JP7185105B1 - light emitting device - Google Patents

Abstract

The light-emitting device includes a substrate made of an insulating member, a first wiring layer made of metal and arranged on the substrate, a conductive first plated layer arranged on the first wiring layer, and A second wiring layer formed and arranged on the substrate, a conductive second plating layer arranged on the second wiring layer, and a comb tooth shape including a plurality of first teeth extending in a predetermined extending direction. and a second terminal having a comb tooth-like planar shape including a plurality of second teeth extending in a direction opposite to the extending direction and alternately arranged with the first teeth. an element, wherein the first plating layer includes a plurality of first rod-shaped plating layers extending in the same direction as the plurality of first teeth, the plurality of first rod-shaped plating layers extending in the same direction as the plurality of first teeth; The second plating layer is connected to a portion of the second terminal other than the plurality of second teeth, and the first wiring layer is connected to a portion of the plurality of first teeth and the plurality of second teeth. It is formed continuously below a portion of the tooth.

Description

The present invention relates to light emitting devices.

A light-emitting device using a light-emitting diode (LED) that emits ultraviolet (UV) light as a light-emitting element is known (see, for example, Japanese Unexamined Patent Application Publication No. 2020-13820). In the light-emitting device described in JP-A-2020-13820, a light-emitting element that emits UV light has a pair of electrode layers each having a comb-like planar shape, and has a comb-like planar shape. Electric power is supplied to the tip electrode, which is one tooth of the pair of electrode layers, through the strip-shaped electrode pattern. In the light-emitting device described in Japanese Patent Application Laid-Open No. 2020-13820, one chip electrode is a plurality of strip-shaped electrodes arranged in parallel, and the other chip electrode has a longitudinal direction in the arrangement direction of the one chip electrode. It is an elongated strip-shaped electrode. In the light-emitting device described in Japanese Patent Application Laid-Open No. 2020-13820, power is supplied to the light-emitting element through a pair of electrode layers having a comb-shaped planar shape, so power is uniformly supplied to the light-emitting layer. , can emit UV light with a uniform luminance distribution.

In the light-emitting device described in Japanese Patent Application Laid-Open No. 2020-13820, electric power is applied to a chip electrode, which is one tooth of a pair of electrode layers having a comb-shaped planar shape, through a strip-shaped electrode pattern. Since the heat is supplied, the heat generated by the light emission of the light emitting element is dissipated through the strip-shaped electrode pattern. In the light-emitting device described in Japanese Patent Laid-Open No. 2020-13820, heat generated in the light-emitting element is dissipated through the strip-shaped electrode pattern, so the heat dissipation efficiency is low, and the temperature of the light-emitting element rises during light emission. As a result, the luminous efficiency of the light emitting element may decrease.

The present disclosure provides a light-emitting device capable of efficiently dissipating heat from a light-emitting element having an electrode having a comb-like planar shape.

A light emitting device according to the present invention comprises a substrate made of an insulating member, a first wiring layer made of metal and arranged on the substrate, and a conductive first plating layer arranged on the first wiring layer. a second wiring layer made of metal and arranged on the substrate; a conductive second plating layer arranged on the second wiring layer; and a plurality of first teeth extending in a predetermined extending direction. and a second terminal having a comb-like planar shape extending in a direction opposite to the extending direction and having a plurality of second teeth arranged alternately with the first teeth. a light emitting element having a terminal, wherein the first plating layer includes a plurality of first rod-shaped plating layers extending in the same direction as the plurality of first teeth, and the plurality of first rod-shaped plating layers includes the first terminal The second plating layer is connected to a portion of the second terminal other than the plurality of second teeth, and the first wiring layer is connected to a portion of the plurality of first teeth and the It is formed continuously below a portion of the plurality of second teeth.

Furthermore, in the light emitting device according to the present invention, it is preferable that the plurality of first teeth are arranged to protrude toward the substrate more than the plurality of second teeth.

Furthermore, in the light-emitting device according to the present invention, it is preferable that the first plating layer is arranged continuously in the arrangement direction.

Furthermore, in the light emitting device according to the present invention, the first plating layer preferably includes a plurality of bar-shaped plating layers extending in the extending direction on the first wiring layer and connected to each of the plurality of first teeth.

Further, in the light-emitting device according to the present invention, the first plating layer includes a nickel layer, a gold layer laminated on the nickel layer, and a gold-tin layer laminated on the gold layer and connected to each of the plurality of first teeth. is preferably included.

Furthermore, in the light-emitting device according to the present invention, the gold layer and the gold-tin layer are preferably formed in a fillet shape from the nickel layer toward the plurality of first teeth of the first terminal.

Furthermore, in the light-emitting device according to the present invention, the gold layer and the gold-tin layer are preferably formed on the side surface of the nickel layer and the side surfaces of the plurality of first teeth of the first terminal, respectively.

Furthermore, in the light emitting device according to the present invention, it is preferable that the first wiring layer includes a copper layer and an oxide film layer formed on the surface of the copper layer.

The light-emitting device according to the embodiment can efficiently dissipate heat from the light-emitting element having the electrode having a comb-like planar shape.

1 is a perspective view of a light emitting device according to a first embodiment; FIG. FIG. 2 is a plan view of the housing shown in FIG. 1; FIG. 3 is a cross-sectional view taken along line AA shown in FIG. 2; FIG. 2 is a plan view of the accommodating portion from which the wiring board, the light emitting element, and the overvoltage protection element shown in FIG. 1 are removed; (a) is a plan view of the wiring substrate shown in FIG. 1, and (b) is a bottom view of the wiring substrate shown in FIG. FIG. 5(a) is a cross-sectional view taken along the line BB shown in FIG. 5(a); (a) is a bottom view of the light emitting device shown in FIG. 1, and (b) is a cross-sectional view taken along line CC shown in (a). FIG. 2 is a plan view of a light-emitting element mounted on the wiring substrate shown in FIG. 1; FIG. 9 is an enlarged cross-sectional view of a portion indicated by an arrow D in FIG. 8; 2 is a flowchart showing a method for manufacturing the light emitting device shown in FIG. 1; FIG. 10 is a perspective view of a light emitting device according to a second embodiment; FIG. 12 is a plan view of the accommodating portion from which the light emitting element and the overvoltage protection element shown in FIG. 11 are removed; FIG. 11 is a plan view of a mounting substrate according to a first modified example; FIG. 11 is a plan view of a mounting substrate according to a second modified example; 14A is a cross-sectional view taken along line DD shown in FIG. 14, and FIG. 14B is a cross-sectional view taken along line EE shown in FIG.

A light emitting device according to the present invention will be described below with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to those embodiments, but extends to the invention described in the claims and equivalents thereof.

(Structure and Function of Light Emitting Device According to First Embodiment)
1 is a perspective view of the light emitting device according to the first embodiment, FIG. 2 is a plan view of the accommodating portion shown in FIG. 1, and FIG. 3 is a sectional view along line AA shown in FIG.

The light emitting device 1 includes a housing 10, a first wiring pattern 11, a second wiring pattern 12, a wiring substrate 13, a light emitting element 14, an overvoltage protection element 15, a sealing member 16, and a first electrode 17. , and a second electrode 18 . In the light-emitting device 1, UV light emitted from the light-emitting element 14 passes through the sealing member 16 through which the UV light can pass in response to application of a voltage between the first electrode 17 and the second electrode 18. released to the outside.

The housing 10 is a high temperature co-fired ceramics (HTCC) member formed of ceramics such as aluminum nitride (AlN), which is an insulating member that is resistant to deterioration by ultraviolet light and has high thermal conductivity, or It is a low temperature co-fired ceramics (LTCC) member in which glass or the like is contained in ceramics. The housing 10 includes a plate-like base portion 10a which is an example of a substrate, a frame-like wall portion 10b arranged along the outer edge of the surface of the base portion 10a, a first through electrode 10c, and a second through electrode 10d. have The housing 10 has a cavity structure in which a recessed accommodating portion 19 is formed by a planar base portion 10a and a frame-like wall portion 10b arranged along the outer edge of the surface of the base portion 10a. The housing 10 is integrally molded by integrating and firing green sheets of the base portion 10a and the wall portion 10b before firing, and high airtightness is obtained. The base portion 10a and the wall portion 10b may be baked separately and joined with an adhesive or the like when airtightness is not required. Also, the wall portion 10b may be omitted.

The first through-electrode 10c and the second through-electrode 10d are arranged in through-holes penetrating between the front surface and the back surface of the base portion 10a, and are formed of a conductive material such as copper. The first through electrode 10 c connects the first wiring pattern 11 and the first electrode 17 , and the second through electrode 10 d connects the second wiring pattern 12 and the second electrode 18 .

The first wiring pattern 11 and the second wiring pattern 12 are arranged on the surface of the base portion 10a. The first wiring pattern 11 and the second wiring pattern 12 are formed of a base layer, which is a conductive thin film such as copper (Cu), and a plated layer laminated on the base layer. The plated layers are formed of a nickel (Ni) layer, a palladium (Pd) layer laminated on the nickel layer, and a gold (Au) layer laminated on the palladium layer.

The overvoltage protection element 15 shown in FIG. 2 is a Zener diode having an anode and a cathode, and is connected to the first wiring pattern 11 and the second wiring pattern 12 via bonding wires 15a. The overvoltage protection element 15 causes a current to flow in response to the application of the breakdown voltage and prevents the application of the overvoltage to the light emitting element 14 . In addition, the overvoltage protection element 15 may be an electronic component such as a varistor other than the Zener diode capable of preventing the application of overvoltage to the light emitting element 14 .

The sealing member 16 shown in FIG. 1 is a UV light transmitting member such as quartz glass that does not absorb deep ultraviolet rays and transmits UV light. The sealing member 16 is bonded to the upper surface of the wall portion 10b by a connection method such as metal bonding that does not use an adhesive member made of synthetic resin. The housing portion 19 sealed by the sealing member 16 may be in a vacuum state, for example, or may be filled with an inert gas such as nitrogen gas or argon gas.

The first electrode 17 and the second electrode 18 shown in FIG. 3 are rear electrodes formed of a conductive member such as copper and arranged on the rear surface of the base 10a. The first electrode 17 is connected to the anode 41 of the light emitting element 14 via the first through electrode 10 c , first wiring pattern 11 , third wiring layer 33 , first internal electrode 35 and first wiring layer 31 . Also, the first electrode 17 is connected to the anode of the overvoltage protection element 15 via the first through electrode 10 c and the first wiring pattern 11 . The second electrode 18 is connected to the cathode 42 of the light emitting element 14 via the second through electrode 10d, the second wiring pattern 12, the fourth wiring layer 34, the second internal electrode 36 and the second wiring layer 32. Also, the second electrode 18 is connected to the cathode of the overvoltage protection element 15 via the second through electrode 10 d and the second wiring pattern 12 .

FIG. 4 is a plan view of the accommodating portion 19 with the wiring substrate 13, the light emitting element 14 and the overvoltage protection element 15 removed.

The first wiring pattern 11 has a first base portion 21 and a first projection portion 22 . The first base portion 21 has a rectangular planar shape, and one of a pair of short sides and a pair of long sides is arranged to face the inner wall of the wall portion 10b of the housing 10 . The first protrusion 22 has a rectangular planar shape and is arranged in the center of the other of the pair of long sides of the first base 21 so as to protrude toward the second wiring pattern 12 . The second wiring pattern 12 has a second base portion 23 and a second projection portion 24 and has a planar shape line-symmetrical to the first wiring pattern 11 .

5(a) is a plan view of the wiring board 13, FIG. 5(b) is a bottom view of the wiring board 13, and FIG. 6 is a cross-sectional view taken along line BB shown in FIG. 5(a). . Note that FIG. 6 shows a state before the light emitting element 14 is connected.

The wiring board 13 includes a base 30, a first wiring layer 31, a second wiring layer 32, a third wiring layer 33, a fourth wiring layer 34, a first internal electrode 35, and a second internal electrode 36. , a first plating layer 37 and a second plating layer 38 . The base 30 is an HTCC substrate formed of ceramics such as aluminum nitride (AlN), which is an insulating member that is resistant to deterioration by ultraviolet light and has high thermal conductivity, or an LTCC substrate in which glass or the like is contained in ceramics. It has a rectangular planar shape. The thickness of the base 30 is thinner than the thickness of the base 10 a of the housing 10 . A first wiring layer 31 and a second wiring layer 32 are arranged on the front surface of the base 30 , and a third wiring layer 33 and a fourth wiring layer 34 are arranged on the rear surface of the base 30 .

The first wiring layer 31, the second wiring layer 32, the third wiring layer 33, and the fourth wiring layer 34 are thin films made of a conductive member such as copper. Copper is a material with high thermal conductivity and low cost compared to gold, silver, and the like. The first wiring layer 31 and the second wiring layer 32 have a rectangular planar shape and are arranged such that one of a pair of long sides faces each other. The first wiring layer 31 is connected to the light emitting element 14 via the first plating layer 37 , and the second wiring layer 32 is connected to the light emitting element 14 via the second plating layer 38 . The third wiring layer 33 and the fourth wiring layer 34 have a rectangular planar shape and are arranged on the back surface of the base 30 . The third wiring layer 33 is connected to the first protrusions 22 of the first wiring pattern 11 via conductive connecting members 39 containing gold (Au) and tin (Sn). The fourth wiring layer 34 is connected to the second protrusion 24 of the second wiring pattern 12 via the connection member 39 .

The first internal electrodes 35 and the second internal electrodes 36 are made of a conductive material such as copper, and are arranged in through holes penetrating from the front surface to the rear surface of the base 30 . The first internal electrode 35 connects between the first wiring layer 31 and the third wiring layer 33 , and the second internal electrode 36 connects between the second wiring layer 32 and the fourth wiring layer 34 .

The first plating layer 37 includes five rod-shaped plating layers 371 to 375 that extend in a predetermined extending direction (direction of arrow X in FIG. 5A) and connect the first wiring layer 31 and the light emitting element 14. . Each of the rod-shaped plating layers 371 to 375 is composed of a nickel (Ni) layer 37a, a gold (Au) layer 37b, a gold tin (AuSn) layer 37c, and a flash gold plating layer 37d, as shown in FIG. ing. A nickel layer 37a is laminated on the first wiring layer 31, a gold layer 37b is laminated on the nickel layer 37a, a gold-tin layer 37c is laminated on the gold layer 37b, and a flash gold-plated layer 37d is laminated on the gold-tin layer 37c. is laminated to The nickel layer 37 a also functions as a barrier layer that prevents the gold layer 37 b from diffusing into the copper layer forming the first wiring layer 31 . The gold layer 37b also functions as a protective layer that prevents oxidation of the nickel layer 37a and the like. The gold-tin layer 37c also functions as a bonding layer. Note that the number of rod-shaped plating layers 371 to 375 does not necessarily have to be five.

Only one second plating layer 38 is formed in a direction perpendicular to the five rod-shaped plating layers 371-375. The second plated layer 38 has the same structure as the bar-shaped plated layers 371 to 375, so detailed description thereof will be omitted here. In addition, the number of the second plating layers 38 does not necessarily have to be one.

Note that when the first wiring layer 31 is made of copper, the first plating layer 37 and the second plating layer 38 may be formed of only the copper layer, and the nickel layer 37a or the like may be laminated on the copper layer. may be configured Moreover, the thicknesses of the first plating layer 37 and the second plating layer 38 can be arbitrarily determined. When adjusting the thickness of the first plating layer 37 and the second plating layer 38, it is preferable to adjust the thickness of the copper layer because the nickel layer tends to vary in thickness and the gold layer increases the manufacturing cost. When the first plating layer 37 and the second plating layer 38 are made of a material different from that of the first wiring layer 31, the surface processing of the first wiring layer 31 becomes unnecessary, so that the generation of unevenness can be suppressed, and the surface can be flattened. Thus, for example, inclination of the light emitting element 14 can be suppressed. In other words, when the first plated layer 37 and the second plated layer 38 do not require a high height, it is preferable to use a material different from that of the first wiring layer.

7(a) is a bottom view of the light emitting element 14, and FIG. 7(b) is a cross-sectional view taken along line CC shown in FIG. 7(a).

The light emitting element 14 is a UV LED die that has a semiconductor multilayer film 40, an anode 41, and a cathode 42, and emits UV light in response to a forward voltage being applied between the anode 41 and the cathode 42. It has a rectangular planar shape. The dominant wavelength of the UV light emitted from the light emitting element 14 is within the range between 200 nm and 405 nm, and is 280 nm in one example. The light emitting element 14 is formed by stacking a PN junction layer formed of an aluminum gallium nitride (AlGaN) layer on a transparent sapphire substrate.

The anode 41 has an anode base 43 , a first anode connection surface 44 , a second anode connection surface 45 , a third anode connection surface 46 , a fourth anode connection surface 47 and a fifth anode connection surface 48 . . The anode 41 has a comb-like planar shape having five first teeth 41a extending in a predetermined extending direction (the direction of arrow X1 in FIG. 7A) toward the cathode 42 . The anode base 43 has a rectangular planar shape, and five first teeth 41a extend parallel to each other from the inner long side. Each of the first anode connection surface 44 to the fifth anode connection surface 48 has substantially the same width as the width of the first plating layer 37, and the five first teeth of the anode 41 extending from the long side of the anode base 43. 41a. By forming the first anode connection surface 44 to the fifth anode connection surface 48 and the rod-shaped plating layers 371 to 375 into substantially the same shape, when the tin contained in the gold/tin layer 37c melts, the wiring board is formed by the self-alignment effect. The light-emitting element 14 can be arranged on 13 with high accuracy.

Each of the first anode connection surface 44 to the fifth anode connection surface 48 is connected to the first wiring layer 31 via the first plating layer 37 . The first anode connection surface 44 to the fifth anode connection surface 48 are connected to the first wiring layer 31 by solidifying after the gold/tin layer 37c of the first plating layer 37 is melted by heating such as reflow.

The cathode 42 extends in the direction opposite to the direction in which the first teeth 41a of the anode 41 extend (the direction of the arrow X2 in FIG. 7A), and the second teeth 41a and the first teeth 41a of the anode 41 are alternately arranged. It has a comb-shaped planar shape with teeth 42 a and has a cathode connection surface 49 . The width of the second teeth 42 a of the cathode 42 is narrower than the width of the first teeth 41 a of the anode 41 . The width of the second teeth 42 a of the cathode 42 may be wider than the width of the first teeth 41 a of the anode 41 .

The anode 41 and the cathode 42 have first teeth 41a and second teeth 42a that are alternately arranged, and have a shape in which the current paths are substantially uniform on the back surface of the light emitting element 14, and the current density is substantially constant. Therefore, the light extraction efficiency from the inside of the light emitting element 14 is improved, and the light emission intensity is improved. Since the light emitting element 14 emits ultraviolet light, which has a lower light extraction efficiency than visible light, the shape of the first teeth 41a and the second teeth 42a in which the anodes 41 and cathodes 42 are alternately arranged makes the light emitting element 14 luminescence intensity tends to be stronger. Note that the light emitting element 14 has a shape in which the anode 41 and the cathode 42 are considerably close to each other in order to reduce the size.

The first wiring layer 31 is connected to the anode 41 via a first plating layer 37 having substantially the same width as each of the first to fifth anode connection surfaces 44 to 48 of the anode 41 . The potential of the first wiring layer 31 is the same as the potential of the anode 41, and a power supply voltage VDD is supplied from an external power supply (not shown). On the other hand, since the second wiring layer 32 is connected to the cathode 42 via the second plating layer 38, the potential of the second wiring layer 32 is the same as the potential of the cathode 42 and is ground level.

As shown in FIG. 7(b), the height Hc of the cathode is lower than the height Ha of the anode, and the first teeth 41a of the anode 41 are closer to the wiring substrate 13 than the second teeth 42a of the cathode 42 are. placed protruding. The cathode connection surface 49 is arranged between both ends of the side facing the anode base portion 43, and the second wiring layer 32 is formed by melting the gold-tin layer of the second plating layer 38 by heating such as reflow and then solidifying it. connected to The cathode connection surface 49 is arranged at a portion of the cathode 42 where the second teeth 42a are not formed.

Since the anode 41 and the cathode 42 are formed as shown in FIG. 7B, the second plating layer 38 is thicker than the first plating layer 37 by the difference between the anode height Ha and the cathode height Hc. Higher is preferred. By making the second plating layer 38 higher than the first plating layer 37 by the difference between the anode height Ha and the cathode height Hc, the first plating layer 37 and the anode 41 and the second plating layer 38 and the cathode 42 are separated. The distances can be made equal, and the occurrence of problems when connecting the wiring board 13 and the light emitting element 14 can be suppressed. The second plating layer 38 may be higher than the sum of the difference between the anode height Ha and the cathode height Hc of the first plating layer 37 . This is because the second plated layer 38 faces only the cathode connection surface 49 of the cathode 42, avoiding the range where the first teeth 41a of the anode 41 and the second teeth 42a of the cathode 42 are alternately arranged. For example, even if a bonding agent made of gold and tin spreads over the surface of the second wiring layer 32 when melted, it is unlikely to connect to the anode 41 .

The first wiring layer 31 is arranged to face the plurality of second teeth 42a of the anode 41 supplied with the power supply voltage VDD and the cathode 42 grounded at the ground level. The first plating layer 37 arranged on the first wiring layer 31 is connected to the anode 41 via the first to fifth anode connection surfaces 44 to 48 projecting downward from the cathode 42 . Since the first plating layer 37 is connected to the anode 41 through the first anode connection surface 44 to the fifth anode connection surface 48 protruding below the cathode 42, the first wiring 31 and the cathode 42 have different potential levels. can suppress the magnitude of the parasitic capacitance formed by On the other hand, the second wiring layer 32 is arranged so as to face the cathode connection surface 49 of the cathode 42 grounded at the ground level.

As shown in FIG. 7B, an insulating layer 50 is arranged on the surface of the semiconductor multilayer film 40 of the light emitting device 14 in a region other than the anode 41 and the cathode 42 . The side surface of the anode 41 and the side surface of the cathode 42 may also be covered with the insulating layer 50 . Further, on the surface of the anode 41 as well, regions other than the first to fifth anode connection surfaces 44 to 48 may be covered with the insulating film 50 . Similarly, on the surface of the cathode 42 as well, the area other than the cathode connection surface 49 may be covered with the insulating film 50 .

FIG. 8 is a plan view of the light emitting element 14 mounted on the wiring board 13. FIG.

When the wiring board 13 is mounted on the light emitting element 14 , the first wiring layer 31 of the wiring board 13 is arranged below the five first teeth 41 a , the five second teeth 42 a , and the anode base 43 . Formed continuously.

The short sides of the first wiring layer 31 having a rectangular planar shape are continuous parallel to the direction in which the first teeth 41a of the anode 41 and the second teeth 42a of the cathode 42 extend (direction of arrow X in FIG. 8). stretched. The long side of the first wiring layer 31 extends continuously parallel to the arrangement direction (direction of arrow Y in FIG. 8) in which the plurality of first teeth 41a of the anode 41 and the second teeth 42a of the cathode 42 are arranged. . The short sides of the first wiring layer 31 extend continuously in the direction in which the first teeth 41a and the second teeth 42a extend, and the long sides extend in the direction in which the first teeth 41a and the second teeth 42a are aligned. By extending continuously, it is formed continuously below a part of the first tooth 41a and the second tooth 42a. Note that the first wiring layer 31 may be formed continuously below the entire first tooth 41a.

9 is an enlarged cross-sectional view of a portion indicated by arrow D in FIG. 8. FIG.

The light emitting element 14 is mounted on the wiring board 13 via the first plating layer 37 . The first plated layer 37 is formed of a nickel layer 37a and a bonding layer 37e arranged to cover the nickel layer 37a when the light emitting element 14 is bonded to the wiring substrate 13 . The bonding layer 37e is formed by integrating and solidifying the gold layer 37b, the gold-tin layer 37c, and the flash gold-plated layer 37d after being dissolved.

The bonding layer 37e is arranged on the first tooth portion 41a and the nickel layer 37a, and is arranged along the side surface of the nickel layer 37a so as to surround the nickel layer 37a. The bonding layer 37e arranged along the side surface of the nickel layer 37a has a fillet-like fillet portion 37f extending linearly from the vicinity of the lower end of the nickel layer 37a toward the outer edge of the first tooth 41a. The fillet portion 37f is formed so as to be separated from the nickel layer 37a as the first wiring layer 31 approaches the first tooth portion 41a.

An oxide film layer 31a, which is an insulator layer containing copper oxide, is formed on the surface of the first wiring layer 31 in a region where the first plating layer 37 is not arranged. By forming the oxide film layer 31 a on the surface of the region where the first plating layer 37 is not arranged, it is possible to prevent the bonding layer 37 e from spreading over the surface of the first wiring layer 31 . The nickel layer 37a can be made thin because the bonding layer 37e does not wet and spread on the surface of the first wiring layer 31 . In other words, the nickel layer 37a, which is a metal layer with a relatively low thermal conductivity, can be made thinner and the heat resistance value is lowered, so that the heat generated by the light emitting element 14 can be efficiently dissipated to the first wiring layer 31.

FIG. 10 is a flow chart showing a method for manufacturing the light emitting device 1. As shown in FIG.

First, in a housing preparation step, the housing 10 is prepared in which the first wiring pattern 11 and the second wiring pattern 12 are arranged on the surface, and the connection member for connecting the sealing member 16 is arranged on the upper surface of the wall portion 10b. (S101). Next, in the step of arranging the first connection member, the connection member 39 is arranged on the surface of each of the first protrusion 22 of the first wiring pattern 11 and the second protrusion 24 of the second wiring pattern 12 (S102). Next, in the wiring board arrangement step, the wiring board 13 is arranged so as to cover the first protrusions 22 of the first wiring patterns 11 and the second protrusions 24 of the second wiring patterns 12 (S103). Next, in the second connection member placement step, the first wiring of the wiring substrate 13 is formed by, for example, a printing method using a metal mask so that the first plating layer 37 and the second plating layer 38 have a substantially uniform thickness. It is arranged on the surface of the layer 31 and the second wiring layer 32 (S104).

Next, in the device arrangement step, the light emitting device 14 and the overvoltage protection device 15 are arranged (S105). The light emitting element 14 is arranged to cover the first wiring layer 31 and the second wiring layer 32 of the wiring board 13 , and the overvoltage protection element 15 is arranged between the first wiring pattern 11 and the second wiring pattern 12 . In a heating process such as reflow, the housing 10 in which the wiring board 13, the light emitting element 14 and the overvoltage protection element 15 are arranged is heated (S106), and the wiring board 13, the light emitting element 14 and the overvoltage protection element 15 are fixed. Next, in a wire bonding process, the first wiring pattern 11, the second wiring pattern 12 and the overvoltage protection element 15 are connected by the bonding wires 15a (S107). Then, in the sealing member arrangement step, the sealing member 16 is connected to the upper surface of the wall portion 10b of the housing 10 (S108), whereby the light emitting device 1 is manufactured.

In the heating step (S106), it was explained that the light emitting element 14 was connected to the first wiring pattern 11 and the second wiring pattern 12 by reflow. may be connected by thermocompression bonding. As described above, the bonding layer in which the Au layer 37d and the gold/tin layer 37c are mixed bonds the light emitting element 14 and the first wiring pattern 11 and the second wiring pattern 12. It is empirically known that the thickness of the bonding layer becomes thinner than when reflow is used. When the thickness of the bonding layer is reduced, heat generated by the light emitting element 14 can be efficiently dissipated.

(Action and effect of the light emitting device according to the first embodiment)
In the light emitting device 1, the first wiring layer 31 is arranged continuously in the arrangement direction of the first teeth 41a and the second teeth 42a of the anode 41 and the cathode 42. Therefore, a material that can be electrically connected to the anode 41 Therefore, the heat capacity of the surface of the base 30 can be increased, and the heat generated in the light emitting element 14 due to light emission is efficiently dissipated from the light emitting element 14 through the first wiring layer 31. be able to.

In the light-emitting device 1, the gold-tin layer 37c connected to the anode of the light-emitting element 14 is laminated on the gold layer 37b. There is little risk of poor light emission due to contact.

Further, in the light emitting device 1, the bonding layer 37e is arranged along the side surface of the nickel layer 37a so as to surround the nickel layer 37a in addition to the first tooth portion 41a and the nickel layer 37a. and the nickel layer 37a can be bonded more firmly. Also, the bonding layer 37e may be arranged on the side surface of the first tooth portion 41a. The first tooth portion 41a and the nickel layer 37a can be joined more firmly.

Further, since the oxide film layer 31a is formed on the surface of the first wiring layer 31, it is possible to prevent the bonding layer 37e arranged along the side surface of the nickel layer 37a from wetting and spreading on the surface of the first wiring layer 31. It is possible to further reduce the risk of poor light emission due to contact with the cathode of the light emitting element 14 .

In the light-emitting device 1, the gold-tin layer 37c connected to the anode of the light-emitting element 14 suppresses the area that spreads out when heated, so that the anode of the light-emitting element 14 is supported at a substantially uniform height. be able to. When connecting the anode of the light emitting element 14 and the first plating layer 37, the thickness of the connection material is increased to increase the amount of the connection material, thereby improving the bonding between the anode of the light emitting element 14 and the first plating layer 37. May increase strength. For example, the bonding strength between the anode of the light-emitting element 14 and the first plating layer 37 can be increased by increasing the thickness of the gold-tin layer 37c. If the thickness of the gold-tin layer 37c is increased, when the tin contained in the gold-tin layer 37c is melted, air may be mixed thereinto, forming voids, which may result in poor connection. In addition, there is a possibility that heat radiation and luminous efficiency may be reduced due to problems such as tilting of the light emitting element 14 caused by timing deviation of melting of tin contained in the gold/tin layer 37c. Such a problem can be eliminated by pressing the upper surface of the light emitting element 14 downward to reduce the thickness of the gold-tin layer 37c between the anode of the light emitting element 14 and the first plating layer 37. is. The gold-tin layer 37c flows out from the side surface of the bar-shaped plating layer 371 due to the pressing force that presses the light-emitting element 14, and the gold-tin layer 37c that has flowed out contacts the adjacent bar-shaped plating layer 372 through the surface of the first wiring layer 31. I have something to do. In this embodiment, since the same voltage is applied to the first wiring layer 31, the rod-shaped plating layer 371, and the rod-shaped plating layer 372, the first wiring layer 31, the rod-shaped plating layer 371, and the rod-shaped plating layer 372 are in contact with each other. No electrical problems occur. In addition, since the gold-tin layer 37c flowing out from the side surface of the bar-shaped plating layer 371 fills the space surrounded by the bar-shaped plating layer 371, the first wiring layer 31, and the bar-shaped plating layer 372, the heat capacity increases and the heat dissipation of the light emitting device 1 increases. sex improves.

(Structure and Function of Light Emitting Device According to Second Embodiment)
11 is a perspective view of the light emitting device according to the second embodiment, and FIG. 12 is a plan view of the accommodating portion 19 with the light emitting element 14 and the overvoltage protection element 15 shown in FIG. 11 removed.

The light emitting device 2 differs from the light emitting device 1 in that it has a first wiring pattern 51 and a second wiring pattern 52 instead of the first wiring pattern 11 and the second wiring pattern 12 . The light-emitting device 2 further differs from the light-emitting device 1 in that it does not have a wiring board 13 . The configurations and functions of the constituent elements of the light-emitting device 2 other than the first wiring pattern 51 and the second wiring pattern 52 are the same as those of the constituent elements of the light-emitting device 1 to which the same reference numerals are attached, and therefore a detailed description will be given here. are omitted.

The first wiring pattern 51 has a first base portion 61 , a first projection portion 62 and a first plating layer 63 . The first base portion 61 has a rectangular planar shape like the first base portion 21, and one of a pair of short sides and a pair of long sides faces the inner wall of the wall portion 10b of the housing 10. placed. The first protrusion 62 has a rectangular planar shape and is arranged in the center of the other of the pair of long sides of the first base 61 so as to protrude toward the second wiring pattern 52 . The first protrusion 62 is a wiring layer formed of metal and arranged on the housing 10, which is an example of a substrate.

The first plating layer 63 is a conductive member arranged on the first protrusion 62 and includes five bar-shaped plating layers 631 to 635 connecting the first protrusion 62 and the light emitting element 14 . The rod-shaped plated layers 631 to 635 have the same configuration as the rod-shaped plated layers 371 to 375, so detailed description thereof will be omitted here.

The second wiring pattern 52 has a second base portion 64 , a second projection portion 65 and a second plating layer 66 . Like the second base 23, the second base 64 has a rectangular planar shape, and one of a pair of short sides and a pair of long sides faces the inner wall of the wall 10b of the housing 10. placed. The second protrusion 65 has a rectangular planar shape and is arranged in the center of the other of the pair of long sides of the second base 64 so as to protrude toward the first wiring pattern 51 . The second protrusion 65 is a wiring layer formed of metal and arranged on the housing 10, which is an example of a substrate.

The second plating layer 66 is a conductive member arranged on the second protrusion 65 and connects the second protrusion 65 and the light emitting element 14 . The second plated layer 66 has the same configuration as the rod-shaped plated layers 371 to 375, so detailed description thereof will be omitted here.

(Light-emitting device according to modification)
In the light-emitting device 1, the first plating layer 37 includes five bar-shaped plating layers 371-375, but in the light-emitting device according to the embodiment, the first plating layer 63 is the first tooth 41a of the anode 41 of the light-emitting element 14. The number of bar-shaped plating layers may be included according to the number of. Further, in the light emitting device according to the embodiment, the first plating layer 63 may be arranged continuously in the arrangement direction of the first teeth 41 a and the second teeth 42 a of the anode 41 and the cathode 42 of the light emitting element 14 . The light-emitting device 2 has the same effects as the light-emitting device 1 .

FIG. 13 is a plan view of a mounting board according to a first modified example.

The wiring board 73 differs from the wiring board 13 in that it has a first plating layer 77 instead of the first plating layer 37 . The configuration and function of the components of the wiring board 73 other than the first plating layer 77 are the same as the configuration and function of the components of the wiring board 13 to which the same reference numerals are attached, so detailed descriptions thereof are omitted here.

The first plating layer 77 differs from the first plating layer 37 in planar shape. Since the configuration and function of the first plating layer 77 other than the planar shape are the same as those of the first plating layer 37, detailed description thereof will be omitted here. The first plating layer 77 is formed on the bottom surface of the light emitting element 14 in the direction in which the plurality of first teeth 41a and the second teeth 42a of the anode 41 and the cathode 42 are arranged, perpendicular to the direction in which the first teeth 41a of the anode 41 extend. It has a planar shape that is continuous over the entire surface of the opposing surface. Since the height Hc of the cathode of the light emitting element 14 is lower than the height Ha of the anode of the light emitting element 14 , the first plating layer 77 is connected to the anode of the light emitting element 14 and not connected to the cathode of the light emitting element 14 .

Since the wiring board 73 has the first plated layer 77 having a planar shape that is continuous over the entire surface facing the bottom surface of the light emitting element 14 , the heat generated from the light emitting element 14 can be absorbed more efficiently than the wiring board 13 . Can dissipate heat.

In the light emitting device 1, the first plating layer 37 and the second plating layer 38 have the nickel layer 37a, the gold layer 37b, the gold tin layer 37c, and the flash gold plating layer 37d. The first plating layer and the second plating layer may have other layer structures.

FIG. 14 is a plan view of a mounting substrate according to a second modified example.

The wiring board 83 differs from the wiring board 13 in that it has a first plating layer 87 and a second plating layer 88 instead of the first plating layer 37 and the second plating layer 38 . The configuration and function of the components of the wiring board 83 other than the first plating layer 87 and the second plating layer 88 are the same as the configuration and function of the components of the wiring board 13 to which the same reference numerals are assigned. are omitted. The first plating layer 87 has five rod-shaped plating layers 871-875. The bar-shaped plated layers 871-875 are different in layer structure from the bar-shaped plated layers 371-375.

15(a) is a cross-sectional view taken along line DD shown in FIG. 14, and FIG. 15(b) is a cross-sectional view taken along line EE shown in FIG.

The first plating layer 87 includes five rod-shaped plating layers 871 to 875 extending in a predetermined extending direction and connecting the first wiring layer 31 and the light emitting element 14 . Each of the bar-shaped plated layers 871-875 has a nickel layer 87a, a first gold layer 87b, and a second gold layer 87c. The nickel layer 87a is laminated on the first wiring layer 31, the first gold layer 87b is laminated on the nickel layer 87a, and the second gold layer 87c is laminated on the first gold layer 87b. The longitudinal length of the first gold layer 87b is the same as the longitudinal length of the nickel layer 87a, and the longitudinal length of the second gold layer 87c is shorter than the longitudinal length of the nickel layer 87a. The length of the second gold layer 87c is substantially the same as the length of the first anode connection surface 44 to the fifth anode connection surface 48 of the light emitting element 14, and the second gold layer 87c extends from the first anode connection surface 44 to the fifth anode connection surface 48. 5 is connected to the anode connection surface 48 . The second plated layer 88 has the same structure as the bar-shaped plated layers 871 to 875, so detailed description thereof will be omitted here.

In the wiring substrate 83, the second gold layer 87c is arranged so as to cover one end of the first gold layer 87b over the entire surface. In comparison, the connection area between the anode of the light emitting element 14 is increased, and the heat dissipation characteristics can be improved. Further, in the wiring substrate 83, the second gold layer 87c is arranged so as to cover one end of the first gold layer 87b over the entire surface, so a gold stud bump is arranged on the first gold layer 87b. Compared to the case, the flatness of the light emitting element 14 can be improved when the light emitting element 14 is connected to the first plating layer 87 . In other words, the second gold layer 87c has a higher surface flatness than a stud bump, and spreads evenly to the corners of the surface of the first gold layer 87b. It has high heat dissipation.

In the first plating layer 87, the length of the second gold layer 87c in the longitudinal direction is shorter than the length of the first gold layer 87b in the longitudinal direction. Since the amount of gold used can be reduced compared to the case of arranging it over the entire surface, the manufacturing cost can be reduced.

Claims (6)

a substrate formed of an insulating member;
a first wiring layer formed of metal and arranged on the substrate;
a conductive first plating layer disposed on the first wiring layer;
a second wiring layer formed of metal and arranged on the substrate;
a conductive second plating layer disposed on the second wiring layer;
a first terminal having a comb tooth-like planar shape including a plurality of first teeth extending in a predetermined extending direction; and a plurality of terminals extending in a direction opposite to the extending direction and alternately arranged with the first teeth. a light emitting element having a second terminal having a comb tooth-like planar shape including the second teeth;
The first plating layer includes a plurality of first bar-shaped plating layers extending in the same direction as the plurality of first teeth,
The plurality of first bar-shaped plating layers are connected to the plurality of first tooth portions of the first terminal, respectively;
the second plating layer is connected to a portion of the second terminal other than the plurality of second teeth;
The first wiring layer is formed continuously below a portion of the plurality of first teeth and a portion of the plurality of second teeth,
A light emitting device characterized by: 2. The light emitting device according to claim 1, wherein said plurality of first teeth are arranged to protrude in said substrate direction more than said plurality of second teeth. 2. The first plating layer includes a nickel layer, a gold layer laminated on the nickel layer, and a gold-tin layer laminated on the gold layer and connected to each of the plurality of first teeth. 3. Or the light-emitting device of 2. 4. The light emitting device of claim 3, wherein the gold layer and the gold tin layer are formed in a fillet shape from the nickel layer toward the plurality of first teeth of the first terminal. 5. The light-emitting device of claim 4, wherein the gold layer and the gold-tin layer are formed on side surfaces of the nickel layer and side surfaces of the plurality of first teeth of the first terminal, respectively. 5. The light emitting device according to claim 1, wherein said first wiring layer includes a copper layer and an oxide film layer formed on a surface of said copper layer.

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