Prototyping complex PCBs

[Lukas05]

Hi guys,

this is my first post on this forum, but I've been a silent reader for a long time now.
English isn't my first language, but I hope you can somehow extract a meaning out of my words. 

To the subject:
I've started a project a while ago, containing an ARM based SoC.
I finished the schematic and I am ready to start the layout. The board is going to be quite complex. I am aiming at a 10 layer board with 0.1mm clearance and 0.2mm through hole VIAs. The board also needs to be impedance controlled by the manufacturer. Finding a manufacturer capable of doing this isn't a problem, but the price is. 

I want to get some prototype boards manufactured (5-40 pcs.) Unfortunately prototyping these kind of boards seems to be very expensive. Unfortunately I can't invest 3-6k€ in a prototype when I don't even know if i will ever make money with this project. Yes I know, thats kind of the risk that you've got to take. 

But to be sure I want to ask:
Is there a way to get a complex prototype pcb manufactured and assembled, without loosing 3-6k€ in the worst case? (The first board wont work perfectly for sure, if at all^^) How do you prototype complex boards?

Any tips are appreciated!
Thanks!

[asmi]

Check this thread: https://www.eevblog.com/forum/manufacture/ourpcb-affordable-multi-layer-board-manufacturer-my-experience/
This is the only shop I know of which can manufacture that kind of boards for a reasonable price.

[rx8pilot]

The short answer is:
NO.

While I am sure you can find some rock bottom price on PCB/ASSEMBLY etc, but that does not account for the mistakes and issues you will likely have on a 10 layer design with impedance control. At that level of complexity, it would be a risk to sell them without some validation to make sure you have some SI margins, power rails clean, and many other little things. It is entirely possible (and likely) that you could get a proto to work only to find that after making 50 pcs you have issues that are hard to explain or find.

If you have to do 2 revisions of the board before you get a release level - it will cost real $$.