Topic: Klondike heatsink sourcing - page 4. (Read 11721 times)

Sorry, i overread the setting. So its 4 heatsinks for each K16 board.

I now found what i referred to with the holes under the chips... Its this post: https://bitcointalksearch.org/topic/m.2179575
If i understand it correctly it means the holes are filled with heat dissipating stuff so that the chip can connect to the heatsink. The heatsink doesnt have to reach to the chip, its already done in the pcb.

I dont think that asking for prices for different quantities is bad business behaviour. Often they will give a list with quantity to create and the attached price to it. I thought that you maybe have such list.

Forgive my noobness but whats the problem with such heatsink for example: http://uk.farnell.com/h-s-marston/890sp-01000-a-100/heat-sink-100mm/dp/4105977
Its the first result searching "heatsink 100mm". Wouldnt it be possible to drill in the needed holes to attach it at the pcb? I mean the pcb on the other side is flat, theres no parts built in.
The price for these arent low though... i only wanted to ask why such things wont work.

This is correct. The chip package has an air gap between the chip and the package top. This is why placing a heatsink on the top of the chip would not work (this is also why you can see the chip when you open the case). Instead, they chose to route the heat dissipation through the board to the backside, where they have mechanically attached an enormous heatsink to dissipate all the heat. The following picture shows this heatsink installed on the backside of the PCB.




While I have experience with chip cooling and heatsink requirements, and I know how to read a thermal graph, I am not the only one working on this. I have been working closely with BkkCoins since the beginning to tackle several of the logistical concerns regarding this design.

I have outlined the type of heatsink. Please see the OP.

BkkCoins did not place the hole under the chip. This is impossible. He placed 4 holes on the corners of the board, and a hole in the center of each 4 chip cluster for mounting the heatsink. Without a corresponding hole in the heatsink, there is nothing to attach to. Again, there are no holes under the ASICs.

I need to have a rough estimate for the amount of heatsinks required before I move forward. Asking for a price range between 500 and 5000 heat sinks implies a lack of organization and business plan.

I am speaking with manufacturers in China and the US.

Please reference How heatsinks work for questions regarding basic heatsink properties.

I would like to know if you did the design and if you are experienced in this field (airflow, heat dissipation and so on...).

And i would know what kind of heatsink it will be... one heatsink for a K16 board or 4 heatsinks for a K16 board.

What i wonder is... i understood it the way that bkkcoins makes holes in the pcb under the chips... so that the heatsink can connect to the chip to shuffle away the heat. So the holes for mounting are other holes in the pcb? I only ask because i only have read about the holes under the ASIC's.

Could you say a price per heatsink per ordered quantity?

Edit: Where would the heatsinks be produced, i mean in which country?

Okay, you know better. I just repeated what has been said on bkk thread.
Heatsink goes on the other side, is it?
Here is a copy...

Many of us have personally spent hours searching for a pre-made solution and have not found one. If you have any leads, please let me know.

I am based in Florida, USA. Different shipment locations may be arranged within reason. Ex. the batch split into three parts, with shipments to BkkCoins, Myself, and an EU member.

I am working on pricing now. I cannot get solid numbers without a quantity.

Heat sink holes are necessary to attach the heatsink to the board via the holes BkkCoins has provided.

No. The heatsinks are much too heavy to rely solely on thermal compound for a secure fit. This also puts great pressure on the ASIC chips themselves, and can result in them popping off the board.


Heat sinks work by increasing the surface area of the chip for greater heat dissipation. In order to function, the heat sink must be in contact with the surface of the chip, with no air gaps. The heat sinks Avalon used are attached directly to the backside of the chip.

Every board will require a heat sink. The chips do not have enough surface area to dissipate the heat quickly enough, and will overheat.

Are you sure you want 1mm fins? That'll be very, very sharp. Additionally only a 3mm base isn't much heat storage at all, might want that thicker.

I think there is a small gap between asic and pcb. Why just do not cool it like avalon design e.g. board is placed in separate housing with fans?

Of course, somebody who want only one board heatsink is the way to go.

I don't have the schematics or requirements for burnin's boards. The hole layout and thermal requirements are based on the Klondike board. If he would like to send me that information I can check it out and see if its possible.

One concern with multiple mounting holes is where they would fall on the board in regards to chip placement.

Additionally, more holes will increase the price, though this may be offset by higher quantities.

Is there really no heatsink out there that will match? I mean there are a huge amount of different models isnt it?
Where are you located again? Or where would a buyer get the shipping from?
Whats the price in which quantity?
And you mentioned drilling holes. I believe bkkcoins wrote that the pcb will have holes so that a heatsink could connect through the pcb and attach to the asic for heat dissipation. Why are holes needed? Wouldnt it be sufficient to make them at the back of pcb with thermal compound?

I suppose this won't work with burnin's boards? Could the stock be chosen such as to be usable by both projects?

I am speaking with manufacturers to have heatsinks made for the Klondike board. Having heatsinks made is going to be less expensive than purchasing and modifying any current solution. I need to know who is planning on purchasing boards, what quantity, and whether or not they would want a heatsink.

Specs are:
100x100x25mm
3mm base
1mm fins
2mm spacing
6000 series aluminum
4 mounting holes drilled, located in center of each 4 chip group.
Flat base/underside

This is a one time deal. Enough heatsinks need to be purchased to cover all the boards, with a few extra. Purchasing additional heatsinks in low quantity will be prohibitively expensive. These heatsinks will not be made available to the general public. They will only be made available to those offering bulk purchasing as I cannot sell these piecemeal. I will be offering them as part of a package to those who purchase chips through me.

Group buy coordinators, Large private buyers, and Klondike resellers need to contact me ASAP.