Forum

About the via annular ring, you wrote :

> Firstly we remove unused innerlayer pads
> as standard for our manufacturing process.
> When this is done the clearance [...]
> must be 1mm greater than the drill size.

OK, so when a via does not connect to the current inner layer, there is a circle around the via hole where there is no copper allowed.

Now the interesting question is, what is the dimension of this circle ?

a) diameter = drill diameter + 1 mm ?
(ie. leave 0.5mm from the border of the hole to next copper)

b) diameter = drill diameter + 2 mm ?
(ie. leave 1mm from the border of the hole to next copper)

c) something else ?

-----------------------

Second question : I have 0.5mm pitch SMDs in my design. If I use the pcb-pool soldermask tolerance, a tiny little bit of mask gets between the pins (0.05 mm) which is not good. So, should I :

- increase the soldermask to pad distance so the tiny bit of mask is removed (in this case there will be no soldermask at all between the pins)

- decrease the distance so I get good soldermask between my pads but if it's off, the pads are covered (risky).

: About the via annular ring, you wrote :
:
: > Firstly we remove unused innerlayer pads
: > as standard for our manufacturing process.
: > When this is done the clearance [...]
: > must be 1mm greater than the drill size.
:
: OK, so when a via does not connect to the current inner layer, there is a circle around the via hole where there is no copper allowed.
:
: Now the interesting question is, what is the dimension of this circle ?
:
: a) diameter = drill diameter + 1 mm ?
: (ie. leave 0.5mm from the border of the hole to next copper)
:
: b) diameter = drill diameter + 2 mm ?
: (ie. leave 1mm from the border of the hole to next copper)
:
: c) something else ?
:
: -----------------------
:
: Second question : I have 0.5mm pitch SMDs in my design. If I use the pcb-pool soldermask tolerance, a tiny little bit of mask gets between the pins (0.05 mm) which is not good. So, should I :
:
: - increase the soldermask to pad distance so the tiny bit of mask is removed (in this case there will be no soldermask at all between the pins)
:
: - decrease the distance so I get good soldermask between my pads but if it's off, the pads are covered (risky).
:
:


Hi Pierre
The answer to your first question is option "A"
For you second question we recommend that you increase the soldermask so that there will be no soldermask between the pads.
If you need any more questions answered do not hesitate to ask.

Best Regards
Seamus Noonan (Your Pcb-Pool Team)