JP4408044B2 - Method for manufacturing liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a transmissive liquid crystal display device mounted on a portable electronic device. The present invention also relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for manufacturing a transmissive liquid crystal display device mounted on a portable electronic device. Further, the present invention relates to an electronic device using the liquid crystal display device.

  In addition to flat panel displays for displaying images, portable electronic devices typified by mobile phones and electronic notebooks are required to have various functions such as sending and receiving mail, voice recognition, and video capture with a small camera. On the other hand, user needs for downsizing and weight reduction are still strong. Therefore, it is necessary to mount more ICs having a larger circuit scale and memory capacity in the limited volume of portable electronic devices.

  In order to secure a space for housing an IC and to reduce the size and weight of a portable electronic device, it is important to make a flat panel display thin and light. For example, in the case of a liquid crystal display device that is used relatively frequently in portable electronic devices, the thickness of the glass substrate used for the panel in which the liquid crystal is sealed can be reduced, or a reflection type that can eliminate the need for a light source, a light guide plate, etc. By doing so, it is possible to reduce the thickness and weight to some extent.

  However, if the mechanical strength of the panel is taken into consideration, the glass substrate cannot be made too thin. For example, when barium borosilicate glass, alumino borosilicate glass, or the like is used, the thickness of a 3-inch square panel is limited to about 1 to 2 mm at most and about 10 g in weight. In addition, reflective liquid crystal display devices that use external light are difficult to recognize images in a dark place and cannot fully utilize the advantages of portable electronic devices that can be used anywhere.

  An object of the present invention is to enhance the functionality of a portable electronic device without hindering weight reduction or downsizing, and more specifically, a liquid crystal display device mounted on the portable electronic device has a mechanical strength. It is an object to reduce the thickness and weight without damage.

  The liquid crystal display device of the present invention uses a light emitting element such as a light-emitting diode (LED) or an electroluminescence element as a light source. Then, the light-emitting element provided on the flexible plastic substrate is covered with a light-transmitting resin to flatten the surface, and the liquid crystal cell and the liquid crystal cell are driven on the flattened resin. A semiconductor element is provided for this purpose. A light source in a state where the light emitting element is covered with a resin is referred to as a solidified light source in this specification.

  In general, a plastic substrate is superior in mechanical strength against vibration and impact compared to a glass substrate because of its flexibility, and its thickness can be easily suppressed. However, a plastic substrate and a resin are often not excellent in heat resistance to withstand heat treatment in a manufacturing process of a semiconductor element used in a liquid crystal display device. Therefore, in the present invention, after a semiconductor element is formed over a substrate having heat resistance enough to withstand the heat treatment, the semiconductor element is transferred onto a solidified light source.

  The liquid crystal display device of the present invention is provided with means for reflecting the light emitted from the light emitting element to the liquid crystal cell side. Specifically, an existing reflecting plate is bonded to a plastic substrate, or a metal film (hereinafter referred to as a reflecting film) is formed on the surface of the plastic substrate by vapor deposition or the like to reflect light. Further, a polarizing plate is provided between the resin covering the light emitting element and the semiconductor element and the liquid crystal cell.

  The first manufacturing method of the liquid crystal display device of the present invention will be specifically described below.

  First, a first substrate having heat resistance that can withstand heat treatment in a manufacturing process of a semiconductor element is prepared. Then, a metal film is formed on the first substrate, and the surface of the metal film is oxidized to form a very thin metal oxide film of several nm. Next, an insulating film and a semiconductor film are sequentially stacked on the metal oxide film. The insulating film may be a single layer or a stack of a plurality of films. For example, silicon nitride, silicon nitride oxide, silicon oxide, or the like can be used. Then, a semiconductor element used for a liquid crystal display device is manufactured using the semiconductor film.

  After the semiconductor element is formed, before the liquid crystal cell is completed, a second substrate is bonded so as to cover the semiconductor element, and a state in which the semiconductor element is sandwiched between the first substrate and the second substrate is created. . The liquid crystal cell includes a pixel electrode, a counter electrode, and a liquid crystal provided between the pixel electrode and the counter electrode. Specifically, before the liquid crystal cell is completed, specifically, after the pixel electrode of the liquid crystal cell electrically connected to the TFT, which is one of the semiconductor elements, and the alignment film covering the pixel electrode are manufactured. This corresponds to before the counter substrate on which the counter electrode is formed is bonded.

  Then, a third substrate is bonded to the side of the first substrate opposite to the side where the semiconductor element is formed in order to reinforce the rigidity of the first substrate. When the first substrate is higher in rigidity than the second substrate, the semiconductor element is less likely to be damaged when the first substrate is peeled off, and can be removed smoothly. Note that the third substrate is not necessarily bonded to the first substrate if the first substrate has sufficient rigidity when the first substrate is peeled off from the semiconductor element later.

  Next, heat treatment or the like is performed to crystallize the metal oxide film, increase the brittleness of the metal oxide film, and facilitate separation of the first substrate from the semiconductor element. Then, the first substrate is peeled off from the semiconductor element together with the third substrate. Note that the heat treatment for crystallizing the metal oxide film may be performed before the third substrate is bonded, or may be performed before the second substrate is bonded. Alternatively, the heat treatment performed in the step of forming the semiconductor element may also serve as the step of crystallizing the metal oxide film.

  Then, the first substrate is peeled off from the semiconductor element together with the third substrate. By this peeling, a portion that is separated between the metal film and the metal oxide film, a portion that is separated between the insulating film and the metal oxide film, and a portion where the metal oxide film itself is separated into both are generated. In any case, the semiconductor element is peeled off from the first substrate so as to stick to the second substrate side.

  On the other hand, a plastic substrate on the light source side for bonding the semiconductor elements is prepared. Hereinafter, this plastic substrate is referred to as an element substrate in order to distinguish it from a plastic substrate on the counter electrode side used later. A light emitting element is disposed on the element substrate, and a resin is applied to cover the light emitting element. Then, the first polarizing plate is bonded onto the flattened resin.

  Next, by peeling off the first substrate, the semiconductor element attached to the second substrate side is attached to the first polarizing plate with an adhesive or the like. Then, the second substrate is peeled off so that the semiconductor element is fixed to the element substrate.

  Next, a liquid crystal cell provided in the liquid crystal display device is manufactured. Specifically, a plastic substrate (hereinafter referred to as a counter substrate) on which a counter electrode, a second polarizing plate and the like are formed is separately prepared, the counter substrate is bonded to the element substrate, and liquid crystal is injected. Complete the liquid crystal cell. Note that a counter substrate, a second polarizing plate, a color filter, an alignment film, a black matrix, and the like may be formed over the counter substrate.

  Next, a second manufacturing method of the liquid crystal display device of the present invention will be described.

  First, a first substrate having heat resistance that can withstand heat treatment in a manufacturing process of a semiconductor element is prepared. Then, a metal film is formed on the first substrate, and the surface of the metal film is oxidized to form a very thin metal oxide film of several nm. Next, an insulating film and a semiconductor film are sequentially stacked on the metal oxide film. The insulating film may be a single layer or a stack of a plurality of films. For example, silicon nitride, silicon nitride oxide, silicon oxide, or the like can be used. Then, a semiconductor element used for a liquid crystal display device is manufactured using the semiconductor film.

  Next, a liquid crystal cell provided in the liquid crystal display device is manufactured. The liquid crystal cell includes a pixel electrode, a counter electrode, and a liquid crystal provided between the pixel electrode and the counter electrode. Specifically, a plastic substrate (hereinafter referred to as a counter substrate) on which a counter electrode, a second polarizing plate, and the like are formed is separately prepared, the counter substrate is bonded, liquid crystal is injected, and a liquid crystal cell is formed. Finalize. Note that a counter substrate, a second polarizing plate, a color filter, an alignment film, a black matrix, and the like may be formed over the counter substrate.

  After the semiconductor element and the liquid crystal cell are formed, the second substrate is bonded so as to cover the semiconductor element and the liquid crystal cell, and the semiconductor element and the liquid crystal cell are sandwiched between the first substrate and the second substrate. create.

  Then, a third substrate is bonded to the side of the first substrate opposite to the side where the semiconductor element and the liquid crystal cell are formed in order to reinforce the rigidity of the first substrate. When the first substrate has higher rigidity than the second substrate, the semiconductor element and the liquid crystal cell are less likely to be damaged when the first substrate is peeled off, and can be removed smoothly. Note that the third substrate is not necessarily bonded to the first substrate if the first substrate has sufficient rigidity when the first substrate is peeled off from the semiconductor element later.

  Next, heat treatment or the like is performed to crystallize the metal oxide film, increase the brittleness of the metal oxide film, and facilitate separation of the first substrate from the semiconductor element. Then, the first substrate is peeled off from the semiconductor element together with the third substrate. Note that the heat treatment for crystallizing the metal oxide film may be performed before the third substrate is bonded, or may be performed before the second substrate is bonded. Alternatively, the heat treatment performed in the step of forming the semiconductor element may also serve as the step of crystallizing the metal oxide film.

  Then, the first substrate is peeled off from the semiconductor element and the liquid crystal cell together with the third substrate. By this peeling, a portion that is separated between the metal film and the metal oxide film, a portion that is separated between the insulating film and the metal oxide film, and a portion where the metal oxide film itself is separated into both are generated. In any case, the semiconductor element and the liquid crystal cell are peeled off from the first substrate so as to stick to the second substrate side.

  On the other hand, a plastic substrate (element substrate) on the light source side for bonding the semiconductor element and the liquid crystal cell is prepared. A light emitting element is disposed on the element substrate, and a resin is applied to cover the light emitting element. Then, the first polarizing plate is bonded onto the flattened resin.

  Next, when the first substrate is peeled off, the semiconductor element and the liquid crystal cell attached to the second substrate side are attached to the first polarizing plate with an adhesive or the like. Then, the second substrate is peeled off to form a state in which the semiconductor element and the liquid crystal cell are fixed to the element substrate, and the liquid crystal display device is completed.

  Note that when a plurality of liquid crystal display devices are formed from one large substrate, dicing is performed in the middle so that the liquid crystal display devices are separated from each other.

  In the present invention, the thickness of the liquid crystal display device can be 0.6 mm or more and 1.5 mm or less.

  As described above, since the element substrate and the counter substrate are flexible, they have excellent mechanical strength against vibration and impact compared to the glass substrate, and the thickness can be easily suppressed. In addition, since the element substrate and the counter substrate have flexibility, the degree of freedom in the shape of the liquid crystal display device is increased. Therefore, for example, the liquid crystal display device can be formed in a shape having a curved surface that can be attached to a cylindrical bin or the like.

  Note that by covering with a light-transmitting resin, light emitted from the light-emitting element can be diffused and the brightness of the pixel portion of the liquid crystal display device can be made uniform to some extent. Brightness can be made more uniform by providing a diffusion plate between the covering resin.

  According to the present invention, the liquid crystal display device can be remarkably thinned and reduced in weight without losing mechanical strength. By using the liquid crystal display device of the present invention for an electronic device, a wider space can be secured for the IC, and higher functionality can be realized without hindering weight reduction or miniaturization of the electronic device. In particular, in the case of a portable electronic device, it is very useful to use the liquid crystal display device of the present invention because the usability is greatly improved by reducing the weight and size. On the contrary, in the present invention, even if the size of the pixel portion of the liquid crystal display device is made larger, the weight can be almost the same as that of a liquid crystal display device using a conventional glass substrate.

  According to the present invention, the liquid crystal display device can be remarkably thinned and reduced in weight without losing mechanical strength. By using the liquid crystal display device of the present invention for an electronic device, a wider space can be secured for the IC. Therefore, more ICs with larger circuit scales and memory capacities can be mounted, and higher functionality can be realized without hindering weight reduction or downsizing of electronic devices. In particular, in the case of a portable electronic device, it is very useful to use the liquid crystal display device of the present invention because the usability is greatly improved by reducing the weight and size. On the other hand, in the present invention, the size of the pixel portion of the liquid crystal display device can be increased so as to have a weight comparable to that of a liquid crystal display device using a conventional glass substrate.

  The configuration of the liquid crystal display device of the present invention will be described with reference to FIG. FIG. 1A is a cross-sectional view of the element substrate 101 before a semiconductor element is attached. 1B corresponds to a top view of the element substrate 101 illustrated in FIG. 1A, and a cross-sectional view taken along line A-A ′ in FIG. 1B corresponds to FIG.

  An element substrate 101 illustrated in FIGS. 1A and 1B includes a recess 102, and one or more LEDs 103 are provided in the recess 102. The recessed part 102 can be formed using a well-known method, for example, can be shape | molded using a metal mold | die. The driving of the LED 103 is controlled by a thin film circuit for driving the LED 103 (hereinafter referred to as an LED driving thin film circuit) 104. The LED driving thin film circuit 104 is not necessarily provided in the recess 102 and may be formed in a portion other than the recess 102. A method of forming the LED driving thin film circuit 104 will be described later.

  Reference numeral 105 denotes a wiring formed on the element substrate 101. In addition to electrically connecting the LED 103 and the LED driving thin film circuit 104, the LED driving thin film circuit 104, a semiconductor element to be bonded later, and a liquid crystal display device It is used to make an electrical connection with the outside. The wiring 105 can be formed on the element substrate 101 using a known method such as a plating method.

  Reference numeral 106 denotes a reflective film, which is formed by vapor-depositing a metal in the recess 102 using a vapor deposition method or the like. The reflective film 106 is formed so as to be electrically separated from the wiring 105 and the LED 103 so as not to be short-circuited. In this embodiment, a reflective film formed by vapor deposition is used as a means for reflecting the light of the LED 103 toward the liquid crystal cell side, but a separately formed reflective plate is bonded to the element substrate 101. Also good. In this case, it is desirable that the reflecting plate is bonded to a position where the light of the LED 103 can be reflected to the liquid crystal cell side. For example, it can be provided on the surface of the element substrate 101 that is opposite to the side on which the LEDs 103 are provided, on which the recess 102 is not provided.

  The LED 103 is covered with a resin 107. In the present embodiment, the recess 107 is filled with a resin 107. When the LED driving thin film circuit 104 is formed in the recess 102, the LED driving thin film circuit 104 is covered with the resin 107. As the resin 107, for example, a known resin such as an acrylic resin, an epoxy resin, a urethane resin, a polycarbonate resin, or a vinyl resin can be used. Translucent particles having a refractive index different from that of the resin may be dispersed in the resin 107. For example, spherical particles made of silicon resin dispersed in polymethylmethacrylate resin can be used. It is desirable that the resin is appropriately selected in accordance with a semiconductor element bonding step to be performed later.

  In FIG. 1A and FIG. 1B, an area where the LED 103 and the reflective film 106 are provided and covered with the resin 107 corresponds to the light source unit 108.

  FIG. 1C is a cross-sectional view of the liquid crystal display device of the present invention in a state where a semiconductor element is bonded to complete a liquid crystal cell. 1D corresponds to a top view of the liquid crystal display device in the state illustrated in FIG. 1C, and a cross-sectional view taken along line B-B ′ in FIG. 1D corresponds to FIG.

  The semiconductor element 110 is bonded onto the resin 107 with an adhesive 109. Note that although not illustrated in FIG. 1C, a first polarizing plate is provided between the resin 107 and the adhesive 109. In this embodiment mode, as illustrated in FIGS. 1C and 1D, the semiconductor element 110 is used not only for a pixel portion of a liquid crystal display device, but also for driving a liquid crystal display device and the like. Also included are those used for the thin film circuit 111 for performing signal processing.

  Reference numeral 113 denotes a counter substrate, in which a liquid crystal 112 is sealed with a sealing material 114. A region in which the liquid crystal 112 is sealed by the counter substrate 113 corresponds to the panel 115. The pixel portion 116 provided on the panel 115 is irradiated with light from the light source portion 108. The thin film circuit 111 is electrically connected to the wiring 105 by using a wire bonding method, a flip chip method, or the like.

  Note that in this embodiment mode, a signal or a power supply voltage can be supplied to the liquid crystal display device through the wiring 105; however, the present invention is not limited to this, and for example, a light-emitting element, an optical sensor, or the like is used. A signal or power supply voltage may be supplied by light, or a signal or power supply voltage may be supplied by electromagnetic induction using an antenna coil.

  As the plastic substrate, ARTON: JSR made of norbornene resin with a polar group can be used. Polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), nylon, polyetheretherketone (PEEK), polysulfone (PSF), polyetherimide (PEI), poly A plastic substrate such as arylate (PAR), polybutylene terephthalate (PBT), or polyimide can be used.

  Note that in this embodiment mode, an example in which a concave portion is provided in an element substrate and an LED is provided in the concave portion has been described, but the present invention is not necessarily limited to this mode. A flat plastic substrate that is not provided with a recess may be used as the element substrate.

  A configuration of a liquid crystal display device using a flat plastic substrate as an element substrate will be described with reference to FIG. FIG. 2A is a cross-sectional view of the element substrate 201 before the semiconductor element is attached. The element substrate 201 is not provided with a recess and is flat. 2B corresponds to a top view of the element substrate 201 illustrated in FIG. 2A, and a cross-sectional view taken along line A-A ′ in FIG. 2B corresponds to FIG.

  One or more LEDs 203 are provided over the element substrate 201 illustrated in FIGS. Reference numeral 204 denotes an LED driving thin film circuit, and the LED 203 and the LED driving thin film circuit 204 are electrically connected by a wiring 205. The wiring 205 is used to electrically connect the LED driving thin film circuit 204, a semiconductor element to be bonded later, and the outside of the liquid crystal display device. In addition, the reflective film 206 is formed so as to be electrically separated so as not to be short-circuited with the wiring 205 and the LED 203. In addition, you may use the reflecting plate formed separately instead of the reflecting film formed by the vapor deposition method.

  The LED 203 is covered with a resin 207. In this embodiment mode, a photosensitive resin is applied and then partially exposed to form a resin 207 so that a part of the wiring 205 is exposed. The LED driving thin film circuit 204 may also be covered with the resin 207. 2A and 2B, the LED 203 and the reflective film 206 are provided, and a region covered with the resin 207 corresponds to the light source unit 208.

  2C is a cross-sectional view of the liquid crystal display device of the present invention in a state where a semiconductor element is bonded to the element substrate 201 shown in FIGS. 2A and 2B to complete a liquid crystal cell. Show. 2D corresponds to a top view of the liquid crystal display device in the state illustrated in FIG. 2C, and a cross-sectional view taken along line B-B ′ in FIG. 2D corresponds to FIG.

  The semiconductor element 210 is bonded onto the resin 207 with an adhesive 209. Note that although not illustrated in FIG. 2C, a first polarizing plate is provided between the resin 207 and the adhesive 209. Reference numeral 211 corresponds to a thin film circuit formed using the semiconductor element 210.

  Reference numeral 213 denotes a counter substrate, in which a liquid crystal 212 is sealed by a sealing material 214. A region in which liquid crystal is sealed by the counter substrate 213 corresponds to the panel 215. The pixel portion 216 provided in the panel 215 is irradiated with light from the light source portion 208. The thin film circuit 211 is electrically connected to the wiring 205 using a wire bonding method, a flip chip method, or the like.

  By providing a recess in the element substrate, the LED can be easily covered with the resin while the wiring is exposed by simply dropping the resin into the recess, and a reflective film is formed in the recess to emit light from the LED. The emitted light can be efficiently applied to the pixel portion. On the other hand, when the recess is not provided, the strength of the element substrate can be further increased as compared with the case where the recess is provided.

  Next, a specific method for manufacturing a semiconductor element used for a thin film circuit and a liquid crystal display device, and a method for bonding the semiconductor element to an element substrate will be described. Note that in this embodiment, two TFTs are described as an example of a semiconductor element; however, a semiconductor element included in a thin film circuit and a liquid crystal display device is not limited to this, and any circuit element can be used. For example, in addition to the TFT, a memory element, a diode, a photoelectric conversion element, a resistance element, a coil, a capacitor element, an inductor, and the like can be typically given.

  First, as shown in FIG. 3A, a metal film 501 is formed over the first substrate 500 by a sputtering method. Here, tungsten is used for the metal film 501, and the film thickness is 10 nm to 200 nm, preferably 50 nm to 75 nm. Note that in this embodiment, the metal film 501 is directly formed over the first substrate 500; however, the metal film is covered after the first substrate 500 is covered with an insulating film such as silicon oxide, silicon nitride, or silicon nitride oxide. 501 may be formed.

Then, after the metal film 501 is formed, the oxide film 502 is formed without being exposed to the air. Here, a silicon oxide film is formed as the oxide film 502 so as to have a thickness of 150 nm to 300 nm. Note that in the case where a sputtering method is used, film formation is also performed on an end surface of the first substrate 500. Therefore, in order to prevent the oxide film 502 from remaining on the first substrate 500 side at the time of peeling in a later process, the metal film 501 and the oxide film 502 formed on the end surface are subjected to O ₂ ashing. It is preferable that the first substrate 500 is selectively removed or the end portion of the first substrate 500 is cut by dicing or the like.

When the oxide film 502 is formed, pre-sputtering is performed in which plasma is generated by blocking the target and the substrate with a shutter as a pre-sputtering step. Pre-sputtering is performed with Ar at a flow rate of 10 sccm and O ₂ at a flow rate of 30 sccm, the temperature of the first substrate 500 being 270 ° C., and the deposition power being 3 kW in an equilibrium state. By pre-sputtering, a very thin metal oxide film 503 having a thickness of several nm (here, 3 nm) is formed between the metal film 501 and the oxide film 502. The metal oxide film 503 is formed by oxidizing the surface of the metal film 501. Therefore, in this embodiment, the metal oxide film 503 is formed using tungsten oxide.

  Note that although the metal oxide film 503 is formed by pre-sputtering in this embodiment mode, the present invention is not limited to this. For example, oxygen or an inert gas such as Ar may be added to oxygen, and the surface of the metal film 501 may be intentionally oxidized by plasma to form the metal oxide film 503.

  Next, after an oxide film 502 is formed, a base film 504 is formed by a PCVD method. Here, a silicon oxynitride film is formed as the base film 504 so as to have a thickness of about 100 nm. Then, after the base film 504 is formed, the semiconductor film 505 is formed without being exposed to the air. The thickness of the semiconductor film 505 is 25 to 100 nm (preferably 30 to 60 nm). Note that the semiconductor film 505 may be an amorphous semiconductor or a polycrystalline semiconductor. As the semiconductor, not only silicon but also silicon germanium can be used. When silicon germanium is used, the concentration of germanium is preferably about 0.01 to 4.5 atomic%.

  Next, as shown in FIG. 3B, the semiconductor film 505 is crystallized by a known technique. Known crystallization methods include a thermal crystallization method using an electric furnace, a laser crystallization method using laser light, and a lamp annealing crystallization method using infrared light. Alternatively, a crystallization method using a catalytic element can be used according to the technique disclosed in Japanese Patent Application Laid-Open No. 7-130552.

  Note that the semiconductor film 505 which is a polycrystalline semiconductor film may be formed in advance by a sputtering method, a plasma CVD method, a thermal CVD method, or the like.

In this embodiment mode, the semiconductor film 505 is crystallized by laser crystallization. By using a solid-state laser capable of continuous oscillation and irradiating laser light of the second to fourth harmonics of the fundamental wave, a crystal having a large grain size can be obtained. For example, typically, it is desirable to use the second harmonic (532 nm) or the third harmonic (355 nm) of an Nd: YVO ₄ laser (fundamental wave 1064 nm). Specifically, laser light emitted from a continuous wave YVO ₄ laser is converted into a harmonic by a non-linear optical element to obtain laser light with an output of 10 W. There is also a method of emitting harmonics using a nonlinear optical element. Then, the semiconductor film 505 is irradiated with a laser beam that is preferably shaped into a rectangular or elliptical shape on the irradiation surface by an optical system. At this time, the energy density of approximately 0.01 to 100 MW / cm ² (preferably 0.1 to 10 MW / cm ²⁾ is required. Then, irradiation is performed at a scanning speed of about 10 to 2000 cm / s.

  Laser crystallization may be performed by irradiating a continuous wave fundamental laser beam and a continuous wave harmonic laser beam, or a continuous wave fundamental laser beam and a pulsed harmonic laser beam. You may make it irradiate with light.

  Note that laser light may be irradiated in an inert gas atmosphere such as a rare gas or nitrogen. Thereby, roughness of the semiconductor surface due to laser light irradiation can be suppressed, and variation in threshold value caused by variation in interface state density can be suppressed.

  By irradiating the semiconductor film 505 with the laser light, the semiconductor film 506 with higher crystallinity is formed. Next, as shown in FIG. 3C, the semiconductor film 506 is patterned to form island-shaped semiconductor films 507 and 508, and various islands represented by TFTs using the island-shaped semiconductor films 507 and 508 are formed. A semiconductor element is formed. Note that in this embodiment mode, the base film 504 and the island-shaped semiconductor films 507 and 508 are in contact with each other. However, depending on the semiconductor element, an electrode or an electrode may be provided between the base film 504 and the island-shaped semiconductor films 507 and 508. An insulating film or the like may be formed. For example, in the case of a bottom gate TFT which is one of semiconductor elements, a gate electrode and a gate insulating film are formed between a base film 504 and island-shaped semiconductor films 507 and 508.

  In this embodiment mode, top-gate TFTs 509 and 510 are formed using island-shaped semiconductor films 507 and 508 (FIG. 3D). Specifically, a gate insulating film 511 is formed so as to cover the island-shaped semiconductor films 507 and 508. Then, a conductive film is formed over the gate insulating film 511 and patterned to form gate electrodes 512 and 513. Then, using the gate electrodes 512 and 513 or a resist film formed and patterned as a mask, an impurity imparting n-type is added to the island-shaped semiconductor films 507 and 508, and the source region, the drain region, and further LDD regions and the like are formed. Note that the TFTs 509 and 510 are n-type here, but in the case of a p-type TFT, an impurity imparting p-type conductivity is added.

  The TFTs 509 and 510 can be formed through the above series of steps. Note that a method for manufacturing a TFT is not limited to the above-described steps.

  Next, a first interlayer insulating film 514 is formed so as to cover the TFTs 509 and 510. Then, after forming contact holes in the gate insulating film 511 and the first interlayer insulating film 514, terminals 515 to 518 connected to the TFTs 509 and 510 through the contact holes are in contact with the first interlayer insulating film 514. Form.

  Then, a pixel electrode 540 of a liquid crystal cell is manufactured using a transparent conductive film such as ITO so as to be in contact with the wiring 515. Then, an alignment film 541 is formed so as to cover the pixel electrode 540, and the alignment film 541 is rubbed. Note that. A part of the wiring 518 is exposed by etching or the like so as not to be covered with the alignment film 541.

  Next, a protective layer 521 is formed on the alignment film 541. The protective layer 521 has a function of protecting the surfaces of the TFTs 509 and 510, the alignment film 541, and the terminals 515 to 518 when the second substrate is attached or peeled later. A material that can be removed after peeling is used. For example, the protective layer 521 can be formed by applying an epoxy-based, acrylate-based, or silicon-based resin soluble in water or alcohols over the entire surface and baking it.

  In this embodiment, a water-soluble resin (manufactured by Toagosei Co., Ltd .: VL-WSHL10) is applied by spin coating so as to have a film thickness of 30 μm, and after exposure for 2 minutes for temporary curing, UV light is applied from the back surface. Exposure is performed for 2.5 minutes and 10 minutes from the surface for a total of 12.5 minutes, followed by main curing to form a protective layer 521 (FIG. 3E).

Note that although an example in which the protective layer 521 is formed after the alignment film 541 is formed is described in this embodiment mode, the alignment film 541 may be formed after the protective layer 521 is removed in a later step. . However, when laminating a plurality of organic resins, the organic resins may be partially dissolved at the time of coating or baking depending on the solvent used, or the adhesiveness may become too high. Therefore, when forming the protective layer 521 after forming the alignment film 541, when an organic resin soluble in the same solvent is used for the first interlayer insulating film 514 and the protective layer 521, the protective layer 521 is used in a later step. Inorganic insulating film (SiN _x film) so as to cover the first interlayer insulating film 514 and so as to be sandwiched between the first interlayer insulating film 514 and the terminals 515 to 518 so that the removal can be performed smoothly. , SiN _x O _y film, AlN _x film, or AlN _x O _y film) is preferably formed.

  Next, the metal oxide film 503 is crystallized in order to facilitate subsequent peeling. By crystallization, the metal oxide film 503 is easily broken at the grain boundary, and brittleness can be increased. In this embodiment mode, heat treatment is performed at 420 ° C. to 550 ° C. for about 0.5 to 5 hours to perform crystallization.

  Next, treatment for partially reducing the adhesion between the metal oxide film 503 and the oxide film 502 or the adhesion between the metal oxide film 503 and the metal film 501 to form a part that triggers the start of peeling. To do. Specifically, pressure is locally applied from the outside along the periphery of the region to be peeled to damage a part of the metal oxide film 503 or a portion near the interface. In this embodiment, a hard needle such as a diamond pen is pressed perpendicularly near the end of the metal oxide film 503 and moved along the metal oxide film 503 with a load applied as it is. Preferably, a scriber device is used, the pushing amount is 0.1 mm to 2 mm, and the pressure is applied. In this way, by forming a portion with reduced adhesion that triggers the start of peeling before peeling, defects in the subsequent peeling step can be reduced, leading to improved yield. .

  Next, the second substrate 523 is attached to the protective layer 521 using the double-sided tape 522, and the third substrate 525 is attached to the first substrate 500 using the double-sided tape 524 (FIG. 4A). Note that an adhesive may be used instead of the double-sided tape. For example, by using an adhesive that is peeled off by ultraviolet rays, it is possible to reduce the burden on the semiconductor element when the second substrate is peeled off.

  By attaching the third substrate 525, the first substrate 500 can be prevented from being damaged in a subsequent peeling step. As the second substrate 523 and the third substrate 525, it is preferable to use a substrate having higher rigidity than the first substrate 500, such as a quartz substrate or a semiconductor substrate.

  Next, the metal film 501 and the oxide film 502 are physically peeled off. The peeling starts from a region where the adhesion of the metal oxide film 503 to the metal film 501 or the oxide film 502 is partially lowered in the previous step.

  A portion separated between the metal film 501 and the metal oxide film 503, a portion separated between the oxide film 502 and the metal oxide film 503, and a portion where the metal oxide film 503 itself is separated into both by peeling. Arise. Then, the semiconductor element (here, TFTs 509 and 510) is separated on the second substrate 523 side, and the first substrate 500 and the metal film 501 are separated on the third substrate 525 side, respectively. The peeling can be performed with a relatively small force (for example, a human force, a wind pressure of a gas blown from a nozzle, an ultrasonic wave, etc.). The state after peeling is shown in FIG.

  Next, the first polarizing plate 527 provided over the resin 533 and the oxide layer 502 to which the metal oxide film 503 is partially attached are bonded to each other with an adhesive 526 (FIG. 4C). At the time of this adhesion, the adhesion force between the oxide layer 502 and the first polarizing plate 527 by the adhesive 526 is larger than the adhesion force between the second substrate 523 and the protective layer 521 by the double-sided tape 522. It is important to select the material of the adhesive 526 so that it is higher.

  Note that if the metal oxide film 503 remains on the surface of the oxide film 502, the adhesiveness to the first polarizing plate 527 may be deteriorated. It may be adhered to a polarizing plate to improve the adhesion.

  In the case where the semiconductor elements 509 and 510 are used for a thin film circuit, the semiconductor elements 509 and 510 are not necessarily attached to a position overlapping with the first polarizing plate 527.

  Examples of the adhesive 526 include a reactive curable adhesive, a thermosetting adhesive, a photocurable adhesive such as an ultraviolet curable adhesive, and various curable adhesives such as an anaerobic adhesive. More preferably, the adhesive 526 is also provided with high thermal conductivity by including powder or filler made of silver, nickel, aluminum, aluminum nitride.

  Reference numeral 530 denotes a wiring formed on the element substrate 534. The wiring 530 is formed by plating, for example, solder, gold or tin on copper.

  Next, as shown in FIG. 5A, the double-sided tape 522 and the second substrate 523 are peeled from the protective layer 521 sequentially or simultaneously. Note that by using an ultraviolet curable adhesive as the adhesive 526 and using a tape or an adhesive that is peeled off by ultraviolet rays on the double-sided tape 522, the double-sided tape 522 is peeled off and the adhesive 526 is simultaneously cured by ultraviolet irradiation. it can.

Then, as shown in FIG. 5B, the protective layer 521 is removed. Here, since a water-soluble resin is used for the protective layer 521, it is dissolved in water and removed. In the case where the protective layer 521 remains causes a failure, it is preferable to perform a cleaning process or an O ₂ plasma process on the surface after removal to remove a part of the remaining protective layer 521.

  Note that in this embodiment mode, tungsten is used for the metal film 501, but the metal film is not limited to this material in the present invention. Any metal-containing material may be used as long as a metal oxide film 503 is formed on the surface and the substrate can be peeled off by crystallizing the metal oxide film 503. For example, in addition to tungsten, TiN, WN, Mo, or the like can be used. Further, when these alloys are used as metal films, the optimum temperature for the heat treatment during crystallization differs depending on the composition ratio. Therefore, by adjusting the composition ratio, heat treatment can be performed at a temperature that does not interfere with the manufacturing process of the semiconductor element, and options for the process of the semiconductor element are not easily limited.

  Next, a liquid crystal cell is produced as shown in FIG.

  After the protective layer 521 is removed, a counter substrate 542 that is separately formed is attached using a sealant 543. A filler may be mixed in the sealing material. The counter substrate 542 has a thickness of about several hundred μm, and is formed with a counter electrode 543 made of a transparent conductive film and an alignment film 544 that has been subjected to rubbing treatment. In addition to these, a color filter or a black matrix (shielding film) for preventing disclination may be formed. Further, the second polarizing plate 545 is attached to a surface opposite to the surface where the counter electrode 543 of the counter substrate 542 is formed.

  Then, liquid crystal 546 is injected and sealed, and the panel 550 is completed. The liquid crystal may be injected by a dispenser type or a dip type. In order to secure a cell gap, a spacer may be provided between the pixel electrode 540 and the counter electrode 543. The terminal 518 and the wiring 530 provided on the element substrate 534 are electrically connected using a wire bonding method or the like, whereby the liquid crystal display device is completed.

  Next, a method for manufacturing the liquid crystal display device of the present invention, which is different from the method shown in FIGS. Note that although a TFT is shown as an example of the semiconductor element, the semiconductor element included in the thin film circuit and the panel is not limited to this, and any circuit element can be used. For example, in addition to the TFT, a memory element, a diode, a photoelectric conversion element, a resistance element, a coil, a capacitor element, an inductor, and the like can be typically given.

  First, as illustrated in FIG. 7A, a metal film 1501 is formed over the first substrate 1500 by a sputtering method. Here, tungsten is used for the metal film 1501, and the film thickness is 10 nm to 200 nm, preferably 50 nm to 75 nm. Note that in this embodiment mode, the metal film 1501 is directly formed over the first substrate 1500; however, the metal film is covered after the first substrate 1500 is covered with an insulating film such as silicon oxide, silicon nitride, or silicon nitride oxide. The film 1501 may be formed.

After the metal film 1501 is formed, an oxide film 1502 that forms an insulating film is formed so as to be stacked without being exposed to the air. Here, a silicon oxide film is formed as the oxide film 1502 so as to have a thickness of 150 to 300 nm. Note that in the case of using a sputtering method, film formation is also performed on an end surface of the first substrate 1500. Therefore, in order to prevent the oxide film 1502 from remaining on the first substrate 1500 side at the time of peeling in a later process, the metal film 1501 and the oxide film 1502 formed on the end surface are subjected to O ₂ ashing. It is preferable to remove selectively.

Further, when the oxide film 1502 is formed, pre-sputtering is performed in which plasma is generated by blocking the target and the substrate with a shutter as a preliminary stage of sputtering. Pre-sputtering is performed with Ar at a flow rate of 10 sccm and O ₂ at a flow rate of 30 sccm, the temperature of the first substrate 1500 being 270 ° C., and the deposition power being 3 kW in a parallel state. By pre-sputtering, a very thin metal oxide film 1503 having a thickness of several nm (here, 3 nm) is formed between the metal film 1501 and the oxide film 1502. The metal oxide film 1503 is formed by oxidizing the surface of the metal film 1501. Therefore, in this embodiment, the metal oxide film 1503 is formed using tungsten oxide.

  Note that although the metal oxide film 1503 is formed by pre-sputtering in this embodiment mode, the present invention is not limited to this. For example, oxygen or an inert gas such as Ar may be added to oxygen, and the surface of the metal film 1501 may be intentionally oxidized by plasma to form the metal oxide film 1503.

  Next, after an oxide film 1502 is formed, a base film 1504 that forms an insulating film is formed by a PCVD method. Here, as the base film 1504, a silicon oxynitride film is formed to a thickness of about 100 nm. After the base film 1504 is formed, the semiconductor film 1505 is formed without being exposed to the air. The thickness of the semiconductor film 1505 is 25 to 100 nm (preferably 30 to 60 nm). Note that the semiconductor film 1505 may be an amorphous semiconductor or a polycrystalline semiconductor. As the semiconductor, not only silicon but also silicon germanium can be used. When silicon germanium is used, the concentration of germanium is preferably about 0.01 to 4.5 atomic%.

  Next, the semiconductor film 1505 is crystallized by a known technique. Known crystallization methods include a thermal crystallization method using an electric furnace, a laser crystallization method using laser light, and a lamp annealing crystallization method using infrared light. Alternatively, a crystallization method using a catalytic element can be used according to the technique disclosed in Japanese Patent Application Laid-Open No. 7-130552.

  In this embodiment mode, the semiconductor film 1505 is crystallized by laser crystallization. Prior to laser crystallization, thermal annealing at 500 ° C. for 1 hour is performed on the semiconductor film in order to increase the resistance of the semiconductor film to the laser. In this embodiment mode, this heat treatment increases the brittleness of the metal oxide film 1503 and facilitates subsequent peeling of the first substrate 1500. By crystallization, the metal oxide film 1503 is easily broken at the grain boundary, and brittleness can be increased. In this embodiment mode, the metal oxide film 1503 is preferably crystallized by heat treatment at 420 ° C. to 550 ° C. for about 0.5 to 5 hours.

By using a solid-state laser capable of continuous oscillation and irradiating laser light of the second harmonic to the fourth harmonic of the fundamental wave, a crystal having a large grain size can be obtained. For example, typically, it is desirable to use the second harmonic (532 nm) or the third harmonic (355 nm) of an Nd: YVO ₄ laser (fundamental wave 1064 nm). Specifically, laser light emitted from a continuous wave YVO ₄ laser is converted into a harmonic by a non-linear optical element to obtain laser light with an output of 10 W. There is also a method of emitting harmonics using a nonlinear optical element. Then, it is preferably formed into a rectangular or elliptical laser beam on the irradiation surface by an optical system, and the semiconductor film 1505 is irradiated. At this time, the energy density of approximately 0.01 to 100 MW / cm ² (preferably 0.1 to 10 MW / cm ²⁾ is required. Then, irradiation is performed at a scanning speed of about 10 to 2000 cm / s.

  Laser crystallization may be performed by irradiating a continuous wave fundamental laser beam and a continuous wave harmonic laser beam, or a continuous wave fundamental laser beam and a pulsed harmonic laser beam. You may make it irradiate with light.

  Note that laser light may be irradiated in an inert gas atmosphere such as a rare gas or nitrogen. Thereby, roughness of the semiconductor surface due to laser light irradiation can be suppressed, and variation in threshold value caused by variation in interface state density can be suppressed.

  Crystallinity is further improved by irradiation of the semiconductor film 1505 with the laser light described above. Note that the semiconductor film 1505 that is a polycrystalline semiconductor film may be formed in advance by a sputtering method, a plasma CVD method, a thermal CVD method, or the like.

Next, as illustrated in FIG. 7B, the semiconductor film 1505 is patterned to form island-shaped semiconductor films 1507 and 1508, and various islands such as TFTs are formed using the island-shaped semiconductor films 1507 and 1508. A semiconductor element is formed. Note that in this embodiment, the base film 1504 and the island-shaped semiconductor films 1507 and 1508 are in contact with each other; however, depending on the semiconductor element, an electrode or an electrode may be provided between the base film 1504 and the island-shaped semiconductor films 1507 and 1508. An insulating film or the like may be formed. For example, in the case of a bottom-gate TFT which is one of semiconductor elements, a gate electrode and a gate insulating film are formed between a base film 1504 and island-shaped semiconductor films 1507 and 1508.

  In this embodiment mode, top-gate TFTs 1509 and 1510 are formed using island-shaped semiconductor films 1507 and 1508 (FIG. 7C). Specifically, a gate insulating film 1511 is formed so as to cover the island-shaped semiconductor films 1507 and 1508. Then, a conductive film is formed over the gate insulating film 1511 and patterned to form gate electrodes 1512 and 1513. Then, an impurity imparting n-type is added to the island-shaped semiconductor films 1507 and 1508 using the gate electrodes 1512 and 1513 or a resist film formed and patterned as a mask, and the source region, drain region, and further LDD regions and the like are formed. Note that both TFTs 1509 and 1510 are n-type here, but in the case of a p-type TFT, an impurity imparting p-type conductivity is added.

  The TFTs 1509 and 1510 can be formed through the above series of steps. Note that a method for manufacturing a TFT is not limited to the above-described steps.

  Next, a first interlayer insulating film 1514 is formed so as to cover the TFTs 1509 and 1510. Then, after forming contact holes in the gate insulating film 1511 and the first interlayer insulating film 1514, terminals 1515 to 1518 connected to the TFTs 1509 and 1510 through the contact holes are in contact with the first interlayer insulating film 1514. Form.

  A TFT 1510 used as a switching element in the pixel portion of the liquid crystal display device is electrically connected to a terminal 1518. Next, a pixel electrode 1550 of a liquid crystal cell is formed so as to be in contact with the terminal 1518 using a transparent conductive film such as ITO. Then, a spacer 1519 using an insulating film is formed. Next, an alignment film 1520 is formed so as to cover the pixel electrode 1550, the terminal 1518, and the spacer 1519, and a rubbing process is performed. Note that the alignment film 1520 may be formed so as to overlap with the thin film circuit.

  Next, a sealing material 1521 for sealing the liquid crystal is formed. Then, as shown in FIG. 8A, liquid crystal 1522 is dropped in a region surrounded by the sealant 1521. Then, a counter substrate 1523 which is separately formed is attached using a sealant 1521. FIG. 8B illustrates a state after the counter substrate 1523 is attached. A filler may be mixed in the sealing material 1521. The counter substrate 1523 has a thickness of about several hundred μm, and a counter electrode 1524 made of a transparent conductive film and an alignment film 1526 subjected to rubbing treatment are formed. In addition to these, a color filter, a shielding film for preventing disclination, and the like may be formed. Further, the polarizing plate 1527 is attached to the surface opposite to the surface where the counter electrode 1524 of the counter substrate 1523 is formed.

  A portion where the counter electrode 1524, the liquid crystal 1522, and the pixel electrode 1550 overlap corresponds to the liquid crystal cell 1528. When the liquid crystal cell 1528 is completed, the panel 1529 is completed. Note that although the thin film circuit 1530 and the counter substrate 1523 are not stacked in this embodiment mode, the counter substrate 1523 and the thin film circuit 1530 may be stacked. In that case, in order to increase the mechanical strength of the liquid crystal display device, an insulating resin may be filled between the counter substrate and the thin film circuit.

  In the present embodiment, liquid crystal is sealed using a dispenser type (dropping type), but the present invention is not limited to this. A dip type (pumping type) in which liquid crystal is sealed using a capillary phenomenon after the counter substrate is bonded may be used.

  Next, as shown in FIG. 9A, a protective layer 1531 is formed to cover the thin film circuit 1530 and the panel 1529. The protective layer 1531 can protect the thin film circuit 1530 and the panel 1529 when the second substrate 1533 is attached or peeled later, and can be removed after the second substrate 1533 is peeled off. Use materials. For example, the protective layer 1531 can be formed by applying an epoxy-based, acrylate-based, or silicon-based resin soluble in water or alcohols over the entire surface.

  In this embodiment, a water-soluble resin (manufactured by Toagosei Co., Ltd .: VL-WSHL10) is applied by spin coating so as to have a film thickness of 30 μm. The protective layer 1531 is formed by performing exposure for 2.5 minutes and 10 minutes from the surface for a total of 12.5 minutes.

In addition, when laminating | stacking several organic resin, there exists a possibility that it may melt | dissolve partially at the time of application | coating or baking with the solvent currently used between organic resins, or adhesiveness may become high too much. Therefore, when both the first interlayer insulating film 1514 and the protective layer 1531 are made of an organic resin that is soluble in the same solvent, the first interlayer insulating film is removed so that the protective layer 1531 can be removed smoothly in the subsequent process. An inorganic insulating film (SiN _x film, SiN _x O _y film, AlN _x film, or AlN _x O _y film) is preferably formed so as to cover 1514.

  Next, treatment for partially reducing the adhesion between the metal oxide film 1503 and the oxide film 1502 or the adhesion between the metal oxide film 1503 and the metal film 1501 to form a part that triggers peeling. To do. Specifically, pressure is locally applied from the outside along the periphery of the region to be peeled to damage a part of the metal oxide film 1503 or a part near the interface. In this embodiment mode, a hard needle such as a diamond pen is pressed vertically near the end portion of the metal oxide film 1503 and moved along the metal oxide film 1503 with a load applied as it is. Preferably, a scriber device is used, the pushing amount is 0.1 mm to 2 mm, and the pressure is applied. In this way, by forming a portion with reduced adhesion that triggers the start of peeling before peeling, defects in the subsequent peeling step can be reduced, leading to improved yield. .

  Next, the second substrate 1533 is attached to the protective layer 1531 using the double-sided tape 1532, and the third substrate 1535 is attached to the first substrate 1500 using the double-sided tape 1534. Note that an adhesive may be used instead of the double-sided tape. For example, by using an adhesive that is peeled off by ultraviolet rays, the burden on the semiconductor element when the second substrate 1533 is peeled can be reduced. The third substrate 1535 is bonded to prevent the first substrate 1500 from being damaged in a later peeling step. As the second substrate 1533 and the third substrate 1535, it is preferable to use a substrate having higher rigidity than the first substrate 1500, such as a quartz substrate or a semiconductor substrate.

  Next, the metal film 1501 and the oxide film 1502 are physically peeled off. The peeling starts from a region where the adhesion of the metal oxide film 1503 to the metal film 1501 or the oxide film 1502 is partially lowered in the previous step.

  A portion separated between the metal film 1501 and the metal oxide film 1503, a portion separated between the oxide film 1502 and the metal oxide film 1503, and a portion where the metal oxide film 1503 itself is separated into both by peeling. Arise. Then, the semiconductor elements (here, TFTs 1509 and 1510) are separated from the second substrate 1533 side, and the first substrate 1500 and the metal film 1501 are separated from each other while being adhered to the third substrate 1535 side. The peeling can be performed with a relatively small force (for example, a human force, a wind pressure of a gas blown from a nozzle, an ultrasonic wave, etc.). The state after peeling is shown in FIG.

  Next, the element substrate 1540 is bonded to the oxide layer 1502 to which the metal oxide film 1503 is partially attached with an adhesive 1539 (FIG. 10). At the time of bonding, the adhesive force between the oxide layer 1502 and the element substrate 1540 by the adhesive 1539 is higher than the adhesive force between the second substrate 1533 and the protective layer 1531 by the double-sided tape 1532. As such, it is important to select the material of the adhesive 1539.

  Examples of the adhesive 1539 include various curable adhesives such as a reactive curable adhesive, a thermosetting adhesive, a photocurable adhesive such as an ultraviolet curable adhesive, and an anaerobic adhesive. More preferably, the adhesive 1539 is also provided with high thermal conductivity by including powder or filler made of silver, nickel, aluminum, aluminum nitride.

  Note that if the metal oxide film 1503 remains on the surface of the oxide film 1502, the adhesion to the element substrate 1540 may be deteriorated. Therefore, the metal oxide film 1503 is completely removed by etching or the like and then adhered to the printed wiring board. The adhesion may be improved.

  Next, as shown in FIG. 10, the double-sided tape 1532 and the second substrate 1533 are sequentially or simultaneously peeled from the protective layer 1531. Note that an ultraviolet curable adhesive is used as the adhesive 1539 and a tape or an adhesive that is peeled off by ultraviolet rays is used for the double-sided tape 1532, so that the double-sided tape 1532 is peeled off and the adhesive 1539 is simultaneously cured by ultraviolet irradiation. it can.

Then, as shown in FIG. 11A, the protective layer 1531 is removed. Here, since a water-soluble resin is used for the protective layer 1531, it is dissolved in water and removed. If the remaining protective layer 1531 causes a failure, it is preferable to perform a cleaning process or an O ₂ plasma process on the surface after removal to remove a part of the remaining protective layer 1531.

  Next, the terminal 1518 and the wiring 1551 provided on the element substrate 1540 are electrically connected by the wiring 1552 using a wire bonding method, whereby the liquid crystal display device is completed. The wiring 1551 can be formed, for example, by plating copper, solder, gold, or tin. Note that the timing at which the terminal 1518 and the wiring 1551 are connected is not limited thereto.

  In this state, the liquid crystal display device may be completed; however, in this embodiment, the liquid crystal display device is further sealed with a sealing material to increase mechanical strength.

  As shown in FIG. 11B, the thin film circuit 1530 and the panel 1529 are covered with a resin 1542, and a cover material 1543 for protecting the thin film circuit 1530 and the panel 1529 is provided. The cover material 1543 is not necessarily provided, and the element substrate 1540 may be sealed with a sealing material as it is.

Liquid crystal display materials commonly used can be used for sealing devices, such as polyester, acrylic acid, polyvinyl acetate, propylene, vinyl chloride, acrylonitrile butadiene styrene resins, high such ports triethylene terephthalate Molecular materials can be used. Note that at the time of sealing, the material of the resin 1542 and the cover material 1543 is appropriately selected so that the pixel portion of the liquid crystal display device is exposed or light from the pixel portion is transmitted.

  Sealing with a sealing material increases the mechanical strength of the liquid crystal display device, dissipates heat generated from the liquid crystal display device, or blocks electromagnetic noise from adjacent circuits from the outside of the liquid crystal display device. can do.

  Note that a plastic substrate can be used as the element substrate 1540, the cover material 1543, and the counter substrate 1523. As the plastic substrate, ARTON: JSR made of norbornene resin with a polar group can be used. Polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), nylon, polyetheretherketone (PEEK), polysulfone (PSF), polyetherimide (PEI), poly A plastic substrate such as arylate (PAR), polybutylene terephthalate (PBT), or polyimide can be used. The element substrate 1540 preferably has a high thermal conductivity of about 2 to 30 W / mK in order to diffuse the heat generated in the liquid crystal display device.

  Note that although tungsten is used for the metal film 1501 in this embodiment, the metal film is not limited to this material in the present invention. Any metal-containing material may be used as long as a metal oxide film 1503 is formed on the surface and the metal oxide film 1503 is crystallized so that the substrate can be peeled off. For example, in addition to tungsten, TiN, WN, Mo, or the like can be used. Further, when these alloys are used as metal films, the optimum temperature for the heat treatment during crystallization differs depending on the composition ratio. Therefore, by adjusting the composition ratio, heat treatment can be performed at a temperature that does not interfere with the manufacturing process of the semiconductor element, and options for the process of the semiconductor element are not easily limited.

  Note that the semiconductor element used for the LED driving thin film circuit can also be manufactured with reference to the above-described method for manufacturing a semiconductor element.

  Note that the material of the resin covering the light emitting diode is preferably selected as appropriate in accordance with the first substrate, the second substrate, and the adhesive curing method.

  Next, an example in which the wiring formed on the element substrate and the thin film circuit or the LED driving thin film circuit are electrically connected using the flip chip method instead of the wire bonding method will be described.

  FIG. 12A is a cross-sectional view of a thin film circuit provided with solder balls or a thin film circuit for LED driving.

  In FIG. 12A, the semiconductor element 301 and the wiring on the element substrate are electrically connected by a solder ball 302. The solder ball 302 is provided on the element substrate side of the semiconductor element 301 and is connected to an electrode 303 that is electrically connected to the semiconductor element 301. When the semiconductor element 301 is a TFT, the electrode 303 may be formed of the same conductive film as the gate electrode of the TFT.

  Next, FIG. 12B is a cross-sectional view of a thin film circuit or an LED driving thin film circuit in which semiconductor elements are stacked using a flip chip method. In FIG. 12B, semiconductor elements 310 and 311 formed in two layers are stacked. The wiring formed on the element substrate is electrically connected to the semiconductor element 310 by using a solder ball 312. In addition, electrical connection between the semiconductor element 311 and the semiconductor element 310 is performed using a solder ball 313.

  Next, FIG. 12C shows an example in which wiring formed on the element substrate and a solder ball are connected so that the direction of the semiconductor element is opposite to that in the case of FIG. In FIG. 12C, the solder ball 322 is formed so as to be connected to the wiring 321 directly connected to the semiconductor element 320.

  In the case of the flip chip method, even if the number of wirings to be connected is increased, a relatively wide pitch between the wirings can be secured as compared with the wire bonding method. This is effective when the number of wiring connections is large.

  For the connection between the solder ball and the wiring on the element substrate, various methods such as thermocompression bonding and thermocompression bonding with vibration by ultrasonic waves can be used. Note that the underfill may fill the gaps between the solder balls after the pressure bonding so as to increase the mechanical strength of the connecting portion and the efficiency of diffusion of heat generated in the thin film circuit. The underfill is not necessarily used, but connection failure can be prevented from occurring due to a stress caused by a mismatch between the thermal expansion coefficients of the element substrate and the semiconductor element. When crimping by applying ultrasonic waves, poor connection can be suppressed as compared to the case of simply thermocompression bonding. This is particularly effective when there are more than 300 bumps to be connected.

  By combining FIGS. 12A to 12C, the wiring formed on the element substrate and the thin film circuit or the LED driving thin film circuit can be electrically connected in various forms. It is also possible to connect by combining the flip chip method and the wire bonding method.

  Note that although an active matrix liquid crystal display device has been described in this embodiment mode, the present invention may be a passive matrix liquid crystal display device.

  According to the present invention, the liquid crystal display device can be remarkably thinned and reduced in weight without losing mechanical strength. By using the liquid crystal display device of the present invention for an electronic device, a wider space can be secured for the IC, and higher functionality can be realized without hindering weight reduction or miniaturization of the electronic device. In particular, in the case of a portable electronic device, it is very useful to use the liquid crystal display device of the present invention because the usability is greatly improved by reducing the weight and size. On the contrary, in the present invention, even if the size of the pixel portion of the liquid crystal display device is made larger, the weight can be almost the same as that of a liquid crystal display device using a conventional glass substrate.

  In this embodiment, a case where the liquid crystal display device of the present invention is used for a card typified by an electronic card will be described.

  The configuration of the electronic card of this embodiment will be described with reference to FIG. FIG. 13A shows a cross-sectional view of the element substrate 401 at the time when the panel is completed. 13B corresponds to a top view of the element substrate illustrated in FIG. 13A, and a cross-sectional view taken along line A-A ′ in FIG. 13B corresponds to FIG.

  An element substrate 401 illustrated in FIGS. 13A and 13B includes a recess 402, and one or more LEDs 403 are provided in the recess 402. The concave portion 402 is provided with an LED driving thin film circuit 404, and both the LED 403 and the LED driving thin film circuit 404 are covered with a resin 407.

  Reference numeral 415 denotes a panel, and reference numeral 411 denotes a thin film circuit, both of which are separately formed and bonded onto the element substrate 401. The thin film circuit 411 has an antenna coil 406. A wiring 405 formed on the element substrate 401 is electrically connected to the antenna coil 406.

  FIG. 13C is a cross-sectional view of the liquid crystal display device of the present invention at the time when the electronic card is completed. 13D corresponds to a top view of the liquid crystal display device in the state illustrated in FIG. 13C, and a cross-sectional view taken along line B-B ′ in FIG. 13D corresponds to FIG.

  In the electronic card shown in FIGS. 13C and 13D, a panel 415 and a thin film circuit 411 formed over the element substrate 401 are covered with a cover material 420 so as to be sealed with a resin 422. In this embodiment, light from the panel 415 is transmitted through a portion 421 of the cover material 420 that overlaps the panel 415. Note that the present invention is not limited to this, and the cover material may be formed of a material that allows light to pass through portions other than the panel.

  Note that in this embodiment mode, the structure of an electronic card that can supply a signal and a power supply voltage by electromagnetic induction using an antenna coil has been described. It may be an electronic card that supplies the card. The electronic card is not limited to a non-contact type, and may be a contact type electronic card that directly exchanges signals with a terminal device via a terminal.

  Electronic cards are used for various purposes such as cash cards, credit cards, prepaid cards, ID cards that can be used as identification cards, and commuter passes. By mounting the liquid crystal display device of the present invention, it is possible to display data in the electronic card on the pixel portion, and it is possible to increase the certainty of personal authentication by displaying a face photograph. If a face photograph is used instead of an ID photograph, it is considered that a resolution of at least about QVGA (320 × 240) is necessary.

  FIG. 14 illustrates a method for manufacturing a plurality of liquid crystal display devices from a large element substrate.

  As shown in FIG. 14A, when a large element substrate 601 is used, a plurality of recesses 603 are provided in an area 602 corresponding to each liquid crystal display device. An LED 604 is provided in each recess 603. Then, after providing wirings electrically connected to the LED 604, LED driving thin film circuits, reflective films, etc. (all not shown), each recess 603 is filled with resin 605 as shown in FIG. 14B. To do.

  A plurality of liquid crystal display devices can be manufactured from one element substrate by forming a panel or a thin film circuit and dicing in accordance with the method shown in the embodiment mode. The dicing timing can be performed in any step before or after the panel or thin film circuit is formed.

  In this embodiment, an example in which an LED is connected to a flexible printed circuit board (FPC) and the FPC is connected to a wiring on the element substrate, instead of directly connecting the LED to the wiring provided on the element substrate. .

  FIG. 15A shows a top view of an FPC to which an LED is connected. The LED 701 is connected to a lead 702 sandwiched between plastic films 703. The terminal 704 connected to the lead 702 is not covered with the plastic film 703 and is exposed.

  FIG. 15B illustrates a state where the LED 701 illustrated in FIG. 15A is attached to the recess 705 included in the element substrate 706. FIG. 15C illustrates a back surface of the element substrate 706 illustrated in FIG.

  In the element substrate 706, wiring 707 is provided on the back surface of the surface provided with the recess 705. The LED 701 provided in the recess 705 and the wiring 707 are electrically connected by a lead 702.

  A recess 710 is provided on the surface of the element substrate 706 where the wiring 707 is provided. In consideration of the strength of the element substrate 706, it is preferable that the regions where the recesses 705 and 710 are provided do not overlap each other. The recess 710 is provided with a solar cell 708 and a drive circuit 709 for controlling driving of the solar cell 708, and the wiring 707 is electrically connected to the drive circuit 709.

  Thus, by using FPC, it becomes easy to electrically connect elements formed on both surfaces of the element substrate to each other. Therefore, the element substrate can be utilized without waste.

  FIG. 15D shows a cross-sectional view of the recess 705 along the broken line A-A ′. A metal reflection film 711 is formed on the surface of the recess 705. In this embodiment, the reflective film 711 is corroded or sandblasted to polish the surface with gold sand or the like, so that light is diffusely reflected by providing fine irregularities on the surface, and the light from the LED is made uniform. Irradiation to the pixel portion can be facilitated.

  In this embodiment, a method for forming an element substrate having a recess will be described.

  FIG. 16A illustrates two plastic substrates 801 each having an opening 803 and two flat plastic substrates 802. By bonding the plastic substrates 801 and 802, an element substrate 805 having a recess 804 is formed in a region where the opening 803 overlaps the flat plastic substrate 802.

  In this embodiment, an example in which an area sensor is provided on an electronic card using the liquid crystal display device of the present invention will be described.

  FIG. 17A shows a diagram in which a finger is pressed against the pixel portion 910 that functions not only as an image display but also as an area sensor. FIG. 17B is a cross-sectional view of the pixel portion 910 illustrated in FIG.

  As shown in FIG. 17B, the element substrate 901 is provided with a recess 905, and a reflective film 902 is provided on the surface of the recess 905. The recess 905 is provided with an LED 903, and the LED 903 is covered with a resin 904.

  On the element substrate 901, a TFT 906 for applying a voltage to the liquid crystal 907 and a photodiode 908 are provided. The TFT 906 and the photodiode 908 are separately formed on different substrates, then peeled off and bonded to the element substrate 901.

  Then, the light emitted from the LED 903 is reflected by the finger 911 that is a subject, and is applied to the photodiode 908, whereby image data of the finger 911 can be acquired.

  The liquid crystal display device of the present invention can be used for various electronic devices. However, in the case of portable electronic devices in particular, the liquid crystal display device of the present invention is greatly improved in terms of weight and size. It is very useful to use a display device.

  FIG. 18A shows a sheet-type mobile phone, which includes a main body 2101, a display portion 2103, an audio input portion 2104, an audio output portion 2105, a switch 2106, an external connection port 2107, and the like. A separately prepared earphone 2108 can be connected through the external connection port 2107. A touch panel type liquid crystal display device of the present invention is used for the display portion 2103, and a series of operations can be performed by touching a touch panel type operation key 2109 displayed on the display portion 2103. it can. The thin film circuit included in the liquid crystal display device of the present invention can be used as various signal processing circuits provided in the main body 2101.

  FIG. 18B shows an electronic book, which includes a main body 2201, a display portion 2202, operation keys 2203, and the like. A modem may be built in the main body 2201. The display portion 2202 uses the liquid crystal display device of the present invention. The thin film circuit of the liquid crystal display device of the present invention can be used as various signal processing circuits.

  FIG. 18C shows a wristwatch, which includes a main body 2301, a display portion 2302, a fastener 2303, and the like. The display portion 2302 uses the liquid crystal display device of the present invention. The thin film circuit of the liquid crystal display device of the present invention can be used as various signal processing circuits provided in the main body 2301.

  FIG. 18D shows a sheet-type personal computer, which includes a main body 2401, a display portion 2402, a touch panel keyboard 2403, a mouse 2404, an external connection port 2405, a power plug 2406, and the like. The liquid crystal display device of the present invention is used for the display portion 2402. Further, the touch panel keyboard 2403 and the mouse 2404 use the touch panel type liquid crystal display device of the present invention provided with a sensor, and a series of operations can be performed by touching the touch panel keyboard 2403 and the mouse 2404. Can do. The thin film circuit of the liquid crystal display device of the present invention can be used as various signal processing circuits.

  FIG. 18E corresponds to a windshield viewed from the inside of a car. A liquid crystal display device 2503 of the present invention is attached to the windshield 2501, and various information required by the driver can be displayed on the display portion 2502. Although FIG. 18E illustrates an example in which the liquid crystal display device of the present invention is attached to the windshield, the liquid crystal display device may be attached to a window glass disposed on the side or back of the driver's seat. In addition to the window glass, it can be attached regardless of the inside or outside of the automobile.

  FIG. 18F illustrates an electronic card, which includes a main body 2601, a display portion 2602, a connection terminal 2603, and the like. The pixel portion of the liquid crystal display device of the present invention can be used as the display portion 2602. Further, the thin film circuit of the liquid crystal display device of the present invention can be used as various signal processing circuits provided in the main body 2601.

  As described above, the applicable range of the present invention is so wide that it can be used for electronic devices in various fields. Further, the electronic apparatus of this embodiment may use the liquid crystal display device having any configuration shown in Embodiments 1 to 5.

  In this example, a result of TEM observation of a cross section on the first substrate side and the insulating film side after peeling is shown.

  On a glass substrate, a W film is deposited by sputtering to a thickness of 50 nm, a silicon oxide film by sputtering to a thickness of 200 nm, a silicon oxynitride film by plasma CVD to a thickness of 100 nm, and an amorphous silicon film as a semiconductor film being deposited by plasma CVD to a thickness of 50 nm. Formed. Thereafter, heat treatment was performed at 500 ° C. for 1 hour and 550 ° C. for 4 hours, and the film was peeled off by physical means such as polytetrafluoroethylene tape. FIG. 19 shows a TEM photograph of the W film and oxide layer on the substrate side, and FIG. 20 shows a TEM photograph of the oxide layer and silicon oxide film on the semiconductor film side.

  In FIG. 19, the metal oxide film remains unevenly in contact with the metal film. Similarly, also in FIG. 20, the metal oxide film remains unevenly in contact with the silicon oxide film. Both TEM photographs demonstrate that peeling was performed in the metal oxide film layer and at both interfaces, and that the metal oxide film is in close contact with the metal film and the silicon oxide film and remains unevenly.

    In other words, in the liquid crystal display device of the present invention, it is considered that the metal oxide film remains on the element substrate side of the insulating film with some adhesion.

  In this embodiment, a liquid crystal material used in the case where the first substrate is peeled after the liquid crystal display device is completed will be described.

  FIG. 21 shows a cross-sectional view of the liquid crystal display device of this example. In the liquid crystal display device illustrated in FIG. 21A, a columnar spacer 1401 is provided in a pixel, and the columnar spacer 1401 improves adhesion between the counter substrate 1402 and the element-side polarizing plate 1403. . Accordingly, it is possible to prevent the semiconductor element other than the region overlapping with the sealant from being left on the first substrate side when the first substrate is peeled off.

  FIG. 21B is a cross-sectional view of a liquid crystal display device using a nematic liquid crystal, a smectic liquid crystal, a ferroelectric liquid crystal, or PDLC (polymer dispersion type liquid crystal) containing them in a polymer resin. By using the PDLC 1404, the adhesion between the counter substrate 1402 and the polarizing plate 1403 on the element side is improved, and the semiconductor element other than the region overlapping with the sealant when the first substrate is peeled off is on the first substrate side. Can be prevented from remaining on the surface.

Sectional view of the liquid crystal display device of the present invention Sectional view of the liquid crystal display device of the present invention 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. 4A and 4B illustrate a method for manufacturing a liquid crystal display device of the present invention. Sectional drawing of the thin film circuit or the thin film circuit for LED drive. Sectional drawing of the electronic card using the liquid crystal display device of this invention. The perspective view of a large sized element substrate. The figure which shows a mode that LED using FPC and this LED were affixed on the element substrate. The figure which shows the structure of an element substrate. The perspective view and sectional drawing of an electronic card with a sensor. FIG. 11 is a diagram of an electronic device using the liquid crystal display device of the present invention. The TEM cross-sectional image of the metal oxide film before peeling. The TEM cross-sectional image of the insulating film after peeling. Sectional drawing of the liquid crystal display device of this invention.

Claims (12)

A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
The second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element interposed therebetween,
The metal oxide film is crystallized by applying heat treatment,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on a plastic substrate, and a resin is applied on the plastic substrate so as to cover the light emitting element.
Using the second adhesive, the semiconductor element is bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin,
A method for manufacturing a liquid crystal display device, comprising: forming a liquid crystal cell after removing the second substrate by removing the first adhesive. A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
The second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element interposed therebetween,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on a plastic substrate, and a resin is applied on the plastic substrate so as to cover the light emitting element.
Using the second adhesive, the semiconductor element is bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin,
After removing the second substrate by removing the first adhesive, a liquid crystal cell is formed,
A method for manufacturing a liquid crystal display device, wherein the metal oxide film is crystallized by a heat treatment performed when the semiconductor element is formed. A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
The second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element interposed therebetween,
The metal oxide film is crystallized by applying heat treatment,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on the concave portion of the plastic substrate having the concave portion, and a resin is applied to the concave portion so as to cover the light emitting element,
Using the second adhesive, the semiconductor element is bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin,
A method for manufacturing a liquid crystal display device, comprising: forming a liquid crystal cell after removing the second substrate by removing the first adhesive. A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
The second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element interposed therebetween,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on the concave portion of the plastic substrate having the concave portion, and a resin is applied to the concave portion so as to cover the light emitting element,
Using the second adhesive, the semiconductor element is bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin,
After removing the second substrate by removing the first adhesive, a liquid crystal cell is formed,
A method for manufacturing a liquid crystal display device, wherein the metal oxide film is crystallized by a heat treatment performed when the semiconductor element is formed. A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
Forming a liquid crystal cell ,
A second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element and the liquid crystal cell in between.
The metal oxide film is crystallized by applying heat treatment,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on a plastic substrate, and a resin is applied on the plastic substrate so as to cover the light emitting element.
Using the second adhesive, the semiconductor element and the liquid crystal cell are bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin.
A method for manufacturing a liquid crystal display device, wherein the second substrate is removed by removing the first adhesive. A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
Forming a liquid crystal cell ,
A second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element and the liquid crystal cell interposed therebetween,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on a plastic substrate, and a resin is applied on the plastic substrate so as to cover the light emitting element.
Using the second adhesive, the semiconductor element and the liquid crystal cell are bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin.
Removing the second substrate by removing the first adhesive;
A method for manufacturing a liquid crystal display device, wherein the metal oxide film is crystallized by a heat treatment performed when the semiconductor element is formed. A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
Forming a liquid crystal cell ,
A second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element and the liquid crystal cell interposed therebetween,
The metal oxide film is crystallized by applying heat treatment,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on the concave portion of the plastic substrate having the concave portion, and a resin is applied to the concave portion so as to cover the light emitting element,
Using the second adhesive, the semiconductor element and the liquid crystal cell are bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin.
A method for manufacturing a liquid crystal display device, wherein the second substrate is removed by removing the first adhesive. A metal film, a metal oxide film, an insulating film, and a semiconductor film are sequentially stacked on one surface of the first substrate,
A semiconductor element is formed using the semiconductor film,
Forming a liquid crystal cell ,
A second substrate is bonded using a first adhesive so as to face the first substrate with the semiconductor element and the liquid crystal cell interposed therebetween,
By separating the metal oxide film into the metal film side and the insulating film side, the first substrate is removed,
A light emitting element is disposed on the concave portion of the plastic substrate having the concave portion, and a resin is applied to the concave portion so as to cover the light emitting element,
Using the second adhesive, the semiconductor element and the liquid crystal cell are bonded to the plastic substrate by adhering the insulating film with a part of the metal oxide film adhered to the resin.
Removing the second substrate by removing the first adhesive;
A method for manufacturing a liquid crystal display device, wherein the metal oxide film is crystallized by a heat treatment performed when the semiconductor element is formed. In any one of Claims 1 thru | or 8 ,
The method for manufacturing a liquid crystal display device before Symbol liquid crystal cell, which is a transmissive type. In any one of Claims 1 thru | or 9 ,
A method for manufacturing a liquid crystal display device, wherein the light-emitting element is a light-emitting diode. In claim 10 ,
The method for manufacturing a liquid crystal display device, wherein the light emitting diode is connected to an FPC, and current is supplied through the FPC. In any one of Claims 1 thru | or 11 ,
A method for manufacturing a liquid crystal display device, comprising using a nematic liquid crystal, a smectic liquid crystal, a ferroelectric liquid crystal, or a polymer dispersed liquid crystal in which the liquid crystal is contained in a polymer resin as the liquid crystal constituting the liquid crystal cell .