Manufacturing method of light-emitting device and light-emitting device

Abstract

To provide a manufacturing method of a light-emitting device having a high reliability of mounting of a light-emitting element, and provide a light-emitting device.SOLUTION: A manufacturing method of a light-emitting device, comprises the steps of: preparing a first structure body 110 having a support substrate 50, an adhesion layer 60 that is arranged on a first main surface 50a of the support substrate, and a plurality of light-emitting elements 20 in which a first surface 20a that is on the side opposite to a second surface 20b on which a pair of element electrodes 22 is arranged and an adhesion layer are arranged in contract; preparing a second structure body 120 having a substrate 10 that has a base material 11 and a plurality of a pair of wirings 12 arranged on an upper surface of the base material, and a bonding member 70 that is arranged between the pair of wirings on the upper surface of the base material and is thicker than the thickness of each wiring; obtaining a third structure body 130 by making a pair of element electrodes of the first structure body face the pair of wirings of the second structure body, and bonding each light-emitting element and the substrate via the bonding member in a state of being heated at a first temperature; heating it at a second temperature that is higher than the first temperature; and peeling the support substrate from the third structure body.SELECTED DRAWING: Figure 2E

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a light emitting device and a light emitting device. [Background technology]

[0002] A light-emitting device having a light-emitting element mounted on a substrate is known. In a manufacturing process of such a light-emitting device, when transferring the light-emitting element onto the substrate, for example, a process of forming a bonding member on the substrate, a process of providing the light-emitting element on the carrier substrate to prepare a light-emitting element-mounted carrier substrate, a process of providing the light-emitting element-mounted carrier substrate on the bonding member so that the light-emitting element and the bonding member face each other, and a process of peeling off the carrier substrate from the light-emitting element-mounted carrier substrate are performed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-103774 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a manufacturing method for a light emitting device that enables highly reliable transfer of a light emitting element, and the light emitting device. [Means for solving the problem]

[0005] A manufacturing method for a light emitting device according to one embodiment of the present disclosure includes the steps of: preparing a first structure including a supporting substrate, an adhesive layer disposed on a first main surface of the supporting substrate, and a plurality of light emitting elements having a first surface and a second surface opposite to the first surface on which a pair of element electrodes are disposed, the first surface being in contact with the adhesive layer; preparing a second structure including a substrate having a base material, a plurality of pairs of wirings disposed on an upper surface of the base material, and a bonding member disposed on the upper surface of the base material between the pair of wirings and having a thickness greater than that of the wirings; obtaining a third structure by bonding the light emitting elements and the substrate via the bonding member while heating the pair of element electrodes of the first structure and the pair of wirings of the second structure at a first temperature; heating the third structure at a second temperature equal to or higher than the first temperature; and peeling the supporting substrate from the third structure.

[0006] Furthermore, a light-emitting device according to one embodiment of the present disclosure includes a substrate having a base material and a plurality of pairs of wirings arranged on the base material, a first surface and a second surface on which a pair of element electrodes are arranged on the opposite side of the first surface, and a plurality of light-emitting elements arranged such that the pair of element electrodes and the pair of wirings face each other, and a first metal plating portion and a second metal plating portion electrically connecting the pair of element electrodes of the light-emitting elements and the pair of wirings, wherein in a cross-sectional view cut through the first surface and the pair of element electrodes of the light-emitting elements, the first metal plating portion has an upper surface in contact with the element electrodes, a first side surface connected to one end of the upper surface and located on the second metal plating portion side, and a second side surface connected to the other end of the upper surface and located on the opposite side of the first side surface, and the shape of the first side surface is different from the shape of the second side surface, and the first side surface has a convex portion. Effect of the Invention

[0007] According to an embodiment of the present disclosure, it is possible to provide a manufacturing method for a light emitting device and a light emitting device having a high reliability in transferring a light emitting element. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a schematic diagram of a light-emitting device according to an embodiment of the present invention. [Figure 2A] FIG. 1 is a diagram (1) illustrating a schematic diagram of an example of a manufacturing process of the manufacturing method of the light emitting device according to the present embodiment. [Figure 2B] FIG. 4(2) is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 2C] FIG. 3 is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 2D] FIG. 4 is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 2E] FIG. 5 is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 2F] FIG. 6 is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 2G] FIG. 7 is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 2H] FIG. 8 is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 2I] FIG. 9 is a schematic diagram showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the embodiment. [Figure 3A] FIG. 1 is a plan view (1) illustrating a schematic diagram of an example of a manufacturing process of a manufacturing method for a light emitting device according to a modified example of the present embodiment. [Figure 3B] FIG. 11 is a plan view (2) illustrating a schematic example of a manufacturing process of a manufacturing method for a light emitting device according to a modified example of the present embodiment. [Figure 3C] FIG. 11 is a plan view (3) illustrating a schematic example of a manufacturing process of a manufacturing method for a light emitting device according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a manufacturing method of an embodiment according to the present disclosure and a light-emitting device obtained by the manufacturing method (hereinafter, sometimes referred to as a "light-emitting device according to an embodiment") will be described with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper", "lower", and other terms including these terms) will be used as necessary. However, the use of these terms is for the purpose of facilitating understanding of the invention with reference to the drawings, and the technical scope of the present disclosure is not limited by the meaning of these terms. In addition, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or members.

[0010] In addition, the embodiments shown below are examples of light-emitting devices and the like for embodying the technical ideas of the present disclosure, and do not limit the present disclosure to the following. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are intended to be illustrative, and are not intended to limit the scope of the present disclosure, unless otherwise specified. In addition, the contents described in one embodiment can be applied to other embodiments and modified examples. In addition, the size and positional relationship of the members shown in the drawings may be exaggerated in order to clarify the explanation. In addition, in order to avoid the drawings becoming overly complicated, schematic diagrams that omit the illustration of some elements, or end views that show only the cut surface as a cross-sectional view may be used.

[0011] <Light-emitting device according to an embodiment> FIG. 1 is a cross-sectional view showing a schematic diagram of a light-emitting device according to the present embodiment. FIG. 1 shows a cross section cut so as to pass through a first surface and a pair of element electrodes of a light-emitting element. As shown in FIG. 1, the light-emitting device 1 according to the present embodiment has a substrate 10, a plurality of light-emitting elements 20, a first metal plating portion 31, a second metal plating portion 32, a protective film 35, and a light-reflective member 40. The light-emitting device 1 does not necessarily have to have the protective film 35. The light-emitting device 1 does not necessarily have to have the light-reflective member 40. In the light-emitting device 1, a plurality of light-emitting elements 20 are arranged on the substrate 10. For example, a plurality of light-emitting elements 20 are arranged in a matrix on the substrate 10.

[0012] The substrate 10 has a flat base material 11 and a plurality of pairs of wirings 12 arranged on the base material 11. The pair of wirings 12 are arranged facing each other with a predetermined gap on the upper surface 11a of the base material 11. The light emitting element 20 has a first surface 20a, a second surface 20b on which a pair of element electrodes 22 are arranged on the opposite side of the first surface 20a, and one or more side surfaces 20c connecting the first surface 20a and the second surface 20b. In each light emitting element 20, the pair of element electrodes 22 are arranged facing the pair of wirings 12. The pair of wirings 12 may include three or more wirings as long as it has an anode side wiring and a cathode side wiring. The pair of element electrodes 22 may include three or more electrodes as long as it has an anode side electrode and a cathode side electrode.

[0013] The pair of element electrodes 22 of the light-emitting element 20 and the pair of wirings 12 of the substrate 10 are electrically connected by a first metal plating portion 31 and a second metal plating portion 32. Specifically, one of the pair of element electrodes 22 and one of the pair of wirings 12 are electrically connected by the first metal plating portion 31. In addition, the other of the pair of element electrodes 22 and the other of the pair of wirings 12 are electrically connected by the second metal plating portion 32.

[0014] 1, the first metal plating portion 31 has an upper surface 31a in contact with the element electrode 22, a first side surface 31b connected to one end of the upper surface 31a and located on the second metal plating portion 32 side, and a second side surface 31c connected to the other end of the upper surface 31a and located on the opposite side of the first side surface 31b. The second metal plating portion 32 has an upper surface 32a in contact with the element electrode 22, a first side surface 32b connected to one end of the upper surface 32a and located on the first metal plating portion 31 side, and a second side surface 32c connected to the other end of the upper surface 32a and located on the opposite side of the first side surface 32b. The upper surface 31a of the first metal plating portion 31 may be partially or entirely in contact with the element electrode 22. Similarly, the upper surface 32a of the second metal plating portion 32 may be in contact with the element electrode 22 partially or entirely.

[0015] The shape of the first side surface 31b is different from the shape of the second side surface 31c. The first side surface 31b has a convex portion that is convex toward the second metal plating portion 32 side. The second side surface 31c has no convex portion. The second side surface 31c may or may not be perpendicular to the upper surface 11a of the base material 11. In the example of FIG. 1, the second side surface 31c is inclined in a direction approaching the second metal plating portion 32 side as it moves from the upper surface 11a of the base material 11 toward the light emitting element 20 side.

[0016] The shape of the first side surface 32b is different from the shape of the second side surface 32c. The first side surface 32b has a convex portion that is convex toward the first metal plating portion 31. The second side surface 32c has no convex portion. The second side surface 32c may or may not be perpendicular to the upper surface 11a of the base material 11. In the example of FIG. 1, the second side surface 32c is inclined in a direction approaching the first metal plating portion 31 as it moves from the upper surface 11a of the base material 11 toward the light emitting element 20.

[0017] The protective film 35 covers the second side surface 31c of the first metal plating portion 31 and the second side surface 32c of the second metal plating portion 32. The protective film 35 is, for example, a film containing silicon oxide or aluminum oxide. By providing the protective film 35, the risk of the second side surface 31c and the second side surface 32c being corroded by corrosive substances such as sulfur can be reduced. In the example of FIG. 1, the protective film 35 extends from the second side surface 31c and the second side surface 32c to the outer periphery of the second surface 20b of the light-emitting element 20 and the side surface 20c. The protective film 35 does not have to extend to the outer periphery of the second surface 20b of the light-emitting element 20 and the side surface 20c. The protective film 35 may also cover the first side surface 31b and the first side surface 32b in addition to the second side surface 31c and the second side surface 32c.

[0018] The light reflective member 40 is provided on the upper surface 11a of the base material 11, exposes the first surface 20a of the light emitting element 20, and covers the second surface 20b and the side surface 20c. The light reflective member 40 may also cover the side surfaces of the wiring 12, the side surfaces of the element electrodes 22, the first side surface 31b and the second side surface 31c of the first metal plating portion 31, and the first side surface 32b and the second side surface 32c of the second metal plating portion 32.

[0019] By covering the side surface 20c of the light-emitting element 20 with the light-reflective member 40, the light emitted from the side surface 20c of the light-emitting element 20 is reflected by the light-reflective member 40. Also, by covering the second surface 20b of the light-emitting element 20 with the light-reflective member 40, the light proceeding downward from the light-emitting element 20 is reflected by the light-reflective member 40. As a result, the light extraction efficiency of the light-emitting device 1 can be improved. Also, the light-reflective member 40 can clearly define the boundary between the light-emitting area and the non-light-emitting area when the light-emitting element 20 is individually turned on. This improves the contrast ratio between the light-emitting area and the non-light-emitting area.

[0020] Thus, in the light emitting device 1, the first side surface 31b of the first metal plating portion 31 has a convex portion, and the second side surface 31c does not have a convex portion. During the manufacturing process or use of the light emitting device 1, corrosive substances such as sulfur floating outside the light emitting device 1 may enter the inside. In this case, the corrosive substances such as sulfur first reach the second side surface 31c located on the outside of the light emitting element 20, and if the first metal plating portion 31 contains a metal such as copper that is corroded by sulfur, corrosion occurs from the second side surface 31c side of the first metal plating portion 31. Therefore, a protective film 35 may be formed on the surface of the first metal plating portion 31 (particularly the second side surface 31c). In this case, if a convex portion is provided on the second side surface 31c side, when the first metal plating portion 31 expands or contracts due to heat during operation of the light emitting device 1, a crack or a penetration portion may be formed in the protective film 35 by the convex portion of the second side surface 31c. As a result, the first metal plating portion 31 may be corroded by corrosive substances such as sulfur. On the other hand, in the light emitting device of the present disclosure, the second side surface 31c side does not have a convex portion, so it is difficult to come into contact with corrosive substances such as sulfur that enter from the atmosphere. Therefore, it is possible to reduce the risk of the first metal plating portion 31 being sulfurized starting from the second side surface 31c side. Note that the first side surface 31b is located in the region where the light emitting element 20 and the substrate 10 face each other, and is away from the intrusion path of corrosive substances such as sulfur, so there is little risk of it being sulfurized. Therefore, the first side surface 32b may have a convex portion. In addition, by having a convex portion on the first side surface 31b, the volume of the first metal plating portion 31 increases compared to when there is no convex portion, and as a result, the heat dissipation property of the light emitting device 1 can be improved. The above has been described with respect to the first metal plating portion 31, but the same is true for the second metal plating portion 32.

[0021] Furthermore, the first side surface 31b of the first metal plating portion 31 and the first side surface 32b of the second metal plating portion 32 have convex portions facing each other, and the light reflective member 40 fits into the gap between the facing convex portions. This creates an anchor effect, and the adhesion between the light reflective member 40 and the first metal plating portion 31 and the second metal plating portion 32 can be improved.

[0022] Each component of the light emitting device 1 will now be described.

[0023] (Substrate 10) The substrate 11 has, for example, a substantially rectangular shape in a plan view. As the substrate 11, a transparent substrate may be used, or an opaque substrate may be used. Examples of the material of the transparent substrate include glass, quartz, sapphire, ceramics (for example, transparent alumina), and organic films (for example, PET). Examples of the material of the opaque substrate include semiconductors (for example, Si, Ge, GaAs, InP), ceramics (for example, alumina, aluminum nitride, silicon nitride), and organic materials (for example, FR4).

[0024] Examples of the wiring 12 include metals such as Cu, Ag, Au, Al, Pt, Ti, W, Pd, Fe, and Ni, and / or alloys containing at least these metals. On the upper surface 11a of the base material 11, a region where the wiring 12 is not arranged may or may not be covered with an insulating film.

[0025] (Light emitting element) The light emitting element 20 is, for example, substantially rectangular or square in plan view. The light emitting element 20 may be, for example, a square with one side of 40 μm or more and 100 μm or less in plan view. In the light emitting element 20, the first surface 20a and the second surface 20b are, for example, parallel to each other. The side surface 20c may be perpendicular to the first surface 20a or may be inclined with respect to the first surface 20a. In the example of FIG. 1, the opposing side surfaces 20c are inclined in a direction narrowing from the first surface 20a side to the second surface 20b side in cross-sectional view.

[0026] The light emitting element 20 includes a semiconductor laminate and element electrodes 22, which are positive and negative electrodes, arranged on a second surface 20b, which is the surface of the semiconductor laminate. The light emitting element 20 is flip-chip mounted on the substrate 10 with the second surface 20b, on which the element electrodes 22 are arranged, facing the substrate 10. In this case, the first surface 20a, which is located on the opposite side to the second surface 20b, serves as the main light extraction surface of the light emitting element 20.

[0027] In the light emitting device 1, the light emitting elements 20 may be arranged two-dimensionally in a matrix on the substrate 10. In this case, the light emitting elements 20 can be arranged in an array with a predetermined interval in each row and column direction. For example, the number of light emitting elements 20 included in the light emitting device 1 can be 100 or more and 2,000,000 or less, preferably 1,000 or more and 500,000 or less, and more preferably 3,000 or more and 150,000 or less. When the light emitting device 1 includes 100 or more light emitting elements, road projection including simple messaging and the like is possible when used for road projection in vehicle headlights and the like. Furthermore, when the light emitting device 1 includes 2,000,000 or less light emitting elements, high-definition road projection can be realized, the light emitting device 1 can be made small, and each light emitting element 20 can emit light with sufficient illuminance when individually turned on.

[0028] The light emitting element 20 can be selected to emit light of any wavelength. For example, a light emitting element 20 that emits blue light or green light can be selected from nitride semiconductors (In X Al Y Ga 1-X-Y N, 0≦X, 0≦Y, X+Y≦1) can be selected. As the light emitting element 20 that emits red light, a semiconductor represented by GaAlAs or AlInGaP can be used. Furthermore, a semiconductor light emitting element made of a material other than these can also be used. The composition and emitted color of the light emitting element 20 used can be appropriately selected depending on the purpose.

[0029] (First metal plating section, second metal plating section) The first metal plating portion 31 and the second metal plating portion 32 may be formed, for example, from copper plating or gold plating. The first metal plating portion 31 and the second metal plating portion 32 may be formed from zinc (Zn), chromium (Cr), and / or nickel (Ni), etc. The thickness of the first metal plating portion 31 and the second metal plating portion 32 may be, for example, 3 μm or more and 10 μm or less.

[0030] (Light-reflecting member) The light reflecting member 40 is preferably made of a soft resin having a relatively low elasticity and excellent shape conformability. As the material of the light reflecting member 40, a resin material having good transparency and insulating properties, for example, a thermosetting resin such as an epoxy resin or a silicone resin, can be suitably used. In addition, the light reflecting member 40 is preferably made of a white resin containing particles of a light reflecting material in a base resin. Examples of the light reflecting material include titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, and glass filler.

[0031] <Method of Manufacturing the Light-Emitting Device According to the Embodiment> A manufacturing method for a light emitting device according to an embodiment includes the steps of: preparing a first structure including a supporting substrate, an adhesive layer disposed on a first main surface of the supporting substrate, and a plurality of light emitting elements having a first surface and a second surface opposite the first surface on which a pair of element electrodes are disposed, the first surface being in contact with the adhesive layer; preparing a second structure including a substrate having a base material, a plurality of pairs of wirings disposed on an upper surface of the base material, and a bonding member disposed on the upper surface of the substrate between the pair of wirings and having a thickness greater than that of the wirings; obtaining a third structure by bonding the light emitting elements and the substrate via the bonding member while heating the pair of element electrodes of the first structure and the pair of wirings of the second structure at a first temperature; heating the third structure at a second temperature equal to or higher than the first temperature; and peeling the supporting substrate from the third structure.

[0032] The method for manufacturing a light emitting device according to the embodiment may further include, after the step of peeling off the support substrate, a step of forming metal plating that electrically connects a pair of element electrodes of the light emitting element and a pair of wirings of the substrate.

[0033] The method for manufacturing a light emitting device according to the embodiment may further include a step of removing the bonding member after the step of forming the metal plating.

[0034] Hereinafter, each manufacturing step of the method for manufacturing a light emitting device according to the embodiment will be described with reference to the drawings.

[0035] 2A to 2I are diagrams showing an example of a manufacturing process of the manufacturing method of the light emitting device according to the present embodiment. Specifically, FIG. 2B is a plan view illustrating the manufacturing process of the light emitting device. Also, FIG. 2A and FIGS. 2C to 2I are cross-sectional views illustrating the manufacturing process of the light emitting device. In the explanation of the manufacturing method, "preparing" a component is not limited to manufacturing the component, but also includes acquiring the component, such as purchasing the component or receiving the component.

[0036] (Step of preparing a first structure) First, as shown in FIG. 2A, a first structure 110 is prepared, which includes a support substrate 50, an adhesive layer 60 arranged on a first main surface 50a of the support substrate 50, a first surface 20a, and a second surface 20b opposite the first surface 20a on which a pair of element electrodes 22 are arranged, and a plurality of light-emitting elements 20 arranged with the first surface 20a and the adhesive layer 60 in contact with each other.

[0037] Specifically, first, an adhesive material is continuously applied to the first main surface 50a of the support substrate 50 to arrange the adhesive layer 60. As the support substrate 50, for example, a glass substrate or the like can be used. As the adhesive material, for example, at least one adhesive material selected from the group consisting of a silicone adhesive material, an epoxy adhesive material, and an acrylic adhesive material can be used.

[0038] Next, a plurality of light emitting elements 20 are prepared, and each light emitting element 20 is attached to the adhesive layer 60 so that the first surface 20a of each light emitting element 20 contacts the adhesive layer 60 on the support substrate 50. For example, 100 to 2,000,000 light emitting elements 20 can be attached in a matrix form to the adhesive layer 60. With the above steps, preparation of the first structure 110 is completed.

[0039] (Step of preparing a second structure) 2B and 2C, a second structure 120 is prepared, which includes a substrate 10 having a base material 11 and a plurality of pairs of wirings 12 arranged on an upper surface 11a of the base material 11, and a bonding member 70 arranged between the pairs of wirings 12 on the upper surface 11a of the base material 11 and having a thickness greater than that of the wirings 12. Note that FIG. 2C is a cross-sectional view taken along line IIC-IIC in FIG. 2B.

[0040] Specifically, first, a substrate 10 is prepared, which has a base material 11 and a plurality of pairs of wirings 12. The substrate 10 can be prepared, for example, by forming a plurality of pairs of wirings 12 on an upper surface 11a of a flat base material 11 such as a silicon plate by a plating method, a sputtering method, a vapor deposition method, or the like.

[0041] Next, a bonding member 70 is formed on the upper surface 11a of the base material 11, which is disposed between the pair of wirings 12 and is thicker than the thickness of the wirings 12. Specifically, the bonding member 70 having a planar size smaller than the planar size of the light emitting element 20 in a cross-sectional view is formed in the region where the light emitting element 20 is to be placed, so that the pair of element electrodes 22 of the light emitting element 20 and the pair of wirings 12 of the substrate 10 can face each other at a distance when the light emitting element 20 is placed later.

[0042] The bonding member 70 can be formed by using a photolithography method or a screen printing method. The photolithography method is preferable because it can form a fine pattern. The bonding member 70 is preferably adhesive. When the bonding member 70 has adhesiveness, the light emitting element 20 to be placed later can be attached and supported on the bonding member 70.

[0043] The bonding member 70 is preferably one that has the above-mentioned adhesiveness and is also chemically resistant to the metal plating performed in the subsequent process. For example, the bonding member 70 can be a phenolic resin, an epoxy resin, a silicone resin, or an acrylic resin. The bonding member 70 is, for example, a resist. When the bonding member 70 is used, it is not necessary to provide a member suitable for each purpose as a mask for supporting the light emitting element 20 and for plating bonding, and therefore the number of processes can be reduced. In addition, there are no restrictions due to the combination of the formation conditions of each of the materials (e.g., dissolving in one solvent, different appropriate processing temperatures, etc.) that may occur when using separate materials, and therefore the process can be easily carried out.

[0044] The cross-sectional shape of the bonding member 70 may be rectangular or square. That is, the contact surface (upper surface) of the bonding member 70 that contacts the light emitting element 20 and the side surface can be in a substantially perpendicular relationship. This makes it possible to accurately secure the contact area between the light emitting element 20 and the bonding member 70, and the plating growth area that will later bond the wiring 12 of the substrate 10 and the element electrode 22 of the light emitting element 20.

[0045] The cross-sectional shape of the bonding member 70 may be tapered. The cross-sectional shape may be such that the width becomes wider from the upper surface 11a of the base material 11 toward the light emitting element 20, or the width may become narrower from the upper surface 11a of the base material 11 toward the light emitting element 20. If the cross-sectional shape becomes wider from the upper surface 11a of the base material 11 toward the light emitting element 20, the contact area between the light emitting element 20 and the bonding member 70 can be increased, and the light emitting element 20 and the bonding member 70 can be more reliably attached to each other.

[0046] By forming the bonding member 70 thicker than the wiring 12, when the light emitting element 20 is later placed on the bonding member 70, the wiring 12 provided on the base material 11 and the element electrode 22 of the light emitting element 20 to be placed on the bonding member 70 can be spaced apart from each other with the bonding member 70 sandwiched therebetween. The thickness of the bonding member 70 can be, for example, 5 μm or more and 20 μm or less.

[0047] (Step of obtaining the third structure) Next, as shown in FIG. 2D, a pair of element electrodes 22 of the first structure 110 and a pair of wirings 12 of the second structure 120 are opposed to each other, and while heated at a first temperature, the light-emitting element 20 and the substrate 10 are bonded via a bonding member 70 to obtain a third structure 130.

[0048] Specifically, first, the second structure 120 is placed on a stage with the pair of wirings 12 facing upward. Then, the first structure 110 is placed on the second structure 120 so that the pair of element electrodes 22 faces the pair of wirings 12. At this time, the upper surface of the bonding member 70 contacts the second surface 20b located between the pair of element electrodes 22. A part of the upper surface of the bonding member 70 may cover the ends of the pair of element electrodes 22. The pair of element electrodes 22 of the light emitting element 20 and the pair of wirings 12 of the substrate 10 are placed apart from each other.

[0049] Next, the light emitting element 20 and the substrate 10 arranged on the stage are heated and pressurized at a first temperature. At this time, the light emitting element 20 and the substrate 10 are thermocompression bonded on the stage via the bonding member 70. That is, the bonding member 70 softens, and the light emitting element 20 and the substrate 10 are bonded via the bonding member 70 by the tack force of the bonding member 70, and the third structure 130 is obtained. The first temperature is set to a temperature at which the bonding member 70 softens or higher. For example, if the temperature at which the bonding member 70 softens is 90°C, it is preferable to set the first temperature to 95°C or higher, including a margin. In addition, it is preferable that the heating time at the first temperature is, for example, 1 minute or more and 1 hour or less. By heating under such conditions, the bonding member 70 can be softened to a degree that it exhibits tack force.

[0050] (Step of heating at a second temperature) Next, the third structure 130 is moved from the stage, and the third structure 130 is heated at a second temperature equal to or higher than the first temperature. FIG. 2E shows the third structure 130 after being heated at the second temperature. For example, an oven can be used for heating at the second temperature. The second temperature is preferably equal to or higher than the first temperature and equal to or lower than 140° C. By setting the second temperature to be equal to or higher than the first temperature, the bonding member 70 can be sufficiently softened. By setting the second temperature to be equal to or lower than 140° C., it is possible to reduce the risk of copper being oxidized when the wiring 12 or the element electrode 22 contains copper.

[0051] In the process of obtaining the third structure, the second structure 120 may wait for a long time on the stage. In this case, the solvent evaporates from the surface side of the bonding member 70, and the tackiness of the surface side decreases. In this state, if the first structure 110 is placed on the second structure 120, the bonding member 70 with the reduced tackiness cannot obtain a sufficient adhesive force. Therefore, in the next process of peeling the support substrate from the third structure, there is a risk that the light emitting element 20 will peel off from the bonding member 70 and be carried away together with the support substrate 50.

[0052] By heating the bonding member 70 with reduced tackiness at the second temperature in this step, it is possible to improve the adhesion between the light emitting element 20 and the bonding member 70 compared to before the step of heating at the second temperature. This is thought to be because the bonding member 70 softens and the light emitting element 20 is slightly buried in the bonding member 70 due to its own weight, so that the light emitting element 20 adheres to the inner part of the bonding member 70, which has stronger tackiness than the surface.

[0053] When the third structure 130 is heated at the second temperature, the thickness of the bonding member 70 tends to decrease. For example, the bonding member 70 that had a thickness of 3 μm before being heated at the second temperature may become thinner by about 10%. By making the bonding member 70 thinner, the light emitting device 1 can be made thinner. Furthermore, by making the bonding member 70 thinner, the amount of metal plating used to form the first metal plating portion 31 and the second metal plating portion 32 can be reduced in the step of forming the metal plating described below.

[0054] 2E, in a cross-sectional view, the center of the bonding member 70 is recessed more than the upper and lower surfaces, and a recess 70x is formed on the side surface. The recess 70x is formed, for example, in a shape having an acute angle in a cross-sectional view. The recess 70x is formed because the bonding member 70 is softened by heating at the second temperature and spreads to the element electrode 22 of the light-emitting element 20 and the wiring 12 of the substrate 10.

[0055] This wetting and spreading is greater on the element electrode 22 side of the light emitting element 20 than on the wiring 12 side of the substrate 10. Therefore, the ratio (W2 / W1) of the width W2 of the upper surface of the bonding member 70 to the width W1 of the lower surface of the bonding member 70 after the step of heating at the second temperature is greater than the ratio (W2 / W1) before the step of heating at the second temperature.

[0056] [Table 1] Table 1 shows the results of measuring the changes in the width of the upper surface and the width of the lower surface of the bonding member 70. Here, as an example, the time that the second structure 120 waits on the stage is set to 0.5 hr (30 minutes), and each of the following cases is considered: when not heated at the second temperature, when the second temperature is 95° C. and heating is performed for two hours, when the second temperature is 110° C. and heating is performed for two hours, and when the second temperature is 130° C. and heating is performed for two hours.

[0057] As shown in Table 1, when heating at the second temperature, the ratio of the width of the upper surface to the width of the lower surface is larger at all temperatures than when heating at the second temperature is not performed. Specifically, in a cross-sectional view, when heating at the second temperature is not performed, the ratio of the width of the upper surface to the width of the lower surface of the bonding member 70 is less than 0.910, whereas when heating at the second temperature, the ratio of the width of the upper surface to the width of the lower surface of the bonding member 70 is 0.910 or more at all temperatures. In other words, the ratio of the width of the upper surface of the bonding member 70 to the width of the lower surface of the bonding member 70 after the step of heating at the second temperature is 0.910 or more.

[0058] Since the width W2 of the upper surface of the bonding member 70 becomes wider than before heating at the second temperature, the contact area between the upper surface of the bonding member 70 and the second surface 20b of the light emitting element 20 becomes larger, and therefore the adhesion between the bonding member 70 and the light emitting element 20 can be improved. Also, as shown in Table 1, the width W1 of the lower surface of the bonding member 70 is the same as or wider than before heating at the second temperature. That is, the contact area between the lower surface of the bonding member 70 and the base material 11 becomes equal to or larger than the contact area before heating at the second temperature, and therefore the adhesion between the bonding member 70 and the base material 11 can be maintained or improved.

[0059] (Step of peeling off the support substrate from the third structure) Next, as shown in FIG. 2F, the support substrate 50 and the adhesive layer 60 are peeled off from the third structure 130. For example, by applying a force in the direction of the arrow in FIG. 2F to the support substrate 50 using a suction tool or the like while the substrate 10 is fixed, the support substrate 50 and the adhesive layer 60 can be peeled off from the light emitting element 20. Since the adhesion between the light emitting element 20 and the bonding member 70 is improved in the step of heating at the second temperature, the interface between the second surface 20b of the light emitting element 20 and the upper surface of the bonding member 70 does not peel off in this step, but the interface between the first surface 20a of the light emitting element 20 and the lower surface of the adhesive layer 60 peels off. This reduces the risk that the light emitting element 20 will peel off from the bonding member 70 and be carried away together with the support substrate 50.

[0060] (Process for forming metal plating) Next, after the step of peeling off the support substrate, as shown in FIG. 2G, metal plating is formed to electrically connect the pair of element electrodes 22 of the light emitting element 20 to the pair of wirings 12 of the substrate 10. As a result, one of the pair of element electrodes 22 is electrically connected to one of the pair of wirings 12 via the first metal plating portion 31, and the other of the pair of element electrodes 22 is electrically connected to the other of the pair of wirings 12 via the second metal plating portion 32. The metal plating can be formed by, for example, electrolytic plating or electroless plating. The metal plating is, for example, copper plating or gold plating. Zinc (Zn), chromium (Cr), and / or nickel (Ni), etc., may be used as the metal plating.

[0061] (Step of removing the joining member) Next, after the step of forming the metal plating, the bonding members 70 are removed as shown in FIG. 2H. The bonding members 70 may be removed by immersing them in a remover liquid capable of removing the bonding members 70, or by other methods. For example, any remover liquid may be sprayed onto the bonding members 70 using a nozzle in a chamber to remove the remover liquid. The bonding members 70 are dissolved by the remover liquid, and the dissolved bonding members 70 are sent out from the base material 11 using a predetermined gas or the like.

[0062] The stripping liquid may be a mixed liquid containing sulfuric acid and an organic solvent. As the organic solvent, for example, at least one solvent selected from the group consisting of an alcohol solvent such as 2-propanol, a ketone solvent such as acetone, an ester solvent such as ethyl acetate, and an ether solvent can be used. As the gas used to send out the dissolved bonding member 70, for example, argon gas, nitrogen gas, etc. can be used.

[0063] After removing the bonding member 70, a protective film 35 may be provided to cover the second side surface 31c of the first metal plating portion 31 and the second side surface 32c of the second metal plating portion 32, as shown in FIG. 2H. The protective film 35 may be provided by, for example, an atomic layer deposition method. The protective film 35 may extend from the second side surface 31c and the second side surface 32c to the outer periphery of the second surface 20b of the light-emitting element 20 and the side surface 20c. The protective film 35 may be provided on the first side surface 31b and the first side surface 32b in addition to the second side surface 31c and the second side surface 32c.

[0064] (Step of placing light reflective member) Next, as shown in FIG. 2I, a light-reflecting member 40 is disposed on the substrate 10 as necessary. For example, an uncured white resin that covers the multiple light-emitting elements 20 is disposed on the substrate 10, and the white resin is made to flow and fill between the opposing side surfaces 20c of the adjacent light-emitting elements 20 and between the second surface 20b of the light-emitting element 20 and the upper surface 11a of the base material 11. The white resin is then cured to form the light-reflecting member 40. The uncured white resin can be disposed on the substrate 10 by, for example, potting, spraying, or printing. When the first surface 20a of the light-emitting element 20 is covered with the white resin, the first surface 20a is exposed by polishing or the like.

[0065] Through the above steps, the light emitting device 1 in which a plurality of light emitting elements 20 are mounted on the substrate 10 can be manufactured.

[0066] <Modification> In a variant, there are a plurality of first structures 110, and obtaining the third structure 130 comprises arranging the plurality of first structures 110 on the second structure 120.

[0067] 3A to 3C are plan views each showing a schematic example of a manufacturing process of a manufacturing method for a light emitting device according to a modified example of the present embodiment, illustrating a process for obtaining a third structure 130. In FIG.

[0068] As shown in FIG. 3A, in the modified example, the second structure 120 is a wafer having N (N is a natural number) regions 120R to be diced into a plurality of light emitting devices 1. The regions 120R are arranged, for example, vertically and horizontally at a predetermined interval. Each region 120R has a structure similar to that shown in FIG. 2B and FIG. 2C. That is, each region 120R has a plurality of pairs of wirings 12 and a bonding member 70. The substrate 10 is common to the N regions 120R. The second structure 120 is placed on a stage 150. The stage 150 is heated to a first temperature in advance.

[0069] In the step of obtaining a third structure, N first structures 110 are sequentially arranged in N regions 120R of second structure 120. First, as shown in Fig. 3B, first structure 1101 is arranged in the first region 120R. The bonding member 70 is softened by the first temperature, and the light emitting element 20 and the substrate 10 are bonded to each other via the bonding member 70.

[0070] Next, as shown in FIG. 3C, the first structures 110 are arranged in order from the second region 120R, and finally the first structures 110 are arranged in the Nth region 120R. N Each bonding member 70 is softened by the first temperature, and the light emitting element 20 and the substrate 10 are bonded to each other in each region 120R via the bonding member 70. In this way, a third structure 130 in which a plurality of first structures 110 are arranged on the second structure 120 can be obtained.

[0071] The time required to arrange the N first structures 110 is, for example, 0.5 hours or more and 10 hours or less. That is, the bonding members 70 in the first region 120R are bonded to the light-emitting elements 20 of the first structures 1101 with almost no waiting time on the stage 150. In contrast, the bonding members 70 in the Nth region 120R wait on the stage 150 for 0.5 hours or more and 10 hours or less before being bonded to the first structures 110. N The light emitting element 20 is bonded to the light emitting element 20 .

[0072] In FIG. 3C, the adhesive strength between the light emitting element 20 of the first structure 1101 arranged in the first region 120R and the bonding member 70 of the second structure 120 is high. N The adhesion between the light emitting element 20 and the bonding member 70 of the second structure 120 is reduced. This is because, as described above, the bonding member 70 in the Nth region 120R waits on the stage 150 for a long time, causing the solvent to evaporate from the front surface side of the bonding member 70, thereby reducing the tackiness of the front surface side.

[0073] 3C, the third structure 130 is heated at a second temperature equal to or higher than the first temperature. This makes it possible to improve the adhesion between the bonding members 70 and the light-emitting element 20, which has been weakened due to a long waiting time on the stage 150, including the bonding members 70 in the Nth region 120R, compared to before the heating step at the second temperature. The reason for the improvement in adhesion is as described above.

[0074] Thereafter, the support substrate is peeled off from the third structure in the same manner as in FIG. 2F. In the step of heating at the second temperature, the adhesive strength between the light emitting element 20 and the bonding member 70 is improved, so that the risk of the light emitting element 20 peeling off from the bonding member 70 and being carried away together with the support substrate 50 can be reduced. Conventionally, the adhesive strength of the bonding member 70 is particularly reduced in the N-th region 120R and regions nearby it, so that the light emitting element 20 is often carried away together with the support substrate 50 in these regions. By providing the step of heating at the second temperature, the risk of the light emitting element 20 being carried away together with the support substrate 50 can be reduced in the N-th region 120R and regions nearby it as well as in other regions. In particular, the larger the value of N is and the longer the waiting time on the stage is, the more effective it is to provide the step of heating at the second temperature to improve the adhesive strength between the light emitting element 20 and the bonding member 70.

[0075] Thereafter, after performing steps similar to those in FIGS. 2F to 2I, each region 120R is separated by dicing or the like, whereby N light emitting devices 1 in which a plurality of light emitting elements 20 are mounted on the substrate 10 can be manufactured.

[0076] In the step of heating at the second temperature, the M-1-th (M is a natural number of 2 or more and N or less) first structure 110 is heated at the second temperature. M-1 The first structure 110 is arranged Mth from the first structure 110. M It is preferable to heat the bonding members 70 at a higher temperature than the bonding members 70. By heating the bonding members 70 with a lowered adhesive strength at a higher temperature, the adhesive strength can be improved significantly.

[0077] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0078] For example, in the above description, when the step of heating at the second temperature is performed, the third structure is moved from the stage used in the step of heating at the first temperature to another heating device (e.g., an oven). Note that in the present disclosure, after the step of heating at the first temperature, the third structure may be heated at the second temperature on the same stage used in the step of heating at the first temperature. This can shorten the time required for the manufacturing process. On the other hand, when the step of heating at the second temperature is performed, the third structure is moved from the stage used in the step of heating at the first temperature to another heating device (e.g., an oven), which can improve the operating rate of the stage and improve mass productivity.

[0079] In addition to the above-described embodiment, the following supplementary notes are further disclosed. (Appendix 1) A support substrate; an adhesive layer disposed on a first main surface of the support substrate; preparing a first structure having a first surface and a second surface opposite to the first surface on which a pair of element electrodes are arranged, the first surface being in contact with the adhesive layer; A substrate having a base material and a plurality of pairs of wirings disposed on an upper surface of the base material; preparing a second structure including a bonding member disposed between the pair of wirings on the upper surface of the base material and having a thickness greater than that of the wirings; a step of obtaining a third structure by bonding the light emitting element and the substrate via the bonding member while heating the first structure and the second structure so that the pair of element electrodes and the pair of wirings face each other and are heated at a first temperature; heating the third structure at a second temperature equal to or higher than the first temperature; peeling the support substrate from the third structure; A method for manufacturing a light emitting device comprising the steps of: (Appendix 2) The first structures are multiple, the step of obtaining the third structure includes a step of arranging a plurality of the first structures on the second structure; The time required for disposing the plurality of first structures is 0.5 hours or more and 10 hours or less. A method for manufacturing the light emitting device described in Appendix 1. (Appendix 3) In the step of obtaining the third structure, N (N is a natural number) first structures are arranged in order; In the step of heating at the second temperature, the first structure arranged at the Mth position is heated at a higher temperature than the first structure arranged at the M-1th position (M is a natural number not less than 2 and not more than N), A method for manufacturing a light emitting device according to claim 1 or 2. (Appendix 4) In the step of obtaining the third structure, the pair of element electrodes of the light-emitting element and the pair of wirings of the substrate are disposed apart from each other, The method further includes the step of forming metal plating that electrically connects the pair of element electrodes of the light-emitting element and the pair of wirings of the substrate after the step of peeling off the support substrate. A method for manufacturing a light emitting device according to any one of claims 1 to 3. (Appendix 5) The metal plating is copper plating or gold plating. A method for manufacturing the light emitting device described in Appendix 4. (Appendix 6) The second temperature is 140° C. or less. A method for manufacturing the light emitting device described in Appendix 5. (Appendix 7) The method further includes removing the bonding member after the step of forming the metal plating. A method for manufacturing a light emitting device according to any one of claims 4 to 6. (Appendix 8) In a cross-sectional view taken along a line passing through the first surface of the light-emitting element and the pair of element electrodes, a ratio of a width of an upper surface of the bonding member to a width of a lower surface of the bonding member after the step of heating at the second temperature is 0.910 or more. A method for manufacturing a light emitting device according to any one of claims 1 to 7. (Appendix 9) A substrate having a base material and a plurality of pairs of wirings disposed on the base material; A plurality of light emitting elements each having a first surface and a second surface on which a pair of element electrodes are disposed on the opposite side of the first surface, the pair of element electrodes being disposed opposite the pair of wirings; a first metal plating portion and a second metal plating portion electrically connecting a pair of element electrodes of the light emitting element and the pair of wirings; having A cross-sectional view taken along a line passing through a first surface of the light-emitting element and the pair of element electrodes, the first metal plating portion has an upper surface in contact with the element electrode, a first side surface connected to one end of the upper surface and located on the second metal plating portion side, and a second side surface connected to the other end of the upper surface and located on the opposite side to the first side surface, The shape of the first side surface is different from the shape of the second side surface, The first side surface has a protrusion. [Explanation of symbols]

[0080] 1 Light emitting device 10 Substrate 11 Base material 11a Top side 12 Wiring 20 Light emitting element 20a Page 1 20b 2nd side 20c side 22 Element electrode 31 No. 1 Metal Plating Department 31a Top surface 31b 1st side 31c 2nd side 32 No. 2 Metal Plating Department 32a top surface 32b 1st side 32c 2nd side 35 Protective film 40 Light-reflective material 50 Support substrate 50a First main surface 60 Adhesive layer 70 Joint materials 110 First structure 120 Second structure 120R area 130 Third structure 150 Stages

Claims

1. A support substrate; an adhesive layer disposed on a first main surface of the support substrate; preparing a first structure having a first surface and a second surface opposite to the first surface on which a pair of element electrodes are arranged, the first surface being in contact with the adhesive layer; A substrate having a base material and a plurality of pairs of wirings disposed on an upper surface of the base material; preparing a second structure including a bonding member disposed on the upper surface of the base material between the pair of wirings and having a thickness greater than that of the wirings; a step of obtaining a third structure by bonding the light emitting element and the substrate via the bonding member while heating the first structure and the second structure so that the pair of element electrodes and the pair of wirings face each other and are heated at a first temperature; heating the third structure at a second temperature equal to or higher than the first temperature; peeling the support substrate from the third structure; A method for manufacturing a light emitting device comprising the steps of:

2. The first structures are multiple, the step of obtaining the third structure includes a step of arranging a plurality of the first structures on the second structure; The time required for arranging the plurality of first structures is 0.5 hours or more and 10 hours or less. A method for manufacturing the light emitting device according to claim 1 .

3. In the step of obtaining the third structure, N (N is a natural number) first structures are arranged in order; In the step of heating at the second temperature, the first structure arranged at the Mth position is heated at a temperature higher than the first structure arranged at the M-1th position (M is a natural number not less than 2 and not more than N), A method for manufacturing the light emitting device according to claim 1 .

4. In the step of obtaining the third structure, the pair of element electrodes of the light-emitting element and the pair of wirings of the substrate are disposed apart from each other, The method further includes the step of forming metal plating that electrically connects the pair of element electrodes of the light-emitting element and the pair of wirings of the substrate after the step of peeling off the support substrate. A method for manufacturing the light emitting device according to claim 1 .

5. The metal plating is copper plating or gold plating. A method for manufacturing a light emitting device according to claim 4 .

6. The second temperature is 140° C. or less. A method for manufacturing the light emitting device according to claim 5 .

7. The method further includes removing the bonding member after the step of forming the metal plating. A method for manufacturing a light emitting device according to claim 4 .

8. In a cross-sectional view taken along a line passing through the first surface of the light-emitting element and the pair of element electrodes, a ratio of a width of an upper surface of the bonding member to a width of a lower surface of the bonding member after the step of heating at the second temperature is 0.910 or more. A method for manufacturing the light emitting device according to claim 1 .

9. A substrate having a base material and a plurality of pairs of wirings disposed on the base material; A plurality of light emitting elements each having a first surface and a second surface on which a pair of element electrodes are disposed on the opposite side of the first surface, and the pair of element electrodes and the pair of wirings are disposed opposite to each other; a first metal plating portion and a second metal plating portion electrically connecting a pair of element electrodes of the light emitting element and the pair of wirings; having A cross-sectional view taken along a line passing through a first surface of the light-emitting element and the pair of element electrodes, the first metal plating portion has an upper surface in contact with the element electrode, a first side surface connected to one end of the upper surface and located on the second metal plating portion side, and a second side surface connected to the other end of the upper surface and located on the opposite side to the first side surface, The shape of the first side surface is different from the shape of the second side surface, The first side surface has a protrusion.

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