There is no way that CEM1 single-sided will be your highest quality option, but if lands on the PCB are designed for single sided and component leads are clinched or partially clinched, and 63/37 solder is used throughout (board finish, process, and component finish) it is possible to make a reliable product. Maybe I should say WAS possible back in the day.... As with any design (but ever so much more so in this case), it's important that no additional mechanical stresses are introduced by the packaging (housing/enclosure/mounting features/etc), also considering thermal excursions (ie: is a connector pushing or pulling at the solder joints when the unit is at an extreme temp?) I haven't had any personal experience with PbFree single-sided through-hole products, but I hear it can be done for class 2. Also have heard that CEM1 is still possible with PbFree, but don't know any details, so maybe not for though-hole designs. Hard to imagine... PTH is always going to be better quality. Unsupported holes might be good enough. It depends. Have a great weekend, -Chris Charming Chan <chancharming@AOL .COM> To Sent by: TechNet [log in to unmask] <[log in to unmask]> cc Subject 11/20/2009 09:21 Re: [TN] Discussion on the AM reliability of single-sided PCB & PCBA Please respond to TechNet E-Mail Forum <[log in to unmask]> ; Please respond to [log in to unmask] COM Thanks to all the inputs. The holes on the pcb are non-plated through and no solder fill for through-hole component, is the solder joint robust and reliable? Our products are networking application and need high reliability, the power supply part is out-sourcing, we need to make sure the reliability of the out-sourcing power supply part. Best Regards Charming Chan -----Original Message----- From: Chris Ball <[log in to unmask]> To: [log in to unmask] Sent: Fri, Nov 20, 2009 12:36 am Subject: Re: [TN] Discussion on the reliability of single-sided PCB & PCBA I would say.... it depends. Some CEM1 out there in pretty harsh env. for any many years. Not recommending it, but it could be made to work, at east prior to PbFree processes and finishes.... Best Regards, Chris Charming Chan <chancharming@AOL .COM> To Sent by: TechNet [log in to unmask] <[log in to unmask]> cc Subject 11/19/2009 09:37 [TN] Discussion on the reliability AM of single-sided PCB & PCBA Please respond to TechNet E-Mail Forum <[log in to unmask]> ; Please respond to [log in to unmask] COM ello All, Our power system suppliers build single-sided pcb with paper-based ubstrates, the holes on the pcb are non-plated and no solder fill for hrough-hole component. As I know, paper-based substrates are generally sed for the pcb build of low-cost, low-reliability, consumer products. Our company sells CLASS 2 networking products, which are supposed to work n harsh environment. Is it reliable enough to use such single-sided power ssembly? Thanks a lot for kindly input. 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