JP7438326B2 - Light emitting device, manufacturing method thereof, and planar light emitting device - Google Patents

Description

The present invention relates to a light emitting device, a method for manufacturing the same, and a planar light emitting device.

BACKGROUND ART Backlights that emit light in a planar manner are used as light sources for display devices such as liquid crystal displays or lighting devices such as ceiling lights. The backlight is configured as a so-called edge-light type backlight, in which the light emitted by a light emitting device placed on the side of the case is converted into planar light using a light guide plate, and then irradiated from the main surface of the backlight. It is common that

A light source used for a backlight is generally formed by mounting light emitting elements on a collective board made by bonding a mounting board and a circuit board. For example, the LED lighting device described in JP-A-2015-207743 includes an aluminum substrate, a plurality of reflection-enhancing treatment layers provided on the aluminum substrate, and an LED element bonded on the plurality of reflection-enhancement treatment layers. , a printed wiring board adhered to an area other than the area where the plurality of reflective treatment layers are provided on the aluminum substrate, wires connecting the printed wiring board and the LED element, and wires arranged around the LED element. It has a dam material and a phosphor resin disposed in an inner region of the dam material.

In order to improve manufacturing efficiency, light emitting devices for backlights are produced by forming multiple light emitting devices on a single large collective board with a mounting board and a circuit board glued together, and then cutting the collective board. It is common to form a plurality of light emitting devices by separating them into individual pieces. On the other hand, as light emitting devices become smaller, the area of the bonding part that bonds the mounting board and the circuit board becomes smaller, and the distance between the cutting part and the wiring pattern decreases. With the progress of miniaturization of light emitting devices, the area of the adhesive part has become smaller and the distance between the cut part and the wiring pattern has decreased, resulting in peeling between the mounting board and the circuit board and disconnection of the wiring pattern. This may cause a decrease in the manufacturing yield of the light emitting device.

An object of the present disclosure is to provide a light-emitting device that is less likely to cause peeling of the substrate and disconnection of the wiring pattern when cutting a collective substrate to form a plurality of individualized light-emitting devices.

A light emitting device according to the present disclosure includes a mounting board, a circuit board bonded to the surface of the mounting board, and a plurality of light emitting elements mounted in a mounting area that is the front surface of the mounting board, and includes a mounting board and a circuit board. A non-overlapping portion is formed in which the outer edges do not overlap in plan view.

Further, in the light emitting device, it is preferable that the mounting board and the circuit board have a linear planar shape extending in the first direction, and the non-overlapping part is arranged along the side extending in the first direction.

Further, in the light emitting device, it is preferable that the length of the mounting board in the second direction orthogonal to the first direction is longer than the length of the circuit board in the second direction.

Further, in the light emitting device, it is preferable that the length of the mounting board in the second direction orthogonal to the first direction is shorter than the length of the circuit board in the second direction.

Moreover, in the light emitting device, it is preferable that a plurality of non-overlapping parts are arranged on each of a pair of sides extending in the first direction.

Further, in the light emitting device, it is preferable that the non-overlapping portions have a fan-shaped planar shape and are arranged at the four corners of the mounting board.

The light emitting device further includes a metal plate bonded to the back surface of the mounting board, the mounting board is formed of a material having a first coefficient of thermal expansion, and the circuit board is smaller than the first coefficient of thermal expansion. Preferably, the metal plate is formed of a material having a second coefficient of thermal expansion, and the metal plate is formed of a metal having a third coefficient of thermal expansion smaller than the first coefficient of thermal expansion.

In addition, a planar light emitting device includes a case having a light emitting device, a bottom surface, and a side surface that extends upright from an end of the bottom surface and to which the light emitting device is fixed, and a case that receives light emitted from a plurality of light emitting elements. and a light exit surface that outputs the light incident from the light entrance surface, the light entrance surface facing the plurality of light emitting elements, and the surface opposite to the light exit surface facing the bottom surface. an optical sheet placed so as to cover the entire light emitting surface, a first edge placed close to the side surface to which the mounting board is fixed, and an optical sheet placed on the top of the light guide plate. The light guide plate includes a second edge and is arranged between the first edge and the second edge to block direct light emitted from the light emitting device and directed toward the optical sheet. It is preferable to have a light shielding member.

In addition, in the planar light emitting device, the light emitting device further includes a sealing material that seals the plurality of light emitting elements, and the distance in the vertical direction from the plurality of light emitting elements to the light shielding member is H, and the light emitting device is directly above the surface of the sealing material. When the distance from to the second end side is D, it is preferable that H/D is 1.0 or less.

In addition, in the planar light emitting device, the light emitting device further includes a sealing material that seals the plurality of light emitting elements, and the light guide plate is provided on the light entrance surface, and the light guide plate is provided on the light entrance surface to control the light emitting device according to the heat generation of the plurality of light emitting elements. The length of the convex portion of the light guide plate in a non-emission state in which the plurality of light emitting elements are not emitting light is equal to or longer than the light emitting surface separation distance from the light incident surface to the surface of the encapsulant. , and preferably less than or equal to the substrate separation distance from the light incident surface to the substrate of the light emitting device.

A method for manufacturing a light emitting device includes bonding the back side of a circuit board to the front surface of a mounting board to form a collective board, mounting a plurality of light emitting elements on the mounting area, and bonding the outer edge of the mounting board and the circuit board along a first direction. The method includes the step of cutting the collective substrate along the first direction so as to form a plurality of light emitting devices so that a non-overlapping portion in which the light emitting devices do not overlap in plan view is formed.

Further, in the method for manufacturing a light emitting device, the step of forming the collective board includes the step of arranging the plurality of circuit boards on the surface of the mounting board so as to be spaced apart from each other in a second direction perpendicular to the first direction. Preferably, the step of forming the light emitting device includes the step of cutting the collective substrate along the first direction between the plurality of circuit boards.

Further, in the method for manufacturing a light emitting device, it is preferable that the step of forming the plurality of light emitting devices further includes a step of cutting the collective substrate along the second direction between the plurality of circuit boards.

Further, in the method for manufacturing a light emitting device, the step of forming the collective board includes the step of arranging a plurality of mounting boards on the back side of the circuit board so as to be spaced apart from each other in the second direction, and forming a plurality of light emitting devices. Preferably, the step includes cutting the collective substrate along the first direction between the plurality of mounting substrates.

Further, in the method for manufacturing a light emitting device, the circuit board is formed with a plurality of holes arranged in the first direction at predetermined intervals in the second direction, and the step of forming the collective board is performed on the back surface of the circuit board. Preferably, the step of forming a plurality of light emitting devices, including the step of adhering to the surface of the mounting board, includes the step of cutting the collective board and the circuit board along the first direction so as to cut the holes.

According to the present disclosure, there is provided a light emitting device that is less likely to cause peeling of the substrate and disconnection of the wiring pattern when a plurality of individualized light emitting devices are formed by cutting a collective substrate.

FIG. 1 is a perspective view schematically showing a backlight using a light emitting device according to a first embodiment. FIG. 2 is an exploded perspective view of the backlight shown in FIG. 1. FIG. FIG. 1 is a diagram schematically showing the configuration of a light emitting device according to a first embodiment. FIG. 3 is a plan view schematically showing the configuration of a backlight. 5 is a sectional view taken along line CC'' of the backlight shown in FIG. 4. FIG. FIG. 5 is an enlarged cross-sectional view taken along lines CC' and B-B' of the backlight shown in FIG. 4. FIG. It is a figure showing an example of a process of forming a collective board in a manufacturing method of a light emitting device concerning a 1st embodiment. 8 is a sectional view taken along line DD' of the collective substrate shown in FIG. 7. FIG. It is a figure which shows an example of the process of mounting a light emitting element, and the process of dividing into a plurality of light emitting devices. It is a figure which shows an example of the process of forming a collective board|substrate in the manufacturing method of the light emitting device based on 2nd Embodiment. 11 is a sectional view taken along line DD' of the collective substrate shown in FIG. 10. FIG. It is a figure which shows an example of the process of mounting a light emitting element, and the process of dividing into a plurality of light emitting devices. FIG. 7 is a diagram schematically showing the configuration of a light emitting device manufactured using a method for manufacturing a light emitting device according to a second embodiment. FIG. 7 is a diagram showing a collective substrate for manufacturing a light emitting device according to a third embodiment. It is a figure which shows the collective board|substrate for manufacturing the light emitting device based on 4th Embodiment. It is a figure which shows the collective board|substrate for manufacturing the light emitting device based on 5th Embodiment. It is a figure showing the collective board for manufacturing the light emitting device concerning a 6th embodiment. FIG. 7 is an exploded perspective view of a backlight according to a first modification. 19 is an enlarged sectional view of the backlight shown in FIG. 18. FIG. In the backlight shown in FIG. 18, FIG. 19 is a diagram showing simulation results of the amount of luminous flux at the lower surface position of the optical sheet when the amount of light emitted from the light emitting device and the value of the distance H are changed. shows a simulation result when the light emitting device emits light with a brightness of 30,000 (cd/m ² ), and (b) shows a simulation result when the light emitting device emits light with a brightness of 45,000 (cd/m ² ). (c) shows simulation results when the light emitting device emits light with a brightness of 60,000 (cd/m ² ). FIG. 7 is an enlarged sectional view of a backlight according to a second modification. FIG. 7 is an exploded perspective view of a backlight according to a third modification. (a) is a plan view schematically showing the configuration of the backlight shown in FIG. 22, and (b) is an enlarged plan view of a convex portion of the light guide plate shown in FIG. 22. (a) is an enlarged cross-sectional view taken along the line CC' shown in FIG. 22, and (b) is an enlarged cross-sectional view taken along the line B-B' shown in FIG. 23 is an enlarged plan view schematically showing how the convex portion of the light guide plate expands due to heat generation of the light emitting device in the backlight shown in FIG. 22. FIG. (a) is an enlarged sectional view showing how the convex part of the light guide plate shown in FIG. 24(a) is extended, and (b) is an enlarged sectional view showing how the convex part of the light guide plate shown in FIG. 24(b) is extended. It is an enlarged sectional view. It is a figure which shows the stopper part of the light shielding member shown to Fig.24 (a) and 24 (b), and a modification of a light guide plate. It is a top view which shows typically the structure of the backlight based on the 5th modification. 29 is an enlarged cross-sectional view of the backlight shown in FIG. 28 taken along line C-C', and FIG. 29 is an enlarged cross-sectional view of the backlight shown in FIG. 28 taken along line B-B'. (a) is a diagram showing a modified example (part 1) of the light shielding member, and (b) is a diagram showing a modified example (part 2) of the light shielding member. It is a figure which shows the modification (part 3) of a light shielding member. (a) is a sectional view of a light emitting device according to a first modification, and (b) is a bottom view of the light emitting device shown in (a). (a) is a sectional view of a light emitting device according to a second modification, and (b) is a bottom view of the light emitting device shown in (a). (a) is a sectional view of a light emitting device according to a third modification, and (b) is a bottom view of the light emitting device shown in (a). (a) is a sectional view of a light emitting device according to a fourth modification, and (b) is a bottom view of the light emitting device shown in (a). (a) is a cross-sectional view of a light-emitting device according to a fifth modification, and (b) is a cross-sectional view of a light-emitting device according to a sixth modification.

Hereinafter, preferred embodiments of the present disclosure will be described using the drawings. Note that the present invention is not limited to the following embodiments, and can be modified as appropriate without departing from the gist thereof. Further, in each figure, the same reference numerals are used to refer to the same or equivalent functions, and the explanation thereof may be omitted or simplified.

(First embodiment)
FIG. 1 is a perspective view schematically showing a backlight 1 using a light emitting device 2 according to an embodiment. The backlight 1 is a planar light-emitting device that emits light in a planar manner from a light-emitting surface 10 on the case 6 in response to power being supplied via a cable 23 from an external power source (not shown). The backlight 1 is used, for example, as a light source for a display device such as a liquid crystal display or a lighting device such as a ceiling light. Although the backlight 1 has the shape of a flat rectangular parallelepiped extending in a predetermined direction, the shape of the backlight according to the embodiment may be determined as appropriate depending on the application. Further, the shape of the light emitting surface of the backlight according to the embodiment may be determined as appropriate, and may be a polygon of pentagon or more, or a shape other than a rectangle such as an ellipse.

FIG. 2 is an exploded perspective view of the backlight 1. The backlight 1 includes a light emitting device 2, a light guide plate 3, a reflective sheet 4, an optical sheet 5, and an upper case 6a and a lower case 6b that constitute a case 6 that houses these.

The light emitting device 2 is arranged along one inner surface of the lower case 6b so that the longitudinal direction, also called the first direction, coincides with the longitudinal direction of the lower case 6b. The light-emitting device 2 has a light-emitting region 21 in which light-emitting elements such as LEDs (Light-Emitting Diodes) are arranged in the longitudinal direction of a substrate 20 . The light emitting device 2 is supplied with power via a cable 23 and emits light with a luminance of 30,000 (cd/m ² ) or more and 45,000 (cd/m ² ) or less in a linear manner from the light emitting region 21 . When the brightness at the center of the backlight 1 is 100 (cd/m ² ), the total luminous flux of the light emitting device 2 is 1 (lm/mm ² ). The light emitting device 2 is supplied with power via the cable 23 and emits light from the light emitting region 21 . Although the light emitting device 2 has two light emitting regions 21, the light emitting device according to the embodiment may have one or three or more light emitting regions.

The light guide plate 3 has a light output surface 32 that is one main surface and a light input surface 31 that is a side surface facing the light emitting device 2, and is arranged in the lower case 6b so that the light output surface 32 is arranged upward. be done. Light emitted from the light emitting region 21 of the light emitting device 2 enters the light guide plate 3 from the light entrance surface 31. A fine uneven structure is formed on the lower surface of the light guide plate 3 opposite to the light output surface 32, and the light that enters the light guide plate 3 from the light input surface 31 is reflected by the uneven structure formed on the lower surface and passes through the light output surface 32. It is emitted from. The light guide plate 3 is made of, for example, resin such as polycarbonate and acrylic, and a light-transmitting member such as highly light-resistant glass.

The reflective sheet 4 is arranged between the light guide plate 3 and the lower case 6b. The reflective sheet 4 reflects the light incident on the reflective sheet 4 from the lower surface of the light guide plate 3 onto the light guide plate 3, thereby improving the light emitting efficiency of the light emitting device 2. The reflective sheet 4 is formed by depositing or coating a metal with high light reflectance, such as aluminum or silver, on a resin such as nylon, liquid crystal polymer, or polyethylene terephthalate. The surface of the reflective sheet 4 may be coated with a reflective film. Further, as the reflective sheet 4, a white sheet or the like that reflects light may be used.

The optical sheet 5 is composed of one or a combination of a diffusion sheet, a light condensing sheet, and a polarizing sheet, and is arranged so as to cover the light output surface 32 of the light guide plate 3. The light emitted from the light emitting surface 32 of the light guide plate 3 is subjected to various optical effects by the optical sheet 5, and then is irradiated planarly from the opening 61 of the upper case 6a, which becomes the light emitting surface 10 of the backlight 1. Ru.

The diffusion sheet diffuses the light emitted from the light output surface 32 of the light guide plate 3. The diffusion sheet is formed by, for example, dispersing silica particles in a resin such as polycarbonate, polyethylene terephthalate, or acrylic. The light condensing sheet adjusts the light distribution of light emitted from the light emitting surface 32 of the light guide plate 3. The light condensing sheet is, for example, a prism sheet made of resin such as acrylic. The polarizing sheet transmits one of mutually orthogonal polarized components of the light emitted from the light exit surface 32 of the light guide plate 3, and absorbs or reflects the other. The polarizing sheet has a multilayer structure made of, for example, resin. In the optical sheet 5, the arrangement of the diffusion sheet, the condensing sheet, and the polarizing sheet is not limited, and the optical sheet 5 may further include sheets other than the diffusing sheet, the condensing sheet, and the polarizing sheet.

The upper case 6a and the lower case 6b are made of a material with high hardness such as synthetic resin or metal, and house the light emitting device 2, the light guide plate 3, the reflective sheet 4, and the optical sheet 5. The light emitting device 2 is disposed on one side of the lower case 6b, and the reflective sheet 4, the light guide plate 3, and the optical sheet 5 are sequentially stacked on the bottom surface of the lower case 6b so that their outer shapes match. The backlight 1 is formed by further disposing the upper case 6a so as to cover the lower case 6b. The upper case 6a has an opening 61 through which the optical sheet 5 is exposed. Further, the lower case 6b has a pull-out hole 62 at one of the four corners, and the cable 23 connected to the light-emitting device 2 is pulled out to the outside of the backlight 1 through the pull-out hole 62.

The elastic member 7 is made of a highly flexible resin such as silicone, and is formed between the side surface of the lower case 6b facing the side surface on which the light emitting device 2 is disposed, and the side surface of the light guide plate 3 opposite to the light incident surface 31. The light guide plate 3 is placed in between and presses the light guide plate 3 in the direction of the light emitting device 2 . By arranging the elastic member 7, the light emitting device 2 and the light guide plate 3 are elastically fixed within the lower case 6b. The elastic member 7 may be made of a material having a light-shielding property such as black, or may be made of a white material that reflects light. Since the elastic member 7 is made of a white material that reflects light, even if the elastic member 7 and the light guide plate 3 come into contact, a dark area does not occur, and the frame of the backlight 1 can be made narrower.

3(a) is a plan view schematically showing the configuration of the light emitting device 2, and FIG. 3(b) is a sectional view of the light emitting device 2 taken along the line AA' shown in FIG. 3(a). . The light emitting device 2 has a substrate 20 on which a light emitting element 24 such as an LED is mounted.

The board 20 includes a mounting board 20a and a circuit board 20b bonded to the surface of the mounting board 20a. The mounting board 20a and the circuit board 20b have an elongated linear planar shape, but may have a rectangular planar shape such as a square or a rectangle. When the mounting board 20a and the circuit board 20b have a linear planar shape, the longitudinal direction of the mounting board 20a and the circuit board 20b coincides with the longitudinal direction of the light emitting device 2, and the width direction of the mounting board 20a and the circuit board 20b coincides with the longitudinal direction of the light emitting device 2. , coincides with the width direction of the light emitting device 2. The circuit board 20b has an opening 29, the longitudinal direction of the opening 29 coincides with the longitudinal direction of the light emitting device 2, and the width direction of the opening 29 coincides with the width direction of the light emitting device 2.

The mounting board 20a is formed of a material with high thermal conductivity that is mainly composed of metal such as aluminum or copper, or ceramics. The mounting board 20a has a flat surface, and a plurality of light emitting elements 24 are directly arranged on the flat surface of the mounting board 20a exposed to the opening 29 of the circuit board 20b. In the light emitting state in which the plurality of light emitting elements 24 are emitting light, heat generated from the light emitting elements 24 is conducted through the mounting substrate 20a having high thermal conductivity and is efficiently radiated.

The circuit board 20b is made of a second material, which is mainly made of resin such as phenol, epoxy, polyimide, or polyester, and has high insulation properties and has a lower coefficient of thermal expansion than the first material forming the mounting board 20a. It is made of resin, a material with a coefficient of thermal expansion of . A pair of wiring lines 25a and 25b are formed on the surface of the circuit board 20b so as to extend in the longitudinal direction of the circuit board 20b with an interval in the width direction so as to sandwich the opening 29 of the circuit board 20b. Electrodes 22a and 22b are formed at one end of the wirings 25a and 25b in the longitudinal direction. The electrodes 22a and 22b supply power supplied via the cable 23 to the light emitting element 24. The wirings 25a and 25b and the electrodes 22a and 22b are formed by patterning metal such as gold or copper on the circuit board 20b. The wirings 25a and 25b are further covered and protected with a solder resist which is an insulating film.

The length of the mounting board 20a in the lateral direction, which is orthogonal to the longitudinal direction and also referred to as the second direction, is longer than the length of the circuit board 20b in the lateral direction. Since the length of the mounting board 20a in the lateral direction is longer than the length of the circuit board 20b in the lateral direction, the light emitting device 2 has the outer edges of the mounting board 20a and the circuit board 20b on a pair of sides extending in the longitudinal direction. It has a non-overlapping portion 41 that does not overlap in plan view. In the light emitting device 2, the non-overlapping portion 41 is formed so as to extend over the entire pair of sides extending in the longitudinal direction of the light emitting device 2.

The light emitting element 24 is a blue LED die that emits blue light. The light emitting element 24 is adhered by die bonding to the surface of the mounting board 20a exposed through the opening 61 of the circuit board 20b, and the cathode and anode are electrically connected to the wirings 25a and 25b by bonding wires. The plurality of light emitting elements 24 are arranged so that their sides are opposite to each other, but the light emitting elements 24 may be rotated by 45 degrees and arranged so that their vertices are opposite to each other. The plurality of light emitting elements 24 are arranged so that their upper surfaces are parallel to the surface of the mounting board 20a.

The plurality of light emitting elements 24 are electrically connected by bonding wires to form one column. In the light emitting device 2, eight light emitting elements 24 are connected in series in one column, but the number of light emitting elements 24 connected in one column is determined as appropriate depending on the voltage supplied via the cable 23. be done. For example, when eight light emitting elements 24 having a forward voltage of about 3V are connected in series to form one column, a voltage exceeding 24V is supplied. The light emitting elements 24 located at both ends of the column are electrically connected to the wiring 25a or the wiring 25b via bonding wires. The light emitting element 24 emits light when power is supplied through the cable 23, the electrodes 22a and 22b, the wirings 25a and 25b, and the bonding wire. A Zener diode that prevents overvoltage from being applied to the light emitting element 24 is connected between the wiring 25a and the wiring 25b.

The frame body 26 is arranged in an annular or rectangular shape so as to surround the opening 29 of the circuit board 20b. The frame body 26 is made of silicone resin or epoxy resin, for example. The frame body 26 is made of a white resin containing fine particles of titanium oxide or the like that reflect light. The frame body 26 reflects the light emitted from the light emitting element 24, thereby improving the light emitting efficiency of the light emitting device 2.

The sealing material 27 protects the light emitting element 24 by sealing the opening 29 of the mounting board 20 a surrounded by the frame 26 . The area sealed with the sealing material 27 is the light emitting area 21 of the light emitting device 2 . The sealing material 27 is made of a resin such as epoxy or silicon that transmits the light emitted by the light emitting element 24 . The sealing material 27 contains a phosphor that converts the wavelength of the light emitted by the light emitting element 24 into light with a longer wavelength. The phosphor used as the sealant 27 is, for example, a particulate phosphor material such as YAG (Yttrium Aluminum Garnet) that absorbs blue light emitted by the light emitting element 24 and emits yellow light. The blue light emitted by the light emitting element 24 and the yellow light whose wavelength has been converted by the phosphor are mixed to obtain white light. The sealing material 27 may contain a phosphor that converts the wavelength of blue light into light of a color other than yellow light, such as red light or green light, or may not contain a phosphor. Further, in the light emitting device 2, the frame 26 may be removed after the sealing material 27 is formed, and the sealing material 27 may be disposed and the frame 26 may not be disposed.

FIG. 4 is a plan view schematically showing the configuration of the backlight 1. As shown in FIG. 5 is a cross-sectional view of the backlight 1 shown in FIG. 4 taken along line CC''. 6(a) and 6(b) are enlarged cross-sectional views of the backlight 1 shown in FIG. 4 along lines CC' and B-B', respectively.

The light emitting device 2 is arranged along one side of the lower case 6b so that its longitudinal direction coincides with the longitudinal direction of the lower case 6b. The light emitting device 2 is bonded to the side surface of the lower case 6b on the back surface opposite to the light emitting area 21 using an adhesive sheet, adhesive tape, or adhesive. In order to improve positioning accuracy, the light emitting device 2 may be screwed to the lower case 6b, or may be fixed with a pin through a through hole formed in the substrate 20 of the light emitting device 2 or the side surface of the lower case 6b. It's okay.

The light guide plate 3 has a convex portion 33 facing the light emitting device 2 on the light entrance surface 31 . The convex portion 33 of the light guide plate 3 includes a first convex portion and a second convex portion located at both ends of the light incident surface 31 , and a third convex portion located at the center of the light incident surface 31 . The light guide plate 3 is pressed by the elastic member 7, and the convex portion 33 presses the substrate 20 of the light emitting device 2 against the side surface of the lower case 6b. The elastic members 7 are arranged on the side surfaces of the light guide plate 3 opposite to where the convex portions 33 are provided, so that the pressing force of the elastic members 7 is applied to the substrate 20 of the light emitting device 2 via the convex portions 33. is applied efficiently.

The convex portion 33 of the light guide plate 3 is provided on the light incident surface 31 of the light guide plate 3 so as to come into contact with the light emitting device 2 in a non-light emitting area that is an area other than the light emitting area 21, so that the convex part 33 is provided around the light emitting area 21. The frame body 26 and the sealing material 27 arranged are prevented from coming into contact with the convex portion 33 and being damaged.

FIG. 7 is a diagram showing an example of the process of forming the collective substrate 20c in the method for manufacturing the light emitting device 2 according to the first embodiment. Further, FIG. 8 is a cross-sectional view of the collective substrate 20c taken along the line D-D'.

A plurality of circuit boards 20b each having an opening 29 having a longitudinal direction in the first direction d1 and having a shape extending in the first direction d1 are bonded to one mounting board 20a, and FIGS. A collective substrate 20c having a rectangular planar shape shown in 8 is formed. In the step of forming the collective board 20c, the plurality of circuit boards 20b are arranged side by side on the mounting board 20a with a predetermined arrangement width d in a second direction d2 orthogonal to the first direction d1, and are mounted via the adhesive layer 200. It is bonded to the substrate 20a. For example, an adhesive sheet, an adhesive tape, or an adhesive is used as the adhesive layer 200. However, by using molecular bonding and diffusion bonding techniques, the plurality of circuit boards 20b can be bonded to the mounting board 20a without using the adhesive layer 200. may be done. The arrangement width d is, for example, less than 10 (mm). The arrangement width d is set to less than 10 (mm) because the width in the second direction d2 of the CL-L104 series manufactured by Citizen Electronics Co., Ltd. is 7 (mm) and the cutting width is approximately 3 (mm). It was done.

9(a) to 9(c) are diagrams illustrating an example of the process of mounting the light emitting element 24 and the process of singulating it into a plurality of light emitting devices 2. Similar to FIG. 8, FIGS. 9(a) to 9(c) are cross-sectional views of the collective substrate 20c shown in FIG. 7 taken along the line D-D'.

First, as shown in FIG. 9(a), the light emitting element 24 is mounted in a mounting area that is the surface of the mounting board 20a exposed through the opening 29 of the circuit board 20b. In the process of mounting the light emitting element 24, the light emitting element 24 is first adhered onto the surface of the mounting substrate 20a by die bonding. Then, the cathode and anode of the light emitting element 24 are electrically connected by wire bonding to wirings 25a and 25b formed on the surface of the circuit board 20b opposite to the mounting board 20a. When the light emitting element 24 is flip-connected, the light emitting element 24 is electrically connected to the wirings 25a and 25b via the connecting portion provided on the circuit board 20b.

Next, as shown in FIG. 9B, a frame 26 is formed to surround the opening 29 of the circuit board 20b, and the area surrounded by the frame 26 is sealed with a sealant 27. Then, by moving the cutting means in the first direction d1 along the cutting line, the aggregate substrate 20c is cut, and has a pair of cutting sides extending in the first direction d1, as shown in FIG. 9(c). The light emitting devices 2 are individually divided into a plurality of light emitting devices 2. The cutting means may be, for example, scissors or a cutter that cuts the collective substrate 20c by applying shear stress so as to shift the collective substrate 20c vertically using the cutting line as a boundary. Further, the cutting means may be a rotary polishing device or a saw that cuts the collective substrate 20c by scraping the collective substrate 20c along the cutting line. Further, the cutting means may cut the collective substrate 20c by irradiating a laser along a cutting line in the first direction d1, or apply bending stress in a second direction d2 perpendicular to the cutting line to cut the collective substrate 20c. The aggregate substrate 20c may be cut by bending the .

If the mounting board 20a made of a material whose main component is metal and the circuit board 20b made of a material whose main component is resin are cut at the same time, there is a risk that the mounting board 20a and the circuit board 20b will separate from each other due to the stress applied during cutting. There is. Further, there is a possibility that the cut surface of the collective board 20c may be deformed due to the heat generated by the laser irradiation, and the mounting board 20a and the circuit board 20b may be separated from each other. In particular, when the arrangement width d of the circuit board 20b is less than 10 (mm) and the light emitting device 2 has an elongated linear shape, the area of the adhesive layer 200 becomes small, so that the mounting board 20a and the circuit board 20b It is easy to separate between the two. When stress is applied to the circuit board 20b, there is a risk that the bonding wires connecting the wirings 25a and 25b formed on the circuit board 20b and the light emitting element 24 will be disconnected. In the experiment, when the length of the adhesive layer 200 in the first direction d1 was 25 (mm) or more and the length of the adhesive layer 200 in the second direction d2 was 2.55 (mm), the mounting board was cut by cutting. Peeling occurred between the circuit board 20a and the circuit board 20b. If the length in the second direction d2 is at least 2.55 (mm) or less, there is a possibility that separation may occur between the mounting board 20a and the circuit board 20b.

In the manufacturing method according to the present embodiment, in the process of cutting the collective board 20c into individual pieces into a plurality of light emitting devices 2, the mounting board 20a is cut in the area between adjacent circuit boards 20b where the circuit boards 20b are not bonded. disconnected. By cutting the mounting board 20a in the area where the circuit board 20b is not bonded, when the plurality of light emitting devices 2 are separated into pieces, separation between the mounting board 20a and the circuit board 20b, and wiring patterns and bonding are avoided. Wire breakage is prevented. Note that although the mounting board 20a and the circuit board 20b shown in FIG. Similar effects can be obtained even when the plate has a rectangular planar shape.

Further, when the mounting board 20a has a laminated structure, the mounting board 20a may be cut in several steps for each layer. For example, when the mounting board 20a has a two-layer structure, the second layer of the two-layer structure may be cut after the first layer of the two-layer structure is cut. Further, the first layer and the second layer of the mounting board 20a may be cut simultaneously from opposite directions. By simultaneously cutting the first layer and the second layer of the mounting board 20a from opposite directions, when cutting the collective board 20c into individual pieces into a plurality of light emitting devices 2, the laminated layers constituting the mounting board 20a are cut. Delamination between the layers of the structure is prevented.

As shown in FIG. 3(b), the light emitting device 2 manufactured using the collective board 20c has a mounting board 20a and a circuit board 20b in a cross section taken along line AA' in the width direction of the light emitting device 2. The end position is different between and. The end positions are the positions of the mounting board 20a and the circuit board 20b when the mounting board 20a and the circuit board 20b are viewed from above. In particular, in the light emitting device 2 manufactured using the manufacturing method according to this embodiment, the length of the mounting board 20a in the width direction is longer than the length of the circuit board 20b in the width direction.

(Second embodiment)
FIG. 10 is a diagram showing an example of the process of forming the collective substrate 20d in the method of manufacturing the light emitting device 2a according to the second embodiment, and FIG. 11 is a diagram showing an example of the process of forming the collective substrate 20d shown in FIG. FIG.

A plurality of mounting boards 20a1 extending in the first direction d1 are bonded to a single circuit board 20b1 in which a plurality of openings 29 having a longitudinal direction in the first direction d1 are formed spaced apart from each other in the second direction d2. Thus, one rectangular collective substrate 20d is formed. In the step of forming the collective board 20d, the plurality of mounting boards 20a1 are arranged side by side on the circuit board 20b1 with a predetermined arrangement width d in a second direction d2 orthogonal to the first direction d1, and the circuit board 20a1 is arranged with a predetermined arrangement width d on the circuit board 20b1. It is bonded to the substrate 20b. As the adhesive layer 200, for example, an adhesive sheet, an adhesive tape, an adhesive, or the like is used. The arrangement width d is, for example, less than 10 (mm).

FIGS. 12(a) to 12(c) are diagrams showing an example of the process of mounting the light emitting element 24 and the process of singulating it into a plurality of light emitting devices 2a. 12(a) to 12(c) are cross-sectional views taken along the line DD' shown in FIG. 10, similar to FIG. 11. The steps shown in FIGS. 12(a) to 12(c) are the same as the steps shown in FIGS. 9(a) to 9(c) except that the shape of the collective substrate 20d is different. - Points different from the process shown in FIG. 9(c) will be explained.

In the steps shown in FIGS. 12(a) to 12(c), the mounting boards 20a1 between adjacent mounting boards 20a1 are not bonded together in the step of cutting the collective board 20d into individual pieces into a plurality of light emitting devices 2. The circuit board 20b1 is cut in the area. The method of manufacturing the light emitting device 2 shown in FIGS. 12(a) to 12(c) also provides the same effects as the method of manufacturing the light emitting device 2 shown in FIGS. 9(a) to 9(c).

FIG. 13(a) is a plan view schematically showing the configuration of a light emitting device 2a manufactured using the method for manufacturing a light emitting device 2 according to the second embodiment, and FIG. FIG. 3 is a cross-sectional view of the light emitting device 2 shown in a) taken along line AA'.

Similar to the light emitting device 2 shown in FIG. 3(b), the light emitting device 2a manufactured using the collective substrate 20d has a cross section along the line AA' in the width direction of the light emitting device 2a. The end position is different between the circuit board 20b1 and the circuit board 20b1. In the light emitting device 2 manufactured using the manufacturing method according to this embodiment, the length of the mounting board 20a in the width direction is shorter than the length of the circuit board 20b1 in the width direction.

The length of the mounting board 20a1 in the lateral direction is shorter than the length of the circuit board 20b1 in the lateral direction. Since the length of the mounting board 20a1 in the lateral direction is shorter than the length of the circuit board 20b1 in the lateral direction, the light emitting device 2a has the outer edges of the mounting board 20a and the circuit board 20b on a pair of sides extending in the longitudinal direction. It has a non-overlapping portion 42 that does not overlap in plan view. The non-overlapping portion 42 is formed to extend over the entire pair of sides extending in the longitudinal direction of the light emitting device 2a.

(Third embodiment)
FIG. 14 is a diagram showing a collective substrate 20e for manufacturing a light emitting device 2b according to the third embodiment. FIG. 14 shows a plan view and a cross-sectional view of the collective substrate 20e along line DD', respectively. The collective board 20e shown in FIG. 14 differs from the collective board 20c in that one circuit board 20b2 is bonded to one mounting board 20a2. The other configurations of the collective board 20e are similar to the collective board 20c, so the points that are different from the collective board 20c will be described.

The collective board 20e is formed by bonding one circuit board 20b2 in which a plurality of openings 29 are formed to one mounting board 20a2. A hole 28 having an elongated linear planar shape is formed in the circuit board 20b2 along the cutting line S1. The holes 28 do not need to be formed in the form of perforations at regular intervals, but only need to be formed on at least a portion of the cutting line S1 in the first direction d1. The width of the hole 28 in the second direction d2 is, for example, 3 (mm).

In the method for manufacturing the light emitting device 2 according to the first embodiment shown in FIGS. 9(a) to 9(c), even when the light emitting device according to the embodiment is manufactured using the collective substrate 20e instead of the collective substrate 20c. , the same effects as in the first embodiment can be obtained. Since the hole 28 is formed in the circuit board 20b2 along the cutting line S1, the distance between the mounting board 20a2 and the circuit board is smaller than when cutting a collective board in which circuit boards are arranged over the entire surface of the mounting board. 20b2 is prevented from peeling off. Furthermore, since the collective board 20e is formed from one mounting board 20a2 and one circuit board 20b2, compared to the case where the collective board 20c is formed from one mounting board 20a and a plurality of circuit boards 20b, , the process of forming the collective substrate 20e is simplified.

In the light emitting device 2b manufactured using the collective board 20e, the end position of the mounting board 20a2 is different from the end position of the circuit board 20b2 at a part of the cut side S1 of the mounting board 20a2. The plurality of non-overlapping parts 43 are formed in a portion where the end position of the mounting board 20a2 is different from the end position of the circuit board 20b2. The plurality of non-overlapping parts 43 are arranged along a pair of sides extending in the longitudinal direction of the light emitting device 2b. The plurality of non-overlapping portions 43 are arranged in a portion where the end position of the mounting board 20a3 is different from the end position of the circuit board 20b3. The non-overlapping portion 43 is arranged along each of a pair of sides extending in the longitudinal direction of the light emitting device 2b.

(Fourth embodiment)
FIG. 15 is a diagram showing a collective substrate 20f for manufacturing a light emitting device 2c according to the fourth embodiment. FIG. 15 shows a plan view and a cross-sectional view of the collective substrate 20f along line DD', respectively. The collective board 20f differs from the collective board 20e in that the hole 28a formed in the circuit board 20b extends long and thin from near one end to near the other end in the first direction d1 of the collective board 20f. The other configuration of the collective board 20f is the same as that of the collective board 20e, so the points that are different from the collective board 20e will be explained.

The collective board 20f, like the collective board 20e, is formed by bonding a single circuit board 20b3 in which a plurality of openings 29 and holes 28a are formed to a single mounting board 20a3. In the circuit board 20b3, a plurality of circuit parts each having an opening 29 extending in the first direction d1 and wires 25a and 25b are connected to each other at both ends of the circuit part in the first direction d1.

In the method for manufacturing the light emitting device 2 according to the first embodiment shown in FIGS. Effects similar to those of the embodiment can be obtained. Since the hole 28a shown in FIG. 15 is formed continuously from near one end of the circuit board 20b3 to near the other end, it can be used not only when cutting the collective board 20f along the cutting line S1, but also when cutting the collective board 20f in the second direction d2 orthogonal to the cutting line S1. Even when cutting the collective substrate 20f along the cutting line S2, cutting becomes easy. For example, when cutting the end of the circuit board 20b3 that is not a circuit part along the cutting line S2 in the second direction d2 in order to align the end positions of the collective board 20f, the peeling of the collective board 20f and the wiring pattern And disconnection of the bonding wire is suppressed. The aggregate substrate 20f may be cut along the cutting line S1 and then along the cutting line S2, or may be cut along the cutting line S2 and then cut along the cutting line S1.

In the light emitting device 2c according to the embodiment manufactured using the collective board 20f, the end position of the mounting board 20a3 is the same as the end position of the circuit board 20b3 at the cut side S1 of the mounting board 20a3 along the first direction d1. different. On the other hand, in the light emitting device 2c manufactured using the collective board 20f, the edge position of the mounting board 20a3 is located at the circuit at the cut side S2 along the second direction d2 orthogonal to the first direction d1 of the mounting board 20a3. This is the same as the end position of the substrate 20b3. The plurality of non-overlapping parts 44 are arranged in a portion where the end position of the mounting board 20a3 is different from the end position of the circuit board 20b3. The non-overlapping portion 44 is arranged along each of a pair of sides extending in the longitudinal direction of the light emitting device 2c.

(Fifth embodiment)
FIG. 16 is a diagram showing a collective substrate 20g for manufacturing a light emitting device 2d according to the fifth embodiment. FIG. 16 shows a plan view of the collective substrate 20g and a cross-sectional view thereof taken along line DD'. The collective board 20g differs from the collective board 20c in that a plurality of circuit boards 20b4 are arranged side by side in both the first direction d1 and the second direction d2, which are orthogonal to each other. The other configurations of the collective board 20g are similar to the collective board 20c, so the points that are different from the collective board 20c will be described.

In the collective board 20g shown in FIG. 16, a plurality of circuit boards 20b4 each having an opening 29 are arranged side by side in both the first direction d1 and the second direction d2, which are orthogonal to each other, on a single mounting board 20a. It is formed by

In the method for manufacturing the light emitting device 2 according to the first embodiment shown in FIGS. 9(a) to 9(c), even when the light emitting device 2d is manufactured using the collective substrate 20g instead of the collective substrate 20c, the The same effects as in the first embodiment can be obtained. The collective substrate 20g is first cut along the cutting line S1 in the first direction d1, as shown in FIG. 9(b). Then, the collective substrate 20g is further cut along the cutting line S2 in the second direction d2, and is separated into a plurality of light emitting devices 2d. Even when the collective substrate 20g is cut along both the first direction d1 and the second direction d2, which are orthogonal to each other, into a plurality of light emitting devices 2d, peeling of the collective substrate 20g and disconnection of wiring patterns and bonding wires will occur. is prevented.

The light emitting device 2d manufactured using the collective board 20g has an edge position of the mounting board 20a4 on both the cut side S1 along the first direction d1 and the cut side S2 along the second direction d2 of the mounting board 20a4. is different from the end position of the circuit board 20b4. The plurality of non-overlapping portions 45 are arranged in a portion where the end position of the mounting board 20a4 is different from the end position of the circuit board 20b4. The non-overlapping portion 45 is arranged along each of a pair of sides extending in the longitudinal direction of the light emitting device 2d.

(Sixth embodiment)
FIG. 17 is a diagram showing a collective substrate 20h for manufacturing a light emitting device 2e according to the sixth embodiment. FIG. 17 shows a plan view of the collective substrate 20h and a cross-sectional view of the collective substrate 20h along line DD'. The collective board 20h shown in FIG. 17 differs from the collective board 20e in that a plurality of circuit boards 20b5 are arranged side by side in both the first direction d1 and the second direction d2, which are orthogonal to each other, and the holes 28b are circular. They differ in that they are shaped or arcuate. The other configuration of the collective board 20h is the same as that of the collective board 20e, so the points that are different from the collective board 20e will be described.

The collective board 20h is formed by bonding one circuit board 20b5 in which a plurality of openings 29 are formed to one mounting board 20a5. The circuit board 20b5 has a circular hole 28b or an arcuate notch 28c in the intersection area of the cutting line S1 along the first direction d1 and the cutting line S2 along the second direction d2. The diameter of the circular hole 28b and the arc-shaped notch 28c is, for example, 3 (mm).

In the method for manufacturing the light emitting device 2 according to the first embodiment shown in FIGS. 9(a) to 9(c), even when the light emitting device 2e is manufactured using the collective substrate 20h instead of the collective substrate 20c, the The same effects as in the first embodiment can be obtained. The collective substrate 20h is first cut along the cutting line S1 in the first direction d1, as shown in FIG. 9(b). Then, the collective substrate 20h is further cut along the cutting line S2 in the second direction d2, and is separated into a plurality of light emitting devices 2e. Even when the collective substrate 20h is cut along both the first direction d1 and the second direction d2, which are orthogonal to each other, into a plurality of light emitting devices 2e, peeling of the collective substrate 20h and disconnection of wiring patterns and bonding wires will occur. is prevented. Furthermore, since the circuit board 20b5 has holes 28b or cutouts 28c formed along the cutting lines S1 and S2, it is easier to cut than when cutting a collective board in which circuit boards are arranged over the entire surface of the mounting board. Thus, separation between the mounting board 20a5 and the circuit board 20b5 is prevented. In particular, since the hole 28b or notch 28c is formed in the intersection area of the cutting line S1 and the cutting line S2, when cutting the collective substrate 20h along the cutting line S1, and when cutting the collective substrate 20h along the cutting line S2, The effect can be obtained both when cutting along. Furthermore, since the collective board 20h is formed of one mounting board 20a5 and one circuit board 20b5, compared to the case where the collective board 20c is formed of one mounting board 20a and a plurality of circuit boards 20b, , the process of forming the collective substrate 20h is simplified.

In the light emitting device 2e according to the embodiment manufactured using the collective substrate 20h, the outer edge of the circuit board 20b5 is in the intersection area of the cut side S1 along the first direction d1 and the cut side S2 along the second direction d2. It has an arcuate planar shape. In the light emitting device according to the embodiment manufactured using the collective board 20h, the end position of the mounting board 20a5 is different from the end position of the circuit board 20b5 in the intersection area. The plurality of non-overlapping parts 46 have a fan-shaped planar shape, and are arranged in a portion where the end position of the mounting board 20a5 is different from the end position of the circuit board 20b5. The two non-overlapping parts 46 are arranged at the four corners of the mounting board 20a5.

As described above, the light emitting device according to the embodiment is capable of emitting light that can prevent peeling of the substrate and disconnection of the wiring pattern and bonding wire when cutting the collective substrate into a plurality of individual light emitting devices. A method of manufacturing a device is provided.

(Modified example)
FIG. 18 is an exploded perspective view of the backlight 1a according to the first modification.

The backlight 1 a differs from the backlight 1 in that it includes a light shielding member 8 . The configurations and functions of the components of the backlight 1a other than the light shielding member 8 are the same as those of the components of the backlight 1 with the same reference numerals, so detailed explanations will be omitted here.

The light shielding member 8 has a first end 8a arranged on the side surface of the lower case 6b and a second end 8b arranged above the light guide plate 3. The light blocking member 8 is provided between the light guide plate 3 and the optical sheet 5 so as to block direct light emitted from the light emitting device 2 and directed toward the optical sheet between the first end side 8a and the second end side 8b. Placed. By arranging the light shielding member 8, the optical sheet 5 is prevented from discoloring and deteriorating due to direct light that directly enters the optical sheet 5 from the light emitting device 2.

FIG. 19 is an enlarged sectional view of the backlight 1a. FIG. 19 is an enlarged sectional view corresponding to the enlarged sectional view taken along line C-C' of the backlight 1 shown in FIG.

The light shielding member 8 is arranged between the light guide plate 3 and the optical sheet 5 so as to cover a part of the upper part of the light guide plate 3. The light shielding member 8 is a rectangular sheet-like member having a first end 8a on the light emitting device 2 side and a second end 8b on the light guide plate 3 side. Further, the light shielding member 8 has a light shielding surface 8c on the light guide plate 3 side. The light shielding surface 8c is formed by printing (gradation) with ink or the like that does not allow light to pass through.

The first end side 8a of the light shielding member 8 is located near right above the end surface of the lower case 6b. Since the light emitted from the light emitting element 24 is blocked by the frame 26 of the light emitting device 2, the first end 8a of the light blocking member 8 is disposed at least directly above the top of the frame 26 toward the lower case 6b side. It is preferable that For example, the first end side 8a of the light shielding member 8 is arranged directly above the side surface of the mounting board 20a of the light emitting device 2.

The light shielding surface 8c of the light shielding member 8 allows direct light 9a emitted from the light emitting device 2 to directly reach the optical sheet 5 at a position 9a' without passing through the light guide plate 3, and direct light 9a that passes through the light guide plate 3 at a position 9b'. The light 9b reaching the optical sheet 5 is blocked. The light 9c emitted from the light emitting device 2 enters the optical sheet 5 through a position 9c' without being blocked by the light blocking surface 8c.

The light shielding member 8 is sandwiched and disposed between the light guide plate 3 and the optical sheet 5. The light shielding member 8 is positioned at a predetermined position by fitting the upper case 6a into the lower case 6b from above. However, the light shielding member 8 is positioned with high precision by being adhered to the end surface of the lower case 6b with an adhesive tape. Further, the light shielding member 8 may be resin molded integrally with the lower case 6b. Furthermore, when the lower case 6b is formed of a metal material, it may be bent and formed by press working. Further, the light shielding member 8 may be adhered to the side surface of the mounting board 20a of the light emitting device 2 with an adhesive tape.

The light shielding surface 8c of the light shielding member 8 may be a reflective surface that reflects the light incident from the light emitting device 2 onto the light guide plate 3. When the light shielding surface 8c is a reflective surface, the light emitted from the light emitting device 2 is reused, so that the light emitting efficiency of the backlight 1a is improved.

The distance from the surface of the sealing material 27 directly above the light emitting element 24 to the second end side 8b of the light shielding member 8 is D (mm), and the vertical distance from the center position of the light emitting element 24 to the light shielding member 8 is H (mm). In FIG. 19, the light guide plate 3 is arranged with a gap formed between the optical sheet 5 and the lower case 6b, but the light guide plate 3 is arranged without a gap formed between the optical sheet 5 and the lower case 6b. Therefore, the distance H is approximately equal to 1/2 of the thickness of the light guide plate 3.

FIG. 20 shows the amount of luminous flux (( It is a figure showing the simulation result of lm). The simulation was performed using Lighttools manufactured by SYNOPSYS. Further, in the simulation, the light distribution of the light emitting device 2 is Lambertian light distribution, and the luminance is 30,000 (cd/m ² ), 45,000 (cd/m ² ), and 60,000 (cd/m ² ). Furthermore, in the simulation, the distance H is 0.7 (mm), 1.0 (mm), 1.25 (mm), 1.5 (mm), 1.6 (mm), 1.75 (mm). , 2.0 (mm) and 3.0 (mm), and the light guide plate 3 has a thickness twice the distance H.

FIG. 20(a) shows simulation results when the light emitting device 2 emits light with a brightness of 30,000 (cd/m ² ). FIG. 20(b) shows simulation results when the light emitting device 2 emits light with a brightness of 45,000 (cd/m ² ). FIG. 20(c) shows simulation results when the light emitting device 2 emits light with a brightness of 60,000 (cd/m ² ). In FIGS. 20(a) to 20(c), the horizontal axis is the distance D (mm), and the vertical axis is the amount of luminous flux (lm) at the lower surface position of the optical sheet 5. Further, the distances H of curves 40a to 40h are 0.7 (mm), 1.0 (mm), 1.25 (mm), 1.5 (mm), 1.6 (mm), and 1, respectively. The amount of luminous flux is shown when the diameter is .75 (mm), 2.0 (mm), and 3.0 (mm).

When the amount of light flux received by the optical sheet 5 exceeds 0.012 (lm), the optical sheet 5, especially the polarizing sheet included in the optical sheet 5, may deteriorate over time. The thickness of the light guide plate 3 and the position of the second end side 8b of the light shielding member 8 are selected so that the amount of light flux received by the optical sheet 5 does not exceed 0.012 (lm). 5 is prevented from deteriorating.

Table 1 shows the minimum H/D when the amount of luminous flux of light incident on the optical sheet 5 is less than 0.012 (lm), calculated from the simulation results shown in FIG. 20. In Table 1, the distance H (mm) is 0.7 (mm), 1.0 (mm), 1.25 (mm), 1.5 (mm), 1.6 (mm), 1.75 (mm). ), 2.0 (mm) and 3.0 (mm). Further, the brightness of the light emitted from the light emitting device 2 is 30,000 (cd/m ² ), 45,000 (cd/m ² ), and 60,000 (cd/m ² ).

When the luminance of the light emitted from the light emitting device 2 is 30,000 (cd/m ² ) or more and 60,000 (cd/m ² ) or less, when the value of H/D is 1.0, the light is incident on the optical sheet 5. The amount of luminous flux of the light is less than 0.012 (lm). By selecting the thickness of the light guide plate 3 and the position of the second end side 8b of the light shielding member 8 so that the value of H/D is 1.0 or less, deterioration of the optical sheet 5 over time is prevented.

FIG. 21 is an enlarged sectional view of a backlight 1b according to a second modification. FIG. 21 is an enlarged sectional view corresponding to the enlarged sectional view taken along line C-C' of the backlight 1 shown in FIG.

The backlight 1b differs from the backlight 1a in that it further includes a light-transmitting member 9 disposed on the surface of the light-shielding member 8 on the light-emitting device 2 side. The configurations and functions of the components of the backlight 1b other than the transparent member 9 are the same as those of the backlight 1a with the same reference numerals, so detailed explanations will be omitted here.

The light-transmitting member 9 is colorless and transparent, unlike polyimide which has a yellow or reddish-brown color. By disposing the light-transmitting member 9 on the surface of the light-shielding member 8 on the light-emitting device 2 side, loss of light incident on the light-shielding surface 8c of the light-shielding member 8 can be reduced.

FIG. 22 is an exploded perspective view of a backlight 1c according to a third modification. 23(a) is a plan view schematically showing the configuration of the backlight 1c, and FIG. 23(b) is an enlarged plan view of the convex portion 33 of the light guide plate 3. 24(a) and 24(b) are enlarged cross-sectional views of the backlight 1c along lines CC' and B-B' shown in FIG. 23(a).

The backlight 1c differs from the backlight 1a in that it has light shielding members 81 and 82 instead of the light shielding member 8. The configurations and functions of the components of the backlight 1c other than the light shielding members 81 and 82 are the same as those of the backlight 1a with the same reference numerals, so detailed explanations will be omitted here.

Like the light blocking member 8, the light blocking members 81 and 82 have light blocking surfaces facing the light emitting device 2, and block direct light emitted from the light emitting device 2 to the optical sheet 5. The light blocking members 81 and 82 block direct light emitted from the light emitting region 21 of the light emitting device 2 to the optical sheet 5 only above the light emitting region 21 of the light emitting device 2. Since the light-shielding members 81 and 82 block light only above the light-emitting region 21, light is not blocked above the non-light-emitting region outside the light-emitting region 21 of the light-emitting device 2, so that the light-emitting device 2 becomes dark in the non-light-emitting region. is suppressed.

The light shielding members 81 and 82 have a stopper portion 83 that is one end facing the light incident surface 31 of the light guide plate 3 . The stopper portion 83 functions as a stopper that faces toward the light entrance surface 31 or comes into contact with the light entrance surface 31 to prevent the light guide plate 3 from approaching the light emitting region 21 of the light emitting device 2 . By the stopper portion 83 functioning as a stopper, a substrate separation distance of at least the first distance d1 is ensured between the light incident surface 31 of the light guide plate 3 and the substrate 20 of the light emitting device 2. At least a light emitting surface separation distance a1 is ensured between the light incident surface 31 of the light guide plate 3 and the surface of the light emitting region 21 of the light emitting device 2, so that the light guide plate 3 is not deteriorated by heat or light emitted by the light emitting device 2. This will be prevented. The stopper portion 83 of the light shielding member 8 does not necessarily need to be in constant contact with the light guide plate 3, and a gap may temporarily occur between the stopper portion 83 and the light guide plate 3.

For example, the first distance d1 prevents the light guide plate 3 from deteriorating due to heat generated by the light emitting device 2 until a predetermined first period t1 (for example, 1 minute) has elapsed after the light emitting device 2 enters the light emitting state. The minimum value of the substrate separation distance is determined in advance by actual measurement or the like. Further, the first distance d1 prevents the light guide plate 3 from deteriorating due to heat generated by the light emitting device 2 when the temperature of the light guide plate 3 is lower than a predetermined first temperature T1 (for example, 85 (°C)). The minimum value of the substrate separation distance may be determined in advance by actual measurement or the like.

FIG. 25 is an enlarged plan view schematically showing how the convex portion 33 of the light guide plate 3 expands due to heat generated by the light emitting device 2. As shown in FIG. Moreover, FIGS. 26(a) and 26(b) are enlarged cross-sectional views showing the extended state of the convex portion 33 of the light guide plate 3 shown in FIGS. 24(a) and 24(b), respectively.

When power is supplied to the light emitting device 2 and the light emitting element 24 enters a light emitting state, the temperature of the convex portion 33 of the light guide plate 3 increases due to heat or light emitted by the light emitting device 2. The convex portion 33 of the light guide plate 3 expands to length x2 due to the heat generated by the light emitting device 2 as the temperature rises. While the convex portion 33 expands, the elastic member 7 contracts in accordance with the expansion of the convex portion 33, so that the light guide plate 3 as a whole is displaced within the lower case 6b away from the light emitting device 2.

The substrate separation distance from the light incident surface 31 of the light guide plate 3 to the substrate 20 of the light emitting device 2 is maintained at a second distance d2 or more, which is larger than the first distance d1, in the light emitting state of the light emitting device 2. For example, even if a predetermined first period t1 has elapsed since the light emitting device 2 entered the light emitting state, or even if the temperature of the light guide plate 3 exceeds the predetermined first temperature T1, due to the heat generated by the light emitting device 2, Deterioration of the light guide plate 3 is suppressed.

Difference Δx between the length x1 of the convex portion 33 when the temperature is T0 in the non-emission state of the light emitting device 2 and the length x2 of the convex portion 33 when the temperature is T2 in the light emitting state of the light emitting device 2 = (x2 -x1) is determined by equation (1) using the linear expansion coefficient α of the convex portion 33.
Δx=α(x1)(T2-T0) (1)

In order for the substrate separation distance to increase when a predetermined first period t1 has elapsed after the light emitting device 2 enters the light emitting state, or when the temperature of the light guide plate 3 reaches a predetermined first temperature T1 or higher, , it is preferable that the linear expansion coefficient α of the convex portion 33 is large. The convex portion 33 is preferably made of a material whose main component is a resin such as polycarbonate having a coefficient of linear expansion α of 50×10 ⁻⁶ (1/K) or more. In addition, when the glass transition temperature of about 85 (° C.) is exceeded, the linear expansion coefficient α increases and the elongation of the protrusions 33 becomes more noticeable. It may also be used as a material.

However, when a special material is used for the convex portion 33, the cost of the backlight 1c increases. Even when a general resin such as polycarbonate is used as the convex part 33, the tip of the convex part 33 is close to or in contact with the light emitting device 2 when the light emitting device 2 is in a light emitting state so that the distance between the substrates is large. It is preferable. The length of the convex portion 33 of the light guide plate 3 in the non-light emitting state is equal to or more than the light emitting surface separation distance a1 from the light entrance surface 31 to the surface of the light emitting region 21, and the distance from the light entrance surface 31 to the substrate 20 of the light emitting device 2. The distance is adjusted to be equal to or less than the substrate separation distance. The surface of the light emitting region 21 is, for example, the highest surface of the frame 26 and the surface passing through the closest position to the light guide plate 3.

For example, by the stopper portions 83 of the light shielding members 81 and 82, the substrate separation distance from the light incident surface 31 of the light guide plate 3 to the substrate 20 of the light emitting device 2 is reduced to the first distance d1 = 5.00 (mm) in the non-emission state. When the convex portion 33 is held in a non-emitting state, the length x1 of the convex portion 33 is 4.99 (mm). The length x1 of the convex portion 33 is adjusted so as to satisfy the above-mentioned conditions of the light emitting surface separation distance a1 (for example, 4.90 (mm)) or more and the substrate separation distance (5.00 (mm)) or less. The gap between the tip of the convex portion 33 and the substrate 20 of the light emitting device 2 is 0.01 (mm). When the length of the protrusion 33 increases by 0.01 (mm) to 5.00 (mm) due to the heat generated by the light emitting device 2 , the tip of the protrusion 33 comes into contact with the contact area of the substrate 20 . When the length of the convex portion 33 increases by 0.01 (mm) to x2 = 5.01 (mm), the substrate separation distance also increases due to the expansion of the convex portion 33, and the second distance becomes larger than the first distance d1. d2 is maintained at 5.01 (mm) or more.

The extension width (Δx=0.02 (mm)) of the convex portion 33 is, for example, in equation (1), the linear expansion coefficient α=50×10 ^-6 (1/K), and the expansion width of the convex portion 33 in the non-emission state. This is achieved when length x1≈5.00 (mm) and temperature rise (T2-T0)=80 (K). Furthermore, by using a special material such as PMMA (polymethyl methacrylate resin) whose linear expansion coefficient α increases when the glass transition temperature is exceeded as the material for the convex portion 33, the extension width Δx of the convex portion 33 can be increased. can be made even larger.

Since the length x1 of the convex part 33 of the light guide plate 3 has an error due to manufacturing variations, etc., the gap between the tip of the convex part 33 and the substrate 20 of the light emitting device 2 is, for example, 0.00 to 0.00 in the non-emission state. It may be adjusted to 0.01 (mm). By adjusting the gap between the tip of the convex portion 33 and the substrate 20 of the light emitting device 2 to be 0.00 to 0.01 (mm), the convex portion 33 is adjusted to at least 0.00 mm due to the heat generated by the light emitting device 2. When extended by 01 (mm), the tip of the convex portion 33 comes into contact with the contact area of the substrate 20 . Further, when the length of the convex portion 33 increases by 0.01 (mm), the substrate separation distance is maintained at the second distance d2 = 5.01 (mm) or more.

FIG. 27 is a diagram showing a modification of the stopper portions 83 of the light shielding members 81 and 82 and the light guide plate 3 shown in FIGS. 24(a) and 24(b). FIG. 27 shows a configuration in which the width of expansion of the substrate separation distance due to heat generation of the light emitting device 2 can be further increased. FIG. 27 shows an enlarged plan view of a backlight 1d according to a fourth modification, and an enlarged cross-sectional view of the backlight 1d along lines CC' and B-B'.

The light guide plate 3 a has a receding surface 34 that is recessed from the light entrance surface 31 on the side surface facing the light emitting device 2 . A step x0 is formed between the light incident surface 31 and the retreating surface 34. The stopper portion 83 faces toward or comes into contact with the retreating surface 34 of the light guide plate 3 to maintain the distance from the retreating surface 34 to the substrate 20 of the light emitting device 2 at d1+x0 or more, thereby reducing the substrate separation distance. The distance is maintained at a predetermined first distance d1 or more. The stopper portion 83 is arranged at the interface between the light incident surface 31 and the receding surface 34. The step-shaped corners of the interface between the light incident surface 31 and the receding surface 34 are curved. Since the corners of the step shape are curved, it is suppressed that the light incident from the light entrance surface 31 of the light guide plate 3a changes direction at the retreating surface 34 and concentrates on the light exit surface 32 of the light guide plate 3, thereby preventing the generation of bright lines. be done.

In the non-emission state, when the distance from the retreating surface 34 to the substrate 20 is maintained at d1+x0, when the length x1 of the convex portion 33 extends by Δx with respect to the light incident surface 31, the light guide plate 3 and the convex portion 33 It is expanded by (x0+x1)/(x1)Δx with the retreating surface 34 as a reference. The backlight 1d can further increase the distance between the substrates due to the heat generated by the light emitting device 2. For example, when the step x0 is approximately the same as the length x1 of the convex portion 33, the extension width based on the receding surface 34 of the light guide plate 3 and the convex portion 33 is based on the light incident surface 31 of the convex portion 33. This is approximately twice the expansion width Δx.

When the temperature of the convex portion 33 of the light guide plate 3 is, for example, less than the predetermined first temperature T1, the substrate separation distance is less than the second distance d2. By approaching the region 21, the light incidence efficiency of light entering the light guide plate 3 from the light emitting device 2 is improved. On the other hand, when the temperature of the convex portion 33 of the light guide plate 3 becomes, for example, a predetermined first temperature T1 or higher, the substrate separation distance becomes a second distance d2 or more, and the light guide plate 3 may be deteriorated by the heat generated by the light emitting device 2. suppressed. This predetermined first temperature T1 is, for example, 85 (°C), which is the maximum operating temperature of the light emitting device 2, or 85 (°C), which is the glass transition temperature of PMMA (polymethyl methacrylate resin).

FIG. 28 is a plan view schematically showing the configuration of a backlight 1e according to a fifth modification. 29(a) and 29(b) are enlarged sectional views taken along lines CC' and B-B' of the backlight 1e shown in FIG. 28.

In the backlight 1c, when the convex portion 33 of the light guide plate 3 expands due to heat generated by the light emitting device 2, a gap is created between the stopper portion 83 of the light shielding member 81 and the light incident surface 31 of the light guide plate 3. The backlight 1c has a gap between the stopper part 83 and the light incident surface 31 of the light guide plate 3. Therefore, when the backlight 1c emits high-intensity light exceeding a certain luminance (45,000 (nits)), the optical sheet 5 There is a risk that the optical sheet 5 will deteriorate over time due to direct incidence of light from the light emitting device 2.

The light shielding member 85 of the backlight 1e further includes an extension portion 84 extending between the light guide plate 3 and the optical sheet 5. The extension portion 84 of the light shielding member 8 blocks direct light from the light emitting device 2 that is emitted to the optical sheet 5 from the gap between the light shielding member 8 and the light guide plate 3 that is generated when the convex portion 33 of the light guide plate 3 is extended. .

The light shielding member 85 has the shape of a large eaves and is arranged to completely cover the end of the light guide plate 3 on the light entrance surface 31 side, including the upper part of the convex portion 33 of the light guide plate 3. Ru. Direct light emitted from the light emitting device 2 to the optical sheet 5 is completely blocked by the light shielding member 8, and deterioration of the optical sheet 5 due to the direct light emitted from the light emitting device 2 is further prevented.

Note that the extension part is separate from the light shielding member 8, and instead of the extension part 84, for example, as shown in a modification of the light shielding member 8 in FIG. 30, a second light shielding member is provided between the light guide plate 3 and the optical sheet 5. 86 may be arranged. At this time, the second light shielding member 86 is formed by depositing or coating a metal with high light reflectance, such as aluminum or silver, on a resin such as nylon, liquid crystal polymer, or polyethylene terephthalate. The surface of the second light shielding member 86 facing the light guide plate 3 may be further coated with a reflective film or the like. Further, as the second light shielding member 86, a white sheet or the like that easily reflects light may be used. If the extension part 84 is formed separately, for example, the extension part 84 can be made of polyethylene terephthalate, and the lower case 6b can be made of different materials, such as metal. Since a softer material such as metal can be used for the extension portion 84, damage to the light guide plate 3 and the optical sheet 5 can be prevented. The second light shielding member 86 which is separate from the light shielding member 8 may be adhered to the upper surface of the light shielding member 8 or may be adhered to the lower surface of the optical sheet 5 facing the light guide plate 3. The second light shielding member 86 is arranged so as to completely cover the end of the light guide plate 3 on the light incident surface 31 side, including above the convex portion 33 of the light guide plate 3.

FIG. 31 is an enlarged sectional view schematically showing still another modification of the light shielding member. Although the light shielding member was integrated with the lower case 6b, the light shielding member 87 may be integrated with the mounting board 20a of the light emitting device 2. For example, the light shielding member 87 may be formed by bending the mounting board 20a of the light emitting device 2 by pressing or the like and standing up from the side surface of the mounting board 20a. The light shielding member 87 is made of the same metal as the mounting board 20a of the light emitting device 2, such as aluminum or copper, or a material with high thermal conductivity mainly composed of ceramics. Such a configuration also provides the same effects as the light shielding members 81 and 82.

FIG. 32(a) is a sectional view of a light emitting device 2f according to the first modification, and FIG. 32(b) is a bottom view of the light emitting device 2f. FIG. 32(a) is a sectional view corresponding to the AA' section in FIG. 4.

The light emitting device 2f differs from the light emitting device 2 in that it includes a metal plate 120. The configurations and functions of the components of the light-emitting device 2 other than the metal plate 120 are the same as those of the components of the light-emitting device 2 with the same reference numerals, so detailed explanations will be omitted here.

The metal plate 120 has a bonding surface bonded to the lower surface of the mounting board 20a. The metal plate 120 is a linear member. The metal plate 120 is formed of metal having a third coefficient of thermal expansion smaller than the first coefficient of thermal expansion. When the mounting board 20a is made of aluminum, the metal plate 120 is made of iron, invar, or silver, for example. The thermal expansion coefficient of iron is approximately 11 to 13×10 ⁻⁶ (1/° C.), and the thermal conductivity is approximately 60 to 90 (W/m·K). Invar has a thermal expansion coefficient of about 1.2 to 2.0×10 ⁻⁶ (1/° C.) and a thermal conductivity of about 10 to 15 (W/m·K). Silver has a thermal expansion coefficient of approximately 18 to 20×10 ⁻⁶ (1/° C.) and a thermal conductivity of approximately 410 to 430 (W/m·K).

Note that the metal plate 120 is made of iron, which means that the material of the metal plate 120 has iron as a main component. When the metal plate 120 is made of silver, it means that the material of the metal plate 120 has silver as a main component. When the metal plate 120 is made of invar, it means that the material of the metal plate 120 is an alloy of iron and nickel. Preferably, the material of the metal plate 120 is made of iron and nickel in a weight ratio of 36%. It is an alloy added to.

The outer periphery of the metal plate 120 has the same shape as the outer periphery of the lower surface of the mounting board 20a. The metal plate 120 is bonded to the mounting board 20a so that the outer periphery of the metal plate 120 and the outer periphery of the lower surface of the mounting board 20a match. The metal plate 120 is bonded to the mounting board 20a by, for example, diffusion bonding. Note that the same shape is not limited to a case where the two members have exactly the same shape, but also includes a state where the two members have a difference that is recognized as a manufacturing error.

The light emitting device 2f has a metal plate 120 bonded to the lower surface of the mounting board 20a. Further, the circuit board 20b is formed of a material having a coefficient of thermal expansion smaller than that of the material of the mounting board 20a. Further, the metal plate 120 is formed of a metal having a coefficient of thermal expansion smaller than that of the material of the mounting board 20a. By having the metal plate 120 bonded to the lower surface of the mounting board 20a, the light emitting device 2f can reduce the possibility of damage due to thermal expansion. Further, the metal plate 120 is preferably made of iron, invar, or silver. Invar is particularly preferable because it has a small coefficient of thermal expansion and suppresses curvature of the light emitting device 2f.

Further, in the light emitting device 2f, the metal plate 120 is bonded so that the outer periphery of the metal plate 120 and the outer periphery of the lower surface of the mounting board 20a match. That is, the metal plate 120 is bonded to the entire lower surface of the mounting board 20a. In the light emitting device 2f, the bending rigidity of the metal plate 120 is improved compared to the case where the metal plate 120 is bonded to a part of the lower surface of the mounting board 20a, and curving of the mounting board 20a is suppressed.

FIG. 33(a) is a sectional view of a light emitting device 2g according to a second modification, and FIG. 33(b) is a bottom view of the light emitting device 2g. FIG. 33(a) is a sectional view corresponding to the AA' section in FIG. 4. The light emitting device 2g is different from the light emitting device 2 in the shape of the metal plate.

The outer periphery of the metal plate 120a included in the light emitting device 2g has the same shape as the outer periphery of the lower surface of the mounting board 20a. The metal plate 120a is joined to the mounting board 20a so that the outer periphery of the metal plate 120a and the outer periphery of the lower surface of the mounting board 20a match. The metal plate 120a has an opening formed in the center of the joint surface. The opening has a rectangular shape extending in the longitudinal direction.

Since the metal plate 120a has an opening, the light emitting device 2g has almost the same bending rigidity as the light emitting device 2f, while reducing the amount of metal material required for its formation, improving manufacturing efficiency. . Further, in the light emitting device 2g, since the metal plate 120a has an opening, the surface area of the metal plate 120a increases and a part of the lower surface of the mounting board 20a is exposed, improving heat dissipation efficiency.

Although the shape of the opening in the metal plate 120a is rectangular, the shape of the opening in the metal plate may be any shape such as an ellipse or a polygon. Further, the metal plate 120a may have a plurality of openings.

FIG. 34(a) is a sectional view of a light emitting device 2h according to a third modification, and FIG. 34(b) is a bottom view of the light emitting device 2h. FIG. 34(a) is a sectional view corresponding to the AA' section in FIG. 4. The light emitting device 2h is different from the light emitting device 2f in the shapes of the mounting board and metal plate.

The mounting board 20i included in the light emitting device 2h has a convex portion 211b at the center of the lower surface. The convex portion 211b has a rectangular shape extending in the longitudinal direction, and is surrounded by a surface 212b perpendicular to the lower surface of the mounting board 20i.

The surface of the metal plate 120b of the light emitting device 2h that is joined to the mounting board 20i has the same shape as the lower surface of the mounting board 20i. Furthermore, the metal plate 120b has the same thickness as the height of the convex portion 211b of the mounting board 20i. The metal plate 120b has an opening 271b in the center that has substantially the same shape as the outer periphery of the protrusion 211b.

The diameter of the opening 271b of the metal plate 120b is formed to be smaller than the diameter of the protrusion 211b. The opening 271b of the metal plate 120b is press-fitted into the protrusion 211b, so that the protrusion 211b is fitted into the opening 271b and joined to the mounting board 20i.

In the light emitting device 2h, the mounting substrate 20i has a convex portion 211b, and the metal plate 120b is joined to the mounting substrate 20i by fitting the opening 271b and the convex portion 211b. The cross-sectional area of the mounting board 20i can be increased by the amount of the convex portion 211b without increasing the overall thickness of the light-emitting device 2h, and the bending rigidity is increased, so the possibility that the light-emitting device 2h will curve is reduced. Ru.

Furthermore, in the light emitting device 2h, the material forming the mounting board 20i may have a higher thermal conductivity than the metal forming the metal plate 120b in order to efficiently dissipate heat from the convex portion 211b. For example, when aluminum with high thermal conductivity is used as the mounting board 20i, even if iron or invar with low thermal conductivity is used as the metal plate 120b, high heat dissipation is maintained because the protrusions 211b are aluminum with high thermal conductivity. can. Note that since the light emitting element 24 emits heat as well as emitting light, it is preferable that at least a portion of the convex portion 211b is provided at a position facing the light emitting element 24 in order to efficiently dissipate heat.

In the light emitting device 2h, the metal plate 120b and the mounting board 20i are bonded by press-fitting, but the metal plate 120b and the mounting board 20a may be bonded by diffusion bonding. In this case, the diameter of the opening 271b may be larger than the diameter of the convex portion 211b.

Note that the shapes of the opening 271b and the convex portion 211b may be any shape such as a rectangle, an ellipse, or a polygon. Further, a plurality of openings 271b and a plurality of convex portions 211b may be provided.

FIG. 35(a) is a sectional view of a light emitting device 2i according to a fourth modification, and FIG. 35(b) is a bottom view of the light emitting device 2i. FIG. 35(a) is a sectional view corresponding to the AA' section in FIG. 4. The light emitting device 2i is different from the light emitting device 2f in the shape of the metal plate.

The metal plate 120c included in the light emitting device 2i is formed to extend in the longitudinal direction, and its width in the transverse direction is narrower than the width of the mounting board 20a. Further, the length in the longitudinal direction of the metal plate 120c is formed to be shorter than the length in the longitudinal direction of the mounting board 20a. The metal plate 120c is bonded to the center of the lower surface of the mounting board 20a. In the light emitting device 2f, a part of the lower surface of the mounting board 20a is exposed to the outside, improving heat dissipation efficiency.Aluminum with high thermal conductivity is used as the mounting board 20a, and silver with an even higher thermal conductivity is used as the metal plate 120c. This can increase heat dissipation. Note that since the light emitting element 24 emits heat as well as emitting light, it is preferable that at least a portion of the metal plate 120c be provided at a position facing the light emitting element 24 in order to improve heat generation efficiency.

Note that the length of the metal plate 120c in the longitudinal direction may be formed to be the same as the length of the mounting board 20a in the longitudinal direction, or may be formed to be larger than the length of the mounting board 20a. Alternatively, a recess may be provided on the lower surface of the mounting board 20a, and the metal plate 120c may be placed in the recess. Thereby, it is possible to suppress the light emitting device 2i from becoming thicker.

FIG. 36(a) is a cross-sectional view of a light emitting device 2j according to a fifth modification. FIG. 36(a) is a sectional view corresponding to the AA' section in FIG. 4. The light emitting device 2g is different from the light emitting device 2f in the shape of the metal plate.

The metal plate 120d included in the light emitting device 2j further includes a wall portion 271d extending along the side surface of the mounting board 20a in the normal direction of the bonding surface from one side of a pair of sides extending in the longitudinal direction of the bonding surface. The wall portion 271d is formed, for example, by bending the metal plate 120d. The wall portion 271d is arranged over the entirety of one side of the joint surface. In the light emitting device 2j, the metal plate 120d has high bending rigidity in the vertical direction of the light emitting device 2d, so that curvature can be further suppressed.

Note that the wall portion 271d may be arranged on a part of one side of the bonding surface, may be in contact with the side surface of the mounting board 20a, or may be spaced apart from the side surface of the mounting board 20a.

FIG. 36(b) is a sectional view of a light emitting device 2k according to a sixth modification. FIG. 36(a) is a sectional view corresponding to the AA' section in FIG. 4. The light emitting device 2k is different from the light emitting device 2f in the shape of the metal plate.

The metal plate 120e included in the light emitting device 2k further includes a first wall portion 271e and a second wall portion 272e. The first wall portion 271e extends from one side of a pair of sides extending in the longitudinal direction of the joint surface in the normal direction of the joint surface to the side opposite to the joint surface. The second wall portion 272e extends in a direction perpendicular to the lateral direction from the side opposite to the side in contact with the joint surface of the first wall portion 271e. In the light emitting device 2, the metal plate 120e has higher bending rigidity in the vertical direction of the light emitting device 2k, so that curvature can be further suppressed.

Note that in the light emitting device 2k, the second wall portion 272e extends in the same direction as the joint surface with respect to the first wall portion 271e, but the example is not limited to this; On the other hand, it may be stretched in the opposite direction to the bonding surface.

The above-mentioned embodiments are merely examples of implementation of the present invention, and the technical scope of the present invention should not be construed to be limited by these embodiments. That is, the present invention can be implemented in various forms without departing from its technical idea or its main features. For example, the configurations of the above embodiments can be implemented in combination. Further, the light emitting device according to the above embodiment has an elongated linear planar shape, but in the manufacturing method of the above embodiment, the light emitting device 2 has a rectangular planar shape such as a square or a rectangle. Effects can be obtained even if

Claims (7)

a mounting board having a linear planar shape extending in a first direction;
a circuit board having a linear planar shape extending in the first direction and having an opening extending in the first direction, and bonded to the surface of the mounting board;
a plurality of light emitting elements mounted by being bonded to the surface of the mounting substrate through the opening so as to be arranged in the first direction;
A non-overlapping portion is formed in which the outer edges of the mounting board and the circuit board do not overlap in plan view,
The non-overlapping portion is arranged along a side extending in the first direction,
The length of the mounting board in a second direction perpendicular to the first direction is shorter than the length of the circuit board in the second direction,
At least a portion of the end of the mounting board in the first direction does not overlap with the circuit board;
A light emitting device characterized by: a mounting board having a linear planar shape extending in a first direction;
a circuit board having a linear planar shape extending in the first direction and having an opening extending in the first direction, and bonded to the surface of the mounting board;
a plurality of light emitting elements mounted by being bonded to the surface of the mounting substrate through the opening so as to be arranged in the first direction;
A non-overlapping portion is formed in which the outer edges of the mounting board and the circuit board do not overlap in plan view,
The non-overlapping portion is arranged along a side extending in the first direction,
A plurality of the non-overlapping parts are arranged on each of the pair of sides extending in the first direction,
At least a portion of the end of the mounting board in the first direction does not overlap with the circuit board;
A light emitting device characterized by: The light emitting device according to claim 2, wherein a length of the mounting board in a second direction perpendicular to the first direction is longer than a length of the circuit board in the second direction. The light emitting device according to claim 2 or 3, wherein the non-overlapping portion has a fan-shaped planar shape and is arranged at four corners of the mounting board. further comprising a metal plate bonded to the back surface of the mounting board,
The mounting board is formed of a material having a first coefficient of thermal expansion,
The circuit board is formed of a material having a second coefficient of thermal expansion smaller than the first coefficient of thermal expansion,
The metal plate is formed of a metal having a third coefficient of thermal expansion smaller than the first coefficient of thermal expansion.
The light emitting device according to any one of claims 1 to 4. a mounting board having a linear planar shape extending in a first direction;
a circuit board having a linear planar shape extending in the first direction and having an opening extending in the first direction, and bonded to the surface of the mounting board;
A method for manufacturing a light emitting device, comprising: a plurality of light emitting elements mounted by die bonding to the surface of the mounting substrate through the opening so as to be arranged in the first direction,
forming a collective board including a board in which a plurality of the mounting boards and a plurality of the circuit boards are integrated;
mounting a plurality of light emitting elements on the mounting substrate through the opening so as to be arranged in the first direction;
The collective board is cut along the first direction so that a non-overlapping part is formed in which the outer edges of the mounting board and the circuit board along the first direction do not overlap in a plan view, and a plurality of light emitting devices are formed by cutting the collective board along the first direction. form,
including the process,
The step of forming the collective board includes the step of arranging the plurality of mounting boards on the back surface of the board on which the plurality of circuit boards are integrated so as to be spaced apart from each other in a second direction perpendicular to the first direction. including,
The step of forming the plurality of light emitting devices includes the step of cutting the collective substrate between the plurality of mounting substrates along the first direction,
At least a portion of the end of the mounting board in the first direction does not overlap with the circuit board;
A method for manufacturing a light emitting device, characterized by: a mounting board having a linear planar shape extending in a first direction;
a circuit board having a linear planar shape extending in the first direction and having an opening extending in the first direction, and bonded to the surface of the mounting board;
A method for manufacturing a light emitting device, comprising: a plurality of light emitting elements mounted by die bonding to the surface of the mounting substrate through the opening so as to be arranged in the first direction,
forming a collective board including a board in which a plurality of the mounting boards are integrated, and a board in which a plurality of the circuit boards are integrated;
mounting a plurality of light emitting elements on the mounting substrate through the opening so as to be arranged in the first direction;
The collective board is cut along the first direction so that a non-overlapping part is formed in which the outer edges of the mounting board and the circuit board along the first direction do not overlap in a plan view, and a plurality of light emitting devices are formed by cutting the collective board along the first direction. form,
including the process,
The board in which the plurality of circuit boards are integrated has a plurality of holes arranged in the first direction at predetermined intervals in a second direction perpendicular to the first direction,
The step of forming the collective board includes the step of bonding the back side of the board on which the plurality of circuit boards are integrated to the front surface of the board on which the plurality of mounting boards are integrated,
The step of forming the plurality of light emitting devices includes the step of cutting the collective substrate along the first direction so as to cut the holes,
At least a portion of the end of the mounting board in the first direction does not overlap with the circuit board;
A method for manufacturing a light emitting device, characterized by:

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