JP2008108750A - Linear light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize and thin a linear light source device capable of obtaining linear light having high luminance and little uneven luminance. <P>SOLUTION: A plurality of light emitting elements 5 are disposed along the longitudinal direction of a slender and square bar-shaped printed board 4, a reflectors 6 are disposed on both sides of each light emitting element 5 so as to alternate with each light emitting element 5, The facing surfaces 6a of both reflectors 6 are slanted so that an open area becomes larger as it goes toward the light emitting direction of each light emitting element 5, a light transmitting resin sealing material is filled in a recessed part formed by the light emitting elements 5 and the reflectors 6 to form a trapezoidal column-shaped or a trapezoidal cone-shaped resin sealing layer 10, a region from the end face adjacent to the mounting surface of the printed board 4 to the tip part of the reflector 6 is coated with a belt-like reflecting member comprising a reflection sheet 1 or the deposition film 12, and the rectangular cross section of the resin sealing layer 10 located between the tip parts of the reflectors 6 is positioned on the same surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a linear light source device that can be used as a backlight of a liquid crystal display panel such as a mobile phone and a digital camera, a manufacturing method thereof, and a surface light emitting device.

  As a conventional light source device and surface light emitting device, for example, as shown in FIGS. 6 and 7, a wide lower reflection sheet 20 laid on a liquid crystal display unit such as a mobile phone or a digital camera, and a lower reflection sheet 20 The light guide plate 21 whose one end protrudes from the one end of the lower reflection sheet 20 on the upper surface, the light source unit 22 provided to face the side surface of the light guide plate 21, and the light emission of the light guide plate 21 It is comprised from the edge part of a surface, and the upper reflection sheet 27 integrated so that the light source part 22 might be covered from upper direction.

  The light source unit 22 includes an elongated flat plate-shaped flexible substrate 23 as a wiring substrate, a part of which is disposed on the lower surface of the protruding end portion of the light guide plate 21, the upper surface of the flexible substrate 23, and the side surface of the light guide plate 21. A horizontally-long rectangular parallelepiped case 24 arranged side by side, a light emitting element (not shown) housed in each case 24, and a transparent light-transmitting resin sealing layer 25 filled in the case 24. And.

  Each case 24 has a surface parallel to the side surface of the light guide plate 21, that is, a main light extraction surface, and is filled with a resin sealing material from the opening of each case 24, and the opening of each case 24 is resin-sealed. It is blocked by a stopper. Further, lead terminals 26 for light-emitting element conduction are led out on the side surfaces of the respective cases 24 and soldered to the wiring pattern of the flexible substrate 23 to be electrically connected.

  The light of the light emitting element enters the light guide plate 21 from the main light extraction surface of each case 24 and emits light from the light emitting element, and the upper and lower light components leaking through the case 24 are reflected by the upper reflection sheet 27 and guided. The light is incident on the light plate 21 and reused to increase the luminance of the light emitting surface of the light guide plate 21.

  As another conventional surface light emitting device, for example, as shown in FIGS. 8 and 9, a recess 31 for accommodating the light emitting element 32 is provided at the end of the light guide plate 30 and is a long and thin flat plate as a wiring board. The light-emitting element 32 mounted on the flexible substrate 33 is immersed in the recess 31 of the light guide plate 30 so that the main light extraction surface of the light-emitting element 32 is in the same direction as the light-emitting surface of the light guide plate 30, and the periphery of the light-emitting element 32 is sealed. A resin sealing layer 34 is formed in the recess 31 of the light guide plate 30 to be stopped, and in addition, an upper reflection sheet 35 having a width of the recess 31 is formed at the end of the light emitting surface of the light guide plate 30, and A dot pattern 36 is formed on the bottom surface of the light guide plate 30 excluding the recess 31.

A part of the component of light emitted from the light emitting element 32 to the side is reflected by the upper reflection sheet 35 to the inner side of the light guide plate 30, and the light from the light emitting element 32 and the upper reflection are further reflected in the light guide plate 30. The reflected light from the sheet 35 is diffused by the dot pattern 36, so that light emission with uniform luminance can be obtained on the light emitting surface of the light guide plate 30 (see, for example, Patent Document 1).
JP 2001-67917 A (page 3-6, FIG. 2 and FIG. 3)

  However, in the former surface light emitting device, since the light emitting element is housed in the case 24, the light of the light emitting element is blocked by the upper, lower, left and right wall surfaces of the case 24, and the light distribution characteristic of the light emitting element is narrow. The light source section 22 is a cause of a spot and easily causes uneven brightness. In addition, since the lead terminal 26 of the light emitting element is soldered on the flexible substrate 23, there is a problem that the height dimension A of the surface light emitting device becomes large and the overall thickness cannot be reduced.

  Moreover, since the case 24 on which the light emitting element is mounted is soldered on the flexible substrate 23, it is not easy to improve the mounting accuracy, and the optical axis of the light emitting element is set to the main light extraction surface (light guide plate 21) of the case 24. It is not easy to be provided so as to be orthogonal to the side surface of the light-emitting element, and the position of the optical axis in the lateral direction of the light-emitting element housed in each case 24 and the position of the longitudinal center line of the side surface of the light guide plate 21 Are liable to shift, and there is a problem that the efficiency of taking light into the light guide plate 21 is lowered.

  Furthermore, since the flexible substrate 23 extends to the end of the light guide plate 21, the reflection by the lower reflection sheet 20 is reduced, and there is a problem that the efficiency of taking light into the light guide plate 21 becomes lower.

  In addition, since the width dimension B of the installation space of the light source unit 22 is determined by the size of the flexible substrate 23, there is a problem that it is difficult to reduce the overall size.

  In addition, since there is a limit to changing the light distribution characteristics of the light emitting element depending on the side wall of the case 24, there is a problem that the luminance unevenness is increased particularly when the number of used light emitting elements is reduced.

  Further, in the case of the latter surface light emitting device, it is preferable that the light of the light emitting element 32 is directly incident from the side surface of the light guide plate 30 in consideration of increasing the light capturing efficiency into the light guide plate 30.

  Furthermore, since a space for reflecting the light of the light emitting element 32 to the upper reflection sheet 35 is required, there is a case where it is limited to make the whole thin.

  Therefore, in view of the above problems, the present invention can reduce the overall size and thickness of the light source, achieve uniform brightness and improve brightness, and even if the number of light-emitting elements used is changed, It is an object of the present invention to provide a linear light source device and a manufacturing method thereof, and a surface light emitting device and a manufacturing method thereof, which can reduce luminance unevenness by freely changing light distribution characteristics.

  In order to solve the above-described problems, a linear light source device according to the present invention includes a plurality of light-emitting elements die-bonded at predetermined intervals along the longitudinal direction of an elongated rectangular bar-like wiring board. Furthermore, reflectors are disposed on both sides of each light-emitting element and alternately with each light-emitting element, and the opposing surfaces of the two reflectors further emit light from each light-emitting element. It is slanted so that the opening area increases as it goes in the direction, and the light-transmitting resin sealing material is formed by the mounting surface of the wiring board, the light emitting element, and the opposing surfaces of both reflectors The resin sealing layer is formed by filling the recessed portion to be formed.

  Therefore, unlike the conventional case, the light emitting element is directly connected to the wiring board without being housed in the case, and the light from the light emitting element is emitted while being diffused by the reflecting plate. Light can be obtained. In addition, the two light reflectors can easily adjust the light distribution characteristics of the light source unit, and even if the number of light emitting elements used is changed, the luminance of the light source unit in the longitudinal direction can be made uniform, and the luminance can be increased. Luminance unevenness is reduced.

  The elongated rectangular bar-like wiring board includes a substantially flat wiring board having a slightly larger thickness.

  Further, the shape of the opposing surface of the reflecting plate is either rectangular or trapezoidal.

  For example, when the shape of the opposing surface of the reflecting plate is rectangular, light emitted from the light emitting element travels substantially straight, and linear light having a small width is obtained. On the other hand, when the shape of the opposing surface of the reflecting plate is trapezoidal, the light emitted from the light emitting element is slightly diffused in the vertical direction, and a wide, high-brightness linear light is obtained.

  Furthermore, a resin-sealing layer is filled with a light-transmitting resin sealing material in a recess formed by the mounting surface of the wiring board, the light-emitting element, and the opposing surfaces of both reflectors. Good.

  Then, by filling the recess formed by the mounting surface of the wiring board, the light emitting element, and the opposing surfaces of both reflectors with the light-transmitting resin sealing material, the air layer in the recess is eliminated. Thus, the efficiency of taking light from the light emitting element is improved. Further, the periphery of each light emitting element is covered with the resin sealing material, and the light emitting element is protected from the surrounding environment. As the shape of the resin sealing layer, for example, a trapezoidal shape, a truncated cone shape, and a truncated cone shape are preferable. In addition, the case where each side surface of these three-dimensional shapes is a curved surface (arc, wave shape, unevenness) is also included.

  In addition, in each resin sealing layer, it is preferable that the cross section located in the site | part formed with a wiring board and both reflectors is mirror-finished.

  In this case, the light emitted from the light emitting element is reflected by the mirror-finished cross section of the resin sealing layer, and is condensed toward the cross section of the resin sealing layer that emits linear light. Higher brightness linear light can be obtained. For example, a trapezoidal shape is preferable as the cross-sectional shape of the resin sealing layer. However, the trapezoidal hypotenuse may be curved.

  Moreover, in each resin sealing layer, the cross section located between the opposing surfaces of both reflectors is located on the same plane.

  Therefore, since the cross sections of the resin sealing layers located between the opposing surfaces of the two reflecting plates are located on the same surface, a substantially linear light source unit can be easily configured. The cross-sectional shape of the resin sealing layer may be, for example, a rectangular shape, an elliptical shape, or a track shape. In short, the shape may be any shape as long as a substantially linear light source unit can be formed.

  Furthermore, it is preferable to provide a reflection member made of a reflection sheet or a vapor-deposited film in a region extending from both longitudinal end surfaces adjacent to the mounting surface of the wiring board to the tip of the opposing surface of each reflection plate.

  Then, the light emitted from the light emitting element orthogonal to the axis of the wiring board is reflected by the reflecting member made of the reflective sheet or the vapor deposition film, and the cross section of the resin sealing layer that emits linear light. As a result, light is condensed and linear light with higher luminance is obtained.

  In the method of manufacturing the linear light source device of the present invention, the light emitting elements are arranged on the wiring board at a predetermined interval and die-bonded, and then the opening area increases toward the light emitting element emission direction. Reflective plates having opposing surfaces that are inclined as described above are provided on both sides of each light emitting element, and subsequently, a light-transmitting resin sealing material is mounted on the mounting surface of the wiring board, the light emitting element, and the inclined surface of the reflective plate. And the reflector is diced so as to be positioned on both sides of each light emitting element and alternately with each light emitting element to form a square bar.

  Therefore, since the overall shape is a square bar shape, it can be easily installed inside a thin and miniaturized device.

  Furthermore, the tip section is diced from the back side of the wiring board with a blade having an isosceles triangle shape, and the section of the rectangular light source device is processed into a trapezoidal shape.

  If it does so, the linear light source device which discharge | releases high-intensity wide linear light can be obtained easily.

  The surface light-emitting device of the present invention is a surface light-emitting device that includes a light-emitting element that is conductively connected to a wiring board and a light guide plate that takes in light from the light-emitting element and has a substantially light-emitting surface. The element is die-bonded to the wiring board, and the main light extraction surface of the light emitting element is provided so as to be parallel to the side surface of the light guide plate.

  Therefore, unlike the conventional case, the light emitting element is directly connected to the wiring board without being housed in the case, and the light emitted from the light emitting element toward the side surface of the light guide plate is directly taken into the light guide plate. The light from the light emitting element can be incident on the light guide plate with high efficiency without the intensity being attenuated.

  In addition, it is preferable that the center position of the main light extraction surface of the light emitting element and the position of the center line in the longitudinal direction of the side surface of the light guide plate be provided at the same height.

  If it does so, the light from the light emitting element considered to have the highest brightness will pierce the side surface of the light guide plate, and the efficiency of taking light into the light guide plate will be further enhanced.

  Furthermore, the wiring board is preferably processed into a square bar shape in accordance with the thickness of the light guide plate, and the axis of the square bar-like wiring board is arranged to be parallel to the side surface of the light guide plate.

  In this case, by processing the wiring board in accordance with the thickness of the light guide plate, the thickness of the light guide plate determines the overall thickness, so that the surface light emitting device can be thinned and the wiring board has a rectangular bar shape. Therefore, the installation space for the wiring board is reduced, and the overall size can be reduced.

  As described above, according to the linear light source device of the present invention, a plurality of light emitting elements are disposed by die bonding at predetermined intervals along the longitudinal direction of the elongated rectangular bar-like wiring board. Regardless of accuracy, the light distribution characteristics of each light-emitting element can be widened. In addition, reflectors are arranged on both sides of each light emitting element so as to be alternately positioned with each light emitting element, and an opening area increases on the opposing surface of both reflectors toward the emission direction of each light emitting element. Since it is inclined so as to increase, the light between the light emitting elements can be diffused so as to overlap.

  Moreover, since the shape of the opposing surface of the reflecting plate is either rectangular or trapezoidal, the width of the linear light can be easily changed.

  Furthermore, a resin sealing layer is formed by filling a light-transmitting resin sealing material into a recess formed by the mounting surface of the wiring board, the light emitting element, and the opposing surfaces of both reflectors. It is effective to improve the luminance and protect the light emitting element.

  In addition, in each resin sealing layer, the cross section located at the site formed by the wiring board and both reflectors is mirrored, or the cross section located between the opposing surfaces of both reflectors is located on the same plane. By doing so, there is an effect that a linear light source unit with good light-uptake efficiency can be easily configured.

  Furthermore, by providing a reflective member made of a reflective sheet or a vapor-deposited film in a region extending from both longitudinal end faces adjacent to the mounting surface of the wiring board to the tip of the opposing surface of each reflective plate, a linear line with higher brightness Light can be obtained.

  In addition, since the entire shape of the linear light source device of the present invention is processed into a square bar shape, it can be easily installed in a storage unit such as a thin and miniaturized mobile phone or digital camera.

  Furthermore, if the cross section of the rectangular bar-shaped linear light source device is processed into a trapezoidal shape, wide linear light can be emitted, which is effective in improving luminance.

  According to the surface light emitting device of the present invention, the light emitting element is die-bonded and mounted on an elongated rectangular bar-like wiring board, and the main light extraction surface of the die-bonded light emitting element is parallel to the side surface of the light guide plate. Thus, there is an effect that the efficiency of taking light into the light guide plate can be improved.

  The light from the light emitting element having the highest luminance is provided by setting the center position of the main light extraction surface of the light emitting element and the position of the center line in the longitudinal direction of the side surface of the light guide plate at the same height. Is taken in from the side surface of the light guide plate, which is effective in improving the luminance of the light emitting surface of the light guide plate.

  Furthermore, if the wiring board is processed into a square bar shape according to the thickness of the light guide plate, and the axis of the wiring board is arranged so as to be parallel to the side surface of the light guide plate, the overall thickness is reduced and the overall size is reduced. It is effective to plan.

  As the best mode for carrying out the present invention, the following Example 1 and Example 2 will be described with reference to FIGS.

(Example 1)
The outline | summary of the linear light source device of this invention is demonstrated. A plurality of light emitting elements are arranged along the longitudinal direction of the elongated rectangular bar-like wiring board, and reflectors are arranged on both sides of each light emitting element so as to alternate with each light emitting element. The facing surface is inclined so that the opening area becomes larger toward the emission direction of each light emitting element, and a light-transmitting resin sealing material is further formed in the recess formed by the wiring board, the light emitting element, and both the reflecting plates. In addition, the air layer in the concave portion is eliminated, and in addition, the area from the end surface adjacent to the mounting surface of the wiring board to the tip of the reflector is covered with a band-shaped reflector, and between the tip of the reflector The rectangular cross section of the resin sealing layer located on the same surface is positioned on the same plane, so that a linear light source with high luminance and little luminance unevenness is obtained.

  The configuration of the linear light source device of the present invention will be described with reference to FIGS. 1A is a perspective view of a linear light source device according to Embodiment 1 of the present invention, FIG. 1B is a side sectional view of the linear light source device provided with a reflection sheet, and FIG. 1C is provided with a vapor deposition film. FIG. 2A is a perspective view of a state in which a plurality of light emitting elements are arranged on a wiring board, and FIG. 2B is a perspective view of a state in which the light emitting elements are die-bonded. Fig. 2 (C) is a perspective view of a state where a reflector is attached to a wiring board, Fig. 2 (D) is a perspective view of a part of Fig. 2 (C) in an enlarged state, and Fig. 2 (E) is a resin-sealed state. FIG. 3F is a perspective view of a state in which the material is filled, and FIG. 3A is a perspective view of the state in which the material is diced. FIG. (B) is a perspective view of a linear light source device in which the resin sealing layer has a trapezoidal shape, and (C) is a side sectional view of FIG. 3 (B). .

  As shown in FIGS. 1 to 3, the linear light source device of the present invention includes a printed circuit board 4 as an elongated rectangular bar-shaped wiring board, and a plurality of light emitting elements arranged in parallel on the printed circuit board 4 at a predetermined interval. The element 5, the reflecting plate 6 formed on both the left and right sides of each light emitting element 5, and a pillar-shaped recess 7 formed between the reflecting plate 6 and the printed circuit board 4 are filled. It is composed of a light-transmitting resin sealing layer 10 and a belt-like reflection sheet 101 as a reflection member attached from the upper and lower surfaces of the printed circuit board 4 to the tip of the reflection plate 6.

  The printed circuit board 4 is a rectangular printed circuit board 40 shown in FIG. 2 (A) formed into a rectangular bar shape by dicing as shown in FIG. 1 (A), and its upper surface (mounting surface). A plurality of light emitting elements 5 are arranged in a line at predetermined intervals along the longitudinal direction of the elongated rectangular bar-like printed circuit board 4. Furthermore, + and − electrode terminals for supplying current to each light emitting element 5 from both ends of the printed circuit board 4 are led out (not shown).

  The light-emitting element 5 is, for example, a white light emitting element using a GaN-based compound semiconductor, and an n-type electrode and a p-type electrode are formed on each surface of an n-type layer and a p-type layer stacked on a transparent sapphire substrate. These electrodes are die-bonded to the wiring pattern of the printed circuit board 4 by wires 9, and the respective light emitting elements 5 covered with a transparent resin containing a phosphor are electrically connected in series.

  As shown in FIG. 2D, the reflector 6 includes a reflector 60 having a plurality of trapezoidal and mountain-shaped protrusions 61 and 62, as shown in FIG. In addition, the light-emitting elements 5 are diced in a plate shape so as to be alternately positioned. And the thickness dimension of the diced reflecting plate 6 and the thickness dimension of the elongated rectangular bar-shaped printed circuit board 4 are the same dimension (for example, 0.3 to 1.0 mm). Furthermore, the inclined surfaces (opposing surfaces) 6a, 6a of the reflector 6 located on both sides of each light emitting element 5 are formed so that the opening area becomes larger toward the light emitting direction. Is reflected by the inclined surfaces 6a and 6a of the reflecting plate 6 and emits light while being diffused. Therefore, between each light emitting element 5 with poor brightness, the diffused incident light of each light emitting element 5 overlaps, so that the brightness becomes uniform. The shape of the inclined surfaces 6a and 6a of the reflecting plate 6 is rectangular, and the inclination angle can be adjusted as appropriate so as to eliminate luminance unevenness.

  The resin sealing layer 10 is formed by being filled with a transparent resin sealing material such as an epoxy resin. When the resin sealing layer 10 is injected and filled into the concave portion 7 formed by the printed circuit board 4, the light emitting element 5, and the reflection plate 6, the air layer in the concave portion 7 filled with the resin sealing material is excluded. Thus, the efficiency of taking in light from the light emitting element 5 is improved.

  Furthermore, the resin sealing layer 10 has a trapezoidal shape, and has the same cross section as the mounting surface of the printed circuit board 4 having the light emitting elements 5, the same cross section as the inclined surfaces of both reflectors, and the end of the printed circuit board 4. It is located between the trapezoidal cross section located at the part formed by the edge part and the edge parts of the inclined surfaces 6a, 6a of both reflecting plates 6 and the tip part of the inclined surfaces 6a, 6a of both reflecting plates 6. And a rectangular cross section. Furthermore, the trapezoidal cross section of each resin sealing layer 10 is mirror-finished to improve the reflection efficiency, and the rectangular cross section of each resin sealing layer 10 is located on the same surface to form a linear light emitting surface. Will be.

  The reflective sheet 101 is a mirror-like tape or a tape-like one having a high light reflectance such as white, and the inclined surfaces 6a, 6a, and 6b of the reflector 6 from the end surfaces (upper surface and lower surface) adjacent to the mounting surface of the printed circuit board 4. The area extending to the tip of 6a is covered. For this reason, the light emitted from the light emitting element 5 in the vertical direction is reflected by the both reflection sheets 101 without being left over, and is condensed forward and emitted linearly.

  Next, how the linear light source device is used will be described. When each light emitting element 5 is energized through the wiring pattern of the printed circuit board 4, light is emitted from the active layer in the semiconductor layer of each light emitting element 5. The light from the active layer is emitted radially from the main light extraction surface of the light emitting element 5, that is, the surface on which the electrode for die bonding the wire 9 is formed.

  Of the light emitted from the light emitting element 5, the light in the vertical direction is reflected by the reflection sheet 101 and travels forward, the light in the forward direction travels straight as it is, and the light in the horizontal direction is reflected by the reflectors 6 on both sides. The light is reflected by the inclined surfaces 6a and 6a and diffused to travel forward. Then, the light in the left-right direction is diffused, so that the luminance between the light emitting elements 5 is interpolated to make the luminance uniform. Furthermore, by encapsulating each light emitting element 5 with resin, the light capturing efficiency is increased and the luminance is improved.

  Next, a method for manufacturing the linear light source device will be described. For example, a conductive pattern is formed on a white glass BT (bismaleimide triazine) copper-clad laminate. Then, a reflecting plate (in the embodiment, the inclined surface 6a of the reflecting plate 6) is formed using a resin such as LCP (liquid crystal polymer) or PPA (polyphthalamide). Next, as shown in FIG. 2A, the light emitting elements 5 are arranged on the mounting surface of the printed circuit board 40 having a square shape in plan view, and each light emitting element 5 is mechanically attached with an adhesive. Thereafter, as shown in FIG. 2 (B), the light emitting element 5 is die-bonded to be electrically connected, and then, as shown in FIG. 2 (C), the molded reflector 60 is bonded with an adhesive or the like. To the printed circuit board 40. As shown in FIG. 2D, the reflector 60 has protrusions 61 with a trapezoidal cross section at both ends, and a cross section between the protrusions 61 at both ends. A plurality of protrusions 62 are formed. Further, as shown in FIG. 2 (E), the transparent resin sealing material 10 is filled in the concave portion 7 formed by the printed board 4 and the inclined surfaces 6a and 6a of the reflecting plate 6 to seal the light emitting element 5. Stop. Next, as shown in FIG. 2 (F), dicing is performed so that the printed circuit board 40 having a rectangular shape in plan view is formed into an elongated rectangular bar shape. Thereafter, a trapezoidal cross section of each resin sealing layer located at a portion formed by the end edge portion of the elongated rectangular bar-like printed board 4 and the end edge portions of the inclined surfaces 6a and 6a of the reflecting plates 6 is mirror-finished. Turn into. For example, a blade having a particle size of 800 or more is selected, the rotation speed is set to 20,000 to 30,000 rpm, and the cutting speed is set to 5 mm / sec. In addition, you may make it mirror-finish with an abrasive. Next, the reflective sheet 101 covers a region from the end surfaces (upper surface and lower surface) adjacent to the mounting surface of the printed circuit board 4 to the tip portions of the inclined surfaces 6 a and 6 a of the reflective plate 6.

  In the case of Example 1, the reflective sheet 101 covers the area from the end surface (upper surface and lower surface) adjacent to the mounting surface of the printed circuit board 4 to the tip of the inclined surfaces 6a, 6a of the reflective plate 6. However, as shown in FIG. 1C, the region may be covered with a deposited film 12 made of silver or aluminum. In this case, a thin film of about several microns is formed by sputtering or vacuum deposition. Then, as with the reflective sheet 101, the luminance can be improved. Moreover, you may form the vapor deposition film | membrane 12 after mirror-finishing.

  Further, in the case of the first embodiment, the inclined surfaces 6a and 6a of the reflecting plate 6 are rectangular, and the resin sealing layer has a trapezoidal shape. However, as shown in FIG. May be diced from the back side of the printed circuit board 4 with an isosceles triangular blade 15 to make the inclined surfaces 6a and 6a of the reflecting plate 6 trapezoidal and the shape of the resin sealing layer to be trapezoidal. (See FIG. 3B). In this case, as shown in FIG. 3 (C), compared to the cases of FIGS. 1 (B) and 1 (C), the light is diffused in a wide angle in the vertical and horizontal directions, and a wide line shape with high luminance is obtained. A light emitting surface is formed. Moreover, even if the inclined surfaces 6a and 6a of the reflecting plate 6 are trapezoidal and the shape of the resin sealing layer is trapezoidal, the cross section of the resin sealing layer is mirror-finished, the reflective sheet 101 is adhered, and the vapor deposition film Any of 12 can be formed.

(Example 2)
An outline of the surface light-emitting device of the present invention will be described. The main light extraction surface of the die-bonded light-emitting element and the wiring substrate on which the light-emitting element is die-bonded are parallel to the side surface of the light-guide plate, thereby improving the light-acquisition efficiency of the light-guide plate and two reflection The plates are disposed on both sides of the light emitting element so as to be inclined so that the opening area increases toward the side surface of the light guide plate, and guides the light of the light emitting element emitted along the longitudinal direction of the side surface of the light guide plate. In addition, the resin sealing material is filled in the concave portion formed by the wiring board, the light emitting element, and the two reflecting plates, and the air layer in the concave portion is eliminated, and in addition, one light emitting surface of the light guide plate The area from the wiring board to the wiring board is covered with a flat reflection sheet, and the area from the end of the other light emitting surface of the light guide plate to the wiring board is covered with a belt-like reflection sheet, and the luminance of the light emitting face of the light guide plate Improvement, Beauty, is obtained by the so achieve uniform brightness.

  Next, the configuration of the surface light emitting device of the present invention will be described with reference to FIGS. 4 is a perspective view of a surface light-emitting device according to Embodiment 2 of the present invention, and FIG. 5 is a longitudinal sectional view of a main part showing a mounting portion of a light-emitting element together with a structure for mounting a light guide plate and a printed board. 1 are the same as or correspond to those in FIG. As shown in FIGS. 4 and 5, the surface light emitting device of the present invention is attached to the lower reflection sheet 1 having a rectangular shape in plan view, and a portion of the upper surface of the lower reflection sheet 1 except for one end thereof. The flat light guide plate 2, the linear light source unit 3 provided at one end of the lower reflection sheet 1 and along the side surface of the light guide plate 2, the linear light source unit 3, and the light guide The upper reflection sheet 11 is formed of a long and narrow strip attached to cover the upper surface of the light plate 2, that is, the end of the light emitting surface.

  The lower reflection sheet 1 is, for example, a mirror-like tape or a tape-like one having a high light reflectance such as white, and the lower reflection sheet 1 is used to provide a region from the light guide plate 2 to the printed circuit board 4, that is, the light guide plate. The lower surface of the printed circuit board 4 is covered from one of the light emitting surfaces. For this reason, light emitted downward from the linear light source unit 3 is reflected by the lower reflection sheet 1 and returned to the light guide plate 2.

  The light guide plate 2 is a transparent plate formed with a thickness of 0.3 to 1.0 mm using, for example, acrylic resin or polycarbonate resin, and is a lower surface of a liquid crystal display panel (not shown) provided above the light guide plate 2. It is arranged along.

  The linear light source unit 3 has an elongated rectangular bar-like printed board 4 as a wiring board provided so that its axis is parallel to the side of the light guide plate 2, and the side of the printed board 4 facing the side of the light guide plate 2. A light emitting element 5 arranged in parallel along the side surface of the light guide plate 2 at a predetermined interval, a trapezoidal reflecting plate 6 disposed between the light emitting elements 5, a printed board 4, The cross section formed by the light emitting element 5 and the reflecting plate 6 includes a resin sealing layer 10 provided in the concave portion 7 having a substantially trapezoidal shape.

  The printed circuit board 4 is a flat printed circuit board in which the light emitting elements 5 are mounted in a matrix, and is diced according to the thickness of the light guide plate 2. In the diced printed circuit board 4, the light emitting elements 5 are arranged in a horizontal row. Are lined up. The thickness of the printed board 4 is substantially the same as the thickness of the light guide plate 2, and the thickness dimension A of the surface light emitting device is determined. The thickness dimension A is significantly smaller than the thickness dimension A of the surface light emitting device shown in FIG. Further, + and − electrode terminals 8a and 8b for energizing the light emitting element 5 from both ends of the printed circuit board 4 are respectively led out, and both the electrode terminals 8a and 8b are connected to a circuit ( (Not shown).

  Each light emitting element 5 is die-bonded to the wiring pattern of the printed circuit board 4, and the main light extraction surface is arranged in parallel with the side surface of the light guide plate 2, and the light emitting elements 5 arranged in parallel are arranged. The optical axes in the horizontal direction are opposite to each other at the same height as the longitudinal center line of the side surface of the light guide plate 2.

  The reflecting plate 6 is formed such that the inclined surfaces 6a, 6a on both sides thereof are positioned on both sides of the light emitting element 5 as reflecting plates, and the opening area increases toward the side surface of the light guide plate 2. The light of the element 5 is reflected by the inclined surface 6a of the reflecting plate 6 and enters from the side surface of the light guide plate 2 while being diffused. Therefore, since the incident light of each light emitting element 5 is diffused at a wide angle and enters from the side surface of the light guide plate 2, between the light emitting elements 5 with low luminance in the light guide plate 2, Since the incident light overlaps, the luminance of the linear light source unit 3 becomes uniform, and the luminance of surface light emission in the light guide plate 2 becomes substantially uniform. The inclination angle of the inclined surface 6a of the reflecting plate 6 can be adjusted as appropriate so as to eliminate the luminance unevenness of the light guide plate 2.

  The resin sealing layer 10 is formed by being filled with a transparent resin sealing material such as an epoxy resin. When this resin sealing material is injected and filled into the recess 7 formed by the printed circuit board 4, the light emitting element 5, and the reflection plate 6, the air layer in the recess 7 filled with resin is excluded. The efficiency of taking light from the light emitting element 5 to the light guide plate 2 is improved.

  The upper reflective sheet 11 is made of the same material as that of the lower reflective sheet 1. The region from the end of the light guide plate 2 to the printed circuit board 4, that is, the end of the light guide plate 2 on the light emitting element 5 side, the light emitting element 5. , The upper surface of the reflecting plate 6 and the upper surface of the printed circuit board 4 are respectively covered. For this reason, the light of each light emitting element 5 emitted in the vertical direction by the lower reflection sheet 1 and the upper reflection sheet 11 does not leak light from the gap between the light guide plate 2 and the linear light source unit 3. Thus, the light from each light emitting element 5 can be incident on the light guide plate 2 without leaving any light. Further, since the printed board 4 is not exposed from the upper reflection sheet 11 and the width dimension B of the upper reflection sheet 11 is the width dimension of the installation space of the light source section 3, the light source section of the surface light emitting device shown in FIG. Compared to the width B of the 22 installation spaces, it is greatly reduced.

  Next, how the surface light emitting device is used will be described. When each light emitting element 5 is energized through the wiring pattern of the printed circuit board 4, light is emitted from the active layer in the semiconductor layer of each light emitting element 5. The light from the active layer is emitted from the main light extraction surface of the light emitting element 5, that is, the surface on which the electrode for die bonding the wire 9 is formed.

  The light emitted in the direction perpendicular to the side surface of the light guide plate 2 travels through the light guide plate 2 as it is, and the light emitted parallel to the side surface of the light guide plate 2 is reflected by the reflection plates 6 on both sides. The light that is returned to the light guide plate 2 by the inclined surfaces 6 a and 6 a and is emitted in the vertical direction from the main light extraction surface of each light emitting element 5 is returned to the light guide plate 2 by the upper reflection sheet 11 and the lower reflection sheet 1. .

  In this way, light emitted from each light emitting element 5 is taken into the light guide plate 2, so that there is no luminance unevenness of the light emitting surface of the light guide plate 2, and the luminance of the light emitting surface of the light guide plate 2 can be made uniform. In addition, by sealing each light-emitting element 5 with resin, the efficiency of taking light into the light guide plate 2 is increased, and the luminance is improved.

  Next, a method for manufacturing the surface light emitting device will be described. First, in the linear light source unit 3, for example, a conductive pattern is formed on a white glass BT (bismaleimide triazine) copper-clad laminate. Then, a reflector (in the embodiment, the inclined surface 6a of the reflector 6) is formed using a resin such as LCP (liquid crystal polymer) or PPA (polyphthalamide), and the reflector is attached to the printed circuit board 4 with an adhesive or the like. to paste together. Thereafter, the light emitting element 5 is mechanically attached to the predetermined position with an adhesive. Next, the light emitting element 5 is die-bonded and electrically connected, and the light emitting element 5 is sealed with a transparent resin, and then the printed circuit board 4 is diced into a square bar shape according to the thickness of the light guide plate 2. To split.

  Next, the light guide plate 2 is attached to a portion excluding the end portion of the flat plate-like lower reflection sheet 1, and the main light extraction surface of the square bar-shaped printed board 4 and each light emitting element 5 is placed on the side surface of the light guide plate 2. An area extending from one light emitting surface of the light guide plate 2 to the printed circuit board 4 is covered with a flat lower reflection sheet 1 and printed from the end of the other light emitting surface of the light guide plate 2. A region up to 4 is covered with a strip-shaped upper reflection sheet 11.

  In the above embodiment, the inclined surfaces 6a and 6a of the reflecting plate 6 having a trapezoidal shape in plan view are used. However, the present invention is not limited to the illustration, and the inclined surfaces 6a and 6a of the reflecting plate 6 having a triangular shape in plan view are used. May be used, and a long and thinly cut reflector may be used. Moreover, it is preferable that any reflector 6 has a configuration in which the angle can be adjusted. In short, the shape and angle of the reflecting plate 6 is such that the light of each light emitting element 5 is efficiently reflected and the area where the light of the adjacent light emitting elements 5 and 5 overlaps is enlarged, so that the light guide plate 2 has a poor light. It is sufficient that the luminance between the light emitting elements 5 and 5 is complemented and the luminance of the surface light emission of the light guide plate 2 can be made substantially uniform.

  It is also possible to improve the luminance characteristics of the light guide plate 2 by mixing a light-dispersing material such as glass beads in the light-transmitting resin sealing layer 10.

  Further, in the embodiment, the band-shaped upper reflection sheet 11 covers the region from the substantially end portion of the light guide plate 2 to the printed circuit board 4, but the region from the peripheral edge of the light guide plate 2 to the printed circuit board 4 is copied. You may make it cover with a letter shape or a frame-shaped upper reflection sheet.

  The linear light source device and the surface light-emitting device of the present invention can be used as a backlight of a liquid crystal display panel such as a mobile phone or a digital camera that has been reduced in size and thickness, for example, and a display unit that has high luminance and little luminance unevenness. It can be done.

(A) is a perspective view of the linear light source device according to the first embodiment of the present invention, (B) is a side sectional view of the linear light source device provided with a reflection sheet, and (C) is provided with a vapor deposition film. Sectional view of a linear light source device (A) is a perspective view of a state in which a plurality of light emitting elements are disposed on a wiring board, (B) is a perspective view of a state in which the light emitting elements are die-bonded, and (C) is a reflector on the wiring board. FIG. 2D is a perspective view in which a part of FIG. 2C is enlarged, FIG. 2E is a perspective view in a state where a resin sealing material is filled, and FIG. ) Is a perspective view of the dicing state (A) is a sectional side view of the state where the tip portion is diced from the back side of the wiring board by a blade having an isosceles triangle, and (B) is a perspective view of a linear light source device in which the resin sealing layer has a trapezoidal shape. Fig. 3 (C) is a side sectional view of Fig. 3 (B). The perspective view of the surface emitting device which concerns on Example 2 of this invention. Longitudinal sectional view of the main part showing the mounting part of the light emitting element, together with the mounting structure of the light guide plate and printed circuit board Perspective view of a conventional surface emitting device Longitudinal cross-sectional view of the main part showing the mounting part of the light emitting element together with the mounting structure of the light guide plate and flexible substrate Partially cutaway side view of another conventional surface light emitting device Longitudinal cross-sectional view of the main part showing the mounting part of the light emitting element together with the mounting structure of the light guide plate and flexible substrate

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20 Lower reflection sheet 2, 21, 30 Light guide plate 3, 22 Light source part 4 Printed circuit board (wiring board)
5, 32 Light emitting element 6 Reflector 6a Inclined surface (opposing surface)
7 Recess 8a, 8b Electrode terminal 9 Wire 10, 25, 34 Resin sealing layer 11, 27, 35 Upper reflection sheet 12 Deposition film 15 Blade 23, 33 Flexible substrate (wiring substrate)
24 Case 26 Lead terminal 31 Concave part 36 Dot pattern 40 Printed circuit board 60 Reflector 61 Projection body 62 Projection body 101 Reflection sheet A Thickness dimension of surface light emitting device B Width dimension of light source unit installation space

Claims (1)

A plurality of light emitting elements are disposed by die bonding at predetermined intervals along the longitudinal direction of the elongated rectangular bar-like wiring substrate, and are alternately positioned on both sides of each light emitting element and with each light emitting element. Further, the reflecting plate is disposed, and the opposing surfaces of the reflecting plates are inclined so that the opening area becomes larger toward the emission direction of each light emitting element, A linear light source characterized in that a resin sealing material is filled in a recess formed by a mounting surface of a wiring board, a light emitting element, and opposing surfaces of both reflecting plates to form a resin sealing layer apparatus.

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