Optimization of overlapping holographic lens array for creating via

Abstract

A mask for generating a high density regular matrix of working images for generating a corresponding high density regular matrix of vias in a substrate, the computer generated holographic images from overlapped subapertures are processed for maximum fluence. For each working image, a diverging wave front of the first order is propagated using Fresnel diffraction to produce for that wave front the corresponding first order holographic image at a central unit cell. The first order holographic image for each of the working images to be produced by the unit cell is added until the configuration of a unit mask cell containing portions of all working images to be broadcast is attained. The projection from the unit cell to working image is arbitrarily altered to attain the smallest local maximum first order transmission requirement within the central unit cell; the large local maximum first order transmission requirements are essentially moved outside the bounds of the central unit cell. Thereafter, the obtained first order intensity pattern for the central unit cell that represents the holographic image with the smallest local maximum first order transmission requirement is arbitrarily clipped in transmission of the first order. The remaining clipped first order transmission requirement is re-normalized.