Stretching my memory rather a lot but I recall having exactly this problem which was diagnosed as insufficiently cured resist. I have no idea why that should be the root cause I just recall it was. That conclusion was provided to me by a supplier of material to the pcb manufacturer we were using. Regards Rex Rex Waygood Technical Manager Hansatech EMS provides value manufacturing through engineering and quality Hansatech EMS Limited Benson Road Nuffield Industrial Estate Poole Dorset BH17 0RY +44 (0)1202 338200 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Amarjot Singh Sent: 21 January 2010 19:59 To: [log in to unmask] Subject: Re: [TN] Skipping pads in wave solder Hi Gang: My customer is having a problem in wave soldering. The board has surface mount and through hole components on top side and there are some test points on the bottom side. While passing through wave solder, the holes are filling nicely but solder is not being coated on some of the test points. Some test points are in the ground plane (solder mask defined) and the others is isolated but sorrounded by ground plane. I can cover those pads using solder iron without any problems. When performing the similar process at some other assembly house in wave solder, I noticed the same problem. I played with higher pre-heat temperatures, slower and faster speed but same result. Any thought on this issue? Thanks, Amarjot --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------