| 摘要 |
Electrical insulation of chip wafers (100) located on an intermediate support (110) that maintains the wafers in position after they have been diced involves immersing the chips and support in a treating phase comprising fluosilicic acid saturated with silica at 15-35 deg C, adding an agent to provide silica-supersaturation of the phase, and effecting treatment for at most 10 hours at 15-50 deg C. Preferred Features: Preparation of the treating phase involves adding an appropriate amount of silicic acid to a solution of fluosilicic acid, stirring the mixture for around 6 hours at not more than 35 deg C, and filtering to remove undissolved silica and obtain a silica-saturated fluosilicic acid solution. Alternatively, preparation of the treating phase involves adding an appropriate amount of silica to a solution of fluosilicic acid, stirring the mixture for at most 20 hours at not more than 35 deg C, and filtering to remove undissolved silica and obtain a silica-saturated fluosilicic acid solution. A silica-saturated fluosilicic acid solution of concentration 2-5 mol/l is diluted with water to obtain a solution of concentration 1-4 mol/l. The agent providing silica-supersaturation in the treating phase is selected from boric acid in concentration of around 0.1 mol/l, water or aluminum. Improvement of the breakdown voltage and the quality of the insulating layer is provided by adding 10<-1>-10<-5> mol/l HCl into the treating phase. Independent claims are given for: (a) production of a portable intelligent object such as a smart card, which involves using the above procedure; and (b) the portable intelligent object such as a smart card produced in a process involving the above procedures. |
