No, current board have a pair of Cypress HyperRAM modules running at 166 MHz DDR (so effectively 333 Mt/s). I mentioned DDR3 as example of the case where you need to have set up proper clearances just because there are too many traces to look after manually.
I order my boards at allpcb.com, the basic 4 layer board is just under 35$ for 5 boards of 100x100mm, while 6 layer board with same specs is almost $150. As you can see there’s a huge difference, especially since I pay for it out of my own pocket.
Yes, $35 for 5 is typical for budget 4 layer PCBs out of China. You’ll notice however, as soon as you specify controlled impedance the price shoots to over $100.
Correct, but then $223 is not a very good price for 5 6 layer boards. 50 boards are virtually the same price.
According to their website,
5 4 layer boards with CI = $81 (an hour ago this was $108)
100 4 layer boards with CI = $102
5 6 layer boards with CI = $223
100 6 layer boards with CI = $227
5 8 layer boards with CI = $293
100 8 layer boards with CI = $297
They do have a disproportionate increase from 4 layer to 6 layer, while 6 to 8 layer is a more reasonable 31%. There’s also virtually no difference between prototype and production quantities above 4 layers (it’s mostly tooling costs). But these prices are for 6 mil track/space and 0.3 mm hole, reduce them and the 4 layer board quickly gets more expensive.
Not the best prototype pricing I’ve seen but if you can route your board with 6 mil track/space and 0.3 via holes on 4 layers then you’re all set. Although I would order 25 boards for the same cost.
I think it’s the other way around - they’ve optimized their manufacturing for 2 and 4 layer boards, so that they can make them extremely cheap ($5 for 10 two-layer boards up to 100x100 mm is VERY cheap), while more complex 6+ layer board’s cost is more in line with competition.
This is even more evident if you take a look at “made in USA/Europe” PCBs - 2 and 4 layer boards are many many times more expensive than Chinese fabs, but as you get into more complex boards, the price difference becomes not that insane anymore.
If you know a fab with better pricing (but still good quality) I would appreciate if you’d share this info. I do a lot of boards as hobby projects, and can never get them right on a first try without several re-spins , so any savings will mean more (or better) chips on those boards!
$10 for 200 is even cheaper, $13 for 500 cheaper still. Why would you only order 10??
I’m not sure I trust those prices.
I usually either get boards made locally here in Australia or, if time permits, I deal directly with the Chinese fab. I don’t usually order less than 25 boards.
Maybe because I don’t need 500? And I only have so much room in my home for that stuff? Pick the one you like Most of this boards I only really need in just a singular quantity, I order 5 or 10 just in case I mess it up somehow. If I could order 2-3 (especially as move onto more expensive boards) I definitely would.
I do. Ordered many times there and in another Chinese shop - pcbway.com. They are very fast (7-8 days from order submission to holding boards in hands) and I’ve never had a defective board from them (they do flying probe test, and you can even see marks on pad’s HASL from that probe under microscope).
In response to the original question, I have routed a 484 pin BGA with 600Mbps LVDS pairs (300MHz Clock, DDR) in KiCAD and it did take jumping through some hoops. In my case, these were LVDS bus pairs, so a set of eight pairs needed to be routed deferentially with controlled impedance and length matched. Here is what I did:
Create a Netclass for the LVDS Bus nets
Set the Netclass DRC rules for my BGA escape routing
Route all nets from the BGA pads to the edge of the IC
Check DRC of the escape routing
Change the Netclass DRC rules for board run routing
Complete the differential routing and tune lengths (outside the BGA area)
Check DRC of the routing outside the BGA area (note you will have a lot of red arrows under the BGA)
This was on an 8 Layer board with the LVDS buses on an internal layer.
No problem. Someday having zone-based DRC would be nice to have, but I there are a lot of more important features to tackle in KiCAD for the moment. When I first routed this board, the differential routing wasn’t even the the DRC rules yet, so things have already come a long way fairly quickly.
Do you have cookies enabled?
Some websides try to persuade you to by with them if you come back later.
(Some travel sites make everything more expensive if you come back later because they know there is a high chance you have already decided to buy from them. Amazon does something similar.)
It could also be that their prices depend on their current workload or on some other factors. (Cheaper prices if they have not enough orders, …)
Well there is already support for custom trace width for part of the track, it seems logical to add ability to specify custom clearance along with custom width.
Like I said, I don’t need luck with them, I’ve made several orders there already and have absolutely no complaints about their services (quality and manufacturing time were as promised or better). But of course you’re free to choose whatever you feel like.
Their small quantity prices seem to be reliable but their volume prices are all over the map. Like I posted last night, the site was quoting $13 for 500 2 layer boards 100mm x 100mm. So unbelievable that I refreshed my browser and tried again, same price. Tonight they’re quoting $500 for the same boards. Also last night, within the space of an hour the price for 5 four layer CI boards dropped from $108 to $81. And 100 of the same board was only $102. Tonight those prices are back to $108 and $246. Most of the other prices are 3x what they were last night.
I don’t know if it was just a quirk with the website but others (ie. pcbway) seem much more consistent. By the way, with pcbway there is less than $50 difference between 4 layer CI and 6 layer CI for 5 boards.
Just chimming in to mention OSHPark.com Pricing is a bit higher, but the boards are made in the USA and are lead-free. You can even send your .kicad_pcb file directly. Once you upload the file, there is an online tool to view the different layers of the fabricated board such as in a Gerber viewer.
one problem with oshpark is that their minimum DRC specs can kill most BGA breakout applications. I had to change manufacturers before I even uploaded my board
For me what really killed it is insanely long turnaround time. Last time I’ve ordered anything there it took over a month to arrive. While Chinese shops I mentioned above manage to get it delivered in 7-10 days. Granted, I live in Canada so this might be a part of it, but still. I’m not willing to wait for a month because by that time I will forget what it is I was actually intending to make. So even though Oshpark is really the cheapest option as far as price is concerned for really small breakout boards, the turnaround time is so horrible that it makes me willing to spend more money just to get them faster.
Although I would order 25 boards for the same cost.
, so any savings will mean more (or better) chips on those boards!
Pick the one you like 