Height measurement of wafer bumps

Manufacturers use a highly advanced technique to make computer chips. Every computer chip has thousands of tiny bumps on it—the contacts. But the manufacturing process has some unique challenges; each of these bumps should have a uniform height. With present-day inspection methods, it’s hard to measure whether the chips have the right height if the use of the correct type of sensors is not done. Thus, relying on confocal chromatic sensors from Micro-Epsilon is the best option. 

These sensors have a resolution of 4μm, which makes them well-suited for detecting defects or measuring heights on shiny and structured surfaces. In total, three sensors are used along with three controllers to perform the synchronous measurement. Here the key to achieving high lateral resolution is the use of a focused light spot. The data acquired by the measurement setup can be evaluated with the help of software. Micro-Epsilon sensors have the ability to detect bumps at a rate of 50 kHz, making it possible to measure large amounts of chips and produce high-quality results in a short amount of time.