Electronics Forum | Thu Dec 01 21:17:30 EST 2005 | davef
Does the solder melt when 'hit' with a soldering iron [and maybe a little flux]? If so, what is the appearance of the solder flow? What causes the green tint in the picture you provided?
Electronics Forum | Fri Dec 02 08:10:25 EST 2005 | Amol Kane
Davef and russ, thank you for your input The kester was selected due to a management decision, I shall recommend that other solder be tried out as well. davef, i'll try out the soldering iron......and also look for the green tint (didnt notice that
Electronics Forum | Thu Dec 01 17:24:37 EST 2005 | slthomas
Are you sure you're getting enough paste on the pads? It looks like you may not have enough flux to get the solder to wet properly.
Electronics Forum | Thu Dec 01 14:41:06 EST 2005 | Bill C
It looks to me that your reflow profile is not hot enough. Seeing the granular structure of the solder paste still on the board would indicate the paste has not reflowed entirely.
Electronics Forum | Thu Dec 01 14:42:57 EST 2005 | Amol Kane
my first thought was that too, but all the other components on tha board have reflowed properly. I have tow test boards, one with Imm Sn and other with Imm AG. on both these boards only the QFP has this solder phenemenon
Electronics Forum | Thu Dec 01 16:14:45 EST 2005 | chunks
You need to verify if you're getting up to the needed temps. It looks like you're not. I'd say it started to reflow but never reached a long enough time. Nitrogen may help with further wetting.
Electronics Forum | Thu Dec 01 17:55:26 EST 2005 | russ
Your paste is oxidizing in reflow and not coelescing (spelling?) We failed kester W.S. for reasons such as this. There NoClean is a little better but we do not use that either. I would switch pastes and I will bet that your problem majically disapp
Electronics Forum | Wed Dec 07 11:16:47 EST 2005 | pete_d
I'm curious to know, if using the same paste and profile,would this phenomena would occur on Copper OSP boards...any input?
Electronics Forum | Thu Dec 01 14:24:25 EST 2005 | Amol Kane
Hi, I am having a SAC 305 solder paste with water soluble flux wetting issue. during reflow, the solder melts, but doesnt flow. the reflow profile was developed by the solder company person (Kester). the board is a test assembly to validate our LF pr
Electronics Forum | Fri Dec 02 08:57:39 EST 2005 | russ
You hit it on the nose Pavel, the fluxes in paste are formulated to have 2 activating points if you will, one at low temp and one at high temp. when the low temp flux gets killed this is what you will see. This is the main reason we opted out of K
