AVR-Chat

I believe you're right; don't attempt to solder the crystal case.

I have used a dab of RTV silicone sealant to hold crystals in place if I was
concerned about vibration. Also, a tiny piece of double-sided adhesive foam
rubber will hold things like that down indefinitely. Just make sure any
oil/grease/dirt are removed from both surfaces (I use rubbing alcohol)
before putting on the tape.

Zack

On 12/31/08, George <buggiesmith@gmail.com> wrote:
>
>   --- In AVR-Chat@yahoogroups.com <AVR-Chat%40yahoogroups.com>, "Steven
> Hodge" <stevehodge@...> wrote:
> > am I supposed to solder the can to the big pad under it also?
>
> I dont know the particulay crystal but most 32k watch xtals are in a
> tiny cylindrical metal case. If it is one like that then do not
> attempt to solder it. It may be aluminium anyway which will be next to
> impossible to solder. The heat will likely damage the crystal. The big
> pad is probably to stop you putting any other pcb tracks under the can
> which would short circuit them.
> My suggestion is to use a blob of light glue (e.g. somthing out of a
> tube for general purpose office/home use) to hold the body to the pad
> to prevent mechanical vibration. Don't use anything like bathroom
> sealant which is nice and rubbery but contains an acid which could
> cause damage.
> USe something you can peel off with a knife when you want to re-use
> the crystal for the Mk II pcb...
>
> luck,
>
>  
>


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