Pixel defects on image sensors are sorted by the sensor manufacturer, but particles on the glas lid of an image sensor can be added later in the process (e.g. soldering). To improve yield and prevent from consequential cost, it is important to find particles that are on top of the glas lid to be cleaned, whereas particles inside can’t.
aSpect Systems illuminator idLUX supports solutions to find and clean particles in full automatic production lines or for high end sensors in low volume production that are handled manually. The following setup depicts a “bench top” test station with a automatic particle detection and a microscope for manual cleaning. The image sensor is operated in a test socket and the measurement indicates wheather there are particles on top of the glas which have to be cleaned, or defects that cause a fail because they can not be cleaned.
Cleaning is done by the operator manually with a microscope. Positions of particles are indicated on the screen automatically.