A fab house is raising a strange error on through hole pad connections. In the top layer all connections are made but they are saying the bottom layer is left unconnected.

Its a breakout board for a 32 pin QFN IC. I used a 8-pin through hole connector and connected it to each side of the Chip and connected all the IC pins with each 8-pin connectors on the top layer.

But now the fab house is saying, the bottom layer has pads and there is no connections. Why is it required?

Raised exception - https://drive.google.com/file/d/0B3tW8HqE_ubMMTI4WFBDSDlyd19Ib3NCNU5sS1hkVHl1UUw4/view?usp=sharing

Gerber Files and its images - https://drive.google.com/file/d/0B3tW8HqE_ubMNTZiTlNBamhBRTJTeTlQcE41MVFyNWllT2Uw/view?usp=sharing

BRD file - https://drive.google.com/file/d/0B3tW8HqE_ubMeWVCRm5NRzlhOFdFQzJFeUpYV2VFamVpR25V/view?usp=sharing

SCHEM file - https://drive.google.com/file/d/0B3tW8HqE_ubMWnEtcERCbkZ4UlJSc3Y2QW1pREs1dmVBQkhF/view?usp=sharing

  • 1
    \$\begingroup\$ You need to find a better way to include the relevant information directly in your question. No one is going to download and unpack a bunch of zip files in order to answer what is probably a relatively simple question. \$\endgroup\$ – Dave Tweed Dec 30 '15 at 16:33
  • 1
    \$\begingroup\$ Without doing a lot of digging through this, just make sure that your pads are plated through holes, otherwise I don't see anything wrong with this- they are perhaps just being picky (unlike most Chinese makers who will make whatever is on the Gerbers no matter how obvious the error- sorry your fault). \$\endgroup\$ – Spehro Pefhany Dec 30 '15 at 16:54
  • \$\begingroup\$ Did you somehow say that the through-hole pads should not be plated through? That would be peculiar, and might involve a slightly unusual manufacturing process to drill the holes after plating. This is only a WAG. \$\endgroup\$ – gbulmer Dec 30 '15 at 17:11
  • \$\begingroup\$ @gbulmer They should be plated-through. This board probably has both- the 'mouse bites' should be unplated. It's indeed a separate process, but a very commonly required one. \$\endgroup\$ – Spehro Pefhany Dec 30 '15 at 20:27
  • \$\begingroup\$ @SpehroPefhany - I agree it is not weird to have some unplated holes or routing. However, it would be unusual to have a through hole part soldered into unplated through-hole pads. That's why I made the comment. \$\endgroup\$ – gbulmer Dec 30 '15 at 23:18

If it looks like you expect - and it does - there's nothing wrong with that. They just think it's somewhat odd, and possibly an easy mistake, so instead of having a sad customer they want to make sure it's OK before continuing.

Note that they never claim it is required, as you write in the question.

  • \$\begingroup\$ Agree. The fab house is keeping an eye out for its customers - good for them. And note that their proposed solution is to not make any changes, just make it as drawn, but they want confirmation from the originator. \$\endgroup\$ – WhatRoughBeast Dec 30 '15 at 16:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.