Light source module and method for manufacturing light source module

Abstract

Provided are: a light source module in which heat discharge properties for heat generated in a light-emitting element are enhanced, and in which the occurrence of migration in the light-emitting element is suppressed; and a method for manufacturing the light source module.　The present invention comprises a substrate, a submount disposed on a main surface of the substrate, a plurality of light-emitting elements arranged in a first direction on a mounting surface of the submount, and a gold sintered body that joins the submount and the plurality of light-emitting elements. The gold sintered body spreads to the outside of the light-emitting elements when viewed from the direction normal to the mounting surface of the submount. The height with reference to the mounting surface of the submount in a portion of the plurality of light-emitting elements that is positioned between a first light-emitting element and a second light-emitting element, which are adjacent to each other in the first direction, is lower than that of a light-emitting layer of the first light-emitting element and a light-emitting layer of the second light-emitting element.

Description

Light source module and method for manufacturing the light source module

[0001] The present invention relates to a light source module and a method for manufacturing the light source module.

[0002] Conventionally, light source modules equipped with light emitting elements such as LED elements and LD elements have been required to have higher brightness depending on the application. For example, Patent Document 1 listed below discloses a light source module in which a plurality of LED elements are arranged on a substrate to achieve high brightness.

[0003] JP 2018-081832 A

[0004] It is known that LED and LD elements lose their luminous efficiency and their peak wavelength shifts when the temperature of the element itself rises during lighting. Furthermore, one of the challenges in high-brightness light source modules is to arrange them more densely and to realize materials and structures with better heat dissipation performance.

[0005] A typical light source module is fabricated by mounting a light emitting element on a substrate using a bonding material containing a metal material. Taking into consideration factors such as heat dissipation and cost, a bonding material containing silver as the main component, more specifically, silver paste, is often used as the bonding material used when mounting the light emitting element.

[0006] However, in a light source device in which a light emitting element is mounted using silver paste, repeated application of a voltage to the light emitting element causes a phenomenon called migration near the electrode (anode) of the light emitting element (sometimes called "ion migration"). Specifically, migration here refers to the phenomenon in which silver contained in the silver paste comes into contact with moisture present around the LED element near the electrode, and when a voltage is applied, silver or silver oxide precipitates.

[0007] In consideration of the above-mentioned problems, the light source device of the present invention aims to provide a light source module that improves the heat dissipation properties of heat generated in light-emitting elements and suppresses the occurrence of migration in the light-emitting elements, as well as a method for manufacturing the light source module.

[0008] The light source module of the present invention comprises a substrate, a submount arranged on a main surface of the substrate, a plurality of light-emitting elements arranged in a first direction on the mounting surface of the submount, and a gold sintered body joining the submount and the plurality of light-emitting elements, wherein the gold sintered body extends outside the light-emitting elements when viewed from the normal direction of the mounting surface of the submount, and in a portion of the plurality of light-emitting elements located between a first light-emitting element and a second light-emitting element that are adjacent to each other in the first direction, the height, relative to the mounting surface of the submount, is lower than both the light-emitting layer of the first light-emitting element and the light-emitting layer of the second light-emitting element.

[0009] Here, the terms "first light-emitting element" and "second light-emitting element" are not used to refer to two specific light-emitting elements, but are intended to refer to any combination of light-emitting elements adjacent to each other in the first direction.

[0010] Furthermore, "extending outside the light-emitting element" here refers not only to the case where it extends over the entire periphery surrounding the light-emitting element, but also to the case where it extends outside the light-emitting element in a portion of the periphery of the light-emitting element.

[0011] A submount is a structure that combines, for example, an aluminum nitride (AlN) substrate with a thick copper (Cu) film that has relatively low thermal resistance. When mounting a semiconductor chip on the submount, the semiconductor chip is placed on a predetermined location on the submount that has been coated with a paste containing gold particles, which will be the material for the gold sintered body. The paste is then dried and heat-treated to sinter it, and the resulting gold sintered body bonds the submount to the light-emitting element.

[0012] The gold sintered body forms a conductive path between the substrate and the light-emitting element. Specifically, the gold sintered body electrically connects the conductive portion formed on the submount to at least one electrode of the light-emitting element when joining the submount and the light-emitting element.

[0013] Gold (Au) exhibits a thermal resistivity almost equivalent to that of silver (Ag). Furthermore, gold (Au) has a lower tendency to ionize than silver (Ag), and the migration that occurs when using a silver sintered body hardly occurs. Therefore, light source modules using gold sintered bodies have less migration than conventional ones, achieving longer life and higher reliability.

[0014] In addition, the side of the light-emitting element often has a side surface of the light-emitting layer that generates light when electricity is applied. Therefore, if the height of the gold sintered body, particularly the portion located between the elements, becomes higher than the light-emitting layer when the mounting surface of the submount is used as the reference, there is a risk that the gold sintered body in that portion will electrically short out the light-emitting layer of the light-emitting element. Furthermore, if the gold sintered body is formed to a height that exceeds the light-emitting layer and reaches the light-emitting surface, it may obstruct the progression of light emitted from the light-emitting element, reducing the light-emitting efficiency.

[0015] Therefore, the height of the gold sintered body between the first and second light-emitting elements must be lower than the height of the light-emitting layer of the first light-emitting element and the height of the light-emitting layer of the second light-emitting element. Also, it is preferable that the height of the gold sintered body be lower than the height of any of the light-emitting layers of the respective light-emitting elements.

[0016] As a result, the light source module having the above configuration achieves high heat dissipation performance and suppresses migration, and also prevents electrical shorts between the light-emitting layers of the light-emitting elements via the gold sintered body.

[0017] In the light source module, the distance between the first light emitting element and the second light emitting element may be 10 μm to 100 μm.

[0018] If the first and second light-emitting elements are too close to each other, they may be electrically shorted out. Also, if the first and second light-emitting elements are too close to each other, it becomes difficult to control the height of the gold sintered body located between the first and second light-emitting elements.

[0019] Conversely, if the first light emitting element and the second light emitting element are too far apart, they will not be arranged closely together, and high brightness will not be achieved.

[0020] In view of the above, it is preferable that the separation distance between the first light-emitting element and the second light-emitting element is within the above range.

[0021] In the light source module, the plurality of light emitting elements may have a side length of 50 μm to 2,000 μm when viewed in a direction perpendicular to the light emitting surface.

[0022] If the light emitting element is too small, the bonding strength will be low, making it difficult to achieve high reliability.

[0023] Conversely, if the light emitting element is too large, a large amount of the gold sintered body is pushed aside, causing a large bulge on the side surface of the light emitting element, making the light emitting element more susceptible to short circuits.

[0024] From the above, it is preferable that the length of one side of the light emitting element when viewed in a direction perpendicular to the light emitting surface is within the above range.

[0025] The method for manufacturing a light source module of the present invention is characterized by comprising the steps of: (A) preparing a substrate and a submount; (B) applying a paste containing gold particles onto the main surface of the submount by screen printing; (C) placing the submount, with the paste applied to its main surface, on the main surface of the substrate; (D) placing a light-emitting element on the portion of the main surface of the submount where the paste has been applied; and (E) heating the paste to form a gold sintered body after step (D) is performed.

[0026] Screen printing can form a film with a relatively uniform thickness by adjusting the mesh opening size and thickness according to the diameter of the particles contained in the paste. Therefore, compared to pin transfer, screen printing makes it easier to form a relatively thin and uniform film of paste on the mounting surface of the submount.

[0027] Therefore, according to the above manufacturing method, if the paste film thickness is uniform, the minimum amount of paste required is applied, and the amount of paste extruded when the light-emitting elements are placed is reduced, resulting in the effect of enabling light-emitting elements to be arranged at a higher density.Furthermore, the light source module manufactured by the above method allows the shape and thickness of the gold sintered body to be precisely adjusted, thereby achieving a long life and high reliability of the light source module.

[0028] In view of the above problems, the present invention provides a light source module and a method for manufacturing the light source module that improves the ability to dissipate heat generated in the light-emitting element and suppresses the occurrence of migration in the light-emitting element.

[0029] 1 is a schematic diagram of an embodiment of a light source module viewed as a whole in the X direction; FIG. 2 is a diagram of the light source module with a cover member removed viewed from the +Z side; FIG. 3 is an enlarged view of the periphery of the light-emitting element in FIG. 1; FIG. 4 is a schematic diagram showing the state of a light source module during manufacture; FIG. 5 is a schematic diagram showing the state of a light source module during manufacture; FIG. 6 is a schematic diagram showing the state of a light source module during manufacture; FIG. 7 is a schematic diagram showing the state of a light source module during manufacture; FIG. 8 is a schematic diagram showing the state of a light source module during manufacture;

[0030] The light source module and the manufacturing method of the light source module of the present invention will be described below with reference to the drawings. Note that the drawings are all schematic illustrations, and the dimensional ratios and numbers in the drawings do not necessarily correspond to the actual dimensional ratios and numbers.

[0031] [Configuration] First, the configuration of the light source module 1 of this embodiment will be described. Fig. 1 is a schematic diagram of one embodiment of the light source module 1 as a whole viewed in the X direction. Fig. 2 is a diagram of the light source module 1 with the cover member 2 removed as viewed from the +Z side. Fig. 3 is an enlarged diagram of the periphery of the light-emitting element in Fig. 1.

[0032] As shown in Figures 1 to 3, the light source module 1 in this embodiment comprises a cover member 2, a substrate 10, a submount 11, a gold sintered body 12, a plurality of insulating substrates (13, 13, 13), a plurality of light-emitting elements (20a, 20b, 20c, 20d), a plurality of first wire wirings (21, 21, 21, 21) extending from each of the light-emitting elements (20a, 20b, 20c, 20d), and a plurality of second wire wirings (22, 22) extending from the submount.

[0033] 1 and 2, the plane parallel to the mounting surface 11a of the submount 11 is defined as the XY plane, and the direction perpendicular to the XY plane is defined as the Z direction. 2, the direction in which the second wire wiring 22 extends is defined as the X direction, and the direction in which the first wire wiring 21 extends is defined as the Y direction.

[0034] 2, in the embodiment described below, there is no particular distinction between the X direction and the Y direction regarding the arrangement of the light-emitting elements (20a, 20b, 20c, 20d). Therefore, there is no essential difference between the case where the X direction corresponds to the first direction and the case where the Y direction corresponds to the first direction, but for convenience of explanation, the following description will be given assuming that the Y direction corresponds to the first direction.

[0035] Furthermore, when expressing a direction, if a distinction is made between positive and negative directions, the direction is written with a positive or negative sign, such as "+Z direction" or "-Z direction," and when a direction is expressed without distinguishing between positive and negative directions, it is simply written as "Z direction."

[0036] The cover member 2 includes a light exit window 2a for extracting light emitted from the light emitting elements 20 to the outside of the light source module 1, and a support body 2b that is placed on the insulating substrate 13 and supports the light exit window 2a. The material for forming the light exit window 2a is appropriately selected depending on the wavelength band of the light emitted from each light emitting element (20a, 20b, 20c, 20d), and may be, for example, glass or resin.

[0037] The substrate 10 is a substrate having high heat dissipation properties via one electrode of the light-emitting elements (20a, 20b, 20c, 20d) and the submount 11. Materials for the substrate 10 include, for example, copper (Cu), aluminum (Al), alumina (Al2O3), etc. The substrate 10 may be a substrate made of a single material, or may be a substrate in which layers made of multiple materials are stacked.

[0038] The substrate 10 may be connected to a heat sink for heat dissipation, or may be formed with fins to enhance heat dissipation.

[0039] 3, the submount 11 is a substrate including a ceramic layer 11p made of aluminum nitride (AlN) and a thermally conductive layer 11q made of copper (Cu). The ceramic layer 11p is a layer for ensuring insulation between the substrate 10 and the light-emitting elements (20a, 20b, 20c, 20d). The thermally conductive layer 11q is made of a material with a lower thermal resistance than the ceramic layer 11p and is a layer for more efficiently dissipating heat generated by the light-emitting elements 20.

[0040] Furthermore, a conductive pattern (not shown) is formed on the surface of the submount 11, and the conductive pattern ensures electrical connection between the light-emitting elements (20a, 20b, 20c, 20d) and the substrate 10.

[0041] The ceramic layer 11p may be made of a material other than aluminum nitride (AlN), such as silicon carbide (SiC).

[0042] The material constituting the thermal conduction layer 11q may be, for example, carbon (C) or the like in addition to copper (Cu).

[0043] The gold sintered body 12 is a sintered body formed by applying a paste containing gold particles onto the submount 11, placing the light emitting element 20 to be fixed thereon, and then drying and sintering the paste.

[0044] 2 and 3, the gold sintered body 12 fixes the light-emitting elements (20a, 20b, 20c, 20d) on the submount 11. Furthermore, the gold sintered body 12 electrically connects the electrode 20e formed on the −Z side of the light-emitting elements (20a, 20b, 20c, 20d) to a conductive pattern (not shown) on the submount 11. Note that, as shown in FIG. 2, the gold sintered body 12 does not need to extend over the entire periphery of the light-emitting elements (20a, 20b, 20c, 20d) when viewed from the +Z side, and may extend only partially outside the light-emitting elements (20a, 20b, 20c, 20d).

[0045] The insulating substrate 13 is a substrate for ensuring insulation from the substrate 10. A conductive pattern 13a is formed on the insulating substrate 13. The conductive pattern 13a has a potential different from that of the thermal conduction layer 11q when power is supplied to the light-emitting elements (20a, 20b, 20c, 20d).

[0046] 2, the light-emitting elements (20a, 20b, 20c, 20d) are LED elements fixed so as to be arranged in the X and Y directions on a gold sintered body 12 formed on a submount 11. In the description of this embodiment, since the Y direction corresponds to the first direction, the light-emitting elements 20a and 20c correspond to the first light-emitting elements, and the light-emitting elements 20b and 20d correspond to the second light-emitting elements.

[0047] The light emitting elements 20a and 20c, and the light emitting elements 20b and 20d, which are arranged in the X direction, are spaced apart by 50 μm in the X direction. The light emitting elements 20a and 20b, and the light emitting elements 20c and 20d, which are arranged in the Y direction, are spaced apart by 50 μm in the Y direction.

[0048] As described above, the separation distance between adjacent light-emitting elements is preferably within the range of 10 μm to 100 μm in order to achieve high-density arrangement of the light-emitting elements (20a, 20b, 20c, 20d) and to control the height of the gold sintered body 12. However, if the desired brightness can be obtained or if there is little effect on the height control of the gold sintered body 12, the separation distance between adjacent light-emitting elements may be outside this range.

[0049] As shown in Fig. 3, the light-emitting elements (20a, 20b, 20c, 20d) have a light-emitting layer 20p that emits light when power is supplied and that is partially exposed on the outer surface. In order to prevent an electrical short circuit between the light-emitting layers 20p of the light-emitting elements (20a, 20b, 20c, 20d), the height h1 of the gold sintered body 12 from the mounting surface 11a of the submount 11 is configured to be lower than the height h2 of the light-emitting layers 20p of the light-emitting elements (20a, 20b, 20c, 20d).

[0050] 3, the height of the gold sintered body 12 located between adjacent light-emitting elements (20a, 20b, 20c, 20d) in the X or Y direction is shown as being constant, but the height of the gold sintered body 12 may vary at that position. When the height of the gold sintered body 12 varies, the height h1 is the height of the highest point of the gold sintered body 12 located between adjacent light-emitting elements (20a, 20b, 20c, 20d).

[0051] Furthermore, the light emitting elements (20a, 20b, 20c, 20d) in this embodiment are square elements with a side length of 350 μm when viewed in a direction perpendicular to the light emitting surface 20f, i.e., the Z direction.

[0052] The length of one side of the light-emitting elements (20a, 20b, 20c, 20d) when viewed from the Z direction is arbitrary, but as described above, from the viewpoint of stably arranging the light-emitting elements (20a, 20b, 20c, 20d) in a desired orientation on the mounting surface 11a of the submount 11, the length is preferably within the range of 50 μm to 2,000 μm.

[0053] In addition, in the X direction or Y direction, except for the region between adjacently arranged light-emitting elements (20a, 20b, 20c, 20d), the height h1 of the gold sintered body 12 is arbitrary as long as the light-emitting layers 20p of the multiple light-emitting elements (20a, 20b, 20c, 20d) are not electrically short-circuited.

[0054] As shown in Figures 1 and 2, the first wire wiring 21 is a wire that connects an electrode (not shown) formed on the +Z side surface of each light-emitting element (20a, 20b, 20c, 20d) to a conductive pattern 13a formed on the insulating substrate 13.

[0055] 2, the second wire wiring 22 is a wire that connects the submount 11 to the conductive pattern 13a formed on the insulating substrate 13 arranged on the −X side of the submount 11. Although the first wire wiring 21 and the second wire wiring 22 are described separately, they do not need to be made of different materials, and may be formed by wire bonding in the same manner.

[0056] As a result, the light source module 1 configured as described above achieves high heat dissipation performance and suppresses migration. Furthermore, electrical short circuits via the gold sintered body 12 in the light-emitting layer 20p of each light-emitting element (20a, 20b, 20c, 20d) are avoided. In other words, a light source module 1 with improved reliability compared to conventional light-emitting elements is realized.

[0057] [Manufacturing Method] Next, a description will be given of a manufacturing method for the light source module 1. Figures 4A to 4F are schematic diagrams each showing a state of the light source module 1 during manufacturing.

[0058] First, as shown in FIG. 4A, a substrate 10 is prepared (step S1).

[0059] Furthermore, a submount 11 is prepared (step S2). Steps S1 and S2 correspond to step (A).

[0060] As shown in Fig. 4B, a paste 40 containing gold particles is screen-printed onto the main surface (mounting surface 11a) of the submount 11 using a mesh 30 and a squeegee 31 to form a desired pattern (step S3). Step S3 corresponds to process (B). Note that the screen-printing method shown in Fig. 4B is merely an example.

[0061] As described above, screen printing allows the thickness of the film to be controlled according to the particle diameter of the paste 40 by adjusting the opening size and thickness of the mesh 30. Furthermore, adjusting the shape of the mesh 30 allows precise control of the area to which the paste 40 is applied. Therefore, compared to pin transfer, screen printing makes it easier to spread the gold paste uniformly over the mounting surface of the submount.

[0062] In this embodiment, the particle size of the gold particles contained in the paste 40 is adjusted to 0.2 μm to 0.4 μm. In the screen printing in step S3, a mesh 30 having openings with a side length of 25 μm and a thickness of 50 μm is used.

[0063] The length of one side of the opening of the mesh 30 and the thickness thereof are arbitrary, but from the viewpoint of making it easier to control the thickness of the paste 40 on the main surface (mounting surface 11a) of the submount 11, it is preferable that the length of one side of the opening of the mesh 30 is 100 to 200 times the particle diameter of the gold particles contained in the paste 40, and that the thickness of the mesh 30 is 200 to 300 times the particle diameter of the gold particles contained in the paste 40.

[0064] After step S3, the submount 11 on which the paste 40 is screen-printed is placed on the main surface 10a of the substrate 10 via a bonding material (step S4), as shown in Fig. 4C. Step S4 corresponds to process (C).

[0065] Before, after, or simultaneously with step S4, an insulating substrate 13 having a conductive pattern 13a formed thereon is placed on the main surface 10a of the substrate 10 as shown in FIG. 4D (step S5).

[0066] After steps S4 and S5 are performed, as shown in Fig. 4E, the light emitting elements (20a, 20b) are placed on the paste 40 (step S6). Step S6 corresponds to process (D).

[0067] In step S6, the height of the light emitting surface 20f of each light emitting element (20a, 20b, 20c, 20d) from the mounting surface 11a of the submount 11 is adjusted to be uniform, and the inclination angle of the light emitting surface 20f with respect to the XY plane is adjusted to be within a predetermined range.

[0068] 3, the degree to which the light-emitting elements (20a, 20b, 20c, 20d) are pressed into the paste 40 is adjusted so that the height h1 of the paste 40 (gold sintered body 12) is lower than the height h2 of the light-emitting layer 20p. Here, if the height h2 is too high, heat dissipation becomes poor, and if it is too low, short circuits become more likely, so it is preferable that the height h2 be in the range of 50 μm to 100 μm.

[0069] In step S6, the light-emitting elements (20c, 20d) are also placed, but in FIG. 4E, for convenience of illustration, the light-emitting elements (20c, 20d) are hidden by the light-emitting elements (20a, 20b) and are not shown.

[0070] After step S6, the paste 40 is dried and heated at 200°C for 1 hour to volatilize the solvent contained in the paste 40 and sinter the gold particles, thereby forming the gold sintered body 12 (step S7). Step S7 corresponds to process (E).

[0071] After the gold sintered body 12 is formed in step S7, the light-emitting elements (20a, 20b, 20c, 20d) are connected to the conductive pattern 13a on the insulating substrate 13 by the first wire wiring 21 (step S8), as shown in Figure 4F.

[0072] After step S8 is performed, or simultaneously with step S8, as shown in FIG. 2, the submount 11 and the conductive pattern 13a of the insulating substrate 13 arranged on the −X side of the submount 11 are connected by the second wire wiring 22 (step S9).

[0073] After the steps up to step S9 are completed, the cover member 2 is placed as shown in FIG. 1, and the light source module 1 is completed.

[0074] Another embodiment will now be described.

[0075] <1> In the above-described embodiment, the configuration of the light source module 1 in which two light-emitting elements are arranged in each of the X direction and the Y direction has been described, but the number of light-emitting elements arranged in each direction may be three or more. In other words, for example, the number of light-emitting elements arranged in the X direction may be different from the number of light-emitting elements arranged in the Y direction, and a configuration in which only one light-emitting element is arranged in either the X direction or the Y direction may be used.

[0076] For example, when three light-emitting elements are arranged in each of the X and Y directions, the gold sintered body 12 located on the −Z side of the central light-emitting element may be slightly thicker than the gold sintered bodies 12 located on the −Z side of the surrounding light-emitting elements. In other words, the light-emitting surface of the central light-emitting element may be located slightly closer to the +Z side than the light-emitting surfaces of the surrounding light-emitting elements.

[0077] According to this configuration, the illuminance distribution of the light emitted from the light source module 1 and striking a screen placed a predetermined distance away becomes closer to a normal distribution. Such a characteristic has the effect of facilitating the design of a light source device in which the light source module 1 is installed.

[0078] Furthermore, the above-mentioned gold sintered body 12 is formed over all of the light-emitting elements (20a, 20b, 20c, 20d), but it may also be formed over a group of light-emitting elements arranged in one direction in the X or Y direction, or it may be formed individually for each of the light-emitting elements (20a, 20b, 20c, 20d).

[0079] Even if the gold sintered body 12 is formed individually for each of the light-emitting elements (20a, 20b, 20c, 20d), the paste 40 may swell around the light-emitting elements when they are placed. In this case, it is preferable to adjust the height h1 of the gold sintered body 12 located between adjacent light-emitting elements to be lower than the height h2 of the light-emitting layer 20p of each of the light-emitting elements (20a, 20b, 20c, 20d).

[0080] <2> In the above-described embodiment, the light-emitting element is described assuming a pair of electrodes provided on one surface facing the +Z direction and the other facing the −Z direction. However, the light-emitting element mounted in the light source module 1 may be a flip-chip type light-emitting element in which a pair of electrodes is formed on the same surface. That is, the light source module 1 may employ either a junction-up type or a junction-down type light-emitting element (20a, 20b, 20c, 20d). While any thickness may be used for the light-emitting elements (20a, 20b, 20c, 20d), it is preferable that the thickness be within a range of 100 μm to 130 μm and that the height from the bottom surface of the light-emitting element (20a, 20b, 20c, 20d) to the light-emitting layer 20p be within a range of 70 μm to 95 μm.

[0081] In the case of a light-emitting element in which a pair of electrodes are formed on the same side, conductive patterns that have different potentials when lit are formed on the submount 11, and wire wiring (21, 22) is connected from each conductive pattern to the corresponding conductive pattern 13a on the insulating substrate 13.

[0082] <3> In the above-described embodiment, the light-emitting element is described as an LED element, but the light-emitting element may be an LD element. When the light-emitting element is a surface-emitting LD element, the height h1 of the gold sintered body 12 from the mounting surface 11a of the submount 11 is configured to be lower than the height of the upper surface of the light-emitting element.

[0083] <4> The configuration of the light source module 1 and the manufacturing method of the light source module 1 described above are merely examples, and the present invention is not limited to the illustrated configurations.

[0084] 1: Light source module 2: Cover member 2a: Light exit window 2b: Support 10: Substrate 10a: Main surface 11: Submount 11a: Mounting surface 11p: Ceramic layer 11q: Thermally conductive layer 12: Sintered gold body 13: Insulating substrate 13a: Conductive pattern 20a, 20b, 20c, 20d: Light-emitting element 20e: Electrode 20f: Light exit surface 20p: Light-emitting layer 21: First wire wiring 22: Second wire wiring 30: Mesh 31: Squeegee 40: Paste agent h1, h2: Height

Claims

1. A light source module comprising: a substrate; a submount arranged on a main surface of the substrate; a plurality of light-emitting elements arranged in a first direction on a mounting surface of the submount; and a gold sintered body joining the submount and the plurality of light-emitting elements, wherein the gold sintered body extends outside the light-emitting elements when viewed from the normal direction of the mounting surface of the submount, and a portion of the plurality of light-emitting elements located between a first light-emitting element and a second light-emitting element that are adjacent to each other in the first direction has a height, when taken as the reference point for the mounting surface of the submount, that is lower than both the light-emitting layer of the first light-emitting element and the light-emitting layer of the second light-emitting element.

2. The light source module according to claim 1, wherein the distance between the first light emitting element and the second light emitting element is 10 μm to 100 μm.

3. The light source module according to claim 1 or 2, characterized in that the length of one side of each of the plurality of light-emitting elements when viewed in a direction perpendicular to the light-emitting surface is 50 μm to 2,000 μm.

4. A method for manufacturing a light source module, comprising: a step (A) of preparing a substrate and a submount; a step (B) of applying a paste containing gold particles onto a main surface of the submount by screen printing; a step (C) of placing the submount with the paste applied to its main surface on the main surface of the substrate; a step (D) of placing a light-emitting element on the portion of the main surface of the submount where the paste has been applied; and a step (E) of heating the paste to form a gold sintered body after step (D) is performed.

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