PSU Heatsink assembly

Morning Guys

Following the lead from one of the mentors on here, I purchased a 0 - 30vdc PSU kit from Banggood including a V & A LCD display.
I've now got the rest of the bits - transformer, enclosure, bananas etc to assemble it and I've also got a heatsink to go with the main voltage regulator.

At one point the instructions says :-

1.The output of the regulator should be noted that when the D1047 is installed radiator,it must insulate circuit, because this circuit are linear regulated power supply, if long-term operate with low-voltage high-current,must ensure D1047 in good heat dissipation.

The heatsink is pictured below A Fischer Electronics 104 38 1STS which according to their website and my calculations is correct for the heat likely. There is also a 60mm cooling fan to go in the rear of the enclosure.

Can you tell me - what does the bit in red mean ? Should I use heatsink compound ? I've also seen some little pads the same size as the chip which appear to go between the chip and the heatsink ? Not done this before and I don't want to melt it before I've had some use out of it !!

I'd appreciate some advice

S

Hi S,
Is the regulator IC already fitted to to the heat sink.?

If Yes, then it means that the metal of the heat sink must not be in a electrical contact with any other part or the circuit.

If No, you have to fit the IC to the heat sink, you must an insulating pad between the IC and the sink.

E

EDIT:
Look at this PDF

Hi E

No the regulator is in the kit but I had to buy the heatsink separately.
I'll get some pads and bushes to suit. Mind you, looking at the PCB there is a line of holes to slot the heatsink into but there doesn't appear to be any kind of contact with the rest of the circuit. I would need to explore with a meter to be sure.
Easier to fit the pad and be certain I guess

Thanks for your help E

Regards
S

E
Just found the .PDF 's. That's great Thank you - printed off and in my info book now !

S

FWIW:

There is a mounting kit available for TO-220 packages. https://uk.farnell.com/aavid-thermalloy/4880sg/mounting-kit/dp/1313880 This contains the step collar, screw, washer, bellville washer, nut and thermal insulator. A Bellville washer is a dome shaped washer that exerts constant pressure with thermal expansion. Usually, you don't deform them all the way.

Use a thin layer of grease. It's tough to remove.

Not all thermal insulators require the silicone grease. A sil-pad does not. It's a rubber like material. e.g. https://www.aavid.com/product-group/interface/pads/insil