JP2014049625A - Led module - Google Patents

Abstract

An LED module capable of improving light extraction efficiency is provided.
An LED module includes a substrate, a plurality of LED chips arranged in a prescribed direction on one surface side of the substrate, a first electrode (not shown) of each LED chip, A second electrode (not shown) is provided with a wiring portion 8 electrically connected via a wire 7. In the LED module 1, the substrate 2 has an elongated shape, and the longitudinal direction of the substrate 2 is set as the prescribed direction. Further, the LED module 1 includes LED chips 6 arranged in the prescribed direction and line-shaped sealing portions 11 that cover the wires 7 connected to the LED chips 6. The sealing part 11 consists of resin containing a fluorescent substance. The sealing part 11 is provided with a recess 11b that suppresses total reflection of light emitted from the LED chip 6 between the LED chips 6 adjacent in the prescribed direction.
[Selection] Figure 1

Description

  The present invention relates to an LED module.

  Conventionally, for example, an LED module 40 as shown in FIG. 11 has been proposed as a linear light source (Patent Document 1).

  The LED module 40 is a COB type (Chip On Boad) light emitting module, and is a line light source that emits light in a line shape. The LED module 40 includes a mounting substrate 41, a plurality of LEDs 42 arranged on the mounting substrate 41, and a sealing member 43 that seals the LEDs 42. Further, the LED module 40 includes a wiring 44, an electrostatic protection element 45, an electrode terminal 46, and a wire 47.

  The mounting substrate 41 is an LED mounting substrate for mounting the LEDs 42 and is a long rectangular substrate. As the mounting substrate 41, a ceramic substrate made of alumina or translucent aluminum nitride, an aluminum substrate made of aluminum alloy, a transparent glass substrate, a flexible flexible substrate (FPC) made of resin, or the like can be used.

  The plurality of LEDs 42 are directly mounted on the mounting substrate 41. The plurality of LEDs 42 are arranged in a line (in a straight line) along the longitudinal direction of the mounting substrate 41. Each LED 42 is a bare chip that emits monochromatic visible light, and is die-bonded on the mounting substrate 41 by a die attach material (die bond material). As each LED 42, for example, a blue light emitting LED chip that emits blue light is used. As the blue light emitting LED chip, for example, a gallium nitride based semiconductor light emitting element made of an InGaN based material and having a center wavelength of 440 nm to 470 nm can be used.

  The sealing member 43 is a phosphor-containing resin including a phosphor that is a light wavelength converter, and converts the wavelength of the light from the LED 42 and simultaneously seals all the LEDs 42 on the mounting substrate 41 to form the LED 42. Protect. The sealing member 43 has a substantially semicircular dome shape whose cross-sectional shape is convex upward, and is formed linearly along the arrangement direction of the LEDs 42 so as to cover all the LEDs 42 on the mounting substrate 41. The sealing member 43 is formed without interruption from the end surface of one short side of the mounting substrate 41 to the end surface of the other short side. As the sealing member 43, for example, when the LED 42 is a blue light emitting LED chip, in order to obtain white light, a phosphor containing YAG (yttrium, aluminum, garnet) -based yellow phosphor particles dispersed in a silicone resin is included. Resin can be used.

  The wiring 44 is a metal wiring made of tungsten (W), copper (Cu), or the like, and is patterned in a predetermined shape to electrically connect the plurality of LEDs 42 to each other.

  The wire 47 is an electric wire for electrically connecting the LED 42 and the wiring 44, and is composed of, for example, a gold wire. A p-side electrode and an n-side electrode for supplying current are formed on the upper surface of the chip of the LED 42, and each of the p-side electrode and the n-side electrode and the wiring 44 are wire-bonded by a wire 47.

  Conventionally, as shown in FIG. 12, a line coating method is known as a method for forming the first transparent resin layer 112 including the phosphor 116 into a semi-cylindrical shape (for example, Patent Document 2). .

  In Patent Document 2, the line coating method is described as follows.

  In the line coating method, as shown in FIG. 12A, the dispenser 124 is moved along the arrangement of the light emitting diodes 108 while discharging a predetermined amount of the first transparent resin from the dispenser 124, and connected in a line shape. This is a method of forming a resin layer. When formed by a line coating method, the shape of the first transparent resin layer 112 can be determined by the surface tension of the resin. For example, the outer edges of the negative electrode 104 and the positive electrode 106 are higher than the surface of the insulating substrate 102 by the thickness. Accordingly, if there is a sufficient difference between the heights of the two, the first transparent resin layer 112 may have an outer edge 104a of the negative electrode 104 and the positive electrode 106 due to surface tension, as shown in FIGS. 12 (b) and 12 (c). And 106a do not flow out first. Further, the first transparent resin layer 112 can be maintained at a height slightly exceeding the wire 110 due to surface tension if the discharge amount is appropriate. Furthermore, as shown in FIG. 12C, the cross-sectional shape of the first transparent resin layer 112 is substantially semicircular or substantially semielliptical. Thus, according to the line coating method, a large number of chips can be simultaneously processed in a short time with a very simple configuration, and the shape is stabilized. Therefore, if the first transparent resin layer 112 is formed by a line coating method, there are advantages that mass productivity is high and color variation is reduced.

  Further, as a method of forming a phosphor layer that linearly covers a plurality of light emitting elements arranged on a rectangular mounting substrate, a method of forming a semi-cylindrical phosphor layer by line potting with a dispenser is known. (Patent Document 3).

JP2012-142168A JP 2006-229055 A JP 2008-47851 A

  By the way, the sealing member 43 of the above-described LED module 40 has a substantially semicircular dome shape whose cross-sectional shape is convex upward, and along the arrangement direction of the LEDs 42 so as to cover all the LEDs 42 on the mounting substrate 41. It is formed in a straight line. For this reason, in the above-described LED module 40, it is assumed that light emitted from the LED 42 and incident on the boundary surface between the sealing member 43 and the air exceeding the critical angle is totally reflected, and the light extraction efficiency is reduced. The

  This invention is made | formed in view of the said reason, The objective is to provide the LED module which can aim at the improvement of light extraction efficiency.

  The LED module of the present invention includes a substrate, a plurality of LED chips arranged in a specified direction on one surface side of the substrate, and a first electrode and a second electrode of each LED chip electrically connected via wires. Wiring section connected to each other, and each LED chip made of resin containing phosphor and arranged in the prescribed direction, and a line-shaped sealing section that covers each wire connected to each of the LED chips The sealing portion is characterized in that a recess for suppressing total reflection of light emitted from the LED chip is provided between the LED chips adjacent in the prescribed direction.

  In this LED module, it is preferable that the sealing portion is formed so that each convex portion covering each of the LED chips is formed in a hemispherical shape.

  In this LED module, it is preferable that a connection portion between the wiring portion and each of the wires is on both sides of each of the LED chips in the prescribed direction.

  The LED module includes a plurality of submount members disposed between each of the LED chips and the mounting substrate, and the planar size of the submount members is larger than the planar size of the LED chips. preferable.

  In this LED module, the submount member is a light transmissive member having light diffusibility, and both end portions in the direction along the width direction of the sealing portion are exposed without being covered by the sealing portion. It is preferable.

  In this LED module, it is preferable that the mounting substrate has a long shape, and the longitudinal direction of the mounting substrate is the specified direction.

  In the LED module of the present invention, since a recess for suppressing total reflection of light emitted from the LED chip is provided between the LED chips adjacent in the specified direction among the sealing portions, the sealing is performed. It is possible to suppress total reflection at the boundary surface between the part and the air, and to improve the light extraction efficiency.

(A) is a schematic perspective view of the LED module of Embodiment 1, (b) is AA schematic sectional drawing of (a), (c) is BB schematic sectional drawing of (a). 1 is a schematic perspective view of a main part of an LED module according to Embodiment 1. FIG. It is explanatory drawing of the manufacturing method of the LED module of Embodiment 1. FIG. (A) is a schematic perspective view of the LED module of the comparative example 1, (b) is AA schematic sectional drawing of (a), (c) is BB schematic sectional drawing of (a). 6 is a schematic explanatory view of a traveling path of light rays from an LED chip in Comparative Example 1. FIG. 6 is a schematic explanatory view of a traveling path of light rays from an LED chip in Comparative Example 1. FIG. (A) is a schematic perspective view of the LED module of the comparative example 2, (b) is an AA schematic cross-sectional view of (a), (c) is a BB schematic cross-sectional view of (a), (d) is a comparison. FIG. 10 is a schematic perspective view of a main part of the LED module of Example 2 with a part broken away. (A) is a schematic perspective view of the LED module of Embodiment 2, (b) is an AA schematic sectional drawing of (a), (c) is a BB schematic sectional drawing of (a). 6 is a schematic perspective view of another configuration example of the LED module of Embodiment 2. FIG. (A) is AA schematic sectional drawing of FIG. 9, (b) is BB schematic sectional drawing of FIG. (A) is a top view which shows the structure of a LED module, (b) is A-A 'sectional drawing of (a). (A) is a schematic diagram showing how the first transparent resin layer is formed by a line coating method, (b) is a plan view showing how the first transparent resin layer is formed by a line coating method, and (c) is a first diagram. It is sectional drawing which shows a mode that a transparent resin layer is formed by the line coating method.

(Embodiment 1)
Below, the LED module 1 of this embodiment is demonstrated based on FIGS. 1-3.

  The LED module 1 includes a substrate 2, a plurality of LED chips 6 arranged in a specified direction on one surface side of the substrate 2, and first and second electrodes (not shown) and second electrodes ( (Not shown) includes a wiring portion 8 electrically connected via a wire 7. Each LED chip 6 is bonded to the one surface side of the substrate 2 via a bonding portion (not shown). In the LED module 1, the substrate 2 has an elongated shape, and the longitudinal direction of the substrate 2 (the left-right direction in FIG. 1B) is the prescribed direction. In the LED module 1, the substrate 2 and the wiring portion 8 constitute a mounting substrate on which each LED chip 6 is mounted.

  Further, the LED module 1 includes LED chips 6 arranged in the prescribed direction and line-shaped sealing portions 11 that cover the wires 7 connected to the LED chips 6. The sealing part 11 consists of resin containing a fluorescent substance. The sealing portion 11 is provided with a recess 11b that suppresses total reflection of light emitted from the LED chip 6 between the LED chips 6 adjacent to each other in the prescribed direction.

  Hereinafter, each component of the LED module 1 will be described in detail.

  The substrate 2 may be, for example, a translucent substrate or an opaque substrate.

  As a material for the light-transmitting substrate, for example, alumina, aluminum nitride, or the like can be used.

  The opaque substrate is an opaque medium (opaque body) that does not transmit light in the visible wavelength range, and is an opaque substrate that does not transmit light in the visible wavelength range. The opaque substrate is preferably 0% to 10% in transmittance of ultraviolet light and visible light, and more preferably 0 to 5%. The opaque substrate preferably has a reflectivity of ultraviolet light and visible light of 90% or more, more preferably 95% or more. The transmittance and the reflectance are values measured using an integrating sphere.

  As the material of the opaque substrate, for example, aluminum, aluminum alloy, silver, copper, phosphor bronze, copper alloy (for example, 42 alloy), nickel alloy, or the like can be used.

The light-impermeable substrate may be provided with a reflective layer (not shown) having a higher reflectance with respect to light emitted from the LED chip 6 than the base material on the surface of the base material made of the above-described material. As the reflective layer, for example, a white resist layer can be employed. As a material for the resist layer, for example, a white resist made of a resin containing a filler such as titanium dioxide (TiO ₂ ), zinc oxide (ZnO), barium sulfate (BaSO ₄ ) (for example, a silicone resin) is employed. can do. For example, it is preferable to use a resist layer obtained by kneading a filler of any one of TiO ₂ , ZnO, and BaSO _{4 in} a silicone resin because heat resistance can be improved and discoloration hardly occurs. As the white resist, for example, a white resist material “ASA COLOR RESIST INK” made by Asahi Rubber Co., Ltd. can be used. The white resist layer can be formed by, for example, a coating method. Examples of the reflective layer include a silver film, a laminated film of a nickel film, a palladium film, and a gold film, a laminated film of a nickel film and a gold film, and a laminated film of a silver film, a palladium film, and a gold-silver alloy film. Can be adopted. The reflective layer using a metal material is preferably composed of a plating layer or the like. In short, the reflective layer is preferably formed by a plating method.

As an opaque substrate, an aluminum film having a purity higher than that of an aluminum plate is laminated on one surface side of an aluminum plate that is a base material, and an increase of two kinds of dielectric films having different refractive indexes is formed on the aluminum film. A highly reflective substrate on which a reflective film is laminated can also be used. Here, as the two types of dielectric films, for example, an SiO ₂ film and a TiO ₂ film are preferably employed. The LED module 1 can make the reflectance with respect to visible light 95% or more by using a highly reflective substrate as the opaque substrate. As this highly reflective substrate, for example, MIRO2 or MIRO (registered trademark) of alanod can be used. As the above-mentioned aluminum plate, an anodized surface may be used.

  Further, the opaque substrate may be an insulating substrate formed from a material in which a filler for increasing the reflectance is added to the resin. For such an insulating substrate, for example, unsaturated polyester can be used as the resin, and titania can be used as the filler. The resin for the insulating substrate is not limited to unsaturated polyester, and for example, vinyl ester can be used. Moreover, as a filler, not only titania but magnesium oxide, boron nitride, aluminum hydroxide etc. can be used, for example. Further, as the opaque substrate, a resin substrate formed of a white resin or a resin substrate having a reflective layer formed of a white resin may be used. Further, the opaque substrate may be a ceramic substrate having a reflective layer formed of white resin. Further, the opaque substrate may be a resin substrate formed of a resin other than white or an opaque ceramic.

  In the LED module 1, the substrate 2 preferably has a heat sink function. In this case, the LED module 1 can make the board | substrate 2 have the function of a heat sink by employ | adopting metals with high heat conductivity, such as aluminum and copper, as a material of the board | substrate 2, for example. Thereby, the LED module 1 can dissipate the heat generated in the LED chip 6 more efficiently, and the light output can be increased.

  On the one surface side of the substrate 2, a wiring portion 8 for supplying power to the LED chip 6 is provided. The wiring part 8 is comprised by the conductor part (conductor pattern) patterned by the predetermined shape. In the LED chip 6, electrodes (first electrode and second electrode) are electrically connected to the wiring portion 8 via wires 7. As the wire 7, for example, a gold wire, an aluminum wire, or the like can be employed. As a material of the wiring part 8, for example, copper, phosphor bronze, copper alloy (for example, 42 alloy), nickel alloy, aluminum, aluminum alloy, or the like can be used. The wiring part 8 can be formed using, for example, a lead frame, a metal foil, a metal film, or the like. In the case where the substrate 2 has conductivity, an insulating layer may be provided between the substrate 2 and the wiring portion 8. In the case where a white resist layer is employed as the above-described reflective layer, an insulating layer can be constituted by this resist layer.

  The wiring portion 8 is patterned into a shape that allows a plurality of LED chips 6 to be connected in parallel as the predetermined shape. The wiring portion 8 may be patterned in a shape that allows a plurality of LED chips 6 to be connected in series, or may be patterned in a shape that enables a plurality of LED chips 6 to be connected in series and parallel. It may be made. In short, the LED module 1 may have a circuit configuration in which a plurality of LED chips 6 are connected in parallel, or may have a circuit configuration in which a plurality of LED chips 6 are connected in series. It may have a circuit configuration in which a plurality of LED chips 6 are connected in series and parallel.

  The mounting substrate includes a non-transparent substrate in which the LED chips 6 are arranged on one surface side, and a wiring portion 8 that is disposed on the other surface side of the non-transparent substrate and electrically connected to each LED chip 6. May be good. As such a mounting substrate, for example, one in which the wiring portion 8 is formed of a conductive plate (for example, a lead frame), a metal foil, or the like can be employed. Here, a plurality of first through holes through which the respective wires 7 that electrically connect the LED chip 6 and the wiring portion 8 pass are formed in the opaque substrate. Further, such a mounting substrate includes an insulating layer that electrically insulates the opaque substrate and the wiring portion 8 between the opaque substrate and the wiring portion 8. A plurality of second through holes communicating with each of the first through holes of the opaque substrate are formed in the insulating layer. An insulating layer can be comprised with the epoxy resin layer containing the filler which consists of fillers, such as a silica and an alumina, for example. What is necessary is just to set the thickness of an epoxy resin layer suitably in the range of about 50 micrometers-150 micrometers, for example. The thermal conductivity of the epoxy resin layer is preferably 4 W / m · K or more.

  The LED chip 6 is provided with the first electrode as an anode electrode and the second electrode as a cathode electrode on one surface side in the thickness direction of the LED chip 6.

  The LED chip 6 includes an LED structure having an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer on the main surface side of a support substrate made of a crystal growth substrate or the like. The stacking order of the n-type semiconductor layer, the light-emitting layer, and the p-type semiconductor layer is the n-type semiconductor layer, the light-emitting layer, and the p-type semiconductor layer in order from the side close to the support substrate. However, the order is not limited to the p-type semiconductor layer, the light emitting layer, and the n-type semiconductor layer. When the support substrate is a crystal growth substrate, the LED chip 6 preferably has a structure in which a buffer layer is provided between the LED structure portion and the support substrate. The light emitting layer preferably has a single quantum well structure or a multiple quantum well structure, but is not limited thereto. For example, the LED chip 6 may form a double hetero structure with the n-type semiconductor layer, the light emitting layer, and the p-type semiconductor layer. The structure of the LED chip 6 is not particularly limited. As the LED chip 6, an LED chip having a reflection part such as a Bragg reflector inside may be employed. The LED chip 6 may be one in which the support substrate is bonded to the LED structure portion after the LED structure portion is formed on the main surface side of the crystal growth substrate. In the LED chip 6 in this case, the crystal growth substrate is removed after the support substrate is bonded to the LED structure.

  The other side of the LED chip 6 in the thickness direction of the LED chip 6 is bonded to the substrate 2 via the bonding portion. In the LED chip 6, each of the first electrode and the second electrode is electrically connected to the wiring portion 8 via a wire 7. The joining portion can be formed of a die bond material.

  The LED chip 6 is a blue LED chip that emits blue light. The blue LED chip employs a gallium nitride-based material as the material of the light emitting layer, and uses a sapphire substrate as the support substrate. However, the support substrate of the LED chip 6 is not limited to a sapphire substrate, and may be, for example, a gallium nitride substrate, a silicon carbide substrate, a silicon substrate, or the like.

  The LED chip 6 employs a rectangular planar shape, but is not limited to this, and for example, a square planar shape can be employed.

  The chip size of the LED chip 6 is 0.5 mm × 1.0 mm, but is not particularly limited. Further, as the LED chip 6, for example, a chip having a chip size of 0.3 mm □ (0.3 mm × 0.3 mm), 0.45 mm □, or 1 mm □ can be used.

  Moreover, the LED chip 6 does not specifically limit the material and the emission color of the light emitting layer. That is, the LED chip 6 is not limited to a blue LED chip, and for example, a purple LED chip, an ultraviolet LED chip, a red LED chip, a green LED chip, or the like may be used.

  As the die bond material, for example, a silicone-based die bond material, an epoxy-based die bond material, a silver paste, or the like can be used.

  When the LED module 1 employs a non-transparent substrate as the substrate 2, it is preferable that the bonding portion can transmit light emitted from the LED chip 6. Thereby, the LED module 1 emits light from the light emitting layer of the LED chip 6, and a part of the light that has passed through the LED chip 6 and the joint portion is reflected on the one surface of the substrate 2.

  Moreover, as the wire 7, a gold wire, a silver wire, a copper wire, an aluminum wire etc. can be used, for example.

  The wiring part 8 includes a first wiring pattern part (first pattern) 8a to which the first electrode of the LED chip 6 is connected, and a second wiring pattern part (second pattern) to which the second electrode of the LED chip 6 is connected. Pattern) 8b.

  The first wiring pattern portion 8a and the second wiring pattern portion 8b are each formed in a comb shape in plan view. The first wiring pattern portion 8a and the second wiring pattern 8b are arranged so as to be intertwined with each other in the direction along the short direction of the substrate 2. Here, in the wiring part 8, the first comb part 8aa of the first wiring pattern part 8a and the second comb part 8ba of the second wiring pattern part 8b are opposed to each other. In the wiring portion 8, the first comb tooth portions 8ab of the first wiring pattern portion 8a and the second comb tooth portions 8bb of the second wiring pattern portion 8b are alternately arranged in the direction along the longitudinal direction of the substrate 2 with a gap. Are lined up.

  In the LED module 1, a plurality (9 in the illustrated example) of LED chips 6 arranged in the longitudinal direction of the substrate 2 (that is, the prescribed direction) are connected in parallel. The LED module 1 can supply power to a parallel circuit in which the plurality of LED chips 6 are connected in parallel. In short, the LED module 1 can supply power to all the LED chips 6 by supplying power between the first wiring pattern portion 8a and the second wiring pattern portion 8b. When a plurality of LED modules 1 are used side by side, the adjacent LED modules 1 are electrically connected to each other by a conductive member, an electric wire for feed wiring (not shown), a connector (not shown), or the like. It is only necessary to connect them. In this case, it is possible to supply power from a single power supply unit to the plurality of LED modules 1 to cause all LED chips 6 of each LED module 1 to emit light.

  The wiring portion 8 is preferably formed with a surface treatment layer (not shown). The surface treatment layer is preferably made of a metal material having higher oxidation resistance and corrosion resistance than the material of the wiring portion 8. When the material of the wiring part 8 is copper, examples of the surface treatment layer include a nickel film, a laminated film of a nickel film and a gold film, a laminated film of a nickel film, a palladium film, and a gold film, a nickel film and a palladium film, It is preferable to form a laminated film or the like. Here, the surface treatment layer is more preferably a laminated film of a nickel film and a palladium film from the viewpoint of cost reduction. The surface treatment layer may be formed by, for example, a plating method.

  The sealing part 11 consists of resin containing a fluorescent substance. In the sealing part 11, it is preferable that the phosphor is dispersed in the resin. If the resin of the sealing part 11 is a material which permeate | transmits the light radiated | emitted from each of the LED chip 6 and the said fluorescent substance, it will not specifically limit.

  As said resin of the sealing part 11, a silicone resin, an epoxy resin, an acrylic resin, a urethane resin, an oxetane resin, a polycarbonate resin etc. are employable, for example. As the resin, a silicone resin is preferable from the viewpoint of heat resistance and weather resistance, and rubbery silicone is more preferable from the viewpoint of suppressing the wire 7 from being cut by thermal stress due to a temperature cycle.

  The phosphor functions as a wavelength conversion material that converts light emitted from the LED chip 6 into light having a longer wavelength than the light. Thereby, the LED module 1 can obtain mixed color light of the light emitted from the LED chip 6 and the light emitted from the phosphor. In short, the sealing unit 11 not only functions as a sealing layer that seals each LED chip 6 and each wire 7 but also converts light emitted from the LED chip 6 into light having a longer wavelength than the light. It functions as a wavelength conversion layer.

  For example, if the LED module 1 employs a blue LED chip as the LED chip 6 and a yellow phosphor as the phosphor that is the wavelength conversion material, white light can be obtained. That is, the LED module 1 can emit the blue light emitted from the LED chip 6 and the light emitted from the yellow phosphor from the surface of the sealing portion 11 and obtain white light.

  The phosphor that is the wavelength conversion material is not limited to the yellow phosphor, and for example, the yellow phosphor and the red phosphor, or the red phosphor and the green phosphor are employed. Also good. In addition, the phosphor that is the wavelength conversion material is not limited to one type of the yellow phosphor, and two types of yellow phosphors having different emission peak wavelengths may be employed. The LED module 1 can enhance color rendering by adopting a plurality of types of phosphors as the wavelength conversion material.

  As described above, the sealing portion 11 is provided with the concave portions 11b that suppress the total reflection of the light emitted from the LED chips 6 between the LED chips 6 adjacent in the prescribed direction. Thereby, the LED module 1 can suppress the total reflection of the light emitted from the LED chip 6 and incident on the boundary surface between the sealing portion 11 and the air, and the light confined due to the total reflection is reduced. Therefore, it is possible to improve the light extraction efficiency. In short, the LED module 1 can reduce the total reflection loss, and can improve the light extraction efficiency.

  The sealing part 11 is formed in a cross-sectional shape reflecting a step between the one surface of each LED chip 6 and the one surface of the substrate 2. Therefore, the sealing part 11 has a convex cross-sectional shape orthogonal to the arrangement direction of the LED chips 6, and a cross-sectional shape along the arrangement direction of the LED chips 6 is an uneven shape. In short, in the LED module 1, a concavo-convex structure for improving light extraction efficiency is formed in the line-shaped sealing portion 11.

  The period of the uneven structure is the same as the arrangement pitch of the LED chips 6. Here, the period of the concavo-convex structure is an arrangement pitch of the convex portions 11 a covering each of the LED chips 6.

  What is necessary is just to design the shape of the surface of the sealing part 11 so that the angle | corner which the normal line of the point where the light ray from LED chip 6 crosses in the said surface of the sealing part 11 and the said light ray becomes smaller than a critical angle. . Here, the LED module 1 is sealed so that the incident angle (light incident angle) of the light beam from the LED chip 6 is smaller than the critical angle over substantially the entire surface of each convex portion 11 a of the sealing portion 11. It is preferable to design the shape of the surface of the stopper 11.

  For this reason, as for the sealing part 11, it is preferable that each convex part 11a which covers each of each LED chip 6 is formed in the hemispherical shape. Each of the convex portions 11 a is designed so that the optical axis of the convex portion 11 a that overlaps in the thickness direction of the substrate 2 and the optical axis of the LED chip 6 coincide with each other. Thereby, the LED module 1 can not only suppress total reflection on the surface of the sealing portion 11 (a boundary surface between the sealing portion 11 and air) but also suppress color unevenness. It becomes possible. Color unevenness is a state in which chromaticity changes depending on the light irradiation direction. The LED module 1 can suppress color unevenness to such an extent that it cannot be visually recognized.

  The LED module 1 can make the optical path length from the LED chip 6 to the surface of the convex portion 11a substantially uniform regardless of the light emission direction from the LED chip 6, and can further suppress color unevenness. Become. Each convex part 11a of the sealing part 11 is not limited to a hemispherical shape, and may be a semi-elliptical spherical shape, for example. Each of the convex portions 11a may have a semi-cylindrical shape or a rectangular parallelepiped shape.

  In the LED module 1, the sealing portion 11 is in contact with the substrate 2. Thereby, the LED module 1 can dissipate not only the heat generated in the LED chip 6 but also the heat generated in the sealing portion 11 through the substrate 2, and can increase the light output. Become.

  In manufacturing the LED module 1, first, the substrate 2 is prepared. Thereafter, each LED chip 6 is die-bonded to the one surface side of the substrate 2 by a die-bonding apparatus or the like. Thereafter, the first electrode and the second electrode of the LED chip 6 and the wiring portion 8 are connected via the wire 7 by a wire bonding apparatus or the like. Thereafter, the sealing portion 11 is formed using a dispenser system or the like.

  Hereinafter, the formation method of the sealing part 11 is demonstrated. The dispenser system includes a table for holding the substrate 2, a dispenser head 31 (see FIG. 3), and a nozzle 32 that is held by the dispenser head 31 and discharges an uncured liquid sealing material (see FIG. 3) from the sealing portion 11. (See FIG. 3). FIG. 3 is an explanatory diagram of a method for manufacturing the LED module 1. More specifically, it is a schematic explanatory view of a method for forming the sealing part 11 by the dispenser system, and the dispenser head 31 is moved from the left end position to the right end position in FIG. A state in which the sealing material 111 is discharged and applied is schematically shown. In addition, in FIG. 3, illustration of the wiring part 8 and each wire 7 is abbreviate | omitted.

  In the sealing portion 11, an uncured liquid sealing material 111 is applied in a line shape covering each LED chip 6 and each wire 7 on the one surface side of the substrate 2, and then the one surface of the substrate 2. It is formed by curing the side sealing material 111.

  When the sealing part 11 is formed by the dispenser system, for example, the sealing material 111 is discharged from the nozzle 32 and applied while moving the dispenser head 31 along the arrangement direction of the LED chips 6.

  Here, when applying the sealing material 111 by the dispenser system so as to have an application shape based on the surface shape of the sealing portion 11, for example, while moving the dispenser head 31, as shown in FIG. The sealing material 111 may be discharged and applied. In the example of FIG. 3, the application amount is changed by changing the discharge speed of the dispenser head 31, and the nozzle 32 and the one surface of the substrate 2 immediately below the nozzle 32 are changed by moving the dispenser head 31 up and down. The distance is changed. More specifically, in the case where the sealing material 111 is applied to the location where each convex portion 11a of the sealing portion 11 is based and the location where the portion between the adjacent convex portions 11a of the sealing portion 11 is based In the case of applying the sealing material 111, the movement speed or the discharge speed is relatively different. In the former case, the movement speed is slow or the discharge speed is increased, and in the latter case, the movement speed is increased. Faster or slower discharge speed. Further, the dispenser head 31 is moved up and down based on the surface shape of the sealing portion 11. Accordingly, in the method of forming the sealing portion 11 by the dispenser system, the sealing material 111 can have the application shape based on the surface shape of the sealing portion 11. The application shape may be set in consideration of shrinkage when the sealing material 111 is cured.

  Here, the dispenser system includes a moving mechanism including a robot that moves the dispenser head 31, a sensor unit that measures the height of each of the one surface of the substrate 2 and the nozzle 32 from the table, the moving mechanism, and the nozzle. It is preferable that a controller for controlling the discharge speed of the sealing material 111 from 32 is provided. The controller can be realized, for example, by installing an appropriate program in a microcomputer. In addition, the dispenser system appropriately changes the program installed in the controller, thereby allowing a plurality of types of products having different arrangement pitches of the LED chips 6, the number of LED chips 6, the line width of the sealing portion 11, and the like. It becomes possible to cope with.

  Moreover, the said surface shape of the sealing part 11 can also be controlled by adjusting the viscosity, thixotropy, etc. of the sealing material 111, for example. The curvature of each surface (convex curved surface) of each convex portion 11a can be designed according to the viscosity, thixotropy, surface tension, height of the wire 7, and the like of the sealing material 111. Increasing the curvature can be realized by increasing the viscosity of the sealing material 111, increasing the thixotropy, increasing the surface tension, or increasing the height of the wire 7. Further, the width (line width) of the line-shaped sealing portion 11 can be reduced by increasing the viscosity of the sealing material 111, increasing the thixotropy, or increasing the surface tension. It becomes. The viscosity of the sealing material 111 is preferably set in a range of about 100 to 50000 mPa · s. As the viscosity value, for example, a value measured at room temperature using a conical plate type rotational viscometer can be adopted.

  The dispenser system may include a heater that heats the uncured sealing material 111 to have a desired viscosity. Accordingly, the dispenser system can improve the reproducibility of the application shape of the sealing material 111 and can improve the reproducibility of the surface shape of the sealing portion 11.

  By the way, LED module 1 'of the comparative example 1 shown in FIG. 4 WHEREIN: Sealing part 11' is a semicylindrical shape, The cross section of sealing part 11 'in the direction along the sequence direction of LED chip 6 (FIG. 4 (a) (A-A cross section) is an elongated rectangular shape, and the cross section of the sealing portion 11 '(cross section BB in FIG. 4 (a)) in a cross section orthogonal to the arrangement direction of the LED chips 6 is a semicircle. It becomes a shape. The arrows shown in each of FIGS. 5 and 6 schematically show the traveling path of the light beam from the LED chip 6 in the LED module 1 ′ of Comparative Example 1. As can be seen from the traveling path of the light beam in FIG. 5, in the LED module 1 ′ of Comparative Example 1, there is light that is totally reflected on the surface of the sealing portion 11 ′, and the light extraction efficiency is lowered.

  On the other hand, the sealing part 11 in the LED module 1 of the present embodiment has a recess 11b that suppresses total reflection of light emitted from the LED chip 6 between the LED chips 6 adjacent in the prescribed direction. Is provided. Thereby, the LED module 1 of the present embodiment can improve the light extraction efficiency as compared with the LED module 1 ′ of Comparative Example 1.

  Moreover, since the LED module 1 of this embodiment has the recessed part 11b in the sealing part 11, compared with LED module 1 'of the comparative example 1, the usage-amount of the sealing material 111 (refer FIG. 3) is reduced. It can be reduced, and the cost can be reduced.

  Moreover, the LED module 1 of this embodiment is sealed compared with LED module 1 "of the comparative example 2 provided with the some sealing part 21 which covers each of each LED chip 6 separately as shown in FIG. The tact time of the process can be shortened, and the cost can be reduced.

  By the way, as for the LED module 1, it is preferable that the connection part of the wiring part 8 and each of each wire 7 exists in the both sides of each of each LED chip 6 in the said prescription | regulation direction. Thereby, the LED module 1 is caused by the surface tension of the sealing material 111 and the arrangement of the wires 7 when the sealing portion 11 having a line shape in plan view is formed using the dispenser system or the like. It is possible to suppress the meandering shape of the sealing portion 11 in a plan view. Therefore, the LED module 1 can suppress variations in the surface shape of the sealing portion 11, and can improve light extraction efficiency. Here, as for LED module 1, it is preferable that the said connection part is located on the straight line along the said prescribed direction.

  When the planar shape of each LED chip 6 is rectangular, the LED module 1 is preferably arranged such that the longitudinal direction of the LED chip 6 coincides with the prescribed direction. The LED module 1 includes a wire 7 connected to the first electrode when the first electrode and the second electrode are located on a center line along the prescribed direction in the planar shape of the LED chip 6. It is preferable that the wire 7 connected to the second electrode is disposed along the center line. Thereby, the LED module 1 can make the cross-sectional shape orthogonal to the said centerline of each convex part 11a in the sealing part 11 into a left-right symmetric shape.

  In the LED module 1, the planar shape of each LED chip 6 is a square shape, and the first on the vertical bisector of two sides parallel to each other among the four sides in the plan view of each LED chip 6. When the electrode and the second electrode are located, the wire 7 connected to the first electrode and the wire 7 connected to the second electrode are arranged along the vertical bisector Is preferred. Thereby, the LED module 1 can make the cross-sectional shape orthogonal to the said perpendicular bisector of each convex part 11a in the sealing part 11 into a left-right symmetric shape.

  The LED module 1 is good also as a structure in which the sealing part 11 contains the light-diffusion material. The light diffusing material is in the form of particles and is preferably dispersed in the sealing portion 11. The LED module 1 can further suppress color unevenness because the sealing portion 11 contains a light diffusing material. Examples of the light diffusing material include inorganic materials such as aluminum oxide, silica, titanium oxide, and gold, organic materials such as fluorine-based resins, and organic materials in which organic components and inorganic components are mixed and combined at the nm level or molecular level.・ Inorganic hybrid materials can be used.

  The LED module 1 has a configuration in which the LED chip 6 is a blue LED chip, and the sealing portion 11 includes a plurality of types of phosphors (the green phosphor and the red phosphor) and the light diffusing material. Then, it becomes possible to further improve the color rendering properties. In the LED module 1, the LED chip 6 is an ultraviolet LED chip, and the sealing portion 11 includes a plurality of types of phosphors (the blue phosphor, the green phosphor, and the red phosphor) and the light diffusing material. With this configuration, it is possible to further improve the color rendering properties.

(Embodiment 2)
Below, the LED module 1 of this embodiment is demonstrated based on FIG.

  The LED module 1 of the present embodiment is different from the LED module 1 of Embodiment 1 in that each LED chip 6 is mounted on the one surface side of the substrate 2 via the submount member 4. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The LED module 1 includes a substrate 2, a plurality of submount members 4 bonded to the one surface side of the substrate 2 via a first bonding portion (not shown), and a substrate in each of the submount members 4. A plurality of LED chips 6 bonded to each other on the one surface side opposite to the second side via a second bonding portion (not shown) are provided.

  The planar size of the submount member 4 is set larger than the planar size of the LED chip 6. As a result, the LED module 1 has a step due to the submount member 4 between the LED chip 6 and the one surface of the substrate 2 in the cross section including the center line orthogonal to the thickness direction of the LED chip 6. It becomes easy to form each convex part 11a of the stop part 11 in a hemispherical shape.

  As a material of the first joint portion, for example, a transparent material such as a silicone resin or an epoxy resin can be employed.

  As the material of the second joint portion, for example, a transparent material such as a silicone resin or an epoxy resin can be employed.

  In the LED module 1, the first joint and the second joint can transmit light emitted from the LED chip 6, and the submount member 4 is a translucent member.

  Thereby, the LED module 1 emits light from the light emitting layer of the LED chip 6, and a part of the light that has passed through the LED chip 6 and the second joint portion is diffused in the submount member 4. Therefore, the light that has passed through the LED chip 6 and the second joint is less likely to be reflected at the interface between the second joint and the submount member, and is easily extracted from the side surface of the submount member 4 or the one surface. Become. For this reason, in the LED module 1, it becomes possible to improve the light extraction efficiency and to improve the total luminous flux. In this case, the substrate 2 is preferably an opaque substrate. Further, the support substrate of the LED chip 6 is not limited to the sapphire substrate, but may be any crystal growth substrate that is transparent to the light emitted from the light emitting layer.

  The translucent member constituting the submount member 4 has translucency that transmits light in the ultraviolet wavelength region and visible wavelength region, and transmits light emitted from the light emitting layer of the LED chip 6. Or diffuse. As a material of the translucent member constituting the submount member 4, for example, translucent ceramics (alumina, barium sulfate, etc.) can be employed. The translucent ceramics can adjust the transmittance, reflectance, refractive index, and thermal conductivity depending on the type and concentration of the binder, additive, and the like. In the LED module 1, the LED chip 6 is bonded to the central portion on the one surface side of the submount member 4 via the second bonding portion.

  The submount member 4 preferably has light diffusibility. Thereby, in the LED module 1, the light emitted from the light emitting layer of the LED chip 6 to the other surface side in the thickness direction of the LED chip 6 is diffused in the submount member 4. Thereby, the LED module 1 can further suppress the light emitted from the LED chip 6 to the submount member 4 side from returning to the LED chip 6, and from the one surface or the side surface of the submount member 4. It becomes easy to take out light. Therefore, the LED module 1 can improve the light extraction efficiency.

  The submount member 4 has a rectangular shape in plan view, but is not limited thereto, and may be, for example, a circular shape or a polygonal shape other than a rectangular shape.

  The submount member 4 is configured to have a linear expansion coefficient close to that of the LED chip 6, thereby reducing the stress acting on the LED chip 6 due to the difference in linear expansion coefficient between the LED chip 6 and the substrate 2. It preferably has a relaxation function. Thereby, the LED module 1 can relieve the stress acting on the LED chip 6 due to the difference in linear expansion coefficient between the LED chip 6 and the substrate 2.

  The submount member 4 preferably has a heat conduction function for conducting heat generated in the LED chip 6 to the substrate 2 side. Moreover, it is preferable that the submount member 4 has a heat conduction function that conducts heat generated in the LED chip 6 to a range wider than the chip size of the LED chip 6. Thereby, the LED module 1 can efficiently dissipate the heat generated in the LED chip 6 through the submount member 4 and the substrate 2.

  As a material of the first joint portion that joins the submount member 4 and the substrate 2, for example, a transparent material such as silicone resin or epoxy resin can be employed.

  In the LED module 1, it is preferable that the one surface of the substrate 2 has light diffusibility or specular reflection. When the one surface of the substrate 2 has light diffusibility, the LED module 1 emits light emitted from the light emitting layer of the LED chip 6 and transmitted through the second joint, the submount member 4 and the first joint. It becomes possible to diffusely reflect on the one surface of the substrate 2 and to reduce the light returning to the LED chip 6. When the one surface of the substrate 2 has specular reflectivity, the LED module 1 is radiated from the LED chip 6 and passes through the second joint portion, the submount member 4 and the first joint portion, and the above-described one of the substrate 2. Light obliquely incident on one surface can be regularly reflected, and light extraction from the side surface of the submount member 4 can be improved. Therefore, the LED module 1 can further improve the light extraction efficiency when the one surface of the substrate 2 has light diffusibility or specular reflection.

  By the way, as above-mentioned, if the LED module 1 employ | adopts a blue LED chip as the LED chip 6 and employ | adopts a yellow fluorescent substance as a fluorescent substance of a wavelength conversion material, it will become possible to obtain white light. That is, the LED module 1 can emit the blue light emitted from the LED chip 6 and the light emitted from the yellow phosphor from the LED chip 6 and the submount member 4, thereby obtaining white light.

  In short, the LED module 1 combines the light from the LED chip 6 and the light from the phosphor (wavelength converted light) to obtain mixed color light. For this reason, when the LED module 1 covers the side surfaces of the submount member 4 orthogonal to the width direction of the sealing part 11, the LED module 1 is sealed due to the light distribution characteristics of the LED chip 6. The color tone may be shifted between the central part of the convex part 11a of the part 11 and the peripheral part of the convex part 11a, and color unevenness may occur. In the LED module 1, for example, it is assumed that the LED chip 6 is a blue LED chip and the phosphor is a yellow phosphor, and the light distribution characteristic of the LED chip 6 is such that the radiation intensity on the one side is stronger than the radiation intensity on the side. If the white light having the desired chromaticity is obtained at the central portion of the convex portion 11a, the white light having the desired chromaticity is obtained at the peripheral portion of the convex portion 11a. A slightly yellowish white light may be obtained.

  For this reason, in the LED module 1, when the submount member 4 is a light transmissive member having light diffusibility, both end portions of the submount portion 4 in the direction along the width direction of the sealing portion 11 have the sealing portion 11. It is preferably exposed without being covered with. As a result, the LED module 1 determines the balance between the intensity of the light from the LED chip 6 and the intensity of the light from the phosphor in the mixed color light emitted from the peripheral portion of the convex portion 11 a of the sealing portion 10. 4 can be improved by the light of the LED chip 6 emitted from the one surface at the both end portions, and color unevenness can be further suppressed.

  Further, as the material of the submount member 4, aluminum nitride, composite SiC, Si, CuW, or the like can be adopted. Further, the submount member 4 may be provided, for example, with a reflective film that reflects light emitted from the LED chip 6 on the surface on the substrate 2 side. As a material for the reflective film, for example, silver, aluminum gold alloy, nickel, or the like can be used. The material of the reflective film is not particularly limited, and may be appropriately selected according to the emission wavelength of the LED chip 6, for example.

  The LED module 1 is not limited to the example of FIG. 8, for example, as shown in FIGS. 9 and 10, the opaque substrate 2 is configured by a paper phenolic substrate 2 a that is an opaque resin substrate. But you can. In the LED module 1 shown in FIGS. 9 and 10, the wiring portion 8 made of the first metal foil is provided on one surface side of the paper phenol substrate 2a, and the second metal foil 2c is provided on the other surface of the paper phenol substrate 2a. Is provided. The second metal foil 2c is preferably provided on the entire surface of the other surface of the paper phenol substrate 2a. Moreover, in this LED module 1, the resist layer 2b which covers most of the wiring part 8 on the one surface side of the paper phenolic board 2a on the one surface of the paper phenolic board 2a where the wiring part 8 is not formed. Is provided. The resist layer 2 is provided such that a portion of the wiring portion 8 to which each wire 7 is connected is exposed. As the first metal foil and the second metal foil 2c, for example, a copper foil is preferable. The resist layer 2b may be a white resist or a transparent resist.

  By the way, each LED module 1 of Embodiment 1, 2 can be used as a light source of various illuminating devices. As an example of a lighting device including the LED module 1, for example, there is a lighting fixture in which the LED module 1 is used as a light source and arranged in the fixture body. Moreover, a straight tube type LED lamp can be comprised as another example of the illuminating device provided with the LED module 1. FIG. As for straight tube LED lamps, for example, the Japan Light Bulb Industry Association has standardized “Straight tube LED lamp system with L-type pin cap GX16t-5 (for general lighting)” (JEL 801). Yes.

  In the case of configuring such a straight tube type LED lamp, for example, a straight tubular tube body formed of a translucent material (for example, milky white glass, milky white resin, etc.), and a longitudinal direction of the tube body A first base and a second base provided at one end and the other end of the LED, respectively, and the LED module 1 may be housed in the tube body.

DESCRIPTION OF SYMBOLS 1 LED module 2 Board | substrate 4 Submount member 6 LED chip 7 Wire 8 Wiring part 11 Sealing part 11a Convex part 11b Concave part

Claims (6)

  A wiring portion in which a substrate, a plurality of LED chips arranged in a prescribed direction on one surface side of the substrate, and a first electrode and a second electrode of each LED chip are electrically connected via wires And each LED chip made of a resin containing a phosphor and arranged in the prescribed direction, and a line-shaped sealing portion that covers each wire connected to each of the LED chips, and the sealing The LED module is characterized in that a recess for suppressing total reflection of light emitted from the LED chip is provided between the LED chips adjacent to each other in the prescribed direction.   The LED module according to claim 1, wherein each of the sealing portions is formed in a hemispherical shape so that each convex portion covering each of the LED chips is formed.   3. The LED module according to claim 1, wherein a connection portion between the wiring portion and each of the wires is on both sides of each of the LED chips in the specified direction.   2. A plurality of submount members disposed between each of the LED chips and the substrate, wherein a planar size of the submount members is larger than a planar size of the LED chips. 4. The LED module according to any one of items 1 to 3.   The submount member is a light transmissive member having light diffusibility, and both end portions in a direction along the width direction of the sealing portion are exposed without being covered by the sealing portion. The LED module according to claim 4.   6. The LED module according to claim 1, wherein the substrate has a long shape, and the longitudinal direction of the substrate is the prescribed direction. 7.

Images