This is a design of PCB business card with an LED matrix for display. Traditionally LED matrices are built as modules and mounted as a component. That would be thick for a business card. So, here I plan to use my charlieplexed LED matrix design from the ScrolLED watch project and put it on a business card. This matrix is built from discrete SMD LEDs and is low profile.
Another idea is to mount the CR2032 battery inside a hole in the PCB to help decrease the card thickness. This would mean having non-standard battery contacts on both sides of the PCB with a way of sliding the battery in. Need to work that part out.