Low profile heater apparatus and method of manufacture

A novel low profile heater apparatus and method of manufacture is disclosed, which provides a lower assembly including a first sheet, a heating sheet including at least one heating element, a dielectric sheet, an intermediate sheet and one or more electrical leads configured to supply electrical power to the heating element, the electrical leads extending through a lead sleeve of an upper assembly. The upper assembly includes a top sheet with one or more split sleeves securely attached thereto, thereby forming one or more strain relief assemblies configured to prevent damage to the electrical leads. One or more stitches or coupling features securely attach the upper assembly to the lower assembly. One or more retention device are be used to securely retain the low profile heater apparatus to one or more pipes, tubes or conduits of a plumbing apparatus.

BACKGROUND

Heater jackets and heater assemblies attached to valves and pipeline heaters applied to plumbing lines are used in a wide variety of applications, including semiconductor manufacturing in chemical vapor deposition (CVD) systems. CVD processes often use flammable, pyrophoric, toxic, and corrosive gases or vapors. These need to be handled properly to ensure the safety of the users, and the post-process effluent gases need to be properly treated and neutralized to meet environmental safety standards. Downstream effluents in some thin-film manufacturing processes can lead to yield loss and unplanned equipment downtime due to clogged lines, damaged pumps and valves, and contaminated transducers. Effluent management devices such as gas abatement systems are used to destroy unreacted precursor gases and other byproducts of CVD processes when the reaction chamber is purged. The inlet plumbing of such gas abatement systems may be clogged by the condensation or accretion of various effluents on interior plumbing surfaces. Heater jackets and heater assemblies installed on plumbing lines and other components are used to maintain the various process chemicals in a vapor state, thereby reducing the condensation or accretion of these effluents. Other applications for heater jackets and heater assemblies include analytical instrumentation, pharmaceutical manufacturing, and industrial coating.

While prior art heater jackets and heater assemblies have proven useful in the past, a number of shortcomings have been identified. Specifically, prior art heaters with silicone insulation are bulky and due to space constraints in the inlet heads of gas abatement systems. Further, installation of these silicone heaters onto plumbing can be difficult, time consuming, and the heaters and electrical conductors may be damaged during the installation process, resulting in shortened service lifetime and higher maintenance costs. The difficulty in installation may also result in ineffective or non-uniform heating of the plumbing, resulting in clogging of the inlet head plumbing.

As such, there is an ongoing need for an improved heater jacket or heater assembly for use in a variety of processing systems.

SUMMARY

The present application discloses various embodiments of a low profile heater assembly and its method of manufacture. In one embodiment, the present application discloses a low profile heater assembly. The low profile heater assembly may include at least one lower assembly, that includes at least one first sheet, at least one heating sheet including at least one heating element formed on one or more dielectric sheets, at least one intermediate sheet, and one or more electrical leads in electrical communication with the at least one heating element and configured to supply electrical power to the at least one heating element. The low profile heater assembly may further include at least one upper assembly, with at least one top sheet with one or more passages formed therein, the passages configured to allow at least one lead sleeve to traverse therethrough. The electrical leads may extend through at least one lead sleeve passage formed in the lead sleeve. At least one strain relief structure configured to prevent damage to the electrical leads may be formed in the upper assembly by securing one or more split sleeves to the top sheet with one or more stitches or coupling features. The upper assembly and lower assembly may be securely joined by one or more perimeter stitches or coupling features extending around the perimeter of the upper and lower assemblies, thereby forming a heater body. In another embodiment, the low profile heater assembly further includes one or more retention members configured to engage and securely retain the heater assembly in thermal communication with one or more tubes of a plumbing apparatus. One or more reliefs, apertures, or chamfers may be formed in the heater body to provide clearance for various fittings or other features of one or more tubes of a plumbing apparatus.

In another embodiment, the present application discloses a heater apparatus, comprising at least one lower assembly including at least one first sheet made from at least one heat-resistant fabric, at least one heating sheet including at least one dielectric sheet, at least one heating element formed on the dielectric sheet, and one or more pads formed on the heating element, the pads configured to allow one or more electrical leads to be attached in electrical communication with the heating element. The lower assembly may further include at least one intermediate sheet, including one or more passages formed on or therethrough and configured to permit electrical leads to traverse through the passages and be securely attached in electrical communication with the pads formed on the heating element. The heater apparatus further comprises at least one upper assembly including at least one top sheet with at least one passage formed therein, the passage configured to allow at least one lead sleeve to traverse therethrough, the lead sleeve further including one or more split sleeves and lead sleeve passage extending therethrough, the lead sleeve passage configured to accept the electrical leads from the lower assembly to pass therethrough. One or more stitches or coupling features are used to securely attach the split sleeves to the top sheet, thereby forming a strain relief structure configured to protect the electrical leads from damage during installation or use. One or more perimeter stitches or coupling features may extend around the perimeter of the lower assembly and the upper assembly, thereby securely attaching the upper assembly to the lower assembly, to form at least one heater body.

In another embodiment, the present application discloses a method of manufacture of a low profile heater assembly. The method of manufacture includes providing at least one lower assembly, the lower assembly comprising at least one first sheet, at least one heating sheet including at least one dielectric sheet with at least one heating element formed thereon, at least one intermediate sheet, and one or more electrical leads in communication with the at least one heating element. The method further comprises providing at least one least one upper assembly, the upper assembly comprising at least one top sheet with one or more passages formed therein, the one or more passages configured to allow at least one lead sleeve to traverse therethrough, the lead sleeve further including one or more split sleeves and lead sleeve passage extending therethrough, the lead sleeve passage configured to accept the electrical leads from the lower assembly to pass therethrough. One or more strain relief structures are formed in the at least one upper assembly by stitching or otherwise coupling the split sleeves to the top sheet with one or more stitches or coupling features. The lower assembly and one upper assembly are then securely attached to each other with one or more stitches or coupling features extending around the perimeter of the lower assembly and the perimeter of the upper assembly, the one or more stitches or coupling features configured to securely attach the upper assembly to the lower assembly, to form at least one heater body.

Other features and advantages of the low-profile heater assembly and method of manufacture as described herein will become more apparent from a consideration of the following detailed description.

DETAILED DESCRIPTION

FIG.1shows a schematic of an exemplary gas abatement system100. As shown, the gas abatement system100includes at least one combustion box102and at least one inlet head104configured to route one or more effluents122,132, and142to at least one the combustion box102. Exemplary effluents include, without limitation, fluorinated gases such as NF3, F2, ClF3, C2F6, C3F8, CF4and SF6; dielectric etch input gases CHF3& C4F8; inorganic halides COCl2(phosgene), COF2(fluorophosgene), WF6, SiCl4, TiCl4, and AlCl3; byproducts HF & SiF4; hydrides, organometallics, metal alkoxides, and the like. Those skilled in the art will appreciate that any variety of effluents or byproducts may be processed in the gas abatement system100.

As shown inFIG.1, the inlet head104includes at least one manifold108with one or more tubes, conduits, pipes, transport members, or passage bodies120,130and140connected thereto or extending therefrom, each tube configured to transport at least one effluent to the combustion box102. In one embodiment, the tubes120,130,140come from a single CVD system. Optionally, each of the tubes120,130,140may come from any number or type of CVD systems. Those skilled in the art will appreciate that any number of tubes from any number or combination or types of systems may be connected to the manifold108. At least one flange106configured to mount the inlet head104to the combustion box102may be formed on or attached to the manifold108. Optionally, a flange need not be used to mount the inlet head104to the combustion box102. One or more fittings126,136,146may be attached to or formed on the respective tubes120,130,140. In the illustrated embodiment, the fittings126,136,146are configured to route at least one oxidizer112into the combustion box102via the tubes120,130,140. Optionally, the fittings126,136,146may be configured to route effluents to the tubes120,130,140. One or more fuel input bodies or transport conduits110may be attached to or formed on the manifold108. At least one port111configured to allow at least one fuel114to enter the manifold108may be attached to or formed on the fuel input body110. Optionally, the oxidizer112may also be pumped into the manifold108via port111. At least one igniter116in communication with the port111, the manifold108and the combustion box102may be located on the fuel input body110or manifold108. In the illustrated embodiment, the igniter116is a spark plug such as those used in gasoline engines. Optionally, the igniter116may be a glow plug like those used in diesel engines. The ignitor116may be powered by one or more electrical signals via a conduit118. Those skilled in the art will appreciate that that any variety of ignition devices may comprise the igniter116. During use, the oxidizer112and fuel114are pumped into the combustion box102and ignited by the igniter116, thereby burning the effluents122,132,142and creating at least one exhaust152that may exit the combustion box102via at least one exhaust conduit150. In the illustrated embodiment, the oxidizer112is pure oxygen. Optionally, air, clean dry air (CDA), nitrous oxide or a combination of these may be used as the oxidizer112. Those skilled in the art will appreciate that any variety of oxidizer may be used. In the illustrated embodiment, the fuel114is natural gas (including methane and similar hydrocarbons found in natural gas). Optionally, hydrogen, propane, kerosene, gasoline or diesel fuel or a combination of these may be used as the fuel114. Those skilled in the art will appreciate that any variety of fuels may be used as the fuel114in the gas abatement system100.

During operation of the gas abatement system100, the effluents122,132,142and other materials may condense or accrete onto various components, including the tubes120,130,140, the fittings126,136,146and the interior components or surfaces of the manifold108. At least one heater assembly200configured to maintain the tubes, pipes and fittings at an elevated temperature may be installed on these components or any components used in the gas abatement system100.FIG.2shows an elevated perspective view of an exemplary inlet head assembly104for use in the gas abatement system100shown inFIG.1. During use, heater assemblies200may be used to maintain the tubes120,130,140at a desired temperature. For example, in one embodiment, the heater assemblies200may be configured to maintain the tubes120,130,140at a temperature between about 100° C. and about 250° C. Optionally, the heater assemblies200may be configured to maintain the tubes120,130, and140at different temperatures. For example, in one embodiment, heater assemblies are configured to maintain the tubes120,130, and140at the same temperature. Those skilled in the art will appreciate that the heater assemblies200may be used to maintain the temperature of the tubes120,130,140and other inlet head components at any variety or range of temperatures.

FIGS.3-5show various views of a lower assembly230. As shown inFIG.3, in the illustrated embodiment, the lower assembly230comprises at least one first sheet232, at least one heating sheet236, and at least one intermediate sheet250. Exemplary materials for the first sheet232include polyimide fabric, Kevlar fabric, and the like. Optionally, those skilled in the art will appreciate that any variety of heat-resistant materials may be used in the first sheet232. The first sheet232may include at least one undersurface234configured to transfer heat from the heating sheet236to the tubes120,130and/or140. In one embodiment, the heating sheet236may include at least one heating element242formed on or attached to at least one surface240of at least one dielectric sheet238. In another embodiment, the heating sheet236may include one or more additional dielectric sheets238positioned above the heating element242. One or more pads244configured to provide electrical contact to the heating element242may be formed on or integral to the heating element242. One or more electrical connectors246configured to conduct electrical power or signals to the heating element242may be attached to the pads244. The heating element242may comprise an etched foil resistive material deposited on or otherwise attached to the dielectric sheet238. Exemplary resistive materials include, without limitation, Inconel 600, Nichrome (NiCr), Kanthal (FeCrAl), and Cupronickel (CuNi), although those skilled in the art will appreciate that any variety of resistive material may be used as the heating element242. Optionally, the heating element242may comprise resistance wires, intermetallic compounds, PTC ceramic elements, composite heaters, thick films and the like. In the illustrated embodiment, the dielectric sheet238is a polyimide film. Optionally, the dielectric sheet238may formed from silicone rubber, Kapton, Kevlar, Teflon or PTC rubber, although those skilled in the art will appreciate that the dielectric sheet238may be formed of any variety of materials. Optionally, at least one insulating material (not shown) and/or at least one adhesive (not shown) may be applied to the dielectric sheet238. Exemplary adhesives include, without limitation, pressure sensitive adhesives (PSA), spray adhesives, and the like. At least one temperature sensor248configured to sense the temperature of the heating sheet236and transmit a signal to one or more heater controllers (not shown) may be attached to or formed on or integral to the heating sheet236or heating element242. The upper assembly230also includes at least one intermediate sheet250configured to provide thermal or electrical insulation between the lower assembly230and the upper assembly270. Exemplary materials for the intermediate sheet250include polyimide fabric, Kevlar fabric, and the like. Optionally, those skilled in the art will appreciate that any variety of heat-resistant materials may be used in the intermediate sheet250.

As shown inFIGS.3-5, the intermediate sheet250and the dielectric sheet238include one or more passages260formed in or integral to at least one surface252and configured to allow at least one proximal end256of one or more electrical leads254to traverse therethrough and be electrically connected to the pads244or connectors246of the heating sheet236. Optionally, connectors246need not be used, and the proximal ends256of each lead254may be soldered or otherwise electrically contacted directly to the pads244. Optionally, pads244need not be used, and the proximal ends256of the electrical leads254may be attached in electrical communication directly to the heating element242in any variety of ways.FIG.4shows the completed lower assembly230.FIG.5shows an exploded view of the lower assembly230. The proximal ends256of the electrical leads254may also traverse through the passages260formed in the optional dielectric sheet238. In the illustrated embodiment, the first sheet232, the heating sheet236and the intermediate sheet250are stacked in facing alignment with no adhesive material between them. Optionally, at least one adhesive (not shown) may be applied between the sheets232,236and250. The distal ends258of the leads254extend away from the intermediate sheet250.

FIGS.6-9show various views of an upper assembly270.FIG.6shows an exploded view of the components of the upper assembly270. As shown inFIG.6, at least one passage274configured to allow at least one lead sleeve278to traverse therethrough may be formed in at least one top sheet272. Exemplary materials for the top sheet272include, without limitation, polyimide fabric, Kevlar fabric, and the like. At least one passage286configured to receive the leads254from the lower assembly230may be formed in or integral to the lead sleeve278. In the illustrated embodiment, the lead sleeve278is made of electrical insulation, wire loom material, or similar materials. Optionally, the lead sleeve may be heat-shrink tubing configured to encapsulate the leads254. Those skilled in the art will appreciate that any variety of materials may comprise the lead sleeve278. As shown inFIG.7, in the illustrated embodiment, the lead sleeve278may be split into one or more split sleeves280configured to be securely attached to the top sheet272by one or more stitches or coupling features284. In the illustrated embodiment, the stitches or coupling features284comprise a high-temperature thread. Exemplary high-temperature thread materials include, without limitation, cotton, nylon, polyester, alumina, fiberglass, aramid, Kevlar, Nomex, PTFE-coated quartz, PTFE-coated fiberglass, ceramics and stainless steel. Those skilled in the art will appreciate that any variety of thread materials may be used. Optionally, the stitches or coupling features284may comprise a variety of adhesives or elastomers, though those skilled in the art will appreciate that any variety of coupling materials may be used in the stitches or coupling features284.

FIGS.8and9show cross-sectional views of various embodiments of the upper assembly270. As shown inFIG.8, in the illustrated embodiment, the split sleeves280are fastened to the top sheet272by one or more stitches or coupling features284, thereby creating a strain relief structure290configured to prevent damage to the electrical leads shown inFIG.4, while leaving the passage286open to receive the distal ends258of the leads254.FIG.9shows an alternative embodiment of the upper assembly270wherein a cover sheet282is fastened to the top sheet272and the split sleeves280with one or more stitches or coupling features288to provide additional protection for the heater assembly200, for cosmetic purposes, or to provide additional strength to the strain relief structure290of the upper assembly270. The stitches or coupling features288may be formed from the same or similar materials or combination of materials as described above with respect to the stitches or coupling features284. In the illustrated embodiment, the strain relief structure290is configured to be very compact and provide the same or superior performance compared to strain relief configurations used in prior art silicone heater jackets.

FIGS.10-15Bshow various views of the heater assembly200.FIG.10shows an exploded view of the heater assembly200. As shown, the distal ends258of the leads254from the lower assembly230may traverse through the passage286of the lead sleeve278of the upper assembly270.FIG.11shows an elevated perspective view of the heater assembly200with the distal ends258of the leads254exiting the conduit286of the lead sleeve278. One or more connectors208configured to provide electrical connection to the leads254may be formed on or coupled to the lead sleeve278and the distal ends258of the leads254. Optionally, connectors208need not be used, and the distal ends258may be electrically connected to similar electrical leads from other heater assemblies, either in series (daisy chained) or in parallel, or connected to one or more heater controllers (not shown), in any way desired or beneficial. Those skilled in the art will appreciate that the distal ends258of the electrical leads254may be connected to any variety of device in any number of configurations.FIG.12shows an elevated perspective view of the heater assembly200with one or more perimeter stitches or coupling features212applied around the perimeter210of the heater body202formed by the upper assembly270and the lower assembly230shown inFIG.10. The perimeter stitches or coupling features212may be formed from the same or similar materials or combination of materials as described above with respect to the stitches or coupling features284and288.

FIGS.13and14show various cross-sectional views of the embodiment of the heater assembly200shown inFIG.12. As shown, the heater body202includes the upper assembly270and the lower assembly230stacked and stitched, sewn, or otherwise coupled together with the perimeter stitches or coupling features212in order to form the heater body. The proximal ends256of the leads254are electrically connected to the pads244and the temperature sensor248, as required. The pads244are in electrical contact with the heating element242formed in or on the dielectric sheet238. The distal ends258of the leads254extend through the passage286of the lead sleeve278.

FIGS.15A and15Bshow a cross-sectional view and a plan view of an alternate embodiment of a heater assembly200, respectively. One or more reliefs204configured to provide clearance for the fittings126,136,146shown inFIGS.1and2may be formed in the perimeter210of the heater body202. As shown, the perimeter stitching or coupling feature212as described above with respect toFIG.12extends around the perimeter210and reliefs204of the heater body202thereby securely attaching the upper assembly270to the lower assembly230.

FIGS.16A and16Bshow a cross-sectional view and a plan view of an embodiment of a heater assembly600, respectively. As shown inFIG.16A, the heater assembly600includes at least one lower assembly630and at least one upper assembly650. As shown inFIG.16B, one or more reliefs604analogous to the reliefs204shown in the embodiment of the heater assembly200inFIG.15Bmay be formed in the heater body602. In addition to the reliefs604, one or more apertures614and one or more chamfers616may be formed in the heater body602to provide clearance for various components or fittings126,136,146attached to the tubing120,130,140or for the manifold108shown inFIGS.1and2. As shown, one or more perimeter stitches or coupling features612extend around the perimeter610of the heater body602, around the reliefs604, around the aperture614, and along the chamfer616. The perimeter stitches or coupling features612may be formed from the same or similar materials or combination of materials as described above with respect to the stitches or coupling features212,284and288. Similar to the heater assembly200described above, the heater assembly600may include one or more cables606and one or more connectors608configured to provide electrical communication with one or more heater controllers or other components or systems as described above with respect to the heater assembly200.

FIG.17shows an elevated perspective view of an embodiment of the heater assembly200shown inFIG.15Binstalled on a tube120of the inlet head104shown inFIG.2. As shown, at least one retention member300may be used to retain the heater assembly200in contact with the tube120. In the illustrated embodiment, the retention member300is a spring clip formed from precipitation-hardened corrosion resistant (stainless) steel. Optionally, the retention member300may be formed from austenitic stainless steels, martensitic stainless steels, spring steels or high-temperature polymers such as PEEK polyether ether ketone, Ultem® polyetherimide (PEI) or Torlon® polyamide-imide (PAI), although those skilled in the art will appreciate that the retention member300may be formed from any variety of materials. In the alternative, hose clamps, cable ties, or hook & loop fasteners and straps may be used to secure the heater assembly200to the tube120. In short, any variety of coupling devices may be used to couple the heater assembly200to the tube120.

FIG.18shows a cross-sectional view of an embodiment of the retention member300shown inFIG.17. As shown, the retention member300includes at least one retention member body302with at least one inner surface304. The shape of the inner surface304could be a radius, a variable radius or elliptical shape, although those skilled in the art will appreciate that the inner surface304may have any variety of shapes. One or more tangs306may be formed on the retention member body302, the tangs306defining an opening308configured to allow the retention member300to slide over the heater assembly200without damaging it. During use, the heater assembly200may be wrapped around the tube120and one or more retention members300may be slid over the heater assembly200, thereby securely holding the heater assembly200in thermal contact with the tube120. Optionally, the retention member300may be formed integral to the heater body202.

FIGS.19A and19Bshow various cross-sectional views of an embodiment of the heater assembly200installed on a tube120shown inFIG.17. As shown, the heater assembly200comprises at least one lower assembly230and at least one upper assembly270and at least one cable206. In the illustrated embodiment, when the heater assembly200is wrapped around or otherwise positioned on the tube120, the edges220may not meet on the far side of the tube120. As such, one or more opposing edges220may define one or more gaps214. As shown, at least one surface234of the first sheet232of the lower assembly230may be retained in thermal communication with the tube120by one or more retention members300. A thermal conducting paste228configured to improve heat transfer may be applied between the surface234of the first sheet232of the heater assembly200and the outer diameter of the tube120. Optionally, thermal conducting paste228need not be used.

FIGS.20A and20Bshow various cross-sectional views of an embodiment of a heater assembly700. As shown, the heater assembly700comprises at least one lower assembly730and at least one upper assembly770and at least one cable706. One or more connectors708(not shown) may be installed onto the cable706. In the illustrated embodiment, the lower assembly730and the upper assembly770are fastened together around its perimeter with one or more perimeter stitches or coupling features712. The perimeter stitches or coupling features712may be formed from the same or similar materials or combination of materials as described above with respect to the stitches or coupling features212,284,288and/or612. In the illustrated embodiment, when the heater assembly700is wrapped around or otherwise positioned on the tube120, the edges720substantially meet on the far side of the tube720. As such, any gap722between the edges720may be minimized or eliminated, potentially leading to superior heating performance of the heater assembly700relative to the heater assembly200described above. As shown, the inner surface734of the first sheet732of the lower assembly730is retained in thermal communication with the tube120by one or more retention members300. A thermal conducting paste728configured to improve heat transfer between the heater assembly700and the tube120may be applied between the surface734of the first sheet732of the heater assembly700and the outer diameter of the tube120. Optionally, thermal conducting paste728need not be used. In another embodiment, the edges720of the heater assembly700may overlap or interfere with each other.

FIGS.21and22show various views of the inlet head104with heaters installed on tubes120,130and140. As shown inFIG.21, heater assemblies200are installed on each tube120and130, and a heater assembly700is installed on tube140. As shown, each of the three heater assemblies are securely retained in contact with their respective tubes by three retention members300, although those skilled in the art will appreciate that any number of retention members300may be used. As shown, the gap214is visible on the heater assembly200installed on tube120. The heater assembly700installed on tube140does not exhibit a gap for the reasons described above with respect toFIGS.20A and20B. For the heater assembly200installed on tube130, the gap214is not visible inFIG.21, but it can be seen in the section view onFIG.22. Referring toFIG.22, the design of the retention member300enables its installation over the heaters at a variety of angular orientations with respect to the heater assemblies (hereinafter “heaters”)200,700, the tubes120,130,140, and the fittings126,136,146, thereby enabling flexibility in installation and removal of the heaters200and700on the inlet head104.

FIGS.23and24show various views of an outer insulator jacket400configured to be detachably installed around and/or over the inlet head104.FIG.23shows a cross-sectional view of an embodiment of the outer insulator jacket400. The outer insulator jacket400includes at least one jacket body418. In the illustrated embodiment, the jacket body418comprises at least one outer layer402, at least one middle layer404and at least one inner layer406. Exemplary materials for the layers402,404,406include, without limitation, polyimide fabric, Kevlar fabric, and the like. Those skilled in the art will appreciate that any variety of heat-resistant materials may be used in the layers402,404,406. Those skilled in the art will appreciate that only a single layer or two layers may be used. The inner layer404may comprise at least one insulating material. Exemplary insulating materials include, without limitation, fiberglass, asbestos, Kevlar and the like. Those skilled in the art will appreciate that any variety of insulating materials may be used to form the insulating layer404. Optionally, any of the three layers402,404,406may be made from an insulating material. The layers402,404,406may be joined together by one or more stitches or coupling features408. The perimeter stitches or coupling features712may be formed from the same or similar materials or combination of materials as described above with respect to the stitches or coupling features212,284,288,612and/or712. At least one retention member414may be secured to at least one first fastener412. In the illustrated embodiment, the retention member414is a rubber or fabric strap with at least one attachment region422formed thereon or integral thereto. Those skilled in the art will appreciate that the retention member414may be made from any variety or combination of materials. Exemplary attachment region configurations include, without limitation, holes, slots, grommets, and the like. Those skilled in the art will appreciate that the attachment region422could be any variety of configurations. At least one second fastener416configured to secure the outer insulator jacket400around the inlet head104may be retained in the jacket body418. Exemplary fasteners416include snaps, buckles, D-rings, and the like. One or more tabs420configured to be grasped by an operator during installation of the outer insulator jacket400may be formed on or integral to the retention member414. Those skilled in the art will appreciate that the retention member414may be made of a hook and loop fastening device such as Velcro® formed on or attached to the jacket body418.

FIG.24shows a section view of the embodiment of the outer insulator jacket400installed on the inlet head104. During installation of the outer insulator jacket400, the user may actuate the tab420to urge the attachment region422onto or over the fastener416, enabling the user to detachably install the outer insulator jacket400onto the inlet head104. During operating of the gas abatement system100, the outer insulator jacket400may be installed to reduce the transfer of thermal energy from the inlet head104and heaters200,700to the ambient environment, thereby enabling the user to closely and precisely control the heaters200,700to maintain the inlet head104at a desired temperature or range of temperatures.

FIGS.25-27Bshow various views of an outer heater jacket assembly800(also referred to as heater assembly800).FIGS.25and26show various cross-sectional views of an embodiment of the outer heater jacket assembly800. As shown, the outer heater jacket assembly800includes at least one lower assembly830, at least one upper assembly850and at least one cable804. The lower assembly830may include at least one first sheet832, at least one heating sheet836, at least one dielectric sheet838, and at least one intermediate sheet834. Exemplary materials for the first sheet832include polyimide fabric, Kevlar fabric, and the like as described above with respect to heater assemblies200,600and700. Optionally, those skilled in the art will appreciate that any variety of heat-resistant materials may be used in the first sheet832or the various components forming the jacket assembly800. The heating sheet836may include at least one heating element842formed on or attached to at least one dielectric sheet838. One or more pads844configured to provide electrical contact to the heating element842may be formed on or integral to the heating element842. Optionally, the pads844need not be formed on the heating element842, and the proximal ends856of the electrical leads854may be attached in electrical communication directly to the heating element842. The heating element842may comprise an etched foil resistive material deposited on the dielectric sheet838. Exemplary resistive materials have been listed above with respect to heater assembly200. Optionally, the heating element842may comprise resistance wire, intermetallic compounds, PTC ceramic elements, composite heaters, thick films and the like. In the illustrated embodiment, the dielectric sheet838is a polyimide film. Optionally, the dielectric sheet838may be silicone rubber, Kapton, Kevlar, Teflon or PTC rubber, although those skilled in the art will appreciate that any variety of material may be used in the dielectric sheet838. At least one insulating material (not shown) and/or at least one adhesive (not shown) may be applied to the dielectric sheet838to securely attach the elements of the heating sheet together. Exemplary adhesives have been described above with respect to the heater assembly200. At least one temperature sensor848may be attached to or formed integral to the heating sheet836or the heating element842.

Referring toFIGS.25and26, the upper assembly850may include at least one top sheet852with at least one lead sleeve878extending through at least one aperture860formed in the top sheet852. Optionally, the upper assembly850may include one or more cover sheets882fastened to the top sheet852to provide additional protection for the heater assembly800, for cosmetic purposes, or to provide additional protection of the electrical leads854. As shown inFIG.25, the lead sleeve878may be split into one or more split sleeves880configured to be securely attached to the top sheet852by one or more stitches or coupling features884. The distal ends858of the electrical leads854from the lower assembly830may traverse through the passage886of the lead sleeve878. The upper assembly850is secured to the lower assembly830with one or more perimeter stitches or coupling features812. In the illustrated embodiment, the perimeter stitches or coupling features812comprises a high-temperature thread. The stitches or coupling features812and884may be formed from the same or similar materials or combination of materials as described above with respect to the stitches or coupling features212,284, and288.

Referring toFIGS.27A and27B, at least one retention member806may be secured to at least one first fastener810located in the heater body802. In the illustrated embodiment, the retention member806is a rubber or cloth strap with at least one attachment region822formed thereon or integral thereto. Those skilled in the art will appreciate that the retention member806may be made from any variety of materials. Exemplary attachment region822configurations include, without limitation, holes, slots, grommets, and the like. Those skilled in the art will appreciate that the attachment region could be any variety of configurations. At least one second fastener814configured to secure the outer heater jacket assembly800around the inlet head104may be retained in the heater body802. Exemplary second fasteners814include snaps, buckles, D-rings, and the like. At least one tab816may be formed on or integral to the retention member806. Those skilled in the art will appreciate that the retention member806may be made of a hook and loop fastening device such as Velcro® formed on or attached to the heater body802.

FIG.28shows a section view of the embodiment of the outer heater jacket assembly800installed on the inlet head104. During installation, the user may actuate the tab816to urge the attachment region822onto or over the second fastener814, enabling the user to detachably install the outer heater jacket assembly800onto the inlet head104. During operating of the gas abatement system100, the outer heater jacket assembly800may be installed to reduce the transfer of thermal energy from the inlet head168and heaters200,700to the ambient environment, thereby enabling the users to more closely and precisely control the heaters200,700to maintain the inlet head104at a desired temperature or range of temperatures.

The present application describes various embodiments of a low profile heater apparatus and attachment method. While particular embodiments have been illustrated and described herein, it will be apparent that modifications to the design may be made without departing from the spirit and scope of the embodiments of the invention. As such, it is appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described above herein. Rather, the scope of the present invention includes both combinations and sub-combinations of various features described hereinabove as well as variations and modifications thereto which would occur to a person of skill in the art upon reading the above description and which are not in the prior art.