Resistors for high soldering temperature

[zedols]

Hello guys,
At first sorry for my grammar I'm not native english speaker.

I have a problem to find appropriate resistor. The main properties should be next:

Resistance: 5 Ohm +/- 0.5 Ohm.
Power rating: 0.5 W - 1 W
Enclosure: SMD type of any dimensions

The main problem is that I can't find resistor which will be able to survive temperature 340 °C for at least 20 minutes without any failure or property changes. The soldering will be provide in soldering oven on power hybrid DBC wafer. If you have any solution ideas or knowledge of any supplier in this field, please contact me :)

Best regards
Lukas

[ArakelTheDragon]

Your first problem is that you want it to be "SMD". Use through hole it provides better cooling. Get a 2W resistor and check its ratings on "components supplier". If it can not be used, get a "5W" resistor or you need to cool down the resistor somehow. There are even 100W resistors if the space is not a problem.

[zedols]

Thanks for the answer!
Yes the space is big problem here. This smd will be used in belt production that's why through hole resistors does not come into consideration. Due to DBC wafer connection must be provided on the top of substrate. I can only use through hole if it would be some 'home bastled' device but not in certificated product.

[ArakelTheDragon]

Another option is a cooling system, use the box of the PCB as a cooling system, make it metal and add an external cooler, or add an internal fan if its enough and does not interfere with the work of the controlled oven.