First thing that comes to my mind is copper thickness of the through holes. Extended dwell times will increase the amount of copper etched by the molten solder. The amount of etch per second of dwell time will vary from HASL line to HASL line. Some vertical lines have a localized turbulent zone which can quickly etch the copper plating reducing the overall plating thickness. Most horizontal lines have a more even distribution of solder flow. The fabricator should have an idea the amount of etch, for a given dwell time, their equipment produces. I am sure there are many other factors, but this one came to mind first for me. Jim Kenny Merix Corp 503-359-9300 [log in to unmask] Wrote: | | | From: Stephen Ayotte | EM Quality Engineering | Bldg. 14-3 Col F5 5-1537 | Subject: Fabrication | | Does anybody have any reliability data on the affect of | processing | boards through HASL a number of times, specifically until | the board | material changes color? | | | Thanks. | | **** IBM MD Product Quality Engineer **** | **** OEM Quality Engineer **** | **** Interenterprise Address: USIB6CEF **** | **** Internet Address: [log in to unmask] **** | | ********************************************************** | ***************** | * TechNet mail list is provided as a service by IPC using | SmartList v3.05 * | ********************************************************** | ***************** | * To unsubscribe from this list at any time, send a | message to: * | * [log in to unmask] with <subject: unsubscribe> and | no text. * | ********************************************************** | ***************** | * If you are having a problem with the IPC TechNet forum | please contact * | * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at | [log in to unmask] * | ********************************************************** | ***************** | | *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************