> On Feb 15, 7:20 pm, Jeff Thomas <[email protected]> wrote: > I totally agree with Gene. I was hoping someone else would > recognize the phenomenon. A little too much of stress on a > marginal biscuit frit seal, and it begins a slow return to > atmosphere ;)
>From my limited experience with these PCB soldered in socket pins: http://www.mouser.com/catalog/catalogUSD/643/1603.pdf This may always be a major concern. Unlike 'real' sockets where the pins float in the socket housing, these PCB insert type have no lateral play. You're hoping for two things: (1) Your PCB pattern is made to close tolerance, and also the nixie tube base pattern is made to an equally close tolerance, and (2) whatever remaining misalignment, can be accommodated by the elasticity of the pin. Both pretty iffy, and very limited. These can inflict enough lateral stress that can damage the tube. In old style sockets, the socket pin floated in the phenolic base housing, so there was practically no lateral stress on the tube base, at all. My suggestion, unfortunately not immediately applicable in this instance, is for future users of these PCB socket pins. Layout two concentric hole patterns. The inner one being the diameter of the actual tube pin circle. The hole diameters, in this circle, being large enough so that the sockets pins fit very loosely. These holes have no pads. The outer circle ring has holes with pads, but they can be quite small. Small enough to accommodate a 24 gauge (or smaller) solid bare wire. This wire is soldered into the outer hole/pad, and the wraps around the bottom of the socket pin (which is loosely fitted in one of the inner holes). A one to one correspondence for each outer hole/pad to inner hole. Your other board traces connect to the appropriate outer hole/pad. This should emulate the older style sockets. Its a bit of extra work. But the alternative could be an out- gassed nixie tube. And they are getting more expensive. Your choice. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
