Electronics Forum | Fri Aug 19 01:56:53 EDT 2011 | ppcbs
I've been seeing a lot of product come in with what appears to be black pad lately. I've sent stuff out to labs to be told there is no contamination. Contamination or not solder won't wet to it. Regardless of what it is we have a method to remove
Electronics Forum | Thu Sep 10 15:06:11 EDT 2009 | dyoungquist
My guess is that he is talking about the gold plated pads not fully wetting with solder. We have seen this on some of our ENIG boards with the gold still showing at the far corners of the rectangular pads. Not knowing if this is hand soldering or p
Electronics Forum | Tue Mar 25 13:55:05 EDT 2014 | horchak
Ok lets put it this way. If the PCB house used a high quality mask and properly applied it to a properly cleaned surface and properly cured it, then as Dave stated above there are only two things that can destroy it. Excessive heat and overly aggress
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 | Tue Dec 08 15:19:42 EST 2015 | proceng1
Apply the correct amount of paste for the pad size should work ok, as long as the part starts out in the paste. If you have a reduced aperture and the leg doesn't quite touch any paste could result in non-wetting or insufficient solder issues. I gu
Electronics Forum | Tue Apr 27 21:22:57 EDT 2021 | kwalker
The fact that your cleaning didn't really help reinforces that it probably is oxidation. Cleaning won't remove that.
Electronics Forum | Tue Apr 13 11:41:18 EDT 2021 | jeremy_leaf
I have a SAC305 preform with which I am attempting to bond a gold coated component to an ENIG coated PCB pad. I've specified 2 microinches of gold for the ENIG. It worked previously but now with a new batch of boards, I am having an issue where the p
Electronics Forum | Tue May 23 09:27:37 EDT 2006 | Steve
Sorry I misled you. The PCB pads are wetting, but there is no fillet being formed. After reflow, it looks as though no paste was put down on the pads; however the paste print is fine. All other components solder real nice, it's only the Pd-Ag parts t
Electronics Forum | Mon Apr 19 15:45:21 EDT 2010 | dwonch
Thanks to all for your input. We did have a third party do an analysis on boards from the first shop. They were shipped directly from the board shop to eliminate the possibility that we could contaminate them. The third party (Forsite) did find Sili
Electronics Forum | Fri Sep 20 17:43:03 EDT 2019 | deanm
Looks like poor wetting/solderability to me. I don’t see heel fillets on the leads where the solder balls up. The solder has to go somewhere. It won’t flow where it won’t wet. Try printing a bare board and run through reflow. If the solder balls up o
Products, services, training & consulting for the assembly, rework & repair of electronic assemblies. BGA process experts. Manufacturers Rep, Distributor & Service Provider for Seamark/Zhuomao and Shuttle Star BGA Rework Stations.
Training Provider / Manufacturer's Representative / Equipment Dealer / Broker / Auctions / Consultant / Service Provider
1750 Mitchell Ave.
Oroville, CA USA
Phone: (888) 406-2830
.gif)
