System for diluting ultrapure chemicals which is intended for the microelectronics industry
US6146008A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1998 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Apr 9, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/0329
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
System for diluting an ultrapure concentrated chemical including: (i) a first tank which contains the chemical in concentrated form having a predetermined purity P, (ii) a supply of ultrapure water of purity at least equal to P, (iii) a second tank for mixing the concentrated chemical with the ultrapure water to obtain a solution of diluted chemical whose purity is at least equal to P, (iv) a structure for adjusting the titre of the solution of diluted, chemical to a desired final concentration. The structure for adjusting the titre includes (a) a structure for measuring the titre of the dilute solution after mixing a predetermined quantity of ultrapure water with concentrated chemical of purity P so as to obtain a mixture with a concentration of chemical which is greater than the desired final concentration of the diluted chemical, (b) a structure for adding an additional quantity of ultrapure water to the mixture to obtain a second further diluted mixture, this additional quantity being at most equal to a theoretical quantity necessary for obtaining the desired titre, and (c) a structure for stirring the second further diluted mixture for a time such that the diluted chemical is …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.