The 3FF micro-SIM card (UICC) is the 3rd generation SIM (Subscriber Identification Module) card since this form of card first appeared twenty years ago. It has dimensions of 12mm x 15mm x 0.76mm and the card has the same contact arrangement as its predecessors, i.e. the standard (credit-card size) and mini-SIM (25mm x 15mm) cards. The micro-SIM is backward compatible with larger SIM holders and SIM readers (via additional plastic cut-out surrounds).
Since the micro-SIM was developed specifically for the purpose of fitting into devices otherwise too small for a mini-SIM card, there is clearly a lot of pressure on connector makers to minimize footprint and height of micro-SIM sockets. In this blog I’d like to briefly analyze some of the factors contributing to connector height.