USH1874H - Chair for use in a clean room environment - Google Patents

Chair for use in a clean room environment Download PDF

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Publication number
USH1874H
USH1874H US09/100,381 US10038198A USH1874H US H1874 H USH1874 H US H1874H US 10038198 A US10038198 A US 10038198A US H1874 H USH1874 H US H1874H
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US
United States
Prior art keywords
chair
clean room
cushion
particles
base
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09/100,381
Inventor
Gennaro Nicholas DeSantis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SEH America Inc
Original Assignee
SEH America Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SEH America Inc filed Critical SEH America Inc
Priority to US09/100,381 priority Critical patent/USH1874H/en
Assigned to SEH AMERICA, INC. reassignment SEH AMERICA, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DESANTIS, GENNARO NICHOLAS
Application granted granted Critical
Publication of USH1874H publication Critical patent/USH1874H/en
Abandoned legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C15/00—Other seating furniture
    • A47C15/004—Seating furniture for specified purposes not covered by main groups A47C1/00 or A47C9/00
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C9/00—Stools for specified purposes

Definitions

  • the present invention relates generally to clean room technology and, more particularly, to chairs for use in a clean room environment.
  • Virtually all semiconductor fabrication facilities include one or more clean rooms in which the total number of particles per unit volume is tightly controlled along with the temperature and the humidity.
  • a Class 100 clean room has a dust count of no more than 100 particles having diameters of 0.5 ⁇ m or larger per cubic foot.
  • semiconductor fabrication processes are performed in a clean room since airborne particles can settle on semiconductor wafers and/or lithographic masks and cause defects in the resulting semiconductor wafer or device.
  • a particle on a semiconductor surface can disrupt the single crystal growth of an epitaxial layer and can disadvantageously cause the formation of dislocations.
  • the chairs that are used in clean rooms include a seat, a back rest, a base and, in some instances, arm rests. While the base could be formed by three or four legs, the base of the chairs typically utilized in clean rooms generally include a telescoping pedestal for supporting the seat and for adjusting the height of the chair.
  • the base of the typical chair used in a clean room includes a number of arms which extend radially outward from the lower end of the pedestal as well as a number of wheels, castors or rollers on the end portions of respective ones of the radially extending arms. As such, clean room personnel can move, i.e., roll, about the clean room while seated in the chair.
  • the seat and the back rest of the chairs conventionally used in clean rooms are formed of vinyl or a hard, compressed rubber material.
  • the seat and the back rest generally emit particles into the clean room atmosphere.
  • the telescopic height adjustment of the chair provided by the pedestal also generates a number of particles that are emitted into the clean room atmosphere. As with other particles that enter the clean room atmosphere, a certain percentage of the particles will eventually settle on the semiconductor wafer or the lithographic mask so as to create defects in the resulting semiconductor wafer or device.
  • the present invention therefore provides a chair specifically designed for use in a clean room environment which limits the emission of particles by the chair as clean room personnel alternately sit down and stand up.
  • the chair includes a base and a seat member operably mounted upon the base.
  • the seat member includes a cushion and a shell encapsulating the cushion.
  • the shell is comprised of polytetrafluoroethylene (PTFE), such as GORTEX® PTFE.
  • PTFE polytetrafluoroethylene
  • the base of the chair includes a telescoping pedestal for adjusting the height of the chair.
  • the pedestal can also be covered with a PTFE sleeve so as to similarly limit emission of particles upon adjustment of the height of the chair.
  • the chair of the present invention facilitates the fabrication of semiconductor wafers and semiconductor devices by further limiting the exposure of the semiconductor wafers and devices and the lithographic masks to undesired particles.
  • FIG. 1 is a perspective view of a chair according to one embodiment of the present invention.
  • FIG. 2 is a cross-sectional view of the seat member of the chair of FIG. 1 illustrating the cushion and the PTFE shell which encapsulates the cushion.
  • FIG. 3 is a fragmentary plan view of a portion of the pedestal of the chair of FIG. 1 in which the pedestal is covered with a PTFE sleeve.
  • FIG. 1 a portion of a clean room including a chair 10 is illustrated. Although a variety of activities could be conducted in the clean room, the clean room is typically utilized for the fabrication of semiconductor wafers and semiconductor devices. As such, the number of particles within the clean room must be precisely controlled.
  • the chair 10 generally includes a base 12 and a seat member 14 mounted upon the base for supporting clean room personnel.
  • the chair also includes a back rest 16 and a pair of arm rests 18 so as to have the overall appearance of a conventional office chair.
  • the chair of the present invention need not include a back rest and/or arm rests and can, instead, have the general appearance of a stool, if so desired.
  • the chair 10 of one advantageous embodiment includes a base 12 having a telescoping pedestal 20.
  • the base can be formed of a variety of materials, the base is preferably formed of anodized aluminum or is plated with chrome or nickel.
  • the seat member 14 is operably mounted to the upper end of the pedestal.
  • the telescoping pedestal of this embodiment is comprised of at least two partially nested sections and a height selection member 22. As known to those skilled in the art, the various sections of the pedestal are adapted to be telescopically extended and retracted so as to raise and lower the chair, respectively.
  • the height selection member such as a threaded post or the like, has an engaged position and a nonengaged position.
  • the height selection member engages the various sections of the pedestal so as to fix the relative positions of the various sections of the pedestal.
  • the height selection member permits relative movement of the various sections of the pedestal. As such, clean room personnel can adjust the height of the chair as desired.
  • the base 12 of the chair 10 of the illustrated embodiment also includes a plurality of casters, rollers, wheels or the like 24 for facilitating movement of the chair within the clean room.
  • the base of the chair of the illustrated embodiment includes a number of arms 26 extending radially outward from a lower end of the pedestal to a respective caster as known to those skilled in the art.
  • the base of the illustrated embodiment includes a telescoping pedestal, a number of radially extending arms attached to a lower end of the pedestal and a number of casters
  • the chair can include a variety of other bases without departing from the spirit and scope of the present invention.
  • the base can include three, four or more legs extending downwardly from the seat member, if so desired.
  • the seat member 14 includes a cushion 28, typically formed of foam rubber, and a shell 30 encapsulating the cushion.
  • the shell is comprised of polytetrafluoroethylene (PTFE), such as GORTEX® PTFE supplied by W. L. Gore & Associates, Inc., to limit emission of particles by the cushion.
  • PTFE polytetrafluoroethylene
  • GORTEX® PTFE supplied by W. L. Gore & Associates, Inc.
  • the relatively small pore size of the PTFE shell limits the emission of particles by the cushion, particularly the emission of particles having a relatively large diameter.
  • the shell can be of various thicknesses, the shell of one advantageous embodiment has a thickness of 100 microns.
  • the shell 30 and the cushion 28 are preferably mechanically attached to each other and to the base 12.
  • the chair can include a circumferentially extending frame that overlies the shell and the cushion such that by securing the frame to an underlying support, the shell and the cushion are secured to one another and to the underlying support.
  • the support in turn, can be connected to the base.
  • the back rest 16 and the arm rests 18 of a chair 10 can also include an outer shell 30 of PTFE to similarly limit emission of particles by the cushioning material which form the back rest and the arm rests.
  • the base 12 and, more particularly, the telescoping pedestal 20 can also be covered with a PTFE sleeve 32 to limit emission of particles as the various sections of the telescoping pedestal are extended and retracted.
  • the PTFE sleeve would preferably define a slit 34 in which the height selection member 22 travels as the chair is raised and lowered.
  • the PTFE sleeve is preferably designed to fit the pedestal in its fully extended position. As such, in all instances in which the telescoping pedestal is not fully extended, such as shown in FIG. 3, the excess portion of the PTFE sleeve will generally accumulate in an accordion style about lower portions of the pedestal.
  • the chair 10 of the present invention is particularly well adapted for use in a clean room environment in which the number of particles of various sizes is strictly controlled.
  • the chair of the present invention can be utilized in other applications if so desired.

Abstract

A chair is provided that is specifically designed for use in a clean room environment by limiting the emission of particles by the chair as clean room personnel alternately sit down and stand up. The chair includes a base and a seat member operably mounted upon the base. The seat member, in turn, includes a cushion and a shell encapsulating the cushion. The shell is comprised of polytetrafluoroethylene (PTFE). By encapsulating the cushion, such as a foam rubber cushion, in a PTFE shell, the chair limits emission of particles by the cushion.

Description

FIELD OF THE INVENTION
The present invention relates generally to clean room technology and, more particularly, to chairs for use in a clean room environment.
BACKGROUND OF THE INVENTION
Virtually all semiconductor fabrication facilities include one or more clean rooms in which the total number of particles per unit volume is tightly controlled along with the temperature and the humidity. For example, a Class 100 clean room has a dust count of no more than 100 particles having diameters of 0.5 μm or larger per cubic foot. As known to those skilled in the art, semiconductor fabrication processes are performed in a clean room since airborne particles can settle on semiconductor wafers and/or lithographic masks and cause defects in the resulting semiconductor wafer or device. For example, a particle on a semiconductor surface can disrupt the single crystal growth of an epitaxial layer and can disadvantageously cause the formation of dislocations.
While significant measures are taken to limit the number of particles which enter a clean room, such as by requiring clean room personnel to wear various lab coats, hats, masks and/or bunny suits, the equipment, including the furniture, within a clean room unfortunately also tends to emit a number of particles. For example, chairs used in clean rooms oftentimes emit particles when clean room personnel alternately sit down and stand up.
Typically, the chairs that are used in clean rooms include a seat, a back rest, a base and, in some instances, arm rests. While the base could be formed by three or four legs, the base of the chairs typically utilized in clean rooms generally include a telescoping pedestal for supporting the seat and for adjusting the height of the chair. In addition, the base of the typical chair used in a clean room includes a number of arms which extend radially outward from the lower end of the pedestal as well as a number of wheels, castors or rollers on the end portions of respective ones of the radially extending arms. As such, clean room personnel can move, i.e., roll, about the clean room while seated in the chair.
Typically, the seat and the back rest of the chairs conventionally used in clean rooms are formed of vinyl or a hard, compressed rubber material. As a result of the alternate compression and expansion of the seat member and the back rest as clean room personnel sit down in the chair and stand up from the chair, respectively, the seat and the back rest generally emit particles into the clean room atmosphere. In addition, the telescopic height adjustment of the chair provided by the pedestal also generates a number of particles that are emitted into the clean room atmosphere. As with other particles that enter the clean room atmosphere, a certain percentage of the particles will eventually settle on the semiconductor wafer or the lithographic mask so as to create defects in the resulting semiconductor wafer or device.
SUMMARY OF THE INVENTION
The present invention therefore provides a chair specifically designed for use in a clean room environment which limits the emission of particles by the chair as clean room personnel alternately sit down and stand up. In particular, the chair includes a base and a seat member operably mounted upon the base. The seat member, in turn, includes a cushion and a shell encapsulating the cushion. According to the present invention, the shell is comprised of polytetrafluoroethylene (PTFE), such as GORTEX® PTFE. By encapsulating the cushion, such as a foam rubber cushion, in a PTFE shell, the chair of the present invention limits emission of particles by the cushion.
In one advantageous embodiment, the base of the chair includes a telescoping pedestal for adjusting the height of the chair. As such, the pedestal can also be covered with a PTFE sleeve so as to similarly limit emission of particles upon adjustment of the height of the chair. By limiting the emission of particles into the atmosphere of the clean room, the chair of the present invention facilitates the fabrication of semiconductor wafers and semiconductor devices by further limiting the exposure of the semiconductor wafers and devices and the lithographic masks to undesired particles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a chair according to one embodiment of the present invention.
FIG. 2 is a cross-sectional view of the seat member of the chair of FIG. 1 illustrating the cushion and the PTFE shell which encapsulates the cushion.
FIG. 3 is a fragmentary plan view of a portion of the pedestal of the chair of FIG. 1 in which the pedestal is covered with a PTFE sleeve.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
Referring now to FIG. 1, a portion of a clean room including a chair 10 is illustrated. Although a variety of activities could be conducted in the clean room, the clean room is typically utilized for the fabrication of semiconductor wafers and semiconductor devices. As such, the number of particles within the clean room must be precisely controlled.
The chair 10 generally includes a base 12 and a seat member 14 mounted upon the base for supporting clean room personnel. In the illustrated embodiment, the chair also includes a back rest 16 and a pair of arm rests 18 so as to have the overall appearance of a conventional office chair. However, the chair of the present invention need not include a back rest and/or arm rests and can, instead, have the general appearance of a stool, if so desired.
As shown in FIG. 1, the chair 10 of one advantageous embodiment includes a base 12 having a telescoping pedestal 20. Although the base can be formed of a variety of materials, the base is preferably formed of anodized aluminum or is plated with chrome or nickel. As illustrated, the seat member 14 is operably mounted to the upper end of the pedestal. The telescoping pedestal of this embodiment is comprised of at least two partially nested sections and a height selection member 22. As known to those skilled in the art, the various sections of the pedestal are adapted to be telescopically extended and retracted so as to raise and lower the chair, respectively. The height selection member, such as a threaded post or the like, has an engaged position and a nonengaged position. In the engaged position, the height selection member engages the various sections of the pedestal so as to fix the relative positions of the various sections of the pedestal. In contrast, in the nonengaged position, the height selection member permits relative movement of the various sections of the pedestal. As such, clean room personnel can adjust the height of the chair as desired.
The base 12 of the chair 10 of the illustrated embodiment also includes a plurality of casters, rollers, wheels or the like 24 for facilitating movement of the chair within the clean room. In addition, the base of the chair of the illustrated embodiment includes a number of arms 26 extending radially outward from a lower end of the pedestal to a respective caster as known to those skilled in the art. While the base of the illustrated embodiment includes a telescoping pedestal, a number of radially extending arms attached to a lower end of the pedestal and a number of casters, the chair can include a variety of other bases without departing from the spirit and scope of the present invention. For example, the base can include three, four or more legs extending downwardly from the seat member, if so desired.
As best illustrated in cross section in FIG. 2, the seat member 14 includes a cushion 28, typically formed of foam rubber, and a shell 30 encapsulating the cushion. According to the present invention, the shell is comprised of polytetrafluoroethylene (PTFE), such as GORTEX® PTFE supplied by W. L. Gore & Associates, Inc., to limit emission of particles by the cushion. Although applicant does not wish to be bound by any particular theory of operation, it is believed that the relatively small pore size of the PTFE shell limits the emission of particles by the cushion, particularly the emission of particles having a relatively large diameter. In addition, although the shell can be of various thicknesses, the shell of one advantageous embodiment has a thickness of 100 microns.
The shell 30 and the cushion 28 are preferably mechanically attached to each other and to the base 12. For example, the chair can include a circumferentially extending frame that overlies the shell and the cushion such that by securing the frame to an underlying support, the shell and the cushion are secured to one another and to the underlying support. The support, in turn, can be connected to the base.
Although not separately illustrated, the back rest 16 and the arm rests 18 of a chair 10 according to the present invention can also include an outer shell 30 of PTFE to similarly limit emission of particles by the cushioning material which form the back rest and the arm rests. As shown in FIG. 3, the base 12 and, more particularly, the telescoping pedestal 20 can also be covered with a PTFE sleeve 32 to limit emission of particles as the various sections of the telescoping pedestal are extended and retracted. As illustrated, the PTFE sleeve would preferably define a slit 34 in which the height selection member 22 travels as the chair is raised and lowered. The PTFE sleeve is preferably designed to fit the pedestal in its fully extended position. As such, in all instances in which the telescoping pedestal is not fully extended, such as shown in FIG. 3, the excess portion of the PTFE sleeve will generally accumulate in an accordion style about lower portions of the pedestal.
By limiting emission of particles, the chair 10 of the present invention is particularly well adapted for use in a clean room environment in which the number of particles of various sizes is strictly controlled. However, the chair of the present invention can be utilized in other applications if so desired.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims (1)

That which is claimed:
1. A chair adapted for use in a clean room environment, the chair comprising:
a base; and
a seat member operably mounted upon said base, said seat member comprising:
a cushion; and
a shell encapsulating said cushion, said shell comprised of polytetrafluoroethylene to limit emission of particles by said cushion.
US09/100,381 1998-06-19 1998-06-19 Chair for use in a clean room environment Abandoned USH1874H (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US09/100,381 USH1874H (en) 1998-06-19 1998-06-19 Chair for use in a clean room environment

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Application Number Priority Date Filing Date Title
US09/100,381 USH1874H (en) 1998-06-19 1998-06-19 Chair for use in a clean room environment

Publications (1)

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USH1874H true USH1874H (en) 2000-10-03

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060082202A1 (en) * 2004-10-19 2006-04-20 Gasser Chair Company, Inc. Objects including gaming stools with an easy rolling support base

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982785A (en) * 1974-07-29 1976-09-28 Center For Design Research And Development Chair
US4690859A (en) * 1985-04-09 1987-09-01 United Merchants & Manufacturers Inc. Fire barrier fabrics
US4746565A (en) * 1986-09-26 1988-05-24 United Merchants And Manufacturers, Inc. Fire barrier fabrics
US4757968A (en) * 1986-02-10 1988-07-19 Orion-Yhtyma Oy Apparatus for implementation of vertical movement of a chair, especially of a patient chair
US4779921A (en) * 1986-06-17 1988-10-25 Holmstroem Erik F Adjustable chair
US4806185A (en) * 1987-07-16 1989-02-21 Springs Industries, Inc. Method of making coated fire barriers for upholstered furnishings
US5090770A (en) * 1989-04-27 1992-02-25 Stabilus Gmbh Electrical seat adjustment device
US5131718A (en) * 1991-01-31 1992-07-21 Flux Enterprises Incorporated Adjustable chair
US5190349A (en) * 1990-03-29 1993-03-02 A-Dec, Inc. Dental chair
US5369805A (en) * 1991-09-05 1994-12-06 Bergsten; Jeffrey D. Ergonomic arm support
US5433409A (en) * 1992-08-20 1995-07-18 Stabilus Gmbh Height-adjustable support device, in particular for the seat of a chair
US5711575A (en) * 1995-06-09 1998-01-27 Herman Miller, Inc. Office chair and adjustable lumbar support therefor
US5791733A (en) * 1996-02-09 1998-08-11 Knoll, Inc. Adjustable lumbar support

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982785A (en) * 1974-07-29 1976-09-28 Center For Design Research And Development Chair
US4690859A (en) * 1985-04-09 1987-09-01 United Merchants & Manufacturers Inc. Fire barrier fabrics
US4757968A (en) * 1986-02-10 1988-07-19 Orion-Yhtyma Oy Apparatus for implementation of vertical movement of a chair, especially of a patient chair
US4779921A (en) * 1986-06-17 1988-10-25 Holmstroem Erik F Adjustable chair
US4746565A (en) * 1986-09-26 1988-05-24 United Merchants And Manufacturers, Inc. Fire barrier fabrics
US4806185A (en) * 1987-07-16 1989-02-21 Springs Industries, Inc. Method of making coated fire barriers for upholstered furnishings
US5090770A (en) * 1989-04-27 1992-02-25 Stabilus Gmbh Electrical seat adjustment device
US5190349A (en) * 1990-03-29 1993-03-02 A-Dec, Inc. Dental chair
US5131718A (en) * 1991-01-31 1992-07-21 Flux Enterprises Incorporated Adjustable chair
US5369805A (en) * 1991-09-05 1994-12-06 Bergsten; Jeffrey D. Ergonomic arm support
US5433409A (en) * 1992-08-20 1995-07-18 Stabilus Gmbh Height-adjustable support device, in particular for the seat of a chair
US5711575A (en) * 1995-06-09 1998-01-27 Herman Miller, Inc. Office chair and adjustable lumbar support therefor
US5791733A (en) * 1996-02-09 1998-08-11 Knoll, Inc. Adjustable lumbar support

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060082202A1 (en) * 2004-10-19 2006-04-20 Gasser Chair Company, Inc. Objects including gaming stools with an easy rolling support base
US7922134B2 (en) * 2004-10-19 2011-04-12 Gasser Chair Company, Inc. Objects including gaming stools with an easy rolling support base

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AS Assignment

Owner name: SEH AMERICA, INC., WASHINGTON

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DESANTIS, GENNARO NICHOLAS;REEL/FRAME:009273/0186

Effective date: 19980612

STCF Information on status: patent grant

Free format text: PATENTED CASE