AU6158094A - Non-adhesive ecologically-pure electroadhesion method of clamping and fixing materials - Google Patents
Non-adhesive ecologically-pure electroadhesion method of clamping and fixing materialsInfo
- Publication number
- AU6158094A AU6158094A AU61580/94A AU6158094A AU6158094A AU 6158094 A AU6158094 A AU 6158094A AU 61580/94 A AU61580/94 A AU 61580/94A AU 6158094 A AU6158094 A AU 6158094A AU 6158094 A AU6158094 A AU 6158094A
- Authority
- AU
- Australia
- Prior art keywords
- polymer
- article
- electroadhesion
- electrode
- adhesive
- 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
Links
- 238000000034 method Methods 0.000 title claims description 8
- 239000000463 material Substances 0.000 title description 10
- 239000000853 adhesive Substances 0.000 title description 9
- 229920000642 polymer Polymers 0.000 claims description 16
- 230000003287 optical effect Effects 0.000 claims description 4
- 239000004014 plasticizer Substances 0.000 claims description 4
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 4
- 239000004800 polyvinyl chloride Substances 0.000 claims description 4
- 230000005684 electric field Effects 0.000 claims description 3
- NEHDRDVHPTWWFG-UHFFFAOYSA-N Dioctyl hexanedioate Chemical compound CCCCCCCCOC(=O)CCCCC(=O)OCCCCCCCC NEHDRDVHPTWWFG-UHFFFAOYSA-N 0.000 claims description 2
- 230000001939 inductive effect Effects 0.000 claims description 2
- 238000012545 processing Methods 0.000 claims description 2
- 239000004065 semiconductor Substances 0.000 claims description 2
- 230000001070 adhesive effect Effects 0.000 description 7
- 230000001965 increasing effect Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 238000003754 machining Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- MQIUGAXCHLFZKX-UHFFFAOYSA-N Di-n-octyl phthalate Chemical compound CCCCCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCCCC MQIUGAXCHLFZKX-UHFFFAOYSA-N 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- JJWKPURADFRFRB-UHFFFAOYSA-N carbonyl sulfide Chemical compound O=C=S JJWKPURADFRFRB-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000000407 epitaxy Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000009878 intermolecular interaction Effects 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000000191 radiation effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
- H01L21/6831—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using electrostatic chucks
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Adhesives Or Adhesive Processes (AREA)
Description
TITLE: NON-ADHESIVE ECOLOGICALLY-PURE ELECTROADHESION METHOD OF CLAMPING AND FIXING MATERIALS FIELD OF THE INVENTION
This invention relates to a non-adhesive ecologically-pure electroadhesion method of clamping and fixing materials, and apparatus therefor.
BACKGROUND OF THE INVENTION
Electroadhesion of materials has, in the past, been limited because of several factors. The most important factor was the presence of gaseous media in the space between the surface of the electrode and the surface of the material required to be clamped or adhered due to irregularities in the surface or surfaces. The increase in the voltage applied to the electrode did not overcome this problem.
The application of a dielectric coating to the electrode increased the field strength but this force could not be increased by the increase of the voltage above a certain value.
It is an object of the present invention to provide a method and apparatus for achieving a far greater adhesion between materials than hitherto achieved and thereby extending the applications and materials.
THE INVENTION
According to the invention apparatus for electroadhesion includes one
or more electrodes coated with a polymer capable of being polarised and presenting a conformable (for example, flat) surface to the article or articles to be adhered, the polymer having a predetermined plasticity for accommodating any irregularities in the surface of the article or articles to be adhered for minimum presence of gaseous media between the surface of the polymer and the surface of the article/s, and a source of electrical current for charging the electrode/s and inducing an electrical field on the article/s.
In a preferred form of the invention the surface of the apparatus, including the electrode/s is prepared to substantial optical precision. This ensures that the space between the surfaces of the apparatus and the article/s is minimal so that gaseous media are virtually excluded therebetween.
Although many polymers are useful, it will be appreciated that some polymers have a greater dielectric permittivity than others and, more importantly, some have a greater degree of polarisation and it is an important aspect of the invention that the polymer provides sufficient polarisation, to present a concentrated charged surface. Polyvinyl chloride has proved itself to be ideal for the purpose not only for the reason that it is capable of being dipolarised but it can also be provided in a mechanically strong form and which, at the same time, is able to be plasticised to a predetermined plasticity.
The preferred plasticisers are di-octyl phthalate, or di-octyl
adipate and any other known plasticisers. The amount of plasticiser may be between about 15 to about 50 percent by mass.
The plasticised polymer sheet may be orientated in both directions and may be stretched over the surface of the apparatus to exclude gaseous media and then anchored in position in any suitable manner.
It will be appreciated that the force of adhesion is the sum of the mechanic force of the electrical force, the force due to the polarisation of the polymer and the force of molecular attraction (due to the creation of a double electrical layer in zones of close contact). The total attraction can, if as much gaseous media as possible is excluded be as much as from 0,0001 to 100 MPa. At about 2 MPa the apparatus can be used as a manipulator for.heavy objects and it will be appreciated that the apparatus can be designed for any particular purpose.
The- layer of polymer may be between about 4 to 1000 mem for many applications and may have a tensile strength v/hen in position of between about 0,0001 and 0,5 MPa.
The electrode or electrodes should be as thin as possible and -may be applied to the surface of the apparatus by any known method, but preferably by vacuum deposition and may be etched. The thickness may be between about 0,05 and 5 mem.
The source of electrical voltage may be alternating or direct and will be chosen according to the desired application. An important application of the invention is for the grinding, polishing and super-finishing processing of semi-conductor (e.g. silicon) discs for the electronic industry. This was previously carried out by using an adhesive for the discs to be stuck to a surface. After the necessary grinding, the very thin discs are removed and then the adhesive layer has to be removed. This limited the degree of grinding and the desired precise parameters of the discs which could be attained. With the present invention, the avoidance of the adhesive makes it possible to machine these discs to precise parameters necessary for sub-micron technology, and to a fraction of the thickness achieved hitherto. The apparatus in such a case may be small and may be powered by a small dry cell or any other independent power source, or any other source. The electrodes may be annular and may alternate in polarity. EMBODIMENT OF THE INVENTION
An embodiment of the invention is described below with reference to the accompanying drawings in which:
Figure 1 is a plan view of the surface of an apparatus according to the invention;
and
Figure 2 is a side view thereof.
In the drawing the apparatus includes a shell 10 which houses the electrical circuit. This may comprise a dry cell and an oscillator
(not visible) or any other power source. The surface 12 is machined to optical precision and includes annular electrodes 14,15 which have alternate polarities. The electrodes and surface are covered with a sheet of plasticised and orientated polyvinyl chloride (not visible) held in a ring 20.
Apparatus according to the invention for other applications will be designed specifically. The applications are extensive and include temporary fixing, transportation, assembly and machining, the invention avoiding the use of mechanical, electromechanical, suction, adhesive and other labour consuming and otherwise inconvenient methods. This results in the avoidance of multiple heating, cooling, sticking off, pollution, clearing of adhesives, use of solvents for adhesives, for vacuum equipment, toxicity, explosive production and other inconveniences.
Among the advantages of the invention include the speed regimes of machining, increasing accuracy parameters, increased quality decreasing reject ratios and the saving of expenses of manufacturing, power, staff and the like. The apparatus may be used in outer space, under water, in corrosive media and in remote control circumstances.
Other uses include instrumentation, electronic, radio, optical, medial, machine building, mechanical machining of dielectric and current conductive parts, packing systems, hatches, covers, thermal vacuum chambers, robotic equipment and in aviation, rocket and cosmic technology at various temperatures, in rarified media and under radiation effects.
It may also be used in submicron technology to automate processes and considerably increase efficiency in operations such as thermal impurity diffusion, alloying by ion implantation, epitaxy, covering formation, metallization, photolighography, assembly and hermetic sealing of mircocircuits. Complex uses include electronic indication, check and control systems, with operation sensing devices which permits the use of automated lines and production sections.
An advantage of the invention is that the polymeric material is easily stripped and replaced when damaged - merely by removing the ring, replacing the polymeric material and replacing the ring.
Referring now to Figures 3 to 8 the values of the widths of the electrodes and the distances therebetween are shown to be critical.
For the purpose of defining the present invention it is necessary to assign specific references to the pertinent dimensions and regard to be had to Figure 3 which is a cross-sectional view on the line 3-3 of
Figure 2.
In Figure 4, the pertinent dimensions are indicated as d, L and λ. d being half of the distance apart of the electrodes 12, 15, L being the thickness of the polymer layer and being the distance equal to 2d plus the width of an electrode.
These dimensions are shown in detail in Figure 4 in which X and Y axes are shown for the graphs which follow as Figures 5 to 8.
It has been found that the following equations must be observed in order to obtain optimal results
L/λ < 0,4
d/λ ≤ 0,25
The results of numerous experiments with varying values of the dimensions are expressed in the graphs of Figures 5 to 8.
In Figures 5 to 7 it is clear that the optimum results are obtained at λ = 0,33
λ = 0,25
λ = 0,167
In Figure 8 it is clear that the optimum ratio d/Λ,must be less than or equal to 0,25
It is also to be noted that the width of the space 2d is limited by
L≤λ. the inter-electrode arcing distance, which means that L≤ d and
Δ
The minimum possible width 2d is limited by the electrical field strength of the space. If it is required to to increase the average field density for a chosen space 2d, the distance λ should be increased, the maximum increase being limited by the size or sizes of the object or objects to be attached.
The degree of fixing of an article on the surface of the apparatus is dependent to a large extent on the width of the electrodes but this dimension is limited by the drop in the intensity of the electrical forces over a wide electrode.
It is clear that if the article to be fixed to the surface is an electrically conducting material, the forces of adhesion are due to the oppositely polarised charges. Thus, if one considers Figures 3 and 4, the opposite charges are on the surface of electrode, the under surface of the dielectric (via the gap d1) the top surface of the dielectric and the underside of the artice (via the gap d2).
If the article to be fixed is a dielectric, the adhesion is due to a non-uniform field over the surface of the device with a high gradient of normal electrical intensity. The dielectric article tends to move
to the area of maximum electrical intensity to fasten on the surface of the device.
Thus, the mechanism of interaction of oppositely polarised charges which are involved in the fixing of electrical conducting materials, and the residual polarisation of the dielectric, as well as the adhesion component of the adhesive force, due to intermolecular interaction caused by the plasticity of the dielectric, contribute significantly to the efficency of the fixing.
As far as a dielectric article is concerned, it is the migration and dipole polarisation in the polymer film material, which contribute to the fixing force.
The roughness of the surface of the article and of the device results in randomly arranged series of microcavities which are referred to hereunder as Ra, and Rz, in which Ra is the arithmetic means of the deviation of the surface of the article from a reference line within the limits of the basic length; and Rz is the average height of the microcavities.
Thus, assuming that the term 2Ra is approximately equal to d1 and Rz/2 for d2, then the following relationships exist.
At Ra = I,25mcm;
d2 = 2 Ra article +2 Ra dielectric; dI = 2 Ra dielectric + 2 Ra base; or d2 = Rz article/2 + Rz diel./2;
dI = Ra diel./2 = Rz base/2.
At Ra = I,25 mem;
d2 = Rz article/2 + Rz diel./2; d1 = Rz diel./2 = Rz base/2.
Claims (10)
1.
Apparatus for electroadhesion includes one or more electrodes (14,16) coated with a polymer characterised in that it is capable of being polarised and presenting a conformable (for example, flat) surface to the article or articles to be adhered, the polymer having a predetermined plasticity for accommodating any irregularities in the surface of the article or articles to be adhered for minimum presence of gaseous media between the surface of the polymer and the surface of the article/s, and a source of electrical current for charging the electrode/s and inducing an electrical field on the article/s.
2.
The. .apparatus of claim 1 in which the surface of the apparatus, including the electrode/s is characterised in that it is prepared to substantial optical precision.
3.
The apparatus of either of the above claims characterised in that the polymer is polyvinyl chloride.
4.
The apparatus of claim 3 characterised in that the polyvinyl chloride is plasticised.
5.
The apparatus of claim 4 characterised in that the plasticiser is chosen from di-octyl adipate.
6.
The apparatus of any of the above claims characterised in that the polymer is orientated in both directions.
7.
The apparatus of any of the above claims characterised in that
L/a < 0,4
d/a ≤ 0,25
in which d is half the distance apart of the electrodes, L is the thickness of the polymer layer and is the distance equal to 2d plus the width of an electrode.
8.
The apparatus of claim 7 in which λ is between 0,167 and 0,33 and the ratio d/ λ is less than or equal to 0,25.
9.
Apparatus for electroadhesion substantially as herein described with reference to the accompanying drawings.
10.
A method of processing semi-conductors including the step of locating the workpieces on apparatus according to any one of the above claims and then carrying out the finishing operation.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA93/1623 | 1993-03-08 | ||
| ZA931623 | 1993-03-08 | ||
| ZA93/6179 | 1993-08-24 | ||
| ZA936179 | 1993-08-24 | ||
| PCT/NZ1994/000016 WO1994020984A1 (en) | 1993-03-08 | 1994-03-08 | Non-adhesive ecologically-pure electroadhesion method of clamping and fixing materials |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AU6158094A true AU6158094A (en) | 1994-09-26 |
Family
ID=27142239
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU61580/94A Abandoned AU6158094A (en) | 1993-03-08 | 1994-03-08 | Non-adhesive ecologically-pure electroadhesion method of clamping and fixing materials |
Country Status (8)
| Country | Link |
|---|---|
| CN (1) | CN1105740A (en) |
| AU (1) | AU6158094A (en) |
| CA (1) | CA2157875A1 (en) |
| FI (2) | FI941079A0 (en) |
| IL (1) | IL108893A0 (en) |
| NO (1) | NO953558L (en) |
| WO (1) | WO1994020984A1 (en) |
| ZA (1) | ZA941587B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1737564B1 (en) | 2004-03-12 | 2019-09-11 | SRI International | Mechanical meta-materials |
| US7554787B2 (en) | 2006-06-05 | 2009-06-30 | Sri International | Wall crawling devices |
| US7551419B2 (en) * | 2006-06-05 | 2009-06-23 | Sri International | Electroadhesion |
| US8515510B2 (en) | 2009-03-31 | 2013-08-20 | Covidien Lp | Electroadhesive medical devices |
| BR112013013277A2 (en) | 2010-12-01 | 2016-09-06 | Mattel Inc | drying resistant moldable dough composition |
| US9261336B2 (en) | 2013-03-15 | 2016-02-16 | Mattel, Inc. | Toy projectile and method of making |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL56224A (en) * | 1978-01-16 | 1982-08-31 | Veeco Instr Inc | Substrate clamp for use in semiconductor fabrication |
| US4384918A (en) * | 1980-09-30 | 1983-05-24 | Fujitsu Limited | Method and apparatus for dry etching and electrostatic chucking device used therein |
| JPS6156843A (en) * | 1984-08-27 | 1986-03-22 | Kokusai Electric Co Ltd | Electrostatic attractive plate |
| JP2525593Y2 (en) * | 1988-02-05 | 1997-02-12 | 株式会社 アビサレ | Electrostatic suction sheet |
| DE69103915T2 (en) * | 1990-01-25 | 1995-05-11 | Applied Materials Inc | Electrostatic clamp and method. |
| FR2661039B1 (en) * | 1990-04-12 | 1997-04-30 | Commissariat Energie Atomique | ELECTROSTATIC SUBSTRATE HOLDER. |
| JPH04342155A (en) * | 1991-05-20 | 1992-11-27 | Fujitsu Ltd | Semiconductor manufacturing device |
-
1994
- 1994-03-08 ZA ZA941587A patent/ZA941587B/en unknown
- 1994-03-08 FI FI941079A patent/FI941079A0/en unknown
- 1994-03-08 CA CA002157875A patent/CA2157875A1/en not_active Abandoned
- 1994-03-08 WO PCT/NZ1994/000016 patent/WO1994020984A1/en active Application Filing
- 1994-03-08 CN CN94104274A patent/CN1105740A/en active Pending
- 1994-03-08 AU AU61580/94A patent/AU6158094A/en not_active Abandoned
- 1994-03-08 IL IL10889394A patent/IL108893A0/en unknown
-
1995
- 1995-09-08 NO NO953558A patent/NO953558L/en unknown
- 1995-09-08 FI FI954226A patent/FI954226A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| NO953558L (en) | 1995-10-25 |
| NO953558D0 (en) | 1995-09-08 |
| FI954226A (en) | 1995-10-30 |
| FI941079A0 (en) | 1994-03-08 |
| ZA941587B (en) | 1995-03-28 |
| CA2157875A1 (en) | 1994-09-15 |
| IL108893A0 (en) | 1994-06-24 |
| FI954226A0 (en) | 1995-09-08 |
| CN1105740A (en) | 1995-07-26 |
| WO1994020984A1 (en) | 1994-09-15 |
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