(October 21, 2010) — DEK has teamed up with Irisys, infrared products supplier, to develop a robust fine-pitch isotropic conductive adhesive (ICA) interconnection process designed to drive Irisys’ latest generation of advanced infrared sensor products. The project led to the development of an optimized process for the assembly of pyroelectric thermal sensing arrays.
A leading designer and manufacturer of intelligent infrared products in the areas of thermal imaging, people counting, queue management and security solutions, Irisys has been working in partnership with DEK for more than a decade to develop an optimized fine-pitch ICA interconnection process for its range of infrared people counting products. Most recently, the company upgraded its screen printing technology to DEK’s high-speed, high accuracy Europa platform in order to meet the requirements of its latest product generation.
The project required DEK to deliver stencil support to extend Irisys’ fine-pitch process yield. In addition to printer alignment accuracy, stencil design considerations were also central to the fine pitch interconnect process optimization. Having designed and manufactured an electroformed Nickel stencil to meet the precise demands of the process, DEK then worked with Irisys to refine performance further.
Improvements included a new stencil surface texture, modifying aperture design from 200µm towards 85µm bumps to incur an increase of aperture total density in excess of 540,000 bumps per wafer. Heightening a combined complexity of controlling pitch over full array from 500 to 170µm, processes were successfully implemented to control stretch, repeatedly at micron level. Apertures were further developed towards vertical, while the team also devised smoother sidewalls to optimize ICA roll. Process optimization also involved managing common electroforming defects, such as nodules, debris, stress and stretch. The result was significantly enhanced release of the ICA.
This particular project has seen us develop a reliable 47 × 47 array assembly process based on 170µm pitch for sophisticated people-counting applications. The detailed yield engineering contributed to a stable platform for shrinking to finer pitch, Irisys’ Dr Alan Butler explained.
DEK is a global provider of advanced materials deposition technologies and support solutions including printing equipment platforms, stencils, precision screens and mass imaging processes. For more information, visit DEK at www.dek.com.
Irisys was founded on the belief that advanced infrared technologies developed for military and aerospace could be applied to transform the effectiveness and viability of many everyday applications. Learn more at http://www.irisys.co.uk/
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