I did a design of experiment on Entek Plus Cu-106A. we used WS paste and the board was a 2 side, 8-layer rigid-flex board w/ only 1 fountain-soldered TH component. Since we did not use no-clean process, I could not offer help on some of your Qs. 2. Marginal effect of storgae time. We found little difference btwn days and 1 year storage time on solderability. I think factory environment(~30C and 50%) is OK. Our guideline is storage < 1 month. 3. Highly recommend N2 use, especially if you use no-clean. 4. Hold time btwn reflows is the most significant factor on solderability. Try to minimize it. We recommended < 12 hrs for our supplier. 5. We use in-line aqueous cleaner to clean misprint. 6 Other considerations: Prebake in N2. Be careful about misprint clean. Read the Spec. for Entek Plus, most solvents remove some of OSP. Even water clean (140F) can move ~15% of OSP. We used water clean and found that it did remove some of the OSP. However, the remaining OSP is thick enough to preserve solderability. To eliminate test and other concerns, we covered all test points and ground rings with solder. Yuan Li Exabyte Corporation 1685 38th St. Boulder, CO 80301 ______________________________ Reply Separator _________________________________ Subject: Entek Plus Cu-106A Author: [log in to unmask] at UNIXMAIL Date: 1/10/97 12:41 AM Dear All: Our customer is asking us how to implement no-clean assembly process on Entek Plus Cu-106A from Enthone.Our customer's product is 2 side SMT/BGA without lead component. Is there anyone help us to get below answer. 1.What kind of no-clean solder paste is most compatible to Cu-106A ? 2.What will the max. storgae time after open bag to assembly? Is there any concern to store in controlled environment ? 3.Is it necessary to reflow in Nitrogen environment ? 4.What is the max. hold time between first and second IR reflow ? 5.How to rework bad paste printing like skip or misalignment ? 6.Any other concern using Cu-106 A? Your input will be highly appreciated. *************************************************************************** * 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] * ***************************************************************************