Method of loading and unloading a furnace
US4636140A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1985 |
| Grant date | Jan 13, 1987 |
| Priority date | — |
| Expiry date | Apr 3, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67126
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A soft landing cantilever boat loader for loading semiconductor wafer carrying boats into a furnace process tube includes a loading station having one or more loading assemblies, an automatically controlled door associated with each loading assembly for selectively closing an end of the process tube and a microcomputer based control system for controlling and coordinating process operations. The loading assemblies are of a low profile configuration and each include a boat supporting, cantilevered paddle that is mounted by a quick release mechanism on a carriage which is driven along ways by a motor. A motor speed control circuit provides closed loop motor speed using a pulse width modulated motor drive. A door operating mechanism provides movement of the door along two transverse axes to assure tight sealing of the door against the tube. The control system employs a self-teaching technique that permits rapid reprogramming of the carriage travel limits which may be required when the paddle is replaced by a paddle of a different type or length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.