| abstract |
A method of inspecting a stencil having apertures through which a substance is deposited onto an electronic substrate includes depositing the substance through the stencil and onto the substrate, capturing a first image of the stencil after the deposit of the substance and detecting variations in texture of the substance in the first image, capturing a second image of the electronic substrate having the substance on its surface and detecting variations in texture of the substance in the second image, defining a region of interest in the first image and in the second image to determine whether at least one feature exists in the region of interest, measuring a first span of the at least one feature in the region of interest in the first image and a second span of the at least one feature in the region of interest in the second image, and correlating the first span of the at least one feature and the second span of the at least one feature to determine whether a threshold span of the at least one feature has been reached. |