# Choosing proper heat sink for a high power relay

I'm using this Solid-State-Relay to transfer 350 Watt:

Input: 45VDC x 10A
Output: 10VDC x 10A

The following is derived from it's data sheet:

Maximum junction temperature 150 C
Junction to Ambient 30 C/W
Junction to Case 7 C/W

In order to keep it's features from changing because of a high temperature, I'd rather for it to have a maximum temperature of 50 Celsius degrees.
The ambient temperature is 25 C.

A simple calculation shows that a proper thermal resistance of a heat sink for this job is: (50-25)/350 = 0.07 C/W which is crazy!!!

What do you suggest for me to do in order to keep the device below 50 C ?
Would it be unrealistic to use this kind of component for this kind of task?

• Have you considered using multiple devices? – Ignacio Vazquez-Abrams Sep 1 '13 at 20:32
• @IgnacioVazquez-Abrams: Multiples of the same SSR? Thought of that, but I think it's not reliable. Not all of them would work synchronously (one will pass power before the other etc). Do you think it's a good solution? – Dor Sep 1 '13 at 20:37