JP4952235B2 - Light emitting device and backlight using the same - Google Patents

Description

  The present invention relates to a light emitting device and a backlight using the same, and more particularly to a thin light emitting device suitable for a side view and a backlight using 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 (see, for example, Patent Documents 1 to 4). In recent years, light-emitting devices have been miniaturized, and accordingly, components such as electrodes of the light-emitting devices have also been reduced in size. When the light emitting device is mounted on the mounting substrate, the electrodes of the light emitting device and the wiring pattern of the mounting substrate are connected by solder. However, when the electrodes of the light emitting device are reduced in size, there is a high possibility that the solder protrudes and the electrodes are short-circuited. . If the amount of solder is reduced to avoid a short circuit, the fixing power of the light emitting device may be insufficient.

In order to solve these problems, a light-emitting device including a substrate having a step 229 as shown in FIGS. 9 and 10 is known (see, for example, Patent Document 5).
In the light emitting device 200, a light emitting element 218 is mounted on the front surface of a laminated substrate 215 in which two substrates having different lengths (a first substrate 212 and a second substrate 214) are stacked, and the light emitting element 218 is sealed. A cylindrical lens is formed by the sealing member 219.
The first substrate 212 and the second substrate 214 have a substantially rectangular shape when viewed from the front side, and the first substrate 212 is longer than the second substrate 214 in the longitudinal direction. Therefore, a step 229 is formed at both ends in the longitudinal direction on the rear surface 215b side of the multilayer substrate 215. A rear electrode 227 of the light emitting device 200 is formed on the rear surface 212b of the first substrate 212 facing the step 229 and the side surface 214c of the second substrate 214, and is connected to the wiring pattern 232 of the mounting substrate 230 using the solder 228. And can be fixed.

In the light emitting device 200, the solder 228 at the time of mounting tends to stay at the step 229, so that the short circuit can be sufficiently suppressed without reducing the amount of solder. Further, since the rear electrode 227 is widened by an amount corresponding to the area of the side surface 212c of the first substrate 212, the area for fixing the light emitting device 200 can be widened. For these reasons, the light emitting device 200 of FIGS. 9 and 10 can be mounted on the mounting substrate 230 with a high fixing force.
JP 2001-177156 A JP 2000-196153 A Japanese Patent Laid-Open No. 10-290029 JP 2006-229055 A Design Registration No. 1257104

When the light emitting device 200 as shown in FIGS. 9 and 10 is manufactured, the multilayer substrate 215 is manufactured, the light emitting element 218 is mounted, and sealed in a form in which a plurality of light emitting devices 200 are coupled in the Y direction of FIG. A method in which the stop member 219 is formed and then divided into a predetermined thickness and divided into individual light emitting devices 200 can be employed. 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 200 can be manufactured at the same time, so that the productivity is excellent.
However, when formed by this manufacturing method, there is a problem that burrs are generated when the light emitting elements are divided. The generation of burrs will be described below.

  When the light emitting device 200 is divided, the light emitting device 200 is divided from the sealing member 219 toward the multilayer substrate 215 with a cutting blade. At this time, the rear electrode 227 made of metal is pulled by the cutting blade, and the pulled portion remains as a burr of the cut surface later (see FIG. 11). When the light emitting device 200 is mounted on the mounting substrate, the mounter automatically recognizes the surface shape of the light emitting device 200 and positions it on the mounting substrate such as a flexible substrate, but when the burr 250 is generated and the apparent surface shape changes, There is a possibility that the mounter misidentifies the shape of the light emitting device 200 and reduces the mounting accuracy.

The cause of the misidentification of the mounter depends on the burr 250 on the front surface 200a rather than the burr 250 on the mounting surface of the light emitting device 200 (this is referred to as the back surface 200b). Therefore, a method of removing a portion of the rear electrode 227 in contact with the surface 200a of the light emitting device 200 before being divided into the light emitting devices 200 is employed. Etching using a photoresist is optimal because the back electrode of the minute portion is removed. Photoresist is applied to the rear electrode 227, the photoresist is exposed using a mask that matches the shape of the region to be left or the shape of the region to be removed, and then the rear electrode 227 is partially removed by etching. In the case of the rear electrode 227 of the light emitting device 200, light is irradiated from the rear surface 215b of the multilayer substrate 215 toward the Z direction during exposure of the photoresist. However, since the side surface 214c of the second substrate 214 is parallel to the light irradiation direction, the photoresist formed on the side surface 214c is not sufficiently exposed. As a result , the first substrate on the side surface 214c of the second substrate 214 is not exposed. An unremoved portion 270 of the rear electrode 227 remains in the vicinity of 212 (see FIG. 12). If the cutting blade passes through the unremoved portion 270 when the light emitting device 200 is divided, a needle-like burr 250 is generated. Such a needle-like burr 250 is likely to drop from the light emitting device 200 to the mounting substrate 230 during mounting, and is likely to cause a short circuit of the wiring pattern.
Accordingly, an object of the present invention is to provide a light-emitting device in which needle-like burrs are less likely to occur.

The light emitting device of the present invention includes a light emitting element, a laminated substrate having a first substrate on which the light emitting element is placed on the front surface side, a second substrate laminated on the rear surface side of the first substrate, and the first substrate. A front electrode formed on the front surface and electrically connected to the light emitting element; a rear electrode extending from the rear surface to the side surface of the second substrate; and a conductive means for electrically connecting the front electrode and the rear electrode; A light-emitting device including a covering member that covers the light-emitting element and a front surface of the first substrate, wherein the thickness of the first substrate in the stacking direction of the stacked substrate is equal to the thickness of the second substrate. der least twice the is, the thickness of the laminated substrate in the stacking direction, characterized in that it is 100 m to 1000 m.

  According to the present invention, since the thickness of the second substrate is reduced, the photoresist on the surface of the rear electrode formed on the side surface of the second substrate can be sufficiently exposed. Therefore, the unremoved portion of the rear electrode is not formed, and no needle-like burrs are generated. Therefore, it is possible to reduce the possibility of problems such as a short circuit of the wiring pattern during mounting.

<Embodiment 1>
The light emitting device 10 according to the present embodiment shown in FIGS. 1 and 2 includes a light emitting element (for example, a light emitting diode) 18 and a covering member 19 on the front surface 15 a side of the multilayer substrate 15.

  The laminated substrate 15 includes a first substrate 12 and a second substrate 14 arranged so that the longitudinal direction is in the X direction. These substrates are laminated in the Z direction, and the laminated substrate 15 is configured by fixing the rear surface 12b of the first substrate 12 and the front surface 14a of the second substrate 14 by a fixing member 36. A pair of front substrates 16 are formed on the front surface 15 a of the multilayer substrate 15, and a pair of rear electrodes 27 are formed on the rear surface 15 b of the multilayer substrate 15. The front electrode 16 and the electrode of the light emitting element 18 are connected by a conductive wire 38.

  The first substrate 12 and the second substrate 14 are formed of rectangular parallelepiped members that extend long in one direction. The thickness 12t (dimension in the Z direction) of the first substrate 12 is more than twice the thickness 14t of the second substrate, preferably 2 to 5 times. Thereby, even when the thickness of the laminated substrate is constant, the thickness 12t of the first substrate 12 can be made relatively thick, and the thickness 14t of the second substrate 14 can be made relatively thin.

  In this embodiment, the length of the first substrate 12 (dimension in the X direction) is longer than the length of the second substrate 14. Therefore, when the second substrate 14 is laminated on the rear surface 12 b of the first substrate 12, a step 29 is formed at both ends of the rear surface 15 b of the laminated substrate 15. When the step 29 is used to form a fillet of the solder 28 when the light emitting device 10 is mounted, the solder 28 contacts both the rear surface 12b of the first substrate 12 and the side surface 14c of the second substrate 14. There is an advantage that the light emitting device 10 can be firmly fixed even with a small amount of solder 28.

In the case of the multilayer substrate 15 having such a step 29, the solder 28 easily collects in the step 29, so that the solder 28 does not leak out between the two rear electrodes 27 of the multilayer substrate 15. However, because the thickness (dimension in the Z direction) of the multilayer substrate 15 is thin, even when the fillet of the solder 28 is formed in the step 29, if the solder 28 leaks slightly, the multilayer substrate 15 and the covering member 19 It was easy to reach the interface (corresponding to the front surface 15a of the multilayer substrate 15). When the solder 28 comes into contact with the interface between the multilayer substrate 15 and the covering member 19, peeling occurs at the interface and the light emitting device 10 may be damaged.
However, in the light emitting device 10 of the present invention, by increasing the thickness of the first substrate 12, the front surface 15 a of the laminated substrate 15 can be separated from the step 29 where the fillet of the solder 28 is formed. Even if leakage occurs, it is difficult to reach the interface between the laminated substrate 15 and the covering member 19. Therefore, the adhesive force between the laminated substrate 15 and the covering member 19 due to the solder 28 is hardly reduced and peeling is hardly caused.

The thickness of the multilayer substrate 15 of the light emitting device 10 is preferably 100 μm to 1000 μm. When the thickness is greater than 100 μm, it becomes easy to produce a laminated substrate, and heat dissipation is improved. Moreover, the size of the light emitting device 10 can be reduced by setting the thickness to 1000 μm or less.
In the present embodiment, the width (dimension in the Y direction) of the first substrate 12 is substantially equal to the width of the second substrate 14, 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 rear electrode 27 is formed on the rear surface 15 b side of the multilayer substrate 15. The formation position of the rear electrode 27 will be described in detail. The rear electrode 27 is formed from the rear surface 12 b of the first substrate 12 facing the step 29 to the rear surface 14 b of the second electrode 14 through the side surface 14 c of the second electrode 14. . In the present embodiment, the rear electrode 27 is composed of three metal films. The first metal film 24 is formed on the rear surface 12b of the first substrate 12, and the second metal film 25 is formed on a part of the rear surface 12b and the side surface 14c of the second substrate 14. The front surface 14 a of the second substrate 14 is bonded to a part of the first metal film 25. Furthermore, the third metal film is formed so that the first metal film 24 and the second metal film 25 are integrated so as to cover the exposed portion of the first metal film 24 and the second metal film 25. 26 is formed.

  A through hole 34 penetrating from the front surface 15 a to the rear surface 15 b of the multilayer substrate 15 is formed immediately below the front electrode 16. A plated layer (not shown) is applied to the inner surface of the through hole 34, and a hole filling material 54 is filled therein. Since the front electrode 16 is electrically connected to the rear electrode 27 through the conductive means 22 such as the plated through-hole 34, the light emitting element 18 emits light when the rear electrode 27 is connected to an external power source. Can be made.

  An adhesive layer 36 is used when the laminated substrate 15 is laminated. The adhesive layer 61 is made of an insulating adhesive material in order to prevent a short circuit of the rear electrode 27 and a short circuit of the plating layer in the through hole 34.

  The front surface 15a of the multilayer substrate 15 is covered with a covering member 19 to protect the light emitting element 18 from the external environment. In particular, when the covering member 19 is formed into a cylindrical lens protruding in the Z direction, the light spreading from the light emitting element 18 in the YZ plane can be converged in the Z direction.

  In this example, the covering member 19 includes two layers, a first covering layer 20 and a second covering layer 21. The first coating layer 20 covers the light emitting element 18, and the second coating layer 21 is disposed so as to cover the front side of the first coating layer 20. When it has such a two-layer structure, different functions can be imparted to each. For example, it is preferable to use a silicone resin having excellent heat resistance for the first coating layer 20 because the first coating layer 20 is unlikely to deteriorate even when the light emitting element 18 emits light and the vicinity thereof reaches a high temperature. In addition, it is preferable to use an epoxy resin having good releasability for the second coating layer 21 because processing when a mold is used for molding the covering member 19 is facilitated and productivity is improved.

  When using a material (silicone resin, etc.) with poor releasability for the first coating layer 20, a mold is often not used to mold the first coating layer 20. In that case, the 1st coating layer 20 can be shape | molded by the line application | coating using surface tension. For example, when the first coating layer 20 in a liquid state is applied only between the front electrodes 16, the first coating layer 20 swelled in a mountain shape can be formed only in the range where the front electrodes 16 are formed. If the 1st coating layer 20 is hardened in this state, the 1st coating layer 20 like FIG. 1 can be formed.

However, when the first covering layer 20 is formed using the surface tension, the conductive wire 38 causes unevenness on the surface of the first covering layer 20.
As shown in the schematic diagrams of FIGS. 3A and 3B, the first covering layer 20 has a convex portion 20 a partially formed by the shape of the mountain of the conductive wire 38. When the two conductive wires 38 are stretched around the light emitting element 18, a recess 20 b is formed between the two conductive wires 38. The concave portion 20 b is pulled while the wire is lowered toward the light emitting element 18, and is recessed more than the portion without the conductive wire 38.

The irregularities on the surface of the first coating layer 20 are schematically shown in FIG. The α-α line and γ-γ line in FIG. 4A pass directly above the light emitting element 18, the β-β line passes through the highest position of the conductive wire 38, and the δ-δ line indicates the light emitting device. 10 end faces.
FIG. 4B shows the cross-sectional shape of the first coating layer 20 taken along the line α-α in FIG. 4A, and it can be seen that the recess 20 b is located immediately above the light emitting element 18. . FIG. 4B shows the cross-sectional shape of the first coating layer 20 taken along the γ-γ line in FIG. 4A, but the height of the first coating layer 20 visible on the end face of the light emitting device 10 is high. It can be seen that the recessed portion 20b is at a lower position than the above.

  The first cover layer 20 is selected to have light resistance and heat resistance against light emitted from the light emitting element 18, but the second cover layer 21 is selected with emphasis on performance other than light resistance and heat resistance. Often done. Therefore, when the second coating layer 21 is formed, the concave portion 20b of the first coating layer 20 is filled with the second coating layer 21, and when the light emitting device 10 is turned on, the second coating layer 21 in the concave portion 20b There is a high risk of local degradation.

  Therefore, in the present embodiment, it is preferable to adjust the shape of the conductive wire 38 so that the first coating layer 20 located immediately above the light emitting element 18 does not include the extreme recess 20b. As described above, the surface shape of the first coating layer 20 varies depending on the presence of the conductive wire 38, and in particular, the height from the front surface of the first substrate 12 to the vertex of the conductive wire 38 (reference numeral in FIG. 3A). It was found that the recess of the recess 20b can be relaxed when 38t) is 100 μm to 300 μm. When the wire height is 100 μm or more, the recess 20b does not appear remarkably, and local deterioration of the second coating layer 21 is unlikely to occur. Further, when the wire height is lower than 300 μm, the first coating layer 20 follows the conductive wire 38 and the possibility that the conductive wire 38 jumps out from the first coating layer 20 becomes low and reaches the surface of the second coating layer 21. Less likely to do.

  Additives such as a light diffusing material, an antioxidant, an ultraviolet reflecting member, and a viscosity modifier can be added to the first coating layer 20 and the second coating layer 21. When adjusting the color tone of the light emitting device 10, a fluorescent material can be mixed in, but it is preferable to add the fluorescent material to the first coating layer 20. (1) A fluorescent material is added in the vicinity of the light emitting element 18. By arranging it, it can be brought closer to a point light source, (2) even a small amount of fluorescent material can have a predetermined color, and (3) a small amount of fluorescent material can emit light more efficiently. It has the advantage that it can.

  As shown in FIG. 1, the light emitting device 10 of the present invention is soldered to a wiring pattern 32 of a mounting substrate (for example, a flexible substrate) 30 in a horizontal state, and a light guide plate 33 is disposed on the front surface 10 a side of the light emitting device 10. By doing so, it can be used as a backlight. In the present embodiment, in order to introduce light emitted from the light emitting device 10 into the light guide plate 33 without waste, the cut portion 40 is formed on the end surface 33a of the light guide plate 33, and the front surface 10a of the light emitting device 10 is fitted. If the shape of the cut portion 40 matches the shape of the front surface 10a of the light emitting device 10 and the gap between the light emitting device 10 and the light guide plate 33 is reduced, light from the light emitting device 10 can be introduced into the light guide plate 33 without waste. preferable.

  However, in the case of the cut portion 40 that matches the shape of the front surface 10a of the light emitting device 10, the conventional light emitting device 10 may be difficult to fit. For example, as shown in FIG. 9, when the backlight is configured using the conventional light emitting device 200, the distance d between the end surface 233 a of the light guide plate 233 and the end surface 230 a of the mounting substrate 230 is narrow. For this reason, if the light guide plate 233 is to be fitted after the light emitting device 200 is mounted on the mounting substrate 230, the mounting substrate 230 and the light guide plate 233 may come into contact with each other, or the light emitting device 200 may be difficult to fit. Problems such as falling off the mounting substrate 230 were likely to occur.

  However, in the light emitting device 10 of the present invention, the amount of the front surface 10a of the light emitting device 10 protruding from the end 30a of the mounting substrate 30 can be increased by increasing the thickness of the first substrate 12. This is because when the light emitting device 10 is mounted on the mounting substrate 30, the rear surface 12 b of the first substrate 12 of the light emitting device 10 is aligned with the reference position BB line of the mounting substrate. Therefore, since the first substrate 12 is thicker in the light emitting device 10 of the present invention than the conventional light emitting device 200, the front surface 10a of the light emitting device 10 is not changed without changing the position of the reference position BB line of the mounting substrate 30. Can be increased from the end 30a of the mounting substrate 30. As a result, the distance d between the end surface 33 a of the light guide plate 33 and the end surface 30 a of the mounting substrate 30 is widened compared to the conventional case, and the light guide plate 33 is easily fitted into the light emitting device 10. Therefore, the backlight using the light-emitting device 10 of the present invention has good work efficiency in the manufacturing process and can suppress the defective product generation rate low.

Next, a method for manufacturing the light emitting device according to this embodiment will be described.
(1. Production of laminated plate-like body 152)
FIG. 5 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.

  The first plate 122 has a plurality of first metal films 24 (two in this example) extending in the Y direction on the back surface 122b side. Adjacent first metal films 24 are formed with an interval so as not to contact each other.

In the second plate-like body 142, a plurality of (two in this example) through-holes 52 that are long in the Y direction are formed substantially in parallel. In the through long hole 52, the second metal film 25 is covered on the periphery and the inner wall of the second plate 142 on the rear surface 142 a side. The front side 142a around the through hole 52 is not covered with a metal film. The second metal film 25 formed in the vicinity of the adjacent through-hole 52 is formed with an interval so as not to contact each other.
The first metal film 24 and the through long hole 52 of the second plate-like body 142 are formed in alignment with each other.

The first plate 122 and the second plate 142 shown in FIG. 5 and the adhesive layer 36 are stacked to form a stacked plate 152 as shown in FIG. 6A. At this time, the first plate 122 is observed from the Z direction so that the first metal film 24 of the first plate 122 is partially exposed from the through hole 52 of the second plate 142. 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 that the positions of the first metal film 24 of the first plate-like body 122 and the through-hole 52 of the second plate-like body 142 are aligned as accurately as possible.

(2. Processing of laminated plate-like body 152)
The through hole 34 is formed in the laminated plate-like body 152 laminated as shown in FIG. 6A (see FIG. 6B). Two through holes 34 are formed side by side in the X direction between the two through long holes 52 of the second plate-like body 142. In particular, it is preferable to determine the position so that each through hole 34 penetrates the first metal film 24. When a plurality of light emitting devices 10 are formed simultaneously, a necessary number of through holes 34 are formed in the laminated plate-like body 152 so that one light emitting device 10 includes two through holes 34 arranged in the X direction. .

  The inner surface of the formed through hole 34 is subjected to metal plating, and the inside thereof is filled with a filling material 54 to form the conduction means 22. A metal film is formed on the upper and lower ends of the conducting means 22 to electrically connect the conducting means 22 to the front electrode 16 and the rear electrode 27 (see FIG. 6C).

(3. Formation of rear electrode 27)
When the first plate 122 and the second plate 142 are laminated, the first metal film 24 and the second metal film 25 are insulated by the insulating adhesive layer 36 or slightly in contact with each other. It is. Therefore, in order to ensure conduction between the first metal film 24 and the second metal film 25, a third metal film 26 covering the metal films is formed. The third metal film 26 is preferably formed by an electrolytic plating method, and can be selectively plated on the conductive first metal film 24 and the second metal film 25.
Thus, the rear electrode 27 composed of the first metal film 24, the second metal film 25, and the third metal film 26 is formed (see FIG. 6D).

  The formed rear electrode 27 is further patterned by a photolithography technique to be formed into a desired electrode shape (see FIG. 6D). The patterning is performed by etching using a photoresist (not shown). First, a photoresist is applied to the surface of the rear electrode 27, and light L is irradiated in a state of being covered with a mask 46 having a desired electrode shape, thereby exposing the photoresist to a predetermined pattern. Then, the rear electrode 27 partially protected by the photoresist is etched to obtain the rear electrode 27 having a desired pattern.

By this patterning, the rear electrodes 27a and 27b are separated by a striped removal portion 272 that is continuous in the X direction and intermittent in the Y direction (see FIG. 7A). From the removal portion 272, the inner wall side surface of the through long hole 52 of the second plate-like body 142 (which later becomes the side surface 14c of the second substrate 14) is exposed. Further, the portion of the second metal film 25 sandwiched between the first plate-like body 122 and the second plate-like body 142 remains unetched and is exposed from the removal portion 272.
In the present invention, since the thickness of the second substrate 14 (that is, the second plate-like body 142) is thin, the rear electrode 27 of the side surface 12c of the second substrate 14 is sufficiently absorbed by the light L when the photoresist is exposed. Can be exposed. Therefore, the photoresist is exposed according to the shape of the mask 46, and the rear electrode 27 can be patterned into a predetermined shape.

(4. Mounting of light emitting element 18)
The light emitting element 18 is mounted on the laminated plate-like body 152 in which the patterning of the rear electrode 27 is completed. The light emitting element 18 is die-bonded so as to be positioned between the two front electrodes 16 on the front surface side of the laminated plate-like body 152. Then, the electrode of the light emitting element 18 and the front electrode 16 are wire-bonded by the conductive wire 38 (see FIG. 6E). 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 covering member 19)
A covering member 19 including the first covering layer 20 and the second covering layer 21 is formed on the front surface of the laminated plate-like body 152.
First, the 1st coating layer 20 is formed in the front side of the laminated plate-like body 152 so that the light emitting element 18, the front electrode 16, and the electroconductive wire 38 may be coat | covered (refer FIG. 6F and FIG. 7B). At this time, the melted first coating layer 20 is applied on the light emitting element 18, but if a plurality of light emitting elements 18 arranged in the Y direction are applied along the Y direction as shown in FIG. A first coating layer can be simultaneously formed on the light emitting element 18.
In FIG. 6F, the first coating layer 20 is schematically illustrated in a semi-elliptical shape. However, in the present invention, the height of the conductive wire 38 is set higher than usual. A part of the conductive wire 38 is partially lifted.

Next, the second coating layer 21 is formed on the front surface side of the first coating layer 20 so as to cover the first coating layer (see FIGS. 6G and 7B). The second coating layer 21 can be formed by a method such as transfer molding, compression molding or injection molding using a lens-shaped mold.
Thus, the covering member 19 as shown in FIGS. 6G and 7B is formed.

(6. Division into light-emitting device 10)
Finally, the laminated plate-like body 152 is divided along the cutting lines C ₁ and C ₂ in FIGS. 7A and 7B. The cutting lines C ₁ and C ₂ are set so that each light emitting device 10 after cutting includes one light emitting element 18 and a pair of conducting means 22. Note that the cutting line C ₂ coincides with the center line of the through long hole 52 of the second plate-like body 142.
After the division, a plurality of light emitting devices 10 can be obtained simultaneously as shown in FIG. 6G. As shown in FIG. 8, the step 29 of the obtained light emitting device 10 is not removed as shown in FIG. 12 because the rear electrode 27 is sufficiently removed by the removing portion 272 on the surface 10 c side of the light emitting device 10. Needle-like burrs 50 are not generated by the removing unit 270.

In the manufacturing method of the present embodiment, the first plate-like body 122 and the second plate-like body 142 having the through long hole 52 are stacked, and finally coincide with the center line extending in the longitudinal direction of the through long hole 52. By cutting along the cutting line C ₂ and the cutting line C ₁ perpendicular to the cutting line C ₂ , a large number of light emitting devices including the laminated substrate 15 can be formed at the same time. Further, 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.

(Front electrode 16, first metal film 24, second metal film 25)
The front electrode 16 formed on the first substrate 12 and the second substrate 14, the first metal film 24 and the second metal film 25, and a metal layer mainly composed of Cu are preferable. For example, Cu / Ni / Ag Can be configured.

(Third metal film 26)
The third metal film 26 is formed by electrolytic plating, and preferably has a configuration in which Ni is used as a base layer and Ag is 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.

(Conduction means 22)
The conduction means 22 is composed of a metal plating formed on the inner surface of the through hole 34 and a filling material filled therein. Metal plating can be formed from a plating film formed by electroless plating. The through hole 34 can be formed by filling a conductive material such as copper paste or silver paste, which is a filling material, or an insulating member such as epoxy resin.
Note that the plated layer may be formed thick to fill the entire through hole 34. In this case, the plated layer also serves as a filling material.

(Adhesive member 36)
The adhesive 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 lower surface electrodes 27a and 27b and the connection portions 22a and 22b. be able to.

(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 fluorescent material using a light emitting diode that emits a short wavelength to the light emitting element can be employed. Below, the combination of the light emitting diode and fluorescent substance which can be utilized for a white light-emitting device 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.
When white light is emitted, considering the complementary color relationship with the light emitted from the fluorescent material, the light emission wavelength of the light emitting diode 8 is preferably set to 400 nm or more and 530 nm or less, and is set to 420 nm or more and 490 nm or less. It is more preferable. Note that an LED chip that emits light having an ultraviolet wavelength shorter than 400 nm can also be applied by selecting the type of fluorescent material.

  For example, the fluorescent material may be any material that absorbs light from a light emitting diode having a nitride semiconductor as a light emitting layer and converts the light to light of a different wavelength. For example, it is mainly activated by nitride-based fluorescent materials / oxynitride-based fluorescent materials mainly activated by lanthanoid-based elements such as Eu and Ce, lanthanoid-based fluorescent materials such as Eu, and transition metal-based elements such as Mn. Alkaline earth halogen apatite fluorescent material, alkaline earth metal borate halogen fluorescent material, alkaline earth metal aluminate fluorescent material, 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.

The nitride fluorescent materials mainly activated by lanthanoid elements such as Eu and Ce are M ₂ Si ₅ N ₈ : Eu, MAlSiN ₃ : Eu, MAl _1-X B _X SiN ₃ : Eu (M is Sr , Ca, Ba, Mg, and Zn, and 0 ≦ X <1). In addition to M ₂ Si ₅ N ₈ : Eu, MSi ₇ N ₁₀ : Eu, M _1.8 Si ₅ O _0.2 N ₈ : Eu, M _0.9 Si ₇ O _0.1 N ₁₀ : Eu (M Is at least one selected from Sr, Ca, Ba, Mg, and Zn.

An oxynitride fluorescent material mainly activated by a lanthanoid element such as Eu or Ce is MSi ₂ O ₂ N ₂ : Eu (M is at least one selected from Sr, Ca, Ba, Mg, Zn) Etc.).

Eu, SiAlON-based fluorescent material activated mainly with lanthanoid elements such as Ce _{is, M p / 2 Si 12-} p-q Al p + q O q N 16-p: Ce, M-Al-Si-O-N (M is at least one selected from Sr, Ca, Ba, Mg, and Zn. Q is 0 to 2.5, and p is 1.5 to 3).

Alkaline earth halogen apatite fluorescent materials mainly activated by lanthanoid-based elements such as Eu and transition metal-based elements such as Mn include M ₅ (PO ₄ ) ₃ X: R (M is Sr, Ca, Ba). X is at least one selected from F, Cl, Br and I. R is any one of Eu, Mn, Eu and Mn. Etc.).

The alkaline earth metal borate halogen fluorescent substance includes M ₂ B ₅ O ₉ X: R (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is F, Cl , Br, or I. R is Eu, Mn, or any one of Eu and Mn.).

Alkaline earth metal aluminate fluorescent materials include SrAl ₂ O ₄ : R, Sr ₄ Al ₁₄ O ₂₅ : R, CaAl ₂ O ₄ : R, BaMg ₂ Al ₁₆ O ₂₇ : R, BaMg ₂ Al ₁₆ O ₁₂ : R, BaMgAl ₁₀ O ₁₇ : R (R is Eu, Mn, or any one of Eu and Mn).

Examples of the alkaline earth sulfide fluorescent material include La ₂ O ₂ S: Eu, Y ₂ O ₂ S: Eu, and Gd ₂ O ₂ S: Eu.

Rare earth aluminate fluorescent materials mainly activated with lanthanoid elements such as Ce include Y ₃ Al ₅ O ₁₂ : Ce, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce, Y ₃ (Al _0.8 Ga _0.2 ) ₅ O ₁₂ : Ce, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ There is a YAG-based fluorescent material represented by a composition formula. Further, there are Tb ₃ Al ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce, etc. in which a part or all of Y is substituted with Tb, Lu or the like.

Other fluorescent materials include ZnS: Eu, Zn ₂ GeO ₄ : Mn, MGa ₂ S ₄ : Eu (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is At least one selected from F, Cl, Br, and I).

The above-mentioned fluorescent substance contains at least one selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti instead of Eu or in addition to Eu as desired. You can also
In addition, fluorescent materials other than the above-described fluorescent materials and having the same performance and effect can be used.

  These fluorescent materials can use fluorescent materials having emission spectra in yellow, red, green, and blue by the excitation light of the light-emitting element, and emission spectra in yellow, blue-green, orange, etc., which are intermediate colors between them. Fluorescent materials having can also be used. By using these fluorescent materials in various combinations, surface-mounted light emitting devices having various emission colors can be manufactured.

For example, using a GaN-based compound semiconductor that emits blue light, a Y ₃ Al ₅ O ₁₂ : Ce or (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce fluorescent material is irradiated to convert the wavelength. Do. A surface-mount light-emitting device that emits white light by a mixed color of light from a light-emitting element and light from a fluorescent material can be provided.

For example, CaSi ₂ O ₂ N ₂ : Eu or SrSi ₂ O ₂ N ₂ : Eu that emits light from green to yellow, and (Sr, Ca) ₅ (PO ₄ ) ₃ Cl: Eu that emits blue light as a fluorescent material, By using a fluorescent material 60 composed of Ca ₂ Si ₅ N ₈ : Eu or CaAlSiN ₃ : Eu that emits red light, a surface-mount light-emitting device that emits white light with good color rendering can be provided. . This uses the three primary colors of red, blue, and green, so that the desired white light can be achieved simply by changing the blend ratio of the first and second fluorescent materials. Can do.

(First coating layer 20)
The material of the first coating layer 20 is preferably a material that transmits light emitted from the light emitting element 18 and has excellent heat resistance. For example, resins such as 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 coating layer 20. Further, when a white light emitting device is formed using a fluorescent material, if the fluorescent material is mixed in the first coating layer 20, the fluorescent material can be unevenly distributed in the vicinity of the light emitting element 18, and color unevenness due to the viewing direction. Is preferable.
The viscosity of the first coating 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. Further, the covering member 19 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.

(Second coating layer 21)
The material of the second coating layer 20 is preferably a material that transmits light emitted from the light emitting element 18 and has good releasability. For example, a resin such as epoxy 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 coating layer 20. The viscosity of the first coating 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. Further, the covering member 19 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 second coating layer 21, 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.

  The semiconductor device of the present invention can be used for a device that uses a device that requires extremely thin light-emitting components, such as a backlight of a liquid crystal display.

1 is a schematic front view showing a backlight including a light emitting device according to a first embodiment. 1 is a schematic perspective view showing a backlight including a light emitting device according to a first embodiment. It is a schematic top view which shows the 1st coating layer with which the conventional light-emitting device was equipped. It is a fragmentary sectional perspective view which shows the 1st coating layer with which the conventional light-emitting device was equipped. (A) is a front view of the 1st coating layer with which the conventional light-emitting device was equipped, (B) and (C) are the 1st coating in the delta-delta line from the alpha-alpha line illustrated in (A). It is a graph which shows the height change of a layer. FIG. 3 is a schematic perspective view illustrating a method for manufacturing the multilayer 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. 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 steps formed on the substrate of the light emitting device according to the first embodiment. It is a schematic top 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

  10, 200 Light emitting device, 12, 122 First substrate, 12t Thickness of first substrate, 14, 142 Second substrate, 14t Thickness of second substrate, 15 Laminated substrate, 16 Front electrode, 18 Light emitting element, 19 Covering Member, 20 first covering layer, 21 second covering layer, 22 conducting means, 24 first metal film, 25 second metal film, 26 third metal film, 27 rear electrode, 28 solder, 29 step, 30 mounting substrate, 30a End portion of mounting substrate, 32 Wiring pattern of mounting substrate, 33 Light guide plate, 33a End surface of light guide plate, 34 Through hole, 36 Adhesive layer, 38 Conductive wire, 38t Height of conductive wire, 40 Cut portion of light guide plate, 46 mask, 50 burr, 52 through-hole of second substrate, 270 unremoved portion of rear electrode, 272 removed portion of rear electrode

Claims (7)

A light emitting element;
A laminated substrate having a first substrate on which the light emitting element is placed on the front surface side and a second substrate laminated on the rear surface side of the first substrate;
A front electrode formed on the front surface of the first substrate and electrically connected to the light emitting element;
A rear electrode extending from the rear surface to the side surface of the second substrate;
Conductive means for electrically connecting the front electrode and the rear electrode;
A light-emitting device comprising: the light-emitting element and a covering member that covers the front surface of the first substrate;
The thickness of the first substrate in the stacking direction of the multilayer substrate state, and are more than twice the thickness of the second substrate,
A light-emitting device, wherein the thickness of the multilayer substrate in the stacking direction is 100 μm to 1000 μm .   2. The light emitting device according to claim 1, wherein a thickness of the first substrate is 2 to 5 times a thickness of the second substrate. The front shape of the first substrate and the second substrate is a substantially long rectangle,
The length of the long side of the first substrate of the substantially long rectangle is longer than the length of the long side of the second substrate,
Steps are formed at both longitudinal ends on the rear surface side of the laminated substrate,
The light emitting device according to claim 1, wherein the rear electrode extends from a rear surface side of the second substrate to a side surface in a step direction. The light emitting element and the front electrode are connected by a conductive wire,
The height from the front surface of the first substrate to the top of the conductive wire is 100 μm to 300 μm,
The said covering member is formed by laminating | stacking the 1st coating layer which covers the said light emitting element and the said conductive wire, and the 2nd coating layer which covers the front side of the said 1st coating member. Item 4. The light emitting device according to any one of Items 1 to 3 . The light emitting device according to claim 4 , wherein the first coating layer contains a fluorescent material. The first coating layer is made of silicone resin;
The light emitting device according to claim 4 or 5 wherein the second coating layer is characterized by comprising an epoxy resin. The light emitting device according to any one of claims 1 to 6 ,
A light guide plate that guides light emission to the front side of the light emitting device;
A mounting board for mounting the light emitting device in a horizontal direction,
The light emitting device is mounted such that a front surface of the light emitting device protrudes from an edge of the mounting substrate with reference to a corner on the rear surface side of the first substrate.
The light guide plate is fitted with the front surface of the light emitting device in a cut portion formed on an end surface thereof.
The backlight characterized in that an end portion of the mounting substrate and an end surface of the light guide plate are separated from each other.

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