spartan/virtex 6 + ddr2/3 ?

Topic: spartan/virtex 6 + ddr2/3 ? (Read 41498 times) previous topic - next topic

Re: spartan/virtex 6 + ddr2/3 ?

Reply #30 – July 23, 2012, 02:06:59 pm

[font=Georgia:]comment

[quote author="IPenguin"]Here is a memory-Spartan-6 haiku - Trenz Electronic TE0630 Series
... a "little" short on memory/width for what you are looking for (it's only 128MB/16-bit) :P
Don't check the price ;)[/quote]
Interestingly enough, the same site has a (link) to the ZedBoard that was announced in early June. The ZedBoard is based on the Xilinx Zynq-7020 and is nominally a "community-based" design effort (link) available from Avnet Electronics and Digilent. Quite a bit of documentation is already available online (see previous link). The ZedBoard (6.3" x 5.3" ~ 160 mm x 135 mm) is quite a bit larger (10x) than the SO-DIMM (67.6 mm x 31.75 mm) proposed for the Hardware Haiku. The student price from Digilent is roughly $299. Keep in mind that this design is one of the first Xilinx Zynq-70x0 products announced, that it currently has no real competition, and that it contains a bunch of circuitry that would not be on the Hardware Haiku design.

Thanks for your time.

dsm[/font:]

Re: spartan/virtex 6 + ddr2/3 ?

Reply #31 – July 23, 2012, 02:35:46 pm

[font=Georgia:]comment

[quote author="arhi"]we're talking more then $100 for a board the size of OBLS at 100+ quantity [/quote]
The OBLS board is 3.65" x 1.90" ~ 92.71 mm x 48.26 mm.
The Hardware Haiku SO-DIMM size board is 67.6 mm x 31.75 mm.
So the OBLS board is roughly 2x the size of the Hardware Haiku board.

I requested some online cost estimates from a European PCB vendor (link) for eight-layer SO-DIMM size boards with an electroless gold finish and was quoted 497 GBP for 100 boards (before VAT and shipping).

Thanks for your time.

dsm

[0] GBP = $1.5522 @ 23Jul2012[/font:]

Re: spartan/virtex 6 + ddr2/3 ?

Reply #32 – July 23, 2012, 03:16:30 pm

5gbp per board, are you sure there are no hidden cost?

Re: spartan/virtex 6 + ddr2/3 ?

Reply #33 – July 23, 2012, 09:38:17 pm

[font=Georgia:]comment

[quote author="arhi"]5 gbp per board, are you sure there are no hidden cost?[/quote]
I've never used the firm referenced by the above link. I found their site after an extensive 60 second search of the internet using Google and the search key "multilayer PCB board cost estimates". The 497 GBP per 100 estimate in my last posting assumed 1.6 mm thick boards, but SO-DIMMs are 1.0 mm +-0.1mm thick according to JEDEC MO-268C. The revised cost estimates are

As a sanity check, how many products (that are not subsidized like cellular telephones) with multi-layer boards do you know of that are sold for $50 (1/2 of your initial $100 estimate for multi-layer OBLS-size bare boards) or less?

Thanks for your time.

dsm

[0] GBP = $1.5522 @ 23Jul2012
[1] hh8gxxx means SO-DIMM size Hardware Haiku with eight layers and gold flash at xxx volume.[/font:]

Re: spartan/virtex 6 + ddr2/3 ?

Reply #34 – July 23, 2012, 10:00:14 pm

[quote author="dsm"]As a sanity check, how many products (that are not subsidized like cellular telephones) with multi-layer boards do you know of that are sold for $50 (1/2 of your initial $100 estimate for multi-layer OBLS-size bare boards) or less?
[/quote]

none, that's why I do believe mine cost estimate of min $100 for pcb makes sense. Maybe that quote you got is per board and not per 100 of them. If they can make 8 layer board for 5GBP that would be a game changer, but I think that's impossible... it's cheaper then chinese 4 layer board without fancy vias ..

EDIT: interesting, for 10 boards they charge 36GBP per board, but for 100 they charge under 6GBP .. they are seriously cheaper then seeed/itead for large quantities ..

Re: spartan/virtex 6 + ddr2/3 ?

Reply #35 – July 23, 2012, 11:22:43 pm

For comparison I did a quick check on SO-DIMM size (68mm x 32mm) 6 and 8-layer chem gold finish boards with two local (German) companies I know and consider rather expensive.

6-layer - cost for 100 pcbs
A - 651 EUR --> 6,51 EUR/pcb
B - 484 EUR --> 4,84 EUR/pcb

8-layer (incl. 1 progr. blind vias) - cost for 100 pcbs
A - 965 EUR --> 9,65 EUR/pcb
B - 778 EUR --> 7,78 EUR/pcb

More than doubling the size (to OBLS size ca. 90mm x 50mm) will raise the price by roughly 50%.

Prices excl. VAT and shipping ... no hidden cost!

Does this mean: Expensive German 8-layer board is still cheaper than cheap Chinese 4-layer board?

Re: spartan/virtex 6 + ddr2/3 ?

Reply #36 – July 23, 2012, 11:52:32 pm

[font=Georgia:]comment

arhi,

I know of quite a few relatively low-volume medical products with multi-layer boards (typically to control emissions) that cost roughly $1.00 to $1.25 per square inch of board.

You're absolutely right about both

cost-volume connection
cost comparisons with low-volume multiple-design-aggregation fabrication vendors [2] [3] [4]

For example, the estimated board cost comes down with volume pretty quickly...

Thanks for your time.

dsm

[0] GBP = $1.5522 @ 23Jul2012
[1] hh8gxxx means SO-DIMM size Hardware Haiku with eight layers and gold flash at xxx volume.
[2] Seeed Studio's Fusion PCB Service
[3] OSHPark
[4] Itead Studio's PCB Prototyping Service[/font:]

Re: spartan/virtex 6 + ddr2/3 ?

Reply #37 – July 24, 2012, 05:16:17 am

[quote author="IPenguin"]
Does this mean: Expensive German 8-layer board is still cheaper than cheap Chinese 4-layer board?[/quote]

It's really weird .. locally 8 layer cost arm and a leg so I assumed PRC prices are as low as they can go.. look at itead - 10pcs Green 4Layer PCBs with 100% e-test. - $65 so it's $65 for 10 boards but seriously limited (no blind/buried vias etc etc) ... they don't have offer for a 100 and they are cheaper compared to 10pcs compared to this uk company but I was not expecting that high drop in price for 100pcs. The only problem is - what the hack is a hobbyist going to do with 100 pcb's :( .. It's again the "DP could make and sell", a single hobbyist just don't see a point in paying that much :(

Re: spartan/virtex 6 + ddr2/3 ?

Reply #38 – July 24, 2012, 07:38:25 am

[font=Georgia:]comment

[quote author="IPenguin"]Expensive German 8-layer board is still cheaper than cheap Chinese 4-layer board?[/quote]
The short answer is that the cost depends on your specific situation...

Low-volume multiple-design-aggregation PCB fabrication vendors make their living by being easy to use, not by providing low high-volume pricing. High-volume traditional PCB fabrication vendors are typically harder to use, but provide low high-volume pricing.

The weird cost-volume connection that IPenguin and dsm have documented is fairly typical of the PCB fabrication industry. There are a bunch of other considerations [1] about number of layers, substrate material, dimensions, accuracy, solder-masks, silk-screens, hole-size pallet, pad pallet, blind vias, buried vias, plating options, RoHS, wiring rules, CAD formats, but fabrication volume and setup costs often predominate the board cost. Think of the market opportunity this situation represents if the demand for your design is high enough.

Thanks for your time.

dsm

[1] Printed Circuits Handbook (Sixth Edition) ~ Clyde F. Coombs, Jr.[/font:]

Re: spartan/virtex 6 + ddr2/3 ?

Reply #39 – July 26, 2012, 09:46:08 pm

Hi arhi, just today I found this through Hack a Day. It reminded me of your trial of BGA soldering with vias. I guess the problem was using vias maybe?

Re: spartan/virtex 6 + ddr2/3 ?

Reply #40 – July 26, 2012, 11:47:00 pm

That is one great post. Does not explain why I had issues with vias as mine were 100% filled with solder before I tried to reflow the darn thing so there was no capillary action to suck the balls from bga

Re: spartan/virtex 6 + ddr2/3 ?

Reply #41 – July 28, 2012, 04:41:33 am

[quote author="tayken"]Hi arhi, just today I found this through Hack a Day. It reminded me of your trial of BGA soldering with vias. I guess the problem was using vias maybe?[/quote]
tayken, great find! So it doesn't (directly?) explain what arhi experienced during his trials.
I have asked a friend to get me a batch of (similar "failed" silicon in) BGAs with a working
JTAG chain (access to all pins) ... I think there is a demand for BGA soldering capability for
hobbyists to assemble prototypes/test boards with rather simple tools ... however, production
will remain the domain of PCB assembly/testing services.

@arhi, even if you didn't experience capillary effects directly you may have run into a combination
of gravity and surface tension that still sucked/pulled the tin away from the pin(s) ...

Re: spartan/virtex 6 + ddr2/3 ?

Reply #42 – July 28, 2012, 04:58:47 am

[quote author="IPenguin"]@arhi, even if you didn't experience capillary effects directly you may have run into a combination
of gravity and surface tension that still sucked/pulled the tin away from the pin(s) ...[/quote]
I was thinking the same thing. Lots of variables over there, this is the most likely scenario IMO.

And yeah, currently we have a demand for BGA soldering, but I am really scared of this thing. I ordered the brusless DC motor kit of TI, I was expecting just ICs but it turns out the processor comes with as a BGA package although there is a LQFP package. Leadless packages are OK, I can solder them, but BGA is hard to design a 2 layer prototype PCB for and real hard to solder.

Re: spartan/virtex 6 + ddr2/3 ?

Reply #43 – July 28, 2012, 10:53:05 am

[font=Georgia:]ZedBoard for review

Someone kindly offered to let me borrow a ZedBoard (link) to review for Dangerous Prototypes.
The overall features of this board include...

Xilinx Zynq-70x0 (link) EPP XC7Z020-CLG484-1
Memory ~ 512 MB DDR3 ~ 256 Mb Spansion Quad-SPI Flash ~ 4 GB SD card
Onboard USB-JTAG Programming
10/100/1000 Ethernet
USB OTG 2.0 and USB-UART
PS & PL I/O expansion (FMC, Pmod™ compatible, XADC)
Multiple displays (1080p HDMI, 8-bit VGA, 128 x 32 OLED)
I2S Audio CODEC

Any suggestions about what you want to see?

Thanks for your time.

dsm[/font:]

Re: spartan/virtex 6 + ddr2/3 ?

Reply #44 – July 28, 2012, 03:23:34 pm

[quote author="IPenguin"]@arhi, even if you didn't experience capillary effects directly you may have run into a combination
of gravity and surface tension that still sucked/pulled the tin away from the pin(s) ...[/quote]

everything is possible, but soldering is not the only problem, I'd probably figure out the way to solder them I plan to make a proper rework oven anyhow ... but 4+ layer boards are too expensive for my blood so it just won't cut it .. I was hoping DP was secretly working on a new version of OBLS but from lack of any comments from them I concluded they are not ... I can't design with bga chip, it's too expensive and I won't be selling the product later (so low price on 500 boards is not important) so it's cheaper for me to get a professional LA and forget the story completely ... or play with my 3AN dev board and make some LA there myself for myself