I have a .4mm pitch BGA that will be included on my next design, so I'd like to get set up to use microvias. I thought I could edit the dimensions of an existing thru via to make it a microvia in Pad Designer, but under Parameters/Usage options in Pad Designer, the Microvia option is greyed out.
Am I trying to do this the wrong/hard way? For what it's worth, I'd like to make a 10mil pad with a 4 mil drill for my microvia.
Maybe a better way to ask the question: How do I make a microvia padstack in PCB Designer 16.5?
Thanks in advance for any help. Best Regards.
Not sure why the Microvia is greyed out, but you should be able to do as you suggested. Open up an existing via, save it as you new via and edit the drill diameter and the layers to achieve what you require and save.
The only way to enable the microvia option, that I can tell, is to modify the layer structure of the padstack to make the via blind/buried. Null out the default and bottom layers pads, then insert "layer2" below "begin layer" and the microvia option is enabled.
Not really sure what the microvia option buys you. I have some blind/buried laser drill vias where the microvia option is enabled but it is not checked. Don't recall it being a problem. I guess if the via is a thru via, it cannot be defined as a microvia....no matter how small.
There are two reasons that this option may be greyed:
The benefit of assgning a padstack to be a micovia is that you can employ a different set of spacing rules. If your spacing rules are the same for bbvia and mircro vias you can don't need to set this padstack optin
Thanks for the responses, everyone.
My problem was that I did not null everything in the "bottom" layer for the via I used as a template.