JP2004046223A - Translucent liquid crystal display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an electrolytic corrosion reaction between a reflective electrode film containing Al or Al alloy and a transparent electrode film formed from ITO, etc., and to inhibit an occurrence of flicker resulting from a residual DC voltage of the reflective electrode film. <P>SOLUTION: The translucent liquid crystal display device has, in its pixel area PX, a transmissive area PXa for casting light from a backlight source and a reflective area PXb for receiving external ambient light. In such a constitution, the transparent electrode film 5 is formed, via a second passivating film 24, on the upper layer (liquid crystal insertion face side) of the reflective film 6 formed on the reflective area PXb on an active matrix substrate 12. <P>COPYRIGHT: (C)2004,JPO

Description

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

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 due to their features of small size, thin shape, and low power consumption. In this liquid crystal display device, two driving systems, an active matrix system and a passive matrix system, are known, but the former which can display high-quality images is widely adopted. . In addition, liquid crystal display devices driven by an active matrix method are classified into a transmission type and a reflection type. In each case, a liquid crystal panel constituting a main part of the liquid crystal display device operates 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 by itself. Therefore, when an image is displayed on the liquid crystal display device, a light source is separately required for each 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 the liquid crystal panel switches transmission / blocking of light incident from the backlight. The display is configured to be controlled.

In such a transmissive liquid crystal display device, it is possible to obtain a bright screen irrespective of the brightness around the place where the transmissive liquid crystal display device is used by constantly entering the backlight. 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, when the transmissive liquid crystal display device is driven by a battery, the usable time is shortened. If a large battery is installed to extend the usable time, the weight of the entire device increases, so the size and weight of the device must be reduced. It hinders.

Therefore, in order to solve the problem of power consumption of a backlight light source in a transmissive liquid crystal display device, the backlight light source is not required, and light existing around a place where the liquid crystal display device is used (hereinafter referred to as an external light source). A reflective liquid crystal display device configured to use ambient light) as a light source has been proposed. In this reflection type liquid crystal display device, display is controlled by providing a reflection plate inside a liquid crystal panel and switching transmission / blocking of external ambient light that enters the inside of the liquid crystal panel and is reflected by the reflection plate. It is configured as follows. This reflective liquid crystal display device does not require a backlight light source as in a transmissive liquid crystal display device, so that 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 significantly reduced because external ambient light does not sufficiently function as a light source when the surroundings are dark.

As described above, the transmissive liquid crystal display device and the reflective liquid crystal display device each have advantages and disadvantages, and a backlight light source is indispensable to obtain a stable display. An increase in power consumption is inevitable. In order to reduce the power consumption of the backlight light source and improve the visibility even when the external ambient light is dark, the liquid crystal panel is provided with a transmissive area and a reflective area in the pixel area, and is provided with a transmissive liquid crystal display. There has been proposed a transflective liquid crystal display device configured to realize the operation as a device and a reflective liquid crystal display device with one liquid crystal panel.

According to the transflective liquid crystal display device as described above, by providing a transmissive region and a reflective region in the pixel region of the liquid crystal panel, when external ambient light is dark, the backlight is turned on and the transmissive region is used. By operating as a transmissive liquid crystal display device, the characteristics of a transmissive liquid crystal display device, such as improved visibility, can be exhibited even when the surroundings are dark. On the other hand, when the 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 be.

In this transflective liquid crystal display device, incident light from the backlight passes through the liquid crystal layer in a transmissive region for operating as a transmissive liquid crystal display device, while in a 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. For this reason, in the transflective liquid crystal display device, as described later, the first gap (reflection gap) dimension of the reflection region and the second gap (transmission gap) dimension of the transmission region, which are the thickness of the liquid crystal layer, are set as follows. If the optimum value is not set according to the twist angle of the liquid crystal, the intensity of the light emitted from the display surface cannot be optimized due to the difference in the retardation between the reflection region and the transmission region. Hereinafter, the optimization of the emission light intensity of the transmission region and the reflection region of the pixel region in the transflective liquid crystal display device will be described.

(About optimization of the output light intensity of the transmission area and the reflection area)
FIG. 34 is a diagram schematically showing a configuration of a transflective liquid crystal display device necessary for optimizing the intensity of light emitted from the transmissive area PXa and the reflective area PXb. As shown in the figure, the transflective liquid crystal display device includes an active matrix substrate 112, a counter substrate 116, a liquid crystal layer 117 sandwiched between the substrates 112, 116, and a rear surface of the active matrix substrate 112. And a phase difference plate (λ / 4 plate) 120a, 120b and a polarizing plate 119a, 119b provided outside each of the active matrix substrate 112 and the counter substrate 116. Here, on the surface of the active matrix substrate 112 facing the counter substrate 116, a transmission electrode film 105 serving as a transmission region PXa of the pixel region PX and a reflection film 106 serving as a reflection 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 output light is controlled as described later.

(About the arrangement of the upper polarizer and retarder)
First, a case where the above-described transflective liquid crystal display device is operated as a reflective liquid crystal display device will be described. The liquid crystal molecules of the liquid crystal layer 117 are displayed because the reflective region PXb has 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. Is white (state lying horizontally), liquid crystal molecules are standing by applying a voltage between the counter electrode and the pixel electrode (state standing vertically). In order to obtain a black display in the above, a retardation plate 120b is disposed between the liquid crystal layer 117 and the polarizing plate 119b. By arranging the phase difference plate 120b by rotating it by 45 ° with respect to the optical axis of the polarizing plate 119b, the linearly polarized light (horizontal), which is the external ambient light passing 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 a predetermined value for the reflection gap dr, which is the thickness of the liquid crystal layer 117. In the reflection 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 exiting the liquid crystal layer 117. This is changed to linearly polarized light (horizontal) by the phase difference plate 120b, and the light is emitted from the polarizing plate 119b having an optical axis in the horizontal direction, and white display is performed. On the other hand, when a voltage is applied between the counter electrode and the pixel electrode, the liquid crystal molecules rise. At this time, the light incident on the liquid crystal layer 117 as clockwise circularly polarized light arrives at the reflection film 106 as clockwise circularly polarized light, and the clockwise circularly polarized light is changed by the reflection film 106 into counterclockwise circularly polarized light and reflected. After exiting the liquid crystal layer 117 with left-handed circularly polarized light, it is changed to linearly polarized light (vertical) by the retardation plate 120b, and is absorbed by the polarizing plate 120b and does not emit light. Therefore, black display is performed.

(About the arrangement of the lower polarizer and retarder)
Next, a case of operating as a transmission type liquid crystal display device will be described. The arrangement angle of the optical axes of the lower retardation plate 120a and the polarizing plate 119a is determined so that black display is performed when a voltage is applied. The lower polarizing plate 119a is arranged in a crossed Nicols state with the upper polarizing plate 119b, that is, in a direction rotated by 90 °. In order to cancel (compensate for) the influence of the upper retardation plate 120b, the lower retardation plate 120a is also rotated by 90 °. Since the liquid crystal molecules rise when a voltage is applied, the polarization state of the light does not change. Therefore, the liquid crystal molecules are optically equivalent to the arrangement of the polarizing plates 119a and 119b in a crossed Nicols state. The display is black in the state of being turned on. As described above, the arrangement of the optical members and the arrangement angles of the optical axes of the liquid crystal panel of the transflective liquid crystal display device are determined.

(About twist angle setting)
The twist angle φ (0 °) of the liquid crystal in the transflective liquid crystal display device in which the optical members are arranged at the above arrangement angles and the liquid crystal layer 117 is formed using nematic liquid crystal having a refractive index anisotropy Δn = 0.086. FIG. 35 shows the relationship between the reflection gap dr and the transmission gap df (that is, the thickness of the liquid crystal layer). 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 decreases, the utilization rate of light in the transmission mode increases, while the color shift when the field of view is shaken increases. As is clear from FIG. 35, the reflection gap dr and the transmission gap df at which the reflectance and the transmittance of white become the maximum, respectively, coincide with the twist angle φ of about 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 approximately 72 ° are approximately The agreement is 2.7 μm. When the twist angle φ is set to approximately 0 °, the optimal 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 approximately 60 °, the optimal reflection gap dr is approximately 2.0 μm, and the transmission gap df is approximately 2.8 μm.

As described above, in order to correct the optical path difference between the two incident lights passing through the transmissive area PXa and the reflective area PXb of the pixel area PX and optimize the intensity of the emitted light in the transflective liquid crystal display device, It is necessary to set the optimum reflection gap dr and transmission gap df at which the reflectance and the transmittance of white are maximized as shown in FIG. 35 according to the twist angle of the liquid crystal. Accordingly, like 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 case of the display device, the active matrix substrate 112 is formed so that the reflection gap is equal to the transmission gap, and the optimum reflection gap dr and transmission gap df are obtained in accordance with a predetermined twist angle. This has been done in the past.

Hereinafter, a 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 and 116. The liquid crystal display device includes a liquid crystal layer 117 interposed therebetween and a backlight light source 118 disposed on the back surface of the active matrix substrate 112.

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 drawn from both ends of the semiconductor layer 103a and connected to a data line and a pixel electrode, respectively, and a passivation film 110. The pixel region PX is divided into a transmission region PXa for transmitting the incident light from the backlight light source 118 and a reflection region PXb for reflecting the incident external ambient light, and the transmission region PXa is formed on the passivation film 110 by ITO. (Indium Tin Oxide) or the like, and a reflective electrode film 106a containing Al or an Al alloy is connected to the reflective region PXb via the uneven film 111 such as an organic film on the transparent electrode film 105. It is formed as if it were done. The transparent electrode film 105 and the reflective electrode film 106a connected to the source electrode 102b through the contact holes 107 formed in the uneven film 111 function as pixel electrodes, and an alignment film 129 is formed on both the electrode films 105 and 106a. I have. Here, the TFT 103 includes 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, is emitted from the opposite substrate 116, and is reflected from 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 106a, passes through the liquid crystal layer 117 again, and is emitted from the counter substrate 116. The step of the uneven film 111 is provided such that the reflection gap dr is about half of the transmission gap df (however, the twist angle φ is approximately 0 °), and the step between the two incident lights passing through the respective regions is provided. 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 reflection plate having irregularities via 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, if liquid crystals having different retardations in the transmissive display region and the reflective display region are aligned with the same driving voltage, a high-contrast display cannot be obtained, and it is difficult to obtain a bright display. In order to solve the above problem, the alignment of the liquid crystal is controlled after adjusting the retardation of the portion performing the transmissive display and the portion performing the reflective display so as to be in a near range. However, the transflective liquid crystal display device does not take into account display defects caused by an electrolytic corrosion reaction and flicker caused by a residual DC voltage, which will be described later in the present invention. In the transflective liquid crystal display device, the reflective electrode film (reflective plate) is formed at the center of the pixel, and the TFT element is not covered with the reflective plate. I can't.

However, in the conventional transflective liquid crystal display device as described above, since the reflective electrode film 106a containing Al or an Al alloy is formed on the transparent electrode film 105 made of ITO or the like, the reflective electrode film 106a is processed. Al and ITO are eroded by an electrolytic corrosion reaction during the formation of a resist pattern (first problem), and a flicker occurs due to a residual DC voltage generated in the reflective electrode film 106a region (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 formed inside each pixel. And the reflective electrode film 106a are formed so as to overlap with each other. However, since it is necessary to electrically separate each pixel between adjacent pixels, the transparent electrode film 105 of a certain pixel and the adjacent pixel It cannot overlap with the reflective electrode film 106a. Therefore, as shown in FIG. 31A, when forming the resist pattern 121 for processing the reflective electrode film 106a, the reflective region PXb of each pixel in the conductive film for the reflective electrode film formed in advance on the entire surface is formed. It must be formed so as to cover only the side (left side in the figure). However, as shown in FIG. 31B, when a crack 127 is generated for some reason in the reflective electrode film 106a on the end region (the region surrounded by the broken line) of the previously formed transparent electrode film 105, The developing solution 126 permeates through the crack 127.

Here, the Al-based material that is the reflective electrode film 106a is rich in reactivity and easily reacts with oxygen. Therefore, when the developer 126 permeates from the crack 127 as described above, the Al-based material becomes transparent. Reacts with ITO which is an oxide conductor constituting the electrode film. As a result, corrosion (oxidation) of Al and dissolution (reduction) of ITO called an electrolytic corrosion reaction using the developing solution 126 as an electrolytic solution occur, causing a contact failure between Al and ITO, or as shown in FIG. 31 (c). Thus, separation 128 occurs between the transparent electrode 105 having poor adhesion and the passivation film 110. This electrolytic corrosion reaction is considered to occur by the mechanism described below.

(1) Al portions having many lattice defects and impurities are dissolved as local anodes, 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 in the developing solution 126 and the reduction potential of ITO serves as a driving force for the reaction, and the oxidation of Al and the reduction of ITO represented by the following formula 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 the structure in which Al or an Al alloy is formed on ITO. This is an essential problem, and a proposal for a structure that can reliably prevent the occurrence of the 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 a counter electrode is used as a reference voltage, and a positive polarity and a negative polarity are applied to a pixel electrode at regular intervals. A voltage is supplied which varies with the voltage. It is desirable that the voltage applied to the liquid crystal is such that the positive voltage waveform and the negative voltage waveform are symmetrical, but even if an AC voltage whose voltage waveform is symmetrical is applied to the pixel electrode, the voltage is actually applied to the liquid crystal. The voltage waveform is not symmetrical due to unintended DC components as described later. For this reason, the light transmittance when a positive voltage is applied is different from the light transmittance when a negative voltage is applied, and the brightness varies with the cycle of the AC voltage applied to the pixel electrode, and a flicker called flicker occurs. appear. As will be described later, this flicker occurs due to the alignment films 129 formed on the surfaces of the opposing substrate 116 and the active matrix substrate 112 on both sides of the liquid crystal layer 117 for controlling the alignment of the 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 degrees, and after the rubbing, the film is washed with water or an organic solvent, so that it is resistant to these solvents. Polyimide is usually used because of the fact that the epoxy resin used as a sealing material at the time of enclosing the liquid crystal has heat resistance to the heat curing conditions. However, it is known that electrons are generated inside this polyimide when it is subjected to a rubbing treatment or strong light irradiation.

In the transflective liquid crystal display device of FIG. 30, a transparent electrode film 105 and a reflective electrode film 106a are formed on an active matrix substrate 112, and the upper layer (the surface on the interposed surface side of the liquid crystal layer 117) is made of polyimide. Although the alignment film 129 is applied, electrons are generated inside the polyimide by the rubbing treatment 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 interface between the polyimide and the Al, so that electrons inside the polyimide hardly escape to the outside via 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. Since the waveform of the AC voltage applied to the pixel electrode is not symmetrical due to the DC component, flicker occurs.

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

Of 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. FIG. 32 is a plan view showing the configuration of the transflective liquid crystal display device, and FIG. 33 is a sectional view taken along the line HH of 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, a gate line 101 and a data line 102 formed on the transparent insulating substrate 108, and 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 drawn out 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 formed so as to overlap the entire periphery of the transparent electrode film 105. And a reflection electrode film 106a having a laminated structure, which is one of means for suppressing an electrolytic corrosion reaction. Proposes 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, a major cause of the electrolytic corrosion reaction is that a crack 127 is formed in the reflective electrode film 106a having a small thickness at the end of the transparent electrode film 105, and the developer 126 seeps from the crack 127. Therefore, in the invention of the prior application, as shown in FIGS. 32 and 33, the reflective electrode film 106a overlaps the entire periphery of the transparent electrode film 105 with a width of, for example, 2 μm or more, so that the end of the transparent electrode film 105 is formed. The entire periphery of the portion is covered with the resist pattern 121 to prevent the developer 126 from entering.

Further, since the electrolytic corrosion reaction is caused by the developer 126 entering the interface between Al and the ITO through the Al pinhole, the reflective electrode film 106a is formed on the barrier metal film such as molybdenum or the like by a metal such as Al or an Al alloy. A film is laminated, and each metal film is formed to have a thickness of 100 nm or more to prevent the developer 126 from reaching the ITO, or to peel off at the interface between the transparent electrode film 105 and the uneven film 111. In order to suppress this, by appropriately setting 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, the transparent electrode film 105 and the uneven film 111 Has been proposed to improve the adhesiveness of the developer and suppress the intrusion of the developer 126.

By using various structures and manufacturing methods described in the above-mentioned prior application, it is possible to suppress an electrolytic corrosion reaction at the time of forming a 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, it is not possible to prevent the occurrence of flicker due to the residual DC voltage for the above-described reason. Then, the inventor of the present invention diligently studied a structure that solves the two problems of the electrolytic corrosion reaction and the flicker. As a result, the stacking relationship between the transparent electrode film 105 and the reflective electrode film 106a was changed, A semi-transmissive liquid crystal display device based on a structure in which a reflective film 106 containing Al or an Al alloy is formed as a lower layer and a transparent electrode film 105 made of ITO is formed thereon directly or via an insulating film is effective. I found it.

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

In order to solve the above-mentioned problem, an invention according to claim 1 includes a first substrate having a plurality of signal electrodes arranged in parallel with each other along a first direction, and a first substrate having a plurality of signal electrodes arranged orthogonally to the first direction. A second substrate including a plurality of scanning electrodes arranged in parallel with each other along the direction of 2, and a plurality of pixel regions provided in one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes; A liquid crystal layer interposed between the first substrate and the second substrate, and a backlight light source for supplying light to the liquid crystal layer. A reflective area provided with a reflective film for receiving and displaying external ambient light and performing a reflective display, and a transmissive area including a transparent electrode film for transmitting and displaying through the backlight light source when the transmissive display mode is operated. The transflective liquid crystal display device Transparent electrode film, in a manner covering a part or the whole of the reflective film is characterized in that it extends to above the reflective film.

According to a second aspect of the present invention, there is provided the transflective liquid crystal display device according to the first aspect, wherein the transparent electrode film is formed on the reflective film via an insulating film.

According to a third aspect of the present invention, there is provided the transflective liquid crystal display device according to the first aspect, wherein the transparent electrode film is formed directly on the reflective film.

According to a fourth aspect of the present invention, there is provided the transflective liquid crystal display device according to the second aspect, wherein the reflective film and the transparent electrode film are electrically connected to each other through a contact hole formed in the insulating film. It is characterized by that.

According to a fifth aspect of the present invention, there is provided the transflective liquid crystal display device according to any one of the first to fourth aspects, wherein the liquid crystal is provided on a surface of the first substrate facing the second substrate. A switching element for turning on and off a signal applied to the layer is formed, and the reflection film is formed so as to cover the switching element.

According to a sixth aspect of the present invention, there is provided the transflective liquid crystal display device according to the fifth aspect, wherein the reflective film covers the switching element via an insulating film having an uneven surface.

According to a seventh aspect of the invention, there is provided the transflective liquid crystal display device according to the fifth or sixth aspect, wherein a common contact hole is formed in the insulating film, and the switching element is provided in the common contact hole. The reflection film and the transparent electrode film are electrically connected to an arbitrary one of the plurality of electrodes.

The invention according to claim 8 relates to the transflective liquid crystal display device according to claim 5 or 6, wherein first and second contact holes are formed in the insulating film, and the plurality of switching elements constitute the switching element. The reflective film is electrically connected to any one of the electrodes through the first contact hole, and the transparent electrode film is electrically connected to the arbitrary electrode through the second contact hole. It is characterized by:

According to a ninth aspect of the present invention, there is provided the transflective liquid crystal display device according to any one of the fifth to eighth aspects, wherein the transmissive area on the surface of the first substrate facing the second substrate. A GD converter is provided outside the reflection region, and a signal line for applying the signal to the liquid crystal layer is led out by a gate layer.

According to a tenth aspect of the present invention, there is provided the transflective liquid crystal display device according to any one of the first to ninth aspects, wherein the reflective film is made of a conductive material containing Al or an Al alloy, and the transparent electrode film is made of a transparent electrode film. Is made of ITO.

According to the eleventh aspect of the present invention, there is provided a first substrate having a plurality of signal electrodes arranged in parallel with each other along a first direction, and a second substrate having a plurality of signal electrodes arranged along a second direction orthogonal to the first direction. A second substrate including a plurality of scanning electrodes arranged in parallel with each other, a plurality of pixel regions provided in one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes; A liquid crystal layer interposed between the liquid crystal layer and the second substrate; and a backlight light source for supplying light to the liquid crystal layer. Each of the pixel regions receives external ambient light during a reflective display mode operation. -Transmissive liquid crystal provided with a reflective area provided with a reflective film for reflective display and a transmissive area provided with a transparent electrode film for transmissive display through the backlight light source in a transmissive display mode operation. According to the display device, a first key of the reflection area is provided. Tsu and second gap-flop and the transmissive region, in accordance with the twist angle of the liquid crystal, reflectance or transmittance in the white display is characterized in that it is adjusted to maximize.

According to a twelfth aspect of the present invention, there is provided the transflective liquid crystal display device according to the eleventh aspect, wherein when the twist angle of the liquid crystal is set to about 72 °, the first gap of the reflection region and the transmission It is characterized in that the second gap of the region is adjusted to substantially match.

According to a thirteenth aspect of the present invention, there is provided the transflective liquid crystal display device according to the eleventh aspect, wherein when the twist angle of the liquid crystal is set to approximately 0 °, the first gap of the reflection region is caused to pass through the transmissive region. It is characterized in that it is adjusted so as to be substantially half of the second gap of the region.

According to a fourteenth aspect of the present invention, there is provided the transflective liquid crystal display device according to the eleventh aspect, wherein when the twist angle of the liquid crystal is set to approximately 60 °, the first gap of the reflection region is caused to have the first transmission gap. It is characterized in that it is adjusted to be approximately 70% of the second gap of the region.

According to a fifteenth aspect of the present invention, a first substrate including a plurality of signal electrodes arranged in parallel with each other along a first direction, and a second substrate extending along a second direction orthogonal to the first direction are provided. A second substrate including a plurality of scanning electrodes arranged in parallel with each other, a plurality of pixel regions provided in one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes; A liquid crystal layer interposed between the liquid crystal layer and the second substrate; and a backlight light source for supplying light to the liquid crystal layer. Each of the pixel regions receives external ambient light during a reflective display mode operation. -Transmissive liquid crystal provided with a reflective area provided with a reflective film for reflective display and a transmissive area provided with a transparent electrode film for transmissive display through the backlight light source in a transmissive display mode operation. The present invention relates to a method for manufacturing a display device, wherein the first substrate A first step of forming the reflective film constituting the reflective region on the opposite surface of the second substrate,
Next, a second step of forming the transparent electrode film forming the transmission region so as to cover a part or the entirety of the reflection film is provided.

The invention according to claim 16 relates to the method of manufacturing a transflective liquid crystal display device according to claim 15, wherein an insulating film is provided on the reflective film between the first step and the second step. And a third step of forming.

The invention according to claim 17 relates to the method of manufacturing a transflective liquid crystal display device according to claim 16, wherein the reflective film is provided on the insulating film between the third step and the second step. A fourth step of forming a contact hole for electrically connecting the transparent electrode film with the transparent electrode film.

The invention according to claim 18 provides a first substrate having a plurality of signal electrodes arranged in parallel with each other along a first direction, and a second substrate having a plurality of signal electrodes arranged along a second direction orthogonal to the first direction. A second substrate including a plurality of scanning electrodes arranged in parallel with each other, a plurality of pixel regions provided in one-to-one correspondence with intersections of the signal electrodes and the scanning electrodes; A liquid crystal layer interposed between the liquid crystal layer and the second substrate; and a backlight light source for supplying light to the liquid crystal layer. Each of the pixel regions receives external ambient light during a reflective display mode operation. -Transmissive liquid crystal provided with a reflective area provided with a reflective film for reflective display and a transmissive area provided with a transparent electrode film for transmissive display through the backlight light source in a transmissive display mode operation. The present invention relates to a method for manufacturing a display device, Forming the reflection film constituting the reflection region on the surface facing the second substrate, and then covering the transmission region on the reflection film in such a manner as to partially or entirely cover the reflection film. Using the first substrate completed at least including the step of forming the transparent electrode film to be configured and the second substrate completed in advance, interposing the liquid crystal layer between both substrates, The first gap of the reflection region and the second gap of the transmission region are adjusted in accordance with the twist angle of the liquid crystal layer so that the reflectance or the transmittance in white display is maximized. I have.

According to a nineteenth aspect of the present invention, there is provided the method of manufacturing a transflective liquid crystal display device according to the eighteenth aspect, wherein the first substrate has an uneven surface on a surface facing the second substrate. By forming the reflective film via a film, the first gap of the reflective region and the second gap of the transmissive region can be changed in reflectivity or transmissivity in white display according to the twist angle of the liquid crystal layer. It is characterized in that the rate is adjusted to the maximum.

According to a twentieth aspect of the present invention, there is provided the method of manufacturing a semi-transmissive liquid crystal display device according to the eighteenth aspect, wherein the surface of the first substrate facing the second substrate is processed to thereby form the liquid crystal display. The first gap of the reflection region and the second gap of the transmission region are adjusted so that the reflectance or the transmittance in white display is maximized in accordance with the twist angle.

According to a twenty-first aspect of the present invention, there is provided the method for manufacturing a transflective liquid crystal display device according to the nineteenth aspect, wherein the thickness of the insulating film is made different between the transmission region and the reflection region. .

According to the transflective liquid crystal display device and the method of manufacturing the same of the present invention, a reflective film made of Al or an Al alloy is used as a lower layer, and a transparent electrode film made of ITO or the like is formed thereon directly or via an 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.

(4) A reflective film made of Al or an Al alloy 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 the structure 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 of FIG. 1, and FIGS. FIG. 5 is a process chart showing a manufacturing method of the liquid crystal display device in the order of steps, FIG. 5 is a cross-sectional view showing another structure of an active matrix substrate used in the transflective liquid crystal display device, and FIG. FIG. 7 is a cross-sectional view showing a first modification (twist angle is approximately 0 °) of FIG. 7, and FIG. 7 is a cross-sectional view showing a second modification (twist angle is approximately 60 °) of the transflective liquid crystal display device. In this example, 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 will be described.
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, an opposing substrate 16, and an intervening substrate 12. The inserted liquid crystal layer 17, a backlight light source 18 disposed on the back surface of the active matrix substrate 12, and a phase difference plate (λ / 4 plate) 20a 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 the auxiliary capacitance electrode 4a, the gate insulating film 9, the semiconductor layer 3a, and drawn from both ends of the semiconductor layer 3a and connected to the data line 2 and the pixel electrode (transparent electrode film 5), respectively. It includes a drain electrode 2a and a source electrode 2b, a storage electrode for capacitance 2c, and a passivation film 10. 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 for transmitting the incident light from the backlight source 18 and a reflection area PXb for reflecting the incident external ambient light. It is covered by the film 11. In the reflection region PXb, a reflection film 6 containing Al or an Al alloy (in this example, the metal film formed in the reflection region PXb does not need to be used as an electrode and is called the reflection film 6) is formed, and covers the reflection film 6. In this embodiment, a transparent electrode film 5 made of ITO or the like is formed on the entire surface of each pixel region PX via a second passivation film 24. 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, the TFT 3 includes 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, by forming the transparent electrode film 5 on the reflection film 6 via the second passivation film 24, the ITO which is the transparent electrode film 5 at the time of forming a resist pattern when processing the reflection film 6 is formed. Is not formed, no electrolytic corrosion reaction occurs even when the developer enters through the Al pinhole, and the occurrence of pixel defects such as peeling can be prevented. However, by simply reversing the vertical relationship between the reflective film 6 and the transparent electrode film 5 in the conventional example, when forming a resist pattern for processing the transparent electrode film 5, 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 of Al may come into contact with the developer to cause an electrolytic corrosion reaction, and Al or ITO may be eroded.

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

Therefore, when the resist pattern for processing the transparent electrode film 5 is formed, the reflection 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. As a result, 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.

By covering the TFT 3 with the reflective film 6 as described above, when external ambient light enters the TFT 3, the incident light can be blocked by the reflective film 6. Accordingly, it is possible to prevent a problem that the off-state current of the TFT 3 increases due to a photoelectric effect caused by the incident light and causes a malfunction. However, when the distance between the reflective film 6 and the TFT 3 is short, the potential of the electrically floating reflective film 6 changes due to the voltage applied to the TFT 3 (particularly, the gate voltage), and the control electric field of the liquid crystal is changed. May be disturbed. 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 so that the reflective film 6 by the voltage applied to the TFT 3 is formed. To mitigate the impact.

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. Since no contact occurs, the accumulation of electric charges inside the polyimide is suppressed, the occurrence of flicker due to the residual DC voltage is prevented, and the problems of the electrolytic corrosion reaction and flicker are simultaneously solved.

In the structure of this example, Al as the reflective film 6 does not come into contact with polyimide as the alignment film 29, 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, a Schottky barrier cannot be formed at the interface between the polyimide and the ITO, and electrons generated by rubbing or the like escape from the ITO to the outside, so that no residual DC voltage is generated.

Next, a method of manufacturing the transflective liquid crystal display device of this example will be described in order of steps with reference to FIGS. In the method of manufacturing a transflective liquid crystal display device of this example, in addition to the method of manufacturing a pixel structure described above, a G (Gate) -D (Drain) conversion unit for preventing a short circuit of a lead line due to a conductive seal is provided. A specific method of manufacturing the structure will also be described.
Here, when it is necessary to electrically pull out the drain electrode 2a to the outside, the GD conversion section is likely to be short-circuited due to structural restrictions and is difficult to directly pull out. It is provided for drawing out by a gate line.
First, as shown in FIG. 3A, after a metal such as Cr is deposited on the entire surface of a transparent insulating substrate 8 such as glass, unnecessary metal is removed by 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. The components not shown in FIG. 3 are shown in FIG. Next, a gate insulating film 9 of SiO ₂ , SiN _x , _SiOx or the like is formed on the entire surface. Next, a (amorphous) -Si or the like is deposited on the entire surface and then patterned in an island shape to form a semiconductor layer 3a. Next, after depositing a metal such as Cr on the entire surface, patterning is performed to form a data line 2, a drain electrode 2a, a source electrode 2b, and a storage electrode for capacitance 2c. Thus, the TFT 3 is formed. Thereafter, a passivation film 10 made of the SiN _x film or the like by a plasma CVD (Chemical Vapor Deposition) method or the like is deposited on the entire surface, to protect the TFT 3. Further, the above-mentioned 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, for example, PC403, 415G, 405G made by JSR, or the like is applied on the passivation film 10 by a spin coating method, and the uneven film 11 is formed on the pixel region PX. Form. The uneven film 11 is formed to enhance the visibility of the reflected light when the incident light, which is the external ambient light, is reflected by the reflective film 6 described later. In the photosensitive acrylic resin, the concave portions of the concave and convex film 11 are exposed with a relatively small amount of light, while the convex portions are left unexposed, and the region where the contact hole 7 is formed, the GD conversion portion, and the terminal portion are formed. Are exposed with a relatively large amount of light.

In order to perform such exposure, for example, a reflection film is formed on a portion corresponding to the convex portion, a transmission film is formed on a portion corresponding to the contact hole 7, the GD conversion portion and the terminal portion, and a portion is formed on a portion corresponding to the concave portion. May use a half-tone (gray-tone) mask on which a semi-transmissive film is formed. By using such a halftone mask, unevenness can be formed by one exposure. The unevenness can be formed by using the reflection film and the transmission film as a photomask, or by separately exposing the contact hole 7 and the concave portion and changing the exposure amount.

(4) Thereafter, using an alkali developing solution, unevenness is formed by utilizing the difference in the dissolution rate of each of the concave portion, the convex portion, the contact hole 7 and the like with the alkaline solution. In the drawing, the uneven film 11 is formed over the entire pixel region PX including the reflection region PXb and the transmission region PXa. However, the surface of the uneven film 11 formed in the transmission region PXa is flattened without providing unevenness. Is also good. When the uneven film 11 is also formed in the transmission region PXa, the acrylic film is decolorized by performing exposure processing on the entire surface in order to suppress attenuation of transmitted light due to the uneven film 11. Thereafter, for example, curing is performed at 220 ° C. for about 1 hour to form the uneven film 11 having a desired shape.

Here, as described above, when the distance between the TFT 3 and the reflective film 6 formed thereon is small, the potential of the reflective film 6 fluctuates due to a gate voltage or the like applied to the TFT 3, and the control electric field of the liquid crystal is disturbed. 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 depositing Al over the entire surface by using a sputtering method or an evaporation method, only the internal reflection area PXb of the pixel area PX is covered with a resist pattern, and the exposed Al is partially removed. The reflective film 6 is formed by dry etching or wet etching. At this time, a 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 reflection 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 completely cover the gate electrode 1 and the data line 2 thereafter. Note that Al or an Al alloy is usually used as the reflection film 6, but not limited to these materials, any metal having a high reflectance and suitable for a liquid crystal process can be used.

Next, as shown in FIG. 4 (a), after depositing an insulating film made of SiO _x or the like on the entire surface by plasma CVD method or the like, a resist pattern is formed on this insulating film, a second passivation film 24 To 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 to perform the G-D conversion and A contact hole is also formed in the terminal portion.

Next, as shown in FIG. 4B, after a transparent conductive film such as ITO is deposited on the entire surface by a sputtering method, a transparent electrode film 5 covering the entire surface of each pixel using a resist pattern, and a G-D conversion. The electrode 22 and the terminal electrode 23 are formed simultaneously. At that time, in order to prevent the electrolytic corrosion reaction of the lower reflective film 6, the transparent electrode film 5 is formed so as to cover, for example, the gate line 1 and the data line 2 so as to cover the entire reflective film 6. With such a laminated structure and a layout structure of the reflective film 6 and the transparent electrode film 5, it is possible to 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 reflection film 6 and the transparent electrode film 5 and the reflection 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 the voltage or the like, as described above, the uneven film 11 is also formed on the TFT 3, and the distance between the TFT 3 and the reflective film 6 is secured by the uneven film 11. Thus, the effect of the TFT 3 on the reflection film 6 can be sufficiently reduced.

(4) 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 counter substrate 16 completed by sequentially forming a color filter 14, a black matrix, a counter electrode 15, an alignment film 29, and the like on the transparent insulating substrate 13 is prepared. Then, a liquid crystal layer 17 is interposed between the two substrates 12 and 16, and retardation plates 20 a and 20 b and polarizing plates 19 a and 19 b are provided on both sides of each of the substrates 12 and 16. 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 FIGS. 1 and 2 is manufactured.

As described above, according to the transflective liquid crystal display device of this example and the method of manufacturing the same, the transparent electrode film 5 is formed on the reflective film 6 (on the liquid crystal insertion surface side) via the second passivation film 24. Therefore, it is possible to prevent the occurrence of pixel defects by preventing the electrolytic corrosion reaction between Al and ITO, and to prevent the occurrence of flicker due to the residual DC potential by preventing the contact between Al and polyimide. And a transflective liquid crystal display device in which GD conversion is performed on the outer periphery of the liquid crystal panel.

In this example, the example in which the second passivation film 24 is provided in both the reflection region PXb and the transmission region PXa has been described, but the second passivation film 24 directly connects the reflection film 6 and the transparent electrode film 5 to each other. The second passivation film 24 may be formed only on the reflection film 6 as shown in FIG. In this case, after forming a SiN _x in the step of FIG. 4 (a), the the source electrode 2b, before forming the contact hole in the G-D conversion portion and the terminal portion, the transmissive region using the resist pattern as a mask The second passivation film 24 of PXa is removed. Alternatively, in the step of FIG. 3C, Al and SiN _x are continuously formed, and the second passivation film 24 and the reflection film 6 in the transmission region PXa are simultaneously removed using the resist pattern as a mask. Steps substantially similar to the steps described above are performed. Thus, the active matrix substrate 12 having the structure shown in FIG. 5 is finally completed, and a transflective liquid crystal display device using the active matrix substrate 12 can be manufactured.

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

FIG. 6 is a sectional view showing a first modification of the transflective liquid crystal display device of this example. In the transflective liquid crystal display device, as shown in the figure, the twist angle of the liquid crystal is set to approximately 0 °, the uneven film 11 is formed only in the reflection region PXb, and the film thickness is approximately 1. 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 application condition of the photosensitive acrylic resin is adjusted so that the film thickness becomes approximately 1.4 μm. It is sufficient to set and remove the concavo-convex film 11 in the transmission region PXa at the same time as forming the contact hole 7 on the source electrode 2b. Thereafter, by performing steps substantially similar to the above-described steps, finally, as shown in FIG. 6, the reflection gap dr corresponds to about 1.5 μm, and the transmission gap df corresponds to about 2. A 9 μm transflective liquid crystal display device is manufactured.

FIG. 7 is a sectional view showing a second modification of the transflective liquid crystal display device of this example. In the transflective liquid crystal display device, as shown in the figure, the twist angle of the liquid crystal is set to approximately 60 °, and the uneven film 11 is formed in both the reflection region PXb and the transmission region PXa, and the transmission region PXa is formed. The reflection gap dr is optimized to about 2.0 μm and the transmission gap df is optimized to about 2.8 μm by setting the thickness of the uneven film 11 slightly thinner. 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 on both the reflection area PXb and the transmission area PXa ( The surface of the transmissive area PXa may or may not have irregularities, and only the transmissive area PXa of the opposing substrate 16 is provided with a recess having a depth of approximately 0.8 μm (2.8 μm-2.0 μm) to transmit light. 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 step of forming the color filter 14, or a depression may be formed in the transparent insulating substrate 13 in advance. Thereafter, by performing substantially the same steps as those described above, finally, the reflection gap dr is approximately 2.0 μm and the transmission gap df is approximately 2.10 corresponding to a twist angle of approximately 60 ° as shown in FIG. An 8 μm transflective liquid crystal display device is manufactured.

FIG. 8 is a sectional view showing the structure of a transflective liquid crystal display device according to a second embodiment of the present invention, and FIGS. 9 and 10 are process diagrams showing a method of manufacturing the transflective liquid crystal display device in the order of processes. 11 is a cross-sectional view showing a first modification of the transflective liquid crystal display device (with a twist angle of approximately 0 °), and FIG. 12 is a second modification of the transflective liquid crystal display device (with a twist angle of approximately 60 °). FIG. The structure of the transflective liquid crystal display device of the second embodiment is greatly different from that of the first embodiment described above. In order to simplify the process, the second passivation film is not required and the direct passivation film is directly formed on the reflection film. Is that a transparent electrode film is formed on the substrate. In this example, 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 will be described.
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 entire pixel region PX is covered with the reflective film 6. A transparent electrode film 5 made of ITO or the like is formed. In this example, as described later, the reflection film 6 is connected to the transparent electrode film 5 and used as a part of the pixel electrode.
Other than this, it is substantially the same as the first embodiment described above. Therefore, in FIG. 8, the components corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

Next, a method of manufacturing the transflective liquid crystal display device of this example will be described in order of steps with reference to FIGS.
As in the first embodiment, first, as shown in FIG. 9A, a gate line 1 and a gate electrode 1a are formed on a transparent insulating substrate 8 made of glass or the like in substantially the same manner as in the first embodiment. After forming the common storage line 4 and the auxiliary capacitance electrode 4a, the semiconductor layer 3a is formed via the gate insulating film 9. Next, after forming the data line 2, the drain electrode 2a, the source electrode 2b, and the storage electrode for capacitance 2c to form the TFT 3, 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 in substantially the same manner as in the first embodiment, and then the contact holes 7 and the G-portion outside the pixel region PX are coated. By removing the acrylic resin of the D conversion part and the terminal part, the uneven film 11 is formed on the reflection area PXb and the transmission area PXa including the TFT 3. In this case, in order to suppress the attenuation of the transmitted light due to the uneven film 11, it is preferable to perform an exposure process on the entire surface to decolorize the acrylic film.

Next, as shown in FIG. 9C, Al is formed on the entire surface in substantially the same manner as in the first embodiment, and thereafter, the Al in the transmission region PXa is removed using the resist pattern as a mask, and the reflection region PXb is formed. Only the reflection film 6 is formed. At this time, it is preferable to form a reflective film 6 on the TFT 3 so that external light 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 of the GD conversion part and the terminal part, and the gate insulating film 9 are selectively etched to form the source electrode 2b. And a contact hole is also formed in the GD conversion part and the terminal part.

Next, as shown in FIG. 10B, ITO is formed on the entire surface, and the transparent electrode film 5 and the G-D are formed using the resist pattern as a mask to cover the entire surface of each pixel including the reflection film 6 and the transmission region PXa. The conversion electrode 22 and the terminal electrode 23 are formed at the same time. 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 portion where the reflective film 6 is not covered with the transparent electrode film 5, the transparent electrode film processing is performed. When an area where the coverage of the transparent electrode film 5 is insufficient at the end of the reflective film 6 at the time of forming the resist pattern for use, an electrolytic corrosion reaction may occur in a portion where the reflective film 6 is exposed. It is important to form the transparent electrode film 5 so as to cover the entire surface (that is, to leave the resist pattern on the entire surface of the reflection film 6).

Further, in the first embodiment, the second passivation film 24 is formed between the reflection film 6 and the transparent electrode film 5, and the reflection film 6 is in an electrically floating state. Although there is a concern that the potential of the reflective film 6 fluctuates due to the applied gate voltage or the like, in this example, the reflective film 6 is in direct contact with the transparent electrode film 5 and is conductive, so that the reflective film 6 The potential does not change. Therefore, it is not necessary to secure a distance between the TFT 3 and the reflection film 6, so that the uneven film 11 need not be formed on the TFT 3.

Then, 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, and the active matrix substrate 12 is completed. Next, a counter substrate 16 completed by sequentially forming a color filter 14, a black matrix, a counter electrode 15, an alignment film 29, and the like on the transparent insulating substrate 13 is prepared. Then, a liquid crystal layer 17 is interposed between the two substrates 12 and 16, and retardation plates 20a and 20b and polarizing plates 19a and 19b are provided on both sides of each of the substrates 12 and 16 in substantially the same manner as in the first embodiment. Then, by installing the backlight light source 18 on the back surface of the polarizing plate 19a on the side of the active matrix substrate 12, 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 about 72 ° is interposed between the substrates 12 and 16 so that there is no step between the reflection area PXb and the transmission area PXa (the reflection gap dr and the transmission gap df are smaller). (Both coincident at about 2.7 μm). 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, according to the transflective liquid crystal display device of this example and the method of manufacturing the same, the transparent electrode film 5 is formed on the reflective film 6 so as to cover the reflective film 6. It is possible to prevent the occurrence of pixel defects by preventing an erosion reaction, and to prevent the occurrence of flicker caused by the residual DC voltage by preventing the contact between Al and the polyimide. A transflective liquid crystal display device provided with a -D conversion section can be obtained.

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

FIG. 12 is a cross-sectional view showing a second modification of the transflective liquid crystal display device of this example (the twist angle is approximately 60 °). In order to realize this structure, as shown in FIG. 12, the uneven film 11 is formed on both the reflection region PXb and the transmission region PXa (the surface of the transmission region PXa may or may not have unevenness). A recess may be provided in the transmission area PXa of the substrate 16 to adjust the gap. Thereafter, by performing substantially the same steps as those described above, a transflective liquid crystal display device having a reflection gap 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 obtained. To manufacture.

FIG. 13 is a diagram showing the structure 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 method of manufacturing 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 significantly different from that of the above-described first embodiment in that a contact hole (reflection film connection portion) is provided to prevent a potential change of the reflection film. That is, the reflective film and the transparent electrode film are connected to each other.
In the transflective liquid crystal display device of this example, as shown in FIG. 13, a reflection film 6 containing Al or an Al alloy is formed in the reflection region PXb, and this reflection film 6 is formed on the second passivation film 24. It is connected to the transparent electrode film 5 via the reflection film connecting portion 25.
Other than this, it is substantially the same as the first embodiment described above. Therefore, in FIG. 13, the respective parts corresponding to the components in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

Next, a method for manufacturing the transflective liquid crystal display device of this example will be described in the order of steps with reference to FIGS. 14 and 15 are cross-sectional views taken along the line BB of 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 made of glass or the like in substantially the same manner as in the first and second embodiments. After forming the capacitor electrode 4a, the semiconductor layer 3a is formed via the gate insulating film 9. Next, after forming the data line 2, the drain electrode 2a, the source electrode 2b, and the storage electrode for capacitance 2c to form the TFT 3, the passivation film 10 is formed.

Next, as shown in FIG. 14B, a photosensitive acrylic resin is applied on the passivation film 10 and the contact holes 7 and the G- By removing the acrylic resin of the D conversion part and the terminal part, the uneven film 11 is formed on the reflection area PXb and the transmission area PXa including the TFT 3. In this case, in order to suppress the attenuation of the transmitted light due to the uneven film 11, it is preferable to perform an exposure process on the entire surface to decolorize the acrylic film.

Next, as shown in FIG. 14C, Al is formed on the entire surface and Al in the transmission region PXa is removed using the resist pattern as a mask, and the reflection region is formed in substantially the same manner as in the first and second embodiments. The reflection film 6 is formed on PXb. At this time, it is preferable to form a reflective film 6 on the TFT 3 so that external light does not enter the TFT 3.

Next, as shown in FIG. 15 (a), after depositing an insulating film made of SiO _x or the like on the entire surface by plasma CVD method or the like, a resist pattern is formed on this insulating film, a second passivation film 24 To form Next, the second passivation film 24 under the contact hole 7 and the second passivation film 24 of the GD conversion part and the terminal part are selectively etched, and at the same time, the reflection film 6 is formed on 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 part, the passivation film 10 at the terminal part, and the gate insulating film 9 are selectively etched to expose the source electrode 2b and the GD conversion part. Also, a contact hole is formed in the terminal portion. Although the reflective film connecting portion 25 can be formed at an arbitrary position on the reflective film 6, Al may be eroded by contact with the developing solution when the reflective film connecting portion 25 is etched. As shown in FIG. 13, it is preferable to form it around 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. 15 (b), after a transparent conductive film such as ITO is deposited on the entire surface by sputtering, the transparent electrode film 5, G- The D conversion electrode 22 and the terminal electrode 23 are formed at the same time. With such a laminated structure and a layout structure of the reflective film 6 and the transparent electrode film 5, it is possible to prevent the reflective film 6 from coming into contact with the developer.

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

(4) 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 counter substrate 16 completed by sequentially forming a color filter 14, a black matrix, a counter electrode 15, an alignment film 29, and the like on the transparent insulating substrate 13 is prepared. Then, a liquid crystal layer 17 is interposed between the two substrates 12 and 16, and retardation plates 20 a and 20 b and polarizing plates 19 a and 19 b are provided on both sides of each of the substrates 12 and 16. 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, according to the transflective liquid crystal display device of this example and the method of manufacturing the same, the transparent electrode film 5 is formed on the reflective film 6 so as to cover the reflective film 6. It is possible to prevent the occurrence of pixel defects by preventing an erosion reaction, and to prevent the occurrence of flicker caused by the residual DC voltage by preventing the contact between Al and the polyimide. A transflective liquid crystal display device subjected to -D conversion can be obtained.

FIG. 16 is a diagram showing the structure of a transflective liquid crystal display device according to a fourth embodiment of the present invention, FIG. 17 is a cross-sectional view taken along the line CC of FIG. 16, and FIG. 19 is a plan view showing an enlarged structure of a main part of FIG. 19, FIG. 19 is a cross-sectional view taken along the line DD of FIG. 18, and FIGS. is there. The structure of the transflective liquid crystal display device of the fourth embodiment is significantly different from that of the third embodiment in that a contact hole formed in a second passivation film is formed in order to prevent a potential change of the reflection film. And a reflective film and a transparent electrode film are respectively connected to the source electrode at two different places.
In the transflective liquid crystal display device of this example, as shown in FIGS. 16 to 19, the transparent electrode film 5 is formed by forming the reflective film 6 through the second passivation film 24 as in the first embodiment. In the configuration in which the reflection film 6 and the transparent electrode film 5 are connected as in the third embodiment, the source electrode 2b and the reflection film 6 are formed in the first region 7a in the contact hole 7 formed in the second passivation film 24. Are connected, and the source electrode 2b and the transparent electrode film 5 are connected in the second region 7b.
Other than this, it is substantially the same as the third embodiment described above. Therefore, in FIG. 16 and FIG. 17, the respective parts corresponding to the constituent parts in FIG.

When the reflection film 6 and the transparent electrode film 5 are connected as in the third embodiment in order to prevent the potential fluctuation of the reflection film 6, the Al constituting the reflection film 6 and the transparent electrode film 5 are connected as described above. When the constituent ITO is combined, a non-conductor such as Al oxide may be formed on the sea surface of Al and ITO depending on the process, 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, the variation in potential of the reflective film 6 cannot be sufficiently suppressed due to the static electricity characteristics in the manufacturing process of the liquid crystal panel, and the display quality may be deteriorated.

Therefore, in this example, at two different places (first and second regions 7a and 7b) in the contact hole 7 formed in the second passivation film 24, the reflection film 6 and the transparent electrode The membrane 5 is connected. As a result, since the reflection film 6 and the transparent electrode film 5 are not directly connected to each other, the high contact resistance is not formed as described above, and the fluctuation of the potential of the reflection film 6 can be sufficiently suppressed. Can be prevented from deteriorating.

Next, a method of manufacturing the transflective liquid crystal display device of this example will be described in the order of steps with reference to FIGS. 20 and 21 are cross-sectional views taken along the line CC of 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 made of glass or the like in substantially the same manner as in the first to third embodiments. After forming the capacitor electrode 4a, the semiconductor layer 3a is formed via the gate insulating film 9. Next, after forming the data line 2, the drain electrode 2a, the source electrode 2b, and the storage electrode for capacitance 2c to form the TFT 3, 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 holes 7 and the G- By removing the acrylic resin of the D conversion part and the terminal part, the uneven film 11 is formed on the reflection area PXb and the transmission area PXa including the TFT 3. In this case, in order to suppress the attenuation of the transmitted light due to the uneven film 11, it is preferable to perform an exposure process on the entire surface to decolorize the acrylic film.

Next, as shown in FIG. 20C, using the resist pattern formed on the uneven 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 of the GD conversion part and the terminal part are not removed.

Next, as shown in FIG. 20D, after forming Al 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 a reflective film 6 on the TFT 3 so that external light does not enter the TFT 3.

Next, as shown in FIG. 21 (a), after depositing an insulating film made of SiO _x or the like on the entire surface by plasma CVD method or the like, a resist pattern is formed on this insulating film, a second passivation film 24 To form Next, the second passivation film 24 under the contact hole 7 and the second passivation film 24 of the GD conversion part and the terminal part are selectively etched. Subsequently, the passivation film 10 under the contact hole 7, the GD conversion part, the passivation film 10 at the terminal part, and the gate insulating film 9 are selectively etched to expose the source electrode 2b and the GD conversion part. Also, a contact hole is formed in the terminal portion. 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 a transparent conductive film such as ITO is deposited on the entire surface by a sputtering method, the transparent electrode film 5, G- The D conversion electrode 22 and the terminal electrode 23 are formed at the same time.

(4) 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 counter substrate 16 completed by sequentially forming a color filter 14, a black matrix, a counter electrode 15, an alignment film 29, and the like on the transparent insulating substrate 13 is prepared. Then, a liquid crystal layer 17 is interposed between the two substrates 12 and 16, and retardation plates 20 a and 20 b and polarizing plates 19 a and 19 b are provided on both sides of each of the substrates 12 and 16. 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 FIGS. 16 and 17 is manufactured.

As described above, according to the transflective liquid crystal display device of this example and the method of manufacturing the same, 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 connected to the source electrode 2b at two different places 7a and 7b in the contact hole 7 formed in the second passivation film 24 in order to prevent potential fluctuation of the second passivation film 24. Since the connection resistance between the reflection film and the transparent electrode film is reduced, display quality can be improved.

FIG. 22 is a diagram showing the structure 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 the line EE in FIG. 22, and FIG. 25 is a plan view showing an enlarged structure of a different main part, FIG. 25 is a sectional view taken along the line FF of 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 the line GG of 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 structure of the transflective liquid crystal display device of the fifth embodiment is significantly different from that of the fourth embodiment in that two contact holes are formed in the second passivation film in order to prevent potential fluctuation of the reflection film. Is formed so that the reflection film and the transparent electrode film are respectively 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, as in the first embodiment, the reflective film 6 is formed through the second passivation film 24 and the transparent electrode film 5 is formed. In the configuration in which the reflection film 6 and the transparent electrode film 5 are connected to the source electrode 2b, respectively, as in the fourth embodiment, the source electrode 2b is formed via the first contact hole 7A formed in the second passivation film 24. And the transparent electrode film 5, and the source electrode 2b and the reflective film 6 are connected via the second contact hole 7B.

The positional relationship between the passivation film 10, the concavo-convex film 11, the reflection 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 7A, the uneven film 11 is arranged on the outermost periphery, and the reflection film 6, the passivation film 10, the second passivation film 24, and the transparent electrode film 5 are arranged inside the uneven film 11. In the second contact hole 7B, the uneven film 11 is arranged on the outermost periphery, and the passivation film 10, the reflection film 6, the second passivation film 24, and the transparent electrode film 5 are arranged inside the uneven film 11. Then, as shown in FIG. 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. In the case where the reflection film 9 is disposed outside the uneven film 11 in the first contact hole 7A as shown in FIG. 25, the transparent electrode film 5 is formed by the step of the reflective film 6 and the steep inclination due to the unevenness of the uneven film 11. It is preferable that the reflection film 6 be disposed inside the uneven film 11 in the first contact hole 7A because of the possibility of disconnection.

In order to prevent the potential fluctuation of the reflection film 6, two different places (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 reflection film 6 and the transparent electrode film 5 are connected to the source electrode 2b, 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, in the first and second contact holes 7A and 7B formed in the second passivation film 24, the reflection film 6 and the transparent electrode film 5 are connected to the source electrode 2b, respectively. Thus, the diameters of the first and second contact holes 7A and 7B can be reduced, so that the degree of freedom of the arrangement positions of the contact holes 7A and 7B is increased. Therefore, since the contact holes 7A and 7B can be arranged at positions (flat portions of the concave and convex portions) that do not contribute to the reflection characteristics among the concave and convex portions of the reflective film 6, the reflection film 6 can be disposed without deteriorating the reflective characteristics. Can be connected to the TFT3.

Next, a method of manufacturing the transflective liquid crystal display device of this example will be described in the order of steps with reference to FIGS. 28 and 29 are cross-sectional views taken along the 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 made of glass or the like in substantially the same manner as in the first to fourth embodiments. After forming the capacitor electrode 4a, the semiconductor layer 3a is formed via the gate insulating film 9. Next, after forming the data line 2, the drain electrode 2a, the source electrode 2b, and the storage electrode for capacitance 2c to form the TFT 3, 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 first contact hole 7A, the second contact hole 7B, and the GD conversion outside the pixel region PX are performed. By removing the acrylic resin of the portion and the terminal portion, the uneven film 11 is formed on the reflection region PXb and the transmission region PXa including the TFT 3. In this case, in order to suppress the attenuation of the transmitted light due to the uneven film 11, it is preferable to perform an exposure process on the entire surface to decolorize the acrylic film.

Next, as shown in FIG. 28C, using the resist pattern formed on the uneven 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 of 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 a reflective film 6 on the TFT 3 so that external light 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 the GD conversion part is formed in advance to form the second passivation film 24 made of SiO _X or the like by a sputtering method. In this case, the TFT array or the data line is lowered to the ground potential by using the GD conversion unit, or the shunt transistor is formed. This is for suppressing deterioration.

Next, as shown in FIG. 29 (a), after depositing an insulating film made of SiO _x or the like on the entire surface by plasma CVD method or the like, a resist pattern is formed on this insulating film, a second passivation film 24 To 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 a contact hole is also formed in the GD conversion portion and the terminal portion. 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 below the second contact hole 7B in FIG.

Next, as shown in FIG. 29 (b), after a transparent conductive film such as ITO is deposited on the entire surface by sputtering, the transparent electrode film 5, G- The D conversion electrode 22 and the terminal electrode 23 are formed at the same time.

(4) 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 counter substrate 16 completed by sequentially forming a color filter 14, a black matrix, a counter electrode 15, an alignment film 29, and the like on the transparent insulating substrate 13 is prepared. Then, a liquid crystal layer 17 is interposed between the two substrates 12 and 16, and retardation plates 20 a and 20 b and polarizing plates 19 a and 19 b are provided on both sides of each of the substrates 12 and 16. 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 FIGS. 23 and 24 is manufactured.

In this example, the example in which the transparent electrode film 5 is formed on the reflective film 6 with the second passivation film 24 interposed therebetween has been described. However, even in a configuration without the second passivation film, the reflective film 6 and the transparent electrode film 5 are formed. In such a case, it is possible to suppress the fluctuation of the potential of the reflective film by adopting the structure of this example.

As described above, according to the transflective liquid crystal display device of this example and the method of manufacturing the same, the source electrode is formed using the contact hole 7 formed in the second passivation film 24 in order to prevent the potential change of the reflection film 6. In the configuration in which the reflection film 6 and the transparent electrode film 5 are connected to the second electrode 2b, respectively, the source electrode 2b is connected to the first and second contact holes 7A and 7B formed in the second passivation film 24. On the other hand, since the reflection 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 determined. The degree can be increased. Therefore, the reflection film 6 can be connected to the TFT 3 without lowering 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 to lower the TFT array, the data lines, and the like to the ground potential. Of the TFT array due to plasma damage during the formation of the passivation film 24 can be suppressed.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention is applicable even if there is a design change within the scope of the present invention. include. For example, in the embodiment, an example has been described in which the transmission gap and the reflection gap are optimized when the twist angles of the liquid crystal are set to approximately 0 °, approximately 60 °, and approximately 72 °. However, the twist angle is not limited to the above value and may be other values. And the transmission gap and the reflection gap may be optimized according to these twist angles. Further, although an example was described in which a material containing Al or an Al alloy was used as the reflective film and ITO was used as the transparent electrode film, an electrolytic corrosion reaction easily occurs when a resist pattern is formed between the reflective film and the transparent electrode film. The combination of materials is not limited to the combination of a material containing Al or an Al alloy with 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 need 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 not limited to each pixel, but is applied to each sub-pixel constituting the pixel.

FIG. 1 is a plan view illustrating a configuration of a transflective liquid crystal display device according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along the line AA in FIG. 1. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. FIG. 9 is a cross-sectional view showing another structure of the active matrix substrate used in the transflective liquid crystal display device. It is sectional drawing which shows the 1st modification (twist angle is about 0 degree) of the same transflective liquid crystal display device. It is sectional drawing which shows the 2nd modification (twist angle is about 60 degrees) of the same transflective liquid crystal display device. FIG. 7 is a cross-sectional view illustrating a configuration of a transflective liquid crystal display device according to a second embodiment of the present invention. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. It is sectional drawing which shows the 1st modification (twist angle is about 0 degree) of the same transflective liquid crystal display device. It is sectional drawing which shows the 2nd modification (twist angle is about 60 degrees) of the same transflective liquid crystal display device. FIG. 9 is a plan view showing a configuration of a transflective liquid crystal display device according to a third embodiment of the present invention. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. FIG. 13 is a plan view showing a 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 in FIG. 16. FIG. 3 is a plan view showing an enlarged structure of a main part of the transflective liquid crystal display device. FIG. 19 is a cross-sectional view taken along the line DD in FIG. 18. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. FIG. 13 is a plan view showing a configuration of a transflective liquid crystal display device according to a fifth embodiment of the present invention. FIG. 23 is a sectional view taken along the line EE in FIG. 22. FIG. 3 is a plan view showing an enlarged structure of a main part of the transflective liquid crystal display device. FIG. 25 is a sectional view taken along the line FF in FIG. 24. FIG. 3 is a plan view showing an enlarged structure of a main part of the transflective liquid crystal display device. FIG. 25 is a sectional view taken along the line GG of FIG. 24. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. It is process drawing which shows the manufacturing method of the same transflective liquid crystal display device in a process order. FIG. 9 is a plan view showing a structure of a conventional transflective liquid crystal display device. FIG. 9 is a diagram showing a problem in a conventional transflective liquid crystal display device. FIG. 3 is a plan view showing a structure of a transflective liquid crystal display device according to the prior application. FIG. 2 is a cross-sectional view illustrating a structure of a transflective liquid crystal display device according to the 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. FIG. 4 is a diagram illustrating a relationship between a twist angle of a liquid crystal and a film thickness (gap) of a liquid crystal layer in a transflective liquid crystal display device. FIG. 4 is a diagram illustrating a relationship between a twist angle of a liquid crystal, a light transmittance, and a reflectance in a transflective liquid crystal display device.

Explanation of reference numerals

1 Gate line (scanning electrode)
1a Gate electrode 2 Data line (signal electrode)
2a drain electrode 2b source electrode 2c storage electrode for capacitor 3 TFT
Reference Signs List 3a semiconductor layer 4 common storage line 4a storage capacitor 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)
Reference Signs List 17 liquid crystal layer 18 backlight light source 19a, 19b polarizing plate 20a, 20b retardation plate 21 resist pattern 22 G-D conversion electrode 23 terminal electrode 24 second passivation film 25 reflection film connection part (contact hole)
26 developer 27 crack 28 peeling 29 alignment film

Claims (21)

A first substrate including a plurality of signal electrodes arranged in parallel with each other along a first direction, and a plurality of scanning electrodes arranged in parallel with each other along a second direction orthogonal to the first direction; A second substrate having a plurality of pixel regions provided in one-to-one correspondence with the intersections of the signal electrodes and the scanning electrodes; and a second substrate provided between the first substrate and the second substrate. In addition to the interposed liquid crystal layer and a backlight light source for inputting light to the liquid crystal layer, each of the pixel regions includes a reflective film for receiving and receiving external ambient light to perform a reflective display during a reflective display mode operation. A transflective liquid crystal display device provided with a reflective region and a transmissive region having a transparent electrode film for transmissive display by transmitting the backlight light source during a transmissive display mode operation,
The transflective liquid crystal display device, wherein in each of the pixel regions, the transparent electrode film extends to the reflective film so as to cover part or all of the reflective film. 4. The transflective liquid crystal display device according to claim 1, wherein the transparent electrode film is formed on the reflection film via an insulating film. 2. The transflective liquid crystal display device according to claim 1, wherein the transparent electrode film is formed directly on the reflection film. 3. The transflective liquid crystal display device according to claim 2, wherein the reflective film and the transparent electrode film are electrically connected through a contact hole formed in the insulating film. A switching element for turning on and off a signal applied to the liquid crystal layer is formed on a surface of the first substrate facing the second substrate, and the reflection film is formed to cover the switching element. The transflective liquid crystal display device according to any one of claims 1 to 4, wherein 6. The transflective liquid crystal display device according to claim 5, wherein the reflective film covers the switching element via an insulating film having an uneven surface. A common contact hole is formed in the insulating film, and in the common contact hole, the reflective film and the transparent electrode film are provided for any one of a plurality of electrodes constituting the switching element. The transflective liquid crystal display device according to claim 5, wherein the transflective liquid crystal display device is electrically connected. First and second contact holes are formed in the insulating film, and the reflective film is electrically connected to any one of the plurality of electrodes constituting the switching element through the first contact hole. 7. The transflective liquid crystal display device according to claim 5, wherein the transparent electrode film is electrically connected to the transparent electrode film through the second contact hole. A G / D converter is formed outside the transmission region and the reflection region on the surface of the first substrate facing the second substrate, the signal line applying the signal to the liquid crystal layer being led out by a gate layer. 9. The transflective liquid crystal display device according to claim 5, wherein 10. The transflective liquid crystal display device according to claim 1, wherein the reflection film is made of a conductive material containing Al or an Al alloy, and the transparent electrode film is made of ITO. A first substrate including a plurality of signal electrodes arranged in parallel with each other along a first direction, and a plurality of scanning electrodes arranged in parallel with each other along a second direction orthogonal to the first direction; A second substrate having a plurality of pixel regions provided in one-to-one correspondence with the intersections of the signal electrodes and the scanning electrodes; and a second substrate provided between the first substrate and the second substrate. In addition to the interposed liquid crystal layer and a backlight light source for inputting light to the liquid crystal layer, each of the pixel regions includes a reflective film for receiving and receiving external ambient light to perform a reflective display during a reflective display mode operation. A transflective liquid crystal display device provided with a reflective region and a transmissive region having a transparent electrode film for transmissive display by transmitting the backlight light source during a transmissive display mode operation,
The first gap of the reflective region and the second gap of the transmissive region are adjusted according to the twist angle of the liquid crystal layer such that the reflectivity or transmissivity in white display is maximized. Transflective liquid crystal display device. 12. The liquid crystal display device according to claim 11, wherein when the twist angle of the liquid crystal is set to approximately 72 degrees, the first gap of the reflection region and the second gap of the transmission region are adjusted to substantially match. Transflective liquid crystal display device. 12. When the twist angle of the liquid crystal is set to approximately 0 [deg.], The first gap of the reflection region is adjusted to be substantially half of the second gap of the transmission region. The transflective liquid crystal display device as described in the above. The liquid crystal device according to claim 1, wherein when the twist angle of the liquid crystal is set to approximately 60 °, the first gap of the reflection region is adjusted to be approximately 70% of the second gap of the transmission region. 12. The transflective liquid crystal display device according to 11. A first substrate including a plurality of signal electrodes arranged in parallel with each other along a first direction, and a plurality of scanning electrodes arranged in parallel with each other along a second direction orthogonal to the first direction; A second substrate having a plurality of pixel regions provided in one-to-one correspondence with the intersections of the signal electrodes and the scanning electrodes; and a second substrate provided between the first substrate and the second substrate. In addition to the interposed liquid crystal layer and a backlight light source for inputting light to the liquid crystal layer, each of the pixel regions includes a reflective film for receiving and receiving external ambient light to perform a reflective display during a reflective display mode operation. A method of manufacturing a transflective liquid crystal display device, comprising: a reflective region and a transmissive region including a transparent electrode film for transmissive display by transmitting the backlight light source during a transmissive display mode operation,
A first step of forming the reflection film constituting the reflection region on a surface of the first substrate facing the second substrate;
Next, a second step of forming the transparent electrode film constituting the transmission region in a manner to cover part or all of the reflection film,
A method for manufacturing a transflective liquid crystal display device, comprising: The method of manufacturing a transflective liquid crystal display device according to claim 15, further comprising a third step of forming an insulating film on the reflection film between the first step and the second step. Method. A fourth step of forming a contact hole for electrically connecting the reflection film and the transparent electrode film to the insulating film between the third step and the second step. 17. The method for manufacturing a transflective liquid crystal display device according to claim 16, wherein: A first substrate including a plurality of signal electrodes arranged in parallel with each other along a first direction, and a plurality of scanning electrodes arranged in parallel with each other along a second direction orthogonal to the first direction; A second substrate having a plurality of pixel regions provided in one-to-one correspondence with the intersections of the signal electrodes and the scanning electrodes; and a second substrate provided between the first substrate and the second substrate. In addition to the interposed liquid crystal layer and a backlight light source for inputting light to the liquid crystal layer, each of the pixel regions includes a reflective film for receiving and receiving external ambient light to perform a reflective display during a reflective display mode operation. A method of manufacturing a transflective liquid crystal display device, comprising: a reflective region and a transmissive region including a transparent electrode film for transmissive display by transmitting the backlight light source during a transmissive display mode operation,
Forming the reflection film constituting the reflection region on the surface of the first substrate facing the second substrate, and then covering a part or all of the reflection film on the reflection film. Using the first substrate completed at least including a step of forming the transparent electrode film constituting the transmission region, and the second substrate completed in advance, using both substrates to form the liquid crystal layer. And the first gap of the reflection region and the second gap of the transmission region are adjusted according to the twist angle of the liquid crystal layer so that the reflectance or the transmittance in white display is maximized. A method of manufacturing a transflective liquid crystal display device. By forming the reflective film on the surface of the first substrate facing the second substrate via an insulating film having an uneven surface, the reflective region of the reflective region is formed in accordance with the twist angle of the liquid crystal layer. 20. The transflective liquid crystal display device according to claim 18, wherein the first gap and the second gap of the transmission region are adjusted so that the reflectance or the transmittance in white display is maximized. Method. By processing the surface of the first substrate facing the second substrate, a first gap of the reflection region and a second gap of the transmission region are changed according to a twist angle of the liquid crystal. 19. The method for manufacturing a transflective liquid crystal display device according to claim 18, wherein the reflectance or the transmittance in white display is adjusted to be maximum. 20. The method of manufacturing a transflective liquid crystal display device according to claim 19, wherein the thickness of the insulating film is different between the transmission region and the reflection region.

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