Which PCB prototype service for 0.5mm BGA (max via incl. ring = 0.35mm dia.)

[AloyseTech]

Hi,

I have a board which includes a BGA package with 0.5mm ball pitch, 0.2mm ball land pattern diameter. I need a 4 layers board. Without via-in-pad I can route the BGA if the finished via diameter of 350µm (external diameter of the annular ring). Most of the cheapest PCB prototype manufacturer offer only down to 0.45mm finished diameter... Do you guys know of a fab house which can go down to 0.35 without exploding costs? The trace/clearance minimum requirement is 0.1mm trace width / 0.1mm copper clearance (to route between the BGA pads).

Thanks

[asmi]

Send an email to OurPCB/WellPCB and ask them. These guys can go down to 3/3 mil traces and 0.15 mm drills, so they should be able to do what you want. They are fairly affordable too.

[Dubbie]

I had this done recently by allpcb. It wasn’t that  cheap but was a good job. The main cost contributor was filled vias

[AloyseTech]

I had this done recently by allpcb. It wasn’t that  cheap but was a good job. The main cost contributor was filled vias

Do I need filled vias if I use the dog bones technic for the BGA?

[Dubbie]

No. Not for 0.5mm. I did 0.4 which has no room for dog bones.

[asmi]

Forgot to mention -  I've done 0.2/0.4 mm vias on 6 layer controlled impedance boards with custom stackup with OurPCB/WellPCB, and they all came at about $160-$200 per 10 boards 10x10cm each. I consider this price a bargain as PCBWay's online quote was showing me over twice that price. So if you down to 0.15/0.35 or 0.2/0.35 - they should be able to do it.

[Dubbie]

That is a very good price. Better than allpcb.