I want to monitor the temperature of a large peltier element's heatsink to control a fan. I think I'm going to use a DS18B20.
The 3 pin TO-92 looks like it's plastic, so I'm already worried about low thermal conductivity.* However, how should I secure this to ensure that the chip has the best thermal conduction? Thermal paste crossed my mind, but it'd be pointless to add that with plastic unless there is a big gap there.
I haven't picked out a heatsink yet, but there are plenty of them with a fairly large, flat surface that I could attach the sensor to if I needed. However, I can't glue it onto the heatsink because most glue doesn't conduct heat.
*They make thermally conductive plastics that can insulate (electronically), so the point about the plastic might be moot.