Method for preparing substrates for optical sensors

• Main Authors: KRONEIS; HERBERT, OFFENBACHER; HELMUT
• Format: Patent
• Language: English
• Published: 11.10.1988
• Edition: 4
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; GLASS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; JOINING GLASS TO GLASS OR OTHER MATERIALS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; MEASURING; METALLURGY; MINERAL OR SLAG WOOL; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS; TESTING

Bodies of borosilicate glass with a B2O3 content of less than 13 percent by weight are provided with a microporous layer of a thickness of 5 to 20 mu m, and are thus turned into carriers for optical sensors. This process is characterized by the following steps. Thermal decomposition for 5 to 10 days at 500 DEG to 560 DEG C.; removal of the topmost layer of glass to a depth of at least 10 mu m in the part of the surface to be rendered porous; leaching of the separated borate phase with diluted mineral acids for a minimum of 2 days at 70 DEG to 98 DEG C.; and after-treatment of the microporous layer, including (a) chemical treatment with concentrated sulphuric acid and concentrated nitric acid for 2 hours at 20 DEG C., and (b) heat-treatment for 10 minutes to 2 hours at 450 DEG to 700 DEG C.