> Hi Werner,
>
> Are you referring to the differing thermal coefficients contributing to
> unreliability?
>
> Hi Eric,
> Get a copy of IPC-SM-782.
> But why are you considering LCCs (leadless ceramic chip carriers)? Are you
> mounting them on ceramic? If you are using FR-4 or any other polymer-based
> substrates you can forget about reliabilty in any environment other then a
> really benign one, such as sub-ocean cable repeaters. You could of course
> put
> solder columns on the component.
>
> Werner Engelmaier


Werner,

I'm not considering using LCC we actually do use LCC and have done for some
years. We make CMOS optical sensors so we need to put them in something with a
window in it so the sensor can look out (yes I know there are other ways but
this is the simplest).

We've sold several million sensors/cameras over the last few years in a 48 LCC
pack made by Kyocera. Reliability of the solder joints has never been an issue
although the sensors are invariably mounted on FR4.

Perhaps we get away with it because the sensors generally go into Webcams and
toys.

Regards,




Eric Christison

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