Modular LED heater, LED array and processing chamber

Abstract

A modular LED heater, an LED array, and a processing chamber are disclosed. The modular LED heater includes a base having one or more internal conduits through which a coolant fluid can flow. The base also includes a conduit port located on one side wall of the base and a recessed port located on an opposite side of the base. These ports are configured so that the conduit port of one modular LED heater can be inserted into the recessed port of an adjacent modular LED heater to form a fluid-tight seal. A printed circuit board having a plurality of LEDs is disposed on a front surface of the base. In addition, in some embodiments, the base includes one or more wedge clamps on its side walls for locking the modular LED heater to an adjacent modular LED heater. An LED array can be formed by assembling a plurality of modular LED heaters.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to systems for heating substrates, and more particularly, to a modular light emitting diode heater, a light emitting diode array, and a processing chamber. A modular light emitting diode (LED) heater has electrical and plumbing connections that can be used as part of an LED array. Background Art

[0002] The fabrication of semiconductor devices involves a number of discrete and complex processes. In certain processes, it may be advantageous to heat the substrate in order for the process to achieve the desired result. One method of heating the substrate is by using an array of light emitting diodes (LEDs).

[0003] In some embodiments, these LED arrays can be very large, for example, up to 8,000 light emitting diodes. Since each diode has two connections to the printed circuit board, a total of 8,000 functioning diodes and 16,000 perfect solder connections are required to obtain a fully functioning LED array. However, it is common for a small percentage (e.g., 1% to 2%) of the LEDs to not function. Reworking these arrays to replace faulty LEDs or correct solder bridges is non-trivial and time consuming. Furthermore, given the number of LEDs provided on each array, the cost of replacing the entire array is high.

[0004] Additionally, the illumination output tolerance of LEDs is typically ±2%. Therefore, it can be difficult to create an array with good thermal uniformity given the variation in illumination patterns.

[0005] Therefore, it would be advantageous if there were a more cost-effective and reliable LED array. It would be beneficial if a new LED array alleviated the above-mentioned problems. Summary of the invention

[0006] The present invention discloses a modular LED heater and an LED array. The modular LED heater includes a base having one or more internal conduits through which a coolant fluid can flow. The base also includes a plumbing port located on one side wall of the base and a matching recessed port located on the opposite side of the base. These ports are configured so that the plumbing port of one modular LED heater can be inserted into the recessed port of an adjacent modular LED heater to form a fluid-tight seal. A printed circuit board with a plurality of LEDs is disposed on the front surface of the base. In addition, in some embodiments, the base includes one or more wedge-shaped clamps on its side walls for locking the modular LED heater to an adjacent modular LED heater. An LED array can be formed by assembling a plurality of these modular LED heaters.

[0007] According to one embodiment, a modular light emitting diode (LED) heater is disclosed. The modular LED heater includes: a base having a conduit for passing a coolant fluid therethrough, the conduit being in communication with a conduit port and a recessed port; a printed circuit board disposed on a front surface of the base and including a plurality of LEDs; and a power feedthrough passing through the base and in communication with the printed circuit board to supply power to the LEDs. In some embodiments, the printed circuit board includes a metal clad printed circuit board. In some embodiments, the top side of the conduit is a bottom surface of the metal clad printed circuit board. In some embodiments, the modular LED heater includes a flex circuit disposed on a back surface of the base and in electrical communication with the power feedthrough. In some embodiments, the plurality of LEDs are divided into a plurality of zones, wherein each of the plurality of zones is powered by a dedicated power supply. In some embodiments, the base is hexagonal. In some embodiments, a wedge-shaped clamp is disposed on at least one side wall of the base to lock the modular LED heater to an adjacent modular LED heater. In yet another embodiment, the at least one side wall includes a screw channel, and the wedge clamp includes: a first screw holder having a protrusion and a through hole; a second screw holder having a protrusion and a threaded hole; and a screw passing through the first screw holder and screwed into the second screw holder, wherein tightening the screw locks the wedge clamp. In yet another embodiment, the modular LED heater includes a vertical pin disposed in the screw channel, wherein tightening the screw presses the protrusion against the vertical pin to lock the wedge clamp.

[0008] According to another embodiment, an LED array is disclosed. The LED array includes a plurality of modular LED heaters, the plurality of modular LED heaters being nested together, wherein each of the plurality of modular LED heaters includes: a base having a conduit for passing a coolant fluid therethrough, the conduit being in communication with a duct port and a recessed port; a printed circuit board disposed on a front surface of the base, comprising a plurality of LEDs; and a power feedthrough passing through the base and in communication with the printed circuit board to supply power to the LEDs; wherein the duct port of a modular LED heater in the plurality of modular LED heaters enters the recessed port of an adjacent modular LED heater and forms a fluid-tight seal, wherein the modular LED heater and the adjacent modular LED heater form a fluid path. In certain embodiments, each of the plurality of modular LED heaters includes a wedge-shaped clamp disposed on at least one side wall of the base to lock each of the plurality of modular LED heaters to an adjacent modular LED heater. In some embodiments, the LED array includes a flexible circuit disposed on a rear surface of the LED array, wherein each of the power feedthroughs is in communication with the flexible circuit. In some embodiments, the LED array includes a plurality of fluid paths, each of the plurality of fluid paths including at least one modular LED heater through which a coolant fluid passes. In some embodiments, the LED array further includes a first header and a second header, wherein the first header includes an external conduit port and a plurality of internal ports, wherein each of the plurality of internal ports communicates with a corresponding one of the plurality of fluid paths to supply coolant fluid to each of the plurality of fluid paths, and wherein the second header includes an external conduit port and a plurality of internal ports, wherein each of the plurality of internal ports communicates with a corresponding one of the plurality of fluid paths to receive coolant fluid from each of the plurality of fluid paths. In some embodiments, the plurality of modular LED heaters are identical in size and shape.

[0009] According to another embodiment, a process chamber is disclosed. The process chamber includes a workpiece support for holding a workpiece, an LED array disposed in the process chamber, and a cooler, wherein each of the plurality of modular LED heaters includes: a base having a conduit for passing a coolant fluid therethrough, the conduit communicating with a duct port and a recessed port, wherein the duct port of a modular LED heater in the plurality of modular LED heaters enters the recessed port of an adjacent modular LED heater and forms a fluid-tight seal, wherein the modular LED heater and the adjacent modular LED heater form a fluid path; a printed circuit board disposed on a front surface of the base, including a plurality of LEDs; and a power feedthrough passing through the base and communicating with the printed circuit board to supply power to the LEDs, wherein the cooler is in communication with each of the fluid paths to remove heat from the coolant fluid and recirculate the coolant fluid as the coolant fluid is discharged from the LED array. In some embodiments, the LED array further comprises: a first header, wherein the first header comprises an external conduit port and a plurality of internal ports, wherein the external conduit port is in communication with the cooler and each of the plurality of internal ports is in communication with a corresponding one of a plurality of fluid paths to supply a coolant fluid to each of the plurality of fluid paths; and a second header, wherein the second header comprises an external conduit port and a plurality of internal ports, wherein the external conduit port is in communication with the cooler and each of the plurality of internal ports is in communication with a corresponding one of the plurality of fluid paths to receive a coolant fluid from each of the plurality of fluid paths. In some embodiments, the process chamber further comprises a flexible circuit in electrical communication with each of the power feedthroughs and a power controller in electrical communication with the flexible circuit, wherein the power controller controls the power supplied to the LED in each of the plurality of modular LED heaters. In some embodiments, each of the plurality of modular LED heaters is calibrated and a power output graph is generated for each of the plurality of modular LED heaters, and the power controller uses the power output graph to control the power supplied to each of the plurality of modular LED heaters. In certain other embodiments, a plurality of power output maps are generated for each modular LED heater, and the power controller uses the temperature of the modular LED heater and the power output map to control the power supplied to each modular LED heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For a better understanding of the present invention, reference is made to the accompanying drawings, which are incorporated herein by reference and in which:

[0011] Figure 1A to Figure 1BA first embodiment of a base that can be used to form a modular LED heater is shown.

[0012] Figure 2 Shown by multiple Figure 1A The LED array formed by the base shown.

[0013] Figure 3A The fixture is shown.

[0014] Figure 3B Show use Figure 3A A second embodiment of the base of the clamp is shown.

[0015] Figure 4 Shown by multiple Figure 3B The LED array formed by the base shown.

[0016] FIG. 5A to FIG. 5B Show use Figure 1A View of a modular LED heater formed from a base shown.

[0017] Figure 6 Show use Figure 3B A modular LED heater formed from a base is shown.

[0018] Figure 7 An LED array with a flexible circuit is shown.

[0019] FIG. 8A to FIG. 8B An LED array with a header is shown.

[0020] Figure 8C A base for forming a header is shown.

[0021] Fig. 9 Shown with Fig. 8A The LED array shown is used in conjunction with a flexible circuit.

[0022] Fig.10 Show use Fig. 8A Processing chamber for the LED array shown. DETAILED DESCRIPTION

[0023] As described above, large arrays of LEDs are used to heat workpieces such as silicon wafers. Thermal uniformity of the LED array is a goal because variations in thermal uniformity can affect semiconductor processing yields.

[0024] In order to overcome the above problems, the present disclosure divides the LED array into a plurality of modular LED heaters. Each of these modular LED heaters is independently manufactured and tested. In addition, each of these modular LED heaters has its own electrical connector. The modular LED heater also includes a pipe connector so that each modular LED heater can be cooled by a fluid (e.g., cooling water).

[0025] Figure 1A A first view of one embodiment of a base 110 of a modular LED heater is shown according to one embodiment. Figure 1B The same embodiment is shown as viewed from behind the base 110. The base 110 can be any shape suitable for nesting. For example, shapes such as rectangles, hexagons, octagons, etc. can be used. In Figure 1, a hexagonal shape is shown. Therefore, in this embodiment, the base 110 has a front surface 111, a bottom surface 112 and six side walls 113. Of course, other shapes can have a different number of side walls. The base 110 includes one or more conduits 121 passing through the interior of the base. For example, the base 110 may have a conduit port 120 extending outwardly from one of the side walls 113. This conduit port 120 is used to allow coolant fluid to pass through the conduit 121 in the base 110. On an opposite side wall of the base, a mating recessed port 125 (such as Figure 1B ). The conduit port 120 and the mating recessed port 125 are configured so that when two bases 110 are placed adjacent to each other, the conduit port 120 of one base 110 is aligned with the mating recessed port 125 of the adjacent base 110, so that the conduit port 120 enters the recessed port, thereby forming a fluid-tight connection. Such a fluid-tight connection can be formed, for example, using a one-touch fitting or an orifice seal.

[0026] In some embodiments, the side wall 113 including the pipe port 120 may also include one or more alignment pins 130. A corresponding alignment slot 135 may be provided on the side wall 113 including the mating recessed port 125. Of course, the alignment pin 130 may be provided on the side wall 113 having the recessed port 125, while the alignment slot is located on the side wall 113 having the pipe port 120.

[0027] Additionally, there may be one or more vertical channels 115 extending from the front surface 111 to the bottom surface 112. These vertical channels 115 may be used to pass electrical signals (e.g., power and ground) to a printed circuit board disposed on the front surface 111 of the base, as described in more detail below.

[0028] By including the conduit port 120 and the recessed port 125, multiple bases 110 can be arranged in series so that the coolant fluid flows through the conduits 121 of several bases 110. Using this technology, the number of conduits, pipes and connections leading to the LED array can be reduced. Figure 1A to Figure 1B As shown, in one embodiment, the conduit 121 can flow through the interior of the base 110 in a serpentine pattern. Of course, other shapes are also possible. In some embodiments, the conduit 121 has a diameter between 0.1 inches and 0.5 inches. The coolant fluid can be water or another cooling liquid or gas.

[0029] As described above, the base 110 is designed to support the nesting of adjacent bases so that the pipe connections from one base 110 are attached to the adjacent base. Therefore, external pipe attachments are only used at both ends of the multiple interconnected bases. For example, Figure 2 An LED array 200 is shown constructed from a plurality of bases 110. In this embodiment, each modular LED heater 100 is identical in size and shape. Of course, modular LED heaters 100 of different sizes and / or shapes can be used to form an LED array 200.

[0030] exist Figure 2 In the illustrated embodiment, three fluid paths are defined. One fluid path is through bases 110a, 110b. A second fluid path is through bases 110c, 110d, 110e. A third fluid path is through bases 110f, 110g. Thus, in this embodiment, there are three conduit ports 120 and three mating recessed ports 125 utilizing external connections.

[0031] In one embodiment, these three fluid streams are in parallel. In other words, there is a coolant fluid source connected to the conduit ports of the bases 110a, 110c, 110f such that the coolant fluid source provides coolant directly to each of these fluid streams. In this embodiment, a fluid sink is attached to the recessed ports of the bases 110b, 110e, 110g.

[0032] In yet another embodiment, each fluid path can be connected to form a single fluid stream. For example, a first external connector can be used to connect the recessed port of base 110b with the recessed port of base 110e. A second external connector can be used to connect the pipeline port 120 of base 110c with the pipeline port 120 of base 110f. In this embodiment, only one fluid concentrator is used, and it is connected to the recessed port of base 110g. In this embodiment, each base 110 can be arranged so that the pipeline port 120 of different fluid streams is oriented in an alternating manner. In this way, the recessed port of base 110b will be connected to the pipeline port 120 of base 110e.

[0033] There are various mechanisms that may be used to connect the bases 110 together. Figure 1A to Figure 1B and Figure 2 A first embodiment is shown. In this embodiment, a screw channel 140 is formed in one or more side walls 113. In some embodiments, the screw channel 140 is disposed in a plurality of side walls 113. To this end, the screw channel 140 may be disposed at different heights. For example, Figure 1BTwo screw channels 140 are shown disposed at different heights on two adjacent side walls 113. The screw channel 140 in each base 110 may be a semicircular channel, wherein a matching semicircular screw channel 140 is disposed on an adjacent base 110. For example, referring to Figure 2 , bases 110d and 110f may each include a screw channel 140 at the same height so that when the bases are placed adjacent to each other, there is a hollow cylinder through which a clamping screw 150 may pass. One end of the screw channel 140 may include a larger radius to accommodate the head of the clamping screw 150. For example, Figure 2 The clamping screws 150 are shown disposed in the plurality of screw channels 140. The base 110 may also include one or more threaded holes 145. The distal end of each of the clamping screws 150 is screwed into a corresponding threaded hole 145. This may be Figure 2 As shown on the base 110f.

[0034] FIG. 3A to FIG. 3B Another embodiment of a base 110 that can be used to attach bases 110 together to form an array is shown. In this embodiment, Figure 3A As shown, each clamping screw 150 has a first screw holder 160a and a second screw holder 160b. The first screw holder 160a has a clearance hole, and the second screw holder 160b has a threaded hole. Therefore, the clamping screw 150 can pass through the first screw holder 160a and be screwed into the second screw holder 160b. As the clamping screw 150 is tightened, the two screw holders are pulled together.

[0035] Figure 3B Shows that it can be used Figure 3A An embodiment of a base 110 of a screw holder shown in FIG. In this embodiment, two pins 170a, 170b are vertically arranged in a screw channel 180. The size of the screw channel 180 is such that the first screw holder 160a can be installed in front of the first pin 170a in the screw channel 180. Similarly, the size of the screw channel 180 is such that the second screw holder 160b can be installed behind the second pin 170b in the screw channel 180. Adjacent bases 110 have the same configuration. The screw holders 160a, 160b each include a protrusion that is configured to extend into the gap between the corresponding pin and the base 110. In some embodiments, the screw holders 160a, 160b may have a "C" or "V" shape.

[0036] Therefore, to assemble, the second screw holder 160b is inserted into the screw channel 180 behind the second pin 170b of one base 110. Then, the second base is adjacent to the first base so that the second screw holder 160b is also behind the second pin 170b of the second base. Then, the first screw holder 160a is slid into the screw channel 180. Then, the clamping screw 150 is inserted through the first screw holder 160a and into the second screw holder 160b. When the clamping screw 150 is tightened, the protrusions on the first screw holder 160a and the second screw holder 160b are pressed against their respective pins 170, thereby forming a wedge-shaped clamp.

[0037] In other embodiments, the side wall 113 may be formed with a groove against which the protrusion of the screw holder is pressed to lock the wedge clamp in place.

[0038] Figure 4 A plurality of bases 110 connected using a wedge clamp 190 are shown. As described above, the wedge clamp 190 includes a plurality of screw holders 160a, 160b and a clamping screw 150. The screw channel 180 is also configured to ensure that the screw holders 160a, 160b have a surface that can be clamped to. In some embodiments, as described above, the pins 170a, 170b may be disposed in the screw channel 180 to provide such a surface. In other embodiments, the screw channel 180 may be formed to have such a surface.

[0039] Figure 1 to Figure 4 Mechanical interconnections between adjacent pedestals 110 are shown that allow fluid to pass through multiple pedestals 110 and also allow pedestals 110 to be joined to form an array.

[0040] Figure 5A Show Figure 1A In the modular LED heater 100 shown, a printed circuit board 300 is disposed on the front surface 111 of the base 110 . Figure 5B yes Figure 5A A cross-sectional view of a modular LED heater 100 is shown.

[0041] In some embodiments, the printed circuit board 300 is a metal clad printed circuit board. The metal clad printed circuit board has conductive traces disposed on the front side of the dielectric layer. The metal layer is bonded to the back side of the dielectric layer. Therefore, no conductive traces may be disposed on the back side of the dielectric layer. In this embodiment, the back side of the printed circuit board 300 is a metal such as aluminum or copper. In some embodiments, the back surface of the printed circuit board 300 can be soldered to the front surface 111 of the base 110 using a solder having a lower melting point than the solder used for the connectors on the printed circuit board 300. As another option, a thermal paste can be disposed between the printed circuit board 300 and the front surface 111 of the base 110. In this embodiment, the top side of the conduit 121 is the back surface of the printed circuit board 300, which provides an excellent thermal path for the coolant fluid. In other words, the back surface of the printed circuit board 300 serves as one of the walls of the conduit 121. In other embodiments, the conduit 121 can be embedded in the base 110.

[0042] In another embodiment, the front surface 111 of the base 110 may include threaded holes. In this way, the printed circuit board 300 can be fastened to the base 110, for example, by using screws attached to the threaded holes in the front surface 111 of the base 110. This can provide thermal conductivity between the printed circuit board 300 and the base 110. Thermal conductivity can be further improved by introducing a thermal paste or adhesive between the back surface of the printed circuit board and the front surface of the base 110.

[0043] A plurality of LEDs 310 are disposed on the front surface of the printed circuit board 300. In some embodiments, each printed circuit board 300 may have 250 to 1000 LEDs 310, but the number of LEDs is not limited by the present disclosure. In some embodiments, each LED 310 may be a high-power LED that emits light of one or more wavelengths that are easily absorbed by the workpiece. For example, silicon exhibits high absorptivity and low transmittance in the wavelength range between about 0.4 μm and 1.0 μm. Silicon absorbs more than 50% of the energy emitted in the wavelength range of 0.5 μm to 1.0 μm. LEDs that emit light in this wavelength range can be used. In some embodiments, LEDs made of GaN are used. These GaN LEDs emit light with a wavelength of about 450 nm. In some embodiments, GaPLEDs are used that emit light with a wavelength between 610 nm and 760 nm.

[0044] The size of LED 310 can vary. In some embodiments, each LED 310 can be 1.3 mm x 1.7 mm. In another embodiment, each LED 310 can be 1 mm x 1 mm. Of course, other sizes of LEDs are within the scope of the present disclosure. The LEDs can be conventional packaged dies, bare dies, or flip chip dies.

[0045] Each LED 310 may consume up to 3 W. Thus, a printed circuit board 300 with 500 LEDs 310 may consume 1.5 kW.

[0046] In some embodiments, the LEDs 310 may be arranged in a rectangular pattern such that there are several rows, each having a plurality of LEDs 310. The spacing between any two adjacent LEDs in a given row may be equal, except for deviations caused by the power feedthroughs. Additionally, there may be multiple columns, where each column is a row of LEDs 310. The spacing between any two adjacent columns may also be equal. Since the base 110 may be hexagonal, the number of LEDs 310 in each row may not be equal, as can be seen in FIG. 1 .

[0047] In some embodiments, all LEDs 310 are connected to a common power source. In this way, the current passing through each LED 310 is equal. In other embodiments, the LEDs 310 can be divided into multiple zones, where each zone is connected to a respective power source. In this way, the current passing through the LEDs in different zones may be different, so that there is a difference in illumination between the zones. For example, LEDs 310 closer to the side wall 113 may be located in a first zone, while LEDs 310 closer to the center of the printed circuit board 300 may be located in a second zone. The number and configuration of zones are not limited by the present disclosure.

[0048] As described above, the printed circuit board 300 may be a metal clad printed circuit board, in which the bottom surface of the printed circuit board is metal. Therefore, in order to electrically connect to the traces on the front surface of the dielectric layer, a power feedthrough 320 is provided on the top surface of the printed circuit board 300. In other words, there may be holes in the printed circuit board 300 that allow wires or other conduits to pass through to the top surface of the printed circuit board 300. The power feedthrough 320 of each printed circuit board 300 may include a common ground feedthrough and one or more voltage feedthroughs, one voltage feedthrough for each region in the printed circuit board 300. Figure 5B As shown, power feedthrough 320 passes from printed circuit board 300 through vertical channel 115 to bottom surface 112 of base 110 .

[0049] Figure 6 Show Figure 3B The base 110 is shown, wherein the printed circuit board 300 is disposed on the top surface of the base 110 .

[0050] Figure 7The bottom surface of the modular LED heater 100 array (i.e., the side opposite the LEDs 310) is shown. A flex circuit 400 can be used to connect to a power connector 410 and route these signals to the back surface of multiple modular LED heaters 100. The flex circuit 400 can have a recessed socket to connect to the power feedthrough 320 in each modular LED heater 100. The flex circuit is a thin dielectric material with multiple traces that are used to connect the power feedthrough 320 to the power connector 410. In certain embodiments, the flex circuit is flexible and bendable.

[0051] Thus, an LED array may be formed by assembling a plurality of modular LED heaters 100 into a plurality of rows, wherein each row has one or more modular LED heaters 100. As described above, plumbing connections are automatically made between adjacent modular LED heaters 100 in a row, and electrical connections are made to each modular LED heater 100 individually via the flexible circuit 400. The ability to independently supply power to each modular LED heater 100 has additional benefits, as described below.

[0052] As described above, each modular LED heater 100 has a power feedthrough 320. In other words, each modular LED heater 100 can be powered at a certain power level independently of each other modular LED heater 100. For example, modular LED heaters 100 near the outer edge of the LED array 200 can be powered at a higher power level than modular LED heaters 100 near the center of the LED array 200. Of course, the power level applied to each modular LED heater 100 is an implementation decision and is not limited by the present disclosure.

[0053] The modular LED heaters 100 are nested together and provide an effective packing density that, when properly fine-tuned, provides a uniform thermal response in the substrate. The modular LED heaters 100 also provide a method for dealing with the inherent tolerances associated with high-volume LED production. The light output of a typical die in a given batch can vary by + / -2%. It is quite troublesome to design a large LED heater with thousands of die and provide uniform light output. The modular LED heaters 100, each with hundreds of die, can be calibrated in an integrating sphere. Each modular LED heater 100 is placed in an integrating sphere, and a power output graph is generated in which the output power is plotted against the input power and the substrate temperature. In certain embodiments, some modular LED heaters may also include an optional thermistor or resistance temperature detector (RTD) to monitor the substrate temperature. Therefore, in some embodiments, multiple power output graphs are formed for each modular LED heater, each of which is generated at a different substrate temperature. The power output map for each modular LED heater 100 may be loaded into the control software so that a uniform power output may be provided to the entire LED array 200 .

[0054] For example, the control software may be used to control the input power to each of the modular LED heaters 100. The control software may be aware of the location of each modular LED heater 100 and its respective power output map. In one embodiment, the control software may then provide the input power to each modular LED heater 100 such that the output power of each modular LED heater 100 in the LED array 200 is the same. In another embodiment, the control software may then provide the input power to each modular LED heater 100 such that the output power of the LED array 200 meets a certain predefined pattern.

[0055] In one embodiment, off-the-shelf dies that are not binned can be used. In this case, each modular LED heater 100 to be used in the LED array 200 is calibrated in an integrating sphere. This technique of calibrating each modular LED heater 100 also facilitates maintenance of the LED array 200. For example, if a modular LED heater 100 fails or begins to fail, the modular LED heater 100 can simply be replaced instead of replacing the entire LED array 200. When replacing one modular LED heater 100, the power output diagram of the modular LED heater 100 is also replaced. This process ensures that the light output of the entire LED array 200 remains uniform.

[0056] In some embodiments, the LED array 200 is composed of identical modular LED heaters 100. However, other embodiments are possible. For example, in some embodiments, the density of LEDs 310 in some modular LED heaters 100 in the LED array 200 may be less than that in other modular LED heaters 100. For example, a modular LED heater 100 forming the center of the LED array 200 may have a lower LED density than a modular LED heater 100 disposed near the outer edge of the LED array 200.

[0057] In certain embodiments, it may be desirable to form an LED array 200 having a shape that cannot be formed using multiple modular LED heaters 100. Additionally, it may be desirable to minimize the number of plumbing connections.

[0058] Therefore, in certain embodiments, a first header and a second header may be employed. Fig. 8A The front surface of the LED array 500 including the first header 510a and the second header 510b is shown. Figure 8B The LED array 500 is shown without a printed circuit board installed. Figure 8B As best seen in FIG. 5 , the LED array 500 includes five fluid paths, each of which includes a variable number of modular LED heaters 100. For example, in FIG. FIG. 8A to FIG. 8B , there are 3 modular LED heaters 100 in the center fluid path; there are 2 modular LED heaters 100 in the fluid paths on each side of the center fluid path; and there is one modular LED heater 100 in the outermost fluid path.

[0059] As in FIG. 8A to FIG. 8B As can be seen in FIG. 1 , the headers 510a, 510b are located at the front and rear of the fluid path. Furthermore, the shape of the headers 510a, 510b allows for seamless interconnection with the modular LED heater 100. Additionally, the headers 510a, 510b may also include a printed circuit board 520 with LEDs 310 and power feedthroughs 320, similar to the printed circuit board 300 described above. The difference between the printed circuit board 520 for the headers 510a, 510b and the printed circuit board 300 for the modular LED heater 100 may be the shape.

[0060] Figure 8B The bases of the headers 510a, 510b and a plurality of other bases 110 are shown. Figure 8CThe base of the header 510b is shown. It can be seen that the first header 510a has an external conduit port 530 and one or more internal ports 540. When multiple modular LED heaters 100 are arranged in an array, these internal ports 540 are configured to align with the conduit ports 120 or mating recessed ports 125 of the modular LED heaters. In other words, the first header 510a has an external conduit port 530 and multiple internal ports 540, wherein the number of internal ports 540 may be equal to the number of fluid paths in the LED array 500. The first header 510a also has a conduit 550 that communicates with the external conduit port 530 and the internal port 540 to allow coolant fluid to flow through the first header 510a and reach the modular LED heater 100. Therefore, the first header 510a includes a conduit 550 to supply coolant fluid from the external conduit port 530 to each of the fluid paths in the LED array 500.

[0061] Screws 560 or other fasteners may be used to mechanically couple the first header 510a to the outermost modular LED heater 100 in the LED array 500. Additionally, there may be one or more vertical channels 525 that pass from the front surface to the bottom surface. These vertical channels 525 may be used to pass electrical signals (e.g., power and ground) to a printed circuit board disposed on the front surface of the base of the header.

[0062] The second header 510b is almost the same as the first header 510a, but may have different pipe connections. For example, the first header 510a may be a male connector as the internal port 540, while the second header 510b may be a female connector. Similarly, the external pipe port 530 of the first header 510a may be a male connector, and the external pipe port 530 of the second header 510b may be a female connector. The second header 510b includes a conduit in communication with each of the fluid paths in the LED array 500 to receive the coolant fluid from each fluid path and route the coolant fluid to the external pipe port 530.

[0063] Additionally, when headers 510a, 510b are used to form the LED array 500, the flex circuit can be modified to accommodate the power feedthroughs of the headers 510a, 510b. Fig. 9 Such a flex circuit 570 is shown with a power connector 580. The flex circuit 570 has connections to each modular LED heater 100 and each header 510a, 510b.

[0064] Fig.10A heating system is shown using an LED array 500. The heating system includes a process chamber 600 that can be used to process a workpiece 610. In some embodiments, the process chamber 600 is dedicated to heating the workpiece 610. In other embodiments, another semiconductor process, such as implantation, can also be performed in the process chamber 600.

[0065] An LED array 500 including a plurality of modular LED heaters 100 may be disposed within a processing chamber 600. FIG. 8A to FIG. 8C As shown, the LED array 500 may also include a first header 510a and a second header 510b. The workpiece 610 may be supported by a workpiece support 620. This workpiece support 620 may be movable. For example, the workpiece support 620 may be used to transport the workpiece 610 from a vacuum load lock or other port to its processing position. In other embodiments, the workpiece support 620 may be able to move vertically. In some embodiments, the workpiece support 620 may be stationary.

[0066] The LED array 500 may be disposed on or near a top surface of the process chamber 600. In some embodiments, the LED array 500 may be attached to the top surface of the process chamber 600. In other embodiments, the LED array 500 may be supported in a different manner.

[0067] Disposed outside the processing chamber 600 is a cooling system 650 that includes a coolant fluid source 651 and a coolant fluid manifold 652. In certain embodiments, the cooling system includes an external cooler 653 or heat exchanger to remove heat from the coolant fluid exhausted from the LED array 500. The coolant exhausted from the external cooler 653 can then be recirculated through the LED array 500.

[0068] A power controller 670 is also disposed near the top surface of the processing chamber 600. The power controller 670 includes a processing unit and a memory device, wherein the memory device contains instructions including the control software described above. The power controller 670 includes a plurality of power supplies, each power supply being adapted to connect to a power connector 580 of the flexible circuit 570. The power supplied to each modular LED heater 100 and each header 510a, 510b can be determined using the power diagrams described previously.

[0069] The system of the present invention has many advantages. First, as mentioned above, current LED arrays contain up to 8,000 LEDs. The probability that all 8,000 LEDs are functioning correctly and properly soldered is quite small. Typically, at least 1% of the LEDs are non-functional. Therefore, these arrays can be reworked to achieve thermal uniformity. In addition, since all LEDs are located on a single array, it is impossible to calibrate only a portion of these LEDs to ensure thermal uniformity. Therefore, it is difficult to achieve thermal uniformity. In contrast, the system of the present invention discloses an LED array consisting of a plurality of modular LED heaters, which are designed to be nested together, locked together and share pipe connections. These modular LED heaters can be tested and characterized individually so that the input power of each modular LED heater can be customized for the heater. This achieves better uniformity. In addition, if one of the modular LED heaters fails, that modular LED heater is replaced, and the remaining modular LED heaters in the LED array remain in place. This reduces the cost of repair and rework.

[0070] The scope of the present invention is not limited by the specific embodiments described herein. In fact, various other embodiments of the present invention and various modifications to the present invention in addition to the embodiments and modifications described herein will also be apparent to those of ordinary skill in the art upon reading the above description and accompanying drawings. Therefore, these other embodiments and modifications are intended to fall within the scope of the present invention. Furthermore, although the present invention has been described herein in the context of a specific implementation in a specific environment for a specific purpose, those of ordinary skill in the art will recognize that the applicability of the present invention is not limited thereto and that the present invention may be advantageously implemented in any number of environments for any number of purposes. Therefore, the claims set forth above should be interpreted in light of the full breadth and spirit of the invention as set forth herein.

Claims

1. A modular light emitting diode heater, comprising: a base having a conduit for passing a coolant fluid therethrough, the conduit communicating with a duct port and a recessed port, wherein the duct port is adapted to enter the recessed port of an adjacent modular LED heater such that the base of the modular LED heater contacts the base of the adjacent modular LED heater; A printed circuit board, disposed on the front surface of the base, comprising a plurality of light emitting diodes; as well as A power feed-through passes through the base and communicates with the printed circuit board to supply power to the light emitting diode.

2. The modular LED heater of claim 1, wherein the printed circuit board comprises a metal clad printed circuit board.

3. The modular LED heater of claim 2, wherein the top side of the conduit is the bottom surface of the metal clad printed circuit board.

4. The modular LED heater of claim 1 further comprising a flexible circuit disposed on a back surface of the base and in electrical communication with the power feedthrough.

5. The modular LED heater of claim 1, wherein a wedge-shaped clamp is disposed on at least one side wall of the base to lock the modular LED heater to another adjacent modular LED heater.

6. The modular LED heater of claim 5, wherein the at least one side wall includes a screw channel and the wedge-shaped clamp comprises: A first screw holder having a protrusion and a through hole; a second screw holder having a protrusion and a threaded hole; as well as A screw is passed through the first screw holder and threaded into the second screw holder, wherein tightening the screw locks the wedge clamp.

7. The modular LED heater according to claim 6 further includes a vertical pin disposed in the screw channel, wherein tightening the screw presses the protrusion of the first screw holder and the protrusion of the second screw holder against the vertical pin to lock the wedge clamp.

8. A light emitting diode array, comprising: A plurality of modular light emitting diode heaters are nested together, wherein each of the plurality of modular light emitting diode heaters comprises: a base having a conduit for passing a coolant fluid therethrough, the conduit being in communication with the conduit port and the recessed port; a printed circuit board disposed on the front surface of the base and comprising a plurality of light emitting diodes; and a power feedthrough, passing through the base and communicating with the printed circuit board to supply power to the light emitting diode; The pipe port of a modular LED heater among the multiple modular LED heaters enters the recessed port of an adjacent modular LED heater, so that the base of the modular LED heater and the base of the adjacent modular LED heater contact each other and form a fluid-tight seal, wherein the modular LED heater and the adjacent modular LED heater form a fluid path.

9. The LED array of claim 8, wherein each of the plurality of modular LED heaters comprises a wedge-shaped clamp disposed on at least one side wall of the base to lock each of the plurality of modular LED heaters to an adjacent modular LED heater.

10. The LED array of claim 8, further comprising a flexible circuit disposed on a rear surface of the LED array, wherein each of the power feedthroughs is in communication with the flexible circuit.

11. The LED array of claim 8, wherein the LED array comprises a plurality of fluid paths, each of the plurality of fluid paths comprising at least one modular LED heater through which a coolant fluid passes, and the LED array further comprises a first header and a second header, wherein the first header comprises an external pipe port and a plurality of internal ports, wherein each of the plurality of internal ports of the first header communicates with a corresponding one of the plurality of fluid paths to supply coolant fluid to each of the plurality of fluid paths, and wherein the second header comprises an external pipe port and a plurality of internal ports, wherein each of the plurality of internal ports of the second header communicates with a corresponding one of the plurality of fluid paths to receive coolant fluid from each of the plurality of fluid paths.

12. A processing chamber comprising: A workpiece support for holding the workpiece; A light emitting diode array is arranged in the processing chamber, and the light emitting diode array comprises: a plurality of modular light emitting diode heaters; wherein each of the plurality of modular light emitting diode heaters comprises: a base having a conduit for passing a coolant fluid therethrough, the conduit communicating with a conduit port and a recessed port, wherein the conduit port of a modular LED heater among the plurality of modular LED heaters enters the recessed port of an adjacent modular LED heater such that the base of the modular LED heater and the base of the adjacent modular LED heater contact each other and form a fluid-tight seal, wherein the modular LED heater and the adjacent modular LED heater form a fluid path; a printed circuit board disposed on the front surface of the base and comprising a plurality of light emitting diodes; and a power feedthrough passing through the base and communicating with the printed circuit board to supply power to the light emitting diode; and A cooler is in communication with each of the fluid paths to remove heat from and recirculate the coolant fluid as it is exhausted from the LED array.

13. The process chamber of claim 12, wherein the light emitting diode array further comprises: a first header, wherein the first header includes an external conduit port and a plurality of internal ports, wherein the external conduit port of the first header is in communication with the cooler, and each of the plurality of internal ports of the first header is in communication with a corresponding one of a plurality of fluid paths to supply coolant fluid to each of the plurality of fluid paths; as well as a second header, wherein the second header includes an external pipe port and a plurality of internal ports, wherein the external pipe port of the second header is in communication with the cooler, and each of the plurality of internal ports of the second header is in communication with a corresponding one of the plurality of fluid paths to receive coolant fluid from each of the plurality of fluid paths.

14. The processing chamber of claim 12, further comprising a flexible circuit electrically connected to each of the power feedthroughs and a power controller electrically connected to the flexible circuit, wherein the power controller controls power supplied to the LED in each of the plurality of modular LED heaters.

15. A processing chamber according to claim 14, wherein each of the plurality of modular LED heaters is calibrated and a power output graph is generated for each of the plurality of modular LED heaters, and the power controller uses the power output graph to control the power supplied to each of the plurality of modular LED heaters.

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