JP5236366B2 - Linear light source device and planar illumination device - Google Patents

Description

  The present invention relates to a linear light source device configured by arranging a plurality of bare-chip light emitting elements in one direction, and a sidelight type planar illumination device using the same, and in particular, has a relatively large display area. The present invention relates to a planar illumination device suitable for a backlight for a liquid crystal display panel.

  Since the liquid crystal display panel, which is characterized by being thin, does not emit light by itself, an illuminating unit is required to display an image. As this illumination means, a so-called side-light type planar illumination device in which a light source is disposed on the side surface (light incident surface) of the light guide plate is advantageous in reducing the thickness, so that the field of small portable information devices such as cellular phones is used. Widely adopted mainly in As a light source arranged on the light incident surface of the light guide plate, an LED (Light Emitting Diode) excellent in miniaturization and low power consumption is frequently used.

  Recently, as the performance of side-light type planar lighting devices using LED as a light source has increased, its application fields have expanded, for example, relatively display used in car navigation, notebook computers, desktop computers, etc. It is also being applied to liquid crystal display panels having a large area.

  In order to apply a sidelight type planar illumination device using LEDs as a light source to such a liquid crystal display panel having a relatively large display area, a larger number of LEDs are inserted into the light guide plate in response to the expansion of the illumination area. It is necessary to increase the amount of light emitted from each LED by arranging it on the light surface or increasing the current supplied to the LED. As a means for increasing the number of LEDs, instead of a point light source configured by arranging one LED chip (LED bare chip) in one conventional package, a plurality of LED chips are arranged in one direction in one package ( The use of linear light sources that are arranged close to each other (linearly) has been studied.

  Conventionally, for example, a linear illumination device 70 shown in FIG. 11 is known as a light source configured by arranging a plurality of LED chips in one package. The linear illumination device 70 is configured by resin-sealing a plurality (three) of LED chips 72 mounted on a strip-like insulating substrate 71 provided with a wiring pattern with a translucent sealing resin 73. ing. In addition, housings (frame bodies) 74 formed of white resin are attached to both ends of the insulating substrate 71. A lead wire is connected to the insulating substrate 71, and power is supplied to the LED chip 72 mounted on the insulating substrate 71 via the lead wire (see Patent Document 1).

JP 2004-165124 A

  By the way, when a relatively large number of LED chips are arranged close to each other, the temperature of the LED chip rises due to the heat generated by the light emission of the LED chip, the light emission efficiency of the LED chip is lowered and the product life is shortened. There is a problem. In this regard, the linear illumination device 70 disclosed in Patent Document 1 is excellent in thermal conductivity instead of the insulating substrate 71 because the wiring pattern is formed on the insulating substrate 71 on which the LED chip 72 is mounted. A metal substrate cannot be used. Therefore, the heat generated from the LED chip 72 cannot be efficiently released to the outside through the mounting substrate (insulating substrate 4), resulting in a problem that the temperature of the LED chip rises.

  Further, since there is no housing (frame body) at both ends in the short direction (direction orthogonal to one direction) of the insulating substrate 71, light emitted from the LED chip 72 in the short direction is forward (light guide plate). In order to travel in the direction toward the light incident surface, there is a problem that it is necessary to separately arrange a reflecting member (reflecting wall) that changes the traveling direction of the light in the short direction.

  On the other hand, with respect to the longitudinal direction (one direction) of the insulating substrate 71, housings (frame bodies) 74 formed of white resin are attached to both ends of the insulating substrate 71. With this configuration, the light emitted from the LED chip 72 in the longitudinal direction can be reflected forward by the housing 74. However, since the housing (frame body) 74 does not exist between the two adjacent LED chips 72, it is impossible to control the light traveling direction (emission direction) for each LED chip 72, and the linear illumination device 70. There is a problem that a luminance distribution may occur in the light emitted from the light source. Further, there is a problem that the emitted light is absorbed by the adjacent LED chip 72 and the luminance may be lowered.

  Further, when a plurality of linear illumination devices 70 composed of a plurality of LED chips 72 are arranged along the light incident surface of the light guide plate, the wiring around the power supply to the LED chips becomes complicated. When assembling, it is necessary to pay sufficient attention to disconnection or the like, and there is a problem that the assembling workability of the apparatus is lowered.

  Therefore, the present invention has been made in view of the above problems, and even when the number of light emitting element chips (LED bare chips) arranged close to each other is increased, heat generated from the light emitting element chips is efficiently generated. And a linear light source device capable of adjusting the traveling direction of light for each light emitting element chip, and using this linear light source device, high luminance and uniform luminance It is an object of the present invention to provide a planar lighting device that is excellent in device assembly workability.

In order to achieve the above object, the present invention is characterized in that a plurality of light emitting element chips arranged in one direction, an insulating substrate in which through holes for accommodating the plurality of light emitting element chips are formed, and the insulating substrate A metal substrate on which the plurality of light emitting element chips are mounted, a conductor pattern formed on the other surface side of the chip housing substrate, and the plurality of light emitting element chips on the conductor pattern. A metal connection electrically connected to the plurality of light emitting element chips and a resin sealing body that covers the metal connection, and the metal substrate has a substantially intermediate position between two adjacent light emitting element chips, The linear light source device is configured by forming a slit extending in a direction orthogonal to the one direction .

  In this case, it is preferable that the side surface of the through hole formed in the insulating substrate is formed so as to expand from one surface side of the insulating substrate toward the other surface side. Moreover, it is preferable that a reflective film is formed on the side surfaces of the plurality of through holes formed in the insulating substrate.

According to this invention, the conductor pattern is formed on the surface (the other surface) of the insulating substrate in which the through holes for accommodating the plurality of light emitting element chips are formed. For this reason, a metal substrate (conductive substrate) excellent in thermal conductivity can be used as a substrate which is disposed on the back surface (one surface) of the insulating substrate and mounts a plurality of light emitting element chips. Thereby, the heat generated from the plurality of light emitting element chips can be released to the outside (back side) through the metal substrate. As a result, the temperature rise of the plurality of light emitting element chips is suppressed, and the decrease in the effective efficiency is suppressed. In addition, the current supplied to the light emitting element chip can be increased, and the amount of light emitted from the linear light source device can be increased without increasing the number of light emitting element chips. According to the invention, the slit extending in the direction orthogonal to the one direction is formed at a substantially intermediate position between the two adjacent light emitting element chips on the metal substrate. Thereby, it is expected that the unevenness of heat generated from the plurality of light emitting element chips is suppressed, and the temperature of each light emitting element chip is equalized. By equalizing the temperature of the light emitting element chip, the amount of emitted light for each light emitting element chip is equalized.

  The plurality of light emitting element chips are accommodated in through holes formed in the insulating substrate. For this reason, the side surface of the through-hole in the short direction can function as a reflecting wall that changes the traveling direction of light. In addition, when a plurality of through holes are provided and one LED chip is assigned to each through hole, the emission direction can be controlled for each light emitting element chip with respect to the short side direction and the long side direction. Become. As a result, a linear light source device having high luminance and excellent luminance uniformity can be realized.

  Further, by forming a conductor pattern on the surface of the insulating substrate, a circuit board for transmitting an electric signal supplied from the outside to the light emitting element chip can be arranged along the longitudinal direction of the linear light source device, The conductor pattern and the circuit board can be easily connected. As a result, the wiring area is simplified and the assembly workability of the apparatus is improved.

Another feature of the present invention is that a frame-like body having a light reflecting function and covering the periphery of the resin sealing body is formed on the other surface side of the insulating substrate.
According to this invention, since the outer peripheral surface of the resin sealing body is covered with the frame-like body having a light reflecting function, leakage of light from the outer peripheral surface of the resin sealing body is suppressed. Thereby, the light quantity (effective light) radiate | emitted from the light emission surface of a linear light source device increases more.

  Another feature of the present invention is that the linear light source device having any one of the above features, a light incident surface that receives light emitted from the linear light source device, and light that enters from the light incident surface. A light guide plate having an emission surface to be emitted; and a heat sink to be brought into contact with the metal substrate of the linear light source device.

  In this case, the heat sink can be constituted by a part of a housing frame made of a metal material for accommodating the linear light source device and the light guide plate.

  In this case, the heat sink may be formed by cutting and raising a part of a floor plate portion on which the linear light source device and the light guide plate of the housing frame made of the metal material are mounted.

  According to this invention, heat generated from a plurality of light emitting element chips can be released to a heat sink (a housing frame made of a metal material) via the metal substrate of the linear light source device. Thereby, the temperature rise of a light emitting element chip | tip can be suppressed, and the fall of effective efficiency can be suppressed. Further, the current supplied to the light emitting element chip can be increased, and the amount of light emitted from the linear light source device, and thus the planar illumination device, can be increased without increasing the number of light emitting element chips. In addition, it is possible to realize a planar illumination device that effectively exhibits other functions and effects of the linear light source device according to the present invention.

[First Embodiment]
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an exploded perspective view showing the overall configuration of a planar illumination device 1 according to the first embodiment of the present invention, and FIG. 2 shows the linear light source device 2 according to the first embodiment of the present invention. It is a see-through | perspective perspective view which shows the whole structure. FIG. 3 is a transverse sectional view of the linear light source device 2, and FIG. 4 is a longitudinal sectional view of the linear light source device 2.

(Device configuration)
As shown in FIG. 1, the planar illumination device 1 includes a linear light source device 2 formed in a linear shape and a top view in which the linear light source device 2 is disposed along a light incident surface 12 a that is one side end surface. A rectangular light guide plate 12, a box-shaped housing frame 13 that accommodates the linear light source device 2 and the light guide plate 12, and a strip-shaped FPC (Flexible Printed) arranged in parallel with the upper surface of the linear light source device 2 in the figure. Circuit; flexible printed circuit board) 14. A diffusion sheet 15 and two prism sheets 16 and 17 are superimposed on the upper surface (outgoing surface) side of the light guide plate 12, and a reflective sheet 18 is disposed on the lower surface (reflective surface) side of the light guide plate 11. Has been.

  As shown in FIG. 2, the linear light source device 2 includes a plurality (four in this embodiment) of LED chips 3 (light emitting element chips) arranged in a straight line (one direction) and a central portion in the thickness direction. Insulating substrate 4 having a rectangular shape in plan view and a plurality of LED chips 3 that are formed along the longitudinal direction (coincident with one direction) of insulating substrate 4 and accommodate each of the plurality of LED chips 3 (in this embodiment, 4) through-holes 5, a metal substrate 6 on which the plurality of LED chips 3 are mounted, and a front surface 4f which is the other surface of the insulating substrate 4 are disposed on the back surface 4b side which is one surface of the insulating substrate 4. And a conductor pattern 7 formed on the side. Further, the linear light source device 2 includes a plurality of LED wires 3 that are electrically connected to the conductor pattern 6 from a bonding wire 8 (metal connection, not shown in FIG. 4) and a surface 4f side of the insulating substrate 4. And a resin sealing body 9 that integrally covers the LED chip 3 and the bonding wire 8.

  In the present embodiment, the LED chip 3 is a blue LED chip that emits blue light (410 nm to 480 nm). The four LED chips 3 are arranged with a predetermined distance from the adjacent LED chips 3. Each LED chip 3 is formed with a pair of electrode pads (not shown) on the surface (light emitting surface of the LED chip) 3a side.

  The insulating substrate 4 is, for example, a substrate (in this embodiment, a glass epoxy substrate) excellent in insulation and workability, and the thickness thereof is formed to be larger than the thickness of the LED chip 3. In the insulating substrate 4, four through holes 5 penetrating in the thickness direction are formed at predetermined intervals in the longitudinal direction (corresponding to the arrangement intervals of the LED chips 3). Each of the four LED chips 3 is accommodated in the four through holes 5. Moreover, each LED chip 3 is arrange | positioned in the approximate center part of each through-hole 5 in planar view.

  The through-hole 5 has a rectangular opening shape, and as shown in FIGS. 3 and 4, the side surface 5a has four side walls 5aa to 5ad (longitudinal side walls 5aa and 5ab, short side walls 5ac and 5ad). It is composed of The four side walls 5aa to 5ad are formed so as to expand from the back surface 4b side of the insulating substrate 4 toward the front surface 4f side. Further, a reflective film 5r made of, for example, silver or aluminum is formed on the four side walls 5aa to 5ad. Thereby, the light radiate | emitted to the side from LED chip 3 can be efficiently guide | induced to the light-guide plate 11 direction by reflecting by side wall 5aa-5ad.

  The metal substrate 6 is formed using a metal material (copper in this embodiment) excellent in thermal conductivity. The metal substrate 6 is formed in a size that integrally covers the openings of the four through holes 5 when the front surface 6 a is bonded to the back surface 4 b of the insulating substrate 4. Four LED chips 3 are mounted on the surface 6 a side of the metal substrate 6. Therefore, the back surface 3b of the LED chip 3 and the back surface 4b of the insulating substrate 4 are arranged to be flush with each other. Moreover, since the thickness of the insulating substrate 4 is thicker than the thickness of the LED chip 3 as described above, the front surface 3a of the LED chip 3 is located closer to the back surface 4b side of the insulating substrate 4 than the front surface 4f of the insulating substrate 4. . That is, the entire periphery of the LED chip 3 is covered with the side surface 5a (side walls 5aa to 5ad) of the through hole 5.

  The conductor pattern 7 is formed on the surface 4f of the insulating substrate 4 by, for example, copper foil, and is arranged at three relay portions 7a arranged between two adjacent through holes 5 and at both ends in the longitudinal direction of the insulating substrate 4. And a pair of terminal portions 7b. The four LEDs 4 are connected in series by connecting the pair of electrode pads formed on the emission surface 3a, the relay portion 7a, and the pair of terminal portions 7b with bonding wires 8, respectively. The pair of terminal portions 7 b are terminals for electrical connection with the FPC 14. In the present embodiment, the pair of terminal portions 7b are formed so as to cover the side end surfaces of the insulating substrate 4. However, the present invention is not limited to this, as long as it can be electrically connected to the FPC 13. Good.

  The resin sealing body 9 is formed from a translucent material (silicone resin in the present embodiment). In the translucent material, a yellow phosphor that receives blue light emitted from the LED chip 3 and emits yellow component light is dispersed. That is, the resin sealing body 9 is formed so that predetermined white light can be obtained by mixing blue light emitted from the LED chip 3 and yellow light emitted from the yellow phosphor.

  The resin sealing body 9 includes a filling portion 10 that fills the inside of the through hole 5 and an emission portion 11 that is exposed on the surface 4 f side of the insulating substrate 4 so as to cover the entire bonding wire 8. The emission part 11 is in the form of a horizontally long thin plate, and is located at the light emitting surface 11a (which is also the light emitting surface 2a of the linear light source device 2) which is a rectangular flat surface on the front side of the LED chip 3 and at both ends in the longitudinal direction. A pair of short end surfaces 11b having a short length and a pair of long end surfaces 11c having a long length located at both ends in the short direction. The short end surface 11 b is located inside the corresponding side surface of the insulating substrate 4 in order to expose a part of the pair of terminal portions 7 b of the conductor pattern 7. On the other hand, the long end surface 11 c is formed flush with the corresponding side surface (the longer side surface) of the insulating substrate 4.

  The light guide plate 12 is formed of, for example, a transparent resin (in this embodiment, polycarbonate). A light incident prism (not shown) is formed on the light incident surface 12 a of the light guide plate 12, and the linear light source device 2 is disposed so that the light emitting surface 2 a faces the light incident surface 12 a. The light incident prism is for allowing the light emitted from the linear light source device 2 to propagate through the light guide plate 12 with a predetermined spread angle. Further, on the lower surface (reflecting surface) of the light guide plate 12, optical path changing means (not shown) for scattering the light incident from the linear light source device 2 into the light guide plate 12 and emitting it from the exit surface of the light guide plate 12. ) Is formed.

  The housing frame 13 is formed using, for example, a metal material (aluminum in this embodiment) excellent in light reflectivity and heat transfer property, and a light guide plate on a planar floor plate portion 13a via a reflection sheet 18. 12 and the linear light source device 2 are placed. Further, the linear light source device 2 is arranged such that the back surface 6 b of the metal substrate 6 is in contact with the inner side surface of the side frame portion 13 b of the housing frame 13. With this configuration, heat generated from the plurality of LED chips 3 is transmitted to the housing frame 13 via the metal substrate 6 and is radiated to the outside. As a result, the temperature rise of the LED chip 3 is suppressed. That is, the side frame portion 13 b of the housing frame 13 is configured to function as a heat sink that absorbs and dissipates heat generated from the linear light source device 2.

  The FPC 14 is a circuit board for supplying an electric signal from the outside to the linear light source device 2, and is arranged along the longitudinal direction on the upper surface side of the linear light source device 2. The FPC 14 has a wiring pattern (not shown) formed on the surface facing the upper surface of the linear light source device 2. Further, as shown in FIG. 1, the FPC 14 is formed with a pair of branch wiring portions 14b extending vertically from both end portions of the rectangular main body portion 14a. The branch wiring portion 14 b is electrically connected to the pair of terminal portions 7 b of the conductor pattern 7 in the linear light source device 2. With this configuration, an electrical signal from a drive circuit unit (not shown) arranged outside can be energized to the plurality of LED chips 3 via the FPC 14 to cause the LED chips 3 to emit light.

  The diffusion sheet 15 has a function of diffusing the light emitted from the exit surface of the light guide plate 12 to make the brightness uniform. The prism sheets 16 and 17 are light beams whose brightness is made uniform by the diffusion sheet 15. It has a function of adjusting the viewing angle distribution in the biaxial direction. The reflection sheet 18 is for returning light leaking from the lower surface of the light guide plate 12 to the light guide plate 12. These optical sheets are appropriately selected and used in accordance with the specifications required for the lighting device.

(Method for producing linear light source device)
Next, an example of a method for manufacturing the linear light source device 2 will be described with reference to FIG. In addition, although the figure is sectional drawing, hatching is abbreviate | omitted in order to make a figure legible. First, the copper foil 7f used as the conductor pattern 7 is affixed on the surface 4f of the glass epoxy board | substrate 4s used as the insulated substrate 4 (the figure (a)). Note that the copper foil 7f may be formed by plating instead of attaching the copper foil 7f. Next, the through-hole 5 is formed from the copper foil 7f side toward the back surface 4b of the glass epoxy substrate 4s using a drill with a thin tip. At this time, the through-hole 5 in which the side surface 5a is inclined can be formed by gradually approaching the processing outer edge toward the center every time the processing depth of the drill is increased. Thereby, the insulating substrate 4 having the through holes 5 having a predetermined shape is obtained (FIG. 5B).

  Next, a copper plate as the metal substrate 6 is attached to the back surface 4b of the insulating substrate 4 ((c) in the figure). Subsequently, silver plating is applied from the side where the copper foil 7f is adhered, and a reflective film 5r is formed on the side surface 5a of the through hole 5 and the exposed surface of the metal substrate 6 ((d) in the figure). Next, the reflective film 5r and the copper foil 7f are etched to form a conductor pattern 7 having a predetermined shape ((e) in the figure).

  Next, the LED chip 3 is inserted into the through hole 5 and fixed on the metal substrate 6 using an adhesive. Subsequently, the electrode of the LED chip 3 and the conductor pattern 7 are electrically connected by the bonding wire 8 ((f) in the figure). And finally, the linear light source device 2 is completed by forming the resin sealing body 9 by a molding method ((g) of the figure).

(Operation / effect of the device)
Next, the operation of the linear light source device 2 and the planar illumination device 1 according to the first embodiment will be described.
An electric signal from a control circuit unit that drives an object to be illuminated (in this embodiment, a liquid crystal display panel) is energized to the plurality of LED chips 3 via the FPC 14. The plurality of LED chips 3 emit blue light based on the electrical signal. Part of the blue light is converted into yellow light by the yellow phosphor mixed in the resin sealing body 9, and the blue light and the yellow light are mixed to generate white light. The light emitted from the light emitting surface 2 a of the linear light source device 2 enters the light guide plate 12 from the light incident surface 12 a of the light guide plate 12. The light that has entered the light guide plate 12 is propagated through the light guide plate 12, the light path is changed by the light path changing means formed on the reflection surface of the light guide plate 12, and is emitted from the light exit surface of the light guide plate 12. The light emitted from the emission surface of the light guide plate 12 is adjusted to a predetermined luminance distribution by passing through the diffusion plate 15 and the pair of prism sheets 16 and 17 and then incident on the back surface of the liquid crystal display panel. Thereby, the image produced | generated by a liquid crystal display panel is visually recognized by the observer of the surface side.

  The linear light source device 2 and the planar illumination device 1 configured as described above have the following effects. That is, the metal substrate 6 excellent in thermal conductivity is used for the substrate on which the plurality of LED chips 3 are mounted. Thereby, the heat generated from the plurality of LED chips 3 can be released to the heat sink (the side frame portion 13b of the housing frame 13 made of a metal material constituting the planar lighting device 1) via the metal substrate 6. . As a result, the temperature rise of the plurality of LED chips 3 is suppressed, and the decrease in the effective efficiency is suppressed. In addition, the current to be supplied to the LED chip 3 can be increased, and the amount of light emitted from the linear light source device 2 can be increased without increasing the number of LED chips 3. Thereby, the brightness | luminance of the planar illuminating device 1 improves.

  The plurality of LED chips 3 are accommodated in the plurality of through holes 5 formed in the insulating substrate 4 and having rectangular openings. For this reason, the side walls 5ac and 5ad in the short direction of the through-hole 5 can function as reflecting walls in the short direction. Further, when a plurality of through-holes 5 are provided and one LED chip 3 is arranged for each through-hole 5 as in this embodiment, the LED chips 3 are formed by the side walls 5aa and 5ab in the longitudinal direction. It becomes possible to control the emission direction with respect to the longitudinal direction for each. Thereby, the linear light source device 2 and the planar illumination device 1 having high luminance and excellent luminance uniformity can be realized.

  Further, by forming the side surface 5a of the through hole 5 so as to expand from the back surface 4b side of the insulating substrate 4 toward the front surface 4f side, the light reflected by the side surface 5a of the through hole 5 is directed toward the light emitting surface 2a. Can be guided efficiently. Further, by forming the reflective film 5 r on the side surface 5 a of the through hole 5, a high reflectance can be ensured without depending on the reflectance of the insulating substrate 4.

  In addition, a conductor pattern 7 that transmits an electrical signal to the LED chip 3 is formed on the surface 4f of the insulating substrate 4 in which the through holes 5 that accommodate the plurality of LED chips 3 are formed. And a part of a pair of terminal part 7b for electrically connecting with a pair of branch wiring part 14b of FPC14 is exposed to the both ends of the insulating substrate 4. FIG. Thereby, the strip-shaped FPC 14 can be arranged along the longitudinal direction of the linear light source device 2, and the conductor pattern 7 and the FPC 14 can be easily connected. As a result, the wiring area is simplified and the assembly workability of the apparatus is improved.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to the accompanying drawings. The difference between the second embodiment and the first embodiment is a linear light source device 22, and other components are common to the first embodiment. Therefore, the linear light source device 22 will be described below. Moreover, the same code | symbol is attached | subjected about the component which is common in the linear light source device 2, and duplication description is abbreviate | omitted.

  As shown in FIGS. 6A and 6B, the linear light source device 22 is arranged in a plurality of (four in the present embodiment) LED chips 3 arranged in one direction and in the center in the thickness direction. Insulating substrate 4 having a rectangular shape in plan view, and a plurality of (four in this embodiment) penetrations that are formed along the longitudinal center line of insulating substrate 4 and each accommodate a plurality of LED chips 3. A hole 5, a metal substrate 6 disposed on the back surface 4 b side of the insulating substrate 4 and on which the plurality of LED chips 3 are mounted, and a conductor pattern 7 formed on the surface 4 f side of the insulating substrate 4 are provided.

  Further, the linear light source device 22 integrates the bonding wires 8 that electrically connect the plurality of LED chips 3 to the conductor pattern 7 and the plurality of LED chips 3 and the bonding wires 8 from the surface 4f side of the insulating substrate 4. And a resin sealing body 29 covered therewith. The resin sealing body 29 includes a filling portion 30 that fills the inside of the through hole 5 and an emission portion 31 that is exposed on the surface 4 f side of the insulating substrate 4 so as to cover the entire bonding wire 8. The linear light source device 22 includes a frame body 24 that covers the outer peripheral surface of the emitting portion 31 of the resin sealing body 29.

  The frame-like body 24 is formed in a frame shape having a rectangular shape in plan view using, for example, a resin material excellent in light reflection performance (in this embodiment, a liquid crystal polymer mixed with a white pigment such as titanium oxide). Yes. That is, the frame-like body 24 is composed of a pair of long side walls 24a and 24b having a long length and a pair of short side walls 24c and 24d having a short length.

  The pair of long side walls 24 a and 24 b are formed so that the outer peripheral surfaces thereof are flush with the corresponding outer peripheral surfaces of the insulating substrates 4 as shown in FIG. On the other hand, the pair of short side walls 24c and 24d are formed such that the outer peripheral surfaces thereof are located inside the corresponding outer peripheral surfaces of the insulating substrates 4 as shown in FIG. With this configuration, a part of the pair of terminal portions 7b constituting the conductor pattern 7 is exposed to the outside.

  In addition, the frame-like body 24 is formed so that an end surface 24e on the emission side is flush with a light emitting surface 31a (also a light emitting surface 22a of the linear light source device 22) that is a flat surface in front of the emitting unit 31. ing.

  The resin sealing body 29 is different from the resin sealing body 9 in the first embodiment only in the shape of the emission part 31. Specifically, the emission part 31 is smaller in outer thickness than the emission part 11 in the first embodiment by the thickness of the frame-like body 24. The resin sealing body 29 can be formed by, for example, filling the frame material 24 to the surface 4f of the insulating substrate 4 and then filling the resin material constituting the resin sealing body 29 by a potting method. it can.

  The linear light source device 22 having the above-described configuration and the planar illumination device 21 (not shown) using the linear light source device 22 as a light source can obtain the operations and effects described in the first embodiment. In addition, the linear light source device 22 has the following effects because the outer peripheral surface of the emitting portion 31 of the resin sealing body 29 is covered with the frame body 24 having excellent light reflection performance. That is, in the case of the emission part 11 according to the first embodiment, light may leak somewhat from the outer peripheral surface (the short end face 11b and the long end face 11c) of the emission part 11. On the other hand, in the linear light source device 22, since the outer peripheral surface of the emitting part 31 is covered with the frame body 24, the light traveling on the outer peripheral surface of the emitting part 31 is reflected by the frame body 24. The light can be emitted from the light emitting surface 31a. Therefore, the amount of light emitted from the light emitting surface 31a increases, and the amount of light incident on the light guide plate 12 increases. Thereby, the brightness | luminance of the planar illuminating device 21 improves.

  In the above-described embodiment, the frame-like body 24 is formed as a separate body from the insulating substrate 4, but is not limited thereto, and may be formed integrally with the insulating substrate 4. Thereby, the number of parts can be reduced and workability is improved.

  Moreover, you may comprise a frame-shaped body as the frame-shaped body 34 of 22 A of linear light source devices shown in FIG. That is, in addition to the pair of long side walls 34a and 34b having a long length constituting the outer frame (frame) and the pair of short side walls 34c and 34d having a short length, the emitting portion 31a of the resin sealing body 29a is formed in the through hole 5. A plurality of (three in the illustrated example) partition walls 34e may be provided. Thereby, the traveling direction of light can be adjusted also by the partition wall 34e. Moreover, according to the light emission color of the LED chip 3 arrange | positioned at each through-hole 5, the component (for example, content of yellow fluorescent substance) which comprises the resin sealing body 29a for every through-hole 5 is adjusted. Is possible.

  In the above-described embodiment, the end surface 24e of the frame-like body 24 and the light emitting surface 31a of the emitting portion 31 are formed to be flush with each other. However, the present invention is not limited to this, and as shown in FIG. The end surface 44e of the shaped body 44 may be configured to project forward from the light emitting surface 31a of the emitting portion 31. In this case, the linear light source device 22B and the light guide plate are inserted by inserting a portion in the vicinity of the light incident surface 12a of the light guide plate 12 indicated by a two-dot chain line in FIG. 12 can be integrated. Thereby, the light emitted from the linear light source device 22B can be stably guided to the light guide plate 12, and stable illumination light can be obtained. Further, the light emitted from the linear light source device 22B can be guided to the light guide plate 12 without leaking outside in the vicinity of the light incident surface 12a.

  Further, after inserting a portion in the vicinity of the light incident surface 12a of the light guide plate 12 inside the protruding portion 44f of the frame-like body 44, the resin constituting the resin sealing body 29 is thermally cured, thereby sealing the resin. The body 29 and the light guide plate 12 can be integrated (adhered) without an air layer. Thereby, Fresnel reflection loss is reduced, and further improvement in luminance can be expected.

[Modification]
The preferred embodiments of the present invention have been described above, but the embodiments are not limited to the above, and various modifications and combinations are possible.

  For example, like the linear light source device 32 shown in FIG. 9, a slit 26 a extending in the short direction may be provided at a substantially intermediate position between the two LED chips 3 adjacent to each other on the metal substrate 26. By providing the slit 26a in the metal substrate 26, uneven distribution and concentration of heat generated from the LED chip 3 is suppressed, and the temperature of the LED chip 3 is equalized. By equalizing the temperature of the LED chip 3, it is possible to expect equalization of the amount of light emitted from each LED chip 3.

  Moreover, about the heat sink, although the side frame part 13b which is a part of the housing frame 13 which consists of metal materials demonstrated the form which also serves as a heat sink, it is not limited to this. For example, a block-shaped heat sink may be configured to contact the metal substrates 6 and 26 of the linear light source devices 2 to 32. In this case, a housing frame made of a resin material can be used. The chip mounting substrate on which the plurality of LED chips 3 are mounted is replaced with a substrate made of a metal material (metal substrates 6 and 26), and an insulating substrate (Al2O3) such as a ceramic substrate or a single crystal substrate having excellent thermal conductivity. , AlN, diamond, etc.) can also be used. Alternatively, a substrate formed by laminating a metal material and an insulating material can be used as the chip mounting substrate.

  Further, as shown in FIG. 10, the floor plate portion 23a constituting the housing frame 23 made of a metal material is cut and raised upright at a position where the linear light source devices 2 to 32 are arranged on the floor plate portion 23a. It is good also as a structure which forms the part 23c by sheet metal processing etc., and this cut-and-raised part 23c contacts the metal substrates 6 and 26 of the linear light source devices 2-32. Thereby, the heat | fever of the linear light source devices 2-32 can be discharge | released outside via the cut-and-raised part 23c. In this case, the cut-and-raised portion 23c can also function as a pressing means for pressing the linear light source devices 2 to 32 against the light guide plate 12 side.

  Moreover, in the said embodiment, although it was set as the structure which arrange | positions one LED chip 3 in each through-hole 5, it is good also as a structure which arranges two or more LED chips 3 in one through-hole 5. FIG.

  Further, in the above embodiment, the inclination angle of the side walls 5aa to 5ad of each through hole 5 is constant regardless of the through hole 5, but considering the luminance distribution of the entire light emitting surface 2a, 22a, for each through hole 5, Alternatively, the inclination angle may be changed for each of the side walls 5aa to 5ad. Further, the side walls 5aa to 5ad may be formed in a curved shape instead of a flat shape. Moreover, the opening shape of the through-hole 5 is not limited to a rectangle, For example, it may be formed in the shape of a curve. Furthermore, the reflective film 5r is not necessarily provided on the side surface 5a of each through-hole 5.

  The LED chip 3 is not limited to the blue LED chip, and may be, for example, a red LED chip that emits red light or a green LED chip that emits green light. Further, when three types (three primary colors) of LED chips are applied as light emitting element chips, three types of LED chips may be arranged as a set in each of the through holes 5. Further, the phosphor dispersed in the resin sealing bodies 9 and 29 in the case of using a blue LED chip is not limited to the yellow phosphor. For example, the phosphor that emits green light and the phosphor that emits red light. The fluorescent substance which consists of may be sufficient.

  Moreover, although the case where the several LED chip 3 was connected in series was demonstrated, it is not limited to this, You may connect in parallel. Furthermore, the number of the linear light source devices 2 to 32 arranged along the light incident surface 12a of the light guide plate 12 is not limited to one, and may be plural. Further, the linear light source devices 2 to 32 may be arranged on other side end surfaces of the light guide plate 12 other than the light incident surface 12a.

It is a disassembled perspective view which shows the whole structure of the planar illuminating device which concerns on the 1st Embodiment of this invention. 1 is a perspective view showing an overall configuration of a linear light source device according to a first embodiment of the present invention. It is a cross-sectional view of the same linear light source device. It is a longitudinal cross-sectional view of the same linear light source device. It is a figure for demonstrating the manufacturing process of the linear light source device which concerns on the 1st Embodiment of this invention. It is a figure which shows the linear light source device which concerns on the 2nd Embodiment of this invention, (a) is a see-through | perspective perspective view which shows the whole structure, (b) is a longitudinal cross-sectional view. It is a cross-sectional view which shows the modification of the linear light source device which concerns on the 2nd Embodiment of this invention. It is a cross-sectional view which shows the other modification of the linear light source device which concerns on the 2nd Embodiment of this invention. It is a cross-sectional view which shows the other modification of the linear light source device which concerns on embodiment of this invention. It is a perspective view which shows the modification of the housing frame applied to embodiment of this invention. It is a perspective view which shows the conventional linear illuminating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planar illuminating device 2,22,22A, 22B, 32 Linear light source device 3 LED chip 4 Insulating substrate 5 Through-hole 6,26 Metal substrate 7 Conductive pattern 8 Bonding wire 9,29 Resin sealing body 10,30 Filling part DESCRIPTION OF SYMBOLS 11, 31 Light emission part 12 Light-guide plate 12a Light-incidence surface 13, 23 Housing frame 13a, 23a Floor board part 13b Side frame part 14 FPC
15 Diffusers 16 and 17 Prism sheet 18 Reflective sheet 23c Cut and raised portions 24, 34 and 44 Frame-like body

Claims (7)

A plurality of light emitting device chips arranged in one direction;
An insulating substrate having a through hole in which the plurality of light emitting element chips are accommodated;
A metal substrate disposed on one surface side of the insulating substrate and on which the plurality of light emitting element chips are mounted;
A conductor pattern formed on the other surface side of the insulating substrate;
Metal connection for electrically connecting the plurality of light emitting element chips to the conductor pattern;
And a resin sealing body covering the plurality of light emitting device chips and a metal wiring, Ri Tona,
The linear light source device according to claim 1, wherein a slit extending in a direction orthogonal to the one direction is formed at a substantially intermediate position between two adjacent light emitting element chips on the metal substrate .   The side surface of the plurality of through holes formed in the insulating substrate is formed so as to expand from one surface side to the other surface side of the insulating substrate. The linear light source device described.   The linear light source device according to claim 1, wherein a reflective film is formed on side surfaces of the plurality of through holes formed in the insulating substrate. Wherein the other surface of the insulating substrate has a light reflecting function, one of claims 1 to 3, characterized in that said frame body which covers the outer peripheral surface of the resin sealing body is formed Item 2. The linear light source device according to item 1. The linear light source device according to any one of claims 1 to 4 ,
A light guide plate having a light incident surface for receiving light emitted by the linear light source device and an output surface for emitting light incident from the light incident surface;
A planar lighting device comprising: a heat sink that contacts the metal substrate of the linear light source device. The planar lighting device according to claim 5 , wherein the heat sink is constituted by a part of a housing frame made of a metal material for accommodating the linear light source device and the light guide plate. The planar illumination according to claim 6 , wherein the heat sink is formed by cutting and raising a part of a floor plate portion of the housing frame on which the linear light source device and the light guide plate are mounted. apparatus.

Images