SOT-227 water block?

[davygrvy]

Pondering a crazy idea to use four of these in a class-A amp.

I need help with ideas for mounting to a water block. It's a rather standard package style, but no off-the-shelf water blocks nor clamping systems seem to stand out with a quick google search.

Looking for construction examples and ideas. A 250W class-A amp sounds like a fun project

[Alexontherocks]

I opened a thread already

Some thoughts on alternative cooling

I guess a common place to discuss watercooling and audio aplications can be helpful...

Persoanlly I am going for the common rail approach, providing a single water channel inbetween the devices and the finned heatsinks.

P.s. I had a look at the datasheet...an intiial approach could be based on adhesive pads however mechanical pressure and thermal compound would be preferable. It is difficult to accomplis with conventional waterblocks so alternative "blocks" must be used..

[davygrvy]

You rock.. I am not alone.

There's some water blocks here, but they're sized for PECs. I can't really bolt the devices to them either as the holes will extend into the water path. There seems to be a slot in the magnatec dimensional drawings for use with a clamp, but I can't really tell until I buy them.

Hmmm... Still thinking.

In the big wide world, I'm sure there has to be an off-the-shelf SOT-227 water block somewhere.

[davygrvy]

http://www.aavidthermalloy.com/sites...-hicontact.pdf

close.. too wide

[davygrvy]

Not right, but way awesome none the less.

[Alexontherocks]

I really think thre is no other way than either using extrusions or creating large highflow waterblocks from pure copper.

Anyother application would either force construction issues and/or limit the number and size of output devices...

[jcx]

the datasheet shows 4x parallel Q - why not just use 4x of the same Q in more conventional packaging?

are you pushing frequency to beyond TO-247 lead inductance limit? - is the sot-277 any better?

with the lower power density normal solid metal heatsinks work pretty well

[CBS240]

I have some old scrap, 1/2" thick plate of white brass. Using small blocks for one (or multiple) devices, I use thermal mica pads and HS grease to mount the block to a 1/4" aluminum angle bracket, then directly mount the transistor tabs to the block, and energize the block with the rail voltage for the drain/collector. The density of the brass is much higher than aluminum and white brass happens to be an excellent thermal conductor. Mounting the brass to a waterblock would be an interesting idea.

[davygrvy]

jcx,

The BUZ901X4S in the SOT-227 (ISOTOP) package is equal electrically to a pair of the BUZ900DPs in the TO3P (TO-247) package. Sure, I could use double in that package. There's just something cool about them in the bigger ISOTOP one.

When the amp is done, there's going to be three big copper buss bars attaching them and (hopefully) sitting on a copper water block. To me, it has a high 'cool' factor by being different.

[davygrvy]

A pair could fit on this. I'd have to crunch the math for natural convection, but might suffice if I go that route.