language: en

Sensor-based Registration and Stacking of Electronic Substrate Layers

Andrew E. Brennemann, 1 Robert Hammer, 2 William V. Jecusco II, 3 and Ralph L. Hollis 4
IBM Research Division Thomas J. Watson Research Center
Yorktown Heights, New York, USA

Abstract Substrates for most of today's electronic products contain many wiring layers which are individually fabricated, mechanically registered with one another, and laminated together. Alignment tolerances of 0.05 mm to 0.1 mm are sufficient to register the vertical connection pads or vias on each layer. More aggressive designs of the future will, however, require manufacturing accuracies of at least an order of magnitude better to accommodate much finer wire widths and pin spacings. Conventional equipment relying on mechanical "pin-in-slot" methods will likely be inadequate, and a new approach will be needed. We describe here a sensor-based approach for registration and stacking of electronic substrate sublaminates that replaces pin-in-slot methods, yet does not require accurate automation equipment. A pilot work cell for this approach is presented, which has an IBM 7576 coarse-positioning robot, a specially-developed fine-positioning robot, optical sensors, and several routine low accuracy fixtures. A novel robot bracing method was used to minimize environmental vibration during sublaminate stacking. Pairs of test sublaminates, each containing an identical pattern of 100 m holes, were aligned, stacked and bonded. The accuracy of registration

[1 Retired,]

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