JP2003150078A - Electrooptical unit, wiring board, and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress low the connection resistance between an electrooptical panel and external equipment. SOLUTION: The electrooptical unit 1 has a liquid crystal panel 2 and a flexible substrate 3. The flexible substrate 3 has a base material 31 which is overlaid having one surface directed to an observation-side substrate 22, a panel-side terminal 32 which is provided on the one surface and electrically connected to a panel terminal 223, a circuit-board side terminal 33 which is provided on the other surface of the base material 31 and electrically connected to the panel-side terminal 32, and a chip capacitor 34 which is provided on the other surface. A mold 27 is provided nearby the part of the observation-side substrate 22 to which the base material 31 is connected. Further, a coating layer 35 is formed covering an area of the surface of the base material 31 which faces the observation-side substrate 22 against at lest the chip capacitor 34. This coating layer 35 is formed of a material which has higher wettability to the mold than that of the base material 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-optical unit and an electronic apparatus including the same, and more particularly to a wiring board used in the electro-optical unit.

[0002]

2. Description of the Related Art Electro-optical panels, typified by liquid crystal panels and EL (electroluminescence) panels, use liquid crystal or E
In general, a panel substrate for holding an electro-optical material such as an L light-emitting layer is provided, and an input terminal for inputting a drive signal for driving the electro-optical material is provided on the panel substrate. is there. Further, a configuration has been proposed in which an external device such as a circuit board is arranged so as to face the panel board. That is, a connector such as a rubber connector is interposed between the panel substrate and the external device to electrically connect the input terminal on the panel substrate and the output terminal of the external device.

[0003]

By the way, the input terminal on the panel substrate is generally formed of a material having a relatively high resistance value such as ITO (Indium Tin Oxide), and the connector is on the panel substrate. Since it is simply pressure-welded to, the connection resistance becomes large especially in the connection portion between the input terminal and the connector. Then, due to this connection resistance, there is a problem in that pixels that do not light up are generated and display quality is degraded such that the display becomes dark.

The present invention has been made in view of the circumstances described above, and an electro-optical unit capable of suppressing the connection resistance between the electro-optical panel and an external device to be low, a wiring board used for the electro-optical unit, and It is an object to provide an electronic device including the electro-optical unit.

[0005]

In order to solve the above problems, an electro-optical unit according to the present invention has a panel substrate provided with a panel terminal, and the panel terminal of the panel substrate is provided. An electro-optical panel in which a circuit board is arranged facing the surface, a plate-shaped base material with one surface facing the part of the panel board where the panel terminals are provided, and a base material of the base material. The first connection terminal provided on the one surface and electrically connected to the panel terminal, and the first connection terminal provided on the other surface of the base material and electrically connected to the connection terminal of the circuit board, A second connection terminal that is electrically connected to the connection terminal, and an electronic component that is provided in a region of the other surface of the base material that overlaps with the panel substrate,
A sealing material provided in the vicinity of a portion of the panel substrate to which the base material is joined, and a coating layer that covers at least a region behind the electronic component of the one surface of the base material, And a coating layer having a higher wettability with respect to the sealing material than the base material.

According to this electro-optical unit, the second connection terminal on the board and the connection terminal of the circuit board are electrically connected. That is, for example, each end of the rubber connector is brought into contact with the second connection terminal on the base material and the connection terminal of the circuit board to electrically connect the panel terminal and the connection terminal of the circuit board. It is in good condition. Therefore, it is possible to avoid direct contact of a conductive member such as a rubber connector with the panel terminal on the panel substrate. As a result, the connection resistance can be suppressed lower than in the case where the panel terminal and the connection terminal of the circuit board are directly connected (that is, the rubber connector is brought into direct contact with the panel terminal). Further, since the electronic component is provided on the base material, as compared with the case where the electronic component is directly mounted on the panel substrate,
The connection resistance between the panel terminal and the electronic component can be kept low. Note that the electronic component provided on the base material includes, for example, a chip capacitor.

Further, a coating layer having higher wettability with respect to the encapsulant (mold) than the substrate (that is, more easily wet with the encapsulant) is formed on at least a region of the substrate which is behind the electronic component. ing. Therefore, the sealing material easily spreads (penetrates) between the electronic component, the area behind the electronic component, and the panel substrate. As a result, the electronic component and the area behind it and the panel substrate can be bonded to each other with high strength by using the sealing material, so that the mechanical strength of the base material can be increased.

[0008] It is desirable that the base material entirely overlaps with the panel substrate. This makes it possible to reduce the size of the electro-optical unit as compared with the case where a part of the base material protrudes from the panel substrate. It is also preferable that the second connection terminal is electrically connected to the first connection terminal through a through hole provided in the base material. According to this configuration, the first connection terminal and the second connection terminal can be electrically connected easily and reliably. Furthermore, when the present invention is applied to an electro-optical panel including a driver IC mounted on the panel substrate, the panel terminal includes a terminal connected to an input terminal of the driver IC. Is desirable.

Here, when the present invention is applied to the electro-optical panel provided with the routing wiring provided on the panel substrate, the coating layer is provided with the routing wiring of the panel substrate. A configuration having a portion facing the area is desirable. In this case, the encapsulating material that has penetrated between the coating layer and the panel substrate can cover a part or all of the routing wiring. Therefore, it is possible to prevent the routing wiring from being exposed to the outside air and corroding. Alternatively, a flexible substrate may be used. In this case, since the variation in the thickness of the panel terminal is absorbed by the base material, the panel substrate and the first connection terminal can be surely electrically connected.

An example of the electro-optical panel is a liquid crystal panel having a liquid crystal between the panel substrate and a counter substrate facing the panel substrate. Of course, the electro-optical panel to which the present invention can be applied is not limited to this. For example, the present invention can be applied to other electro-optical panels such as an EL panel using an EL light emitting element as an electro-optical material.

In order to solve the above-mentioned problems, an electronic apparatus according to the present invention is the above-mentioned electro-optical unit and a circuit board arranged at a predetermined distance from the panel substrate of the electro-optical unit. And a circuit board having a connection terminal that is electrically connected to the second connection terminal. According to this electronic device, the connection resistance between the panel terminal and the connection terminal of the circuit board can be suppressed to a low level, so that the deterioration of display quality due to the connection resistance can be suppressed. Note that examples of the electronic device according to the present invention include a mobile phone, a portable personal computer, a digital camera, and the like.

The present invention can also be implemented as a wiring board used in the electro-optical unit described above. That is, the wiring board is interposed between the panel board of the electro-optical panel and the circuit board facing the panel board with a predetermined gap, and the panel terminals of the panel board are provided. A plate-shaped base material, one surface of which is superposed on the other side, a first connection terminal which is provided on the one surface of the base material and is electrically connected to the panel terminal, and the other of the base materials. A second connection terminal that is provided on a surface and electrically connected to the connection terminal of the circuit board, and that is electrically connected to the first connection terminal, and overlaps the panel board on the other surface of the base material. An electronic component provided in a region and a coating layer that covers at least a region behind the electronic component on the one surface of the base material, in the vicinity of a portion of the panel substrate to which the base material is joined. To the sealing material provided in Wettability, it is characterized by having a high coating layer than the substrate. According to this wiring board, the connection resistance between the panel terminal and the connection terminal of the circuit board can be kept low and the base material and the panel board are sealed for the same reason as described above for the electro-optical unit. A material can be used for strong bonding.

Also in this wiring board, the second
The connection terminal may be electrically connected to the first connection terminal through a through hole provided in the base material, or the base material may be flexible. Also, various electronic components such as a chip capacitor and an IC chip can be considered as the electronic components mounted on the base material.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Such an embodiment shows one aspect of the present invention, does not limit the present invention, and can be arbitrarily modified within the scope of the present invention. In each drawing shown below, the scales are different for each layer and each member in order to make each layer and each member recognizable in the drawing.

<A: Structure of the Embodiment> FIG. 1 is a perspective view showing the external structure of a mobile phone adopting the electro-optical unit according to the present invention. As shown in the figure, in this mobile phone 7, an upper case 71 and a lower case 72 are overlapped with each other, and the electro-optical unit 1 is provided inside both cases.
In addition, various electronic components for realizing functions related to wireless communication are housed. The upper case 71 is provided with a substantially rectangular window portion 711, and the electro-optical unit 1 is arranged so as to correspond to the window portion 711. Therefore, the user of the mobile phone 7 can visually recognize the display by the electro-optical unit 1 through the window 711. Further, the upper case 71 has a speaker hole 712 for outputting sound and a microphone hole 713 for inputting sound.
And an operation section 714 in which operation buttons 714b are arranged in a plurality of button holes 714a.

Next, FIG. 2 is an exploded perspective view showing the structure of the main part of the mobile phone 7. As shown in the figure, between the upper case 71 and the lower case 72, a circuit board 5 provided with various electric circuits for operating the mobile phone 7, a lighting device 6, and an electro-optical unit. 1 and 1 are stacked in this order from the lower case 72 to the upper case 71. Note that, in FIG. 2, only elements related to the electro-optical unit 1 are illustrated, and other elements, such as a speaker and a microphone, are not illustrated.

The lighting device 6 is an LED (Light Emitting D).
a light source 61 such as iode), a light guide plate 62 made of plastic or the like, a first reflecting material 63 and a second reflecting material 64.
Have and. Of these, the light guide plate 62 is a member for guiding the light emitted from the light source 61 to the electro-optical unit 1 and the operation unit 714. The light guide plate 62 is a substantially rectangular plate-like member corresponding to the lower case 72, and has an indentation 621 for accommodating the light source 61 in the edge face in the longitudinal direction. Further, the light guide plate 62 has a substantially rectangular recess 622 in a portion where the electro-optical unit 1 is arranged. A through hole 62 for electrically connecting the electro-optical unit 1 and the circuit board 5 is formed in a portion of the bottom surface of the recess 622 near the light source 61.
2a is formed. Further, a button hole 623 for disposing the operation button 714b is formed in a portion of the light guide plate 62 corresponding to the operation portion 714.

The first reflecting material 63 and the second reflecting material 64
Is a member for reflecting the light emitted from the light guide plate 62 to the side opposite to the electro-optical unit 1 to the electro-optical unit 1 side. Of these, the second reflecting material 64 is a sheet-like member, and the button hole 6 overlapping the button hole 623 of the light guide plate 62.
41. Each of the plurality of operation buttons 714b contacts a part of the circuit board 5 and is exposed from the button hole 714a of the upper case 71 through the button holes 641 and 623.

On the other hand, the first reflecting material 63 includes side wall portions 631, 632 and 633 which surround the light guide plate 62 in three directions.
And a bottom wall portion 634 overlaid on the lower surface of the recess 622 of the light guide plate 62. A through hole 634a is formed in the bottom wall portion 634 at a position overlapping the light source 61. The through hole 634 a is a hole for passing the light source 61 mounted on the circuit board 5 into the recess 621 of the light guide plate 62 when the first reflector 63 and the light guide plate 62 are stacked on the circuit board 5. . Further, a through hole 634b is formed in the bottom wall portion 634 at a position overlapping the through hole 622a of the light guide plate 62.

Here, FIG. 3 is a cross-sectional view of an element in the vicinity of the electro-optical unit 1 among the elements shown in FIG. 2 as viewed from a cross section along the longitudinal direction of the mobile phone 7. As shown in this figure, when the circuit board 5, the first reflecting material 63, the light guide plate 62 and the electro-optical unit 1 are stacked, the light guide plate 62 and the electro-optical unit 1 are placed between the electro-optical unit 1 and the circuit board 5. The first reflecting material 63 is interposed.
However, the circuit board 5 and the observation-side board 22 of the liquid crystal panel 2 forming the electro-optical unit 1 face each other through the through holes 622a and 634b. The panel terminal 223 formed on the observing side substrate 22 has the through hole 6
It is electrically connected to the input / output terminal 51 formed on the circuit board 5 via the rubber connector 4 penetrating 22a and 634b.

Next, the structure of the electro-optical unit 1 will be described in detail. FIG. 4 is a perspective view showing an external configuration of the electro-optical unit 1 according to this embodiment, and FIG. 5 is an exploded perspective view of the electro-optical unit 1. As shown in the figure, the electro-optical unit 1 has a liquid crystal panel 2 and a flexible substrate 3. Of these, the liquid crystal panel 2 is the rear substrate 2
1 and the observation-side substrate 22 are bonded together via a sealing material 23, and in a region surrounded by both substrates and the sealing material 23, for example, a TN (Twisted Nematic) type or ST
A liquid crystal 24 of N (Super Twisted Nematic) type or the like is enclosed. That is, as shown in FIG. 5, a part of the sealing material 23 provided in a substantially rectangular frame shape is open, and a liquid crystal 24 (not shown in FIGS. 4 and 5) is injected between both substrates. And then sealed. Also,
Outside of the rear side substrate 21 and the observation side substrate 22 (the liquid crystal 24
Polarizing plates 212 and 224 for polarizing the incident light are attached to the surface (on the side opposite to the surface). Under such a configuration, the illumination light from the illumination device 6 is emitted from the rear substrate 2
1. The light passes through the liquid crystal and the observation side substrate 22 and is visually recognized by an observer.

The rear side substrate 21 and the observation side substrate 22 are
It is a transparent plate member made of glass or plastic. Of these, as shown in FIGS. 4 and 5, the observation-side substrate 22 is a region that projects from the edge of the back-side substrate 21 (that is, a region that does not face the back-side substrate 21. In the following, it will be referred to as a “projection region”. 22a). A driver IC 26 for driving the liquid crystal panel 2 is mounted in the overhang area 22a by using COG (Chip On Glass) technology. Further, in the overhang area 22a, FIG.
The flexible board 3 is joined to the portion facing the circuit board 5 through the through holes 622a and 634b shown in FIG. As shown in FIGS. 3 and 4, the flexible substrate 3 overlaps the observation side substrate 22 over the entire area.

A plurality of segment electrodes 211 extending in the Y direction are formed on the inner surface of the rear substrate 21 (the surface facing the liquid crystal 24). This segment electrode 21
Reference numeral 1 is an electrode formed of a transparent conductive material such as ITO (Indium Tin Oxide). Note that in FIG. 5, each segment electrode 211 is shown as a single line in order to prevent the drawing from becoming complicated, but the actual segment electrode 211 has a predetermined width as shown in FIG. This is a strip-shaped electrode (the same applies to the common electrode 221 described later).

As shown in FIGS. 3 and 5, one end of each segment electrode 211 reaches a portion of the rear substrate 21 which overlaps with the seal material 23. Then, this end portion is electrically connected to the routing wiring 222 formed on the observation side substrate 22 via the conductive particles (not shown) dispersed in the sealing material 23. The wiring line 222 is provided with a driver IC in the overhang area 22a.
26, and its end is connected to a bump (projection electrode) 26a of the driver IC 26. More specifically, as shown in FIG. 3, the driver IC 26 is bonded to the observing side substrate 22 by the adhesive 281 in the anisotropic conductive film 28.
Bumps 26a formed on the terminals of 26 and the wiring 22
2 is the conductive particles 2 in the anisotropic conductive film 28.
It is conducted through 82.

On the other hand, the inner surface of the observation side substrate 22 (the liquid crystal 2
4, a plurality of common electrodes 221 extending in a direction orthogonal to the segment electrodes 211 (that is, the X direction shown in FIGS. 4 and 5) are formed in a region facing the rear substrate 21 of the front surface (4). Has been done. Each common electrode 221
Is a strip-shaped electrode formed of ITO or the like.
Each common electrode 221 is laid out on the observation side substrate 22 from a region (a region inside the seal frame) facing the rear substrate 21 to a projecting region 22a, and its end portion is a bump of the driver IC 26. 26a.

The surface of the rear substrate 21 on which the segment electrodes 211 are formed and the surface of the observation substrate 22 on which the common electrode 221 is formed are covered with an alignment film (not shown). This alignment film is an organic thin film such as polyimide and has been subjected to a rubbing treatment for defining the alignment direction of the liquid crystal when no voltage is applied.

As shown in FIGS. 3 to 5, a plurality of panel terminals 223 are formed on the bulging area 22a of the observing side substrate 22. One end of each panel terminal 223 is connected to the bump 26b of the driver IC 26. That is, as shown in FIG. 3, one end of each panel terminal 223 is
The conductive particles 282 in the anisotropic conductive film 28 are electrically connected to the bumps 26b formed on the terminals of the driver IC 26.

Here, FIG. 6 is a plan view showing the structure in the vicinity of the panel terminal 223 in the overhang area 22a. Note that, in FIG. 6, the outer shape of the flexible substrate 3 is shown by a dashed line. As shown in the figure, the plurality of panel terminals 223 are divided into driver IC panel terminals 223a and electronic component panel terminals 223b. Of these, the driver IC panel terminal 223a is the driver IC 2
6 is a terminal for inputting various signals such as a clock signal for defining the operation of the circuit 6 from the circuit board 5 to the driver IC 26. On the other hand, the electronic component panel terminal 223b is a terminal for connecting the chip capacitor 34 mounted on the flexible substrate 3 to the driver IC 26.

Further, as shown in FIG. 3, the observation side substrate 22
Of the region where the driver IC 26 is mounted and the region in the vicinity thereof (that is, the region where the common electrode 221 and the routing wiring 222 are formed), after the flexible substrate 3 is bonded onto the observation side substrate 22, the mold ( It is sealed by a sealing material) 27 (see FIG. 9). The mold 27 is made of, for example, silicon and is applied so as to reach the edge of the flexible substrate 3.

Next, the structure of the flexible substrate 3 will be described with reference to FIGS. 7 (a) and 7 (b). Figure 7 (a)
FIG. 3 is a diagram showing a configuration on a surface of the flexible substrate 3 facing the side opposite to the observation side substrate 22 (that is, a surface facing the circuit board 5. Hereinafter, referred to as “circuit board side surface”). . On the other hand, FIG. 7B shows the flexible substrate 3
FIG. 3 is a diagram showing a configuration on a surface (hereinafter, referred to as a “panel side surface”) that faces an observation side substrate 22 among them. In addition, in FIG. 7B showing the configuration of the panel side surface,
The components on the surface on the circuit board side are indicated by broken lines.

The flexible substrate 3 has a film-shaped base material 31. The base material 31 is made of, for example, polyimide and has flexibility, and is bonded to the observing side substrate 22 by an adhesive 291 in the anisotropic conductive film 29, as shown in FIG.

A plurality of panel side terminals 32 are formed on the panel side surface of the base material 31, as shown in FIG. 7B. The panel-side terminal 32 is, for example, a layer made of copper plated with gold. As shown in FIG.
In a state where the base material 31 is bonded to the observation side substrate 22 via the adhesive 291 in the anisotropic conductive film 29, the panel-side terminals 32 have the conductive particles 292 in the anisotropic conductive film 29. Through the panel terminal 22 on the observation side substrate 22
3 (driver IC panel terminal 223a and electronic component panel terminal 223b). The plurality of panel-side terminals 32 can be divided into connection terminals 32a and connection terminals 32b. As can be seen by comparing FIGS. 6 and 7B, the connection terminal 32a is electrically connected to the driver IC panel terminal 223a on the observation side substrate 22. On the other hand, the connection terminals 32b are the electronic component panel terminals 2 on the observation side substrate 22.
Conductive with 23b.

On the other hand, on the circuit board side surface of the base material 31, as shown in FIG. 7A, a plurality of circuit board side terminals 3 are provided.
3 is formed. The circuit board side terminals 33 are, as with the panel side terminals 32, made of, for example, a layer of copper plated with gold. Each of these circuit board side terminals 33 is formed so as to be behind each panel side terminal 32 formed on the panel side surface, that is, to overlap each panel side terminal 32 with the base material 31 interposed therebetween. The plurality of circuit board side terminals 33 can be divided into connection terminals 33a and connection terminals 33b. As shown in FIGS. 7A and 7B, the connection terminal 33a is electrically connected to the connection terminal 32a on the panel-side surface through the through hole 311 provided in the base material 31. Similarly, the connection terminal 33b is connected to the base material 3
Through the through hole 311 provided in No. 1, it is electrically connected to the connection terminal 32b on the panel side surface.

As shown in FIG. 3, when the electro-optical unit 1 is incorporated in the mobile phone 7, the connection terminals 33a of the circuit board side terminals 33 are the through holes 622a of the light guide plate 62 and the first reflecting material. The rubber connector 4 arranged so as to penetrate through the through hole 634b of 63 is opposed to the output terminal 51 on the circuit board 5. Rubber connector 4
Has an elastic member such as synthetic rubber and a large number of conductive wires penetrating the elastic member. By making this elastic member elastically contact the base material 31 of the flexible substrate 3 and the circuit board 5, the connection terminal 33a on the base material 31 and the input / output terminal 51 on the circuit board 5 are connected. It is electrically connected by the conductive wire in the elastic member. With the above configuration, the input / output terminal 51 of the circuit board 5
Is a plurality of panels on the observation side substrate 22 via the conductive wire of the rubber connector 4, the circuit board side terminal 33 (connection terminal 33a) of the flexible substrate 3, the through hole 311, and the panel side terminal 32 (connection terminal 32a). The terminal 223 is electrically connected to the driver IC panel terminal 223a.

On the other hand, the connection terminal 33b of the circuit board side terminal 33 is connected to each electrode of the chip capacitor 34 mounted on the base material 31. That is, FIG. 7 (a)
As shown in FIG. 5, the wiring line 331 is formed on the surface of the base material 31 on the circuit board side corresponding to each connection terminal 33b. One end of this wiring line 331 has a connection terminal 3
3b, the other end of the base material 31 which reaches the area where the chip capacitor 34 is mounted is connected to the land 332. And the chip capacitor 3
4 is mounted on this land 332. With the above configuration, the electrodes of the chip capacitor 34 are the lands 332,
Of the plurality of panel terminals 223 on the observation-side substrate 22 via the lead wiring 331, the circuit-board-side terminal 33 (connection terminal 33b) of the flexible substrate 3, the through hole 311, and the panel-side terminal 32 (connection terminal 32b). It conducts with the panel terminal 223b for electronic parts.

Here, as shown in FIG. 7B, the base material 3
At least a region behind the chip capacitor 34 of 1, that is, a region on the back side of the region where the chip capacitor 34 is mounted is covered with the coating layer 35. However, in the present embodiment, the coating layer 35 is formed so as to reach not only the region of the base material 31 that is behind the chip capacitor 34 but also the peripheral region and the edge of the base material 31. In FIG. 7B, the coating layer 35 of the base material 31 is used.
A region (hereinafter, referred to as “electronic component mounting region”) 312 in which is formed is hatched. As described with reference to FIG. 6, a part of the flexible substrate 3 overlaps with a part of the common electrode 221 formed on the observation side substrate 22. As can be seen by comparing FIG. 5 and FIG. 7B, the coating layer 35 reaches not only the region of the base material 31 behind the chip capacitor 34, but also the region overlapping with a part of the common electrode 221. Is formed.

The coating layer 35 is a layer formed of, for example, an epoxy or acrylic resin material. However, the coating layer 35 is formed so that the wettability of its surface with respect to the mold 27 is higher than that of the surface of the base material 31 made of polyimide or the like. Here, the wettability is
This is the amount that represents the degree to which the target surface gets wet when the liquid material is dropped onto the surface of the target member (hereinafter referred to as the “target surface”), and the shape of the target surface. It is an amount determined according to (surface roughness) and the surface tension of the dropped liquid. More specifically, when the liquid is dropped on the target surface and the contact angle α of the drop 92 on the target surface 91 is small as shown in FIG. 8A, it is referred to as “high wettability”. On the contrary, as shown in FIG. 8B, when the contact angle α of the droplet 92 on the target surface 91 is large, the wettability is low. Therefore, in the present embodiment, when the mold 27 is dropped (applied) on the surface of the coating layer 35, the contact angle α of the mold droplet is
It can be said that it is smaller than the contact angle α of the mold droplet when the mold 27 is dropped on the surface of the base material 31.

As described above, in this embodiment, the panel-side terminal 32 of the flexible board 3 is electrically connected to the panel terminal 223 on the observation-side board 22, while the circuit board-side terminal 33 of the flexible board 3 is made of rubber. Connector 4
The circuit board 5 is electrically connected to the input / output terminal 51 via the. Therefore, the connection resistance can be suppressed lower than in the case where the rubber connector 4 is brought into direct contact with the panel terminal 223 on the observation side substrate 22. Further, in the present embodiment, the chip capacitor 34 is mounted on the base material 31 of the flexible substrate 3. Therefore, as compared with the case where the chip capacitor 34 is brought into direct contact with the electronic-parts panel terminal 223b on the observation-side substrate 22, the connection resistance can be suppressed low.

By the way, the base material 31 of the flexible substrate 3
The vicinity of the portion where the panel-side terminal 32 is formed is covered with the adhesive 291 in the anisotropic conductive film 29 so that the observation-side substrate 2
It is joined to 1. On the other hand, the electronic component mounting area 312 of the base material 31 cannot be bonded to the rear substrate 21 by this method. That is, in order to bond the base material 31 to the observation-side substrate 22 by the anisotropic conductive film 29, the base material is formed with the anisotropic conductive film 29 interposed between the observation-side substrate 22 and the base material 31. This is because it is necessary to press 31 toward the observing side substrate 22, but the chip capacitor 34 cannot be pressed in an area where the chip capacitor 34 and the like are mounted because the chip capacitor 34 is an obstacle. Therefore, the portion of the base material 31 on which the chip capacitor 34 is mounted cannot be joined to the observation side substrate 22, and as a result, the base material 31 may be easily damaged in this portion. Even under such circumstances, according to the present embodiment, the base material 31 is provided in the electronic component mounting area 312.
Since the coating layer 35 having higher wettability with respect to the mold 27 is formed, the portion of the flexible substrate 3 on which the coating layer 35 is formed and the observation-side substrate 22 are separated from each other by the mold 2.
7 makes it possible to bond with high strength. The details are as follows.

Here, as a contrast to this embodiment, consider a case where the base material 31 having no coating layer 35 is bonded to the observation side substrate 22. As described above, the base material 31 made of polyimide or the like has low wettability with respect to the mold 27. Therefore, even if the vicinity of the portion of the base material 31 on which the panel-side terminal 32 is formed is joined to the observation-side substrate 22 by using the anisotropic conductive film 29, the electronic component mounting region 312 and the observation-side substrate 22 are The mold 27 does not enter between them. Therefore, the electronic component mounting area 312 and the observation side substrate 22 are not joined.

On the other hand, according to this embodiment, the wettability of the coating layer 35 to the mold 27 is high. For this reason,
When the mold 27 is applied in the vicinity of the base material 31 after the base material 31 is bonded to the observation side substrate 22 via the anisotropic conductive film 29, the mold 27 is formed between the coating layer 35 and the observation side substrate 22. It will enter. Here, FIG. 9 is a plan view showing a configuration in the vicinity of the overhang region 22a after the mold 27 is applied. In addition, in order to prevent the drawing from being complicated, the panel terminal 223 and the common electrode 2 are not shown in FIG.
21 and the like are indicated by broken lines. As shown by hatching in FIG. 9, according to the present embodiment, the covering layer 35 and the observation side substrate 2 are provided over the entire electronic component mounting area 312.
The mold 27 is inserted between the two. Therefore, the coating layer 35 and the observation side substrate 22 are bonded with high strength by the mold 27.

Further, in contrast to the above case in which the coating layer 35 is not provided on the base material 31, the wiring provided on the surface of the observing side substrate 22 (for example, the common electrode 211. Hereinafter referred to as “board wiring”). Consider a case in which a part of (Yes) and a part of the electronic component mounting area 312 of the base material 31 overlap. At this time, since the mold 27 does not enter between the observation side substrate 22 and the electronic component mounting area 312 of the base material 31, the portion of the wiring on the substrate overlapping the base material 31 is molded.
It cannot be covered by 7. That is, since the wiring on the substrate is exposed to the outside air, there is a problem that it easily corrodes.

On the other hand, according to the present embodiment, since the mold 27 can be spread between the coating layer 35 and the observation side substrate 22, even if a part of the wiring on the substrate overlaps the coating layer 35. Even in this case, a part of the wiring on the substrate can be covered with the mold 27. Therefore, according to this embodiment, it is possible to effectively prevent the corrosion and damage of the wiring on the substrate.

<B: Modification> Although one embodiment of the present invention has been described above, the above embodiment is merely an example, and various modifications can be made to the above embodiment without departing from the spirit of the present invention. Can be added. For example, the following may be considered as modifications.

<B-1: Modification 1> In the above embodiment, the common electrode 221 formed on the observation side substrate 22.
Although a part of the above structure overlaps with the electronic component mounting area 312 of the base material 31, it is not always necessary to adopt this structure. That is, the wiring (common electrode) on the observation side substrate 22
It is also possible to adopt a configuration in which a part of the above and the electronic component mounting area 312 do not overlap each other.

<B-2: Modified Example 2> In the above embodiment, the flexible substrate 3 is arranged to overlap the observation side substrate 22 over the entire substrate 31, but a part of the substrate 31 is observed side 22. It may be configured to protrude from the edge of. In other words, a part of the base material 31 may overlap the observation side substrate 22.

<B-3: Modification 3> In the above-described embodiment, the rubber connector 4 is used as a conductive member for electrically connecting the liquid crystal panel 2 and the circuit board 5, but elastic force is applied to both of them. Any connector that makes contact may be used. For example, a connector having a spring structure may be used, which makes a pressure contact by the restoring force of a V-shaped metal spring.

<B-4: Modification 4> In the above embodiment, the chip capacitor 34 is exemplified as the electronic component mounted on the base material 31, but other electronic components are mounted on the base material 31. You may do it. For example, instead of the chip capacitor 34 in the above embodiment, an IC chip or the like that performs a part of the function of the driver IC 26 is used as the base material 3.
It may be mounted on one.

<B-5: Modification 5> In the above embodiment, the passive matrix type liquid crystal panel 2 having no switching element has been exemplified, but the TFD (Thin Film) is used.
Two-terminal type switching element typified by Diode) and T
The present invention can also be applied to an active matrix liquid crystal display device including a three-terminal switching element represented by an FT (Thin Film Transistor). Further, in the above-described embodiment, the transmissive liquid crystal panel 2 that performs display by using the irradiation light from the illumination device 6 has been exemplified, but the reflective layer formed on the inner surface of the rear substrate 21 prevents the light from the observing side. It goes without saying that the present invention can be applied to a liquid crystal panel that reflects incident light and performs a reflective display by this reflected light, or a so-called transflective liquid crystal panel that can perform both reflective display and transmissive display. Absent. Further, the present invention can be similarly applied to a liquid crystal panel capable of color display using a color filter.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the liquid crystal panel using the liquid crystal as the electro-optical material is exemplified, but an EL (electroluminescence) element or the like is used as the electro-optical material and the The present invention can be applied to various electro-optical panels that perform display by the optical effect. As described above, the present invention can be applied to any electro-optical panel in which the panel terminals to be connected to the circuit board are provided on the panel board, regardless of the aspect of other components.

<B-6: Modification 6> In the above embodiment, the case where the electro-optical unit according to the present invention is applied to a mobile phone is illustrated, but the present invention can be applied to other electronic devices. Needless to say. That is, as an electronic device to which the electro-optical unit according to the present invention can be applied, in addition to the mobile phone described in the above embodiment, a display of a personal computer, a liquid crystal television, a viewfinder type / monitor direct-viewing type video tape. Examples include recorders, car navigation devices, pagers, electronic organizers, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, and the like. According to the electro-optical unit of the present invention, the connection resistance between the panel terminal on the panel substrate and the input / output terminal on the circuit board can be suppressed to be low, and the deterioration of the display quality due to the connection resistance can be suppressed. Therefore, it is particularly suitable for electronic devices that require good display quality.

[0052]

As described above, according to the present invention,
The connection resistance between the electro-optical panel and the external device can be kept low.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a mobile phone using an electro-optical unit according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a configuration of a main part of the mobile phone.

FIG. 3 is a cross-sectional view showing a configuration in the vicinity of an electro-optical unit of the mobile phone.

FIG. 4 is a perspective view showing a configuration of the same electro-optical unit.

FIG. 5 is an exploded perspective view showing a configuration of a main part of the electro-optical unit.

FIG. 6 is a plan view showing a configuration of an overhang area 22a in a liquid crystal panel of the electro-optical unit.

FIG. 7A is a plan view showing the configuration of the circuit board side surface of the flexible substrate 3 of the electro-optical unit, and FIG. 7B is a plan view showing the configuration of the panel side surface.

FIG. 8 is a diagram for explaining wettability.

FIG. 9 is a plan view showing a state of molding in the electro-optical unit.

[Explanation of symbols]

1 ... Electro-optical unit, 2 ... Liquid crystal panel (electro-optical panel), 21 ... Rear side substrate, 211 ... Segment electrode, 22 ... Observation side substrate (panel substrate), 221 ...
Common electrode, 223 ... Panel terminal, 223a ... Driver IC panel terminal, 223b ... Electronic component panel terminal, 23 ... Sealing material, 24 ... Liquid crystal, 26 ... Driver IC, 27 ... Mold (sealing) (Stopping material), 3 ... Flexible substrate (wiring substrate), 31 ... Base material, 311 ... Through hole, 312 ... Electronic component mounting area, 32 ... Panel side terminal (first connection terminal), 32a, 32b ... connection terminal, 33 ... circuit board side terminal (second connection terminal),
33a, 33b ... Connection terminal, 34 ... Chip capacitor (electronic component), 35 ... Covering layer, 4 ... Rubber connector (conductive member), 5 ... Circuit board, 51 ... Input / output terminal, 6 ... Lighting device, 61 ... Light source, 62 ... Light guide plate,
622a, 634b ... through-hole, 63 ... first reflecting material, 7 ... mobile phone, 71 ... upper case, 72 ... lower case.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 1/14 H05K 1/14 C H F term (reference) 2H092 GA50 GA57 HA28 MA32 MA34 MA35 MA37 NA15 NA16 NA25 NA28 5C094 AA21 BA43 DA07 DA09 DA14 DA15 DB01 DB02 DB03 EA02 EA04 EA05 EA07 EB02 5E344 AA01 AA15 AA22 AA28 BB02 BB04 CC05 CC09 CD18 CD27 CD38 EE06 5F044 MM03 NN13 NN19 5G435 AA16H37EE12 BB12 EE12 BB12EE33

Claims (16)

[Claims] 1. An electro-optical panel having a panel substrate provided with panel terminals, wherein a circuit substrate is arranged facing a surface of the panel substrate provided with the panel terminals; A plate-shaped base material, one surface of which is overlapped with a portion provided with the panel terminal, and a first connection terminal which is provided on the one surface of the base material and is electrically connected to the panel terminal, A second connection terminal that is provided on the other surface of the base material and is electrically connected to the connection terminal of the circuit board and that is electrically connected to the first connection terminal; and the other surface of the base material. Of the electronic component provided in a region overlapping with the panel substrate, a sealing material provided in the vicinity of the portion of the panel substrate where the base material is joined, and the one surface of the base material At least the area behind the electronic component And a coating layer that has a higher wettability with respect to the sealing material than the base material. 2. The electro-optical unit according to claim 1, wherein the base material overlaps the panel substrate over the entire surface. 3. The electro-optical unit according to claim 1, wherein the second connection terminal is electrically connected to the first connection terminal through a through hole provided in the base material. 4. The electro-optical device according to claim 1, further comprising a driver IC mounted on the panel substrate, wherein the panel terminal includes a terminal connected to an input terminal of the driver IC. unit. 5. The wiring board is provided on the panel substrate, and the coating layer has a portion facing a region of the panel board where the wiring board is provided. The electro-optical unit according to claim 1. 6. The electro-optical unit according to claim 1, wherein the electronic component is a chip capacitor. 7. The electro-optical unit according to claim 1, wherein the base material has flexibility. 8. The electro-optical unit according to claim 1, wherein the base material is made of polyimide, and the sealing material is made of silicon. 9. The electro-optical unit according to claim 1, wherein the electro-optical panel is a liquid crystal panel having liquid crystal between the panel substrate and a counter substrate facing the panel substrate. 10. The electro-optical unit according to claim 1, and a circuit board arranged at a predetermined distance from a panel board of the electro-optical unit, the connection being conductive with the second connection terminal. An electronic device comprising: a circuit board having a terminal. 11. The connection terminal of the circuit board is electrically connected to the second connection terminal via a conductive member interposed between the circuit board and the base material.
The electronic device according to 0. 12. A wiring board interposed between a panel board of an electro-optical panel and a circuit board facing the panel board at a predetermined interval, in a portion of the panel board where a panel terminal is provided. A plate-shaped base material that is superposed with its one surface facing, a first connection terminal that is provided on the one surface of the base material and is electrically connected to the panel terminal, and is provided on the other surface of the base material. And a second connection terminal electrically connected to the connection terminal of the circuit board and electrically connected to the first connection terminal, and provided in an area of the other surface of the base material that overlaps with the panel board. And a coating layer that covers at least a region behind the electronic component on the one surface of the base material, and is provided in the vicinity of a portion of the panel substrate to which the base material is joined. Wetting the encapsulant Sex, wiring board, characterized by having a high coating layer than the substrate. 13. The wiring board according to claim 12, wherein the second connection terminal is electrically connected to the first connection terminal through a through hole provided in the base material. 14. The wiring board according to claim 12, wherein the base material has flexibility. 15. The wiring board according to claim 12, wherein the electronic component is a chip capacitor. 16. The base material is made of polyimide, and the sealing material is made of silicon.
The wiring board according to.