Flexi < rigid-flex
An arrangement of printed wiring onto a flexible base material with or without flexible cover layers. Mostly they are passive wiring structures, used to interconnect electronic components such as integrated circuits, resistors, capacitors etc, however some are used for making interconnections between other electronic assemblies.
SMD < uSMD
Surface mount devices (or technology) is a technique for building electronic circuits where the components (SMC, or Surface Mounted Components) are mounted directly onto the surface of the printed circuit boards (PCBs).
A ball grid array (BGA) is a type of surface-mounting by balls of solder on the underside of the chip, then placed onto the PCB then heated causing the solder to melt and thus join to the PCB. The BGA solves the problem of creating a miniature package for an integrated circuit with many pins.
Bed of nails
The Bed of nails are testers used primarily for PCB fabrication which checks traces and vias are complete, also used for PCB assembly to test for correct operation of the circuit. Can also be used to program EEPROMs, FLASH and microcontrollers.
Electromagnetic compatibility (EMC) studies the unintentional propagation and reception of electromagnetic energy with reference to the unwanted effects (Electromagnetic interference, or EMI) that such energy may induce. EMC is to test in the same electromagnetic environment, of different equipment which use electromagnetic phenomena, and to avoid any possible interference.
An electrostatic sensitive device (ESD) is any component (primarily electrical) which can be damaged by common static charges which build up on people, tools, and other non-conductors or semiconductors. Electrostatic discharge is also commonly referred to as ESD.