HDI PCB manufacturer recommendations

[nexely]

Dear members, I am seeking advice for a reliable quality HDI manufacturer. Searched for reddit channels, google, eevblog and still have no clarity 

What I am looking for:

Asia or Europe based, with capabilities to manufacture prototype and scale to mid-volume production.

Good quality for 6 layers HDI, 4/4 mil traces, 0.25 mm min holes, controlled impedance.

Any advice and experience sharing highly appreciated.

[asmi]

Good quality for 6 layers HDI, 4/4 mil traces, 0.25 mm min holes, controlled impedance.

This is not HDI. Not anymore. OurPCB/WellPCB can do down to 3/3 mil and 0.15 mm (mechanical) vias. And they are fairly cheap too. See my thread here: https://www.eevblog.com/forum/manufacture/ourpcb-affordable-multi-layer-board-manufacturer-my-experience/

[exmadscientist]

Saying "HDI" kind of implies laser microvias, or at the very least small (<6mil ~ 0.15mm) buried/blind vias. I agree with @asmi that 0.25mm/10mil min drill is really not HDI, unless there is also some kind of via stacking going on. Just about any midrange fab should be able to meet that spec.

If you need true HDI, I'd look at Wuerth out of Germany. I don't know how bad their pricing will be for mid-volume production but they will certainly be able to do the job.

[Siwastaja]

4/4 mils and 0.25mm holes is not HDI and is easily done by most cheap manufacturers. Look at pcbshopper.com. JLCPCB and PCBWay are examples of very well known and widely used Chinese manufacturers.

[nigelwright7557]

In the UK pcb manufacture prices are extortionate.
So I buy from JLCPCB or PCBWAY at a fraction of the UK price.