Hazard Evaluation and Risk Control For HF Glasses Thinner Process

• Main Authors: Pei-Jean Jhong, 鍾佩珍
• Other Authors: Shu-Wei Yu
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/87600703982772300245

碩士 === 國立中央大學 === 環境工程研究所碩士在職專班 === 96 === Advanced liquid crystal displays have been widely used in modern electronic devices such as notebooks and mobile phones. To meet customers’ demands on weight, user-friendliness, multiple functions, thinner displays have become the latest development trend and the most economic glass thinning process is hydrofluoric acid etching. Hydrofluoric acid etching is a common process in the semiconductor industry but it is seldom used for flat panel display manufacturing. In addition, the concentration of hydrofluoric acid in the glass thinning process is much higher than the acid used in the semiconductor industry. The glass thinner process consists primarily of units such as hydrofluoric acid soaking and drip washing, hydrofluoric acid dilution and storage, exhaust treatment and waste hydrofluoric acid collection. To achieve desired glass thickness, hydrofluoric acid with 25% concentration is used in the soaking and drip washing unit. Because of the extremely corrosive nature of hydrofluoric acid, hazard identification and risk assessment of the glass thinner process must be conducted and appropriate risk control implemented to ensure the safety of the process and its operations. Hybrid methodologies are developed for hazard identification and risk assessment of the hydrofluoric glass thinner process. The first method integrates Job Safety Analysis and the SEMI S10 standard for risk assessment while the other method is developed by combining HazOp and SEMI S10. Job Safety Analysis is adopted since the hydrofluoric acid dilution process involves manual hauling of high-concentration hydrofluoric acid drums to the dilution unit. The proposed techniques are capable of providing both qualitative and quantitative risk assessments. Potential hazards and relevant risks with the basic design of the thinning process have been successfully identified with the proposed methodologies.