JP5103805B2 - Light emitting device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device hard to fail in forming a lower electrode and hard to cause burs on a surface, and to provide its manufacturing method. <P>SOLUTION: The light emitting device 10 includes a light emitting element 18, a substrate 15 having an upper surface for mounting the light emitting element 18 and a lower surface opposite to the upper surface, a pair of upper surface electrodes 16a and 16b formed on the upper surface of the substrate 15 and connected with the light emitting element 18, a pair of lower surface electrodes 27a and 27b formed on the lower surface of the substrate 15, and connections 22a and 22b for bringing the upper surface electrodes 16a and 16b and the lower surface electrodes 27a and 27b into conduction. The substrate 15 has a step 33 on the side of the lower surface. The side face 12d of the step 33 is inclined from the lower surface to make an angle &theta; of the step 33 into an obtuse angle, and the lower surface electrodes 27a and 27b are extended at least to the side face 12d where the step 33 is inclined. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a side-view type light emitting device including a substrate having a step and a method for manufacturing the same.

  As a light emitting device for a backlight of a liquid crystal screen such as a cellular phone, a so-called side view type light emitting device in which a light emitting surface is mounted sideways is known (for example, see Patent Documents 1 and 2). With the progress of miniaturization of light emitting devices, parts such as electrodes of the light emitting devices are also reduced in size. When mounting the light-emitting device on the mounting substrate, the electrodes of the light-emitting device and the wiring pattern of the mounting substrate are connected by soldering, but when the electrodes of the light-emitting device become smaller, the solder protrudes and the electrodes are short-circuited, Alternatively, if the amount of solder is reduced to avoid a short circuit, there is a problem that the fixing force of the light emitting device is insufficient.

In order to solve these problems, a light emitting device including a substrate having a vertical vertical step 29 as shown in FIGS. 9 and 10 is known (see, for example, Patent Document 3).
In the light emitting device 100, the light emitting element 18 is mounted on the upper surface of the laminated substrate 15 in which two substrates (first substrate 12 and second substrate 14) having different lengths are stacked, and the light emitting element 18 is further sealed. A cylindrical lens is formed by the transparent resin layer 20.
Since the multilayer substrate 15 is configured by laminating the second substrate 14 having a long length on the upper surface 12a of the first substrate 12 having a short length, the vertical step 29 is formed at both ends on the lower surface 15b side of the multilayer substrate 15. Is done. Lower surface electrodes 27a and 27b of the light emitting device 100 are formed on the side surface 12c of the first substrate 12 facing the vertical step 29 and the lower surface 14b of the second substrate 14, and the wiring pattern of the mounting substrate 30 using the solder 28 is formed. 32 can be connected and fixed.

In the light emitting device 100, since the solder 28 during mounting tends to stay at the vertical step 29, a short circuit can be sufficiently suppressed without reducing the amount of solder. Moreover, since the lower surface electrodes 27a and 27b are widened by an amount corresponding to the area of the side surface 12c of the first substrate 12, the area for fixing the light emitting device 100 can be widened. For these reasons, the light emitting device 100 of FIGS. 9 and 10 can be mounted on the mounting substrate 30 with a high fixing force.
JP 2001-177156 A JP 2003-234507 A Design Registration No. 1257104

When the light emitting device 100 as shown in FIGS. 9 and 10 is manufactured, the multilayer substrate 15 is manufactured, the light emitting element 18 is mounted, and the transparent substrate 100 is formed in a form in which a plurality of light emitting devices 100 are coupled in the Y direction of FIG. In many cases, the resin layer 20 is formed and then cut into a predetermined thickness and divided into individual light emitting devices 100. This manufacturing method is advantageous in that most of the steps can be performed with a large size and shape that is easy to handle, and that a large number of light emitting devices 100 can be manufactured at the same time, so that the productivity is excellent.
However, some problems have occurred when formed by this manufacturing method.

The first problem is a problem of poor formation of the lower surface electrodes 27a and 27b.
As shown in FIG. 9, the lower surface electrodes 27a and 27b are composed of first plating layers 24a and 24b, second plating layers 25a and 25b, and plating layers 26a and 26b. The first plating layers 24a and 24b and the second plating layers 25a and 25b are formed at predetermined positions by electroless plating, physical vapor deposition, chemical vapor deposition, or the like before the first substrate 12 and the second substrate 14 are laminated. Is done. And after laminating | stacking the 1st board | substrate 12 and the 2nd board | substrate 14, in order to ensure conduction | electrical_connection with 1st plating layer 24a, 24b and 2nd plating layer 25a, 25b, plating layer 26a, 26b is electroplated. Is forming.
When the plating layers 26a and 26b are formed, the laminated substrate 15 that has been laminated is immersed in the plating bath, but air may not escape from the vertical step 29 simply by immersion. For this reason, the plating layers 26a and 26b are not formed on the portion facing the vertical step 29, and the formation of the lower surface electrodes 27a and 27b is poor.

A second problem is a problem of burrs when the light emitting devices 100 are divided.
When dividing the light emitting device 100, the transparent resin layer 20 is cut from the transparent resin layer 20 toward the 39-layer substrate 15 with a cutting blade. At this time, the lower surface electrodes 27a and 27b formed of metal are pulled by the cutting blade and the burrs are cut. (See FIG. 11). When the light emitting device 100 is mounted on the mounting substrate, the mounter recognizes the surface shape of the light emitting device 100 and positions the mounting position. However, when the apparent surface shape changes due to the generation of the burr 50, the mounter moves the mounting surface of the light emitting device 100. There is a risk that the mounting accuracy may be lowered by misidentifying the shape.

  The cause of the misidentification of the mounter depends on the burr 50 on the front surface 100a rather than the burr on the mounting surface of the light emitting device 100 (this is referred to as the back surface 100b). Therefore, it is conceivable to remove portions of the lower surface electrodes 27 a and 27 b that are in contact with the surface 100 a of the light emitting device 100 before being divided into the light emitting elements 100. In order to remove the lower surface electrode in such a small region, the method of etching the lower surface electrode using a photoresist is optimal, and the shape of the region of the lower surface electrode to be left or the shape of the region to be removed is adjusted. Is used to expose the photoresist and then the bottom electrode is removed by etching. In the case of the lower surface electrodes 27a and 27b of the light emitting device 100, light is irradiated from the lower surface 15b of the laminated substrate 15 toward the Z direction during exposure of the photoresist, but the side surface 12c of the first substrate 12 is irradiated with light. As a result, the photoresist formed on the side surface 12c is not sufficiently exposed, and as a result, the unremoved portion 270 remains on the lower surface electrodes 27a and 27b (see FIG. 12). When the light emitting device 100 is divided and the cutting blade passes through the unremoved portion 270, a needle-like burr 50 is generated. Such needle-like burrs 50 are likely to fall from the light emitting device 100 to the mounting substrate 30 during mounting, and are likely to cause a short circuit of the wiring pattern.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a light emitting device in which formation of a lower electrode is unlikely to occur and burrs are hardly formed on the surface. Moreover, an object of this invention is to provide the manufacturing method suitable for manufacture of said light-emitting device.

A light emitting device of the present invention includes a light emitting element, a substrate including an upper surface on which the light emitting element is mounted and a lower surface facing the upper surface, and a pair of upper surfaces formed on the upper surface of the substrate and connected to the light emitting element. A light-emitting device comprising: an electrode; a pair of lower surface electrodes formed on the lower surface of the substrate; and a connection portion that conducts the upper surface electrode and the lower surface electrode, wherein the substrate is disposed on the lower surface side. By providing a projecting portion having an inverted trapezoidal cross section, a step is provided, and a side surface of the step is inclined with respect to the lower surface so that an angle θ of the step is an obtuse angle, and the lower electrode is at least the step It is extended to the said inclined side surface. The upper surface and the lower surface of the substrate are preferably parallel.
In this specification, “the angle θ of the step portion” refers to the angle of the opening portion of the step. When the step angle θ is an obtuse angle, a side surface inclined from the lower surface side of the substrate is observed.

  The light emitting device of the present invention maintains the same area of the lower surface electrode as that of the light emitting device of Patent Document 3 by providing the lower surface electrode on the side surface of the stepped portion. And by making the angle θ of the step portion an obtuse angle, air escape from the step portion when immersed in the plating bath can be improved. Therefore, the surface of the lower electrode formed on the inclined step portion side surface can be subjected to metal plating with a sufficient thickness in contact with the electrolytic solution. Further, in the patterning of the lower surface electrode using the photolithography technique, since the side surface of the step portion is inclined, the entire surface of the lower surface electrode can be sufficiently exposed. Therefore, it is possible to divide the light emitting devices into individual light emitting devices without generating burrs that are generated when the light emitting devices formed in a continuous form are divided.

  The method for manufacturing a light emitting device according to the present invention includes a step of laminating a second plate-like body on the upper surface side of the first plate-like body including a strip-like portion having an inverted trapezoidal cross section to form a laminated plate-like body, Forming a plurality of through-holes penetrating from the upper surface to the lower surface of the rod-shaped body, a step of forming a connecting portion by disposing a conductive material inside the through-hole, and the connection on the upper surface of the laminated plate-shaped body Forming a top electrode in contact with the upper end of the portion, forming a bottom electrode in contact with the lower end of the connecting portion on the lower surface of the laminated plate-like body, and forming a light emitting element on the upper surface of the laminated plate-like body A mounting step; and a step of cutting the laminated plate-like body in a direction substantially perpendicular to a longitudinal direction of the first substrate and separating the laminated plate-like body into individual light emitting devices.

  The manufacturing method of the present invention forms a laminated plate-like body having a step having an obtuse angle θ by using a first plate-like body and a second plate-like body including a band-shaped portion having an inverted trapezoidal cross section. In this laminated plate-like body, the plurality of substrates described above are in a continuous form, and at the stage of the laminated plate-like body, a necessary structure for the light-emitting element is formed, and then the laminated plate-like body is divided at the same time. Many light emitting devices can be formed. Further, by laminating the first plate-like body 122 and the second plate-like body 142, a substrate having an inclined step side surface can be easily formed. Further, even a small light-emitting device can be easily manufactured by manufacturing a substrate having a dimension and shape that is relatively easy to handle and finally cutting in parallel.

  Since the light emitting device of the present invention is less likely to cause a lower electrode formation failure, the cost performance of the product is high, and burrs are hardly formed on the surface, so there is no risk of burrs falling during mounting. Moreover, according to the manufacturing method of this invention, said light-emitting device can be manufactured easily.

<Embodiment 1>
As shown in FIGS. 1 and 2, the light emitting device 10 of the present embodiment includes a first substrate 12 and a second substrate 14 that are arranged so that the longitudinal direction thereof is in the X direction. These substrates are laminated in the Z direction, and the laminated substrate 15 is configured by fixing the upper surface 12a of the first substrate 12 and the lower surface 14b of the second substrate 14 by a fixing member 36.

The first substrate 12 has an inverted trapezoidal cross-sectional shape that narrows from the upper surface 12a toward the lower surface 12b, and the second substrate 14 has an oblong cross-sectional shape. Assuming that the upper surface 12a of the first substrate 12 has a length 12X in the X direction and a length 4X in the X direction of the second substrate 14, the dimensional relationship between the first substrate 12 and the second substrate 14 is 12X> 14X. ing. Therefore, when forming the laminated substrate 15, the first substrate 12 and the second substrate 14 are laminated so that the inclined surfaces 12 d at both ends of the first substrate 12 are positioned inward of the side surfaces 14 c of the second substrate 14. can do. An inclined step portion 33 is formed between the inclined surface 12d of the first substrate 12 and the lower surface 14b of the second substrate.
In the present embodiment, the dimension of the first substrate 12 in the Y direction is substantially the same as the dimension of the second substrate 14 in the Y direction, and the first substrate 12 and the second substrate 14 are substantially separated in the Y direction. Can be laminated flush with each other.

A pair of upper surface electrodes 16a and 16b are formed on the upper surface 14a of the second substrate 14, and a light emitting element (for example, a light emitting diode) 18 is fixed between the upper surface electrodes 16a and 16b. The light emitting element 18 is connected to the upper surface electrodes 16a and 16b and the conductive wires 38a and 38b.
The upper surface 14a of the second substrate 14 is covered with a transparent resin layer 20 made of a transparent resin, and protects the light emitting element 18 from the external environment. In the present embodiment, the light emitting surface 42 of the transparent resin layer 20 is formed into a cylindrical lens protruding in the Z direction, so that the light spreading from the light emitting element 18 in the YZ plane is converged in the Z direction. .

A through hole 34 penetrating from the lower surface 12b of the first substrate 12 to the upper surface 14a of the second substrate 14 is formed immediately below the upper surface electrodes 16a and 16b, and the inside of the through hole 34 is filled with a conductive material. Thus, the connecting portions 22a and 22b are configured.
On the lower surface 14 b of the first substrate 14, first metal films 24 a and 24 b that are in contact with the lower surfaces of the connection portions 22 a and 22 b and seal the through holes 34 are formed.

  A first metal film is formed on a part of the lower surface 12b of the first substrate 12 and the inclined surface 12d. In addition, second metal films 25a and 25b are formed on the lower surface 14a of the second substrate 14 with an appropriate interval between the first substrate 12 and the second substrate 14, and the connection portions 22a and 22b. In contact. Plated layers 26a and 26b are formed on the exposed surfaces of the first metal films 24a and 24b and the second metal films 25a and 25b. The plated layers 26a and 26b cover the first metal films 24a and 24b to the corresponding second metal films 25a and 25b, and establish conduction between them. In the present embodiment, first metal films 24a and 24b, second metal films 25a and 25b, plating layers 26a and 26b, and lower surface electrodes 27a and 27b are formed.

  In the light emitting device 10, the solder 28 at the time of mounting tends to stay at the inclined step 33, so that the leakage of the solder 28 between the adjacent lower surface electrodes 27 a and 27 b hardly occurs, and therefore short-circuiting without reducing the amount of solder. Can be sufficiently suppressed. Moreover, since the lower surface electrodes 27a and 27b are widened by an amount corresponding to the area of the inclined surface 12d of the first substrate 12, the area for fixing the light emitting device 10 can be widened. Furthermore, since it is a side view type light emitting device, the mounting stability is good. For these reasons, the light emitting device 10 can be mounted on the mounting substrate 30 with a high fixing force.

  The angle θ of the inclined step portion 33 is at least an obtuse angle (an angle greater than 90 ° and less than 180 °), but is preferably 95 ° to 165 °, and more preferably 110 ° to 130 °. preferable. When the angle θ is less than 95 °, the air is difficult to escape from the inclined step portion 33 when the plated layers 26a and 26b are formed, and the first electrode is used when the lower surface electrodes 27a and 27b are etched using a photolithography technique. This is not preferable because the photoresist on the inclined surface 12d of the substrate 12 is not sufficiently exposed. If the angle θ is larger than 165 °, the solder 28 is likely to leak from the inclined step portion 33, which is not preferable.

  In addition, since the length 120X in the X direction of the lower surface 12b of the first substrate 12 affects the opening position of the lower ends of the connecting portions 22a and 22b, it is preferably formed in a certain range of length. In particular, the length 120X is preferably adjusted such that the distance d between 22a and 22b and the corner of the lower surface 12b of the first substrate 12 is 100 μm or more. If the distance d is less than 100 μm, it is difficult to form the connection portions 22a and 22b, which is not preferable. The length 120X can be adjusted by changing three settings: the length 12X of the upper surface of the first substrate 12, the angle θ of the inclined step portion 33, and the thickness 12t of the first substrate 12.

  Since the second metal films 25a and 25b are in contact with the connection portions 22a and 22b between the first substrate 12 and the second substrate 14, heat dissipation that releases heat that tends to be trapped inside the connection portions 22a and 22b to the outside. It is effective as a route. Thereby, the bad influence by heat, such as the multilayer substrate 15 of the semiconductor light-emitting device 10, warping can be suppressed. Further, the heat generated from the light emitting element 18 can be efficiently released to the outside. The second metal films 25a and 25b are formed at intervals so as not to be short-circuited. In order to avoid short-circuiting of the second metal films 25a and 25b, the fixing member 36 has an insulating fixing material ( For example, an adhesive) is used.

Next, a method for manufacturing the light emitting device according to this embodiment will be described.
1. Production of Laminate Plate 152 FIG. 3 shows a first plate 122 for forming the first substrate 12 and a second plate 142 for forming the second substrate 14. The first plate body 122 and the second plate body 142 can form a plurality of light emitting devices 10 simultaneously.

In the first plate-like body 122, a plurality (two in this example) of slots 52 that are long in the Y direction are formed in parallel. The slot 52 is covered with portions 241a and 241b of the first metal film (distinguished on the left and right of the slot) on the periphery and the inner wall of the first plate 122 on the lower surface 122a side. The upper surface 122a around the slot 52 is not covered with a metal film. The portions 241a and 241b of the first metal film formed around the adjacent slot 52 are formed at intervals so as not to contact each other.
The dimension of the slot 52 in the X direction is formed so as to become narrower from the lower surface 122b of the first plate-like body 122 toward the upper surface 122a, whereby the cross-sectional shape of the slot 52 is trapezoidal. As a result, the cross-sectional shape of the band-like portion 123 (which will later become the first substrate 12) of the first plate-like body 122 located between the slots 52 can be inverted trapezoidal.

  The second plate-like body 142 has a plurality of second metal films 25a and 25b (two in this example) extending in the Y direction on the back surface 142b side. The second metal films 25 a and 25 b are patterned in alignment with the positions where the slots 52 of the first plate-like body 122 are formed. Further, the adjacent second metal films 25a and 25b are formed at intervals so as not to contact each other.

The first plate 122 and the second plate 142 in FIG. 3 are stacked with the fixing material layer 36 interposed therebetween to form a stacked plate 152 as shown in FIG. 4A. At this time, the first plate 122 is observed from the Z direction so that the second metal films 25 a and 25 b of the second plate 142 are partially exposed from the slot 52 of the first plate 122. And the second plate-like body 142 are aligned and stacked.
If this alignment is misaligned, the cutting positions set for the first substrate 12 and the second substrate 14 will be deviated when the light emitting device 10 is divided into individual light emitting devices 10, so that the light emitting device 10 after the division is defective. There is a risk of becoming. Therefore, it is preferable to align the slots of the first plate 122 and the second metal films 25a and 25b of the second plate 142 as accurately as possible.

2. Processing of laminated plate-like body 152 Through-hole 34 penetrating from the lower surface of first plate-like body 122 to the upper surface of second plate-like body 142 is formed in laminated plate-like body 152 laminated as shown in FIG. 4A (FIG. 4B). reference). Two through holes are formed side by side in the X direction between the two slots 52 of the first plate-like body 122. In particular, the position of each through hole 34 is preferably determined so as to penetrate the second metal films 25a and 25b. When a plurality of light emitting devices 10 are simultaneously formed, the necessary number of through holes 34 are formed in the laminated plate-like body 152 so that each light emitting device 10 includes two through holes 34 arranged in the X direction. To do.

  The formed through-hole 34 is filled with a metal paste, or metal plating is performed in the through-hole 34 to form the connecting portions 22a and 22b. Upper surface electrodes 16a and 16b are formed on the upper ends of the connection portions 22a and 22b (the upper surface side of the second plate-like body 142). Further, at the lower ends of the connection portions 22a and 22b (the lower surface side of the first plate-like body 122), a metal film extending from the first metal film portions 241a and 241b (this extended metal film and The first metal films 24a and 24b are formed from the first metal film portions 241a and 241b) (see FIG. 4C).

3. Formation of lower surface electrodes 27a, 27b When the first plate 122 and the second plate 142 are laminated, the first metal films 24a, 24b and the second metal films 25a, 25b are insulative fixing material layers. Insulated by 36 or in slight contact. Therefore, in order to ensure electrical continuity between the first metal films 24a and 24b and the second metal films 25a and 25b, plating layers 26a and 26b covering these metal films are formed. The plating layers 26a and 26b are preferably formed by electrolytic plating, and can be selectively plated on the conductive first metal films 24a and 24b and the second metal films 25a and 25b. In the present embodiment, air escape can be improved by making the stepped portion of the laminated plate-like body 152 where the air hardly escapes when immersed in the electrolytic bath into the inclined stepped portion 33 having the angle θ. As a result, the electrolytic solution is sufficiently in contact with the surfaces of the first metal films 24a and 24b and the second metal films 25a and 25b formed on the inclined step portion 33, thereby forming plated layers 26a and 26b having desired thicknesses. can do.
In this way, lower surface electrodes 27a and 27b composed of the first metal films 24a and 24b, the second metal films 25a and 25b, and the plating layers 26a and 26b are formed (see FIG. 4D).

  The formed lower surface electrodes 27a and 27b are further patterned by a photolithography technique to be formed into a desired electrode shape (see FIG. 4D). The patterning is performed by etching using a photoresist (not shown). First, a photoresist is applied to the surfaces of the lower surface electrodes 27a and 27b, and the light L is irradiated in a state of being covered with a mask 46 having a desired electrode shape. Then, the photoresist is exposed to a predetermined pattern. Then, the lower surface electrodes 27a and 27b partially protected with the photoresist are etched to obtain the lower surface electrodes 27a and 27b having a desired pattern.

As shown in FIG. 5A, the patterned lower surface electrodes 27a and 27b are divided by striped removal portions 272 that extend in the X direction and are intermittent in the Y direction. From the removal portion 272, the inclined portion 12d of the substrate 12 is exposed. In addition, the second metal films 25 a and 25 b that are located between the first plate 122 and the second plate 142 and remain without being etched are also exposed from the removing portion 272.
In the present embodiment, the side portions of the first plate-like body 122 are inclined portions 12d, so that the lower surface electrodes 27a and 27b including the inclined portions 12d of the first plate-like body 122 are exposed during photoresist exposure. The entire surface can be sufficiently exposed by the light L. Therefore, the photoresist is exposed according to the shape of the mask 46, and the lower surface electrodes 27a and 27b can be patterned into a predetermined shape.

4). The light emitting element 18 is mounted on the laminated plate-like body 152 in which the patterning of the mounting lower surface electrodes 27a and 27b of the light emitting element 18 is completed. The light emitting element 18 is die-bonded on the upper surface of the laminated plate-like body 152 so as to be positioned between the two upper surface electrodes 16a and 16b. And the electrode of the light emitting element 18 is wire-bonded to the upper surface electrodes 16a and 16 of the laminated plate-like body 152 by the conductive wires 38a and 38b (see FIG. 4E). When a plurality of light emitting devices 10 are manufactured at the same time, a plurality of light emitting elements 18 can be mounted along the Y direction.

5). Formation of the transparent resin layer 20 The transparent resin layer 20 that seals the light emitting element 18, the upper surface electrodes 16a and 16b, and the conductive wires 38a and 38b is formed on the upper surface of the laminated plate-like body 152 (see FIGS. 4F and 5B). . As shown in FIG. 4F, the transparent resin 20 can be simultaneously formed on the plurality of light emitting elements 18 mounted in parallel in the X direction. Further, as shown in FIG. 5B, the transparent resin layer 20 can be provided simultaneously on the plurality of light emitting elements 18 mounted in the Y direction. The transparent resin layer 20 may be two or more layers. For example, the transparent resin layer 20 is formed so that the first layer containing the phosphor covers the light emitting element, and the second layer containing the filler covers the first layer. You can also.
The transparent resin layer 20 can be formed by a method such as transfer molding, compression molding, injection molding, or the like, using a lens-shaped mold. The transparent resin layer 20 may include a phosphor for converting the wavelength of light emitted from the light emitting element 18.

6). The split end of the light emitting device 10 to cut the laminate plate body 152 along section line _{C 1} and _{C 2} in FIG. 5A and 5B. Cut lines _{C 1} and _{C 2,} each light emitting device 10 after cutting, one of the light emitting element 18 and a pair of connecting portions 22a, is set to include and 22b. The cutting line C ₂ coincides with the center line of the slot 52 of the first substrate 12.
After the cutting, as shown in FIG. 4G, a plurality of individually divided light emitting devices 10 can be obtained at the same time. As shown in FIG. 6, the lower surface electrodes 27a and 27b in contact with the surface 10a side of the light emitting device 10 are sufficiently removed by the removing portion 272 in the obtained inclined step portion 33 of the light emitting device 10. The unremoved portion 270 as shown in FIG. 6 does not exist, and therefore the burr 50 is not generated on the surface 10 a of the light emitting device 10.

Manufacturing method of the present embodiment, by laminating a first plate-like body 122 having a slot 52 in the second plate member 142, the cutting line C _2, which coincides with the center line of the last extending in the longitudinal direction of the slot 52, by cutting by the cutting line C ₁ perpendicular thereto, a light-emitting device having multilayer substrate 15 obtained by laminating a first substrate 12 having different lengths and the second substrate may be a large number at the same time. Further, the laminated substrate 15 having the first substrate 12 having the inverted trapezoidal cross section can be easily manufactured by using the first plate-like body 122 having the trapezoidal cross section. Furthermore, even if the light emitting device 10 is manufactured in a small size, it can be easily manufactured by manufacturing it with a substrate having a dimension and shape that is relatively easy to handle and finally cutting in parallel.

  Hereinafter, each configuration of the light emitting device 10 will be described in detail.

(First substrate 12, second substrate 14)
The first substrate 12 and the second substrate 14 are not particularly limited as long as the materials have appropriate mechanical strength and insulating properties. For example, BT resin, glass epoxy, or the like can be used. Moreover, what laminated | stacked the multilayered epoxy resin sheet may be used.

(Top electrodes 16a and 16b, first metal films 24a and 24b, second metal films 25a and 25b)
The top electrodes 16a and 16b, the first metal films 24a and 24b, and the second metal films 25a and 25b formed on the first substrate 12 and the second substrate 14 are preferably metal layers mainly composed of Cu, For example, it can be composed of Cu / Ni / Ag.

(Plating layers 26a, 26b)
The plated layers 26a and 26b formed on the surface of the first substrate 12 are formed by electrolytic plating, and it is preferable that Ni be an underlayer and Ag be disposed on the surface. Au or the like may be provided between Ni and Ag. Further, Pd, Rh, etc. may be used instead of Ag. The thickness of the Ni layer is preferably 3 μm or more, and the thickness of the Ag layer is preferably 2 μm or more, but can be appropriately changed.

(Connection 22a, 22b)
The connecting portions 22a and 22b can be formed by filling the through holes 34 with a conductive member such as copper paste or silver paste. The metal paste is sealed in the through hole by the upper surface electrodes 16a and 16b and the first metal films 24a and 24b.
Moreover, the connection parts 22a and 22b can also be formed from a conductive film formed by electroless plating or the like. At this time, the conductive coating may fill part or all of the through-hole 34, or only the inner wall of the through-hole 34 may be covered to leave the cavity. If the cavity remains, it may be filled with an insulating material such as an epoxy resin.

(Fixing member 36)
The fixing member 36 is formed of an insulating adhesive or adhesive sheet that has good adhesion to the first substrate 12 and the second substrate 14 and can insulate between the plating layers 26a and 26b and the connection portions 22a and 22b. be able to. As the preferable fixing member 36, an epoxy resin, a modified silicone resin, a silicone resin, or the like can be used.

(Light emitting element 18)
A semiconductor light emitting element is preferably used for the light emitting element 18. In particular, when a white light emitting device for a backlight is manufactured, a method of converting a part of emitted light into another color by a phosphor using a light emitting diode that emits a short wavelength to the light emitting element can be adopted. Below, the combination of the light emitting diode which can be utilized for a white light-emitting device and fluorescent substance is demonstrated.

As a light-emitting diode suitable for constituting a white light-emitting device, used after using nitride semiconductor _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) that the be able to. This light emitting diode has In _x Ga _1-x N (0 <x <1) as a light emitting layer, and the light emission wavelength can be arbitrarily changed from about 365 nm to 650 nm depending on the degree of mixed crystal.
In the case of emitting white light, considering the complementary color relationship with the light emitted from the phosphor, the emission wavelength of the light emitting diode 8 is preferably set to 400 nm or more and 530 nm or less, and set to 420 nm or more and 490 nm or less. It is more preferable. An LED chip that emits light having a wavelength in the ultraviolet region shorter than 400 nm can also be applied by selecting the type of phosphor.

The phosphor may be any material that absorbs light from the semiconductor light-emitting diode 8 having a nitride-based semiconductor as a light-emitting layer and converts the light into light having a different wavelength. For example, it is mainly activated by nitride-based phosphors / oxynitride-based phosphors mainly activated by lanthanoid elements such as Eu and Ce, lanthanoid-based phosphors such as Eu, and transition metal elements such as Mn. Alkaline earth halogen apatite phosphor, alkaline earth metal borate phosphor, alkaline earth metal aluminate phosphor, alkaline earth silicate, alkaline earth sulfide, alkaline earth thiogallate, alkaline earth nitriding Selected from organic and organic complexes mainly activated by lanthanoid elements such as silicon, germanate or lanthanoid elements such as Ce, rare earth aluminate, rare earth silicate or Eu It is preferable that it is at least any one or more. In particular, aluminum garnet M ₃ Al ₅ O ₁₂ : Ce (M is Y, Tb, Lu or the like) activated with cerium is preferable, and a part of the composition may be substituted with other elements such as Gd or Ga.

(Transparent resin layer 20)
The material of the transparent resin layer 20 is not particularly limited as long as it is a material that transmits the light emitted from the light emitting element 18 and hardly changes its quality during use. For example, resins such as epoxy, silicone, modified silicone, urethane resin, oxetane resin, acrylic, polycarbonate, and polyimide can be used. Furthermore, glass can be used in addition to the resin. A filler or a diffusing material may be dispersed in the first transparent resin layer 12. In addition, since the transparent resin layer 20 is easy to receive the heat | fever of the light emitting element 18, it is preferable that it is resin with favorable heat resistance. For example, it is preferable to use an epoxy, a silicone resin, a modified silicone resin, or an oxetane resin. The viscosity of the transparent resin layer 20 is preferably 100 to 2000 mPa · s before curing. Here, “viscosity” refers to a value measured at room temperature using a conical plate type rotational viscometer. In addition, the transparent resin layer 20 is desirably a resin having a hardness that can maintain the shape under curing conditions of 80 ° C. to 180 ° C. and several minutes to several hours.

In the present embodiment, a cylindrical lens is formed on the transparent resin layer 20, but this lens preferably has a large lens diameter in a direction parallel to the mounting surface. This is because the direction parallel to the mounting surface needs to control the light distribution characteristics higher than the direction perpendicular to the mounting surface.
Moreover, when forming a white light emitting device using a phosphor, it is preferable to mix the phosphor into the transparent resin layer 20. The phosphor may be uniformly dispersed in the transparent resin layer, but it is particularly preferable that the phosphor is unevenly distributed in the vicinity of the light emitting element 18 because color unevenness due to the viewing direction can be suppressed.

<Embodiment 2>
As shown in FIGS. 7 and 8, the light emitting device 10 according to the present embodiment has a portion corresponding to the first substrate 12 and a portion corresponding to the second substrate 14 formed integrally. One substrate 150 is configured. Therefore, unlike the first embodiment, the second metal films 25a and 25b are not formed on the lower surface 12a of the second substrate 14 in the present embodiment. Further, instead of forming the first metal films 24a and 24b on the first substrate 12, the lower surface electrodes 27a and 27b are formed directly. Further, in the present embodiment, the fixing member 36 as in the first embodiment is not provided. Except for these configurations, the second embodiment is the same as the first embodiment.
Due to these differences, in the manufacturing method of the first embodiment, instead of laminating the first plate 122 and the second plate 142 to form the laminated plate 152, a single plate is used. The same shape is formed by processing.

Production of Single Layer Plate 151 FIG. 8 is a single layer plate 151 for forming a single layer substrate 150. Instead of the slot 52 of the first plate 122 in FIGS. 3 and 4A, the substrate A counterbore hole 54 is formed by digging partway through the thickness. The counterbore hole 54 has a trapezoidal cross-sectional shape and is elongated in the Y direction. Thereby, the single layer plate-like body 151 which has a cross section similar to the laminated plate-like body 152 of FIG. 4A is obtained. In the present specification, a continuous portion of the single-layer plate-like body 151 where the spot facing hole 54 has not reached is a first substrate equivalent portion 121, and an island portion separated by the spot facing hole 54 is a second substrate equivalent portion 141. Called.

The single-layer plate-like body 151 formed in this way forms connection portions 22a and 22b, upper surface electrodes 16a and 16b, lower surface electrodes 27a and 27b, and lower surface electrodes 27a and 27b as in the first embodiment. After patterning and mounting the light emitting element 18, the transparent resin layer 20 is formed. Then, when divided into the light-emitting device 10 along the line C ₁ and C ₂ as shown in Figure 5B, the cutting line C _2, to coincide with the center line of the longitudinal direction of the spot facing hole 54 (Y-direction).

The manufacturing method of this embodiment is to form an elongated countersunk holes 54 in the substrate, a cutting line C _2, which coincides with the center line extending in the longitudinal direction of the last counterbore hole 54, and the cutting line C ₁ perpendicular thereto By cutting by the step, a large number of light emitting devices 10 including the single layer substrate 150 including the first substrate 12 and the second substrate having different lengths can be formed at the same time. Further, the single-layer substrate 150 having the first substrate equivalent portion 121 having the inverted trapezoidal cross section can be easily manufactured by using the single-layer plate-shaped body 151 having the counterbore countersunk hole 54. Furthermore, even if the light emitting device 10 is manufactured in a small size, it can be easily manufactured by manufacturing the single layer plate 151 having a dimension and shape that is relatively easy to handle and finally cutting in parallel.
In the present embodiment using the single-layer plate-like body 151, alignment between the first plate-like body 122 and the second plate-like body 142 is not necessary. Generation of defective products of the light emitting device due to misalignment can be prevented.

FIG. 2 is a schematic front view showing a mounted state of the light emitting device according to the first embodiment. FIG. 2 is a schematic perspective view showing a mounted state of the light emitting device according to the first embodiment. FIG. 3 is a schematic perspective view illustrating a method for manufacturing a substrate of the light emitting device according to the first embodiment. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 3 is a schematic side view showing patterning of a lower surface electrode of the light emitting device according to the first embodiment. FIG. 3 is a schematic perspective view illustrating a method for dividing the light emitting device according to the first embodiment. FIG. 3 is a partial schematic perspective view showing an inclined step formed on the substrate of the light emitting device according to the first embodiment. It is a schematic front view which shows the mounting state of the light-emitting device concerning Embodiment 2. FIG. 10 is a schematic cross-sectional view illustrating a method for manufacturing a substrate of a light emitting device according to Embodiment 2. FIG. It is a schematic front view which shows the mounting state of the conventional light-emitting device. It is a schematic perspective view which shows the mounting state of the conventional light-emitting device. It is a partial schematic perspective view which shows the vertical level | step difference formed in the board | substrate of the conventional light-emitting device. It is a partial schematic perspective view which shows the vertical level | step difference formed in the board | substrate of the conventional light-emitting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light-emitting device, 12 1st board | substrate, 12a Upper surface of 1st board | substrate, 12b Lower surface of 1st board | substrate, 12d The inclined side surface of 1st board | substrate, 14 2nd board | substrate, 15 Laminated board | substrate, 16a, 16b Upper surface electrode, 18 Light emitting element 20 transparent resin layer, 22a, 22b connecting portion, 24a, 24b first metal film, 25a, 25b second metal film, 26a, 26b plating layer, 27a, 27b bottom electrode, 28 solder, 33 inclined step, 36 fixing member , 46 mask, 50 burr, 52 slot of first substrate, 54 counterbore hole, 121 first substrate equivalent, 122 first plate-like body, 123 band-like portion, 141 second substrate equivalent portion, 142 second plate-like body , 150 single-layer substrate, 152 laminated plate-like body, 270 unremoved portion of lower surface electrode, 272 removed portion of lower surface electrode

Claims (7)

A light emitting element;
A substrate having an upper surface on which the light emitting element is mounted and a lower surface facing the upper surface;
A pair of upper surface electrodes formed on the upper surface of the substrate and connected to the light emitting element;
A pair of lower surface electrodes formed on the lower surface of the substrate;
A light-emitting device comprising: a connecting portion for conducting the upper surface electrode and the lower surface electrode;
The substrate is provided with a step by having an inverted trapezoidal protrusion on the lower surface side,
The side surface of the step is inclined with respect to the lower surface so that the angle θ of the step is an obtuse angle,
The light emitting device, wherein the lower surface electrode extends to at least the side surface inclined by the step.   The light emitting device according to claim 1, wherein the angle θ is 95 ° to 165 °. The substrate is
A first substrate having an inverted trapezoidal cross section and disposed on the lower surface side of the substrate;
A second substrate laminated on the upper surface side of the first substrate;
The light emitting device according to claim 1, wherein the light emitting device is a laminated substrate including a fixing member that fixes the first substrate and the second substrate. The connection portion is made of a conductive material filled in a through-hole penetrating from the lower surface of the first substrate to the upper surface of the second substrate,
The light emitting device further includes a metal film in contact with the connecting portion between the first substrate and the second substrate,
The light emitting device according to claim 3, wherein the metal film extends along a lower surface of the second substrate and is in contact with the lower surface electrode. The substrate is
A portion corresponding to a first substrate disposed on the lower surface side of the substrate with an inverted trapezoidal cross section;
3. The light emitting device according to claim 1, wherein the light emitting device is a single layer substrate including a portion corresponding to a second substrate integrally formed on an upper surface side of the first substrate. A step of laminating a second plate-like body on the upper surface side of the first plate-like body including a strip-like portion having an inverted trapezoidal cross section to form a laminated plate-like body;
Forming a plurality of through holes penetrating from the upper surface to the lower surface of the laminated plate-like body;
A step of forming a connecting portion by disposing a conductive material inside the through hole; a step of forming an upper surface electrode in contact with the upper end of the connecting portion on the upper surface of the laminated plate-like body;
Forming a lower surface electrode in contact with the lower end of the connection portion on the lower surface of the laminated plate-like body;
Mounting a light emitting element on the top surface of the laminated plate,
A step of cutting the laminated plate-like body in a direction substantially perpendicular to the longitudinal direction of the first substrate and separating the laminate into individual light emitting devices. A light emitting device substrate comprising an upper surface for mounting a light emitting element and a lower surface facing the upper surface,
A pair of upper surface electrodes formed on the upper surface of the substrate and connected to the light emitting element;
A pair of lower surface electrodes formed on the lower surface of the substrate;
A connection portion for conducting the upper surface electrode and the lower surface electrode,
The substrate is provided with a step by having an inverted trapezoidal protrusion on the lower surface side,
The side surface of the step is inclined with respect to the lower surface so that the angle θ of the step is an obtuse angle,
The substrate for a light-emitting device, wherein the lower surface electrode is extended to at least the side surface inclined by the step.

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