Optical heating device and channel structure

Abstract

To provide an optical heating device which is capable of more uniformly cooling mounted light-emitting elements as a whole and which is entirely small-sized further than the prior arts.SOLUTION: An optical heating device comprises: a light-emitting element substrate where a plurality of light-emitting elements are mounted on a mounting surface which is one principal surface; a heat sink including a plurality of heat absorption channels, in which a cooling medium is circulated, and provided on a principal surface of the light-emitting element substrate at the opposite side of the mounting surface; and a channel structure which includes a main body part, a supply port for making the cooling medium flow from the outside to the inside of the main body part and a discharge port for discharging the cooling medium from the inside of the main body part to the outside and is provided on a side face of the heat sink at the opposite side of the light-emitting element substrate. The main body part of the channel structure includes: a split portion communicating with the supply port; a confluent portion communicating with the discharge port; a plurality of first channels communicating between the split portion and each of the plurality of heat absorption channels of the heat sink; and a plurality of second channels communicating between the confluence portion and a portion different from the portion, with which the first channel communicates, in each of the plurality of heat absorption channels of the heat sink.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light heating device and also to a flow path structure mounted on the light heating device. [Background technology]

[0002] In the semiconductor manufacturing process, various heat treatments such as film formation, oxidation and diffusion, modification, and annealing are performed on objects to be treated, including semiconductor wafers. Light is often used in carrying out these heat treatments. Heating an object to be treated using light in this manner is called "light heating." Furthermore, light used for heating is called "heating light."

[0003] As a device for heat-treating a semiconductor wafer using light heating, a heating device in which LEDs, which are one type of light-emitting element, are densely mounted is known. It is known that the light-emitting efficiency of light-emitting elements such as LEDs and LDs decreases when the temperature of the element itself increases. For this reason, for example, a heating device has been proposed that includes a cooling member into which a cooling medium is supplied in order to cool the LEDs mounted as light-emitting elements, as described in Patent Document 1 below. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-153734 A Summary of the Invention [Problem to be solved by the invention]

[0005] 2. Description of the Related Art Heating devices used in the manufacturing process of semiconductor wafers are expected to be able to uniformly heat-treat the entire semiconductor wafer, which is the object to be treated.

[0006] However, the temperature of the cooling medium gradually rises as it flows through a specific flow path while absorbing heat from the light-emitting elements. Therefore, the longer the total length of the flow path through which the cooling medium flows while absorbing heat, the less heat the cooling medium can absorb as it moves downstream. This characteristic creates a difference in light emission efficiency between the light-emitting elements arranged upstream and downstream of the flow path through which the cooling medium flows, resulting in uneven heating of the semiconductor wafer.

[0007] In view of the above, the inventors have considered providing a plurality of flow paths through which the cooling medium flows and making each of the flow paths relatively short. However, when providing a plurality of flow paths, it is necessary to provide a pipe for introducing the cooling medium and a pipe for guiding the discharged cooling medium for each flow path.

[0008] When piping for introducing the cooling medium and piping for guiding the discharged cooling medium are provided for each of the multiple flow paths, space is required for providing the piping, which leads to an increase in the size of the entire device.

[0009] It is also possible to install a manifold and consolidate the piping midway in order to split or join the cooling medium, but installing a manifold requires space for the manifold and the connection between the manifold and the cooling flow path becomes complicated, which increases the installation area and may increase the size of the entire device.

[0010] In view of the above problems, an object of the present invention is to provide a light heating device that can cool all of the mounted light-emitting elements more uniformly and that is smaller in size than conventional devices. [Means for solving the problem]

[0011] The light heating device according to the present invention is a light emitting element substrate having a plurality of light emitting elements mounted on a mounting surface which is one of the main surfaces; a heat sink provided on a main surface of the light-emitting element substrate opposite to the mounting surface, the heat sink having a plurality of heat absorption flow paths through which a cooling medium flows; a flow path structure provided on a side of the heat sink opposite to the light emitting element substrate, the flow path structure having a main body and a supply port for supplying the cooling medium from an outside to an inside of the main body and a discharge port for discharging the cooling medium from the inside to the outside of the main body; The main body portion of the flow path structure is A flow dividing portion connected to the supply port; A confluence portion connected to the discharge port; a plurality of first flow paths connecting the flow dividing portion and each of the plurality of heat absorption flow paths of the heat sink; The heat sink is characterized in that it comprises a plurality of second flow paths which connect the junction portion to portions of the plurality of heat absorption flow paths of the heat sink different from the portions to which the first flow paths are connected.

[0012] The optical heating device having the above configuration can supply cooling medium that has absorbed almost no heat to each of the multiple heat absorption flow paths, and can cool the entire light-emitting element substrate uniformly compared to a heat sink with only one heat absorption flow path.

[0013] Furthermore, since the optical heating device of the above configuration is equipped with a flow path structure, there is no need to provide separate piping for flowing the cooling medium into each heat absorption flow path of the heat sink, separate piping for discharging the cooling medium, and a manifold for dividing or merging the cooling medium.

[0014] In addition, the flow path structure has a structure equivalent to these pipes and manifolds formed integrally inside the main body. Therefore, the flow path structure can be arranged in a smaller space than when the pipes and manifolds are provided separately. In other words, the light heating device having the above configuration has a smaller overall device size than conventional devices.

[0015] In the above-mentioned light heating device, The main body portion of the flow path structure is a first flow path plate having the flow dividing portion and the plurality of first flow paths; The liquid supply device may further include a second flow path plate having the junction portion and the plurality of second flow paths.

[0016] With the above configuration, the entire flow path structure can be made smaller, and therefore the entire light heating device can be made smaller. In addition, if the first flow path plate and the second flow path plate are separable from each other, they can be replaced or cleaned individually.

[0017] Furthermore, in the above-mentioned light heating device, In the main body of the flow path structure, the second flow path plate may be disposed closer to the heat sink than the first flow path plate.

[0018] The first flow path of the first flow path plate is used for a cooling medium having a relatively low temperature before absorbing heat from the light emitting element substrate, and the second flow path of the second flow path plate is used for a cooling medium having a relatively high temperature after absorbing heat from the light emitting element substrate.

[0019] If the first flow path plate is disposed closer to the heat sink than the second flow path plate, the cooling medium flowing through the first flow path absorbs heat from the heat sink and the second flow path plate, causing the temperature to rise before flowing into the heat sink, which leads to a decrease in the amount of heat that can be absorbed from the light-emitting element substrate when flowing through the heat absorption flow path.

[0020] In the optical heating device having the above configuration, the cooling medium flowing through the first flow path is prevented from absorbing heat from the heat sink, and therefore the heat sink included in the optical heating device having the above configuration can achieve a higher heat dissipation effect.

[0021] In addition, in the above-mentioned light heating device, The main body of the flow path structure may have a heat insulating material disposed between the first flow path plate and the second flow path plate.

[0022] In the optical heating device having the above configuration, the cooling medium flowing through the first flow path is prevented from absorbing heat from the second flow path plate, and therefore the heat sink included in the optical heating device having the above configuration can achieve a higher heat dissipation effect.

[0023] The flow path structure of the present invention comprises: The light heating device includes a flow path structure. Effect of the Invention

[0024] According to the present invention, it is possible to realize a light heating device that can cool the mounted light emitting elements more uniformly as a whole and that is smaller in size than the conventional device. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of a light heating device. [Diagram 2] This is a drawing of the heat sink as seen from the +Z side. [Diagram 3] 1 is a diagram showing the first flow path plate as viewed from the +Z side. [Figure 4] 13 is a diagram showing the second flow path plate as viewed from the +Z side. [Diagram 5] This is a drawing of the top plate as seen from the +Z side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The light heating device and the flow path structure of the present invention will be described below with reference to the drawings. Note that the drawings are all schematic illustrations, and the numbers on the drawings do not necessarily correspond to the actual numbers.

[0027] Fig. 1 is a cross-sectional view showing a schematic configuration of one embodiment of a light heating device 1. As shown in Fig. 1, the light heating device 1 includes a light source unit 10 and a chamber 20 in which a substrate W1 to be processed is housed. The substrate W1 to be processed is assumed to be a semiconductor wafer, a display panel, a glass substrate, or the like. The semiconductor wafer is not particularly limited to a Si substrate, and a SiC substrate, or the like, is also assumed.

[0028] 1, the direction in which the light source unit 10 and the chamber 20 face each other is defined as the Z direction, and the plane perpendicular to the Z direction is defined as the XY plane. Note that in this embodiment, there is no need to distinguish between the X direction and the Y direction which are perpendicular to each other and form the XY plane, but for ease of explanation, the direction in which a supply port 15 and a discharge port 16, which will be described later, are aligned is defined as the X direction.

[0029] In addition, when expressing a direction, if a distinction is made between positive and negative directions, a positive or negative sign is added, such as "+Z direction" and "-Z direction." When expressing a direction without distinguishing between positive and negative directions, it is simply written as "Z direction."

[0030] 1, the light source unit 10 includes a plurality of light-emitting elements 11 that emit heating light L1, a light-emitting element substrate 12, a heat sink 13, and a flow path structure 14. The flow path structure 14 is provided with a supply port 15 for supplying a cooling medium C1 and an exhaust port 16 for exhausting a cooling medium C2, and is connected to a device (not shown) that controls the supply and exhaust of the cooling media (C1, C2).

[0031] 1, the chamber 20 of this embodiment includes a light-transmitting window 21 for taking in the heating light L1 emitted from the light source unit 10, and a support member 22 for supporting the substrate W1 to be processed inside. That is, the substrate W1 to be processed supported by the support member 22 is heated by irradiating the main surface W1a of the substrate W1 with the heating light L1 emitted from the light source unit 10 and taken in through the light-transmitting window 21.

[0032] The light emitting element 11 in this embodiment is an LED having a wavelength of 395 nm that shows an intensity peak of the spectrum of emitted light. However, the light emitting element 11 may be an LED that shows an intensity peak in another wavelength band, or may be a light emitting element other than an LED, such as an LD, or a combination of an LED and an LD.

[0033] The light-emitting element substrate 12 is a substrate having a plurality of light-emitting elements 11 mounted on one of its main surfaces, the mounting surface 12a, on which patterns for mounting the light-emitting elements 11 and circuit elements, and a wiring pattern are formed.

[0034] 1, only one light emitting element substrate 12 is shown, but the light source unit 10 may include a plurality of light emitting element substrates 12. Note that, although this is merely an example, in consideration of the temperature distribution during lighting, the light emitting elements 11 are arranged at a density of 2 pieces / cm on the mounting surface 12a of the light emitting element substrate 12. 2 ~12 pieces / cm 2 The total number of light emitting elements 11 mounted in the light source unit 10 is about 1500 to 8500. The mounting density of the light emitting elements 11 does not need to be uniform over the entire mounting surface 12a of the light emitting element substrate 12, and it is sufficient that the light emitting elements 11 are mounted within the above-mentioned mounting density range in a predetermined arrangement area.

[0035] 2 is a diagram of the heat sink 13 as viewed from the +Z side. The heat sink 13 is provided on the main surface opposite to the mounting surface 12a (+Z side) of the light-emitting element substrate 12. The heat sink 13 of this embodiment has a plurality of heat absorption flow paths 13a formed on the main surface on the +Z side for circulating the cooling medium C1. The shape of the heat absorption flow paths 13a is appropriately adjusted according to the temperature distribution during operation of the light-emitting element substrate 12, and the shape of the heat absorption flow paths 13a shown in FIG. 2 is merely one example.

[0036] The heat sink 13 in this embodiment is a copper plate, but the material of the heat sink 13 may be, for example, aluminum or stainless steel, other than copper.

[0037] The heat absorption flow path 13a is a recess formed on the main surface on the +Z side of the heat sink 13, and becomes a closed flow path through which the cooling medium C1 can flow by arranging the flow path structure 14 (second flow path plate 14b) on the +Z side and closing it as shown in Fig. 1. Note that the heat absorption flow path 13a may be formed inside the heat sink 13 and configured so that the cooling medium C1 can flow without the need for the flow path structure 14.

[0038] The cooling medium C1 is flowed from the flow path structure 14 into one end 13b of the heat absorption flow path 13a, flows through the heat absorption flow path 13a while absorbing heat generated by the light emitting element 11, and is discharged from the other end 13c to the flow path structure 14 as the cooling medium C2 having absorbed heat. Note that the flow direction of the cooling medium C1 may be reversed, and the configuration may be changed so that the cooling medium C1 flows to the other end 13c and is discharged from the one end 13b to the flow path structure 14 as the cooling medium C2.

[0039] Here, the terms cooling medium C1 and cooling medium C2 are used to distinguish between the cooling medium up to the other end 13c of the heat absorption flow path 13a and the cooling medium after being discharged from the other end 13c of the heat absorption flow path 13a.

[0040] In the present embodiment, the cooling medium (C1, C2) is water, but a cooling medium other than water may be used.

[0041] As shown in FIG. 1, the flow path structure 14 includes a main body portion 14p formed by stacking a first flow path plate 14a, a second flow path plate 14b, and a top plate 14c, a supply port 15 through which the cooling medium C1 is supplied, and a discharge port 16 through which the cooling medium C2 is discharged.

[0042] In the main body 14p in this embodiment, the second flow path plate 14b, the first flow path plate 14a, and the top plate 14c are stacked in this order from the surface opposite to the mounting surface 12a of the light-emitting element substrate 12 toward the +Z side so as to absorb as little heat as possible before the cooling medium C1 reaches the heat sink 13. However, when heat exchange between the flow path plates does not become a major problem, the order in which the first flow path plate 14a, the second flow path plate 14b, and the top plate 14c are combined does not have to be in this order.

[0043] Fig. 3 is a drawing of the first flow path plate 14a as viewed from the +Z side, Fig. 4 is a drawing of the second flow path plate 14b as viewed from the +Z side, and Fig. 5 is a drawing of the top plate 14c as viewed from the +Z side. In Fig. 3 and Fig. 4, the supply port 15 and the discharge port 16 are virtually shown by dashed lines at the positions of the supply port 15 and the discharge port 16 as viewed in the Z direction. However, in Fig. 3, the dashed line indicating the discharge port 16 overlaps with a through hole 33 described later and has the same shape.

[0044] 1 to 5, for convenience of illustration, the specific structure for stacking and fixing the heat sink 13 and the plates (14a, 14b, 14c) is omitted. These members may be fixed by any method, such as fixing with bolts and nuts, fixing with a clamping member, fixing with a fitting portion formed on each member, or joining by brazing using a brazing material.

[0045] 3, the first flow path plate 14a is provided on a main surface on the +Z side with a flow dividing section 30, a plurality of through holes 32 that communicate with one end 13b of the heat absorption flow path 13a of the heat sink 13 in a state where the first flow path plate 14a is combined with the heat sink 13, and a plurality of first flow paths 31 that communicate with the flow dividing section 30 and each of the plurality of through holes 32. Note that the first flow paths 31 only need to be able to sequentially supply the cooling medium C1 to the heat sink 13, and are not necessarily required to be connected to one end 13b of the heat absorption flow path 13a.

[0046] The shapes of the flow dividing section 30 and the first flow passage 31 are appropriately adjusted according to the shape of the heat absorption flow passage 13a of the heat sink 13, and the shape of the first flow passage 31 shown in FIG. 3 is merely one example.

[0047] The first flow path plate 14a is provided with through holes 33 for guiding the cooling medium C2 discharged from the second flow path plate 14b to the discharge port 16 of the top plate 14c.

[0048] The first flow path plate 14a in this embodiment is a plate made of copper, but other materials such as aluminum and stainless steel may be used as the material of the first flow path plate 14a in addition to copper.

[0049] The flow dividing section 30 and the first flow path 31 are recesses formed on the main surface on the +Z side of the first flow path plate 14a, and as shown in FIG. 1, by placing the top plate 14c on the +Z side and closing it, a closed flow path is formed through which the cooling medium C1 can flow.

[0050] The flow dividing section 30 and the first flow passage 31 may be formed by excavating the inside of the first flow passage plate 14a, and may be configured to allow the cooling medium C1 to flow therethrough without requiring the top plate 14c.

[0051] 4, the second flow path plate 14b is provided on its +Z-side main surface with a junction 40, a plurality of through holes 42 that communicate with the other end 13c of the heat absorption flow path 13a of the heat sink 13 in a state where the second flow path plate 14b is combined with the heat sink 13, and a plurality of second flow paths 41 that communicate with the junction 40 and each of the plurality of through holes 42. Note that the second flow paths 41 only need to be able to sequentially discharge the cooling medium C2 from the heat sink 13, and are not necessarily required to be connected to the other end 13c of the heat absorption flow path 13a.

[0052] The shapes of the junction 40 and the second flow passage 41 are appropriately adjusted according to the shape of the heat absorption flow passage 13a of the heat sink 13, and the shape of the second flow passage 41 shown in FIG. 4 is merely one example.

[0053] The second flow path plate 14b is provided with a through hole 43 for guiding the cooling medium C1 discharged from the first flow path plate 14a to one end 13b of the heat absorption flow path 13a of the heat sink 13.

[0054] The second flow path plate 14b in this embodiment is a plate made of copper, but other materials such as aluminum and stainless steel may be used as the material of the second flow path plate 14b in addition to copper.

[0055] The confluence 40 and the second flow path 41 are recesses formed on the main surface on the +Z side of the second flow path plate 14b, and as shown in FIG. 1, the first flow path plate 14a is placed on the +Z side to close the confluence 40 and the second flow path 41, thereby forming a closed flow path through which the cooling medium C2 can flow.

[0056] In addition, the confluence portion 40 and the second flow path 41 may be formed by excavating the inside of the second flow path plate 14b, and may be configured to allow the cooling medium C2 to flow without the need for the first flow path plate 14a.

[0057] 5, the top plate 14c is a member having a supply port 15 and a discharge port 16 formed on a main surface on the +Z side. As described above, the top plate 14c in this embodiment functions as a lid for forming the flow path of the first flow path 31 of the first flow path plate 14a.

[0058] For example, in a case where the first flow path 31 is formed inside the first flow path plate 14a and the top plate 14c is not necessary, the top plate 14c may not be provided, and the supply port 15 and the discharge port 16 may be formed directly in the first flow path plate 14a or the second flow path plate 14b.

[0059] In this embodiment, the top plate 14c is a copper plate, but the material of the top plate 14c may be aluminum, stainless steel, or the like, in addition to copper. Although preferred materials have been exemplified for each of the plates (14a, 14b, 14c), in consideration of ease of joining by brazing and occurrence of electrolytic corrosion, it is preferable that the materials of the plates (14a, 14b, 14c) are all the same material. Furthermore, in consideration of thermal conductivity, it is preferable that the plates (14a, 14b, 14c) are all copper plates.

[0060] Here, the thickness of each of the plates (14a, 14b, 14c) is arbitrary, but in order to prevent the entire device from becoming large, the thickness of each of the plates (14a, 14b, 14c) is preferably within the range of 1 mm to 50 mm, and more preferably within the range of 2 mm to 30 mm. Note that the thickness of each of the plates (14a, 14b, 14c) may be different from each other.

[0061] Furthermore, the main body 14p may not be separable into a plurality of plates, but may be configured as an integral member having all the functions of the plates (14a, 14b, 14c). For example, the main body 14p may be a member that has been machined to form the flow dividing section 30, the plurality of first flow paths 31, the flow merging section 40, and the plurality of second flow paths 41 inside a block-shaped object, or may be an integral member in which the plates (14a, 14b, 14c) are all bonded or welded together.

[0062] With the above configuration, it is possible to supply the cooling medium C1 that has not absorbed much heat to each of the multiple heat absorption flow paths 13a of the heat sink 13, and it is possible to cool the entire light-emitting element substrate 12 more uniformly and more efficiently than a conventional heat sink having only one heat absorption flow path.

[0063] Furthermore, since the optical heating device 1 having the above configuration is provided with the flow path structure 14, it is not necessary to provide separate pipes for feeding the cooling medium C1 into each heat absorption flow path 13a of the heat sink 13, pipes for discharging the cooling medium C2, and manifolds for dividing or merging the cooling media (C1, C2). In other words, the optical heating device 1 as a whole is smaller than the conventional device.

[0064] [Another embodiment] Another embodiment will be described below.

[0065] <1> In the embodiment described above, the main body 14p of the flow path structure 14 has been described as having a configuration in which the first flow path plate 14a and the second flow path plate 14b are in direct contact with each other. However, the flow path structure 14 may have a thermal insulating material disposed between the first flow path plate 14a and the second flow path plate 14b.

[0066] The heat insulating material is, for example, a ceramic plate, etc. When the heat insulating material is sandwiched between the first flow path plate 14a and the second flow path plate 14b, holes for passing the cooling media (C1, C2) are formed at positions corresponding to the through holes (32, 33, 42, 43) formed in each plate (14a, 14b) so as not to hinder the flow of the cooling media (C1, C2).

[0067] It should be noted that the heat insulating material does not need to have the same shape as the first flow path plate 14a or the second flow path plate 14b when viewed in the Z direction, and may have any shape.

[0068] <2> The configurations of the light heating device 1 and the flow path structure 14 described above are merely examples, and the present invention is not limited to the respective configurations shown in the drawings. [Explanation of symbols]

[0069] 1 : Optical heating device 10: Light source section 11: Light emitting element 12: Light emitting element substrate 12a: Placement surface 13: Heat sink 13a: Endothermic channel 14: Flow path structure 14a: First flow path plate 14b: Second flow path plate 14c: Top plate 14p: Main body 15: Supply port 16: Outlet 20: Chamber 21: Translucent window 22: Support member 30: Diversion section 31: First channel 32: Through hole 33: Through hole 40: Junction 41: Second flow path 42: Through hole 43: Through hole C1: Cooling medium C2: Cooling medium L1: Heating light W1: Substrate to be processed W1a: Main surface

Claims

1. a light emitting element substrate having a plurality of light emitting elements mounted on a mounting surface which is one of the main surfaces; a heat sink provided on a main surface of the light-emitting element substrate opposite to the mounting surface, the heat sink having a plurality of heat absorption flow paths through which a cooling medium flows; a flow path structure provided on a side of the heat sink opposite to the light emitting element substrate, the flow path structure having a main body and a supply port for supplying the cooling medium from an outside to an inside of the main body and a discharge port for discharging the cooling medium from the inside to the outside of the main body; The main body portion of the flow path structure is A flow dividing portion connected to the supply port; A confluence portion connected to the discharge port; a plurality of first flow paths connecting the flow dividing portion and each of the plurality of heat absorption flow paths of the heat sink; An optical heating device characterized by comprising the confluence portion and a plurality of second flow paths that connect portions of each of the plurality of heat absorption flow paths of the heat sink that are different from the portions to which the first flow paths are connected.

2. The main body portion of the flow path structure is a first flow path plate having the flow dividing portion and the plurality of first flow paths; The light heating device according to claim 1 , further comprising a second flow path plate having the junction and the plurality of second flow paths.

3. The light heating device according to claim 2 , wherein in the main body of the flow path structure, the second flow path plate is disposed closer to the heat sink than the first flow path plate.

4. The light heating device according to claim 2 , wherein the main body of the flow path structure has a heat insulating material disposed between the first flow path plate and the second flow path plate.

5. A flow path structure provided in the light heating device according to any one of claims 1 to 4.

Images