How put an heatsink

Hello guys,

i have to put a radiator on a componant but i don’t know how to proced. Does i have to had a footprint or i just put some copper on the PCB ?

Ty for help :smiley:

You mean a heatsink? if it will be put on top of a component you need only to check the clearences around that component. If the heatsink needs holes for screws or the like, then a footprint would be in order.

Yeah, but mine is not on the top on the component, He tuch the component from bellow

Add a second symbol / footprint pair or alternatively adapt the symbol / footprint for your original component to include the heatsink (depending on if you want an extra entry in BOM or POS files for the heatsink or not)

Your heatsink looks like:

Eeschema also has a generic symbol for a heatsink you can add to your schematic, to make it show up in the BOM:

I’m far from a Kicad expert, however if there were my project, I would modify the IC footprint to include the copper areas that are shown in you example.

Logic, If done in the footprint, there is little chance they heatsink “pads” can be moved accidentally during the layout.

Also if you try to create a heatsink footprint it will give you ERC check as its overhanging other components.

I just put that AAVID heatsink on a PCB just for fun, and indeed it looks like:

It also has a courtyard defined for the full size of the heatsink, so you can not put any components under it without KiCad complaining…

As it is a separate component which must be ordered, and picked & placed it must be a separate entity in the schematic and on the board. You want it to appear in the BOM, and it’s location in the pick&place file.

Modifying the footprint to include the heatsink is only viable for hand assembly, and even then, it is more work than just putting the thing on the schematic, assigning the footprint and putting it on the PCB.

I’ve seen this heatsink used on the Internet as an example for hard to rework / repair.
AOI (Automatic Optical Inspection) can not look under it to see if the compontents are soldered properly, and if there is a soldering error you almost can not reach it. It may influence soderability of nearby components as it shields IR heat during reflow.

Ty for your help everyone, i’m going to create a symbo/footprint for the component (which is a TO-268 ref: 573400D00010G). (He is not available on footprint library of heat sink and can’t found it on the web, but it look easy to create :slight_smile: )

Can you tell me what is your part number?

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