Electronics Forum | Fri May 08 09:44:23 EDT 2009 | davef
Board fabricators use solder as a resist to protect copper traces from process chemicals. Fabricators remove this resist in later processing. It's possible that board fabrication processing is the source of the tin that you see.
Electronics Forum | Sat May 02 08:48:32 EDT 2009 | davef
You have a board defect. Any moisture and/or organic contaminants trapped by the solder resist during lamination may cause solder mask delamination, blistering and/or adhesion loss during subsequent soldering operations or during extended use.
Electronics Forum | Sat May 02 23:31:06 EDT 2009 | kareal
Thanks davef. The defect always occurred during UHAST reliability, but not find in reflow. The key is that there is tin diffuse to copper trace under solder mask. is it a "normal" board defect and what is the potential risk for device? thanks!
Electronics Forum | Thu May 07 08:11:58 EDT 2009 | davef
We don't have a good answer for you, but we do have several thoughts on the issue: * First, tin in your solder or solderability protection is going to diffuse into the copper trace or pad on the board naturally. You can stop that by using a protectiv
Electronics Forum | Sat May 09 09:00:54 EDT 2009 | davef
For more on using tin as a resist during bare board fabrication, read "2.5.6 Introduction To Tin And Tin/Lead Plating" here: http://books.google.com/books?id=etfNcpiR5ZUC&pg=PT570&lpg=PT570&dq=%22circuit+board%22+%22etch+resist%22+%22acid+sulfate%22&
Electronics Forum | Thu May 07 20:28:35 EDT 2009 | davef
From our notes, the following is a series of snips from: "Copper Dissolution in Tin" LJ Turbini, PhD, adjunct faculty member, University of Toronto, Materials Science and Engineering, SMT 2/07 As the solder becomes molten, copper from the board diff
Electronics Forum | Mon Aug 22 15:57:28 EDT 2005 | pr
Is there a test to check for delamination on a pcb? We are looking at new board houses and along with our standard solderability tests my boss wants to test for delamination. thanks, pr
Electronics Forum | Fri May 27 04:31:56 EDT 2016 | leeg
We have recently had a jig get caught in the chain of the flowsolder machine, causing the board to delaminate, is there any hard and fast rules as to if the area needs evacuating due to fumes, and if the air quality has to be checked before allowing
Electronics Forum | Mon Nov 06 12:19:25 EST 2000 | Tom Gervascio
I ma trying to get some information on possible causes and screening tests for PCB delamination. Is the main cause moisture absorption of PCB material or entrapped chemicals and or air in innerlayers that expand when expsoed to subsequent reflow and
Electronics Forum | Thu Sep 01 18:53:08 EDT 2005 | Board House
Pr. I agree with some of the above responses. if you are seeing Delam issues with incoming PCB's the following should be check. 1) Check the OEM Print to what Material they are calling out to be manufactured with. 2) If they are calling out for S
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
