Browse Prior Art Database

Screening Mask

IP.com Disclosure Number: IPCOM000086271D
Original Publication Date: 1976-Aug-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Gibney, JT: AUTHOR [+2]

Abstract

The screening masks used to form circuit patterns in a conductive paste on a substrate, typically a multilayer ceramic substrate, are relatively complex and require supporting tabs to support the various portions thereof. The tabs are provided to support portions of the mask and allow the pattern to be completed by flowing beneath same. This mask configuration is relatively difficult and expensive to produce.

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Screening Mask

The screening masks used to form circuit patterns in a conductive paste on a substrate, typically a multilayer ceramic substrate, are relatively complex and require supporting tabs to support the various portions thereof. The tabs are provided to support portions of the mask and allow the pattern to be completed by flowing beneath same. This mask configuration is relatively difficult and expensive to produce.

In this technique, screening masks can be provided which incorporate supporting tabs to support the various portions of the mask with an undercut portion, to permit forming of the complete paste pattern. In this process, a laminate is first formed by adhering two metal layers 10 and 12 to an adhesive layer 13. The layer 13 can be an organic polymer sheet such as RISTON* photoresist. The laminate is formed by adhering the various sheets under heat and pressure.

Photoresist layers 14 and 16 are then deposited on the top and bottom of the laminate, using conventional techniques. The resist layers 14 and 16 are exposed to form the suitable patterns, developed, and the exposed portions removed, as indicated in Fig. 1. The exposed portions of metal layers 10 and 12 are etched from both sides using a suitable metal etchant, as indicated in Fig. 2.

The resist layers 14 and 16 are then removed and the exposed portions of layer 13 dissolved using the foil edges as a mask. This is shown in Fig. 3. The resultant structure has portions 18 and 20 supported...