| Sponsor |
|
pH Employment in Electronic Cleaning
The pH of a cleaning agent affects the entire cleaning process and must be considered when determining the appropriate chemistry and process parameters for success. Download now.
KYZEN
|
|
Lead-Free Flux and Influence on Cleaning
Lead-free flux technology is more difficult to clean. Cleaners with a better matching solvency for the residues are needed.
Production Floor
DOWNLOAD
|
Authored By:
Dr. Ning-Cheng Lee
Indium Corporation, Clinton, NY USA
Summary
Lead-free flux technology for electronic industry is mainly driven by high soldering temperature, high alloy surface tension, miniaturization, air soldering due to low cost consideration, and environmental concern. Accordingly, the flux features desired included high thermal stability, high resistance against burn-off, high oxidation resistance, high oxygen barrier capability, low surface tension, high fluxing capacity, slow wetting, low moisture pickup, high hot viscosity, and halogen-free.
For each of the feature listed above, corresponding desired chemical structures can be deduced, and the
impact of those structure on flux residue cleanability can be speculated. Overall, lead-free flux technology results in a greater difficulty in cleaning. Cleaner with a better matching solvency for the residue as well as a higher cleaning temperature or agitation are needed. Alkaline and polar cleaner are often needed to deal with the larger quantity of fluxing products. Reactive cleaner is also desired to address the side reaction products such as crosslinked residue.
Conclusions
Lead-free flux technology for electronic industry is mainly driven by high soldering temperature, high alloy surface tension, miniaturization, air soldering due to low cost consideration, and environmental concern. Accordingly, the flux features desired included high thermal stability, high resistance against burn-off, high oxidation resistance, high oxygen barrier capability, low surface tension, high fluxing capacity, slow wetting, low moisture pickup, high hot viscosity, and halogen-free.
For each of the feature listed above, corresponding desired chemical structures can be deduced, and the
impact of those structure on flux residue cleanability can be speculated. Overall, lead-free flux technology results in a greater difficulty in cleaning. Cleaner with a better matching solvency for the residue as well as a higher cleaning temperature or agitation are needed. Alkaline and polar cleaner are often needed to deal with the larger quantity of fluxing products. Reactive cleaner is also desired to address the side reaction products such as crosslinked residue.
Initially Published in the IPC Proceedings
|
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 |
|
"Flying" SMD Components
This paper deals with the fundamentals of heat transfer and the test procedures show how the SOD323 can be processed given a suitable selection of solder paste and oven settings. Read more.
Rehm Thermal Systems
|
|
|
