Browse Prior Art Database

Multilevel Electroforming

IP.com Disclosure Number: IPCOM000089760D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Smith, MC: AUTHOR

Abstract

The density of any electronic packaged device is affected by the width of its current-carrying conductors. Printed circuits, for instance, contain various width conductors to provide for high or low current capacity. The wider the conductor the more space required to contain it; thus, the larger the package eventually becomes.

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Multilevel Electroforming

The density of any electronic packaged device is affected by the width of its current-carrying conductors. Printed circuits, for instance, contain various width conductors to provide for high or low current capacity. The wider the conductor the more space required to contain it; thus, the larger the package eventually becomes.

By means of multilevel electroforming, the current-carrying conductors can be maintained at the same width, but their height is varied according to their required current capacity. By reducing conductors to their minimum possible width, it becomes possible to populate substrate materials with a higher density of conductors, thereby, reducing the overall size of the substrate and subsequently the final package.

Multilevel electroforming is achieved by the following process steps: 1. Substrate 10 contains electrically conductive surface 12. 2. Surface 12 is coated with photoresist 14 (liquid or film) by well-known methods. 3. Required conductor pattern 16 is then photoprinted to resist coat 14 and developed to surface 12. 4. Substrate 10 containing the pattern of conductors 16 is placed in a metal electroplating bath, and the desired metal is plated to a height X, the height of resist coat 14. 5. Substrate 10 is then removed from the electroplating bath and recoated with photoresist layer 18. 6. Further required conductor pattern 16a is then photoprinted to surface 14, developed and yielding certain conductors, requi...