Light-emitting module and lighting device

Abstract

To provide a light-emitting module and a lighting device that can prevent misalignment of the individual light-emitting elements when multiple light-emitting elements are solder-mounted on a substrate.SOLUTION: A light-emitting module includes a substrate, a group of element mounting pads consisting of first and second wiring pads arranged on one main surface of the substrate with their long sides parallel to each other and aligned along their respective short sides, a group of wirings connected to each of the first and second wiring pads on the one main surface, and light-emitting elements mounted in element mounting areas including the element mounting pads on the one main surface, and the wiring connected to at least one of the first and second wiring pads in each of the element mounting pads extends from a central portion of one of the long sides of one of the wiring pads, or extends from each of the opposing short sides of one of the wiring pads.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a light-emitting module and a lighting device.

Background Art

[0002] A lighting device including a light-emitting module in which a plurality of light-emitting elements are mounted on a substrate is disclosed. For example, Patent Document 1 discloses a lighting device having a plurality of light-emitting elements arranged in a matrix on one main surface of an insulating substrate and heat-radiating means provided on the other main surface of the insulating substrate for discharging heat generated in each of the plurality of light-emitting elements to the outside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When attempting to apply the lighting device disclosed in Patent Document 1 to a vehicle headlight, such as an ADB (Adaptive Driving Beam) unit, a plurality of light-emitting elements are mounted on a substrate at a high density.

[0005] For example, when each of a plurality of light-emitting elements is mounted on a substrate at a high density via solder, self-alignment of the light-emitting elements by the molten solder during reflow of the light-emitting elements may not be successfully performed.

[0006] When such self-alignment is not successfully performed, there is a risk that the light-emitting element may deviate from the position where the light-emitting element is originally intended to be arranged. For example, in a plan view of the mounting surface of the light-emitting elements on the substrate as viewed from above, rotational deviation or deviation in the vertical, horizontal, or left-right direction may occur in the light-emitting elements.

[0007] The present invention has been made in view of the above points, and provides a light-emitting module and a lighting device capable of suppressing displacement of the arrangement of each of a plurality of light-emitting elements when solder-mounting them on a substrate.

Means for Solving the Problems

[0008] The light-emitting module according to the present invention includes a substrate, an element mounting pad group formed by a first wiring pad and a second wiring pad that have a rectangular upper surface shape together and are arranged side by side along the short side direction on one main surface of the substrate so that their long sides are parallel to each other, a wiring group connected to each of the first wiring pad and the second wiring pad on one main surface, and light-emitting elements respectively mounted in an element mounting region including the element mounting pads on one main surface. In each of the element mounting pads, the wiring connected to at least one of the first wiring pad or the second wiring pad extends from a central portion on one side of the long side of one of the wiring pads or from each of the opposing short sides of one of the wiring pads.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are given to the same components, and the description of the overlapping components is omitted.

Examples

[0011] [Outline of Lighting Device 100] FIG. 1 is an exploded perspective view showing the configuration of a lighting device 100 according to Example 1. In FIG. 1, for simplicity of explanation, the axis in the depth direction (front-rear direction) of the lighting device 100 is defined as the X-axis, the axis in the width direction (left-right direction) of the lighting device 100 is defined as the Y-axis, and the axis in the height direction (up-down direction) of the lighting device 100 is defined as the Z-axis, and the XYZ axes are defined.

[0012] The lighting device 100 includes a light-emitting module 110 including a light-emitting element, a module holder 120 that holds the light-emitting module 110, a lens holder 130, and a lens 140 held by the lens holder 130. The lighting device 100 is incorporated in the front part of a vehicle, for example, as an ADB (Adaptive Driving Beam) unit as a headlight of the vehicle.

[0013] [Light-Emitting Module 110] The light-emitting module 110 includes a substrate 10 composed of a first substrate portion 11 and a second substrate portion 12, various elements arranged on the substrate 10, and wirings electrically connected thereto.

[0014] The first substrate portion 11 of the substrate 10 is a plate-shaped portion having a rectangular planar shape and being insulating. The first substrate portion 11 has circular through-holes 11H1 formed at one location upward and one location each on the right and left, penetrating the first substrate portion 11 in the front-rear direction. The first substrate portion 11 is, for example, a glass epoxy substrate (FR-4) composed of multiple layers.

[0015] On the front surface of the first substrate portion 11, driving elements for driving each of the plurality of light-emitting elements by signals from external devices, such as ICs (Integrated Circuits), protection elements, capacitors, resistors, etc., are provided, but these are omitted in the figure.

[0016] The second substrate portion 12 of the substrate 10 is a plate-shaped portion having a rectangular planar shape and being integrated with the first substrate portion 11 and being insulating. The second substrate portion 12 is made of a material having a higher thermal conductivity than the first substrate portion 11.

[0017] The second substrate portion 12 is, for example, a ceramic substrate such as aluminum oxide (Al 2 O 3 ) having a thermal conductivity of 15 to 30 W / m·K, or aluminum nitride (AlN) having a thermal conductivity of 150 to 200 W / m·K and excellent heat dissipation properties. Note that the first substrate portion 11 of the substrate 10 may also be a ceramic substrate.

[0018] On the front surface of the second substrate portion 12, a plurality of light-emitting elements are provided (not shown in FIG. 1). Note that the specific arrangement mode, configuration of the light-emitting elements, the element mounting pads on which the light-emitting elements are mounted, and the formation mode of the wirings connected to the element mounting pads will be described later.

[0019] [Module Holder 120] The module holder 120 is configured by integrating a base portion 14, heat dissipation fins 15, and an external attachment portion 16. The module holder 120 is made of a metal with high thermal conductivity such as aluminum (Al), iron (Fe), or copper (Cu).

[0020] The base portion 14 is a plate-shaped portion with a substantially circular planar shape. The base portion 14 has screw holes 14H1 formed at three locations in the center of the front surface. The base portion 14 also has screw holes 14H2 formed at three locations in a portion along the outer edge of the front surface.

[0021] The module holder 120 fixes the light-emitting module 110 by screwing each location in a state where the positions of the through holes 11H1 provided in the substrate 10 of the light-emitting module 110 and the positions of the screw holes 14H1 provided in the base portion 14 are aligned respectively. As a result, the rear surface of the substrate 10 comes into contact with the front surface of the base portion 14.

[0022] Therefore, when the light-emitting module 110 is attached to the base portion 14 and each light-emitting element provided on the front surface of the second substrate portion 12 is driven, the front surface of the base portion 14 functions as a heat-receiving surface that receives the heat generated in each of the light-emitting elements.

[0023] The heat dissipation fins 15 protrude rearward from the rear surface of the base portion 14, and are plate-shaped portions provided in a plurality of rows in the width direction. The heat dissipation fins 15 dissipate the heat received by the base portion 14 to the outside. That is, the module holder 120 functions as a heat sink that dissipates the heat generated in the light-emitting module 110.

[0024] The external attachment portion 16 is a plate-shaped portion having an L-shape that protrudes rearward from the right and left sides of the rear surface of the base portion 14. The external attachment portion 16 is composed of a first portion 16A that extends along a direction perpendicular to the rear surface from the rear surface of the base portion 14 and a second portion 16B that extends outward along a direction parallel to the rear surface of the base portion 14 from one end of the first portion 16A.

[0025] The second portion 16B of the external attachment portion 16 has circular through-holes 16H that are formed at three locations along the vertical direction in each external attachment portion 16 and penetrate the second portion 16B in the front-rear direction. The second portion 16B is fixed to an external device by, for example, bolts inserted into the through-holes 16H.

[0026] Note that between the rear surface of the second substrate portion 12 on the substrate 10 of the light-emitting module 110 and the region corresponding to the second substrate portion 12 on the front surface of the base portion 14 of the module holder 120, in order to enhance the adhesion and heat conductivity between them, for example, alumina (Al 2 O 3 ) particles, aluminum nitride (AlN) particles, flake-like silver (Ag) fillers, flake-like graphite fillers, etc., a thermally conductive adhesive made of a silicone resin containing the same may be used.

[0027] [Lens Holder 130] The lens holder 130 is composed of a plate-like base portion 18 having a circular planar shape and a cylindrical wall portion 19 protruding forward from approximately the center of the base portion 18. The base portion 18 of the lens holder 130 has circular through-holes 18H that are formed at three locations along the outer edge of the base portion 18 (one location not shown) and penetrate the base portion 18 in the front-rear direction.

[0028] The lens holder 130 is fixed to the module holder 120 by screwing each location in a state where the positions of the through-holes 18H provided in the base portion 18 and the positions of the screw holes 14H2 provided in the base portion 14 of the module holder 120 are aligned with each other.

[0029] When the lens holder 130 is fixed to the module holder 120, the light-emitting module 110 is disposed within the cylindrical wall portion 19 of the lens holder 130. In other words, in a plan view, the light-emitting module 110 is surrounded by the cylindrical wall portion 19.

[0030] [Lens 140] The lens 140 is a light-transmissive optical member joined to the edge portion 19E of the cylindrical wall portion 19 of the lens holder 130 so as to close the opening of the cylindrical wall portion 19. The lens 140 condenses or diffuses the light emitted from each of the light-emitting elements provided on the front surface of the second substrate portion 12 of the light-emitting module 110.

[0031] [Forming Modes of Element Mounting Pads and Wiring] Hereinafter, with reference to FIG. 2, the forming modes of the element mounting pads and wiring provided on the front surface of the substrate 10 of the light-emitting module 110 will be described. FIG. 2 is a plan view showing a portion A including the second substrate portion 12 of the light-emitting module 110 in FIG. 1.

[0032] In the following description, for convenience of explanation, the direction perpendicular to the front surface, which is the surface on which the light-emitting elements of the light-emitting module 110 are mounted in FIG. 1, is defined as the vertical direction. That is, the front in FIG. 1 becomes the upper side in the figures after FIG. 2. In short, the X-axis direction in FIG. 1 will be described as the vertical direction.

[0033] Further, in FIG. 2, the center line of the upper surface of the second substrate portion 12 parallel to the opposing long sides of the second substrate portion 12 is indicated by a dashed-dotted line as the center line CL1, and the center line of the upper surface of the second substrate portion 12 perpendicular to the center line CL1 is indicated by a dashed-dotted line as the center line CL2.

[0034] As described above, the substrate 10 is configured by integrating the first substrate portion 11 and the second substrate portion 12. Specifically, the substrate 10 is configured such that the second substrate portion 12 is inserted into a rectangular through-hole 11H2 provided in the first substrate portion 11, and the first substrate portion 11 and the second substrate portion 12 are joined to each other by an adhesive layer 21 made of epoxy resin.

[0035] In a plan view of the second substrate portion 12 as viewed from above, on the upper surface of the second substrate portion 12, element mounting pads 23 arranged in a row in the direction along the center line CL1 and wirings 24 connected to each of the element mounting pads 23 are formed. The element mounting pads 23 and the wirings 24 are made of a copper (Cu) material, and a gold (Au) plating is applied to their surfaces.

[0036] In the light emitting module 110, a light emitting element 25 is mounted on each of the element mounting pads 23. In FIG. 2, only the outer contour line of the light emitting element 25 is shown by a broken line in order to clarify the shapes of the element mounting pads 23 and the wirings 24. The detailed configuration of the light emitting element 25 will be described later.

[0037] Each of the element mounting pads 23 is composed of an anode pad 26 as a first wiring pad and a cathode pad 27 as a second wiring pad juxtaposed in the direction along the center line CL1. Both the anode pad 26 and the cathode pad 27 have a rectangular upper surface shape, and are arranged side by side along the center line CL1 so that their long sides are parallel to each other.

[0038] In each of the element mounting pads 23, the anode pad 26 is larger than the cathode pad 27 in both the long side and the short side. Also, in each of the element mounting pads 23, the anode pad 26 and the cathode pad 27 are arranged so that their longitudinal sides (long sides) are located on the same straight line parallel to the center line CL1. Note that the embodiment is merely an example, and the sizes of the anode pad 26 and the cathode pad 27 may be reversed.

[0039] In the light emitting module 110 of this embodiment, the element mounting pads 23 are arranged in a total of 4 rows, 2 rows on each side of the center line CL1. The anode pads 26 and the cathode pads 27 of each of the element mounting pads 23 above the center line CL1 in the figure are connected to a wiring 24 extending above the second substrate portion 12 in the figure.

[0040] Further, each anode pad 26 and cathode pad 27 of the element mounting pads 23 located below the center line CL1 in the figure are connected to a wiring 24 extending downward below the second substrate portion 12 in the figure.

[0041] Hereinafter, the light-emitting module 110 in this embodiment will be described on the assumption that it has seven pad wiring groups G1 to G7, each of which includes element mounting pads 23 arranged in 2 rows × 4 columns on the upper surface of the second substrate portion 12 and wirings 24 connected to each of the element mounting pads 23. In FIG. 2, the first pad wiring group G1 to the seventh pad wiring group G7 are each surrounded by a two-dot chain line and shown.

[0042] Specifically, the first pad wiring group G1 to the fourth pad wiring group G4 are formed in the region above the center line CL1 of the second substrate portion 12 in the figure, and the fifth pad wiring group G5 to the seventh pad wiring group G7 are formed in the region below the center line CL1 of the second substrate portion 12. In the following description, the first pad wiring group G1 to the seventh pad wiring group G7 are also collectively referred to as pad wiring groups G1 to G7.

[0043] In each of the pad wiring groups G1 to G7, the anode pad 26 of the upper element mounting pad 23 and the cathode pad 27 of the lower element mounting pad 23 in one column along the center line CL2 in the figure are connected via a wiring 24.

[0044] Further, in each of the pad wiring groups G1 to G7, the anode pad 26 of the lower element mounting pad 23 in the above-mentioned one column and the cathode pad 27 of the upper element mounting pad 23 in another column adjacent to the one column along the center line CL1 are connected via a wiring 24.

[0045] Therefore, each of the eight light-emitting elements 25 placed on each of the element mounting pads 23 in each of the pad wiring groups G1 to G7 is electrically connected in series to each other by the anode pad 26, the cathode pad 27, and the wiring 24. That is, the upper-left light-emitting element 25 in each of the pad wiring groups G1 to G7 bears one end side of the series connection, and the lower-right light-emitting element 25 bears the other end side of the series connection.

[0046] Here, with reference to FIGS. 3 and 4, a detailed formation mode of the wiring 24 connected to the anode pad 26 and the cathode pad 27 of the element mounting pad 23 will be described. FIG. 3 is a plan view showing the first pad wiring group G1 in FIG. 2. Further, FIG. 4 is a plan view showing the second pad wiring group G2 in FIG. 2. Also in FIGS. 3 and 4, the outer contour line of the light-emitting element 25 is shown by a broken line in the same manner as in FIG. 2.

[0047] Among the pad wiring groups G1 to G7, the first pad wiring group G1 and the seventh pad wiring group G7 have the same wiring shape, the second pad wiring group G2, the third pad wiring group G3, and the sixth pad wiring group G6 have the same wiring shape, and the fourth pad wiring group G4 and the fifth pad wiring group G5 have the same wiring shape.

[0048] In each of the pad wiring groups G1 to G7, the pad wiring pattern composed of the element mounting pad 23 under the light-emitting element 25, that is, the element mounting pad 23 surrounded by the broken line indicating the light-emitting element 25 in FIG. 2 and the wiring 24 connected to each of them, is classified into four types, namely, the first pad wiring pattern P1 to the fourth pad wiring pattern P4, according to the formation mode of the wiring 24 extending from each of the anode pad 26 and the cathode pad 27.

[0049] As shown in FIG. 3, in the first pad wiring pattern P1, the wiring 24 extends from the center of the long side of the anode pad 26, and the wiring 24 extends from one short side of the cathode pad 27.

[0050] As shown in FIG. 3, in the second pad wiring pattern P2, wiring 24 extends from each of the opposing short sides of the anode pad 26, and wiring 24 extends from the center of one long side of the cathode pad 27.

[0051] As shown in FIG. 3, in the third pad wiring pattern P3, wiring 24 extends from each of the opposing short sides of the anode pad 26, and wiring 24 extends from the center of one long side and one short side of the cathode pad 27, respectively.

[0052] As shown in FIG. 4, in the fourth pad wiring pattern P4, wiring 24 extends from each of the opposing short sides of the anode pad 26, and wiring 24 extends from one short side of the cathode pad 27.

[0053] In the light emitting module 110 of the present embodiment, the wiring 24 extending from each of the anode pads 26 of the first pad wiring pattern P1 to the fourth pad wiring pattern P4 is in line symmetry with respect to the perpendicular bisector PB of the long side of the wiring pads with each other in the mounting region of the light emitting element 25 including the element mounting pad 23 of the second substrate portion 12, that is, in the region corresponding to the lower surface of the light emitting element 25.

[0054] Specifically, the wiring 24 extending from the center of the long side of the anode pad 26 in the first pad wiring pattern P1 extends in a direction perpendicular to the long side within the mounting region of the light emitting element 25. Therefore, the wiring 24 is in line symmetry with respect to the perpendicular bisector PB.

[0055] Also, the wiring 24 extending from the short sides of the anode pads 26 of the second pad wiring pattern P2 to the fourth pad wiring pattern P4 extends in a direction perpendicular to the short side within the mounting region of the light emitting element 25 together. Therefore, the wiring 24 is in line symmetry with respect to the perpendicular bisector PB.

[0056] Note that the number of the pad wiring groups and the number of the element mounting pads 23 in each of the pad wiring patterns described above are merely illustrative, and may be appropriately changed according to, for example, the formation mode of the wiring 24 provided on the upper surface of the second substrate portion 12 of the substrate 10.

[0057] [Detailed Configuration of Light-Emitting Element] Next, with reference to FIG. 5, the detailed configuration of each of the light-emitting elements 25 mounted on the upper surface of the second substrate portion 12 of the substrate 10 via the element mounting pads 23 will be described. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 3.

[0058] The light-emitting element 25 is mounted on each of the element mounting pads 23 provided on the upper surface of the second substrate portion 12 of the substrate 10 as described above, and is a light-emitting diode (LED: Light Emission Diode) having a rectangular upper surface shape.

[0059] The light-emitting element 25 includes a semiconductor structure layer 33 having a light-emitting layer, a support substrate 34 disposed on the upper surface of the semiconductor structure layer 33, a p electrode 35 and an n electrode 36 (hereinafter, when not distinguishing between the two, referred to as "element electrodes 35, 36") disposed on the lower surface of the semiconductor structure layer 33, and a phosphor portion 37 disposed on the upper surface of the support substrate 34.

[0060] The semiconductor structure layer 33 is a semiconductor laminate composed of an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer (none of which are shown), each of which mainly uses gallium nitride (GaN). When the light-emitting element 25 is driven, blue light having a peak wavelength of 450 nm is emitted from the light-emitting layer of the semiconductor structure layer 33.

[0061] The support substrate 34 is a flat substrate having a rectangular upper surface shape. The support substrate 34 is made of a material having translucency with respect to the blue light emitted from the light-emitting layer of the semiconductor structure layer 33, such as sapphire (Al2O3) or GaN. Note that the support substrate 34 of the present light-emitting element 25 is also a growth substrate for the semiconductor structure layer 33.

[0062] The p - electrode 35 is an electrode electrically connected to the p - type semiconductor layer of the semiconductor structure layer 33. The p - electrode 35 has the same shape and size as the anode pad 26 and is joined to the anode pad 26 via the solder 39.

[0063] The n - electrode 36 is an electrode electrically connected to the n - type semiconductor layer via a through - electrode (not shown) that vertically penetrates the light - emitting layer and the p - type semiconductor layer of the semiconductor structure layer 33 and whose side surfaces are covered with an insulator. In other words, the n - electrode 36 is electrically connected only to the n - type semiconductor layer and is insulated from the light - emitting layer and the p - type semiconductor layer.

[0064] The n - electrode 36 has the same shape and size as the cathode pad 27 and is joined to the cathode pad 27 via the solder 39. That is, in the light - emitting module 110, the light - emitting element 25 is flip - chip mounted on the upper surface of the second substrate portion 12 of the substrate 10.

[0065] The phosphor part 37 is a plate - like body having a rectangle with substantially the same size as the upper surface of the light - emitting element 25 in a top view. The phosphor part 37 is composed of a phosphor that is excited by blue light as excitation light emitted from the light - emitting element 25 and emits fluorescence. The fluorescence generated from the phosphor when excited by blue light has a broad green - to - orange wavelength range spanning 480 - 700 nm and has a yellow peak wavelength at 520 - 570 nm.

[0066] The phosphor part 37 is, for example, a ceramic phosphor plate of alumina or a glass medium (base material) containing yttrium aluminum garnet (YAG:Ce) phosphor particles with cerium (Ce) as an activator.

[0067] Note that the phosphor part 37 is not limited to a phosphor plate composed of YAG:Ce phosphor particles. For example, a phosphor plate in which YAG, which is the base material of the phosphor particles, serves as the medium may be used. In this case, the phosphor part 37 may be a polycrystal or a single crystal.

[0068] When blue light emitted from the light-emitting element 25 enters the phosphor part 37, a part of it directly passes through the phosphor part 37, and a part excites the phosphor, causing fluorescence to be emitted from the excited phosphor.

[0069] Therefore, from the upper surface of the phosphor part 37, excitation light that has passed through the phosphor part 37 without contributing to the generation of fluorescence and fluorescence emitted from the phosphor are emitted. As a result, white light in which blue light and yellow fluorescence emitted from the upper surface of the phosphor part 37 are mixed is extracted from each of the light-emitting elements 25.

[0070] [Suppression of misalignment during solder mounting of light-emitting elements] Here, with reference to FIGS. 6 and 7, suppression of misalignment when solder-mounting each of the light-emitting elements 25 on the upper surface of the second substrate portion 12 during the manufacture of the light-emitting module 110 of the present embodiment will be described.

[0071] FIG. 6 is a plan view showing a fourth pad wiring pattern P4 as an example among the above-described first pad wiring pattern P1 to fourth pad wiring pattern P4. FIG. 6 shows a state in which solder paste 39P before the formation of solder 39 is applied to each of the anode pad 26 and the cathode pad 27.

[0072] FIG. 7 is a plan view showing the fourth pad wiring pattern P4 in the same manner as FIG. 6. FIG. 7 shows a state in which the solder paste 39P applied to each of the anode pad 26 and the cathode pad 27 melts and spreads. In FIGS. 6 and 7, the outer contour line of the lower surface of the light-emitting element 25 indicating the mounting region of the light-emitting element 25 is shown by a dashed line.

[0073] During the manufacture of the light-emitting module 110, the solder paste 39P applied to each of the anode pad 26 and the cathode pad 27 is melted and cured by a reflow process, whereby the p-electrode 35 and the n-electrode 36 of the light-emitting element 25 are respectively joined to the anode pad 26 and the cathode pad 27.

[0074] When the solder paste 39P melts and spreads over the surface of the element mounting pad 23 and the surfaces of the element electrodes 35 and 36, a so-called self-alignment effect is exerted, in which the element electrodes 35 and 36 of the light-emitting element 25 are positioned so as to overlap as much as possible on the element mounting pad 23 due to surface tension and capillary action.

[0075] When the solder paste 39P is applied to each of the anode pad 26 and the cathode pad 27, the solder paste 39P spreads as shown by the arrows in FIG. 6. Specifically, in the anode pad 26, the solder paste 39P spreads evenly toward the wiring 24 extending from the short side along the longitudinal direction of the anode pad 26, and in the cathode pad 27, the solder paste 39P spreads toward the wiring 24 extending from one short side along the longitudinal direction of the cathode pad 27.

[0076] In the light-emitting module 110, the width 27W in the short-side direction of each cathode pad 27 of the element mounting pad 23 (hereinafter referred to as the cathode pad width 27W) is shorter than the width 26W in the short-side direction of the anode pad 26 (hereinafter referred to as the anode pad width 26W), and is also close to the width 24W of the wiring 24 (hereinafter referred to as the wiring width 24W).

[0077] Therefore, in the cathode pad 27 as shown in FIG. 6, the solder paste 39P easily spreads toward the side where the wiring 24 is formed. Therefore, in the cathode pad 27, the solder paste 39P spreads asymmetrically (asymmetric solder spread) with respect to the perpendicular bisector PB, and the molten solder paste 39P moves upward as shown in FIG. 7.

[0078] Here, in the light-emitting module 110 of the present embodiment, the wiring width 24W is 0.15 mm, and the cathode pad width 27W is 0.174 mm. The asymmetric solder spread during the melting of the solder paste 39P significantly occurs when the pad width ratio obtained by dividing the cathode pad width 27W by the wiring width 24W is 1.2 or less. That is, the asymmetric solder spread is caused by the melted solder paste 39P easily flowing out from the cathode pad 27 to the wiring 24.

[0079] When the wetting spread of the solder paste 39P is different between the anode pad 26 and the cathode pad 27 in this way, the self-alignment property of the solder paste 39P with respect to the light-emitting element 25 deteriorates.

[0080] When the self-alignment property of the light-emitting element 25 by the solder paste 39P deteriorates in this way, the light-emitting element 25 may have a rotational misalignment as shown by the two-dot chain line in FIG. 7, for example. That is, the misalignment of the arrangement of the light-emitting element 25 from the position where it is originally desired to be arranged may occur.

[0081] Here, in the light-emitting module 110 of the present embodiment, the area of the cathode pad 27 is 0.087 (0.5 × 0.174) mm 2 and the area of the anode pad 26 is 0.132 (0.6 × 0.22) mm 2 That is, the area of the anode pad 26 is about 1.5 times larger than the area of the cathode pad 27.

[0082] Also, in the light-emitting module 110 of the present embodiment, the wiring width 24W is 0.15 mm, and the anode pad width 26W is 0.22 mm. The asymmetric solder spread during the melting of the solder paste 39P can be suppressed when the pad width ratio obtained by dividing the anode pad width 26W by the wiring width 24W is larger than about 1.5. That is, the self-alignment property of the solder paste 39P with respect to the light-emitting element 25 can be maintained by using a pad with a large pad width ratio for the element mounting pad 23.

[0083] In the light-emitting module 110 of the present embodiment, as described above, the size of the anode pad 26 in a top view is larger than that of the cathode pad 27, and the wiring 24 extending from the anode pad 26 is line-symmetric with respect to the perpendicular bisector PB in the element placement region of the light-emitting element 25.

[0084] Therefore, in the anode pad 26, the solder paste 39P spreads symmetrically with respect to the perpendicular bisector PB, thereby improving the stability of the light-emitting element 25 joined to the anode pad 26. As a result, it is possible to suppress a decrease in the self-alignment property of the solder paste 39P with respect to the light-emitting element 25.

[0085] Thus, in the light-emitting module 110 of the present embodiment, even when the solder paste 39P spreads in one direction in the cathode pad 27, that is, even when the solder paste 39P spreads asymmetrically with respect to the perpendicular bisector PB, it is possible to suppress the occurrence of misalignment in the arrangement of the light-emitting elements 25 by increasing the area and pad width ratio of the anode pad 26 with respect to the cathode pad 27.

[0086] Note that the effect of suppressing the misalignment in the arrangement of the light-emitting elements 25 that occurs in the above-described fourth pad wiring pattern P4 also occurs in the first pad wiring pattern P1, the second pad wiring pattern P2, and the third pad wiring pattern P3.

[0087] Therefore, according to the light-emitting module 110 of the present embodiment, it is possible to suppress the occurrence of misalignment in each of the light-emitting elements 25 when the light-emitting elements 25 are solder-mounted on the upper surface of the second substrate portion 12 during manufacturing.

[0088] In the light-emitting module 110 of this embodiment, the case where the wiring 24 extending from the anode pad 26 is line-symmetric with respect to the perpendicular bisector PB has been described. However, it does not necessarily have to be line-symmetric. As long as the wiring 24 extends from the center of one long side of the anode pad 26 or the wiring 24 extends from the opposing short sides of the anode pad 26, the effects of the present invention can be obtained.

[0089] [Modification of Example 1] Next, with reference to FIG. 8, the formation mode of the wiring 24 of the light-emitting module 110 according to the modification of Example 1 will be described. FIG. 8 is a plan view showing the first pad wiring group G1, similar to FIG. 3.

[0090] In the light-emitting module 110 of this modification, the first pad wiring group G1 has a configuration that does not include the element mounting pad 23 (second pad wiring pattern P2) in the upper left in the figure. That is, the first pad wiring group G1 is composed of seven element mounting pads 23.

[0091] In the light-emitting module 110 of this modification, as shown in FIG. 8, the wiring 24 extends from the center of one long side of the anode pad 26, and the wiring 24 extends from the center of one long side of the cathode pad 27.

[0092] As described above, as shown in the fifth pad wiring pattern P5, since the wiring 24 is not connected to the short side of the pad in either the anode pad 26 or the cathode pad 27, the solder paste 39P during melting spreads symmetrically. That is, the self-alignment property is not impaired.

[0093] Even when the first pad wiring group G1 has such a pad wiring pattern, according to the light-emitting module 110 of this modification, when each of the light-emitting elements 25 is soldered and mounted on the upper surface of the second substrate portion 12, it is possible to suppress the occurrence of misalignment in each of the light-emitting elements 25.

Example

[0094] Next, with reference to FIGS. 9 and 10, the formation mode of the wiring 24 of the light-emitting module 110 according to Example 2 will be described. FIG. 9 is a plan view showing the first pad wiring group G1. FIG. 10 is a plan view showing the second pad wiring group G2. Hereinafter, only the differences from Example 1 will be described.

[0095] In the light-emitting module 110 of this embodiment, a dummy wiring 41 that terminates within the mounting region of the light-emitting element 25 and does not make an electrical connection to the outside is formed on each cathode pad 27 of the element mounting pads 23 in each of the pad wiring groups G1 to G7.

[0096] Specifically, in the first pad wiring pattern P1, as shown in FIG. 9, while the wiring 24 extends from one short side of the cathode pad 27, the dummy wiring 41 extends from the other short side and one long side, respectively.

[0097] Also, in the second pad wiring pattern P2, as shown in FIG. 9, while the wiring 24 extends from one long side of the cathode pad 27, the dummy wiring 41 extends from each of the mutually opposing short sides.

[0098] Also, in the third pad wiring pattern P3, as shown in FIG. 9, while the wiring 24 extends from one long side and one short side of the cathode pad 27, the dummy wiring 41 extends from the other short side opposite to one short side.

[0099] Also, in the fourth pad wiring pattern P4, as shown in FIG. 10, while the wiring 24 extends from one short side of the cathode pad 27, the dummy wiring 41 extends from the other short side opposite to one short side and one long side, respectively.

[0100] Thus, in the light-emitting module 110 of this embodiment, the dummy wiring 41 extends from a side other than the side where the wiring 24 of the cathode pad 27 is formed. In the light-emitting module 110 of this embodiment, the dummy wiring 41 is line-symmetric with respect to the perpendicular bisector PB together with the wiring 24 extending from the cathode pad 27.

[0101] Therefore, in the light-emitting module 110 of this embodiment, in the mounting region of the light-emitting element 25, the wirings including the wiring 24 extending from the anode pad 26 and the wiring 24 and the dummy wiring 41 extending from the cathode pad 27 are each line-symmetric with respect to the perpendicular bisector PB.

[0102] Thus, in the light-emitting module 110 of this embodiment, since the wiring including the wiring 24 extending from the cathode pad 27 and the dummy wiring 41 is line-symmetric with respect to the perpendicular bisector PB, the solder paste 39P spreads evenly. Therefore, the self-alignment property of the solder paste 39P with respect to the light-emitting element 25 is improved.

[0103] In particular, the solder paste 39P in the initial melting stage can be retained at the central portion of the cathode pad 27 by the wiring 24 and the dummy wiring 41 extending along the perpendicular bisector PB from the center of the long side of the cathode pad 27. Thereafter, the solder paste 39P spreads in both short directions of the cathode pad 27 and thus becomes uniform. Therefore, stable self-alignment is possible even when the pad width ratio is 1.2 or less.

[0104] Therefore, according to the light-emitting module 110 of this embodiment, when each of the light-emitting elements 25 is solder-mounted on the upper surface of the second substrate portion 12 during manufacturing, it is possible to suppress the occurrence of misalignment in each of the light-emitting elements 25.

[0105] Further, according to the light-emitting module 110 of the present embodiment, for example, when the solder paste 39P is applied to the cathode pad 27 in an amount exceeding the original application amount, the one-way flow of the solder is suppressed, and the solder paste 39P can spread wetly so as to be dispersedly applied to the wiring 24 and the dummy wiring 41 from the cathode pad 27 in a targeted manner.

[0106] Specifically, when the solder paste 39P is applied to the cathode pad 27 in an excessive amount, the molten solder paste 39P can be stored in the center of the cathode pad 27. That is, it is possible to prevent the occurrence of the so-called one-way flow of the solder flowing in an undesired direction.

Embodiment

[0107] Next, with reference to FIGS. 11 and 12, the formation mode of the wiring 24 of the light-emitting module 110 according to Embodiment 3 will be described. FIG. 10 is a plan view showing the first pad wiring group G1. FIG. 12 is a plan view showing the second pad wiring group G2. Hereinafter, only the differences from Embodiment 2 will be described.

[0108] In the light-emitting module 110 of the present embodiment, a dummy wiring 43 that terminates within the mounting region of the light-emitting element 25 and does not make an electrical connection to the outside is formed on each anode pad 26 of the element mounting pads 23 in each of the pad wiring groups G1 to G7.

[0109] Specifically, in the first pad wiring pattern P1, as shown in FIG. 11, while the wiring 24 extends from one long side of the anode pad 26, the dummy wirings 43 extend from the short sides facing each other, respectively.

[0110] In the second pad wiring pattern P2, as shown in FIG. 11, while the wiring 24 extends from each of the short sides facing each other of the anode pad 26, the dummy wiring 43 extends from the center of one long side.

[0111] Also, in the third pad wiring pattern P3, as shown in FIG. 11, while the wiring 24 extends from each of the opposing short sides of the anode pad 26, the dummy wiring 43 extends from the center of one of the long sides.

[0112] Also, in the fourth pad wiring pattern P4, as shown in FIG. 12, while the wiring 24 extends from each of the opposing short sides of the anode pad 26, the dummy wiring 43 extends from the center of one of the long sides.

[0113] Thus, in the light-emitting module 110 of the present embodiment, the dummy wiring 43 extends from a side other than the side where the wiring 24 of the anode pad 26 is formed. In the light-emitting module 110 of the present embodiment, the dummy wiring 43 is line-symmetric with respect to the perpendicular bisector PB together with the wiring 24 extending from the anode pad 26.

[0114] Therefore, in the light-emitting module 110 of the present embodiment, the wiring including the wiring 24 extending from the anode pad 26 and the dummy wiring 43 and the wiring including the wiring 24 extending from the cathode pad 27 and the dummy wiring 41 in the mounting region of the light-emitting element 25 are each line-symmetric with respect to the perpendicular bisector PB.

[0115] Thus, in the light-emitting module 110 of the present embodiment, since the wiring including the wiring 24 extending from the anode pad 26 and the dummy wiring 43 is line-symmetric with respect to the perpendicular bisector PB, the solder paste 39P spreads evenly. Therefore, the self-alignment property of the solder paste 39P with respect to the light-emitting element 25 is improved.

[0116] Particularly, the wiring 24 extending from the center of the long side of the anode pad 26 along the perpendicular bisector PB and the dummy wiring 43 can hold the solder paste 39P in the initial melting stage at the center of the anode pad 26. Then, since the solder paste 39P wets and spreads in both short directions of the anode pad 26, it becomes uniform. For example, even if the light-emitting element 25 is misaligned and placed on the solder paste 39P, self-alignment can be achieved at a predetermined position in the reflow process stage.

[0117] Therefore, according to the light-emitting module 110 of the present embodiment, when each of the light-emitting elements 25 is solder-mounted on the upper surface of the second substrate portion 12 during manufacturing, it is possible to suppress the occurrence of misalignment in each of the light-emitting elements 25.

[0118] Also, according to the light-emitting module 110 of the present embodiment, for example, when the solder paste 39P is applied in an amount excessive than the original amount to be applied to the anode pad 26, it suppresses the one-way flow of solder that occurs, allows the solder paste 39P to wet and spread so as to be dispersed to the wiring 24 and the dummy wiring 43 from the anode pad 26, and enables the solder paste 39P to wet and spread so as to be dispersed to the wiring 24 and the dummy wiring 43 from the anode pad 26.

[0119] Specifically, when the solder paste 39P is applied in an excessive amount to the anode pad 26, the melted solder paste 39P can be stored at the center of the anode pad 26. That is, it can prevent the occurrence of the so-called one-way flow of solder flowing in an unwanted direction.

[0120] Also, as in Embodiment 3, when each of the wiring 24 and the dummy wirings 41 and 43 extending in three directions from the anode pad 26 and the cathode pad 27 is arranged symmetrically with respect to the perpendicular bisector PB, even if the anode pad 26 and the cathode pad 27 have the same size as each other or a pad width ratio of 1.2 or less to each other, the light-emitting element 25 is self-aligned.

[0121] At this time, the pad width ratio only needs to exceed 1. That is, for example, if the wiring 24 or the dummy wirings 41 and 43 are arranged at the center of the outer long side and both ends of the short side of the anode pad 26 and the cathode pad 27, the light-emitting element 25 is self-aligned.

[0122] As described above, according to the light-emitting module 110, as shown in the first embodiment, the second embodiment, and the third embodiment, when each of the light-emitting elements 25 is soldered and mounted on the upper surface of the second substrate portion 12 during manufacturing, it is possible to suppress the occurrence of misalignment in each of the light-emitting elements 25.

[0123] This enables the provision of a light-emitting module and a lighting device capable of suppressing misalignment of the arrangements of the respective light-emitting elements when a plurality of light-emitting elements are soldered and mounted on a substrate.

[0124] In the light-emitting module 110 of the present embodiment, the anode pad 26 and the cathode pad 27 of the element mounting pad 23 may have the same size as each other. That is, in the mounting region of the light-emitting element 25, the anode pad 26, the cathode pad 27, and the wirings extending from each of them may be configured to be symmetric with each other.

Explanation of Reference Numerals

[0125] 10 Substrate 11 First Substrate Portion 12 Second Substrate Portion 14, 18 Base Portion 15 Heat Dissipation Fin 16 External Attachment Portion 19 Cylindrical Wall Portion 21 Adhesive Layer 23 Element Mounting Pad 24 Wiring 25 Light-Emitting Element 26 First Wiring Pad 27 Second Wiring Pad 100 Lighting Device 110 Light-Emitting Module 120 Module Holder 130 Lens Holder 140 Lens

Claims

1. A substrate, An element mounting pad group comprising a first wiring pad and a second wiring pad, both having a rectangular upper surface shape, arranged side by side along the short side direction of each so that their long sides are parallel to each other and disposed on one main surface of the substrate, and the element mounting pads are arranged in a row along the short side direction, A wiring group connected to each of the first wiring pad and the second wiring pad on the one main surface, A light-emitting element respectively mounted in an element mounting region including the element mounting pad on the one main surface, and having, In each of the element mounting pads, the wiring connected to at least one of the first wiring pad or the second wiring pad is extended from a central portion of one of the long sides of the one wiring pad or extended from each of the opposing short sides of the one wiring pad, and a light-emitting module characterized by this.

2. The light-emitting module according to claim 1, wherein the wiring connected to the one wiring pad is line-symmetric with respect to the perpendicular bisector of the long side of the one wiring pad in the element mounting region.

3. The light-emitting module according to claim 1 or 2, wherein the one wiring pad is larger in size in top view than the other wiring pad.

4. The light-emitting module according to claim 1, wherein the wiring connected to the first wiring pad and the wiring connected to the second wiring pad are each line-symmetric with respect to the perpendicular bisector of the long side of each wiring pad in the element mounting region.

5. The light-emitting module according to claim 4, wherein the wiring connected to the other wiring pad includes a dummy wiring that extends from the other wiring pad, terminates within the element mounting region, and does not make an electrical connection with the outside.

6. The light-emitting module according to claim 5, wherein the wiring connected to the other wiring pad extends from different sides of the other wiring pad, respectively.

7. The light-emitting module according to claim 5 or 6, wherein the wiring connected to the one wiring pad includes a dummy wiring that extends from the one wiring pad, terminates within the element mounting region, and does not make an electrical connection with the outside.

8. The light-emitting module according to claim 7, wherein the wiring connected to the one wiring pad extends from different sides of the one wiring pad, respectively.

9. The substrate comprises a first substrate portion provided with a through hole and a second substrate portion provided in the through hole so as to close the through hole and having a higher thermal conductivity than the one substrate portion integrated with the first substrate portion. The light-emitting module according to claim 1 or 2, wherein each of the element mounting pads is formed on the surface of the second substrate portion.

10. The light-emitting module according to claim 9, wherein the second substrate portion is made of aluminum nitride.

11. The light-emitting module according to claim 1 or 2, a heat sink provided on the other main surface of the substrate of the light-emitting module opposite to the one main surface and releasing heat generated in the light-emitting element to the outside, a lens provided so as to cover the light-emitting module and transmitting light emitted from the light-emitting element. An illumination device, characterized by comprising the above.

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