Matthew- As for where to get depanel tooling... Wand Tool does a great job. -Chris "Hybiske, Tom" <Tom_Hybiske@BOS To: [log in to unmask] E.COM> cc: Sent by: Subject: [DC] How to break off IPC mouse bite DesignerCouncil breakaways ?? <DesignerCouncil @IPC.ORG> 06/26/02 11:22 AM Please respond to "(Designers Council Forum)"; Please respond to "Hybiske, Tom" Matthew, For prototype runs and pilot runs we use a simple plastic fixture with a milled groove the thickness of the board and the depth of the breakaway. The operator places the edge into the grooved fixture and levers the breakaway off. It produces a very clean break and is also very efficient. For high volume runs, we switch to shears. Tom Hybiske Bose Corporation The Mountain Framingham, MA 01701 > -----Original Message----- > From: Matthew Lamkin [mailto:[log in to unmask]] > Sent: Wednesday, June 26, 2002 10:54 AM > To: [log in to unmask] > Subject: Re: [DC] How to break of IPC mousebyte breakaways ?? > > > Hi there Chris, thanks for the reply, > > What is puzzling me is, > These break off tabs, when manually broken off instead of getting a > depanelling machine > is the stress to the board, less than cutting an ordinary > routed tab with > cutters? > > Either way I can see the board stressed, and yes placement of > ceramic caps > is thought about, but does > anyone know anywhere on the net where possible studies have > been done on > breakoff tab stresses etc? > > The reason I ask this is because we do not have (and I doubt > if we would > get) a depannelling machine that > will break these tabs. > > We do relatively small volumes and use FR4 only. > > Most boards get scored where possible, but some have > overhanging connectors > that need tabs instead > and I want to find out the very best method of supporting > them in the panel. > > Also, is there any spec on the ordinary tab, how thick the > centre should be > etc? > > Actually, thinking about it, if we were to get a depannelling > machine, what > sort should we get? > > Thankyou - Matthew Lamkin. > > > -----Original Message----- > > From: [log in to unmask] [SMTP:[log in to unmask]] > > Sent: Tuesday, June 25, 2002 2:14 PM > > To: [log in to unmask] > > Subject: Re: [DC] How to break of IPC mousebyte breakaways ?? > > > > Hi Matthew- > > Never saw a reply to this so I'll give it a go. My advice > is; if your > > volumes are at all significant, don't do the by-hand or pliers thing > > unless > > you can lay the board out such that components, solder > joints, and small > > traces, are REALLY far away from the breakaways. Especially > X7R caps. We > > recently saw a problem where a cap more than 5MM from a breakaway > > sometimes > > cracked even though we were using special tooling for > singulation. Turned > > out that it was happening during ICT due to flexing. Easy > to fix at the > > ICT > > process but points out the potential for problems associated with > > breakaway > > tabs. > > > > Low tech material like CEM-1 will often delaminate badly around the > > breakaway if done by hand (or pliers). > > > > We use punch and/or shear tooling, routers, or Vscore, but > all our stuff > > is > > pretty high volume. > > > > Lastly, I've never seen a plated hole used on a breakaway tab. > > Regards, > > -Chris > > > --------------------------------------------------------------------------------- DesignerCouncil 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 DesignerCouncil. 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