Abstract:
In each configuration, at least one TDI sensor is used to image substrate portions of interest, with those portions illuminated with substantially uniform illumination. In one configuration, a substrate is compared to prestored expected characteristic features. In a second configuration, first and second patterns in a region of the surface of at least one substrate are inspected by comparing one pattern against the other and noting whether they agree with each other. This is accomplished by illuminating the two patterns, imaging the first pattern and storing its characteristics in a temporary memory, then imaging the second pattern and comparing it to the stored characteristics from the temporary memory. Then the comparisons continue sequentially with the second pattern becoming the first pattern in the next imaging/comparison sequence against a new second pattern. Each time the comparison is performed, it is noted whether or not there has been agreement between the two patterns and which two patterns where compared. This inspection technique is useful for doing die-to-die inspections. A variation of the second configuration uses two TDI sensors to simultaneously image the first and second patterns, thus eliminating the need for temporary memory. In this configuration, the two patterns are simultaneously imaged and compared, then additional patterns are compared sequentially, in the same manner with the results of the comparisons and the pattern locations stored to determine which patterns are bad when the inspection of all patterns is completed.
Abstract:
A temperature-compensated apparatus and method for determining the percentage of solid particles in a suspension (consistency) is provided. A source of diffused radiant energy is directed toward a suspension to be measured. The portion of the energy which is forward-scattered by the suspension is detected and a first signal indicative of the magnitude of the forward-scattered energy is produced. The portion of energy which is back-scattered by the suspension is detected and a second signal indicative of the magnitude of back-scattered energy is produced. The first and second signals are combined at a predetermined ratio to produce a feedback signal used to control the intensity of energy emitted from the radiant energy source. The intensity of energy emitted from the source is a function of the forward-scattered and back-scattered energy and is directly proportional to the consistency of the suspension being measured. By monitoring the power driving the radiant energy source, a display calibrated in terms of percent consistency can be provided. The apparatus includes temperature compensation so that the temperature of the suspension will not produce erroneous readings in the energy detectors. Likewise, variations in ambient temperature will not adversely affect the operation of the energy detectors.
Abstract:
The present invention relates to a scattering light source photometer. In particular, the present invention relates to a portable, low cost, multi-wavelength photometer and methods for its use.
Abstract:
The present invention relates to a scattering light source photometer. In particular, the present invention relates to a portable, low cost, multi-wavelength photometer and methods for its use.