Introduction Micro SMD is a wafer level CSP （WLCSP） with the following features： 1. Package size equal to die size. 2. Smallest footprint per I/O count. 3. No need for underfill material. 4. Interconnect layout at 0.5 mm pitch. 5. No interposer between the silicon IC and the printed circuit board. 6. Both Lead-free and Eutectic solder versions available.

　　Package Construction Figure 1 shows typical micro SMD products. They have solder bumps located on the active side of silicon IC. The micro SMD is offered in the standard and thin version. The micro SMD manufacturing process steps include standard wafer fabrication process， wafer re-passivation， deposition of solder bumps on i/o pads， backgrinding （for thin version）， application of protective encapsulation coating， testing using wafer sort platform， laser marking， singulation and packing in tape and reel. The package is assembled on PCB using standard surface mount assembly techniques （SMT）.