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Screening Inks with Non Vaporizable Solids

IP.com Disclosure Number: IPCOM000094697D
Original Publication Date: 1965-May-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Miller, LF: AUTHOR [+2]

Abstract

These inks eliminate undesirable secondary flow and produce sharp well-defined printing. Non-vaporizable ionic solids included in the inks improve drift characteristics of resistors with respect to time and temperature. They also provide a printed line which is more dense, uniform in characteristics and superior in solderability.

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Screening Inks with Non Vaporizable Solids

These inks eliminate undesirable secondary flow and produce sharp well- defined printing. Non-vaporizable ionic solids included in the inks improve drift characteristics of resistors with respect to time and temperature. They also provide a printed line which is more dense, uniform in characteristics and superior in solderability.

The ink composition consists essentially of pigment, liquid vehicle, non- vaporizable ionic solid and binder material for retaining the pigment on a substrate after removal of said vehicle.

The presence of a sufficient amount of non-vaporizable solids in inks results in essential dimensional stability of the ink line. The improvement is attributed to the formation of mild thixotropic structure in a relatively non-polar paste by a highly polar ionic salt. Typically, the non-vaporizable solids are highly polar inorganic salt, for example, sodium chloride, ammonium sulphate and the like. The solid is present in an amount sufficient to maintain dimensional stability of the ink line while the liquid vehicle portion of the ink is removed. The amount present is dependent upon the type of ink and the type of solid. In screening inks for printed images, the usage of non-vaporizable inorganic solids falls in the general region of about 1-10% by weight based on ink composition.

The pigment type is determined by the ink. For ordinary inks which are dried at moderate temperatures, the pigment can be carbon black, organic dyes, iron compounds and the like. For higher temperatures, metallic compounds and glass or enamel frit can be used as pigment. In printed images, the pigment can be electrically conductive metal or metal oxide, or alloy powders, such as platinum, gold, silver and the like. The amount of pigment present is determined by the type of ink. In the case of conductive ink, normally the ink composition includes about 60-80% by weight of pigment and binder.

The binder material...