JP2005038776A - Light guide plate and its manufacturing method, surface light emitting device, and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide plate capable of realizing thinning of an optical equipment. <P>SOLUTION: This is the light guide plate 10 in which a plurality of flip chip LED elements 2 are provided on one side face 1S of a translucent light guide plate main body 1. Since the thickness of these flip chip LED elements 2 is smaller than the that of conventional resin package type LED elements, the thickness of the light guide plate main body 1 determined by the thickness of this flip chip LED elements 2 is smaller than the conventional light guide plate determined by the thickness of the resin package type LED elements. Therefore, since the light guide plate 10 is made thin based on the thin structure of the flip chip LED elements 2, thinning of an optical equipment (for example, liquid crystal display device) mounting this light guide plate 10 can be realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light guide plate that emits surface light, a method for manufacturing the same, a surface light-emitting device that includes the light guide plate, and a liquid crystal display device that includes the surface light-emitting device.

  In recent years, display devices having various display mechanisms are known, and among them, liquid crystal display devices that can be reduced in thickness are becoming popular. This liquid crystal display device displays an image using a liquid crystal drive mechanism, and includes, for example, a surface light emitting device as a light source for backlight.

  FIG. 23 shows a perspective configuration of a conventional liquid crystal display device 100. As shown in FIG. 23, the liquid crystal display device 100 includes a liquid crystal display panel 200 that displays an image, and a surface light emitting device 300 that is disposed to face the liquid crystal display panel 200 and emits light toward the liquid crystal display panel 200. And. The surface light emitting device 300 mainly includes a light emitting plate 310 and a light source 320 for surface light emission, a reflection sheet 330 disposed on the opposite side of the liquid crystal display panel 200 with the light guide plate 310 and the light source 320 interposed therebetween, The prism sheet 340 and the light diffusion sheet 350 are provided between the light guide plate 310 and the light source 320 and the liquid crystal display panel 200. That is, the reflective sheet 330 and the light guide plate 310 are sequentially arranged from the side far from the liquid crystal display panel 200. The light source 320, the prism sheet 340, and the light diffusion sheet 350 are laminated in this order.

  The light source 320 has, for example, a configuration in which a plurality of resin package light emitting diode (Light Emitting Diode) elements (hereinafter simply referred to as “LED elements”) 322 are arranged and mounted on one surface of an L-shaped wiring board 321. A series of resin package type LED elements 322 are arranged to face one side surface 310S of the light guide plate 310. For example, a reflection pattern (not shown) for improving the light reflection efficiency is provided on the surface of the light guide plate 310 facing the reflection sheet 330. Note that a power supply terminal 323 for supplying power to the resin package type LED element 322 is provided at one end of the wiring substrate 321.

  In the liquid crystal display device 100, when the light generated from each resin package type LED element 322 of the light source 320 is guided from one side surface 310S and the light guide plate 310 emits light, the light during the surface light emission is transmitted to the liquid crystal display panel 200. Therefore, the liquid crystal display panel 200 reproduces an image using a light transmission or non-transmission phenomenon associated with a liquid crystal driving mechanism.

  24 and 25 are enlarged views of the configuration of the resin package type LED element 322 shown in FIG. 23, FIG. 24 shows a perspective configuration, and FIG. 25 is along the XY plane of the main part shown in FIG. FIG. The resin package type LED element 322 is mainly covered with a mold resin 301 that also serves as a reflector function, and is electrically connected to the anode electrode 302 and the cathode electrode 303 that are partially exposed on both sides, and the anode electrode 302. It is configured to include a bare chip LED element 304 and a translucent sealing resin 305 embedded in the mold resin 301, and emits light in the direction of arrow Y1. A p-type electrode layer (not shown) of the bare chip LED element 304 is wire-bonded to the anode electrode 302 via a wire 306A, and an n-type electrode layer (not shown) is connected to the cathode electrode 303 via a wire 306B. Wire bonded. Although not shown in FIG. 25, for example, the bare chip LED element 304 or the translucent sealing resin 305 may be provided with a phosphor, pigment, dye, or the like for light emission wavelength conversion.

  FIG. 26 shows an enlarged cross-sectional configuration of the bare chip LED element 304 constituting the resin package type LED element 322 shown in FIG. 25 and its peripheral structure. 27 and 28 are for explaining the mounting procedure of the bare chip LED element 304, and show a cross-sectional configuration corresponding to FIG. As shown in FIG. 26, the bare chip LED element 304 is mounted on a power supply wiring substrate 324. This bare chip LED element 304 mainly has a configuration in which a light-transmitting substrate 3041, a light emitting compound layer 3042, and an auxiliary electrode layer 3043 partially provided on the light emitting compound layer 2042 are laminated in this order. is doing. The auxiliary electrode layer 3043 is made of a light transmissive or semi-light transmissive material such as ITO (Indium Tin Oxide). In this bare chip LED element 304, a p-type electrode layer 3044A is provided on the auxiliary electrode layer 3043, and an n-type electrode layer 3044B is provided on the exposed surface of the light emitting compound layer 3042. The p-type electrode layer 3044A is connected to a power supply connection terminal 325A provided on the wiring substrate 324 via a wire 306A, and further connected to the anode electrode 302 (see FIG. 25) via the connection terminal 325A. The n-type electrode layer 3044B is connected to the connection terminal 325B provided on the wiring board 324 together with the connection terminal 325A via the wire 306B, and further connected to the cathode electrode 303 (via the connection terminal 325B). (See FIG. 25). In FIG. 25, the wiring board 324 and the connection terminals 325A and 325B are not shown.

  When the bare chip LED element 304 is mounted on the wiring board 324, first, as shown in FIG. 27, the region between the connection terminals 325A and 325B on the wiring board 324 is transparent to the wiring board 324. The bare-chip LED element 304 is aligned so that the conductive substrate 3041 faces. Subsequently, as shown in FIG. 28, the bare chip LED element 304 is mounted on the wiring substrate 324 by die bonding. Finally, as shown in FIG. 26, the p-type electrode layer 3044A is wire-bonded to the connection terminal 325A using the wire 306A, and the n-type electrode layer 3044B is wire-bonded to the connection terminal 325B using the wire 306B. Thus, the mounting of the bare chip LED element 304 is completed.

  For example, as shown in FIG. 29, the resin package type LED element 322 shown in FIG. 25 may include a flip chip LED element 307 instead of the bare chip LED element 304 described above. The flip-chip LED element 307 has electrode layers on the side facing the anode electrode 302 and the cathode electrode 303, that is, a p-type electrode layer 3071A and an n-type electrode layer 3071B. Unlike the above, the p-type electrode layer 3071A and the n-type electrode layer 3071B are directly joined to the anode electrode 302 and the cathode electrode 303, respectively. The remaining configuration of the resin package type LED element 322 shown in FIG. 29 is the same as that shown in FIG.

  FIG. 30 shows an enlarged cross-sectional configuration of the flip-chip LED element 307 and its peripheral structure in the resin package type LED element 322 shown in FIG. As shown in FIG. 30, the flip-chip LED element 307 has a configuration in which the p-type electrode layer 3071A and the n-type electrode layer 3071B, the light emitting compound layer 3072, and the translucent substrate 3073 are laminated in this order. have. The flip-chip LED element 307 emits light in the direction of the arrow Y1 by being fed through a p-type electrode layer 3071A and an n-type electrode layer 3071B provided as the lowermost layer.

Regarding liquid crystal display devices, various configurations are already known. Specifically, for example, in order to control the light emission angle when the light generated from the light source device enters the light guide plate, the liquid crystal in which the light source device or the light guide plate is provided with optical means for controlling the light emission angle. A display device is known (for example, refer to Patent Document 1).
JP 2003-162913 A

  Recently, new optical equipment equipped with a liquid crystal display device, specifically, a digital still camera and a mobile phone equipped with a camera function have appeared, and the spread of this type of optical equipment is rapidly spreading. In the field of development of this type of optical equipment, in consideration of ease of handling during use, downsizing, specifically, downsizing, has been promoted, and accordingly, downsizing of liquid crystal display devices is demanded. . However, in the past, even though liquid crystal display devices have been required to be thin, physical size reduction is already the limit when using resin packaged LED elements. There was a limit. Therefore, considering the current market trend of thinning optical devices, it is urgent to establish a thinning technology for liquid crystal display devices that can realize thinning of optical devices. is there. In this case, it is also important to establish a manufacturing technique capable of easily and stably manufacturing the liquid crystal display device in order to ensure mass productivity of the liquid crystal display device.

  The present invention has been made in view of the above problems, and a first object thereof is to provide a light guide plate capable of realizing a thin optical device and a surface light emitting device including the light guide plate. is there.

  The second object of the present invention is to provide a method of manufacturing a light guide plate capable of easily and stably manufacturing the above-described light guide plate.

  Furthermore, a third object of the present invention is to provide a liquid crystal display device that can be made thin.

  The light guide plate according to the present invention includes a light guide plate main body for guiding light to cause surface light emission, and a light source for generating light is provided on one side surface of the light guide plate main body.

  Moreover, the manufacturing method of the light-guide plate which concerns on this invention is the 1st process of forming a light-guide plate main body using translucent resin, and the 2nd process of forming a light source in one side of this light-guide plate main body, And a light guide plate having a light source provided on one side surface of the light guide plate main body.

  In addition, a surface light emitting device according to the present invention includes a light guide plate having a light source that generates light and a light guide plate body that guides light generated from the light source to cause surface light emission, and the light source is one side of the light guide plate body. Is provided.

  The liquid crystal display device according to the present invention includes a surface light emitting device including a light guide plate having a light source that generates light and a light guide plate body that guides light generated from the light source to emit light. The light source is provided on one side surface of the light guide plate main body.

  In the light guide plate according to the present invention, since the light source is provided on one side surface of the light guide plate main body, the thickness of the light guide plate main body is determined based on the thickness of the light source. Thus, for example, if the light guide plate body is configured using a light source that is thinner than a conventional light source, the thickness of the light guide plate body determined based on the thickness of the thin light source is the thickness of the conventional light source. It becomes smaller than the thickness of the light guide plate determined based on the thickness.

  Further, in the light guide plate manufacturing method according to the present invention, in order to manufacture the light guide plate, only the existing molding technique and joining technique are used, and a new and complicated processing technique is not used.

  Moreover, in the surface light-emitting device which concerns on this invention, since the light-guide plate of this invention is provided, the whole surface light-emitting device is thinned based on thickness reduction of the light-guide plate.

  Further, since the liquid crystal display device according to the present invention includes the surface light emitting device of the present invention, the entire liquid crystal display device is thinned based on the thinning of the surface light emitting device.

  According to the light guide plate of the present invention, for example, by using a thin light source, the light guide plate body is thinned based on the thin light source, so that the entire light guide plate is thinned. Therefore, it is possible to reduce the thickness of the optical device on which the light guide plate is mounted.

  In addition, according to the method for manufacturing a light guide plate according to the present invention, the light guide plate can be formed with good reproducibility using only the existing molding technique and joining technique, so that the light guide plate can be manufactured easily and stably. can do.

  Further, according to the surface light emitting device according to the present invention, the entire device is thinned based on the thinning of the light guide plate. Therefore, it is possible to reduce the thickness of an optical device equipped with this surface light emitting device.

  In addition, according to the liquid crystal display device of the present invention, since the entire device is thinned based on the thinning of the surface emitting device, the thinning can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, with reference to FIGS. 1-3, the structure of the light-guide plate which concerns on one embodiment of this invention is demonstrated. 1 to 3 show the configuration of the light guide plate 10, FIG. 1 shows a perspective configuration, FIG. 2 shows a planar configuration, and FIG. 3 shows a side configuration.

  The light guide plate 10 is mounted on an optical device such as a liquid crystal display device, for example. As shown in FIGS. 1 to 3, the light guide plate 10 includes a light guide plate main body 1 for guiding light to cause surface emission. The light guide plate main body 1 has a configuration in which a plurality of flip chip LED elements 2 as light sources for generating light are provided on one side surface 1S of the light guide plate body 1. 1 to 3 show a case where, for example, three flip chip LED elements 2A, 2B, and 2C are provided as the plurality of flip chip LED elements 2.

  As shown in FIGS. 1 to 3, the light guide plate body 1 substantially constitutes the main part of the light guide plate 10, and is made of, for example, a translucent resin material. On one side surface 1S of the light guide plate body 1, for example, three depressions 1K for embedding the flip chip LED elements 2A to 2C are provided at predetermined intervals. The number of depressions 1K installed is not necessarily limited to three, and can be freely changed according to the number of flip chip LED elements 2 installed.

  The flip chip LED element 2 (2A to 2C) is a light emitting source for surface light emission, and is a wiring board using flip chip bonding (not shown in FIGS. 1 to 3; see FIG. 9 described later). It is the LED element which has the characteristic structure which can be mounted in. As shown in FIGS. 1 to 3, the flip-chip LED elements 2 </ b> A to 2 </ b> C have a p-type electrode layer 21 </ b> A and an n-type on the side opposite to the side facing the light guide plate body 1 (that is, the side facing the wiring board) The electrode layer 21 </ b> B is included, and the p-type electrode layer 21 </ b> A and the n-type electrode layer 21 </ b> B are embedded in the depression 1 </ b> K provided on the one side surface 1 </ b> S of the light guide plate body 1. The detailed configuration of the flip chip LED element 2 will be described later. Note that the number of flip-chip LED elements 2 is not limited to three and can be freely changed.

  Next, a detailed configuration of the flip-chip LED element 2 will be described with reference to FIGS. FIG. 4 shows an enlarged cross-sectional configuration of the flip-chip LED element 2, and shows a cross section along the XY plane shown in FIGS.

  For example, as shown in FIG. 4, the flip-chip LED element 2 includes a p-type electrode layer 21 </ b> A and an n-type electrode layer 21 </ b> B and a light emitting compound layer configured to include, for example, a nitride semiconductor having a quantum well structure. 22 and a translucent substrate 23 made of, for example, sapphire or silicon carbide (SiC) are included so as to be laminated in this order, and light is emitted in the direction of arrow Y2. . That is, in the flip-chip LED element 2, the p-type electrode layer 21A and the n-type electrode layer 21B are provided on the lower surface of the light emitting compound layer 22.

  Next, the surface light emission mechanism of the light guide plate 10 will be described with reference to FIGS. In this light guide plate 10, as shown in FIGS. 1 to 3, when power is supplied to a series of flip-chip LED elements 2 </ b> A to 2 </ b> C from a wiring board (not shown) through a p-type electrode layer 21 </ b> A and an n-type electrode layer 21 </ b> B. As shown in FIG. 4, light generated from the light emitting compound layer 22 of each of the flip chip LED elements 2 </ b> A to 2 </ b> C is emitted in the direction of the arrow Y <b> 2 and guided to the light guide plate body 1. Thereby, the light guide plate body 1 emits surface light.

  Next, with reference to FIGS. 1-6, the manufacturing method of the light-guide plate 10 is demonstrated. FIGS. 5 and 6 are for explaining the manufacturing process of the light guide plate 10, and both show a perspective configuration corresponding to FIG.

  When manufacturing the light guide plate 10, first, for example, as shown in FIG. 5, a translucent resin is molded using a molding tool such as a mold, so that one side surface 1S is formed at predetermined intervals. The light guide plate main body 1 provided with three recesses 1K is formed.

  Subsequently, as shown in FIG. 6, the flip-chip LED element 2 (2 </ b> A to 2 </ b> C) shown in FIG. 4 is used, and the p-type electrode layer 21 </ b> A and the n-type electrode are formed in the depression 1 </ b> K provided in the light guide plate body 1. By inserting and mounting the flip chip LED elements 2A to 2C so that the 21B layer is exposed, a series of flip chip LED elements 2A to 2C are embedded in the recess 1K. In this case, for example, although not specifically illustrated, a translucent adhesive or a liquid translucent resin (in order to stabilize the insertion / mountability of the flip chip LED elements 2A to 2C in the recess 1K ( For example, a thermosetting resin, a room temperature curable resin, or an ultraviolet curable resin) is applied in advance to the inside of the flip chip LED elements 2A to 2C or the recess 1K, and the flip chip LED elements 2A to 2C are inserted and mounted in the recess 1K. Alternatively, the light-transmitting adhesive or the light-transmitting resin may be bonded by drying or curing. Thereby, as shown in FIGS. 1-3, the light-guide plate 10 by which flip chip LED element 2A-2C was provided in one side 1S of the light-guide plate main body 1 is completed.

  The light guide plate 10 described above is bonded to a power supply wiring board through the following procedure in order to supply power to the series of flip chip LED elements 2A to 2C, for example. 7-9 is for demonstrating the joining process of the light-guide plate 10, and all have shown the cross-sectional structure corresponding to the planar structure shown in FIG.

  When the light guide plate 10 is joined, as shown in FIG. 7, after manufacturing the light guide plate 10 through the above-described manufacturing process, first, for example, as shown in FIG. The conductive adhesive 40 is applied to the p-type electrode layer 21 </ b> A and the n-type electrode 21 </ b> B layer of ˜2C, and the light guide plate 10 is opposed to the power supply wiring substrate 50. As the conductive adhesive 40, for example, a silver paste is preferably used. The wiring substrate 50 is provided with a wiring pattern (not shown) for supplying power to the series of flip chip LED elements 2A to 2C collectively on one surface 50S facing the light guide plate 10. Thereafter, by pressing one side surface 1S of the light guide plate 10 against one surface 50S of the wiring board 50, the p-types of the flip-chip LED elements 2A to 2C are interposed via the conductive adhesive 40 as shown in FIG. The electrode layer 21A and the n-type electrode layer 21B are bonded to the wiring board 50. Thus, power can be supplied from the wiring board 50 to the series of flip chip LED elements 2A to 2C, and the joining of the light guide plate 10 is completed.

  The light guide plate 10 according to the present embodiment has a configuration in which a plurality of flip-chip LED elements 2 are provided on one side surface 1S of the light guide plate main body 1. Therefore, the prior art described in the above "Background Art" section. Compared with the light guide plate 310 (see FIG. 23), the optical device on which the light guide plate 10 is mounted can be made thinner for the following reasons.

  10 and 11 are for explaining the problems of the conventional light guide plate 310 shown in FIG. 23. FIG. 10 is an enlarged side view of the light guide plate 310 and the resin package type LED element 322. FIG. 11 shows an enlarged side view configuration when the light guide plate 310 is thinned in the case shown in FIG. FIG. 12 is for explaining the advantages of the light guide plate 10 shown in FIGS. 1 to 3 and shows a side structure corresponding to FIGS. 10 and 11.

  In the conventional light guide plate 310, as shown in FIG. 10, in order to guide the light L emitted from the light emission surface 322E of the resin package type LED element 322 from the one side surface 310S to the light guide plate 310, The thickness (that is, the height of one side 310S) T1 is designed based on the thickness H1 of the resin package type LED element 322 (that is, the height of the light emitting surface 322E), and specifically, the thickness T1 is It is designed to be equal to the thickness H1 (T1 = H1). In this case, since most of the light L emitted from the light emission surface 322E is guided to the one side surface 310S by making the thickness T1 equal to the thickness H1, the resin package type LED element 322 is guided to the light guide plate 310. The guiding loss of the light L guided to the light beam is reduced, that is, the guiding efficiency of the light L is improved. However, in the conventional light guide plate 310, the thickness T1 of the light guide plate 310 is reduced, that is, the thickness is reduced, as shown in FIG. 11, for the purpose of reducing the thickness of the entire optical device on which the light guide plate 310 is mounted. When the thickness T1 is made smaller than the thickness H1 of the resin packaged LED element 322 (T1 <H1), the light L emitted from the light emitting surface 322E of the resin packaged LED element 322 passes through one side surface 310S. Since the ratio of the light L that is not guided to the light guide plate 310 increases, that is, the guiding efficiency of the light L that is guided to the light guide plate 310 decreases, the luminance (surface emission intensity) decreases when the optical device is made thin. End up.

  On the other hand, in the light guide plate 10 of the present embodiment, as shown in FIG. 12, the thickness T2 of the light guide plate body 1 based on the thickness H2 of the flip chip LED element 2 provided on the one side surface 1S. Therefore, the thickness T2 of the light guide plate body 1 is smaller than the thickness T1 of the light guide plate 310 shown in FIGS. 10 and 11 (T2 <T1). This is because the resin package type LED element 322 that determines the thickness T2 of the conventional light guide plate 310 is a bare chip LED element 304 or a flip chip as a substantial light emitting source, as shown in FIGS. The light guide plate main body 1 according to the present embodiment has a complicated structure including other peripheral components such as the mold resin 301 and the translucent sealing resin 305 in addition to the LED element 307. The flip-chip LED element 2 that determines the thickness T1 is configured by itself and has a simple configuration that does not include other peripheral components such as the mold resin 301 and the translucent sealing resin 305 described above. Since the thickness H2 of the flip-chip LED element 2 is smaller than the thickness H1 of the resin package type LED element 322 (H2 <H1), it is defined based on the thickness H2. That the thickness T2 of the light guide plate main body 1 is also similar to, because smaller than the thickness T1 of the light guide plate 310 which is determined based on the thickness H1 (T2 <T1). In addition, of course, most of the light L emitted from the flip-chip LED element 2 is guided to the light guide plate body 1, that is, the guiding efficiency of the light L guided to the light guide plate body 1 is ensured, so that the thickness can be reduced. Luminance is also ensured when trying. Therefore, the light guide plate 10 of the present embodiment can be made thinner than the conventional light guide plate 310 while ensuring the luminance, and as a result, the optical device equipped with the light guide plate 10 can be made thinner. It can be realized. Furthermore, in this embodiment, other peripheral parts such as the above-described mold resin 301 and translucent sealing resin 305 are not included, and further, the mounting process of the mold resin 301 and translucent sealing resin 305 can be omitted. The cost of the light guide plate 10 can be reduced.

  In particular, in the present embodiment, as described above, since the flip chip LED element 2 is used as the light generation source of the light guide plate 10, for example, the bare chip including the conventional wires 306A and 306B for electrical connection is used. Unlike the case where the LED element 304 (see FIG. 26) is used, the following advantages can be obtained.

  That is, in the conventional bare chip LED element 304, as shown in FIG. 26, since the wires 306A and 306B are exposed when mounted on the wiring board 324, the wires 306A and 306B are unintentionally cut. There is a risk. Causes of cutting of the wires 306A and 306B include, for example, (1) the wiring board 324 is excessively curved because the bare chip LED element 304 is mounted, or (2) when other components are formed after mounting. For example, it may be affected by the forming process, or (3) when the light source 320 (see FIG. 23) is transported after mounting, it may be affected by shaking or vibration during the transport. When the wires 306A and 306B are cut, the bare chip LED element 304 cannot be energized, and the light source 320 becomes defective. On the other hand, since the flip chip LED element 2 of the present embodiment does not fundamentally include the wires 306A and 306B, the occurrence of defects due to the cutting of the wires 306A and 306B is prevented. Therefore, in the present embodiment, the manufacturing efficiency of the light guide plate 10 can be improved.

  Further, in the method for manufacturing the light guide plate 10 according to the present embodiment, the light guide plate main body 1 having a plurality of dents 1K provided on one side surface 1S is formed using a translucent resin, and then the light guide plate main body 1 is formed. Since the light guide plate 10 is manufactured by embedding the flip-chip LED element 2 in the recess 1K, the light guide plate does not require a new and complicated processing technique and uses only the existing molding technique and joining technique. 10 can be formed with good reproducibility. Therefore, the light guide plate 10 can be manufactured easily and stably.

  In the present embodiment, for example, as shown in FIG. 4, after using the flip chip LED element 2 as a light generation source, the color of light generated from the flip chip LED element 2 is blue, red, The color is not limited to a single color such as purple or green, and can be converted into, for example, white or another color. Specifically, for example, by using a light emission wavelength conversion agent 24 for converting a light emission wavelength to reproduce a desired light emission color, the light emission wavelength conversion agent 24 is made translucent as shown in FIG. Alternatively, the emission wavelength conversion agent 24 may be dispersed in the light-transmitting resin layer 25 provided on the light-transmitting substrate 23 as shown in FIG. May be. Examples of the light emission wavelength conversion agent 24 include phosphors, pigments, and dyes having characteristics capable of controlling the light emission wavelength. In any case, the desired emission color can be reproduced using the emission wavelength conversion agent 24.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  FIG. 15 shows a configuration of the light guide plate 60 according to the present embodiment, and shows a perspective configuration corresponding to FIG. In FIG. 15, the same components as those described in the first embodiment are denoted by the same reference numerals. The light guide plate 60 is provided with a power supply wiring pattern 3 connected to the flip chip LED element 2 together with the light guide plate body 1 and the flip chip LED elements 2 (2A to 2C), except for the above. It has the same configuration as the light guide plate 10 described in the first embodiment.

  The wiring pattern 3 is for supplying power to the flip chip LED element 2 and is made of, for example, a conductive material such as silver paste. The wiring pattern 3 is configured, for example, as an assembly of a plurality of pattern groups for connecting a series of flip chip LED elements 2A to 2C in series. Specifically, the wiring pattern 3 is a p-type of the flip chip LED element 2A. A feed terminal pattern 31 connected to the electrode layer 21A, a connection pattern 32 for connecting the n-type electrode layer 21B of the flip-chip LED element 2A and the p-type electrode layer 21A of the flip-chip LED element 2B, and a flip-chip LED A connection pattern 33 for connecting the n-type electrode layer 21B of the element 2B and the p-type electrode layer 21A of the flip-chip LED element 2C, and a connection pattern 34 connected to the n-type electrode layer 21B of the flip-chip LED element 2C; The power supply terminal pattern integrated with the connection pattern 34 and arranged in parallel with the power supply terminal pattern 31. It is configured to include a over emissions 35. The electrical connection relationship between the flip chip LED elements 2 (2A to 2C) and the wiring patterns 3 (31 to 35) is schematically shown in FIG. FIG. 16 shows the flip chip LED element 2 (2A to 2C) and the wiring pattern 3 (31 to 35) as well as an external power source 70 for supplying power to the flip chip LED element 2 through the wiring pattern 3. Yes.

  In this light guide plate 60, when power is supplied to the wiring pattern 3 from the external power supply 70 shown in FIG. 16, that is, when power is supplied to the power supply terminal patterns 31 and 35 and the connection patterns 32 to 34 shown in FIG. A current flows through each of the flip-chip LED elements 2A to 2C through 21A and the n-type electrode layer 21B. Thereby, since the light generated from each of the flip chip LED elements 2A to 2C is guided to the light guide plate body 1, the light guide plate body 1 emits surface light.

  Next, a method for manufacturing the light guide plate 60 will be described with reference to FIGS. FIG. 17 and FIG. 18 are for explaining the manufacturing process of the light guide plate 60, and both show a cross-sectional configuration along the line AA shown in FIG.

  When manufacturing the light guide plate 60, first, as shown in FIGS. 15 and 16, the light guide plate main body 1 is first subjected to the procedure described with reference to FIGS. 5 and 6 in the first embodiment. After embedding the flip chip LED elements 2 </ b> A to 2 </ b> C in the recess 1 </ b> K, the wiring pattern 3 is formed on one side surface 1 </ b> S of the light guide plate body 1 as an aggregate of a plurality of pattern groups (feeding terminal patterns 31 and 35, connection patterns 32 to 34) Pattern printing is performed, and a series of flip chip LED elements 2A to 2C are connected in series using the wiring pattern 3, so that power can be supplied to each flip chip LED element 2A to 2C from an external power supply 70.

  If the formation process of this wiring pattern 3 is demonstrated in detail, when forming the electric power feeding terminal patterns 31 and 35 in the wiring pattern 3, for example, as shown in FIG. After embedding the flip-chip element 2A, as shown in FIG. 18, the power supply terminal pattern 31 is pattern-printed so as to be connected to the p-type electrode layer 21A of the flip-chip LED element 2A, and the n-type electrode 21B The power feeding pattern 35 is pattern-printed so as to be connected. Thereby, the light guide plate 60 is completed.

  In the light guide plate 60 according to the present embodiment, the wiring pattern 3 is provided together with the light guide plate main body 1 and the flip-chip LED element 2, so that the wiring pattern 3 is formed by the same operation as in the first embodiment. Even when it is newly provided, it is possible to reduce the thickness of the optical device on which the light guide plate 60 is mounted.

  In particular, in the present embodiment, the wiring pattern 3 for feeding is provided, and the wiring pattern 3 can be used to directly feed power to the flip-chip LED element 2, and thus the wiring pattern 3 is not provided. Unlike the case of the first embodiment, the power supply wiring board 50 (see FIG. 9) becomes unnecessary. Therefore, the power supply mode of the light guide plate 60 can be simplified to further reduce the cost, and the power can be easily supplied to the light guide plate 60 using the wiring pattern 3.

  Further, in the method of manufacturing the light guide plate 60 according to the present embodiment, since the pattern printing technique is used to form the wiring pattern 3, it is compared with the case where a film forming technique other than the pattern printing technique is used. Thus, the formation efficiency of the wiring pattern 3 is improved. In addition, in this case, the wiring board 50 is not necessary as described above, and the process of bonding the flip chip LED element 2 to the wiring board 50 is also unnecessary, so that a complicated and time-consuming manufacturing process is reduced. Therefore, in this embodiment, the mass productivity of the light guide plate 60 can be improved.

  In the light guide plate 60 according to the present embodiment, as shown in FIG. 15, after the wiring pattern 3 is connected to the flip-chip LED element 2, for example, as shown in FIG. 3 may be provided with a spring terminal 71 for external power feeding. The spring terminal 71 includes, for example, a set of crank-type terminals 71A and 71B, and these terminals 71A and 71B are connected to the power supply terminal patterns 31 and 35, respectively. In this case, power can be easily supplied to the light guide plate 10 using the spring terminal 71.

  Further, in the present embodiment, as shown in FIG. 15, the wiring pattern 3 is configured as an aggregate of the power supply terminal patterns 31 and 35 and the connection patterns 32 to 34, but is not limited thereto, The configuration of the pattern 3 can be freely changed. Specifically, for example, as shown in FIG. 20, the wiring pattern 3 may be configured as an assembly of pattern groups for connecting a series of flip chip LED elements 2 </ b> A to 2 </ b> C in parallel. The wiring pattern 3 is connected to, for example, the power supply terminal pattern 36 connected to the p-type electrode layer 21A of each flip chip LED element 2A to 2C and the n-type electrode layer 21B of each flip chip LED element 2A to 2C. It is configured as an aggregate with the power supply terminal pattern 37. The electrical connection relationship between the flip chip LED elements 2 (2A to 2C) and the wiring pattern 3 (36, 37) is schematically shown in FIG. Even in this case, the same effect as the above embodiment can be obtained. In this case, for example, although not specifically illustrated, when insulation treatment is necessary from the viewpoint of short circuit between the patterns constituting the wiring pattern 3, an insulating paint is applied between the patterns. Alternatively, an insulating sheet material having an adhesive layer may be provided to electrically separate the patterns through the insulating material. The other configuration of the light guide plate 60 shown in FIG. 20 is the same as that shown in FIG. Of course, the electrical separation between the patterns via the insulating material described above is not limited to the case shown in FIG. 20, but can also be applied to the case shown in FIG.

  It should be noted that the configuration, the surface light emitting mechanism, the operation, the effect, and the modification other than the above regarding the light guide plate 60 according to the present embodiment, and the procedure, the operation, and the effect other than the above regarding the manufacturing method of the light guide plate 60 are the above-described first. This is the same as the embodiment.

  This is the end of the description of the light guide plate and the manufacturing method thereof according to the embodiment of the present invention.

  Next, with reference to FIG. 22, the configuration of a liquid crystal display light device including the light guide plate will be described as an application example of the light guide plate of the present invention. FIG. 22 shows a perspective configuration of the liquid crystal display device.

  For example, as shown in FIG. 22, the liquid crystal display device mainly includes a liquid crystal display panel 80 that displays an image in a predetermined direction (image display direction G) using a liquid crystal drive mechanism, and an image display direction. A surface light emitting device 90 as a backlight light source disposed opposite to the liquid crystal display panel 80 on the opposite side to G is provided.

  The liquid crystal display panel 80 mainly has a configuration in which liquid crystal is sealed between two glass substrates provided with wirings such as transparent electrodes.

  The surface light emitting device 90, together with the light guide plate 10 (the light guide plate main body 1, the flip chip LED element 2) described in the first embodiment, directs light emitted from the light guide plate 10 toward the liquid crystal display panel 80. As a light guiding member for guiding, a light reflecting reflection sheet 91, a light collecting prism sheet 92, and a light diffusion light diffusion sheet 93 are included, and from a side far from the liquid crystal display panel 80. The reflective sheet 91, the light guide plate 10, the prism sheet 92, and the light diffusion sheet 93 are sequentially laminated in this order. For example, a reflection pattern (not shown) for improving the light reflection efficiency may be provided on the surface of the light guide plate main body 1 constituting the light guide plate 10 on the side facing the reflection sheet 91. . In FIG. 22, the combination of the reflection sheet 91, the prism sheet 92, and the light diffusion sheet 93 is illustrated as the light guide member. However, the combination is not necessarily limited to this. For example, the combination of the light guide members is the liquid crystal display device. It can be freely changed according to the optical characteristics (for example, brightness). More specifically, for example, the light guiding member may be one in which some of the reflection sheet 91, the prism sheet 92, and the light diffusion sheet 93 are omitted.

  In this liquid crystal display device, when light generated from the flip chip LED element 2 of the light guide plate 10 is guided and the light guide plate main body 1 emits light, the light during the surface light emission does not pass through the reflection sheet 91 and is a prism sheet. The light is transmitted through the light guide sheet 92 and the light diffusing sheet 93, or after being reflected by the reflecting sheet 91 and then transmitted through the prism sheet 92 and the light diffusing sheet 93, thereby being guided to the liquid crystal display panel 80. Thus, an image is displayed from the liquid crystal display panel 80 toward the image display direction G by utilizing the light transmission or non-transmission phenomenon associated with the liquid crystal driving mechanism.

  Since the liquid crystal display device includes the light guide plate 10 of the present invention, the entire surface light emitting device 90 is thinned based on the advantage that the light guide plate 10 described in the first embodiment is thinned. The Accordingly, since the optical device equipped with the surface light emitting device 90 is thinned, the entire liquid crystal display device can be thinned.

  In the liquid crystal display device shown in FIG. 22, the light guide plate 10 described in the first embodiment is provided. However, the present invention is not necessarily limited to this. For example, the light guide plate 10 is replaced with the light guide plate 10. The light guide plate 60 described in the second embodiment may be provided. In this case as well, the same effect as when the light guide plate 10 is provided can be obtained.

  Other configurations, surface emitting mechanisms, operations, effects, and modifications of the light guide plates 10, 60 constituting the liquid crystal display device, and procedures, operations, and effects other than those described above regarding the manufacturing method are the same as those in the above embodiments. It is.

  As described above, the present invention has been described with application examples together with some embodiments. However, the present invention is not limited to the above embodiments and application examples, and the same effects can be obtained as long as possible. Can be freely deformed. Specifically, for example, in each of the above-described embodiments and application examples, the case where the present invention is applied to a liquid crystal display device has been described. However, the present invention is not necessarily limited thereto. The present invention can also be applied to optical equipment. Examples of the “other optical devices” include operation switch keys for portable electronic devices such as mobile phones, PDAs (Personal Digital Assistants), digital still cameras, and video recorders with cameras, logos, and automotive instruments. The present invention can be applied as backlight illumination for these various optical devices.

  The light guide plate and the manufacturing method thereof according to the present invention, and the surface light emitting device including the light guide plate can be applied to an optical apparatus such as a liquid crystal display device.

It is a perspective view showing the perspective structure of the light-guide plate which concerns on the 1st Embodiment of this invention. It is a top view showing the plane structure of the light-guide plate shown in FIG. It is a side view showing the side structure of the light-guide plate shown in FIG. It is sectional drawing which expands and represents the cross-sectional structure of a flip chip LED element. It is a perspective view for demonstrating one process among the manufacturing processes of the light-guide plate which concerns on the 1st Embodiment of this invention. It is a perspective view for demonstrating the process following FIG. It is a top view for demonstrating one process among the joining processes of a flip-chip LED element. It is a top view for demonstrating the process following FIG. It is a top view for demonstrating the process following FIG. It is a side view for demonstrating the problem regarding the conventional light-guide plate. It is a side view for demonstrating the problem of the conventional light-guide plate following FIG. It is a side view for demonstrating the advantage regarding the light-guide plate which concerns on the 1st Embodiment of this invention. It is sectional drawing for demonstrating the modification regarding the structure of a flip chip LED element. It is sectional drawing for demonstrating the other modification regarding the structure of a flip-chip LED element. It is a perspective view showing the perspective structure of the light-guide plate which concerns on the 2nd Embodiment of this invention. It is a figure showing the electrical connection relation of the flip chip LED element and wiring pattern regarding the light-guide plate shown in FIG. It is sectional drawing for demonstrating one process among the manufacturing processes of the light-guide plate which concerns on the 2nd Embodiment of this invention. FIG. 18 is a cross-sectional view for explaining a process following the process in FIG. 17. It is a perspective view for demonstrating the modification regarding the structure of the light-guide plate which concerns on the 2nd Embodiment of this invention. It is a perspective view for demonstrating the other modification regarding the structure of the light-guide plate which concerns on the 2nd Embodiment of this invention. It is a figure showing the electrical connection relation of the flip chip LED element and wiring pattern regarding the light-guide plate shown in FIG. It is a perspective view showing the perspective structure of a liquid crystal display device. It is a perspective view showing the perspective structure of the conventional liquid crystal display device. It is a perspective view showing the perspective structure of the conventional resin package type LED element. It is sectional drawing showing the cross-sectional structure of the resin package type LED element shown in FIG. It is sectional drawing which expands and represents the cross-sectional structure of the bare chip LED element of the resin package type LED elements shown in FIG. 25, and its peripheral structure. It is sectional drawing for demonstrating the mounting procedure of the bare chip LED element shown in FIG. It is sectional drawing for demonstrating the procedure following FIG. It is sectional drawing showing the cross-sectional structure of the other conventional resin package type LED element. It is sectional drawing which expands and represents the cross-sectional structure of the flip chip LED element among the resin package type LED elements shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light guide plate main body, 1K ... Depression, 1S ... One side surface, 2 (2A-2C) ... Flip chip LED element, 3 ... Wiring pattern 10, 60 ... Light guide plate, 21A ... P-type electrode layer, 21B ... N-type Electrode layer, 22 ... Luminescent compound layer, 23 ... Translucent substrate, 24 ... Emission wavelength converting agent, 25 ... Translucent resin layer, 31, 35-37 ... Feed terminal pattern, 32-34 ... Connection pattern, 40 ... Conductive adhesive, 50 ... wiring board, 50S ... one side, 70 ... external power supply, 71 ... spring terminal, 71A, 71B ... terminal, 80 ... liquid crystal display panel, 90 ... surface light emitting device, 91 ... reflective sheet, 92 ... prism Sheet, 93: Light diffusion sheet, G: Image display direction, L: Light.

Claims (13)

A light guide plate main body for guiding light to emit light is provided.
A light source for generating light is provided on one side of the light guide plate main body. As the light source, a light emitting diode element having a flip chip structure in which an electrode layer is provided on the lower surface of the light emitting layer is mounted,
The light source plate according to claim 1, wherein the light source is embedded in the light guide plate body so as to expose the electrode layer. The light guide plate according to claim 2, wherein a light emission wavelength converting agent for converting a wavelength of light generated from the light emitting layer is provided in the light emitting layer. The light guide plate according to claim 1, wherein a wiring pattern for supplying power to the light source is provided on one side surface of the light guide plate main body. The light guide plate according to claim 4, wherein the wiring pattern is made of a silver paste. The wiring pattern is configured to include a power supply terminal pattern for power supply,
The light guide plate according to claim 4, wherein the power supply terminal pattern is provided with a spring terminal for enabling power supply from the outside. A first step of forming a light guide plate body using a translucent resin;
Including a second step of forming a light source on one side of the light guide plate body,
A method of manufacturing a light guide plate, comprising: manufacturing a light guide plate in which the light source is provided on one side surface of the light guide plate body. In the second step, a light emitting diode element having a flip chip structure in which an electrode layer is provided on the lower surface of the light emitting layer is used as the light source.
The method of manufacturing a light guide plate according to claim 7, wherein the light source is embedded in the light guide plate body so that the electrode layer is exposed. The light emitting plate manufacturing method according to claim 8, wherein a light emission wavelength converting agent for converting a wavelength of light generated from the light emitting layer is provided on the light emitting layer. The method of manufacturing a light guide plate according to claim 7, further comprising a third step of forming a wiring pattern for supplying power to the light source on one side surface of the light guide plate main body. The method of manufacturing a light guide plate according to claim 10, wherein in the third step, the wiring pattern is formed by pattern printing of a silver paste. A light guide plate having a light source for generating light and a light guide plate body for guiding the light generated from the light source to cause surface emission;
The surface light-emitting device, wherein the light source is provided on one side surface of the light guide plate body. A surface light emitting device including a light guide plate having a light source for generating light and a light guide plate main body for guiding the light generated from the light source to cause surface emission;
The liquid crystal display device, wherein the light source is provided on one side surface of the light guide plate body.

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