Elastomeric seal

Abstract

An elastomeric seal for use in semiconductor manufacturing apparatus comprising an ink on at least a portion of the upper surface thereof, wherein the ink comprises a barrier material, the barrier material being operable to prevent or reduce degradation of the elastomeric seal from ultraviolet (UV) radiation.

Claims

1. An elastomeric seal for use in semiconductor manufacturing apparatus comprising an ink printed on at least a portion of the upper surface thereof, wherein the ink comprises a barrier material and a binder, the barrier material being operable to prevent or reduce degradation of the elastomeric seal from ultraviolet (UV) radiation.

2. An elastomeric seal according to claim 1, wherein the seal is generally elongate, preferably comprising a continuous loop operable to fit into a channel.

3. An elastomeric seal according to claim 2, wherein the elastomeric seal comprises a lower portion and an upper portion, wherein the lower portion is operable to fit into a channel via friction fit.

4. An elastomeric seal according to claim 3, wherein the upper portion of the elastomeric seal protrudes from the channel into which the lower portion is operable to fit and which upper portion may be exposed to UV radiation, in use.

5. An elastomeric seal according to claim 1, wherein in the elastomeric seal is to be a simple O-ring, face seal, lip seal, D-seal, X seal T-Seal, cap seal, wiper seal, energising lip seal or spring seal or wafer handling elastomeric parts such as end effector pads or suction cups.

6. An elastomeric seal according to claim 1, comprising a polymeric material comprising one or more fluoropolymer materials, respectively comprising one or more homopolymers or copolymers derived from combinations of monomers comprising fluorine.

7. An elastomeric seal according to claim 1, wherein the barrier material comprises metallic particles.

8. An elastomeric seal according to claim 7, wherein the metallic particles include one or more of the following: aluminium, silver, nickel, titanium, zinc, gold and copper.

9. An elastomeric seal according to claim 7, wherein the metallic particles are incorporated into the ink in the form of flakes.

10. An elastomeric seal according to claim 7, wherein the metallic particles have an average particle size of from about 0.5 to 75 microns.

11. An elastomeric seal according to claim 1, wherein the barrier material comprises inorganic compounds.

12. An elastomeric seal according to claim 11, wherein the inorganic compounds include one or more of the following: titanium dioxide, aluminium dioxide, carbon black.

13. An elastomeric seal according to claim 11, wherein the inorganic compounds have an average particle size of from about 0.1 to 10 microns.

14. A method of forming an elastomeric seal for use in semiconductor manufacturing apparatus comprising printing an ink on at least a portion of an upper surface thereof, wherein the ink comprises a barrier material and a binder, the barrier material being operable to prevent or reduce degradation of the seal from ultraviolet (UV) radiation.

15. A method of preventing or reducing degradation of an elastomeric seal by ultraviolet (UV) radiation, the method comprising printing an ink on at least a portion of an upper surface of the said elastomeric seal, wherein the ink comprises a barrier material and a binder, the barrier material being operable to prevent or reduce degradation of the elastomeric seal from ultraviolet (UV) radiation.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) For a better understanding of the invention and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic diagrams in which:

(2) FIG. 1 shows a perspective view of an elastomeric seal having an ink on the upper surface thereof.

(3) FIG. 2 shows a circular cross sectional view perpendicular to the longitudinal axis of an elastomeric seal having an ink on the upper surface thereof.

(4) FIG. 3 shows a cross sectional view perpendicular to the longitudinal axis of an elastomeric seal having an ink on the upper surface of the upper portion thereof.

DETAILED DESCRIPTION

(5) Referring to FIG. 1, there is provided an elastomeric seal 102 that is elongate, comprising a longitudinal axis along its length. The elastomeric seal 102 comprises a continuous loop that fits into a channel (not shown) via a friction fit. The elastomeric seal 102 comprises an inner edge 104 and an outer edge 106. The elastomeric seal 102 comprises a lower portion (not shown) and an upper portion (not shown). The lower portion fits into the channel (not shown) via a friction fit and the upper portion (not shown) protrudes from the channel into which the lower portion is fitted. The dimensions of the channel correspond to the dimensions and shape of the lower portion of the elastomeric seal (not shown).

(6) The elastomeric seal 102 is formed from FFKM, however, it will be appreciated by a skilled person that the elastomeric material used to form the elastomeric seal 102 may be varied.

(7) The upper portion (not shown) comprises an upper surface 108 which, when the elastomeric seal is utilised in semiconductor manufacturing apparatus (not shown), is exposed to ultraviolet (UV) radiation. An ink 110 is on the upper surface 108 of the elastomeric seal 102.

(8) Referring to FIG. 2, there is provided a cross section 202 of an elastomeric seal 204 perpendicular to the longitudinal axis (not shown) of the elastomeric seal (204). The elastomeric seal 204 fits into channel 206 via a friction fit. The elastomeric seal 204 comprises an inner edge 208 and an outer edge 210. The elastomeric seal 204 comprises a lower portion 212 and an upper portion 214. The lower portion 212 fits into the channel 206 via a friction fit and the upper portion 214 protrudes from the channel 206 into which the lower portion 212 fits. The dimensions of the channel 206 correspond to the dimensions and shape of the lower portion 212 of the elastomeric seal. The upper portion 214 comprises an upper surface 216. The upper surface is exposed to ultraviolet (UV) radiation when the elastomeric seal is utilised in semiconductor manufacturing apparatus (not shown). An ink 218 is on the upper surface 216 of the upper portion 214 of the elastomeric seal 204.

(9) The cross section 202 of the elastomeric seal 204 perpendicular to the longitudinal axis (not shown) of the elastomeric seal is circular. The elastomeric seal 204 is cylindrical (not shown). The cross section 202 of the elastomeric seal 204 has a diameter that corresponds to the width of the channel 206 into which the lower portion 212 of the elastomeric seal 204 fits.

(10) The elastomeric seal 204 is formed from FFKM, however, it will be appreciated by a skilled person that the elastomeric material used to form the elastomeric seal 204 may be varied.

(11) Referring to FIG. 3, there is provided a cross section 302 of an elastomeric seal 304 perpendicular to the longitudinal axis (not shown) of the elastomeric seal 304. The elastomeric seal 304 fits into a channel 306 via a friction fit. The elastomeric seal 304 comprises a lower portion 308 and an upper portion 310. The lower portion 308 fits into the channel via a friction fit and the upper portion 310 protrudes from the channel 306 into which the lower portion 308 fits. The dimension of the channel 306 correspond to the dimensions and shape of the lower portion 308 of the elastomeric seal 304. The upper portion 310 comprises an upper surface 312. The upper surface 312 is exposed to ultraviolet (UV) radiation when the elastomeric seal 304 is utilised in semiconductor manufacturing apparatus (not shown). An ink 314 is on the upper surface 312 of the upper portion 310 of the elastomeric seal 304.

(12) The lower portion 308 of the elastomeric seal 304 is part oval in cross section perpendicular to the longitudinal axis (not shown) of the elastomeric seal 304. The lower portion 308 comprises an inner edge 316 and an outer edge 318.

(13) The upper portion 310 of the elastomeric seal 304 is rectangular in cross section perpendicular to the longitudinal axis (not shown) of the elastomeric seal 304. The upper surface 312 comprises two corners of the upper portion 310 which are curved. The upper portion 310 sits on top of the lower portion 308 to make a conjoined shape. The upper portion 310 comprises an inner edge 320 and an outer edge 322.

(14) The width of the upper portion 310 of the elastomeric seal 304 is wider than the width of the lower portion 308 of the elastomeric seal 304. The point of attachment 324 between the lower portion 308 and the upper portion 310 of the elastomeric seal 304 is narrower than the width of the lower portion 308 of the elastomeric seal 304. The lower portion 308 of the elastomeric seal 304 has a cross section that corresponds to the width of the channel 306 into which the lower portion 308 is fitted. The width of the upper portion 310 is wider than that of the channel 306 into which the lower portion 308 is fitted. The inner edge 320 and the outer edge 322 of the upper portion 310 of the elastomeric seal 304 overlap the edges of the channel 306 into which the lower portion 308 is fitted.

(15) The elastomeric seal 304 is formed from FFKM, however, it will be appreciated by a skilled person that the elastomeric material used to form the elastomeric seal 304 may be varied.

(16) For a better understanding of the invention and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the following experimental data.

EXAMPLES

(17) Ink Compositions

(18) Ink compositions (composition 1 and composition 2) were prepared according to the formulations in Table 1.

(19) TABLE-US-00001 TABLE 1 Ink compositions Composition 1 Composition 2 (wt %) (wt %) Aluminium 35 60 Barrier flake material Epoxy acrylate 10 Resin resin binder binder* Tripropylene 20 Resin glycol binder diacrylate** Petroleum spirit 10 Solvent (40-60) 1-Propanol 10 Solvent Ethanol 35 Solvent Cyclohexanone 20 Solvent *Aliphatic epoxy acylate from Sartomer ® CN152 **Tripropylene glycol diacrylate (TPGDA) from Sartomer ® SR306

(20) The properties of elastomeric seals having the ink compositions (coating compositions 1 and 2) deposited thereon and comparative elastomeric seals without such compositions deposited thereon, were tested via the following methods.

(21) Preparation of Test Substrates:

(22) Compositions 1 and 2 were applied to 20×10×2 mm sheets of elastomeric material at 50 micron thickness, as shown in Table 2.

(23) TABLE-US-00002 TABLE 2 Test substrates Exam- Exam- Exam- Exam- Exam- Exam- ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 Ink com- 1 1 1 2 2 2 position Elasto- Perlast V75SC Nanofluor Perlast V75SC Nanofluor meric G67P Y75N G67P Y75N Material

(24) The same elastomeric materials were exposed to the same conditions without ink compositions 1 and 2 applied thereon, to form comparative examples 1-3.

(25) The sheets were exposed to UV radiation (185-254 nm) for 1100 hours at 75° C. exposed to UV radiation at 2 cm distance under a 600 watt UV source producing 185 and 254 nm wavelength light in a closed/ventilated chamber.

(26) The samples were tested and evaluated for weight, colour, surface and hardness changes before and after exposure to the UV radiation according to the procedures below.

(27) Weight Change:

(28) Weight change of the samples was calculated according to the following formula:
Weight change (%)=((Initial weight−final weight)/Initial weight)*100

(29) Colour Change:

(30) Change in colour was evaluated against a fresh sample of the same elastomeric material having the ink applied thereon. The change was analysed under fluorescent white light.

(31) Surface Change:

(32) Change in surface was evaluated according to the extent of cracking. The change was analysed using a low powered light microscope at 30× and 97× magnification and using a rating of 1 to 5, with 5 being the least degradation.

(33) Hardness Change:

(34) Change in hardness was evaluated according to ASTM D2240 using a Shore A durometer.

(35) The results are shown in Table 3, below.

(36) TABLE-US-00003 TABLE 3 Test Results Weight change Colour Surface after UV change change Hardness exposure after UV after UV change after (%) exposure exposure UV exposure Example 1 2.1 — 5 — Example 2 2.4 — 5 — Example 3 3.4 — 5 — Example 4 1.2 — 5 — Example 5 1.6 — 5 — Example 6 1.8 — 5 — Comparative 6.2 — 5 +2 example 1 Comparative 6.8 white to 1 +3 example 2 yellow Comparative 10.2 translucent 2 +2 example 3 to opaque

(37) Surface Change:

(38) 5 No Change

(39) 4 Slight Change

(40) 3 Moderate Change

(41) 2 Moderate/Severe Change

(42) 1 Severe Change

(43) The results demonstrate that the elastomeric seals according to the present invention comprising Aluminium-based ink printed on at least a portion of an upper surface thereof, show less change in the characteristics of the seal, thus demonstrating increased resistance to degradation upon exposure to short wave ultraviolet (UV) radiation than non-coated elastomeric seals. The elastomeric seals according to the present invention therefore have longer lifetimes when utilised in semiconductor processing apparatus and processes.

(44) Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to the public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

(45) All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

(46) Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

(47) The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination of the features disclosed in this specification (including any accompanying claims, abstract or drawings), or to any novel one, or any novel combination of the steps of any method or process so disclosed.