IMPROVEMENTS IN RELIABILITY OF HC-27/U GLASS CRYSTAL HOLDERS.
Abstract
Previous studies had found the failure rate of HC-27/u glass crystal holders to be on the order of 1% per thousand hours. Reduction to a maximum of 0.1% was needed to meet the expected reliability requirements. This project was to find means of achieving this goal. The project was successful. The HC-27's met the goal, also achieving good sealing yields and minimum disturbance of crystal parameters. This was accomplished by using holders of better quality (free from leaks, with improved uniformity and fit); minor modifications in crystal processing (uniform plating, better curing of mounting cement); slight changes in the sealing arrangement ('concentrator rings', 'molds'); and post-seal annealing of sealed holders. A continuous sequence including pre-seal heating, quick sealing, and immediate post-seal annealing gave best results. We believe that processing methods using this principle will significantly improve both yields and reliability without demanding extensive changes in present crystal designs and processes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1967
- Accession Number
- AD0820309
Entities
People
- J. M. Wolfskill
- R. C. Mouck