Electronics Forum | Thu Jun 19 10:36:54 EDT 2003 | Jacob
Hi all I am having a reflow problem. Recently we started using a through hole connector with solder flux bearing technology on a densly populated board. The connector reflows at the same time as the smt components through reflow. The problem I am ha
Electronics Forum | Tue Jul 15 22:50:12 EDT 2003 | iman
We have an internal engineering study on blowhole solder joints and had helped reduce the problem to pinholes symtoms. The pinhole occurs in solder joint of a Land-Grid-Array (LGA) side-wall (external perimeter of package) fillets. Our customer is a
Electronics Forum | Mon Jul 28 08:54:52 EDT 2003 | davef
You are 100% correctomundo about ENIG. When it's good it's good, BUT when it's bad, you just want something else. You know you have black pad, when you see parts falling from the board. First, there is not perfect solderability protection. Second
Electronics Forum | Tue Sep 09 20:32:10 EDT 2003 | davef
The maximum ratio of gold weight to solder alloy weight can be calculated, to help prevent a problem from excessive gold-tin intermetallic compound (i.e., AuSn4). For the equation and its derivation, please refer to "The Use of Capillary Action Measu
Electronics Forum | Tue Oct 28 17:40:58 EST 2003 | davef
We theorize a secondary [bottom] side BGA can be wave soldered with planning. Issues are: * Keepout between the BGA and one side of the board that is clear of PTH parts requiring wave soldering, so to support the fixture. * Keepout around the BGA. *
Electronics Forum | Tue Mar 09 22:26:17 EST 2004 | davef
You should to be soldering to the nickel. The intermetallic is Ni3Sn4. "At relatively low temperatures, the tin-nickel layers form about as rapidly as the tin-copper layers do, but at higher temperatures their growth rate is distinctly lower. At 10
Electronics Forum | Fri Mar 19 11:48:06 EST 2004 | Ken
This is the dilema during this transition period. Here is a tip: If you see typcial solder joints on a lead free process, but only on one component type....it probably has a significant quantity of lead in it (ex. Sn90/Pb10...and so on) If using T
Electronics Forum | Thu Apr 01 11:27:17 EST 2004 | Jimmy
I have some fine pitch QFP's to rework with our smt rework system (forced air). There are no intitial concerns in removing the component (we havent actually begun the rework process) however, installing a new chip presents a problem. The QFP has
Electronics Forum | Tue Apr 20 20:11:58 EDT 2004 | davef
First, how oxidized are these solder balls? Will the take solder using your routine flux / paste? Second, on restoring solderability, the three basic methods you can use to restore solderability on components are: * Highly active fluxes in a retinn
Electronics Forum | Fri Apr 23 16:36:27 EDT 2004 | davef
Comments. Comments. Hell yeh, we got comments!!! You are correct to question the appearance of this solder connection. Based on your description, it's defective. Well at best, it's VERY suspect. That's the rule. If it's suspect, question it.
