Ian, Effectively, this kind of PCB are only used with stable mechanical support (generally machined RF enclosures). The "optional" breakable part of the PCB is considered like a "totally" independent print with it's own mechanical fixation; holes have sufficient tolerances in diameter to avoid constraints. The only precautions are taken during components placement, soldering, initial test and transport, In fact, it is as if we had 2 well fixed independant PCB connected by some resistors.
Have a nice day, Rudolf ----- Original Message ----- From: "Ian Wilson" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Wednesday, June 26, 2002 10:19 AM Subject: Re: [PEDA] PCB breakoffs > On 08:15 AM 26/06/2002 +0200, Rudolf Schaffer said: > >Hello, > > > >In this case, we use v-grooving and SMD 0 ohm > >with a convenient foot-print, for each > >net (if not too many!) crossing over. > > > >We naturally have 2 "plans d'implantation" depending > >upon the cutted/non cutted PCB part. > > > >Have a nice day, > > > >Rudolf Schaffer > > Rudolf, > > I am intrigued by this. > > How do you prevent flexing of the board from transferring stress onto the > small surface mount resistors and cracking them or the solder joints? A > V-groove flexes at quite a sharp angle. (by design). I guess some thing > like this would never be used in anything but very stable controlled > environments. > > Actually now that I think about it this stress is a problem also for the > routed/break-off tab implementation but maybe the copper is a little more > malleable than those ceramic resistors. > > Ian Wilson > > > > ************************************************************************ > * Tracking #: 533015C9F8865B4F90F49353E155EDDCD7B65F11 > * > ************************************************************************ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
