Browse Prior Art Database

Screened Ceramic Sheet Dryness Monitor

IP.com Disclosure Number: IPCOM000048187D
Original Publication Date: 1981-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Lindh, CL: AUTHOR [+2]

Abstract

This monitor uses simultaneous surface reflectance and electrical resistance measurements to determine the paste solvent content in screened ceramic sheets used in a multilayer ceramic substrate.

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Screened Ceramic Sheet Dryness Monitor

This monitor uses simultaneous surface reflectance and electrical resistance measurements to determine the paste solvent content in screened ceramic sheets used in a multilayer ceramic substrate.

It has been experimentally determined that for screened sheets with a similar paste weight loss, different electrical resistance values will be obtained, depending on the temperature at which the sheets were dried. It has also been experimentally determined that for screened sheets with similar paste weight losses, different surface reflectance values will be obtained, also depending on the temperature at which the sheets were dried. Therefore, the combined usage of both resistance and surface reflectivity is necessary to obtain an accurate indication of solvent content in a screened sheet.

In this apparatus, and related technique, a screened ceramic sheet 10 is supported on tray 12 on a mechanism 14 which raises and lowers the sheet to present the sheet for examination by reflectance sensor 16 and DC conductivity probe 18. Sensor 16 provides an indication of surface reflectivity at 400 to 700 nm wavelength. The outputs from sensor 16 and probe 18 are processed by instrumentation 17 and 19 and are monitored by electronic comparators 20 and 22, respectively. If the signals are less than the threshhold values, determined experimentally, the comparators trip a relay 24, indicating that the sheet meets an acceptable standard for solvent...