Pixel array substrate

Abstract

The invention provides a pixel array substrate. The pixel array substrate comprises a substrate, an insulating layer and a plurality of pixel structures, the insulating layer is disposed on the substrate. The plurality of pixel structures are arranged on the substrate, and each pixel structure comprises an active component and a reflecting layer. The active component is disposed between the substrate and the insulating layer. The reflecting layer is arranged on the insulating layer and comprises a silver-based reflecting layer and a protective layer. The silver-based reflective layer has a reflective surface. The protection layer covers the silver-based reflection layer. The thickness of the protective layer in the normal direction of the reflecting surface is larger than or equal to 30 angstroms and smaller than or equal to 80 angstroms. Another pixel array substrate provided with the buffer layer is also provided.

Description

Technical Field

[0001] The present invention relates to a pixel array substrate, and in particular to a pixel array substrate provided with a reflective layer. Background Art

[0002] Reflective display panels primarily utilize natural or ambient light as a light source, making them energy-efficient. Consequently, they are often used outdoors or in well-lit areas, such as outdoor billboards, electronic labels, and sports watches. Silver is the preferred metal for the reflective layer due to its high reflectivity and low resistivity.

[0003] Silver's poor chemical, heat, and weather resistance, coupled with its high electrochemical mobility, present numerous challenges and limitations in the production of reflective electrodes for reflective or transflective display panels. For example, subsequent processes involving etching and heating can alter the optical properties of the silver reflective layer (e.g., reduced reflectivity or color shift of reflected light) and reduce reliability (e.g., delamination of the silver reflective layer from the underlying film). Summary of the Invention

[0004] The present invention is directed to a pixel array substrate having a higher manufacturing yield and better optical performance.

[0005] According to an embodiment of the present invention, a pixel array substrate includes a substrate, an insulating layer, and a plurality of pixel structures. The insulating layer is disposed on the substrate. The plurality of pixel structures are disposed on the substrate, each including an active component and a reflective layer. The active component is disposed between the substrate and the insulating layer. The reflective layer is disposed on the insulating layer and includes a silver-based reflective layer and a protective layer. The silver-based reflective layer has a reflective surface. The protective layer covers the silver-based reflective layer. The thickness of the protective layer along a normal direction to the reflective surface is greater than or equal to 30 angstroms and less than or equal to 80 angstroms.

[0006] According to an embodiment of the present invention, a pixel array substrate includes a substrate, an insulating layer, and a plurality of pixel structures. The insulating layer is disposed on the substrate. The plurality of pixel structures are disposed on the substrate, each including an active component and a reflective layer. The active component is disposed between the substrate and the insulating layer. The reflective layer is disposed on the insulating layer and includes a silver-based reflective layer and a buffer layer. The silver-based reflective layer has a reflective surface. The buffer layer is disposed between the insulating layer and the silver-based reflective layer. The buffer layer is made of a conductive material. The insulating layer has an opening and sidewall surfaces defining the opening. The silver-based reflective layer and the buffer layer extend to cover the sidewall surfaces of the insulating layer. The first thickness of the sidewall portion of the buffer layer covering the sidewall surface along the normal direction of the sidewall surface is greater than or equal to 30 angstroms and less than or equal to 80 angstroms.

[0007] Based on the above, in a pixel array substrate of one embodiment of the present invention, in order to increase the chemical resistance and weather resistance of the silver-based reflective layer during the manufacturing process, a protective layer is covered on the silver-based reflective layer, and the thickness of the protective layer is in the range of 30 angstroms to 80 angstroms. In addition to having better film thickness uniformity, the protective layer can also prevent the reflectivity of the reflective layer from decreasing or causing color deviation due to the provision of the protective layer. In a pixel array substrate of another embodiment of the present invention, a buffer layer is provided between the silver-based reflective layer and the insulating layer, and the thickness of the sidewall portion of the buffer layer within the opening of the insulating layer is in the range of 30 angstroms to 80 angstroms. In addition to increasing the adhesion between the silver-based reflective layer and the insulating layer, it can also prevent the buffer layer from being too thick and causing unclean etching during the patterning process of the reflective layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic cross-sectional view of a display panel according to an embodiment of the present invention;

[0009] Figure 2 yes Figure 1 An enlarged schematic diagram of a local area of ​​a display panel;

[0010] Figure 3 yes Figure 2 An enlarged schematic diagram of a pixel array substrate;

[0011] Figure 4 is a schematic cross-sectional view of a display panel according to another embodiment of the present invention;

[0012] Figure 5 yes Figure 4 An enlarged schematic diagram of a pixel array substrate.

[0013] Description of Reference Numerals

[0014] 10, 20: display panel;

[0015] 100, 100A: pixel array substrate;

[0016] 101: Substrate;

[0017] 101s: substrate surface;

[0018] 110: gate insulating layer;

[0019] 120, 130: insulation layer;

[0020] 130fs: surface;

[0021] 130OP: Opening;

[0022] 130sw: side wall;

[0023] 151: silver-based reflective layer;

[0024] 152: protective layer;

[0025] 153: buffer layer;

[0026] 153f: horizontal part;

[0027] 153sw: side wall part;

[0028] 200: color filter substrate;

[0029] 300: liquid crystal layer;

[0030] ABL: ambient light or light from the front light module;

[0031] CL1, CL2: conductive layer;

[0032] D1, D2, D3: direction;

[0033] DE: drain;

[0034] GE: gate;

[0035] PDL: pixel driver layer;

[0036] PE: pixel electrode;

[0037] PX: pixel structure;

[0038] RFL: reflective layer;

[0039] RL: reflected light;

[0040] RS: reflecting surface;

[0041] SC: semiconductor pattern;

[0042] SE: source;

[0043] TH: contact hole;

[0044] TFT: active component;

[0045] t: thickness;

[0046] t1: first thickness;

[0047] t2: second thickness;

[0048] USR: user. DETAILED DESCRIPTION

[0049] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0050] Figure 1is a schematic cross-sectional view of a display panel according to an embodiment of the present invention. Figure 2 yes Figure 1 An enlarged schematic diagram of a local area of ​​a display panel. Figure 3 yes Figure 2 An enlarged schematic diagram of a pixel array substrate.

[0051] Please refer to Figure 1 and Figure 2 The display panel 10 may include a pixel array substrate 100, a color filter substrate 200, and a liquid crystal layer 300. The pixel array substrate 100 and the color filter substrate 200 are arranged to overlap each other, and the liquid crystal layer 300 is disposed between the pixel array substrate 100 and the color filter substrate 200. That is, the display panel 10 is, for example, a liquid crystal display panel, but is not limited thereto. In other embodiments, the liquid crystal layer 300 may be replaced with another type of display medium layer.

[0052] First, the overlapping relationship between the pixel array substrate 100 and the color filter substrate 200 is, for example, that they overlap along direction D3. Unless otherwise specified, the overlapping relationship between the two components is defined in the same manner, and the overlapping direction is not repeated.

[0053] The pixel array substrate 100 includes a substrate 101 and a plurality of pixel structures PX disposed on the substrate 101. The substrate 101 may be made of glass, quartz, polymer (eg, polyimide, polycarbonate, polymethyl methacrylate, or other suitable flexible plates), or other suitable plates.

[0054] In this embodiment, a plurality of pixel structures PX are arrayed on a substrate 101. For example, these pixel structures PX may be arranged along mutually perpendicular directions D1 and D2 to form a plurality of pixel rows and a plurality of pixel columns. The pixel array substrate 100 may be provided with a pixel drive layer PDL. Each pixel structure PX may include an active device TFT disposed within the pixel drive layer PDL and a reflective layer RFL disposed on the pixel drive layer PDL. For example, the pixel drive layer PDL may also include a plurality of scan lines (not shown) and a plurality of data lines (not shown), wherein the active device TFT may electrically connect one scan line to one data line, but this is not limited to this. It should be noted that in this embodiment, the reflective layer RFL may be conductive and also serve as the pixel electrode PE of the pixel structure PX, but this is not limited to this. The distribution range of the reflective layer RFL may be defined as the reflective area RA of the display panel 10. In this embodiment, the display panel 10 may be a reflective display panel, but this is not limited to this. In other embodiments, the display panel may also be a transflective display panel. For example, each of the plurality of pixel structures PX of the display panel 10 may further include a transmission area (not shown), the reflective layer RFL is disposed in the reflective area RA but not in the transmission area, and light from the backlight module (not shown) may pass through the transmission area.

[0055] On the other hand, the color filter substrate 200 may be provided with a color filter layer (not shown) and a common electrode layer (not shown), but this is not limiting. The electric field generated between the common electrode layer and the reflective layer RFL (i.e., the pixel electrode PE) is suitable for driving the liquid crystal molecules (not shown) in the liquid crystal layer 300 to rotate, forming an alignment corresponding to the direction and intensity of the electric field. By changing the alignment of these liquid crystal molecules, the polarization state of ambient light or light from the front light module ABL passing through the liquid crystal layer 300 is altered, resulting in a light intensity corresponding to the alignment.

[0056] In this embodiment, the display panel 10 uses external ambient light or light from a frontlight module ABL as the illumination source for display. The ambient light or light from the frontlight module ABL passes through the liquid crystal layer 300, is reflected by the reflective layer RFL, and then passes through the liquid crystal layer 300 again, forming reflected light RL having a specific light intensity. By controlling the electric field strength between each of the multiple pixel electrodes PE of the multiple pixel structures PX and the common electrode layer, the multiple reflected lights RL reflected by the multiple reflective layers RFL of the pixel structures PX and transmitted to the user USR can have different light intensities, thereby achieving the desired image display effect.

[0057] Furthermore, the steps for forming the active device TFT include, for example, sequentially forming a gate electrode GE, a gate insulating layer 110, a semiconductor pattern SC, a source electrode SE, and a drain electrode DE on a substrate 101. The semiconductor pattern SC is disposed overlapping the gate electrode GE. The source electrode SE and the drain electrode DE overlap the semiconductor pattern SC and are in electrical contact with two different regions of the semiconductor pattern SC. In this embodiment, the gate electrode GE of the active device TFT is optionally disposed below the semiconductor pattern SC to form a bottom-gate thin-film transistor (TFT), but this is not limiting. In other embodiments, the gate electrode of the active device may also be disposed above the semiconductor pattern to form a top-gate thin-film transistor (TFT).

[0058] Furthermore, the active device TFT may be sequentially covered with an insulating layer 120 and an insulating layer 130. In this embodiment, the insulating layer 120 is, for example, a passivation layer, and the insulating layer 130 is, for example, a planarization layer. In some embodiments, the pixel array substrate 100 may not include the insulating layer 120. In this embodiment, the insulating layer 120 has a contact hole TH, and the contact hole TH penetrates the insulating layer 120. The insulating layer 130 has an opening 130OP overlapping the contact hole TH, a sidewall surface 130sw defining the opening 130OP, and a surface 130fs connected to the sidewall surface 130sw, and the opening 130OP penetrates the insulating layer 130. The surface 130fs is the surface of the insulating layer 130 facing away from the substrate 101, and the extension direction of the sidewall surface 130sw intersects with the substrate surface 101s.

[0059] The reflective layer RFL of the pixel structure PX is disposed on the surface 130fs of the insulating layer 130 and is electrically connected to the drain electrode DE of the active device TFT via the opening 130OP in the insulating layer 130 and the contact hole TH in the insulating layer 120. For example, in this embodiment, the pixel driving layer PDL may further include a conductive layer CL1 extending from the drain electrode DE of the active device TFT, with the opening 130OP and the contact hole TH exposing a portion of the surface of the conductive layer CL1. The reflective layer RFL disposed on the surface 130fs also extends to cover the sidewall surface 130sw of the insulating layer 130 and the contact hole TH in the insulating layer 120, thereby electrically connecting the conductive layer CL1.

[0060] It should be noted that the gate GE, source SE, drain DE, semiconductor pattern SC, gate insulating layer 110, passivation layer (i.e., insulating layer 120) and planarization layer (i.e., insulating layer 130) can be respectively realized by any gate, any source, any drain, any semiconductor pattern, any gate insulating layer, any passivation layer and any planarization layer for a reflective display panel known to any person skilled in the art, and the gate GE, source SE, drain DE, semiconductor pattern SC, gate insulating layer 110, passivation layer and planarization layer can be respectively formed by any method known to any person skilled in the art, and therefore will not be described in detail here.

[0061] Please refer to Figure 2 and Figure 3 The reflective layer RFL is a stacked structure of multiple film layers. In this embodiment, the reflective layer RFL includes, for example, a silver-based reflective layer 151, a protective layer 152, and a buffer layer 153. However, the present invention is not limited thereto. In other embodiments, in addition to the silver-based reflective layer 151, the reflective layer may include only one of the protective layer 152 and the buffer layer 153. In this embodiment, the material of the silver-based reflective layer 151 is, for example, silver or a metal alloy containing silver.

[0062] The silver-based reflective layer 151 has a reflective surface RS, and the protective layer 152 covers the reflective surface RS of the silver-based reflective layer 151. The protective layer 152 is made of a light-transmitting conductive material. In this embodiment, the protective layer 152 may include an indium-containing oxide, such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0063] It should be noted that the provision of the protective layer 152 can prevent the silver-based reflective layer 151 from being exposed to air for a long time during the manufacturing process, thereby causing material deterioration and affecting the optical properties (such as color change and / or reduced reflectivity of the reflective layer RFL). When the thickness of the protective layer 152 is too thick, the reflectivity of the reflective layer RFL is reduced, and the image appears yellowish. When the thickness of the protective layer 152 is too thin, the protective layer 152 is prone to film breakage. Therefore, in this embodiment, the thickness t of the protective layer 152 along the normal direction of the reflective surface RS is greater than or equal to 30 angstroms and less than or equal to 80 angstroms. Preferably, the thickness t can be greater than or equal to 50 angstroms and less than or equal to 60 angstroms. Considering the film thickness uniformity of the protective layer 152 in actual production, when the thickness t of the protective layer 152 is 30 angstroms, its film thickness uniformity can still be maintained without film breakage, thereby ensuring the chemical resistance and weather resistance of the reflective layer RFL during the manufacturing process. Furthermore, the protective layer 152 can also reduce the impact of the protective layer 152 on the optical properties of the silver-based reflective layer 151 (i.e., reduce the extent of the decrease in the reflectivity of the reflective layer RFL). Furthermore, even if the thickness t of the protective layer 152 is 80 angstroms, the reflective layer RFL will not be completely etched during the patterning process.

[0064] In this embodiment, the buffer layer 153 is disposed between the insulating layer 130 and the silver-based reflective layer 151. The material of the buffer layer 153 may be similar to the material of the protective layer 152, and may include, for example, indium oxide, but is not limited thereto. In this embodiment, the material of the buffer layer 153 may include a light-transmitting or light-impermeable conductive material. For example, the material of the buffer layer 153 may include, for example, a metal oxide (e.g., ITO, IZO, MoTaO x or MoO x ), Mo, MoTa, AlNd, Ti, or Cr. Of particular note, the buffer layer 153 covering the surface 130fs of the insulating layer 130 also extends to cover the sidewall surfaces 130sw of the insulating layer 130 and is electrically connected to the conductive layer CL1. More specifically, the silver-based reflective layer 151 is connected to the insulating layer 130 via the buffer layer 153.

[0065] The buffer layer 153 enhances adhesion between the silver-based reflective layer 151 and the insulating layer 130, thereby preventing the silver-based reflective layer 151 from peeling off the insulating layer 130. In this embodiment, the buffer layer 153 includes a sidewall portion 153sw covering the sidewall surface 130sw and a horizontal portion 153f covering the surface 130fs. The sidewall portion 153sw of the buffer layer 153 extends along the sidewall surface 130sw of the insulating layer 130, and the horizontal portion 153f of the buffer layer 153 extends along the surface 130fs of the insulating layer 130. Due to the shadow effect, the thickness of the sidewall portion 153sw is thinner than that of the horizontal portion 153f.

[0066] When the thickness of the buffer layer 153 is too thick, the reflective layer RFL may not be etched cleanly during the patterning process. When the thickness of the buffer layer 153 is too thin, the sidewall portion 153sw of the buffer layer 153 is easily too thin, resulting in discontinuous film deposition, causing the silver-based reflective layer 151 to peel off. Therefore, in this embodiment, the first thickness t1 of the sidewall portion 153sw of the buffer layer 153 along the normal direction of the sidewall surface 130sw is greater than or equal to 30 angstroms and less than or equal to 80 angstroms. The second thickness t2 of the horizontal portion 153f of the buffer layer 153 along the normal direction of the surface 130fs is greater than or equal to 40 angstroms and less than or equal to 100 angstroms. Preferably, the first thickness t1 may be greater than or equal to 50 angstroms and less than or equal to 60 angstroms, and the second thickness t2 may be greater than or equal to 70 angstroms and less than or equal to 80 angstroms.

[0067] In particular, when the first thickness t1 of the sidewall portion 153sw of the buffer layer 153 is 30 angstroms, the film thickness can still be maintained uniformly without breaking the film, thereby ensuring the adhesion between the silver-based reflective layer 151 and the insulating layer 130. On the other hand, even if the first thickness t1 of the sidewall portion 153sw of the buffer layer 153 is 80 angstroms, or the second thickness t2 of the horizontal portion 153f of the buffer layer 153 is 100 angstroms, the reflective layer RFL will not be completely etched during the patterning process.

[0068] Some other embodiments will be listed below to illustrate the present disclosure in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the aforementioned embodiments and will not be repeated below.

[0069] Figure 4 is a schematic cross-sectional view of a display panel according to another embodiment of the present invention. Figure 5 yes Figure 4 Please refer to the enlarged schematic diagram of the pixel array substrate. Figure 4 and Figure 5 The display panel 20 of this embodiment is Figure 2 The difference between the display panels 10 is that the electrical connection between the reflective layer and the drain of the active device is different.

[0070] For example, in this embodiment, the pixel array substrate 100A optionally further includes another conductive layer CL2. The conductive layer CL2 is disposed between the insulating layer 120 and the insulating layer 130 and is electrically connected to the conductive layer CL1 extending from the drain electrode DE of the active device TFT via the contact hole TH in the insulating layer 120. An opening 130OP in the insulating layer 130 exposes a portion of the surface of the conductive layer CL2, and the reflective layer RFL extends over the portion of the surface of the conductive layer CL2 to electrically connect to the conductive layer CL2.

[0071] More specifically, in this embodiment, the reflective layer RFL (i.e., the pixel electrode PE) is electrically connected to the drain electrode DE of the active device TFT via a bridge structure formed by the conductive layer CL2 and the conductive layer CL1. The conductive layer CL2 may be made of, but not limited to, a light-transmitting conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). In other embodiments, the conductive layer CL2 may also be made of a metal or alloy.

[0072] Since the components not mentioned in this embodiment are similar to Figure 2 The display panel 10, and the thickness t of the protective layer 152 and the first thickness t1 and the second thickness t2 of the buffer layer 153 are in the same range as those in the aforementioned embodiment. For detailed description, please refer to the relevant paragraphs of the aforementioned embodiment and will not be repeated here.

[0073] In summary, in a pixel array substrate of one embodiment of the present invention, in order to increase the chemical resistance and weather resistance of the silver-based reflective layer during the manufacturing process, a protective layer is covered on the silver-based reflective layer, and the thickness of the protective layer is in the range of 30 angstroms to 80 angstroms. In addition to having better film thickness uniformity, the above-mentioned thickness range of the protective layer can also avoid the problem of the reflectivity of the reflective layer being reduced or the color deviation being caused by the provision of the protective layer. In a pixel array substrate of another embodiment of the present invention, a buffer layer is provided between the silver-based reflective layer and the insulating layer, the thickness of the horizontal portion of the buffer layer is in the range of 40 angstroms to 100 angstroms, and the thickness of the sidewall portion of the buffer layer within the opening of the insulating layer is in the range of 30 angstroms to 80 angstroms. In addition to increasing the adhesion between the silver-based reflective layer and the insulating layer, it can also avoid the problem of unclean etching during the patterning process of the reflective layer due to the buffer layer being too thick.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pixel array substrate, characterized in that: include: substrate; an insulating layer, disposed on the substrate; as well as A plurality of pixel structures are provided on the substrate, and each of the pixel structures comprises: an active component disposed between the substrate and the insulating layer; and A reflective layer is disposed on the insulating layer and comprises: a silver-based reflective layer having a reflective surface; and a protective layer covering the silver-based reflective layer, The thickness of the protective layer along the normal direction of the reflective surface is greater than or equal to 30 angstroms and less than or equal to 80 angstroms.

2. The pixel array substrate according to claim 1, wherein: The material of the protective layer includes a light-transmitting conductive material.

3. The pixel array substrate according to claim 1, wherein: The thickness of the protective layer is greater than or equal to 50 angstroms and less than or equal to 60 angstroms.

4. The pixel array substrate according to claim 1, wherein: The reflective layer further includes a buffer layer disposed between the insulating layer and the silver-based reflective layer, and a material of the buffer layer includes a conductive material.

5. The pixel array substrate according to claim 4, wherein: The insulating layer has an opening and a sidewall surface defining the opening, the silver-based reflective layer and the buffer layer extend to cover the sidewall surface of the insulating layer, and the first thickness of the sidewall portion of the buffer layer covering the sidewall surface along the normal direction of the sidewall surface is greater than or equal to 30 angstroms and less than or equal to 80 angstroms.

6. The pixel array substrate according to claim 5, wherein: The insulating layer also has a surface connected to the sidewall surface, the surface facing away from the substrate, and the second thickness of the buffer layer covering the horizontal portion of the surface of the insulating layer along the normal direction of the surface is greater than or equal to 40 angstroms and less than or equal to 100 angstroms.

7. The pixel array substrate according to claim 6, wherein: The first thickness is greater than or equal to 50 angstroms and less than or equal to 60 angstroms, and the second thickness is greater than or equal to 70 angstroms and less than or equal to 80 angstroms.

8. A pixel array substrate, characterized in that: include: substrate; an insulating layer, disposed on the substrate; as well as A plurality of pixel structures are provided on the substrate, and each of the pixel structures comprises: an active component disposed between the substrate and the insulating layer; and A reflective layer is disposed on the insulating layer and comprises: a silver-based reflective layer having a reflective surface; and a buffer layer, disposed between the insulating layer and the silver-based reflective layer, wherein the material of the buffer layer comprises a conductive material, The insulating layer has an opening and a sidewall surface defining the opening, the silver-based reflective layer and the buffer layer extend to cover the sidewall surface of the insulating layer, and the first thickness of the sidewall portion of the buffer layer covering the sidewall surface along the normal direction of the sidewall surface is greater than or equal to 30 angstroms and less than or equal to 80 angstroms.

9. The pixel array substrate according to claim 8, wherein: The reflective layer further comprises: A protective layer covers the silver-based reflective layer, wherein the thickness of the protective layer along the normal direction of the reflective surface is greater than or equal to 30 angstroms and less than or equal to 80 angstroms.

10. The pixel array substrate according to claim 8, wherein: The insulating layer also has a surface connected to the sidewall surface, the surface facing away from the substrate, and the second thickness of the buffer layer covering the horizontal portion of the surface of the insulating layer along the normal direction of the surface is greater than or equal to 40 angstroms and less than or equal to 100 angstroms.

Images