Hey Earl, This subject brings back a time of trials and tribulations concerning solder joint crack propogation using LCCCs and "like" devices. Beginning with the Coffin-Manson Law and the Engelmaier (Sir Werner's) equation, it was determined that solder joint volume needed to be increased and the "acceptable geometry" needed to be modified, almost to point of "the bigger the blob the better the job". Without getting into too many specifics, the pad dimensions for these parts require augmentation from the norm by increasing the pad length that extends outward from the device periphery to a length equal to the pad length that is under the part. The idea is to increase the solder joint volume up the castellation and outward to the pad creating a "bulbous" fillet -- this portion of the joint contributes to 85% of the solder joint life with respect to crack formation and propogation. The attained solder joints do go against general Rf rules of thumb (the shortest path is best) but I was unaware of any performance issues with applications below 2gHz. As one Rf designer told me years ago, ..."don't put a stress relief bend on that ribbon, just add more solder..." Hope this helps, if not, sorry for adding clutter to your cave! Steve Sauer Manufacturing Engineer Northrop Grumman, Xetron -----Original Message----- From: Earl Moon [mailto:[log in to unmask]] I have another board/adventure requiring simple coplanaty issues be resolved and I know how to do this so don't need advice. Need to know, from R/F folks, if anyone is using the following: EM Research Inc. LX-2050-05 EM Research Inc. LX-1450-01 These parts are castellated, are gold plated castellations, are PCB material interposer types requiring very flat surfaces on which to be mounted. No problems but for leadless and gold plating. Wondering if anyone out there has experience with the aforementioned parts and results. MoonMan ---------------------------------------------------------------------------- ----- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest 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 ---------------------------------------------------------------------------------