JP2011113989A - Display panel and projection type display device - Google Patents

Abstract

A display panel excellent in heat dissipation and the like and a projection display device using the display panel are realized.
In a display panel, a plurality of via holes 11 covered with a heat conductive layer 12 are formed on a mounting substrate 10, a base substrate 20 is mounted on the mounting substrate 10, and a laminated thin film made of an inorganic material is further formed. The LED array 30 is joined, and the LED array 30 has a plurality of LEDs 31 arranged in a two-dimensional matrix obtained by separating the elements in a semiconductor process. The plurality of LEDs 31 are selectively driven by an anode driver IC and a cathode driver IC mounted on the base substrate 20. Therefore, the display panel 3 that has a simple structure, is not damaged during assembly, can be reduced in size, and has excellent heat dissipation, and a projection display device using the display panel 3 can be realized.
[Selection] Figure 1

Description

  The present invention relates to a display panel and a projection display device using the display panel.

  Conventionally, in vehicles such as automobiles and airplanes, a projection type is used to display various information such as display information of various instruments such as a speedometer and a fuel gauge, map information of a navigation device, and image information acquired by a photographing device. A head-up display device (Head-Up Display, hereinafter referred to as “HUD”), which is one of display devices, is used.

  For example, a HUD used in a vehicle has a light source, a liquid crystal display panel, a dichroic mirror, a hologram mirror, and the like, and is incorporated on the back side of an instrument panel in the vehicle. Then, after various information displayed on the liquid crystal display panel is reflected by the light from the light source by the dichroic mirror and the hologram mirror, a part of the windshield glass (laminated glass) of the vehicle or a predetermined position in front of the driver The image is displayed on a reflective layer disposed on the screen. Thereby, various information can be displayed as a virtual image in front of the driver, and the driver can visually recognize various information without diverting the line of sight from the front.

  In addition, HUDs using light emitting panels (that is, organic EL panels) in which organic electroluminescent elements (hereinafter referred to as “organic EL elements”), which are organic electroluminescent elements, are arranged in a matrix instead of light sources and liquid crystal display panels are also available. It has been proposed (Patent Document 1).

JP-A-11-67448

  However, a conventional display panel such as an organic EL panel and a projection display device such as a HUD using the same have the following problems.

  The conventional organic EL panel has a structure in which it is sandwiched between two upper and lower glass plates and sealed with resin, so that the glass surface of the organic EL panel is directly attached to the HUD housing in order to be attached to the HUD. It is necessary to bond and fix or to fix the bracket to the HUD housing after being fixed to the bracket. However, since the adhesive fixing surface is the glass surface of the organic EL panel, it is vulnerable to impact and easily damaged when fixed to the housing. In addition, since the organic EL panel is fixed to the HUD through the glass substrate, the thermal conductivity is poor and the heat dissipation is not good, so that the luminance is deteriorated.

  The display panel of the present invention includes a first substrate having a plurality of through holes, the surface including the inner surface of the through hole being covered with a heat conductive layer, and one surface of the first substrate. And selectively driving each of the plurality of thin film semiconductor light emitting elements bonded via a bonding film formed on the surface of the second substrate, and the second substrate. And a driving circuit for forming an optical image by emitting light, and the back surface of the second substrate is fixed to one surface of the first substrate by a heat conductive member.

  A projection display device according to the present invention includes the display panel according to the present invention and an optical system that projects the optical image formed by light emission of the plurality of thin film semiconductor light emitting elements.

  According to the present invention, a plurality of through-holes covered with a heat conductive layer is formed in the first substrate, and the second substrate is fixed on the first substrate by the heat conductive member. Since a plurality of thin-film semiconductor light-emitting elements are bonded on the second substrate, a display panel that has a simple structure, is not damaged during assembly, can be reduced in size, and has excellent heat dissipation. It is possible to realize a projection display device using the above.

FIG. 1 is a partially enlarged view of FIG. 4 in Embodiment 1 of the present invention. FIG. 2 is a schematic configuration diagram illustrating the entire projection display apparatus according to the first embodiment of the present invention. FIG. 3 is a block diagram showing an outline of the display panel in FIG. FIG. 4 is a schematic diagram showing a circuit configuration of the display panel of FIG. FIG. 5 is a schematic circuit diagram showing the configuration of the anode driver IC and the cathode driver IC in FIG. FIG. 6 is a cross-sectional view of a manufacturing / assembling process showing an example of a manufacturing method for the display panel of FIG. FIG. 7 is a cross-sectional view showing an example of a configuration and a manufacturing method in the display panel of Example 2 of the present invention. FIG. 8 is a schematic configuration diagram showing the whole of another projection type display apparatus in Embodiment 3 of the present invention.

  Modes for carrying out the present invention will become apparent from the following description of the preferred embodiments when read in light of the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Overall Configuration of Projection Display Device of Example 1)
FIG. 2 is a schematic configuration diagram illustrating the entire projection display apparatus according to the first embodiment of the present invention.

  The projection display device 1 is, for example, a HUD, and various types of information such as display information of various instruments such as a speedometer and a fuel meter, map information of a navigation device, and image information acquired by a photographing device in a vehicle, an aircraft, and the like. It displays information and has a housing 2. The housing 2 has a window 2a formed on the upper surface thereof, and is incorporated, for example, on the back side of an instrument panel in the vehicle. A display panel 3 is disposed in the lower part of the housing 2. The display panel 3 has a dot matrix LED structure in which a plurality of thin film semiconductor light emitting elements (for example, light emitting diodes, hereinafter referred to as “LEDs”) are two-dimensionally arranged, and emits an optical image of various information. It is a display panel.

  An optical system for projecting an optical image emitted from the display panel 3 (for example, the reflecting flat mirror 4 and the magnifying concave mirror 5) is arranged on the upper side of the display panel 3 on the outgoing light surface side. The plane mirror 4 reflects the optical image emitted from the display panel 3 in a predetermined direction (for example, substantially horizontal direction), and the concave mirror 5 is disposed in the reflection direction of the plane mirror 4. The concave mirror 5 enlarges the reflected light from the plane mirror 4 and forms an image on the upper windshield glass (W / S) 6 through the window 2a of the housing 2.

  In this type of projection display device 1, an optical image of various information emitted from the display surface of the display panel 3 is reflected by the reflecting mirror 4 and enlarged by the concave mirror 5, and is formed on a part of the windshield glass 6 of the vehicle. Is displayed. Accordingly, various information can be displayed as a virtual image 8 in front of the driver 7, and the driver 7 can visually recognize various information without diverting the line of sight from the front.

(Configuration of Display Panel of Example 1)
3 (a) and 3 (b) are configuration diagrams schematically showing the display panel 3 in FIG. 2, FIG. 3 (a) is a plan view showing the entire display panel, and FIG. It is a top view which shows the mounting substrate which deleted the base substrate and flexible cable in the figure (a). FIG. 4 is a schematic diagram showing a circuit configuration of the display panel of FIG. 1 (a) and 1 (b) are partially enlarged views of FIG. 4 in Embodiment 1 of the present invention. FIG. 1 (a) is a plan view, and FIG. It is the I1-I2 sectional view taken on the line in a).

  As shown in FIG. 3A, the display panel 3 according to the first embodiment includes a first substrate (for example, a flat mounting substrate) 10 on which the display panel constituent members are mounted. In addition, a second substrate (for example, a square base substrate) 20 is fixed. An LED array 30 in which a plurality of LEDs are arranged in a two-dimensional matrix is joined on the base substrate 20, and further spaced apart from the LED array 30 to be connected to a first wiring (for example, an anode) of the LED array 30. A first driving circuit (for example, an anode driver integrated circuit, hereinafter referred to as “anode driver IC”) 40 for driving the wiring) side and a second driving circuit for driving the second wiring (for example, cathode wiring) side of the LED array 30. Drive circuit (for example, a cathode driver IC, hereinafter referred to as “cathode driver IC”) 50 is disposed. On the mounting substrate 10, wiring (not shown) connected to the anode driver IC 40 and the cathode driver IC 50 is formed, and this wiring is connected to a control device (not shown) via the flexible cable 60. The flexible cable 60 is formed by forming a plurality of conductive wires on a thin film substrate formed of, for example, a polyimide material.

  As shown in FIG. 3B, the mounting substrate 10 is formed with a plurality of through holes (for example, via holes) 11 penetrating in the vertical direction, which is the thickness direction, in order to improve heat dissipation. The inside and the front surface and back surface of the mounting substrate 10 are covered with the heat conductive layer 12. The heat conductive layers 12 formed on the front and back surfaces of the mounting substrate 10 and the via holes 11 are connected to each other. The heat conductive layer 12 formed on the front surface and the back surface has a function of transmitting heat generated from the LED evenly in the horizontal direction and transmitting the heat to the heat conductive layer 12 formed in the via hole 11. The heat conductive layer 12 formed in 11 has a function of transferring heat in the vertical direction.

  Here, the mounting substrate 10 formed on the base of the heat conductive layer 12 is formed of a substrate having a low thermal conductivity (for example, a glass epoxy substrate) and insulates the heat of the heat conductive layer 12. The heat conductive layer 12 is formed by, for example, copper plating, or plating of copper and nickel alloy, gold (Au), palladium, or the like. The base substrate 20 is, for example, a high resistance silicon substrate, a silicon substrate on which a thermal oxide film is formed (that is, a thermal oxide film on silicon substrate), or a silicon substrate on which silicon nitride is formed (that is, a silicon nitride on silicon substrate). ) And the like.

  As shown in FIG. 1B, the mounting substrate 10 is fixed to the heat radiating plate 70, the HUD casing 2, or an instrument panel (not shown) by a screw member such as an adhesive heat radiating sheet or a screw. The heat radiating plate 70 is constituted by a heat sink formed of aluminum, copper, or the like.

  A reflective film 21 is formed on the surface of the base substrate 20 on the mounting substrate 10, and the LED array 30 is bonded to the reflective film 21 via a bonding layer (for example, a planarizing film) 22. . The reflective film 21 is, for example, a metal book film made of titanium, silver or the like having a thickness of 20 nm to 1 μm, and is patterned on the base substrate 20 by vapor deposition or the like. For example, the planarizing film 22 has a thickness of 20 to 1000 nm and is formed of an organic insulating film such as polyimide resin. The surface of the planarizing film 22 is planarized so that the surface roughness is 20 to 100 nm or less.

  As shown in FIG. 4 and FIG. 1A, the LED array 30 has a plurality of LEDs 31 as LED thin films, and these LEDs 31 are arranged in a two-dimensional matrix so as to form rows and columns. The LED array 30 is a laminated thin film made of a material such as, for example, indium aluminum gallimin, gallium arsenide phosphorus, gallium nitride, indium gallium nitride, indium aluminum gallium phosphide, gallium phosphide, and the light emitting structure of the LED. This is a pn junction device having a heterostructure and a double heterostructure, and this LED array 30 is separated into a plurality of LEDs 31 and arranged in a matrix.

  An anode wiring 32 is connected to a first electrode (for example, an anode electrode) of each LED 31, and a cathode wiring is connected to a second electrode (for example, a cathode electrode) of each LED 31 via a cathode contact layer 33. 34 is connected. An insulating film 35 made of polyimide material, silicon nitride, or the like is formed under the anode wiring 32 and the cathode wiring 34. Even if the anode wiring 32 and the cathode wiring 34 have a matrix connection structure, they are electrically short-circuited. It has a configuration that does not. Each LED 31 is connected to an anode driver IC 40 and a cathode driver IC 50 that drive the LED array 30 via an anode wiring 32 and a cathode wiring 34.

  FIG. 5 is a schematic circuit diagram showing the configuration of the anode driver IC 40 and the cathode driver IC 50 in FIG.

  The anode driver IC 40 is a row of LEDs 31 connected to each anode wiring 32 of the LED array 30 in accordance with display data (for example, light emission data meaning that light is emitted or not emitted) supplied from a control device (not shown). Has a function of supplying current. The anode driver IC 40 includes, for example, a shift register 41 that inputs serial light emission data SDA supplied by serial transmission from a control device (not shown) and outputs parallel light emission data PDA that has been subjected to serial-parallel conversion. A latch circuit 42 is connected. The latch circuit 42 is a circuit that latches the parallel light emission data PDA output from the shift register 41, and a drive circuit 43 is connected to the output side. The drive circuit 43 is a circuit that amplifies the output signal of the latch circuit 42, and a plurality of anode wirings 32 are connected to this output side.

  The cathode driver IC 50 has a function of scanning a row of LEDs 31 connected to each cathode wiring 34 of the LED array 30 based on a clock CLK and a frame signal FS supplied from a control device (not shown). It consists of

(Method for Manufacturing Display Panel of Example 1)
6A to 6C are cross-sectional views of a manufacturing / assembling process showing an example of a manufacturing method for the display panel 3 of FIG.

  First, in the manufacturing process of FIG. 6A, a mounting substrate 10 such as a glass epoxy substrate having a low thermal conductivity is prepared. A plurality of via holes 11 are formed in the mounting substrate 10, and the inside of the via holes 11 and the front and back surfaces of the mounting substrate 10 are covered with a heat conductive layer 12. The heat conductive layer 12 is made of, for example, copper, copper and nickel alloy, gold, palladium, or the like. On the mounting substrate 10, an adhesive 13 that is a heat conductive member is applied. As the adhesive 13, a heat conductive resin or various paste-like heat conductive adhesives (for example, a resin containing silver (Ag) paste or metal particles excellent in heat dissipation) is used.

  Next, in the manufacturing process of FIG. 6B, the LED array 30 and the base substrate 20 are generated in advance. The LED array 30 is a crystallized laminated thin film made of a material such as indium aluminum gallium, for example, and is a pn junction device having a heterostructure that is a light emitting structure of the LED 31 and a double heterostructure. A crystallized thin film formed by epitaxial growth on a single crystal substrate (for example, a gallium arsenide wafer, a nitrogen gallium wafer, a sapphire wafer, or a silicon wafer) is peeled off. The LED array 30 is separated into a plurality of LEDs 31, and these LEDs 31 are arranged in a two-dimensional matrix.

  As the base substrate 20, a high resistance silicon substrate, a silicon substrate on which a thermal oxide film or aluminum nitride having a thickness of 20 nm to 2 μm is formed, or the like is used. A reflective film 21 is formed on the base substrate 20. The reflective film 21 is a metal book film made of titanium, silver, or the like having a thickness of 20 nm to 1 μm, and is patterned on the base substrate 20 by vapor deposition or the like.

  A planarizing film 22 is formed on the reflective film 21, and the LED array 30 peeled from another single crystal substrate is bonded onto the planarizing film 22. At this time, the LED array 30 is bonded onto the planarizing film 22 by an intermolecular force such as hydrogen bonding.

  The LED array 30 is formed by peeling a thin film laminated on another single crystal substrate (not shown) in a large area (for example, in a strip shape) where a plurality of LED elements (light emitting elements) can be formed, and on the planarizing film 22. After bonding, the elements may be separated into a plurality of LEDs 31 by photolithography etching. Alternatively, a thin film laminated on another single crystal substrate may be peeled off in an area corresponding to the row or column of the LEDs 31 and bonded onto the planarizing film 22 and then separated into a plurality of LEDs 31 by photolithography etching. . Alternatively, a thin film laminated on another single crystal substrate may be peeled off in an area corresponding to each LED 31 and bonded onto the planarizing film 22.

  An insulating film 35 made of polyimide material, silicon nitride, or the like is formed on the entire surface of the LED array 30 thus bonded, and the insulating film 35 at the cathode contact layer 33 and the cathode electrode of the LED 31 is formed by photolithography. Remove. A metal thin film of gold or aluminum, or gold or aluminum and nickel, titanium, or the like is formed on the entire surface, and the metal thin film is selectively etched by a photolithography etching method to form a cathode wiring 34, and a cathode contact layer 33 Join with. Similarly, after the insulating film 35 similar to the above is selectively formed except for the anode terminal portion of the LED 31, the metal thin film similar to the above is selectively formed to form the anode wiring 32. Thereby, the cathode wiring 34 and the anode wiring 32 are connected to the cathode terminal and the anode terminal of the LED 31, respectively, and a matrix connection structure is formed.

  When the base substrate 20 to which the LED array 30 is bonded is pressed against the adhesive 13 on the mounting substrate 10, the base substrate 20 is adhered to the mounting substrate 10 by the adhesive 13, and the display panel 3 is manufactured. finish.

  Thereafter, in the assembly process of FIG. 6C, the back surface of the mounting substrate 10 is fixed to a heat sink for a heat sink 70 formed of aluminum or copper or the like by a sticky heat radiating sheet or a screw member such as a screw. 2, the assembly of the HUD that is the projection display device 1 is completed.

(Operation of Projection Display Device of Example 1)
In the HUD which is the projection display device 1 in FIG. 2, when information to be displayed is input to a control device (not shown), the control device converts the serial light emission data SDA in FIG. 5 according to the information to be displayed. Supply to the anode driver IC 40.

  Then, the serial light emission data SDA is sequentially stored in the shift register 41 in the anode driver IC 40 for each of the LEDs 31 included in the first row of the LED array 30. The serial light emission data SDA stored in the shift register 41 is converted into parallel light emission data PDA by the shift register 41 and then stored in the latch circuit 42. The output signal of the latch circuit 42 is amplified by the drive circuit 43, a constant current is output from the drive circuit 43, and is supplied to the anode terminal of each LED 31 via the anode wiring 32.

  At this time, when the clock CLK and the frame signal FS output from the control device (not shown) are input to the cathode driver IC 50, the selection circuit 51 in the cathode driver IC 50 causes the cathode wiring in the first row of the LED array 30. 34 is selected. Therefore, a drive current is supplied from the anode wiring 32 of the first row of the LED array 30 to the LEDs 31 included in the first row, and each of the LEDs 31 included in the first row performs a light emission operation according to the serial light emission data SDA. To do.

  Such a light emitting operation is repeated a plurality of times for the number of cathode wirings 34 (that is, the number of rows of the LED array 30), and an image which is an optical image for one screen is displayed. That is, the display panel 3 emits an image for one screen including information to be displayed.

  The light emitted by the light emission of the display panel 3 is reflected by the flat mirror 4 in FIG. 2 and enlarged by the concave mirror 5, and then irradiated on the windshield glass 6. Then, a virtual image 8 of an image emitted from the display panel 3 is displayed in front of the windshield glass 6 in the line of sight of the driver 7. Thereby, the driver | operator 7 can visually recognize the information contained in the image which the display panel 3 light-emitted, without diverting eyes from the front.

(Effect of Example 1)
According to the display panel 3 of the first embodiment, a plurality of via holes 11 covered with the heat conductive layer 12 are formed on the mounting substrate 10, the base substrate 20 is mounted on the mounting substrate 10, and further, an inorganic material is used. A laminated thin film LED array 30 is joined, and the LED array 30 has a plurality of LEDs 31 arranged in a two-dimensional matrix obtained by separating the elements in a semiconductor manufacturing process (process). Therefore, it is possible to provide a display panel 3 that has a simple structure, is not damaged during assembly, can be reduced in size, and has excellent heat dissipation, and a HUD that is a projection display device 1 using the display panel 3. .

(Configuration / Manufacturing Method of Example 2)
FIGS. 7A to 7C are cross-sectional views showing an example of a configuration and a manufacturing method in the display panel 3A of the second embodiment of the present invention, and are common to the elements in FIG. 6 showing the first embodiment. Are marked with a common reference.

  In the display panel 3A of the second embodiment, instead of the adhesive 13 in the display panel 3 of the first embodiment, a metal is formed on a part of the surface of the mounting substrate 10 having a plurality of via holes 11 covered with the heat conductive layer 12. A plurality of micro-bumps 14 (for example, gold (Au) or copper (Cu)) are formed, and furthermore, heat is formed in each via hole 11 by a metal pin (for example, copper or aluminum) that is a heat conductive material. Conductive pins) 15 are embedded, and the heat dissipation characteristics are further improved. A base substrate 20 similar to that of the first embodiment is formed on the region of the microbump 14 in the mounting substrate 10, and an LED array 30, an anode driver IC 40, and a cathode driver similar to those of the first embodiment are formed on the base substrate 20. IC50 is fixed.

  Further, in the second embodiment, unlike the first embodiment, a metal (for example, Au) metal film 24 is formed on the entire back surface of the base substrate 20, and the metal film 24 and the micro bumps 14 on the mounting substrate 10 are formed. Are connected by Au—Au bonding, Au—Cu bonding, or the like. As in the first embodiment, the mounting substrate 10 is formed of, for example, a glass epoxy substrate or the like, and wirings for connecting to the anode driver IC 40 and the cathode driver IC 50 are formed thereon. Other configurations are the same as those of the first embodiment.

  In the manufacturing method of the display panel 3A in the second embodiment, first, in the manufacturing process of FIG. 7A, a mounting substrate 10 such as a glass epoxy substrate having a low thermal conductivity is prepared as in the first embodiment. Similar to the first embodiment, a plurality of via holes 11 are formed in the mounting substrate 10, and the inside of the via holes 11 and the front and back surfaces of the mounting substrate 10 are covered with a heat conductive layer 12. Unlike the first embodiment, heat conduction pins 15 formed of copper, aluminum, or the like are embedded in the plurality of via holes 11, respectively, and a plurality of Au, Cu, or the like is partially formed on the mounting substrate 10. The micro bumps 14 are formed.

  In the formation of the plurality of micro bumps 14 made of Au, Cu, etc., bumps having a diameter of 2 to 10 μm, a height of 1 to 5 μm, and a bump cycle of 10 μm are formed by evaporating or sputtering Au, Cu or the like by a lift-off process.

  Next, in the manufacturing process of FIG. 7B, the LED array 30 and the base substrate 20 are generated in advance as in the first embodiment. A reflective film 21 is formed on the surface of the base substrate 20 in the same manner as in the first embodiment. In the second embodiment, for example, Au having a thickness of 0.2 to 5 μm is deposited on the entire back surface of the base substrate 20. Alternatively, the metal film 24 is formed by sputtering. A planarizing film 22 is formed on the reflective film 21 in the same manner as in the first embodiment, and the LED array 30 peeled from another substrate is joined to the planarizing film 22 by an intermolecular force such as hydrogen bonding. To do.

  On the LED array 30 bonded in this manner, the cathode contact layer 33, the cathode wiring 34, and the anode wiring 32 are formed in the same manner as in the first embodiment, and the cathode wiring 34 and the anode wiring 32 are A matrix connection structure connected to the cathode terminal and the anode terminal of the LED 31 is formed.

  Then, after a plurality of micro bumps 14 made of Au, Cu, etc. and the Au metal film 24 on the back surface of the base substrate 20 are activated by plasma treatment with argon, nitrogen, oxygen, etc., both are brought into contact with each other, and 150 to 300 If the plurality of micro bumps 14 and the metal film 24 are connected by Au-Au bonding, Au-Cu bonding, or the like by performing an annealing process at 0 ° C., the manufacturing of the display panel 3A is completed.

  Thereafter, in the assembly process of FIG. 7C, as in the first embodiment, the back surface of the mounting substrate 10 is fixed to the heat sink for heat sink 70 and mounted in the housing 2 in FIG. The assembly of the HUD that is the display device 1 is completed.

(Operation of Projection Type Display Device of Example 2)
The HUD that is the projection display device 1 of the second embodiment operates in the same manner as the first embodiment.

(Effect of Example 2)
According to the display panel 3A of the second embodiment, a plurality of via holes 11 covered with the heat conductive layer 12 are formed in the mounting substrate 10, and the heat conductive pins 15 are embedded in the via holes 11, and the mounting substrate is also provided. A plurality of microbumps 14 are formed on 10, a base substrate 20 is mounted on the mounting substrate 10 via a metal film 24, and a laminated thin-film LED array 30 made of an inorganic material is bonded to the LED. It has a plurality of LEDs 31 arranged in a dimensional matrix obtained by separating the array 30 by a semiconductor process.

  Therefore, it is possible to provide a display panel 3A that has a simple structure, is not damaged during assembly, can be reduced in size, and has excellent heat dissipation, and a HUD that is a projection display device 1 using the display panel 3A. . Furthermore, since the mounting substrate 10 and the base substrate 20 are connected by Au—Au bonding, Au—Cu bonding, or the like, the heat generated from the LED array 30 can be released to the back surface of the mounting substrate. The display panel 3 </ b> A and the projection type display device 1 that have a small decrease in luminance can be realized.

  FIGS. 8A and 8B are schematic configuration diagrams showing the whole of another projection display device according to the third embodiment of the present invention, and FIG. 8A is a configuration diagram of a front projection display device, FIG. 2B is a configuration diagram of the rear projection display device.

  A front projection display device 70 in FIG. 8A is a front projection projector, and includes the display panel 3 or 3A according to the first embodiment or the second embodiment, and an optical image emitted from the display panel 3 or 3A. The optical system (for example, a projection lens) 71 is enlarged and displayed on a front screen 72.

  8B is a rear projection type projector, and includes the display panel 3 or 3A according to the first or second embodiment, and the optical light emitted from the display panel 3 or 3A. The image is enlarged and reflected by an optical system (for example, the projection lens 81 and the reflecting mirror 82), and is displayed on the screen 83 from the back.

  According to such projection type display devices 70 and 80, since the display panel 3 or 3A of Example 1 or Example 2 is used, the same effects as those of the projection type display device 1 of Example 1 can be obtained. Can do.

(Modification)
This invention is not limited to the said Examples 1-3, A various utilization form and deformation | transformation are possible. For example, the following forms (a) to (c) are available as usage forms and modifications.

  (A) The heat conduction pins 15 may be embedded in the via holes 11 in the mounting substrate 10 of the first embodiment. Thereby, the heat dissipation of Example 1 can be improved more.

  (B) The display panels 3 and 3A of the first and second embodiments may be changed to configurations and manufacturing methods other than those illustrated. For example, even if the display panel is configured using an EL array having a plurality of EL elements instead of the LED array 30, substantially the same operational effects as those of the first to third embodiments can be obtained.

  (C) The display panel of the present invention is not limited to the form of the projection display device shown in the first to third embodiments, and can be applied to, for example, a direct-view display device that does not use a projection optical system.

DESCRIPTION OF SYMBOLS 1 Projection type display apparatus 3,3A Display panel 4 Plane mirror 5 Concave mirror 6 Windshield glass 10 Mounting board 11 Via hole 12 Thermal conduction layer 14 Micro bump 15 Thermal conduction pin 20 Underlying board 21 Reflective film 22 Flattening film 30 LED array 31 LED
40 Anode driver IC
50 Cathode driver IC
DESCRIPTION OF SYMBOLS 70 Front projection type display apparatus 80 Rear projection type display apparatus 71,81 Projection lens 82 Reflective mirror

Claims (12)

A first substrate having a plurality of through holes, the surface including the inner surface of the through holes being covered with a heat conductive layer;
A second substrate provided on one surface of the first substrate;
A plurality of thin-film semiconductor light-emitting elements bonded through a bonding film formed on the surface of the second substrate;
A drive circuit that emits light by selectively driving each of the plurality of thin film semiconductor light emitting elements to form an optical image;
The display panel, wherein the back surface of the second substrate is fixed to one surface of the first substrate by a heat conductive member.   The display panel according to claim 1, wherein the bonding film is a flattening film that bonds the plurality of thin film semiconductor light emitting elements by intermolecular force.   The display panel according to claim 2, wherein the planarizing film is formed on the surface of the second substrate via a reflective film.   The display panel according to claim 1, wherein the heat conductive member is a heat conductive resin or a heat conductive adhesive.   The display panel according to claim 1, wherein the heat conductive member is a metal micro bump.   The display panel according to claim 1, wherein the through hole is filled with a heat conductive material.   The display panel according to claim 1, further comprising a heat sink provided in contact with the other surface side of the first substrate.   The display panel according to claim 1, wherein the first substrate is a glass epoxy substrate.   The display panel according to claim 1, wherein the heat conductive layer is a metal film of any one of copper, a copper / nickel alloy, gold, or palladium.   10. The substrate according to claim 1, wherein the second substrate is any one of high resistance silicon, silicon including a thermal oxide film structure, or silicon including an aluminum nitride structure. Display panel as described.   The display panel according to claim 6, wherein the heat conductive material is a copper or aluminum metal pin. The display panel according to any one of claims 1 to 11,
An optical system for projecting the optical image formed by light emission of the plurality of thin film semiconductor light emitting elements;
A projection-type display device comprising:

Images