Does have anyone have any links to resources they can share that give any kind of figures for thermal resistance (Rth) for surface-mount resistors?
I am considering using a 2512-size SMD resistor as a minimum load on an otherwise-unused power supply rail (my board will only load one rail, and I'm concerned the PSU may not regulate well if there's zero load on the other rail), but I'm not sure whether thermally it's going to work well. And of course, to ascertain that I need some kind of idea what the thermal resistance of a 2512 resistor may be.
I plan to dissipate about 1.5W from the resistor. I think that might be okay for a 2W-rated resistor - given that rating is typically at 70C ambient, and I'm only concerned with room-temperature operation. Although, I guess suitability depends on how hot it's going to get. Most 2512 that I see are rated for 155C operating temp, but I don't want to get anywhere near that, if at least for the sake of PCB material rating (e.g. common TG130).
The reason why I want to use an SMD resistor is because of space constraints. I thought about using 3W through-hole resistor, but I don't have enough board space in the layout. Can't mount one vertically either due to height constraints.