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Topic: Klondike - 16 chip ASIC Open Source Board - Preliminary - page 152. (Read 435369 times)

legendary
Activity: 2674
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Legendary Escrow Service - Tip Jar in Profile

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Since you already will place big orders of parts... can you imagine to check out a passive cooling solution for the boards? So that in case a customer wants to go the easy way he can buy the cooling from you? I guess you would be in the best position to lower the prices through mass-order. I can imagine 4 cooling parts for 4 chips each... putting them on top of the chips or on the other side of the pcb when this is better.

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Sebastian  -  All good points! I just wanted to make a clarification about the heatsinks. These ASICs dissipate their heat from the under side of the ASIC. Direct word from Avalon is that a heatsink should NOT be placed on the top of the ASIC (even with an under-mount heatsink). Has to do with the internal structure/air gap/some-such. This information is posted somewhere...I just don’t have time to go hunting for it right now.


I remember this... i believe they created it this way so that they can add the heatsink on the other side of the pcb... but i wonder if it would hurt the asic when another heatsink would be directly on the chip. I mean cant this lead only to even more heat dissipation?

Another pcb-assembling-noob-question... how long will a normal experienced user take to assemble a k16-board? Maybe after he had created the first boards successfully. Im asking myself if a reasonable amount of pcbs can be done by one person alone or if i have to search for help because the amount of time needed is more than it makes sense...

Perhaps BKKcoins can recommend someone from his country?

I'm assuming assembly in Thailand would be ALOT cheaper then in the US or EU.

Interesting question... and another way for bkkcoins to earn some money. Plus i think way way more users would use his service then because many fear the DIY or finding an assembler.
hero member
Activity: 756
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Perhaps BKKcoins can recommend someone from his country?

I'm assuming assembly in Thailand would be ALOT cheaper then in the US or EU.
legendary
Activity: 1806
Merit: 1090
Learning the troll avoidance button :)
Sounds interesting keeps watching  Grin
newbie
Activity: 21
Merit: 0
Phew, I'm finally able to post in other places then the n00b forum.

I would be interested in having an assembly company build a few boards for me in the US (sensei's guys?) depending on how much they charge.
it seems like I would be able to assemble my own boards pretty easily either from a kit or from parts ordered from digikey or somewhere like that directly. I've been watching smt soldering tutorials and reading what I can, seems like it's something a home user can handle, although you probably don't want to build too many boards before it becomes tedious.

I guess I better jump on an avalon group buy and try to grab say 64 chips.

Nice work BKK, your efforts are appreciated.
newbie
Activity: 11
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Sometimes they use Kaplon or Mylar cut by laser. Not sure of benefits of one over the other. But the cheap one I saw was a polyethylene synthetic paper, which apparently works also and was cut by regular vinyl cutter.

I've seen Kaplon/Mylar ones for $35 on some US site, and the synthetic paper one was $10.

Kapton has a very high melting point and as a result when cut with a laser it doesn't warp as easily, making it a better stencil. I have reballed BGAs using a Kapton stencil to keep the balls in place when applying heat.
member
Activity: 80
Merit: 10

...

Since you already will place big orders of parts... can you imagine to check out a passive cooling solution for the boards? So that in case a customer wants to go the easy way he can buy the cooling from you? I guess you would be in the best position to lower the prices through mass-order. I can imagine 4 cooling parts for 4 chips each... putting them on top of the chips or on the other side of the pcb when this is better.

...


Sebastian  -  All good points! I just wanted to make a clarification about the heatsinks. These ASICs dissipate their heat from the under side of the ASIC. Direct word from Avalon is that a heatsink should NOT be placed on the top of the ASIC (even with an under-mount heatsink). Has to do with the internal structure/air gap/some-such. This information is posted somewhere...I just don’t have time to go hunting for it right now.
legendary
Activity: 2674
Merit: 1083
Legendary Escrow Service - Tip Jar in Profile
I want to see you rewarded. I think the ultimate test would be the sample miner anyway. But i think the sample chips will be a few only, so probably you need to think about how to test a board with only some chips on it.
I think I've figured out how to make the board auto-detect how many chips are installed. At this time I believe you'll be able to have anywhere from 1 to 16 chips on a board and it will mine with whatever is present. This kind of depends on the protocol specs coming soon, but if things go as I expect then this will be possible, and I'll write the code to support this functionality so that people can install more chips as they get them.

Also, the I2C daisy chain will auto-detect how many boards are connected. I've got that worked out regardless of Avalon specs. Smiley

( As an aside, I'd like to know if using silver epoxy solder available at some electronics shops is viable for on the fly upgrades. It may be easy to paint a little bit on the QFN tabs and then carefully place and hold until hardened. My question would be heat transfer - whether silver/epoxy will conduct enough heat? )

Have updated original post now.

*g* Great news... your design gets more and more perfect.

We would need solder stencils with and without the ASICs in place as I bet a fair number of boards will be assembled without the ASICs and it would be better when placing the ASICs on unpopulated boards to have clean pads instead of solder puddled up on the pads.
When I get further along I'll be testing my computer cutter with synthetic papers to make stencils. I've had this thing for a couple years and never used it hardly. I have read online this works quite well for short runs, and at least one vendor sells this type for $10 each. Real stencils (steel) are quite expensive and would be worthwhile for someone doing a larger assembly run (these can be had for $70 in China).

With this cutter method you use postscript output to create the stencil so I can provide such a file with/without ASICs later on github. If this cutting method works well enough then I'll either include a stencil with each kit order or make it an optional item for a low added cost. A stencil without ASICs could have a separate footprint of a single ASIC to be used individually.

Would be really cool if that works out. The stencil is one of the things i worry about.

Since you already will place big orders of parts... can you imagine to check out a passive cooling solution for the boards? So that in case a customer wants to go the easy way he can buy the cooling from you? I guess you would be in the best position to lower the prices through mass-order. I can imagine 4 cooling parts for 4 chips each... putting them on top of the chips or on the other side of the pcb when this is better.

Zefirs first batch was bought on april 16th. 4 weeks after he should get the sample chips. A week later you probably will get sample chips for testing. Hm... in fact 4 weeks were over yesterday... i hope the samples arent delayed much longer.
Anyway... in case you get the chips, you test the boards maybe a week, testing, tweaking and so on... and when its ready you order the pcb and the parts. Can you already say how long it will take to produce the pcbs and receive the parts so that you can ship them? Its only that i need to save bitcoins for that time then.
Or maybe you plan to collect the bitcoins before? In this case... when will you start collecting?
full member
Activity: 176
Merit: 100
I can't install KiCad and check the layout right now, will in the next few days.

Was wondering about bringing the power and control to each ASIC though cuttable traces so people can bypass/isolate dead chips?  Or in pairs perhaps?
sr. member
Activity: 420
Merit: 250
So that's about 25% more, without shipping and import levies.

"Please note: this is for ONE board assembly with 16x chips without delivery costs for EU." Its only a prototype price.



Yes ONE, but I don't suppose you'll get "singles" orders. What would be the price for 25+ ?

Just have asked the team. Waiting for reply. Smiley
hero member
Activity: 686
Merit: 500
That seems good.

If there are many local options like this then the real savings in time and shipping / import taxes will be where these DIY avalons will beat the competition. No more waiting in a pre-order limbo either. Also if you can add reflow for the asics to that with heat sink let people get their own PSU I think you will see more people opt for this method.

Price comparable and time is lessened which makes all the difference. What I am keen on is January 2014 when I bet something gets unveiled... heck maybe even a small hint at the bitcoin conference from Avalon might even happen.

So will you be do this Chefnet or are you just giving everyone idea on prices?

yes I want to do so, but I have to do some crowdfunding for the initial costs (prototype) or we do it together.
With this method compared to the manual one we will have a very high quality. The other + point is all is done via a company and there will be an invoice with/out vat what make guarentee easier.

Normal time for a prototype is 2 -4 weeks because of the distributors and the inital pattern. after that it depends on the time for the assembler and the ordered pieces for the board.
sr. member
Activity: 350
Merit: 250
dont we all m8 lol

KS
sr. member
Activity: 448
Merit: 250
* evilscoop pokes ks
it'll be cheaper on bulk through one of the assembly threads, thats for sure Wink

Just need 10K chips now... Smiley
sr. member
Activity: 350
Merit: 250
* evilscoop pokes ks
it'll be cheaper on bulk through one of the assembly threads, thats for sure Wink
KS
sr. member
Activity: 448
Merit: 250
So that's about 25% more, without shipping and import levies.

"Please note: this is for ONE board assembly with 16x chips without delivery costs for EU." Its only a prototype price.



Yes ONE, but I don't suppose you'll get "singles" orders. What would be the price for 25+ ?
hero member
Activity: 784
Merit: 1009
firstbits:1MinerQ
I saw a vendor selling stencils for $50, but I assumed they were steel. Steel stencils are the only ones I've ever seen. So possibly they were mylar or something else. Seems expensive for mylar though. Is that what non-steel stencils are made of?
Sometimes they use Kaplon or Mylar cut by laser. Not sure of benefits of one over the other. But the cheap one I saw was a polyethylene synthetic paper, which apparently works also and was cut by regular vinyl cutter.

I've seen Kaplon/Mylar ones for $35 on some US site, and the synthetic paper one was $10.
newbie
Activity: 20
Merit: 0
I saw a vendor selling stencils for $50, but I assumed they were steel. Steel stencils are the only ones I've ever seen. So possibly they were mylar or something else. Seems expensive for mylar though. Is that what non-steel stencils are made of?

They can make them out of a nylon screen sort of like a silk screen for t-shirt printing. That type needs a wood or metal frame and the screen with the stencil you want to use is stretched and attached to the frame.  You either manually align the screen and board or use a machine that holds the board and screen in alignment
sr. member
Activity: 420
Merit: 250
So that's about 25% more, without shipping and import levies.

"Please note: this is for ONE board assembly with 16x chips without delivery costs for EU." Its only a prototype price.

full member
Activity: 378
Merit: 100
I saw a vendor selling stencils for $50, but I assumed they were steel. Steel stencils are the only ones I've ever seen. So possibly they were mylar or something else. Seems expensive for mylar though. Is that what non-steel stencils are made of?
newbie
Activity: 20
Merit: 0
If you are going to offer stencils, it would probably be helpful to people to include the location of any through holes to use as alignment makers.  That way people without a Stencil8 or similar setup wont have to fiddle to much with aligning their boards.

KS
sr. member
Activity: 448
Merit: 250
So that's about 25% more, without shipping and import levies.
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