Would it be an acceptable to tent the via on the secondary side? Just wondering, Alain Savard, B.Sc. Chemical Process Analyst CAE Electronics Ltd. e-mail: [log in to unmask] -----Original Message----- From: Kelly M. Schriver Subject: Re: [TN] VIAS IN PAD The thru vias in pads will do two things: 1] scavenge solder from the soldered connection on the pad. If their size is sufficient, this will result in a solder starved condition at the component lead; 2] Gravity and surface tension will generally cause a solder bead of some proportions, on the opposite side of the board. Dependent on the design, this may produce a risk of shorting, or simply an increase in solder starvation on the component pad. There would appear to be several possible solutions: plug the vias while in the bare copper state and allow an imperfection in the soldered connection; plug the vias and copper plate over them, prior to tin/led plate of the board; redesign to convert to either blind or microvia, in order to eliminate/control the solder scavenging. Steve Mikell should have good clear recollections of a job we did about ten years ago, where the customer had designed boards with this charactaristic, then beat us up because we couldn't change the laws of physics to accomodate the design. Have a good day and a better week - tell old what's-his-name across the hall, "Good morning". Kelly -----Original Message----- From: Bill Robinson Subject: [TN] VIAS IN PAD >We have pruchased a PWB design for use in one of our products. This design >has through vias in the surface mount pads. Has anyone had experience with >this situation? My first concern is losing solder through the via during >reflow. Is there a good way to fill the via and still have a good solder >joint? And what other kinds of problems can we expect? thanks for the help. > >Bill Robinson ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################