Electronics Forum | Wed May 08 23:18:58 EDT 2002 | ianchan
Hi mates, have this SMT production issue : A) We have a leadless-chip-carrier(LCC) IC package that is classified under the Land-Grid-Array(LGA) package family. B) The LCC is 4mm x 4mm, and has 28 tin plated pads located beneath the outside perimet
Electronics Forum | Mon Jul 29 16:43:55 EDT 2002 | mcm4me
I have a customer with up to 8% scrap from one board supplier and 1% from another supplier for solder dewett and no wet over ENIG finish with mask defined pads. Initially I suspected mask residue on pads because of the no wets but I have come to find
Electronics Forum | Thu Aug 01 08:58:47 EDT 2002 | Rick Lathrop
Good morning Dave F. I am not going to try to touchup the solder pad until I get surface analysis work done, don't want to ruin the evidence. I am getting XPS work done not XRF, XPS is X-ray Photoelectron Spectroscopy and can see very thin films of o
Electronics Forum | Tue Jul 30 17:47:50 EDT 2002 | davef
Dewetting: Solder does not adhere to lead or land, caused by: * Poor solderability of lands. * Poor solderability of leads. * Solder paste integrity. * Lead plating integrity. Need more information, please: * What is dewetting [ie, component, pad, e
Electronics Forum | Wed Mar 11 10:58:58 EST 1998 | Earl Moon
| | What does the term "poor wetting" mean as a defect code ? "Poor" should mean unacceptable when surface (component or PCB solder termination areas) wetting does not provide acceptable solder joints. Unacceptable wetting of PCB solder termination
Electronics Forum | Mon Nov 12 19:47:33 EST 2007 | sin4d
Hi, Thanks. Waitng for your reponse. BTW, if I were to perform a test as below will this give me some result to indicate if the component is defective. 1) Print solder paste on plain PCB without copper track. 2) Mount the QFP & reflow 3) If the sol
Electronics Forum | Mon Nov 12 01:18:29 EST 2007 | sin4d
Hi, ALL I experience some QFP with wetting issue on the heel of the lead. There is no fillet wetting on the heel which causes reject bt the customer, but not all the QFP. Could anyone pls help what is the causes of this problem, it is due to oxidati
Electronics Forum | Tue Dec 18 18:36:58 EST 2001 | guicho_v
Is the Sn% of the plating of the pin related to wetting quality?. I am having issues with one IC maker where some pins are OK and one or two pins are not soldered, even when there is weeting evidence underneath the pin. I am blaming the %Sn too hig
Electronics Forum | Tue Nov 05 09:57:45 EST 2013 | cuperpeter
Hello All, We have a problem with dewetting of solder paste. Problem is most visible on the pads without components (see attached pictures) and occurs randomly, 20% of PCB's. Pcb supplier sent us a cross-section of pads with thickness of Cu, Ni and
Electronics Forum | Fri Apr 09 20:47:36 EDT 2010 | 89jeong
I think the oxidation on the pad happens easily but do not on Au plated pad.The reason may be caused by improper cleaning or Au plating thickness in plating process. But,before suspecting the pcb board, you need to check your process or used material
