JP5458500B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device, and particularly to an electro-optical device using a flexible substrate.

  In recent years, organic semiconductor materials have attracted attention as semiconductor materials for TFTs (thin film transistors). When an organic semiconductor material is used, (1) a plastic substrate or a film can be used because an extremely low temperature process can be applied as compared with an inorganic semiconductor. Therefore, a flexible, lightweight, and hardly breakable element can be manufactured. In addition, a simple method such as (2) solution application or printing can be used, and the device can be manufactured in a short time. Therefore, it is possible to keep process costs and apparatus costs low. Further, (3) there is an advantage that the material selection range is widened, and the material characteristics and device characteristics can be easily changed by changing the molecular structure of the material.

  In view of this, research has been actively conducted on techniques for producing display devices such as liquid crystal displays, organic EL (Electro-Luminescence) displays, and electronic papers using the organic transistors.

For example, Patent Document 1 below discloses a technology for realizing a high-definition wiring connected to an organic transistor and manufacturing an electro-optical device substrate at low cost, low temperature, and low energy by using an inkjet method. ing.
JP 2005-215616 A

  However, in the technique described in Patent Document 1, the electro-optical device substrate (10) and the driver circuit (integrated circuit) for driving the organic transistor (10a) of the electro-optical device substrate (10) are flexible. They are connected via a printed circuit board (50).

  Therefore, as will be described in detail later, a bonding process between the electro-optical device substrate (10) and the flexible printed circuit board (50) is required, which complicates the manufacturing process. Furthermore, this process is performed by thermocompression bonding with ACF (Anisotropic Conductive Film) or ACP (Anisotropic Conductive Paste) sandwiched between them. However, heat conduction failure, substrate distortion, etc. are likely to cause deterioration of device characteristics. .

  Accordingly, a specific aspect of the present invention is to provide an electro-optical device having a simple configuration. Another object is to improve the characteristics of the electro-optical device. One of the purposes is to improve the productivity.

The electro-optical device according to the present invention includes a display unit formed on a flexible substrate, and a connection unit that connects an external circuit and the display unit, and the display unit is formed on the flexible substrate. Source line, source region, and drain region, an organic semiconductor film formed between the source region and the drain region, a gate insulating film formed on the organic semiconductor film, and the gate insulating film And the gate line connected to the gate electrode, the source line and the gate line are wired to the connection portion, and the connection portion is a part of the flexible substrate. is configured as a part, an end of the connecting portion has a plurality of electrode pads for connecting with the circuit board is provided, the plurality of electrode pads are formed on the display unit the It consists over scan line or the gate line and the same material layer, the electrode pads, plating layer is formed.

  According to such a configuration, the flexible board and the circuit board can be connected by the connecting portion that is configured as a part of the flexible board and integrated with the flexible board, and a cable such as an FPC (Flexible Printed Circuit) can be connected. It can be unnecessary. Therefore, the configuration of the electro-optical device can be simplified. In addition, the thermocompression bonding process between the flexible substrate and the FPC is not required, and the deterioration of the characteristics of the device due to heat can be prevented. Moreover, the productivity can be improved.

For example, the plurality of electrode pads may be formed simultaneously with the source line or the source line. That is, they can be formed in the same process.

  For example, a reinforcing film is provided on a surface opposite to the surface having the electrode pad of the connection portion. As the reinforcing film, for example, glass epoxy, composite, paper phenol, aluminum, SUS (stainless steel, iron alloy), PET (polyethylene terephthalate), or the like can be used. According to such a configuration, the connection between the connector and the electrode pad is improved by the reinforcing film.

  For example, the display unit includes a first electrode formed on the flexible substrate, an electrophoretic layer formed on the first electrode, and a second electrode formed on the electrophoretic layer. Thus, an electro-optical device using the electrophoretic layer can be obtained.

  An electronic apparatus according to the present invention is characterized in that the electro-optical device is incorporated. According to such a configuration, the characteristics of the electronic device can be improved.

  An electronic apparatus according to the present invention is an electronic apparatus having a bent portion and incorporating the electro-optical device, wherein the electro-optical device is incorporated so that the connection portion corresponds to the bent portion. According to such a configuration, the characteristics of the electronic device can be improved. In particular, since the flexibility is ensured by the connecting portion without using the FPC, the bent portion of the electronic device can be easily bent.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same or related code | symbol is attached | subjected to what has the same function, and the repeated description is abbreviate | omitted.

<Embodiment 1>
1 and 2 are a plan view and a circuit diagram showing a configuration of a substrate used in the electro-optical device according to the present embodiment. FIG. 3 is a plan view showing a comparative example for explaining the effect of the present embodiment.

  As shown in FIG. 1, the substrate (active matrix substrate) S1 includes a plurality of source lines SL arranged in the y direction and a plurality of gate lines GL arranged in the x direction in the display unit (display region) 1a. Have Further, as shown in FIG. 2, a plurality of pixels are arranged in a matrix at the intersections of the source lines SL and the gate lines GL. This pixel has a pixel electrode (first electrode) PE and a thin film transistor T. Here, it is assumed that the display unit 1a includes an array unit 1d and a portion where the lead wiring 1c is formed (FIG. 1).

  For example, the source line SL is driven by an X driver, and the gate line GL is driven by a Y driver. A circuit necessary for driving such a display device such as an X driver or a Y driver is called a drive circuit and is constituted by another member such as an IC chip. A circuit board on which this drive circuit is formed (mounted) is indicated by S2 (FIG. 1).

  Here, in the present embodiment, the substrate S1 is formed of a flexible substrate. The flexible substrate is configured using, for example, an insulating resin material. The plurality of source lines SL and gate lines GL are routed to the connection portion (connection region, wiring portion) 1b, and the surface of the routed wiring is used as a plurality of electrode pads P at the end of the connection portion 1b. Exposed. In addition, each wiring (SL, GL) is connected with the electrode pad P of the connection part 1b by the routing wiring 1c in FIG.

  On the other hand, a connector (connector member, socket) C is connected to the circuit board S2, and the connecting portion 1b is inserted into the socket C. Thereby, the drive circuit in the circuit board S2 and the electrode pad P are connected.

  The structure of the connector C is not particularly limited, but has a cavity extending from the insertion opening. For example, an internal electrode 21 corresponding to the plurality of pad electrodes P is provided on the ceiling surface of the cavity. 21 passes through the wall surface of the connector C and is connected to the external electrode 23. The external electrode 23 is fixed by soldering or the like so as to be connected to the wiring on the circuit board S2.

  As described above, in the present embodiment, the flexibility of the substrate S1, which is a flexible substrate, is used to provide the connection portion 1b that is connected to the display region 1a as a part of the substrate, and the connection portion 1b is connected to the circuit substrate S2. Since it is directly connected to the connector C on the side, other cables such as FPC can be dispensed with. Therefore, the configuration of the electro-optical device can be simplified.

  On the other hand, as shown in FIG. 3, when the board S1 and the connector C on the circuit board S2 side are connected using the FPC 30, in the bonding process of the terminal of the FPC 30 and the terminal P on the board S1 side, Continuity failure due to heat of crimping and distortion of the substrate are likely to occur.

  On the other hand, in the present embodiment, it is possible to avoid the above problems and improve the yield. Further, the cost can be reduced by reducing the number of parts and the bonding process, and the throughput can be improved.

<Embodiment 2>
In FIG. 1, the number of connectors C on the circuit board S2 side is one, but as shown in FIG. 4, the connector C1 connected to the source line SL and the connector C2 connected to the gate line GL are separated. Good. FIG. 4 is a plan view showing the configuration of the substrate used in the electro-optical device of the present embodiment. In FIG. 4, the display of the internal electrodes 21 and the external electrodes 23 of the connectors C1 and C2 is omitted. Also, components having the same functions as those in FIG. 1 are denoted by the same or related reference numerals, and repeated description thereof is omitted.

(Manufacturing process of active matrix substrate)
Next, the structure of the substrate used in the electro-optical device according to the present embodiment will be described and the configuration will be clarified. 5 to 9 are plan views or cross-sectional views showing the manufacturing process of the substrate used in the electro-optical device of this embodiment. In addition, (A) of each figure is a top view of the whole board | substrate, (B) is an enlarged plan view of a pixel part, (C) is sectional drawing of CC part of a pixel part.

  As shown in FIG. 5, for example, a substrate (flexible substrate) S1 made of polyimide resin or the like is prepared and processed into a shape in which two connection portions 1b protrude from a substantially rectangular region. Next, the surface of the substrate S1 is degreased. For example, the flexible substrate S1 is immersed in an isopropyl alcohol solvent, subjected to ultrasonic cleaning for 5 minutes, and dried.

  Next, as shown in FIG. 6A, a source line SL extending in the y direction is formed. At this time, as shown in FIGS. 6B and 6C, the source region S connected to the source line SL and the pixel electrode (drain region D) PE arranged at a certain distance from the source region S. Also forms.

  Specifically, for example, the substrate S1 is set in a resistance heating vapor deposition machine, and the film forming chamber is evacuated to about 10 to 4 Pa. Thereafter, after depositing a gold (Au) film of about 200 nm as a conductive film, patterning is performed using a photolithography method to form a source line SL, a source region S, and a pixel electrode PE extending in the y direction. At this time, the lead wiring 1c and the electrode pad P are also patterned (FIG. 6A).

  Next, the surface of the substrate S1 is cleaned with oxygen plasma. For example, using a plasma processing apparatus, oxygen plasma processing is performed for about 5 minutes under the conditions of power 200 W, oxygen flow rate 100 sccm, and argon flow rate 100 sccm.

  Next, as shown in FIGS. 7B and 7C, the organic semiconductor film 3 is formed between the source region S and the pixel electrode PE (channel region) in each pixel. In FIG. 7B, the broken line region is a region where the organic semiconductor film 3 is formed. For example, as an organic semiconductor material, a coating solution prepared by dissolving F8T2 (polyfluorene-bithiophene copolymer) in xylene at a concentration of 0.5 Wt% is prepared, and this solution is applied to the region (channel region) using an inkjet coating apparatus. ). Next, drying is performed for about 10 minutes in a drying oven heated in advance to 100 ° C., and the solvent xylene is removed to form the organic semiconductor film 3.

  Next, as illustrated in FIG. 8C, the gate insulating film 5 is formed over the organic semiconductor film 3. For example, a polyimide solution is prepared as an insulating film material and applied onto the substrate S1 using an inkjet method. At this time, coating is performed only on the display area, and coating is not performed on the connection portion 1b. Accordingly, the electrode pad P remains exposed at the connection portion 1b. Next, the substrate S1 is mounted on a hot plate and heated at 60 ° C. for about 1 hour to volatilize the solvent of the solution to form the gate insulating film 5 having a thickness of about 1 μm.

  Next, a gate electrode G is formed over the channel region via the gate insulating film 5 (FIGS. 8B and 8C). At this time, a gate line GL connected to the gate electrode G and extending in the x direction is also formed (FIG. 8A).

  Specifically, for example, an aqueous dispersion of silver fine particles is applied in a pattern of the gate electrode G and the gate line GL using an ink jet coating apparatus, and then dried at 80 ° C. for about 30 minutes on a hot plate. At this time, the lead wiring 1c and the electrode pad P are formed in the same manner.

  Next, a plating film (not shown) is formed on the electrode pads P of the two connection portions 1b. For example, a nickel gold plating film is formed to a thickness of about 20 μm using an electroless plating method. As the plating material, gold, silver, copper, nickel, tin, lead, or an alloy layer thereof may be used.

  Next, a reinforcing film (reinforcing film) is attached to the back surface of the two connection portions 1b. This reinforcing film is made of a material such as glass epoxy, composite, paper phenol, aluminum, SUS (stainless steel, iron alloy), PET (polyethylene terephthalate), and has a thickness of about 50 to 300 μm. This film improves the contact between the electrode pad P and the internal electrode of the connector C.

(Electrophoresis device manufacturing process)
Thereafter, as shown in FIG. 9, an electrophoretic sheet S3 having a counter electrode (second electrode) 33 and an electrophoretic capsule layer (electrophoretic layer) 31 formed thereon is laminated on the display region on the substrate S1.

  Next, the connecting portion 1b is inserted into the connectors C1 and C2 of the substrate circuit S2 and connected (see FIG. 4). The electrophoretic display (electrophoresis apparatus) is completed through the above steps.

  Thus, also in this embodiment, other cables such as an FPC can be dispensed with. In addition, the same effects as those of the first embodiment can be obtained, such as the step of bonding the terminals of the FPC and the terminals on the active matrix substrate S1 side can be omitted, and the throughput can be improved. Further, according to the above manufacturing process, the electrode pad P can be formed in the connection part 1b of the flexible substrate 1 in the process of forming the gate line GL and the source line SL, and the FPC alternative part is formed in a simple process. be able to.

  Note that, also in the substrate of the first embodiment (FIG. 1), the substrate can be formed in the same process as in the present embodiment, except that the pattern of the routing wiring 1c is different.

<Electronic equipment>
The electrophoresis apparatus can be incorporated in various electronic devices.

(Electronic paper)
For example, the electrophoresis apparatus can be applied to electronic paper. FIG. 10 is a perspective view illustrating an electronic paper which is an example of an electronic apparatus.

  An electronic paper 1000 illustrated in FIG. 10 includes a main body 1001 formed of a rewritable sheet having the same texture and flexibility as paper, and a display unit 1002. In such electronic paper 1000, the display unit 1002 is configured by the electrophoresis apparatus as described above.

  In the above embodiment, the electrophoretic device has been described as an example. However, the present invention can be applied to various electro-optical devices (display devices) such as a liquid crystal device and an organic EL (Electro-Luminescence) device. .

(Other electronic devices)
Examples of the electronic apparatus having the various electro-optical devices include those shown in FIGS.

  FIG. 11 is a perspective view illustrating a mobile phone which is an example of an electronic apparatus. The cellular phone 1100 includes a display portion 1101. The electro-optical device can be incorporated in the display portion. Further, the cellular phone 1100 has a bent portion (bent portion). By incorporating the electro-optical device so that the connecting portion 1b corresponds to this portion, the connecting portion can be connected to the connecting portion without using an FPC. The mobile phone can be easily folded.

  FIG. 12 is a perspective view illustrating a portable information processing apparatus which is an example of an electronic apparatus. The portable information processing apparatus 1200 includes an input unit 1201 such as a keyboard, a main body unit 1202 in which a calculation unit, a storage unit, and the like are stored, and a display unit 1203. The electro-optical device can be incorporated in the display portion. Further, the portable information processing apparatus 1200 has a bent portion (bent portion), and the connection portion is incorporated without using an FPC by incorporating the display device so that the connection portion 1b corresponds to this portion. Thus, the device can be easily folded.

  In addition, for example, TV, viewfinder type, monitor direct view type video tape recorder, car navigation device, pager, electronic notebook, calculator, electronic newspaper, word processor, personal computer, workstation, videophone, POS terminal, touch panel It can also be applied to other equipment. The electro-optical device can be incorporated in the display unit and the drive circuit unit of these various electronic devices.

  It should be noted that the examples and application examples described through the above embodiment can be used in appropriate combination according to the application, or can be used with modifications or improvements, and the present invention is limited to the description of the above embodiment. Is not to be done.

3 is a plan view illustrating a configuration of a substrate used in the electro-optical device according to Embodiment 1. FIG. 2 is a circuit diagram illustrating a configuration of a substrate used in the electro-optical device according to Embodiment 1. FIG. 6 is a plan view showing a comparative example for explaining the effect of the first embodiment. FIG. 6 is a plan view illustrating a configuration of a substrate used in the electro-optical device according to Embodiment 2. FIG. FIG. 10 is a plan view illustrating a manufacturing process for a substrate used in the electro-optical device according to the second embodiment. 5A and 5B are a plan view and a cross-sectional view illustrating a manufacturing process of a substrate used in the electro-optical device according to the second embodiment. 5A and 5B are a plan view and a cross-sectional view illustrating a manufacturing process of a substrate used in the electro-optical device according to the second embodiment. 5A and 5B are a plan view and a cross-sectional view illustrating a manufacturing process of a substrate used in the electro-optical device according to the second embodiment. FIG. 10 is a cross-sectional view illustrating a manufacturing process of a substrate used in the electro-optical device according to the second embodiment. It is a perspective view which shows the electronic paper which is an example of an electronic device. It is a perspective view which shows the mobile telephone which is an example of an electronic device. It is a perspective view which shows the portable information processing apparatus which is an example of an electronic device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a ... Display part (display area), 1b ... Connection part, 1c ... Lead-out wiring, 1d ... Array part, 3 ... Organic-semiconductor film, 5 ... Gate insulating film, 21 ... Internal electrode, 23 ... External electrode, 30 ... FPC, DESCRIPTION OF SYMBOLS 31 ... Electrophoresis capsule layer, 33 ... Counter electrode, 1000 ... Electronic paper, 1001 ... Main body, 1002 ... Display unit, 1100 ... Mobile phone, 1101 ... Display part, 1200 ... Portable information processing apparatus, 1201 ... Input part, 1202 ... Main body part 1203 ... Display part, C, C1, C2 ... Connector, D ... Drain region, G ... Gate electrode, GL ... Gate line, P ... Pad electrode (terminal), PE ... Pixel electrode, S ... Source region, SL ... Source line, S1 ... Substrate, S2 ... Circuit board, S3 ... Electrophoresis sheet, T ... Thin film transistor

Claims (7)

A display unit formed on a flexible substrate;
A connection part for connecting an external circuit and the display part;
Have
The display unit
A source line, a source region, and a drain region formed on the flexible substrate;
An organic semiconductor film formed between the source region and the drain region;
A gate insulating film formed on the organic semiconductor film;
A gate electrode formed on the gate insulating film and a gate line connected to the gate electrode;
The source line and the gate line are wired to the connection portion,
The connecting portion is configured as a part of the flexible substrate ,
A plurality of electrode pads for connecting to the external circuit are provided at the end of the connection portion,
The plurality of electrode pads are made of the same material layer as the source line or the gate line formed in the display unit,
A plating layer is formed on the electrode pad,
Electro-optic device. The plating layer of gold, silver, copper, nickel, tin, lead or an electro-optical device according to claim 1, characterized in that it comprises an alloy of these layers. The surface of the surface side opposite with the electrode pads of the connecting portion, an electro-optical device according to claim 1, wherein a reinforcing film. The display unit includes a first electrode formed on the flexible substrate, an electrophoretic layer formed on the first electrode , and a second electrode formed on the electrophoretic layer .
Electro-optical device according to any one of claims 1 to 3. The plurality of electrode pads are formed simultaneously with the source line or the source line.
The electro-optical device according to claim 1. Electronic apparatus, characterized in that the electro-optical device according to any one of claims 1 to 5 is incorporated. It has a bent portion, an electronic apparatus to which the electro-optical device is incorporated in any one of claims 1 to 5,
An electronic apparatus in which an electro-optical device is incorporated so that the connecting portion corresponds to the bent portion.

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