JP4714480B2 - Liquid crystal display element - Google Patents

Description

  The present invention relates to a one-side substrate terminal type liquid crystal display element in which terminals of respective electrodes provided on a pair of substrates are combined on one substrate.

  In a conventional liquid crystal display element, a single-side substrate terminal type liquid crystal display element in which a plurality of electrodes are provided on a pair of substrates and wiring terminals for supplying voltage to these electrodes are collectively installed on one substrate is provided. is there. This one-side substrate terminal type liquid crystal display element has the advantage that the connection structure with an external electric circuit is easy and the mounting structure is simplified.

  However, in this one-side substrate terminal type liquid crystal display element, it is necessary to conductively connect an electrode provided on one substrate and a lead wiring for supplying a voltage to the electrode provided on the other substrate, The structure and process for that cause cost increase. That is, since a wiring is drawn out from the electrode on one substrate to form a connection pad, and a connected pad provided on the routing wiring on the other substrate is conductively connected by a conductive member (hereinafter referred to as inter-substrate conduction), The material cost of the conductive member and the number of steps for arranging the conductive member and connecting between the substrates increase.

  In particular, in a simple matrix type liquid crystal display element in which a plurality of display electrodes are provided on one substrate and a plurality of scanning electrodes are disposed on the other substrate so as to be orthogonal to the display electrodes, the structure is obtained by forming a single-side substrate terminal. And the manufacturing process becomes more complicated.

Even in a simple matrix type liquid crystal display element having a single-sided substrate terminal structure as described above, as a conventional method capable of conducting conduction between substrates with good workability, the conductive material is contained in a sealing material provided to join a pair of substrates. A method is known in which particles are contained, and corresponding connection pads and connection pads are conductively connected through the conductive particles. (For example, see Patent Document 1)
However, in recent years, there has been a strong demand for higher definition for the display of the user, and in order to meet this demand, higher definition is also required for the liquid crystal display element. In a high-definition liquid crystal display element, the wiring for supplying a signal voltage to each pixel is also densified as the pixel density increases. Therefore, in a simple matrix type liquid crystal display element with a single-sided substrate terminal structure, the connection pads and the pads to be connected are also densified in accordance with the densified wiring, and the individual pad area is reduced, and the reliability in inter-substrate conduction is reduced. As the value decreases, the electrical resistance varies. Variation in the electric resistance value of the wiring causes display unevenness.

Further, in order to cope with the higher density of wiring, the routing pattern is optimized so that the minimum required line width can be secured for each wiring, and as a result, the wiring routing area increases. In this case, since it is necessary to make the width of the frame portion as small as possible in order to promote downsizing of the liquid crystal display element, the wiring routing area is a seal that joins both substrates as disclosed in Patent Document 2. It is set in a wide range along the outside of the material.
JP 63-29729 A JP-A-9-101535

  However, in the liquid crystal display element disclosed in Patent Document 2, the wiring routing area along the outside of the sealing material is a gap where the edges of both substrates face each other. Since these narrow objects are easy to enter and difficult to remove, there is a risk that the wiring may be eroded. In the case of overcoating a protective film to prevent electrical corrosion of the wiring, the material cost and man-hours for that purpose increase.

  The object of the present invention is to achieve highly reliable inter-substrate conduction with little variation in electrical resistance value even when the wiring density is increased due to high definition, and the deterioration due to electrolytic corrosion of wiring is remarkably suppressed. An object of the present invention is to provide a single-sided substrate terminal type liquid crystal display element capable of stably obtaining a good display quality over a long period of time.

  The liquid crystal display element of the present invention includes a plurality of first electrodes, a plurality of front first wirings connected to the first electrodes and supplying a voltage to the plurality of first electrodes, and these A first substrate on which a first connection pad provided on each of the front first wirings is formed, a plurality of second electrodes, and a voltage applied to the plurality of second electrodes. A plurality of second wirings for supplying power, a plurality of first connected pads provided corresponding to the first connection pads, and a plurality of rear sides for supplying voltages to the first connected pads, respectively. The second substrate on which the first wiring is formed and the insulating resin base material contain conductive particles, and the first substrate and the second substrate are arranged with their respective electrode formation surfaces facing each other. A bonding member for bonding while maintaining a gap between the first substrate and the first substrate And a liquid crystal display element comprising a liquid crystal sealed in a space surrounded by each of the opposing inner surfaces of the second substrate and the bonding member, wherein the bonding member includes the first electrode and the second electrode. A frame-shaped first seal portion that encloses a display region composed of a plurality of pixels formed in each region where the electrodes face each other through the liquid crystal, and a first region that surrounds a predetermined region outside the first seal portion. The first connection pad and the corresponding first connected pad corresponding to the first connection pad are arranged corresponding to at least one of the first seal portion and the second seal portion. It is provided and is electrically connected through the conductive particles.

  According to the liquid crystal display element of the present invention, even when the wiring density increases due to high definition, a large area of the connection pad and the connection pad in the inter-substrate conductive portion can be ensured. In addition to being able to obtain a rich inter-substrate conduction, deterioration due to electrolytic corrosion or the like of the routing wiring is remarkably suppressed, and good display quality can be stably obtained over a long period of time.

  In the liquid crystal display element of the present invention, the first connection pad and the first connected pad are formed in pairs on the front first wiring and the rear first wiring, respectively, and both in the first seal part and the second seal part. It is preferable that each of the first connection pads and the first connected pads is large, and a parallel wiring circuit is formed, and the electric resistance value of the inter-substrate conductive portion is increased. An absolute value can be reduced and variations thereof can be suppressed, and a one-side substrate terminal type liquid crystal display element that is more reliable and promotes high definition with good display quality can be obtained.

  In the liquid crystal display element of the present invention, the first connection pad and the first connected pad are formed one by one for the front first wiring and the rear first wiring, respectively. The conductive connection portion with the connected pad is preferably formed in a different seal portion of the first seal portion and the second seal portion, thereby reducing the area of the first connection pad and the first connected pad. A large amount can be secured, and the first connection pad and the second connection pad can be easily aligned at the time of joining the first substrate and the second substrate.

  Furthermore, in the liquid crystal display element of the present invention, a plurality of auxiliary second wirings are disposed on the first substrate so as to correspond to the second wirings, and the second connection pads are respectively provided on the second wirings and the auxiliary second wirings. And a pair of second connected pads corresponding to each other, and the pair of second connected pads and the pair of second connected pads are electrically connected to each other by both the first seal portion and the second seal portion. In this way, a parallel circuit is formed not only in the first wiring but also in the second wiring, and the electric resistance value can be reduced.

(First embodiment)
FIG. 1 is a plan view showing a liquid crystal display device as an embodiment of the present invention, FIG. 2 is a partial plan view showing an enlarged main part Q, and FIGS. 3 (a) and 3 (b) are respectively A in FIG. It is the typical partial sectional view of the -A line, and the typical partial sectional view of the other part cut | disconnected similarly to this.

  The liquid crystal display element of the present embodiment is a simple matrix type liquid crystal display element. As shown in FIG. 1, a pair of glass substrates 1 and 2 having a rectangular outer shape in plan view have a predetermined gap by a sealing material 3. Keep joined. The pair of glass substrates 1 and 2 are different in size, and the end portions 1a and 1b on the two adjacent sides of the one large glass substrate 1 are more suitable than the corresponding end surfaces of the other small glass substrate 2, respectively. Protrusions are joined.

  A plurality of stripe electrodes 4 and 5 are arranged on each facing surface (inner surface) of the pair of bonded glass substrates 1 and 2 so as to extend in parallel in directions orthogonal to each other. In the present embodiment, a plurality of scanning electrodes 4 are disposed on the inner surface of the glass substrate 2 so as to extend in parallel to the longitudinal direction of the substrate, and a plurality of display electrodes 5 are disposed on the inner surface of the glass substrate 1 in the lateral direction of the substrate. It is arranged to extend in parallel.

The region where the scanning electrode 4 and the display electrode 5 are opposed to each other is a pixel p, and thus a display region Dd in which the plurality of pixels p are arranged in a dot matrix is formed.
The liquid crystal display element of the present embodiment is a COG (Chip On Glass) mounting type liquid crystal display element in which a driver chip for driving a liquid crystal is directly mounted on the glass substrate 1. That is, the scanning driver chip 6 that supplies the scanning drive voltage to the scanning electrode 4 is mounted on the protruding portion 1a, and the display driver chip 7 that supplies the display driving voltage to the display electrode 5 is mounted on the protruding portion 1b by the COG method. .

  And the sealing material 3 which makes the substantially frame shape surrounding the said display area Dd is arrange | positioned between the both glass substrates 1 and 2, and both the substrates 1 and 2 are joined. As shown in FIG. 3, the sealing material 3 is formed by dispersing and mixing conductive particles 3b in an insulating resin base material 3a. The conductive particles 3b of this example are formed by depositing gold on the surface of the resin particles by plating. At the time of substrate bonding, a material in which conductive particles 3b are dispersed and mixed in this insulating resin base material 3a is applied to the pattern shown in FIG.

  Here, as shown in FIG. 1, the sealing material 3 includes a first seal portion 3A having a rectangular frame shape that surrounds the display region Dd inside, and a substrate protruding portion 1a on the outside of the first seal portion 3A, It consists of the 2nd seal | sticker part 3B surrounding the outer edge area | region Df along two adjacent sides of the glass substrate 2 corresponding to 1b. A liquid crystal injection hole 3c for injecting liquid crystal is formed in the first seal portion 3A. In the present embodiment, since the liquid crystal is not sealed in the outer edge region Df surrounded by the second seal portion 3B, the second seal portion 3B is not provided with a liquid crystal injection hole, but on the side opposite to the liquid crystal injection side. A minute air escape hole (not shown) for stabilizing the internal air pressure is provided at an appropriate position.

  A front scanning wiring 8 is formed by extending one end of each scanning electrode 4 disposed on the inner surface of the glass substrate 2. These front scanning wires 8 are routed in a pattern that converges toward the center of the end corresponding to the protruding portion 1a of the glass substrate 2. As shown in FIG. 2, each of the front scanning wirings 8 includes a pair of inter-substrate connection pads 8a and 8a corresponding to the arrangement portions of the first seal portion 3A and the second seal portion 3B. Each is formed. These connection pads 8a are arranged in parallel at a predetermined narrow pitch along the extending direction of the corresponding seal portions 3A, 3B.

  On the other hand, on the glass substrate 1 side, rear scanning wirings 9 are arranged corresponding to the above-mentioned front scanning wirings 8. In these rear scanning lines 9, a pair of connected pads 9a and 9a are formed in the same size at positions facing each other so as to correspond to the pair of connection pads 8a of the front scanning line 8. Each rear scanning wiring 9 is formed in a pattern that converges toward the area where the scanning driver chip 6 is arranged, and the pattern between the pair of connected pads 9a, 9a is a portion corresponding to the corresponding part of the front scanning wiring 8. They are formed in substantially the same pattern.

  The front scanning wiring 8 and the rear scanning wiring 9 arranged as described above are conductively connected via the conductive particles in the sealing material 3 by joining the glass substrates 1 and 2 with the sealing material 3. . In this case, as shown in FIG. 3 (a), the front scanning wiring 8 and the rear scanning wiring 9 corresponding thereto have a pair of connection pads 8a and 8a and connected pads 9a and 9a as the first seal portion 3A. The conductive particles 3b and the conductive particles 3b in the second seal portion 3B are connected to each other to form a parallel circuit. Accordingly, the area of each connection pad 8a and each connected pad 9a can be reduced to about half that of the conventional case where conductive connection is made at one place, and a pair of connection pads 8a, 8a and connected pads 9a, The scanning wirings 8 and 9 between 9a can also be formed narrower. As a result, it is possible to easily cope with narrowing of the wiring pitch due to high definition of the liquid crystal display element.

  In addition, since the front scanning wiring 8 and the rear scanning wiring 9 disposed in the outer edge region Df surrounded by the second seal portion 3B outside the first seal portion 3A can be formed narrow, they are routed accordingly. The degree of freedom is increased and pattern design is facilitated, and since it is disposed in a substantially closed space surrounded by the first and second seals 3A and 3B, it can be caused by electrolytic corrosion without being covered with a protective film or the like. Degradation is effectively prevented.

  Connection terminals 9b are formed at the tip portions of the rear scanning wiring 9 extending toward the area where the scanning driver chip 6 is disposed, and these connection terminals 9b are connected to the output terminal electrodes 6a (FIG. 3) of the scanning driver chip 6. are arranged in parallel at a predetermined pitch at a position corresponding to (a).

  On the other hand, as shown in FIG. 1, the display wiring 10 for supplying the display signal voltage to each display electrode 5 has a plurality of display wirings 10 drawn from the end of each display electrode 5. It is arranged by being drawn around the inner surface of the glass substrate 1 in a pattern that converges toward the arrangement area. In this case, each display wiring 10 passes through the outer edge region Df surrounded by the second seal portion 3B outside the first seal portion 3A from the end portion of each display electrode 5, and then the arrangement area of the display driver chip 7 It is routed toward the head. As shown in FIG. 3B, a connection pad 10a is formed at each intersection position of the first seal portion 3A and the second seal portion 3B of each display wiring 10. A pair of connection pads 10a and 10a formed on each display wiring 10 are arranged in parallel at a predetermined narrow pitch along the extending direction of the seal portions 3A and 3B.

  A plurality of bypass wirings 11 are arranged on the inner surface of the glass substrate 2 in the outer edge region Df so as to correspond to the plurality of display wirings 10. Each of the bypass wirings 11 is formed in substantially the same pattern with substantially the same line width so as to overlap the wiring portion between the pair of connection pads 10a and 10a in the corresponding display wiring 10. Connected pads 11 a and 11 a are formed at both ends of each bypass wiring 11 so as to face the connection pads 10 a and 10 a of the display wiring 10.

  The display wiring 10 and the bypass wiring 11 arranged as described above are electrically connected through the conductive particles in the sealing material 3 by joining the glass substrates 1 and 2 with the sealing material 3. In this case, as shown in FIG. 3B, the display wiring 10 and the detour wiring 11 corresponding to the display wiring 10 include a pair of connection pads 10a and 10a and connected pads 11a and 11a that are electrically conductive to the first seal portion 3A. The particles 3b and the conductive particles 3b in the second seal portion 3B are electrically connected to each other to form a parallel circuit. Therefore, each line width of the display wiring 10 and the bypass wiring 11 in the parallel circuit portion can be formed narrower. As a result, it is possible to easily cope with narrowing of the wiring pitch due to high definition of the liquid crystal display element.

  Further, since the display wiring 10 and the bypass wiring 11 in the outer edge region Df are disposed in a closed space surrounded by the first and second seals 3A and 3B, even if they are not covered with a protective film or the like. It is possible to effectively prevent the deterioration due to the

  As shown in FIGS. 3A and 3B, a liquid crystal 12 is sealed in a space surrounded by the first seal portion 3A between the glass substrates 1 and 2. The liquid crystal 12 is injected from the liquid crystal injection hole 3c shown in FIG. 1 by a known vacuum injection method. The liquid crystal injection hole 3c is filled and sealed with the sealing material 13 after the liquid crystal is injected.

  As shown in FIG. 3A, the scanning driver chip 6 is connected to the connection terminal 9b of the rear scanning wiring 9 and the input wiring terminal 15 for inputting the scanning signal voltage via the anisotropic conductive adhesive material 14. Are conductively installed in the arrangement area arranged side by side. The anisotropic conductive adhesive 14 is formed by dispersing and mixing conductive particles 14b in a thermosetting insulating resin base material 14a in the same manner as the sealing material 3. When the scanning driver chip 6 is mounted on the COG, first, the scanning driver chip 6 is placed on the connection terminal 9 b and the input wiring terminal 15 corresponding to the output terminal electrode 6 a and the input terminal electrode 6 b through the anisotropic conductive adhesive 14. Then, the anisotropic conductive adhesive 14 is heated and pressed while the thermal bonding tool is pressed against the scanning driver chip 6 to heat the conductive particle 14b to the output terminal electrode. The insulating resin base material 14a is cured while being sandwiched between the connection terminals 9b and the input wiring terminals 15 corresponding to the input terminals 6a and the input terminal electrodes 6b. As a result, the scanning driver chip 6 is accurately placed in a predetermined arrangement area.

  As shown in FIG. 3B, the display driver chip 7 also inputs the display signal voltage to the connection terminal 10 b of the display wiring 10 through the anisotropic conductive adhesive 14, similarly to the scanning driver chip 6. For this purpose, the input wiring terminals 16 are installed in a conductive area by the COG method.

  As described above, in the liquid crystal display element of the present embodiment, the inter-substrate conduction circuit for electrically connecting the scan electrode 4 and the scan driver chip 6 installed on the counter substrate side is provided on both the glass substrates 1 and 2. A pair of connection pads 8a, 8a and connected pads 9a, 9a respectively formed on the front scanning wiring 8 and the rear scanning wiring 9 are connected in parallel via the first seal portion 3A and the second seal portion 3B. Since the circuit is configured, the respective areas of the connection pads 8a and the pads 9a to be connected can be reduced as compared with the conventional inter-substrate conduction structure in one place, and the wirings 8 and 9 of the inter-substrate conduction part forming a parallel circuit are provided. It can be formed with a narrow width, and can sufficiently cope with a narrow pitch of wiring due to high definition of the liquid crystal display element.

In addition, since the wirings 8 and 9 of the inter-substrate conducting portion constituting the parallel circuit are disposed in the outer edge region Df surrounded by the first seal portion 3A and the second seal portion 3B of the sealing material 3, the wiring 8 , 9 can be effectively prevented from being deteriorated by electrolytic corrosion or the like without being covered with a protective film, and as a result, the reliability of the liquid crystal display element is improved.
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component same as the said 1st Embodiment, and the description is abbreviate | omitted.

  In the present embodiment, one connection pad 21a and one connection pad 22a are formed on the front scanning wiring 21 and the rear scanning wiring 22, respectively, and wirings adjacent to each other by the connection pad 21a and the connection pad 22a are adjacent to each other. The seal portions are different from each other.

  That is, of the pair of adjacent front scanning lines 21, 21 on the glass substrate 2, one front scanning line 21 has a connection pad 21 a formed at a portion intersecting the first seal portion 3 </ b> A, and the other front scanning line 21. The connection pad 21a is formed in the part (tip part) which cross | intersects the 2nd seal | sticker part 3B in 21, and this structure is repeated and the several connection pad 21a is formed in zigzag arrangement. Also in the glass substrate 1 on the opposite side, the connection pads 22a are similarly formed in a staggered arrangement corresponding to the above-described connection pads 21a on each rear scanning wiring 22.

  The connection pads 21a and the connection pads 22a formed in a staggered arrangement are conductively connected via conductive particles (not shown) in the first seal portion 3A or the second seal portion 3B. Other configurations are the same as those in the first embodiment.

  According to the liquid crystal display element of the present embodiment configured as described above, since there is one inter-substrate conduction portion provided in each scanning wiring, each area of the connection pad 21a and the connection pad 22a is set to the first area. Although it is difficult to make it small as in the embodiment, since the inter-substrate conductive portions are arranged in a staggered manner, even in the case of a high-definition liquid crystal display element in which the wiring pitch is narrow as in the first embodiment, The individual areas of the connection pad 21a and the connection pad 22a can be secured larger than in the case of the first embodiment. As a result, even if it is a narrow pitch wiring, the connection pad 21a and the pad 22a to be connected can be easily aligned and reliably connected, and the occurrence of connection failure in the inter-substrate conductive portion is remarkably suppressed, and the product yield is increased. improves.

  In addition, this invention is not limited to said embodiment. For example, the present invention is not limited to a liquid crystal display element that conducts scanning electrode wiring between substrates as in the above-described embodiment, but is also effectively applied to a liquid crystal display element that conducts display electrode wiring between substrates.

  In the first embodiment, the display electrode wiring is also provided with a parallel circuit portion extending over both glass substrates in order to reduce the wiring width. In this way, the electrode and the driver chip for supplying voltage thereto are provided on the same substrate. The wiring of the electrodes provided on the upper side may be arranged straight on only one substrate without providing a parallel circuit section straddling both substrates.

  Furthermore, in the above embodiment, the outer edge region Df of the first seal portion surrounded by the second seal portion is a cavity, but liquid crystal may be sealed in the outer edge region Df. Thereby, deterioration due to electrolytic corrosion or the like of each wiring arranged in the outer edge region Df is more reliably prevented.

It is a top view which shows the liquid crystal display element as 1st Embodiment of this invention. It is a fragmentary top view which expands and shows the principal part Q of the said liquid crystal display element. 2A is a schematic partial sectional view showing the scanning wiring portion in FIG. 2 cut along the line AA, and FIG. 2B is a schematic partial sectional view showing the display wiring portion cut in the same manner as in FIG. It is. It is the elements on larger scale corresponding to FIG. 2 which shows the liquid crystal display element as 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Glass substrate 3 Sealing material 3A 1st seal | sticker part 3B 2nd seal | sticker part 4 Scan electrode 5 Display electrode 6 Scan driver chip 7 Display driver chip 8, 21 Front scan wiring 8a, 10a, 21a Connection pad 9, 22 Rear side Scanning wiring 9a, 11a, 22a Connected pad 10 Display wiring 11 Detour wiring 12 Liquid crystal 13 Sealing material 14 Anisotropic conductive adhesive 15, 16 Input wiring terminal

Claims (4)

A plurality of first electrodes, a plurality of front first wirings connected to each of the first electrodes and supplying a voltage to the plurality of first electrodes, and a front first wiring of the plurality of first electrodes. A first substrate having a first connection pad formed thereon;
A plurality of second electrodes, respectively connected to these second electrodes, and provided corresponding to a plurality of second wirings for supplying a voltage to the plurality of second electrodes and the first connection pads, respectively. A plurality of first connected pads, and a second substrate on which a plurality of rear first wirings for supplying a voltage to each of the first connected pads are formed,
A bonding member containing conductive particles in an insulating resin base material, and bonding the first substrate and the second substrate with their electrode formation surfaces facing each other while maintaining a predetermined gap;
A liquid crystal display element comprising liquid crystal sealed in a space surrounded by each of the opposing inner surfaces of the first substrate and the second substrate and the bonding member,
The bonding member includes a frame-shaped first seal portion that encloses a display region including a plurality of pixels formed in each region where the first electrode and the second electrode are opposed to each other through the liquid crystal. A second seal portion surrounding a predetermined region outside the first seal portion,
The first connection pad and the first connected pad corresponding to the first connection pad are arranged corresponding to at least one of the first seal portion and the second seal portion, and the conductive particles A liquid crystal display element, wherein the liquid crystal display element is conductively connected through the substrate.   The first connection pads and the first connected pads are formed in pairs on the front first wiring and the rear first wiring, respectively, and are electrically connected to both the first seal portion and the second seal portion. The liquid crystal display element according to claim 1, wherein the liquid crystal display element is a liquid crystal display element.   One first connection pad and one first connection pad are formed for each of the front first wiring and the rear first wiring, and the first connection pad and the first connection pad are adjacent to each other. The liquid crystal display element according to claim 1, wherein the conductive connection portions are formed at different seal portions of the first seal portion and the second seal portion.   A plurality of auxiliary second wirings are disposed on the first substrate in correspondence with the second wirings, respectively, and a second connection pad and a second second pad corresponding thereto are provided on the second wiring and the auxiliary second wiring, respectively. A pair of connection pads are formed, and the pair of second connection pads and the pair of second connected pads are electrically connected by both the first seal portion and the second seal portion, respectively. The liquid crystal display element according to claim 1.