JP4513963B2 - Electro-optical device manufacturing method and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device such as an organic EL display device, and more particularly to a method for manufacturing an electro-optical device manufactured by bonding two substrates.

  A manufacturing technique has been proposed in which a thin film transistor (TFT) circuit substrate and an organic EL substrate are separately manufactured and bonded together with a bonding material to form one organic EL display device. In this way, a thin film transistor (TFT) circuit board can be produced by a high temperature process, and an organic EL substrate having low heat resistance can be produced by a low temperature process. In addition, a top emission structure can be easily realized. For example, Japanese Patent Laid-Open Nos. 11-3048 and 2004-95251 describe such examples.

When the TFT circuit substrate and the organic EL substrate are bonded to each other, the gap between the two substrates is maintained constant to maintain electrical connection between the substrates, or the substrates are in direct contact with each other to cause damage or the like. It is necessary to avoid that. For this reason, in the thing of Unexamined-Japanese-Patent No. 11-3048, a soft material (spacer) is bonded between two board | substrates. Moreover, in the thing of Unexamined-Japanese-Patent No. 2004-95251, the electrical connection terminal part between two board | substrates is utilized for ensuring the gap between board | substrates.
Japanese Patent Laid-Open No. 11-3048 JP 2004-95251 A

  However, if an attempt is made to produce a large-screen display device using a soft spacer or inter-terminal connection material, the gap between the substrates tends to vary, which causes a failure in electrical connection between the substrates. In addition, when a spacer made of a hard material is dispersed between two substrates and the two substrates are bonded to each other, the hard spacer disposed on the organic EL element is used as an electrode layer or an organic EL layer constituting the organic EL element. It destroys the thin film and causes pixel defects.

  Therefore, an object of the present invention is to reduce pixel omission in an organic EL display device (electro-optical device) manufactured by bonding two substrates.

  Another object of the present invention is to provide an organic EL manufacturing method capable of reducing pixel omission in an organic EL display device (electro-optical device) manufactured by bonding two substrates.

  In order to achieve the above object, an organic EL display device of the present invention includes a first substrate in which a plurality of pixels are surrounded by partition walls and arranged in a matrix, and is disposed to face the first substrate. A second substrate on which a plurality of drive circuits connected to each other through a conductive connection body are formed, and a fixing means for fixing the first and second substrates to each other via a spacer. Is arranged in a region other than the plurality of pixels.

  By adopting such a configuration, it is possible to avoid disconnection of electrical connection between the substrates by keeping the gap between the substrates constant while avoiding the destruction of the pixels due to the spacers.

  Preferably, the spacer is disposed on the partition wall.

  Preferably, the spacer is disposed on a partition wall where the partition wall intersects.

  In the electro-optical device manufacturing method of the present invention, a step of forming a plurality of pixels surrounded by a partition on a first substrate in a matrix shape, and a driving for driving the plurality of pixels on a second substrate. Forming a circuit, applying an adhesive at a position on the second substrate corresponding to the partition on the first substrate, and on the adhesive applied on the second substrate And a step of bonding the first and second substrates through the spacer.

  By adopting such a manufacturing method, it is possible to create an electro-optical device capable of avoiding breakage of the electrical connection between the substrates by keeping the gap between the substrates constant while avoiding the destruction of the pixels due to the spacers. Become.

  Preferably, the application of the adhesive and the dispersion of the spacers are respectively performed by a droplet discharge method. By applying an adhesive to a portion where the spacer is to be placed first, the discharged or dispersed (dispersed) spacer is prevented from dropping or moving from a predetermined placement position.

  Preferably, the application of the adhesive and the dispersion of the spacers are simultaneously performed by a droplet discharge method. By discharging the spacer with the adhesive, it is fixed at a predetermined position of the spacer, and the spacer is prevented from moving and dropping.

  In addition, the electro-optical device of the present invention is used as a display device for electronic equipment.

  Here, the electro-optical device refers to a device including a liquid crystal element, an electrophoretic element having a dispersion medium in which electrophoretic particles are dispersed, an EL element, and the like, and a device in which a thin film transistor or the like is applied to a drive circuit, Such an electro-optical device may be applied to an electronic apparatus.

  The electronic apparatus refers to a general apparatus having a certain function provided with the electro-optical device according to the present invention, and includes, for example, an electro-optical device and a memory. The configuration is not particularly limited, but for example, an IC card, a mobile phone, a video camera, a personal computer, a head-mounted display, a rear-type or front-type projector, a fax machine with a display function, a digital camera finder, a portable TV, A DSP device, PDA, electronic notebook, electronic bulletin board, advertising display, etc. are included.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 5 shows an organic EL display device (electro-optical device) of the present invention. The organic EL display device 1 includes an organic EL substrate (first substrate) 20 in which a plurality of pixels 203 are surrounded by a partition wall 206 and arranged in a matrix, and is connected to the plurality of pixels 203 via a conductive connector 120. The TFT circuit substrate (second substrate) 10 on which the drive circuit 12 to be formed is formed, the TFT circuit substrate 10 and the organic EL substrate 20 are connected to the pixel 203 and the drive circuit 12 via the conductive connector 120. As shown in the figure, there is provided a bonding and fixing means for bonding with an adhesive on the outer peripheral portion (not shown) of both substrates via the spacer 122. The spacers 122 are arranged on the partition 206, which is an area other than the plurality of pixels 203, and in an outer peripheral area and an interface area of a display panel (not shown).

  By disposing the spacer 122 in a portion other than the pixel region, the pixel is prevented from being damaged by being pushed by the spacer. In addition, the distance between the pixel electrode 205, the conductive connection body 120, and the connection electrode 113 is maintained constant by the spacer 122, thereby preventing electrical connection from being interrupted.

  1 to 5 are process charts for explaining the manufacturing process of the organic EL device of the present invention. FIG. 1 shows a TFT circuit substrate 10. FIG. 8 shows an enlarged part of the TFT circuit substrate 10.

  The TFT circuit substrate 10 uses a substrate 101 such as glass or resin as a base substrate. An insulating protective film 102 is formed on this substrate. The protective film 102 can be formed by, for example, a silicon oxide film or a silicon nitride film. An amorphous silicon film is formed on the protective film 102 by a CVD method or the like, and a heat treatment such as laser irradiation or lamp annealing is performed to form a polysilicon film (semiconductor film) 103. The polysilicon film 103 is thermally oxidized, or a silicon oxide film is formed on the polysilicon film 103 by a CVD method using TEOS or the like as a material to form a gate insulating film 104. Next, ion implantation for adjusting the threshold value of the transistor is performed. The polysilicon film 103 and the gate insulating film 104 are patterned to perform element isolation, thereby forming a transistor region (island). A gate wiring film is formed thereon. For example, the gate wiring film can be formed by depositing a metal such as aluminum by sputtering or vapor deposition and patterning the gate wiring film. Alternatively, polysilicon may be deposited and ion implantation may be performed to provide conductivity, followed by patterning to form the gate electrode wiring 105.

  Impurity ion implantation is performed using the gate electrode 105 as a mask, heat treatment is performed to activate the impurities, and source / drain regions 106 are formed. Further, a silicon oxide film is formed on the entire substrate by a CVD method or the like so as to cover the gate electrode 105 and the gate insulating film 104 to form an interlayer insulating film 108. A contact hole 109 is opened at a position corresponding to the source / drain of the interlayer insulating film 108. The contact hole 109 is buried so as to cover the substrate, and a metal film such as aluminum is formed by sputtering, vapor deposition or the like, and this is patterned to form the connection wiring 110.

  Next, a photoresist is applied by spin coating or the like and baked to form the planarizing film 111. The planarizing film 111 may be formed by forming a thick silicon oxide film and planarizing the surface by chemical mechanical (CMP) polishing or the like. A contact hole 112 is opened in the planarizing film 111, and a metal film such as aluminum is formed on the planarizing film 111 by sputtering, vapor deposition, metal plating, or the like to form a conductive layer. The conductive layer is patterned to form the connection electrode 113. In this way, the TFT circuit substrate 10 is formed.

  Next, a conductive adhesive and a spacer are disposed on the TFT circuit substrate 10 so that the TFT circuit substrate 10 thus formed and an organic EL substrate 20 described later are bonded together.

  As shown in FIG. 2, an electrical connection conductor 120 such as a conductive adhesive or solder paste is formed on the connection electrode 113 on the TFT circuit substrate 10 by screen printing, offset printing, a droplet discharge method (inkjet method), or the like. To do. The conductive adhesive is made of a resin or conductive polymer containing a large amount of metal fine particles.

  Further, a material having a high viscosity (adhesiveness) for holding the spacer in a portion corresponding to a region other than the pixel of the organic EL substrate on the TFT circuit substrate 10, for example, a region corresponding to a partition wall of a pixel of the organic EL substrate described later. For example, an adhesive or a solvent is applied as the holding film 121 by a droplet discharge method.

  As shown in FIG. 3, a droplet discharge method is applied to a portion (corresponding to a partition wall region of a pixel in the illustrated example) corresponding to a region other than the pixel of the organic EL substrate to which the above-described holding film 121 is applied. The spacer 122 is discharged by the above. The spacer 122 is dispersed in a volatile solvent, and is ejected by a droplet ejection head whose scanning position is accurately controlled. By disposing the spacer 122 on the holding film 121, the spacer 122 is prevented from dropping or moving during assembly. Note that the solvent discharged together with the spacer can function as the holding film 121 by appropriately setting the viscosity (adhesiveness) of the solvent in which the spacer is dispersed.

  As the spacer 122, for example, silicon-based particles (balls) having a diameter of about 20 microns or plastic particles can be used. This size corresponds to the width of the partition wall region described later. If the spacer size is reduced, the number of spacers 122 positioned on the partition wall increases, and the gap between the substrates can be more reliably maintained. When the size of the spacer 122 is reduced, it is necessary to match the film thickness (height) of the electrical connection body 120 with the size of the spacer 122. In screen printing, the mask thickness and printing position accuracy are in a trade-off relationship. If the spacer size is reduced, the position accuracy of the screen printing is lowered. Therefore, it is not necessary to simply reduce the size of the spacer 122. Therefore, in the embodiment, the size of the spacer 122 is set to be approximately the width of the partition wall.

  FIG. 4 shows an organic EL substrate 20 manufactured by a process separate from the above-described TFT circuit substrate.

  The organic EL substrate 20 shown in the figure is manufactured as follows. First, a protective film 202 is formed on a transparent glass or resin substrate 201, a transparent metal film such as ITO is formed, and this is patterned to form pixel electrodes / wirings 203. Next, a resist is applied on the substrate and patterned to form partition walls 206 that define pixel regions. An organic EL light-emitting film 204 is formed on the pixel electrode 203 surrounded by the partition wall 206 by a droplet discharge method or the like. Next, a cathode layer 205 made of a calcium / aluminum layer is formed on the light emitting film 204, and the organic EL substrate 20 is formed.

  Next, as shown in FIG. 5, an organic EL substrate is bonded to a TFT circuit substrate in which spacers are arranged in the boundary region of the pixel. For the bonding, for example, a curable resin (not shown) is applied to the outer periphery of the TFT circuit substrate 10 or the organic EL substrate 20 as a sealing material by screen printing or a dispenser, and the TFT circuit substrate 10 and the organic EL substrate 20 are aligned with each other. Crimp mechanically. Alternatively, after the TFT circuit substrate 10 and the organic EL substrate 20 are aligned with each other, the gap between them is reduced and the pressure is reduced. The sealing material is cured by ultraviolet irradiation or heating to complete the bonding. At the time of this bonding, a spacer disposed in the non-pixel region, for example, a spacer located on the partition wall 206 shown in FIG. It works to keep the gap constant.

  FIG. 6 is an explanatory diagram schematically illustrating an example of the arrangement positions of the pixels (ITO) 203 and the spacers 122. For example, the size of the pixel 203 is 450 μm (vertical) × 150 μm (horizontal), the partition 206 has a width of 20 μm, and the spacer 122 has a diameter of 20 microns. As shown in the figure, spacers 122 are arranged on the partition walls 206 that define pixel regions arranged in a matrix, preferably at the intersections of the partition walls 206. In addition, the spacer 122 is also disposed in a portion (area) (not shown) other than the screen display area by the pixel group, so that the TFT circuit substrate 10 and the organic EL substrate 20 can be uniformly bonded to each other.

  Thus, the spacer 122 does not exist on the pixel 203 and does not hinder pixel display. Further, the light emitting layer in the pixel region is not pressed and destroyed.

  FIG. 7 is a cross-sectional view showing a cross section in the A-A ′ direction (partition wall region) of FIG. 6.

In the figure, parts corresponding to those in FIG. Spacers 122 are arranged on the partition walls 206 in the screen display region in which pixels are arranged in a matrix.
As a result, wiring connection between the TFT circuit substrate 10 and the organic EL substrate 20 is performed with an appropriate gap, and the bonded substrates are not uneven.

  In the embodiment described above, the electrical connector forming process shown in FIG. 2 and the spacer arrangement process shown in FIG. 3 may be reversed.

  In the case where the spacer 120 is disposed on the substrate prior to the formation of the electrical connection body 120, a solvent having an appropriate viscosity mixed with the spacer can be performed by screen printing or offset printing.

  Moreover, you may use the type | mold which transfers an adhesive agent. That is, a partition mold of the organic EL substrate is prepared in advance. An adhesive is applied to the mold, the mold is aligned with the TFT circuit board, the mold is pressed against the TFT circuit board (stamp), and the adhesive is transferred to the TFT circuit board. Spacers are sprayed on the TFT circuit board to fix the spacers to the adhesive portion, and extra parts are removed (dropped) from the TFT circuit board. When the two substrates are bonded to each other, an organic EL display device in which spacers are arranged on the partition walls is obtained.

  In addition, the method of manufacturing the TFT circuit substrate and the organic EL substrate is not limited to that of the embodiment. For example, various manufacturing methods such as a liquid silicon process can be appropriately employed.

  According to the embodiment described above, an organic EL display device (electro-optical device) free from pixel defects can be obtained. Reliability and yield are also improved.

(Electro-optical device and electronic equipment)
The electro-optical device manufactured by the above method is suitably used for an electronic device or the like. Specific examples of the electro-optical device and the electronic apparatus according to the invention will be described with reference to FIG. FIG. 1 is a diagram illustrating examples of various electronic devices that include the electro-optical device 1 (eg, an organic EL display device).

  FIG. 9A shows an application example to a mobile phone, and the mobile phone 530 includes an antenna portion 531, an audio output portion 532, an audio input portion 533, an operation portion 534, and the electro-optical device 1 of the invention. .

  FIG. 9B shows an application example to a video camera. The video camera 540 includes an image receiving unit 541, an operation unit 542, an audio input unit 543, and the electro-optical device 1.

  FIG. 9C shows an application example to a television, and the television 550 includes the electro-optical device 1. The electro-optical device 1 can be similarly applied to a monitor device used for a personal computer or the like.

  FIG. 9D illustrates an application example to a roll-up television, and the roll-up television 560 includes the electro-optical device 1.

  In the above example, the organic EL display device is described as an example of the electro-optical device. However, the organic EL display device is not limited to this, and is configured using other various electro-optical elements (for example, an inorganic EL display device). The present invention can also be applied to a method for manufacturing an electro-optical device. The present invention can also be widely applied to various devices formed using a thin film semiconductor circuit layer (thin film device) peeling transfer technique. The electro-optical device is not limited to the above-described example, and can be applied to various electronic devices such as a fax machine with a display function, a digital camera finder, a portable TV, and an electronic notebook.

FIG. 1 is a cross-sectional view illustrating a manufacturing process of a TFT circuit substrate. FIG. 2 is a cross-sectional view illustrating an example in which a conductive material is disposed on an electrode of a TFT circuit substrate. FIG. 3 is a cross-sectional view for explaining an example in which spacers are arranged on the boundary region between the pixels of the TFT circuit substrate. FIG. 4 is a cross-sectional view illustrating an organic EL substrate. FIG. 5 is a cross-sectional view for explaining the bonding of the TFT circuit substrate and the organic EL substrate through the spacer. FIG. 6 is an explanatory diagram for explaining an example of a pixel arrangement and a spacer arrangement position in the electro-optical device. FIG. 7 is a cross-sectional view of the electro-optical device in the A-A ′ direction of FIG. 6. FIG. 8 is an explanatory diagram enlarging a part of the TFT circuit substrate. FIG. 9 is an explanatory diagram illustrating an example of an electronic apparatus using the electro-optical device of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic EL substrate (electro-optical device), 10 TFT circuit substrate, 20 Organic EL substrate 101 Substrate, 102 Protective film, 103 Semiconductor film, 104 Gate insulating film, 105 Gate electrode / wiring, 106 Source region or drain region, 108 interlayer Insulating film, 111 planarization film, 113 connection electrode, 120 electrical connection body, 122 spacer, 201 substrate, 203 ITO, 204 organic EL (light emitting) film, 205 cathode, 206 partition

Claims (7)

A first substrate having a plurality of pixels surrounded by partition walls and arranged in a matrix;
A second substrate on which a plurality of drive circuits that are arranged to face the first substrate and are connected to the pixels via a conductive connector;
Fixing means for fixing between the first and second substrates via a spacer that keeps a gap between the substrates constant, and
The spacer is disposed on the partition and between the second substrate;
The conductive connector is disposed between the second substrate and the pixel surrounded by the partition;
The spacer is particulate and harder than the conductive connector,
An electro-optical device. The electro-optical device according to claim 1, wherein the pixel is an organic EL light emitter . Said spacer, said partition wall with each other are disposed on the partition wall of the intersection, the electro-optical device according to claim 1 or 2. Forming a plurality of pixels surrounded by partition walls in a matrix on a first substrate;
Forming a plurality of drive circuits for driving the pixels on the second substrate , and a conductive connector for connecting the drive circuits and the pixels ;
Applying an adhesive to a position on the second substrate corresponding to the partition on the first substrate;
Dispersing the spacers in the form of particles harder than the conductive connector on the adhesive applied on the second substrate, and removing excess spacers ;
Bonding the first and second substrates through the spacer and connecting the pixel and the conductive connector;
A method for manufacturing an electro-optical device.   The method of manufacturing an electro-optical device according to claim 4, wherein the application of the adhesive and the dispersion of the spacers are each performed by a droplet discharge method.   The method of manufacturing an electro-optical device according to claim 4, wherein the application of the adhesive and the dispersion of the spacers are simultaneously performed by a droplet discharge method.   An electronic apparatus using the electro-optical device according to claim 1 as a display unit.

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