Thermal runaway evaluation using DSC1, VSP2, and kinetics models on Cu etchant and its waste in high-tech etching process

• Published in: Journal of thermal analysis and calorimetry Vol. 144; no. 2; pp. 285 - 294
• Main Authors: Lin, Yu-Jung, Lin, Zih-Syuan, Wang, Yih-Wen
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.04.2021; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Atmospheric models; Backup software; Calorimetry; Chemical reaction, Rate of; Chemistry; Chemistry and Materials Science; Copper; Enthalpy; Etchants; Etching; Evaluation; Exothermic reactions; Gas evolution; Hydrogen peroxide; Inorganic Chemistry; Kinetics; Measurement Science and Instrumentation; Occupational health and safety; Parameter identification; Peroxides; Physical Chemistry; Polymer Sciences; Pyrolysis; Reaction kinetics; Thermal decomposition; Thermal runaway; Hydrogen peroxide; Cu etchant; Thermal decomposition; Thermokinetic analysis
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-020-10094-2

Cu etchant solutions have been widely used in etching processes because of their high etching efficiency and low cost for manufacturing electric products. Hydrogen peroxide (H 2 O 2 ), a major components of Cu etchants, is known for its instability and reactivity under thermal induction, metal-ion catalysis, or pyrolysis; thus, Cu etchants have a higher risk of thermal explosion than other etchant solutions do. In this study, the exothermic reaction of the Cu etchant was initiated at approximately 70 °C, and the exothermic enthalpy (Δ H ) of the first peak was measured to be approximately 274.4 J g −1 using differential scanning calorimetry 1 (DSC1). The American Society for Testing and Materials (ASTM)—Ozawa/Kissinger method, and Advanced Kinetics and Technology Solutions (AKTS)—Friedman simulation, were used to calculate the reaction kinetics. Thermal runaway and gas evolution were evaluated through vent sizing package 2 (VSP2). The pressure of the Cu etchant surged from atmospheric pressure to a maximum pressure of 225.075 psig, with a pressure increase of 168.684 psig min −1 in the VSP 2 adiabatic test. Finally, to improve the safety operation during the etching process, thermokinetic analysis was used to identify appropriate kinetic parameters for the thermal decomposition of the Cu etchant.