JP2001166301A - Liquid crystal display device with built-in back light and method of manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin liquid crystal display device having a thin film device and a surface light emitting type light source which are integrated with each other formed on a substrate having flexibility to impart deforming ability to the device. SOLUTION: A TFT part 14 is transferred to a third substrate 36 having flexibility and a back light part 16 including an EL element is formed on the rear surface of the substrate by a laminating method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be used for a thin film device with a built-in backlight, in which a thin film device is transferred between a plurality of substrates and a backlight is integrated, particularly for both a direct-view type and a projection type. The present invention relates to a liquid crystal display device, and further relates to a method for manufacturing the same.

[0002]

2. Description of the Related Art As a thin film device, for example, a liquid crystal display device uses a thin film transistor (TFT) as a driving circuit source. This liquid crystal display device includes a TFT on a substrate, and controls the optical rotation of liquid crystal molecules (liquid crystal display element) sealed between the substrate and the counter substrate by a voltage controlled by the TFT, and controls each pixel. The image is expressed by controlling the translucency of the image.

FIG. 15 shows a configuration of such a liquid crystal display device. The active matrix substrate 220 on which the thin film devices such as the active matrix 222 and / or the drive circuit 224 are formed, and the counter substrate 240 are separated by a sealing material (not shown) formed along the outer peripheral edge of the counter substrate 240. The layers are bonded via a predetermined gap, and a liquid crystal 230 is sealed in the gap.

A pixel electrode formed on the active matrix 222 and a transparent counter electrode formed on the counter substrate 240 are opposed to each other with the liquid crystal 230 interposed therebetween, and liquid crystal molecules are generated by an electric field applied between the pixel electrode and the counter electrode. Driven. An alignment film is formed on the surface of the active matrix 222 on the side in contact with the liquid crystal 230 and on the surface of the counter substrate 240 on the side in contact with the liquid crystal 230, and determines the alignment of the liquid crystal molecules in the absence of an electric field. .

[0005] Active matrix substrate 220, liquid crystal 2
The liquid crystal driving section composed of the liquid crystal driving section 30 and the counter substrate 240 further includes two polarizing plates 21 having polarization directions different from each other.
It is sandwiched between 0 and 250. The polarization directions of the polarizing plates 210 and 250 are aligned with the alignment directions of the alignment films formed on the respective surfaces of the active matrix substrate 220 and the counter substrate 240. In order to enable color display, a color filter and / or a black matrix are formed on the counter substrate 240.

As described above, the liquid crystal display device has a structure in which a large number of substrates are bonded to each other, and thus has a disadvantage that the thickness of the display device is increased. In particular, as shown in FIG. 15, the backlight 200 required for the transmission type liquid crystal display device causes an increase in the thickness of the liquid crystal display device.

On the other hand, a liquid crystal display device having the above-mentioned thin film device is formed on a lightweight and flexible (flexible) substrate material such as a plastic substrate to provide a novel liquid crystal display device having deformability. There is a growing demand for manufacturing. To achieve this, the heat resistance temperature of the plastic substrate (10
It is necessary to form a thin film device at a process temperature of 0 to 150 ° C. or lower. However, a decrease in the process temperature tends to cause a decrease in the characteristics of the thin film device, and it is difficult to manufacture a high performance thin film device. In order to cope with this, there has been proposed a method of transferring the thin film device onto a plastic substrate by a technique for transferring a thin film device formed on a glass substrate. As a transfer technique, for example, a method described in JP-A-10-125931 can be applied.

However, even if a thin-film device can be formed on a plastic substrate by the above-described configuration procedure, the thin-film device shown in FIG.
As shown in FIG. 5, in the transmissive liquid crystal display device, the backlight 200 is required, so that it was difficult to manufacture a liquid crystal display device as a whole having deformability.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thin film device with a built-in backlight and a method of manufacturing the thin film device in which a thin film device and a surface emitting light source are integrated. To provide. Another object of the present invention is to provide a thin film device with a built-in backlight which has flexibility. Another object of the present invention is to provide a thin film device with a built-in backlight, which can have deformability by forming a thin film device and a surface emitting light source on a flexible substrate.

[0010]

In order to achieve the above object, the present invention provides a thin film with a built-in backlight, in which a planar thin film light emitting type light source is laminated on the back surface of a flexible substrate on which a thin film element is transferred. Provide a device.

In order to obtain this thin-film device, after the thin-film element is transferred to a flexible substrate, the planar thin-film light-emitting light source is laminated on the back surface of the substrate, or this light source is laminated in advance. The thin film element is transferred to the opposite surface of the flexible substrate. As a thin film device, a liquid crystal display device having the above-described liquid crystal element is representative. The flexible substrate is a transparent (translucent) substrate. If the flexible substrate also serves as a polarizing plate, one of the polarizing plates can be omitted, and thus the device can be made thin. Further, a step for manufacturing a polarizing plate can be omitted. The method of manufacturing a thin film device with a built-in backlight according to the present invention comprises:
A first step of forming a release layer on the substrate, a second step of forming a thin film element divided for each pixel in order to form a matrix of pixels on the release layer, A third step of peeling off from the first substrate and transferring the thin film element on the second substrate, and a third step of providing a back surface of the thin film element transferred on the second substrate with at least a light-transmitting property. A fourth step of forming the substrate, a fifth step of peeling the thin film element from the second substrate, and a step of removing the thin film element from the second substrate. And a sixth step of forming a surface-emitting light source.

A method of peeling a thin film element formed on a first substrate via a peeling layer from the first substrate and transferring the thin film element onto an arbitrary substrate is described in, for example, Japanese Patent Application Laid-Open No. 10-125931.
It may be based on the method disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11-26095.

As the planar light source, electroluminescence (EL) which is an organic or inorganic electroluminescent element which can be formed by using a thin film manufacturing process and laminating a light emitting layer on a substrate is preferable. This electroluminescent device is a few μm
Since the respective films forming the electroluminescent element in the form of a thin film having a thickness of about several tens μm can be sequentially laminated, the electroluminescent element is formed as a surface emitting light source on the back surface of the substrate on which the thin film element has been transferred. This makes it possible to obtain a semiconductor device having excellent flexibility without increasing the thickness of the entire device. In addition, the organic electroluminescent device can be manufactured at a low temperature and with a simple process. The third substrate is made of a flexible material.
By making the third substrate flexible, the thin-film device has deformability, and can be developed into a curved surface without being restricted to a planar shape together with a surface-emitting light source as a backlight. A liquid crystal display device can be realized.

There are white or monochromatic light sources for the planar light source. In this case, by providing a color filter, liquid crystal color display becomes possible. The color filter is formed by laminating a color filter on the exposed surface of the thin-film device when the substrate-side surface is exposed in the process of transferring the thin-film element to the flexible substrate. Alternatively, an EL element may be used in which the surface light source is divided corresponding to the pixels formed in the thin film element, and emits light in a predetermined arrangement for each of RGB in each divided area.

According to the present invention, since a TFT can be formed by using a thin layer forming process, a switching element for each pixel and a drive circuit for the switching element can be formed on the same substrate.

[0016]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a conceptual diagram of a liquid crystal display device 10 with a built-in backlight according to the present embodiment.
The liquid crystal display device 10 is roughly divided into a liquid crystal display
, A thin film element (TFT) unit 14, and a backlight unit 16
And a substrate 17.

The liquid crystal display device is a so-called monochrome image display device in which only a gradation expression is performed by the liquid crystal display section 12. On the other hand, FIGS. 2 and 3 show a liquid crystal display device capable of displaying a color image. Apparatus 10 is shown.

FIG. 2 shows that a TFT is provided on the surface of the liquid crystal display unit 12.
A filter composed of a color filter 18 of each color (RGB) arranged in a matrix in accordance with a predetermined rule corresponding to each pixel formed in the portion 14 and a black matrix frame 20 provided so as to surround these. 5 shows a display device provided with a unit 22.

FIG. 3 shows an EL (electroluminescence) element as an organic or inorganic electroluminescent element applied as the backlight section 16, wherein a bank 24 is formed corresponding to each pixel of the TFT section 14, and each bank is formed. By providing components of each color (RGB) for every 24 pixels, the backlight unit 16 itself can emit light of each color of RGB.

The liquid crystal display device 10 shown in FIGS.
Since the basic structure does not change, a detailed configuration will be described in the following description using the color image liquid crystal display device 10 shown in FIG. 2 as an example.

FIG. 4 shows the detailed configuration of the liquid crystal display device 10 with a built-in backlight shown in FIG. In the liquid crystal display device 10, layers constituting the backlight unit 16, the TFT unit 14, and the liquid crystal display unit 12 are stacked with the support layer 25 of the backlight unit 16 being the lowermost layer.

At the product stage, the liquid crystal display device 10
The third substrate 25 serves as a basic support layer, and layers constituting the backlight section 16, the TFT section 14, and the liquid crystal display section 12 are laminated. It should be noted that, during the course of stacking the components on the third substrate, that is, at the manufacturing stage, the first
The substrate 100 and the second substrate 180 of FIG.
3 (see process drawing).

The backlight section 16 is provided with the electron transport layer 2.
8 and the hole transport layer 30 sandwich the EL layer 32. Further, on the upper layer of the hole transport layer 30,
An ITO layer 34 is provided. That is, the ITO layer 3
When an electric field (voltage) is applied between the electrode layer 4 and the base electrode layer 26, a current flows through the EL layer 32 to emit white or monochromatic light, thereby functioning as a backlight.

The direction of polarization of the light emitted from the EL layer 32 is determined by subjecting the surface to a rubbing process using a rubbing roller or the like. As a result, a pair of polarized light necessary for a liquid crystal display is obtained. By omitting one of the plates, the surface-emitting light source can be provided directly on the back surface of the thin-film device. The rubbing process is described in detail in, for example, IEICE technical report E1D95-106 (issued in 1995). These are unnecessary when the third substrate is a polarizing plate.

A transparent third substrate 36 is provided on the upper layer of the ITO layer 34, and the TFT portion 14 as a thin film device is provided on the third substrate 36.

The TFT section 14 forms a matrix in which a TFT array 38 is provided for each pixel. TFT
The array 38 includes a drain electrode 38D, a gate electrode 38
G and the source electrode 38S. Also,
The drain electrode 38D and the source electrode 38S have a source /
The drain regions 39D and 39S correspond to each other, and the gate electrode 38G corresponds to the active silicon region 39G.
A transparent pixel electrode (arranged corresponding to each pixel) 40 is provided for each of the TFT arrays 38.

Above the pixel electrode 40, a pair of alignment films 44 and 46 in which a liquid crystal 42 is sealed in an intermediate space via the flattening film 4 are provided. The liquid crystal 42 is collectively filled in all pixel regions and sealed with a sealant 47,
It does not leak.

On the upper surface of the upper alignment film 46, the counter electrode 4
8 is provided, and when an electric field (voltage) is applied between the pixel electrode 40 and the common electrode 48, the orientation of the liquid crystal 42 changes according to the applied voltage, and a pair of orientation films 44,
It has a predetermined transmittance with respect to light having a predetermined polarization direction passing through the gap between the light beams 46.

On the upper surface of the common electrode 48, a counter substrate 49 and a polarizing plate 50 are provided in this order via a color filter layer 52. The polarizing plate 50 is capable of transmitting only the light having the predetermined polarization direction, and emits the light emitted from the EL layer 32.
With respect to the% light amount, light is emitted at a light amount based on the transmittance set by the orientation of the liquid crystal 42.

The color filter layer 52 is composed of a filter section in which filters of each color of RGB are arranged in order corresponding to each pixel. In some cases, a non-light emitting area of each pixel (the TFT array 38 is disposed) And the like), and includes a black matrix portion for improving color separation of each pixel.

The third substrate 36 is made of a transparent and transparent synthetic resin (plastic or the like) plate, and the liquid crystal display device 10 having a built-in backlight is not fixed in a flat shape but has a curved surface. It can take the shape along.

An example of such a curved support is a dome (hemispherical) ceiling. The backlight-type built-in type liquid crystal display device 10 can be arranged on such a dome-shaped ceiling. Further, by providing the liquid crystal display device 10 over the entire inner peripheral surface of the cylindrical room,
It is possible to display a 60 ° panoramic image.

A preferred modification of this embodiment is that the third substrate that transmits light is a polarizing plate. Since the third substrate also serves as a polarizing plate, there is no need to provide a polarizing plate in addition to the substrate even when the rubbing treatment of the EL layer is not performed, which increases the thickness of the entire liquid crystal display device including the backlight. Can be avoided.

The installation position of the color filter is not limited to the opposite substrate side of the liquid crystal display device, but may be on the rear surface of the transparent substrate (polarizing plate) 36 or on it. When a color filter is formed on the substrate 36, the back surface of the thin film element portion is exposed when the thin film element portion 14 is transferred from the second substrate to the third substrate 36. Just do it. The backlight section is formed as follows. TF
Each layer of the backlight section is laminated on the back surface of the substrate 36 on which the T section 14 is formed. Alternatively, a backlight portion is formed in advance on one surface of the third substrate 36, and the thin film element portion is transferred to the other surface.

Using a flexible substrate from the beginning, T
Since it is difficult to form the FT portion 14 from the viewpoint of process temperature, photolithography accuracy, and the like, the thin film device is manufactured using the conventional transfer / peeling technique as described above. FIGS. 5 to 13 show TFTs using the prior art.
The process of forming the part 14 is shown.

[Step 1] As shown in FIG. 5, the first substrate 1
First separation layer (light absorption layer) as first release layer on layer 00
120 is formed. The first substrate 100 and the first separation layer 120 are as follows. (Description of first substrate 100) First substrate 100
Preferably has a light-transmitting property through which light can pass. In this case, the light transmittance is preferably 10% or more,
More preferably, it is 50% or more. If this transmittance is too low, the attenuation (loss) of light increases, and the first separation layer 1
A larger amount of light is required to peel off 20.

The first substrate 100 is preferably made of a highly reliable material, and in particular, is made of a material having excellent heat resistance. The reason for this is that, for example, when forming a TFT layer 140 (corresponding to the TFT portion 14 in FIG. 4) described later, the process temperature may be high (for example, about 350 to 1200 ° C.) depending on the type and formation method. However, even in this case, if the first substrate 100 is excellent in heat resistance, the range of setting of film forming conditions such as temperature conditions in forming the TFT layer 140 and the like on the first substrate 100 is widened. Because.

Therefore, the first substrate 100 is formed of a TFT
Assuming that the maximum temperature at the time of forming the layer 140 is Tmax, a material having a strain point of Tmax or more is preferable. Specifically, the constituent material of the first substrate 100 preferably has a strain point of 350 ° C. or higher, more preferably 500 ° C. or higher. Such materials include, for example, quartz glass, Corning 7059, NEC Glass OA-
And 2 heat-resistant glasses.

The thickness of the first substrate 100 is not particularly limited, but is usually preferably about 0.1 to 5.0 mm, and more preferably about 0.5 to 1.5 mm.
If the thickness of the first substrate 100 is too small, the strength is reduced. If the thickness is too large, light attenuation is likely to occur when the transmittance of the first substrate 100 is low. When the light transmittance of the first substrate 100 is high, the thickness may exceed the upper limit. To be able to irradiate light evenly,
The thickness of the first substrate 100 is preferably uniform. (Description of First Separation Layer 120) The first separation layer 120 absorbs the irradiated light, and peels off in the layer and / or at the interface (hereinafter, referred to as “intralayer peeling” or “interface peeling”).
Having the property of producing, preferably,
By light irradiation, the interatomic or intermolecular bonding force of the substance constituting the first separation layer 120 disappears or decreases,
That is, it is preferable that abrasion occurs to result in delamination and / or interfacial delamination.

Further, the first separation layer 12 is irradiated with light.
In some cases, gas is released from zero, and the separation effect is exhibited. That is, when the component contained in the first separation layer 120 is released as a gas, and when the first separation layer 120 absorbs light and instantaneously turns into a gas, the vapor is released and contributes to separation. There are cases. Such a first separation layer 12
Examples of the composition of 0 include those described in the following AE.

A. A. Amorphous silicon (a-Si) Various oxide ceramics such as silicon oxide or silicate compound, titanium oxide or titanate compound, zirconium oxide or zirconate compound, lanthanum oxide or lanthanum oxide compound, conductive body (ferroelectric substance) or semiconductor C.I. C. Ceramic or dielectric (ferroelectric) such as PZT, PLZT, PLLZT, PBZT, etc. B. Nitride ceramics such as silicon nitride, aluminum nitride, titanium nitride, etc. Organic polymer material F. Metal The thickness of the first separation layer 120 varies depending on the purpose of peeling and various conditions such as the composition of the first separation layer 120, the layer structure, and the forming method, but is usually preferably about 1 nm to 20 μm. It is more preferably about 10 nm to 2 μm,
More preferably, it is about 40 nm to 1 μm. First
If the thickness of the separation layer 120 is too small, the uniformity of the film may be impaired, and uneven peeling may occur. If the thickness is too large, good separation of the first separation layer 120 is ensured. Therefore, it is necessary to increase the light power (light amount), and it takes time to remove the first separation layer 120 later. Note that the thickness of the first separation layer 120 is preferably as uniform as possible.

The method for forming the first separation layer 120 is not particularly limited, and is appropriately selected according to various conditions such as a film composition and a film thickness. For example, CVD (MOCVD, low pressure CVD, EC
R-CVD), vapor deposition, molecular beam deposition (MB), sputtering, ion plating, various vapor deposition methods such as PVD, electroplating, immersion plating (dipping),
Various plating methods such as electroless plating, Langmuir-Projet (LB) method, coating methods such as spin coating, spray coating and roll coating, various printing methods, transfer methods, ink jet methods, powder jet methods, and the like. Can be formed by combining two or more of the above.

For example, when the composition of the first separation layer 120 is amorphous silicon (a-Si), it is preferable to form the film by CVD, especially low pressure CVD or plasma CVD.

When the first separation layer 120 is made of ceramics by a sol-gel method or when it is made of an organic polymer material, it is preferable to form a film by a coating method, particularly spin coating.

[Step 2] Next, as shown in FIG. 6, a TFT layer 140 is formed on the first separation layer 120.

FIG. 2 shows an enlarged cross-sectional view of the K portion (the portion surrounded by a dashed line in FIG. 6) of the TFT layer 0140. As shown, the TFT layer 1
Reference numeral 40 denotes a structure including a TFT array (thin film transistor) 38. The TFT array 38 includes source and drain regions 58 and 60 formed by introducing an n-type impurity or a p-type impurity into a polysilicon layer, and a gate insulating layer. Film layer 62
, A gate electrode 64, and a gate electrode line 66 and a drain electrode line 68 made of, for example, aluminum.

In this embodiment, the first separation layer 120
As an intermediate layer provided by _TwoUsing membrane
Is Si_ThreeN_FourYou can also use other insulating films such as
Wear. Si0_TwoThe thickness of the film (intermediate layer) depends on its purpose
It is appropriately determined according to the degree of function that can be exhibited, but usually
Is preferably about 10 nm to 5 μm,
More preferably, it is about 1 μm. The intermediate layer is made of various
For example, the TFT 140 is physically or
Chemically protective protective layer, insulating layer, conductive layer, laser light
Light shielding layer, barrier layer for preventing migration, reflection layer
That perform at least one of the functions
I can do it. In some cases, Si0_TwoForm an intermediate layer such as a membrane
Without forming the TFT layer 140 directly on the first separation layer 120.
May be implemented. The TFT layer 140 is shown on the right side of FIG.
This is a layer including a thin film device such as a TFT.

[Step 3] As shown in FIG. 7, the TFT layer 14
A second separation layer (for example, a water-soluble adhesive or a hot-melt adhesive layer) 160 as a second peeling layer is formed on the lower layer 0.

As the second separation 160, for example, an electron wax such as a proof wax (trade name), which is less likely to contaminate impurities (sodium, potassium, etc.) into the thin film device, can be given.

[Step 4] As shown in FIG. 7, the second separation layer 1
A second substrate 180 is adhered on 60. Since the second substrate 180 is bonded after the TFT layer 140 is manufactured, there is no restriction on the process temperature or the like at the time of manufacturing the TFT layer 140, and it is sufficient that the second substrate 180 retains the shape at room temperature. In this embodiment mode, a relatively inexpensive material having shape retention properties, such as a glass substrate and a synthetic resin, is used.

[Step 5] Next, as shown in FIG. 8, light is irradiated from the back side of the first first substrate 100.

This light is applied to the first separation layer 120 after passing through the first substrate 100. Thereby, intra-layer peeling and / or interfacial peeling occurs in the first separation layer 120,
The binding force decreases or disappears.

The principle of the occurrence of intra-layer separation and / or interface separation of the first separation layer 120 is that ablation occurs in the constituent material of the first separation layer 120 and that the first separation layer 1
It is presumed that this is due to the release of the gas contained in 20 and further to a phase change such as melting and evaporation occurring immediately after irradiation.

Here, ablation means that the fixing material (the constituent material of the first separation layer 120) that has absorbed the irradiation light is excited photochemically or thermally, and the bonding of atoms or molecules on its surface or inside is cut off. To release, mainly
All or a part of the constituent material of the first separation layer 120 is melted,
It appears as a phenomenon that causes a phase change such as transpiration (vaporization). In addition, the phase change may cause a very small firing state, and the bonding force may be reduced.

Whether the first separation layer 120 causes peeling within the layer,
Whether or not interfacial delamination occurs, or both, depends on the first
Depending on the composition of the separation layer 120 and other various factors,
As one of the factors, conditions such as the type, wavelength, intensity, and reaching depth of the irradiated light are given.

Irradiation light may be any light as long as it causes intra-layer separation and / or interfacial separation of the first separation layer 120, such as X-rays, ultraviolet rays, visible light, infrared rays (heat rays), and the like. Examples include laser light, millimeter waves, microwaves, electron beams, and radiation (α rays, β rays, γ rays). Among them, a laser beam is preferable, and an excimer laser is more preferable, in that the separation (ablation) of the first separation layer 120 is easily caused.

As shown in FIG. 9, a force is applied to the first substrate 100 to separate the first substrate 100 from the first separation layer 120. Although not shown in FIG. 9, after this separation,
The first separation layer 120 may adhere to the first substrate 100.

[Step 6] Next, as shown in FIG. 10, the remaining first separation layer 120 is removed by a method such as cleaning, etching, ashing, polishing, or a combination thereof. Thereby, the TFT layer 140
Has been transferred to the second substrate 180.

[Step 7] Next, as shown in FIG.
The third substrate 200 (corresponding to the third substrate 36 in FIG. 4) is bonded to the lower surface (exposed surface) of the T layer 140 via an adhesive layer 190.

Preferable examples of the adhesive constituting the adhesive layer 190 include a light-curable adhesive such as a reaction-curable adhesive, a thermosetting adhesive, and an ultraviolet-curable adhesive, and an anaerobic-curable adhesive. Various curable adhesives can be used. The adhesive may be of any composition, for example, epoxy, acrylate, or silicone. Such an adhesive layer 190
Is formed by, for example, a coating method.

When the above-mentioned curable adhesive is used, for example, T
After a curable adhesive is applied to the lower surface of the FT layer 140 and the third substrate 200 is bonded, the curable adhesive is cured by a curing method according to the characteristics of the curable adhesive.
The FT layer 140 and the third substrate 200 are bonded and fixed.

When the adhesive is of a photo-curing type, the light is preferably irradiated from outside the light-transmitting third substrate 200. As the adhesive, if a light-curing adhesive such as an ultraviolet-curing adhesive that does not easily affect the thin film device layer is used, the light-transmitting second substrate 180 side or the light-transmitting first and second light-transmitting adhesives may be used. Light irradiation may be performed from both sides of the substrates 180 and 200.
There is no particular limitation on the third substrate 00, and as a result, a light-transmitting thin film substrate having flexibility and flexibility can be used.

[Step 8] Next, as shown in FIG.
The separation layer 160 is heated and melted. As a result, the second
Since the adhesive strength of the separation layer 160 is weakened, the second substrate 180
Can be separated from the TFT layer 140. Note that by removing the second separation layer 160 attached to the second substrate 180, the second substrate 180 can be reused repeatedly.

Here, when the second separation layer is a water-soluble adhesive, the device being manufactured can be separated from the second substrate by immersing the device being manufactured in water.

[Step 9] Finally, by removing the second separation layer 160 adhered to the surface of the TFT layer 140, the TFT layer 1 transferred to the third substrate 200 as shown in FIG.
40 can be obtained. Here, the third substrate 20
2, the lamination relationship of the TFT layer 140 with respect to the TFT layer 1 with respect to the first first substrate 100 as shown in FIG.
This is the same as the stacking relationship of 40.

Through the above steps, the TFT layer 14
0 is completely transferred to the third substrate 200. Then, T
Removal of the SiO ₂ film adjacent to the FT layer 140, formation of a conductive layer such as wiring on the TFT layer 140, or formation of a desired protective film can also be performed.

In the present invention, the TFT layer 14 to be peeled is
0 is not directly peeled off, but the first separation layer 120
And the third substrate 20 separated at the second separation layer 160.
0, the transfer can be performed easily, reliably, and uniformly regardless of the characteristics, conditions, and the like of the TFT layer 140, without any damage to the TFT layer 140 due to the separation operation, and the high quality of the TFT layer 140. Reliability can be maintained.

When the above steps are completed, the backlight section 16 is formed on the surface of the third substrate 36 opposite to the surface on which the TFT layer 140 is formed, and the liquid crystal is formed on the TFT layer 140. By forming the display element 14 and providing the color filter layer 52, the liquid crystal display device 10 with a built-in backlight is completed. (Other Embodiments) In the liquid crystal display device 10 with a built-in backlight according to the above embodiment, by providing the color filter layer 22 on the upper layer, it is possible to display a full-color image together with the gradation expression of the liquid crystal display unit 12. However, there is also a configuration in which a full-color image can be displayed without providing the color filter layer 22 (see FIG. 2).

That is, as shown in FIG. 14, the EL layer 32 of the backlight section 16 is turned on by the bank 32A.
An element (RGB) for dividing into pixel matrices formed by the FT unit 14 and emitting light of each color of RGB in advance.
Light emitting layer). In this case, the RGB colors are arranged vertically or horizontally and arranged so as to be repeated, so that the original three pixels can be displayed as one pixel in color.

As a method of forming the light emitting layers of the respective colors of RGB, there are the following methods. A method in which a light emitting layer is filled by an ink jet method and dried to form a colored layer. Forming a colored resist layer on the underlayer, exposing and developing the colored resist layer with a photomask for each pixel area,
A method of forming a coloring layer corresponding to a pixel region. A light-emitting layer is applied to an underlayer, and a resist layer is formed thereon, and in a state where the resist layer is formed, the resist layer is exposed using a photomask in units of pixel regions.
Developing, etching the light emitting layer from above the resist layer corresponding to the pixel region, and removing the resist layer to form a colored layer corresponding to the pixel region. A method of forming a light emitting layer corresponding to a pixel region by attaching a light emitting layer to a base layer in a pixel region unit by a printing method.

In the case of monochrome display, since an image is formed by gradation expression by the liquid crystal display section, the above-mentioned color filter is not required at all. That is, in the configuration of FIG. 4, the color filter layer 52 is eliminated. In the monochrome display, one image data is generated by three pixels in the color display, whereas one image data is generated by one pixel. Therefore, the resolution is tripled.

According to the present embodiment, TF is used for the thin film device.
In the configuration including the driving circuit made of T, it is not necessary to use an external circuit such as an LSI as the driving circuit, and the restriction caused by connecting the external circuit to the liquid crystal display device can be avoided.
The selection range of a suitable material for the third substrate can be expanded. Circuits necessary for the liquid crystal display device (active matrix and drive circuit) are mounted on a single flexible substrate (third
On the substrate), and advantages such as reduction in the number of components can be exhibited.

[0073]

As described above, according to the present invention, it is possible to provide a thin film device with a built-in backlight and a method of manufacturing the thin film device in which the thin film device and the surface-emitting light source are integrated. Further, a thin film device with a built-in backlight which has flexibility can be provided. Further, by forming a thin film device and a surface-emitting type light source on a flexible substrate, it is possible to provide a thin film device with a built-in backlight, which can have deformability.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram (monochrome type) of a liquid crystal display device with a built-in backlight according to the present embodiment.

FIG. 2 is a conceptual diagram (full color type using a filter) of a liquid crystal display device with a built-in backlight according to the present embodiment.

FIG. 3 is a conceptual diagram of a liquid crystal display device with a built-in backlight according to the present embodiment (full-color type with built-in light source color separation).
It is.

FIG. 4 is a detailed configuration diagram of the liquid crystal display device with a built-in backlight shown in FIG. 2;

FIG. 5 is a manufacturing process diagram (process 1) for forming a TFT portion.

FIG. 6 is a manufacturing process diagram (process 2) for forming a TFT portion.

FIG. 7 is a manufacturing process diagram (process 3) for forming a TFT portion.

FIG. 8 is a manufacturing process diagram (process 4) for forming a TFT portion.

FIG. 9 is a manufacturing process diagram (process 5) for forming a TFT portion.

FIG. 10 is a manufacturing process diagram (process 6) for forming a TFT portion.

FIG. 11 is a manufacturing process diagram (process 7) for forming a TFT portion.

FIG. 12 is a manufacturing process diagram (process 8) for forming a TFT portion.

FIG. 13 is a manufacturing process diagram (process 9) for forming a TFT portion.

14 is a detailed configuration diagram of the liquid crystal display device with a built-in backlight shown in FIG. 3;

FIG. 15 is an exploded perspective view showing a configuration of a conventional liquid crystal display device with a backlight.

[Explanation of symbols]

 Reference Signs List 10 backlight built-in type liquid crystal display device 12 liquid crystal display unit 14 TFT unit 16 backlight unit 22 color filter layer 26 EL layer 36 third substrate 40 pixel electrode 38 TFT array 42 liquid crystal 48 common electrode 52 color filter layer 100 first Substrate 180 Second substrate 200 Third substrate

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H091 FA04Z FA08Z FA41Z FA44Z FC01 FC14 FC22 FC23 FD06 FD15 GA01 GA13 LA11 LA13 2H092 GA59 JA24 MA29 MA30 MA31 NA27 PA08 PA11 PA13 5G435 AA00 AA18 BB12 BB15 CC12 EE12 FF25 GG12 EE12 GG12 HH12 HH13 HH14 KK05

Claims (11)

[Claims] 1. A backlight built-in type in which a planar thin-film light-emitting light source is laminated on the back surface of a flexible translucent substrate onto which a thin-film element is transferred, and the thin-film element and the light source are integrated. Liquid crystal display. 2. The device according to claim 1, wherein the thin-film device is a liquid crystal display device, and the light source is an electroluminescent device.
A liquid crystal display device with a built-in backlight as described in the above. 3. The liquid crystal display device with a built-in backlight according to claim 2, wherein the translucent substrate also functions as a polarizing plate of the liquid crystal display element. 4. A liquid crystal display device, comprising: a common electrode provided over the entire light emitting surface; a pixel switching thin film transistor arranged in a matrix; and a gate and a source of the thin film transistor connected to a drain of the thin film transistor. A pixel electrode for generating a predetermined potential difference between the common electrode and the common electrode based on an input data signal; a driving circuit for driving the thin film transistor; and a liquid crystal between the common electrode and the pixel electrode. The liquid crystal display device with a built-in backlight according to claim 1. 5. The liquid crystal display device with a built-in backlight according to claim 1, wherein the light source is an electroluminescent element having polarization characteristics. 6. A first step of forming a release layer on a first substrate, a second step of forming a thin film device in which a plurality of pixels in a matrix are formed on the release layer, and the thin film device A third step of peeling the thin film element from the first substrate and transferring the thin film element on the second substrate to a third transparent substrate. A fourth step of transferring, a fifth step of peeling the thin film element from the second substrate, and a step opposite to the side on which the thin film element transferred to the third substrate is formed. And a sixth step of laminating and forming a thin-film surface-emitting light source. 7. The method according to claim 6, further comprising the step of the thin film element being a liquid crystal display element having a liquid crystal. 8. The method according to claim 7, wherein the third substrate also serves as one of a pair of polarizing plates as a component of the liquid crystal display device. 9. The method according to claim 6, wherein the light source is an electroluminescence element that emits white light in all areas or emits light in an RGB pattern in a matrix corresponding to the pixels. 10. An electroluminescent element which emits white light over the entire area, and a color filter is provided on a peeling surface of the thin film element from the first substrate when the thin film element is transferred to a second transfer substrate. 8. A step of providing
Or the method of 8. 11. The device according to claim 1, wherein said third substrate is made of a synthetic resin having flexibility.