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Technology for Direct Write Customized Capture Pad in Multilayer Ceramic Package

IP.com Disclosure Number: IPCOM000113981D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Sarfaraz, MA: AUTHOR [+4]

Abstract

Due to the large via positioning error from via punch and additional distortion introduced during the ceramic sintering process, processing thin film wiring on Multilayer Ceramic (MLC) package requires the use of large size "capture" pads to ensure the continuity between the ceramic vias and the thin film studs. It was estimated that the capture pads along account for nearly 60% of the overall thin film wiring capacitance in a MLC substrate. The capacitance in the capture pad layer can be reduced by re-routing the connection between the ceramic vias and thin film studs by designing a custom capture pad structure. Use e-beam direct write technology and electron sensitive resists, positive or negative, the linkage between thin film studs and ceramic vias can be fabricated. Electron beam can be data drive.

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Technology for Direct Write Customized Capture Pad in Multilayer
Ceramic Package

      Due to the large via positioning error from via punch and
additional distortion introduced during the ceramic sintering
process, processing thin film wiring on Multilayer Ceramic (MLC)
package requires the use of large size "capture" pads to ensure the
continuity between the ceramic vias and the thin film studs.  It was
estimated that the capture pads along account for nearly 60%  of the
overall thin film wiring capacitance in a MLC substrate.  The
capacitance in the capture pad layer can be reduced by re-routing the
connection between the ceramic vias and thin film studs by designing
a custom capture pad structure.  Use e-beam direct write technology
and electron sensitive resists, positive or negative, the linkage
between thin film studs and ceramic vias can be fabricated.  Electron
beam can be data drive.  Once the customized thin film-to-ceramic
capture pad pattern data is generated by merging the mapped ceramic
via data and the thin film stud design data, the new data can be
processed for e-beam direct write tool for the actual delineation.
Two processes are used to create the custom capture pad structures:
(1) use negative resist patterning and etch back, and (2) patterning
with positive resist and plate up.

      Both processes are highly efficient since e-beam writes the
customized capture pad features which size is greatly reduced to only
a very small fraction of t...