JP6617452B2 - Linear light source - Google Patents

Description

  The present disclosure relates to a linear light source.

  Conventionally, a linear light source including an annular reflecting wall and a light emitting light source disposed in the reflecting wall has been proposed (for example, Patent Document 1). This linear light source has a long frame portion formed so that a plurality of light emitting elements are arranged on a plate-like base substrate and surrounds all of the plurality of light emitting elements.

JP 2012-227369 A

  Such a linear light source is filled with a translucent resin containing a wavelength conversion member in a region surrounded by a long frame portion surrounding the light emitting element. However, as the length of the light emitting portion increases, the concentration of the wavelength conversion member contained in the translucent resin in the light emitting portion may be biased. For example, the concentration of the wavelength conversion member is different between the first filling point and the last filling point, and color unevenness may occur in the light emitting portion. In view of such circumstances, an object of the present invention is to provide a linear light source in which color unevenness in a light emitting unit is suppressed.

  A linear light source according to an embodiment of the present invention includes a substrate, a pair of electrodes disposed on the substrate, and a plurality of light-emitting elements electrically connected to the electrodes, and the plurality of light-emitting elements. The element is separated into a plurality of light emitting element groups, each of the light emitting element groups is surrounded by a frame body that is spaced apart from each other, and a translucent resin is disposed in the frame body, The resin contains a wavelength converting substance.

  According to the embodiment of the present invention, it is possible to provide a linear light source in which color unevenness in the light emitting unit is suppressed.

It is a top view of the light-emitting device of Embodiment 1 concerning the present invention. It is a side view of the light-emitting device of FIG. It is a part of sectional drawing about the AA line of FIG. It is the elements on larger scale which show an example of embodiment which concerns on this invention. It is the elements on larger scale which show an example of embodiment which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, terminology indicating a specific direction or position as necessary (for example, the “x” direction in the figure is the “longitudinal” direction, the “y” direction is the “width” direction, and the “z” direction is "Height (thickness)" direction, etc.). The use of these terms is to facilitate understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms. Moreover, the part of the same code | symbol which appears in several drawing shows the same part or member.

<First Embodiment>
The linear light source 100 according to the first embodiment will be described with reference to FIGS. For convenience of explanation, the frame bodies 60a, 60b, and 60c in FIG. 1 are illustrated with only the outer shape shown by the two-dot chain lines and transmitted, and the transparent resins 70a, 70b, and 70c are also transmitted. It is shown in a state.

  As shown in FIGS. 1 and 2, the linear light source 100 according to the present embodiment includes a substrate 10, at least a pair of electrodes 21 and 22 disposed on the substrate 10, and disposed on the substrate 10. A plurality of light-emitting elements 50 (81 in this case) electrically connected to 22 are provided. The substrate 10 is long and long in the longitudinal direction (x direction) in a plan view, and has a rectangular flat plate shape.

  The plurality of light emitting elements 50 are arranged in two rows along the longitudinal direction (x direction) of the substrate 10. The light emitting elements arranged in two rows are arranged at shifted positions so as not to overlap in the width direction (y direction). In other words, the lower row of light emitting elements are disposed between the upper row of light emitting elements.

  The plurality of light emitting elements 50 are separated into a plurality of light emitting element groups, and the periphery of each light emitting element group is surrounded by a frame body that is separated from each other. In this embodiment, 27 light emitting elements 50 are separated into three light emitting element groups, each of which is surrounded by frames 60a, 60b, and 60c. That is, 27 light emitting elements 50 are surrounded by one frame, and three frames are arranged.

  As shown in FIG. 1 and FIG. 2, translucent resins 70a, 70b, and 70c are disposed in the regions surrounded by the frames 60a, 60b, and 60c so as to cover the light emitting elements for each light emitting element group. Is done. Light emitted from the light emitting element 50 covered with the light transmitting resin is emitted so as to pass through each light transmitting resin. Here, the frame body is an insulator and is preferably formed of a material capable of reflecting light emitted from the light emitting element 50. The translucent resin is formed in a convex shape so that its upper surface is higher than the upper surface of the frame, thereby reducing the total reflection amount at the interface between the translucent resin and the outside air and increasing the light extraction efficiency. be able to.

  As shown in FIG. 1, each frame body is long and long in the longitudinal direction (x direction), and has a substantially rectangular ring (square ring) shape. That is, the substrate and the frame have a long shape with the same longitudinal direction. Adjacent frames (60a and 60b, 60b and 60c) are arranged so that the short sides of the rectangular shape of the frame are adjacent to each other with an interval at the end in the longitudinal direction. In this way, a linear light source is formed such that the light emitting region is linear by arranging the long light emitting regions side by side in the longitudinal direction.

  In the present embodiment, a linear light source in which color unevenness is suppressed can be formed by arranging a plurality of long frames in a line. In addition, by dividing the frame into a plurality of parts, for example, when forming the frame while discharging resin, the width and height of the frame itself can be stably formed. The shape of is stable. Thereby, it can be set as the linear light source with the uniform width | variety of a light emission area | region.

  The translucent resin contains a wavelength conversion substance such as a phosphor. The wavelength conversion substance absorbs at least a part of the light emitted from the light emitting element 50 and converts it into light having a different wavelength. When forming linear light sources of the same length, the amount of translucent resin filled in one frame can be reduced by arranging a plurality of frames instead of one frame, Variations in the amount of the wavelength converting substance can be suppressed, and color unevenness of the emission color within the frame can be suppressed.

It is sufficient that at least one pair of the electrodes 21 and 22 is provided. In FIG. 1, a pair of electrodes 21 and 22 are provided on one end in the longitudinal direction of the substrate 10 while being outside the frame. In this way, the positive and negative electrodes can be formed at close positions. In order to apply the driving voltage of the light emitting element from the outside, it is preferable that the ends of the pair of electrodes are formed wide. Further, an anode mark or a cathode mark for displaying the polarity may be provided in the vicinity of the end portion.
A pair of electrodes may be provided on a different side of the substrate 10, for example, at one end and the other end. Moreover, you may have a pair or more electrode, for example, when it has two pairs of electrodes, a light emitting element can be lighted by a circuit of two systems. At this time, each light emitting element group may have a pair of electrodes, or one light emitting element group may have two or more electrodes.

  The linear light source of FIG. 1 has a pair of electrodes for lighting all of the plurality of light emitting element groups at a position closer to the end than the frame body 60c. That is, all 81 light emitting elements 50 are electrically connected to the pair of electrodes 21 and 22 via the wires 80 and the light emitting elements 50. The light emitting elements 50 adjacent to each other in the longitudinal direction are electrically connected by a wire 80, and the light emitting elements located at the ends of the adjacent light emitting element groups are adjacent to each other through the relay wiring 23 and the wires. Is electrically connected to the light emitting element located at the end of the. As described above, since the wire can be shortened by connecting the adjacent frames together using the wire and the relay wiring, the wire is stressed when the frame is formed. Can be suppressed.

  The relay wiring 23 provided on the substrate 10 is preferably arranged so that the length of the wire connected to the light emitting element 50 is the shortest. Therefore, in the example of FIG. 1, among the light emitting elements formed in two rows along the longitudinal direction, the relay wiring that connects the light emitting elements on the left side of the sheet is I-shaped, and the light emitting elements on the right side of the sheet are connected. The connecting relay wire is formed in an L shape. In addition, the light emitting elements at the lower end of the sheet, which are folded in two rows, are connected by a wire. Thus, in the example of FIG. 1, 81 light emitting elements are connected in series.

Hereinafter, the elements constituting the linear light source 100 will be described in detail.
(substrate)
The board | substrate 10 is a base material of the linear light source 100, and is a support body which arrange | positions the light emitting element 50 grade | etc.,. It is preferable that the length is long in accordance with the long light emitting region. The substrate 10 is preferably formed of an insulating material having a certain degree of strength, like a substrate of a general semiconductor element. Specific examples thereof include ceramics (Al ₂ O ₃ , AlN, etc.), phenol resins, epoxy resins, polyimide resins, BT resins, polyphthalamides, and the like. These materials are formed into a flat plate shape by a known method. In addition, the magnitude | size of the board | substrate 10 is not restrict | limited, It designs suitably according to the form and application of the light-emitting device provided to a user as a product.

(electrode)
The electrodes 21 and 22 are conductive materials. It only needs to be exposed after sealing with the translucent resin and electrically connectable from the outside. In addition to applying a driving voltage to the light emitting element 50, a voltage may be simultaneously applied to other electronic components (for example, a protective element, a capacitor, etc.).
As a material of the electrode, a metal used as a wiring or an electrode for a general substrate for a semiconductor element can be used, and examples thereof include Au, Cu, Al and the like, and Au is particularly preferable. As will be described later, an Au wire is often applied to the wire, and if it is the same material as the wire, it is easy to join firmly. Alternatively, two or more different metals may be stacked such as by stacking Au on Cu. Lamination may be performed by electroless plating or electrolytic plating. The thickness is not particularly limited, and can be appropriately designed according to wire bonding conditions, resistance as an electrode, and the like. For example, the thickness can be set to 5 to 70 μm.

(Light emitting element)
A known semiconductor light emitting element can be applied to the light emitting element 50. The light emitting element 50 may be selected with an arbitrary wavelength in order to obtain a desired emission color. Specifically, as a light emitting diode that emits blue light (wavelength 430 nm to 490 nm) or green light (wavelength 490 nm to 570 nm), In _X Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, As a light emitting diode that emits red light (wavelength of 620 nm to 750 nm), a nitride semiconductor represented by X + Y ≦ 1), an arsenic compound or a phosphorous compound semiconductor represented by GaAlAs, AlInGaP, etc. Can be applied.

  Further, the light emitting element 50 mounted on the linear light source 100 according to the present embodiment corresponds to face-up (FU) mounting, and the light emitting element 50 has a pair of electrodes formed on the upper surface. Therefore, as shown in FIG. 3, when arranged in the mounting region of the substrate 10, the bottom surface of the light emitting element 50 is bonded to the substrate surface by a known bonding member 52 such as a resin material or solder. Then, both the p electrode and the n electrode of the light emitting element are connected to the wire 80.

(Wire)
The wire 80 is for electrically connecting the light emitting element 50 and other electronic components to the electrodes 21 and 22. The wire 80 is a wire generally used in wire bonding, and examples of the material include Au, Ag, Cu, Pt, Al, and alloys thereof. In particular, Au that is excellent in thermal conductivity and the like and generally applied to the electrode material of the light emitting element 50 is preferable. The diameter of the wire 80 is not particularly limited, and is appropriately selected according to the material of the wire 80, resistance, wire bonding conditions, the specification of the light emitting element 50, and the like.

(Relay wiring)
The plurality of light emitting elements 50 can be connected in series or in parallel by connecting the electrodes of the adjacent light emitting elements with wires, but may be connected through wiring formed on the substrate 10. Such wiring is called relay wiring. For the relay wiring, a metal used as a wiring or an electrode on a general substrate for a semiconductor element can be used in the same manner as the electrodes described above.

  In the example of FIG. 1, two relay wirings 23 are arranged between the frame bodies 60a and 60b and between the frame bodies 60b and 60c. Of the relay wiring 23, two connection portions with the wire are covered with different frame bodies, and the intermediate portion is exposed from the frame body. In FIG. 1, wirings 28 that are intermittently formed along the longitudinal direction are arranged in portions covered by the frame. By using this wiring as a relay wiring, it is possible to freely change the wiring, such as series, parallel, and parallel series.

  At the same time as forming the wiring, the anode mark, the cathode mark, etc. may be formed of the same member, and the temperature measurement point 90 for measuring the temperature when the linear light source is driven may be formed together. The temperature measurement point is preferably provided at a location outside the frame body and close to the frame body.

(Frame)
The frame body protects this by sealing (embedding) the wire 80 and the like together with the translucent resin. Therefore, as shown in FIG. 1, the frame is formed in a rectangular (long rectangular shape) annular shape on the upper surface of the substrate so as to surround the mounting area, and accordingly, the wire 80 connected to these and the relay wiring are formed. Buried. Furthermore, the frame can also function as a reflector for improving the light emission efficiency of the linear light source 100 by reflecting light emitted from the light emitting element 50 to the side by the inner wall surface upward. Or a frame is good also as a structure which is formed with the material which permeate | transmits light, and light is irradiated also to the side of a frame.

The frame body is an insulator and is preferably formed of a material having a certain degree of strength and having a low light transmittance that is difficult for light emitted from the light emitting element 50 and external light to pass through, similarly to the substrate 10. Furthermore, in order to embed the wire 80 previously provided by wire bonding so as not to be deformed as much as possible, the frame is applied with a material that can be formed on the substrate 10 in a liquid or paste form and solidified as it is. Is preferred. In order to form the frame body at a sufficient height as a weir at the time of filling with the translucent resin, a paste-like, that is, a liquid material having a high viscosity (for example, a viscosity of 380 to 450 Pa · s at 25 ° C.) is preferable. . Examples of such materials include thermosetting resins and thermoplastic resins, and specific examples include phenol resins, epoxy resins, BT resins, PPA, and silicone resins. Moreover, it is preferable that a frame is white in order to make a reflectance high. Further, in order to further increase the reflectance of the frame, the resin material is difficult to absorb the light emitted by the light emitting element 50 and has a large refractive index difference with respect to the resin as a base material ( For example, a powder of TiO ₂ , Al ₂ O ₃ , ZrO ₂ , MgO, ZnO, etc.) may be dispersed in advance.

  The frame body does not particularly define the height from the substrate 10, but as shown in FIG. 3, the light emitted from the light emitting element 50 to the side and going outside the irradiation region is directly emitted outside the linear light source 100. It is preferable to set the height so as to form the reflecting surface. In addition, the width of the frame body does not particularly define a width (wall thickness) in plan view, and may be a width that can cover the relay wiring 23 and be formed at a desired height.

As a specific method of forming the frame, a resin discharge device having a discharge port (nozzle) is used to discharge a paste-like resin material to the formation position of the frame on the substrate 10 to form a resin material such as heat treatment. Cured or solidified by corresponding treatment. Alternatively, the frame body is formed by discharging the resin material while horizontally moving the base on which the substrate 10 is placed in accordance with the planar view shape of the frame body so as to draw a rectangle with the discharge port having a diameter matching the width of the frame body. Can also be formed.
In the example of FIGS. 1 and 2, the length of the outermost longitudinal direction (x direction) of one frame is 23 mm, the width of the frame is 1 mm, and the height (z direction) is 0.5 mm. . For example, the length in the longitudinal direction of one frame is preferably about 15 to 30 mm.

(Translucent resin)
A linear light source 100 according to the present embodiment seals (embeds) the light emitting element 50 and the wire 80 to protect them, and transmits light emitted by the light emitting element 50 to extract the light to the outside. And as shown in FIG. 2, each of the area | region divided and divided into three by planar view is equipped with translucent resin 70a, 70b, 70c. Specifically, the translucent resin is formed at a height that does not expose the light emitting element 50 and the wire 80 as described above by filling the inside of the frame with a liquid resin material on the substrate 10 as described above. The Further, the light-transmitting resin contains a wavelength conversion substance and converts the wavelength when light is transmitted.

  As the translucent resin, a translucent resin material used for sealing a general light emitting device on which a light emitting diode or the like is mounted can be applied. Specifically, silicone resin, epoxy resin, urea resin, and the like can be used. Can be mentioned. Moreover, since the frame previously formed on the board | substrate 10 becomes a weir in translucent resin, it is a liquid resin material with comparatively low viscosity (For example, the viscosity in 25 degreeC is 0.01-5. The linear light source 100 according to the present embodiment is suitable for sealing an elongated region. The translucent resins 70a, 70b, and 70c are not mixed with each other because the resin materials are separated from each other by a frame, so that the wavelength conversion substance is contained only in a part of the frame or different types. Other wavelength converting substances may be contained.

  Further, when a wavelength converting substance (for example, a phosphor having a certain specific gravity, for example) is mixed with such a low-viscosity resin material, the wavelength converting substance is likely to settle before being cured, and is thus placed on the substrate 10. The wavelength conversion material is distributed in the vicinity of the surface (upper surface and side surface) of the light emitting element 50, and the light emitted from the light emitting element 50 is suitably wavelength-converted. Further, these resin materials may contain a colorant, a light diffusing agent, a filler, and the like in addition to the wavelength converting substance according to the purpose and application of the linear light source 100. Hereinafter, the wavelength conversion substance contained in the translucent resin will be described.

Any wavelength converting substance may be used as long as it is excited by at least light emitted from the light emitting element and emits light having a different wavelength. For example,
(i) Garnet-based phosphors such as aluminum garnet (eg, yttrium-aluminum-garnet (YAG) phosphors activated with cerium, lutetium-aluminum-garnet (LAG) -based phosphors activated with cerium) ,
(ii) a nitrogen-containing calcium aluminosilicate (CaO—Al ₂ O ₃ —SiO ₂ ) -based phosphor activated with europium and / or chromium,
(iii) a silicate-based ((Sr, Ba) ₂ SiO ₄ ) phosphor activated with europium,
(iv) β-SiAlON phosphor
(v) a nitride phosphor such as CASN (CaAlSiN ₃ : Eu) or SCASN;
(vi) rare earth nitride phosphors such as LnSi ₃ N11 and LnSiAlON (Ln is a rare earth element),
(vii) oxynitride phosphors such as BaSi ₂ O ₂ N ₂ : Eu, Ba ₃ Si ₆ O ₁₂ N ₂ : Eu,
(viii) Fluoride complex phosphor activated with manganese (for example, KSF (K ₂ SiF ₆ : Mn) phosphor),
(iX) sulfide phosphors such as CaS (CaS: Eu), SrGa ₂ S ₄ (SrGa ₂ S ₄ : Eu), SrAl ₂ O ₄ , ZnS,
(X) Chlorosilicate phosphor and the like.

Further, semiconductor materials such as II-VI group, III-V group, IV-VI group semiconductors, specifically, nano-sized high dispersion such as CdSe, core-shell type CdS _x Se _1-x / ZnS, GaP, etc. A so-called nanocrystal, which is a particle, or a light-emitting substance called a quantum dot (Q-Dots) may be used. Since the quantum dot phosphor is unstable, the surface of the particles may be coated or stabilized with PMMA (polymethyl methacrylate), a silicone resin, an epoxy resin, or a hybrid resin thereof.

(Other electronic components)
The linear light source may have other electronic components other than the light emitting element 50 on the substrate 100. For example, rectifiers, fuses, resistors, capacitors, coils, diodes, transistors, and the like. These electronic components may be mounted on electrodes and wirings formed on the substrate 100.

  4 and 5 show examples in which electronic components are mounted on the linear light source 100 of FIG. FIG. 4 is an example in which an electronic component is mounted on the lower end of the linear light source 100 of FIG. 1. A ceramic capacitor and a chip resistor are mounted so as to straddle the wiring 24 and the wiring 25 for connecting the electronic component. Yes. FIG. 5 shows an example in which an electronic component is mounted on the upper end of the linear light source 100 in FIG. 1, and a fuse is mounted so as to straddle the wiring 26 and the wiring 27 for connecting the electronic component. Further, a rectifier is mounted so as to straddle the pair of electrodes 21 and 22 and the wirings 25 and 26 that connect the electronic components. The wirings 24 and 27 are formed at the ends in the longitudinal direction of the substrate 10 so as to extend in a direction orthogonal to the longitudinal direction. Further, the wiring 25 is long in the longitudinal direction and is arranged extending from one end to the other end, and a portion adjacent to the frame is covered with a resist 30.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is not limited to the said embodiment, What was variously changed and changed based on these description is also contained in the meaning of this invention. Needless to say.

  The linear light source according to the embodiment of the present disclosure includes an illumination light source, various indicator light sources, an in-vehicle light source, a display light source, a liquid crystal backlight light source, a sensor light source, a traffic light, an in-vehicle component, a signboard channel letter, and the like. Can be used for various light sources.

DESCRIPTION OF SYMBOLS 100 Linear light source 10 Board | substrate 21, 22 Electrode 23 Relay wiring 24, 25, 26, 27, 28 Wiring 30 Resist 42 Ceramic capacitor 44 Chip resistance 46 Fuse 48 Rectifier 50 Light emitting element 52 Joining member 60a, 60b, 60c Frame 70a, 70b, 70c Translucent resin 80 Wire 90 Temperature measurement point

Claims (10)

A substrate,
A pair of electrodes disposed on a substrate;
A plurality of light emitting elements electrically connected to the electrodes,
The plurality of light emitting elements are separated into a first light emitting element group and a second light emitting element group adjacent to the first light emitting element group, and the first light emitting element group is surrounded by a first frame. The periphery of the two light emitting element groups is surrounded by a second frame , a first translucent resin is disposed in the first frame, and a second translucent resin is disposed in the second frame. ,
The first translucent resin and the second translucent resin contain a wavelength conversion substance ,
The first frame and the second frame contain a light reflecting material,
The first light emitting element group is electrically connected to wiring arranged on the substrate via a first wire,
The second light emitting element group is electrically connected to the wiring via a second wire,
The first frame body embeds the wiring and the first wire,
The second frame is a linear light source in which the wiring and the second wire are embedded . The linear light source according to claim 1, wherein the substrate , the first frame body, and the second frame body have a long shape having the same longitudinal direction. The linear light source according to claim 2, wherein the pair of electrodes is disposed at one end of the substrate in the longitudinal direction. The linear light source according to claim 2 , wherein the plurality of light emitting elements are arranged along a longitudinal direction of the substrate. 5. The linear light source according to claim 2, further comprising a wiring extending in a direction orthogonal to the longitudinal direction at an end of the substrate in the longitudinal direction. The linear light source according to claim 1 , wherein all of the plurality of light emitting elements are connected in series. The first frame body embeds a connection portion between the first wire and the wiring,
The linear light source according to claim 1, wherein the second frame body embeds a connection portion between the second wire and the wiring. The linear light source according to claim 1, wherein the wiring has an intermediate portion exposed from the first frame body and the second frame body. The linear light source according to claim 3, wherein the light emitting elements adjacent to each other in the longitudinal direction are electrically connected to each other by a third wire. The linear light source according to claim 3, which is dependent on claim 2 or claim 2, wherein the plurality of light emitting elements are arranged in two rows along the longitudinal direction. .

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