WO2016194753A1

WO2016194753A1 - Display device

Info

Publication number: WO2016194753A1
Application number: PCT/JP2016/065541
Authority: WO
Inventors: 加藤　純男
Original assignee: シャープ株式会社
Priority date: 2015-06-01
Filing date: 2016-05-26
Publication date: 2016-12-08

Abstract

A frame region (100f) of this display device (100) comprises a seal part (60s) and a transition part (60t) that electrically connects an active matrix substrate (10) and a counter substrate (30) with each other by means of conductive particles (62). A drive TFT (11A) provided in the frame region comprises a semiconductor layer (15), a first gate electrode (12gA), a source electrode (14sA), a drain electrode (14dA) and a second gate electrode (16gA) that is positioned opposite to the first gate electrode with respect to the semiconductor layer. In a display region (100d), the active matrix substrate has a projection structure that protrudes toward the counter substrate. In the frame region, the active matrix substrate has an insulating member (19) that is provided on the drive TFT and covers the second gate electrode. The insulating member is formed of the same dielectric film as the projection structure.

Description

Display device

The present invention relates to a display device.

A display device such as a liquid crystal display device includes, for example, an active matrix substrate, a counter substrate disposed so as to face the active matrix substrate, and a display medium layer (for example, a liquid crystal layer) provided between the two substrates. . A display area of the display device is defined by a plurality of pixels included in the active matrix substrate.

An area other than the display area (for example, an area around the display area) of the display device is called a frame area or a non-display area. The frame region is, for example, a driving circuit unit that drives a switching element (for example, a thin film transistor (hereinafter, “TFT”)) provided for each pixel, a transition that electrically connects an active matrix substrate and a counter substrate. Part, a sealing part formed from a sealing material for sealing a display medium (for example, liquid crystal). The seal portion sometimes has a role of bonding the active matrix substrate and the counter substrate together.

In recent years, there has been an increasing demand for narrower, thinner, and higher-functional display devices (for example, display devices combined with touch panels (including in-cell touch panels)). In particular, the narrowing of the frame of the display device refers to the narrowing of the frame region. For example, the frame can be narrowed by reducing the area of at least one of the drive circuit portion, the transition portion, and the seal portion. ing.

Patent Document 1 discloses that in a frame region, a seal portion formed from a seal material, a transition portion configured from a conductor that electrically connects an active matrix substrate and a counter substrate, and between the seal portion and the transition portion. A liquid crystal display device having a barrier is disclosed. The barrier prevents the sealing material from covering the conductor when the active matrix substrate and the counter substrate are bonded to each other, and prevents a conduction failure between the substrates. Since the liquid crystal display device of Patent Document 1 has the seal portion, the conductor, and the barrier separately in the frame region, it is difficult to narrow the frame.

On the other hand, Patent Document 2 discloses that a sealing material containing conductive particles integrally forms a seal portion and a transition portion. Patent Document 2 discloses that a short-circuit prevention pattern is provided on the counter substrate in order to prevent unintentional conduction between the two substrates due to the conductive particles.

Further, by using a TFT having high mobility as a TFT constituting the drive circuit (hereinafter, also referred to as “drive TFT”), the area of the drive circuit portion can be reduced. For example, a TFT used as an oxide semiconductor layer and an active layer (hereinafter referred to as an “oxide semiconductor TFT”) has a higher mobility than amorphous silicon. A frame can be made. However, the characteristics of the oxide semiconductor TFT may vary (for example, the threshold voltage Vth shifts). In Patent Document 3, in order to control the threshold voltage Vth of an oxide semiconductor TFT, an additional gate electrode (hereinafter referred to as a back gate electrode) located on the opposite side of the gate electrode with the semiconductor layer interposed therebetween may be referred to. .) Is disclosed. It is described that the threshold voltage Vth of the TFT can be controlled by fixing the potential of the back gate electrode to a predetermined value different from the potential of the gate electrode. Further, the mobility of the TFT can be improved by making the potential of the back gate electrode the same as the potential of the gate electrode. Thereby, the driving TFT is not limited to the oxide semiconductor TFT, and the frame can be narrowed.

JP 2006-268020 A JP 2007-156414 A JP 2010-251735 A

In response to a request for narrowing the frame, when the present inventor made a prototype of a display device, the reliability of the display device was sometimes lowered. According to the study by the present inventor, it was found that the problem was not caused by the conventional display device. Details will be described later.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a display device having a narrow frame and excellent reliability without increasing the number of manufacturing steps.

A display device according to an embodiment of the present invention includes an active matrix substrate and a counter substrate disposed so as to face the active matrix substrate, and a display region defined by a plurality of pixels arranged in a matrix, A display device having a frame region around the display region, wherein the frame region is electrically connected to the active matrix substrate and the counter substrate by conductive particles and a seal portion surrounding the display region. The active matrix substrate includes a driving TFT provided in the frame region and a substrate that supports the driving TFT, and the driving TFT includes a channel region, a source region, and a drain region. A semiconductor layer that overlaps the channel region of the semiconductor layer with a first insulating layer interposed therebetween, and A first gate electrode located between the substrates, a source electrode and a drain electrode electrically connected to the source region and the drain region of the semiconductor layer, respectively, and a second insulating layer in the channel region of the semiconductor layer And the second gate electrode positioned opposite to the first gate electrode with respect to the semiconductor layer. In the display region, the active matrix substrate protrudes to the counter substrate side. In the frame region, the active matrix substrate is provided on the driving TFT and has an insulating member that covers the second gate electrode, and the insulating member is the same as the protruding structure. It is formed from a dielectric film.

In one embodiment, the protruding structure is a first columnar spacer that defines a distance between the active matrix substrate and the counter substrate.

In one embodiment, the protruding structure is a second columnar spacer that is lower than a first columnar spacer that defines a distance between the active matrix substrate and the counter substrate.

In one embodiment, the second columnar spacer is formed of the same dielectric film as the first columnar spacer.

In one embodiment, the height of the insulating member is substantially the same as the height of the protruding structure.

A display device according to another embodiment of the present invention includes an active matrix substrate and a counter substrate arranged to face the active matrix substrate, and is defined by a plurality of pixels arranged in a matrix. And a frame region around the display region, wherein the frame region electrically connects the active matrix substrate and the counter substrate with a sealing portion that surrounds the display region, and conductive particles. The active matrix substrate includes a driving TFT provided in the frame region and a substrate that supports the driving TFT. The driving TFT includes a channel region, a source region, and a drain. A semiconductor layer including a region and the channel region of the semiconductor layer through a first insulating layer, the semiconductor layer and A first gate electrode located between the substrates, a source electrode and a drain electrode electrically connected to the source region and the drain region of the semiconductor layer, respectively, and a second insulation in the channel region of the semiconductor layer A second gate electrode that is located on a side opposite to the first gate electrode with respect to the semiconductor layer, and the active matrix substrate emits light of different colors in the display region. A color filter layer including a first color filter, a second color filter, and a third color filter to transmit; and in the frame region, the active matrix substrate is provided on the driving TFT, and the second gate electrode An insulating member that covers the first color filter, the second color filter, and the third color filter; It is formed from at least one same dielectric film of the color filter.

In one embodiment, the height of the insulating member is greater than half of the average particle diameter of the conductive particles.

In one embodiment, the seal part includes a first granular spacer that defines a distance between the active matrix substrate and the counter substrate.

In one embodiment, the seal part is a second granular spacer located between the insulating member and the counter substrate, and defines a distance between the active matrix substrate and the counter substrate together with the insulating member. A second granular spacer.

In one embodiment, the insulating member covers the entire driving TFT.

In one embodiment, the transition portion is provided on one side of the display region, and the insulating member covers substantially the entire area between the transition portion and the display region.

In one embodiment, the second gate electrode is electrically connected to the source electrode.

In one embodiment, the active matrix substrate includes a contact electrode provided in the frame region, the counter substrate includes a counter electrode including a portion facing the contact electrode, and the transition portion includes The contact electrode and the counter electrode are electrically connected.

In one embodiment, the contact electrode includes a first conductive layer formed from the same conductive film as the first gate electrode and / or a second conductive layer formed from the same conductive film as the source electrode and the drain electrode. Electrically connected to the layer.

In one embodiment, the transition portion is provided in the first insulating layer and the second insulating layer, and a first opening that electrically connects the first conductive layer, the second conductive layer, and the contact electrode to each other. Part.

In one embodiment, the transition portion further includes a third conductive layer between the contact electrode and the second insulating layer, and the third conductive layer is in contact with the contact electrode in the first opening. ing.

In one embodiment, the second gate electrode is formed of the same conductive film as the third conductive layer.

In one embodiment, the second gate electrode is formed of the same conductive film as the contact electrode.

In one embodiment, the second gate electrode is in contact with the source electrode in a second opening provided in the second insulating layer.

In one embodiment, the driving TFT further includes an additional electrode provided on the second gate electrode and electrically connected to the second gate electrode, and the additional electrode includes the second insulating layer. Is electrically connected to the source electrode in a second opening provided in the first electrode.

In one embodiment, the additional electrode is formed of the same conductive film as the contact electrode.

In one embodiment, the insulating member covers the additional electrode in addition to the second gate electrode.

In one embodiment, the semiconductor layer includes an oxide semiconductor.

In one embodiment, the oxide semiconductor includes an In—Ga—Zn—O-based semiconductor.

In one embodiment, the In—Ga—Zn—O-based semiconductor includes a crystalline portion.

According to the embodiment of the present invention, a display device having a narrow frame and excellent reliability can be provided without increasing the number of manufacturing steps.

(A) is a cross-sectional view schematically showing a frame region 100f of the liquid crystal display device 100 according to Embodiment 1 of the present invention, taken along lines 1At-1At ′ and 1Ad-1Ad ′ in FIG. FIG. 4B is a cross-sectional view schematically showing the display region 100d of the liquid crystal display device 100 along the line 1b-1b ′ in FIG. 4 is a plan view schematically showing a frame region 100f of the liquid crystal display device 100. FIG. 4 is a plan view schematically showing a display area 100d of the liquid crystal display device 100. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of the liquid crystal display device 100, (b) is process cross section which shows the manufacturing process of the display area 100d of the liquid crystal display device 100 typically. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of the liquid crystal display device 100, (b) is process cross section which shows the manufacturing process of the display area 100d of the liquid crystal display device 100 typically. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of the liquid crystal display device 100, (b) is process cross section which shows the manufacturing process of the display area 100d of the liquid crystal display device 100 typically. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of the liquid crystal display device 100, (b) is process cross section which shows the manufacturing process of the display area 100d of the liquid crystal display device 100 typically. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of the liquid crystal display device 100, (b) is process cross section which shows the manufacturing process of the display area 100d of the liquid crystal display device 100 typically. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of the liquid crystal display device 100, (b) is process cross section which shows the manufacturing process of the display area 100d of the liquid crystal display device 100 typically. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of the liquid crystal display device 100, (b) is process cross section which shows the manufacturing process of the display area 100d of the liquid crystal display device 100 typically. FIG. FIG. 13A is a cross-sectional view schematically showing a frame region 100f of a liquid crystal display device 100A that is a modified example of the liquid crystal display device 100, taken along lines 11At-11At ′ and 11Ad-11Ad ′ in FIG. (B), It is sectional drawing which shows typically the display area 100d of 100 A of liquid crystal display devices along the 11b-11b 'line in FIG. It is a top view which shows typically the frame area | region 100f of 100 A of liquid crystal display devices. It is a top view which shows typically the display area 100d of 100 A of liquid crystal display devices. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of 100 A of liquid crystal display devices, (b) Process cross section which shows typically the manufacturing process of the display area | region 100d of 100 A of liquid crystal display devices. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of 100 A of liquid crystal display devices, (b) Process cross section which shows typically the manufacturing process of the display area | region 100d of 100 A of liquid crystal display devices. FIG. (A) is process sectional drawing which shows typically the manufacturing process of the frame area | region 100f of 100 A of liquid crystal display devices, (b) Process cross section which shows typically the manufacturing process of the display area | region 100d of 100 A of liquid crystal display devices. FIG. It is sectional drawing which shows typically the frame area | region 100f of liquid crystal display device 100B which is the other modification of the liquid crystal display device 100. FIG. FIG. 20 is a cross-sectional view schematically showing a frame region 200f of the liquid crystal display device 200 according to Embodiment 2 of the present invention along the 18At-18At 'line and the 18Ad-18Ad' line in FIG. 4 is a plan view schematically showing a frame region 200f of the liquid crystal display device 200. FIG. (A) is sectional drawing which shows typically the frame area | region 300f of the liquid crystal display device 300 by Embodiment 3 of this invention, (b) is sectional drawing which shows typically the display area 300d of the liquid crystal display device 300 It is. It is sectional drawing which shows typically the frame area | region 900f of the liquid crystal display device 900 of a comparative example.

First, the problem that the reliability of the liquid crystal display device found by the present inventor will be described with reference to FIG. FIG. 21 is a cross-sectional view schematically showing a frame region 900f of a liquid crystal display device 900 of a comparative example. The display area of the liquid crystal display device 900 of the comparative example is not shown. In FIG. 21, components common to the embodiment of the present invention may be denoted by common reference numerals, and description thereof may be omitted.

As shown in FIG. 21, the liquid crystal display device 900 of the comparative example includes an active matrix substrate 10, a counter substrate 30 disposed so as to face the active matrix substrate 10, and between the active matrix substrate 10 and the counter substrate 30. And a provided liquid crystal layer. The liquid crystal display device 900 of the comparative example has a plurality of pixels arranged in a matrix having a plurality of rows and a plurality of columns. The liquid crystal display device 900 of the comparative example includes a display area defined by a plurality of pixels and a frame area 900f around the display area.

The frame region 900f includes a seal portion 60s that surrounds the display region, a transfer portion 60t that electrically connects the active matrix substrate 10 and the counter substrate 30 by the conductive particles 62, and a drive circuit portion 60d that includes the drive TFT 11A. Including.

The driving TFT 11A includes a semiconductor layer 15A, a first gate electrode 12gA, a source electrode 14sA and a drain electrode 14dA, and a second gate electrode 16gA. The semiconductor layer 15A includes a channel region 15cA, a source region 15sA, and a drain region 15dA. The first gate electrode 12gA overlaps the channel region 15cA of the semiconductor layer 15A via the first insulating layer 2i, and is located between the semiconductor layer 15A and the substrate 1s. The source electrode 14sA and the drain electrode 14dA are electrically connected to the source region 15sA and the drain region 15dA of the semiconductor layer 15A, respectively. The second gate electrode 16gA overlaps the channel region 15cA of the semiconductor layer 15A via the second insulating layer 4i, and is located on the opposite side of the semiconductor layer 15A from the first gate electrode 12gA. The second gate electrode 16gA may be called a back gate electrode. The drive TFT 11A may be called a back gate TFT having a back gate electrode.

As shown in FIG. 21, in the liquid crystal display device 900 of the comparative example, the seal portion 60s is provided overlapping the drive circuit portion 60d. In the liquid crystal display device 900 of the comparative example, the frame area is further narrowed compared to the conventional liquid crystal display device, and the seal portion and the drive circuit portion are provided closer to each other than the conventional liquid crystal display device. It depends. For example, when the active matrix substrate 10 and the counter substrate 30 are bonded to each other, the seal material that forms the seal portion 60s extends to the drive TFT 11A.

In the conventional liquid crystal display device, the seal portion is provided separately from the drive circuit portion. Further, the seal portion and the drive circuit portion are provided so that the seal material forming the seal portion does not overlap the drive TFT even when the active matrix substrate and the counter substrate are bonded to each other. For example, in the above-described liquid crystal display device of Patent Document 2 (see FIGS. 3 and 4 of Patent Document 2), the seal portion does not overlap the drive circuit portion. Here, in Patent Document 2, the drive circuit section is referred to as a “gate circuit region” and is composed of a circuit block having a switching element.

In the liquid crystal display device 900 of the comparative example, the second gate electrode 16gA and the counter electrode 34 included in the counter substrate 30 are electrically connected by the conductive particles 62 because the seal material forming the seal portion 60s overlaps the driving TFT 11A. There are things to do. As a result, the drive TFT 11A malfunctions, which may cause a problem that the reliability of the liquid crystal display device is lowered.

The conductive particles 62 are included in, for example, a transition material that forms the transition portion 60t. When the seal part 60s and the transition part 60t are provided close to each other, the sealing material forming the seal part 60s and the transition material forming the transition part 60t are in contact with each other, so that the conductive particles 62 are in contact with the second gate electrode 16gA. In addition, the counter electrode 34 is electrically connected. In particular, the seal part 60s and the transition part 60t, both of which are made of a resin material, are often provided close to each other. Both the sealing material and the transition material may include conductive particles 62. The sealing material and the transition material may be the same resin material. Or like the liquid crystal display device of the said patent document 2, the seal | sticker part and the transfer part may be integrally formed from the resin material containing electroconductive particle. In either case, the above problem can occur.

Further, as shown in FIG. 21, even if the third insulating layer 6i is formed on the second gate electrode 16gA, the second gate electrode 16gA and the counter electrode 34 can be electrically connected by the conductive particles 62. there were. The third insulating layer 6i is a dielectric layer provided, for example, for forming an auxiliary capacitance, and may be relatively thin, for example, 10 nm to 300 nm. Even when the second gate electrode 16gA is covered with the third insulating layer 6i, the conductive particles 62 partially penetrate the third insulating layer 6i, and the conductive particles 62 and the second gate electrode 16gA are electrically connected. Can be connected to each other.

As described above, the problem that the reliability of the liquid crystal display device 900 of the comparative example is lowered is caused by the fact that the frame region is further narrowed compared to the conventional liquid crystal display device and the back gate TFT is used as the driving TFT. It is a problem.

Hereinafter, a display device according to an embodiment of the present invention will be described with reference to the drawings. In addition, this invention is not restricted to embodiment illustrated below. In the following drawings, components having substantially the same function are denoted by common reference numerals, and description thereof may be omitted.

(Embodiment 1)
A liquid crystal display device 100 according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 3 are a cross-sectional view and a plan view schematically showing the liquid crystal display device 100. FIG. FIG. 1A is a cross-sectional view schematically showing a frame region 100f of the liquid crystal display device 100 along the 1At-1At ′ line and the 1Ad-1Ad ′ line in FIG. FIG. 1B is a cross-sectional view schematically showing the display region 100d of the liquid crystal display device 100 along the line 1b-1b ′ in FIG.

As shown in FIGS. 1A and 1B, a liquid crystal display device 100 includes an active matrix substrate 10, a counter substrate 30 disposed so as to face the active matrix substrate 10, and the active matrix substrate 10 and the counter substrate. 30 and a liquid crystal layer 50 provided between 30. The liquid crystal display device 100 includes a plurality of pixels arranged in a matrix having a plurality of rows and a plurality of columns. The liquid crystal display device 100 includes a display area 100d defined by a plurality of pixels, and a frame area 100f around the display area 100d.

The frame region 100f includes a seal portion 60s that surrounds the display region 100d, a transition portion 60t that electrically connects the active matrix substrate 10 and the counter substrate 30 by the conductive particles 62, and a drive circuit portion 60d that includes the drive TFT 11A. including. As shown in FIG. 1, the seal portion 60s is provided overlapping the drive circuit portion 60d.

In the transfer portion 60t, the active matrix substrate 10 has a contact electrode 64 provided in the frame region 100f, and the counter substrate 30 has a counter electrode 34 including a portion facing the contact electrode 64. The transition part 60 t electrically connects the contact electrode 64 and the counter electrode 34.

The active matrix substrate 10 includes a drive TFT 11A provided in the frame region 100f, and a substrate (for example, a glass substrate) 1s that supports the drive TFT 11A.

The driving TFT 11A includes a semiconductor layer 15A, a first gate electrode 12gA, a source electrode 14sA and a drain electrode 14dA, and a second gate electrode 16gA.

The semiconductor layer 15A includes a channel region 15cA, a source region 15sA, and a drain region 15dA. Of the semiconductor layer 15A, a region in contact with the source electrode 14sA is called a source region 15sA, and a region in contact with the drain electrode 14dA is called a drain region 15dA. A region of the semiconductor layer 15A that overlaps with the first gate electrode 12gA and is located between the source region 15sA and the drain region 15dA is called a channel region 15cA.

The first gate electrode 12gA overlaps the channel region 15cA of the semiconductor layer 15A via the first insulating layer 2i and is located between the semiconductor layer 15A and the substrate 1s.

The source electrode 14sA and the drain electrode 14dA are electrically connected to the source region 15sA and the drain region 15dA of the semiconductor layer 15A, respectively.

The second gate electrode 16gA overlaps the channel region 15cA of the semiconductor layer 15A via the second insulating layer 4i, and is located on the opposite side of the semiconductor layer 15A from the first gate electrode 12gA. For example, the second gate electrode 16gA is electrically connected to the source electrode 14sA. The second gate electrode 16gA may be called a back gate electrode. The drive TFT 11A may be called a back gate TFT having a back gate electrode.

The active matrix substrate 10 has an insulating member 19 provided on the driving TFT 11A in the frame region 100f and covering the second gate electrode 16gA. The active matrix substrate 10 has a protruding structure protruding toward the counter substrate 30 in the display region 100d. In the example shown in FIG. 1, the protruding structure is a first columnar spacer 23a or a second columnar spacer 23b. The insulating member 19 is formed of the same dielectric film as the protruding structure (the first columnar spacer 23a or the second columnar spacer 23b).

Since the driving TFT 11A includes the second gate electrode 16gA that functions as a back gate electrode, fluctuations in the electrical characteristics of the driving TFT 11A are suppressed. Thereby, the fall of the reliability of the liquid crystal display device 100 is suppressed. Since the liquid crystal display device 100 includes the insulating member 19 that covers the second gate electrode 16gA, the second gate electrode 16gA and the counter electrode 34 included in the counter substrate 30 are electrically connected by the conductive particles 62. Can be prevented. Accordingly, malfunction of the driving TFT 11A is suppressed, so that the liquid crystal display device 100 has excellent reliability. Further, since the seal portion 60s and / or the transition portion 60t and the driving TFT 11A can be provided close to each other, the area of the frame region 100f can be reduced. Since the insulating member 19 is formed of the same dielectric film as the protruding structure of the active matrix substrate 10 in the display region 100d, the liquid crystal display has a narrow frame and excellent reliability without increasing the number of manufacturing steps. A device is obtained.

The insulating member 19 may be in direct contact with the second gate electrode 16gA to cover the second gate electrode 16gA, or may cover the second gate electrode 16gA with another layer interposed therebetween. The insulating member 19 covering the second gate electrode 16gA means a state in which all of the second gate electrode 16gA overlaps with the insulating member 19 when viewed from the normal direction of the active matrix substrate 10. For example, in the example shown in FIG. 1, the third insulating layer 6i is provided on the second gate electrode 16gA, and the insulating member 19 covers the second gate electrode 16gA via the third insulating layer 6i. The insulating member 19 prevents the conductive particles 62 from breaking through the third insulating layer 6i, thereby preventing the second gate electrode 16gA and the counter electrode 34 from being electrically connected by the conductive particles 62. it can. The shape and size of the insulating member 19 are not particularly limited as long as it covers the second gate electrode 16gA. For example, the insulating member 19 may cover the entire driving TFT 11A. That is, when viewed from the normal direction of the active matrix substrate 10, the entire driving TFT 11 </ b> A may overlap with the insulating member 19.

The first columnar spacer 23 a is a spacer that defines the distance between the active matrix substrate 10 and the counter substrate 30. That is, the first columnar spacer 23 a controls the thickness of the liquid crystal layer 50 (sometimes referred to as “cell gap”). The second columnar spacer 23b is a spacer lower than the first columnar spacer 23a. The first columnar spacers 23 a are in contact with the counter substrate 30, and the second columnar spacers 23 b are not in contact with the counter substrate 30. The first columnar spacers 23a are also called “main spacers”, and the second columnar spacers 23b are also called “subspacers”. For example, the second columnar spacer 23b is formed of the same dielectric film as the first columnar spacer 23a. The second columnar spacer 23b may be formed of a dielectric film different from the first columnar spacer 23a.

Although the second columnar spacer 23b can be omitted, the following effects can be obtained by having the second columnar spacer 23b in addition to the first columnar spacer 23a. In the conventional liquid crystal display device, when the arrangement density of columnar spacers (the number of columnar spacers per unit area) is increased in order to improve load bearing characteristics, there is a problem that low-temperature foaming is likely to occur. In the liquid crystal display device 100, as shown in FIG. 1, since the cell gap is basically controlled only by the first columnar spacers 23a, the effective spacer density is defined only by the first columnar spacers 23a. Therefore, the cell gap can easily follow the contraction of the liquid crystal layer 50, and the occurrence of low temperature foaming can be suppressed. Further, when a load is applied to the liquid crystal display device 100 and the cell gap becomes narrow, both the substrates are supported by both the first columnar spacer 23a and the second columnar spacer 23b (the effective spacer density at this time is the columnar shape). Therefore, a high load resistance characteristic can be realized.

The insulating member 19 is formed in the same manufacturing process as the protruding structure (the first columnar spacer 23a or the second columnar spacer 23b). The height h19 of the insulating member 19 may be substantially the same as the height of the protruding structure (the height h23a of the first columnar spacer 23a or the height h23b of the second columnar spacer 23b). Details of the manufacturing process of the liquid crystal display device 100 will be described later.

The height h <b> 19 of the insulating member 19 is not limited to the above example, and may be as long as the second gate electrode 16 g </ i> A and the counter substrate 30 can be prevented from being electrically connected by the conductive particles 62. Good. The height h19 of the insulating member 19 is preferably larger than half of the average particle diameter of the conductive particles 62, for example. The insulating member 19 may be in contact with the counter substrate 30 or may not be in contact with the counter substrate 30.

The conductive particles 62 are, for example, metal particles (for example, gold (Au), silver (Ag), nickel (Ni)), resin particles subjected to metal plating (for example, Ni plating), carbon particles, or transparent conductive particles (for example, ITO). The particle size of the conductive particles 62 is, for example, 0.1 μm to 10 μm. The conductive particles 62 are included in, for example, a transition material that forms the transition portion 60t. The conductive particles 62 may be included in a sealing material that forms the seal portion 60s. The conductive particles 62 may be included in both the sealing material and the transition material. The seal portion 60s and the transition portion 60t may be integrally formed from the same resin material.

For example, the same resin material can be used for the sealing material and the transition material. As the sealing material and the transition material, for example, a photo-curing resin (including those that use thermosetting together) is widely used. Note that the sealing material and the transition material are not limited to the ultraviolet curable resin, and a resin curable with light of other wavelengths (for example, visible light) may be used, and various photocurable resins can be suitably used. . In addition, the photo-curable resin includes a resin that allows a curing reaction to proceed by irradiating with light of a predetermined wavelength, and that can be further thermally cured after photo-curing. By using thermosetting together, the physical properties (hardness and elastic modulus) of the cured product are generally improved. Furthermore, you may mix the particle | grains (filler (filler)) for providing a scattering property with a sealing material and a transfer material with a photocurable resin, respectively. Since the sealing material and the transition material in which particles are dispersed scatter or diffusely reflect light, an effect of spreading the light over a wider portion in the sealing material or the transition material can be obtained.

The seal portion 60 s may further include a first granular spacer 66 a that defines the distance between the active matrix substrate 10 and the counter substrate 30. The first granular spacer 66a is included in, for example, a sealing material. The first granular spacer 66a may be included in the sealing material and / or the transition material.

As described above, since the driving TFT 11A includes the second gate electrode 16gA that functions as a back gate electrode, variation in characteristics of the TFT is suppressed. As will be described later, the third conductive layer 16 including the second gate electrode 16gA is formed of, for example, a transparent conductive film. The second gate electrode 16gA may be made of, for example, a metal material. Since the second gate electrode 16gA formed of a metal material also functions as a light shielding film for the channel region 15cA of the semiconductor layer 15A, the shift of the threshold voltage Vth of the driving TFT 11A can be more effectively suppressed. As illustrated in FIG. 1, the second gate electrode 16gA of the drive TFT 11A is electrically connected to the source electrode 14sA of the drive TFT 11A. For example, the second gate electrode 16gA is in contact with the source electrode 14sA in the opening CH2 provided in the second insulating layer 4i. When the second gate electrode 16gA is electrically connected to the source electrode 14sA, the potential of the second gate electrode 16gA is fixed to a predetermined value, so that the threshold voltage Vth of the driving TFT 11A is shifted or driven. It can suppress that the hysteresis of TFT11A becomes large. Thereby, the characteristic variation of the driving TFT 11A is suppressed, and the variation in the characteristics of the driving TFT 11A can be reduced.

The second gate electrode 16gA may be electrically connected to an arbitrary electrode or wiring. When the electrode or wiring electrically connected to the second gate electrode 16gA is fixed at a predetermined potential, the same effect as described above can be obtained. However, the electrical connection of the second gate electrode 16gA is not limited to this. For example, the second gate electrode 16gA may be electrically connected to the first gate electrode 12gA. By applying a gate voltage to both the first gate electrode 12gA and the second gate electrode 16gA, the apparent mobility of the semiconductor layer 15A can be improved, and the effect of reducing power consumption and / or narrowing the drive circuit portion 60d is effective. Can be done automatically. For example, the second gate electrode 16gA may be electrically connected to the drain electrode 14dA. When the second gate electrode 16gA is electrically connected to the drain electrode 14dA, the threshold voltage Vth of the driving TFT 11A can be changed depending on the value of the voltage applied to the drain electrode 14dA.

As described above, the insulating member 19 is formed of the same dielectric film as the protruding structure of the active matrix substrate 10 in the display region 100d. Here, the protruding structure is not limited to the illustrated

columnar spacers

23a and 23b. Any protrusion structure that protrudes toward the counter substrate 30 in the active matrix substrate 10 in the display region 100d may be used. For example, the protrusion structure may be an alignment control structure that defines the alignment state of the liquid crystal. The insulating member 19 is not limited to the protruding structure, and may be formed of the same dielectric film as the layer of the active matrix substrate 10 in the display region 100d. For example, as will be described later with reference to FIG. 20, the insulating member 19 may be formed of the same dielectric film as the color filter layer included in the active matrix substrate 10 in the display region 100d.

Since the insulating member 19 covers the second gate electrode 16gA, in the liquid crystal display device 100, the parasitic capacitance formed between the second gate electrode 16gA and the counter electrode 34 in the liquid crystal display device 900 of the comparative example. It can be reduced compared to. This is because the insulating member 19 can have a lower relative dielectric constant than the seal portion 60s. The seal portion 60s and the insulating member 19 are both formed of, for example, an organic insulating film, and the seal material forming the seal portion 60s is typically filled with a filler. The filler is typically an inorganic insulating powder, for example, a silica powder. In general, since the relative dielectric constant of an inorganic insulator tends to be higher than the relative dielectric constant of an organic insulator, the liquid crystal display device 100 having the insulating member 19 is formed between the second gate electrode 16gA and the counter electrode 34. The parasitic capacitance that is done can be reduced.

In the liquid crystal display device 100, as described above, the active matrix substrate 10 includes the insulating member 19 and the protruding structure. By providing the insulating member 19 and the protruding structure on the active matrix substrate 10 side, the following effects can be further obtained.

Since the insulating member 19 covers the second gate electrode 16gA of the driving TFT 11A, the driving TFT 11A can be effectively protected from moisture contained in the seal portion 60s. In particular, moisture can be prevented from entering the channel region 15cA of the semiconductor layer 15A. In addition, for example, in the process of curing the sealing material, it is possible to reduce the incidence of ultraviolet rays that are irradiated on the sealing material and scattered by the filler included in the sealing material to the channel region 15cA of the semiconductor layer 15A. These effects can prevent characteristic fluctuations and / or malfunctions of the driving TFT 11A, so that the reliability can be improved more effectively.

Further, by providing the active matrix substrate 10 with the first columnar spacers 23a that define the distance between the active matrix substrate 10 and the counter substrate 30, it is possible to suppress cell gap variations. When the first columnar spacers 23a are provided on the counter substrate 30, when the film thickness varies in the manufacturing process of the active matrix substrate 10, the film thickness variation of the active matrix substrate 10 is reflected in the cell gap. Obtained. On the other hand, when the first columnar spacers 23a are provided on the active matrix substrate 10, the film thickness varies in the steps up to the step of providing the first columnar spacers 23a during the manufacturing process of the active matrix substrate 10. Even in this case, the cell gap can be controlled by aligning the height h23a of the first columnar spacers 23a.

Furthermore, the insulating member 19 can prevent the characteristic variation and / or malfunction of the driving TFT 11A by reducing the influence on the driving TFT 11A when stress is applied to the liquid crystal display device 100 from the outside. Therefore, for example, this embodiment is also suitable for a flexible display device. The stress applied to the driving TFT 11A can also be caused by a change in the environment (for example, temperature and humidity) in which the display device is used.

Hereinafter, the structure of the liquid crystal display device 100 will be described in more detail.

As shown in FIG. 1, the active matrix substrate 10 includes a substrate 1s, a first conductive layer 12 including a first gate electrode 12gA, a first insulating layer 2i, a semiconductor layer 15A, a source electrode 14sA, and a second electrode including a drain electrode 14dA. The third conductive layer 16 including the conductive layer 14, the second insulating layer 4i, and the second gate electrode 16gA is provided. The active matrix substrate 10 further includes a third insulating layer 6 i and a fourth conductive layer 18.

The active matrix substrate 10 has a pixel TFT 11B in the display area 100d as shown in FIG. The pixel TFT 11B includes a semiconductor layer 15B including a channel region 15cB, a source region 15sB, and a drain region 15dB, a gate electrode 12gB that overlaps the channel region 15cB of the semiconductor layer 15B via the first insulating layer 2i, and a source region of the semiconductor layer 15B. A source electrode 14sB and a drain electrode 14dB are electrically connected to 15sB and the drain region 15dB, respectively.

The first conductive layer 12 is provided on the substrate 1s. The first conductive layer 12 includes a first gate electrode 12gA of the driving TFT 11A, a gate electrode 12gB of the pixel TFT 11B, and a gate wiring G. The first conductive layer 12 may have a single layer structure or a stacked structure in which a plurality of layers are stacked. The first conductive layer 12 includes at least a layer formed of a metal material. When the 1st conductive layer 12 is a laminated structure, a part layer may be formed from the metal nitride and the metal oxide.

The first insulating layer (gate insulating layer) 2 i is provided on the first conductive layer 12. That is, the first insulating layer 2i is formed so as to cover the first gate electrode 12gA, the gate electrode 12gB, and the gate wiring G. The first insulating layer 2i is formed from an inorganic insulating material.

The semiconductor layers 15A and 15B are provided on the first insulating layer 2i. The semiconductor layers 15A and 15B are formed from a common semiconductor film, for example. As described above, the semiconductor layer 15A of the driving TFT 11A includes the channel region 15cA, the source region 15sA, and the drain region 15dA. The semiconductor layer 15B of the pixel TFT 11B includes a first portion 15aB that overlaps the gate electrode 12gB, and a second portion 15bB that extends from the first portion 15aB across the edge of the gate electrode 12gB on the drain electrode 14dB side. The first portion 15aB includes a channel region 15cB, a source region 15sB, and a drain region 15dB.

The second conductive layer 14 is provided on the semiconductor layers 15A and 15B. The second conductive layer 14 includes a source electrode 14sA and a drain electrode 14dA of the driving TFT 11A, a source electrode 14sB and a drain electrode 14dB of the pixel TFT 11B, and a source wiring S. The second conductive layer 14 may have a single layer structure or a stacked structure in which a plurality of layers are stacked. The second metal layer 14 includes at least a layer formed of a metal material. When the second conductive layer 14 has a laminated structure, some layers may be formed from a metal nitride or a metal oxide. Since the first conductive layer 12 and the second conductive layer 14 including a layer formed from a metal material are generally more conductive than a conductive layer formed from a transparent conductive material, the width of the wiring can be reduced. This is possible, and can contribute to higher definition and improved pixel aperture ratio.

The second insulating layer (interlayer insulating layer) 4 i is provided on the second conductive layer 14. The second insulating layer 4i is formed from an inorganic insulating material.

In the second insulating layer 4i, an opening CH2 provided in the drive circuit unit 60d and an opening CH3 provided in the display region 100d are formed. The opening CH2 overlaps the source electrode 14sA when viewed from the normal direction of the active matrix substrate 10. The opening CH3 overlaps the second portion 15bB of the semiconductor layer 15B when viewed from the normal direction of the active matrix substrate 10. The opening CH3 also overlaps with the end 14de of the drain electrode 14dB on the second portion 15bB side when viewed from the normal direction of the active matrix substrate 10. That is, the opening CH3 is formed so that the end 14de of the drain electrode 14dB and the second portion 15bB of the semiconductor layer 15B are exposed.

The third conductive layer 16 is provided on the second insulating layer 4i. The third conductive layer 16 is made of, for example, a transparent conductive material. The third conductive layer 16 may be referred to as the first transparent electrode layer 16. The third conductive layer 16 includes a second gate electrode 16gA of the driving TFT 11A and a pixel electrode 16B of the pixel TFT 11B. The second gate electrode 16gA is in contact with the source electrode 14sA in the opening CH2. The pixel electrode 16B is in contact with the second portion 15bB of the semiconductor layer 15B in the opening CH3. The pixel TFT 11B and the pixel electrode 16B are provided for each pixel. That is, each pixel is defined by each pixel electrode 16B.

The third insulating layer (auxiliary capacitor insulating layer) 6 i covers the third conductive layer 16. The third insulating layer 6i is formed from an inorganic insulating material.

The fourth conductive layer 18 is provided on the third insulating layer 6i. The fourth conductive layer 18 is made of, for example, a transparent conductive material. The fourth conductive layer 18 may be referred to as the second transparent electrode layer 18. The fourth conductive layer 18 includes an electrode 18B that is not electrically connected to the pixel electrode 16B. This electrode 18B functions as a common electrode, for example. The common electrode 18B is opposed to the pixel electrode 16B via the third insulating layer 6i, and the pixel electrode 16B and the common electrode 18B, and the third insulating layer 6i positioned therebetween constitute an auxiliary capacitor. Yes. For example, at least one slit (not shown) is formed in the common electrode 18B. An alignment film (not shown) is provided on the common electrode 18B. The active matrix substrate 10 having the above-described configuration is suitably used for the liquid crystal display device 100 in FFS (Fringe Field Switching) mode.

In the pixel TFT 11B shown in FIG. 1, the opening CH3 overlaps the end portion 14de of the drain electrode 14dB on the second portion 15bB side and the second portion 15bB of the semiconductor layer 15B when viewed from the normal direction of the substrate 1s. Therefore, a part of the opening CH3 can be a light transmission region that is not shielded by either the gate electrode 12gB or the drain electrode 14dB. Since the second insulating layer (interlayer insulating layer) 4i is formed of an inorganic insulating material, that is, does not include an organic insulating layer, the opening CH3 is relatively shallow. Accordingly, the disturbance in the liquid crystal alignment due to the opening CH3 is small, and the light leakage in the vicinity of the opening CH3 is small. Therefore, even if the above-described light transmission region is provided, the display is not adversely affected. In this way, by using a part of the opening CH3 as a light transmission region, it is possible to increase the light use efficiency.

Note that the structures of the drive TFT 11A and the pixel TFT 11B of the present embodiment are not limited to those illustrated. For example, the back gate electrode (second gate electrode) 16 gA may be formed of the same conductive film as the fourth conductive layer 18. Modification examples will be described later with reference to FIGS. The driving TFT 11A can have various known back gate TFT structures, and the pixel TFT 11B can have various known TFT structures.

The driving TFT 11A and the pixel TFT 11B of the present embodiment are not limited to the channel etch type TFTs exemplified. Each of the driving TFT 11A and the pixel TFT 11B may be an etch stop type TFT. In the “channel etch type TFT”, the etch stop layer is not formed on the channel region, and the end portions on the channel side of the source and drain electrodes are arranged in contact with the upper surface of the semiconductor layer. The channel etch type TFT is formed, for example, by forming a conductive film for a source / drain electrode on a semiconductor layer and performing source / drain separation. In the source / drain separation step, the surface portion of the channel region may be etched. On the other hand, in a TFT (etch stop type TFT) in which an etch stop layer is formed on the channel region, the channel-side end portions of the source and drain electrodes are located on the etch stop layer, for example. For example, an etch stop type TFT is formed by forming an etch stop layer that covers a portion of a semiconductor layer that becomes a channel region, and then forming a conductive film for a source / drain electrode on the semiconductor layer and the etch stop layer. Formed by performing separation.

As shown in FIG. 1, the counter substrate 30 includes, for example, a substrate (for example, a glass substrate) 31, a color filter layer 32 (including a color filter and a black matrix) provided on the substrate 31, and a color filter layer 32. The overcoat layer 33 is covered, and the counter electrode 34 is provided on the overcoat layer 33. In the frame region 100f, the color filter layer 32 may not include a color filter. In FIG. 1, the counter electrode 34 is omitted in the display area 100d, but the counter substrate 30 includes the counter electrode 34 in the display area 100d and the frame area 100f, for example.

In the VA mode liquid crystal display device 100, the counter electrode 34 can function as a common electrode. When the FFS mode liquid crystal display device 100 is applied to a touch panel, the counter electrode 34 can be used as a detection electrode or a drive electrode of the touch panel. In the case where the VA mode liquid crystal display device 100 is applied to a touch panel, the counter electrode 34 functioning as a common electrode can also serve as a detection electrode or a drive electrode of the touch panel.

The transition part 60t of the liquid crystal display device 100 electrically connects the contact electrode 64 and the counter electrode 34 by the conductive particles 62 as described above. As shown in FIG. 1, the active matrix substrate 10 has a contact electrode 64 at the transition portion 60 t. Further, in the transition portion 60t, the active matrix substrate 10 further includes the first conductive layer 12, the second conductive layer 14, and the third conductive layer 16, and the contact electrode 64 has the same conductivity as the fourth conductive layer 18. It is formed from a film. The transition portion further includes an opening CH1 provided in the first insulating layer 2i and the second insulating layer 4i. The opening CH1 electrically connects the first conductive layer 12, the second conductive layer 14, the third conductive layer 16, and the contact electrode 64 to each other. The third conductive layer 16 is in contact with the contact electrode 64 in the opening CH1.

The structure of the transfer portion 60t is not limited to the example shown in FIG. For example, the contact electrode 64 only needs to be formed of the same conductive film as any one of the first conductive layer 12, the second conductive layer 14, the third conductive layer 16, and the fourth conductive layer 18. Alternatively, the contact electrode 64 only needs to be electrically connected to the first conductive layer 12 and / or the second conductive layer 14. In the transition portion 60t, the active matrix substrate 10 only needs to have a contact electrode 64 electrically connected to the counter substrate 30 via the conductive particles 62, and a conductive layer that does not include the contact electrode 64 (example of FIG. 1). Then, the first conductive layer 12, the second conductive layer 14, and the third conductive layer 16) need not be provided. The contact portion (opening) that electrically connects the contact electrode 64 and another conductive layer may be provided in the transition portion 60t, or provided in a region other than the transition portion 60t in the frame region 100f. May be.

Subsequently, a method for manufacturing the liquid crystal display device 100 will be described with reference to FIGS. 4 to 10 are process cross-sectional views schematically showing the manufacturing process of the liquid crystal display device 100, respectively. 4 to 10, (a) shows the process of manufacturing the frame area 100f, and (b) shows the process of manufacturing the display area 100d.

First, as shown in FIG. 4, the first conductive layer 12 including the first gate electrodes 12gA and 12gB of the driving TFT 11A and the pixel TFT 11B is formed on a substrate (for example, a glass substrate) 1s. Specifically, after depositing a first conductive film on the substrate 11, the first conductive layer 12 is formed by patterning the first conductive film. As a material of the first conductive film, for example, aluminum (Al), chromium (Cr), copper (Cu), tantalum (Ta), titanium (Ti), molybdenum (Mo), tungsten (W), or these Alloys can be used. The first conductive film may have a single layer structure or a stacked structure in which a plurality of layers are stacked. For example, a laminate of Ti / Al / Ti (upper layer / intermediate layer / lower layer) or a laminate of Mo / Al / Mo can be used. The stacked structure of the first conductive film is not limited to a three-layer structure, and may be a two-layer structure or a stacked structure of four or more layers. Furthermore, the first conductive film only needs to include at least a layer formed of a metal material. When the first conductive film has a stacked structure, some layers are formed of metal nitride or metal oxide. May be. Here, after forming the first conductive film by successively depositing a TaN layer having a thickness of 5 nm to 100 nm and a W layer having a thickness of 50 nm to 500 nm by, for example, sputtering, the first conductive film is formed. The first conductive layer 12 is formed by patterning one conductive film by a photolithography process.

Next, a first insulating layer (gate insulating layer) 2 i is formed on the first conductive layer 12. The first insulating layer 2i includes, for example, a silicon dioxide (SiO ₂ ) film, a silicon nitride (SiN _x ) film, a silicon oxynitride (SiO _x N _y (x> y)) film, and a silicon nitride oxide (SiN _x O _y (SiN _x O _y ( x> y)) film, aluminum oxide film or tantalum oxide film, or a laminated film thereof. Here, the first insulating layer 2i is formed by successively depositing a SiN _x film having a thickness of 100 nm to 500 nm and a SiO ₂ film having a thickness of 20 nm to 100 nm by, for example, CVD (Chemical Vapor Deposition). Form.

Subsequently, as shown in FIG. 5, the semiconductor layers 15A and 15B of the driving TFT 11A and the pixel TFT 11B are formed on the first insulating layer 2i. Specifically, after depositing a semiconductor film on the first insulating layer 2i, the semiconductor film is patterned to form island-shaped

semiconductor layers

15A and 15B. Here, after depositing an In—Ga—Zn—O-based semiconductor film having a thickness of 20 nm to 200 nm, the semiconductor layers 15A and 15B are formed by patterning the semiconductor film by a photolithography process.

The semiconductor layers 15A and 15B are, for example, oxide semiconductor layers. The oxide semiconductor included in the semiconductor layers 15A and 15B may be an amorphous oxide semiconductor or a crystalline oxide semiconductor having a crystalline portion. Examples of the crystalline oxide semiconductor include a polycrystalline oxide semiconductor, a microcrystalline oxide semiconductor, and a crystalline oxide semiconductor in which the c-axis is oriented substantially perpendicular to the layer surface.

The semiconductor layers 15A and 15B may have a laminated structure of two or more layers. When the semiconductor layers 15A and 15B have a stacked structure, the semiconductor layers 15A and 15B may include an amorphous oxide semiconductor layer and a crystalline oxide semiconductor layer. Alternatively, a plurality of crystalline oxide semiconductor layers having different crystal structures may be included. When the semiconductor layers 15A and 15B have a two-layer structure including an upper layer and a lower layer, the energy gap of the oxide semiconductor included in the upper layer is preferably larger than the energy gap of the oxide semiconductor included in the lower layer. However, when the difference in energy gap between these layers is relatively small, the energy gap of the lower oxide semiconductor may be larger than the energy gap of the upper oxide semiconductor.

The material, structure, film forming method, and structure of an oxide semiconductor layer having a stacked structure of the amorphous oxide semiconductor and each crystalline oxide semiconductor described above are described in, for example, Japanese Patent Application Laid-Open No. 2014-007399. . For reference, the entire disclosure of Japanese Patent Application Laid-Open No. 2014-007399 is incorporated herein by reference.

The semiconductor layers 15A and 15B may contain at least one metal element of In, Ga, and Zn, for example. In the present embodiment, the semiconductor layers 15A and 15B include, for example, an In—Ga—Zn—O based semiconductor. Here, the In—Ga—Zn—O-based semiconductor is a ternary oxide of In (indium), Ga (gallium), and Zn (zinc), and a ratio (composition ratio) of In, Ga, and Zn. Is not particularly limited, and includes, for example, In: Ga: Zn = 2: 2: 1, In: Ga: Zn = 1: 1: 1, In: Ga: Zn = 1: 1: 2, and the like.

Such semiconductor layers

15A and 15B can be formed of an oxide semiconductor film containing an In—Ga—Zn—O-based semiconductor. Note that a channel-etch TFT having an active layer containing an In—Ga—Zn—O-based semiconductor may be referred to as a “CE-InGaZnO-TFT”.

The In—Ga—Zn—O-based semiconductor may be amorphous or crystalline. As the crystalline In—Ga—Zn—O-based semiconductor, a crystalline In—Ga—Zn—O-based semiconductor in which the c-axis is oriented substantially perpendicular to the layer surface is preferable.

Note that the crystal structure of a crystalline In—Ga—Zn—O-based semiconductor is disclosed in, for example, the above-described Japanese Patent Application Laid-Open Nos. 2014-007399, 2012-134475, and 2014-209727. ing. For reference, the entire contents disclosed in Japanese Patent Application Laid-Open Nos. 2012-134475 and 2014-209727 are incorporated herein by reference. A TFT having an In—Ga—Zn—O-based semiconductor layer has high mobility (more than 20 times that of an a-Si TFT) and low leakage current (less than one hundredth of that of an a-Si TFT). It is suitably used as a drive TFT and a pixel TFT.

The semiconductor layers 15A and 15B may include another oxide semiconductor instead of the In—Ga—Zn—O-based semiconductor. For example, an In—Sn—Zn—O-based semiconductor (eg, In ₂ O ₃ —SnO ₂ —ZnO) may be included. The In—Sn—Zn—O-based semiconductor is a ternary oxide of In (indium), Sn (tin), and Zn (zinc). Alternatively, the semiconductor layers 15A and 15B may be made of an In—Al—Zn—O based semiconductor, an In—Al—Sn—Zn—O based semiconductor, a Zn—O based semiconductor, an In—Zn—O based semiconductor, or a Zn—Ti—O semiconductor. Semiconductor, Cd—Ge—O semiconductor, Cd—Pb—O semiconductor, CdO (cadmium oxide), Mg—Zn—O semiconductor, In—Ga—Sn—O semiconductor, In—Ga—O semiconductor In addition, a Zr—In—Zn—O based semiconductor, an Hf—In—Zn—O based semiconductor, or the like may be included.

Next, an opening 2a for electrically connecting the first conductive layer 12 and the second conductive layer 14 is formed in the first insulating layer 2i in the frame region 100f. Specifically, the first insulating layer 2i is patterned so that the first conductive layer 12 is exposed.

Next, as shown in FIG. 6, the second conductive layer including the source electrode 14sA and the drain electrode 14dA of the driving TFT 11A, the source electrode 14sB and the drain electrode 14dB of the pixel TFT 11B, and the source wiring S on the semiconductor layers 15A and 15B. 14 is formed. Specifically, after forming the second conductive film on the semiconductor layers 15A and 15B, the second conductive layer 14 is formed by patterning the second conductive film. As a material of the second conductive film, for example, aluminum (Al), chromium (Cr), copper (Cu), tantalum (Ta), titanium (Ti), molybdenum (Mo) or tungsten (W), or these These alloys can be used. The second conductive film may have a single layer structure or a stacked structure in which a plurality of layers are stacked. For example, a laminate of Ti / Al / Ti (upper layer / intermediate layer / lower layer) or a laminate of Mo / Al / Mo can be used. The stacked structure of the second conductive film is not limited to a three-layer structure, and may be a two-layer structure or a stacked structure of four or more layers. Further, the second conductive film only needs to include at least a layer formed of a metal material. When the second conductive film has a stacked structure, some layers are formed of metal nitride or metal oxide. May be. Here, a Ti layer having a thickness of 10 nm to 100 nm, an Al layer having a thickness of 50 nm to 400 nm, and a Ti layer having a thickness of 50 nm to 300 nm are successively deposited by sputtering, for example. After the second conductive film is formed, the second conductive layer 14 is formed by patterning the second conductive film by a photolithography process.

Subsequently, as shown in FIG. 7, a second insulating layer 4 i is formed on the second conductive layer 14. Further, an opening 4a is formed by patterning in a region of the second insulating layer 4i corresponding to the opening 2a of the first insulating layer 2i. That is, a part of the second insulating layer 4i is removed so that the second conductive layer 14 is exposed. Further, an opening CH2 for electrically connecting the source electrode 14sA of the driving TFT 11A and the second gate electrode 16gA is formed in the second insulating layer 4i of the driving circuit unit 60d. Further, an opening CH3 is formed in the second insulating layer 4i in the display region 100d by patterning. The opening CH3 is formed by removing a part of the second insulating layer 4i so that a part of the drain electrode 14dB of the pixel TFT 11B and a part of the semiconductor layer 15B are exposed. The second insulating layer 4i is, for example, a silicon dioxide (SiO ₂ ) film, a silicon nitride (SiN _x ) film, a silicon oxynitride (SiO _x N _y (x> y)) film, or a silicon nitride oxide (SiN _x O _y (SiN _x O _y ( x> y)) film, aluminum oxide film or tantalum oxide film, or a laminated film thereof. Here, after depositing a SiO ₂ film having a thickness of 50 nm to 500 nm, the SiO ₂ film is heat-treated at 200 ° C. to 400 ° C. for 0.5 hours to 4 hours in an air atmosphere, and then 50 nm A SiN _x film having a thickness of ˜500 nm is deposited, and these stacked films are used as the second insulating layer 4i.

Next, as shown in FIG. 8, a third conductive layer (first transparent electrode layer) 16 including the second gate electrode 16gA of the driving TFT 11A and the pixel electrode 16B of the pixel TFT 11B is formed on the second insulating layer 4i. . Specifically, after depositing a third conductive film on the second insulating layer 4i, the third conductive layer 16 is formed by patterning the third conductive film. At this time, patterning is performed so that the third conductive layer 16 is in contact with the second conductive layer 14 in the opening 4a. Patterning is performed so that the second gate electrode 16gA of the driving TFT 11A is in contact with the source electrode 14sA in the opening CH2. Further, patterning is performed so that the pixel electrode 16B of the pixel TFT 11B is in contact with the drain electrode 14dB and the second portion 15bB of the semiconductor layer 15B in the opening CH3. As the material of the third conductive film, various transparent conductive materials can be used, and for example, metal oxides such as ITO, IZO, and ZnO can be used. Here, a third conductive film is formed by depositing a metal oxide film having a thickness of 20 nm to 300 nm by, for example, a sputtering method, and then the third conductive film is patterned by a photolithography process to form the third conductive film. A conductive layer 16 is formed.

Subsequently, as shown in FIG. 9, a third insulating layer (auxiliary capacitor insulating layer) 6 i is formed on the third conductive layer 16. In the region of the third insulating layer 6i corresponding to the opening 4a of the second insulating layer 4i, the opening 6a is formed by patterning. That is, a part of the third insulating layer 6i is removed so that the third conductive layer 16 is exposed. The third insulating layer 6i includes, for example, a silicon dioxide (SiO ₂ ) film, a silicon nitride (SiN _x ) film, a silicon oxynitride (SiO _x N _y (x> y)) film, and a silicon nitride oxide (SiN _x O _y (SiN _x O _y ( x> y)) film, aluminum oxide film or tantalum oxide film, or a laminated film thereof. Here, as the third insulating layer 6i, a SiN _x film having a thickness of 50 nm to 500 nm is deposited by, for example, CVD.

Thereafter, as shown in FIG. 10, a fourth conductive layer (second transparent electrode layer) 18 including the contact electrode 64 and the common electrode (transparent electrode) 18B of the pixel TFT 11B is formed on the third insulating layer 6i. Specifically, after depositing a fourth conductive film on the third insulating layer 6i, the fourth conductive layer 18 is formed by patterning the fourth conductive film. At this time, patterning is performed so that the contact electrode 64 is in contact with the third conductive layer 16 in the opening 6a. An opening CH1 (see FIG. 1) is formed by the

openings

2a, 4a, and 6a. As the material of the fourth conductive film, various transparent conductive materials can be used, and for example, metal oxides such as ITO, IZO, ZnO, and the like can be used. Here, a fourth conductive film is formed by depositing a metal oxide film having a thickness of 20 nm to 300 nm by, for example, a sputtering method, and then the fourth conductive film is patterned by a photolithography process to form the fourth conductive film. A conductive layer 18 is formed.

Next, the first columnar spacer 23 a, the second columnar spacer 23 b, and the insulating member 19 are formed on the fourth conductive layer 18. Specifically, after the dielectric film is deposited on the fourth conductive layer 18, the

spacers

23a and 23b and the insulating member 19 are formed by patterning the dielectric film. As a material for the dielectric film, for example, a negative or positive photosensitive resin can be used. Further, by performing an exposure process using a multi-tone mask, the first columnar spacers 23a and the second columnar spacers having different heights from the common dielectric film without increasing the number of manufacturing steps and the number of photomasks. 23b can be formed. At this time, by making the height h19 of the insulating member 19 the same as either the height h23a of the first columnar spacer 23a or the height h23b of the second columnar spacer 23b, the number of manufacturing steps and the number of photomasks are not increased. The insulating member 19 can also be formed from a common dielectric film. As the multi-tone mask, a gray-tone mask or a half-tone mask can be used. The gray tone mask is formed with a slit below the resolution of the exposure machine, and intermediate exposure is realized by blocking a part of the light by the slit. On the other hand, in the halftone mask, intermediate exposure is realized by using a semi-transmissive film. Here, a negative heat-resistant transparent photosensitive resist (manufactured by JSR Corporation, heat-resistant transparent photosensitive protective film Optmer NN700G (Optomer is a registered trademark)) is used as the dielectric film. Here, after the dielectric film is deposited, the first columnar spacer 23a having a height of 1 μm to 10 μm and a height of 0.1 μm to 9.9 μm are obtained by performing exposure and development through a gray tone mask. The second columnar spacer 23b and the insulating member 19 having the same height as the second columnar spacer 23b are formed.

An alignment film (not shown) is formed on the surfaces of the active matrix substrate 10 thus formed and the counter substrate 30 prepared separately. The counter substrate 30 can be manufactured by various known methods, for example. Thereafter, a sealing material including the first granular spacer 66a is applied so as to surround an area of the active matrix substrate 10 or the counter substrate 30 corresponding to the display area 100d. A transition material including conductive particles 62 is applied along the contact electrode 64. The sealing material and the transfer material are applied by, for example, a dispenser method or a screen printing method. A liquid crystal layer is formed by dropping a liquid crystal material by a dropping method onto a substrate provided with a sealing material and a transition material. Thereafter, the active matrix substrate 10 and the counter substrate 30 are bonded together in a vacuum. Thereafter, the sealing material and the transition material are cured by, for example, ultraviolet irradiation to form the seal portion 60s and the transition portion 60t. For example, the ultraviolet rays are irradiated from the active matrix substrate 10 side.

Through the above steps, the liquid crystal display device 100 can be manufactured.

Subsequently, a modified example of the liquid crystal display device in the present embodiment will be described.

11 to 13 show a liquid crystal display device 100A which is a modified example of the liquid crystal display device 100. FIG. 11 to 13 are a cross-sectional view and a plan view schematically showing the liquid crystal display device 100A. FIG. 11A is a cross-sectional view schematically showing the frame region 100f of the liquid crystal display device 100A along the 11At-11At 'line and the 11Ad-11Ad' line in FIG. FIG. 11B is a cross-sectional view schematically showing the display region 100d of the liquid crystal display device 100A along the line 11b-11b 'in FIG.

In the liquid crystal display device 100, as shown in FIG. 1, the second gate electrode 16gA is in contact with the source electrode 14sA in the opening CH2 provided in the second insulating layer 4i. On the other hand, in the liquid crystal display device 100A, as shown in FIG. 11, the driving TFT 11A further includes an additional electrode 18A provided on the second gate electrode 16gA and electrically connected to the second gate electrode 16gA. The additional electrode 18A is electrically connected to the source electrode 14sA in the second opening CH2 provided in the second insulating layer 4i. The second opening CH2 is also provided in the third insulating layer 6i. The additional electrode 18A is formed of the same conductive film as the fourth conductive layer 18. The additional electrode 18A may be formed of the same conductive film as the contact electrode 64. The insulating member 19 covers the additional electrode 18A in addition to the second gate electrode 16gA. The insulating member 19 covers the second gate electrode 16gA and the additional electrode 18A when the second gate electrode 16gA and the additional electrode 18A overlap with the insulating member 19 when viewed from the normal direction of the active matrix substrate 10. The state that is.

Also in the liquid crystal display device 100A having such a configuration, the same effect as that of the liquid crystal display device 100 can be obtained. Since the drive TFT 11A includes the second gate electrode 16gA that functions as a back gate electrode, fluctuations in the electrical characteristics of the drive TFT 11A are suppressed. Thereby, the fall of the reliability of 100 A of liquid crystal display devices is suppressed. Since the liquid crystal display device 100A includes the insulating member 19 that covers the second gate electrode 16gA and the additional electrode 18A, the second gate electrode 16gA and / or the additional electrode 18A and the counter electrode 34 of the counter substrate 30 are electrically conductive particles. It is possible to prevent electrical connection by 62. As a result, malfunction of the driving TFT 11A is suppressed, so that the liquid crystal display device 100A has excellent reliability. Further, since the seal portion 60s and / or the transition portion 60t and the driving TFT 11A can be provided close to each other, the area of the frame region 100f can be reduced. Since the insulating member 19 is formed of the same dielectric film as the protruding structure of the active matrix substrate 10 in the display region 100d, the liquid crystal display has a narrow frame and excellent reliability without increasing the number of manufacturing steps. A device is obtained.

In the liquid crystal display device 100, as shown in FIG. 1, a third insulating layer 6i is formed on the second gate electrode 16gA. On the other hand, in the liquid crystal display device 100A, as shown in FIG. 11, the additional electrode 18A electrically connected to the second gate electrode 16gA is covered with an insulating film or dielectric film other than the insulating member 19. Not. Therefore, if the liquid crystal display device 100A does not have the insulating member 19, the second gate electrode 16gA and the counter electrode 34 are likely to be electrically connected by the conductive particles 62. That is, the liquid crystal display device 100 </ b> A can improve the reliability more effectively by including the insulating member 19.

Furthermore, the liquid crystal display device 100A can be manufactured with a smaller number of masks than the liquid crystal display device 100.

The manufacturing process of the liquid crystal display device 100A differs from the manufacturing process of the liquid crystal display device 100 in the following points. In the manufacturing process of the second insulating layer 4i of the liquid crystal display device 100, as described with reference to FIG. 7, after depositing the insulating film, openings (opening 4a, opening CH2 and opening CH3 are formed in the insulating film. ) By patterning. Thereafter, the third conductive layer 16 is formed. In the liquid crystal display device 100A, after the insulating film is deposited to form the second insulating layer 4i, the manufacturing process (see FIG. 14) of the third conductive layer 16 is performed without providing an opening in the insulating film. Thereafter, in the manufacturing process of the third insulating layer 6i (see FIG. 15), the second insulating layer 4i and the third insulating layer are removed by removing a part of the second insulating layer 4i and a part of the third insulating layer 6i. An opening is formed in 6i. Accordingly, the liquid crystal display device 100A can be manufactured with a smaller number of masks than the liquid crystal display device 100. Details will be described below.

The manufacturing process of the liquid crystal display device 100A will be described with reference to FIGS. The description will focus on the differences from the manufacturing process of the liquid crystal display device 100. 14 to 16 are process cross-sectional views schematically showing the manufacturing process of the liquid crystal display device 100A. 14 to 16, (a) shows the process of manufacturing the frame area 100f, and (b) shows the process of manufacturing the display area 100d.

As shown in FIG. 14, after the second insulating layer 4i is formed, a third conductive layer (first transparent electrode) including the second gate electrode 16gA of the driving TFT 11A and the electrode 16B of the pixel TFT 11B is formed on the second insulating layer 4i. Layer) 16 is formed. The electrode 16B of the pixel TFT 11B can function as a common electrode.

Subsequently, as shown in FIG. 15, a third insulating layer (auxiliary capacitor insulating layer) 6 i is formed on the third conductive layer 16.

Openings

4a and 6a are formed by patterning in a region of the third insulating layer 6i corresponding to the opening 2a of the first insulating layer 2i. That is, part of the second insulating layer 4i and the third insulating layer 6i is removed so that the second conductive layer 14 is exposed. An opening CH1 (see FIG. 11) is formed by the

openings

2a, 4a, and 6a. In addition,

openings

4b and 6b are formed in the second insulating layer 4i and the third insulating layer 6i of the drive circuit unit 60d by patterning. In the

openings

4b and 6b, a part of the second insulating layer 4i and a part of the third insulating layer 6i are removed so that a part of the source electrode 14sA of the driving TFT 11A and a part of the second gate electrode 16gA are exposed. Is formed. An opening CH2 (see FIG. 11) is formed by the

openings

4b and 6b. Further,

openings

4c and 6c are formed in the second insulating layer 4i and the third insulating layer 6i in the display region 100d by patterning. The

openings

4c and 6c are formed by removing a part of the second insulating layer 4i and the third insulating layer 6i so that a part of the drain electrode 14dB of the pixel TFT 11B and a part of the semiconductor layer 15B are exposed. It is formed. An opening CH3 (see FIG. 11) is formed by the

openings

4c and 6c.

Next, as shown in FIG. 16, a fourth conductive layer (second transparent electrode layer) 18 including the contact electrode 64 and the pixel electrode 18B of the pixel TFT 11B is formed on the third insulating layer 6i. Specifically, after depositing a fourth conductive film on the third insulating layer 6i, the fourth conductive layer 18 is formed by patterning the fourth conductive film. At this time, patterning is performed so that the contact electrode 64 is in contact with the second conductive layer 14 in the opening CH1. Further, patterning is performed so that the additional electrode 18A is in contact with the second gate electrode 16gA and the source electrode 14sA in the opening CH2. Further, patterning is performed so that the pixel electrode 18B is in contact with the second portion 15bB and the drain electrode 14dB of the semiconductor layer 15B in the opening CH3.

In the liquid crystal display device 100, as described above with reference to FIGS. 1 to 3, the pixel electrode 16B of the pixel TFT 11B is formed from the third conductive layer 16, and the common electrode 18B is formed from the fourth conductive layer 18. . In contrast, in the pixel TFT 11B of the liquid crystal display device 100A shown in FIGS. 11 to 13, the common electrode 16B is formed of the third conductive layer 16, and the pixel electrode 18B is formed of the fourth conductive layer 18.

Thereafter, the

columnar spacers

23a and 23b and the insulating member 19 are formed on the fourth conductive layer 18 in the same process as the liquid crystal display device 100, whereby the active matrix substrate 10 of the liquid crystal display device 100A is manufactured.

FIG. 17 shows a liquid crystal display device 100B which is another modified example of the liquid crystal display device 100. FIG. 17 is a cross-sectional view schematically showing a frame region 100f of the liquid crystal display device 100B. Hereinafter, the liquid crystal display device 100B will be described with a focus on differences from the liquid crystal display device 100A.

As shown in FIG. 17, in the driving TFT 11A of the liquid crystal display device 100B, the second gate electrode 18gA is formed of the same conductive film as the fourth conductive layer 18. The second gate electrode 18gA may be formed of the same conductive film as the contact electrode 64. The second gate electrode 18gA is in contact with the source electrode 14sA in the opening CH2 provided in the second insulating layer 4i and the third insulating layer 6i.

Also in the liquid crystal display device 100B having such a configuration, the same effect as that of the liquid crystal display device 100A can be obtained.

In the liquid crystal display device 100A and the liquid crystal display device 100B described above, the contact electrode 64 is formed of the same conductive film as the fourth conductive layer 18. The contact electrode 64 may be formed of, for example, the same conductive film as the third conductive layer 16.

(Embodiment 2)
18 and 19 show a liquid crystal display device 200 according to Embodiment 2 of the present invention. 18 and 19 are a cross-sectional view and a plan view schematically showing the frame region 200f of the liquid crystal display device 200. FIG. FIG. 18 is a cross-sectional view schematically showing a frame region 200f of the liquid crystal display device 200 along the 18At-18At ′ line and the 18Ad-18Ad ′ line in FIG. Hereinafter, a description will be given focusing on differences from the liquid crystal display device 100 of the first embodiment.

18 and 19, the liquid crystal display device 200 is different from the liquid crystal display device 100 of the first embodiment in the size of the insulating member 19. For example, the transition part 60t is provided on one side of the display area 200d, and the insulating member 19 covers substantially the entire area between the transition part 60t and the display area 200d. For example, when the display area 200d is substantially rectangular, the transition part 60t is provided on one side of the display area 200d, and the insulating member 19 covers substantially the entire area between the transition part 60t and the display area 200d. The insulating member 19 may be provided so as to expose at least the contact electrode 64, for example.

Also in the liquid crystal display device 200 having such a configuration, the same effect as that of the liquid crystal display device 100 can be obtained. Since the drive TFT 11A includes the second gate electrode 16gA that functions as a back gate electrode, fluctuations in the electrical characteristics of the drive TFT 11A are suppressed. Thereby, the fall of the reliability of the liquid crystal display device 200 is suppressed. Since the liquid crystal display device 200 includes the insulating member 19 that covers the second gate electrode 16gA, the second gate electrode 16gA and the counter electrode 34 of the counter substrate 30 are electrically connected by the conductive particles 62. Can be prevented. As a result, malfunction of the driving TFT 11A is suppressed, so that the liquid crystal display device 200 has excellent reliability. Further, since the seal portion 60s and / or the transition portion 60t and the driving TFT 11A can be provided close to each other, the area of the frame region 200f can be reduced. Since the insulating member 19 is formed of the same dielectric film as the protruding structure of the active matrix substrate 10 in the display area 200d, a liquid crystal display having a narrow frame and excellent reliability without increasing the number of manufacturing steps. A device is obtained.

Since the liquid crystal display device 200 includes the insulating member 19 larger than the liquid crystal display device 100, the driving TFT 11A (particularly the channel region 15cA of the semiconductor layer 15A) can be more effectively protected from moisture contained in the seal portion 60s. . In addition, for example, it is possible to more effectively reduce the incidence of ultraviolet rays that are irradiated on the sealing material and scattered by the filler contained in the sealing material in the step of curing the sealing material, into the channel region 15cA of the semiconductor layer 15A. . Since the characteristic variation and / or malfunction of the driving TFT 11A can be effectively prevented, the reliability can be improved more effectively.

Since the liquid crystal display device 200 has the insulating member 19 larger than the liquid crystal display device 100, the distance between the active matrix substrate 10 and the counter substrate 30 can be easily maintained (easily controlled). As shown in FIG. 18, the seal portion 60 s of the liquid crystal display device 200 is a second granular spacer 66 b positioned between the insulating member 19 and the counter substrate 30, and the active matrix substrate 10 and the counter substrate together with the insulating member 19. A second granular spacer 66b that defines a distance between the first and second particles may be included. The second granular spacer 66b is included in the sealing material that forms the seal portion 60s. The second granular spacer 66b may also be included in the transition material that forms the transition portion 60t.

In the liquid crystal display device 200, the structure of the driving TFT 11A, the pixel TFT 11B, and the transition portion 60t is the same as that of the liquid crystal display device 100 of the first embodiment. The present embodiment is not limited to this, and the structure of the driving TFT 11A, the pixel TFT 11B, and the transition portion 60t may be the same as the modified example of the liquid crystal display device 100 (including the liquid

crystal display devices

100A and 100B).

(Embodiment 3)
FIG. 20 shows a liquid crystal display device 300 according to Embodiment 3 of the present invention. FIG. 20 is a cross-sectional view schematically showing the frame region 300f and the display region 300d of the liquid crystal display device 300. Hereinafter, a description will be given focusing on differences from the liquid crystal display device 100 of the first embodiment.

In the liquid crystal display device 300, the active matrix substrate 10 has the color filter layer 22 in the display region 300d. That is, a color filter on array structure is adopted. The color filter layer 22 includes three types of color filters that transmit light of different colors, that is, a first color filter 22a, a second color filter 22b, and a third color filter (not shown). The three types of color filters are, for example, a red color filter that transmits red light, a green color filter that transmits green light, and a blue color filter that transmits blue light. The insulating member 19 is formed of the same dielectric film as at least one of the first color filter 22a, the second color filter 22b, and the third color filter. The color filter layer 22 may further include a black matrix BM.

Also in the liquid crystal display device 300 having such a configuration, the same effect as that of the liquid crystal display device 100 can be obtained. Since the drive TFT 11A includes the second gate electrode 16gA that functions as a back gate electrode, fluctuations in the electrical characteristics of the drive TFT 11A are suppressed. Thereby, the fall of the reliability of the liquid crystal display device 300 is suppressed. Since the liquid crystal display device 300 has the insulating member 19 that covers the second gate electrode 16gA, the second gate electrode 16gA and the counter electrode 34 of the counter substrate 30 are electrically connected by the conductive particles 62. Can be prevented. As a result, malfunction of the driving TFT 11A is suppressed, so that the liquid crystal display device 300 has excellent reliability. Further, since the seal portion 60s and / or the transition portion 60t and the driving TFT 11A can be provided close to each other, the area of the frame region 300f can be reduced. The insulating member 19 is formed of the same dielectric film as the color filter layer 22 included in the active matrix substrate 10 in the display region 300d. A display device is obtained.

Furthermore, the liquid crystal display device 300 may have a higher aperture ratio than the liquid crystal display device 100. In the liquid crystal display device 100, since the counter substrate 30 includes the color filter layer 32, the black matrix may be set wider in consideration of misalignment between the active matrix substrate 10 and the counter substrate 30. On the other hand, in the liquid crystal display device 300, since the active matrix substrate 10 includes the color filter layer 22, it is not necessary to consider misalignment. Since the width of the black matrix can be reduced, the aperture ratio is improved accordingly.

The manufacturing process of the liquid crystal display device 300 will be described. Hereinafter, a description will be given focusing on differences from the manufacturing process of the liquid crystal display device 100.

The third conductive layer 16 is formed in the same manner as the manufacturing process of the liquid crystal display device 100 described with reference to FIGS.

Thereafter, the color filter layer 22 is formed on the third conductive layer 16. Specifically, first, a black matrix BM is formed on the third conductive layer 16, and then a red color filter 22a, a blue color filter 22b, and a green color filter (not shown) are sequentially formed, so that the color filter Layer 22 is formed. As a material of the black matrix BM, for example, a black photosensitive resin material can be used. As a material of the red color filter 22a, the blue color filter 22b, and the green color filter, for example, a colored photosensitive resin material can be used. For example, a red color filter 22a and a blue color filter 22b are formed on the back gate electrode 16gA of the drive TFT 11A. The red color filter 22a and the blue color filter 22b provided on the back gate electrode 16gA of the driving TFT 11A constitute the insulating member 19. When the insulating member 19 is formed by overlapping the red color filter 22a and the blue color filter 22b, the insulating member 19 can function as a light shielding film for the channel region 15cA of the semiconductor layer 15A. Therefore, it is not necessary to provide the black matrix BM as a light shielding film for the channel region 15cA of the semiconductor layer 15A. The insulating member 19 can be formed by stacking two or more color filters that transmit light of different colors. Even in this case, the same effect as described above can be obtained.

Subsequently, an organic insulating layer 24 for planarization is formed on the color filter layer 22. The organic insulating layer 24 is made of, for example, a photosensitive resin. In the organic insulating layer 24, an opening is formed in a region to be the opening CH1 or CH3 (see FIG. 20) later.

Thereafter, a fourth conductive layer (second transparent electrode layer) 18 including the pixel electrode 18B of the pixel TFT 11B is formed on the organic insulating layer 24. Subsequently, a third insulating layer (auxiliary capacitor insulating layer) 6 i is formed on the fourth conductive layer 18. Thereafter, the fifth conductive layer (third transparent electrode layer) 20 including the common electrode (transparent electrode) 20B and the contact electrode 64 of the pixel TFT 11B is formed on the third insulating layer 6i. The common electrode 20B is opposed to the pixel electrode 18B through the third insulating layer 6i, and the pixel electrode 18B and the common electrode 20B and the third insulating layer 6i located therebetween constitute an auxiliary capacitor. Yes. As a material for the conductive film forming the fifth conductive layer 20, various transparent conductive materials can be used. For example, metal oxides such as ITO, IZO, ZnO, and the like can be used.

Then, the active matrix substrate 10 of the liquid crystal display device 300 is manufactured by forming the

columnar spacers

23a and 23b on the fifth conductive layer 20 in the same process as the liquid crystal display device 100.

The counter substrate 30 of the liquid crystal display device 300 may be the same as the counter substrate 30 of the liquid crystal display device 100 except that it does not have a color filter layer.

According to the embodiment of the present invention, a display device having a narrow frame and excellent reliability can be obtained without increasing the number of manufacturing steps. Embodiments of the present invention are widely used in various display devices.

10 active matrix substrate 1s substrate 2i first insulating layer 4i second insulating layer 6i third insulating layer 11A driving TFT
11B pixel TFT
12 First conductive layer 12gA, 12gB Gate electrode (first gate electrode)
14 Second conductive layer 14sA, 14sB Source electrode 14dA,

14dB Drain electrode

15A, 15B Semiconductor layer 15cA, 15cB Channel region 15sA, 15sB Source region 15dA, 15dB Drain region 16 Third conductive layer 16gA Second gate electrode 18 Fourth conductive layer 19 Insulating Member 20 Fifth Conductive Layer 22 Color Filter Layer 23a First Columnar Spacer 23b Second Columnar Spacer 24 Organic Insulating Layer 30 Counter Substrate 31 Substrate 32 Color Filter Layer 33 Overcoat Layer 34 Counter Electrode 50 Liquid Crystal Layer

60s Sealing Section

60t Transition Section 60d Drive circuit section 62 Conductive particles 64 Contact electrode 66a First granular spacer 66b Second

granular spacer

100, 100A, 100B, 200, 300, 900 Liquid crystal

display device 100f

200f, 300f, 900f frame region 100d, 200d display area

Claims

An active matrix substrate, and a counter substrate arranged to face the active matrix substrate,
A display device having a display area defined by a plurality of pixels arranged in a matrix and a frame area around the display area,
The frame area is
A seal portion surrounding the display area;
A transition portion that electrically connects the active matrix substrate and the counter substrate by conductive particles;
The active matrix substrate is
A driving TFT provided in the frame region;
A substrate for supporting the driving TFT,
The drive TFT is
A semiconductor layer including a channel region, a source region and a drain region;
A first gate electrode that overlaps the channel region of the semiconductor layer via a first insulating layer and is located between the semiconductor layer and the substrate;
A source electrode and a drain electrode respectively electrically connected to the source region and the drain region of the semiconductor layer;
A second gate electrode that overlaps the channel region of the semiconductor layer via a second insulating layer and is located on the opposite side of the semiconductor layer from the first gate electrode;
In the display area, the active matrix substrate has a protruding structure protruding toward the counter substrate,
In the frame region, the active matrix substrate is provided on the driving TFT and has an insulating member that covers the second gate electrode,
The display device, wherein the insulating member is formed of the same dielectric film as the protruding structure.
2. The display device according to claim 1, wherein the protruding structure is a first columnar spacer that defines a distance between the active matrix substrate and the counter substrate.
The display device according to claim 1, wherein the protruding structure is a second columnar spacer that is lower than the first columnar spacer that defines a distance between the active matrix substrate and the counter substrate.
4. The display device according to claim 3, wherein the second columnar spacer is formed of the same dielectric film as the first columnar spacer.
The display device according to any one of claims 1 to 4, wherein a height of the insulating member is substantially the same as a height of the protruding structure.
An active matrix substrate, and a counter substrate arranged to face the active matrix substrate,
A display device having a display area defined by a plurality of pixels arranged in a matrix and a frame area around the display area,
The frame area is
A seal portion surrounding the display area;
A transition portion that electrically connects the active matrix substrate and the counter substrate by conductive particles;
The active matrix substrate is
A driving TFT provided in the frame region;
A substrate for supporting the driving TFT,
The drive TFT is
A semiconductor layer including a channel region, a source region and a drain region;
A first gate electrode that overlaps the channel region of the semiconductor layer via a first insulating layer and is located between the semiconductor layer and the substrate;
A source electrode and a drain electrode respectively electrically connected to the source region and the drain region of the semiconductor layer;
A second gate electrode that overlaps the channel region of the semiconductor layer via a second insulating layer and is located on the opposite side of the semiconductor layer from the first gate electrode;
In the display region, the active matrix substrate has a color filter layer including a first color filter, a second color filter, and a third color filter that transmit light of different colors,
In the frame region, the active matrix substrate is provided on the driving TFT and has an insulating member that covers the second gate electrode,
The display device, wherein the insulating member is formed of the same dielectric film as at least one of the first color filter, the second color filter, and the third color filter.
The display device according to any one of claims 1 to 6, wherein a height of the insulating member is larger than half of an average particle diameter of the conductive particles.
The display device according to any one of claims 1 to 7, wherein the seal portion includes a first granular spacer that defines a distance between the active matrix substrate and the counter substrate.
The seal portion is a second granular spacer positioned between the insulating member and the counter substrate, and defines a distance between the active matrix substrate and the counter substrate together with the insulating member. The display device according to claim 1, comprising:
The display device according to claim 1, wherein the insulating member covers the entire driving TFT.
The display device according to claim 1, wherein the transition portion is provided on one side of the display region, and the insulating member covers substantially the entire area between the transition portion and the display region.
The display device according to claim 1, wherein the second gate electrode is electrically connected to the source electrode.
The active matrix substrate has a contact electrode provided in the frame region,
The counter substrate includes a counter electrode including a portion facing the contact electrode;
The display device according to claim 1, wherein the transition portion electrically connects the contact electrode and the counter electrode.
The contact electrode is electrically connected to a first conductive layer formed from the same conductive film as the first gate electrode and / or a second conductive layer formed from the same conductive film as the source electrode and the drain electrode. The display device according to claim 13, wherein the display device is connected.
The transition portion is provided in the first insulating layer and the second insulating layer, and has a first opening that electrically connects the first conductive layer, the second conductive layer, and the contact electrode to each other. Item 15. The display device according to Item 14.
The transition portion further includes a third conductive layer between the contact electrode and the second insulating layer, and the third conductive layer is in contact with the contact electrode in the first opening. 15. The display device according to 15.
The display device according to claim 16, wherein the second gate electrode is formed of the same conductive film as the third conductive layer.
The display device according to claim 13, wherein the second gate electrode is formed of the same conductive film as the contact electrode.
The display device according to claim 1, wherein the second gate electrode is in contact with the source electrode in a second opening provided in the second insulating layer.
The driving TFT further includes an additional electrode provided on the second gate electrode and electrically connected to the second gate electrode, and the additional electrode is provided on the second insulating layer. The display device according to claim 1, wherein the display device is electrically connected to the source electrode in two openings.