Electronics Forum | Sat May 29 16:04:49 EDT 1999 | M Cox
I have always thought it to be a good practice to wash SMA's with water soluble paste (WS609) soon after reflow. Is there a time limit as to how long a board should sit after reflow before washing said board? For instance; processing a double-sided
Electronics Forum | Thu Jun 25 16:13:05 EDT 1998 | Mike McMonagle
I am looking for a little enlightenment with an issue that we have been seeing. We have SMT assemblies with poor solderability on TSOP and mini-QFP type devices. The solder appears to have incomplete reflow and/or grainyness to the joints. Everything
Electronics Forum | Thu Sep 13 11:21:45 EDT 2001 | aldo_maldonado
We've had several instances of parts (1206R, SOT-23) popping off of their location during reflow. Parts placement is OK, paste brick is aligned and compact before oven. But we get random parts off their location just lying somewhere else on the boar
Electronics Forum | Tue Apr 23 14:20:48 EDT 2002 | russ
We have not yet sent this out for analysis, So, I don't really know what it is. initial evaluation would lead me to believe that it is flux since it is only present on the solder joints themselves and nowhere else. I noticed that you also mentioned
Electronics Forum | Fri Oct 18 07:14:51 EDT 2002 | cyber_wolf
Have you tried using a paste with a more aggressive flux? Our main paste is Indium, but whenever we run into oxidized parts or have soldering problems due to oxidation on pads we use an older Alpha WS paste called WS609. The drawback of this paste is
Electronics Forum | Tue Dec 10 19:30:49 EST 2002 | Vijay
Hi Dave, The peak temp on the leads is 216-218 Deg C and duration above MP (179 degC) is 55-60 sec. Alloy(solder paste) used 62 Sn,36 Pb 2Ag (Alpha WS 609 Ty 3 Water eash) This is a SMT connector wth Gulwing leads Gold plating on the PCB is 2-5 micr
Electronics Forum | Tue Dec 10 20:42:43 EST 2002 | davef
Vijay, Sounds like you're not spending enough time at liquidous plus 20*C. And you need to stay there for 5 to 10 seconds. I know, I know. We have used bucketsful of WS609 over the years. See, as you say, the melting point of your solder alloy
Electronics Forum | Wed Apr 09 23:37:52 EDT 2003 | MA/NY DDave
Hi I know what DaveF is saying about the Kapton situation, yet from what I remember also at a KIC presentation the Kapton technique wasn't given as bad a billing as Dave describes. You do have to make sure you get a good firm contact and verify it
Electronics Forum | Thu Jun 17 07:04:03 EDT 2004 | davef
It sounds like the parts are not soldering properly [have poor solderability]. This probably due to corroded nickel underplate caused by: * Nickel that oxidized, while awaiting overplating * Poor quality tin overplate, allowing nickel to oxidize aft
Electronics Forum | Sat Jun 26 15:26:10 EDT 2004 | russ
I am very happy with Alpha Metals WS709 or even WS609. Almost all of our product is Immersion gold and we place down to 16mil pitch every day along with 0201 and uBGA. Immersion gold from my experience, solders extremely well with every paste I hav
