JP2002244576A - Method for manufacturing display device, display device and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device and a method for manufacturing the same certainly transferring elements constructed with thin film devices or the like and improving the productivity. SOLUTION: Thin film transistor elements 12 are formed in a thickly arrayed state on a substrate 11 for elements formation. Each block of the elements 13 consisting of a plurality of lots respectively comprising an extracted part of the thin film transistor elements 12 in the thickly arrayed state is transferred to a substrate 14 for the display device. Efficiency of transfer is heightened compared with a case in which individual elements are respectively transferred and handling turns out to be easy because the size of the transferred unit grows larger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a display device for transferring an element such as a pixel control element composed of a thin film device or the like to a predetermined position on a substrate, and a display device provided with a plurality of display elements. And a liquid crystal display device provided with a pixel control element composed of a thin film device or the like.

[0002]

2. Description of the Related Art As a liquid crystal display device, pixel control elements such as thin film transistors (TFT) are arranged in a matrix on a display device substrate, and a wiring layer connected to each pixel control element is formed to form a required peripheral circuit. An active matrix type liquid crystal display device that displays an image based on a liquid crystal drive signal supplied from a liquid crystal display device is widely known. Each pixel control element is connected to a pixel electrode consisting of a transparent electrode formed for each pixel, and the voltage between the pixel electrode and a common electrode formed on the substrate on the opposite side is changed to change the voltage between the substrates. It operates so as to change the alignment state of the liquid crystal material arranged in the matrix.

Incidentally, since a pixel control element such as a thin film transistor (TFT) is formed by using a semiconductor manufacturing process accompanied by a high-temperature heat treatment, the element formation precision largely depends on the precision of alignment of a mask and the like. 2. Description of the Related Art Forming using a substrate having high heat resistance such as a quartz glass substrate has been performed. However, it is not easy to form a fine element with high precision over a large area. Therefore, once a pixel control element such as a thin film transistor (TFT) is formed on a substrate for element formation while performing fine processing, and after forming, A method of transferring the thin film transistor on a display substrate has been studied.

A method for transferring such a pixel control element to a display device substrate is disclosed in, for example, Japanese Patent Application Laid-Open No. H11-267.
As described in JP-A-34-34, there is known a method of manufacturing a liquid crystal display device in which a thin film device is formed after a separation layer is formed on a substrate, and the separation layer is separated by laser irradiation from the substrate side. ing. Further, Japanese Patent Application Laid-Open No. 10-177
In the technique described in Japanese Patent Application Publication No. 187, first, a transfer block for transferring a thin film structure block onto a transfer body is formed by using a transfer method of a thin film structure, and the transfer is performed for each transfer block. A technique for manufacturing the device is disclosed, and by using such a technique, the degree of freedom in selecting a substrate can be increased.

[0005]

The above-described transfer method has an advantage that the degree of freedom in selecting a substrate used as an apparatus can be increased. However, for example, in the technology described in JP-A-11-26734, a thin-film device is transferred from an element-forming substrate onto a transfer body to manufacture an apparatus as a product. Because it is transferred while the pitch is maintained,
In the case of forming a liquid crystal display device having a large area, it is necessary to form an element in a large area from the state of the element forming substrate before transfer, and there is a limit to the fine processing.

In the technique described in Japanese Patent Application Laid-Open No. H10-177187, a transfer method is performed for each transfer block having a plurality of thin film devices. The thin film device can be transferred block by block. But,
Since the transfer block itself has a structure in which the pixel electrode is also built at the same time, the space between the elements in the block is maintained before and after transfer, and it is also necessary to configure a large-area display device Then, fine processing according to the area is required.

On the other hand, these techniques are disclosed in
In the method of manufacturing a liquid crystal display device described in Japanese Patent No. 142828, a thin film transistor element is first formed at a 1 / m × 1 / n pitch on a transfer source substrate, and the pitch of the thin film transistor element is increased by a factor of m and n. A method of transferring while enlarging is described. However, according to the technique disclosed in Japanese Patent Application Laid-Open No. H11-142878, when the transfer is ultimately performed selectively from the transfer source substrate to the substrate for the liquid crystal display device, the transfer is performed for each individual thin film transistor element. In addition, since the bonding force is weakened by selectively irradiating light to the separation film interposed between the element and the transfer source substrate during transfer, the transfer itself is not easy. Further, even when the transfer is performed so as to enlarge the space between the thin film transistors, the unit to be transferred is for each individual device, and the accuracy of the transfer is important for increasing the throughput, and even a single thin film transistor cannot be transferred. In that case, the whole will be defective.

In view of the above-mentioned technical problems, the present invention provides a method of manufacturing a display device capable of reliably transferring elements and increasing the productivity thereof, and a display manufactured by the manufacturing method. A device and a liquid crystal display device are provided.

[0009]

In order to solve the above-mentioned problems, a method of manufacturing a display device according to the present invention comprises forming elements on an element forming substrate in a densely arranged state, and arranging the elements in the densely arranged state. It is characterized in that a part of this state is transferred to a display device substrate for each of a plurality of sets taken out. In this manufacturing method, the element is, for example, a light emitting element, a pixel control element, a photoelectric conversion element, a piezoelectric element, a thin film transistor element,
It may be an element selected from a thin film diode element, a resistance element, a switching element, a micro magnetic element, a micro optical element, or a part thereof. At least a part of a wiring layer electrically connected to the element may be a common wiring layer between adjacent elements.

According to the method of manufacturing a display device of the present invention, by transferring the elements for each of a plurality of sets, the transfer efficiency is increased as compared with the case where the individual elements are transferred. Since the size of the unit to be used also becomes large, handling becomes easy. The plurality of sets have a structure in which a part of the densely arranged state is taken out, and do not have a separated structure such as a transfer block, which is advantageous in forming a large-area display device. .

In a display device according to the present invention, in a display device in which display elements are arranged in a matrix, each set of display elements comprising a plurality of display elements is arranged adjacent to each other, and At least a part of a wiring layer electrically connected to the display element is a common wiring layer between adjacent display elements.

According to the display device of the present invention, at least a part of the wiring layer electrically connected to the display element is a common wiring layer between the adjacent display elements, and is transferred at a time. Even if the display elements are arranged inside, the area occupied by the wiring layer itself can be reduced.

Further, in the liquid crystal display device of the present invention, in a liquid crystal display device in which pixel electrodes for driving a liquid crystal material are arranged in a matrix, each set of a plurality of pixel control elements is provided. A liquid crystal display, characterized in that each pixel electrode is formed in a pattern in which no wiring layer is interposed between at least one side of a substantially rectangular pixel electrode and another pixel electrode adjacent to the pixel electrode. In a liquid crystal display device in which pixel electrodes for driving materials are arranged in a matrix, each set of pixel control elements including a plurality of pixel control elements is arranged adjacent to each other, and electrically connected to the pixel control elements. At least a part of the wiring layer to be connected is a common wiring layer between the adjacent pixel control elements.

By arranging the pixel control elements adjacent to each other in each set of a plurality of pixel control elements, the positions of the pixel control elements are arranged in a group so that a plurality of pixel electrodes are arranged. The electrodes can be arranged in a portion other than the position of the pixel control element while increasing the area of each electrode. At the same time, the pixel electrodes are adjacent to each other in a pattern that does not pass through the wiring layer,
Alternatively, by sharing the wiring layer, the area of the pixel electrode can be increased, and the aperture ratio is increased due to the effect of the increase in the pixel electrode area, so that a clear image can be displayed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a display device according to the present embodiment will be described with reference to the drawings. 1 to 4
FIG. 4 is a plan view in the manufacturing method. The present embodiment is an example of a method of manufacturing an active matrix type liquid crystal display device using a thin film transistor (TFT) element as a pixel control element, and is a method of performing transfer using four thin film transistor elements as one set.

First, as shown in FIG. 1, a thin film transistor element 12 as a pixel control element is formed on an element forming substrate 11 as a transfer source substrate. The element forming substrate 11 has a structure in which an insulating film is formed on a semiconductor substrate such as a silicon substrate or a glass substrate used in a normal semiconductor manufacturing process. On the element forming substrate 11, thin film transistor elements 12 are densely arranged in a matrix. In FIG. 1, each thin film transistor element 12 is shown as a square, but this square is merely an example of a shape that each thin film transistor element 12 can take, and a structure that can control liquid crystal by changing the potential of a pixel electrode as described later. If so, any shape may be used. At this time, a transparent electrode or the like serving as a pixel electrode is not formed on the element forming substrate 11, and therefore, the interval between the thin film transistors 12 may be a distance that can separate the elements.

Each thin film transistor element 12 is, for example,
A thin semiconductor film is formed on an insulating film such as a silicon oxide film (not shown), and a gate electrode is formed on the semiconductor film via a gate insulating film. A channel region is formed below the gate electrode. And a structure in which source / drain regions are formed in the semiconductor film with the channel region interposed therebetween. In the circuit, one of the source / drain regions is connected to a signal line, and the other of the source / drain regions is connected to a pixel electrode described later.

In FIG. 1, the individual thin film transistor elements 12 are arranged in a matrix, but as shown in FIG.
One thin film transistor element 12 constitutes an element block 13 as one set, and the element block 13 is separated from the element forming substrate 11 in units. Four thin film transistor elements 12 constituting one element block 13
In FIG. 1, four thin film transistors 12 arranged in two rows and two columns are adjacent among the thin film transistors 12 arranged in a matrix in FIG. 1, and the four adjacent thin film transistors 12 constitute one element block 13. .

Although one element block 13 includes four thin film transistors 12, the thin film transistors 12 do not need to be completely separated from each other, and may have a common source (drain) connection or gate. The structure which aims at connection may be sufficient. For example, when a common power supply line is used in the vertical direction in FIG. 2, the terminal connected to the power supply line is made common in the vertical direction, so that the area occupied by the contact region and the like can be reduced. Advantageously, similarly, by using a common signal line in the horizontal direction, for example, the number and area of the contact portion with the gate electrode can be reduced. Further, the element block 13 itself may have a configuration including a member or a support layer that supports the four thin film transistor elements 12, and has a configuration without such a support layer or a support member, and simply includes four thin film transistor elements. It may be an aggregate of twelve.

The element block 13 having the four thin film transistors 12 in two rows and two columns can be peeled off by using a mechanical chucking jig such as vacuum suction. A separation film or a separation film is formed between the substrate 12 and the element forming substrate 11, and four thin film transistor elements 1 are formed in the separation film.
2 may be peeled off. A structure in which the separation film itself is cut in advance for each block corresponding to the portion of 2 rows and 2 columns of the thin film transistor element 12, a structure in which the separation film itself is cut for each block in accordance with the patterning of the thin film transistor element 12, Alternatively, a structure may be used in which separation is caused between the thin film transistor element 12 and the element forming substrate 11 in block units using selective energy beam irradiation. Further, the element block 13
May be a combination of a method using a separation membrane or the like, a mechanical peeling method, and a method such as selective irradiation. Further, the element can be separated by laser ablation.

An important point in this separation step is that the four thin film transistors 12 constituting one block unit are selectively separated from the element forming substrate 11. Since the area peeled off from the formation substrate 11 is four times as large as the case of each element, the handling is easy and the yield is improved. Also, compared to the case where the elements are peeled and transferred one by one, four thin film transistors 12 are transferred at a time, so that the transfer efficiency is quadrupled.

From the element forming substrate 11 to the element block 13
For example, there is a method of sequentially peeling each block, or a method of peeling or transferring a plurality of element blocks at corresponding positions at a time after a transfer source substrate and a transfer destination substrate are opposed to each other. Further, as shown in FIG. 3, it is also possible to transfer directly from the element forming substrate 11 to the display device substrate 14 of the liquid crystal display device. Can also be transferred to the display device substrate 14.

FIG. 3 shows the arrangement of the element blocks 13 after transfer. As shown in FIG. 3, on the display device substrate 14, the element blocks 13 of the thin film transistor elements 12 are arranged for each of the element blocks 13 apart from a state in which the element blocks 13 are densely arranged on the element forming substrate 11. That is, in the state before the transfer (see FIGS. 1 and 2), the element block 13 is also in a dense state, reflecting the densely arranged state of the thin film transistors 12, but as shown in FIG. After the transfer, the interval between the element blocks 13 is enlarged. The distance between the element blocks 13 corresponds to the size of the pixel electrode formed in the expanded portion. On the other hand, since the respective thin film transistors 12 in the element block 13 are integrally transferred, the distance between the respective thin film transistors 12 does not change. This is extremely advantageous when a common contact is made between adjacent elements.

As shown in FIG. 4, pixel electrodes 15 are formed around the element block 13 having the four thin film transistors 12 so as to correspond to each of the thin film transistors 12. The pixel electrode 15 is a transparent electrode such as an ITO film, for example, and is formed on the display device substrate 14 before the transfer of the element block 13 or after the transfer of the element block 13. The display device substrate 14 is made of a light-transmitting material, has a function of holding the element block 13 formed thereon, the pixel electrode 15, an alignment film (not shown), a liquid crystal material, and the like, and performs the function. The material is not particularly limited as long as it is a material. As an example of the material constituting the display device substrate 14, a transparent glass substrate, a transparent plastic substrate, a sheet, or the like can be used.

The pixel electrodes 15 are formed on the entire surface of the display device substrate 14, and are patterned for each individual electrode.
The pixel electrode 15 has a substantially rectangular shape, but has a planar shape in which a corner facing the thin film transistor element 12 to be connected is cut out. Each element block 13 is connected to a horizontal signal line 16 as a striped wiring layer extending in the horizontal direction and a vertical signal line 17 as a striped wiring layer extending in the vertical direction, and Horizontal signal line 16
And the vertical signal line 17 intersects each element block 1
The position matches the position of No. 3. The connection between the horizontal signal line 16 and the vertical signal line 17 and the thin film transistor element 12 in each element block 13 is not shown, but the horizontal signal line 16 and the vertical signal line 17 may be partially extended, This is performed by making a contact on the upper or lower surface of the horizontal signal line 16 or the vertical signal line 17 or by further forming a short wiring layer for connection.

In FIG. 4, a horizontal signal line 16 is formed on each element block 13 and a vertical signal line 17 is formed on the horizontal signal line 16, but the order is different. Alternatively, after the horizontal signal lines 16 and the vertical signal lines 17 are formed in advance, the respective element blocks 13 can be transferred. The constituent materials of the horizontal signal lines 16 and the vertical signal lines 17 are not particularly limited, and may have a structure such as a required metal wiring layer or a combination of a metal layer and a semiconductor layer. Each of the horizontal signal lines 16 and the vertical signal lines 17 has a striped pattern.
May have a configuration having two signal lines extending in the horizontal direction, and the vertical signal line 17 may have a configuration having two signal lines extending in the vertical direction.

Each of the pixel electrodes 15 has a substantially rectangular pattern as described above.
And in the area surrounded by the vertical signal line 17,
One pixel electrode 15 is provided. In other words, four regions in a region surrounded by a pair of horizontal signal lines 16 and vertical signal lines 17
The signal line does not pass between the two pixel electrodes 15, and the area of the pixel electrode 15 can be increased accordingly. In the conventional typical active matrix type, since the signal lines pass through the four edges of the pixel electrode 15, the area secured as the pixel electrode is narrowed by that amount, which is a problem with respect to the improvement of the aperture ratio. Was. However, in the manufacturing method of the liquid crystal display device according to the present embodiment, the other pixel electrode 1 adjacent to at least one side of the substantially rectangular pixel electrode 15 is provided.
Since each pixel electrode 15 is formed in a pattern that does not include a wiring layer serving as a signal line between the pixel electrode 15 and the pixel electrode 5, the area of the pixel electrode 15 can be increased, and the aperture ratio of the liquid crystal display device can be increased. . In FIG. 4, the interval between the adjacent pixel electrodes 15 is set to S1, and it is understood that it is sufficient if the size is in accordance with the lithography margin. It can be set narrower than the margin for the wiring layer.

In the following, a counter substrate provided with a counter electrode is attached, and a liquid crystal material is injected between the electrode and the alignment film.
A liquid crystal display device can be manufactured. According to the above-described embodiment, the transfer efficiency is higher and the transfer efficiency is higher than in the case of transferring each element individually by transferring the data for each element block 13 which is a set of four thin film transistor elements 12. Since the size of the unit is at least four times as large, handling becomes easy. Further, since the signal lines can be shared, the area of the pixel electrode 15 can be increased correspondingly, and the aperture ratio of the liquid crystal display device can be increased.

FIGS. 5 to 7 show examples of element blocks. FIG. 5 shows an element block 23 in which the same four thin film transistor elements 22 as in the above-described embodiment are arranged in a pattern of 2 rows and 2 columns. It is an example. In this example, wiring and contacts can be shared in the horizontal direction and the vertical direction. FIG. 6 shows two thin film transistors 2
4 is an example of an element block 25 in which elements 4 are arranged in the vertical direction. In the example of FIG. 6, it is possible to share wiring and contacts in the vertical direction. FIG. 7 shows a structure in which six thin film transistor elements 26 are arranged in an element block 27 having a hexagonal pattern. In the structure of the element block 27, wiring and contacts can be shared.

FIG. 8 is a view showing gripping means which can be used at the time of transfer in the manufacturing method of this embodiment.
A vacuum chucking is formed at one end of 3, and a gas vent hole 34 is formed at the center of the jig 33 to reduce the pressure of the hollow portion 35 when gripped.
Such a jig 33 is connected to a plurality of thin film transistor elements 3.
By holding the thin film transistor 31 above the base 30 in element block units by facing the element block 1 on the base 30 and performing vacuum suction while discharging gas from the gas vent hole 34. Becomes possible.

By using such mechanical gripping means, the transfer step in the manufacturing method of the present embodiment can be advanced. In particular, since a plurality of thin film transistor elements 31 are gripped simultaneously, the gripping size becomes large. In addition, the element can be easily handled.

In the above embodiment, the image control element to be transferred is described as a thin film transistor element. However, the present invention is not limited to this, and may be a thin film diode element or another thin film semiconductor device. The element block may have a structure including a part of a wiring layer or a structure including a contact layer, a contact metal layer, and the like. Further, in the above embodiment, the transferred element is described as an image control element. However, in the display device and the method of manufacturing the same according to the present invention, the element is a light emitting element, a pixel control element, a photoelectric conversion element, a piezoelectric element, a thin film transistor element. , An element selected from a thin film diode element, a resistance element, a switching element, a micro magnetic element, and a micro optical element, or a portion thereof.

[0033]

According to the above-described display device and the method of manufacturing the display device, the transfer is performed for each set of elements such as a plurality of thin film transistors, so that compared to the case where each element is transferred, The transfer efficiency is increased, and the size of the unit to be transferred is enlarged by a plurality of units, so that the handling becomes easy. Further, since the signal lines can be shared, for example, the area of the pixel electrode can be increased accordingly, and the aperture ratio of the liquid crystal display device can be increased.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state in which thin film transistors are densely arranged in an example of an embodiment of a method for manufacturing a display device of the present invention.

FIG. 2 is a plan view showing a peeling step for each element block in an example of an embodiment of a method for manufacturing a display device of the present invention.

FIG. 3 is a plan view showing a layout after transfer for each element block in an example of an embodiment of a method for manufacturing a display device of the present invention.

FIG. 4 is a plan view illustrating a structure including a pixel electrode and a signal line in an example of an embodiment of a method for manufacturing a display device of the present invention.

FIG. 5 is a schematic plan view showing an example of an element block in the embodiment of the method for manufacturing a display device of the present invention.

FIG. 6 is a schematic plan view showing another example of the element block in the embodiment of the method for manufacturing the display device of the present invention, in which the element block has a pattern in which two thin film transistor elements are vertically arranged.

FIG. 7 is a schematic plan view showing still another example of the element block in the embodiment of the display device manufacturing method of the present invention, in which the element block has a substantially hexagonal pattern.

FIG. 8 is a cross-sectional view illustrating an example of a jig in the embodiment of the method for manufacturing a display device of the present invention.

[Explanation of symbols]

 Reference Signs List 11 element forming substrate 12 thin film transistor element 13 element block 14 display device substrate 15 pixel electrode 16 horizontal signal line 17 vertical signal line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/336 F term (Reference) 2H092 JA24 MA01 NA07 NA27 NA29 5C094 BA03 BA04 BA24 BA43 CA19 DA14 DA15 DB04 EA04 EA07 EB02 5F110 AA16 BB02 DD02 DD05 QQ16 5G435 BB04 BB12 EE33 HH13 KK05

Claims (13)

[Claims] An element is formed on an element forming substrate in a state where the elements are densely arranged, and the element is transferred onto a display device substrate for each of a plurality of sets obtained by extracting a part of the state where the elements are densely arranged. A method for manufacturing a display device, comprising: 2. An element selected from a light emitting element, a pixel control element, a photoelectric conversion element, a piezoelectric element, a thin film transistor element, a thin film diode element, a resistance element, a switching element, a micro magnetic element, and a micro optical element, or a part thereof. The method for manufacturing a display device according to claim 1, wherein: 3. The display device according to claim 1, wherein, after transferring the device on the display device substrate for each of a plurality of sets, a wiring layer electrically connected to the device is formed. Production method. 4. The method according to claim 1, wherein at least a part of a wiring layer electrically connected to the element is a common wiring layer between adjacent elements. 5. The pixel control element, which is adjacent to at least one side of a substantially rectangular pixel electrode before or after transferring the pixel control element on the display device substrate for each of a plurality of sets. 2. The method according to claim 1, wherein each pixel electrode is formed in a pattern in which no wiring layer is interposed between the pixel electrode and another pixel electrode. 6. The method according to claim 5, wherein the pixel control element comprises a thin film transistor or a thin film diode. 7. The method of manufacturing a display device according to claim 1, wherein the transfer of the element onto the display device substrate for each of a plurality of sets is performed mechanically by a gripping means. 8. The method according to claim 7, wherein said holding means has a vacuum suction mechanism. 9. The method according to claim 9, wherein the transfer of the elements onto the display device substrate for each of the plurality of sets causes the sets of the elements to be arranged more apart than the densely arranged state for each set. The method for manufacturing a display device according to claim 1, wherein: 10. The method according to claim 1, wherein the number of the sets of the elements is two or more. 11. In a display device in which display elements are arranged in a matrix, each set of display elements including a plurality of display elements is arranged adjacent to and electrically connected to the display elements. A display device, wherein at least a part of the wiring layer to be formed is a common wiring layer between adjacent display elements. 12. In a liquid crystal display device in which pixel electrodes for driving a liquid crystal material are arranged in a matrix, each set of a plurality of pixel control elements is disposed adjacent to each other and has a substantially rectangular shape. A liquid crystal display device, wherein each pixel electrode is formed in a pattern in which a wiring layer is not interposed between at least one side of a shaped pixel electrode and another pixel electrode adjacent thereto. 13. A liquid crystal display device in which pixel electrodes for driving a liquid crystal material are arranged in a matrix, wherein each set of a plurality of pixel control elements is arranged adjacent to each other, and A liquid crystal display device, wherein at least a part of a wiring layer electrically connected to a control element is a common wiring layer between adjacent pixel control elements.