New challenges in the rework of 0201 passives

The continued drive toward miniaturization has seen component sizes decrease while board densities have increased. The world´s most advanced semiconductor packages are facing new challenges with the adoption of 0201 passive components. These challenging components will push high-speed assembly equipment to even more exacting parameters. However, failures will still occur during manufacturing, and rework and repair will be needed to salvage these dense and often expensive assemblies. Often times, the 0201 component will be located in a densely populated area of a printed circuit board (PCB) or module. The rework process must be accomplished not only in a very precise manner for placement, but also in an exacting thermal manner to reflow the solder for component removal and replacement. The surrounding components must not be disturbed in this process, or additional defects will be created. When the surrounding components are also 0201´s, tight spacing between components and small mass leave little margin for process variables. As more advanced technology is needed to rework these passive devices, equipment with high placement precision (in the order of 5 to 10 microns) is emerging. These systems have high magnification with good optics and lighting. In addition, specialized heating methods are employed. Many of these important equipment features and capabilities are also utilized in the high-accuracy world of micro-assembly, flip chip, MEMS, and opto-electronics. This paper will look at the major considerations in successful 0201 component rework.