|
Sponsor
|
|
You need clear soldering results?
The SEHO PowerVision AOI system is for fast, automated optical inspection. Designed for THT processes & focusses on 2 points: Continuous quality assurance & cost-efficient production processes.
SEHO Systems GmbH
|
|
|
Sponsor
|
|
The Right Tools for Every PCB Repair
Damaged circuit boards don't always need to be replaced. CircuitMedic offers professional-grade repair kits, tools, and materials for restoring damaged pads, traces, plated holes, and circuit board surfaces.
Circuit Technology Center
|
|
| Ask the Experts |
|
QUESTIONS
SUBMIT
MEMBERS
JOIN
|
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?
https://www.circuitnet.com/experts/uploads/1/dross_2_200150.jpg https://www.circuitnet.com/experts/uploads/1/dross_1_200150.jpg
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.
|
|
|
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
|
|
Bring IPC Training to Your Facility
Mobile training center offers IPC certified classes at your company’s facility making solder training effective and convenient for your entire team.
BEST Inc.
|
|
|
