Klondike heatsink sourcing

[steamboat]

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.

[shapemaker]

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

[SebastianJu]

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?

[steamboat]

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

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.

[alfabitcoin]

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.

[dogie]

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.

[steamboat]

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?

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.

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.

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.

[alfabitcoin]

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...

Any idea of cooling requirements for these? The units BFL released into the wild seem to run very hot with large heatsinks. At the risk of getting ahead of myself, once we know the heatsink size needed, custom orders could be placed with a company like, say Heatsinks USA. I have dealt with them in the past when building LED lighting and they are inexpensive and cut custom widths.

The BFL units use a different chip, its not related to the discussion(DIY PCB with AVALON).  The Avalon chip specs you should refer to are here: https://en.bitcoin.it/wiki/Avalon#Chip_Specification

Avalon made a note about heat sinks. "there is a air gap between the die and package top, install a heatsink on chip is useless. and will cause overheating. because the top PCB copper act as a heatsink too. do not cover them."

If the statement applies to this proposed configuration is yet to be determined. I hope burnin is looking into it.

-R

[SebastianJu]

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?

[steamboat]

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...

Any idea of cooling requirements for these? The units BFL released into the wild seem to run very hot with large heatsinks. At the risk of getting ahead of myself, once we know the heatsink size needed, custom orders could be placed with a company like, say Heatsinks USA. I have dealt with them in the past when building LED lighting and they are inexpensive and cut custom widths.

The BFL units use a different chip, its not related to the discussion(DIY PCB with AVALON).  The Avalon chip specs you should refer to are here: https://en.bitcoin.it/wiki/Avalon#Chip_Specification

Avalon made a note about heat sinks. "there is a air gap between the die and package top, install a heatsink on chip is useless. and will cause overheating. because the top PCB copper act as a heatsink too. do not cover them."

If the statement applies to this proposed configuration is yet to be determined. I hope burnin is looking into it.

-R

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.

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?

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.

[SebastianJu]

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.

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://bitcointalk.org/index.php?topic=161715.msg2179575#msg2179575
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.

[bassclef]

Any heatsink would work potentially, however having the holes pre drilled is a huge timesaver.

If Bkk gives the go-ahead that these will dissipate the heat well enough, given multiple boards stacked together and a fan blowing at them, I'm in for at least 50.

[steamboat]

I have outlined the type of heatsink. Please see the OP.
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://bitcointalk.org/index.php?topic=161715.msg2179575#msg2179575
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.

Yes, the thermal vias are necessary to give channels for the heat to pass through to the heatsink. The heatsink physically attaches to the board at the contact patch located directly behind the chips.

The problem with such a heatsink is the ridiculous cost, and hole drilling costs need to be added on top of that.

Also, please note copper standoffs will be required for attaching the board to the heatsink, in order to raise it above the surface of the PCB.

Any heatsink would work potentially, however having the holes pre drilled is a huge timesaver.

If Bkk gives the go-ahead that these will dissipate the heat well enough, given multiple boards stacked together and a fan blowing at them, I'm in for at least 50.

[/quote]
That is correct, there are plenty of options out there, the purpose of the thread is to find the most cost effective solution, which is made possible by buying in bulk.

Sebastian, I think it will work. With thermal compond.

I found pined heat sink with the price of $9,30 for 200-299pcs. (100mmx100mmx25mm) Price for more need to quote request.
I'am not sure will pined heat sink work.... ??

https://www.micforg.co.jp/cgi-local/an/wse4.cgi?webpage=c_n100e.html&cmd=CMD_ITMSEL&itemcode=S001YS05

This particular heatsink is one of the options I am looking at to have custom made holes drilled in. The goal is sub $6 per heatsink.

Edit: quote fail

[SebastianJu]

I have outlined the type of heatsink. Please see the OP.
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://bitcointalk.org/index.php?topic=161715.msg2179575#msg2179575
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.

Yes, the thermal vias are necessary to give channels for the heat to pass through to the heatsink. The heatsink physically attaches to the board at the contact patch located directly behind the chips.

The problem with such a heatsink is the ridiculous cost, and hole drilling costs need to be added on top of that.

Also, please note copper standoffs will be required for attaching the board to the heatsink, in order to raise it above the surface of the PCB.

Any heatsink would work potentially, however having the holes pre drilled is a huge timesaver.

If Bkk gives the go-ahead that these will dissipate the heat well enough, given multiple boards stacked together and a fan blowing at them, I'm in for at least 50.

That is correct, there are plenty of options out there, the purpose of the thread is to find the most cost effective solution, which is made possible by buying in bulk.

Sebastian, I think it will work. With thermal compond.

I found pined heat sink with the price of $9,30 for 200-299pcs. (100mmx100mmx25mm) Price for more need to quote request.
I'am not sure will pined heat sink work.... ??

https://www.micforg.co.jp/cgi-local/an/wse4.cgi?webpage=c_n100e.html&cmd=CMD_ITMSEL&itemcode=S001YS05

This particular heatsink is one of the options I am looking at to have custom made holes drilled in. The goal is sub $6 per heatsink.

Edit: quote fail

$6 per heatsink sounds good... though its a bit strange that even at that price the K16 will cost $35 and the heatsinks for it cost $24... I had thought that such things could be pennyware from china or india or similar. Looks like i had a wrong view.

What do you mean with copper standoffs? I thought the heatsink only has to be flat at the bottom, put thermal paste at it and mount it together with the pcb...

I thought that drilling wouldnt be a big problem. I probably could do it myself in some minutes... marking the holes at the back and drilling... aluminium should be possible to drill very easily.

What i dont like so much at the moment is the inflexibility... one batch has to be ordered, thats it... that means you have to plan everything beforehand which i cant... i dont know how many chips i will buy in total. Thats why i would have preferred if bkkcoins could sell the heatsink together with the sets. So i wouldnt need to plan and i could reorder.

I think i will search a bit now... by the way... the heatsink could be everything from 5cm-the border with the holes at the border... so maybe 4x4cm to 0.1x0.1cm. Ill check if there isnt a very cheap offer.

[sensei]

I've also been looking into heatsinks for this board. 100x100 won't do unless you really want to cover up the standoff/mounting holes.

Something like 3.6 x 4 in is what I was thinking. I priced this out, extruded, but without the 4 mounting holes located in the middle of each group of 4 ASICs is about $4.52 in quantities of 1000 and $5.52  for 500.

The is an estimated per piece without tax or shipping. A group buy would be required which I would be willing to undertake if needed.

[alfabitcoin]

I am confused.
Is it K16 board dimension at 10cmx10cm, price for those for 300pcs are at 9,3$, steamboat will ask for better pricing? So if you have heat sink at 10cmx10cm it goes on one K16 board?

Summary Preliminary Specs:

10cm x 10cm board
16 chips/board
24A 1.2V, 1A 3.3V supply on board (~32W total)
PCI Express Power connector for use with ATX PSU
USB mini type B connector, no power draw
PIC USB micro controller on board with bootloader for USB firmware upgrades
I2C board-to-board, daisy chain connector
Fan 3 pin connector (on board temp sensor and PWM speed control)

[wrenchmonkey]

I have outlined the type of heatsink. Please see the OP.
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://bitcointalk.org/index.php?topic=161715.msg2179575#msg2179575
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.

Yes, the thermal vias are necessary to give channels for the heat to pass through to the heatsink. The heatsink physically attaches to the board at the contact patch located directly behind the chips.

The problem with such a heatsink is the ridiculous cost, and hole drilling costs need to be added on top of that.

Also, please note copper standoffs will be required for attaching the board to the heatsink, in order to raise it above the surface of the PCB.

Any heatsink would work potentially, however having the holes pre drilled is a huge timesaver.

If Bkk gives the go-ahead that these will dissipate the heat well enough, given multiple boards stacked together and a fan blowing at them, I'm in for at least 50.

That is correct, there are plenty of options out there, the purpose of the thread is to find the most cost effective solution, which is made possible by buying in bulk.

Sebastian, I think it will work. With thermal compond.

I found pined heat sink with the price of $9,30 for 200-299pcs. (100mmx100mmx25mm) Price for more need to quote request.
I'am not sure will pined heat sink work.... ??

https://www.micforg.co.jp/cgi-local/an/wse4.cgi?webpage=c_n100e.html&cmd=CMD_ITMSEL&itemcode=S001YS05

This particular heatsink is one of the options I am looking at to have custom made holes drilled in. The goal is sub $6 per heatsink.

Edit: quote fail

$6 per heatsink sounds good... though its a bit strange that even at that price the K16 will cost $35 and the heatsinks for it cost $24... I had thought that such things could be pennyware from china or india or similar. Looks like i had a wrong view.

What do you mean with copper standoffs? I thought the heatsink only has to be flat at the bottom, put thermal paste at it and mount it together with the pcb...

I thought that drilling wouldnt be a big problem. I probably could do it myself in some minutes... marking the holes at the back and drilling... aluminium should be possible to drill very easily.

What i dont like so much at the moment is the inflexibility... one batch has to be ordered, thats it... that means you have to plan everything beforehand which i cant... i dont know how many chips i will buy in total. Thats why i would have preferred if bkkcoins could sell the heatsink together with the sets. So i wouldnt need to plan and i could reorder.

I think i will search a bit now... by the way... the heatsink could be everything from 5cm-the border with the holes at the border... so maybe 4x4cm to 0.1x0.1cm. Ill check if there isnt a very cheap offer.

The heatsinks have to be physically connected to the copper thermal ducts on the board. I'm assuming that the board isn't completely flat on the bottom, so you'll need material to contact the copper thermal layer on the bottom of the board, and conduct it into the heat sink. I personally would prefer either one large heatsink which covers all 16 chips; or even better, water blocks for water cooling. Am I the only person who would like to be able to over-clock these, and not have to run a massive box of fans?

[SebastianJu]

Ok, looks like i made an error... the K16 board is 10x10cm... the cooler is 100x100mm, thats the same dimension... so only one heatsink per K16 is needed... but im wondering too now... 16 chips match on 10x10cm? And when the heatsink is the same size then the 4 holes in the edges not only have to hold the heatsink but the whole pcb too. For example mounted to a rack or something.

[klondike_bar]

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.

agreed. 1mm will also bend if there is too much rough handling during shipping/installation.

I personally would prefer either one large heatsink which covers all 16 chips; or even better, water blocks for water cooling. Am I the only person who would like to be able to over-clock these, and not have to run a massive box of fans?

interesting concept, though for first-gen waterblocks will be overkill. these boards will create less heat then most highend graphics cards, so I would imagine that in an environment with cooler temps and reasonable airflow there would be almost no need to actively cool it at stock speeds. Basic overclocking should be easily dissipated by a 100mm fan if you consider that a 400w GPU is usually handled by 2-3 60mm fans while in an enclosed space.

second-gen would be the time to consider options like liquid cooling

[wrenchmonkey]

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.

agreed. 1mm will also bend if there is too much rough handling during shipping/installation.

I personally would prefer either one large heatsink which covers all 16 chips; or even better, water blocks for water cooling. Am I the only person who would like to be able to over-clock these, and not have to run a massive box of fans?

interesting concept, though for first-gen waterblocks will be overkill. these boards will create less heat then most highend graphics cards, so I would imagine that in an environment with cooler temps and reasonable airflow there would be almost no need to actively cool it at stock speeds. Basic overclocking should be easily dissipated by a 100mm fan if you consider that a 400w GPU is usually handled by 2-3 60mm fans while in an enclosed space.

second-gen would be the time to consider options like liquid cooling

Probably valid points, but fans cost more electricity to run, and they're noisy. Liquid cooling probably IS overkill at this point, but it would allow more units to be stuffed into a case, would be silent, consumes less electricity.

Either way, I've got enough chips already ordered for 5 K16 boards, so whatever's decided, I'll be in for 5. Although, once these are up and mining, I'll be buying more chips, so, depending on price, I'd be willing to order 3-5 times that amount.