JP2013165188A - Semiconductor light-emitting device, light source device, image forming apparatus and image display device - Google Patents

Abstract

Provided are a semiconductor light emitting device and a light source device capable of realizing miniaturization and high light output, and an image forming apparatus and an image display device capable of realizing miniaturization and high light output.
A semiconductor light emitting device (101) is arranged on a main surface (112a) of a substrate (112) and a plurality of semiconductor light emitting elements each having a cathode electrode (114) and an anode electrode (113). From the cathode electrode of the element (103, 104, 105) and one of the semiconductor light emitting elements adjacent to each other (103, 104) of the plurality of semiconductor light emitting elements, the other of the semiconductor light emitting elements adjacent to each other (104, 105) And a thin film wiring layer (116, 117) for electrically connecting up to the anode electrode.
[Selection] Figure 5

Description

  The present invention relates to a semiconductor light emitting device, a light source device, an image forming device, and an image display device.

  A bullet-type LED module on which a bare-chip light emitting diode (LED) is mounted has been put into practical use. FIG. 1 is a longitudinal sectional view schematically showing a structure of a bullet-type LED module 11, and FIGS. 2 and 3 are a plan view and a longitudinal section schematically showing a structure of an LED bare chip 12 in the LED module 11. FIG. As shown in FIGS. 1 to 3, the LED module 11 includes a cathode lead frame 13, a reflective cup 14 provided on the cathode lead frame 13, and an LED bare chip fixed in the reflective cup 14 with a transparent adhesive resin 15. 12, an anode lead frame 16, a cathode electrode 17 as a bonding pad, an anode electrode 18 as a bonding pad, a cathode bonding wire 19, an anode bonding wire 20, a lens case 21, and a phosphor 22. It has a simple structure.

  In such an LED module 11, when the light output is increased, the injection current is increased. However, when the LED module 11 is used with an injection current larger than a predetermined range, the amount of generated heat increases, the internal quantum efficiency decreases as the temperature rises, and the light output increases in proportion to the increase in injection current. I can't let you. In addition, when the LED module 11 continues to emit light under an excessively large injection current, the light output may be reduced or the LED may be destroyed.

  Patent Document 1 describes a proposal of mounting a plurality of bare chip-shaped LEDs in one bullet-type LED module in order to increase light output without increasing injection current.

JP 2002-141558 A

  However, in the apparatus described in Patent Document 1, it is necessary to die-bond a plurality of LED bare chips on a mounting substrate, and then connect bonding wires to each of the plurality of LED bare chips. It is necessary to provide a pad electrode (anode electrode or cathode electrode). In general, the size of a pad electrode for a bonding wire needs to be about 100 [μm □]. For this reason, the apparatus described in Patent Document 1 has a problem that high-density mounting cannot be performed.

  Further, in the apparatus described in Patent Document 1, since a bonding wire is connected on the light emitting portion, there is a problem that output light is shielded by the anode electrode and light extraction efficiency is lowered.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor light emitting device and a light source device that can achieve miniaturization and high light output, and an image forming apparatus to which the semiconductor light emitting device that can achieve miniaturization and high light output is applied, and An image display device is provided.

  A semiconductor light emitting device according to an aspect of the present invention includes a substrate, a plurality of semiconductor light emitting elements arranged on a main surface of the substrate, each having a cathode electrode and an anode electrode, and a plurality of the semiconductor light emitting elements. And a thin film wiring layer for electrically connecting one cathode electrode of the semiconductor light emitting elements adjacent to each other to the other anode electrode of the semiconductor light emitting elements adjacent to each other.

  A light source device according to another aspect of the present invention includes a mounting member and a semiconductor light-emitting device installed on the mounting member, and the semiconductor light-emitting device is arranged on a substrate and a main surface of the substrate. A plurality of semiconductor light emitting elements each having an anode electrode and a cathode electrode, and one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements, to the other of the semiconductor light emitting elements adjacent to each other And a thin-film wiring layer electrically connected to the anode electrode.

  An image forming apparatus according to another aspect of the present invention includes: an image carrier; and an exposure device that irradiates the image carrier with light corresponding to image data to form an electrostatic latent image on the image carrier. A developing device that develops the electrostatic latent image to form a developer image, and the exposure device is arranged in a one-dimensional direction, and a plurality of light emitting pixels that are selectively lit based on input image data Each of the plurality of light emitting pixels is arranged on a main surface of the substrate, the plurality of semiconductor light emitting elements each having an anode electrode and a cathode electrode, and the plurality of semiconductor light emitting elements And a thin-film wiring layer for electrically connecting one cathode electrode of the adjacent semiconductor light emitting elements to the other anode electrode of the adjacent semiconductor light emitting elements.

  An image display device according to another aspect of the present invention includes a semiconductor light-emitting element array light source device having a plurality of light-emitting pixels arranged in a one-dimensional direction and selectively lit based on input image data, and the semiconductor light-emitting element array. A scanning unit that scans a light beam from the light source device in a direction perpendicular to the one-dimensional direction; and an image display surface that displays the image by being irradiated with the light beam. A plurality of semiconductor light emitting elements arranged on the main surface of the substrate, each having an anode electrode and a cathode electrode, and one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements, And a thin film wiring layer for electrically connecting the other anode electrodes of the semiconductor light emitting elements adjacent to each other.

  An image display device according to another aspect of the present invention includes a semiconductor light-emitting element array light source device that has a plurality of light-emitting pixels that are arranged in a two-dimensional direction and selectively light on the basis of input image data. Each of the light emitting pixels is arranged on a substrate, a main surface of the substrate, each having a plurality of semiconductor light emitting elements each having an anode electrode and a cathode electrode, and semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements And a thin film wiring layer for electrically connecting one cathode electrode of the element to the other anode electrode of the semiconductor light emitting element adjacent to each other.

  According to the semiconductor light emitting device and the light source device of the present invention, it is possible to realize a reduction in size of the device and high light output.

  According to the image forming apparatus of the present invention, the exposure apparatus can be downsized and high light output can be realized.

  According to the image display device of the present invention, it is possible to reduce the size of the device and improve the brightness of the displayed image.

It is a longitudinal cross-sectional view which shows the conventional bullet-type LED module roughly. It is a top view which shows schematically the LED bare chip in the LED module of FIG. It is a longitudinal cross-sectional view which shows schematically the LED bare chip in the LED module of FIG. (A) And (b) is a top view which shows roughly the LED bare chip of a bullet-type LED module as a semiconductor light-emitting device concerning the 1st Embodiment of this invention, and the equivalent circuit schematic of an LED bare chip. It is a figure which shows roughly the cross-sectional shape which cuts the LED bare chip of Fig.4 (a) by S5-S5 line. It is a longitudinal cross-sectional view which shows roughly the structure of the bullet-type LED module as a light source device which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows schematically the LED bare chip of an LED module as a light source device which concerns on the modification of 1st Embodiment. (A) And (b) is the top view which shows schematically the LED bare chip as a semiconductor light-emitting device concerning the 2nd Embodiment of this invention, and the equivalent circuit schematic of a LED bare chip. It is a partially notched top view which shows schematically the light source device which concerns on the 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which shows schematically the light source device which concerns on 3rd Embodiment. It is a partial notch external perspective view which shows roughly the illuminating device provided with the light source device which concerns on 3rd Embodiment. (A) And (b) is the top view which shows roughly the light source device which concerns on the modification of 3rd Embodiment, and the equivalent circuit schematic of a light source device. (A) And (b) is the top view which shows roughly the light source device which concerns on the modification of 3rd Embodiment, and the equivalent circuit schematic of a light source device. (A) And (b) is the top view which shows roughly the light source device which concerns on the modification of 3rd Embodiment, and the equivalent circuit schematic of a light source device. It is a figure which shows roughly the cross-sectional shape which cuts Fig.14 (a) by S15-S15 line. It is a top view which shows roughly the LED array light source device as a light source device which concerns on the 4th Embodiment of this invention. It is a figure which shows schematically the structure of the LED printer as an image forming apparatus which concerns on the 5th Embodiment of this invention. It is a perspective view which shows roughly the external appearance structure of the head mounted display as an image display apparatus concerning the 6th Embodiment of this invention. It is a figure which shows schematically the internal structure of the head-up display as an image display apparatus concerning 6th Embodiment. It is a top view which shows roughly the LED bare chip of the semiconductor light-emitting device concerning the 7th Embodiment of this invention. FIG. 21 is a diagram schematically showing a cross-sectional shape of the semiconductor light emitting device of FIG. 20 taken along line S21-S21. It is a figure which shows roughly the cross-sectional shape of LED bare chip of the semiconductor light-emitting device which concerns on the modification of 7th Embodiment. It is a top view which shows the element structure which applies the LED thin film comprised by connecting the some LED by 7th Embodiment in series to a LED array light source device. (A) And (b) is an external appearance perspective view which shows the portable terminal to which the image display apparatus which concerns on the 8th Embodiment of this invention was applied. It is a figure which shows schematically the structure of the head-up display as an image display apparatus concerning the 9th Embodiment of this invention. It is a figure which shows schematically the structure of the projector as an image display apparatus concerning the 10th Embodiment of this invention.

<< 1 >> First Embodiment << 1-1 >> Configuration of the First Embodiment FIGS. 4A and 4B show the LED of the bullet-type LED module (light source device) 100 according to the first embodiment. 2 is a plan view schematically showing a bare chip (semiconductor light emitting device) 101 and an equivalent circuit diagram of the semiconductor light emitting device 101. FIG. FIG. 5 is a diagram schematically showing a cross-sectional shape of the LED bare chip 101 in FIG. 4A taken along line S5-S5. FIG. 6 is a longitudinal sectional view schematically showing the structure of the light source device 100 according to the first embodiment.

  4A, 4B, 5, and 6, the semiconductor light emitting device 101 includes a substrate 112 and a plurality of semiconductor light emitting elements provided on the main surface 112a of the substrate 112. LED (# 1) 103, LED (# 2) 104, and LED (# 3) 105, and a junction wiring (# 1) 116 and a junction wiring (# 2) 117 as a thin film wiring layer. In the present specification, the numbers with the number sign “#” enclosed in parentheses are identification numbers given to distinguish a plurality of components having the same structure from each other.

  The LED (# 1) 103, LED (# 2) 104, and LED (# 3) 105 as a plurality of semiconductor light emitting elements are arranged in a row, for example, on the main surface 112a of the substrate 112, and each is an anode. It has an electrode 106 and a cathode electrode 114.

  Junction wiring (# 1) 116 and junction wiring (# 2) 117 as thin film wiring layers are connected to each other from one cathode electrode of LEDs adjacent in the column direction among a plurality of LEDs arranged in one column. Electrical connection is made to the other anode electrode of the LED adjacent in the direction. Therefore, for example, as shown in FIGS. 4A and 5, one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements (for example, the cathode electrode 114 of the LED 103 in FIG. 5). And the other anode electrode of the semiconductor light emitting element adjacent to each other (for example, the anode contact layer 107 of the LED 104 in FIG. 5) are adjacent to each other in the horizontal direction (direction parallel to the main surface of the substrate) (height direction). May be separated from each other).

  Note that the number of LEDs in one row is not limited to three. Further, the plurality of LEDs may be LEDs two-dimensionally arranged in a plurality of rows and a plurality of columns.

  As shown in FIG. 5, the LED bare chip 101 is configured by connecting a plurality of LEDs 103 to 105 in series. The layer configuration of the LED bare chip 101 may be, in order from the top layer, a transparent conductive film 106, an anode contact layer 107, an anode cladding layer 108, a light emitting layer 109, a cathode cladding layer 110, a cathode contact layer 111, and an insulating growth substrate 112. .

  Each semiconductor layer constituting the LEDs 103 to 105 can be formed by a known metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE).

  The transparent conductive film 106 can be formed from, for example, ITO (indium tin oxide) or IZO (indium zinc oxide).

  The anode contact layer 107 can be formed from, for example, p-GaN.

The anode cladding layer 108 can be formed of, for example, p-Al _x Ga _1-x N (0 ≦ x ≦ 1).

The light-emitting layer 109 is formed by stacking a plurality of quantum wells having a well layer of In _y Ga _1-y N (0 <y ≦ 1) and a barrier layer of In _z Ga _1-z N (0 ≦ z ≦ 1). A multiple quantum well (MQW) structure can be formed.

The cathode cladding layer 110 can be formed from n-Al _x1 Ga _1-x1 N (0 ≦ x1 ≦ 1).

  The cathode contact layer 111 can be formed from n-GaN.

  Further, the substrate 112 can be an insulating growth substrate, for example, a sapphire substrate.

  The semiconductor light emitting device 101 can be formed as follows. First, dry etching is performed on a multilayer structure including a cathode contact layer 111, a cathode clad layer 110, a light emitting layer 109, an anode clad layer 108, an anode contact layer 107, and a transparent conductive film 106 on the substrate 12 to obtain a transparent layer. The light emitting portion 113 is formed by digging from the conductive film 106 to the cathode cladding layer 110 to a depth at which the surface of the cathode contact layer 111 is exposed.

  Next, the cathode contact layer 111 is completely dug down to the depth of the substrate 112 so that the light emitting portions 113 in the LEDs 103 to 105 formed by dry etching become separate islands. In this way, the LEDs 103 to 105 are formed on the substrate 112 as electrically independent elements.

Next, for example, an interlayer insulating film 115 made of SiN, SiO ₂ , or Al ₂ O _{3 that} can be formed by a known chemical vapor deposition (CVD) or sputtering method is formed on the surface of the LED structure. After that, the interlayer insulating film 115 is patterned by dry etching with CF ₄ or wet etching with HF or hot phosphoric acid so as to expose the top surface of each light emitting part and the cathode contact layer 111. On the exposed cathode contact layer 111, a cathode electrode 114 made of Ti / Al (a laminated layer of titanium and aluminum), Ti / Al / Ni / Au (a laminated layer of titanium, aluminum, nickel, gold) or the like is formed. The patterning is performed by combining the lithography technique and the vapor deposition method, or the combination of the lithography technique and the sputtering method.

  Next, the junction wiring (# 1) 116 for connecting the cathode electrode 114 in the LED (# 1) 103 and the transparent conductive film 106 in the LED (# 2) 104, and the cathode electrode 114 in the LED (# 2) 104 The junction wiring (# 2) 117 for connecting the transparent conductive film 106 in the LED (# 3) 105 is made of a metal material mainly composed of Au or Al, by a lithography technique and a vapor deposition method, or a lithography technique. And patterning by sputtering. Then, in conjunction with the formation of the junction wiring (# 1) 116 and the junction wiring (# 2) 117, the anode electrode pad 118 having a size capable of being wire-bonded and connected to the transparent conductive film 106 in the LED (# 1) 103 is interlayer-insulated. Formed on the film 115. Further, a cathode electrode pad 119 sized to be connected to the cathode electrode 114 of the LED (# 3) 104 and capable of wire bonding is also formed on the interlayer insulating film 115.

  The plurality of LEDs connected in series obtained as described above are made into a bare chip shape through dicing or cleaving from the wafer state, so that the plurality of LEDs according to the first embodiment are connected in series. The LED bare chip 101 can be manufactured. As shown in FIGS. 4 (a), 4 (b), 5 and 6, the LED bare chip 101 configured by connecting a plurality of LEDs obtained as described above in series is iron, or iron and copper. In the reflective cup 121 formed on the cathode lead frame 120 made of the above alloy, a transparent adhesive resin 127 such as epoxy or silicone is used for mounting. The cathode lead frame 120 can be plated with Ag, which is a highly reflective material, in order to increase the reflection efficiency in the reflection cup 121.

  The anode lead frame 122 and the anode electrode pad 118 in the LED bare chip 101 formed by connecting a plurality of LEDs in series are connected by a bonding process using an anode bonding wire 123, and the cathode lead frame 120 and the plurality of LEDs are connected. Are connected to the cathode electrode pad 119 in the LED bare chip 101 formed by connecting them in series by a bonding process using a cathode bonding wire 124.

  When the light source device 100 is used as a white light source device, a blue light emitting LED is used as the LED bare chip 101 configured by connecting a plurality of LEDs in series, and a YAG (yttrium, aluminum, garnet) phosphor is used as the phosphor 125. By filling the reflecting cup 121, a part of the blue light emission is changed to yellow light emission by the YAG phosphor, and white light emission can be obtained by the combined color of blue light emission and yellow light emission. In addition, when an ultraviolet light emitting LED is used as the LED bare chip 101 configured by connecting a plurality of LEDs in series, it is converted into white light by filling the reflecting cup 121 with a three-wavelength phosphor as the phosphor 125. can do. In addition, as a method of filling the phosphor 125 into the reflection cup 121, there is a method of filling with a dispense.

  Then, a lens case 126 made of, for example, an epoxy resin is attached to the outer periphery so as to seal the cathode lead frame 120 or the anode lead frame 122 mounted with the LED bare chip 101 configured by connecting a plurality of LEDs in series. Thus, a bullet-type light source device 100 is manufactured.

  FIG. 7 is a longitudinal sectional view schematically showing an LED bare chip of the LED module 100 as a semiconductor light emitting device according to a modification of the first embodiment. The LED bare chip 101 configured by connecting a plurality of LEDs in series has shown an example made of a nitride-based material, but the LED bare chip 101 configured by connecting a plurality of LEDs in series is made of a GaAs-based material. Can also be configured. Hereinafter, modified examples will be described.

  The configuration other than the semiconductor layer is the same as the basic configuration. The difference from the basic configuration in the modification is the configuration of the semiconductor layer. The layer structure from the transparent conductive film 127, the anode contact layer 128, the anode cladding layer 129, the light emitting layer 130, and the cathode cladding layer 131 to the light emitting portion 132 and the cathode contact layer 133 is the same as the basic structure, but below it. An isolation layer 134 is formed, and the growth substrate is a semiconductor growth substrate 135.

In addition, the said semiconductor layer can be grown by well-known MOCVD and MBE similarly to a basic structure (FIG. 5). The transparent conductive film 127 can be formed from ITO or IZO. The anode contact layer 128 can be formed from p-GaP. Further, the anode cladding layer 129 can be formed of p-Al _x Ga _1-x As (0 ≦ x ≦ 1). The light emitting layer 130 has a well layer of (Al _y Ga _1-y ) _y1 In _1-y1 P (C ≦ y, y1 ≦ 1, y + y1 = 1) and a barrier layer of (Al _z Ga _1-z ). and _{z1 in 1-z1 P (0} ≦ z, z1 ≦ 1, z + z1 = 1) and consists in a plurality of layers stacked quantum wells of MQW structure, a cathode clad layer _{131, n-Al w2 Ga 1-} w as (0 ≦ w ≦ 1), and the cathode contact layer 133 can be n-GaAs. The isolation layer 134 can be, for example, p-Al _u Ga _1-u As (0 ≦ u ≦ 1). The semiconductor growth substrate 135 can be an n-type or p-type GaAs substrate.

<< 1-2 >> Operation of the First Embodiment In the first embodiment, in order to operate the bullet-type light source device 100 mounted with the LED bare chip 101 configured by connecting a plurality of LEDs in series, The anode lead frame 122 and the cathode lead frame 120 are connected to the anode wiring provided on the external mounting substrate or the output terminal of the cathode wiring. Then, by injecting current into the anode lead frame 122 from an external mounting circuit, current is supplied to the LED (# 1) 103 in the LED bare chip 101 configured by connecting a plurality of LEDs in series via the anode bonding wire 123. Is injected. In the LED bare chip 101 configured by connecting a plurality of LEDs in series according to the first embodiment, the LEDs (# 1 to # 3) 103 to 105 are formed on an insulating growth substrate, or Since it is formed on the semiconductor growth substrate 135 via the isolation layer 134, an electrically independent layer structure is formed. Therefore, the current injected into the LED (# 1) 103 causes the LED (# 1) to emit light, and then the LED (# 2) connected in series with the LED (#) 1 by the junction wiring (# 1) 116. ) 104 to cause the LED (# 2) 104 to emit light. Furthermore, the current that causes the LED (# 2) 104 to emit light is injected into the LED (# 3) 105 connected in series with the LED (# 2) 104 through the junction wiring (# 2) 117, and the LED (# 3) ) 105 is caused to emit light. Then, current is swept to the cathode lead frame 120 via the bonding wire (# 2) 124, and current is swept to the cathode terminal provided on the external mounting substrate. That is, in the example shown in the first embodiment, it is possible to obtain three times the light output with respect to the same amount of injection current as that of the bullet-type LED module shown in the prior art.

<< 1-3 >> Effects of the First Embodiment The LED bare chip 101 configured by connecting a plurality of LEDs according to the first embodiment in series enables high-definition and high-precision patterning that can be formed by lithography technology. A plurality of LEDs (# 1 to # 3) 103 to 105 can be connected in series by the junction wires (# 1) 116 and (# 2) 117. Therefore, in the prior art, since it is not necessary to provide each LED with a relatively large bonding pad, which is necessary when the bare chip LEDs are connected in series, the chip size can be greatly reduced.

  In addition, since a plurality of semiconductor light emitting elements are connected in series on the same chip, the number of die bonding or wire bonding can be greatly reduced, and the mounting process can be greatly simplified. it can.

  In addition, from the viewpoints of wire bonding and die bonding, the distance between the LEDs 103 to 105 can be significantly narrower than in the prior art, and high-density mounting is possible. Therefore, it becomes possible to mount more semiconductor light emitting elements in the reflection cup. Therefore, it is possible to produce a bullet-type light source device 100 having higher output characteristics even in a bullet-type LED module having the same size as the conventional one.

  In addition, since the high-density mounting can be performed as described above, the mounting area can be concentrated, and a plurality of LEDs can be mounted at a position that does not greatly deviate from the light collecting point by the lens case 126. Become. As a result, it is possible to manufacture a bullet-type light source device 100 that does not impair the light distribution characteristics and has high output characteristics.

  Furthermore, since it is not necessary to wire bonding directly on the anode electrode provided on the light emitting portion, a bullet-type light source device 100 having higher output characteristics as compared with the conventional one can be produced without reducing the external extraction efficiency. Is possible.

  By using the LED bare chip 101 configured by connecting a plurality of LEDs according to the first embodiment in series, it is possible to create a small bullet-type LED module having high output characteristics.

<< 2 >> Second Embodiment << 2-1 >> Configuration and Operation of Second Embodiment FIGS. 8A and 8B show an LED bare chip 201 (as a semiconductor light emitting device) according to the second embodiment. FIG. 2 is a plan view schematically showing the LED and an equivalent circuit diagram of the LED bare chip 201. In the second embodiment, as in the first embodiment, a plurality of LEDs (# 1 to # 9) 202 to 210 are formed on the same insulating substrate or a semiconductor substrate via an isolation layer. Thus, the LEDs (# 1 to # 9) 202 to 210 are in a state of being electrically separated through the semiconductor layer. In the second embodiment, unlike the first embodiment, the plurality of semiconductor light emitting elements (# 1 to # 9) 202 to 210 are not all connected in series, but are connected in series. The columns are configured to be connected in parallel.

  In manufacturing, first, as in the first embodiment, LEDs (# 1 to # 3) 202 to 204, LEDs (# 4 to # 6) 205 to 207, and further LEDs (# 7 to # 9). 208 to 210 are connected in series by a junction wiring 211. Then, the anode electrode pad 212 is connected to the transparent conductive film 213 formed on the light emitting portion of the LED (# 1) 202, the LED (# 4) 205, and the (# 7) 208. Further, the cathode electrode pad 214 is connected to the cathode (215) formed on the LED (# 3) 204, the LED (# 6) 207, and the LED (# 9) 210. In this way, the LED bare chip 201 in which a plurality of LEDs (# 1 to # 9) 202 to 210 are connected in series and in parallel can be manufactured.

  Note that the LED bare chips 201 connected in series and in parallel can be made of a nitride-based semiconductor as in the first embodiment, or can be made of a GaAs-based semiconductor.

  Further, the plurality of series-parallel-connected LED bare chips 201 according to the second embodiment can be mounted in a bullet-type LED module, similarly to the first embodiment.

<< 2-2 >> Effects of Second Embodiment By mounting a plurality of series-parallel-connected LED bare chips 201 according to the second embodiment in a bullet-type LED module, the conventional technique is similar to the first embodiment. Since it is not necessary to provide each LED with a relatively large bonding pad required for connecting bare chip LEDs in series with each other, the chip size can be greatly reduced.

In addition, since the plurality of LEDs 202 to 210 are formed in the form of being connected in series or in parallel on the same chip, the number of die bonding or wire bonding can be greatly reduced, and the mounting process is greatly reduced. It can be simplified.
Further, from the viewpoints of wire bonding and die bonding, the distance between the LEDs can be significantly narrower than that of the prior art, so that high-density mounting is possible. Therefore, it becomes possible to mount more semiconductor light emitting elements in the reflection cup. Therefore, a bullet-type LED module having a higher output can be produced even in a bullet-type LED module having the same size as the conventional one.

  In addition, since the high-density mounting is possible as described above, the mounting area can be concentrated, and a plurality of LEDs can be mounted in a high-density position at a position that does not greatly deviate from the light collecting point by the lens case. . As a result, it is possible to produce a bullet-type LED module that does not impair the light distribution characteristics and has high output characteristics.

  Furthermore, since it is no longer necessary to wire bonding directly on the anode electrode provided on the light emitting part, it is possible to produce a bullet-type LED module having higher output characteristics than before without reducing the external extraction efficiency. It becomes possible.

  In addition to the series connection as in the second embodiment, by combining the parallel connection, even if a failure state occurs in which one LED connected in series is opened due to a failure, the LEDs are connected in parallel. Other lines can emit light, and a failure state in which the entire bullet-type LED module is not lit can be prevented.

  By using the LED bare chip configured by connecting a plurality of LEDs in series according to the second embodiment, it is possible to create a small shell type module having high output characteristics. Further, by using the form according to the second embodiment in which series connection and parallel connection are combined, the failure probability of non-lighting can be greatly reduced.

<< 3 >> Third Embodiment << 3-1 >> Configuration and Operation of Third Embodiment FIG. 9 is a partially cutaway plan view schematically showing a light source device 301 according to the third embodiment. FIG. 10 is a longitudinal sectional view schematically showing a light source device 301 according to the third embodiment. FIG. 11 is a partially cutaway external perspective view schematically showing an illuminating device (LED light bulb) including the light source device according to the third embodiment. FIGS. 12A and 12B are a plan view schematically showing a light source device according to a modification of the third embodiment and an equivalent circuit diagram of the light source device. FIGS. 13A and 13B are a plan view schematically showing a light source device according to a modification of the third embodiment and an equivalent circuit diagram of the light source device. Further, FIGS. 14A and 14B are a plan view schematically showing a light source device according to a modification of the third embodiment and an equivalent circuit diagram of the light source device. FIG. 15 is a diagram schematically showing a cross-sectional shape of FIG. 14A taken along line S15-S15.

  As shown in FIG. 11, in the LED lighting device 300, a mounting substrate 303 on which the light source device 301 is mounted is installed on the lighting circuit cover 304. Then, a circuit for driving the light source device 301 is installed in the lighting cover 304. A base 305 is formed below the lighting cover 304. Then, a globe 306 is formed above the light source device 301 for making the light emitted from the light source device 301 soft by the scattering effect and having a wide light distribution angle.

  Before showing an example in which the semiconductor light emitting device according to the third embodiment is applied as a light source device for LED illumination, the basic configuration of the light source device according to the prior art is shown in FIGS. 12 (a) and 12 (b), FIG. 13 (a) and FIG. This will be described with reference to FIGS. 14B, 14A, 14B, and 15. FIG.

  First, as shown in FIGS. 12A and 12B, the light source device 301 according to the prior art includes, for example, an anodized layer (# 1) 308 and an anodized layer on the front and back of a metal core 307 mainly composed of aluminum (Al). (# 2) Coated with 309, and further coated with an insulating layer and an adhesive layer 310 on the front surface side thereof, an anode electrode connection pad 311 made of copper foil, a cathode electrode connection pad 312, and further a light emitting region back surface reflection A substrate on which the metal 313 is formed is used as the mounting substrate 314. The anode electrode connection pad 311 and the cathode electrode connection pad 312 can be subjected to Au plating in order to increase the adhesion strength of wire bonding. In addition, the light emitting region back surface reflection metal 313 can be subjected to Ag plating in order to increase reflection efficiency. Furthermore, a bank 315 having a height of about 1 [mm] that can be formed by dispensing an epoxy resin is formed on the outer periphery on which the plurality of LED bare chips are mounted.

  A light emitting unit 316 that forms a transparent conductive film on the outermost surface on the mounting substrate 314, an anode electrode pad 317 provided on the light emitting unit 316, and a cathode electrode pad 319 formed on the cathode contact layer 318. A plurality of LED bare chips 320 are mounted on the light emitting region back surface reflecting metal 313 using a transparent adhesive resin 321. Then, the plurality of LED bare chips 320 are connected using a bonding wire (# 2) 322 so that one system is connected in series. Then, the anode electrode pad 317 and the anode electrode connection pad 311 in the first LED bare chip of the LED bare chips 320 connected in series are connected using a bonding wire (# 1) 323. Further, the last LED bare chip 320 connected in series and the cathode electrode connection pad 312 are connected using a bonding wire (# 3) 324. In this way, all of the plurality of LED bare chips 320 are connected in series from the anode electrode connection pad 311 to the cathode electrode connection pad 312 via the bonding wires (# 1) to (# 3) 323, 322, and 324. . Finally, the light source device 301 can be manufactured by dispensing a phosphor 325 such as a VAG phosphor or a three-wavelength phosphor in the bank 315.

  13 (a) and 13 (b), unlike the example shown in FIGS. 12 (a) and 12 (b), a plurality of systems in which LED bare chips are connected in series are provided, and the LED bare chip located at the head of the plurality of systems is provided. The anode electrode pad 317 and the anode electrode connection pad 311 in 320 are connected by a bonding wire (# 1) 323, and the cathode electrode pad 319 and the cathode electrode connection pad 312 in the LED bare chip 320 located at the end of the plurality of systems are bonded. By connecting with a wire (# 3) 325, a plurality of systems connected in series are connected in parallel.

  Application examples in which the semiconductor light emitting element configuration according to the first and second embodiments is used as the light source device 301 are shown in FIGS. The mounting substrate 314 can have the same configuration as the example shown in FIGS. 12A and 12B, FIGS. 13A and 13B, and FIGS. 14A and 14B. Then, a plurality of LED bare chips 327 configured by connecting a plurality of LEDs according to the third embodiment in series are mounted on the light emitting region back surface reflecting metal 313 on the mounting substrate 314 by a transparent adhesive resin 321. Here, an example is shown in which five LED bare chips 327 configured by connecting a plurality of LEDs of five in series are connected in series. The configuration of the LED bare chip 327 configured by connecting a plurality of LEDs in series is the same as the configuration described in the first and second embodiments, and the plurality of LEDs are interposed via an insulating substrate or an isolation layer. By being formed on the semiconductor growth substrate, an electrically independent layer configuration is obtained. And each LED comprises the LED bare chip 327 comprised by connecting a some LED in series by connecting in series using the junction wiring 328. FIG. Then, an anode electrode pad 329 provided on the LED bare chip 327 configured by connecting a plurality of LEDs in series and an anode electrode connection pad 311 provided on the mounting substrate 314 are connected using a bonding wire (# 1) 323. Further, the cathode electrode pad 330 provided on the LED bare chip 327 configured by connecting a plurality of LEDs in series and the cathode electrode connection pad 312 provided on the mounting substrate 314 are connected using a bonding wire (# 3) 324. Then, the light source device 301 is configured by injecting the phosphor 325 into the bank 315 provided in advance on the mounting substrate 314 by dispensing. Although FIG. 9 shows an example in which LED bare chips 327 configured by connecting a plurality of LEDs connected in series are connected in parallel, LED bare chips configured by connecting a plurality of LEDs in series are shown. 327 can be connected in series using a bonding wire to form a single system.

  Next, FIGS. 14A and 14B show a light source device 301 according to a modification of the third embodiment. In this modified example, as in the basic configuration in the third embodiment, an example in which the LED bare chip 327 configured by connecting a plurality of LEDs in series is connected in parallel is configured, but the difference from the basic configuration is By providing the relay electrode pad 331, a plurality of units for connecting the LED bare chips 327 configured in parallel by connecting the plurality of LEDs in series are connected in series. .

<< 3-2 >> Effect of Third Embodiment LED configuration configured by connecting a plurality of LEDs described in the first and second embodiments in series, or by connecting a plurality of LEDs in series and parallel By applying the LED configuration as the light source device 301 shown in FIGS. 9 and 10, it is possible to mount a plurality of LEDs in a limited area at high density. Therefore, since the light source device 301 itself can be reduced in size, it is possible to reduce the size of the LED illumination having a light output equivalent to that of the conventional one. Furthermore, since more LEDs can be integrated in a limited area, a light source device 301 with higher output can be created.

  In addition, by using the LED bare chip 327 configured by connecting a plurality of LEDs formed on the same chip by a junction wiring 328 capable of forming a plurality of LEDs by a lithography technique, the number of die bonding and wire bonding can be increased. Can be greatly reduced, and the mounting cost can be greatly simplified.

  Further, by combining parallel connection in addition to series connection as shown in FIG. 11, even when one element is opened due to a malfunction, the light output does not become zero, and fluctuation of the light output is suppressed. Can do.

<< 4 >> Fourth Embodiment << 4-1 >> Configuration and Operation of Fourth Embodiment FIG. 16 schematically shows an LED array light source apparatus 402 as a light source apparatus according to the fourth embodiment of the present invention. It is a top view.

  In the fourth embodiment, the semiconductor light emitting element can be made of a nitride material or a GaAs material, as in the first and second embodiments. Here, as an example, an LED array light source device 402 is shown in which one pixel is an LED pixel 401 configured by serially connecting a plurality of LEDs having three semiconductor light emitting elements in series. An LED pixel 401 configured by connecting a plurality of LEDs in series connects a light emitting portion 403 having a transparent conductive film as the outermost surface of the LED located at the top of the LED pixel 401 and an anode electrode pad 404 of a size capable of wire bonding. The anode electrode pad 404 is formed in the vicinity of the element end. Then, the cathode electrode 405 and the cathode common electrode pad 406 of the LED located at the tail end of the LED pixel 401 configured by connecting a plurality of LEDs in series are connected, and the cathode common electrode pad 406 is connected to the anode electrode pad. 404 is formed in the vicinity of the element end positioned oppositely. In this way, an LED array light source device 402 having a plurality of LED pixels 401 configured by connecting a plurality of LEDs in series according to the third embodiment in a one-dimensional array is configured.

  Then, the anode output terminal in the drive circuit for driving the LED array light source device 402 and the anode electrode pad 404 in the LED array light source device 402 are connected using a bonding wire, and the cathode output terminal in the drive circuit and the LED array light source device 402 are connected. The cathode common electrode pad 406 is connected using a bonding wire.

  The operation method of the LED array light source device 402 according to the fourth embodiment is to inject current from the anode output terminal in the external drive circuit to the LED pixel 401 configured by connecting a plurality of LEDs that emit light in series, It operates by sweeping current from the cathode output terminal in the drive circuit connected to the cathode common electrode pad 406.

<< 4-2 >> Effects of the Fourth Embodiment Since the LED array light source device 402 according to the fourth embodiment uses LED pixels 401 configured by connecting a plurality of LEDs in series as pixels, For similar current values, the light output can be increased in proportion to the number of LEDs connected in series.

  In addition, since the LED pixel 401 configured by connecting a plurality of LEDs according to the fourth embodiment in series can be connected by a junction wiring that can be formed by a lithography technique, a high dot size can be achieved without increasing the dot size. An LED pixel 401 configured by connecting a plurality of LEDs in series that enables high-density series connection mounting can be formed. For this reason, the high-definition LED array light source device 402 can be produced.

  A plurality of LEDs formed by connecting a plurality of semiconductor light-emitting elements in series are connected in series by using an LED pixel configured by connecting a plurality of LEDs in series according to the fourth embodiment in an LED array light source device. Thus, it is possible to form the LED pixel configured with high definition. Therefore, a one-dimensional LED array having higher light output characteristics can be created when high-definition image formation is possible and a current value equivalent to that of a conventional one is injected.

<< 5 >> Fifth Embodiment << 5-1 >> Configuration of Fifth Embodiment FIG. 17 is a diagram schematically illustrating a configuration of an LED printer as an image forming apparatus according to a fifth embodiment. FIG. 17 shows an example in which the LED array light source device according to the fourth embodiment is applied to an LED printer 501. As shown in FIG. 17, the LED printer 501 includes four process units that form images of each color of yellow (Y), magenta (M), cyan (C), and black (K) using an electrophotographic system. 502-505. The process units 502 to 505 are arranged in tandem along the conveyance path 507 of the recording medium 506. Each of the process units 502 to 505 is disposed around the photosensitive drum 508 as an image carrier, a charging device 509 that charges the surface of the photosensitive drum 508, and a charged photosensitive drum 508. And an exposure device 510 that forms an electrostatic latent image by selectively irradiating the surface with light. The LED array light source device described in the fourth embodiment is applied to the exposure device 510.

  The LED printer 501 includes a developing device 511 that conveys toner to the surface of the photosensitive drum 508 on which the electrostatic latent image is formed, and a cleaning device 512 that removes toner remaining on the surface of the photosensitive drum 508. . The photosensitive drum 508 is rotated in the direction of the arrow by a driving mechanism including a driving source and a gear. The LED printer 501 also includes a paper cassette 513 that stores a recording medium 506 such as paper, and a hopping roller 514 for separating and transporting the recording medium 506 one by one. The pinch rollers 515 and 516 and the recording medium 506 are sandwiched downstream of the hopping roller 514 in the conveying direction of the recording medium 506, and the skew of the recording medium 506 is corrected together with the pinch rollers 515 and 516 to the process units 502 to 505. Registration rollers 517 and 518 are provided. The hopping roller 514 and the registration rollers 517 and 518 are rotated by receiving a driving force from a driving source.

  The LED printer 501 has a transfer roller 519 arranged to face the photosensitive drum 508. The transfer roller 519 is made of semiconductive rubber or the like. The potential of the photosensitive drum 508 and the potential of the transfer roller 519 are set so that the toner image on the photosensitive drum 508 is transferred onto the recording medium 506. Further, the LED printer 501 is provided with discharge rollers 520, 521 and 522, 523 for discharging the recording medium 506.

<< 5-2 >> Operation of Fifth Embodiment The recording media 506 loaded on the paper cassette 513 are separated and conveyed one by one by a hopping roller 514. The recording medium 506 passes through the registration rollers 517 and 518 and the pinch rollers 515 and 516 and passes through the process units 502 to 505 in this order. In each of the process units 502 to 505, the recording medium 506 passes between the photosensitive drum 508 and the transfer roller 519, the toner images of each color are sequentially transferred, and heated and pressed by the fixing device 524, and each color toner is transferred. The image is fixed on the recording medium 506. Thereafter, the recording medium 506 is discharged to the stacker 525 by discharge rollers 520, 521 and 522, 523.

<< 5-3 >> Effect of Fifth Embodiment By applying the LED array light source device described in the fourth embodiment as the exposure device 510 of the LED printer 501, the luminance of the same injection current as that of the conventional case can be reduced. A high exposure apparatus 510 can be provided. Therefore, the latent image time can be shortened, and the printing speed of the LED printer 501 can be increased.

  Further, as the exposure device 510 of the LED printer 501, the printing speed of the LED printer 501 is obtained by using an LED array light source device having LED pixels configured by connecting a plurality of LEDs described in the fourth embodiment in series. This makes it possible to print with high definition.

<< 6 >> Sixth Embodiment << 6-1 >> Configuration and Operation of Sixth Embodiment FIG. 18 schematically shows an external configuration of a head mounted display (HMD) as an image display apparatus according to the sixth embodiment. It is a perspective view shown in FIG. FIG. 18 illustrates a case where the LED array light source device according to the fourth embodiment is applied to an HMD image display unit 601 of a head mounted display (HMD). An HMD image display unit 601 is installed in the HMD device 602. A scanning image emitted from the HMD image display unit 601 is erected in front of the reflection surface 603 via a reflection surface 603 installed in front of the HMD image display unit 601 and an enlarged virtual image display image 604 is displayed. Form. In addition, it can be set as non-transmissive HMD by making the said reflective surface non-transmissive, and it can be set as optical transmissive HMD by making the said reflective surface a half mirror.

  FIG. 19 is a diagram schematically illustrating an internal configuration of an HMD serving as an image display apparatus according to the sixth embodiment. The LED array light source device 605 described in the fourth embodiment is used as a light source device, and a one-dimensional image is scanned by a scanning mirror 606 disposed above the LED array light source device 605 to create a two-dimensional image. Then, a convex lens 607 is disposed at the tip of the light beam reflected by the scanning mirror 606. As for the positional relationship between the scanning mirror 606 and the convex lens 607, the scanning mirror 606 is disposed within the front focal length of the convex lens 607, and a desired magnification is created by adjusting the distance.

  By installing the scanning mirror 606 and the convex lens 607 in the HMD image display unit 601 as described above, a light beam emitted from the convex lens 607 to the rear of the lens is a light beam that forms an upright virtual image as viewed from the rear of the lens. Become. This light beam is reflected toward the user's eyes 609 via the reflecting surface 603, thereby forming a display image 604 as a virtual image enlarged in front of the reflecting surface 603. In FIG. 19, the convex lens 607 is used to form an enlarged erecting virtual image, but a concave mirror can also be used for the purpose of functioning as a turning mirror.

<< 6-2 >> Effects of the Sixth Embodiment By applying the LED array light source device according to the fourth embodiment as an HMD image display unit, the conventional technique can be used without reducing the resolution as compared with the conventional LED array light source apparatus. Even when a current value equivalent to is injected, the light output can be greatly increased.

<< 7 >> Seventh Embodiment << 7-1 >> Configuration and Operation of Seventh Embodiment FIG. 20 is a plan view schematically showing an LED bare chip of a semiconductor light emitting device according to a seventh embodiment. FIG. 21 is a diagram schematically showing a cross-sectional shape of the semiconductor light emitting device of FIG. 20 taken along line S21-S21. 20 and 21 show the configuration of an LED bare chip 702 using an LED thin film 701 configured by connecting a plurality of LEDs in series. FIG. 22 is a diagram schematically showing a cross-sectional shape of the LED bare chip of the semiconductor light emitting device according to the modified example of the seventh embodiment. 22 shows another example of a cross section taken along line S21-S21 in FIG. FIG. 23 is a plan view showing an element configuration in which the LED thin film 701 according to the seventh embodiment is applied to the LED array light source device 703.

  First, the configuration of the LED thin film 701 according to the seventh embodiment and the configuration of the LED bare chip 702 using the LED thin film 701 will be described with reference to FIGS. 20, 21, and 22. The LED thin film 701 formed by connecting a plurality of LEDs in series can be formed of a nitride-based semiconductor material or a GaAs-based semiconductor material, as in the first and second embodiments. FIG. 21 shows the case of being composed of a nitride-based semiconductor material, and FIG. 22 shows the case of being composed of a GaAs-based semiconductor material.

  The LED thin film 701 shown in FIG. 21 and FIG. 22 is connected in series or in series and in parallel by a junction wiring 704 that can be formed by lithography, as in the first and second embodiments. The insulating bonding layer 705 in FIG. 21, the light emitting portion 707 above the semiconductor bonding layer 706 in FIG. 22, and the cathode contact layer 708 can all be the same as in the first and second embodiments.

  The LED thin film 701 in FIG. 21 is obtained by, for example, polishing a sapphire substrate having a substrate thickness of about 400 [μm] or more to a thickness that leaves several [nm] of the insulating bonding layer 705 from the back surface direction. be able to. Desirably, the LED thin film 701 is a thin film having a total film thickness of 5 [μm] or less. Since the insulating bonding layer 705 is made of an insulating material, each light emitting portion has a layer configuration that is electrically independent of each other.

  The LED thin film 701 formed by connecting a plurality of LEDs in FIG. 22 selectively, for example, between a semiconductor bonding layer 706 and a semiconductor growth substrate on which the LED layer structure is grown. An etchable sacrificial layer is epitaxially grown in advance, and this sacrificial layer can be peeled from the growth substrate by etching using a selectively etchable etchant. For example, an AlAs layer can be used as the sacrificial layer, and HF or the like can be used as the etchant. By forming an isolation layer 707 between each LED and an upper layer of the semiconductor bonding layer 706, each LED has an electrically independent layer configuration. The isolation layer 707 is made of the same material as in the first embodiment.

  As the surface roughness of the insulating bonding layer 705 and the semiconductor bonding layer 706 in FIGS. 21 and 22, it is desirable that Rpv defined as a typical peak-to-valley unevenness difference is 2 [nm] or less.

The LED thin film 701 integrates the insulating bonding layer 705 or the semiconductor bonding layer 706 on the insulating coating film 710 formed on the integrated substrate 709 using intermolecular force bonding. Note that a typical surface roughness value Rpv of the insulating coating film 710 is desirably 2 [nm] or less. Further, the LED thin film 701 can be integrated on the insulating coating film 710 with an adhesive such as epoxy. Note that the insulating coating film 710 can be an inorganic insulating film of SiN, SiO ₂ or Al ₂ O ₃ , or an organic insulating film made of polyimide, acrylic, novolac, or a fluorine-based material.

  An anode electrode connection pad 711 or a cathode electrode connection pad 712 made of a material mainly made of Au or Al, which can be formed by a lithography technique, is formed on the insulating coating film 710 in advance on the integrated substrate 709 coated with the insulating coating film 710. To form.

  Then, the light emitting portion 707 in the LED located at the head of the LED thin film 701 configured by connecting the anode electrode connection pad 711 and a plurality of LEDs in series is connected by the bridge wiring 713. Further, the cathode electrode 714 in the LED located at the tail end of the LED thin film 701 configured by connecting the cathode electrode connection pad 712 and a plurality of LEDs in series is connected by the bridge wiring 715. The bridge wirings 713 and 715 are made of a material mainly composed of Au or Al that can be formed by lithography.

The bridge wirings 713 and 715 are made of, for example, an inorganic material made of SiN, SiO _2, or Al ₂ O ₃ , polyimide, or the like in order to prevent contact with the exposed portions on the etching end faces of the insulating bonding layer 705 and the semiconductor bonding layer 706. A bridge interlayer insulating film 716 and 717 made of an organic insulating material made of novolak is formed and then formed.

FIG. 23 is a plan view showing an element configuration in which an LED thin film configured by connecting a plurality of LEDs in series according to the seventh embodiment is applied to an LED array light source device 703. An anode common wire 718 and a cathode common wire 719 made of a material mainly made of Au or Al, which are previously formed on the integrated substrate 709 by lithography, are made of, for example, SiN, SiO ₂ or Al ₂ O _{3 at} the intersections thereof. A common wiring layer insulating film 720 made of an inorganic material or an organic material made of, for example, polyimide or novolac is formed into a matrix. The anode common wiring 718 and the cathode common wiring 719 are extended to the vicinity of the end of the integrated substrate 709, and the anode common wiring connection pad 721 and the cathode common wiring connection pad 722 are formed at the respective ends. It is configured by connecting a plurality of LEDs according to the seventh embodiment in series in an LED thin film integration region configured by connecting a plurality of LEDs provided in the vicinity of the intersection of the anode common wiring 718 and the cathode common wiring 719. The LED thin films 701 are integrated in a matrix and connected to the anode common wiring 718 and the cathode common wiring 719 using the bridge wiring 713 and the bridge wiring 715. In this manner, an LED array light source device 703 to which the LED thin film 701 configured by connecting a plurality of LEDs according to the seventh embodiment in series can be manufactured.

  The LED array light source device 703 can be driven by connecting the anode common wiring connection pad 721 and the cathode common wiring connection pad 722 to the anode output terminal and the cathode output terminal of the drive circuit of the LED array light source device. .

  By using the LED thin film 701 configured by connecting a plurality of LEDs in series, the LED thin film 701 configured by connecting a plurality of LEDs in series is connected to a bridge wiring (# 1) 713 and a bridge wiring (# 2). 715 can be connected to the anode electrode connection pad 711 and the cathode electrode connection pad 712 which are formed in advance on the integrated substrate by lithography. That is, rather than providing a relatively large pad electrode on the LED thin film 701 configured by connecting a plurality of LEDs composed of a relatively expensive compound semiconductor in series, for example, from a relatively inexpensive material such as Si. A relatively large anode electrode connection pad 711 and cathode electrode connection pad 712 can be provided on the integrated substrate 709, which can significantly reduce the material cost.

  In addition, when the LED array light source device 703 shown in FIG. 23 is manufactured, the LED thin film 701 configured by connecting a plurality of LEDs in series has a chip size compared to the bare chip shown in the first and second embodiments. Since it can shrink significantly, it is possible to mount a two-dimensional array with high density. Therefore, compared to the first and second embodiments using LEDs configured by connecting a plurality of bare-chip LEDs in series, it is possible to produce a significantly high-definition image display device.

<< 7-2 >> Effect of Seventh Embodiment By applying an LED thin film configured by connecting a plurality of LEDs according to the seventh embodiment in series to an LED array light source device, the same current value as in the past is injected. Compared to the case, an LED array light source device having a significantly high light output can be created.

  Furthermore, by using the LED configured by serially connecting a plurality of thin film LEDs according to the seventh embodiment, the LED is configured by serially connecting a plurality of LEDs shrinking a relatively expensive semiconductor material. An LED bare chip can be created.

  Furthermore, since the chip size can be greatly shrunk, high-intensity and high-intensity LED array light source devices can be created by high-density integration in a two-dimensional array.

<< 8 >> Eighth Embodiment << 8-1 >> Configuration and Operation of Eighth Embodiment FIGS. 24A and 24B are portable terminals 801 to which an image display device according to the eighth embodiment is applied. FIG. In the eighth embodiment, the LED array light source device described in the seventh embodiment is used as an image display device. As an image display device of the portable terminal 801, there are a main monitor 802 for displaying information such as dial operation confirmation, address book content confirmation, mail creation and mail content confirmation, Internet content browsing, one-seg viewing, time, radio wave reception, etc. Some have a back monitor 803 that displays only partial information such as status and incoming call information.

  The mobile terminal 801 is often used outdoors, and when the luminance of the main monitor 802 and the back monitor 803 is not sufficient, information may not be confirmed unless external light is blocked. In order to improve the luminance of the main monitor 802 and the back monitor 803, when the output of the backlight is significantly increased, there is a problem that the injection current is greatly improved and a heat generation amount is greatly improved. . On the other hand, by using the light source device according to the seventh embodiment as the main monitor 802 or the back monitor 803, the luminance can be greatly improved with respect to the injection current equivalent to the conventional one. Moreover, since the LED array light source device to which the LED configuration configured by connecting a plurality of thin-film LEDs according to the eighth embodiment is connected in series is applied, high-density mounting is possible, high brightness and Image display capable of displaying high-definition images becomes possible.

<< 8-2 >> Effect of Eighth Embodiment According to the eighth embodiment, since the LED array light source device according to the seventh embodiment is applied to a monitor, a monitor display with significantly high light output is realized. be able to.

  Further, according to the eighth embodiment, it is possible to create a semiconductor light-emitting element chip in which a relatively expensive semiconductor material is shrunk by using an LED configured by connecting a plurality of thin-film LEDs in series. Become.

  Furthermore, according to the eighth embodiment, since the chip size can be greatly shrunk, it can be integrated in a two-dimensional array at a high density, thus creating a high-definition and high-brightness LED array light source device. can do. Therefore, a main monitor and a back monitor with high visibility can be created by using the LED array light source device for a portable terminal.

<< 9 >> Ninth Embodiment << 9-1 >> Configuration and Operation of Ninth Embodiment FIG. 25 shows the configuration and optical path 907 of a head-up display (HUD) unit as an image display apparatus according to the ninth embodiment. FIG. The HUD unit 901 includes an LED array light source device. The HUD unit 901 displays, for example, an image that is visually recognized by an automobile driver, which is an in-vehicle unit. In the HUD unit 901, a HUD light source device 902 in which the display image is turned upside down is installed inside the focal length of a concave mirror 903 used as a turning mirror. The magnification of the concave mirror 903 is determined by the position within the focal length with respect to the concave mirror 903 where the HUD light source device 902 is installed. The HUD light source device 902 is an LED array light source device, and has a plurality of bullet-type LED modules arranged in a matrix, and each of the bullet-type LED modules is the first to third embodiments. The structure of any one of the semiconductor light emitting devices is provided.

  The image displayed by the HUD light source device 902 becomes an upright virtual image enlarged by the concave mirror 903. This formed virtual image is taken out through the transparent cover 904 installed on the upper surface of the HUD unit 901 and reflected toward the driver's eyes 906 by the front window 905. When reflected by the front window 905, the formed virtual image magnified by the concave mirror 903 is projected on the driver's eyes 906 with the top and bottom images inverted. Since the HUD light source device 902 is installed with the image turned upside down in advance, the image projected onto the driver's eyes 906 forms an intended display image. Further, since the image reflected by the front window 905 is an enlarged upright virtual image, the driver visually recognizes a display image 908 that is a virtual image in front of the front window 905.

<< 9-2 >> Effect of Ninth Embodiment According to the ninth embodiment, the LED array light source device using the bullet-type LED modules of the first to third embodiments is used as the HUD light source device 902. As a result, the current value for obtaining the desired luminance can be greatly reduced as compared with the LED array light source device according to the prior art. Therefore, the amount of self-heating of the LED array light source device can be significantly reduced, and the luminance can be improved effectively without reducing the efficiency of the LED itself.

  Further, according to the ninth embodiment, since the configuration enables high-density mounting, a high-definition image can be displayed. Further, the thermal influence on other circuits integrated in the periphery can be greatly suppressed.

  Further, according to the ninth embodiment, the heat sink structure can be shrunk or simplified, and the HUD unit itself can be greatly shrunk. Therefore, from the viewpoint of the HUD installation space, it is possible to apply the HUD unit that has been conventionally applicable only to luxury cars having a large instrument panel to a popular vehicle having a relatively small instrument panel.

  Furthermore, since the HUD unit itself can be significantly reduced, a pop-up type post-mounting type HUD unit can also be created.

  In addition, the use of the LED configured by serially connecting a plurality of thin-film LEDs according to the ninth embodiment enables creation of a semiconductor light-emitting element chip in which a relatively expensive semiconductor material is shrunk. Cost can be greatly reduced.

  Further, since the chip size according to the ninth embodiment can be greatly shrunk, it can be integrated in a two-dimensional array at a high density, so that a high-definition LED array light source device can be created. Therefore, by using the LED array light source device for the HUD unit, an image display device with high visibility can be created.

  Further, since the amount of heat generation can be significantly reduced by reducing the current value, the heat dissipation structure can be simplified or shrunk, so that the HUD unit can be greatly reduced in size.

<< 10 >> Tenth Embodiment << 10-1 >> Configuration and Operation of Tenth Embodiment FIG. 26 is a diagram schematically showing a configuration of a projector 1001 as an image display apparatus according to the tenth embodiment. . The image display device shown in FIG. 26 is a projector 1001 using an LED array light source device. A cross dichroic prism 1002 is installed in the projector 1001. LED array light source devices 1003, 1004, and 1005 for red image, blue image, and green image are installed so as to face each of the light incident surfaces of the cross dichroic prism 1002. The LED array light source devices 1003, 1004, and 1005 have a plurality of bullet-type LED modules arranged in a matrix, and each of the bullet-type LED modules is one of the first to third embodiments. The semiconductor light emitting device is configured as described above. The cross dichroic prism 1002 has a function of combining the light rays from the LED array light source devices 1003, 1004, and 1005 and propagating them in the projection plane direction (upward in FIG. 26). The lens 1006 adjusts the magnification and focal length of the combined light and forms an image on a screen that is a projection surface.

  In the projector 1001, the red image, the green image, and the blue image displayed by the LED array light source devices 1003, 1004, and 1005 are combined via the cross dichroic prism 1002, and the combined light flux is multiplied by the lens 1006. The focal length is adjusted, and the image is enlarged and projected onto a screen as a projection surface.

<< 10-2 >> Effect of Tenth Embodiment According to the tenth embodiment, the LED array light source devices 1003, 1004, and 1005 have a plurality of bullet-type LED modules arranged in a matrix. Each of the bullet-type LED modules has the configuration of the semiconductor light-emitting device according to any one of the first to third embodiments. Therefore, even in the condition for obtaining a desired luminance, it is more than conventional. The injection current can be greatly reduced. Therefore, the brightness of the display image can be improved without reducing the light emission efficiency of the LED itself.

  Further, according to the tenth embodiment, the thermal influence on the peripheral circuit can be greatly suppressed, so that the heat sink structure (heat dissipation structure) can be shrunk or simplified. As a result, the size of the projector can be greatly reduced.

  Further, according to the tenth embodiment, since it is possible to integrate a semiconductor light emitting device configured by connecting a plurality of LEDs in series with high density, it is possible to display an image with high brightness and high definition. Become.

  Furthermore, according to the tenth embodiment, since a semiconductor light-emitting device configured by connecting a plurality of thin-film LEDs in series can be used, the amount of relatively expensive semiconductor material used can be reduced. Can be greatly reduced.

  DESCRIPTION OF SYMBOLS 100 LED module (light source device), 101,202 LED bare chip (semiconductor light-emitting device), 112 board | substrate, 112a main surface, 103-105, 202-210 Semiconductor light-emitting device, 113 Anode electrode, 114 Cathode electrode, 116,117 Thin film wiring layer.

Claims (18)

A substrate,
A plurality of semiconductor light emitting devices arranged on the main surface of the substrate, each having a cathode electrode and an anode electrode;
A thin film wiring layer electrically connecting one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements to the other anode electrode of the semiconductor light emitting elements adjacent to each other. A semiconductor light emitting device.   The plurality of semiconductor light emitting elements are formed such that one cathode electrode of the semiconductor light emitting elements adjacent to each other and the other anode electrode of the semiconductor light emitting elements adjacent to each other are adjacent to each other. The semiconductor light emitting device according to claim 1.   The semiconductor light-emitting device according to claim 1, wherein the plurality of semiconductor light-emitting elements are arranged in a line.   The semiconductor light emitting device according to claim 1, wherein the plurality of semiconductor light emitting elements are arranged in a plurality of columns.   The semiconductor light-emitting device according to claim 1, wherein the plurality of semiconductor light-emitting elements are made of a nitride-based semiconductor material. The plurality of semiconductor light emitting elements are made of a GaAs-based semiconductor material.
The substrate is made of a GaAs-based material, is provided between the semiconductor light-emitting device and the substrate, and the semiconductor light-emitting device and the substrate are electrically insulated by an isolation layer made of a GaAs-based material. The semiconductor light-emitting device according to claim 1, wherein: A mounting member;
A semiconductor light emitting device installed on the mounting member,
The semiconductor light emitting device comprises:
A substrate,
A plurality of semiconductor light emitting devices arranged on the main surface of the substrate, each having an anode electrode and a cathode electrode;
A thin film wiring layer electrically connecting one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements to the other anode electrode of the semiconductor light emitting elements adjacent to each other. A light source device. The mounting member is a cathode reed frame,
The light source device is
An anode lead frame;
The semiconductor light emitting device electrically connected to the cathode reed frame and the anode lead frame;
The light source device according to claim 7, further comprising: a lens case that covers the semiconductor light emitting device. The mounting member is a mounting substrate,
The light source device is
A plurality of the semiconductor light emitting devices arranged on the mounting substrate, each having a cathode electrode pad and an anode electrode pad;
A cathode electrode connection pad provided on the mounting substrate;
An anode electrode connection pad provided on the mounting substrate;
A cathode bonding wire for electrically connecting the cathode electrode pad and the cathode electrode connection pad;
The light source device according to claim 7, further comprising: an anode bonding wire that electrically connects the anode electrode pad and the anode electrode connection pad. The mounting member is a mounting substrate,
The light source device is
A plurality of the semiconductor light emitting devices arranged on the mounting substrate, each having a cathode electrode pad and an anode electrode pad;
A cathode electrode connection pad provided on the mounting substrate;
A relay electrode connection pad provided on the mounting substrate;
An anode electrode connection pad provided on the mounting substrate;
A cathode bonding wire for electrically connecting the cathode electrode pad and the cathode electrode connection pad of the semiconductor light emitting device belonging to a first group of the plurality of semiconductor light emitting devices;
A first relay bonding wire that electrically connects the anode electrode pad of the semiconductor light emitting device belonging to the first group and the relay electrode connection pad;
A second relay bonding wire for electrically connecting the cathode electrode pad and the relay electrode connection pad of the semiconductor light emitting device belonging to a second group different from the first group among the plurality of semiconductor light emitting devices. When,
The light source device according to claim 7, further comprising: an anode bonding wire that electrically connects an anode electrode pad of the semiconductor light emitting device belonging to the second group and the anode electrode connection pad. A mounting board;
A plurality of the semiconductor light emitting devices arranged on the mounting substrate, each having a cathode electrode pad and an anode electrode pad;
A cathode electrode connection pad provided on the mounting substrate;
An anode electrode connection pad provided on the mounting substrate;
A cathode electrode thin film wiring layer for electrically connecting the cathode electrode pad and the cathode electrode connection pad;
The light source device according to claim 7, further comprising: an anode electrode thin film wiring layer that electrically connects the anode electrode pad and the anode electrode connection pad. A mounting board;
A plurality of light emitting pixels arranged in a one-dimensional direction on the mounting substrate and selectively lit based on input image data;
Each of these light emitting pixels is the said semiconductor light-emitting device. The light source device of Claim 7 characterized by the above-mentioned. An image carrier;
An exposure device that irradiates the image carrier with light corresponding to image data to form an electrostatic latent image on the image carrier;
A developing device that develops the electrostatic latent image to form a developer image,
The exposure apparatus has a plurality of light emitting pixels arranged in a one-dimensional direction and selectively lit based on input image data,
Each of the plurality of light emitting pixels is
A substrate,
A plurality of semiconductor light emitting devices arranged on the main surface of the substrate, each having a cathode electrode and an anode electrode;
A thin film wiring layer electrically connecting one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements to the other anode electrode of the semiconductor light emitting elements adjacent to each other. An image forming apparatus. A semiconductor light-emitting element array light source device having a plurality of light-emitting pixels arranged in a one-dimensional direction and selectively lit based on input image data;
A scanning unit that scans light from the semiconductor light-emitting element array light source device in a direction perpendicular to the one-dimensional direction; and an image display surface that displays the image irradiated with the light.
Each of the plurality of light emitting pixels is
A substrate,
A plurality of semiconductor light emitting devices arranged on the main surface of the substrate, each having a cathode electrode and an anode electrode;
A thin film wiring layer electrically connecting one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements to the other anode electrode of the semiconductor light emitting elements adjacent to each other. An image display device. A semiconductor light-emitting element array light source device having a plurality of light-emitting pixels arranged in a two-dimensional direction and selectively lit based on input image data;
Each of the plurality of light emitting pixels is
A substrate,
A plurality of semiconductor light emitting devices arranged on the main surface of the substrate, each having a cathode electrode and an anode electrode;
A thin film wiring layer electrically connecting one cathode electrode of the semiconductor light emitting elements adjacent to each other among the plurality of semiconductor light emitting elements to the other anode electrode of the semiconductor light emitting elements adjacent to each other. An image display device.   The image display device according to claim 15, further comprising a communication unit that executes a communication function as a portable terminal.   The image display device according to claim 15, further comprising an optical unit that projects light rays from the plurality of light emitting pixels onto a projection surface. The semiconductor light-emitting element array light source device is provided for each of a red image, a green image, and a blue image,
The optical unit includes a combining unit that combines and outputs light beams from each of the semiconductor light emitting device array light source devices for the red image, the green image, and the blue image. Image display device.

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