Patent EP0569902A2 successfully refreshed from Google Patents.
Patent US5280979A successfully refreshed from Google Patents.
US5280979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tip for a vacuum pipette with improved electrostatic discharge properties
Assignee: Recif SA
•
Filing: 1991-06-20
•
Granted: 1994-01-25
•
Expires: 2011-06-20
Abstract
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.
Inventors
- 👤 Bernard Poli
- 👤 Gerard Chincholle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:29
CPC Classifications
B; B25; B25B; B25B11/00; B25B11/005; B25B11/007; H; H10; H10P; H10P72/00; H10P72/70; H10P72/78
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
126 words
A tip for use with a vacuum tool for manipulating semiconductor wafers, the tool having means to electrically connect the tip to a low potential, the tip comprising: electrically conductive connecting means for coupling the tip to the tool; electrically conductive wafer gripping means for contacting and applying vacuum to a wafer; a source of electrical resistance connecting said connecting means and said wafer gripping means, said source of electrical resistance being operative to limit the discharge of accumulated charge between a wafer and said tip to prevent a discharge having sufficient energy to damage the contents of said wafer; and internal duct means coupled to said wafer gripping means and extending to the tool for communicating vacuum from the tool to said wafer gripping means.
Claim 2
Dependent Claim
126 words
A tip for use with a vacuum tool for manipulating semiconductor wafers, the tool having means to electrically connect the tip to a low potential, the tip comprising: electrically conductive connecting means for coupling the tip to the tool; electrically conductive wafer gripping means for contacting and applying vacuum to a wafer; a source of electrical resistance connecting said connecting means and said wafer gripping means, said source of electrical resistance being operative to limit the discharge of accumulated charge between a wafer and said tip to prevent a discharge having sufficient energy to damage the contents of said wafer; and internal duct means coupled to said wafer gripping means and extending to the tool for communicating vacuum from the tool to said wafer gripping means.
Claim 3
Dependent Claim
24 words
The tip of claim 1 wherein said source of electrical resistance has an electrical resistance in the range of approximately 10 to 50 MΩ.
Claim 4
Dependent Claim
25 words
The tip of claim 1 wherein the wafer gripping means and the connecting means are comprised of a thermoplastic material with conductive fibers embedded therein.
Claim 5
Dependent Claim
32 words
The tip of claim 3 including coupling means for coupling said wafer gripping means to said connecting means, comprising an electrically non-conductive thermoplastic material with the source of electrical resistance embedded therein.
Claim 6
Dependent Claim
30 words
The tip of claim 3 wherein the thermoplastic material is one of poly-ether-ether-ketone and poly-ether-ketone and the conductive fibers are comprised of one of carbon fibers and silicon carbide fibers.
Claim 7
Dependent Claim
24 words
The tip of claim 5 wherein the thermoplastic material is poly-ether-ketone and the fibers are carbon fibers, the percentage of carbon fibers being 8%.
Claim 8
Dependent Claim
34 words
The tip of claim 1 wherein the wafer gripping means is coated with a ceramic coating to minimize chemical contamination from the tip while allowing charge to transfer from the wafer to the tip.
Claim 9
Dependent Claim
17 words
The tip of claim 7 wherein the coating is comprised of silicon carbide, silicon dioxide and silicon.
Claim 10
Dependent Claim
16 words
The tip of claim 8 wherein the coating is between about 3 and 10 microns thick.
Claim 11
Dependent Claim
28 words
The tip of claim 1 wherein said source of electrical resistance is operative to discharge the accumulated charge from a wafer in a series of relatively small discharges.
Claim 12
Dependent Claim
127 words
A tip for a vacuum tool for manipulating semiconductor wafers, the tip comprising: electrically conductive connecting means adapted for coupling the tip to the tool and for connecting the tip to a low potential; an electrically conductive wafer gripping area coupled to the connecting means and having an opening for applying vacuum to a wafer; a coating on the wafer gripping area providing an electrical resistance between the wafer and the tip low enough to allow charge accumulated on the wafer to flow to the tip but high enough to limit the rate of charge flow to prevent damage to the contents of the wafer; and internal duct means coupled to the opening, and extending through the connecting means for communicating vacuum to said wafer gripping area.
Claim 13
Dependent Claim
127 words
A tip for a vacuum tool for manipulating semiconductor wafers, the tip comprising: electrically conductive connecting means adapted for coupling the tip to the tool and for connecting the tip to a low potential; an electrically conductive wafer gripping area coupled to the connecting means and having an opening for applying vacuum to a wafer; a coating on the wafer gripping area providing an electrical resistance between the wafer and the tip low enough to allow charge accumulated on the wafer to flow to the tip but high enough to limit the rate of charge flow to prevent damage to the contents of the wafer; and internal duct means coupled to the opening, and extending through the connecting means for communicating vacuum to said wafer gripping area.
Claim 14
Dependent Claim
18 words
The tip of claim 11 where the resistive coating has a resistance between about 10 to 50 MΩ.
References Cited (Backward Citations)
US3711742A
Cited
SU856790A1
Cited
US4496180A
Cited
US4687242A
Cited
US4619275A
Cited
US4736508A
Cited
US4744594A
Cited
US4697300A
Cited
WO1989004547A1
Cited
US4981315A
Cited
US4866565A
Cited
US5106139A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-24 | 1997-07-26 | 1998-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-24 | 2001-07-26 | 2002-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-24 | 2005-07-26 | 2006-01-25 | $7700.00 | Window Closed / Lapsed |