Heatsinks for A4988

The documentation for the various flavors of the A4988 repeatedly caution about using heatsinks if the current will be over 1.0A.

Could someone post a picture of heatsinks they have used for these chips/boards, or recommend one? Using a heatsink on SMTs is new to me, especially chips like this that have a thermal pad under the chip.

For instance, I have some TO-220 type sinks in my junk box - can I just glue one of those on top of the chip? What kind of glue?

I saw that this question was asked before, but without any direct answers.



I do not know if it could helps you but I found this: bilbycnc.com.au/DisplayProd. … ololuA4988 (end of the page)
It cost 2$ and the size seems ok.

Let me know if you find something better.



Hi again,

I figure out what I am going to do: Use a regular heat sink and cut it to fit the chip. Quicker and less expensive.



Thanks for the reply. I guess am going to use thermal epoxy to permanently mount some kind of heat sink on top of the chip.

BTW, my name is Gary. TIA meant Thanks In Advance.

Consider using thermal tape, not thermal epoxy.

The epoxy would put a lot of stress on the chip whenever someone slightly touches the heatsink sideways.

Its a good point, as long as that will withstand some vibration better than the epoxy.
They sure don’t make it easy! Attached is a closeup of my Black edition A4988, whose higher current capacity is desirable or you probably wouldn’t care about a heatsink to begin with.
Notice the larger brown component all the way to the right? It sticks up lots higher than the IC to be sinked, as well as the current adjuster on the left. Even the header pins sticking up are higher - I’d hate to see what you’d do if you were poking wires in there. This means you have to fab a 5x5mm aluminum plate (about .125 thick would do) to stick on the IC, and then stick the heatsink on top of that! Hopefully you can still reach the adjuster when its on.
Or, if the little one is enough, you can go with the one Dan recommended.

Sorry for being a little late on this. I have been using the Enzotech MOS-C1 heatsink. http://www.enzotechnology.com/mos-c1.htm It is a bit tall, but seems to work. The base is 6.5mm by 6.5mm, just about the same size as the Allegro chip.

They are sold by NEWEGG.com. You can see them here

I hope that helps