JP2011103341A - Image display apparatus - Google Patents

Abstract

Provided is an image display device in which an appropriate stress relaxation film is formed between a resin substrate or the like and an inorganic film so that the inorganic film is hardly peeled off from the resin substrate or the like.
An image display device having a resin substrate or a resin layer on which a thin film transistor is formed,
A first inorganic film and a second inorganic film are sequentially laminated on the surface of the resin substrate or the resin layer where the thin film transistor is formed,
The second inorganic film has a stress in the first direction, whereas the first inorganic film is formed to have a stress in a direction opposite to the first direction.
When the stress of the first inorganic film is σ1, the stress of the second inorganic film is σ2, the film thickness of the first inorganic film is t1, and the film thickness of the second inorganic film is t2,
σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
-200 MPa ≤ σtotal ≤ 0 MPa ...... (2)
It has the relationship of the above formulas (1) and (2).
[Selection] Figure 1

Description

  The present invention relates to an image display device, and more particularly to an image display device in which a thin film transistor is formed on a resin substrate or a resin layer.

  In recent years, image display devices in which the substrate is formed of resin instead of glass have been known. And such an image display apparatus is comprised as what was excellent in the light weight, impact resistance, and flexibility.

  For example, in the case of a liquid crystal display device, it has a pair of substrates sandwiching a liquid crystal, and these substrates are constituted by resin substrates. In this case, a patterned conductive film, a semiconductor film, an insulating film, and the like are stacked in a predetermined order on the liquid crystal side surface of one resin substrate, whereby a gate signal line, a drain signal line, a thin film transistor, and a pixel are stacked. An electrode or the like is formed.

  Here, in the case where the thin film transistor is a so-called bottom gate type in which amorphous silicon is used as a semiconductor layer, the gate insulating film of the thin film transistor is formed over the most part of the resin substrate. Further, when the thin film transistor is a so-called top gate type in which polysilicon is used as a semiconductor layer, the resin substrate avoids direct contact with the thin film transistor, and blocks impurities in the resin substrate from entering the thin film transistor. A barrier layer will be formed.

  The gate insulating film is formed of, for example, a silicon oxide film, and the barrier layer is formed of, for example, a silicon nitride film, both of which are densely formed inorganic films. Such an inorganic film is formed on a resin substrate in a relatively wide area or in contact with the entire area.

  In addition, as a document relevant to this application, there exists the following patent document 1, for example. Patent Document 1 discloses that when a metal electrode or a semiconductor thin film is formed on a plastic substrate, a stress relaxation film is interposed between the plastic substrate and the metal electrode or semiconductor thin film in order to prevent cracks or peeling at the interface. There is a description.

JP 2008-147207 A

  However, as described above, when the inorganic film is formed over a wide area on the resin substrate, the inorganic film has a large stress that compresses the resin substrate (this pressure is referred to as the compressive stress of the inorganic film, for example, several hundred to 1000 MPa) acts, and this compressive stress causes inconvenience that peeling easily occurs from the resin substrate.

  In this case, it is conceivable that a stress relaxation film disclosed in Patent Document 1 is interposed between the resin substrate and the inorganic film. However, for example, a dense inorganic film such as a gate insulating film acts with a compressive stress of several hundred to 1000 MPa, and the stress relieving film also acts with a compressive stress. End up.

  An object of the present invention is to provide an image display device in which an appropriate stress relaxation film is formed between a resin substrate or the like and the inorganic film, so that the inorganic film is hardly peeled off from the resin substrate or the like. .

  The configuration of the present invention can be as follows, for example.

(1) The present invention is an image display device having a resin substrate or a resin layer on which a thin film transistor is formed,
A first inorganic film and a second inorganic film are sequentially laminated on the surface of the resin substrate or the resin layer where the thin film transistor is formed,
The second inorganic film has a stress in the first direction, whereas the first inorganic film is formed to have a stress in a direction opposite to the first direction.
When the stress of the first inorganic film is σ1, the stress of the second inorganic film is σ2, the film thickness of the first inorganic film is t1, and the film thickness of the second inorganic film is t2,
σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
-200 MPa ≤ σtotal ≤ 0 MPa ...... (2)
It has the relationship of the above formulas (1) and (2).

(2) The present invention is an image display device having a resin substrate or a resin layer on which a thin film transistor is formed,
A first inorganic film and a second inorganic film are sequentially laminated on the surface of the resin substrate or the resin layer where the thin film transistor is formed,
The first inorganic film is formed so that the stress changes continuously or intermittently in the film thickness direction,
The stress of the second inorganic film works in the first direction, the average stress of the first inorganic film is formed to work in the direction opposite to the first direction,
When the average stress of the first inorganic film is σ1, the stress of the second inorganic film is σ2, the film thickness of the first inorganic film is t1, and the film thickness of the second inorganic film is t2,
σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
-200 MPa ≤ σtotal ≤ 0 MPa ...... (2)
It has the relationship of the above formulas (1) and (2).

  The above-described configuration is merely an example, and the present invention can be modified as appropriate without departing from the technical idea. Further, examples of the configuration of the present invention other than the above-described configuration will be clarified from the entire description of the present specification or the drawings.

  In the image display device configured as described above, by forming an appropriate stress relaxation film between the resin substrate or the like and the inorganic film, the inorganic film can be made difficult to peel off from the resin substrate or the like.

  Other effects of the present invention will become apparent from the description of the entire specification.

It is the graph which showed the relationship between the film thickness of an inorganic film, and the stress which generate | occur | produces in the said inorganic film at the time of forming and heating an inorganic film by the single layer or laminated | stacked on the upper surface of the resin layer formed on the quartz substrate. It is principal part sectional drawing which shows the outline of the image display apparatus of this invention. It is explanatory drawing which showed the inconvenience when not applying this invention. It is the block diagram which interposed the stress adjustment film | membrane PCL between the resin substrate and the gate insulating film. It is a schematic block diagram which shows a liquid crystal display device. It is principal part sectional drawing which shows the outline of the other Example of the image display apparatus of this invention. It is a schematic block diagram which shows the other Example of a liquid crystal display device. It is a schematic block diagram which shows an organic electroluminescence display. It is a schematic block diagram which shows the other Example of an organic electroluminescence display. It is principal part sectional drawing which shows the other Example of the image display apparatus of this invention. It is a graph which shows the composition ratio with respect to the film thickness direction of a composition change film | membrane, and stress. It is principal part sectional drawing which shows the other Example of the image display apparatus of this invention. It is a graph which shows the composition ratio with respect to the film thickness direction of a composition change film | membrane, and stress. It is explanatory drawing which shows the other Example of this invention. It is a block diagram which shows one Example of the apparatus which forms an inorganic film.

  Embodiments of the present invention will be described with reference to the drawings. In each drawing and each example, the same or similar components are denoted by the same reference numerals and description thereof is omitted.

<Main components of image display device>
FIG. 2 is a cross-sectional view of the main part showing an outline of the image display apparatus of the present invention. In the figure, there is a resin substrate SUB, and a thin film transistor TFT is formed on the upper surface of the resin substrate SUB. The thin film transistor TFT is a switching element for a pixel driving circuit formed as a switching element for selecting a pixel column of each pixel arranged in a matrix or around a display unit formed by a set of pixels. It has come to be formed. The thin film transistor TFT is formed by a stacked body in which patterned conductive layers, semiconductor layers, and insulating layers are stacked in a predetermined order. That is, the gate electrode GT is formed on the surface of the resin substrate SUB, and the gate insulating film GI is formed so as to cover the gate electrode GT. On the upper surface of the gate insulating film GI, a semiconductor layer AS made of amorphous silicon is formed so as to straddle the gate electrode GT. On the upper surface of the semiconductor layer AS, a drain electrode DT and a source electrode ST are formed so that a channel region overlapping the gate electrode GT is disposed to face each other. At the interface between the semiconductor layer AS and the drain electrode DT and at the interface between the semiconductor layer AS and the source electrode ST, a contact layer CN doped with, for example, a high-concentration n-type impurity is formed in the semiconductor layer AS. The thin film transistor TFT thus configured is covered with a protective film PAS. This protective film PAS is formed of, for example, a silicon nitride film or a resin.

  In this case, the resin substrate SUB and the gate insulating film GI of the thin film transistor TFT are in contact with each other over a relatively wide area, but since one is an organic material and the other is an inorganic material, their adhesion is not sufficient. For example, as shown in FIG. 3, a large compressive stress (stress indicated by an arrow in the drawing and intended to be compressed with respect to the resin substrate SUB) is generated in the gate insulating film GI. The compressive stress causes the gate insulating film GI to peel off from the resin substrate SUB.

  Therefore, in the present invention, as shown in FIG. 4, the stress adjustment film PCL (hereinafter referred to as the first inorganic film) is interposed between the resin substrate SUB and the gate insulating film GI (hereinafter sometimes referred to as the second inorganic film). It may be called a film). As the stress adjusting film PCL, an inorganic film that generates tensile stress acting in the opposite direction to the compressive stress generated in the gate insulating film GI is selected. For this reason, the sequential stacked body PL of the stress adjusting film PCL and the gate insulating film GI cancels each other's stress, and the stress of the stacked body PL is configured as a film adjusted to, for example, −200 or more and less than 100 MPa. Yes.

  FIG. 1 shows the thickness of the inorganic film and the inorganic film when an inorganic film (SiN, SiO, SiON) is formed as a single layer or a laminate on the upper surface of a resin layer formed on a quartz substrate, for example. It is the graph which showed the relationship with the generated stress. The horizontal axis represents the film thickness (nm), and the vertical axis represents the stress (MPa). For the sequentially laminated inorganic films (first inorganic film, second inorganic board), the stress σtotal of the entire inorganic film was calculated according to the following formula (1).

σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
Here, σ1 is the stress of the first inorganic film, σ2 is the stress of the second inorganic film 2, t1 is the film thickness of the first inorganic film, and t2 is the film thickness of the second inorganic film. Fig. 1 shows the relationship between the stress and film thickness of inorganic films and defects (cracks, wrinkles). In the figure, cracks are generated in the inorganic film in the plots indicated by black diamonds, and wrinkles are generated in the inorganic film in the plots indicated by black rectangles. In addition, the plots indicated by white circles indicate that there is no problem. Here, when the stress of the inorganic film has a positive sign, the stress is referred to as a tensile stress, and a stress that causes the inorganic film to contract and pull the resin layer acts. When the stress of the inorganic film has a negative sign, the stress is referred to as a compressive stress, and a stress that causes the inorganic film itself to expand and compress the resin layer works.

  As is clear from FIG. 1, when the tensile stress of the inorganic film is 100 MPa or more, cracks occur in the inorganic film in each sample, and when the stress of the inorganic film is a compressive stress of less than -200 MPa, Wrinkles occurred. Here, wrinkles are considered to occur due to the same cause as peeling. Samples with an inorganic film stress of -200 MPa or more and less than 0 MPa did not cause defects such as cracks and wrinkles. This means that cracks and peeling are less likely to occur in the inorganic film by adjusting the stress of the inorganic film formed on the resin layer to −200 MPa or more and 0 MPa or less.

Therefore, in FIG. 4, the stress adjusting film PCL (first inorganic film IO1) and the gate insulating film GI (second inorganic film IO2) are stressed in one direction on one inorganic film, and on the other inorganic film. On the premise that stress acts in a second direction opposite to the first direction, the average stress of the first inorganic film IO1 is σ1, the stress of the second inorganic film IO2 is σ2, and the first inorganic film When the film thickness of IO1 is t1, and the film thickness of the second inorganic film IO2 is t2,
σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
-200 MPa ≤ σtotal ≤ 0 MPa ...... (2)
The configuration is set so as to satisfy the relations of the above formulas (1) and (2), thereby preventing the sequential laminate PL of the first inorganic film IO1 and the second inorganic film IO2 from peeling from the resin film, It has become.

  Here, the first inorganic film IO1 and the second inorganic film IO2 can be formed by, for example, an inductively coupled plasma CVD apparatus shown in FIG. In FIG. 15, there is a chamber VS to which a reaction gas RG is supplied, and a substrate on which an inorganic film is formed can be placed on the substrate table PDS in the chamber VS. The chamber VS is provided with an induction coil INC and a high-frequency window WD for generating plasma in the chamber VS, and the induction coil INC is driven by an RF power source (13.56 MHz) RFP. In such an apparatus, many excited species are generated by the high-density plasma, and film formation at a low temperature is possible. When an inorganic film is formed using this apparatus, a bias can be applied to the substrate table PDS by a DC power source DCP when necessary. Thereby, irradiation of ions can be controlled, and an inorganic film with adjusted stress can be formed.

  By adjusting the power of the RF power source, the voltage of the substrate base PDS, and the flow rate of the reaction gas RG, the composition and stress of the first inorganic film and the second inorganic film can be obtained as desired. Yes.

  The graph shown in FIG. 1 is a sample in which an inorganic film is formed on the upper surface of a resin layer formed on a quartz substrate. However, it has been confirmed that similar results can be obtained even when an inorganic film is formed on the upper surface of a substrate made of resin.

FIG. 5 is a schematic configuration diagram showing a liquid crystal display device. The liquid crystal display device includes a so-called TFT substrate TSB and a filter substrate FSB that are disposed with the liquid crystal LC interposed therebetween. The TFT substrate TSB includes a first substrate SUB1 made of resin. A first inorganic film IO1, a second inorganic film IO2, a protective film PAS, a pixel electrode PX, and a first alignment film ORI1 are sequentially stacked on the surface of the first substrate SUB on the liquid crystal LC side. The first inorganic film IO1 functions as a stress adjusting film, and the second inorganic film IO2 is a gate insulating film. The thin film transistor TFT is not shown in this figure. The pixel electrode PX is made of a translucent conductive film such as ITO (Indium Tin Oxide). The pixel electrode PX generates an electric field between the pixel electrode PX, which will be described later, and causes the molecules of the liquid crystal LC to behave. The first alignment film ORI1 and the second alignment film ORI2 described later determine the initial alignment direction of the molecules of the liquid crystal LC. A first polarizing plate POL1 is disposed on the surface of the first substrate SUB1 opposite to the liquid crystal LC. The first polarizing plate POL1 visualizes the molecular behavior of the liquid crystal LC together with the second polarizing plate POL2 described later. The filter substrate CSB includes a second substrate SUB2 made of resin. A warpage balance film BBL, a color filter CF, a counter electrode CT, and a second alignment film ORI2 are sequentially stacked on the surface of the second substrate SUB2 on the liquid crystal LC side. The warp balance film BBL is a film made of, for example, the same material as the first inorganic film IO1 made of a stress adjusting film. When the warp occurs in the TFT substrate TSB due to the formation of the first inorganic film IO1, the warp balance film BBL is also applied to the filter substrate CSB. For example, it is provided to take the same warp. Therefore, this warpage balance film BBL may not be required. The counter electrode CT is made of a translucent conductive film such as ITO (Indium Tin Oxide). A second polarizing plate POL2 is disposed on the surface of the filter substrate CSB opposite to the liquid crystal LC.

  In Example 1, the thin film transistor TFT formed on the resin substrate SUB has a semiconductor layer formed of amorphous silicon. However, the thin film transistor TFT may have a semiconductor layer made of polysilicon.

  In this case, a thin film transistor TFT of a so-called top gate type whose semiconductor layer is made of polysilicon is configured, for example, as shown in FIG. In FIG. 6, first, there is a resin substrate SUB, and a barrier layer BL made of, for example, a silicon nitride film is formed on the surface of the resin substrate SUB. This barrier layer BL is provided in order to prevent metal atoms in the resin substrate SUB from entering a semiconductor layer PS described later. A semiconductor layer PS made of polysilicon is formed on the surface of the barrier layer BL, and a gate insulating film GI is formed so as to cover the semiconductor layer PS. A gate electrode GT is formed on the upper surface of the gate insulating film GI so as to straddle the semiconductor layer PS. The semiconductor layer PS is doped with impurities using the gate electrode GT as a mask after the formation of the gate electrode GT to form a drain region DD and a source region SD. A protective film PAS is formed on the gate insulating film GI so as to cover the gate electrode GT. Through the openings formed in the protective film PAS and the gate insulating film GI, the drain electrode DT connected to the drain region DD, and the source A source electrode ST connected to the region SD is formed.

  In this case, since the resin substrate SUB and the barrier layer BL are in contact with each other over the entire region, one of them is an organic material and the other is an inorganic material, so that their adhesion is not sufficient, as shown in FIG. Cause peeling. Therefore, the first inorganic film (stress relaxation film) is interposed between the resin substrate SUB and the second inorganic film using the barrier layer BL as the second inorganic film, and in the first inorganic film and the second inorganic film, , And may be configured so as to satisfy the expressions (1) and (2). Thereby, the barrier layer BL can be configured to be difficult to peel off from the resin substrate SUB.

  FIG. 7 is a schematic configuration diagram showing the liquid crystal display device, and is a diagram drawn in association with FIG. As in FIG. 5, the liquid crystal display device includes a so-called TFT substrate TSB and a filter substrate CSB that are disposed with the liquid crystal LC interposed therebetween. A first inorganic film IO1, a second inorganic film IO2, a gate insulating film GI, a protective film PAS, a pixel electrode PX, and a first alignment film ORI1 are sequentially stacked on the surface of the first substrate SUB1 on the liquid crystal LC side. . The first inorganic film IO1 functions as the stress adjustment film PCL, and the second inorganic film IO2 serves as the barrier layer BL. Although the thin film transistor TFT is not shown in this drawing, the gate insulating film GI is one of the constituent materials of the thin film transistor TFT. Since the gate insulating film GI has a smaller thickness than the barrier layer GL and peeling from the resin substrate SUB occurs between the gate insulating film GI and the barrier layer BL, the first inorganic film IO1 functions as the stress adjustment film PCL. Yes. Other configurations are the same as those in FIG.

  In the embodiment described above, the present invention is applied to a liquid crystal display device. However, the present invention is not limited to this, and the present invention can be applied to other image display devices such as an organic EL display device.

  FIG. 8 is a schematic configuration diagram showing the organic EL display device, which is drawn in association with FIG.

  There is a resin substrate SUB, and the first inorganic film IO1, the second inorganic film IO2, the protective film PAS, the first electrode TM1, the light emitting layer EL, the second electrode TM2, and the sealing layer ENC are sequentially formed on the main surface of the resin substrate SUB. Are stacked. The first inorganic film IO1 functions as a stress adjustment film PCL, and the second inorganic film IO2 is a gate insulating film GI. The thin film transistor TFT is not shown in this figure, and uses the second inorganic film IO2 which is the gate insulating film GI as one of the constituent materials. The light emitting layer EL is sandwiched between the first electrode TM1 and the second electrode TM2, and emits light according to the current flowing through the light emitting layer EL through the first electrode TM1 and the second electrode TM2.

  Note that at least one of the first electrode TM1 and the second electrode TM2 is made of a light-transmitting conductive film such as ITO, and the light generated from the light emitting layer EL is irradiated to the outside through the one electrode. It is supposed to let you.

  Also in the organic EL display device, peeling occurs when the gate insulating film GI (second inorganic film IO2) is directly formed on the resin substrate SUB. Therefore, the second EL film is formed between the resin substrate SUB and the second inorganic film IO2. By forming the stress adjusting film PCL which is one inorganic film IO1 interposed, it is possible to obtain a configuration in which peeling is avoided.

  FIG. 9 is a schematic configuration diagram showing another embodiment of the organic EL display device, which is drawn in association with FIG.

  The structure different from the case of FIG. 5 is that a barrier layer BL, which is the second inorganic film IO2, is formed on the main surface of the resin substrate SUB via the stress adjustment film PCL, which is the first inorganic film IO1. It is in. For this reason, a gate insulating film GI, which is a constituent member of a thin film transistor (not shown), is formed on the upper surface of the barrier layer GL. Other configurations are the same as those in FIG.

  Even in such an organic EL display device, peeling occurs when the barrier layer BL (second inorganic film IO2) is directly formed on the resin substrate SUB. Therefore, the organic EL display device is formed between the resin substrate SUB and the second inorganic film IO2. By forming the stress adjusting film PCL which is the first inorganic film IO1 interposed, it is possible to obtain a configuration in which peeling is avoided.

  FIG. 10 is a cross-sectional view of an essential part showing another embodiment of the image display device of the present invention. In FIG. 10, a layer (referred to as a composition change film PVL) having a configuration different from that of the stress adjustment film PCL is formed between the resin substrate SUB and the gate insulating film GI, and the stress adjustment film PCL is formed by the composition change film PVL. This is the same function as. Here, the composition change film PVL is a film having a gentle pressure change in the film thickness direction by making the composition of the material (for example, SiOxNy) different in the film thickness direction.

  The graph on the left side of FIG. 11 shows the composition ratio with respect to the film thickness direction of the composition change film PVL. In the graph, the horizontal axis represents the composition ratio (O / O + N), and the vertical axis represents the film thickness t. In the figure, Z = 0 is the resin substrate / composition change film interface, and Z = t is the composition change film / gate insulating film interface. As can be seen from the graph, the composition change film PVL increases in the proportion of O (oxygen) from the resin substrate SUB side to the gate insulating film GI side.

  And the composition change film | membrane PVL comprised in this way is formed so that a pressure (tensile pressure) may change with respect to a film thickness direction, as shown to the graph of the right side of FIG. In the graph, the horizontal axis represents the tensile pressure, and the vertical axis represents the film thickness t. As in the graph on the left side of FIG. 11, Z = 0 in the figure is the resin substrate / composition change film interface, and Z = t is the composition change film / gate insulating film interface. As apparent from the graph, the composition change film PVL has a tensile stress of 0 at the interface with the resin substrate SUB, and the tensile stress increases toward the gate insulating film side. Thus, when Z = 0 in the figure, considering the poor adhesion at the organic / inorganic interface, the stress concentration at the interface can be prevented by setting the stress to 0. Also, in the figure, Z = t is a compressive stress that cancels the stress of the gate insulating film, and the stress of the entire inorganic film composed of the composition change film and the gate insulating film can be relaxed. Here, in the graph on the right side of FIG. 11, the stress σ1 indicated by the dotted line is the average stress of the composition change film, and is made to coincide with σ1 shown in the above formulas (1) and (2).

That is, when the composition change film PVL having the structure as shown in FIG. 10 is used as the stress adjustment film, the stress of the gate insulating film GI (second inorganic film IO2) acts in the first direction, and the composition change film PVL. The average stress of the (first inorganic film IO1) is formed to work in a direction opposite to the first direction,
When the average stress of the first inorganic film IO1 is σ1, the stress of the second inorganic film IO2 is σ2, the film thickness of the first inorganic film IO1 is t1, and the film thickness of the second inorganic film IO2 is t2,
σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
-200 MPa ≤ σtotal ≤ 0 MPa ...... (2)
By setting so as to be in the relationship of the above formulas (1) and (2), a configuration that can achieve the object of the present invention can be obtained.

  FIG. 12 is a cross-sectional view of an essential part showing another embodiment of the image display apparatus of the present invention, and is a figure drawn in association with FIG.

  In FIG. 12, the composition different from the case of FIG. 10 is that the composition change film PVL is composed of a laminated body of composition adjustment films (PVLa, PVLb, PVLc, PVLd) composed of, for example, four layers from the resin substrate SUB side. It is in.

  And the relationship between the composition ratio and tensile stress of these laminates is shown in FIG. Compared to the case of FIG. 11, the composition ratio and tensile stress of the laminate are only changed stepwise.

  Even in this case, the same effect as that of the fifth embodiment can be obtained.

  FIG. 14 is an explanatory view showing Embodiment 7 of the present invention. Example 7 shows an example in which the present invention is applied to a curved display. In general, a curved display is formed by bending a flat flexible display after creation. However, stress concentration occurs due to bending at an interface with poor adhesion, such as an organic film / gate insulating film interface. There arises a problem that cracks and peeling occur due to this stress concentration.

  For this reason, in the seventh embodiment, this problem is solved by, for example, the stress adjustment film PCL. As shown in the upper part of the figure, when the stress adjustment film PCL for compressive stress is formed on the resin substrate SUB that is held in a flat state, as shown in the middle part of the figure, it is curved convexly downward. It becomes like this. The curvature of this curved surface state depends on the compressive stress of the stress adjustment film PCL. As the stress adjustment film PCL, a film having a compressive stress that has an arbitrary curvature when used as a curved display is used. As a result, the stress is most relaxed at the resin substrate / gate insulating film interface. Thereafter, the display layer DPL is formed on the stress adjustment film. As described above, as shown in the lower part of the figure, it is possible to suppress stress concentration at an interface having poor adhesion, such as a resin substrate / gate insulating film interface, when a curved display is used as an arbitrary curved display. And peeling can be prevented.

  In the above-described embodiments, the first inorganic film is interposed between the resin substrate SUB and the second inorganic film in order to avoid peeling of the inorganic film (second inorganic film) formed on the surface of the resin substrate SUB. (Stress relaxation film) is formed. However, you may make it form the laminated body of a 1st inorganic film and a 2nd inorganic film on the upper surface of the resin layer formed, for example on the glass substrate. This is because even in this case, the first inorganic film can avoid peeling of the second inorganic film formed on the upper surface of the resin layer. That is, the sequential laminated body of the first inorganic film and the second inorganic film in the present invention may be on the resin substrate or the resin layer.

  The present invention has been described using the embodiments. However, the configurations described in the embodiments so far are only examples, and the present invention can be appropriately changed without departing from the technical idea. Further, the configurations described in the respective embodiments may be used in combination as long as they do not contradict each other.

SUB ... Resin substrate, GT ... Gate electrode, GI ... Gate insulating film, AS ... Semiconductor layer (amorphous), CN ... Contact layer, DT ... Drain electrode, ST ... Source electrode, PAS ... Protection Film, TFT: Thin film transistor, PCL: Stress adjustment film, IO1: First inorganic film, IO2: Second inorganic film, PL: Laminate, PX: Pixel electrode, POL1: First polarizing plate, ORI1 ... first alignment film, LC ... liquid crystal, BBL ... warping balance film, CF ... color filter, CT ... counter electrode, POL2 ... second polarizing plate, ORI2 ... second alignment film, TSB ... ... TFT substrate, CSB ... Filter substrate, PS ... Semiconductor layer (poly), BL ... Barrier layer, DD ... Drain region, SD ... Source region, EL ... Light-emitting layer, TM1 ... First electrode, TM2 …… Second Pole, ENC ... Sealing layer, PVL ... Composition deformation layer, DPL ... Display layer, RG ... Reaction gas, VS ... Chamber, PDS ... Substrate base, INC ... Induction coil, WD ... High frequency window , RFP …… RF power supply.

Claims (11)

An image display device having a resin substrate or a resin layer on which a thin film transistor is formed,
A first inorganic film and a second inorganic film are sequentially laminated on the surface of the resin substrate or the resin layer where the thin film transistor is formed,
The second inorganic film has a stress in the first direction, whereas the first inorganic film is formed to have a stress in a direction opposite to the first direction.
When the stress of the first inorganic film is σ1, the stress of the second inorganic film is σ2, the film thickness of the first inorganic film is t1, and the film thickness of the second inorganic film is t2,
σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
-200 MPa ≤ σtotal ≤ 0 MPa ...... (2)
An image display device characterized by having a relationship of the above formulas (1) and (2).   2. The image display device according to claim 1, wherein the first inorganic film has a thickness t1 of 100 nm to 1500 nm and a stress σ1 of 50 MPa to 1500 MPa.   The image display device according to claim 1, wherein the first inorganic film is a gate insulating film of the thin film transistor.   The image display device according to claim 1, wherein the first inorganic film is a barrier layer that prevents impurities in the resin substrate or the resin layer from entering the thin film transistor.   The image display device according to claim 1, wherein the resin substrate or the resin layer is in a curved state due to the formation of the first inorganic film. An image display device having a resin substrate or a resin layer on which a thin film transistor is formed,
A first inorganic film and a second inorganic film are sequentially laminated on the surface of the resin substrate or the resin layer where the thin film transistor is formed,
The first inorganic film is formed so that the stress changes continuously or intermittently in the film thickness direction,
The stress of the second inorganic film works in the first direction, the average stress of the first inorganic film is formed to work in the direction opposite to the first direction,
When the average stress of the first inorganic film is σ1, the stress of the second inorganic film is σ2, the film thickness of the first inorganic film is t1, and the film thickness of the second inorganic film is t2,
σtotal = σ1 ・ t1 / (t1 + t2) + σ2 ・ t2 / (t1 + t2) …… (1)
-200 MPa ≤ σtotal ≤ 0 MPa ...... (2)
An image display device characterized by having a relationship of the above formulas (1) and (2).   The image display device according to claim 6, wherein the stress of the first inorganic film is small on the resin substrate or resin layer side and large on the second inorganic film side.   The image display device according to claim 6, wherein the first inorganic film has a film thickness t1 of 100 nm to 1500 nm and a stress σ1 of 50 MPa to 1500 MPa.   The image display device according to claim 6, wherein the first inorganic film is a gate insulating film of the thin film transistor.   The image display device according to claim 6, wherein the first inorganic film is a barrier layer that prevents impurities in the resin substrate or the resin layer from entering the thin film transistor.   The image display device according to claim 6, wherein the resin substrate or the resin layer is in a curved state by the formation of the first inorganic film.

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