SparkFun Forums

[NleahciM]

None of the quick prototyping companies will do blind vias.

Leon

I'm checking with Gold Phoenix to see if I can get a panel of boards with blind via's.

It is pricey.....but better than having to make the item in a size that can not be tested. The size is important to it's function.

James L

I'd be interested to hear how much it ends up costing. I've never had to get prices for boards with blind or buries vias.

I would think, though - that in most situations it'd be possible to just go from, for example, a 4 layer to a 6 layer board and not have to use blind vias. The cost difference between those is so small - and something tells me that the cost of blind vias will be much higher.

[propellanttech]

Just out of curiosity (I've never done anything that needed more than 2 layers), how does one even specify blind vias in the files you send to the board house? Multiple drill files, I assume?

Yes....you send a drill file for the different layers.

James L

[propellanttech]

The Pulsonix software I use does it automagically for blind and buried vias. It generates separate drill files for the appropriate layers.

I just tried it, out of curiosity. I added two layers to a double-sided PCB of mine, specified the top two as a separate layer span, and unrouted the design. I then placed a track on the top layer, continued it on the upper inner layer, and then finished it on the top layer, giving me two blind vias. I then autorouted the rest of the design. Two additional drill files were generated for the top inner layer - one was for plated holes and one for unplated ones. The whole process was very fast and straightforward. They really were blind vias, as I had a track underneath one of them on the bottom layer and the board passed the DRC.

Leon

I use Diptrace...and it is about the same....not complicated.

Blind/buried via's are great when you have a very small board and chips with a large number of connections.

James L

[propellanttech]

I'd be interested to hear how much it ends up costing. I've never had to get prices for boards with blind or buries vias.

I would think, though - that in most situations it'd be possible to just go from, for example, a 4 layer to a 6 layer board and not have to use blind vias. The cost difference between those is so small - and something tells me that the cost of blind vias will be much higher.

The problem is when you have components on both sides.....a very small board and a lot of high pin number chips. This formula ends only in one way (blind/buried via's).
I tried with a 2 layer board....but no matter what I did, I could never connect all the traces and not have them conflict somwhere.

I'll post on what results I get from the inquiry. I'm hopping it will not cost an arm or leg.....although it might.

James L

[elabudde]

Custompcb.com 5 days, $52 total for 2 4X5.5 two side boards. Apcircuits.com next day $75 total for two 3X4 two side boards.