11 Sep
2012
11 Sep
'12
11:04 p.m.
On Sep 11, 2012, at 4:36 PM, Chuck Guzis wrote:
On 11 Sep 2012 at 12:29, Chris Tofu wrote:
Or, more likely, that go in one side and the opposite side has no
connection. Blind vias have always been pretty expensive, and I
can't recall having seen them on any vintage machines (though I'm
sure there are plenty).
- Dave
are you supposed to be able to tell just by
looking at them if they
have multiple layers? Assuming you have one w/multiple layers, and I
guess I already know the answer,
Hold the PCB up to a very strong light--many if not most multi-layer
PCBs have internal power or ground planes. This makes the PCBs
pretty much opaque--you can't see light shining through where the top
and bottom foil has been edched away. Vias that seeming disappear
into the PCB (i.e. no via visiable on the other side) are a pretty
good hint also.