JPH11326934A - Liquid crystal display panel and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the terminal pitch to extend a display part by connecting plural external input terminals on one substrate and electrode connection parts corresponding to external input terminals on the other substrate by an anisotropic conductive layer used as a seal agent. SOLUTION: A seal agent 13 is printed on three sides other than one side 11a of the peripheral edge of the inside surface of a segment-side substrate 11 to form an injection hole 16. An adhesive containing conductive particles is printed on only one side 12a of the peripheral edge of the inside surface of a common substrate 12. A spacer is scattered on the common substrate 12, and the segment-side substrate 11 and the common substrate 12 are stuck to each other. Therefore, the peripheral edge between both substrates 11 and 12 is completely sealed up except the injection hole 16 by the seal agent 13 and the adhesive 14 containing conductive particles. Liquid crystal is charged from the injection hole 16, and the injection hole 16 is sealed by a seal agent. Consequently, plural common electrode terminals 14 on the segment-side substrate 11 and corresponding common electrodes on the common substrate 12 are made conductive with conductive particles in the adhesive 14 containing conductive particles as the anisotropic conductive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for electrically connecting electrode terminals of an upper substrate and a lower substrate in a liquid crystal display panel and a method of connecting the electrode terminals.

[0002]

2. Description of the Related Art Liquid Crystal Display (LCD)
Display) has been widely used as a display unit of various electronic devices with the miniaturization of electronic devices. As one of the development directions of the LCD related technology in recent years, there is a development of a frame narrowing technology for increasing only the size of a display portion of a liquid crystal display panel in an LCD while maintaining the size of an outer frame.

Here, a method of manufacturing the conventional liquid crystal display panel 3 will be briefly described with reference to FIG.

A plurality of segment electrodes (not shown) are arranged at predetermined positions on a rectangular segment-side substrate 31, and six common electrodes (not shown) are formed on a rectangular common-side substrate 32 in this example. It is laid parallel to the horizontal direction in the figure. Then, one long side edge 31a of the segment side substrate 31
, Common electrode terminals 35, 35... As external input terminals are laid in parallel at three ends, for example. First, the segment side substrate 31 and the common side substrate 32
An alignment film (not shown) is uniformly applied over each of the formed electrodes, and an alignment process is performed by a rubbing method or the like.

Subsequently, a sealant 33 is printed on, for example, the segment-side substrate 31 in order to seal the liquid crystal to be injected later. Here, as the sealant 33, an inorganic material such as a glass frit, or an organic material obtained by mixing an acrylic resin or a silicon resin with an epoxy resin is preferably used. Also, the common side substrate 32 has three crossing agents 34, 34,... On both sides of the long side edge 32a corresponding to the six common electrode terminals 31 of the segment side substrate.
Is printed in a dot pattern. These cross agents 34, 34,...
Common electrode of common side substrate 32 and segment side substrate 31
Are electrically connected to the common electrode terminals 35, 35,. .. Are connected to the six common electrodes via lead wires (not shown), respectively. .. Are electrically connected to the common electrode terminals 35, 35,. Here, as the cloth agent 34, a paste-like conductive agent such as a silver paste, an adhesive containing conductive particles obtained by mixing conductive particles formed of a conductive material such as gold, silver, or copper in a base material, and the like are preferably used. Can be

Subsequently, spacers 37 are sprayed on the common-side substrate 32 in order to make the gap between the segment-side substrate 31 and the common-side substrate 32 after bonding the substrates described later uniform and maintain an appropriate liquid crystal layer thickness. I do. Here, fine particles of glass or plastic are preferably used as the spacer 37. As a method of spraying the spacer 37, a dry spraying in which the spacer 37 is sprayed directly on the common-side substrate 32, or the spacer 37 is scattered in a highly volatile liquid such as alcohol, and the liquid is dispersed in the common-side substrate 32
There is a wet spray to spray on. When plastic fine particles are used as the spacer 37, wet spraying is used exclusively, since static electricity tends to form a dumpling.

Subsequently, the segment-side substrate 31 and the common-side substrate 32 are adhered to each other, and liquid crystal is injected from an injection hole 36, and the injection hole 36 is sealed with a sealing agent such as a silicon-based adhesive to form a liquid crystal. The display panel 3 is completed. Here, when the segment-side substrate 31 and the common-side substrate 32 are bonded to each other, the above-mentioned cross agents 34, 34,.
And the plurality of common electrodes of the common side substrate 32 are electrically connected to each other, so that both the segment electrode (not shown) provided on the segment side substrate 31 and the common electrode provided on the common side substrate 32 Inner peripheral edge 3
This means that it has been pulled out to the side 1a. Although not shown, the connection terminals of the segment electrodes are arranged between the common electrode terminals 35 on both sides in the peripheral portion 31a of the segment-side substrate 31.

[0008]

By the way, in the liquid crystal display panel 3 manufactured by the above-described method, when the size of the display portion is increased while maintaining the size of the outer frame, the size of the display portion is increased in proportion to the size of the display portion. Since the number of terminals increases, the distance between terminals (terminal pitch) decreases. Therefore, in order to prevent a short circuit, it is necessary to reduce the diameter of the cloth material 34 as shown in FIG. 5A or to alternately print the cloth material 34 as shown in FIG. 5B. But,
When the diameter of the cloth material was reduced, a predetermined amount of the cloth material 34 had to be printed with high accuracy in order to secure conduction between the common electrode terminal and the cloth material 34 and the common electrode. And reliability could be reduced. Further, if the printing is performed by alternately shifting the cloth material 34, a larger seal portion (seal area) is required, so that the display portion becomes smaller, which contradicts the original purpose of enlarging the display portion. Was.

According to the present invention, the display portion can be enlarged without changing the yield and reliability of the product due to the printing failure of the cloth agent while maintaining the same outer shape. It is an object of the present invention to provide a liquid crystal display panel and a method of manufacturing the liquid crystal display panel to have the structure.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 has two substrates arranged opposite to each other,
In a liquid crystal display panel in which the two substrates are joined by a seal layer and liquid crystal is sealed between the two substrates, a plurality of external input terminals provided on a part of a peripheral portion of an inner surface of one of the substrates, and the other substrate A plurality of electrode connection portions provided on a peripheral portion of an inner surface of the other substrate in correspondence with the plurality of external input terminals to transmit signals to the plurality of electrodes; An anisotropic conductive layer formed by mixing conductive particles in an insulating material to form a part of the seal layer and to electrically connect the plurality of external input terminals and the plurality of electrical connection portions to be interposed between the plurality of external connection terminals and the plurality of electrical connection portions; And characterized in that:

According to the first aspect of the present invention, the plurality of external input terminals provided on one substrate and the plurality of electrode connection portions corresponding to the external input terminals provided on the other substrate are provided. Since it is connected by one anisotropic conductive layer, it is not necessary to print the cross agent one by one at the positions corresponding to the plurality of external input terminals on the other substrate on a one-to-one basis.
With the same external dimensions, the terminal pitch can be reduced and the display section can be enlarged without lowering the yield or reliability of the conductive connection caused by the printing failure of the cloth agent.

According to a second aspect of the present invention, in the liquid crystal display panel according to the first aspect, the insulating layer of the anisotropic conductive layer and the sealing layer are made of the same material.

According to the second aspect of the present invention, even if a part of the seal layer is formed of the anisotropic conductive layer, the sealing property of the liquid crystal does not decrease.

According to a third aspect of the present invention, in the liquid crystal display panel according to the first aspect, the sealing layer other than the anisotropic conductive layer and the insulating layer of the anisotropic conductive layer are made of different materials and the different materials. The sealing layer other than the isotropic conductive layer is continuous,
The insulating layer is made of a material having excellent chemical resistance to a chemically active solvent, and the seal layer is made of a material having excellent liquid crystal sealing properties.

According to the third aspect of the present invention, the same effects as those of the first aspect of the invention can be obtained, and in addition, a wet spraying method in which a spacer is mixed with a solvent and sprayed can be adopted. As the insulating layer of the anisotropic conductive layer, a material having a poor liquid crystal encapsulating property can be used, and a wider range of materials can be selected.

According to a fourth aspect of the present invention, in the method of manufacturing a liquid crystal display panel having the structure of the first aspect, an edge corresponding to a portion provided with an external input terminal in a peripheral portion of an inner surface of one of the substrates. Forming an anisotropic conductive layer in which conductive particles are mixed in an insulating material in a portion, and a liquid crystal on an edge portion of an inner peripheral edge portion of the other substrate except for a region corresponding to a region where the anisotropic conductive layer is provided. A sealing agent for sealing the first substrate and the other substrate are adhered to each other so that the peripheral portions of the inner surfaces of the two substrates facing each other are sealed with the sealing agent. And the anisotropic conductive layer.

According to the fourth aspect of the invention, the liquid crystal display panel according to the first aspect can be manufactured by a simple procedure.

According to a fifth aspect of the present invention, in the method of manufacturing a liquid crystal display panel having the structure of the first aspect, an edge corresponding to a portion provided with an external input terminal in a peripheral portion of an inner surface of one of the substrates. Form an anisotropic conductive layer in which conductive particles are mixed in an insulating material, and apply a sealant to seal the liquid crystal over the entire periphery of the other substrate except the liquid crystal injection port. Then, the one substrate and the other substrate are opposed to each other and bonded to each other, thereby sealing the inner peripheral edges of the two oppositely disposed substrates with the sealant and the anisotropic conductive layer. It is characterized by.

According to the fifth aspect of the invention, the liquid crystal display panel according to the third aspect can be manufactured by a simple procedure. The invention according to claim 6, wherein in the method of manufacturing a liquid crystal display panel, wherein a spacer for regulating a distance between a pair of substrates is mixed with a solvent and sprayed, a material forming an insulating layer of the anisotropic conductive layer is the solvent. It is characterized by having excellent chemical resistance. According to the sixth aspect of the present invention, it is possible to adopt a wet spraying method in which a spacer is mixed with a solvent and spraying the mixed solution. A wider range of materials can be selected, for example, materials having poor properties can be used. Claim 7
According to the invention, the sealant is formed with a concave portion having an air release port corresponding to the anisotropic conductive layer. According to the invention of claim 7, the reliability of the electrical conductivity between the external input terminal and the connection electrode is improved as compared with the case where the sealant and the anisotropic conductive layer are simply overlapped.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a structure of a liquid crystal display panel 1 according to a first embodiment of the present invention will be described with reference to FIG. In FIG. 1C, the liquid crystal display panel 1
A rectangular segment-side substrate 11 (one substrate) and a rectangular common-side substrate 12 (the other substrate) are arranged to face each other, and a liquid crystal is sealed between the substrates formed by the facing arrangement, and the liquid crystal is further sealed. One side between them is sealed with an adhesive 14 (anisotropic conductive layer) containing conductive particles also serving as a sealant,
The other three sides are sealed with a sealant 13 (seal layer). Here, the adhesive 14 containing conductive particles is
The sealant 13 is used as a base material to secure a sealing function. Further, a part of the sealant 13 has a structure in which the injection hole 16 used for injecting the liquid crystal is sealed with a sealant. The segment side substrate 11 is shown in FIG.
As shown in (A), a common electrode terminal 15 is provided on one side 11a of the inner peripheral edge portion to be brought into contact with the adhesive 14 containing conductive particles.
As shown in FIG. 2B, the common side substrate 12 has a plurality of (external input terminals), and the common electrode terminal 15 Have a plurality of ends (electrode connection portions) of a common electrode (electrode) (not shown) corresponding to. Here, as the conductive particles, for example, metal particles such as Au, Ag, and Cu, and resin particles coated on the surface with these metals are used. Although not shown, the segment-side substrate 11 has a plurality of segment electrodes corresponding to the plurality of common electrodes, and is held at an appropriate interval by a spacer (not shown) while the liquid crystal is sealed. ing.

Next, referring to FIG. 1, the liquid crystal display panel 1
A method of manufacturing the device will be described.

First, similarly to the prior art, an alignment film (not shown) is applied to each of the segment-side substrate 11 and the common-side substrate 12 in which the pattern of the transparent electrode is formed in advance, and the alignment is performed by a rubbing process or the like. Perform processing.

Next, as shown in FIG. 1A, the sealing agent 13 is applied to one side 11 of the peripheral portion of the inner surface of the segment side substrate 11.
Print on the three sides excluding a. Here, by providing a portion where the sealant 13 is not printed, an injection hole 16 for enclosing the liquid crystal later is formed. In addition, as shown in FIG. 1B, the adhesive 14 containing conductive particles is printed only on one side 12a of the peripheral portion of the inner surface of the common-side substrate 12.

Next, as in the prior art, the common side substrate 1
A spacer is sprayed on the substrate 2 and the segment side substrate 11 and the common side substrate 12 are bonded to each other. Here, the sealing agent 13
Since the adhesive and the conductive particles-containing adhesive 14 are in a continuous state, the peripheral portion between the two substrates is completely sealed by the sealant 13 and the conductive particles-containing adhesive 14 except for the injection hole 16. Subsequently, the liquid crystal is injected from the injection hole 16 and the injection hole 16 is further sealed with a sealing agent, thereby obtaining FIG.
The liquid crystal display panel 1 shown in (C) is completed. In addition, the sealing function of the resin such as the adhesive 14 containing conductive particles may be deteriorated by a solvent used for wet spraying as a spacer spraying method. Therefore, it is desirable to use dry spraying as a spacer spraying method.

In the liquid crystal display panel 1 having the above-described structure, the plurality of common electrode terminals 15 of the segment side substrate 11 and the common side substrate 1 corresponding to the common electrode terminals 15
The plurality of common electrodes on the two sides are the adhesive 14 containing conductive particles.
Since conduction is performed through conductive particles (not shown) in the inside, it is not necessary to print a cloth agent, thereby avoiding conduction failure due to poor printing of the cloth agent. In addition, since the conductive particle-containing adhesive 14 does not conduct in the direction parallel to the substrate, it does not short-circuit with other common electrodes or other common electrode terminals 15. That is, since the liquid crystal display panel 1 can be provided with more terminals by reducing the terminal pitch without lowering the product yield and reliability due to poor printing of the cloth material, the external shape of the display unit can be maintained. Can be made larger.

Next, the structure of a liquid crystal display panel 2 according to a second embodiment of the present invention will be described with reference to FIG. Here, the same components as those of the liquid crystal display panel 1 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 2C, the liquid crystal display panel 2
Has a structure in which the segment-side substrate 11 and the common-side substrate 12 are arranged to face each other, a liquid crystal is sealed between the substrates by the above-mentioned opposed arrangement, and all four sides between the sealed liquid crystals are sealed with a sealant 23. It has become. Further, similarly to the liquid crystal display panel 1, a part of the sealant 23 has a structure in which an injection hole 26 used for injecting the liquid crystal is sealed with a sealant.

Here, the sealing portion 23a, which seals one side having the plurality of common electrode terminals, on the peripheral portion of the liquid crystal display panel 2, is provided with a plurality of air release ports 2 shown in FIG.
A shape provided with a slit 23b (dent) having 3c,
Alternatively, it has a shape provided with a plurality of holes 23d (dents) each having an air release port 23e shown in FIG. Then, the common side substrate 1 corresponding to the seal portion 23a
The adhesive 24 containing conductive particles is applied to the area 2. The adhesive 24 containing conductive particles is applied to both substrates 11 and 12.
Are filled in the slits 23b or the holes 23c of the segment-side substrate 11, and the ends of the plurality of common electrodes of the common-side substrate 12 and the common electrode terminals 15, 15,. And are surely electrically connected. Here, as the sealant 23, for example, an inorganic material such as a glass frit or an organic material obtained by mixing an acrylic resin or a silicon resin with an epoxy resin is preferably used as a material having excellent liquid crystal sealing properties. .
As the base material of the adhesive 24 containing conductive particles, for example, a polyamide resin or a polyimide resin is suitably used as a material having excellent chemical resistance to a chemically active solvent (eg, alcohol). .

Next, referring to FIG.
A method of manufacturing the device will be described.

First, similarly to the prior art and the first embodiment, an alignment film (not shown) is formed on each of the segment-side substrate 11 and the common-side substrate 12 in which the pattern of the transparent electrode is formed in advance. A rubbing process is performed.

Next, as shown in FIG. 2A, a sealant having a slit 23b provided with an air release port 23c in a seal portion 23a on one side or a hole 23d provided with an air release port 23e is provided on the segment side substrate 11. 23 is printed. Here, by providing a portion where the sealant 23 is not printed, an injection hole 26 for enclosing the liquid crystal later is formed. Further, as shown in FIG. 2B, the adhesive 24 containing the conductive particles is applied to one side 12 a of the peripheral portion of the inner surface of the common side substrate 12.
Print only on.

Next, similarly to the prior art and the first example, spacers (not shown) are sprayed on the common-side substrate 12, the segment-side substrate 11 and the common-side substrate 12 are bonded, and liquid crystal is injected. The liquid crystal display panel 2 shown in FIG. 2C is completed by sealing the injection hole 26 with a sealant. Here, the segment side substrate 11 and the common side substrate 1
When the conductive adhesive 24 is laminated, the conductive adhesive 24 expels air from the air release port 23c and the air release port 23e while entering the slit 23b and the hole 23d, and thus easily enters the slit 23b or the hole 23d.

In the liquid crystal display panel 2 having the above-described structure, the plurality of common electrode terminals 15 and the plurality of common electrodes corresponding to the common electrode terminals 15 correspond to conductive particles (not shown) in the adhesive 24 containing conductive particles. Since the continuity is ensured by sandwiching between them, it is not necessary to print the cloth agent, and it is possible to avoid a decrease in the reliability of the continuity connection due to poor printing of the cloth agent. Furthermore, the adhesive 24 containing conductive particles
Does not conduct in the direction parallel to the substrate, and does not short-circuit with another common electrode or another common input terminal 15. That is, the liquid crystal display panel 2 can be provided with a larger number of terminals by reducing the terminal pitch without lowering the product yield and reliability due to the printing failure of the cloth agent, so that the outer shape of the liquid crystal display panel is not changed. Can be made larger.

Further, the adhesive 24 containing conductive particles enters the slit 23b or the hole 23c, and the common side substrate 1
2, because it is in direct contact with the ends of the plurality of common electrodes, compared with the case where the slit 23b or the hole 23c is not provided.
The conductivity between the plurality of common electrode terminals 15 and the common electrode corresponding to the common electrode terminals 15 is improved.

Further, since the peripheral portion between the two substrates of the liquid crystal display panel 2 is sealed by the sealant 13 and the sealant,
The adhesive 24 containing conductive particles does not require a sealing function,
Wet spraying can be adopted as a spacer spraying method in the process of manufacturing the liquid crystal display panel 2, and a material having no function as a sealant can be used for the base material of the conductive adhesive 24. That is, the liquid crystal display panel 2
As compared with the liquid crystal display panel 1, the method of distributing the spacers and the choice of the base material of the adhesive 24 containing the conductive particles are wider.

In the method of manufacturing the liquid crystal display panel 1, one side 11a of the peripheral portion of the inner surface of the segment side substrate 11 is used.
The sealant 13 is printed on the three sides except for the common side substrate 1
Although the adhesive 14 containing conductive particles is printed only on one side 12a of the peripheral portion of the inner surface of the second substrate 2, the present invention is not limited to this, and the adhesive 14 containing conductive particles is applied only to the peripheral portion 11a of the inner surface of the segment side substrate 11. The agent 14 is printed, and the common side substrate 12 is printed.
Sealant 1 on three sides except one side 12a of the peripheral portion of the inner surface of
3 may be printed. Similarly, in the manufacturing method of the liquid crystal display panel 2, the peripheral portion 11 on the inner surface of the segment side substrate 11 is used.
a, the adhesive 24 containing conductive particles is printed on the substrate 1 on the common side.
The sealant 13 may be printed in a predetermined shape on all four sides of the peripheral portion of the inner surface of No. 2.

[0037]

According to the liquid crystal display panel of the present invention, a plurality of external input terminals provided on one substrate and a plurality of external input terminals provided on the other substrate correspond to the external input terminals. The electrode connecting portion is connected by one anisotropic conductive layer also serving as a sealing agent, and it is not necessary to print a crossing agent on the other substrate at a position corresponding to the external input terminal. The terminal pitch can be reduced and the display portion can be enlarged without reducing the yield or the reliability of the conductive connection due to the printing failure of the cloth agent while keeping the size of the size.

According to the method for manufacturing a liquid crystal display panel according to the fourth aspect, the liquid crystal display panel according to the first aspect can be manufactured by a simple procedure.

According to the method for manufacturing a liquid crystal display panel according to the fifth aspect, the liquid crystal display panel according to the third aspect can be manufactured by a simple procedure.

[Brief description of the drawings]

FIG. 1 is a diagram showing a production process of a liquid crystal display panel 1 according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a production process of a liquid crystal display panel 2 according to a second example of the embodiment of the present invention.

FIG. 3 is a diagram showing a structure of a seal portion 23a sealing one side of the liquid crystal display panel 2 in FIG.

FIG. 4 is a diagram showing a production process of a liquid crystal display panel 3 according to a conventional technique.

FIG. 5 is a diagram showing a problem of the liquid crystal display panel 3 in the related art.

[Explanation of symbols]

1,2,3 Liquid crystal display panel 11,31 Segment side substrate electrode 12,32 Common side substrate electrode 13,23,33 Sealant 23b Slit 23d Hole 23c, 23e Air escape port 14,24 Adhesive with conductive particles 34 Cross agent 15, 35 Common electrode terminal

Claims (7)

[Claims] 1. A liquid crystal display panel in which two substrates are opposed to each other, and the two substrates are joined by a seal layer and a liquid crystal is sealed between the two substrates. A plurality of external input terminals provided on the other substrate and a plurality of electrodes provided corresponding to the plurality of external input terminals on a peripheral portion of an inner surface of the other substrate for transmitting signals to the plurality of electrodes of the other substrate. A connection portion, interposed between the plurality of external input terminals and the plurality of electrical connection portions, forms a part of the seal layer, and electrically connects the plurality of external input terminals and the plurality of electrical connection portions. A liquid crystal display panel comprising: an anisotropic conductive layer in which conductive particles are mixed in an insulating material. 2. The liquid crystal display panel according to claim 1, wherein a sealing layer other than the anisotropic conductive layer and an insulating layer of the anisotropic conductive layer are made of the same material. 3. The sealing layer other than the anisotropic conductive layer and the insulating layer of the anisotropic conductive layer are made of different materials, and the sealing layer other than the anisotropic conductive layer is continuous. 2. The liquid crystal display panel according to claim 1, wherein the layer is made of a material having excellent chemical resistance to a chemically active solvent, and the sealing layer is made of a material having excellent liquid crystal sealing properties. 4. A method of manufacturing a liquid crystal display panel having a structure according to claim 1, wherein conductive particles are insulated at an edge corresponding to a portion provided with an external input terminal in a peripheral portion of an inner surface of one of the substrates. Forming an anisotropic conductive layer mixed in a substance, and sealing the liquid crystal at an edge of the inner peripheral edge of the other substrate except for a region corresponding to a region where the anisotropic conductive layer is provided. A sealing agent is applied, and then the one substrate and the other substrate are attached to each other so as to be opposed to each other. A method for manufacturing a liquid crystal display panel, comprising sealing with a layer. 5. A method for manufacturing a liquid crystal display panel having a structure according to claim 1, wherein the conductive particles are insulated at an edge corresponding to a portion provided with an external input terminal in a peripheral edge of an inner surface of one of the substrates. Forming an anisotropic conductive layer mixed in a substance, applying a sealant for sealing the liquid crystal over the entire periphery of the other substrate except for the liquid crystal injection port at the inner periphery of the other substrate; A liquid crystal display characterized by sealing the inner peripheral edges of the two substrates facing each other with the sealant and the anisotropic conductive layer by bonding the two substrates facing each other so as to face each other. Panel manufacturing method. 6. The method for manufacturing a liquid crystal display panel according to claim 1, wherein a spacer for regulating a distance between a pair of substrates is mixed with a solvent and sprayed. A material forming an insulating layer of the anisotropic conductive layer is resistant to the solvent. 6. The method for manufacturing a liquid crystal display panel according to claim 5, wherein the method is excellent in chemical properties. 7. The method for manufacturing a liquid crystal display panel according to claim 5, wherein a concave portion having an air escape port is formed in said sealant corresponding to said anisotropic conductive layer.