JP2015163946A - Liquid crystal display element and radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display element having improved luminance while reducing influences of a contact hole, and a radiation-sensitive resin composition used for manufacturing the liquid crystal display element.SOLUTION: A liquid crystal display element 1 includes a liquid crystal 4 held between a TFT substrate 2 and a counter substrate 3. The TFT substrate 2 includes a first insulating film 6 formed from a first radiation-sensitive resin composition, a contact hole 7, a first electrode 8 connected to a source electrode 34 of a TFT via the contact hole 7, and a second insulating film 9 formed from a second radiation-sensitive resin composition to bury the contact hole 7. A second electrode 10 to be connected to the first electrode 8 is disposed on the second insulating film 9. A third electrode 12 is disposed above the first electrode 8 and the second electrode 10 via the third insulating film 11. In the liquid crystal display element 1, the liquid crystal 4 is driven by applying a voltage between the first electrode 8 and the third electrode 12 and between the second electrode 10 and the third electrode 12.

Description

  The present invention relates to a liquid crystal display element and a radiation sensitive resin composition.

  The liquid crystal display element has a structure in which liquid crystal is sandwiched between a pair of substrates. An electrode can be provided on these substrates, and an alignment film can be provided on the surface of the substrate for the purpose of controlling the alignment of the liquid crystal. In addition, the pair of substrates is sandwiched between, for example, a pair of deflecting plates. When an electric field is applied between the substrates, the liquid crystal is driven to change the alignment, and the light is partially transmitted or shielded. Liquid crystal display elements display images using these characteristics. Such a liquid crystal display element has an advantage of being thinner and lighter than a conventional CRT display device.

  The liquid crystal display elements at the beginning of development were used as display elements for calculators and clocks centered on character displays and the like. After that, the simple matrix method was developed, and the dot matrix display became easy. Next, by developing an active matrix system in which a thin film transistor (TFT) for switching is arranged for each pixel, it has become possible to realize good image quality with excellent contrast ratio and response performance. Furthermore, the liquid crystal display element has overcome problems such as high definition, colorization, and widening of the viewing angle, and has come to be used for desktop computer monitors and the like. Recently, a wider viewing angle, faster response of liquid crystal and improved display quality, etc. have been realized, and as a display for large and thin TV display elements and portable electronic devices such as smartphones that require high-density display. It has been used.

  In liquid crystal display elements, various liquid crystal modes having different initial alignment states and different alignment changing operations are known. For example, TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Plane Switching) (FFS (Fringe Field Switching), VA (Vertical Alignment mode), OCB (Oblique).

  Among the liquid crystal modes, the IPS mode and the VA mode are liquid crystal modes that have attracted particular attention in recent years because they have a wide viewing angle, a fast response speed, and a high contrast ratio. Note that the IPS mode in this specification refers to a liquid crystal mode in which the liquid crystal performs switching (alignment change) operation within the plane of the substrate sandwiching the IPS mode, as will be described later. The concept also includes an FFS mode for realizing in-plane switching of liquid crystal using an oblique electric field (fringe electric field).

  For example, in an IPS mode liquid crystal display element including an FFS mode (hereinafter simply referred to as an “IPS mode”), the liquid crystal initial state is set so that the liquid crystal sandwiched between a pair of substrates is substantially parallel to the substrate. The orientation state is controlled. By applying a voltage between the pixel electrode and the common electrode arranged on one of these substrates, an electric field mainly composed of components parallel to the substrate plane (so-called lateral electric field or oblique electric field (fringe electric field)). And the alignment state of the liquid crystal changes. Therefore, in the IPS mode, the change in the orientation of the liquid crystal due to the application of an electric field is, as the name suggests, the rotation of the liquid crystal molecules in a plane parallel to the substrate plane.

  For this reason, the IPS mode has a small change in the tilt angle of the liquid crystal with respect to the substrate sandwiching the liquid crystal, unlike the TN mode in which the liquid crystal aligned in parallel is activated by applying an electric field. For this reason, in the IPS mode liquid crystal display element, the change in the effective value of retardation accompanying voltage application is reduced, and a high-quality image display with a wide viewing angle is possible.

  In the IPS mode liquid crystal display element as described above, an electrode having a slit-shaped cutout on a transparent solid electrode (for example, a common electrode or a pixel electrode) with an inorganic insulating film made of an inorganic material interposed therebetween. (For example, refer to Patent Document 1, Patent Document 2, or Patent Document 3). According to this electrode structure, the aperture ratio of the pixels is improved, and high-luminance image display is realized.

  And in recent years, the IPS mode liquid crystal display elements have been further improved in image quality, particularly in high definition, in order to support displays of mobile electronic devices such as TVs that display moving images and smartphones that require high-density display. Is required.

  In an IPS mode liquid crystal display element, an active element such as a TFT for switching is disposed on one of a pair of substrates sandwiching a liquid crystal. A pixel electrode, a common electrode, wirings connected to them, and the like are also arranged to constitute a TFT substrate. For this reason, in the IPS mode liquid crystal display element, the number of constituent members arranged on the TFT substrate increases, and the electrode structure and wiring arrangement structure on the TFT substrate are more complicated than those of other liquid crystal modes such as the TN mode. It will be something. For this reason, there is a concern that the area of the pixel electrode in the pixel is reduced and the aperture ratio of the pixel is lowered to lower the luminance of the display in order to further increase the definition.

  Patent Document 2 discloses a TFT substrate in which a pixel electrode having a slit-like cutout is disposed on a solid common electrode via an interlayer insulating film made of an inorganic material. Patent Document 3 also discloses a TFT substrate in which a common electrode having a slit-like cutout portion is disposed on a solid pixel electrode via an inorganic interlayer insulating film. In Patent Document 2 and Patent Document 3, an insulating film made of an organic material (hereinafter referred to as “organic insulating film”) is used between a solid common electrode or a solid pixel electrode and a wiring underneath. A technique for providing the above is disclosed. This can be expected to improve the aperture ratio while suppressing an increase in coupling capacitance between the pixel electrode and the wiring.

JP 2011-48394 A JP 2011-59314 A JP 2012-226249 A

  However, in the technique of providing the organic insulating film on the TFT substrate described above, it is necessary to provide a contact hole in order to electrically connect the pixel electrode and the source electrode of the TFT. As the pixel electrode, a so-called transparent electrode having high visible light transmittance is used, and it is usually made of a transparent conductive material such as ITO (Indium Tin Oxide). As described in Patent Document 3, in order to prevent disconnection of the pixel electrode, it is desirable that the taper angle of the contact hole be 45 degrees or less. The organic insulating film has a thickness of about several μm, and the contact hole on the TFT substrate has a large area in plan view.

  In the liquid crystal display element, uniform initial alignment of the liquid crystal when a voltage direction is applied is realized by an alignment film provided on the surface of the substrate sandwiching the liquid crystal. For example, the alignment film is subjected to a rubbing process such as a rubbing process or a photo-alignment process performed by irradiating polarized light or the like, thereby realizing an initial alignment of the liquid crystal.

  In that case, the contact hole formation portion on the above-described substrate is recessed as compared with other portions, and it is difficult to perform the rubbing process or the photo-alignment process. Therefore, the contact hole forming portion of the TFT substrate is a portion in which the alignment disorder of the liquid crystal that causes light leakage is likely to occur.

  In the IPS mode liquid crystal display element, as described above, the contact hole is a recess formed in the TFT substrate, and the formation portion is a portion where the thickness of the liquid crystal is thicker than other portions. . For this reason, the contact hole formation portion is different from the other portions in the transmittance and the response characteristics of the liquid crystal, and there is a concern that the uniformity of image display may be reduced.

  For this reason, in the IPS mode liquid crystal display element, a method of providing a light shielding means for shielding the pixel portion affected by the formation of the contact hole so as not to be used for displaying an image has been studied. However, the arrangement of such a light shielding means causes a decrease in the aperture ratio of the pixel, thereby reducing the transmittance of the liquid crystal display element. That is, in the IPS mode liquid crystal display element, the contact hole is a factor that hinders improvement in luminance characteristics, and further hinders higher definition of display.

  Therefore, in the IPS mode liquid crystal display element, there is a demand for a technique that can reduce the influence of a contact hole provided in a TFT substrate, improve luminance characteristics, and enable higher-definition display.

  As described in Patent Document 3, a technique for improving an aperture ratio by providing an organic insulating film between a pixel electrode and a wiring underneath is also studied in a VA mode liquid crystal display element. . Therefore, even in the VA mode liquid crystal display element having such a structure, it is required to form a contact hole on the TFT substrate in the same manner as in the IPS mode liquid crystal display element. Therefore, in the VA mode liquid crystal display element, there is a demand for a technique that can reduce the influence of a contact hole provided in the TFT substrate, improve the luminance characteristics, and enable higher definition display.

  Further, in other mode liquid crystal display elements as well as the IPS mode liquid crystal display elements having the above-described structure, an organic insulating film is provided between the pixel electrode and the wiring underneath to improve the aperture ratio. Technology can be applied. Therefore, in the liquid crystal display elements of other modes, as described above, there is a demand for a technique that can reduce the influence of the contact hole provided in the TFT substrate, improve the luminance characteristics, and enable further high-definition display.

  The present invention has been made in view of the above problems. That is, an object of the present invention is to provide a liquid crystal display element with improved luminance by reducing the influence of contact holes.

  Another object of the present invention is to provide a radiation-sensitive resin composition used in the production of a liquid crystal display device with improved brightness by reducing the influence of contact holes.

  Other objects and advantages of the present invention will become apparent from the following description.

According to a first aspect of the present invention, there is provided a liquid crystal display element having a liquid crystal sandwiched between a first substrate and a second substrate which are arranged to face each other.
The first substrate is
TFT,
A first insulating film provided on the TFT using the first radiation-sensitive resin composition;
A contact hole formed in the first insulating film;
A first electrode provided on the first insulating film and on the inner wall of the contact hole and electrically connected to the TFT through the contact hole;
A second insulating film provided using the second radiation-sensitive resin composition so as to fill the contact hole;
A second electrode provided on the second insulating film and partially in contact with the first electrode on the first insulating film and electrically connected to the first electrode; Have
A third electrode is provided on the first electrode and the second electrode of the first substrate via a third insulating film, or provided on the liquid crystal side of the second substrate;
The liquid crystal is driven by applying a voltage between the first electrode, the second electrode, and the third electrode.

  In the first aspect of the present invention, the first radiation sensitive resin composition is a positive radiation sensitive resin composition and the second radiation sensitive resin composition is a negative radiation sensitive resin composition. Or the first radiation-sensitive resin composition is a negative radiation-sensitive resin composition and the second radiation-sensitive resin composition is a positive radiation-sensitive resin composition. It is preferable.

  1st aspect of this invention WHEREIN: It is preferable that the 1st radiation sensitive resin composition contains the polymer containing the structural unit which has a carboxyl group, and the structural unit which has a polymeric group.

  1st aspect of this invention WHEREIN: It is preferable that the 2nd radiation sensitive resin composition contains the polymer containing the structural unit which has a carboxyl group, and the structural unit which has a polymeric group.

A second aspect of the present invention is a radiation-sensitive resin composition used in the manufacture of a liquid crystal display element in which a liquid crystal is sandwiched between a first substrate and a second substrate that are arranged to face each other.
The first substrate of the liquid crystal display element is
TFT,
A first insulating film provided on the TFT;
A contact hole formed in the first insulating film;
A first electrode provided on the first insulating film and on the inner wall of the contact hole and electrically connected to the TFT through the contact hole;
A second insulating film provided to fill the contact hole;
A second electrode provided on the second insulating film and partially in contact with the first electrode on the first insulating film and electrically connected to the first electrode; Have
In the liquid crystal display element, the third electrode is provided on the first electrode and the second electrode of the first substrate via a third insulating film, or provided on the liquid crystal side of the second substrate. The liquid crystal is driven by applying a voltage between the first electrode, the second electrode, and the third electrode,
It is used for forming the second insulating film of the first substrate.

    In the second aspect of the present invention, it is preferable that metal oxide particles are further included.

  According to the first aspect of the present invention, a liquid crystal display element with improved luminance can be obtained by reducing the influence of contact holes.

  According to the 2nd aspect of this invention, the radiation sensitive resin composition used for manufacture of the liquid crystal display element with which the influence of the contact hole was made small and the brightness | luminance was improved is obtained.

It is sectional drawing which shows typically the structure of the liquid crystal display element of the IPS mode of 1st Embodiment of this invention. It is a top view which shows typically the structure of the liquid crystal display element of the IPS mode of 1st Embodiment of this invention. It is sectional drawing which shows typically the structure of another example of the liquid crystal display element of the IPS mode of 1st Embodiment of this invention. It is sectional drawing which shows typically the structure of the liquid crystal display element of VA mode of 2nd Embodiment of this invention. It is a top view which shows typically the structure of the liquid crystal display element of VA mode of 2nd Embodiment of this invention. It is sectional drawing which shows typically the structure of another example of the liquid crystal display element of VA mode of 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate.
In the present invention, “radiation” irradiated upon exposure includes visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, and the like.

Embodiment 1. FIG.
<Liquid crystal display device in IPS mode>
FIG. 1 is a cross-sectional view schematically showing the structure of an IPS mode liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a plan view schematically showing the structure of the IPS mode liquid crystal display element according to the first embodiment of the present invention.
FIG. 1 schematically shows a cross section taken along the line AA ′ of FIG.

  As shown in FIG. 1, the IPS mode liquid crystal display element 1 according to the first embodiment of the present invention includes a TFT substrate 2 as a first substrate and a counter substrate 3 as a second substrate, which are arranged to face each other. The liquid crystal 4 is sandwiched. Here, the TFT substrate is a substrate having TFTs which are thin film transistors. As shown in FIG. 2, in the IPS mode liquid crystal display element 1, the TFT substrate 2 includes a TFT 5.

  That is, as shown in FIGS. 1 and 2, the TFT substrate 2 of the liquid crystal display element 1 includes a first insulating film 6 provided on a TFT 5 (not shown in FIG. 1) and a first insulating film. A contact hole 7 formed in the film 6, a first hole provided on the first insulating film 6 and on the inner wall of the contact hole 7 and electrically connected to the source electrode 34 of the TFT 5 through the contact hole 7. The electrode 8 includes a second insulating film 9 provided so as to fill the contact hole 7 and planarizing the surface of the TFT substrate 2.

The TFT substrate 2 has a second electrode 10 provided on the second insulating film 9.
In the TFT substrate 2, the second electrode 10 provided on the second insulating film 9 is electrically connected to the first electrode 8 on the first insulating film 6 by an end part of the second electrode 10. You may connect.
In the TFT substrate 2, the second electrode 10 provided on the second insulating film 9 uses at least a part of the second electrode 10, and a part of the first electrode 8 on the first insulating film 6. It may be electrically connected by touching so as to cover.

  In the liquid crystal display element 1 of the present embodiment, the first electrode 8 and the second electrode 10 electrically connected thereto are integrated to form a solid pixel electrode.

  Further, the liquid crystal display element 1 has a third insulating film 11 on the first electrode 8 and the second electrode 10 of the TFT substrate 2, and further has a third insulating film 11 on the third insulating film 11. It has an electrode 12. That is, the liquid crystal display element 1 has a structure in which the third electrode 12 is provided on the first electrode 8 and the second electrode 10 of the TFT substrate 2 via the third insulating film 11. In the liquid crystal display element 1 of the present embodiment, the third electrode 12 constitutes a common electrode.

With the above-described configuration, the liquid crystal display element 1 applies a voltage between the first electrode 8 and the second electrode 10 on the TFT substrate 2 and the third electrode 12 on the TFT substrate 2, so that the liquid crystal 4 Drive.
The liquid crystal display element 1 is an IPS mode liquid crystal display element.

  Hereinafter, the configuration of the IPS mode liquid crystal display element 1 according to the first embodiment of the present invention will be described in more detail. First, the planar structure of the liquid crystal display element 1, particularly the main planar structure of the pixel, will be described mainly with reference to FIG.

  In the liquid crystal display element 1, as shown in FIG. 2, pixels are formed in a region surrounded by a signal line 30 extending in the vertical direction and a scanning line 31 extending in the horizontal direction. A TFT 5 for switching is formed on the scanning line 31 and controls the supply of video signals to the first electrode 8 and the second electrode 10 constituting the pixel electrode. As shown in FIG. 2, the scanning line 31 also serves as the gate electrode of the TFT 5, and a semiconductor layer 32 of amorphous-silicon (a-Si) or microcrystalline silicon is formed on the scanning line 31.

  On the semiconductor layer 32, a drain electrode 33 connected to the signal line 30 is formed so as to overlap at an end portion, and a source electrode 34 is formed so as to face the drain electrode 33 while being spaced apart. The source electrode 34 extends to the pixel formation region and is electrically connected to the first electrode 8 through the contact hole 7.

  As shown in FIG. 2, the first electrode 8 indicated by a dotted line is formed in a flat solid shape. The second electrode 10 indicated by a dotted line is formed in a solid shape so as to cover the contact hole 7 and to be in contact with the first electrode 8 at an end thereof. On top of these, the third electrode 12 having a slit-like notch 50 serving as an electrode non-formed part is provided via a third insulating film 11 not shown in FIG.

  In the liquid crystal display element 1 shown in FIG. 2, the first electrode 8 schematically indicated by a dotted line extends from an end portion of the TFT 5 and covers the source electrode 34 in the pixel. The second electrode 10 schematically indicated by a dotted line is also provided on the second insulating film 9 (not shown in FIG. 2) filling the contact hole 7 and covers the source electrode 34. As described above, the second electrode 10 covers the first electrode 8 via the second insulating film 9 and is electrically connected to the first electrode 8 at an end portion that is a part thereof. doing.

  Further, the third electrode 12 having the slit-like cutout 50 is formed not only for one pixel but also for other pixels as a common electrode, and a common voltage is applied thereto. As shown in FIG. 1, the notch 50 formed in the third electrode 12 covers the source electrode 34 and the contact hole 7.

  Next, the cross-sectional structure of the liquid crystal display element 1, particularly the cross-sectional structure of the pixel, will be described mainly with reference to FIG.

In the liquid crystal display element 1, as shown in FIG. 1, a gate insulating film 21 used in the TFT 5 of FIG. 2 is formed on the TFT substrate 2, and a source electrode 34 extending from the TFT 5 is formed thereon. Has been. This portion of the source electrode 34 can block light from a backlight (not shown). An inorganic passivation film 22 is formed so as to cover the source electrode 34, and a first insulating film 6 also serving as a planarization film is formed thereon. The inorganic passivation film 22 is formed from, for example, a metal oxide such as SiO ₂ or a metal nitride such as SiN.

  In the liquid crystal display element 1 of the present embodiment, the first insulating film 6 is an organic insulating film formed by patterning using a first radiation-sensitive resin composition described later. The first insulating film 6 is formed with a film thickness of 0.5 μm to 6 μm, for example.

  In the first insulating film 6, a contact hole 7 for electrically connecting the first electrode 8 to the source electrode 34 is formed. As a method for forming the contact hole 7, a through hole is formed after the first insulating film 6 is formed. Thereafter, a through hole is also formed in the inorganic passivation film 22 so that the through hole of the first insulating film 6 and the through hole of the inorganic passivation film 22 communicate with each other. As a result, a contact hole 7 penetrating the first insulating film 6 and the inorganic passivation film 22 is formed in the TFT substrate 2.

  In the example of the liquid crystal display element 1 shown in FIG. 1, the through hole of the first insulating film 6 and the through hole of the inorganic passivation film 22 can be formed using separate masks. As another method, after forming a through hole in the first insulating film 6, the first insulating film 6 is used as a mask, and a through hole of the inorganic passivation film 22 is formed by dry etching to form a contact. It is also possible to provide a hole 7.

  The contact hole 7 formed in the first insulating film 6 in this way includes a pilot hole for connecting the first electrode 8 to the source electrode 34, an upper hole having a larger diameter, a pilot hole, It consists of an inner wall that connects the upper holes. In order to prevent disconnection of the first electrode 8 provided so as to cover the inner wall of the contact hole 7, the taper angle of the contact hole 7 is preferably set to 45 degrees or less. Therefore, the contact hole 7 on the TFT substrate 2 has a large area in plan view.

  A first electrode 8 is provided on the first insulating film 6 and on the inner wall of the contact hole 7 so as to cover the first insulating film 6 and the contact hole 7. The first electrode 8 can be formed using, for example, ITO. In the liquid crystal display element 1, the first electrode 8 serving as a pixel electrode is formed in a flat solid shape. The first electrode 8 is electrically connected to the source electrode 34 through the contact hole 7.

  In addition, the liquid crystal display element 1 includes a second insulating film 9 provided so as to fill the contact hole 7. The 2nd insulating film 9 is an organic insulating film formed using the 2nd radiation sensitive resin composition mentioned later. The second insulating film 9 of the liquid crystal display element 1 has a function of filling the contact hole 7 of the TFT substrate 2. The second insulating film 9 functions to flatten the surface of the TFT substrate 2.

  As a method for forming the second insulating film 9, for example, a photomask used for patterning the first insulating film 6 to form the contact holes 7 and the like is used, and patterning is performed. it can.

  That is, the first insulating film 6 having the contact hole 7 is formed using one kind of photomask, the first electrode 8 covering the first insulating film 6 is provided, the mask is used again, and the second electrode The second insulating film 9 can be formed using a radiation sensitive resin composition.

  In that case, for example, by using a positive first radiation-sensitive resin composition, patterning is performed by exposure and development through a photomask to form the first insulating film 6 in which the contact holes 7 are formed. . Next, the first electrode 8 is formed. Thereafter, using the negative second radiation-sensitive resin composition, the same exposure and development using the same photomask as described above are performed to form the second insulating film 9 filling the contact hole 7. be able to.

  The TFT substrate 2 of the liquid crystal display element 1 is provided on the second insulating film 9 and is electrically connected to the first electrode 8 on the first insulating film 6 by an end portion which is a part thereof. The second electrode 10 is provided. The second electrode 10 can be formed using the same material as the first electrode 8, for example, ITO.

  In the liquid crystal display element 1 of the present embodiment, the first electrode 8 and the second electrode 10 are electrically connected to each other and can function as a solid pixel electrode.

In addition, the liquid crystal display element 1 has a third insulating film 11 serving as an interlayer insulating film on the first electrode 8 and the second electrode 10 of the TFT substrate 2. The third insulating film 11 can be an inorganic insulating film formed of, for example, a metal oxide such as SiO ₂ or a metal nitride such as SiN.

  In addition, the liquid crystal display element 1 includes the third electrode 12 having a slit-like cutout portion 50 which is a portion where no electrode is formed on the third insulating film 11. The third electrode 12 and the notch 50 are also formed in the upper layer of the contact hole 7 so as to cover the contact hole 7. The third electrode 12 can function as a common electrode in the liquid crystal display element 1.

  On the third electrode 12, an alignment film 40 for aligning the liquid crystal 4 is formed. The alignment film 40 is subjected to an alignment process by a rubbing process, and can realize a uniform initial alignment of the liquid crystal 4 when no voltage is applied, that is, a parallel alignment parallel to the substrate surface of the TFT substrate 2.

  The liquid crystal display element 1 includes a counter substrate 3 that is a second substrate with a liquid crystal 4 interposed therebetween. A black matrix 41 and a color filter 42 are formed on the counter substrate 3, a planarizing film 43 is formed so as to cover them, and an alignment film 44 is formed thereon. The alignment film 44 on the counter substrate 3 is the same as the alignment film 40 on the TFT substrate 2 and is subjected to an alignment process by rubbing to realize parallel alignment as an initial alignment of the liquid crystal 4. .

  In the liquid crystal display element 1 of the present embodiment having the above configuration, video signals are applied to the first electrode 8 and the second electrode 10 on the TFT substrate 2 for image display, and these and the third electrode are displayed. When a voltage is applied between them, an oblique electric field is generated around them. That is, when a voltage is applied between the first electrode 8 and the second electrode 10 and the third electrode 12, the liquid crystal 4 passes through the notch 50 of the third electrode 12. An oblique electric field having a component parallel to the substrate surface of the TFT substrate 2 is generated.

  As a result, the liquid crystal 4 is driven by a component parallel to the substrate surface of the oblique electric field, and rotates in a plane parallel to the substrate surface from the initial alignment state.

  The liquid crystal display element 1 has a structure in which a non-illustrated polarizing plate is provided on the anti-liquid crystal side surface of the TFT substrate 2 and the anti-liquid crystal side surface of the counter substrate 3, and the liquid crystal 4 is sandwiched between a pair of polarizing plates. . Therefore, the liquid crystal display element 1 can partially transmit or block light by the rotation operation of the liquid crystal 4 by the above-described oblique electric field, and can display an image using such characteristics. .

  In the liquid crystal display element 1, the contact hole 7 provided in the TFT substrate 2 is filled with the second insulating film 9, and the surface of the TFT substrate 2 is flattened. Therefore, in the liquid crystal display element 1, the alignment disorder of the liquid crystal 4 due to the contact hole 7, the transmittance due to the dent, and the deterioration of the response characteristics of the liquid crystal 4 are reduced. That is, the liquid crystal display element 1 can reduce the influence of the contact hole 7 provided in the TFT substrate 2, and it is not necessary to form a large light shielding means such as the source electrode 34, and the luminance characteristics can be improved. .

  In the liquid crystal display element 1 according to the first embodiment of the present invention, the contact hole 7 is filled with the second insulating film 9, and the surface of the TFT substrate 2 is flattened as shown in FIG. However, in the liquid crystal display element 1 of this embodiment, the second insulating film 9 is selected according to the selection of the composition of the second radiation-sensitive resin composition for forming the second insulating film 9 and the method for forming the second insulating film 9. The upper surface of the film 9 (the surface on the liquid crystal 4 side) may be slightly recessed.

  FIG. 3 is a cross-sectional view schematically showing the structure of another example of the IPS mode liquid crystal display element of the first embodiment of the present invention.

  Incidentally, an IPS mode liquid crystal display device 1-2, which is another example of the first embodiment of the present invention shown in FIG. 3, is shown in FIG. 1, etc., except that the shape of the second insulating film 9-2 is different. The liquid crystal display element 1 has the same structure. Therefore, the same components are denoted by the same reference numerals, and redundant description is omitted.

  In the IPS mode liquid crystal display device 1-2, which is another example of the first embodiment of the present invention, the upper surface (on the liquid crystal 4 side) of the second insulating film 9-2 on which the second electrode 10-2 is provided. (Surface) is formed to be slightly recessed. However, in the liquid crystal display device 1-2, the contact hole 7 provided in the TFT substrate 2 is filled with the second insulating film 9-2, and the surface of the TFT substrate 2 is the second insulating film 9-. Compared with the case where 2 is not provided, it is flattened. Therefore, in the liquid crystal display element 1-2, the alignment disorder of the liquid crystal 4 due to the contact hole 7 is reduced as compared with the case where the second insulating film 9-2 is not provided, and the transmittance due to the depression and the response characteristics of the liquid crystal 4 are reduced. The decline is mitigated. That is, the liquid crystal display element 1-2 can reduce the influence of the contact hole 7 provided in the TFT substrate 2, and does not need to form a large light shielding means such as the source electrode 34, thereby improving the luminance characteristics. Can do.

Embodiment 2. FIG.
<VA mode liquid crystal display element>
FIG. 4 is a cross-sectional view schematically showing the structure of a VA mode liquid crystal display element according to the second embodiment of the present invention.

FIG. 5 is a plan view schematically showing the structure of a VA mode liquid crystal display device according to the second embodiment of the present invention.
FIG. 4 schematically shows a cross section taken along the line BB ′ of FIG.

  As shown in FIG. 4, the VA mode liquid crystal display element 100 according to the second embodiment of the present invention includes a TFT substrate 102 which is a first substrate and a counter substrate 103 which is a second substrate, which are arranged to face each other. The liquid crystal 104 is sandwiched. The liquid crystal 104 is a liquid crystal having negative dielectric anisotropy (Δε).

  As shown in FIG. 5, in the VA mode liquid crystal display element 100, the TFT substrate 102 includes a TFT 105.

  That is, as shown in FIGS. 4 and 5, the TFT substrate 102 of the liquid crystal display element 100 includes a first insulating film 106 provided on the TFT 105 (not shown in FIG. 4) and a first insulating film 106. A contact hole 107 formed in the film 106, a first hole provided on the first insulating film 106 and on the inner wall of the contact hole 107 and electrically connected to the source electrode 134 of the TFT 105 through the contact hole 107. An electrode 108 and a second insulating film 109 provided so as to fill the contact hole 107 and planarizing the surface of the TFT substrate 102 are provided.

  In addition, the TFT substrate 102 is provided on the second insulating film 109 and is electrically connected to the first electrode 108 on the first insulating film 106 by an end portion that is a part of the TFT substrate 102. The electrode 110 is provided.

  In the liquid crystal display element 100 of this embodiment, the first electrode 108 and the second electrode 110 electrically connected to the first electrode 108 constitute a pixel electrode.

  The liquid crystal display element 100 includes a third electrode 112 on the liquid crystal 104 side of the counter substrate 103. In the liquid crystal display element 100 of the present embodiment, the third electrode 112 constitutes a common electrode.

  As a result, the liquid crystal display element 100 drives the liquid crystal 104 by applying a voltage between the first electrode 108 and the second electrode 110 on the TFT substrate 102 and the third electrode 112 on the counter substrate 103. It is configured to The liquid crystal display element 100 applies a voltage between the first electrode 108 and the second electrode 110 and the third electrode 112 on the counter substrate 103, so that the liquid crystal 104 having negative dielectric anisotropy is obtained. The VA mode liquid crystal display element is configured to be driven.

  Hereinafter, the configuration of the VA mode liquid crystal display element 100 according to the second embodiment of the present invention will be described in more detail. First, the planar structure of the liquid crystal display element 100, in particular, the main planar structure of the pixel will be described mainly with reference to FIG.

  In the liquid crystal display element 100, as shown in FIG. 5, pixels are formed in a region surrounded by a signal line 130 extending in the vertical direction and a scanning line 131 extending in the horizontal direction. A TFT 105 for switching is formed on the scanning line 131 to control the supply of video signals to the first electrode 108 and the second electrode 110 constituting the pixel electrode. As shown in FIG. 5, the scanning line 131 also serves as the gate electrode of the TFT 105, and a semiconductor layer 132 made of amorphous-silicon (a-Si) or microcrystalline silicon is formed on the scanning line 131.

  On the semiconductor layer 132, a drain electrode 133 connected to the signal line 130 is formed so as to overlap at an end portion, and a source electrode 134 is formed so as to face the drain electrode 133 apart from the drain electrode 133. The source electrode 134 extends to the pixel formation region and is electrically connected to the first electrode 108 through the contact hole 107.

  As shown in FIG. 5, the first electrode 108 is formed in a flat solid shape. The second electrode 110 is formed in a solid shape so as to cover the contact hole 107 and to be in contact with the first electrode 108 at the end thereof.

  As described above, the first electrode 108 and the second electrode 110 integrally form a pixel electrode, but in the example shown in FIG. 5, each is formed in a solid shape. However, in the liquid crystal display element 100, as another example, the first electrode 108 and the second electrode 110 can each have a slit-shaped notch that is a portion where an electrode is not formed. In that case, after forming the first electrode 108 and the second electrode 110 as shown in FIG. 5, they are collectively patterned to form notches in the first electrode 108 and the second electrode 110. Can be provided.

  Since the first electrode 108 and the second electrode 110 have a cutout portion, the liquid crystal display element 100 includes the first electrode 108 and the second electrode 110, and the third electrode 112 on the counter substrate 103. When a voltage is applied between them, an electric field that is slightly oblique with an electric field perpendicular to the substrate surface can be generated, and the tilt direction of the liquid crystal 104 can be controlled.

  In the liquid crystal display element 100 illustrated in FIG. 5, the first electrode 108 extends from a certain end of the TFT 105 and covers the source electrode 134 in the pixel. The second electrode 110 is also provided on the second insulating film 109 (not shown in FIG. 5) filling the contact hole 107 and covers the source electrode 134. Then, as described above, the second electrode 110 covers the first electrode 108 via the second insulating film 109 and is electrically connected to the first electrode 108 at an end portion that is a part thereof. doing.

  Next, a cross-sectional structure of the liquid crystal display element 100, in particular, a cross-sectional structure of a pixel will be described mainly with reference to FIG.

In the liquid crystal display element 100, as shown in FIG. 4, a gate insulating film 121 used in the TFT 105 of FIG. 5 is formed on the TFT substrate 102, and a source electrode 134 extending from the TFT 105 is formed thereon. ing. This portion of the source electrode 134 can block light from a backlight (not shown). An inorganic passivation film 122 is formed so as to cover the source electrode 134, and a first insulating film 106 that also serves as a planarization film is formed thereon. The inorganic passivation film 122 can be formed from, for example, a metal oxide such as SiO ₂ or a metal nitride such as SiN.

  In the liquid crystal display element 100 of this embodiment, the first insulating film 106 is an organic insulating film formed by patterning using a first radiation-sensitive resin composition described later. The first insulating film 106 can be formed with a film thickness of 0.5 μm to 6 μm, for example.

  A contact hole 107 for electrically connecting the first electrode 108 to the source electrode 134 is formed in the first insulating film 106. The method for forming the contact hole 107 can be the same as the method for forming the contact hole 7 of the liquid crystal display element 1 of the first embodiment described above.

  A contact hole 107 formed in the second insulating film 106 connects a pilot hole for connecting the first electrode 108 to the source electrode 134, an upper hole having a larger diameter, and a lower hole and an upper hole. It consists of an inner wall. In order to prevent disconnection of the first electrode 108 provided so as to cover the inner wall of the contact hole 107, the taper angle of the contact hole 107 is preferably set to 45 degrees or less. Therefore, the contact hole 107 on the TFT substrate 102 has a large area in plan view.

  A first electrode 108 is provided on the first insulating film 106 and on the inner wall of the contact hole 107 so as to cover the first insulating film 106 and the contact hole 107. The first electrode 108 is formed using, for example, ITO. In the liquid crystal display element 100, the first electrode 108 serving as a pixel electrode is formed in, for example, a flat solid shape as described above. The first electrode 108 is electrically connected to the source electrode 134 through the contact hole 107.

  In addition, the liquid crystal display element 100 includes a second insulating film 109 provided so as to fill the contact hole 107. The second insulating film 109 is an organic insulating film formed using a second radiation sensitive resin composition described later. The second insulating film 109 of the liquid crystal display element 100 has a function of filling the contact hole 107 of the TFT substrate 102 and flattening the surface of the TFT substrate 102.

The method for forming the second insulating film 109 can be the same as the method for forming the second insulating film 9 of the liquid crystal display element 1 of the first embodiment described above.
Therefore, for example, the second insulating film 109 can be formed by patterning using a photomask used for patterning the first insulating film 106 in order to form the contact hole 107 and the like.

  That is, the first insulating film 106 having the contact hole 107 is formed using one kind of photomask, the first electrode 108 covering the first insulating film 106 is provided, the mask is used again, and the second radiation sensitive film is formed. The second insulating film 109 can be formed using a conductive resin composition.

  In that case, for example, using a positive first radiation-sensitive resin composition, patterning is performed by exposure and development through a photomask to form the first insulating film 106 in which the contact hole 107 is formed. . Next, the first electrode 108 is formed. Thereafter, using the negative second radiation-sensitive resin composition, the same exposure and development using the same photomask as described above are performed, and the second insulating film 109 filling the contact hole 107 is formed. be able to.

  The TFT substrate 102 of the liquid crystal display element 1 is provided on the second insulating film 109, and is electrically connected to the first electrode 108 on the first insulating film 106 by an end portion that is a part of the TFT substrate 102. The second electrode 110 is connected to the. The second electrode 110 can be formed using a material similar to that of the first electrode 108, for example, ITO.

  In the liquid crystal display element 100 of the present embodiment, the first electrode 108 and the second electrode 110 are electrically connected to each other, and can function as a pixel electrode together.

  On the first electrode 108 and the second electrode 110, an alignment film 140 for aligning the liquid crystal 104 is formed. The alignment film 140 is a vertical alignment type alignment film. The alignment film 140 is subjected to a suitable alignment process such as a rubbing process or a photo-alignment process, and can realize a uniform initial alignment of the liquid crystal 104 when no voltage is applied. That is, the liquid crystal 104 is not aligned completely perpendicular to the substrate surface, but the liquid crystal 104 at the substrate interface has a small pretilt angle and can achieve initial alignment that is uniformly aligned substantially vertically.

  In the liquid crystal display element 100 of this embodiment, the alignment film 140 and the alignment film 144 on the counter substrate 103 described later are not provided, or the alignment films 140 and 144 are provided in the liquid crystal 104. It is also possible to realize the initial alignment of the liquid crystal 104 described above by mixing a photopolymerizable monomer and photopolymerizing it.

  The liquid crystal display element 100 includes a counter substrate 103 that is a second substrate with a liquid crystal 104 interposed therebetween. A black matrix 141 and a color filter 142 are formed on the counter substrate 103, a planarizing film 143 is formed so as to cover them, a third electrode 112 is provided thereon, and an alignment film 144 is further formed thereon. Has been.

  The alignment film 144 on the counter substrate 103 is the same as the alignment film 140 on the TFT substrate 102, and an approximately vertical alignment can be realized as an initial alignment of the liquid crystal 104 by performing an appropriate alignment process. .

  The liquid crystal display element 100 includes a third electrode 112 on the counter substrate 103. As described above, in the liquid crystal display element 100 of the present embodiment, the third electrode 112 constitutes a common electrode that is common to other pixels.

  In the liquid crystal display element 100 of the present embodiment having the above-described configuration, video signals are applied to the first electrode 108 and the second electrode 110 on the TFT substrate 102 for image display, and these are applied to the counter substrate 103. When a voltage is applied to the third electrode 112, an electric field is generated between them. That is, when a voltage is applied between the first electrode 108 and the second electrode 110 and the third electrode 112, an electric field perpendicular to the substrate surface of the TFT substrate 112 is generated in the liquid crystal 104.

  As a result, the liquid crystal 104 having negative dielectric anisotropy is driven by the electric field and tilts so as to be aligned in a direction parallel to the substrate surface from a substantially vertical alignment state which is an initial alignment.

  The liquid crystal display element 100 has a structure in which a non-illustrated polarizing plate is provided on the anti-liquid crystal side surface of the TFT substrate 102 and the anti-liquid crystal side surface of the counter substrate 103, and the liquid crystal 104 is sandwiched between a pair of polarizing plates. . Accordingly, the liquid crystal display element 100 can partially transmit or block light by the change in the orientation of the liquid crystal 104 due to the vertical electric field described above, and can display an image using such characteristics. .

  In the liquid crystal display element 100, the contact hole 107 provided in the TFT substrate 102 is filled with the second insulating film 109, and the surface of the TFT substrate 102 is flattened. Therefore, in the liquid crystal display element 100, the alignment disorder of the liquid crystal 104 due to the contact hole 107, the transmittance due to the depression, and the decrease in the response characteristics of the liquid crystal 104 are reduced. That is, the liquid crystal display element 100 can reduce the influence of the contact hole 107 provided in the TFT substrate 102, and does not need to form a large light shielding means such as the source electrode 134, and can improve luminance characteristics. .

  In the liquid crystal display element 100 according to the second embodiment of the present invention shown in FIG. 4 and the like, the contact hole 107 is filled with the second insulating film 109. The surface of the TFT substrate 102 is flattened with high uniformity. However, in the liquid crystal display element 100 of the present embodiment, the second insulating film 109 is selected according to the selection of the composition of the second radiation-sensitive resin composition for forming the second insulating film 109 and the method for forming the second insulating film 109. The upper surface of the film 109 (the surface on the liquid crystal 104 side) may be slightly recessed.

  FIG. 6 is a cross-sectional view schematically showing the structure of another example of the VA mode liquid crystal display element of the second embodiment of the present invention.

  The VA mode liquid crystal display element 100-2, which is another example of the second embodiment of the present invention shown in FIG. 6, is shown in FIG. 4 and the like except that the shape of the second insulating film 109-2 is different. The liquid crystal display element 100 has the same structure. Therefore, the same components are denoted by the same reference numerals, and redundant description is omitted.

  In the VA mode liquid crystal display element 100-2 which is another example of the second embodiment of the present invention, the upper surface (on the liquid crystal 104 side) of the second insulating film 109-2 on which the second electrode 110-2 is provided. The surface is slightly recessed. However, in the liquid crystal display element 100-2, the contact hole 7 provided in the TFT substrate 102 is filled with the second insulating film 109-2, and the surface of the TFT substrate 102 is the second insulating film 109-. Compared with the case where 2 is not provided, it is flattened. Therefore, in the liquid crystal display element 100-2, the alignment disorder of the liquid crystal 104 due to the contact hole 107 is reduced as compared with the case where the second insulating film 109-2 is not provided, and the transmittance due to the depression and the response characteristics of the liquid crystal 104 are reduced. The decline is mitigated. That is, the liquid crystal display element 100-2 can reduce the influence of the contact hole 107 provided in the TFT substrate 102, and does not need to form a large light shielding means such as the source electrode 134, thereby improving luminance characteristics. Can do.

  In the liquid crystal display elements according to the first and second embodiments of the present invention, the first radiation-sensitive resin composition used for forming the first insulating film, and the contact of the first insulating film The 2nd radiation sensitive resin composition used in order to fill a hole is demonstrated in detail.

Embodiment 3. FIG.
<First radiation sensitive resin composition>
The 1st radiation sensitive resin composition which is 3rd Embodiment of this invention is used suitably for formation of the 1st insulating film of the liquid crystal display element which is 1st and 2nd embodiment of this invention. The first radiation-sensitive resin composition of the present embodiment can be selectively provided with either positive or negative radiation sensitivity.

  The first radiation-sensitive resin composition of the present embodiment has an alkali-soluble resin as an essential component for both positive and negative types, and when it is a positive-type radiation-sensitive resin composition, a photoacid generator as an essential component. When it is a negative radiation sensitive resin composition, it contains a polymerizable compound and a radiation sensitive polymerization initiator.

  The alkali-soluble resin described above may be a polymer containing a structural unit having a carboxyl group and a structural unit having a polymerizable group, and an imide is obtained by dehydrating and ring-closing acrylic resin, polysiloxane, polybenzoxazole, and polyamic acid. A polyimide resin, a novolak resin, a cycloolefin-based resin, and the like that are obtained by forming the resin are preferable.

  Moreover, it is preferable that the structural unit of the alkali-soluble resin contains a heat-crosslinkable group such as an epoxy group, an oxetanyl group, and a (meth) acryloyl group. It is also possible to use in combination with a resin containing a thermally crosslinkable group such as.

  By using a resin containing such a heat crosslinkable group, it is possible to improve the heat resistance and solvent resistance of the insulating film obtained.

  Examples of the acid generator used in the positive first radiation-sensitive resin composition include quinonediazide compounds, oxime sulfonate compounds, onium salts, sulfonimide compounds, halogen-containing compounds, diazomethane compounds, sulfone compounds, and sulfonate esters. Examples thereof include compounds and carboxylic acid ester compounds. Among these, quinonediazide compounds, oxime sulfonate compounds, onium salts and sulfonimide compounds are particularly preferable.

  Examples of the polymerizable compound used in the negative first radiation-sensitive resin composition include ω-carboxypolycaprolactone mono (meth) acrylate, ethylene glycol (meth) acrylate, 1,6-hexanediol di ( (Meth) acrylate, 1,9-nonanediol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, bisphenoxyethanol full orange (meth) acrylate, Dimethylol tricyclodecane di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl methacrylate, 2- (2′-vinyloxyethoxy) ethyl (meth) acrylate, trimethylol group Pantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (2- (meth) acryloyloxy Ethyl) phosphate, ethylene oxide-modified dipentaerythritol hexaacrylate, succinic acid-modified pentaerythritol triacrylate, etc., as well as compounds having a linear alkylene group and an alicyclic structure and having two or more isocyanate groups, and molecules Examples thereof include a urethane (meth) acrylate compound obtained by reacting a compound having one or more hydroxyl groups and having 3 to 5 (meth) acryloyloxy groups.

  Examples of the radiation-sensitive polymerization initiator used in the negative first radiation-sensitive resin composition include O-acyl oxime compounds, acetophenone compounds, and biimidazole compounds. These compounds may be used alone or in combination of two or more.

  Among these radiation-sensitive polymerization initiators, O-acyloxime compounds are particularly preferable, and specifically, 1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)] , Ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2 -Methyl-4-tetrahydrofuranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) or ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl } -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) is preferred.

  The 1st radiation sensitive resin composition of this embodiment can contain a metal oxide particle as needed. By including metal oxide particles, the film properties such as refractive index and dielectric constant of the resulting cured film can be modified.

  Examples of the metal oxide particles include oxide particles of at least one metal selected from the group consisting of aluminum, zirconium, titanium, zinc, indium, tin, antimony, and cerium, and among these, zirconium, titanium, or zinc. Oxide particles are preferred, and zirconium or titanium oxide particles are more preferred. In addition to these, it is also possible to use titanates instead of these.

  These metal oxide particles can be used alone or in combination of two or more. Further, the metal oxide particles described above may be composite oxide particles of the above exemplified metals. Examples of the composite oxide particles include ATO (Antimony-Tin Oxide), ITO, IZO (Indium-Zinc Oxide), and the like. Commercially available particles can be used as these metal oxide particles. For example, Nanotech manufactured by CI Kasei Co., Ltd. can be used.

Embodiment 4 FIG.
<Second radiation sensitive resin composition>
The 2nd radiation sensitive resin composition which is 4th Embodiment of this invention can be used suitably for formation of the 2nd insulating film of the liquid crystal display element which is 1st and 2nd embodiment of this invention. . The second radiation-sensitive resin composition of the present embodiment can be selectively provided with either positive or negative radiation sensitivity.

  And in order to form the 1st insulating film of the liquid crystal display element of this invention, a positive radiation sensitive resin composition is added to the 1st radiation sensitive resin composition which is 3rd Embodiment of this invention mentioned above. When selected, the second radiation-sensitive resin composition of the present embodiment can be provided with a negative-type radiation sensitivity. Thus, in the manufacture of the liquid crystal display element of the present invention, as described above, the formation of the first insulating film and the second insulating film can be realized using the same photomask.

  The second radiation-sensitive resin composition of the present embodiment is an alkali-soluble resin, both positive and negative, as in the first radiation-sensitive resin composition of the third embodiment of the present invention described above. It is an essential ingredient. When the second radiation sensitive resin composition is a positive radiation sensitive resin composition, it contains a photoacid generator as an essential component, and when it is a negative radiation sensitive resin composition, it is polymerizable. Contains a compound and a radiation sensitive polymerization initiator.

  The alkali-soluble resin described above may be a polymer containing a structural unit having a carboxyl group and a structural unit having a polymerizable group, and an imide is obtained by dehydrating and ring-closing acrylic resin, polysiloxane, polybenzoxazole, and polyamic acid. A polyimide resin, a novolak resin, a cycloolefin-based resin, and the like that are obtained by forming the resin are preferable.

  Moreover, it is preferable that the structural unit of the alkali-soluble resin contains a heat-crosslinkable group such as an epoxy group, an oxetanyl group, and a (meth) acryloyl group. It is also possible to use in combination with a resin containing a thermally crosslinkable group such as.

  By using such a resin containing a thermally crosslinkable group, it is possible to improve the heat resistance and solvent resistance of the insulating film obtained.

  Examples of the acid generator used in the positive second radiation-sensitive resin composition include quinonediazide compounds, oxime sulfonate compounds, onium salts, sulfonimide compounds, halogen-containing compounds, diazomethane compounds, sulfone compounds, and sulfonate esters. Compounds, carboxylic acid ester compounds and the like. Among these, quinonediazide compounds, oxime sulfonate compounds, onium salts, and sulfonimide compounds are particularly preferable.

  Examples of the polymerizable compound used in the negative second radiation-sensitive resin composition include ω-carboxypolycaprolactone mono (meth) acrylate, ethylene glycol (meth) acrylate, 1,6-hexanediol di ( (Meth) acrylate, 1,9-nonanediol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, bisphenoxyethanol full orange (meth) acrylate, Dimethylol tricyclodecane di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl methacrylate, 2- (2′-vinyloxyethoxy) ethyl (meth) acrylate, trimethylol group Pantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (2- (meth) acryloyloxy Ethyl) phosphate, ethylene oxide-modified dipentaerythritol hexaacrylate, succinic acid-modified pentaerythritol triacrylate, etc., as well as compounds having a linear alkylene group and an alicyclic structure and having two or more isocyanate groups, and molecules Examples thereof include a urethane (meth) acrylate compound obtained by reacting a compound having one or more hydroxyl groups and having 3 to 5 (meth) acryloyloxy groups.

  Examples of the radiation-sensitive polymerization initiator used in the negative second radiation-sensitive resin composition include O-acyl oxime compounds, acetophenone compounds, and biimidazole compounds. These compounds may be used alone or in combination of two or more.

  Of these radiation-sensitive polymerization initiators, O-acyloxime compounds are particularly preferable. Specifically, 1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)] , Ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2 -Methyl-4-tetrahydrofuranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) or ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl } -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) is preferred.

  The 2nd radiation sensitive resin composition of this embodiment can contain a metal oxide particle as needed. By including such metal oxide particles, film properties such as refractive index and dielectric constant of the obtained cured film can be modified.

  Examples of the metal oxide particles include oxide particles of at least one metal selected from the group consisting of aluminum, zirconium, titanium, zinc, indium, tin, antimony, and cerium, and among these, zirconium, titanium, or zinc. Oxide particles are preferred, and zirconium or titanium oxide particles are more preferred. In addition to these, it is also possible to use titanates instead of these. As the titanate, barium titanate or the like is preferable.

  These metal oxide particles can be used alone or in combination of two or more. Further, the metal oxide particles described above may be composite oxide particles of the above exemplified metals. Examples of the composite oxide particles include ATO (Antimony-Tin Oxide), ITO, IZO (Indium-Zinc Oxide), and the like. Commercially available particles can be used as these metal oxide particles. For example, Nanotech manufactured by CI Kasei Co., Ltd. can be used.

Hereinafter, although an embodiment of the present invention is explained in full detail based on an example, the present invention is not limitedly interpreted by this example.

Example 1
[Synthesis of Alkali-soluble Resin (AI)]
A flask equipped with a condenser and a stirrer was charged with 8 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) and 220 parts by mass of diethylene glycol methyl ethyl ether. Subsequently, 15 parts by weight of methacrylic acid, 45 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate, 20 parts by weight of methyl methacrylate, 5 parts by weight of styrene, 15 parts by weight of N-cyclohexylmaleimide were charged, and after nitrogen substitution, While stirring, the temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours for polymerization to obtain a solution containing the copolymer (AI). The obtained polymer solution had a solid content concentration of 31.9% by mass, and the copolymer (AI) had an Mw of 10,000 and a molecular weight distribution (Mw / Mn) of 2.1. In addition, solid content concentration means the ratio of the copolymer mass which occupies for the total mass of a polymer solution.

Example 2
[Synthesis of alkali-soluble resin (A-II)]
In a container equipped with a stirrer, 144 parts by mass of propylene glycol monomethyl ether was charged, followed by 13 parts by mass of methyltrimethoxysilane, 5 parts by mass of 3-methacryloxypropyltriethoxysilane, and 6 parts by mass of phenyltrimethoxysilane. Charged and heated until the solution temperature reached 60 ° C. After the solution temperature reached 60 ° C., 7 parts by mass of ion exchange water was charged, heated to 75 ° C., and held for 3 hours. Next, 25 parts by mass of methyl orthoformate was added as a dehydrating agent and stirred for 1 hour. Furthermore, the solution temperature was set to 40 ° C., and evaporation was performed while maintaining this temperature, thereby removing water and alcohol generated by hydrolysis condensation. Through the above steps, a siloxane polymer as component (A-II) was obtained. The number average molecular weight (Mn) of the obtained hydrolysis-condensation product was 2500, and the molecular weight distribution (Mw / Mn) was 2.

Example 3
[Preparation of Positive First Radiation Sensitive Resin Composition]
As an alkali-soluble resin, a solution containing an alkali-soluble resin (AI) is prepared in an amount corresponding to 100 parts by mass (solid content) of the polymer, and then 4,4 as the quinonediazide compound that is a photoacid generator. 30 parts by mass of '-[1- [4- [1- [4-hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] bisphenol (1.0 mol) was mixed, and the solid concentration was 30% by mass. 1st radiation sensitive resin composition provided with positive radiation sensitivity after adding diethylene glycol ethyl methyl ether so that it may become and dissolving each component, and filtering with a 0.2 micrometer aperture filter Was prepared.

Example 4
[Negative type second radiation sensitive resin composition]
A solution containing an alkali-soluble resin (A-II) as an alkali-soluble resin is prepared in an amount corresponding to 100 parts by mass (solid content) of the polymer, and then dipentaerythritol pentaacrylate and dipentaerythritol as polymerizable compounds. Mixture of hexaacrylate (KAYARAD (registered trademark) DPHA (above, Nippon Kayaku Co., Ltd.) 100 parts by mass, and ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H as a radiation sensitive polymerization initiator -Carbazol-3-yl] -1- (O-acetyloxime) (Irgacure OXE02, BASF) was mixed with 5 parts by mass, and propylene glycol monomethyl ether acetate was added so that the solid concentration was 30% by mass. After dissolving each component, use a Millipore filter with a pore size of 0.5 μm. By over to, to prepare a second radiation-sensitive resin composition having a radiation-sensitive negative type.

Example 5
[Preparation of Positive Third Radiation Sensitive Resin Composition]
As an alkali-soluble resin, a solution containing an alkali-soluble resin (AI) is prepared in an amount corresponding to 100 parts by mass (solid content) of the polymer, and then 4,4 as the quinonediazide compound that is a photoacid generator. Dispersion 50 containing 30 parts by mass of '-[1- [4- [1- [4-hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] bisphenol (1.0 mol) and barium titanate as metal particles 50 After mixing parts by mass (solid content) and adding diethylene glycol ethyl methyl ether to a solid content concentration of 30% by mass to dissolve each component, the mixture was filtered through a membrane filter having a diameter of 0.2 μm. A third radiation sensitive resin composition having the radiation sensitivity of the mold was prepared.

Example 6
[Evaluation of membrane]
Using the first radiation-sensitive resin composition prepared in Example 3, the second radiation-sensitive resin composition prepared in Example 4, and the third radiation-sensitive resin composition prepared in Example 5, respectively. Each composition was applied on a glass substrate (“Corning (registered trademark) 7059” (manufactured by Corning)) using a spinner and then pre-baked on a hot plate at 100 ° C. for 2 minutes to form a coating film Each film having a thickness of 1 μm was formed on the glass substrate.

  Next, with respect to the obtained coating film on each glass substrate, using a PLA (registered trademark) -501F exposure machine (extra-high pressure mercury lamp) manufactured by Canon Inc., through a mask having a rectangular pattern of 5 cm × 8 cm. Exposure was performed. Thereafter, development was performed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 25 ° C. for 60 seconds. Next, running water was washed with ultrapure water for 1 minute to form a cured film patterned to have a 5 cm × 8 cm rectangular negative pattern or positive pattern.

Next, the edge part of each patterned cured film was observed with the optical microscope, and when there was no image development residue and the pattern was formed linearly, it was judged that patterning property was favorable.
As a result, the first radiation-sensitive resin composition prepared in Example 3, the second radiation-sensitive resin composition prepared in Example 4, and the third radiation-sensitive resin composition prepared in Example 5 were obtained. Each of the cured films formed by patterning using each had good patternability.

  Next, each of the above-described cured films was heated in a clean oven at 220 ° C. for 1 hour to form an insulating film.

  The light transmittance of the glass substrate on which these insulating films were formed was measured at a wavelength in the range of 400 nm to 800 nm using a spectrophotometer “150-20 type double beam” (manufactured by Hitachi, Ltd.). If the minimum light transmittance is 90% or more, it can be said that the light transmittance is good.

  Formed from the first radiation-sensitive resin composition prepared in Example 3, the second radiation-sensitive resin composition prepared in Example 4, and the third radiation-sensitive resin composition prepared in Example 5. Each of the insulating films had a transmittance of 90% or more.

  From the results of the above film evaluation, the insulating film formed from the first radiation-sensitive resin composition prepared in Example 3 and the insulation formed from the second radiation-sensitive resin composition prepared in Example 4 The film and the insulating film formed from the third radiation-sensitive resin composition prepared in Example 5 are both suitable as the first insulating film or the second insulating film of the liquid crystal display element of the present invention. It was found that can be used.

  The liquid crystal display element of the present invention is an active matrix liquid crystal display element that has excellent luminance characteristics and enables high-definition display. Therefore, the liquid crystal display element of the present invention can be suitably used as a display of a portable electronic device such as a smartphone that requires high-definition display with excellent image quality.

1, 1-2, 100, 100-2 Liquid crystal display element 2, 102 TFT substrate 3, 103 Counter substrate 4, 104 Liquid crystal 5, 105 TFT
6, 106 First insulating film 7, 107 Contact hole 8, 108 First electrode 9, 9-2, 109, 109-2 Second insulating film 10, 10-2, 110, 110-2 Second Electrode 11 Third insulating film 12, 112 Third electrode 21, 121 Gate insulating film 22, 122 Inorganic passivation film 30, 130 Signal line 31, 131 Scan line 32, 132 Semiconductor layer 33, 133 Drain electrode 34, 134 Source Electrode 40, 44, 140, 144 Alignment film 41, 141 Black matrix 42, 142 Color filter 43, 143 Flattening film 50 Notch

Claims (6)

A liquid crystal display element in which a liquid crystal is sandwiched between a first substrate and a second substrate that are arranged to face each other,
The first substrate is
TFT,
A first insulating film provided on the TFT using a first radiation-sensitive resin composition;
A contact hole formed in the first insulating film;
A first electrode provided on the first insulating film and on the inner wall of the contact hole and electrically connected to the TFT through the contact hole;
A second insulating film provided using a second radiation-sensitive resin composition so as to fill the contact hole;
A second portion provided on the second insulating film and partially in contact with the first electrode on the first insulating film and electrically connected to the first electrode. An electrode,
A third electrode is provided on the first electrode and the second electrode of the first substrate via a third insulating film, or provided on the liquid crystal side of the second substrate. ,
A liquid crystal display element configured to drive the liquid crystal by applying a voltage between the first electrode, the second electrode, and the third electrode.   The first radiation sensitive resin composition is a positive radiation sensitive resin composition and the second radiation sensitive resin composition is a negative radiation sensitive resin composition, or The first radiation-sensitive resin composition is a negative radiation-sensitive resin composition, and the second radiation-sensitive resin composition is a positive radiation-sensitive resin composition. Item 2. A liquid crystal display device according to item 1.   The liquid crystal display according to claim 1, wherein the first radiation-sensitive resin composition contains a polymer including a structural unit having a carboxyl group and a structural unit having a polymerizable group. element.   The said 2nd radiation sensitive resin composition contains the polymer containing the structural unit which has a carboxyl group, and the structural unit which has a polymeric group, The any one of Claims 1-3 characterized by the above-mentioned. A liquid crystal display element according to 1. A radiation-sensitive resin composition used for manufacturing a liquid crystal display element in which a liquid crystal is sandwiched between a first substrate and a second substrate that are arranged opposite to each other,
The first substrate is
TFT,
A first insulating film provided on the TFT;
A contact hole formed in the first insulating film;
A first electrode provided on the first insulating film and on the inner wall of the contact hole and electrically connected to the TFT through the contact hole;
A second insulating film provided to fill the contact hole;
A second portion provided on the second insulating film and partially in contact with the first electrode on the first insulating film and electrically connected to the first electrode. An electrode,
In the liquid crystal display element, a third electrode is provided on the first electrode and the second electrode of the first substrate via a third insulating film, or the second substrate Provided on the liquid crystal side, and configured to drive the liquid crystal by applying a voltage between the first electrode, the second electrode, and the third electrode,
A radiation-sensitive resin composition used for forming the second insulating film of the first substrate.   Furthermore, the radiation sensitive resin composition of Claim 5 containing a metal oxide particle.

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