| Sponsor |
|
Is My PCB Wash Concentration in Check
Evaluating wash concentration levels through varying testing methods can potentially save process time, reduce overall process costs, and increase cleaning efficacy on PBCs. Read more.
KYZEN
|
|
| Sponsor |
|
Vapor Phase Profiling
Thermal profiling the vapor phase soldering process – especially those with vacuum – is challenging. ECD's M-VP™ sealed barrier can take it. Learn more.
ECD
|
|
| Ask the Experts |
|
|
May 22, 2012 - Updated
May 22, 2012 - Originally Posted
Wave Solder Dross Contamination
We have a problem with out tin/lead wave soldering system.Dross particles are sticking to the PCB and some are not found during visual inspection, but detected during in-circuit test.
The solder pot has a turbulentwave and a laminar wave and no nitrogen supply is used. The system has a wax cage to protectpump shafts. The wax cage uses specialmineral oil. What could be the cause of the contamination and how can we prevent it?
H.R.
|
| Expert Panel Responses |
Several process issues could cause dross sticking to the board.
One being solder pot maintenance, dross may form on the walls orat hot spots in the solder spot or the impeller region. So here regular cleaning of the solder pot can reduce dross frombeing carried out of the pot via the impeller system.
Temperature should be keep to lower limits if possible in 63/37the limits are 465-500F for lead-free it is 510-540F. Lower temperatures create less dross within the pot and impellersystem.
Using solder withlower impurities levels also helps since some elements enhance dross formation.Regular analysis is recommended.
Peter Biocca
Senior Market Development Engineer
Kester
Mr. Biocca was a chemist with many years experience in soldering technologies. He presented around the world in matters relating to process optimization and assembly. He was the author of many technical papers delivered globally. Mr. Biocca was a respected mentor in the electronics industry. He passed away in November, 2014.
|
|
Submit A Comment
|
Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.
|
Free Newsletter Subscription
Circuitnet is built for professionals who bear the responsibility of looking ahead, imagining the future, and preparing for it.
Insert Your Email Address
|
| Sponsor |
|
Thermally Conductive Epoxy
Master Bond Supreme 11AOHTLP is a two component adhesive featuring thermal conductivity and electrical insulation for high performance bonding, sealing and coating.
Master Bond
|
|
|
