JP2004235139A - Linear light source device and its manufacturing method, as well as surface light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a linear light in which downsizing and thinning can be carried out, and which has high brightness and few unevenness of brightness. <P>SOLUTION: A plurality of light emitting elements 5 are arranged and installed along the longitudinal direction of a narrow square bar-shape printed circuit board 4, reflecting plates 6 are arranged at both sides of respective light emitting elements 5 so that they may become alternating with the light emitting element 5, counter faces 6a of the both reflecting plates 6 are made to incline so that opening area may become larger as it goes in the orientations of outgoing of each emitting element 5, a truncated cylinder-shape or truncated cone resin sealing layer 10 is formed by filling a light transmitting resin sealing material in a recess part formed by the printed circuit board 4, the light emitting elements 5, and the reflecting plates 6. The region from the end face adjacent to a mounting face of the printed circuit board 4 to the tip end part of the reflecting plates 6 is covered by a belt-shape reflecting member consisting of a reflecting sheet 1 or a vapor deposition film 12, and a rectangular cross-sectional face of the resin sealing layer 10 positioned between the tip end parts of the reflecting plates 6 is positioned on the same plane. <P>COPYRIGHT: (C)2004,JPO&NCIPI

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 method for manufacturing the same, and a surface light emitting device.

  As a conventional light source device and a 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 are provided. A light guide plate 21 whose one end protrudes from one end of the lower reflection sheet 20 on the upper surface, a light source unit 22 provided to face a side surface of the light guide plate 21, and light emission of the light guide plate 21 It comprises an end of the surface and an upper reflection sheet 27 integrated so as to cover the light source unit 22 from above.

  The light source unit 22 includes an elongated flat flexible substrate 23 as a wiring board, a part of which is disposed on the lower surface of the protruding end of the light guide plate 21, and an upper surface of the flexible substrate 23 and a side surface of the light guide plate 21. Horizontally long rectangular parallelepiped cases 24 juxtaposed to be close to each other, a light emitting element (not shown) stored in each case 24, and a transparent light-transmitting resin sealing layer 25 filled in the cases 24 And

  Each case 24 has an opening on a surface parallel to the side surface of the light guide plate 21, that is, a main light extraction surface. A resin sealing material is filled through the opening of each case 24, and the opening of each case 24 is sealed with a resin. It is closed by the stopper. Further, a lead terminal 26 for conducting a light emitting element is led out from a side surface of each case 24, and is soldered to a wiring pattern of the flexible substrate 23 and electrically connected to the wiring pattern.

  Then, 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 to be guided. Light is reused by making the light incident on the light plate 21 to increase the luminance of the light emitting surface of the light guide plate 21.

  As another conventional surface emitting device, for example, as shown in FIGS. 8 and 9, a concave portion 31 for accommodating a light emitting element 32 is provided at an end of a light guide plate 30, and an elongated flat plate as a wiring board is provided. The main light extraction surface of the light emitting element 32 mounted on the flexible substrate 33 is immersed in the concave portion 31 of the light guide plate 30 so that the main light extraction surface is oriented in the same direction as the light emission surface of the light guide plate 30. A resin sealing layer 34 is formed in the concave portion 31 of the light guide plate 30 so as to be stopped. In addition, an upper reflection sheet 35 having a width of the concave portion 31 is formed at an end of a 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 concave portion 31.

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

  However, in the case of 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 walls of the case 24, and the light distribution characteristic of the light emitting element is narrow, so that the hot light is emitted. The light source unit 22 causes spots and tends to cause uneven brightness. Further, since the lead terminals 26 of the light emitting elements are soldered on the flexible substrate 23, the height dimension A of the surface light emitting device is increased, and there is a problem that the overall thickness cannot be reduced.

  In addition, 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 of the case 24 (the light guide plate 21). It is not easy to provide the light-emitting element housed in each case 24 at right angles to the position of the lateral optical axis 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. However, there is a problem that the light is easily shifted and the efficiency of taking light into the light guide plate 21 is reduced.

  Further, 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 is further reduced.

  In addition, the size B of the flexible substrate 23 determines the width B of the installation space of the light source unit 22, so that it is difficult to reduce the overall size.

  In addition, since there is a limit in 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 increases particularly when the number of light emitting elements used is reduced.

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

  Further, 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 the whole is limited to be thin.

  In view of the above-described problems, the present invention can reduce the size and thickness of the light source unit even when the number of light emitting elements used is changed, while achieving uniform luminance and improving luminance. It is an object of the present invention to provide a linear light source and a method of manufacturing the same, and a surface light emitting device and a method of manufacturing the same, which can reduce luminance unevenness by freely changing light distribution characteristics.

  In order to solve the above-mentioned problems, a linear light source device according to the present invention, as described in claim 1, has a plurality of light emitting elements arranged at predetermined intervals along the longitudinal direction of a long and narrow rectangular rod-shaped wiring board. And a light-emitting element, and a reflecting plate is disposed on both sides of each light-emitting element and alternately positioned with each light-emitting element. It is inclined so that the opening area increases toward the emission direction.

  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 reflection plate. Light can be obtained. Moreover, the two reflectors make it easy to adjust the light distribution characteristics of the light source unit, and even when the number of light emitting elements used is changed, the luminance in the longitudinal direction of the light source unit can be made uniform, and high luminance and Brightness unevenness is reduced.

  The elongated rectangular rod-shaped wiring board also includes a substantially flat wiring board having a slightly large thickness.

  According to a second aspect of the present invention, the shape of the opposing surface of the reflection plate is rectangular or trapezoidal.

  For example, when the shape of the opposing surface of the reflection plate is rectangular, light emitted from the light emitting element travels substantially straight, and linear light with a small width is obtained. On the other hand, when the shape of the opposing surface of the reflector is trapezoidal, the light emitted from the light emitting element is slightly diffused in the up-down direction, so that a somewhat wide high-luminance linear light can be obtained.

  Further, a concave portion formed by the mounting surface of the wiring board, the light emitting element, and the opposing surfaces of the two reflection plates is filled with a light-transmissive resin encapsulant. May be formed.

  Then, the air layer in the concave portion is eliminated by filling the concave portion formed by the light-transmitting resin sealing material with the mounting surface of the wiring board, the light emitting element, and the opposing surfaces of the two reflection plates. As a result, the efficiency of capturing 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 column, a truncated cone, or a truncated cone is preferable. In addition, it is assumed that each side surface of these three-dimensional shapes is a curved surface (arc, wavy shape, unevenness).

  In addition, as described in claim 4, in each resin sealing layer, it is preferable that a cross section located at a portion formed by the wiring board and the two reflection plates is mirror-finished.

  In this case, light emitted from the light-emitting element is reflected on the cross section of the mirror-finished resin sealing layer, and condensed toward the cross section of the resin sealing layer that emits linear light. Higher luminance linear light is obtained. The cross-sectional shape of the resin sealing layer is preferably, for example, trapezoidal. However, the oblique side of the trapezoid may be a curve.

  According to a fifth aspect of the present invention, in each of the resin sealing layers, the cross section located between the opposing surfaces of the two reflection plates is positioned on the same surface.

  Therefore, since the cross section of each resin sealing layer located between the opposing surfaces of both the reflection plates is 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, any of a rectangular shape, an elliptical shape, and a track shape. In short, any shape may be used as long as it can constitute a substantially linear light source unit.

  Further, as set forth in claim 6, it is preferable that the reflection member made of a reflection sheet or a vapor-deposited film is provided in a region from both end surfaces in the longitudinal direction adjacent to the mounting surface of the wiring board to the front end of the opposing surface of each reflection plate. Good.

  Then, the light emitted from the light emitting element perpendicular to the axis of the wiring board is reflected by the reflecting member formed of the reflective sheet or the vapor-deposited film to form a cross section of the resin sealing layer that emits linear light. The light is condensed, and linear light with higher luminance can be obtained.

  In the method of manufacturing a linear light source device according to the present invention, the light emitting elements are arranged on the wiring board at predetermined intervals and die-bonded, and then the light emitting elements are directed in the emission direction of the light emitting elements. Reflector plates having opposing surfaces inclined so that the opening area increases in accordance with are provided on both sides of each light-emitting element, and then, a light-transmissive resin encapsulant is mounted on the mounting surface of the wiring board and the light-emitting element. , Into the recess formed by the inclined surface of the reflector, and further, the reflector is diced on both sides of each light emitting element, and so as to be alternately arranged with each light emitting element so as to form a square rod shape. It was done.

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

  Further, as shown in claim 8, the cross section of the tip is diced from the back side of the wiring board by an isosceles triangular blade, and the cross section of the rectangular linear light source device is processed into a trapezoidal shape.

  Then, a linear light source device that emits high-intensity wide linear light can be easily obtained.

  The surface light emitting device according to the present invention includes a light emitting element conductively connected to the wiring board and a light guide plate that receives light from the light emitting element and has a light emitting surface substantially over the entire surface. In the surface light emitting device, the light emitting element is die-bonded to a 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 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.

  Further, 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.

  Then, light from the light-emitting element, which is considered to have the highest luminance, advances along the side surface of the light guide plate, so that the efficiency of capturing light into the light guide plate is further increased.

  Furthermore, it is preferable that the wiring board is processed into a rectangular rod shape according to the thickness of the light guide plate, and the axis of the rectangular rod-shaped wiring substrate is arranged 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, and the surface emitting device can be made thinner, and the wiring board has a square rod 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, the plurality of light emitting elements are arranged at predetermined intervals along the longitudinal direction of the elongated rectangular rod-shaped wiring board and die-bonded. Therefore, the light distribution characteristics of each light emitting element can be widened regardless of the mounting accuracy. In addition, reflectors are provided on both sides of each light emitting element and alternately positioned with each light emitting element, and the opening area of the opposing surfaces of both reflectors increases in the emission direction of each light emitting element. Since the light is inclined so as to increase, the light between the light emitting elements can be diffused so as to overlap.

  Further, since the shape of the opposing surface of the reflector is made to be either rectangular or trapezoidal, the width of the linear light can be easily changed.

  Further, the resin sealing layer is formed by filling a light transmitting resin sealing material into a concave portion formed by the mounting surface of the wiring substrate, the light emitting element, and the opposing surfaces of the two reflection plates. This is effective for improving the luminance and protecting the light emitting element.

  In addition, in each resin sealing layer, a cross section located at a portion formed by the wiring board and the two reflection plates is mirror-finished, or a cross section located between opposing surfaces of the two reflection plates is positioned on the same surface. By doing so, there is an effect that a linear light source unit having good light capturing efficiency can be easily configured.

  Furthermore, by providing a reflective member made of a reflective sheet or a vapor-deposited film in a region from both longitudinal end surfaces adjacent to the mounting surface of the wiring board to the front end of the opposing surface of each reflective plate, a linear line with higher luminance can be obtained. 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 rod shape, the linear light source device can be easily housed in a thin and small storage unit such as a mobile phone or a digital camera.

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

  According to the surface emitting device of the present invention, the light emitting element is die-bonded and mounted on the elongated rectangular rod-shaped 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. Therefore, there is an effect that the efficiency of taking light into the light guide plate can be improved.

  In addition, the position of the center 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 are provided at the same height, and light from the light emitting element which is considered to have the highest luminance is provided. Is taken in from the side surface of the light guide plate, which is effective for improving the luminance of the light emitting surface of the light guide plate.

  Furthermore, if the wiring substrate is processed into a square rod shape according to the thickness of the light guide plate and the axis of the wiring substrate 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 for planning.

  As the best mode for carrying out the present invention, the following first and second embodiments will be described with reference to FIGS.

  The outline of the linear light source device of the present invention will be described. A plurality of light emitting elements are arranged along the longitudinal direction of the elongated rectangular rod-shaped wiring board, and on both sides of each light emitting element, a reflector is arranged so as to be alternate with each light emitting element. The facing surface is inclined so that the opening area increases toward the emission direction of each light-emitting element, and furthermore, a light-transmissive resin sealing material is provided in the recess formed by the wiring board, the light-emitting element, and the two reflection plates. Filling, eliminating the air layer in the concave portion, and in addition, covering the area from the end face adjacent to the mounting surface of the wiring board to the tip of the reflector with a belt-shaped reflecting member, and between the tip of the reflector. Are arranged on the same plane to obtain a linear light source with high luminance and less luminance unevenness.

  The configuration of the linear light source device of the present invention will be described with reference to FIGS. FIG. 1A is a perspective view of a linear light source device according to a first embodiment of the present invention, FIG. 1B is a side sectional view of a linear light source provided with a reflection sheet, and FIG. 2A is a perspective view showing a state in which a plurality of light emitting elements are arranged on a wiring board, FIG. 2B is a perspective view showing a state in which the light emitting elements are die-bonded, FIG. 2C is a perspective view showing a state in which the reflector is attached to the wiring board, FIG. 2D is a perspective view showing a state in which a part of FIG. 2C is enlarged, and FIG. FIG. 3 (F) is a perspective view of a state in which dicing is performed, and FIG. 3 (A) is a state in which dicing is performed from the back side of the wiring substrate by a blade having a tip having an isosceles triangular shape. FIG. 3B is a side sectional view, FIG. 3B is a perspective view of a linear light source having a truncated cone-shaped resin sealing layer, and FIG. 3C is a side sectional view of FIG.

  As shown in FIGS. 1 to 3, the linear light source device according to the present invention includes a printed board 4 as an elongated rectangular rod-shaped wiring board, and a plurality of light emitting devices arranged in parallel on the printed board 4 at predetermined intervals. The element 5, a reflector 6 formed on both left and right sides of each light emitting element 5, and a columnar recess 7 formed between the reflector 6 and the printed board 4 are formed to be filled. It comprises a light-transmissive resin sealing layer 10 and a belt-shaped reflection sheet 101 as a reflection member adhered from the upper and lower surfaces of the printed circuit board 4 to the tip of the reflection plate 6.

  As shown in FIG. 1A, the printed circuit board 4 is formed by forming a rectangular printed circuit board 40 shown in FIG. 2A into an elongated rectangular bar shape by dicing as shown in FIG. , A plurality of light emitting elements 5 are arranged in a line at predetermined intervals along the longitudinal direction of the elongated rectangular bar-shaped printed board 4. Further, from both ends of the printed circuit board 4, + and-electrode terminals for supplying electricity to the respective light emitting elements 5 are respectively led out (not shown).

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

  As shown in FIG. 2D, a reflector 60 having a plurality of pillar-shaped and mountain-shaped ridges 61 and 62 is provided on both sides of the light emitting element 5 as shown in FIG. The plate is diced so as to be alternately arranged with the light emitting elements 5. Then, the thickness of the diced reflector 6 and the thickness of the elongated rectangular rod-shaped printed board 4 are the same (for example, 0.3 to 1.0 mm). Further, the inclined surfaces (opposed surfaces) 6a, 6a of the reflection plate 6 located on both sides of each light emitting element 5 are formed so that the opening area becomes larger in the light emitting direction. Is reflected by the inclined surfaces 6a of the reflection plate 6, and emits light while being diffused. Therefore, between the light emitting elements 5 having low luminance, the diffused incident light of each light emitting element 5 overlaps, so that the luminance becomes uniform. The shape of the inclined surfaces 6a, 6a of the reflecting plate 6 is rectangular, and the angle of inclination can be appropriately adjusted to eliminate uneven brightness.

  The resin sealing layer 10 is formed by filling a transparent resin sealing material such as an epoxy resin. When the resin sealing layer 10 is injected and filled into the recess 7 formed by the printed board 4, the light emitting element 5, and the reflection plate 6, the air layer in the recess 7 filled with the resin sealing material is removed. As a result, the efficiency of capturing light from the light emitting element 5 is improved.

  Further, the resin sealing layer 10 has a trapezoidal shape, and has a cross section having the same shape as the mounting surface of the printed board 4 having the light emitting element 5, a cross section having the same shape as the inclined surfaces of both the reflection plates, and an end of the printed board 4. A trapezoidal section located at a portion formed by the edge and the end surfaces of the inclined surfaces 6a, 6a of both reflectors 6, and a tip portion of the inclined surfaces 6a, 6a of both reflectors 6. And a rectangular cross section. Further, the trapezoidal cross section of each resin sealing layer 10 is mirror-finished to improve reflection efficiency, and the rectangular cross section of each resin sealing layer 10 is located on the same plane to form a linear light emitting surface. Will be.

  The reflection sheet 101 is a mirror-like tape or a tape-like tape having a high light reflectance such as white, and has an inclined surface 6 a of the reflection plate 6 from an end surface (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 in the vertical direction from the light emitting element 5 is reflected by the two reflection sheets 101 without any excess, is collected forward, and is emitted linearly.

  Next, the usage of the linear light source device will be described. When current is applied to each light emitting element 5 via the wiring pattern of the printed circuit board 4, light is emitted from an active layer in the semiconductor layer of each light emitting element 5. Light from the active layer is radially 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.

  Of the light emitted from the light emitting element 5, the light in the up and down direction is reflected by the reflection sheet 101 and travels forward, the light in the forward direction goes straight as it is, and the light in the left and right direction passes through the reflection plates 6 on both sides. The light is reflected by the inclined surfaces 6a, 6a, diffused, and proceeds forward. Then, by diffusing the light in the left-right direction, the luminance between the light emitting elements 5 is interpolated, and the luminance can be made 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 substrate. 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) and PPA (polyphthalamide). Next, as shown in FIG. 2A, the light emitting elements 5 are arranged on the mounting surface of the printed board 40 having a rectangular shape in plan view, and each light emitting element 5 is mechanically attached with an adhesive. After that, as shown in FIG. 2B, the light emitting element 5 is electrically connected by die bonding, and then, as shown in FIG. To the printed circuit board 40. As shown in FIG. 2 (D), the reflector 60 has a ridge 61 having a trapezoidal cross section at both ends, and a mountain-shaped cross section between the ridges 61 at both ends. Are formed. Further, as shown in FIG. 2 (E), a transparent resin sealing material 10 is filled in the concave portion 7 formed by the printed board 4 and the inclined surfaces 6a, 6a of the reflector 6, and the light emitting element 5 is sealed. Stop. Next, as shown in FIG. 2 (F), dicing is performed on the printed circuit board 40 having a square shape in plan view so as to have an elongated rectangular bar shape. After that, the trapezoidal cross section of each resin sealing layer located at a portion formed by the edge of the elongated rectangular rod-shaped printed circuit board 4 and the edge of the inclined surfaces 6a, 6a of both reflectors 6 is mirror-finished. Become For example, a blade having a grain 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 to perform mirror finishing. In addition, mirror polishing may be performed using an abrasive. Next, the reflection sheet 101 covers an area from the end surface (upper surface and lower surface) adjacent to the mounting surface of the printed circuit board 4 to the distal end portions of the inclined surfaces 6a, 6a of the reflection plate 6.

  In the case of the first embodiment, the reflection sheet 101 covers the region from the end surface (upper surface and lower surface) adjacent to the mounting surface of the printed circuit board 4 to the end portions of the inclined surfaces 6a, 6a of the reflection plate 6. However, as shown in FIG. 1C, the region may be covered with a deposition film 12 made of silver or aluminum. In this case, a thin film of about several microns is formed by sputtering or vacuum evaporation. Then, similarly to the reflection sheet 101, the luminance can be improved. Further, the vapor deposition film 12 may be formed after mirror finishing.

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

  The outline of the surface 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 to which the light-emitting element is die-bonded are parallel to the side surface of the light guide plate, so that the light guide efficiency of the light guide plate is improved, and two reflections are provided. The plates are arranged 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 guide the light of the light emitting element emitted along the longitudinal direction of the side surface of the light guide plate. It is taken into the light plate, and further, a concave portion formed by the wiring board, the light emitting element, and the two reflective plates is filled with a resin sealing material to eliminate an air layer in the concave portion, and additionally, one light emitting surface of the light guide plate. 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 band-shaped reflective sheet, and the brightness of the light emitting surface of the light guide plate is covered. 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. FIG. 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 mounting structure of a light guide plate and a printed circuit board. , The same reference numerals as those in FIGS. 1 to 3 are the same or equivalent. As shown in FIGS. 4 and 5, the surface light-emitting device of the present invention is adhered to a lower reflective sheet 1 having a rectangular shape in a plan view and a portion of the upper surface of the lower reflective sheet 1 except for an end on one side thereof. A flat light guide plate 2, a 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, a linear light source unit 3, It comprises an elongated strip-shaped upper reflection sheet 11 adhered 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 tape having a high light reflectance such as white, and the lower reflection sheet 1 causes an area 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 two light emitting surfaces. Therefore, 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 of, for example, an acrylic resin or a polycarbonate resin to a thickness of 0.3 to 1.0 mm, and 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 includes an elongated rectangular rod-shaped printed board 4 as a wiring board provided with its axis parallel to the side surface of the light guide plate 2, and a side surface of the printed board 4 facing the side surface of the light guide plate 2. A light emitting element 5 arranged side by side at a predetermined interval along the side surface of the light guide plate 2, a reflecting plate 6 having a trapezoidal shape in a plan view disposed between the light emitting elements 5, a printed board 4, It has a resin sealing layer 10 provided in a recess 7 having a substantially trapezoidal cross section formed by the light emitting element 5 and the reflection plate 6.

  The printed circuit board 4 has a flat printed circuit board on which the light emitting elements 5 are mounted in a matrix shape, and is diced according to the thickness of the light guide plate 2. In the diced printed circuit board 4, each light emitting element 5 is arranged in a horizontal line. Lined up. The thickness of the printed circuit 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 A is significantly smaller than the thickness A of the surface light emitting device shown in FIG. Further, + and-electrode terminals 8a and 8b for conducting electricity to the light emitting element 5 are respectively derived from both ends of the printed circuit board 4, and the both electrode terminals 8a and 8b are connected to a circuit (e.g. (Not shown).

  Each light emitting element 5 is die-bonded to the wiring pattern of the printed circuit board 4 and its main light extraction surface is arranged side by side so as to be parallel to the side surface of the light guide plate 2. Are located in the same straight line and 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 located 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 from the inclined surface 6 a of the reflection 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, in the light guide plate 2, between each light emitting element 5 having low brightness, When the incident lights overlap, the luminance of the linear light source unit 3 becomes uniform, and the luminance of the surface light emission in the light guide plate 2 becomes substantially uniform. The angle of inclination of the inclined surface 6a of the reflection plate 6 can be appropriately adjusted so as to eliminate uneven brightness of the light guide plate 2.

  The resin sealing layer 10 is formed by filling a transparent resin sealing material such as an epoxy resin. Then, when this resin sealing material is injected and filled into the concave portion 7 formed by the printed board 4, the light emitting element 5, and the reflecting plate 6, the air layer of the concave portion 7 filled with the resin is eliminated. In addition, the efficiency of capturing 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 the lower reflective sheet 1, and is a 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 reflector 6 and the upper surface of the printed circuit board 4 are respectively covered. Therefore, 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 from the gap between the light guide plate 2 and the linear light source unit 3. As a result, the light from each light emitting element 5 can be incident on the light guide plate 2 without any excess. 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. 22 is significantly reduced in comparison with the width B of the installation space.

  Next, a usage mode of the surface light emitting device will be described. When current is applied to each light emitting element 5 via the wiring pattern of the printed circuit board 4, light is emitted from an active layer in the semiconductor layer of each light emitting element 5. 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 orthogonal to the side surface of the light guide plate 2 proceeds through the light guide plate 2 as it is, and the light emitted in parallel to the side surface of the light guide plate 2 The light returned to the light guide plate 2 by the inclined surfaces 6 a and 6 a and emitted vertically 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. .

  As described above, the light emitted from each light emitting element 5 is taken into the light guide plate 2, so that the light emission surface of the light guide plate 2 has no uneven brightness and the light emission surface of the light guide plate 2 can have uniform brightness. In addition, by encapsulating each light emitting element 5 with resin, the efficiency of capturing light into the light guide plate 2 increases, and the luminance improves.

  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 substrate. 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), and the reflecting plate is mounted on the printed circuit board 4 with an adhesive or the like. to paste together. Thereafter, the light emitting element 5 is mechanically attached to a predetermined position by an adhesive. Next, the light emitting element 5 is electrically connected by die bonding, the light emitting element 5 is sealed with a transparent resin, and then the printed circuit board 4 is diced into a square rod shape in accordance with the thickness of the light guide plate 2. Is divided.

  Next, the light guide plate 2 is adhered to a portion excluding the end of the flat lower reflection sheet 1, and the main light extraction surface of the square rod-shaped printed board 4 and each light emitting element 5 is attached to the side surface of the light guide plate 2. The area from one light-emitting surface of the light guide plate 2 to the printed board 4 is covered with the flat lower reflective sheet 1 and the other end of the light-emitting plate of the light guide plate 2 is connected to the printed board. Up to four areas are covered with a belt-shaped upper reflection sheet 11.

  In the above embodiment, the inclined surfaces 6a, 6a of the reflecting plate 6 having a trapezoidal shape in a plan view are used, but the present invention is not limited to the illustration, and the inclined surfaces 6a, 6a of the reflecting plate 6 having a triangular shape in a plan view are used. May be used, and a long and thin reflecting plate may be used. In addition, it is preferable that each of the reflection plates 6 is configured to be adjustable in angle. In short, the shape and angle of the reflector 6 are 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 poor light. It suffices if the brightness between the light emitting elements 5 and 5 can be complemented and the brightness of the surface light emission of the light guide plate 2 can be made substantially uniform.

  Further, it is also possible to increase the luminance characteristics of the light guide plate 2 by mixing a light dispersing material such as glass beads into the light-transmitting resin sealing layer 10.

  Further, in the above embodiment, the region from the edge of the light guide plate 2 to the printed circuit board 4 is covered by the belt-shaped upper reflection sheet 11, but the region from the peripheral edge of the light guide plate 2 to the printed circuit board 4 is covered. You may make it cover with a character-shaped or frame-shaped upper reflective sheet.

  The linear light source device and the surface light emitting device of the present invention can be used as, for example, a backlight of a liquid crystal display panel such as a miniaturized and thinned mobile phone or a digital camera, and has a display portion with high luminance and less luminance unevenness. Can be made.

(A) is a perspective view of the linear light source device according to the first embodiment of the present invention, (B) is a side cross-sectional view of the linear light source device provided with the reflection sheet, and (C) is provided with a deposition film. Sectional view of the linear light source device (A) is a perspective view showing a state in which a plurality of light emitting elements are arranged on a wiring board; (B) is a perspective view showing a state in which the light emitting elements are die-bonded; FIG. 2D is a perspective view showing a state where a part of FIG. 2C is enlarged, FIG. 2E is a perspective view showing a state where a resin sealing material is filled, and FIG. ) Is a perspective view of the dicing state (A) is a side cross-sectional view of a state in which the tip portion is diced from the back side of the wiring board by an isosceles triangular blade, and (B) is a perspective view of a linear light source having a resin sealing layer having a truncated cone shape. , (C) is a side sectional view of FIG. FIG. 4 is a perspective view of a surface emitting device according to a second embodiment of the present 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 the printed circuit board Perspective view of a conventional surface emitting device 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 the flexible substrate Partially cutaway side view of another conventional surface emitting device 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 the flexible substrate

Explanation of reference numerals

1,20 lower reflection sheet 2,21,30 light guide plate 3,22 light source 4 printed circuit board (wiring board)
5, 32 Light-emitting element 6 Reflector 6a Inclined surface (reflector)
7 Depression 8a, 8b Electrode terminal 9 Wire 10, 25, 34 Resin sealing layer 11, 27, 35 Upper reflective sheet 12 Deposited film 15 Blade 23, 33 Flexible board (wiring board)
Reference Signs List 24 case 26 lead terminal 31 recess 36 dot pattern 40 printed board 60 reflector 61 ridge 62 ridge 101 reflection sheet A thickness of surface light emitting device B width of light source unit installation space

Claims (11)

A plurality of light emitting elements are arranged at predetermined intervals along the longitudinal direction of the elongated rectangular rod-shaped wiring board and die-bonded, and on both sides of each light emitting element, and alternately with each light emitting element. A reflection plate is disposed so as to be positioned, and the opposing surfaces of the two reflection plates are inclined such that the opening area increases toward the emission direction of each light emitting element. Light source device. The linear light source device according to claim 1, wherein the shape of the opposing surface of the reflection plate is one of a rectangular shape and a trapezoidal shape. A resin sealing layer is formed by filling a concave portion formed by a light-transmitting resin sealing material with a mounting surface of a wiring board, a light-emitting element, and an opposing surface of both reflectors. The linear light source device according to claim 1. 4. The linear light source device according to claim 3, wherein in each of the resin sealing layers, a cross section located at a portion formed by the wiring board and the two reflection plates is mirror-finished. 5. 5. The linear light source device according to claim 3, wherein in each of the resin sealing layers, a cross section located between opposing surfaces of both the reflection plates is located on the same surface. 6. A reflection member comprising a reflection sheet or a vapor-deposited film is provided in a region from both end surfaces in the longitudinal direction adjacent to the mounting surface of the wiring board to a front end portion of the opposing surface of each reflection plate. The linear light source device according to any one of claims 1 to 5. The light emitting elements are arranged on the wiring board at predetermined intervals and die-bonded. Next, a reflecting plate having a facing surface inclined so that the opening area becomes larger toward the emission direction of the light emitting element is formed by each light emitting element. Provided on both sides of the element, subsequently, a light-transmissive resin sealing material is filled into the concave portion formed by the mounting surface of the wiring board, the light-emitting element, and the inclined surface of the reflector, and further, the reflector is A method of manufacturing a linear light source device, wherein dicing is performed on both sides of each light emitting element and alternately with each light emitting element to form a square rod shape. 8. The linear light source device according to claim 7, wherein the cross section of the tip is diced from the back side of the wiring board by an isosceles triangular blade, and the cross section of the square rod-shaped linear light source device is processed into a trapezoidal shape. Production method. In a surface-emitting device including a light-emitting element conductively connected to a wiring board and a light guide plate that takes in light from the light-emitting element and has a substantially entire light-emitting surface, the light-emitting element is die-bonded to the wiring board. And a main light extraction surface of the light emitting element is provided so as to be parallel to a side surface of the light guide plate. The surface according to claim 1, wherein 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 are provided at the same height. Light emitting device. The said wiring board is processed in the shape of a square rod according to the thickness of a light-guide plate, and is arrange | positioned so that the axis of a square-bar-shaped wiring board may become parallel with the side surface of a light-guide plate. 3. The surface emitting device according to 2.

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