Electronics Forum | Mon Jun 17 13:45:29 EDT 2002 | genny
When the pad comes off, is it leaving behind a "black" area? Your board may be suffering from black pad - a condition that occasionally affects ENIG finish boards. It is a process control issue with your board fabricator. The nickel is oxidising b
Electronics Forum | Thu Oct 30 15:07:40 EDT 2008 | jemills
Hello I have a new 0402 pad design on a recent board were building in future. On closer look i thought the pad was a thru hole mount , but upon closer inspection the round pads are for 0402 comps. I had a discussion with the engineer and he said
Electronics Forum | Thu Jun 20 03:15:22 EDT 2002 | Paul
I've seen a problem recently where there was 2 deposits of Nickle then Gold, The problem is the Nickle will not adhere to Nickle, see if you can scrape the pad away with a scalpel.
Electronics Forum | Fri May 06 08:47:05 EDT 2016 | davef
You're correct. This design will have a record amount of 0402 rework for tombstoning and misalignments. Suggest that the pads on each end of all components be the same size in order to balance wetting forces during reflow.
Electronics Forum | Thu Oct 30 22:29:58 EDT 2008 | davef
For most applications, a nice square [or rectangle] pad works just fine. Assemblers ship boat loads of boards with these every day. It's reasonable for tight decoupling capacitor requirement applications to use round or radiused pads for components
Electronics Forum | Thu Apr 17 13:37:11 EDT 2014 | anvil1021
Hello All....we have several hundred PCBs that we need to run with a no-clean solder process and the surface finish is OSP. Our preliminary testing has found that the solder will not wet the entire pad even if the pad is over printed? We have contact
Electronics Forum | Wed Jun 12 20:04:03 EDT 2002 | scottxiao
Thank you very much!
Electronics Forum | Fri May 06 08:39:59 EDT 2016 | kahrpr
The first issue I see is that you have a high potential of the 402 tombstoning.
Electronics Forum | Thu Sep 02 21:02:55 EDT 1999 | Paul Wareham
We've noticed that there are many different recommendations for pad sizes for various SMT parts. This seems to vary wildly from manufacturer to manufacturer for the same case sizes. Is there any standards that can used used to specify these sizes?
Electronics Forum | Thu Jun 20 04:49:34 EDT 2002 | scottxiao
according to the ressult of cross-section and removing the component, I find there is no black area in the left pad, and the IMC is also normal, so the black nickle is less impossible. the PCB material is not common FR4, just some thing like ceramic,