Electronics Forum | Tue Feb 17 04:52:13 EST 2004 | John W
There's normally a number of reasons people want to know what melts 1st, 1 - to see if you know, 2 voiding issues - whole can of worms 3 device alignment. One of our collegues has said that most balls are Eutectic, that's in fact not totally correct.
Electronics Forum | Fri Feb 20 13:01:26 EST 2004 | Jay
First, it depends on the alloy composition of the solder. As you might know, eutectic Sn/Pb solder has the lowest melting point among available conventional solder systems. (except those based on Sn-In and Sn-Bi systems.) For example, 63Sn/37Pb - 183
Electronics Forum | Fri May 06 06:51:55 EDT 2016 | abhilash4788
Hi All, One of my customer has provided a pcb design having common pad for 0402 and 1206 package(i.e 3 pads in the gerber, pad1,pad2 belongs to 1206 package and pad2,pad3 belongs to 0402 package) Will this create any solderability issue. Is anyone e
Electronics Forum | Tue Jun 11 22:06:06 EDT 2002 | scottxiao
I encounter the problem, it is easy for pad(copper) to drop off from the PCB, which is Ni/Au finish. so my question is whether there is any specification about the force between pad and laminate material, and does the PCB corpoartion test this parame
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
