TIMs

Question 1

Four factors that affect TIM performance

Answer 1

• Roughness & flatness of both surfaces
• Force between surfaces
• Distribution of force
• Temperature

Question 2

Types of TIMs

Answer 2

• Grease: currently the go-to for common electronics heat sinks
• Phase change materials (PCMs): somewhat more reliable than greases, usually slightly worse performing
• Gap pads: good for surfaces with tricky tolerances that don’t require great thermal resistance
• Solid interface films: not sticky, will not dry out. Performance generally not as good as greases, requires a high pressure.
• Thermal epoxy/tape: Attaches surfaces to each other, has some manufacturing difficulty (epoxy = resin + hardener)
• Gap filler: dispensable, for uncertain gaps
• No TIM: for low heat fluxes, sometimes you can just do without

Question 3

Is Gallium a good candidate for TIM with aluminium?

Answer 3

Gallium is highly corrosive to aluminum, sometimes within minutes-to-hours

Question 4

What is TIM?

Answer 4

thermal interface material