WO2021161379A1

WO2021161379A1 - Display panel and method for producing display device

Info

Publication number: WO2021161379A1
Application number: PCT/JP2020/005117
Authority: WO
Inventors: 克彦岸本; 徹増野; 幸也西岡
Original assignee: 堺ディスプレイプロダクト株式会社
Priority date: 2020-02-10
Filing date: 2020-02-10
Publication date: 2021-08-19

Abstract

A display panel (100A) having: a substrate (10); a plurality of pixel electrodes (32) supported by the substrate; a plurality of switching TFTs (Ts) connected one by one to each of the plurality of pixel electrodes; a plurality of scanning lines (22), with the plurality of switching TFTs being respectively connected to the plurality of scanning lines; a plurality of signal lines (26), with the plurality of switching TFTs being respectively connected to the plurality of signal lines; and, for each of a plurality of pixels, a first silicon island (20A) formed between the scanning lines and the substrate, and/or a second silicon island (20B) formed between the signal lines and the substrate. The first silicon island has a portion protruding in the width direction of the scanning lines when seen from a direction normal to the substrate, and the second silicon island has a portion protruding in the width direction of the signal lines when seen from the direction normal to the substrate.

Description

Manufacturing method of display panel and display device

The present invention relates to a method for manufacturing a display panel and a display device, and more particularly to a display panel capable of efficiently repairing defects in an active matrix type display panel and a method for manufacturing a display device using such a display panel.

Currently, active matrix type display panels (hereinafter, simply referred to as "display panels") having TFTs (switching TFTs) for each pixel, such as liquid crystal display panels and organic EL display panels, are widely used. As the miniaturization and high definition progress, the decrease in yield due to poor patterning of wiring has become a problem. In particular, an organic EL display panel for mobile use has, for example, a total of six or more TFTs including one switching TFT for each pixel (for example, Patent Documents 1 to 3). All of the disclosures of Patent Documents 1 to 3 are incorporated herein by reference.

Therefore, in order to improve the yield of the display panel, various methods for correcting defects are being studied. For example, Patent Document 4 describes a method of irradiating a predetermined layer of an organic layer of a pixel having a bright spot defect with a laser beam to cause multiphoton absorption to form a non-light emitting portion composed of the defective portion. It is disclosed.

JP-A-2007-279655 Japanese Unexamined Patent Publication No. 2010-0264888 Japanese Unexamined Patent Publication No. 2019-74729 Japanese Unexamined Patent Publication No. 2008-235178

The method described in Patent Document 4 cannot deal with the emission line defect. According to the study of the present inventor, when the signal line connected to the TFT of each pixel is short-circuited with the power supply line, a series of pixels (pixel strings) connected to the signal line become bright spots and are recognized as bright line defects. .. Short circuits between signal lines and power lines are often caused, for example, by poor patterning of these wirings. The emission line defect caused by such a short circuit of the wiring can be repaired by blocking the path for supplying the current or voltage to the pixel which is abnormally operating due to the poor patterning.

As a method of cutting off the path for supplying current or voltage to the pixel, a method of cutting the wiring by irradiating a laser beam is known. However, according to the study of the present inventor, although this method is effective for aluminum wiring and aluminum alloy wiring, it is formed of a refractory metal (for example, W, Mo, Ta, etc. having a melting point exceeding 2000 ° C.). It is not easy to cut the wire by irradiating the laser beam. Further, in order to improve reliability, the organic EL display panel is often provided with a sealing structure that covers the organic EL element (which constitutes each pixel), and in such a case, one of the laser beams. Since the portion is absorbed or reflected by the sealing structure, it may be difficult to cut even the aluminum wiring and the aluminum alloy wiring. Even if the laser beam is irradiated from the substrate side instead of from the sealing structure side, there is absorption or reflection by the substrate, so that there is a similar problem. Since the liquid crystal display panel has a pair of substrates facing each other via the liquid crystal layer, there is a problem that it becomes difficult to cut the wiring due to absorption by the substrates or the like.

Therefore, in the present invention, the wiring is easily cut by the laser beam irradiation even if the wiring is made of a refractory metal or when the laser beam is irradiated through the sealing structure or the substrate. It is an object of the present invention to provide a display panel capable of the present invention and a method for manufacturing a display device using such a display panel.

According to an embodiment of the present invention, the solutions described in the following items are provided.

[Item 1]
It has a substrate, a plurality of pixel electrodes supported by the substrate, and a plurality of switching TFTs connected to each of the plurality of pixel electrodes, and the pixel electrodes and the said are described for each of the plurality of pixels. A display panel having a switching TFT, the display panel further
A plurality of scanning lines, each of which is connected to any one of the plurality of scanning lines, and a plurality of scanning lines.
A plurality of signal lines, each of which is connected to any one of the plurality of signal lines, and a plurality of signal lines.
Each of the plurality of pixels has a first silicon island formed between the scanning line and the substrate and / or a second silicon island formed between the signal line and the substrate.
The first silicon island has a portion protruding in the width direction of the scanning line when viewed from the normal direction of the substrate, and the second silicon island has the signal when viewed from the normal direction of the substrate. A display panel that has a portion that protrudes in the width direction of the line.

[Item 2]
The display panel according to item 1, wherein the first silicon island is provided between the scanning line and the gate electrode of the switching TFT, and between the branch line of the scanning line and the substrate.

[Item 3]
The display panel according to item 1, wherein the second silicon island is provided between the signal line and the switching TFT, and between the branch line of the signal line and the substrate.

[Item 4]
The display panel according to item 1, wherein the second silicon island is provided between the main line of the signal line and the substrate for each of the plurality of pixels.

[Item 5]
It also has a plurality of power supply lines and a plurality of driving TFTs.
For each of the plurality of pixels, the gate electrode of the driving TFT is connected to the drain electrode of the switching TFT, the source electrode of the driving TFT is connected to the power supply line, and the driving TFT has. The drain electrode is connected to the pixel electrode and
The item according to any one of items 1 to 4, further comprising a third silicon island formed between the wiring connecting the gate electrode of the driving TFT and the drain electrode of the switching TFT and the substrate. Display panel.

[Item 6]
For each of the plurality of pixels, a third is provided between the drain electrode of the switching TFT and the pixel electrode, and between the wiring between the drain electrode and the pixel electrode of the switching TFT and the substrate. The display panel according to any one of items 1 to 4, further comprising a silicon island. The thickness of the third silicon island is, for example, 10 nm or more and 500 nm or less. When the thickness of the third silicon island is Tsi and the thickness of the wiring on the third silicon island is Trm, the relationship of 0.05 ≦ Tsi / Trm ≦ 1.0 is satisfied. The third silicon island may be formed of polysilicon or amorphous silicon. The third silicon island is formed of, for example, the same semiconductor as the first silicon island and / or the second silicon island.

[Item 7]
The display panel according to any one of items 1 to 6, wherein the plurality of scanning lines and / or the plurality of signal lines are made of a refractory metal.

[Item 8]
The display panel according to any one of items 1 to 7, wherein the thickness of the first silicon island and / or the second silicon island is independently 10 nm or more and 500 nm or less.

[Item 9]
The thickness of the first silicon island or the second silicon island is independently Tsi, and the thickness of an arbitrary scanning line on the first silicon island or the thickness of an arbitrary signal line on the second silicon island is set as Tsi, respectively. The display panel according to any one of items 1 to 8, which satisfies the relationship of 0.05 ≦ Tsi / Trm ≦ 1.0 when Trm is used independently.

[Item 10]
The display panel according to any one of items 1 to 9, wherein the first silicon island and / or the second silicon island is formed of polysilicon.

[Item 11]
The display panel according to any one of items 1 to 9, wherein the first silicon island and / or the second silicon island is formed of amorphous silicon.

[Item 12]
The display panel according to any one of items 1 to 11, wherein the protruding portion has an acute angle.

[Item 13]
The display panel according to any one of items 1 to 12, wherein the length of the protruding portion is 0.5 μm or more and 1 μm or less.

[Item 14]
The display panel according to any one of items 1 to 13, wherein the length of the first silicon island and / or the second silicon island orthogonal to the width direction is 1 μm or more and 2 μm or less.

[Item 15]
The display panel according to any one of items 1 to 14, wherein the substrate includes a polyimide film.

[Item 16]
The display panel according to item 15, wherein the polyimide film is colored.

[Item 17]
Step A to prepare the display panel according to any one of items 1 to 16 and
Step B for identifying a location where a short circuit occurs in the plurality of scanning lines or the plurality of signal lines, and
A laser beam is irradiated to at least the protruding portion of the first silicon island or the second silicon island closest to the location where the short circuit occurs in the scanning line or signal line including the location where the short circuit occurs. A method for manufacturing a display device, comprising the step C of cutting the scanning line or the signal line by melting the first silicon island or the second silicon island.

[Item 18]
In the step A, the display panel according to item 5 is prepared.
In the step B, a location where a short circuit occurs with any of the plurality of power supply lines in the plurality of signal lines is identified.
The method for manufacturing a display device according to item 17, wherein in the step C, the signal line is cut by melting the two second silicon islands sandwiching the short-circuited portion of the signal line in which the short circuit occurs.

[Item 19]
In the step C, the gate electrode of the driving TFT and the switching TFT are formed by melting the third silicon island of the pixel connected to the power supply line through the short-circuited portion of the signal line. The method for manufacturing a display device according to item 18, wherein the wiring connecting the drain electrode is cut.

[Item 20]
The method for manufacturing a display device according to any one of items 17 to 19, wherein in the step C, the laser beam is irradiated to the first silicon island or the second silicon island via the substrate.

[Item 21]
The substrate contains a colored polyimide film.
The method for manufacturing a display device according to item 20, wherein the laser beam has a wavelength of 500 nm or more.

[Item 22]
The substrate contains a transparent polyimide film.
The method for manufacturing a display device according to item 20, wherein the laser beam has a wavelength of 300 nm or more and less than 500 nm.

[Item 23]
The method for manufacturing a display device according to any one of items 17 to 22, wherein the step A is a step of preparing a top emission type organic EL display panel as the display panel.

According to an embodiment of the present invention, even if the wiring is made of a refractory metal, or if the laser beam is irradiated through the sealing structure or the substrate, the wiring can be easily provided by the laser beam irradiation. A display panel that can be cut and a method for manufacturing a display device using such a display panel are provided. The display panel according to the embodiment of the present invention can be easily cut even if the wiring is made of a metal other than the refractory metal (for example, aluminum, copper and alloys thereof).

It is a schematic plan view of one pixel of the OLED display panel 100A according to the embodiment of the present invention. It is a schematic plan view of one pixel of the OLED display panel 100B according to the embodiment of the present invention. It is a typical partial cross-sectional view of the OLED display panel according to the embodiment of the present invention. It is a typical partial cross-sectional view of the OLED display panel according to the embodiment of the present invention. It is a typical partial cross-sectional view of the OLED display panel according to the embodiment of the present invention. It is a figure which shows the example of the shape of a silicon island. It is a figure which shows another example of the shape of a silicon island. It is a figure which shows still another example of the shape of a silicon island. It is a figure which shows still another example of the shape of a silicon island. It is a figure corresponding to FIG. 2 of Patent Document 2. It is a figure corresponding to FIG. 5 of Patent Document 3.

Hereinafter, a display panel according to an embodiment of the present invention and a method for manufacturing a display device using such a display panel will be described with reference to the drawings. Here, an organic EL display panel (hereinafter, may be referred to as an OLED (Organic Light Emitting Diode) display panel) will be described as an example, but the embodiment according to the present invention is not limited to the OLED display panel and is a liquid crystal display panel. It can be widely applied to a display panel having a thin film transistor (TFT) for each pixel, such as a micro LED display panel having an arranged inorganic LED. Such a display panel having a TFT for each pixel is called an active matrix type display panel or a TFT type display panel, but here, for the sake of simplicity, it may be simply referred to as a display panel.

In mass production of TFT type display panels, so-called "multi-chamfering" is adopted. That is, individual display panels are manufactured by cutting a multi-chamfered display panel (sometimes referred to as a "mother display panel") including a plurality of display panels manufactured by using a mother substrate. An external circuit such as a power supply circuit or a control circuit is mounted on each display panel to manufacture a display device. Defect repair, such as cutting short-circuited parts of wiring, is performed in the state of the mother display panel or after cutting into individual display panels. In the present specification, for the sake of clarity, the step of repairing a defect in the display panel is described as being included in the process of manufacturing the display device, but the method of manufacturing the display panel may include the step of repairing the defect. good.

FIG. 1 is a schematic plan view of four pixels of the OLED display panel 100A according to the embodiment of the present invention. The OLED display panel 100A has a plurality of pixels arranged in a matrix. Pixels are defined herein as follows.

The OLED display panel has a plurality of pixels, and each of the plurality of pixels has a pixel electrode, a switching TFT, and a driving TFT. When the display panel is a color display panel capable of performing color display, three or more pixels among the plurality of pixels constitute one color display pixel. The color display pixel is composed of, for example, three pixels of R, G, and B (striped arrangement), or four pixels of, for example, R, G, G, and B (pentile arrangement and diamond pentile arrangement). A definition is also known in the present specification in which a "pixel" is a sub-pixel and a "color display pixel" is a pixel. The micro LED display panel also has a plurality of pixels, and each pixel has a switching TFT and a driving TFT, respectively. The micro LED includes a pixel electrode.

In the case of a striped arrangement, for example, three pixels constituting one color display pixel are selected by switching TFTs connected to a common scanning line, and display signals (data signals) are transmitted from different signal lines to the gate of the driving TFT. A current of a magnitude corresponding to the signal is supplied from the power supply line via the driving TFT. The signal line is typically provided corresponding to the color sequence. That is, for a certain signal line, for example, only R pixels are connected. On the other hand, in the case of the diamond pen tile arrangement, for example, the four switching TFTs included in the four pixels constituting one color display pixel are connected to two or more scanning lines. In addition, pixels that display different colors are connected to one signal line. As described above, the connection relationship between the switching TFT for selecting pixels and the scanning line and the signal line may differ depending on the pixel arrangement (color arrangement).

Further, the liquid crystal display panel typically has only a signal line (data line), a scanning line, and one switching TFT for each pixel, whereas the OLED display panel has at least one for each pixel. One driving TFT is required in addition to the one switching TFT, and usually, a total of six or more TFTs including one switching TFT for each pixel are provided (Patent Documents 1 to 3).

In the following, for the sake of simplicity, the switching TFT, the driving TFT, the scanning line connected to the switching TFT, the signal line (including the main line and the branch line) and the power supply line connected to the driving TFT are referred to. I will explain only the relationship between. Further, the electrode directly connected to the driving TFT (drain) is referred to as a pixel electrode. In the OLED display panel, the pixel electrode can be a cathode or an anode. In the OLED display panel, an electrode (anode or cathode) facing the pixel electrode via an organic layer (including a light emitting layer), and in a liquid crystal display panel, an electrode facing the pixel electrode via a liquid crystal layer (common electrode). Furthermore, the description of the capacitance portion provided for each pixel will be omitted. The structures other than the one switching TFT provided for each pixel, the one driving TFT, the signal line connected to the driving TFT, the power supply line, and the pixel electrode, which will be described below, have the same structure as a known display panel. It can be widely applied.

As shown in FIG. 1, the pixels Px of the OLED display panel 100A include a scanning line (SC) 22, a signal line (DA) 26, a power supply line (EL VDD) 28, one switching TFT Ts, and one. It has a driving TFT Te. The scanning line 22 has a main line 22M extending in the row direction and a branch line 22B branched from the main line 22M, and the signal line 26 has a main line 26M extending in the column direction and a branch line 26B branched from the main line 26M. doing. The extension portion of the branch line 22B of the scanning line 22 constitutes the gate electrode TsG of the TFT Ts, and the extension portion of the branch line 26B of the signal line 26 constitutes the source electrode TsS of the TFT Ts, and the drain electrode TsD. Is formed of the same conductive layer as the signal line 26. The drain electrode TsD of the TFT Ts is formed so as to be connected to the gate electrode TeG of the TFT Te via, for example, a contact hole Ch.

The source electrode TeS of the TFT Te is composed of a part of the power supply line 28, and the drain electrode TeD is formed of the same conductive layer as the power supply line 28. The gate electrode TeG of the driving TFT Te is formed of the same conductive layer as the scanning line 22, and may be formed of a refractory metal. The drain electrode TeD of the TFT Te is connected to the pixel electrode 32 (see FIG. 3A). The semiconductor layer 20a included in the TFT Te and the semiconductor layer 20b included in the TFT Ts are formed of the same semiconductor layer. In the present specification, the gate electrode, the source electrode, and the drain electrode may refer to a portion of the conductive layer constituting each of the conductive layers, which overlaps with the semiconductor layer.

Here, the scanning line 22 is supplied with a scanning signal from the gate driver GD1 (not shown) connected to the terminal (gate terminal) of the scanning line 22 in the direction indicated by the arrow in FIG. 1 (from right to left). Further, a data signal is supplied to the signal line 26 from a source driver SD1 (not shown) connected to a terminal (source terminal) of the signal line 26 in the direction of the arrow in FIG. 1 (from top to bottom).

The driving TFT Te corresponds to, for example, the TFT T3 in FIG. 2 of Patent Document 2 shown in FIG. 6 and the TFT M1 in FIG. 5 of Patent Document 3 shown in FIG. Further, the switching TFT Ts in FIG. 1 corresponds to the TFT T4 in FIG. 2 of Patent Document 2 shown in FIG. 6 and the TFT M3 in FIG. 5 of Patent Document 3 shown in FIG.

First, the repair of bright spot defects will be explained.

The OLED display panel 100A includes a scanning line 22 and a switching TFT Ts (gate electrode TsG) when viewed from the gate terminal to which the gate driver GD1 is connected (that is, when viewed from the direction of the arrow GD1 in FIG. 1). The first silicon island 20A formed between the branch line 22B branched from the main line 22M of the scanning line 22 toward the switching TFT Ts (gate electrode TsG) and the substrate is provided between the two. Further, the OLED display panel 100A is located between the signal line 26 and the switching TFT Ts when viewed from the source terminal to which the source driver SD1 is connected (that is, when viewed from the direction of the arrow SD1 in FIG. 1). It has a second silicon island 20B formed between the branch line 26B branched from the main line 26M of the signal line 26 toward the switching TFT Ts (source electrode TsS) and the substrate.

Here, a state in which the pixel Px does not change the brightness according to the corresponding data signal and black cannot be displayed is referred to as a bright spot defect state, and a pixel in such a state is referred to as a bright spot defect. Further, when the pixels of the bright spot defect are in a continuous state, such a pixel array is referred to as a bright line defect. When the scanning line 22 is cut at the position of the first silicon island 20A, the scanning signal supplied from the gate driver GD1 does not reach the switching TFT Ts. Therefore, the switching TFT Ts is always off, and as a result, the driving TFT Te is not turned on, so that no current is supplied to the pixel electrode 32 and the pixel Px does not emit light. Further, if the signal line 26 is cut at the position of the second silicon island 20B, the data signal supplied from the source driver SD1 does not reach the switching TFT Ts. Therefore, in this case as well, the driving TFT Te does not operate. Therefore, since no current is supplied to the pixel electrode 32, the pixel Px does not emit light. By doing so, the pixel Px that was in the bright spot defect state can be always turned off (black display state). The position where the first silicon island 20A and / or the second silicon island 20B is provided is not limited to the example shown in FIG. 1, and is driven by cutting the wiring on the first silicon island 20A and / or the second silicon island 20B. It is only necessary to prevent the voltage for turning on the driving TFT Te from being supplied to the gate electrode TeG of the driving TFT Te.

The first silicon island 20A and the second silicon island 20B are formed of polysilicon or amorphous silicon. Polysilicon or amorphous silicon absorbs light more easily than metals and generates heat by absorbing light. The heat melts the polysilicon or amorphous silicon, thereby cutting the scanning line 22 formed on the first silicon island 20A and / or the signal line 26 formed on the second silicon island 20B. When the scanning lines 22 and / or the signal lines 26 are made of refractory metal, it is difficult to cut them by irradiating these wires directly with a laser beam, but the first silicon island 20A and the second silicon By using the island 20B, it is possible to cut these wirings efficiently and surely.

The first silicon island 20A and the second silicon island 20B can be formed from the same semiconductor film at the same time, for example, when forming the semiconductor layer 20a of the driving TFT Te and / or the semiconductor layer 20b of the switching TFT Ts. For example, when the semiconductor layer of the driving TFT Te and / or the switching TFT Ts is formed of polysilicon, the first silicon island 20A and the second silicon island 20B may also be formed of polysilicon, or may not be crystallized. , May be formed of amorphous silicon. The wavelength of the laser beam to be irradiated may be appropriately selected depending on polysilicon or amorphous.

The first silicon island 20A has a portion protruding in the width direction of the branch line 22B of the scanning line 22 when viewed from the normal direction of the substrate, and the second silicon island 20B has a portion protruding in the width direction of the branch line 22B of the scanning line 22, and the second silicon island 20B has a portion when viewed from the normal direction of the substrate. It has a portion protruding in the width direction of the branch line 26B of the signal line 26. If the first silicon island 20A and the second silicon island 20B have a portion protruding from these wirings, even if the laser beam is irradiated from above the substrate, the protruding portion absorbs the laser beam. Can be disconnected.

Also, if the protruding part has an acute angle, there is an advantage that alignment when irradiating the laser beam becomes easy. The length of the protruding portion is, for example, 0.5 μm or more and 1 μm or less. If it is less than 0.5 μm, it may be difficult to identify silicon islands with an optical camera using visible light attached to a device that irradiates a laser beam. Further, the length orthogonal to the width direction of the first silicon island 20A and / or the second silicon island 20B is 1 μm or more and 2 μm or less. The sizes and shapes of the first silicon island 20A and the second silicon island 20B will be described later with reference to FIGS. 4A, 4B, 5A, and 5B. The same applies to the second silicon islands 20C1 and 20C2 and the third silicon island 20D, which will be described later.

The thickness of the first silicon island 20A and / or the second silicon island 20B is independently, for example, 10 nm or more and 500 nm or less. For example, when the semiconductor layer 20a of the driving TFT Te is formed at the same time, the thickness of the first silicon island 20A and / or the second silicon island 20B is independently, for example, 10 nm or more and 50 nm or less. The thickness of the first silicon island 20A or the second silicon island 20B is independently set as Tsi, and the thickness of the scanning line 22 on the first silicon island 20A or the thickness of the signal line 26 on the second silicon island 20B is set respectively. When Trm is used independently, it is preferable to satisfy the relationship of 0.05 ≦ Tsi / Trm ≦ 1.0. If this relationship is satisfied, these wires can be cut efficiently.

FIG. 2 shows a schematic plan view of four pixels of another OLED display panel 100B according to the embodiment of the present invention. For example, it is assumed that the power supply line 28 (n-1 row) and the signal line 26 (n row) are short-circuited at the short-circuited portion DF1 shown in FIG. In this case, even if a display signal (data signal) that changes corresponding to each pixel is supplied from the source driver SD1 via the signal line 26, it is higher than the display signal corresponding to the highest gradation from the power supply line 28. Since the voltage is supplied, all of the pixels Px in the single row connected to the signal line 26 (n rows) in which the short circuit occurs have the brightness corresponding to the highest gradation or higher gradation, and the image to be displayed has the brightness corresponding to the highest gradation or higher. Regardless, it will be recognized as a bright line. When the power supply line 28 (n row) and the signal line 26 (n row) are short-circuited at the short-circuited portion DF2 in FIG. 2, only the pixel Px (m, n) becomes a bright spot.

As the definition of OLED display panels progresses, gate drivers will be placed on both sides of the scanning line and source drivers will be placed on both sides of the signal line in order to suppress delays and distortions in the scanning signal and display signal due to the resistance of the wiring. However, a configuration in which each signal is supplied from both sides (hereinafter, may be referred to as a "double-sided input structure") may be adopted.

The OLED display panel 100B shown in FIG. 2 has a double-sided input structure. Therefore, in the OLED display panel 100B, the scanning signal (scan signal) and the display signal (data signal) are supplied to the switching TFT Ts and the driving TFT Te from the drivers arranged on both sides, respectively. In the OLED display panel 100B, it is assumed that n rows of pixels Px connected to the signal line 26 have a emission line defect. The cause (short-circuited portion) causing the emission line defect is the power supply line 28 of the pixel Px (m, n-1) adjacent to the signal line 26 in the pixel Px (m, n).

The defect repair method of the OLED display panel 100B in which such a bright line defect has occurred will be described.

First, when the signal line 26 is cut at the position of the second silicon island 20C1 of the pixel Px (m, n), the high voltage (abnormal voltage) supplied from the power supply line 28 is higher than that of the pixel Px (m-1, n). The pixels in the previous stage (upper row) are no longer reached, and the correct display signal is supplied to the pixels in the previous stage from the pixels Px (m-1, n) via the signal line 26. Further, when the signal line 26 is cut at the position of the second silicon island 20C2 included in the pixel Px (m + 1, n), the high voltage (abnormal voltage) supplied from the power supply line 28 is higher than that of the pixel Px (m + 1, n). Also does not reach the pixels in the latter stage (lower row), and the pixels in one vertical column (n columns) connected to the signal line 26 other than the pixels Px (m, n) return to the normal state.

However, with this alone, the high voltage of the power supply line 28 continues to be applied to the source electrode TsS of the switching TFT Ts of the pixel Px (m, n), so when the switching TFT Ts is turned on, the gate electrode of the driving TFT Te As a result of applying a high voltage to the pixel Px (m, n), the pixel Px (m, n) becomes a bright spot defect. This bright spot defect is cut at a position where the third silicon island 20D is provided between the drain electrode TsD of the switching TFT Ts and the gate electrode TeG of the driving TFT Te, and drives the pixel Px (m, n). By always turning off the TFT Te for use, black spots can be formed by preventing current from being supplied from the power supply line 28 to the pixel electrode 32.

As a method of blackening one pixel, in addition to cutting the third silicon island 20D described above, the organic material layer formed on the pixel electrode 32 is irradiated with a laser to locally make the organic material layer. It is also possible to make it non-luminous by heating it to about 100 ° C.

By cutting the wiring at an appropriate position as described above, it is possible to blacken only one pixel in which a short circuit has occurred and display the other pixels normally in the pixel sequence having a bright line defect.

The second silicon island and / or the third silicon island is not limited to the example shown in FIG. 2, but is somewhere below the signal line 26, and the drain electrode TsD of the switching TFT Ts and the gate electrode TeG of the driving TFT Te. It may be provided somewhere between and.

The

OLED display panels

100A and 100B illustrated in FIG. 1 or 2 have, for example, a cross-sectional structure as shown in FIGS. 3A, 3B and 3C. FIG. 3A is a schematic cross-sectional view of a portion including the driving TFT Te, and FIG. 3B is a schematic cross-sectional view of the portion including the first silicon island 20A provided below the scanning line 22. FIG. 3C. Includes a second silicon island 20B, a second silicon island 20C1, 20C2, and a third silicon island 20D provided under the drain electrode of the signal line 26 or the switching TFT Ts formed of the same conductive layer as the signal line 26. It is a schematic cross-sectional view of a part. The switching TFT Ts is a signal line 26 instead of the source electrode TeS and the drain electrode TeD (formed by the same conductive layer as the power supply line 28) in the cross-sectional structure of the driving TFT Te shown in FIG. 3A. The source electrode TsS and the drain electrode TsD may be formed using the same conductive layer.

Here, since the scanning line 22 is formed ahead of the signal line 26 (the side closer to the substrate 10), only the scanning line 22 may be formed of the refractory metal. Further, contrary to this example, when the signal line 26 is formed ahead of the scanning line 22 (the side closer to the substrate 10), only the signal line 26 may be formed of the refractory metal. In such a case, the silicon islands may be provided only under the wiring formed earlier (the side closer to the substrate 10). The wiring formed earlier is often made of a refractory metal having high heat resistance because it undergoes a thermal history in a subsequent process. Of course, the present invention is not limited to this, and both the scanning line 22 and the signal line 26 may be formed of a refractory metal.

The substrate 10 has, for example, a laminated structure of an inorganic insulating layer 15 / a polyimide film 14 / an inorganic insulating layer 13 / a polyimide film 12. The thicknesses of the

polyimide films

12 and 14 are, for example, about 6 μm, and the thicknesses of the inorganic insulating

layers

13 and 15 are, for example, 0.5 μm and 2 μm, respectively.

As shown in FIG. 3A, the OLED display panel includes a lower electrode (pixel electrode) 32, an organic layer 34 formed on the lower electrode 32, and an upper electrode 36 formed on the organic layer 34. Here, the lower electrode 32 and the upper electrode 36 form, for example, an anode and a cathode, respectively. The upper electrode 36 is a common electrode formed over a plurality of pixels in the display area. On the other hand, the lower electrode (pixel electrode) 32 is formed for each pixel. Each pixel of the OLED display panel has an OLED element.

The lower electrode 32 of the OLED element is formed on the flattening layer 27, and is connected to the drain electrode TeD in the through hole formed in the flattening layer 27.

The bank layer 33 is formed between the lower electrode 32 and the organic layer 34 so as to cover the peripheral portion of the lower electrode 32. If the bank layer 33 is present between the lower electrode 32 and the organic layer 34, holes are not injected from the lower electrode 32 into the organic layer 34. Therefore, since the region where the bank layer 33 exists does not function as a pixel, the bank layer 33 defines the outer edge of the pixel.

The driving TFT Te is a semiconductor layer 20a formed on the substrate 10, a gate insulating layer 21 formed on the semiconductor layer 20a, a gate electrode TeG formed on the gate insulating layer 21, and a gate electrode TeG. It has the

interlayer insulating layers

23 and 25 formed in the above, and the source electrode TeS and the drain electrode TeD formed on the interlayer insulating layer 25. The source electrode TeS and the drain electrode TeD are connected to the source region and the drain region of the semiconductor layer 20a, respectively, in the contact holes formed in the

interlayer insulating layers

25 and 23 and the gate insulating layer 21.

The gate electrode TeG is included in the same metal layer as the scanning line 22 and the like, and the source electrode TeS and the drain electrode TeD are included in the same metal layer as the signal line 26. The metal layer including the scanning line 22 (gate electrode TsG of the switching TFT Ts) is the first metal layer, the metal layer including the signal line 26 is the second metal layer, and the metal layer including the power supply line 28 is the third metal layer. Then, the OLED display panel may have a fourth metal layer in addition to these metal layers. The fourth metal layer can be formed, for example, between the interlayer insulating layer 23 and the interlayer insulating layer 25. For example, in FIG. 3C, instead of the signal line 26, a wiring (electrically connected to the signal line 26) formed by using the fourth metal layer may be used at least partially. That is, when the portion of the signal line 26 arranged so as to overlap the second silicon island 20B, the second silicon islands 20C1, 20C2, and the third silicon island 20D is formed by the fourth metal layer, the fourth metal layer is the first. Since it is closer to the second silicon island 20B, the second silicon island 20C1, 20C2, and the third silicon island 20D than the two metal layers, the second silicon island 20B, the second silicon island 20C1, 20C2, and the third silicon island 20D are melted. This makes it possible to cut more reliably.

Here, an example is shown in which each pixel has a first silicon island, a second silicon island, and a third silicon island, but in color display pixel units, the first silicon island, the second silicon island, and A third silicon island may be provided. That is, the color display pixels including the pixels in which the short-circuit defect has occurred may be hidden. For example, in a display panel having a resolution of 400 ppi, even if several pixels are continuously hidden, it is not noticeable.

The laser beam may irradiate the first silicon island, the second silicon island, and the third silicon island via the substrate. For example, when the substrate contains a colored polyimide film, the laser beam preferably has a wavelength of 500 nm or more. For example, YAG of 539 nm or 532 nm can be used.

Further, when the substrate contains a transparent polyimide film (PI), the laser beam preferably has a wavelength of 300 nm or more and less than 500 nm, more preferably 400 nm or more and less than 500 nm.

Polysilicon can be destroyed even with the fundamental wave (1064 nm) of the YAG laser. However, in the case of visible light, it is possible to align by irradiating a laser beam with reduced output (the illuminated part can be visually recognized), whereas in the case of infrared light, an infrared sensor is used to do the same. Must be used. For example, a CCD sensor or a CMOS sensor that is sensitive not only in the visible light region but also in the near infrared region can be preferably used (however, the confirmation screen is a black and white image).

When irradiating a laser beam through a colored polyimide (that is, a non-transparent polyimide, typically exhibiting brown color), the wavelength is 500 nm or more, and the upper limit is about the oscillation wavelength of the YAG laser. If it is a transparent PI, a blue-violet laser having a wavelength of about 400 nm or a blue laser having a wavelength of about 450 nm can also be used. Since the transmittance of ultraviolet rays on a substrate (resin substrate) made of a resin such as PI is low, an ultraviolet laser is not suitable for laser irradiation through the substrate. However, for laser irradiation that does not pass through a substrate, an ultraviolet laser is preferable because it has a higher energy. Further, the shorter the wavelength, the more suitable for high-definition processing.

With reference to FIGS. 4A, 4B, 5A, 5B, the size of the silicon islands used as the first silicon island 20A, the second silicon island 20B, the second silicon island 20C1, 20C2, the third silicon island 20D, and the like. The shape will be described. 4A, 4B, 5A, and 5B are plan views showing the silicon island and the

wirings

22 and 26 formed on the silicon island, and the silicon island side (board) so that the outer shape of the silicon island can be easily understood. The figure seen from the side) is shown.

The silicon island 20E shown in FIG. 4A and the silicon island 20F shown in FIG. 4B have portions Sc and Sd protruding in the width direction of the

wirings

22 and 26 when viewed from the normal direction of the substrate. If the protruding portion is provided, even if the laser beam is irradiated from above the substrate, the protruding portion absorbs the laser beam, so that the wiring can be cut. Further, if the protruding portion has an acute angle, there is an advantage that alignment when irradiating the laser beam becomes easy. The lengths Lx and Ly of the protruding portion are, for example, 0.5 μm or more and 1 μm or less. If it is less than 0.5 μm, it may be difficult to identify silicon islands with an optical camera using visible light attached to a device that irradiates a laser beam. The length of the silicon island 20E orthogonal to the width direction is 1 μm or more and 2 μm or less.

As shown in FIGS. 5A and 5B, for example, the branch line 22B (see FIG. 1) branched from the main line 22M of the scanning line 22 toward the gate electrode TsG may be cut at the

silicon island

20G or 20H. good. If the

silicon islands

20G or 20H are arranged corresponding to the branch structure, the signal can be prevented from being supplied to the gate electrode TsG by cutting only one place (branch structure) regardless of the signal input direction. The portions (three locations) protruding from the wiring preferably have an acute angle, and the lengths Lx and Ly of the protruding portions are, for example, 0.5 μm or more and 1 μm or less. Similarly, the portion where the source electrode TsS branches from the signal line 26 (see FIG. 1) may be cut at the

silicon island

20G or 20H.

Here, the embodiment according to the present invention has been described by taking an OLED display panel as an example, but the present invention is not limited to this, and can be applied to, for example, an inorganic LED display panel and a micro LED display panel in which a large number of inorganic LED devices are arranged. .. Similar to the OLED display panel, these display panels have a power supply line in addition to the scanning line and the signal line, so that a bright line defect can occur like the OLED display panel. , The emission line defect can be repaired.

The liquid crystal display panel does not have a power supply line and a driving TFT like the OLED display panel, and the drain electrode of the switching TFT is directly connected to the pixel electrode. Even in the liquid crystal display panel, when a short circuit defect (for example, between the signal line and the common electrode) occurs in the signal line, a bright spot defect and / or a bright line defect may occur. Even in such a case, the bright spot defect and / or the bright line defect can be repaired by applying the present invention. That is, as shown in FIG. 1, a silicon island is formed between the branch line of the scanning line and the substrate between the scanning line and the gate electrode of the switching TFT, and / or the signal line and the switching are used. A silicon island may be formed between the branch line of the signal line and the substrate between the source electrode of the TFT and the substrate. Alternatively, as shown in FIG. 2, a silicon island may be formed between the main line of the signal line and the substrate for each pixel, or a drain electrode may be formed between the drain electrode and the pixel electrode of the switching TFT. Silicon islands may be formed between the wiring between the pixel electrodes and the substrate.

The present invention can be used in an active matrix type display panel and a method for manufacturing a display device using such a display panel.

10: Substrate 12: Polygon film 13: Inorganic insulating layer 14: Polyethylene film 15: Inorganic insulating layer 20A: First silicon island 20B: Second silicon island (below the branch line) 20C1, 20C2: Second silicon island (main line) Bottom) 20D:

Third silicon islands

20a, 20b: Semiconductor layer 21: Gate insulation layer 22: Scanning lines 23, 25: Thin film transistor insulation layer 26: Signal line 28: Power supply line 32: Pixel electrode (lower electrode) 33: Bank layer 34: Organic layer 36:

Upper electrodes

100A, 100B: OLED display panel DF1: Short-circuited part DF2: Short-circuited part GD1: Gate driver SD1: Source driver Ts: Switching TFT Te: Driving TFT

Claims

It has a substrate, a plurality of pixel electrodes supported by the substrate, and a plurality of switching TFTs connected to each of the plurality of pixel electrodes, and the pixel electrodes and the said are described for each of the plurality of pixels. A display panel having a switching TFT, the display panel further
A plurality of scanning lines, each of which is connected to any one of the plurality of scanning lines, and a plurality of scanning lines.
A plurality of signal lines, each of which is connected to any one of the plurality of signal lines, and a plurality of signal lines.
Each of the plurality of pixels has a first silicon island formed between the scanning line and the substrate and / or a second silicon island formed between the signal line and the substrate.
The first silicon island has a portion protruding in the width direction of the scanning line when viewed from the normal direction of the substrate, and the second silicon island has the signal when viewed from the normal direction of the substrate. A display panel that has a portion that protrudes in the width direction of the line.
The display panel according to claim 1, wherein the first silicon island is provided between the scanning line and the gate electrode of the switching TFT, and between the branch line of the scanning line and the substrate.
The display panel according to claim 1, wherein the second silicon island is provided between the signal line and the switching TFT, and between the branch line of the signal line and the substrate.
The display panel according to claim 1, wherein the second silicon island is provided between the main line of the signal line and the substrate for each of the plurality of pixels.
It also has a plurality of power supply lines and a plurality of driving TFTs.
For each of the plurality of pixels, the gate electrode of the driving TFT is connected to the drain electrode of the switching TFT, the source electrode of the driving TFT is connected to the power supply line, and the driving TFT has. The drain electrode is connected to the pixel electrode and
The invention according to any one of claims 1 to 4, further comprising a third silicon island formed between the wiring connecting the gate electrode of the driving TFT and the drain electrode of the switching TFT and the substrate. Display panel.
For each of the plurality of pixels, between the drain electrode of the switching TFT and the pixel electrode, the third silicon between the wiring between the drain electrode and the pixel electrode of the switching TFT and the substrate. The display panel according to any one of claims 1 to 4, further comprising an island.
The display panel according to any one of claims 1 to 6, wherein the plurality of scanning lines and / or the plurality of signal lines are made of a refractory metal.
The display panel according to any one of claims 1 to 7, wherein the thickness of the first silicon island and / or the second silicon island is independently 10 nm or more and 500 nm or less.
The thickness of the first silicon island or the second silicon island is independently set as Tsi, and the thickness of an arbitrary scanning line on the first silicon island or the thickness of an arbitrary signal line on the second silicon island is set as Tsi, respectively. The display panel according to any one of claims 1 to 8, which satisfies the relationship of 0.05 ≦ Tsi / Trm ≦ 1.0 when Trm is used independently.
The display panel according to any one of claims 1 to 9, wherein the first silicon island and / or the second silicon island is formed of polysilicon.
The display panel according to any one of claims 1 to 9, wherein the first silicon island and / or the second silicon island is made of amorphous silicon.
The display panel according to any one of claims 1 to 11, wherein the protruding portion has an acute angle.
The display panel according to any one of claims 1 to 12, wherein the length of the protruding portion is 0.5 μm or more and 1 μm or less.
The display panel according to any one of claims 1 to 13, wherein the length of the first silicon island and / or the second silicon island orthogonal to the width direction is 1 μm or more and 2 μm or less.
The display panel according to any one of claims 1 to 14, wherein the substrate includes a polyimide film.
The display panel according to claim 15, wherein the polyimide film is colored.
A step of preparing the display panel according to any one of claims 1 to 16,
Step B for identifying a location where a short circuit occurs in the plurality of scanning lines or the plurality of signal lines, and
A laser beam is irradiated to at least the protruding portion of the first silicon island or the second silicon island closest to the location where the short circuit occurs in the scanning line or signal line including the location where the short circuit occurs. A method for manufacturing a display device, comprising the step C of cutting the scanning line or the signal line by melting the first silicon island or the second silicon island.
In the step A, the display panel according to claim 5 is prepared.
In the step B, a location where a short circuit occurs with any of the plurality of power supply lines in the plurality of signal lines is identified.
The method for manufacturing a display device according to claim 17, wherein in the step C, the signal line is cut by melting the two second silicon islands sandwiching the short-circuited portion of the signal line in which the short circuit occurs. ..
In the step C, the gate electrode of the driving TFT and the switching TFT are formed by melting the third silicon island of the pixel connected to the power supply line through the short-circuited portion of the signal line. The method of manufacturing a display device according to claim 18, wherein the wiring connecting the drain electrode is cut.
The method for manufacturing a display device according to any one of claims 17 to 19, wherein in the step C, the laser beam is irradiated to the first silicon island or the second silicon island via the substrate.
The substrate contains a colored polyimide film.
The method for manufacturing a display device according to claim 20, wherein the laser beam has a wavelength of 500 nm or more.
The substrate contains a transparent polyimide film.
The method for manufacturing a display device according to claim 20, wherein the laser beam has a wavelength of 300 nm or more and less than 500 nm.
The method for manufacturing a display device according to any one of claims 17 to 22, wherein the step A is a step of preparing a top emission type organic EL display panel as the display panel.