Below are the questions asked during the event, along with their respective answers.
Q: TE cooling means to remove heat from hot component level to heatsink level more efficiently. During this cooling process, some heat is generated from electronic power consumed on the TE cooler, and those heat eventually also need to be dissipated to the environment through the heatsink. So, is it true that the thermal burden on the heatsink is getting higher for the TE cooling system?
A: Yes, the heat rejected into the heat sink is (Qc + Pin), with Qc being the cooling power at the cold end and Pin being the electrical power to the thermoelectric.
Q: In TF devices, is the cold side assumed as an ideal heatsink or just kept at constant temp in the simulation?
A: In our design and analysis we do not idealize the heat sink or boundary conditions for the heatsink. We will use tested data or CFD modeling with conjugate heat transfer models to accurately represent the spreading and conduction from the TE device into the heat sinks.
Q: Are there limitations for high duty-factor thermal cycling to locally cool high dissipating components for thin-film devices? Specifically, thermo-elastic fatigue.
A: There are no major limitations. Thin-film devices have been cycled at high frequencies (~1 kHz) and pass Telcordia GR-468 standards without issues
Q: Can you give an example of the power generated when a Peltier device is used as a power source?
A: The power generated is a function of the temperature difference across the TE. In fact, the power is proportional to DT^2, so the larger the DT, the more power. So the power generated can range from mW to kW or higher depending on the application and the environmental conditions. Contact us for a more detailed discussion about your application.
Q: Is published data available for the amount of power that can be generated as a function of delta T?
A: Yes, there are published data and standard equations for how much power can be generated as a function of DT. The power generated is proportional to DT^2, so the larger the DT, the power will increase by a large amount.
Q: Are thin-film devices commercially available or are they still in the design maturation phase?
A: We are still in the development phase but plan on having commercially available products in 2020.
Q: Would these thin-film coolers have to be incorporated into a chip that I’m having heat dissipation problems with?
A: The thin-film devices will be a standalone device that would go between the device being cooled/heated and the heat sink just like a standard bulk thermoelectric device. The thin-film technology could offer integration at the chip level, but that will be in future generations.
Q: How is the thermoelectric device attached to the heat source and sink?
A: The thermoelectric device is usually secured to the heat sink and the device being cooled/heated by mechanical means such as screws or spring-loaded fasteners or the thermoelectric device could have a metalized surface and the heat sink or device being cooled/heated could be soldered or epoxied. The important factor is that in order to minimize contact thermal resistances, the thermoelectric and the heat sink or device being cooled/heated need to be well coupled and also depending on the application the thermal interface may need compliance so that thermal/mechanical stresses do not damage the thermoelectric or device being cooled/heated.
Q: How are the thin films grown?
A: Sheetak used PVD processes for growing the films.