Heat dissipation in a DIP Solid State Relay

I am working on an application that switches a high power (15 W typical, 100 W maximum) resistive load at 230 VAC (RMS) from a 5 VDC control line. For this I plan to use a Solid State Relay. I am currently planning to use the AQH3213A from Panasonic, but I am concerned about the heat dissipation of the part. The load will be switched on regularly anywhere from a few seconds to a few minutes. I performed the following calculation for power dissipation under maximum load conditions:

$$P = I_{Load}\bullet V_{TM}$$ $$= 0.435 A \bullet 2.5 V$$ $$=1.09 W$$

However the datasheet (or any other information I've been able to find from Panasonic) does not list any thermal resistance values for the DIP package the SSR uses.

How can I figure out how hot the SSR will get under maximum conditions, and whether I need a heatsink? Furthermore how could I effectively heatsink a DIP 8?

• figure 1 in reference data says you're golden. it doesn't say how hot it will get, but implies that the temperature will be less than 125C (max storage temperature) I would expect well less than 80C at 25C ambient. – Jasen Jun 26 '17 at 8:09
• heatsinks don't wore well on plastic covered parts. – Jasen Jun 26 '17 at 8:14
• @Jasen Why not? There's a ton of heatsinks available for single-board computers which typically have the CPU packaged in a plastic BGA. – Dmitry Grigoryev Jun 26 '17 at 8:24