Your note suggests that ALL components may become surface mount, but as far as the connector is concerned, perhaps this design may be an "ideal" candidate for intrusive reflow: keeping the connector as a through hole component processed through a reflow environment. The decision may be based on what type of connector this is. Do you have a shielded I/O connector (higher mating/unmating forces)? Is it a high pin count (higher mating/unmating forces)? Is it a tin (versus gold) interface (higher mating/unmating forces)? Is it a "right angle" board connector (higher shear stress)? All of these will affect the stress/strain on the solder joints. If you do go the surface mount route, I'd keep some hold downs on the design. Martha Rupert AMP Incorporated email:[log in to unmask] > -----Original Message----- > From: Michael Lang [SMTP:[log in to unmask]] > Sent: Sunday, June 28, 1998 9:35 PM > To: [log in to unmask] > Subject: [TN] HELP: Cracking Discretes on PCB's > > Hello Technetters, > > I have a PCBA which has been built in PTH configuration with great > success for years. However, due to the need for increased functionality > in the same form factor, it seems that it is time to convert the PCBA to > SMT format. > > My main concern relates to PCB flex and solder joint integrity... > > The PCBA is about 4" x 6". It is held along its 4" sides in a rack. A > cable is plugged into the card via a connector along the top 6" side of > the PCB (NOT a card edge connector, but PTH connector which means you > push against the FACE of the PCBA. I do not know the force, but the PCB > DOES flex significantly. Plus, since this is a home / contractor > product, it does not get handled gingerly... > > THE PRIMARY CONCERN: Inducing cracks in either the components or solder > joints of leadless surface mount components. > > What information exists with respect to this subject? > > > What testing makes sense? What has been done already by others? > > > Any help is appreciated. > > Thanks, > > Michael Lang > [log in to unmask] > > > ps. Hi RH! > > ______________________________________________________ > Get Your Private, Free Email at http://www.hotmail.com > > ################################################################ > TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional > information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or > 847-509-9700 ext.312 > ################################################################ ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################