[MTCB Hardware Development] CaptShaft:
Hello folks!

Someone else here on one of the other threads remarked about adding a heat sink to the CPU for these car stereos.

For my part, I haven't opened up the case itself yet, however from the pictures I have seen of various people doing hardware mods on the radios, it appears that there is very little in terms of a heatsink on some of these radios. Which is to say, nothing at all. It may depend upon your manufacturer.

I find this rather surprising as it is a poor design practice. Not every car dashboard will have adequate ventilation, and it seems to me that some of the folks manufacturing these units are cutting corners. This is not surprising since these car stereos are on the “bleeding edge” of the technology as it stands presently, and the manufacturers are doing it on the cheap. There is not much in the way of “mainstream” android car stereos from big-name manufacturers, currently.

I'd like to give you a couple links for some heatsinks should you wish to add them.

For starters, the RK3188 is a SMD [surface mount device] package of type TFBGA453LD. This microchip is nominally sized at 19mm x 19mm square, plus or minus a small tolerance. Keep this in mind.

A starting idea is to use heatsinks for the Raspberry Pi board. These heatsinks are on the order of 14mm square or so, smaller than the RockChip package, but still good enough to do the job. Here's a passive heatsink:

https://www.amazon.com/Gdstime-Aluminum-Heatsink-Raspberry-Xbox360/dp/B00ZZ9P3QC/

Here's another that comes in sets of large and small heatsinks:

https://www.amazon.com/Aluminum-Heatsink-Cooler-Cooling-Raspberry/dp/B010DG5GM2/

This is good for attempting to cool multiple chips on the board.

Here’s some black aluminum 22mm x 22mm x 10mm heatsinks which ought to be a perfect fit:

https://www.amazon.com/10Pcs-Black-Heatsink-Aluminum-Cooling/dp/B00MJVPA2Q/

You could also use some 30 mm x 30 mm VGA heatsinks. Since these are larger than the chip package size, I’ll leave that to you to research. I don’t suggest them due to their size, and the possibility of potentially shorting out a component next to the CPU during the mounting process. You can do this as long as there are not other components in the nearby vicinity which are sticking up higher than the CPU. Also, check your vertical spacing should you have a stereo with a disk drive in it. The last thing you want is to add your heatsink, then find out the hard way you can't re-assemble your stereo! :crying:

You shall also require some thermal adhesive, for applying the heatsink to the CPU. (Unfortunately there are not any screw receptacles for securing a heatsink to the CPU socket with threaded fasteners.)

http://www.amazon.com/Arctic-Silver-Alumina-Adhesive-AATA-5G/dp/B0087X725S/

Above is a two-part epoxy that is thermally conductive. Use only a very small amount! It will flatten out in no time, and you don’t want too much of the “goop” running out the sides and shorting out traces around your CPU.

You can also acquire some 30 mm x 30 mm cooling fans to get some airflow throughout the entire unit.

https://www.amazon.com/Alpha-Omega-Case-30mm-3-Pin/dp/B000BSJGMO/

The idea behind using this is you would drill Ø1” or Ø7/8” hole on the back side of the stereo case using a hole saw, and then transfer some tapped holes for mounting. You would then have to splice the power wires onto some 12 V leads coming into the stereo. I throw this thought out because I have seen at least one OEM stereo that has a cooling fan built into the back of their stereo. If you go this route, you want the fan to push the hot air out of the back of the unit, otherwise you may get some whistling noises through the front or sides. (You might end up with such noises in any case due to the speed of the fan.)

Here’s another two fans that may fit in this application:

https://www.amazon.com/20mm-Turbine-Brushless-Cooling-Blower/dp/B00LG0EJFK/

https://www.amazon.com/Vktech-Brushless-Cooling-0-1-0-3A-50x15mm/dp/B00EL938E6/

That’s all! Best of luck to you!