Optimizing PCB Design: Choosing Between SD and MicroSD Connectors

[j777]

Hello,

If vias are covered with soldermask is it OK to mount an SD card connector with a metal frame over the top of them?


Thanks

 

[berkeman]

Hello,

If vias are covered with soldermask is it OK to mount an SD card connector with a metal frame over the top of them?


Thanks

That would generally be a question for your assembly house. They will have "Manufacturability Guidelines" that cover things like spacings, soldermask rules, etc.

If you're doing it on your own, consider things like electromigration issues (yes, soldermask has pinholes in it generally), noise coupling, etc.

 

[j777]

Thanks berkeman.

Better safe than sorry...I found a connector made by ALPS (their SCDA series) that has "standoffs" which space the connector off the board 1.8mm.

 

[berkeman]

Thanks berkeman.

Better safe than sorry...I found a connector made by ALPS (their SCDA series) that has "standoffs" which space the connector off the board 1.8mm.

That sounds good. So are you pretty far along with your board now?

 

[fizz_it]

If you are making 50 of them use Kapton tape to improve the separation. If you are making 50k of the boards then move the vias if you can

 

[j777]

That sounds good. So are you pretty far along with your board now?

I'm almost finished with it. Well at least my first attempt; I've never attempted a board as complex as this one so I wouldn't be surprised if I have to make some changes and build another prototype.

Just in case anybody is interested I ended up going with a microSD connector because they are $1 in small quantities, use much less board space (now I can fit it on top and avoid SMT on the bottom of the board), and industrial grade microSD cards are approx. half the cost of equivalent SD cards.