Doug, Your response to Graham's question has got me thinking about some boards we will be building soon. These boards have surface mount actives on both sides. On a sample board I have seen, a few of the components on the bottom side have glue dots since apparently solder surface tension alone will not keep these particular parts on during reflow of the top side. The glue looks like regular SMT adhesive and I am sure it was cured when the board went into the oven for bottom side reflow. I think this is fairly common practice when glue is required. *I don't know that I would say it is a common practice. I'm sure it is done, but most places that I interacted with had a separate glue cure profile prior to any reflow operations. How serious (or common) is the problem you describe and should I be thinking of a different way of processing these boards? *How serious? It was catastrophic in the cases I examined. If you go to the Circuits Assembly archives, you can look for the two articles I wrote in the Process Rx column: "Microcanyons" and "Become One With The Glue". They give more details on the problem. And yes, there was a fair amount of late night liquid engineering in the selection of those column titles. In short, the manufacturer tried to cure the glue at twice the manufacturers recommended rate, leading to the skinning effect and the entrapment of volatiles. When the glue was cured at the recommended rate, surprise, the problem went away. This is why I don't recommend doing glue cure and paste reflow (or wave solder) at the same time. Bad karma. Do you have a specific glue recommendation? *I have always been a fan of the Loctite 3609, but that is more from a cleanliness perspective (very low chloride content), than any other reason. Doug Pauls --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------