VV6501
8 Defect Categorisation
Defect Categorisation
8.1 Introduction
Two distinct categories of defects are discussed in this section:
q Pixel defects (Section 8.2 - Section 8.5)
q Physical aberrations (Section 8.6)
The two categories differ in terms of test methodology as explained below.
8.2 Pixel defects
All packaged CMOS image sensors can contain impurities, either silicon faults, optical blemishes or
external dirt particles which can be introduced in the product at various stages of the manufacturing
process. These impurities can result in pixel defects, that is a pixel whose output is not consistent
with the level of incident light falling on the image sensor. Precise definitions of the type of pixel
defect tested by STMicroelectronics are outlined below. The ability to identify and correct these
defects is central to both the design requirements and quality certification, via test of
STMicroelectronics sensor products.
STMicroelectronics produces a number of hardware co-processors and software drivers that
implement defect correction algorithms. The defect correction algorithms ensure that the VV6501
sensor in conjunction with a companion STMicroelectronics co-processor will produce a high quality
final image.
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