Tip for a vacuum pipette with improved electrostatic discharge properties
US5280979A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1991 |
| Grant date | Jan 25, 1994 |
| Priority date | — |
| Expiry date | Jun 20, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/6838
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A tip for a vacuum pipette having improved electrostatic discharge properties is disclosed. The tip and the coupling sections of a known tip are separated both physically and electrically from one another. A large resistance then electrically couples the two sections together and a plastic insulator surrounds the resistance to physically couple the sections together. This construction forces all static discharges to flow through the resistor, thereby changing the static discharge from one large discharge to a series of small discharges, each small discharge being insufficient to damage the wafers. The tip is also coated with a thin ceramic coating, which acts as a barrier against ionic contamination from the material used to make the tip. This coating is also smoother and more abrasion resistant than the basic material, causing less contamination when used. Finally, the coating can have a controlled conductivity that improves the static discharge behavior of the tip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.