Thin flexible multilayer PCBs are available since the seventies. Applied in most NATO jets circuitry. Allow for 90° bends. Mylar I think. Not sure about 180° folding them (from international aerospace exhibitions visits, like Farnborough and Le Bourget). So I wonder if flex ones crack too. jd _____ Van: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] Namens George Herbert Verzonden: woensdag 20 november 2013 22:17 Aan: arocket@xxxxxxxxxxxxx Onderwerp: [AR] Re: "How Hard Can It Be" rocket episode I'm more worried about boards cracking, solder joints between chips / SMT components and the board cracking, etc. On Wed, Nov 20, 2013 at 1:13 PM, Keith Henson <hkeithhenson@xxxxxxxxx> wrote: > From: George Herbert <george.herbert@xxxxxxxxx> snip > Some of my lawn-dart style manned capsule landers kept G-loads to 10 Gs or > less for the crew. That should be within tolerance bands for electronics, > though one needs to look at the specific equipment. Back in the early 70s part of the testing protocol was to spin bonded chips at 10,000 g upside down to test that the bonding wires didn't come off. -- -george william herbert george.herbert@xxxxxxxxx