JP4214416B2 - Adhesion method and liquid crystal device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhering structure by which an adhering force between two types of materials to be bonded to each other is improved even when the two marterials have different substances from each other, and by which a connection failure between two electrode terminals formed respectively on the two materials to be bonded is prevented. <P>SOLUTION: An electrode terminal 12 has a smaller thickness than that of an electrode terminal 14. A first adhering layer 4 comprising conductive particles 3 has a larger thickness than a diameter of the conductive particles 3 and in a part where no electrode terminal is provided, a second adhering layer 5 has a smaller thickness than that of a first adhering layer 4. By interposing the first adhering layer 4 and the second adhering layer 5 between the first material to be adhered 11 and the second material to be adhered 13 and between the electrode terminal 12 and the electrode terminal 14, and by adhering the first material to be adhered 11 and the second material to be adhered 13 to each other through contact-bonding them, the electrode terminal 12 and the electrode terminal 14 are electrically connected to each other. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to an adhesive method using an anisotropic conductive adhesive containing conductive particles, in particular, an anisotropic conductive adhesive for connection between a liquid crystal panel and an external circuit board, a semiconductor element or the like. The present invention relates to a method for manufacturing the liquid crystal device used.

  Connection between fine pitch terminals, such as connection between input terminals provided on a glass substrate of a liquid crystal panel and TCP (Tape Carrier Package) terminals (there may be bumps formed on the terminals) An anisotropic conductive adhesive is used.

  Conventional anisotropically conductive adhesives are composed of a thermosetting or thermoplastic insulating adhesive material such as an epoxy resin, and a plurality of conductive particles disposed in the adhesive. Here, since the insulating adhesive material is bonded to an adherend, that is, a glass substrate and a polyimide TCP, it is general-purpose so that it can adhere to any of these different adherends with a predetermined adhesive force. A highly adhesive was used.

  However, a versatile adhesive can obtain a certain level of adhesive force for any material to be adhered, but when a certain level of adhesive force is obtained for one object, the other There was a problem in that the adhesive strength with the object to be bonded was reduced, and as a whole, an adhesive strength of a certain level or more could not be obtained.

  In particular, when a glass substrate is used for the liquid crystal panel and the glass substrate is connected to a polymer substrate that is an external circuit substrate, the adhesive properties of the two may be significantly different. For this reason, defects due to adhesion peeling tend to occur only in one of the glass substrate and the polymer substrate.

  An object of the present invention is to realize an adhesion method and a liquid crystal device manufacturing method capable of preventing the outflow of conductive particles during pressure bonding in an adhesion method using an anisotropic conductive adhesive.

In the bonding method of the present invention , a first adherend that is a glass substrate provided with a first electrode terminal and a second adherend that is a circuit board or a semiconductor element provided with a second electrode terminal. An adhesive method for interposing and bonding the first adhesive layer and the second adhesive layer to electrically connect the first electrode terminal and the second electrode terminal, the first electrode terminal of the first electrode terminal the thickness from the surface of the adherend, thinner than the thickness from the surface of the second adherend of the second electrode terminal, said first adhesive layer electrically conductive particles including anisotropic conductive adhesive layer In the bonding method, the second adhesive layer does not include the conductive particles, and the first adhesive layer and the second adhesive layer have the same type of insulating adhesion. A material is used and a different type of coupling agent is added to the first adhesive layer. The added coupling agent is a coupling agent that can increase the adhesive strength with the first adherend, and the coupling agent added to the second adhesive layer is the same as the second adherend. of a coupling agent which can enhance the bonding strength, the first adhesive layer, said first thickness greater than the second adhesive layer at the portion where the first electrode terminal is not provided adherend The second adhesive layer has a thinner thickness than the first adhesive layer in a portion where the second electrode terminal of the second adherend is not provided so as to adhere to the first adherend. And having the first adhesive layer and the second adhesive layer between the first adherend and the second adherend and the first electrode terminal so as to adhere to the first adherend. It is interposed between the second electrode terminals, and the first adherend and the 2, wherein the electrically connected via the conductive particles and adhesive to said first electrode terminal of the adherend and the second electrode terminal.

  In the case of bonding the first adherend and the second adherend using the bonding method of the present invention, the first adhesive layer and the first adherend are brought into contact with each other, 2 The object to be bonded can be brought into contact. By doing so, since each adherend is bonded to the other adherend under the bonding characteristics corresponding to each, the adherence between the adherends becomes strong.

  When it is necessary to establish an electrical connection between the first adherend and the second adherend, conductive particles may be mixed into the first adhesive layer as in the present invention. Of course, conductive particles may also be mixed into the second adhesive layer, but the first is usually used when electrical connection is made between the first adherend and the second adherend. The adherend and the second adherend are bonded together so as to press each other. Therefore, electrical connection can be made by mixing conductive particles only in the first adhesive layer.

  If the conductive particles are arranged only in the first adhesive layer, the number and arrangement of the conductive particles can be easily managed, so that the anisotropic conductive adhesive can be easily manufactured. In this case, since the second adhesive layer only needs to be used for adhesion to the second adherend, the thickness of the adhesive layer can be made thinner than that of the first adhesive layer.

  In general, when the object to be bonded is pressed, the adhesive is pushed out by the electrode terminal and flows out. As a matter of course, the amount of the adhesive pushed out by the electrode terminal having the thick electrode terminal is larger than the amount of the adhesive pushed out by the electrode terminal having the thin thickness. In order to perform reliable electrical connection between the first adherend and the second adherend, it is preferable to eliminate the outflow of the conductive particles.

  In the present invention, since the first adhesive layer mixed with the conductive particles is brought into contact with the substrate having the electrode terminal with a thin electrode terminal, it is possible to prevent the conductive particles from flowing out during the pressure bonding. .

The method for manufacturing a liquid crystal device according to the present invention is a first substrate to be bonded which is a glass substrate of a liquid crystal panel provided with a first electrode terminal, and a circuit board or a semiconductor element provided with a second electrode terminal . A method of manufacturing a liquid crystal device in which a first adhesive layer and a second adhesive layer are interposed between two objects to be bonded, and the first electrode terminal and the second electrode terminal are electrically connected. The thickness of the first electrode terminal from the surface of the first adherend is thinner than the thickness of the second electrode terminal from the surface of the adherend, and the first adhesive layer is made of conductive particles. in including anisotropic conductive adhesive layer has a thickness larger than the diameter of the conductive particles, the second adhesive layer in the manufacturing method of the liquid crystal device that does not include the conductive particles, the first adhesive layer and The second adhesive layer is made of the same type of insulating adhesive material and is of a different type. A coupling agent added to the first adhesive layer is a coupling agent that can increase the adhesive strength with the first adherend, and is added to the second adhesive layer. The coupling agent is a coupling agent that can increase the adhesive strength with the second adherend, and the first adhesive layer is provided with the first electrode terminal of the first adherend. The second adhesive layer is provided with the second electrode terminal of the second adherend so that the second adherent layer is thicker than the second adhesive layer and adheres to the first adherend. to adhere to the second adherend having a thickness less than the first adhesive layer-free portion, the said second adhesive layer and the first adhesive layer wherein the first adherend second Between the adherend and between the first electrode terminal and the second electrode terminal Zaisa allowed, characterized in that the electrically connected through the first adherend and the second adherend adhesion to the conductive particles and the second electrode terminal and the first electrode terminal by crimping And

  In the manufacturing method of the liquid crystal device of the present invention, when the substrate of the liquid crystal panel and the adherend are bonded, the first adhesive layer and the substrate of the liquid crystal panel are brought into contact with each other, and the second adhesive layer and the adherend are Can be touched. By doing so, since each adherend is bonded to the other adherend under the bonding characteristics corresponding to each, the adherence between the adherends becomes strong.

  In the case where it is necessary to establish electrical connection between the substrate of the liquid crystal panel and the adherend, conductive particles may be mixed into the first adhesive layer as in the present invention. Of course, conductive particles may also be mixed in the second adhesive layer, but in general, when electrical connection is made between the liquid crystal panel substrate and the adherend, Bonding is performed by pressing the objects to be bonded together. Therefore, electrical connection can be made by mixing conductive particles only in the first adhesive layer.

  If the conductive particles are arranged only in the first adhesive layer, the number and arrangement of the conductive particles can be easily managed, so that the anisotropic conductive adhesive can be easily manufactured. In this case, since the second adhesive layer only needs to be used for adhesion to the adherend, the thickness of the adhesive layer can be made thinner than that of the first adhesive layer.

  Further, when the substrate of the liquid crystal panel and the adherend are bonded by pressure bonding, the adhesive is pushed out by the electrode terminal and flows out. As a matter of course, the amount of the adhesive pushed out by the electrode terminal having the thick electrode terminal is larger than the amount of the adhesive pushed out by the electrode terminal having the thin thickness. In order to make reliable electrical connection between the substrate of the liquid crystal panel and the adherend, it is preferable to eliminate the outflow of conductive particles. In the present invention, since the first adhesive layer mixed with the conductive particles is brought into contact with the substrate having the electrode terminal with a thin electrode terminal, it is possible to prevent the conductive particles from flowing out during the pressure bonding. .

As a specific means for adjusting the adhesive properties of the first adhesive layer and the second adhesive layer,
(1) The main component of the insulating adhesive material in the first adhesive layer is different from the main component of the insulating adhesive material in the second adhesive layer. (2) The first adhesive layer and the second adhesive layer are different. Add different coupling agent (3) The main component of the insulating adhesive material and the coupling agent to be added may be different for the first adhesive layer and the second adhesive layer. The same insulating adhesive material is used for the second adhesive layer, and a first coupling agent corresponding to the first adherend is added to the first adhesive layer, and the second adhesive layer is attached to the second adhesive layer. If the second coupling agent according to the product is added, the characteristics of the adhesive can be changed simply by changing the type of the coupling agent, so the number of insulating adhesive materials to be used can be reduced, and the production efficiency can be reduced. It can be improved and the cost can be reduced.

  Moreover, the adherend in the method for manufacturing a liquid crystal device of the present invention can be used as a circuit board. According to the liquid crystal device of the present invention, a plurality of adhesive layers having adhesive properties corresponding to each substrate are connected to a circuit board (mainly a polymer substrate) and a substrate of the liquid crystal panel (mainly a glass substrate). Use some adhesive. As a result, the adhesive strength between the two substrates is uniformly strong, and the connection reliability of the liquid crystal device is improved.

  In general, the connection between the substrate of the liquid crystal panel and the external circuit substrate is made by pressure bonding. During the crimping, the adhesive is pushed out by the electrode terminal and flows out. As a matter of course, the amount of the adhesive pushed out by the electrode terminal having the thick electrode terminal is larger than the amount of the adhesive pushed out by the electrode terminal having the thin thickness. In order to ensure reliable electrical connection between the substrate of the liquid crystal panel and the external circuit substrate, it is preferable to eliminate the outflow of conductive particles. In the present invention, since the first adhesive layer mixed with the conductive particles is brought into contact with the substrate on which the electrode terminal having the thin electrode terminal thickness is formed, it is possible to prevent the conductive particles from flowing out during the crimping. it can.

  Moreover, the adherend in the method for manufacturing a liquid crystal device of the present invention can be a semiconductor element. According to the present invention, in a so-called COG (Chip on Glass) type liquid crystal device in which a semiconductor element is directly mounted on a liquid crystal panel substrate, the connection between the liquid crystal panel substrate and the semiconductor element can be strengthened.

  In general, the electrode terminal formed on the liquid crystal panel substrate is a transparent conductive film (ITO), and the electrode terminal formed on the circuit substrate or the semiconductor element is often a metal film. One adhesive layer may be in contact with the liquid crystal panel substrate, and the second adhesive layer may be in contact with the circuit substrate. This is because ITO is usually formed thinner than a metal film.

  The present invention can be applied to an electronic device that includes the liquid crystal device manufactured according to the present invention as a display unit and includes a housing that houses the display unit. This electronic device is, for example, a mobile phone, a wristwatch, a notebook personal computer, etc., and uses the bonding structure of the electronic component of the present invention for bonding between the liquid crystal device and an external circuit or a semiconductor element. Alternatively, the adhesive strength of the semiconductor element can be improved, the incidence of defective products of liquid crystal devices and electronic devices can be reduced, and the manufacturing cost can be reduced.

  Hereinafter, the present invention will be described in more detail with reference to the embodiments of the present invention shown in the drawings.

  FIG. 1 shows an adhesive 1 used in the first embodiment of the present invention. The adhesive 1 includes a first adhesive layer 4 in which a plurality of conductive particles 3 are disposed, and a second adhesive layer 5 laminated on the first adhesive layer 4.

  The conductive particles 3 may be solder particles, single metal particles such as Ni, Au, Ag, Cu, Pb, and Sn, composite metal particles made of a mixture of a plurality of metals, alloys, plating, etc., or plastic particles (polystyrene). Particles, carbon particles, or the like obtained by plating Ni, Au, Cu, Fe or the like alone or plurally on a resin, a polycarbonate-based resin, an acrylic-based resin, or a diphenylbenzene-based resin).

  Further, the first adhesive layer 4 and the second adhesive layer 5 are mainly made of an insulating adhesive material having a high adhesive force with the adherend to which the adhesive layers 4 and 5 are bonded.

  For example, as shown in FIG. 2, when the adhesive 1 is disposed between the electrode terminal 12 provided on the glass substrate 11 of the liquid crystal panel and the electrode terminal 14 of the TCP 13, the first adhesive layer 4 is The second adhesive layer 5 is mainly composed of an insulating adhesive material having a high adhesive force with the glass substrate 11 and the terminal 12 made of ITO or the like. The second adhesive layer 5 is made of a polyimide TCP 13 and an electrode terminal 14 in which a copper surface is plated with tin. An insulating adhesive material having a high adhesive strength is used as a main component.

  The first adhesive layer 4 is bonded to the glass substrate 11 and the electrode terminal 12, but the adhesive area with the glass substrate 11 becomes larger because the adhesive area is larger than that of the glass substrate 11. Such an insulating adhesive material may be used as a main component.

  Similarly, the second adhesive layer 5 may also use an insulating adhesive material as a main component so that the adhesive force with the TCP 13 (made of polyimide) having a large adhesive area becomes larger.

  Specifically, the insulating adhesive material used as the main component of each of the adhesive layers 4 and 5 is a single or a mixture of styrene butadiene styrene (SBS), epoxy, acrylic, polyester, urethane, etc. Compounds and the like. At this time, different types of insulating adhesive materials may be used as the main components of the adhesive layers 4 and 5, but in this embodiment, the same type of insulating adhesive material is used, and the type of coupling agent to be added is changed. Change the adhesive properties.

  Specific examples of the coupling agent used for the adhesive layer 4 include dimethyldimethoxysilane, γ-aminopropyltriethoxysilane, and the like. If the coupling agent contains many methoxy groups or ethoxy groups as functional groups, glass and The adhesive strength can be increased.

  Specific coupling agents used for the adhesive layer 5 include N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and the like. If it is a coupling agent containing many epoxy groups, the adhesive strength with a polyimide can be raised.

  In the adhesive 1 having such a configuration, for example, a first adhesive layer 4 in which conductive particles 3 are blended is laminated on a manufacturing base plate or a separator, and a second adhesive layer 5 is laminated thereon. It is manufactured by things.

  As shown in FIG. 2, the adhesive 1 configured as described above is disposed between the glass substrate 11 of the liquid crystal panel and the TCP 13. Then, the electrode terminals 12 and 14 are pushed into the adhesive 1 side by thermocompression bonding or the like, and the conductive particles 3 are interposed between the electrode terminals 12 and 14, and the glass substrate 11 is made of the adhesive layers 4 and 5. And TCP13 are bonded.

  With such a procedure, as shown in FIG. 3, a liquid crystal device 100 in which the liquid crystal panel 10 and the TCP 13 on which the liquid crystal driver IC 15 is mounted is bonded with the adhesive 1 is configured. The liquid crystal device 100 is used by being incorporated in a housing of various electronic devices. For example, it is incorporated in the case 201 of the mobile phone 200 shown in FIG. 4 or incorporated in the case 301 of the notebook computer 300 shown in FIG.

Such an embodiment has the following effects.
Since the adhesive 1 is configured by laminating the first and second adhesive layers 4 and 5, the first adhesive layer 4 bonded to the glass substrate 11 and the electrode terminal 12 is connected to the glass substrate 11 and the like. The second adhesive layer 5 bonded to the TCP 13 and the electrode terminal 14 can be formed of a type of adhesive layer having a high adhesive force with the TCP 13 or the like. For this reason, compared with the case where the glass substrate 11 and TCP13 are adhere | attached by 1 type of adhesive layers conventionally, the adhesive force with each to-be-adhered object 11 and 13 can be improved, and the adhesive agent 1 excellent in the adhesive characteristic. It can be.

  Since the conductive particles 3 are included only in the first adhesive layer 4, the number and arrangement of the conductive particles 3 are controlled as compared with the case where the conductive particles 3 are arranged in both the adhesive layers 4 and 5. Easy to manufacture. Moreover, when changing the adhesive properties of the adhesive layers 4 and 5, the type of the coupling agent to be added is changed without changing the type of the insulating adhesive material, so that the adhesive properties of the adhesive layers 4 and 5 are reduced in cost. And can be set easily.

  In general, the glass substrate 11 and the TCP 13 are bonded by pressure bonding. During the crimping, the adhesive is pushed out by the electrode terminal and flows out. As a matter of course, the amount of the adhesive pushed out by the electrode terminal having the thick electrode terminal is larger than the amount of the adhesive pushed out by the electrode terminal having the thin thickness. In order to perform reliable electrical connection between the glass substrate 11 and the TCP 13, it is preferable to eliminate the outflow of the conductive particles 3. In the present invention, since the adhesive layer 4 mixed with the conductive particles 3 is brought into contact with the glass substrate 11 on which the electrode terminal 12 having the smaller thickness is formed, the conductive particles 3 flow out during the pressure bonding. Can be prevented. Further, since the adhesive layer 5 is thinner than the adhesive layer 4, the thicker electrode terminal 14 easily penetrates the adhesive layer 5 and reaches the adhesive layer 4, and is electrically connected to the electrode terminal 12. Connection can be made.

  The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

Also, the adhesive 1 of the two-layer structure of the first embodiment may be used for bonding glass substrates 11 and I C.

The material of the adhesive layers 4 and 5 of the adhesive 1 and the conductive particles 3 (the kind of the main component of the insulating adhesive material and the kind of the coupling agent to be added), the size (film thickness and particle diameter), etc. are applied. What is necessary is just to set suitably according to the kind of to-be-adhered thing. Therefore, the electronic device using the adhesive 1 of the present invention is not limited to the electronic device provided with the liquid crystal device 100 as a display unit, such as the mobile phone 200 or the notebook personal computer 300, but also applied to various electronic devices not provided with the liquid crystal device. it can.

It is a figure which shows the cross section of the adhesive agent used in 1st Embodiment of this invention. It is a figure which shows the cross section of the connection part of the liquid crystal panel board | substrate and TCP board | substrate in 1st Embodiment. It is a perspective view of the liquid crystal device in the present invention. It is a perspective view of a mobile phone in the present invention. It is a perspective view which shows the notebook computer in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adhesive 3 Conductive particle 4 1st contact bonding layer 5 2nd contact bonding layer 10 Liquid crystal panel 11 Glass substrate 12 Electrode terminal 13 TCP
14 Electrode terminal 15 Liquid crystal driver IC

Claims (3)

The first adhesive layer and the second adhesive layer are provided between the first adherend that is a glass substrate provided with the first electrode terminal and the second adherend that is a circuit board or semiconductor element provided with the second electrode terminal. An adhesion method in which an adhesive layer is interposed and bonded to electrically connect the first electrode terminal and the second electrode terminal,
The thickness of the first electrode terminal from the surface of the first adherend is thinner than the thickness of the second electrode terminal from the surface of the second adherend, and the first adhesive layer includes conductive particles. in including anisotropic conductive adhesive layer has a thickness larger than the diameter of the conductive particles, the second adhesive layer in the bonding method does not include the conductive particles,
The first adhesive layer and the second adhesive layer are made of the same type of insulating adhesive material, and a different type of coupling agent is added. The coupling agent added to the first adhesive layer is A coupling agent that can increase the adhesive strength with the first adherend, and the coupling agent added to the second adhesive layer can increase the adhesive strength with the second adherend. Ring agent,
The first adhesive layer has a thickness thicker than the second adhesive layer at a portion where the first electrode terminal of the first adherend is not provided, and adheres to the first adherend. The second adhesive layer has a thinner thickness than the first adhesive layer at a portion where the second electrode terminal of the second adherend is not provided, and adheres to the first adherend. And interposing the first adhesive layer and the second adhesive layer between the first adherend and the second adherend and between the first electrode terminal and the second electrode terminal,
Adhesion characterized in that the first adherend and the second adherend are adhered by pressure bonding, and the first electrode terminal and the second electrode terminal are electrically connected via the conductive particles. Method. A first adhesive layer between a first adherend that is a glass substrate of a liquid crystal panel provided with a first electrode terminal and a second adherend that is a circuit board or a semiconductor element provided with a second electrode terminal And a second adhesive layer, and a method of manufacturing a liquid crystal device for electrically connecting the first electrode terminal and the second electrode terminal,
The thickness from the surface of the first adherend of the first electrode terminal, said second electrode wherein less than the thickness from the surface of the adherends of terminals, the first adhesive layer including the conductive particles In the method for manufacturing a liquid crystal device, the anisotropic conductive adhesive layer has a thickness larger than the diameter of the conductive particles, and the second adhesive layer does not include the conductive particles.
The first adhesive layer and the second adhesive layer are made of the same type of insulating adhesive material, and a different type of coupling agent is added. The coupling agent added to the first adhesive layer is A coupling agent that can increase the adhesive strength with the first adherend, and the coupling agent added to the second adhesive layer can increase the adhesive strength with the second adherend. Ring agent,
The first adhesive layer has a thickness thicker than the second adhesive layer at a portion where the first electrode terminal of the first adherend is not provided , and adheres to the first adherend . The second adhesive layer has a thinner thickness than the first adhesive layer at a portion where the second electrode terminal of the second adherend is not provided, and adheres to the second adherend. And interposing the first adhesive layer and the second adhesive layer between the first adherend and the second adherend and between the first electrode terminal and the second electrode terminal,
A liquid crystal characterized in that the first adherend and the second adherend are bonded together by pressure bonding, and the first electrode terminal and the second electrode terminal are electrically connected through the conductive particles. Device manufacturing method.   The method for manufacturing a liquid crystal device according to claim 2, wherein the first electrode terminal is a transparent conductive film, and the second electrode terminal is a metal film.

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