pad.

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Just my opinion:

Top pic - Solder mask registration WAY too far off, without a doubt I would reject.

Bottom pic - I would worry that there was/is a contamination that caused the poor looking mask. This may be cosmetic only, but unknown. I would reject them. If the PCB fab company will not remake the boards for you then get a new fab company. There are plenty of good ones out there. No need to accept sub-par boards. Your customer will not care to hear excuses if these boards fail during/after assembly.

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Hello Julie

Yr supplier is saying that these boards meet the requirement of IPC-A-610. I think that you need to check this requirements at least. But, it does dot mean that these are acceptable.

Thanks.

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Hi Julie,

My opinion is that the top board would not pass IPC, solder mask encroachment on pads.

Second board is what we call Orange peel,this can be caused two way's. 1) the solder mask was not tack dried enough prior to imaging which caused artwork to stick to panel during imaging. 2) these could have been hand screened on a table (Not by a screen coater) and the screen was sticking to the boards do to uneven pressure by the operator.

top board would be easily rejected due to poor registration. Bottom board looks like crap and could be rejected due to uneven solder mask thickness and poor quality control.

I would agree to other comments that if this is typical quality that your are receiving from this shop, I would investigate other suppliers.

My Disclosure:

I am a Direct salesman for a Taiwan board supplier.

Like in the US their are good and bad shops. I would say that 99% of shops in Taiwan & China would not find this product acceptable.

Best Regards, Mike Dupont Active Sales Associates Inc.

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Base on the top picture condition, seems like the boards condition is a lot with solder splash or solder ball which is per IPC-610 is under reject (under 5.6.2)for class 3 product. While the picture 2 is showing those the solder resist is not melt properly during PWB manufacturing side, that's condition as per IPC-610 also under rejectable for class 3 product, check under clause 10.5.1. Before you decide that condition is better to know what's kind class your manufacturing process been build and adopt.

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Has anyone ever done a tape test to see if the solder resist pulls away from the PCB? Is this an acceptable method for testing solder resist acceptability?

This is an issue I am experiencing with our PCBs. I am receiving boards with excess solder on the fiducials. I'm sure this is from the HASL process, but is there an IPC spec for the height of the HASL finish on the fids?

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