Abstract
Today's trend towards ever smaller electronic products, such as cellular phones, demands the evolution of smaller printed wiring boards (PWBs). Along with this requirement for smaller PWBs, new pattern designs and mounting techniques must also be developed, and the importance of accurate positioning has increased. Because of the growing tendency towards the integration of multi-stratified PWB designs, the widths of flexible substrates have decreased to 25 μm. The objective of this research project is to address automatic measurement techniques for PWBs by offering an alternative. As an improvement upon current complicated measurement techniques, such as image processing inspection by pattern matching or optic microscope inspection systems, a capacitance line-width measurement system with a novel measurement probe design has been developed. In this report, we showed the correction systems required to improve the accuracy and a probe shape suitable for measurement. Using the correction systems, we are able to measure the defects of a PWB model (150 μm) with accuracy within 5%.
