JP4237679B2 - Display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a display device and a manufacturing method thereof.

  In general, in a liquid crystal display device, a liquid crystal layer made of liquid crystal is sandwiched between two substrates each having an electrode on the upper surface and the lower surface, and polarizing plates are installed on the upper and lower sides of the two substrates. The thing has the structure where the backlight was installed in the back. Surfaces having electrodes on these substrates are subjected to a so-called alignment treatment, and a director that shows the orientation of liquid crystal molecules on average is birefringent in the desired liquid crystal, and light incident through the polarizing plate from the backlight. Changes to elliptically polarized light due to birefringence and is incident on the polarizing plate on the opposite side. In this state, when a voltage is applied between the upper and lower electrodes, the alignment state of the director is changed, the birefringence of the liquid crystal layer is changed, and the elliptical polarization state incident on the opposite polarizing plate is changed. An electro-optic effect that changes the intensity and spectrum of light transmitted through the liquid crystal display device can be obtained.

  In the liquid crystal display device, a backlight (back light source) is installed on the back or side, and a transmissive liquid crystal display device that displays images and a reflector on the substrate, and ambient light is reflected on the reflector surface. There is a reflective liquid crystal display device that displays an image by performing the above operation. This transmissive liquid crystal display device has a problem in that when the ambient light is very bright, the display cannot be observed because the display light is darker than the ambient light. On the other hand, the reflective liquid crystal display device has a drawback that the visibility is extremely lowered when the ambient light is dark.

  In order to solve these problems, a liquid crystal display device using a transflective film that transmits part of light and reflects part of light (hereinafter referred to as a transflective liquid crystal display device) has been proposed. (Patent Document 1).

  An example of a method for manufacturing the transflective liquid crystal display device will be described with reference to FIG. FIG. 15 is a cross-sectional view showing an example of a manufacturing process of a TFT substrate used in a conventional liquid crystal display device. 1 is a first metal thin film, 2 is a first insulating film, 3 is a semiconductor active film, 4 is an ohmic contact film, 5 is a source electrode, 6 is a drain electrode, 7 is a second insulating film, and 8 is an organic film , 9 are conductive thin films. Reference numerals 10 and 11 denote a third metal thin film, and the metal thin film 10 is disposed below the metal thin film 11. Reference numeral 12 denotes a contact hole.

  First, the first metal thin film 1 is formed on a glass substrate by sputtering or the like. A gate wiring, a gate electrode, and a gate terminal are formed by a first photolithography process. As the first metal thin film, chromium, molybdenum, tantalum, titanium, aluminum, copper, an alloy obtained by adding a small amount of other substances to these, or a laminated film thereof is used. The structure shown in FIG. 15A is formed by the process described above.

  Next, the first insulating film 2, the semiconductor active film 3, and the ohmic contact film 4 are continuously formed by plasma CVD. The first insulating film 2 is made of, for example, SiNx or SiOy, and is used as a gate insulating film. As the semiconductor active film 3, an amorphous silicon (a-Si) film or a polysilicon (p-Si) film is used. As the ohmic contact film 4, an na-Si film or an np-Si film obtained by doping a-Si or p-Si with a small amount of phosphorus (P) or the like is used. Next, the semiconductor active film 3 and the ohmic contact film 4 are patterned at least in a portion where the TFT portion is formed by a second photolithography process. As a result, the structure shown in FIG. 15B is formed.

  A second metal thin film is formed by a method such as sputtering. As the second metal thin film, for example, chromium, molybdenum, tantalum, titanium, aluminum, copper, an alloy obtained by adding a small amount of other substances to these, or a laminated film thereof is used. Next, patterning is performed so that the second metal thin film forms the source electrode 5 and the drain electrode 6 in a third photolithography process. Next, the ohmic contact film 4 is etched. By this process, the central portion of the ohmic contact film 4 in the TFT portion is removed, and the semiconductor active film 3 is exposed. Thereby, the structure shown in FIG. 15C is formed.

  Further, after the second insulating film 7 and the organic film 8 are formed, patterning is performed by a fourth photolithography process. In this process, a contact hole 12 for connecting a conductive thin film formed in a later step to a gate terminal, a source electrode, a drain electrode, or the like is formed. As a result, the configuration shown in FIG.

  Further, a conductive thin film 9 is formed and patterned by a fifth photolithography process. The conductive thin film 9 is made of a transparent conductive film such as ITO. As a result, the configuration shown in FIG. Thereafter, third metal thin films 10 and 11 are formed and patterned by a sixth photolithography process. As a result, the configuration shown in FIG. The conductive thin film 9 and the third metal thin films 10 and 11 serve as pixel electrodes for driving the liquid crystal. The portion where the conductive thin film 9 is provided becomes a transmission portion that transmits light from the backlight, and the portion where the third metal thin films 10 and 11 are provided is a reflection portion that reflects light of outside light. Become. The TFT array substrate formed as described above is bonded to a CF substrate provided with a counter electrode, and liquid crystal is injected therebetween. The liquid crystal panel in which the liquid crystal is sandwiched between the two substrates is placed on the light emitting surface side of the planar light source device. In this way, a transflective liquid crystal display device is manufactured.

  However, the liquid crystal display device formed by such a process has the following problems. In the above-described configuration, the conductive thin film 9 is in direct contact with the first metal thin film 1 or the second metal thin film in the contact hole 12. When the conductive thin film 9 is brought into direct contact with the first metal thin film 1 or the like, there is a problem that the contact resistance (contact resistance) in the contact hole 12 is deteriorated. In particular, when the contact hole is formed by removing the organic film 8 and the second insulating film 7 by dry etching, the resistivity of the contact portion becomes extremely worse compared to normal contact without dry etching. There was a problem. Note that the contact resistance deterioration due to dry etching is particularly noticeable when the material of the metal thin film is chromium. Such deterioration of the contact resistance may deteriorate the resistance of the wiring, terminal, or electrode, leading to deterioration of display characteristics and display quality.

  By the way, in the liquid crystal display device, a transfer pad for electrically connecting the TFT array substrate and the CF substrate is formed. A common potential input to a common potential input terminal provided on the TFT array substrate is passed through the transfer pad. It is supplied to the counter electrode of the CF substrate.

  An example of the configuration of this transfer pad will be described with reference to FIGS. FIG. 16 is a top view showing a configuration around the transfer pad in the TFT substrate. FIG. 17 is a side cross-sectional view schematically showing the configuration around the transfer pad. The transfer pad is usually provided at the end of the substrate outside the display area.

  As shown in FIG. 17, the transfer pad 16 is provided on a glass substrate 25 serving as a TFT array substrate. A transfer is formed on the transfer pad 16 and connected to the counter electrode of the CF substrate. Around the transfer pad 16, a common wiring 17 having a common potential is provided on the glass substrate 25. The common wiring 17 is made of a first metal thin film or a second metal thin film. An insulating film 18 is provided on the common wiring 17, and an organic film 8 is further formed thereon. Holes 24 are formed in the portions of the organic film 8 and the insulating film 18 corresponding to the transfer pads 16 by dry etching. Therefore, the hole 24 is formed by removing the organic film 8 and the insulating film 18 so that the glass substrate 25 is exposed.

  Further, a contact hole 12 for connecting to the common wiring 17 is formed in the organic film 8 and the insulating film 18. The contact hole 12 is formed so that the common wiring 17 is exposed. A transparent conductive thin film 9 is formed so as to cover the hole 24 and the contact hole 12. Since the conductive thin film 9 is provided over the hole 24 and the contact hole 12, the common wiring 17 and the conductive thin film 9 are electrically connected.

  The transfer is usually formed on a transparent conductive thin film 9 such as ITO directly provided on a glass substrate in order to inspect the position and shape after bonding the two substrates. Thereby, the position and shape of the transfer can be inspected from the back side of the TFT array substrate using an optical microscope or the like. That is, since the glass substrate and the conductive thin film are transparent, the transfer can be observed by transmitted light from the back surface side of the TFT array substrate. This is because if the transfer is not formed in the desired position and shape, contact failure may occur, and further, an error in the gap between the two substrates occurs. Therefore, after the two substrates are bonded together as described above, the position and shape of the transfer are inspected by performing inspection from the outside of the substrate.

  Furthermore, there is one in which a vernier for measuring the size of a transfer is formed under a conductive thin film 9 by a metal thin film pattern (Patent Document 2). A metal thin film pattern is formed on a part of the transfer pad under a transparent conductive thin film. This vernier makes it possible to measure the dimensions of the transfer. In some cases, a part of the metal film is removed in a region where the transfer pad is provided, and a light transmission part for inspecting from the back side of the substrate is provided (Patent Document 3).

  In the etching process of the organic film 8 and the insulating film 18, the surface of the common wiring 17 is exposed to form the contact hole 12 as shown in FIG. Therefore, the surface of the common wiring 17 is exposed to an etching process, and surface modification occurs. Since contact is made directly with the conductive thin film 9 made of ITO from above, the contact resistance may be deteriorated. In particular, when the organic film 8 and the insulating film 18 are patterned by dry etching, the surface of the common wiring 17 is exposed to dry etching plasma, so that the contact resistance is significantly deteriorated.

  In addition, there are the following problems. The transfer pad is usually disposed on the outer peripheral portion outside the display area. Since a transfer is provided in the hole 24 using a dispenser, a certain space or more is required. Therefore, the space for forming the contact hole 12 is limited, and there is a possibility that a sufficiently large contact hole cannot be formed. In this case, the contact area between the common wiring and the transparent conductive film is reduced, and the contact resistance may be further deteriorated.

JP 2003-248232 A JP 2000-89247 A (paragraph number 0077) Japanese Patent Laying-Open No. 2001-281689 (paragraph number 0026)

  As described above, the conventional liquid crystal display device has a problem that the contact resistance between the pad and the wiring deteriorates.

  The present invention has been made in view of such a problem, and an object thereof is to provide a display device in which a pad and a wiring are connected with a good contact resistance.

  A display device according to a first aspect of the present invention is a display device including a substrate provided with a connection pad (for example, a transfer pad 16 in an embodiment of the present invention) for connecting to the outside, the substrate Wiring provided on the wiring (for example, the common wiring 17 in the embodiment of the present invention), an organic film provided on the wiring (for example, the organic film 8 in the embodiment of the present invention), and the connection A connection pad hole (for example, hole 24 in an embodiment of the present invention) in which a pad is disposed, the connection pad hole formed in the organic film so as to expose the wiring, and the organic film A transparent conductive film (for example, the conductive thin film 9 in an embodiment of the present invention) provided to be the connection pad, and connected to the wiring in the connection pad hole. Those comprising a transparent conductive film is. Thereby, a good contact resistance can be obtained.

  The display device according to the second aspect of the present invention is the above-described display device, wherein the base metal film (for example, the embodiment of the present invention) provided between the transparent conductive film and the wiring in the connection pad hole. It is desirable that the transparent conductive film and the wiring are connected via a base metal film 13) in the form. As a result, even better contact resistance can be obtained.

  The display device according to the third aspect of the present invention is the display device described above, wherein the base metal film and the wiring are patterned in substantially the same size in the connection pad hole.

  A display device according to a fourth aspect of the present invention is the display device described above, wherein an end of the pattern of the base metal film is disposed in the connection pad hole. Thereby, disconnection on the organic film can be prevented.

  In the display device according to the fifth aspect of the present invention, in the above-described display device, an end portion of the pattern of the base metal film is disposed on the organic film, and the conductive portion is connected to an end portion of the pattern of the base metal film. A protective film (for example, the third metal thin film 10 in the embodiment of the present invention) is formed on the thin film. Thereby, disconnection on the organic film can be prevented.

  A display device according to a sixth aspect of the present invention is a display device including a substrate provided with a connection pad for connection to the outside, the wiring provided on the substrate, and the wiring provided on the wiring. A connection pad hole in which the connection pad is disposed, a connection pad hole formed in the organic film, and a contact hole formed in the organic film so that the wiring is exposed. A transparent conductive film provided on the connection pad hole from above the organic film, and a base metal film provided between the organic film and the transparent conductive film, wherein the connection pad hole The wiring and the transparent conductive film are electrically connected to each other through a base metal film disposed over the contact hole. Thereby, even if the space for providing the pad is limited, good contact resistance can be obtained.

  A display device according to a seventh aspect of the present invention is a preferred embodiment of the above-described display device, and includes a first crossing through an insulating film between the substrate and the organic film in a display region. A wiring and a second wiring are provided.

  A display device according to an eighth aspect of the present invention is a preferred embodiment of the above-described display device, further comprising a counter substrate disposed to face the substrate, via a transfer provided on the connection pad. The counter electrode provided on the counter substrate and the wiring are electrically connected.

  In the display device according to the ninth aspect of the present invention, in the display device described above, in the display device according to the above-described aspect, a light transmission portion that transmits light from the back side of the substrate is formed in the hole. It is a feature. Thereby, the transfer can be inspected from the back side of the substrate.

  In the display device manufacturing method according to the tenth aspect of the present invention, in the display region, the first wiring and the second wiring intersecting each other through an insulating film are disposed between the substrate and the organic film. A display device manufacturing method comprising: a step of forming a wiring on the substrate; a step of forming an organic film on the wiring; and a connection pad hole in which a connection pad connected to the outside is disposed. Providing a connection pad hole formed in the organic film so that the wiring is exposed, and forming a transparent conductive film connected to the wiring in the connection pad hole as the connection pad. It is what you have. Thereby, contact resistance can be reduced.

  A display device manufacturing method according to an eleventh aspect of the present invention is the above-described display device manufacturing method, wherein the wiring and the transparent conductive film are formed in the connection pad hole after the step of forming the organic film. And a step of forming a base metal film therebetween. Thereby, contact resistance can further be reduced.

  A display device manufacturing method according to a twelfth aspect of the present invention is the above-described display device manufacturing method, wherein a protective film disposed on an end portion of the base metal film is formed on the transparent conductive film. Is further included. Thereby, disconnection on the organic film can be prevented.

  In the display device manufacturing method according to the thirteenth aspect of the present invention, in the display region, the first wiring and the second wiring intersecting each other through an insulating film are disposed between the substrate and the organic film. A method of manufacturing a display device, comprising: forming a wiring on the substrate; forming an organic film on the wiring; and a connection pad hole in which the connection pad is disposed, Providing a connection pad hole formed in the organic film; providing a contact hole provided in the organic film so that the wiring is exposed; and a base metal electrically connected to the wiring in the contact hole Forming a base metal film disposed on the organic film from the connection pad hole to the contact hole; and Wherein a base metal film and a transparent conductive film which is electrically connected in Le, in which and forming a transparent conductive film provided in the hole for the connecting pads over the underlying metal film. Thereby, the contact resistance can be reduced even in a limited space.

  A display device manufacturing method according to a fourteenth aspect of the present invention is a responsive example of the above-described display device manufacturing method, wherein a transfer is provided on the transparent conductive film in the connection pad hole. A step, a step of disposing a counter substrate having a counter electrode opposite to the substrate, and a step of electrically connecting the wiring and the counter electrode via the transfer.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus with which the pad and wiring were connected by favorable contact resistance, and its manufacturing method can be provided.

  Embodiments to which the present invention is applicable will be described below. The following description is to describe the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following descriptions are omitted and simplified as appropriate. Moreover, those skilled in the art will be able to easily change, add, and convert each element of the following embodiments within the scope of the present invention. In addition, what attached | subjected the same code | symbol in each figure has shown the same element, and abbreviate | omits description suitably.

Embodiment 1 of the Invention
FIG. 1 shows a manufacturing process flow of a transflective liquid crystal display device according to the present invention. In this manufacturing process, a transflective a-Si TFT array is manufactured by seven photographic processes. 1 is a first metal thin film, 2 is a first insulating film, 3 is a semiconductor active film, 4 is an ohmic contact film, 5 is a source electrode, 6 is a drain electrode, 7 is a second insulating film, and 8 is an organic film , 9 are conductive thin films, 10 and 11 are third metal thin films, 12 are contact holes, and 13 is a base metal film . The pattern shape shown in FIG. 1 shows a gate terminal portion, a source terminal portion, a crossing portion of the source wiring and the gate wiring, a TFT portion, a reflection portion of the display region, and a transmission portion of the display region in order from the left. The gate terminal portion and the source terminal portion are provided, for example, in a region other than the display region at the substrate end portion, and a signal is input from the drive circuit through these terminals. The TFT portion is provided corresponding to each pixel in the display area. The intersection between the source wiring and the gate wiring is provided in the vicinity of the TFT portion. The reflection part is provided with a reflection electrode in each pixel, and the transmission part is provided with a transmission electrode in each pixel. The reflective electrode and the transmissive electrode constitute a pixel electrode of each pixel.

  First, a glass substrate is cleaned as an insulating substrate to clean the surface. As the insulating substrate, a transparent insulating substrate such as a glass substrate is used. The thickness of the insulating substrate may be arbitrary, but it is preferably 1.1 mm or less in order to reduce the thickness of the liquid crystal display device. If the insulating substrate is too thin, the substrate may be distorted due to various film formation and thermal history of the process, resulting in problems such as reduced patterning accuracy. Therefore, the thickness of the insulating substrate takes into account the process used. Need to choose. Further, when the insulating substrate is made of a brittle fracture material such as glass, it is preferable to chamfer the end surface of the substrate in order to prevent foreign matters from being mixed due to chipping from the end surface. In addition, it is preferable to provide a notch in a part of the insulating substrate so that the orientation of the substrate can be specified, because the direction of substrate processing in each process can be specified, thereby facilitating process management.

  Next, the first metal thin film 1 is formed by a method such as sputtering. As the first metal thin film 1, for example, a thin film having a thickness of about 100 nm to 500 nm made of any one of chromium, molybdenum, tantalum, titanium, aluminum, copper, and an alloy obtained by adding a trace amount of other substances to these is used. be able to. In the preferred embodiment, 200 nm thick chromium is used. A contact hole is formed on the first metal thin film 1 by dry etching in a process to be described later, and a conductive thin film is formed on the contact hole. The metal thin film is preferably used for the first metal thin film 1, and at least the surface is preferably made of chromium, titanium, tantalum, molybdenum, or the like. Further, as the first metal thin film 1, a metal thin film in which different kinds of metal thin films are laminated or a metal thin film having a different composition in the film thickness direction can also be used. Further, when a material containing aluminum is used as the first metal thin film 1, it is preferable that at least the surface is aluminum nitride having a specific resistance of about 10 to 1000 μΩ.

  Next, the first metal thin film 1 is patterned by a first photolithography process (photographic process) to form a gate electrode and a gate wiring, an auxiliary capacitance electrode and an auxiliary capacitance wiring, a gate terminal, and the like. Thereby, the structure shown in FIG. 1A is formed. In the photolithography process, after the TFT array substrate is washed, a photosensitive resist is applied and dried, then exposed through a mask pattern in which a predetermined pattern is formed, and developed to make a mask pattern on the TFT array substrate photolithography. This is performed by forming a resist to which the resist is transferred, heating and curing the photosensitive resist, etching, and peeling the photosensitive resist. If the wettability between the photosensitive resist and TFT array substrate is poor and the photosensitive resist repels, UV cleaning is performed before coating, or HMDS (hexamethyldisilazane) is used to improve wettability. Processes such as applying steam.

  Further, when the adhesion between the photosensitive resist and the TFT array substrate is poor and peeling occurs, the heat curing temperature is increased or the time is increased. Etching of the first metal thin film 1 is performed by wet etching using a known etchant (for example, when the first metal thin film 1 is made of chromium, an aqueous solution in which second ceric ammonium nitrate and nitric acid are mixed). It can be etched. The first metal thin film 1 is preferably etched so that the pattern edge has a tapered shape, in order to prevent a short circuit at a step with another wiring. Here, the taper shape means that the pattern edge is etched so that the cross section has a trapezoidal shape. In addition, although it has been shown that the gate electrode and the gate wiring, the auxiliary capacitance electrode and the auxiliary capacitance wiring are formed in this step, various other marks and wirings necessary for manufacturing the TFT array substrate are formed.

  Next, the first insulating film 2, the semiconductor active film 3, and the ohmic contact film 4 are continuously formed by plasma CVD. As the first insulating film 2 serving as a gate insulating film, a SiNx film, a SiOy film, a SiOzNw film, or a laminated film thereof is used (x, y, z, and w are positive numbers). The film thickness of the first insulating film 2 is about 300 nm to 600 nm. When the film thickness is small, a short circuit is likely to occur at the intersection of the gate wiring and the source wiring, and it is preferable that the thickness be about the thickness of the first metal thin film 1. When the film thickness is large, the ON current of the TFT becomes small and the display characteristics are deteriorated. In a preferred embodiment, a first insulating film 2 is formed by forming a 300 nm SiN film and then forming a 100 nm SiN film.

  As the semiconductor active film 3, an amorphous silicon (a-Si) film or a polysilicon (p-Si) film is used. The film thickness of the semiconductor active film 3 is about 100 nm to 300 nm. When the film thickness is thin, the ohmic contact film 4 to be described later disappears during dry etching. When the film thickness is thick, the ON current of the TFT is reduced, so that the etching depth of the ohmic contact film 4 during dry etching is reduced. The film thickness is selected based on the controllability and the required ON current of the TFT. When an a-Si film is used as the semiconductor active film 3, the interface between the first insulating film 2 and the a-Si film is a SiNx film or a SiOzNw film. It is preferable in terms of controllability and reliability of Vth.

  When a p-Si film is used as the semiconductor active film 3, it is preferable that the interface between the first insulating film 2 and the p-Si film is a SiOy film or a SiOzNw film in terms of controllability and reliability of Vth of the TFT. When an a-Si film is used as the semiconductor active film 3, the vicinity of the interface with the first insulating film 2 is formed under a condition with a low film formation rate, and the upper layer is formed under a condition with a high film formation rate. It is more preferable that TFT characteristics with high mobility can be obtained in a short film formation time and that the leakage current when the TFT is turned off can be reduced. In a preferred embodiment, a 150 nm a-Si film is formed as the semiconductor active film 3.

As the ohmic contact film 4, an na-Si film or an np-Si film obtained by doping a-Si with a small amount of phosphorus (P) is used. The thickness of the ohmic contact film 4 can be about 20 nm to 70 nm. These SiNx films, SiOy films, SiOzNw films, a-Si films, p-Si films, na-Si films, and np-Si films are formed of known gases (SiH ₄ , NH ₃ , H ₂ , NO _2). , PH ₃ , N ₂ and a mixed gas thereof). In a preferred embodiment, a 30 nm na-Si film is deposited as the ohmic contact film 4.

  Next, the semiconductor active film 3 and the ohmic contact film 4 are patterned at least in a portion where the TFT portion is formed by a second photolithography process. As a result, the structure shown in FIG. 1B is formed. The first insulating film 2 remains throughout. The semiconductor active film 3 and the ohmic contact film 4 can be left by patterning and remaining in a portion where the source wiring, the gate wiring, and the auxiliary capacitance wiring cross in a plane in addition to the portion where the TFT portion is formed. It is more preferable that the withstand voltage becomes larger. Further, the semiconductor active film 3 and the ohmic contact film 4 in the TFT portion remain in a continuous shape up to the lower portion of the source wiring, so that the source electrode does not get over the step between the semiconductor active film 3 and the ohmic contact film 4 and the step portion This is preferable because disconnection of the source electrode is difficult to occur.

The semiconductor active film 3 and the ohmic contact film 4 can be etched by a known gas composition (for example, a mixed gas of SF ₆ and O ₂ or a mixed gas of CF ₄ and O ₂ ).

  Next, a second metal thin film is formed by a method such as sputtering. As the second metal thin film, for example, chromium, molybdenum, tantalum, titanium, aluminum, copper, an alloy obtained by adding a small amount of other substances to these, or a laminated film thereof is used. Of course, the above-described materials may be laminated. In a preferred embodiment, chromium having a thickness of 200 nm is deposited.

Next, patterning is performed so that the second metal thin film forms the source wiring, the source terminal, the source electrode 5 and the drain electrode 6 by a third photolithography process. Thereby, the structure shown in FIG. 1C is formed. The source electrode 5 is formed over a portion where the source wiring and the gate wiring intersect. The drain electrode 6 is formed over the reflection portion. Next, the ohmic contact film 4 is etched. By this process, the central portion of the ohmic contact film 4 in the TFT portion is removed, and the semiconductor active film 3 is exposed. The ohmic contact film 4 can be etched by a known gas composition (for example, a mixed gas of SF ₆ and O ₂ or a mixed gas of CF ₄ and O ₂ ).

  Next, the second insulating film 7 is formed by plasma CVD. An organic film 8 is formed thereon. The second insulating film 7 can be formed of the same material as that of the first insulating film 2. In a preferred embodiment, SiN having a thickness of 100 nm is used as the second insulating film 7. The organic film 8 is a known photosensitive organic film, and for example, J335 PC335 or PC405 is used. The organic film 8 is formed with a thickness of about 3.0 to 4.0 μm, preferably about 3.2 to 3.9 μm. Of course, other thicknesses may be used.

  Next, the organic film 8, the second insulating film 7, and the first insulating film 2 are patterned into the shape shown in FIG. 1D by a fourth photolithography process. In this step, a contact hole 12 for connecting to the first electrode 1 is formed by dry etching. At this time, unevenness may be provided on the surface of the organic film 8. Thereby, external light is scattered and a favorable display characteristic can be obtained.

  In the gate terminal portion, both the organic film 8 and the first insulating film 2 and the second insulating film 7 are removed to form the contact hole 12 that electrically connects the gate wiring and the drive signal source. 1 of the metal thin film 1 is exposed. In the source terminal portion, the organic film 8 and the second insulating film 7 are removed to form the contact hole 12 that electrically connects the source wiring and the drive signal source, and the second metal thin film is exposed. Between the TFT portion and the reflective portion, the organic film 8 and the second insulating film 7 are removed, and the drain electrode 6 is exposed. Furthermore, in the transmission part, both the organic film 8 and the first insulating film 2 and the second insulating film 7 are removed, and the first insulating substrate is exposed. The contact hole 12 can be formed by the same method as described above.

Thereafter, in the present invention, the base metal film 13 is formed by a method such as sputtering. Here, as the base metal film 13, a thin film having a thickness of about 100 nm to 500 nm made of, for example, chromium, molybdenum, tantalum, titanium, aluminum, copper, or an alloy obtained by adding a trace amount of other substances to these is used. Can do. Of course, the above-described materials may be laminated. In the preferred embodiment, 100 nm thick chromium is used. The underlying metal film 13 is patterned by a fifth photolithography process.

The base metal film 13 is formed so as to cover the upper part of the contact hole 12 as shown in FIG. The first metal thin film 1 is provided below the contact hole 12, the source electrode 5 and drain electrode 6 and the like is exposed, the first metal thin film 1 in patterning, the source electrode 5 and drain electrode 6 This is because they are dissolved in the etching solution. Note that the same method as described above can be used for etching. The underlying metal film 13 is in contact with and electrically connected to a gate terminal, a source terminal, a drain electrode, and the like below the contact hole 12.

Next, the conductive thin film 9 is formed by a method such as sputtering. As the conductive thin film 9, ITO, SnO ₂ , IZO or the like which is a transparent conductive film can be used, and ITO is particularly preferable from the viewpoint of chemical stability. In a preferred embodiment, the conductive thin film 9 is made of ITO having a thickness of 80 nm. The ITO may be either crystallized ITO or amorphous ITO, but when amorphous ITO is used, it is necessary to heat and crystallize to a crystallization temperature of 180 ° C. or higher before forming the third metal thin film. .

  Next, the conductive thin film 9 is patterned into a shape of a pixel electrode or the like as shown in FIG. 1F by a sixth photolithography process. The conductive thin film 9 can be etched using known wet etching (for example, an aqueous solution in which hydrochloric acid and nitric acid are mixed when the conductive thin film 9 is made of crystallized ITO) depending on the material used. is there. When the conductive thin film 9 is ITO, etching by dry etching with a known gas composition (for example, HI, HBr) is also possible. In addition, although it has been shown that the transmissive electrode is formed in this step, a transfer pad for electrically connecting the counter electrode of the counter substrate and the common wiring of the TFT array substrate is formed on the TFT array substrate.

In the case of amorphous ITO, patterning is performed with an aqueous solution in which a known oxalic acid is mixed before heating, as with crystallized ITO, after heating. In a preferred embodiment, amorphous ITO is deposited, etched with oxalic acid, and heated to 220-230 ° C. in air before the third metal thin film is deposited. The conductive thin film 9 provided in the transmission part is used for driving the liquid crystal. Further, since the conductive thin film 9 provided on the contact hole 12 in the gate terminal portion and the source terminal portion is in contact with the base metal film 13, it is electrically connected to the gate terminal, the source terminal, the drain electrode, and the like. It will be.

  Next, the metal thin films 10 and 11 constituting the third metal thin film are formed by a method such as sputtering. As the third metal thin films 10 and 11, for example, chromium, molybdenum, tantalum, titanium, aluminum, copper, silver, or an alloy obtained by adding a trace amount of other substances to these, or the like is about 100 nm to 500 nm. A thin film having a thickness can be used. Of course, the above-described materials may be laminated. The metal thin film 10 has an effect of preventing the metal thin film 11 from being cut off at a step such as a contact hole portion. If this step break is negligible, the metal thin film 10 may not be formed. In this case, the number of processes is reduced, and the cost can be reduced. In a preferred embodiment, after depositing chromium having a thickness of 100 nm, an alloy of aluminum and Cu having a thickness of 300 nm is deposited, and further chromium having a thickness of 100 nm is deposited. If the alloy of aluminum and Cu is exposed, corrosion of the conductive thin film 9 proceeds at the time of development in the next photographic process. To prevent this, chromium (not shown) is provided in the uppermost layer.

  Next, in the seventh photolithography process, the third metal thin films 10 and 11 and the uppermost chromium layer are patterned into the shape of the reflective electrode, and the uppermost chromium layer is removed by etching to form the reflective electrode. In the case where the metal film 10 is chromium, it is possible to etch simultaneously with the uppermost layer of chromium by peeling the resist after the etching of the metal thin film 11. The reflective electrode is formed in a state where a metal thin film 11 made of an alloy of aluminum and Cu is laminated on a metal thin film 10 made of chromium. The uppermost chromium layer is provided to prevent corrosion of the conductive thin film 9, but is removed at this stage in order to increase the reflectivity. Since the 3rd metal thin film 11 is used as a reflective electrode, it is preferable that it is a material with a high reflectance. Therefore, in this embodiment, an alloy obtained by adding copper to aluminum having high electrical conductivity is used. The etching of the third metal thin film can be performed by wet etching using a known etchant. The third metal thin film 11 provided in the reflection part is used as a reflection electrode, and the liquid crystal is driven by the reflection electrode and the transmission electrode. Finally, the structure shown in FIG. 1G is formed.

  An alignment film is applied from above, and a TFT array substrate is manufactured by rubbing in a certain direction. The TFT array substrate thus manufactured is bonded to a CF substrate having a counter electrode via a spacer, and liquid crystal is injected therebetween. A liquid crystal display device is manufactured by attaching the liquid crystal panel sandwiched between the liquid crystal layers to the backlight unit.

  The liquid crystal display device manufactured as described above includes a transfer 19 for connecting the common wiring of the TFT array substrate and the counter electrode of the CF substrate as shown in FIG. The transfer 19 is provided at the substrate end outside the display area. A transfer 19 is formed by providing a resin containing conductive particles, silver paste, Au pearl, or the like on a transfer pad 16 provided on the TFT array substrate 15. The transfer 19 is usually formed outside a sealing material applied to seal the TFT array substrate 15 and the CF substrate.

  A configuration around the transfer pad in the liquid crystal display device according to the present invention will be described with reference to FIGS. FIG. 3 is a plan view schematically showing the configuration around the transfer pad. FIG. 3 is a side sectional view schematically showing the configuration around the transfer pad.

  Reference numeral 17 denotes a common wiring, which is formed of the same layer as the first metal thin film 1 or the source electrode 5 (drain electrode 6) in the manufacturing process shown in FIG. An insulating film 18 is formed of the same layer as the first insulating film 2 or the second insulating film 5. 12 is a contact hole provided in the organic film and the insulating film, 16 is a transfer pad, 23 is an opening provided in the base metal film, and 24 is a hole provided in the organic film and the insulating film.

  A hole 24 larger than the transfer pad 16 is provided in the organic film 8 and the insulating film 18 corresponding to the transfer pad 16 in a region surrounded by a dotted line in FIG. In FIG. 3, an organic film 8 and an insulating film 18 are provided in the hatched portion. As shown in FIG. 3, the transfer pad 16 is usually provided at the center of the hole 24. As shown in FIG. 4, a conductive thin film 9 is disposed on the uppermost layer of the transfer pad 16.

  A contact hole 12 is formed around the hole 24. The hole 24 and the contact hole 12 are formed by patterning the organic film 8 and the insulating film 18 in a dry etching process for providing the contact hole 12 shown in FIG. As a result, holes 24 are formed so that the substrate is exposed as shown in FIGS. Further, a contact hole 12 is formed around the hole 24. In FIG. 3, a plurality of contact holes 12 are provided around the hole 24, but one or more contact holes 12 may be formed.

  A common wiring 17 is formed under the insulating film 18 disposed under the organic film 8. The common wiring 17 is provided in the step of forming the first metal thin film 1 shown in FIG. 1A or the step of forming the source electrode 5 (drain electrode 6) shown in FIG. Further, the common wiring 17 may have a stacked structure of the first metal thin film 1 and the second electrode. The organic film 8 and the insulating film 18 corresponding to the contact hole 12 are patterned so as to be removed, and the common wiring 17 is exposed.

  A base metal film 13 is formed on the organic film 8 so as to cover the contact hole 12. The base metal film 13 is formed by the configuration shown in FIG. The base metal film 13 is disposed on the organic film 7 and in the contact hole. In the contact hole 12, the base metal film 13 and the common wiring 17 are connected. Further, a conductive thin film 9 is provided so as to cover the base metal film 13. The conductive thin film 9 is a transparent conductive film such as ITO, and is formed by the process shown in FIG.

  The underlying metal film 13 is patterned so that the opening 23 is formed in the hole 24. That is, in the region where the transfer pad 16 is provided, the base metal film 13 has a configuration in which a portion corresponding to the opening 23 is removed by etching. In the opening 23, the organic film 8 and the insulating film 18 are removed so that the substrate is exposed. In order to form the conductive thin film 9 from above, the conductive thin film 9 is formed even inside the opening 23. Therefore, the conductive thin film 9 is directly disposed on the substrate in the opening 23. In the opening 23, a metal film serving as a light shielding film is not formed, and only the transparent conductive thin film 9 is provided on the substrate. The region in which the opening 23 is provided becomes a light transmitting portion through which light from the back side of the substrate is transmitted, and transfer inspection can be performed.

  The base metal film 13 is formed from the contact hole 12 to the hole 24. Further, a conductive thin film 9 is provided on the base metal film 13. Therefore, the conductive thin film 9 is connected to the common wiring 17 through the base metal film 13. Since the base metal film 13 is formed after the etching process of the organic film 8 and the insulating film 18, the surface is not modified and a good contact resistance can be obtained. As a result, the common potential can be supplied to the transfer pad by the low resistance wiring. Further, since the conductive thin film 9 is in the uppermost layer, the contact resistance with the transfer can be reduced.

  The base metal film 13 is formed from the contact hole 12 to the hole 24. Accordingly, the pattern end portion of the base metal film 13 is formed inside the hole 24. On the other hand, when the pattern end of the base metal film 13 is arranged on the organic film 8 as shown in FIG. 5, the conductive thin film 9 is directly formed on the organic film in the periphery of the hole. The film quality of the thin film becomes weak. Further, a step is generated in the conductive thin film 9 at the pattern end of the base metal film 13, so that the coverage of the base metal film 13 is lowered. Therefore, in the reflective electrode etching step shown in FIG. 1 (f), the etchant penetrates to the base metal film, and the base metal film 13 is melted.

  As a result, a gap is generated between the conductive thin film 9 and the organic film 8 at a position that is the pattern end of the base metal film 13. There is a possibility that the conductive thin film may be cut off at the step portion of the pattern end of the base metal film 13. When the conductive thin film 9 is cut around the transfer pad, a disconnection occurs, so that a common potential cannot be stably supplied to the counter electrode via the transfer, and display quality is deteriorated. In particular, in the configuration in which the organic film 8 is provided on the insulating film 18, since the surface of the organic film 8 is not flat, irregularities are generated in the base metal film and the conductive thin film 9, and disconnection is more likely to occur.

  In the present embodiment, since the base metal film 13 extends from the contact hole 12 to the inside of the hole 24, the pattern end portion is not disposed on the organic film. Therefore, disconnection around the transfer pad can be prevented.

  The conductive thin film 9 is provided so as to cover the contact hole 12 and the hole 24. Further, the base metal film 13 is formed so as to cover the contact hole 12 and the hole 24 except for the opening 23. Therefore, the base metal film 13 and the conductive thin film 9 have substantially the same pattern, and the contact area can be increased. Thereby, resistance can be further reduced.

In the present embodiment, since the common wiring 17 and the base metal film 13 are connected in the contact hole 12, the size of the hole 24 can be reduced. Therefore, even when the hole 24 cannot be enlarged due to space restrictions, a good contact resistance can be obtained.

  In FIG. 3, the conductive thin film 9 and the base metal film 13 are not shown in order to simplify the drawing. Therefore, the base metal film 13 is formed in the region excluding the opening 23 in FIG. 3, and the conductive thin film 9 is formed in the entire region shown in FIG. In the configuration around the transfer pad 16 described above, the pattern end of the base metal film 13 is not disposed on the organic film 8. The step of the conductive thin film 9 is eliminated on the organic film, and disconnection of the conductive thin film 9 can be prevented. Further, since the base metal film 13 and the conductive thin film 9 are connected inside the hole 24, the base metal film 13 and the conductive thin film 9 are compared with the case where the base metal film 13 and the conductive thin film 9 are connected only in the contact hole 12. The contact area with the conductive thin film 9 can be easily increased. Therefore, good contact resistance can be obtained.

  When the TFT array substrate having the transfer pad 16 provided in this way and the CF substrate are bonded together, a transfer 19 is provided on the transfer pad 16 having the structure shown in FIG. 6 using a dispenser. Then, the CF substrate 21 provided with the counter electrode 22 on the surface is disposed to face the TFT array substrate, and the sealing material (not shown) applied to the outer periphery is cured to bond the substrates. Thereby, the counter electrode 22 and the common wiring 17 are connected, and a common potential can be supplied to the counter electrode 22. In the above configuration, since the conductive thin film 9 is provided in the uppermost layer, the contact with the counter electrode 22 can be improved.

  The above-described hole 24 is formed with, for example, 0.8 to 1.0 mm □. Then, for example, a pattern of the conductive thin film 9 of 1.0 mm □ to 1.2 mm □ is formed so as to cover the hole 24. Furthermore, the opening 23 is formed with a thickness of 0.04 mm □ to 0.05 mm, for example. If the proportion of the opening 23 in the transfer pad 16 is about 30% or more, the transfer can be inspected. Of course, the above example is a typical example and is not limited to these values.

  In the transflective liquid crystal display device or the reflective liquid crystal display device, after forming the gate wiring and the source wiring, the organic film 8 for improving the scattering characteristics of the reflective electrode is formed. A conductive thin film 9 to be a pixel electrode is formed on the organic film 8. In the step of patterning the organic film 8 to provide the hole 24 and the contact hole 12, the surface of the wiring is exposed, so that the contact resistance may be deteriorated. In particular, when the organic film 8 and the insulating film 18 are removed by dry etching, the surface of the common wiring 17 is exposed to dry etching plasma, so that the contact resistance is significantly deteriorated. In the structure shown in the present embodiment, since the base metal film 13 is formed between the common wiring 17 and the conductive thin film 9, good contact resistance can be obtained.

  Further, in the configuration in which the base metal film 13 is disposed between the common wiring 17 and the conductive thin film 9, disconnection is likely to occur when the pattern end of the base metal film 13 is disposed on the organic film. In the configuration in which the base metal film 13 of the conductive thin film 9 to be the pixel electrode is disposed, the base metal film 13 is extended to the inside of the hole, thereby suppressing the occurrence of disconnection without increasing the manufacturing process. it can. Further, by connecting the common wiring 17 and the conductive thin film 9 through the base metal film 13, a liquid crystal display device having a good contact resistance can be formed. The present invention is suitable for a liquid crystal display device having a base metal film between a pixel electrode and an organic film, for example, a transflective liquid crystal display device or a reflective liquid crystal display device.

Embodiment 2 of the Invention
A liquid crystal display device according to this embodiment will be described with reference to FIGS. FIG. 7 is a plan view schematically showing the configuration around the transfer pad. FIG. 8 is a side sectional view showing an outline of the configuration around the transfer pad. In addition, since the manufacturing process in this Embodiment is a process similar to the manufacturing process in Embodiment 1, description is abbreviate | omitted. The description of the same structure as the structure described in Embodiment 1 in the liquid crystal display device in this embodiment is omitted.

  In this embodiment, the contact hole 12 is not disposed around the hole 24. A common wiring 17 is provided so as to extend inside the hole 24. Therefore, as shown in FIG. 3, the common wiring 17 is formed so as to protrude from the insulating film 18 inside the hole. When the hole 24 is formed, the common wiring 17 is exposed inside the hole 24. That is, by removing the organic film 8 and the insulating film 18 on the common wiring 17 and exposing the common wiring 17, a hole 24 is formed.

  A base metal film 13 is formed so as to cover the common wiring 17 extending inside the hole. Further, conductive thin film 9 is formed so as to cover hole 24 from above. In such a configuration, since the common wiring 17 is provided to the inside of the hole 24, the contact area between the common wiring 17 and the base metal film 13 is not limited by the size or number of the contact holes 12. Therefore, the contact area can be increased and the contact resistance can be reduced.

  Also in the present embodiment, since the opening 23 is provided in the base metal film 13 inside the hole 24, a light transmission portion is formed in the transfer pad. With this light transmission portion, the transfer can be inspected from the back side of the substrate.

  Except for the opening 23, the base metal film 13 is provided so as to cover the hole 24. Further, the conductive thin film 9 provided on the base metal film 13 is provided so as to cover the hole 24. Therefore, since the pattern of the base metal film 13 and the conductive thin film 9 can be formed with substantially the same size except for the opening, the contact area can be widened. Therefore, contact resistance can be reduced.

  Since the common wiring 17 extending inside the hole 24 is covered with the base metal film 13, the common wiring 17 and the conductive thin film 9 are in direct contact with each other so that no contact resistance is deteriorated. Even when the organic film 8 and the insulating film 18 are patterned by dry etching to expose the common wiring 17, good contact resistance can be obtained. Furthermore, since the pattern end portion of the base metal film 13 is not disposed on the organic film, disconnection of the conductive thin film 9 can be prevented around the transfer pad.

  In a transflective liquid crystal display device or a reflective liquid crystal display device, an organic film for improving the scattering characteristics of the reflective electrode is formed after the gate wiring and the source wiring are formed. Since the conductive thin film 9 to be the pixel electrode is formed on the organic film 8, disconnection is likely to occur. In this embodiment, since the base metal film 13 is not disposed on the organic film, occurrence of disconnection can be prevented.

  Furthermore, since the base metal film 13 and the conductive thin film 9 are patterned in substantially the same size inside the hole, the area where the conductive thin film 9 and the base metal film 13 are in contact can be increased. Thereby, contact resistance can be reduced. Further, the conductive thin film 9 to be the common wiring 17 and the transfer pad 16 is connected through the base metal film 13. Therefore, even when the organic film 8 and the insulating film 18 are removed by dry etching and the common wiring is exposed, good contact resistance can be obtained. As described above, in the present embodiment, a liquid crystal display device having a base metal film 13 between the conductive thin film 9 serving as a pixel electrode and the organic film 8, for example, a transflective liquid crystal display device or a reflective liquid crystal display device. It is suitable for.

Embodiment 3 of the Invention
A liquid crystal display device according to this embodiment will be described with reference to FIGS. FIG. 9 is a plan view schematically showing the configuration around the transfer pad. FIG. 10 is a side cross-sectional view schematically showing the configuration around the transfer pad. In addition, since the manufacturing process in this Embodiment is a process similar to the manufacturing process in Embodiment 1, description is abbreviate | omitted. Description of the structure of the liquid crystal display device in this embodiment which is similar to the structure described in Embodiment 1 or 2 is omitted.

  In this embodiment, the base metal film 13 is arranged in an island shape inside the hole. Accordingly, since the pattern end of the common wiring 17 is not provided outside the hole 24, the common wiring 17 is not disposed on the organic film 8. Thereby, disconnection of the conductive thin film 9 on the organic film can be prevented.

  Further, since the base metal film 13 is formed in an island shape on the common wiring 17, the common wiring 17 and the conductive thin film 9 are connected via the base metal film 13. Therefore, the contact with the conductive thin film 9 can be improved as in the above-described embodiment. Further, since the conductive thin film 9 is provided in the uppermost layer, the contact with the counter electrode 22 can be improved. Since the contact area between the common wiring 17 and the base metal film 13 can be widened, a better contact resistance can be obtained.

  In the present embodiment, the common wiring 17 is provided in the region corresponding to the transfer pad 16 inside the hole 24 with substantially the same size as the base metal film 13. The common wiring 17 is patterned so that the opening 24 is formed in the same manner as the base metal film 13. As described above, when the common wiring 17 and the base metal film 13 are provided in the region of the transfer pad 16, the common wiring 17 and the base metal film 13 form the opening 23. Thereby, even after bonding the substrates, the state of the transfer can be observed from the back side of the TFT array substrate.

  In the transflective liquid crystal display device or the reflective liquid crystal display device, the organic film 8 for improving the scattering characteristics of the reflective electrode is formed after the gate wiring and the source wiring are formed. Since the conductive thin film 9 to be the pixel electrode is formed on the organic film 8, disconnection is likely to occur. In the structure shown in this embodiment mode, since the base metal film 13 is not disposed over the organic film, occurrence of disconnection can be prevented.

  Furthermore, since the base metal film 13 and the common wiring 17 are patterned with substantially the same size, the area where the common wiring 17 and the base metal film 13 are in contact can be increased. Thereby, contact resistance can be reduced. As described above, in the present embodiment, a liquid crystal display device having a base metal film 13 between the conductive thin film 9 serving as a pixel electrode and the organic film 8, for example, a transflective liquid crystal display device or a reflective liquid crystal display device. It is suitable for.

Embodiment 4 of the Invention
A liquid crystal display device according to this embodiment will be described with reference to FIGS. FIG. 11 is a plan view schematically showing the configuration around the transfer pad. FIG. 12 is a side cross-sectional view schematically showing the configuration around the transfer pad. In addition, since the manufacturing process in this Embodiment is a process similar to the manufacturing process in Embodiment 1, description is abbreviate | omitted. The description of the same structure as the structure described in the above embodiment in the liquid crystal display device in this embodiment is omitted.

  In the present embodiment, the conductive thin film 9 and the common wiring 17 are in direct contact inside the hole 24. And the common wiring 17 which has the opening part 23 is provided in the whole hole. Since the size and number of contact holes are not limited, the contact area with the conductive thin film 9 can be increased. Furthermore, since the opening 23 serving as a light transmission part is formed, the inspection from the back side of the TFT array substrate becomes possible.

  Moreover, since the pattern end of the base metal film 13 is not provided on the organic film 8, it is possible to prevent the conductive thin film 9 from being disconnected on the organic film. In the present embodiment, the conductive thin film 9 and the common wiring 17 are directly connected. However, for example, when the organic film 8 and the insulating film 18 are patterned by wet etching and not via dry etching, it is good. Contact resistance can be obtained. Furthermore, the present embodiment is suitable when good contact resistance can be obtained even when dry etching is performed.

Embodiment 5 of the Invention
A liquid crystal display device according to this embodiment will be described with reference to FIGS. FIG. 13 is a plan view showing an outline of the configuration around the transfer pad. FIG. 14 is a side sectional view showing an outline of the configuration around the transfer pad. In addition, since the manufacturing process in this Embodiment is a process similar to the manufacturing process in the above-mentioned embodiment, description is abbreviate | omitted. The description of the structure of the liquid crystal display device in this embodiment that is similar to the structure described in the above embodiment is omitted.

  In the present embodiment, a third metal thin film is provided on the conductive thin film 9 from the inside to the outside of the hole 24. The third metal thin film 9 is disposed on the base metal film 13 in order to prevent disconnection of the conductive thin film 9 at the pattern end of the base metal film 13. The third metal thin film 9 is provided so as to cover the pattern end outside the hole of the base metal film 13. Therefore, the step portion of the conductive thin film 9 on the organic film is covered with the third metal thin film 9.

The third metal thin film 10 is formed by the process shown in FIG. In the step of forming the third metal thin film 10, a resist for forming the third metal thin film 10 is formed at the pattern end of the base metal film 13 . Therefore, the third metal thin film 10 serves as a protective film, and it is possible to prevent the etchant from penetrating to the base metal film 13, so that disconnection of the conductive thin film 9 at the step portion can be prevented. Of course, the third metal thin film serving as a protective film may be provided on the entire base metal film on the organic film. Thereby, disconnection of the conductive thin film 9 on the organic film can be prevented.

In the region where the transfer pad 16 is provided inside the hole , the base metal film 13 is removed. Therefore, the opening 23 becomes a light transmission part that transmits light from the back side of the substrate, and transfer inspection from the back side becomes possible. Moreover, since the conductive thin film 9 made of a transparent conductive film such as ITO is disposed on the uppermost layer, it is in direct contact with the transfer. Therefore, a good contact can be obtained. Further, since the common wiring 17 is extended inside the hole, the contact area can be increased. Therefore, good contact resistance can be obtained. Further, since the conductive thin film 9 is in the uppermost layer, the contact resistance with the transfer can be reduced.

In the configuration shown in this embodiment, a third metal thin film serving as a reflective electrode is disposed at the pattern end of the base metal film 13 to prevent disconnection of the conductive thin film on the organic film. In particular, when an organic film is provided on the gate wiring and the source wiring in order to improve the reflection characteristics, the surface of the organic film 8 has large unevenness, so that disconnection is likely to occur. By using the third metal thin film 10 serving as a reflective electrode, a protective film for the step portion can be formed without increasing the number of manufacturing steps. Thus, the present invention is suitable for a transflective liquid crystal display device or a reflective liquid crystal display device.
Other embodiments

  In the above embodiment, the configuration around the transfer pad has been described. However, the present invention can also be used for pads other than the transfer pad. For example, for a COG type liquid crystal display device, the same effect can be obtained if it is a pad for connecting to the outside, such as a pad for providing a driver IC. Moreover, it can utilize also about display apparatuses other than a liquid crystal display device.

  Furthermore, it is good also as a structure which combined the above-mentioned embodiment, respectively. Configurations other than those described in the above embodiments may be provided. Further, it can be used for display devices other than a transflective liquid crystal display device.

It is side surface sectional drawing which shows the structure in the manufacturing process of the liquid crystal display device concerning this invention. It is a top view which shows the structure of the liquid crystal display device concerning this invention. FIG. 3 is a plan view schematically showing a configuration around a transfer pad in the TFT array substrate of the liquid crystal display device according to the first exemplary embodiment of the present invention. FIG. 3 is a side cross-sectional view schematically showing a configuration around a transfer pad in the TFT array substrate of the liquid crystal display device according to the first exemplary embodiment of the present invention. It is side surface sectional drawing which shows the outline of a structure of the transfer pad periphery in the comparative example of the TFT array substrate of the liquid crystal display device concerning Embodiment 1 of this invention. It is side surface sectional drawing which shows the structure of the transfer periphery of the liquid crystal display device concerning this invention. It is a top view which shows the outline of a structure of a transfer pad periphery in the TFT array substrate of the liquid crystal display device concerning Embodiment 2 of this invention. It is side surface sectional drawing which shows the outline of a structure of the transfer pad periphery in the TFT array substrate of the liquid crystal display device concerning Embodiment 2 of this invention. It is a top view which shows the outline of a structure of a transfer pad periphery in the TFT array substrate of the liquid crystal display device concerning Embodiment 3 of this invention. It is side surface sectional drawing which shows the outline of a structure of the periphery of a transfer pad in the TFT array substrate of the liquid crystal display device concerning Embodiment 3 of this invention. It is a top view which shows the outline of a structure of the transfer pad periphery in the TFT array substrate of the liquid crystal display device concerning Embodiment 4 of this invention. It is side surface sectional drawing which shows the outline of a structure of the transfer pad periphery in the TFT array substrate of the liquid crystal display device concerning Embodiment 4 of this invention. It is a top view which shows the outline of a structure of the transfer pad periphery in the TFT array substrate of the liquid crystal display device concerning Embodiment 5 of this invention. It is side surface sectional drawing which shows the outline of a structure of the transfer pad periphery in the TFT array substrate of the liquid crystal display device concerning Embodiment 5 of this invention. It is side surface sectional drawing which shows the structure in the manufacturing process of the conventional liquid crystal display device. It is a top view which shows the outline of a structure of a transfer pad periphery in the TFT array substrate of the conventional liquid crystal display device. It is side surface sectional drawing which shows the outline of a structure of the periphery of a transfer pad in the TFT array substrate of the conventional liquid crystal display device.

Explanation of symbols

1 first metal thin film, 2 first insulating film, 3 semiconductor active film,
4 ohmic contact film, 5 source electrode, 6 drain electrode, 7 second insulating film 8 organic film, 9 conductive thin film, 10, 11 third metal thin film, 12 contact hole,
13 Base metal film , 14 Second metal thin film, 15 TFT array substrate,
16 transfer pad, 17 common wiring, 18 insulating film, 19 transfer,
21 CF substrate, 22 counter electrode, 23 opening, 24 holes, 25 glass substrate

Claims (11)

A display device including a substrate provided with a connection pad for connection to the outside, and a transmissive portion that transmits light is provided in a pixel electrode,
Wiring provided on the substrate;
An organic film provided on the wiring;
A connection pad hole in which the connection pad is disposed, the connection pad hole formed in the organic film so as to expose the wiring; and
A base metal film formed on the organic film and in contact with the wiring in the connection pad hole;
A transparent conductive film provided to be the connection pad, formed on the base metal film so as to be in contact with the base metal film, and connected to the wiring in the connection pad hole; equipped with a,
An end of the pattern of the base metal film is disposed on the organic film,
A display device in which a conductive protective film is formed on the transparent conductive film at an end portion of the pattern of the base metal film .   The display device according to claim 1, wherein the transparent conductive film and the wiring are connected through the base metal film in the connection pad hole. The display device according to claim 1, wherein an end portion of the pattern of the base metal film is disposed in the connection pad hole. An insulating film provided between the substrate and the organic film;
Display according to the first wiring and any one of which claims 1 to 3 is provided between the second said organic layer wiring and the substrate of crossing through the insulating film in the display region apparatus. A counter substrate disposed opposite to the substrate;
The display device according to claim 1 , wherein the counter electrode provided on the counter substrate and the wiring are electrically connected via a transfer provided on the connection pad. 6. The display device according to claim 5, wherein a light transmission portion that transmits light from the back side of the substrate is formed in the connection pad hole. Wherein the connection pad, a display device according to any one of claims 1 to 4 driver IC is connected. A method of manufacturing a display device in which a transmissive portion that transmits light is provided in a pixel electrode,
Forming wiring on the substrate;
Forming an organic film on the wiring;
A connection pad hole in which a connection pad to be connected to the outside of the substrate is disposed, and the connection pad hole is provided in the organic film so that the wiring is exposed;
Forming a base metal film on the organic film provided with the connection pad hole;
Patterning the base metal film on the organic film so as to be in contact with the wiring exposed from the connection pad hole;
Forming a transparent conductive film in contact with the base metal film in the connection pad hole and connected to the wiring from above the patterned base metal film;
Patterning the transparent conductive film so that the transparent conductive film connected to the wiring in the connection pad hole becomes the connection pad ;
Forming a conductive protective film disposed on an end portion of the base metal film from above the transparent conductive film . The method for manufacturing a display device according to claim 8 , wherein an end portion of the base metal film is disposed in the connection pad hole. Providing a transfer on the transparent conductive film in the connection pad hole;
The method for manufacturing a display device according to claim 8 , further comprising a step of disposing a counter substrate having a counter electrode so as to face the substrate, and a step of electrically connecting the wiring and the counter electrode via the transfer. The method for manufacturing a display device according to claim 8, wherein a driver IC is connected to the connection pad.

Images