JP4063733B2 - Transflective liquid crystal display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a transflective liquid crystal display device and a manufacturing method thereof, and more particularly to a transflective liquid crystal display device having a transmissive region and a reflective region in a pixel region and a manufacturing method thereof.

  Liquid crystal display devices are being put to practical use in a wide range of fields such as OA (Office Automation) devices and portable devices because of their small size, thinness, and low power consumption. In this liquid crystal display device, two drive systems, an active matrix system and a simple matrix system, are known. The former, which can display high-quality images, is widely used. . In addition, liquid crystal display devices driven by the active matrix method are classified into a transmissive type and a reflective type, and in both cases, the liquid crystal panel constituting the main part of the liquid crystal display device acts as an electronic shutter and is incident from the outside. Since the basic principle is to display an image by passing or blocking light, unlike a CRT (Cathode Ray Tube) or EL (Electroluminescence) display device, it does not have a function of emitting light itself. Therefore, in order to display an image in the liquid crystal display device, a separate light source is required for any type. For example, in a transmissive liquid crystal display device, a light source including a backlight is provided on the back surface of the liquid crystal panel (the surface opposite to the image display surface), and transmission / blocking of light incident from the backlight is switched on the liquid crystal panel. The display is configured to be controlled.

  In such a transmissive liquid crystal display device, it is possible to obtain a bright screen regardless of the surrounding brightness of the place where the transmissive liquid crystal display device is used by always making backlight light incident. The power consumption of the light source is large, and nearly half of the power of the transmissive liquid crystal display device is consumed by the backlight source, which causes an increase in power consumption. In particular, a transmissive liquid crystal display device that is driven by a battery shortens the usable time, and if a large battery is installed to extend the usable time, the overall weight of the device increases. Hinder.

  Therefore, in order to solve the problem of the power consumption of the backlight light source in the transmissive liquid crystal display device, the light that is present around the place where the liquid crystal display device is used without using the backlight light source (hereinafter referred to as external) A reflection type liquid crystal display device has been proposed which is configured to use (also referred to as ambient light) as a light source. In this reflective liquid crystal display device, a display is controlled by providing a reflection plate inside the liquid crystal panel and switching between transmission and blocking of external ambient light incident on the liquid crystal panel and reflected by the reflection plate. It is configured as follows. Since this reflective liquid crystal display device does not require a backlight light source unlike the transmissive liquid crystal display device, power consumption can be reduced, and the size and weight can be reduced. However, the reflection type liquid crystal display device has a problem that visibility is remarkably lowered because external ambient light does not sufficiently function as a light source when the surrounding is dark.

  As described above, each of the transmissive liquid crystal display device and the reflective liquid crystal display device has advantages and disadvantages, and a backlight light source is indispensable for obtaining a stable display. However, when only the backlight is used as the light source, as described above. Increase in power consumption is inevitable. Therefore, a transmissive liquid crystal display is provided with a transmissive area and a reflective area in the pixel area of the liquid crystal panel so that the power consumption of the backlight light source can be suppressed and the visibility can be improved even when the external ambient light is dark. There has been proposed a transflective liquid crystal display device configured to realize the operation of the device and the reflective liquid crystal display device with a single liquid crystal panel.

  According to the transflective liquid crystal display device as described above, by providing the transmission region and the reflection region in the pixel region of the liquid crystal panel, when the external ambient light is dark, the backlight is turned on and the transmission region is used. By operating as a transmissive liquid crystal display device, the characteristics of the transmissive liquid crystal display device such as improved visibility can be exhibited even when the surroundings are dark. On the other hand, when external ambient light is sufficiently bright, the backlight is turned off and the reflective region is used to operate as a reflective liquid crystal display device, thereby exhibiting the characteristics of the reflective liquid crystal display device with low power consumption. Can do.

  In this transflective liquid crystal display device, incident light from the backlight is transmitted through the liquid crystal layer in the transmissive region for operating as a transmissive liquid crystal display device, while in the reflective region for operating as a reflective liquid crystal display device. Since incident light which is external ambient light passes back and forth through the liquid crystal layer of the liquid crystal panel, an optical path difference occurs between the two incident lights in the liquid crystal layer. Therefore, in the transflective liquid crystal display device, as will be described later, the first gap (reflection gap) dimension of the reflective region and the second gap (transmission gap) dimension of the transmissive region, which are the film thickness of the liquid crystal layer, If the optimum value is not set in accordance with the twist angle of the liquid crystal, the intensity of the outgoing light emitted from the display surface cannot be optimized due to the difference in retardation between the reflective region and the transmissive region. Hereinafter, optimization of the emitted light intensity in the transmissive region and the reflective region of the pixel region in the transflective liquid crystal display device will be described.

(Optimization of outgoing light intensity in transmissive and reflective areas)
FIG. 34 is a diagram schematically showing a configuration of a transflective liquid crystal display device necessary for optimizing the emitted light intensity of the transmissive region PXa and the reflective region PXb. As shown in the figure, the transflective liquid crystal display device is arranged on an active matrix substrate 112, a counter substrate 116, a liquid crystal layer 117 sandwiched between the substrates 112 and 116, and a back surface of the active matrix substrate 112. And the retardation plates (λ / 4 plates) 120a and 120b and polarizing plates 119a and 119b provided outside the active matrix substrate 112 and the counter substrate 116, respectively. Here, on the surface of the active matrix substrate 112 facing the counter substrate 116, a transmissive electrode film 105 serving as the transmissive region PXa of the pixel region PX and a reflective film 106 serving as the reflective region PXb are provided. In this way, by arranging the respective optical members to form a transflective liquid crystal display device, the polarization state of incident light and outgoing light is controlled as will be described later.

(About the arrangement of the upper polarizing plate and retardation plate)
First, the case where the above-described transflective liquid crystal display device is operated as a reflective liquid crystal display device will be described. In order to display the reflective region PXb in a normally white display, that is, no voltage is applied between the counter electrode (not shown) of the counter substrate 116 and the pixel electrode (not shown) of the active matrix substrate 112, the liquid crystal molecules of the liquid crystal layer 117 White display in the state of lying (horizontal lying down), voltage applied between the counter electrode and the pixel electrode and liquid crystal molecules standing up (standing up vertically) In order to achieve black display, a retardation plate 120b is disposed between the liquid crystal layer 117 and the polarizing plate 119b. By arranging the phase difference plate 120b to be rotated by 45 ° with respect to the optical axis of the polarizing plate 119b, linearly polarized light (horizontal) that is external ambient light that has passed through the polarizing plate 119b becomes clockwise circularly polarized light. The clockwise circularly polarized light reaches the reflective film 106 as linearly polarized light by selecting the reflection gap dr, which is the film thickness of the liquid crystal layer 117, to a predetermined value. In the reflective film 106, the linearly polarized light is reflected as it is as linearly polarized light, and this linearly polarized light becomes clockwise circularly polarized light when it exits the liquid crystal layer 117. This is changed to linearly polarized light (horizontal) by the phase difference plate 120b, and is emitted from the polarizing plate 119b having an optical axis in the horizontal direction to display white. On the other hand, when a voltage is applied between the counter electrode and the pixel electrode, liquid crystal molecules rise. At this time, the light that entered the liquid crystal layer 117 as clockwise circularly polarized light reached the reflective film 106 as it was in the clockwise circularly polarized light, and the clockwise circularly polarized light was changed to be counterclockwise circularly polarized by the reflective film 106 and reflected. Then, after exiting the liquid crystal layer 117 while being left-handed circularly polarized light, it is changed to linearly polarized light (vertical) by the phase difference plate 120b, absorbed by the polarizing plate 120b, and no light is emitted. For this reason, it becomes black display.

(About the arrangement of the lower polarizing plate and retardation plate)
Next, the case of operating as a transmissive liquid crystal display device will be described. The arrangement angles of the optical axes of the lower phase difference plate 120a and the polarizing plate 119a are determined so that black display is performed in a state where a voltage is applied. The lower polarizing plate 119a is arranged cross Nicol with the upper polarizing plate 119b, that is, in a direction rotated by 90 °. Further, in order to cancel (compensate) the influence of the upper retardation plate 120b, the lower retardation plate 120a is also rotated by 90 °. Since the liquid crystal molecules stand up in a state where a voltage is applied, the polarization state of the light does not change. Therefore, the liquid crystal molecules are optically equivalent to the fact that the polarizing plates 119a and 119b are arranged in crossed Nicols, and the voltage is applied. The display is black. As described above, the arrangement of the optical members and the arrangement angle of the optical axis of the liquid crystal panel of the transflective liquid crystal display device are determined.

(About twist angle setting)
The liquid crystal twist angle φ (0 °) in the transflective liquid crystal display device in which the optical member is arranged at the above arrangement angle and nematic liquid crystal having a refractive index anisotropy Δn = 0.086 is used as the liquid crystal layer 117. The relationship between the reflection gap dr and the transmission gap df (that is, the film thickness of the liquid crystal layer) is shown in FIG. FIG. 36 shows the relationship between the twist angle φ (0 ° to 90 °), the transmittance, and the reflectance when the reflection gap dr and the transmission gap df are optimized. In general, as the twist angle becomes smaller, the utilization factor of light in the transmission mode becomes higher, while the color shift when the field of view is shaken becomes larger. As is clear from FIG. 35, the reflection gap dr and the transmission gap df that maximize the white reflectance and transmittance, respectively, coincide with each other when the twist angle φ is approximately 72 °. Further, as the twist angle φ becomes smaller, the optimum reflection gap dr becomes smaller than the optimum transmission gap df.

  As is clear from FIG. 35, the optimal reflection gap dr and transmission gap df when a nematic liquid crystal having a refractive index anisotropy Δn = 0.086 is used as the liquid crystal and the twist angle φ is set to about 72 ° are substantially equal. It agrees at 2.7 μm. Further, when the twist angle φ is set to approximately 0 °, the optimum reflection gap dr is approximately 1.5 μm and the transmission gap df is approximately 2.9 μm. When the twist angle φ is set to about 60 °, the optimum reflection gap dr is about 2.0 μm and the transmission gap df is about 2.8 μm.

  As described above, in order to correct the optical path difference between the two incident lights passing through the transmission region PXa and the reflection region PXb of the pixel region PX, and to optimize the emitted light intensity in the transflective liquid crystal display device. Depending on the twist angle of the liquid crystal, it is necessary to set the optimum reflection gap dr and transmission gap df that maximize the white reflectance and transmittance, respectively, as shown in FIG. Accordingly, as in the conventional transflective liquid crystal display device of FIG. 30 described later, a step is provided on the active matrix substrate 112 so that the reflection gap and the transmission gap are different, or the conventional transflective liquid crystal of FIG. As in the display device, the active matrix substrate 112 is formed so that the reflection gap and the transmission gap are equal, and the optimum reflection gap dr and transmission gap df are obtained in accordance with a predetermined twist angle. This has been done conventionally.

  Hereinafter, the configuration of a conventional transflective liquid crystal display device will be described with reference to FIG. As shown in the figure, the transflective liquid crystal display device includes an active matrix substrate 112 on which a thin film transistor (TFT) 103 that operates as a switching element is formed, a counter substrate 116, and both substrates 112, 116. A liquid crystal layer 117 sandwiched therebetween and a backlight light source 118 disposed on the back surface of the active matrix substrate 112 are provided.

  Here, the active matrix substrate 112 includes a transparent insulating substrate 108, a gate line and a data line (not shown) formed on the transparent insulating substrate 108, a gate electrode 101a connected to the gate line, and a gate insulating film. 109, a semiconductor layer 103a, a drain electrode 102a and a source electrode 102b which are drawn from both ends of the semiconductor layer 103a and connected to the data line and the pixel electrode, respectively, and a passivation film 110. The pixel region PX is divided into a transmissive region PXa that transmits incident light from the backlight light source 118 and a reflective region PXb that reflects incident external ambient light. The transmissive region PXa includes an ITO on the passivation film 110. A transparent electrode film 105 made of (Indium Tin Oxide) or the like is formed, and a reflective electrode film 106a containing Al or Al alloy is connected on the transparent electrode film 105 via an uneven film 111 such as an organic film in the reflective region PXb. It is formed as it is. The transparent electrode film 105 and the reflective electrode film 106a connected to the source electrode 102b through the contact hole 107 formed in the concavo-convex film 111 function as pixel electrodes, and an alignment film 129 is formed on both the electrode films 105 and 106a. Yes. Here, the TFT 103 is configured by the gate electrode 101a, the gate insulating film 109, the semiconductor layer 103a, the drain electrode 102a, and the source electrode 102b. On the other hand, the counter substrate 116 includes a transparent insulating substrate 113, a color filter 114, a black matrix (not shown), a counter electrode 115, and an alignment film 129.

  In the transflective liquid crystal display device having such a structure, in FIG. 30, in the transmissive region PXa, the backlight light incident from the back surface of the active matrix substrate 112 passes through the liquid crystal layer 117 and is emitted from the counter substrate 116, thereby reflecting the reflective region. In PXb, external ambient light incident from the counter substrate 116 passes through the liquid crystal layer 117, is reflected by the reflective electrode film 106 a, passes through the liquid crystal layer 117 again, and is emitted from the counter substrate 116. Then, the step of the concavo-convex film 111 is provided so that the reflection gap dr is about half of the transmission gap df (however, the twist angle φ is approximately 0 °), and between the two incident lights passing through the respective regions. The polarization state of the emitted light is adjusted by making the optical path lengths substantially equal.

  Here, a reflection type liquid crystal display device having a structure in which a transparent electrode is formed on a reflective plate having projections and depressions through a protective film made of a transparent acrylic resin is disclosed in Japanese Patent Application Laid-Open No. 2001-221995. In the transflective liquid crystal display device, when liquid crystals having different retardations in the transmissive display area and the reflective display area are aligned with the same drive voltage, a high contrast display cannot be obtained, and a bright display is difficult to obtain. In order to solve this problem, the alignment of the liquid crystal is controlled after adjusting the retardation of the portion for performing transmissive display and the portion for performing reflective display to be in a close range. However, the transflective liquid crystal display device does not take into consideration display defects caused by an electrolytic corrosion reaction, which will be described later, and flicker caused by residual DC voltage, which are problems in the present invention. Moreover, the transflective liquid crystal display device has a reflective electrode film (reflective plate) formed at the center of the pixel, and the TFT element is not covered with the reflective plate. I can't do it.

  However, in the conventional transflective liquid crystal display device as described above, since the reflective electrode film 106a containing Al or Al alloy is formed on the transparent electrode film 105 made of ITO or the like, the reflective electrode film 106a is processed (patterned). The problem that Al and ITO are eroded by the electrolytic corrosion reaction during the formation of the resist pattern (first problem), and the problem that the residual DC voltage is generated in the reflective electrode film 106a region and flicker occurs (first problem). 2).

  First, the problem of the first electrolytic corrosion reaction will be described. For example, in the structure of the conventional transflective liquid crystal display device as shown in FIG. 30, in order to connect the transparent electrode film 105 to the source electrode 102b of the TFT 103 through the reflective electrode film 106a, the transparent electrode film 105 is provided inside each pixel. And the reflective electrode film 106a are formed so as to overlap each other. However, between adjacent pixels, it is necessary to electrically separate each pixel. The reflective electrode film 106a cannot be overlapped. Therefore, as shown in FIG. 31A, when the resist pattern 121 for processing the reflective electrode film 106a is formed, the reflective region PXb of each pixel in the reflective electrode film conductive film previously formed on the entire surface. It must be formed to cover only the side (left side in the figure). However, as shown in FIG. 31 (b), when a crack 127 occurs for some reason in the reflective electrode film 106a on the end region (region surrounded by a broken line) of the transparent electrode film 105 formed previously, The developer 126 will permeate through the crack 127.

  Here, since the Al-based material that is the reflective electrode film 106a is rich in reactivity and easily reacts with oxygen, when the developer 126 permeates from the crack 127 as described above, the Al-based material is transparent. It reacts with ITO which is an oxide conductor constituting the electrode film. As a result, Al corrosion (oxidation) and ITO dissolution (reduction) called electrolytic corrosion reaction occur using the developer 126 as an electrolytic solution, and contact failure occurs between Al and ITO, as shown in FIG. As described above, peeling 128 occurs between the transparent electrode 105 and the passivation film 110 having poor adhesion. This electrolytic corrosion reaction is considered to occur by the mechanism described below.

(1) Al part with many lattice defects and impurities dissolves as a local anode, and pinholes are generated.
(2) The developer 126 comes into contact with the underlying ITO through the formed pinhole.
(3) The potential difference between the oxidation potential of Al and the reduction potential of ITO in the developer 126 serves as a driving force for the reaction, and the oxidation of Al and the reduction of ITO represented by the following equations are promoted.

Al + 4OH ⁻ → H ₂ AlO ₃ + H ₂ O + 3e (1)
In ₂ O ₃ + 3H ₂ O + 6e → 2In + 6OH ⁻ (2)

  This electrolytic corrosion reaction can be suppressed to some extent by considering the layout of the transparent electrode film 105 and the reflective electrode film 106a (how the ITO and Al overlap), but in a structure in which Al or an Al alloy is formed on the ITO. This is an essential problem, and a proposal of a structure that can reliably prevent the occurrence of this electrolytic corrosion reaction is desired.

  Next, the second flicker problem will be described. As described above, a transflective liquid crystal display device driven by an active matrix method is usually driven by an AC voltage, and a voltage applied to the counter electrode is set as a reference voltage. A voltage that changes to sex is supplied. It is desirable that the voltage applied to the liquid crystal is symmetrical between the positive voltage waveform and the negative voltage waveform. However, even if an alternating voltage having a symmetrical voltage waveform is applied to the pixel electrode, the voltage is actually applied to the liquid crystal. The voltage waveform is not symmetric due to an unintended DC component as described later. For this reason, the light transmittance when a positive voltage is applied differs from the light transmittance when a negative voltage is applied, and the luminance fluctuates with the period of the AC voltage applied to the pixel electrode, causing flicker called flicker. appear. As will be described later, the flicker occurs due to alignment films 129 formed on the surfaces of the counter substrate 116 and the active matrix substrate 112 on both sides of the liquid crystal layer 117 in order to control the alignment of liquid crystal molecules.

  As the alignment film 129, the mechanical strength of the film itself is sufficient for rubbing a thin film of about several hundreds of millimeters, and resistance to these solvents because it is washed with water or an organic solvent after rubbing. In general, polyimide is used because it has heat resistance against heat curing conditions of an epoxy resin used as a sealing material when liquid crystal is sealed. However, this polyimide is known to generate electrons inside when it is rubbed or irradiated with intense light.

  In the transflective liquid crystal display device of FIG. 30, the transparent electrode film 105 and the reflective electrode film 106a are formed on the active matrix substrate 112, and the upper layer (the surface on the insertion surface side of the liquid crystal layer 117) is made of polyimide. The alignment film 129 is applied, but electrons are generated inside the polyimide by rubbing or light irradiation as described above. The Al surface constituting the reflective electrode film 106a is easily oxidized, and a Schottky barrier is generated at the polyimide / Al interface, so that electrons inside the polyimide are unlikely to escape to the outside through the Al electrode. On the other hand, since the ITO that is the transparent electrode film 105 is not oxidized, a Schottky barrier does not occur at the interface between the polyimide and the ITO, and electrons accumulated in the polyimide can escape from the ITO to the outside. As a result, electrons remain only in the polyimide that is the alignment film 129 on the reflective electrode film 106a, and a residual DC voltage is generated. The waveform of the AC voltage applied to the pixel electrode due to the DC component does not become symmetrical, and flicker occurs.

  This second problem is also an essential problem in the structure in which the reflective electrode film 106a made of Al or the like is formed on the uppermost layer of the active matrix substrate 112 and the alignment film 129 made of polyimide is applied on the upper surface thereof. A proposal of a structure that can suppress the occurrence of flicker due to the residual DC voltage is desired.

  Among the above two problems, the problem of the electrolytic corrosion reaction can be suppressed by improving the planar layout of the transparent electrode film 105 and the reflective electrode film 106a and the structure of the reflective electrode film 106a. The inventor of the present invention has proposed various improvements in the prior application (Japanese Patent Application No. 2001-237887). Hereinafter, the transflective liquid crystal display device according to the prior application will be described with reference to FIGS. 32 and 33. FIG. 32 is a plan view showing the configuration of the transflective liquid crystal display device, and FIG. 33 is a cross-sectional view taken along line HH in FIG.

  As shown in FIGS. 32 and 33, an active matrix substrate 112 used in the transflective liquid crystal display device includes a transparent insulating substrate 108, gate lines 101 and data lines 102 formed on the transparent insulating substrate 108, A gate electrode 101a connected to the gate line 101, a gate insulating film 109, a semiconductor layer 103a, and a drain electrode 102a and a source electrode 102b that are drawn from both ends of the semiconductor layer 103a and connected to the data line 102 and the pixel electrode, respectively. And a passivation film 110, a concavo-convex film 111 formed on the entire surface of the pixel, a transparent electrode film 105 formed on the concavo-convex film 111 in the transmission region PXa, and the entire periphery of the transparent electrode film 105. As one of means for suppressing the electrolytic corrosion reaction, the reflective electrode film 106a having a laminated structure is provided. We propose a structure for adjusting the planar positional relationship between the transparent electrode film 105 and the reflective electrode film 106a.

  That is, as shown in FIG. 31, the galvanic reaction is largely caused by the occurrence of a crack 127 in the reflective electrode film 106a having a thin film at the end of the transparent electrode film 105, and the developer 126 penetrating therefrom. Therefore, in the invention of the prior application, as shown in FIGS. 32 and 33, the end of the transparent electrode film 105 is formed by overlapping the reflective electrode film 106 a with the entire circumference of the transparent electrode film 105 with a width of, for example, 2 μm or more. The entire periphery of the portion is covered with the resist pattern 121 to prevent the developer 126 from entering.

  In addition, since the electrolytic corrosion reaction is caused by the developer 126 penetrating the Al / ITO interface through the Al pinhole, the reflective electrode film 106a is placed on a barrier metal film such as molybdenum and a metal such as Al or Al alloy. A structure in which films are laminated and each metal film is formed with a film thickness of 100 nm or more to prevent the developer 126 from reaching ITO or peeling at the interface between the transparent electrode film 105 and the uneven film 111. In order to suppress this, the conditions of the UV (Ultra-Violet) treatment and the oxygen ashing treatment of the uneven film 111 performed before forming the transparent electrode film 105 are appropriately set. A means for improving the adhesion of the developer 126 and suppressing the intrusion of the developer 126 is proposed.

  By using the various structures and manufacturing methods described in the above-mentioned prior application, it is possible to suppress the electrolytic corrosion reaction during the formation of the resist pattern when patterning the reflective electrode film 106a. Even in the structure of the liquid crystal display device, since the alignment film (polyimide) 129 is formed on the reflective electrode film (Al) 106a, flicker caused by the residual DC voltage cannot be prevented for the reasons described above. Therefore, as a result of intensive studies on the structure that solves the two problems of electrolytic corrosion and flicker, the inventor of the present invention, as a result, the stacking relationship between the transparent electrode film 105 and the reflective electrode film 106a is reversed from the conventional one. A transflective liquid crystal display device based on a structure in which a transparent electrode film 105 made of ITO is formed directly or via an insulating film on a reflective film 106 containing Al or Al alloy is effective. I found it.

  The present invention has been made in view of the above-described circumstances, and prevents the electrolytic corrosion reaction between the reflective electrode film and the transparent electrode film and suppresses the occurrence of flicker due to the residual DC voltage of the reflective electrode film. An object of the present invention is to provide a transflective liquid crystal display device and a manufacturing method thereof.

In order to solve the above problem, the invention according to claim 1 is directed to a plurality of signal electrodes arranged in parallel to each other along a first direction, and along a second direction orthogonal to the first direction. An active matrix substrate comprising a plurality of scanning electrodes arranged in parallel to each other, and a plurality of pixel regions with TFTs provided in a one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes; A counter substrate disposed opposite to the substrate and provided with a counter electrode, a liquid crystal layer interposed between the active matrix substrate and the counter substrate, and a backlight light source for supplying light to the liquid crystal layer In addition, each of the pixel areas includes a reflective area including a reflective film for receiving and reflecting external ambient light during the reflective display mode operation, and the backlight light source during the transmissive display mode operation. And a transflective liquid crystal display device provided with a transmissive region having a transparent electrode film for transmitting and transmissive display. In each of the pixel regions, the reflective film is formed of an uneven first insulating film. And the transparent electrode film extends to the reflective film in a form that covers a part or all of the reflective film via the second insulating film, and Through the first contact hole formed through the first insulating film and the second insulating film , the transparent electrode film, the source electrode of the TFT formed under the first insulating film, Are connected, and the reflective film and the source electrode are connected through a second contact hole formed only through the first insulating film, and the reflective film and the transparent electrode film are connected via the source electrode. Characterized by being electrically connected It is.

Further, an invention according to claim 2 wherein, characterized in that relates to transflective liquid crystal display device according to claim 1, wherein said reflective film is made of a conductive material including Al or Al alloy, the transparent electrode film is made of ITO It is said.

According to a third aspect of the present invention, the plurality of signal electrodes arranged in parallel with each other along the first direction and the plurality of signal electrodes arranged in parallel with each other along the second direction orthogonal to the first direction. An active matrix substrate comprising a plurality of scanning electrodes, and a plurality of pixel regions with TFTs provided in one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes, and disposed opposite the active matrix substrate Each pixel region including a counter substrate having a counter electrode, a liquid crystal layer interposed between the active matrix substrate and the counter substrate, and a backlight light source for supplying light to the liquid crystal layer. However, when the reflective display mode is operated, the reflective area is provided with a reflective film for receiving and displaying external ambient light, and when the transmissive display mode is operated, the backlight light source is transmitted and transmissively displayed. A transflective liquid crystal display device provided with a transparent region for providing a transparent electrode film, wherein in each of the pixel regions, the reflective film is provided on an uneven first insulating film, and The transparent electrode film is extended to the reflective film in a form that covers a part or all of the reflective film via a second insulating film, and the transparent electrode film and the first insulating film and the Through the first contact hole formed through the second insulating film , the transparent electrode film and the source electrode of the TFT formed under the first insulating film are connected , and the first The reflective film and the source electrode are connected through a second contact hole formed only through the insulating film, and the reflective film and the transparent electrode film are electrically connected through the source electrode. And a first gap in the reflective region Serial and second gap in the transmission region, depending on the twist angle of the liquid crystal layer, the reflectance and transmittance in the white display is characterized in that it is adjusted to maximize.

According to a fourth aspect of the present invention, there is provided the transflective liquid crystal display device according to the third aspect , wherein when the twist angle of the liquid crystal is set to approximately 72 °, the first gap of the reflective region and the transmissive The second gap of the region is adjusted so as to substantially match.

According to a fifth aspect of the present invention, in the transflective liquid crystal display device according to the third aspect , when the twist angle of the liquid crystal is set to approximately 0 °, the first gap of the reflective region is the transmissive It is characterized by being adjusted so as to be approximately half of the second gap of the region.

According to a sixth aspect of the invention, there is provided the transflective liquid crystal display device according to the third aspect , wherein when the twist angle of the liquid crystal is set to about 60 °, the first gap of the reflective region is the transmissive side. It is characterized by being adjusted to be approximately 70% of the second gap in the region.

According to a seventh aspect of the present invention, the plurality of signal electrodes arranged in parallel with each other along the first direction and the plurality of signal electrodes arranged in parallel with each other along the second direction orthogonal to the first direction. An active matrix substrate comprising a plurality of scanning electrodes, and a plurality of pixel regions with TFTs provided in one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes, and disposed opposite the active matrix substrate Each pixel region including a counter substrate having a counter electrode, a liquid crystal layer interposed between the active matrix substrate and the counter substrate, and a backlight light source for supplying light to the liquid crystal layer. However, when the reflective display mode is operated, the reflective region is provided with a reflective film on the concavo-convex film for receiving and reflecting external ambient light, and when the transmissive display mode is operated, the backlight light source is transmitted and transmitted. The present invention relates to a method of manufacturing a transflective liquid crystal display device provided with a transmissive region having a transparent electrode film for display, the surface of the active matrix substrate facing the counter substrate, on the counter surface forming a second contact hole penetrating the first insulating film preformed uneven, and forming the reflective film of the reflective region on the first insulating film, said first through second contact hole, forming the a reflecting film, a step of connecting the source electrode of the first of the TFT which is previously formed under the insulating film, a second insulating film on the reflecting film A step of forming a first contact hole penetrating the first insulating film and the second insulating film, and the transparent electrode film constituting the transmissive region extending to the reflective film One of the reflective films Or in a manner to cover the entirety, thereby forming the transparent electrode film on the second insulating film, and connecting the source electrode and the transparent electrode layer through the first contact hole, via the source electrode And a step of electrically connecting the reflective film and the transparent electrode film.

In the invention according to claim 8, the plurality of signal electrodes arranged in parallel to each other along the first direction and the plurality of signal electrodes arranged in parallel to each other along the second direction orthogonal to the first direction. An active matrix substrate comprising a plurality of scanning electrodes, and a plurality of pixel regions with TFTs provided in one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes, and disposed opposite the active matrix substrate Each pixel region including a counter substrate having a counter electrode, a liquid crystal layer interposed between the active matrix substrate and the counter substrate, and a backlight light source for supplying light to the liquid crystal layer. However, when the reflective display mode is operated, the reflective area is provided with a reflective film for receiving and displaying external ambient light, and when the transmissive display mode is operated, the backlight light source is transmitted and transmissively displayed. The present invention relates to a method of manufacturing a transflective liquid crystal display device provided with a transparent region having a transparent electrode film for forming a surface of the active matrix substrate facing the counter substrate, the surface being formed in advance on the counter surface forming a second contact hole penetrating the been uneven of the first insulating film, over the first insulating film, thereby forming the reflective film of the reflective region, the second Connecting the reflective film and the source electrode of the TFT previously formed below the first insulating film through the contact hole, and forming a second insulating film on the reflective film a step, a step of forming a first contact hole penetrating the wherein the first insulating film a second insulating film, the transparent electrode film of the transparent region, is extended to the reflective film some of the reflection film Te or whole In a manner covering said as to form the transparent electrode film on the second insulating film, and connecting the source electrode and the transparent electrode layer through the first contact hole, the via the source electrode Using the active matrix substrate completed including at least a step of electrically connecting the reflective film and the transparent electrode film, and the counter substrate completed in advance, the liquid crystal layer is interposed between both substrates. Then, according to the twist angle of the liquid crystal layer, the first gap of the reflective region and the second gap of the transmissive region are adjusted so that the reflectance and transmittance in white display are maximized. It is a feature.

A ninth aspect of the invention relates to a method of manufacturing a transflective liquid crystal display device according to the eighth aspect of the invention, wherein the surface of the active matrix substrate facing the counter substrate is provided with the first insulating film interposed therebetween. By forming the reflective film, the first gap of the reflective region and the second gap of the transmissive region have maximum reflectance and transmittance in white display according to the twist angle of the liquid crystal layer. It is characterized by adjusting so as to become.

According to a tenth aspect of the present invention, there is provided the method of manufacturing a transflective liquid crystal display device according to the eighth aspect, wherein the surface of the active matrix substrate facing the counter substrate is processed to thereby twist the liquid crystal. Accordingly, the first gap of the reflective region and the second gap of the transmissive region are adjusted so that the reflectance and transmittance in white display are maximized.

The invention according to claim 11 relates to the method of manufacturing a transflective liquid crystal display device according to claim 9 , wherein the thickness of the first insulating film is made different between the transmissive region and the reflective region. It is a feature.

  According to the transflective liquid crystal display device and the manufacturing method thereof of the present invention, the reflective film made of Al or Al alloy or the like is used as the lower layer, and the transparent electrode film made of ITO or the like is formed on the reflective film directly or via the insulating film. Since the transflective liquid crystal display device is configured based on the structure, it is possible to prevent the electrolytic corrosion reaction between the reflective electrode film and the transparent electrode film and to suppress the occurrence of flicker due to the residual DC voltage of the reflective electrode film. it can.

  A reflective film made of Al or Al alloy or the like is used as a lower layer, and a transparent electrode film made of ITO or the like is formed thereon via an insulating film (passivation film).

FIG. 1 is a plan view showing a configuration of a transflective liquid crystal display device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIGS. FIG. 5 is a sectional view showing another structure of an active matrix substrate used in the transflective liquid crystal display device, and FIG. 6 is a transflective liquid crystal display device. FIG. 7 is a cross-sectional view showing a first modified example (twist angle is about 60 °), and FIG. 7 is a cross-sectional view showing a second modified example (twist angle is about 60 °) of the transflective liquid crystal display device. In this example, a description will be given of an example in which the twist angle is set to approximately 72 °, that is, an example in which the reflection gap and the transmission gap are equal.
As shown in FIGS. 1 and 2, the transflective liquid crystal display device of this example includes an active matrix substrate 12 on which a TFT 3 that operates as a switching element is formed, a counter substrate 16, and both substrates 12 and 16. The inserted liquid crystal layer 17, the backlight source 18 disposed on the back surface of the active matrix substrate 12, and a retardation plate (λ / 4 plate) 20 a provided outside each of the active matrix substrate 12 and the counter substrate 16. , 20b and polarizing plates 19a, 19b.

Here, the active matrix substrate 12 includes a transparent insulating substrate 8, a gate line (scanning electrode) 1 and a data line (signal electrode) 2 formed on the transparent insulating substrate 8, and a gate electrode connected to the gate line 1. 1a, the common storage line and auxiliary capacitance electrode 4a, the gate insulating film 9, the semiconductor layer 3a, and the both ends of the semiconductor layer 3a are connected to the data line 2 and the pixel electrode (transparent electrode film 5), respectively. A drain electrode 2a, a source electrode 2b, a capacitor storage electrode 2c, and a passivation film 10 are provided. Here, the pixel electrodes are provided in one-to-one correspondence with the intersections between the signal electrodes 2 and the scanning electrodes 1. The pixel area PX is provided with a transmission area PXa that transmits incident light from the backlight light source 18 and a reflection area PXb that reflects incident external ambient light. Covered by the film 11. In the reflective region PXb, a reflective film 6 containing Al or an Al alloy (in this example, the metal film formed in the reflective region PXb does not need to be used as an electrode and is referred to as the reflective film 6) is formed on the uneven film 11 . Then, the transparent electrode film 5 made of ITO or the like is formed on the entire surface of each pixel region PX with the second passivation film 24 in a manner covering the reflective film 6. The transparent electrode film 5 connected to the source electrode 2b through the contact hole 7 functions as a pixel electrode, and an alignment film 29 made of polyimide or the like is formed on the transparent electrode film 5. Here, TFT3 is comprised by the gate electrode 1a, the gate insulating film 9, the semiconductor layer 3a, the drain electrode 2a, and the source electrode 2b. On the other hand, the counter substrate 16 includes a transparent insulating substrate 13, a color filter 14, a black matrix (not shown), a counter electrode 15, and an alignment film 29.

  As in this example, the transparent electrode film 5 is formed on the reflective film 6 via the second passivation film 24, so that the ITO that is the transparent electrode film 5 is formed when the resist pattern is formed when the reflective film 6 is processed. Therefore, even when the developer enters from the Al pinhole, the electrolytic corrosion reaction does not occur, and pixel defects such as peeling can be prevented. However, when the vertical relationship between the reflective film 6 and the transparent electrode film 5 is simply reversed as in the conventional example, when the resist pattern for processing the transparent electrode film 5 is formed, the transparent electrode film 5 is formed at the end of the reflective film 6. When an area with insufficient coverage occurs, the lower layer Al may come into contact with the developer to cause an electrolytic corrosion reaction, which may erode Al or ITO.

  Therefore, in this example, when the transparent electrode film 5 is formed on the upper layer of the reflective film 6, both are laid out so that the transparent electrode film 5 overlaps the entire periphery of the reflective film 6. Specifically, as shown in FIGS. 1 and 2, the reflective film 6 is formed in the reflective region PXb including the upper layer of the TFT 3, and the transparent electrode film 5 is formed over the entire pixel so as to completely cover the reflective film 6. ing.

  Therefore, when the resist pattern for processing the transparent electrode film 5 is formed, the reflective film 6 is completely covered with the transparent electrode film 5 via the second passivation film 24, thereby preventing contact between Al and the developer. be able to. Thereby, the electrolytic corrosion reaction between Al and ITO can be reliably prevented, and the occurrence of defects due to the electrolytic corrosion reaction can be prevented.

  As described above, by covering the TFT 3 with the reflective film 6, when external ambient light is incident on the TFT 3, this incident light can be shielded by the reflective film 6. As a result, it is possible to prevent a malfunction in which the off-current of the TFT 3 increases due to the photoelectric effect caused by the incident light and causes malfunction. However, if the distance between the reflective film 6 and the TFT 3 is short, the potential of the electrically reflective film 6 changes due to the voltage (particularly the gate voltage) applied to the TFT 3, and the control electric field of the liquid crystal is changed. There is a risk of disturbing. Therefore, in this example, the uneven film 11 is also formed on the TFT 3, and the distance between the TFT 3 and the reflective film 6 is increased by interposing the uneven film 11, whereby the reflective film 6 by the voltage applied to the TFT 3 is obtained. Mitigates the impact on

  Further, since the reflective film 6 is covered with the transparent electrode film 5 via the second passivation film 24, polyimide as the alignment film 29 and Al as the reflective film 6 are formed on the upper surface of the active matrix substrate 12. Therefore, the accumulation of electric charges inside the polyimide is suppressed, the generation of flicker due to the residual DC voltage is prevented, and the problems of the electrolytic corrosion reaction and flicker are solved at the same time.

  In the structure of this example, Al as the reflective film 6 and polyimide as the alignment film 29 do not contact each other, but ITO as the transparent conductive film 5 is formed on the upper surface of the active matrix substrate 12. , ITO contacts the polyimide. However, since ITO is not oxidized, there is no Schottky barrier at the polyimide / ITO interface, and electrons generated by rubbing or the like escape from ITO to the outside, so that no residual DC voltage is generated.

Next, with reference to FIG. 3 and FIG. 4, a manufacturing method of the transflective liquid crystal display device of this example will be described in the order of steps. In the method of manufacturing the transflective liquid crystal display device of this example, in addition to the method of manufacturing the pixel structure, a G (Gate) -D (Drain) conversion unit for preventing a short circuit of the lead wiring due to the conductive seal. A specific structure manufacturing method will also be described.
Here, when the drain electrode 2a needs to be electrically pulled out to the outside, the GD conversion unit is prone to short-circuit due to structural limitations and difficult to directly pull out. It is provided for drawing out by the gate line.
First, as shown in FIG. 3A, a metal such as Cr is deposited on the entire surface of a transparent insulating substrate 8 such as glass, and then unnecessary metal is removed using a known photolithography technique and etching technique. A gate line 1, a gate electrode 1a, a common storage line 4 and an auxiliary capacitance electrode 4a are formed. Note that components not shown in FIG. 3 are shown in FIG. Next, a gate insulating film 9 such as SiO ₂ , SiN _x , or _{SiO x} is formed on the entire surface. Next, a (amorphous) -Si or the like is deposited on the entire surface, and then patterned into an island shape to form the semiconductor layer 3a. Next, after depositing a metal such as Cr on the entire surface, patterning is performed to form the data line 2, the drain electrode 2a, the source electrode 2b, and the capacitor storage electrode 2c. Thus, the TFT 3 is formed. Thereafter, a passivation film 10 made of a SiN _x film or the like is deposited on the entire surface by a plasma CVD (Chemical Vapor Deposition) method or the like to protect the TFT 3. Further, the GD conversion unit and the terminal unit are set outside the pixel region PX on the transparent insulating substrate 8.

  Next, as shown in FIG. 3B, a photosensitive acrylic resin such as PC403, 415G, or 405G made by JSR is applied onto the passivation film 10 by a spin coating method, and the concavo-convex film 11 is applied to the pixel region PX. Form. The uneven film 11 is formed to increase the visibility of the reflected light when incident light, which is external ambient light, is reflected by a reflective film 6 described later. In the photosensitive acrylic resin, the concave portions in the concave-convex film 11 are exposed with a relatively small amount of light, while the convex portions are unexposed, and the region where the contact hole 7 is formed, the GD conversion portion, the terminal portion, This area is exposed with a relatively large amount of light.

  In order to perform such exposure, for example, a portion corresponding to the convex portion is a reflective film, a contact hole 7, a portion corresponding to the GD conversion portion and a terminal portion is a transmission film, and a portion corresponding to the concave portion is used. May be a halftone (gray tone) mask on which a semi-transmissive film is formed. By using such a halftone mask, irregularities can be formed by one exposure. In addition, even if it uses a reflecting film and a transmissive film as a photomask, or the contact hole 7 and a recessed part are separately exposed and the exposure amount is changed, the unevenness can be formed.

  Thereafter, using an alkaline developer, irregularities are formed by utilizing the difference in dissolution rate between the respective alkaline solutions such as the concave portions, the convex portions, and the contact holes 7. In the figure, the uneven film 11 is formed over the entire pixel area PX including the reflective area PXb and the transmissive area PXa, but the surface of the uneven film 11 formed in the transmissive area PXa is flattened without providing any unevenness. Also good. Further, when the uneven film 11 is formed also in the transmission region PXa, the acrylic film is decolored by performing an exposure process on the entire surface in order to suppress attenuation of transmitted light by the uneven film 11. Thereafter, for example, the uneven film 11 having a desired shape is formed by curing at 220 ° C. for about 1 hour.

  Here, as described above, if the distance between the TFT 3 and the reflective film 6 formed on the TFT 3 is narrow, the potential of the reflective film 6 fluctuates due to the gate voltage applied to the TFT 3 and the control electric field of the liquid crystal is disturbed. The display quality may be degraded. Therefore, in this example, the uneven film 11 is also formed on the TFT 3.

  Next, as shown in FIG. 3C, after Al is deposited on the entire surface by using a sputtering method or an evaporation method, only the inner reflection region PXb of the pixel region PX is covered with a resist pattern, and the exposed Al is partially coated. The reflective film 6 is formed by dry etching or wet etching. At this time, the reflective film 6 is also formed on the TFT 3 so that external ambient light does not enter the TFT 3. In this case, the reflective film 6 is formed in a region inside the gate line 1 and the data line 2 so as to suppress the influence of the gate line 1 and the data line 2 and to be completely covered with the transparent electrode film 5 thereafter. In addition, although Al or Al alloy is normally used for this reflective film 6, it is not restricted to these materials, Arbitrary metals with a high reflectance and suitable for a liquid crystal process can be used.

Next, as shown in FIG. 4A, after an insulating film made of SiO _x or the like is deposited on the entire surface by plasma CVD or the like, a resist pattern is formed on the insulating film, and the second passivation film 24 is formed. Form. Next, the exposed portions of the second passivation film 24, the passivation film 10, and the gate insulating film 9 are selectively etched to expose the source electrode 2b through the contact hole 7, and the GD conversion unit and Contact holes are also formed in the terminal portions.

  Next, as shown in FIG. 4B, after depositing a transparent conductive film such as ITO on the entire surface by sputtering, the transparent electrode film 5 covering the entire surface of each pixel using a resist pattern, GD conversion The electrode 22 and the terminal electrode 23 are formed simultaneously. At this time, in order to prevent the electrolytic corrosion reaction of the lower reflective film 6, for example, the transparent electrode film 5 is formed on the gate line 1 and the data line 2 so as to cover the entire reflective film 6. Such a laminated structure and layout structure of the reflective film 6 and the transparent electrode film 5 can prevent the reflective film 6 from coming into contact with the developer.

  In this example, since the second passivation film 24 is formed between the reflective film 6 and the transparent electrode film 5 and the reflective film 6 is in an electrically floating state, the gate applied to the TFT 3 Although there is a concern that the potential of the reflective film 6 fluctuates due to voltage or the like, as described above, the uneven film 11 is also formed on the TFT 3, and the uneven film 11 secures the distance between the TFT 3 and the reflective film 6. Thus, the influence of the TFT 3 on the reflective film 6 can be sufficiently mitigated.

  Thereafter, an alignment film 29 made of polyimide is formed on the transparent electrode film 5 to complete the active matrix substrate 12. Next, a completed counter substrate 16 is prepared by sequentially forming the color filter 14, the black matrix, the counter electrode 15, the alignment film 29, and the like on the transparent insulating substrate 13. Then, the liquid crystal layer 17 is inserted between both the substrates 12 and 16, phase difference plates 20a and 20b and polarizing plates 19a and 19b are disposed on both sides of each of the substrates 12 and 16, and polarization on the active matrix substrate 12 side. By installing the backlight source 18 on the back surface of the plate 19a, the transflective liquid crystal display device of this example as shown in FIGS. 1 and 2 is manufactured.

  Thus, according to the transflective liquid crystal display device of this example and the method for manufacturing the same, the transparent electrode film 5 is formed on the upper layer (the liquid crystal insertion surface side) of the reflective film 6 with the second passivation film 24 interposed therebetween. Therefore, the electrolytic corrosion reaction between Al and ITO can be prevented and pixel defects can be prevented, and the occurrence of flicker due to residual DC potential can be prevented by preventing Al and polyimide from contacting each other. In addition, a transflective liquid crystal display device in which GD conversion is performed on the outer periphery of the liquid crystal panel can be obtained.

In this example, the second passivation film 24 is provided in both the reflective region PXb and the transmissive region PXa. However, the second passivation film 24 directly connects the reflective film 6 and the transparent electrode film 5 to each other. The second passivation film 24 may be formed only on the reflective film 6 as shown in FIG. 5 because it is provided to prevent contact. In this case, after forming the SiN _x film in the step of FIG. 4A and before forming contact holes on the source electrode 2b, the GD conversion portion and the terminal portion, the resist pattern is used as a transmission region. The second passivation film 24 of PXa is removed. Alternatively, Al and SiN _x are continuously formed in the step of FIG. 3C, and the second passivation film 24 and the reflective film 6 in the transmission region PXa are simultaneously removed using the resist pattern as a mask, and thereafter A process substantially similar to the process described above is performed. Thereby, the active matrix substrate 12 having a structure as shown in FIG. 5 is finally completed, and a transflective liquid crystal display device using the active matrix substrate 12 can be manufactured.

  Further, the transflective liquid crystal display device of this example is an example using a liquid crystal having a twist angle of about 72 °, so that the reflection gap dr and the transmission gap df are equal, that is, the reflection region PXb and the transmission region. An uneven film 11 having a film thickness substantially equal to both PXa is formed. However, as shown in the prior art, even when the twist angle of the liquid crystal is set to approximately 0 ° or approximately 60 °, the optimum emission light intensity can be obtained by changing the reflection gap dr and the transmission gap df.

  FIG. 6 is a cross-sectional view showing a first modification of the transflective liquid crystal display device of this example. As shown in the figure, the transflective liquid crystal display device has a twist angle of liquid crystal set to approximately 0 °, and the uneven film 11 is formed only in the reflective region PXb. By setting it to 4 μm (2.9 μm-1.5 μm), the reflection gap is optimized to about 1.5 μm. In order to realize this structure, for example, when forming the concavo-convex film 11 in the step of FIG. 3B, the coating condition of the photosensitive acrylic resin is adjusted so that the film thickness becomes approximately 1.4 μm. When the contact hole 7 is formed on the source electrode 2b, the uneven film 11 in the transmission region PXa may be removed at the same time. Thereafter, a process substantially similar to the above-described process is performed, and finally, as shown in FIG. 6, the twist gap corresponds to approximately 0 °, the reflection gap dr is approximately 1.5 μm, and the transmission gap df is approximately 2. A 9 μm transflective liquid crystal display device is manufactured.

  FIG. 7 is a cross-sectional view showing a second modification of the transflective liquid crystal display device of this example. As shown in the figure, the transflective liquid crystal display device sets the twist angle of the liquid crystal to about 60 ° and forms the concavo-convex film 11 in both the reflective region PXb and the transmissive region PXa. By setting the thickness of the concavo-convex film 11 to be slightly thin, the reflection gap dr is optimized to approximately 2.0 μm and the transmission gap df is optimized to approximately 2.8 μm. In this case, the reflection gap dr is approximately 70% of the transmission gap df. In order to realize this structure, it is difficult to accurately control the thickness of the photosensitive acrylic resin. Therefore, as shown in FIG. 7, the uneven film 11 is formed in both the reflective region PXb and the transmissive region PXa ( In addition, the surface of the transmission region PXa may or may not be uneven), and a recess having a depth of about 0.8 μm (2.8 μm−2.0 μm) is provided only in the transmission region PXa of the counter substrate 16 for transmission. It is desirable that the gap be adjusted. In order to realize this structure, for example, a depression may be provided in the color filter 14 in the process of forming the color filter 14, or a depression may be formed in the transparent insulating substrate 13 in advance. Thereafter, a process substantially similar to the above-described process is performed, so that the twist angle as shown in FIG. 7 finally corresponds to approximately 60 °, the reflection gap dr is approximately 2.0 μm, and the transmission gap df is approximately 2. An 8 μm transflective liquid crystal display device is manufactured.

FIG. 8 is a cross-sectional view showing a configuration of a transflective liquid crystal display device according to a second embodiment of the present invention. FIGS. 9 and 10 are process diagrams showing a method of manufacturing the transflective liquid crystal display device in order of steps. 11 is a sectional view showing a first modification of the transflective liquid crystal display device (twist angle is approximately 0 °), and FIG. 12 is a second modification of the transflective liquid crystal display device (twist angle is approximately 60). FIG. The configuration of the transflective liquid crystal display device according to the second embodiment is greatly different from that of the first embodiment described above, and the second passivation film is not required in order to simplify the process. The transparent electrode film is formed on the surface. In this example, a description will be given of an example in which the twist angle is set to approximately 72 °, that is, an example in which the reflection gap and the transmission gap are equal.
In the transflective liquid crystal display device of this example, as shown in FIG. 8, a reflective film 6 containing Al or an Al alloy is formed in the reflective region PXb, and the reflective region 6 is covered on the entire surface of each pixel region PX. A transparent electrode film 5 made of ITO or the like is formed. In this example, as described later, the reflective film 6 is connected to the transparent electrode film 5 and used as a part of the pixel electrode.
Except this, it is substantially the same as the first embodiment described above. Therefore, in FIG. 8, the same reference numerals are given to the respective parts corresponding to the constituent parts in FIG. 1, and the description thereof is omitted.

Next, with reference to FIG. 9 and FIG. 10, the manufacturing method of the transflective liquid crystal display device of this example will be described in the order of steps.
As in the first embodiment described above, first, as shown in FIG. 9A, a gate line 1 and a gate electrode 1a are formed on a transparent insulating substrate 8 such as glass by a method substantially similar to that in the first embodiment. After forming the common storage line 4 and the auxiliary capacitance electrode 4a, the semiconductor layer 3a is formed through the gate insulating film 9. Next, after forming the TFT 3 by forming the data line 2, the drain electrode 2a, the source electrode 2b, and the capacitor storage electrode 2c, the passivation film 10 is formed. Components not shown in FIG. 9 are shown in the corresponding FIG.

  Next, as shown in FIG. 9B, a photosensitive acrylic resin is applied on the passivation film 10 by a method substantially the same as that in the first embodiment, and then the contact hole 7 and the G− region outside the pixel region PX are applied. The concavo-convex film 11 is formed in the reflection region PXb and the transmission region PXa including the TFT 3 by removing the acrylic resin in the D conversion portion and the terminal portion. In this case, in order to suppress attenuation of transmitted light due to the uneven film 11, it is preferable to perform exposure processing on the entire surface to decolorize the acrylic film.

  Next, as shown in FIG. 9C, Al is formed on the entire surface by a method substantially the same as that of the first embodiment, and then the Al in the transmission region PXa is removed using the resist pattern as a mask, so that the reflection region PXb. Only the reflective film 6 is formed. At this time, it is preferable to form the reflective film 6 also on the TFT so that light from the outside does not enter the TFT 3.

  Next, as shown in FIG. 10A, the passivation film 10 under the contact hole 7, the passivation film 10 in the GD conversion portion and the terminal portion, and the gate insulating film 9 are selectively etched to form the source electrode 2b. And a contact hole is formed in the GD conversion part and the terminal part.

  Next, as shown in FIG. 10B, ITO is formed on the entire surface, and using the resist pattern as a mask, the transparent electrode film 5 covering the entire surface of each pixel including the reflective film 6 and the transmission region PXa, and GD The conversion electrode 22 and the terminal electrode 23 are formed simultaneously. In this example, since the reflective film 6 is not covered with the second passivation film 24 as in the first embodiment, if there is a part where the reflective film 6 is not covered with the transparent electrode film 5, the transparent electrode film processing is performed. When a resist pattern for forming a region having insufficient coverage by the transparent electrode film 5 at the end of the reflective film 6, there is a possibility that an electrolytic corrosion reaction may occur in the exposed part of the reflective film 6. It is important to form the transparent electrode film 5 so as to cover (that is, to leave a resist pattern on the entire reflective film 6).

  In the first embodiment, the second passivation film 24 is formed between the reflective film 6 and the transparent electrode film 5, and the reflective film 6 is in an electrically floating state. There is a concern that the potential of the reflective film 6 may fluctuate due to the applied gate voltage or the like, but in this example, the reflective film 6 is in direct contact with the transparent electrode film 5 and is thus conductive. The potential does not fluctuate. Therefore, since it is not necessary to ensure the distance between the TFT 3 and the reflective film 6, it is not necessary to form the uneven film 11 on the TFT 3.

  Thereafter, an alignment film 29 made of polyimide is formed on the transparent electrode film 5 by a method substantially similar to that of the first embodiment to complete the active matrix substrate 12. Next, a completed counter substrate 16 is prepared by sequentially forming the color filter 14, the black matrix, the counter electrode 15, the alignment film 29, and the like on the transparent insulating substrate 13. Then, the liquid crystal layer 17 is inserted between the substrates 12 and 16, and retardation plates 20a and 20b and polarizing plates 19a and 19b are arranged on both sides of the substrates 12 and 16, respectively, as in the first embodiment. Then, by installing the backlight light source 18 on the back surface of the polarizing plate 19a on the active matrix substrate 12 side, the transflective liquid crystal display device of this example as shown in FIG. 8 is manufactured. That is, in substantially the same manner as in the first embodiment, a liquid crystal having a twist angle of approximately 72 ° is interposed between the substrates 12 and 16, and there is no step between the reflection region PXb and the transmission region PXa (the reflection gap dr and the transmission gap df are Both of them are approximately 2.7 μm, and a transflective liquid crystal display device is manufactured. However, in FIG. 8, illustration of the phase difference plates 20a and 20b, the polarizing plates 19a and 19b, and the backlight light source 18 is omitted.

  As described above, since the transparent electrode film 5 is formed on the reflective film 6 so as to cover the reflective film 6 also by the transflective liquid crystal display device and the manufacturing method thereof of this example, It is possible to prevent the occurrence of pixel defects by preventing the erosion reaction, and by preventing the contact of Al and polyimide, it is possible to prevent the occurrence of flicker due to the residual DC voltage, and at the outer periphery of the liquid crystal panel A transflective liquid crystal display device in which a −D converter is formed can be obtained.

  In this example, as in the first embodiment, it is possible to obtain a modification in which the twist angle of the liquid crystal is set to approximately 0 ° or approximately 60 °. FIG. 11 is a cross-sectional view showing a first modified example (twist angle is approximately 0 °) of the transflective liquid crystal display device of this example. In order to realize this structure, when forming the concavo-convex film 11 in the step of FIG. 9B, the coating condition of the photosensitive acrylic resin is adjusted to set the film thickness to about 1.4 μm. When the contact hole 7 is formed on the source electrode 2b, the uneven film 11 in the transmission region PXa may be removed. Thereafter, a process substantially similar to the above-described process is performed, so that the twist angle as shown in FIG. 11 finally corresponds to approximately 0 °, the reflection gap dr is approximately 1.5 μm, and the transmission gap df is approximately 2. A 9 μm transflective liquid crystal display device is manufactured.

  FIG. 12 is a cross-sectional view showing a second modification (twist angle is approximately 60 °) of the transflective liquid crystal display device of this example. In order to realize this structure, as shown in FIG. 12, the concavo-convex film 11 is formed in both the reflective region PXb and the transmissive region PXa (the surface of the transmissive region PXa may or may not have ruggedness). The gap may be adjusted by providing a depression in the transmission region PXa of the substrate 16. Thereafter, a semi-transmission type liquid crystal display device having a reflection angle dr of about 2.0 μm and a transmission gap df of about 2.8 μm, corresponding to a twist angle of about 60 °, is performed by performing the same steps as those described above. To manufacture.

FIG. 13 is a Heisei diagram showing a configuration of a transflective liquid crystal display device according to a third embodiment of the present invention, and FIGS. 14 and 15 are process diagrams showing a manufacturing method of the transflective liquid crystal display device in the order of steps. . The configuration of the transflective liquid crystal display device of the third embodiment is greatly different from that of the first embodiment described above through a contact hole (reflection film connecting portion) in order to prevent potential fluctuation of the reflection film. Thus, the reflective film and the transparent electrode film are connected.
In the transflective liquid crystal display device of this example, as shown in FIG. 13, a reflective film 6 containing Al or an Al alloy is formed in the reflective region PXb, and this reflective film 6 is formed on the second passivation film 24. The transparent electrode film 5 is connected via the reflective film connecting portion 25.
Except this, it is substantially the same as the first embodiment described above. Therefore, in FIG. 13, parts corresponding to those in FIG.

Next, with reference to FIGS. 14 and 15, a method for manufacturing the transflective liquid crystal display device of this example will be described in the order of steps. 14 and 15 are cross-sectional views taken along the line BB in FIG.
First, as shown in FIG. 14A, a gate line 1, a gate electrode 1a, a common storage line 4 and an auxiliary line are formed on a transparent insulating substrate 8 such as glass by a method substantially the same as in the first and second embodiments. After forming the capacitor electrode 4a, the semiconductor layer 3a is formed through the gate insulating film 9. Next, after forming the TFT 3 by forming the data line 2, the drain electrode 2a, the source electrode 2b, and the capacitor storage electrode 2c, the passivation film 10 is formed.

  Next, as shown in FIG. 14B, a photosensitive acrylic resin is applied on the passivation film 10 in substantially the same manner as in the first and second embodiments, and the contact hole 7 and the G− region outside the pixel region PX are applied. The concavo-convex film 11 is formed in the reflection region PXb and the transmission region PXa including the TFT 3 by removing the acrylic resin in the D conversion portion and the terminal portion. In this case, in order to suppress attenuation of transmitted light due to the uneven film 11, it is preferable to perform exposure processing on the entire surface to decolorize the acrylic film.

  Next, as shown in FIG. 14 (c), Al is deposited on the entire surface, as in the first and second embodiments, and then the Al in the transmissive region PXa is removed using the resist pattern as a mask, thereby reflecting the reflective region. A reflective film 6 is formed on PXb. At this time, it is preferable to form the reflective film 6 also on the TFT so that light from the outside does not enter the TFT 3.

Next, as shown in FIG. 15A, after an insulating film made of SiO _x or the like is deposited on the entire surface by plasma CVD or the like, a resist pattern is formed on this insulating film, and the second passivation film 24 is formed. Form. Next, the second passivation film 24 under the contact hole 7 and the second passivation film 24 in the GD conversion part and the terminal part are selectively etched, and at the same time, the reflective film 6 is applied to the second passivation film 24. A reflection film connecting portion 25 for exposing is formed. Subsequently, the passivation film 10 under the contact hole 7, the GD conversion portion, the passivation film 10 in the terminal portion, and the gate insulating film 9 are selectively etched to expose the source electrode 2 b, and the GD conversion portion. Contact holes are also formed in the terminal portions. The reflective film connecting portion 25 can be formed at any location on the reflective film 6, but Al may be eroded by contact with the developer when the reflective film connecting portion 25 is etched. As shown in FIG. 13, it is preferably formed in the periphery of the pixel. Further, the etching of the second passivation film 24 and the etching of the passivation film 10 and the gate insulating film 9 may be performed simultaneously.

  Next, as shown in FIG. 15B, after depositing a transparent conductive film such as ITO on the entire surface by sputtering, the transparent electrode film 5 that covers the entire surface of each pixel using the resist pattern as a mask, G- The D conversion electrode 22 and the terminal electrode 23 are formed simultaneously. Such a laminated structure and layout structure of the reflective film 6 and the transparent electrode film 5 can prevent the reflective film 6 from coming into contact with the developer.

  In the first embodiment, since the reflective film 6 is in an electrically floating state, there is a concern that the potential of the reflective film 6 may fluctuate due to the gate voltage applied to the TFT 3. As in the second embodiment, since the reflective film 6 is electrically connected to the transparent electrode film 5, the potential of the reflective film 6 does not fluctuate. Therefore, in this example as well, it is not necessary to secure the distance between the TFT 3 and the reflective film 6, so that the uneven film 11 need not be formed on the TFT 3.

  Thereafter, an alignment film 29 made of polyimide is formed on the transparent electrode film 5 to complete the active matrix substrate 12. Next, a completed counter substrate 16 is prepared by sequentially forming the color filter 14, the black matrix, the counter electrode 15, the alignment film 29, and the like on the transparent insulating substrate 13. Then, the liquid crystal layer 17 is inserted between both the substrates 12 and 16, phase difference plates 20a and 20b and polarizing plates 19a and 19b are disposed on both sides of each of the substrates 12 and 16, and polarization on the active matrix substrate 12 side. By installing the backlight light source 18 on the back surface of the plate 19a, the transflective liquid crystal display device of this example as shown in FIG. 13 is manufactured.

  As described above, since the transparent electrode film 5 is formed on the reflective film 6 so as to cover the reflective film 6 also by the transflective liquid crystal display device and the manufacturing method thereof of this example, It is possible to prevent the occurrence of pixel defects by preventing the erosion reaction, and by preventing the contact of Al and polyimide, it is possible to prevent the occurrence of flicker due to the residual DC voltage, and at the outer periphery of the liquid crystal panel A transflective liquid crystal display device subjected to -D conversion can be obtained.

16 is a Heisei diagram showing the configuration of a transflective liquid crystal display device according to a fourth embodiment of the present invention, FIG. 17 is a sectional view taken along the line CC of FIG. 16, and FIG. 18 is the transflective liquid crystal display device. FIG. 19 is a cross-sectional view taken along the line DD in FIG. 18, and FIGS. 20 and 21 are process diagrams showing a method of manufacturing the transflective liquid crystal display device in the order of steps. is there. The configuration of the transflective liquid crystal display device of the fourth embodiment is greatly different from that of the third embodiment described above in that a contact hole formed in the second passivation film in order to prevent potential fluctuation of the reflection film. The reflection film and the transparent electrode film are respectively connected to the source electrode at two different points.
In the transflective liquid crystal display device of this example, as shown in FIGS. 16 to 19, the transparent electrode film 5 is formed on the reflective film 6 via the second passivation film 24 as in the first embodiment. In the configuration in which the reflective film 6 and the transparent electrode film 5 are connected as in the third embodiment, the source electrode 2b is formed in the first region 7a in the contact hole 7 formed in the second passivation film 24 and the passivation film 10. And the reflective film 6 are connected, and the source electrode 2b and the transparent electrode film 5 are connected in the second region 7b .
Except this, it is substantially the same as the third embodiment described above. Therefore, in FIG.16 and FIG.17, the same number is attached | subjected to each part corresponding to the component of FIG. 13, and the description is abbreviate | omitted.

  In order to prevent the potential fluctuation of the reflective film 6, when the reflective film 6 and the transparent electrode film 5 are connected as in the third embodiment, the Al and the transparent electrode film 5 constituting the reflective film 6 are connected as described above. When combined with the constituent ITO, depending on the process, a non-conductor such as Al oxide may be formed on the sea surface of Al and ITO, and the contact resistance between the reflective film 6 and the transparent electrode film 5 becomes as high as 10 MΩ or more. Sometimes. Therefore, in this case, since the potential fluctuation of the reflective film 6 cannot be sufficiently suppressed due to electrostatic characteristics in the manufacturing process of the liquid crystal panel, the display quality may be deteriorated.

  Therefore, in this example, the reflective film 6 and the transparent electrode are respectively formed with respect to the source electrode 2b at two different locations (first and second regions 7a and 7b) in the contact hole 7 formed in the second passivation film 24. The membrane 5 is connected. Thereby, since the reflective film 6 and the transparent electrode film 5 are not directly connected, high contact resistance is not formed as described above, and the potential fluctuation of the reflective film 6 can be sufficiently suppressed. It becomes possible to prevent the deterioration of.

Next, with reference to FIG. 20 and FIG. 21, a manufacturing method of the transflective liquid crystal display device of this example will be described in the order of steps. 20 and 21 are cross-sectional views taken along the line CC in FIG.
First, as shown in FIG. 20A, a gate line 1, a gate electrode 1a, a common storage line 4 and an auxiliary line are formed on a transparent insulating substrate 8 such as glass by a method substantially the same as in the first to third embodiments. After forming the capacitor electrode 4a, the semiconductor layer 3a is formed through the gate insulating film 9. Next, after forming the TFT 3 by forming the data line 2, the drain electrode 2a, the source electrode 2b, and the capacitor storage electrode 2c, the passivation film 10 is formed.

  Next, as shown in FIG. 20B, a photosensitive acrylic resin is applied on the passivation film 10 in substantially the same manner as in the first to third embodiments, and the contact hole 7 and the G− region outside the pixel region PX are applied. The concavo-convex film 11 is formed in the reflection region PXb and the transmission region PXa including the TFT 3 by removing the acrylic resin in the D conversion portion and the terminal portion. In this case, in order to suppress attenuation of transmitted light due to the uneven film 11, it is preferable to perform exposure processing on the entire surface to decolorize the acrylic film.

  Next, as shown in FIG. 20C, using the resist pattern formed on the concavo-convex film 11 as a mask, the passivation film 10 under the contact hole 7 is removed to expose only the source electrode 2b. At this time, the passivation film 10 and the gate insulating film 9 in the GD conversion part and the terminal part are not removed.

  Next, as shown in FIG. 20D, after Al is formed on the entire surface, the Al in the transmission region PXa is removed using the resist pattern as a mask, and the reflection film 6 is formed in the reflection region PXb. At this time, it is preferable to form the reflective film 6 also on the TFT so that light from the outside does not enter the TFT 3.

Next, as shown in FIG. 21A, after an insulating film made of SiO _x or the like is deposited on the entire surface by a plasma CVD method or the like, a resist pattern is formed on the insulating film, and the second passivation film 24 is formed. Form. Next, the second passivation film 24 under the contact hole 7, the GD conversion part, and the second passivation film 24 in the terminal part are selectively etched. Subsequently, the passivation film 10 under the contact hole 7, the GD conversion portion, the passivation film 10 in the terminal portion, and the gate insulating film 9 are selectively etched to expose the source electrode 2 b, and the GD conversion portion. Contact holes are also formed in the terminal portions. Note that the etching of the second passivation film 24 and the etching of the passivation film 10 and the gate insulating film 9 may be performed simultaneously.

  Next, as shown in FIG. 21B, after depositing a transparent conductive film such as ITO on the entire surface by sputtering, the transparent electrode film 5 that covers the entire surface of each pixel using the resist pattern as a mask, G- The D conversion electrode 22 and the terminal electrode 23 are formed simultaneously.

  Thereafter, an alignment film 29 made of polyimide is formed on the transparent electrode film 5 to complete the active matrix substrate 12. Next, a completed counter substrate 16 is prepared by sequentially forming the color filter 14, the black matrix, the counter electrode 15, the alignment film 29, and the like on the transparent insulating substrate 13. Then, the liquid crystal layer 17 is inserted between both the substrates 12 and 16, phase difference plates 20a and 20b and polarizing plates 19a and 19b are disposed on both sides of each of the substrates 12 and 16, and polarization on the active matrix substrate 12 side. By installing the backlight source 18 on the back surface of the plate 19a, the transflective liquid crystal display device of this example as shown in FIGS. 16 and 17 is manufactured.

  Thus, according to the transflective liquid crystal display device of this example and the manufacturing method thereof, in the configuration in which the transparent electrode film 5 is formed on the reflective film 6 via the second passivation film 24, the reflective film 6 The reflection film 6 and the transparent electrode film 5 are respectively connected to the source electrode 2b at two different locations 7a and 7b in the contact hole 7 formed in the second passivation film 24 in order to prevent potential fluctuations in the second passivation film 24. Since the connection resistance between the reflective film and the transparent electrode film is lowered, the display quality can be improved.

22 is a Heisei diagram showing the configuration of a transflective liquid crystal display device according to a fifth embodiment of the present invention, FIG. 23 is a cross-sectional view taken along line EE in FIG. 22, and FIG. 24 is the transflective liquid crystal display device. FIG. 25 is a sectional view taken along the line FF in FIG. 24, and FIG. 26 is a plan view showing an enlarged structure of another main part of the transflective liquid crystal display device. 27 is a cross-sectional view taken along a line G-G in FIG. 26, and FIGS. 28 and 29 are process diagrams showing a method of manufacturing the transflective liquid crystal display device in the order of processes. The configuration of the transflective liquid crystal display device of the fifth embodiment is greatly different from that of the fourth embodiment described above, in order to prevent the potential fluctuation of the reflection film, two contact holes are formed in the second passivation film. The reflective film and the transparent electrode film are connected to the source electrode in each contact hole.
In the transflective liquid crystal display device of this example, as shown in FIGS. 22 to 27, the transparent electrode film 5 is formed on the reflective film 6 via the second passivation film 24 as in the first embodiment. In the configuration in which the reflective film 6 and the transparent electrode film 5 are connected to the source electrode 2b as in the fourth embodiment, the source electrode 2b is passed through the first contact hole 7A formed in the second passivation film 24. And the transparent electrode film 5 are connected, and the source electrode 2b and the reflective film 6 are connected via the second contact hole 7B.

  Further, the positional relationship among the passivation film 10, the concavo-convex film 11, the reflective film 9, the second passivation film 24, and the transparent electrode film 5 in the first and second contact holes 7A and 7B is as shown in FIGS. It has become. That is, in the first contact hole 7 </ b> A, the uneven film 11 is disposed on the outermost periphery, and the reflective film 6, the passivation film 10, the second passivation film 24, and the transparent electrode film 5 are disposed inside the uneven film 11. In the second contact hole 7B, the uneven film 11 is disposed on the outermost periphery, and the passivation film 10, the reflective film 6, the second passivation film 24, and the transparent electrode film 5 are disposed inside the uneven film 11. 25, the transparent electrode film 5 is connected to the source electrode 2b, and the reflection film 6 is connected to the source electrode 2b as shown in FIG. As shown in FIG. 25, when the reflective film 9 is disposed outside the uneven film 11 in the first contact hole 7A, the transparent electrode film 5 is formed by the steep inclination due to the step of the reflective film 6 and the unevenness of the uneven film 11. Since there is a possibility of disconnection, it is preferable that the reflective film 6 is disposed inside the uneven film 11 in the first contact hole 7A.

  In order to prevent the potential fluctuation of the reflective film 6, at two different locations (first and second regions 7a and 7b) in the contact hole 7 formed in the second passivation film 24 as in the fourth embodiment, When the reflective film 6 and the transparent electrode film 5 are connected to the source electrode 2b, respectively, the diameter of the contact hole 7 must be increased, and the degree of freedom of the arrangement position of the contact hole 7 is reduced. Decreases.

  Therefore, in this example, the reflective film 6 and the transparent electrode film 5 are connected to the source electrode 2b in the first and second contact holes 7A and 7B formed in the second passivation film 24, respectively. As a result, the diameters of the first and second contact holes 7A and 7B can be reduced, and the degree of freedom of the arrangement positions of the contact holes 7A and 7B is increased. Accordingly, the contact holes 7A and 7B can be arranged at positions that do not contribute to the reflection characteristics (the flat portions of the concavo-convex portions) among the concavo-convex portions of the reflective film 6, so that the reflective film 6 does not deteriorate the reflective characteristics. Can be connected to the TFT 3.

Next, with reference to FIGS. 28 and 29, a method for manufacturing the transflective liquid crystal display device of this example will be described in the order of steps. 28 and 29 are cross-sectional views taken along line EE in FIG.
First, as shown in FIG. 28A, a gate line 1, a gate electrode 1a, a common storage line 4 and an auxiliary line are formed on a transparent insulating substrate 8 such as glass by a method substantially the same as in the first to fourth embodiments. After forming the capacitor electrode 4a, the semiconductor layer 3a is formed through the gate insulating film 9. Next, after forming the TFT 3 by forming the data line 2, the drain electrode 2a, the source electrode 2b, and the capacitor storage electrode 2c, the passivation film 10 is formed.

  Next, as shown in FIG. 28B, a photosensitive acrylic resin is applied on the passivation film 10, and the GD conversion outside the first contact hole 7A, the second contact hole 7B, and the pixel region PX is performed. The acrylic resin is removed from the portion and the terminal portion, and the uneven film 11 is formed in the reflective region PXb and the transmissive region PXa including the TFT 3. In this case, in order to suppress attenuation of transmitted light due to the uneven film 11, it is preferable to perform exposure processing on the entire surface to decolorize the acrylic film.

  Next, as shown in FIG. 28C, using the resist pattern formed on the concavo-convex film 11 as a mask, the passivation film 10 under the second contact hole 7B is removed to expose only the source electrode 2b. At this time, unlike the fourth embodiment, the passivation film 10 and the gate insulating film 9 in the GD conversion part and the terminal part are removed.

Next, as shown in FIG. 28D, after Al is formed on the entire surface, the Al in the transmission region PXa is removed using the resist pattern as a mask, and the reflection film 6 is formed in the reflection region PXb. At this time, it is preferable to form the reflective film 6 also on the TFT so that light from the outside does not enter the TFT 3. Further, the GD conversion electrode 22 is formed of a reflective film. Unlike the fourth embodiment, the reason why the GD conversion electrode 22 is formed of a reflective film is that a second passivation film 24 made of SiO _X or the like is formed by sputtering by forming a GD conversion portion in advance. When the TFT array is used, the TFT array is affected by plasma damage during sputtering by dropping the TFT array or data line to the ground potential or forming a shunt transistor by using the GD converter. This is to suppress deterioration.

Next, as shown in FIG. 29A, after an insulating film made of SiO _x or the like is deposited on the entire surface by a plasma CVD method or the like, a resist pattern is formed on this insulating film, and the second passivation film 24 is formed. Form. Next, the second passivation film 24 under the first contact hole 7A and the second passivation film 24 in the terminal portion are selectively etched. Subsequently, the passivation film 10 and the gate insulating film 9 in the terminal portion are selectively etched to expose the first source electrode 2b, and contact holes are also formed in the GD conversion portion and the terminal portion. Note that the removal of the passivation film 10 and the gate insulating film 9 in the terminal portion may be performed simultaneously with the step of removing the passivation film 10 under the second contact hole 7B in FIG.

  Next, as shown in FIG. 29B, after depositing a transparent conductive film such as ITO on the entire surface by sputtering, the transparent electrode film 5 that covers the entire surface of each pixel using a resist pattern as a mask, G- The D conversion electrode 22 and the terminal electrode 23 are formed simultaneously.

  Thereafter, an alignment film 29 made of polyimide is formed on the transparent electrode film 5 to complete the active matrix substrate 12. Next, a completed counter substrate 16 is prepared by sequentially forming the color filter 14, the black matrix, the counter electrode 15, the alignment film 29, and the like on the transparent insulating substrate 13. Then, the liquid crystal layer 17 is inserted between both the substrates 12 and 16, phase difference plates 20a and 20b and polarizing plates 19a and 19b are disposed on both sides of each of the substrates 12 and 16, and polarization on the active matrix substrate 12 side. By installing the backlight source 18 on the back surface of the plate 19a, the transflective liquid crystal display device of this example as shown in FIGS. 23 and 24 is manufactured.

  In this example, the transparent electrode film 5 is formed on the reflective film 6 via the second passivation film 24. However, the reflective film 6 and the transparent electrode film 5 are configured even without the second passivation film. In this case, the potential fluctuation of the reflective film can be suppressed by adopting the structure of this example.

Thus, according to the transflective liquid crystal display device of this example and the method of manufacturing the same, the source electrode is utilized using the contact hole 7 formed in the second passivation film 24 in order to prevent the potential fluctuation of the reflective film 6. 2b, the reflective film 6 and the transparent electrode film 5 are connected to the source electrode 2b through the first and second contact holes 7A and 7B formed in the second passivation film 24, respectively. Since the reflective film 6 and the transparent electrode film 5 are connected to each other, the diameters of the first and second contact holes 7A and 7B can be reduced, and the arrangement positions of the contact holes 7A and 7B can be freely set. The degree can be increased. Therefore, the reflective film 6 can be connected to the TFT 3 without deteriorating the reflection characteristics.
Further, according to this example, before the second passivation film 24 is formed, the GD conversion electrode 22 can be formed of a reflective film so that the TFT array, the data line, etc. can be dropped to the ground potential. Degradation of the TFT array characteristics due to plasma damage during the formation of the passivation film 24 can be suppressed.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the present invention can be changed even if there is a design change without departing from the gist of the present invention. include. For example, in the embodiment, the description has been given of the example in which the transmission gap and the reflection gap are optimized when the twist angle of the liquid crystal is set to approximately 0 °, approximately 60 °, and approximately 72 °. However, the twist angle is not limited to the above value. The transmission gap and the reflection gap may be optimized according to these twist angles. Moreover, although the example which uses the material containing Al or Al alloy as a reflecting film and uses ITO as a transparent electrode film demonstrated, the electrolytic corrosion reaction was easy to occur at the time of resist pattern formation between a reflecting film and a transparent electrode film. If it is a combination of materials, it is not limited to a combination of a material containing Al or an Al alloy and ITO. Further, although an example in which a TFT as a switching element is formed on an active matrix substrate has been described, the TFT does not necessarily have to be formed on the active matrix substrate side. Note that the relationship between the reflective film and the transparent electrode film in the transflective liquid crystal display device of this example as described above is applied not only to each pixel but also to each sub-pixel constituting the pixel.

1 is a plan view showing a configuration of a transflective liquid crystal display device according to a first embodiment of the present invention. It is AA arrow sectional drawing of FIG. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is sectional drawing which shows the other structure of the active matrix substrate used for the transflective liquid crystal display device. It is sectional drawing which shows the 1st modification (twist angle is about 0 degree) of the transflective liquid crystal display device. It is sectional drawing which shows the 2nd modification (a twist angle is about 60 degrees) of the transflective liquid crystal display device. It is sectional drawing which shows the structure of the transflective liquid crystal display device which is 2nd Example of this invention. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is sectional drawing which shows the 1st modification (twist angle is about 0 degree) of the transflective liquid crystal display device. It is sectional drawing which shows the 2nd modification (a twist angle is about 60 degrees) of the transflective liquid crystal display device. It is a top view which shows the structure of the transflective liquid crystal display device which is 3rd Example of this invention. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is a top view which shows the structure of the transflective liquid crystal display device which is 4th Example of this invention. It is CC sectional view taken on the line of FIG. It is a top view which shows the enlarged structure of the principal part of the transflective liquid crystal display device. It is DD sectional view taken on the line of FIG. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is a top view which shows the structure of the transflective liquid crystal display device which is 5th Example of this invention. It is EE arrow sectional drawing of FIG. It is a top view which shows the enlarged structure of the principal part of the transflective liquid crystal display device. It is FF arrow sectional drawing of FIG. It is a top view which shows the enlarged structure of the principal part of the transflective liquid crystal display device. It is GG arrow sectional drawing of FIG. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is process drawing which shows the manufacturing method of the transflective liquid crystal display device in order of a process. It is a top view which shows the structure of the conventional transflective liquid crystal display device. It is a figure which shows the problem in the conventional transflective liquid crystal display device. It is a top view which shows the structure of the transflective liquid crystal display device which concerns on a prior application. It is sectional drawing which shows the structure of the transflective liquid crystal display device based on a prior application. It is a figure which shows the polarization state of the incident light and reflected light of a transflective liquid crystal display device. It is a figure which shows the relationship between the twist angle of the liquid crystal, and the film thickness (gap) of a liquid crystal layer in a transflective liquid crystal display device. It is a figure which shows the relationship between the twist angle | corner of a liquid crystal, light transmittance, and a reflectance in a transflective liquid crystal display device.

Explanation of symbols

1 Gate line (scanning electrode)
1a Gate electrode 2 Data line (signal electrode)
2a Drain electrode 2b Source electrode 2c Capacitor storage electrode 3 TFT
3a Semiconductor layer 4 Common storage line 4a Auxiliary capacitance electrode 5 Transparent electrode film 6 Reflective film 7 Contact hole 7A First contact hole 7B Second contact hole 7a First region 7b Second region 8, 13 Transparent insulating substrate 9 Gate insulating film 10 Passivation film 11 Uneven film 12 Active matrix substrate (first substrate)
14 Color filter 15 Counter electrode 16 Counter substrate (second substrate)
17 Liquid crystal layer 18 Backlight light source 19a, 19b Polarizing plate 20a, 20b Retardation plate 21 Resist pattern 22 GD conversion electrode 23 Terminal electrode 24 Second passivation film 25 Reflective film connection part (contact hole)
26 Developer 27 Crack 28 Peel 29 Alignment film

Claims (11)

A plurality of signal electrodes arranged in parallel with each other along a first direction, a plurality of scan electrodes arranged in parallel with each other along a second direction orthogonal to the first direction, and the signal electrodes; An active matrix substrate comprising a plurality of pixel regions with TFTs provided in a one-to-one correspondence with the intersections with the scanning electrodes, a counter substrate disposed opposite to the active matrix substrate and comprising a counter electrode, A liquid crystal layer interposed between the active matrix substrate and the counter substrate; and a backlight light source for supplying light to the liquid crystal layer. A reflective region having a reflective film for receiving and reflecting ambient light, and a transparent electrode film for transmissive display through the backlight light source during transmissive display mode operation; A transflective liquid crystal display device in which a region is provided,
In each of the pixel regions, the reflective film is provided on the concavo-convex first insulating film, and the transparent electrode film is interposed between the part of the reflective film or the second insulating film. In a manner covering the whole, it extends to the reflective film, and
Through the first contact hole formed through the first insulating film and the second insulating film , the transparent electrode film and the source electrode of the TFT formed under the first insulating film And the reflective film and the source electrode are connected through a second contact hole formed only through the first insulating film, and the reflective film and the transparent electrode film are connected via the source electrode. Are electrically connected to each other. A transflective liquid crystal display device, wherein   2. The transflective liquid crystal display device according to claim 1, wherein the reflective film is made of a conductive material containing Al or an Al alloy, and the transparent electrode film is made of ITO. A plurality of signal electrodes arranged in parallel with each other along a first direction, a plurality of scan electrodes arranged in parallel with each other along a second direction orthogonal to the first direction, and the signal electrodes; An active matrix substrate comprising a plurality of pixel regions with TFTs provided in a one-to-one correspondence with the intersections with the scanning electrodes, a counter substrate disposed opposite to the active matrix substrate and comprising a counter electrode, A liquid crystal layer interposed between the active matrix substrate and the counter substrate, and a backlight light source for supplying light to the liquid crystal layer, and each pixel region has an external periphery during the reflective display mode operation. A reflective region having a reflective film for receiving and reflecting light, and a transparent electrode film for transmissive display through the backlight source during transmissive display mode operation A transflective liquid crystal display device in which a band is provided,
In each of the pixel regions, the reflective film is provided on the concavo-convex first insulating film, and the transparent electrode film is part or all of the reflective film through the second insulating film. And extending to the reflective film, and
Through the first contact hole formed through the first insulating film and the second insulating film , the transparent electrode film and the source electrode of the TFT formed under the first insulating film And the reflective film and the source electrode are connected through a second contact hole formed only through the first insulating film, and the reflective film and the transparent electrode film are connected via the source electrode. And are electrically connected,
The first gap of the reflective region and the second gap of the transmissive region are adjusted so that the reflectance and transmittance in white display are maximized according to the twist angle of the liquid crystal layer. A transflective liquid crystal display device.   4. The liquid crystal according to claim 3, wherein when the twist angle of the liquid crystal is set to approximately 72 °, the first gap of the reflective region and the second gap of the transmissive region are substantially matched. Transflective liquid crystal display device.   4. The liquid crystal according to claim 3, wherein when the twist angle of the liquid crystal is set to approximately 0 °, the first gap of the reflective region is adjusted to be approximately half of the second gap of the transmissive region. The transflective liquid crystal display device described.   2. The liquid crystal according to claim 1, wherein when the twist angle of the liquid crystal is set to approximately 60 °, the first gap of the reflective region is adjusted to be approximately 70% of the second gap of the transmissive region. 3. A transflective liquid crystal display device according to 3. A plurality of signal electrodes arranged in parallel with each other along a first direction, a plurality of scan electrodes arranged in parallel with each other along a second direction orthogonal to the first direction, and the signal electrodes; An active matrix substrate comprising a plurality of pixel regions with TFTs provided in a one-to-one correspondence with the intersections with the scanning electrodes, a counter substrate disposed opposite to the active matrix substrate and comprising a counter electrode, A liquid crystal layer interposed between the active matrix substrate and the counter substrate, and a backlight light source for supplying light to the liquid crystal layer, and each pixel region has an external periphery during the reflective display mode operation. A reflective region provided with a reflective film on the concavo-convex film for receiving and reflecting light, and a transparent electrode film for transmissive display through the backlight light source during transmissive display mode operation. A semi-transmissive-type production method of the liquid crystal display device to obtain transmissive region and are provided,
Forming a second contact hole that is a surface facing the counter substrate of the active matrix substrate and penetrates the first insulating film having a concavo-convex shape formed in advance on the counter surface;
And forming the reflective film of the reflective region on the first insulating film, said through second contact hole, wherein a reflective film, the previously formed under the first insulating film Connecting the source electrode of the TFT ;
Forming a second insulating film on the reflective film,
Forming a first contact hole penetrating the first insulating film and the second insulating film;
The transparent electrode film is formed on the second insulating film in such a manner that the transparent electrode film constituting the transmissive region extends to the reflective film and covers part or all of the reflective film. And connecting the transparent electrode film and the source electrode through the first contact hole and electrically connecting the reflective film and the transparent electrode film through the source electrode. A method for manufacturing a transflective liquid crystal display device. A plurality of signal electrodes arranged in parallel with each other along a first direction, a plurality of scan electrodes arranged in parallel with each other along a second direction orthogonal to the first direction, and the signal electrodes; An active matrix substrate comprising a plurality of pixel regions with TFTs provided in a one-to-one correspondence with the intersections with the scanning electrodes, a counter substrate disposed opposite to the active matrix substrate and comprising a counter electrode, A liquid crystal layer interposed between the active matrix substrate and the counter substrate, and a backlight light source for supplying light to the liquid crystal layer, and each pixel region has an external periphery during the reflective display mode operation. A reflective region having a reflective film for receiving and reflecting light, and a transparent electrode film for transmissive display through the backlight source during transmissive display mode operation A method of manufacturing a transflective liquid crystal display device in which a band is provided,
Forming a second contact hole that is a surface of the active matrix substrate facing the counter substrate , penetrating a first insulating film having a concavo-convex shape formed in advance on the counter surface; The reflective film constituting the reflective region is formed on the insulating film, and the reflective film and the TFT formed in advance under the first insulating film are formed through the second contact hole. A step of connecting to the source electrode, a step of forming a second insulating film on the reflective film, and a first contact hole penetrating the first insulating film and the second insulating film. step and the transparent electrode film of the transparent region, in part or aspect which covers the whole of the reflective film extends to the reflective layer, the transparent electrode film on the second insulating film And forming the first contact And connecting the source electrode and the transparent electrode film through hole, and the active matrix substrate electrically connected to the process is at least comprise complete and the transparent electrode film and the reflective film via the source electrode The liquid crystal layer is interposed between the two substrates using the counter substrate completed in advance, and the first gap in the reflective region and the second in the transmissive region according to the twist angle of the liquid crystal layer A method of manufacturing a transflective liquid crystal display device, wherein the gap is adjusted so that the reflectance and transmittance in white display are maximized. By forming the reflective film on the surface of the active matrix substrate facing the counter substrate via the first insulating film, the first of the reflective region is formed according to the twist angle of the liquid crystal layer. 9. The method of manufacturing a transflective liquid crystal display device according to claim 8, wherein the gap and the second gap of the transmissive region are adjusted so that the reflectance and transmittance in white display are maximized. By processing the surface of the active matrix substrate that faces the counter substrate, the first gap in the reflective region and the second gap in the transmissive region are displayed in white according to the twist angle of the liquid crystal. 9. The method of manufacturing a transflective liquid crystal display device according to claim 8, wherein the reflectance and the transmittance are adjusted to maximize.   10. The method for manufacturing a transflective liquid crystal display device according to claim 9, wherein the thickness of the first insulating film is made different between the transmissive region and the reflective region.

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