Cleaning anti-reflective coating process chamber parts

Abstract

A cleaning booth has a handheld blaster, which emits a pulsed electromagnetic wave that is produced by a wave source. A fiber-optic cable feeds the wave from the source to the blaster. An operator can aim the blaster toward a part that rests on a movable table in the booth. When the operator actuates the wave source, a radiation beam from the blaster ablates anti-reflective coating residue from the part. The cleaning operation can be performed in a same room as the anti-reflective coating process equipment.

Claims

1. A system for coating ophthalmic lenses with anti-reflective coating, the system comprising: a room that contains at least: an anti-reflective coating process chamber; and apparatus for removing anti-reflective coating residue from anti-reflective coating process chamber parts, the apparatus comprising: an enclosure; an electromagnetic wave source; a trigger operable to actuate the electromagnetic wave source; a blaster connected to the electromagnetic wave source by a fiber-optic cable for feeding electromagnetic radiation from the electromagnetic wave source through the blaster; a table movably mounted within the enclosure; one or more motors operable for moving the table; and one or more control panels configured to control the electromagnetic wave source and/or the motors.

2. The system of claim 1, wherein the one or more control panels are operable to actuate the one or more motors to move the table into and out of the enclosure.

3. The system of claim 1, wherein the one or more control panels are operable to actuate the one or more motors to rotate the table inside the enclosure.

4. The system of claim 1, wherein the one or more control panels are operable to adjust one or more of beam width, intensity, or pulse length of the electromagnetic wave source.

5. The system of claim 1, further comprising a protective fabric lining at least a portion of the enclosure.

6. The system of claim 5, wherein the protective fabric is non-reflective and fire retardant.

7. The system of claim 6, wherein the protective fabric is welding cloth.

8. The system of claim 1, further comprising a movable eye-protective shutter at the front of the enclosure, wherein the shutter can be opened for loading parts into the enclosure.

9. The system of claim 8, further comprising an interlock that prevents actuating the electromagnetic wave source while the shutter is opened.

10. The system of claim 1, further comprising a vacuum for removing ash from the enclosure.

11. The system of claim 1, further comprising an exhaust system for removing smoke from the enclosure.

Description

DRAWINGS

(1) FIG. 1 depicts a cleaning booth apparatus, according to embodiments of the technology.

(2) FIG. 2 depicts the cleaning booth apparatus that is shown in FIG. 1.

(3) FIG. 3 depicts details of a control panel of the cleaning booth apparatus.

(4) FIG. 4 is a flow chart that depicts steps of a cleaning method, according to embodiments of the technology.

DETAILED DESCRIPTION

(5) Overview

(6) As mentioned, the technology resolves issues of time and dust contamination that are associated with the currently accepted method for cleaning AR coating vapor deposition chamber parts. This may be accomplished by bathing vapor deposition chamber parts in a beam of electromagnetic radiation within a controlled environment, such as a cleaning booth apparatus 100 (shown in FIG. 1 and FIG. 2).

(7) The beam ablates the AR coating residue on the parts and also may heat the parts to about 250? F.-400? F. By heating the contaminated parts, the technology may advantageously open the pores of the stainless steel so that AR coating residue that has been absorbed into the pores can be released and removed in a way that is not accomplished by room-temperature bead blasting.

(8) The electromagnetic radiation is preferably at 1028 nanometer or at 1080 nanometer wavelength. Preferably, the radiation is focused to a spot size between 2 and 15 centimeters at the table surface; in some embodiments, between 3 and 6 centimeters spot size; in some embodiments, about 4 centimeters spot size.

Example System(s)

(9) As shown in FIG. 1, a cleaning booth apparatus 100 may comprise a handheld radiation gun or blaster 102, which may emit a pulsed electromagnetic wave that may be produced by a generator or wave source 104. A fiber-optic cable 105 may feed the wave from the generator 104 to the blaster 102. The wave source 104 and other components of the cleaning booth 100 may be controlled by a panel 110 that is installed at the front of the apparatus.

(10) An operator of the cleaning booth 100 may aim the blaster 102 toward a part 106 that rests on a movable table 108. In operation of the apparatus, the part 106 may be contaminated with anti-reflective coating residue. When the operator actuates the wave source 104 by pressing a trigger 111 of the blaster, a radiation beam from the blaster 102 may ablate the residue from the part.

(11) The table 108 may be provided with a stand 112 for mounting small parts. Larger parts, such as the part 106, may rest on the table. The table may move laterally in and out of the system enclosure 114 on rails 116. When the table is fully loaded into the enclosure, parts at the front side of the table may be within the focal length of the blaster 102. The table also may rotate within the enclosure. Stepper motors 118 may drive the table. At least a portion of the enclosure (e.g., the inner walls near the table 106) may be lined with heat-resistant, non-reflective protective fabric 120 (e.g., welding cloth or similar fire-retardant fabric) to absorb radiation that reflects from or misses the parts to be cleaned.

(12) The cleaning booth 100 also may include an eye-protective shutter 122 that can be opened to permit the table to move out of the enclosure, e.g., for loading parts. The apparatus also may have a safety interlock 124 that prevents the wave source 104 being energized while the shutter is opened. There may be an opening 126 at the bottom of the shutter to permit an operator to insert her arm into the chamber and direct the blaster at the parts.

(13) Referring to FIG. 2, the cleaning booth 100 also may include a vacuum 202 with a hose 204 for removing ablation ash from the table. The cleaning booth 100 also may be provided with an exhaust fan 206 and a filtration assembly 208 at the top of the enclosure. The filtration assembly may include a HEPA filter and a carbon filter, in a flow path between the interior of the enclosure and the exhaust fan, for extracting ablation vapor from the exhaust flow.

(14) FIG. 3 depicts details of the control panel 110. For example, the control panel may include one or more buttons 302, and/or a touch screen 304, which may be operable to energize or de-energize one or more components of the cleaning apparatus. For example, certain buttons may energize or de-energize the vacuum, the motors that rotate or translate the table, the exhaust system, the wave source, or lights that illuminate the enclosure. The touch screen 304 also may be configured to indicate and/or modify one or more of an operating condition, electrical parameters, and/or error status of the electromagnetic wave source. The control panel may be implemented as one or more control panels.

Example Method(s)

(15) A method according to the technology comprises exposing parts, which are contaminated with anti-reflective coating residue, to pulsed electromagnetic radiation at about 1080 nanometer or 1028 nanometer wavelength, a beam width of between 2 and 15 centimeters (in some embodiments, between 3 and 6 centimeters; in some embodiments, about 4 centimeters), and an intensity of between about 65 W/cm.sup.2 and about 250 W/cm.sup.2. In some embodiments, the electromagnetic radiation may be scanned across the parts, either by moving the parts or moving the radiation source or both. In some embodiments, each contaminated surface of each part may be exposed to the radiation for sufficient time to heat the contaminated surface to at least 250?F and in some embodiments at least 300? F. but no more than 450?F. Advantageously, heating the contaminated surface may cause pores of the contaminated surface to expand so that residue can be extracted from the pores. Advantageously, radiation cleaning may take about 20% of time in the chamber compared to bead blasting. Additionally, radiation cleaning may not require the amount of set up, protective apparel, isolation, and clean up compared to bead blasting.

(16) It is of significance to note that, in some embodiments, the proposed electromagnetic bathing apparatus may not contaminate clean room air and may fully comply with FED 209 E 100K or ISO 8 clean room standards. Thus, the proposed apparatus may advantageously eliminate rejects due to scratches of lenses caused by accidental bead particles contamination, and may significantly improve the ergonomics and costs of the cleaning process.

(17) FIG. 4 depicts steps of a method 400, according to embodiments of the technology. At 402, place parts on the table of the cleaning booth. At 404, retract the table into the cleaning booth (if it was not already inside the booth). At 406, optionally, activate the exhaust system of the cleaning booth. At 408, optionally, close the eye protective shutter of the cleaning booth. At 410, actuate and handle the blaster of the cleaning booth to strip the AR coating from the parts. Optionally, at 412, adjust one or more of beam width, intensity, or pulse length of the electromagnetic wave source. Optionally, at 414, rotate the table (e.g., by actuating a motor). At 416, optionally, actuate the vacuum of the cleaning booth to remove ash from the stripped coating.