Manufacturing method for light-emitting device, and light-emitting device

Abstract

To provide a manufacturing method for a light-emitting device that can mount a light-emitting element suitably on a wiring base material, regardless of whether the wiring base material is transparent or not.SOLUTION: A step of installing a light-emitting element including a p-side electrode 31 and an n-side electrode 32 on the same surface side on a base material 10 is included. The following steps are performed: forming a wiring seed layer on a positive electrode side and a wiring seed layer on a negative electrode side in order on the base material, forming at least a part of a resist pattern 20 in a region where a light-emitting element is disposed on the base material, disposing the light-emitting element on the resist pattern so that the p-side electrode and the wiring seed layer on the positive electrode side face each other with a distance therebetween and the n-side electrode and the wiring seed layer on the negative electrode side face each other with a distance therebetween, plating and bonding between the wiring seed layer on the positive electrode side and the p-side electrode disposed apart from the wiring seed layer on the positive electrode side, and between the wiring seed layer on the negative electrode side and the n-side electrode disposed apart from the wiring seed layer on the negative electrode side using the resist pattern as a mask, and removing the resist pattern.SELECTED DRAWING: Figure 1D

Description

[Technical field]

[0001] An embodiment of the present invention relates to a method for manufacturing a light emitting device and a light emitting device. [Background technology]

[0002] Methods for mounting electronic components such as light-emitting elements on a wiring substrate have been known for some time. For example, first, an uncured or semi-cured adhesive is applied to the surface of the wiring substrate, and the main surface of the wiring substrate opposite to the side on which the light-emitting elements are arranged is irradiated with light to cure the adhesive at predetermined locations through the wiring substrate, thereby attaching and supporting the light-emitting elements. After that, the uncured or semi-cured adhesive at locations other than the predetermined locations is removed, and the electrodes provided on the light-emitting elements and the wiring of the wiring substrate are connected in the removed portions by a plating method. In this manner, it becomes possible to mount electronic components such as light-emitting elements on the wiring substrate (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-183458 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been an increasing demand for high thermal conductivity of the substrate and high integration of the driving circuit, especially the wiring, and non-transparent substrates such as Si substrates are expected to satisfy these demands. However, when a non-transparent substrate is used, it is not possible to transmit the irradiated light as in the conventional technology, and as a result, it is not possible to suitably mount the light-emitting element on the wiring substrate.

[0005] An embodiment of the present invention aims to provide a manufacturing method for a light-emitting device that enables light-emitting elements to be suitably mounted on a wiring substrate, regardless of whether the wiring substrate is a transparent substrate or a non-transparent substrate, and a light-emitting device obtained by the manufacturing method. [Means for solving the problem]

[0006] In order to achieve the above object, in one embodiment of the present invention, A method for manufacturing a light emitting device, comprising the steps of: placing a light emitting element having a p-side electrode and an n-side electrode on the same surface side on a substrate; The steps are carried out in order. forming a positive electrode side wiring seed layer and a negative electrode side wiring seed layer on the substrate; forming at least a part of a resist pattern in an area on the substrate where the light emitting element is to be mounted; placing the light emitting element on the resist pattern such that the p-side electrode and the positive electrode side wiring seed layer face each other with a space therebetween, and the n-side electrode and the negative electrode side wiring seed layer face each other with a space therebetween; Using the resist pattern as a mask, plating is performed between the positive electrode side wiring seed layer and the p-side electrode spaced apart from the positive electrode side wiring seed layer, and between the negative electrode side wiring seed layer and the n-side electrode spaced apart from the negative electrode side wiring seed layer; removing the resist pattern; A method for manufacturing a light emitting device is provided, comprising:

[0007] In order to achieve the above object, in one embodiment of the present invention, A wiring substrate including a substrate and a positive electrode wiring and a negative electrode wiring disposed on the substrate; a light-emitting element located on the wiring substrate and including a p-side electrode and an n-side electrode; a first conductive member connecting the positive electrode wiring and the p-side electrode; a second conductive member connecting the negative electrode wiring and the n-electrode; Equipped with A light-emitting device is provided in which, in a cross-sectional view, the outer side surface of at least one of the first conductive member and the second conductive member protrudes outward beyond a straight line connecting the outer end of the wiring and the outer end of the electrode. Effect of the Invention

[0008] According to one embodiment of the present invention, the light emitting element can be suitably mounted on the wiring substrate, regardless of whether the wiring substrate is a transparent substrate or a non-transparent substrate. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 2 is a perspective view showing a schematic diagram of a formation mode of a wiring seed layer on a substrate. [Figure 1B] FIG. 2 is a perspective view showing a typical mode of forming a resist pattern. [Figure 1C] FIG. 2 is a perspective view showing a schematic arrangement of a light-emitting element; [Figure 1D] 1 is a perspective view showing a schematic view of a plating bonding state between a wiring seed layer and an electrode of a light emitting element. FIG. [Figure 1E] FIG. 2 is a perspective view showing a typical manner in which a resist pattern is removed. [Figure 2A] FIG. 2 is a plan view showing a schematic diagram of a formation mode of a wiring seed layer on a substrate. [Figure 2B] 2B is a cross-sectional view showing a schematic diagram of a formation mode of a wiring seed layer on a substrate taken along line II' in FIG. 2A. [Figure 2C] FIG. 2 is a plan view showing a schematic form of a resist pattern formation. [Figure 2D] 2D is a cross-sectional view showing a schematic diagram of a resist pattern formed between II and II' in FIG. 2C. FIG. [Figure 2E] FIG. 2 is a perspective view showing a schematic diagram of a light-emitting element-mounted carrier substrate on which a light-emitting element is mounted. [Figure 2F] FIG. 2 is a plan view showing a schematic view of a mode in which a light-emitting element-mounted carrier base is placed on a first resist pattern. [Figure 2G] 3 is a cross-sectional view showing a schematic view of a state in which a light-emitting element-mounted carrier substrate is placed on a first resist pattern taken along line III-III' in FIG. 2F. FIG. [Figure 2H] FIG. 2 is a plan view showing a schematic view of a mode in which a carrier substrate is peeled off from a light emitting element. [Figure 2I] 4 is a cross-sectional view showing a schematic diagram of a mode in which a carrier substrate is peeled off from a light-emitting element. FIG. [Figure 2J] 4 is a cross-sectional view that illustrates a plating bonding state between a wiring seed layer and an electrode of a light-emitting element. FIG. [Figure 2K] 4A to 4C are cross-sectional views each showing a schematic manner in which a resist pattern is removed. [Figure 2L] 11 is a plan view showing a schematic cut-off state of a local portion of the wiring seed layer corresponding to a portion where the second resist pattern has been removed. FIG. [Figure 2M] 5 is a cross-sectional view showing a schematic cut-off state of a local portion of the wiring seed layer corresponding to a portion where the second resist pattern has been removed. FIG. [Figure 2N] FIG. 2 is a cross-sectional view showing a schematic embodiment of electroless plating treatment. [Diagram 3] 1 is a cross-sectional view illustrating a schematic configuration of a light-emitting device according to one embodiment of the present invention. [Figure 4] FIG. 11 is a cross-sectional view illustrating a schematic configuration of a light-emitting device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Manufacturing method of light emitting device] A method for manufacturing a light emitting device according to an embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions are 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 meanings of these terms do not limit the technical scope of the present invention. In addition, parts with the same reference numerals appearing in multiple drawings refer to the same or equivalent parts.

[0011] Furthermore, the embodiments shown below are merely illustrative of a method for manufacturing a light-emitting device to embody the technical ideas of the present invention, and are not intended to limit the present invention. Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described below are intended to be illustrative, and are not intended to limit the scope of the present invention. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated to clarify the explanation.

[0012] EMBODIMENT 1 A method for manufacturing a light emitting device according to the first embodiment of the present invention will be described below with reference to the drawings.

[0013] In the first embodiment, as an example, a light emitting device is manufactured by mounting a single light emitting element having a p-side electrode and an n-side electrode on the same side on a wiring substrate.

[0014] In this embodiment, the production method according to the first embodiment of the present invention includes the following steps (a) to (e).

[0015] (a) Formation of a wiring seed layer on a substrate FIG. 1A is a perspective view that illustrates a typical manner in which a wiring seed layer is formed on a substrate.

[0016] 1A, a positive electrode side wiring seed layer 11 and a negative electrode side wiring seed layer 12 are formed at a predetermined interval on a substrate 10. A substrate 10 on which a positive electrode side wiring seed layer 11 and a negative electrode side wiring seed layer 12 are formed at a predetermined interval may be prepared.

[0017] The predetermined interval between the wiring seed layers 11 and 12 is preferably such that the p-side electrode of the light emitting element 30 to be mounted later faces the positive wiring seed layer 11, and the n-side electrode faces the negative wiring seed layer 12. For example, when the size of the light emitting element in a plan view is 50 μm×50 μm, the interval between the wiring seed layers 11 and 12 can be 14 μm.

[0018] Not only transparent substrates but also non-transparent substrates may be used as the substrate 10. Examples of transparent substrate materials include glass, quartz, sapphire, ceramics (e.g., transparent alumina), and organic films (e.g., PET). Examples of non-transparent substrate materials include semiconductors (e.g., Si, Ge, GaAs, InP), ceramics (e.g., alumina, AlN), metals (e.g., Al, Cu), and organic materials (e.g., FR4).

[0019] (b) Resist pattern formation process FIG. 1B is a perspective view that illustrates a typical manner in which a resist pattern is formed.

[0020] At least a part of the resist pattern 20 is formed in the region on the substrate 10 where the light emitting element 30 is to be placed. In this specification, the term "resist pattern" refers to a resist patterned to expose a part of the substrate so that a region available for plating growth can be secured later in the region on the substrate 10 where the light emitting element 30 is to be placed, and may also be called a "patterned resist" or a "patterned resist". As shown in FIG. 1B, the resist pattern 20 may be formed in the region on the substrate 10 where the light emitting element 30 is to be placed, or a part of the resist pattern 20 may extend outside the region where the light emitting element 30 is to be placed.

[0021] In the following, an example will be taken of a case in which the entire resist pattern 20 is disposed within a region in which the light emitting element 30 will be mounted later.

[0022] Specifically, a resist pattern 20 having a planar size smaller than that of the light emitting element 30 is formed in the region where the light emitting element 30 is to be placed so that the electrodes (p-side electrodes / n-side electrodes) of the light emitting element 30 and the wiring seed layers 11 and 12 can be spaced apart and opposed to each other when the light emitting element 30 is placed later. That is, the resist pattern 20 is placed so that the electrodes (p-side electrodes / n-side electrodes) of the light emitting element 30 and the wiring seed layers 11 and 12 overlap in the region where the resist pattern 20 is not placed in a planar view. This makes it possible to suitably secure a space (specifically, a narrow space for growing plating later) between the electrodes of the light emitting element 30 and the wiring seed layers 11 and 12. The planar size of the resist pattern 20 can be 20% to 40% of the planar size of the light emitting element 30.

[0023] The resist pattern 20 may be formed, in a plan view, within a region where the light emitting element 30 will be mounted later, and at least between the wiring seed layer 11 on the positive electrode side and the wiring seed layer 12 on the negative electrode side.

[0024] Photolithography or screen printing can be used to form the resist pattern 20. When photolithography is used, a fine resist pattern can be formed.

[0025] It is preferable that the resist of the resist pattern 20 has adhesiveness. If the resist has adhesiveness, it becomes possible to attach and support the light emitting element 30, which will be mounted later, on the resist pattern 20.

[0026] The resist pattern 20 is preferably one that has the above-mentioned adhesiveness and is also chemically resistant to the plating solution used later. For example, phenol resin, epoxy resin, silicone resin, or acrylic resin can be used as the resist pattern 20. When the resist pattern 20 is used, it is not necessary to provide a member suitable for each purpose as a mask for supporting the light-emitting element and for plating bonding, and therefore the number of steps can be reduced. In addition, there are no restrictions due to the combination of forming conditions (dissolving in one solvent, different appropriate processing temperatures, etc.) that may occur when using separate members, and therefore the steps can be easily carried out.

[0027] The cross-sectional shape of the resist pattern 20 may be rectangular or square. That is, the contact surface (upper surface) of the resist pattern 20 that contacts the light emitting element 30 and the side surface can be in a substantially perpendicular relationship. This makes it possible to accurately secure the contact region between the light emitting element 30 and the resist pattern 20 and the plating growth region that will later connect the wiring seed layer and the electrode of the light emitting element.

[0028] The cross-sectional shape of the resist pattern may be tapered. It may be a shape in which the width becomes wider from the substrate 10 toward the light emitting element 30, or a shape in which the width becomes narrower from the substrate 10 toward the light emitting element 30. If the width becomes wider from the substrate 10 toward the light emitting element 30, the contact area between the light emitting element 30 and the resist pattern 20 can be increased, and the light emitting element and the resist pattern can be attached more reliably.

[0029] In a cross-sectional view, it is preferable that the height of the resist pattern 20 is higher than the height of the wiring seed layer 11 on the positive electrode side and the wiring seed layer 12 on the negative electrode side. This allows the wiring seed layer provided on the substrate 10 and the electrode of the light-emitting element 30 to be placed on the resist pattern 20 to be spaced apart from each other, sandwiching the resist pattern 20, when the light-emitting element 30 is later placed on the resist pattern 20, due to the difference in height.

[0030] This separation ensures a space for connecting the wiring seed layer and the electrode of the light emitting element 30 by plating in a later plating process. Electrolytic plating or electroless plating can be used as the plating process.

[0031] The "height of the resist pattern 20" here refers to the thickness of the resist pattern 20. The height of the resist can be 1 μm or more and 3 μm or less. It is preferable that the height of the resist pattern 20 is smaller than the distance between the wiring seed layers 11 and 12. If the height of the resist pattern 20 is larger than the distance between the wiring seed layers 11 and 12, there is a risk that the wiring seed layer 11 and the wiring seed layer 12 will be connected by plating before the wiring seed layer and the electrode of the light-emitting element are connected by plating during plating. However, if the height of the resist pattern 20 is smaller than the distance between the wiring seed layers 11 and 12, it is possible to prevent the wiring seed layer 11 and the wiring seed layer 12 from being connected by plating.

[0032] (c) Step of placing the light-emitting element FIG. 1C is a perspective view showing a schematic arrangement of the light-emitting element.

[0033] As shown in FIG. 1C, a light emitting element 30 is placed on the resist pattern 20.

[0034] In both steps (a) and (b), a prior adjustment is made so that the electrodes of the light emitting element 30 to be placed later can face the wiring seed layers 11 and 12, respectively. As a result, in step (c), when the light emitting element 30 is placed on the resist pattern 20, the p-side electrode 31 of the light emitting element 30 and the positive-side wiring seed layer 11 can face each other at a distance, and the n-side electrode 32 of the light emitting element 30 and the negative-side wiring seed layer 12 can face each other at a distance. As a result, it is possible to suitably secure a narrow space for growing the plating P between the electrodes 31 and 32 of the light emitting element 30 and the wiring seed layers 11 and 12.

[0035] Furthermore, the light emitting element 30 can be reliably placed on the resist pattern 20. In this specification, "the electrode of the light emitting element 30 and the wiring seed layer face each other" refers to a relationship in which a part of the electrode of the light emitting element 30 faces a part of the wiring seed layer in a cross-sectional view.

[0036] When placing the light emitting element 30 on the resist pattern 20, if the material of the resist pattern 20 is thermoplastic, the light emitting element 30 may be placed while being thermocompressed. This allows the light emitting element 30 to be attached and supported on the resist pattern 20, and ensures adhesion between the light emitting element 30 and the resist pattern 20. By applying pressure to the resist pattern by thermocompression or the like, the cross-sectional shape of the resist pattern may be barrel-shaped (a shape bulging outward).

[0037] (d) A plating bonding process between the wiring seed layer and the electrode of the light emitting element FIG. 1D is a perspective view that illustrates a plating bonding state between a wiring seed layer and an electrode of a light-emitting element.

[0038] 1D, using the resist pattern 20 as a mask, the positive electrode side wiring seed layer 11 and the p-side electrode 31 arranged separately from the positive electrode side wiring seed layer 11, and the negative electrode side wiring seed layer 12 and the n-side electrode 32 arranged separately from the negative electrode side wiring seed layer 12 are plated to bond the layers together. As a result, the positive electrode side wiring seed layer 11 and the p-side electrode 31 are electrically connected, and the negative electrode side wiring seed layer 12 and the n-side electrode 32 are electrically connected.

[0039] In step (d), in a state in which the narrow space is appropriately secured, a plating process is carried out using the resist pattern 20 as a mask.

[0040] The plating process may be electrolytic plating or electroless plating. Copper (Cu) may be used as the plating solution. When a copper plating solution is used, the electrode of the light-emitting element and the wiring seed layer are connected by copper, and the electrode of the light-emitting element and the wiring seed layer can be plated together. In addition to copper, the plating solution may be gold (Au), zinc (Zn), chromium (Cr), and / or nickel (Ni).

[0041] (e) Resist pattern removal process FIG. 1E is a perspective view illustrating a typical manner in which the resist pattern is removed.

[0042] As shown in FIG. 1E, the resist pattern 20 is removed.

[0043] The resist pattern 20 may be removed by immersing it in a stripping solution capable of stripping the resist, or by other methods. For example, after the bonding between the wiring seed layers 11, 12 and the electrodes 31, 32 is completed through plating in a chamber, any resist stripping solution is sprayed onto the resist pattern 20 using a nozzle. The resist pattern 20 is dissolved by the resist stripping solution, and the dissolved resist pattern 20 is sent out from the substrate 10 using a predetermined gas or the like.

[0044] The resist 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 resist pattern 20, for example, argon gas, nitrogen gas, etc. can be used.

[0045] In this manner, the light emitting element 30 is mounted on the base material 10, and the light emitting device 70 according to the first embodiment can be manufactured.

[0046] Considering the above steps (a) to (e), the manufacturing method for the light emitting device of embodiment 1 does not require the step of irradiating light from the main surface of the substrate opposite to the side on which the light emitting element is arranged in order to harden the adhesive for adhering the light emitting element to the substrate, as in the conventional manufacturing methods. Therefore, the light emitting element can be suitably mounted on the substrate 10 regardless of whether the substrate 10 is a transparent substrate or a non-transparent substrate.

[0047] EMBODIMENT 2 A method for manufacturing a light emitting device according to the second embodiment of the present invention will now be described with reference to the drawings.

[0048] As described above, the first embodiment is a form in which a single light-emitting element is mounted on a single wiring substrate to manufacture a light-emitting device. In contrast, the second embodiment is an application of the first embodiment, and is a form in which at least two light-emitting elements are mounted on a single wiring substrate to manufacture a light-emitting device. Since the second embodiment is an application of the first embodiment, the description of the parts that overlap with the contents of the first embodiment will be omitted.

[0049] The method for producing a light emitting device according to the second embodiment of the present invention is to place at least two light emitting elements, each having a p-side electrode and an n-side electrode on the same side, on a substrate. In this embodiment, the method for producing a light emitting device according to the second embodiment of the present invention includes the following steps.

[0050] (A) Process for forming a wiring seed layer on a substrate Fig. 2A is a plan view showing a typical embodiment of a wiring seed layer formed on a substrate, and Fig. 2B is a cross-sectional view showing a typical embodiment of a wiring seed layer formed on a substrate taken along line I-I' in Fig. 2A.

[0051] 2A and 2B, a positive electrode side wiring seed layer 110 and a negative electrode side wiring seed layer 120 are formed at a predetermined interval on a substrate 100. A substrate 100 on which a positive electrode side wiring seed layer 110 and a negative electrode side wiring seed layer 120 are formed at a predetermined interval may be prepared.

[0052] Specifically, from the viewpoint of later arranging at least two light emitting elements at a predetermined interval above each wiring seed layer 110, 120, the wiring seed layer 110 on the substrate 100 is formed so that the positive electrode side wiring seed layer 110 and the negative electrode side wiring seed layer 120 extend in approximately the same direction. Here, "the positive electrode side wiring seed layer 110 and the negative electrode side wiring seed layer 120 extend in approximately the same direction" refers to the case where both extend in the completely same direction (parallel direction), but also includes the case where the angle formed between them is within ±1 degree.

[0053] 2A, in plan view, the positive electrode side wiring seed layer 110 and the negative electrode side wiring seed layer 120 may include recesses 111. The recesses 111 provided in the positive electrode side wiring seed layer 110 are provided on a side of the positive electrode side wiring seed layer 110 facing the negative electrode side wiring seed layer 120. The recesses 111 provided in the negative electrode side wiring seed layer 120 are provided on a side of the negative electrode side wiring seed layer 120 facing the positive electrode side wiring seed layer 110.

[0054] The recess 111 can be provided in a region where the light emitting element is mounted. The recess 111 can be formed so that the first resist pattern 210 enters the recess 111 of the wiring seed layer 120 in a plan view. That is, the recess 111 can be formed at a position covered with the first resist pattern 210. The shape of the recess 111 is semicircular in FIG. 2A, but it may be other shapes (e.g., rectangular). The recess 111 may be formed in only one of the wiring seed layer 110 on the positive electrode side or the wiring seed layer 120 on the negative electrode side.

[0055] By forming the recess 111 in a position where it is covered by the first resist pattern 210, the area of ​​the first resist pattern 210 in contact with the wiring seed layer is reduced and the area of ​​the first resist pattern in contact with the substrate 100 is increased, thereby improving the adhesion between the resist pattern and the substrate 100.

[0056] (B) Resist pattern formation process Fig. 2C is a plan view showing a typical aspect of the formation of a resist pattern, and Fig. 2D is a cross-sectional view showing a typical aspect of the formation of a resist pattern between II-II' in Fig. 2C.

[0057] 2C and 2D, first resist patterns 210 are formed on the substrate 100 in regions where at least two light emitting elements 300 are to be mounted at a predetermined interval. The first resist patterns 210 correspond to the resist pattern 20 of the first embodiment.

[0058] Specifically, a first resist pattern 210 having a planar size smaller than the planar size of the light-emitting element 300 is formed in the area where each light-emitting element 300 is to be placed so that, when at least two light-emitting elements 300 are later placed at a predetermined interval, the electrodes of each light-emitting element 300 and the wiring seed layers 110, 120 can be spaced apart and opposed to each other.

[0059] By forming each of such first resist patterns 210, it is possible to secure a space (specifically, a small space for later growing plating) between the electrodes of each light-emitting element 300, which will be later placed on the first resist pattern 210, and the wiring seed layers 110, 120.

[0060] The planar shape of the first resist pattern 210 is preferably a cross shape as shown in Fig. 2C. This is because the light emitting element 300 can be stably placed on the first resist pattern 210 while ensuring a flow path for the plating solution during plating bonding. Other planar shapes of the first resist pattern 210 may be any shape, such as a square, a rectangle, or a triangle.

[0061] The first resist pattern 210 may or may not contact the electrodes 310, 320 of the light-emitting element. When the first resist pattern 210 contacts the electrodes 310, 320 of the light-emitting element, it is possible to secure a predetermined necessary and sufficient plating bonding area and to increase the contact area of ​​the light-emitting element 300 with the first resist pattern. This makes it possible to increase the adhesion of the light-emitting element 300 to the first resist pattern 210.

[0062] Furthermore, if there are depressions on the surfaces of the electrodes 310 and 320 of the light-emitting element, plating growth may be prevented in the depressions, since plating may remain in the depressions after plating bonding is completed. In this case, it is preferable that the tip of the resist pattern, which is cross-shaped in plan view and comes into contact with the electrode surface of the light-emitting element, covers the depressions present on the electrode surface of the light-emitting element.

[0063] On the other hand, when the first resist pattern 210 is not in contact with the electrodes 310, 320 of the light-emitting element, the entire area of ​​the electrodes is plated and thickened. When flash etching is used to cut the thin film of a local portion of the wiring seed layer 110, the plated growth area is also etched by the thickness of the local portion, but since the plated growth area is thickened, the conductivity of the plated growth area can be ensured.

[0064] As in the first embodiment, the first resist pattern 210 preferably has adhesiveness. By using a material for the first resist pattern 210 that has higher adhesiveness than the resin material 400 formed on the carrier substrate 500 described later, when the light emitting element mounted on the carrier substrate 500 is transferred to the substrate 10, the carrier substrate 500 can be peeled off from the light emitting element without the light emitting element peeling off from the first resist pattern.

[0065] The height of the first resist pattern 210 is preferably 10 to 30 times the thickness of the wiring seed layer 110. When flash etching is used to cut a local portion 110A of the wiring seed layer 110 described later, the plating growth region connecting the electrode and the wiring seed layer is also etched, but since the first resist pattern 210 has a height equal to or greater than a predetermined height, the plating growth region is also thickened in the horizontal direction, so that even if the plating growth region is etched by flash etching, good electrical connectivity between the electrode and the wiring seed layer can be maintained.

[0066] In step (B), in addition to forming the first resist pattern 210, a second resist pattern 220 is formed on the wiring seed layer 110 on the positive electrode side or the wiring seed layer 120 on the negative electrode side.

[0067] The second resist pattern 220 may be formed on the positive electrode side wiring seed layer 110 or the negative electrode side wiring seed layer 120 in a portion between adjacent light emitting elements 300. That is, the second resist pattern 220 may be formed after determining in advance the position of the portion between adjacent light emitting elements 300 and the other light emitting element 300.

[0068] 2C, a description will be given based on an embodiment in which the second resist pattern 220 is formed on the wiring seed layer 110 on the positive electrode side. Due to the presence of the second resist pattern 220, plating growth in the wiring seed layer 110 can be suppressed in the area where the second resist pattern 220 is formed in the subsequent plating process.

[0069] In order to maintain the thickness (thin film thickness) before the plating process at the location of the wiring seed layer 110 where the second resist pattern 220 is formed, the wiring seed layer 110 can be electrically disconnected by removing the wiring seed layer at the location where the second resist pattern 220 is formed by flash etching, which will be described later.

[0070] In order to cut the wiring seed layer 110 more reliably, it is preferable to form the second resist pattern 220 continuously from one end to the other end in a direction perpendicular to the extending direction of the wiring seed layer 110 in a plan view.

[0071] The second resist pattern 220 may be formed simultaneously with or separately from the first resist pattern 210. By forming the second resist pattern 220 and the first resist pattern 210 simultaneously, the number of steps can be reduced.

[0072] (C) Light-emitting element placement process Fig. 2E is a perspective view showing a carrier substrate having a light emitting element mounted thereon. Fig. 2F is a plan view showing a state in which the carrier substrate having a light emitting element mounted thereon is placed on a first resist pattern. Fig. 2G is a cross-sectional view showing a state in which the carrier substrate having a light emitting element mounted thereon is placed on the first resist pattern between III-III' in Fig. 2F.

[0073] As shown in Figures 2E to 2G, the light emitting element 300 is placed on each of the first resist patterns 210. Specifically, the light emitting element mounting carrier base 600 is placed on at least two first resist patterns 210 formed at a predetermined interval so that the electrode surface 330 of the light emitting element 300 faces the first resist pattern 210, respectively. At this time, the p-side electrode 310 of the light emitting element 300 faces the positive electrode side wiring seed layer 110 with a space therebetween, and the n-side electrode 320 of the light emitting element 300 faces the negative electrode side wiring seed layer 120 with a space therebetween.

[0074] The following describes the above-mentioned light-emitting element-mounted carrier base 600. The process of preparing the light-emitting element-mounted carrier base includes the following steps.

[0075] 1) Formation of a carrier substrate with a resin material The resin material 400 is continuously applied onto the carrier substrate 500 to obtain the carrier substrate 500 with the resin material 400. For example, the resin material 400 may be at least one resin material selected from the group consisting of silicone-based resin materials, epoxy-based resin materials, and acrylic-based resin materials. The carrier substrate 500 may be a glass substrate or the like.

[0076] 2) Laminating the light-emitting element onto the carrier substrate with resin material The light emitting element 300 is attached to the carrier substrate 500 with the resin material 400. Specifically, the light emitting element 300 is attached to the single carrier substrate 500 with the resin material such that the light emitting surfaces 340 of at least two light emitting elements 300 contact the resin material 400 on the single carrier substrate 500.

[0077] In this manner, it is possible to prepare a light-emitting element-mounted carrier substrate 600 in which the light-emitting elements 300 are mounted on the carrier substrate 500. In Fig. 2E, the light-emitting element-mounted carrier substrate 600 has three light-emitting elements 300 arranged in a row, but the number of light-emitting elements 300 may be three or more, for example, 10,000 to 30,000 light-emitting elements may be arranged in a row.

[0078] After placing the light-emitting element-mounted carrier base 600 on the first resist pattern 210, as shown in Figures 2H and 2I, the carrier base 500 is peeled off from each light-emitting element 300. The carrier base 500 may be peeled off after a plating bonding process between the wiring seed layer and the light-emitting element, which will be described later.

[0079] (D) Plating bonding process between the wiring seed layer and the electrode of the light emitting element FIG. 2J is a cross-sectional view that illustrates a plating bonding state between the wiring seed layer and the electrode of the light-emitting element.

[0080] As shown in FIG. 2J, using the first resist pattern 210 and the second resist pattern 220 as a mask, plating bonding is performed between the positive electrode side wiring seed layer 110 and the p-side electrode 310 spaced apart from the positive electrode side wiring seed layer 110, and between the negative electrode side wiring seed layer 120 and the n-side electrode 320 spaced apart from the negative electrode side wiring seed layer 120.

[0081] Since the second resist pattern 220 also functions as a mask, plating growth can be suppressed at the location of the wiring seed layer 110 where the second resist pattern 220 is formed during plating processing.

[0082] (E) Resist pattern removal process FIG. 2K is a cross-sectional view that illustrates a schematic manner in which the resist pattern is removed.

[0083] As shown in FIG. 2K, the first resist pattern 210 and the second resist pattern 220 are removed.

[0084] 2L is a plan view showing a cut state of a local portion of the wiring seed layer corresponding to a removed portion of the second resist pattern, and FIG 2M is a cross-sectional view showing a cut state of a local portion of the wiring seed layer corresponding to a removed portion of the second resist pattern.

[0085] After removing the first resist pattern 210 and the second resist pattern 220, as shown in Figures 2L and 2M, the local portion 110A of the wiring seed layer 110 corresponding to the removed portion of the second resist pattern 220 is cut. As a result, the wiring seed layer 110 is electrically divided at the local portion 110A.

[0086] The cutting method may be, for example, flash etching, which can remove the localized portion 110A of the wiring seed layer 110 by immersion in an etching solution. Alternatively, the localized portion 110A of the wiring seed layer 110 may be removed by spraying the etching solution.

[0087] As an etching solution for flash etching, at least one selected from the group consisting of hydrogen peroxide, sulfuric acid, ammonium persulfate, sodium persulfate, hydrochloric acid, nitric acid, ferric chloride, copper chloride, and the like can be used.

[0088] FIG. 2N is a cross-sectional view that illustrates a schematic embodiment of electroless plating treatment.

[0089] As shown in FIG. 2N, after cutting off the local portion 110A of the wiring seed layer 110, the conductive member P may be subjected to electroless plating to form a pad conductive member C. By performing such plating, the wiring seed layer (e.g., Cu) is coated so as not to be exposed, so that corrosion of the wiring seed layer can be suppressed and peeling of the wire from the wiring seed layer can be suppressed. Examples of layers formed by electroless plating include a layered structure of Ni (nickel), Pd (palladium), and Au (gold) (with Au as the outermost surface), or a layered structure of Au (gold), Pd (palladium), and Au (gold).

[0090] In this manner, at least two light emitting elements 300 can be suitably mounted on the base material 100. As a result, the light emitting device according to the second embodiment can be manufactured.

[0091] According to the conventional method, the adhesive layer portion that is hardened by exposing the seed layer pattern formed on the upper surface of the transparent substrate to light from the rear surface of the substrate using the seed layer pattern as a mask is used as the adhesive layer pattern for holding the light emitting element during plating. That is, the adhesive layer pattern is inevitably an inverted pattern of the seed layer pattern, so the design of the light emitting element holding pattern and the circuit pattern is inseparable, resulting in restrictions on the circuit pattern. For example, when it is desired to electrically and mechanically connect with an island-shaped circuit portion that is separated from the surroundings directly under the light emitting element, the wiring seed layer needs to be island-shaped in the conventional method, but this makes it impossible to pass electricity, so plating growth by electrolytic plating cannot be performed, and connection with the light emitting element side electrode is impossible.

[0092] Furthermore, since the island region is surrounded by the light emitting element, the base material, and the adhesive layer, the flow path of the plating solution is closed, so that connection is impossible even if electroless plating is used, and therefore it is impossible to hold the island-shaped light emitting element and form a wiring pattern directly below the light emitting element.

[0093] However, in the manufacturing method of embodiment 2, the pattern shape of the wiring seed layer after plating can be defined by a resist in addition to the pattern of the wiring seed layer. Therefore, by combining with subsequent etching (flash etching) or the like, a free pattern shape of the wiring seed layer such as an island-shaped wiring seed layer can be obtained.

[0094] In the second embodiment, the wiring seed layer 110 on the positive electrode side is cut and the wiring seed layer 120 on the negative electrode side is not cut, so that the negative electrode side of each light-emitting element becomes a common electrode and the positive electrode side of each light-emitting element becomes an electrode independent of each other. This allows the lighting of each light-emitting element to be controlled independently. In addition, in the case where the wiring seed layer 120 on the negative electrode side is cut and the wiring seed layer 110 on the positive electrode side is not cut, the positive electrode side of each light-emitting element becomes a common electrode and the negative electrode side of each light-emitting element becomes an electrode independent of each other. Even in this case, the lighting of each light-emitting element can be controlled independently.

[0095] In the above, a description has been given of a case where a "single" light-emitting element mounting carrier base 600 is attached onto at least two first resist patterns 210 formed at a predetermined interval. However, the present invention is not limited to this. For example, "at least two" light-emitting element mounting carrier bases 600 may be attached onto the at least two first resist patterns 210 at a predetermined interval. In this case, the first resist pattern 210 may be shaped to extend in the same direction as the wiring seed layer extends in a plan view.

[0096] [Light emitting device] The light-emitting device obtained by the manufacturing methods of the above-mentioned embodiments 1 and 2 may have the following configuration. FIG. 3 is a cross-sectional view showing a schematic configuration of a light-emitting device according to one embodiment of the present invention. FIG. 4 is a cross-sectional view showing a schematic configuration of a light-emitting device according to another embodiment of the present invention. As shown in FIG. 3, a light-emitting device 70 according to one embodiment of the present invention includes a wiring substrate 10X including a positive electrode side wiring 11 and a negative electrode side wiring 12 arranged on the substrate 10, a light-emitting element 30 located on the wiring substrate 10X and including a p-side electrode 31 and an n-side electrode 32, a first conductive member P1 connecting between the positive electrode side wiring 11 and the p-side electrode 31, and a second conductive member P2 connecting between the negative electrode side wiring 12 and the n-side electrode 32.

[0097] In such a configuration, in one embodiment of the present invention, the outer side surface P11, P21 of at least one of the first conductive member P1 and the second conductive member P2 is configured to protrude outward from a straight line connecting the outer end 11a, 12a of the wiring and the outer end 31a, 32a of the electrode in a cross-sectional view. Note that the "cross-sectional view" here refers to a view seen from a direction cutting the p-side electrode 31, the n-side electrode 32, and the positive electrode side wiring 11 and the negative electrode side wiring 12 arranged opposite to them, respectively.

[0098] In the conductive member formation stage during the manufacture of the light-emitting device, one side of the conductive member grows from the wiring seed layer toward the electrode along the side of the resist, while the other side grows in the free space between the light-emitting element 30 and the wiring substrate 10X, thereby forming the conductive member. The shape of the inner side surfaces P12, P22 of the first conductive member P1 and the second conductive member P2 may depend on the side shape of the resist pattern formed on the substrate in the conductive member formation stage. As described above, when the cross-sectional shape of the resist pattern is rectangular or square, the side surface of the resist pattern is perpendicular to the upper surface of the wiring, and therefore the shapes of the inner side surfaces P12, P22 of the first conductive member P1 and the second conductive member P2 may also be perpendicular to the upper surface of the wiring (corresponding to the wiring seed layer during manufacture) at the time of completion of manufacture. The term "perpendicular" here refers to a state in which the angle between the inner side surface of the conductive member and the upper surface of the wiring is 90 degrees or 90 degrees ± 5 degrees in a cross-sectional view. In addition, the inner side surfaces of the first conductive member P1 and the second conductive member P2 are not limited to being perpendicular to the top surface of the wiring, and the inner side surface of at least one of the first conductive member P1 and the second conductive member P2 may be perpendicular to the top surface of the wiring.

[0099] On the other hand, the shapes of the outer side surfaces P11, P21 of the first conductive member P1 and the second conductive member P2 obtained in the end do not depend on the side surface shape of the resist pattern. For this reason, the outer side surfaces P11, P21 of the conductive members obtained in the end protrude outward from the straight line connecting the ends 11a, 12a of the wiring and the ends 31a, 32a of the electrodes of the light emitting element 30. By the outer side surface of the conductive member protruding, the contact area between the conductive member and the light emitting element increases, so that the heat dissipation can be improved. Furthermore, as described above, since the inner side surface of the conductive member is the side that grows along the side surface of the resist pattern arranged during the manufacturing process, after the resist pattern is removed, the first conductive member P1 and the second conductive member P2 obtained in the end can be in a state where a certain gap is left. Therefore, the occurrence of a short circuit due to contact between the first conductive member P1 and the second conductive member P2 can be suitably avoided. From the above, according to the light emitting device 70 according to one embodiment of the present invention, it is possible to achieve both improvement of heat dissipation and suppression of the occurrence of a short circuit.

[0100] In addition, the position of the protruding end of the conductive member may vary depending on the positional relationship between the ends 31a, 32a of the electrodes and the ends 11a, 12a of the wiring in a cross-sectional view. Specifically, as shown in Fig. 3, when the ends 31a, 32a of the electrodes are located outside the ends 11a, 12a of the wiring in a cross-sectional view, the protruding end PX of the conductive member P may be located on the electrode 31, 32 side. On the other hand, as shown in Fig. 4, when the ends 11αa, 12αa of the wiring are located outside the ends 31αa, 32αa of the electrodes in a cross-sectional view, the protruding end PY of the conductive member may be located on the substrate 10α side.

[0101] In addition, as already described in the section on the manufacturing method of the present invention, since the conductive member can be formed by exposure through the substrate without forming an adhesive layer pattern, not only transparent substrates but also non-transparent substrates can be used as the substrate, and therefore the types of substrates that can be used can be increased.

[0102] The light emitting element used in the first and second embodiments includes a semiconductor laminate and an electrode. The light emitting element includes a light emitting surface (also called a main light emitting surface), a side surface extending in a different direction (for example, a vertical direction) from the light emitting surface, and an electrode surface on the opposite side to the light emitting surface on which a pair of positive and negative electrodes are provided.

[0103] As the light-emitting element, a semiconductor light-emitting element capable of emitting light having any wavelength can be selected. For example, a light-emitting diode or the like can be selected as the light-emitting element. As an example, a light-emitting element that emits blue light can be used. Without being limited thereto, a light-emitting element that emits light of a color other than blue light can be used. When a light-emitting device uses a plurality of light-emitting elements arranged at a predetermined interval, the light-emitting elements may each emit light of the same color, or may emit light of different colors.

[0104] For example, a nitride-based semiconductor (InxAlyGa1-x-yN, 0≦X, 0≦Y, X+Y≦1) can be used as a semiconductor laminate of a light-emitting element capable of emitting blue light. In this case, the nitride-based semiconductor light-emitting element has, for example, a sapphire substrate and a nitride-based semiconductor laminate structure laminated on the sapphire substrate. The nitride-based semiconductor laminate structure includes a light-emitting layer, and an n-type nitride-based semiconductor layer and a p-type nitride-based semiconductor layer positioned so as to sandwich the light-emitting layer. An n-side electrode and a p-side electrode, which are electrodes, are electrically connected to the n-type nitride-based semiconductor layer and the p-type nitride-based semiconductor layer, respectively.

[0105] The light-emitting element 30 may have any shape in plan view, such as a square, a rectangle, or the like. It may also have a polygonal shape such as a triangle, a hexagon, or the like. The size of the light-emitting element 30 in plan view may be, for example, 10 μm to 100 μm, preferably 20 μm to 80 μm in length and width, in plan view. The height of the light-emitting element 30 may be 1 μm to 50 μm, preferably 2 μm to 10 μm.

[0106] In both the first and second embodiments, it is preferable to adopt the following features.

[0107] After arranging the light emitting element on the base material, it is preferable to provide a light reflecting member so as to surround the side of the light emitting element in order to easily guide the light emitted from the light emitting element in a predetermined direction. When a plurality of light emitting elements are arranged adjacent to each other, the light reflecting member may be provided so as to fill the gap between adjacent light emitting elements. The light reflecting member may be, for example, a white resin in which a light reflecting white powder or the like is added to a transparent resin. The light reflecting member may be, for example, a silicone resin containing an inorganic white powder such as titanium oxide. In order to favorably reflect the light emitted from the light emitting element, the light reflecting member may be, for example, a white resin having a reflectance of 60% or more for the light, and is preferably a white resin having a reflectance of 90% or more. As a method for forming a light reflecting member on the side of the light emitting element, a resist is provided on the upper surface of the light emitting element, and a white resin is applied to the upper surface of the light emitting element and between the adjacent light emitting elements, and then the resist arranged on the upper surface of the light emitting element is removed, so that the white resin remaining on the side of the light emitting element becomes the light reflecting member.

[0108] A light-transmitting member may be provided between the side surface of the light-emitting element and the light-reflecting member and / or on the light-emitting surface of the light-emitting element. Examples of materials for the light-transmitting member include silicone resin, epoxy resin, and acrylic resin.

[0109] A wavelength conversion member capable of absorbing light emitted from the light emitting element and converting it into light of a different wavelength may be provided on the light emitting surface side of the light emitting element. The wavelength conversion member includes a wavelength conversion material such as a phosphor. Examples of phosphors include YAG phosphor ((Y,Lu,Gd)3(Al,Ga)5O12:Ce) that emits yellow light, β-sialon phosphor that emits green light, fluoride phosphor (e.g., K2(Si,Ti,Ge)F6:Mn, etc.) that emits red light, and nitride phosphor (e.g., Sr,Ca)AlSiN3:Eu). The wavelength conversion member may include a single type of wavelength conversion material, or may include multiple wavelength conversion materials.

[0110] Although one embodiment of the present invention has been described above, it is merely a typical example within the scope of application of the present invention. Therefore, it will be easily understood by those skilled in the art that the present invention is not limited to this embodiment and that various modifications can be made. [Industrial Applicability]

[0111] The light emitting device according to this embodiment can be suitably used in automobile headlights, projectors, and the like. [Explanation of symbols]

[0112] 10 Base material 10X, 10Xα wiring base material 11 Positive electrode wiring seed layer 11a, 11αa Positive electrode wiring end 12 Negative electrode wiring seed layer 12a, 12αa Negative electrode wiring end 20 Resist Pattern 30, 30α light emitting element 31, 31α P-side electrode of light-emitting element 31a, 31αa End of electrode on P side 32, 32α n-side electrode of light-emitting element 32a, 32αa End of n-side electrode 33 Electrode surface of light-emitting element 70, 70α Light-emitting device 100 Base material 110 Positive electrode wiring seed layer 120 Negative electrode wiring seed layer 210 First resist pattern 220 Second resist pattern 300 Light emitting element 310 P-side electrode of light-emitting element 320 n-side electrode of light-emitting element 330 Electrode surface of light-emitting element 340 Light-emitting surface of light-emitting element 400 Resin material 500 Carrier substrate 600 Light-emitting element-mounted carrier substrate P Conductive material P1, P1α First conductive member P11 Outer side surface of the first conductive member P12 Inner side surface of the first conductive member P2, P2α Second conductive member P21 Outer side of second conductive member P22 Inner side of second conductive member PX, PY Protruding end of conductive member C Pad Conductive Material

Claims

1. A wiring substrate including a substrate and a positive electrode wiring and a negative electrode wiring disposed on the substrate; a light-emitting element located on the wiring substrate and including a p-side electrode and an n-side electrode; a first conductive member connecting the positive electrode wiring and the p-side electrode; a second conductive member connecting the negative electrode wiring and the n-electrode; Equipped with an outer side surface of at least one of the first conductive member and the second conductive member protrudes outward from a straight line connecting an outer end of the wiring and an outer end of the electrode in a cross-sectional view; A light emitting device, wherein the thickness of the first conductive member and the second conductive member is 10 times or more and 30 times or less than the thickness of the wiring.

2. The light emitting device according to claim 1 , wherein, in a cross-sectional view, an end of the electrode is located outside an end of the wiring, and a protruding end of the conductive member is located on the electrode side.

3. The light emitting device according to claim 1 , wherein, in a cross-sectional view, an end of the wiring is located outside an end of the electrode, and a protruding end of the conductive member is located on the substrate side.

4. 4. The light emitting device according to claim 1, wherein an inner side surface of at least one of said first conductive member and said second conductive member is perpendicular to an upper surface of said wiring in a cross-sectional view.

5. The light-emitting device according to any one of claims 1 to 4, wherein the substrate is non-transparent.

Images