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Method for Preparing Seal Rod Preforms Using Lead Titanate As an Expansion Modifier

IP.com Disclosure Number: IPCOM000038812D
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Rita, RA: AUTHOR

Abstract

Lead titanate (PbTiO3) has been proposed as an expansion modifier in place of b-eucryptite when preparing seal rod preforms. The suggested modifier reduces seal temperature/time and sensitivity of seal properties to processing variables. In the manufacture of semiconductors, flat panel displays and other electronic devices, a solder glass or a seal material comprised of a solder glass combined with a low expansion modifier are frequently used to seal parts together. The seal materials must have an expansion coefficient matching that of the parts to be sealed, whether they be glass, ceramic, metals or combinations of the same. They also must flow at sufficiently low temperatures to avoid deformation of the parts being sealed.

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Method for Preparing Seal Rod Preforms Using Lead Titanate As an Expansion Modifier

Lead titanate (PbTiO3) has been proposed as an expansion modifier in place of b-eucryptite when preparing seal rod preforms. The suggested modifier reduces seal temperature/time and sensitivity of seal properties to processing variables. In the manufacture of semiconductors, flat panel displays and other electronic devices, a solder glass or a seal material comprised of a solder glass combined with a low expansion modifier are frequently used to seal parts together. The seal materials must have an expansion coefficient matching that of the parts to be sealed, whether they be glass, ceramic, metals or combinations of the same. They also must flow at sufficiently low temperatures to avoid deformation of the parts being sealed. In certain sealing processes, mixtures of seal materials along with an expansion modifier are fused and shaped into a monolithic part to produce a billet which is thermally rederawn. From this billet rod preforms are produced and thermally fused to produce a seal [1, 2]. During the process, the glass and ceramic modifier phases can react, thereby effectively resulting in the dissolution of the modifier phase. The reaction is undesirable since it will produce a more refractory seal material with a higher coefficient of expansion than otherwise. To partially cope with this, the necessary thermal processing cycles are optimized to minimize the glass-modifier reac...