Apparatuses for heating semiconductor wafers, ceramic heaters and a process for manufacturing the same, a process for manufacturing ceramic articles
US5616024A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1995 |
| Grant date | Apr 1, 1997 |
| Priority date | — |
| Expiry date | Jan 27, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF27D2099/0008
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A ceramic heater composed of a ceramic substrate and a resistant heating element embedded within the ceramic substrate along a predetermined planar pattern is obtained by holding a convolution of a spiral-coiled high melting metallic filament in the above predetermined planar pattern and heat-treating the convolution at a temperature not higher than a primary recrystallization commencement temperature of the high melting metal under a non-oxidative atmosphere to provide the resistant heating element, embedding the resulting resistant heating element within a ceramic shaped body, and then, sintering the ceramic shaped body. In a preferred embodiment, the resistant heating element is a convolution of a spiral coil, the number of coils per a unit length of said convolution is set at a predetermined value in each of defined domains of the ceramic heater, and when the number of coils per a unit length of the convolution is determined, the relation of the maximal value, the minimal value and the mean value, of all the determined numbers of coils in the above domains, satisfies the formula: EQU (maximal value-minimal value)/mean value.ltoreq.0.1. Another preferred embodiment comprising a …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.