JP2008069357A - Winding having adhesive layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive winding-like connecting member that does not transfer to the confronting separator base and can attain very stable release of the separator base. <P>SOLUTION: The material having a significant difference between the surface tension on the front face and the back face is used as a separator base material and an adhesive layer is formed on one-side face to give the winding. The base material of the separator is composed of at least two layers and the surface tension of the face formed with the adhesive is made larger than that of the back face layer (provided that the case that coated with silicone treatment solution is omitted), has a width of less than 3 mm, and the separator base material comprises only two layers namely the layer on the face side formed with the adhesive and the back face layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention mainly includes a conductive connection between a liquid crystal panel electrode and a tape carrier package (TCP) electrode, a conductive connection between a TCP electrode and a PCB (printed circuit board) electrode, a conductive connection between a liquid crystal panel electrode and an IC bare chip, and a plasma display. The present invention relates to a wound body of an adhesive or a film-like material (hereinafter referred to as a connection member) used for conductive connection between a panel (PDP) and an FPC, and conductive connection between an FPC or PCB and an IC bare chip.

  In recent years, with the miniaturization and thinning of electronic components, the circuits used for them have become denser and higher definition, and it is difficult to connect such electronic components and fine electrodes with conventional solder or rubber connectors. For this reason, anisotropically conductive connecting members having excellent resolution have been frequently used recently. This connecting member is made of an adhesive containing a predetermined amount of conductive material such as conductive particles, and is formed on one side of a separator substrate such as a polyethylene terephthalate film (PET film) or a polytetrafluoroethylene film (Teflon film). It is supplied as a rolled body. At this time, if the surface tension of the separator base material is the same on the front and back, there is a possibility that the connection member will transfer to the separator base material facing the connection member. As a method for solving the above, it has been proposed that the surface tension of the connecting member forming layer is made larger than the surface tension of the back surface layer by applying a silicone-based treatment agent or the like on the front and back of the separator substrate. Moreover, the method etc. which provide a protective film on the connection member formed in the single side | surface of a separator base material are also proposed.

  Among the conventional methods described above, a method of providing a protective film on a connection member formed on one side of a separator base material requires a new protective film, and thus an increase in cost is an important problem. Furthermore, when using it as a connecting member, a process for peeling off the protective film or equipment equivalent thereto is required, which complicates the operation and increases the cost of the equipment. On the other hand, the method of providing a difference in surface tension by applying surface treatment to the front and back of the separator substrate is difficult to form a uniform treated surface state, and is stable when the separator substrate is peeled from the connecting member. However, there is a problem that the peelability cannot be obtained. In addition, after the surface treatment on the front and back of the separator base material, the end surface of the separator base material slit to the required width is not subjected to the surface treatment, and when the connecting member adheres to the end surface of the separator base material, There are problems such as adhesion to the end face. The present invention has been made in view of such a situation. By using a return layer material having a superior difference in surface tension as a separator base material, it is not transferred to the separator base material facing the connecting member. An object of the present invention is to provide a winding-like connecting member that is stable and can be peeled even when the separator substrate is peeled from the connecting member.

In order to achieve the above object, the present invention is a wound body in which a material having a superior difference in surface tension between the front and back surfaces is used as a separator base material and an adhesive layer is formed on one side, and the separator base material is at least 2 The surface tension of the adhesive forming surface is larger than the surface tension of the back surface layer (except when a silicone treatment liquid is applied), and the width is 3 mm or less. The wound body is characterized by comprising only two layers, the layer on the adhesive forming surface side and the back layer.

Moreover, this invention provides the wound body which contains the electroconductive fine particles with an average particle diameter of 1-20 micrometers in an adhesive layer in the said wound body.

  According to the present invention, by using a material whose surface tension of the adhesive forming layer is smaller than the surface tension of the back layer as the separator base material, the separator is extremely stable without being transferred to the separator base material facing the connecting member. It is possible to provide an inexpensive wound-like connecting member that can obtain the peelability of the substrate.

The present invention is a wound body in which a material having a superior difference in surface tension between the front and back surfaces is used as a separator base material and an adhesive layer is formed on one side, and the separator base material is composed of at least two layers, and an adhesive is formed. it was the surface tension of the surface larger than the surface tension of the back surface layer (except when applying a silicone-based treatment liquid), a width of Ri der less 3 mm, the separator substrate, said adhesive forming surface And an adhesive layer comprising conductive particles having an average particle diameter of 1 to 20 [mu] m in the adhesive layer, wherein the adhesive layer is composed of only two layers, the back layer and the back layer. about the MakiShigeru having a. The separator base material on which the connection member that is currently supplied is formed is obtained by applying a silicone treatment liquid to the front and back of a polyethylene terephthalate film having a film thickness of about 25 to 100 μm. The tension is greater than the surface tension of the back layer. In many cases, the separator wound body on which the connection member is formed is slit to a width of about 1 to 20 mm depending on the application. The width of the wound body tends to be further narrowed in order to reduce the area of the connecting portion, and the area ratio of the end faces in the separator base material area tends to increase.

  The separator base material on which these connection members are formed is thermocompression-bonded onto a circuit electrode such as a glass substrate or a printed board, and only the connection member is transferred onto the circuit electrode, and then the separator base material is peeled off from the connection member. FIG. 1 shows an example of an actual usage method. FIG. 1A shows a state in which a separator base material on which a connecting member having a required length drawn from a wound body is formed is attached to a circuit electrode 2 on a glass substrate 1. At this time, the connecting member is located on the circuit electrode side. FIG. 1B shows a process of fixing the portion pasted in FIG. 1A by thermocompression bonding. FIG. 1C shows a process of peeling the separator base material 5 from the connection member 6. At this time, the separator peelability varies greatly depending on the surface tension state of the separator substrate. FIG. 2 shows an example in which a connection member is formed on the separator substrate of the present invention. FIG. 3 shows an example in which a connecting member is formed on a conventionally used separator substrate. In general, when a separator base material on which a connection member is formed is used as a wound body, the surface tension of the adhesive forming surface must be larger than the surface tension of the back layer. The surface tension can be considered as an index as to whether or not the adhesive layer as a connection member wets the separator substrate surface well. For example, the greater the surface tension of the separator substrate surface, the easier the adhesive layer gets wet. Conversely, when the surface tension becomes smaller, the adhesive layer becomes harder to wet. Therefore, when the separator base material on which the connection member is formed is used as a wound body, the surface tension of the adhesive forming surface must be larger than the surface tension of the back surface layer. When the value is equal to or greater than the surface tension, there is a possibility that the connection member is transferred to the separator substrate facing the connection member.

  In the conventional separator base material shown in FIG. 3, in order to give a superior difference in the surface tension between the front and back surfaces, a silicon-based material or the like is applied to the front and back surfaces of the separator, and the superiority difference is adjusted by changing the coating amount. Yes. At this time, the end surface of the separator base material is not subjected to the above-described treatment, and when the connection member adheres to the end surface of the separator base material, the end surface may adhere to the end surface, or stable peelability may not be obtained. There's a problem. This phenomenon is remarkably observed when the width of the end face in the separator substrate surface area is narrow and the area ratio is increased. In addition, the above-described processing method has a problem that the surface tension varies and stable peelability cannot be obtained. Therefore, the present inventors have made the separator base material itself a material having a different surface tension without using a secondary treatment method such as surface treatment in order to reduce the variation in the surface tension between the front and back surfaces of the separator base. It was decided to suppress variations in surface tension.

  The separator base material of FIG. 2 shown as an example of the present invention is a film-like material having a two-layer structure of a low surface tension layer and a high surface tension layer. For example, when the low surface tension layer is a polypropylene material (about 28 dyn / cm) and the high surface tension layer is a polyethylene material (about 31 dyn / cm), an adhesive layer (about 40 to The object can be achieved by forming (60 dyn / cm). As the material of the separator base material, polytetrafluoroethylene (22 dyn / cm), polyvinylidene fluoride (25 dyn / cm), polyvinyl fluoride (28 dyn / cm), polypropylene (28 dyn / cm), polyethylene (31 dyn / cm) , Polytrifluorochloroethylene (31 dyn / cm), polystyrene (33 dyn / cm), polyvinyl alcohol (37 dyn / cm), polymethyl methacrylate (39 dyn / cm), polyvinyl chloride (39 dyn / cm), polyvinylidene chloride (40 dyn / cm) cm) and the like, and a solid polymer in which the surface tension of these modified products is a film having a surface tension of 40 dyn / cm 2 or less. The surface tension in the above is, for example, W.W. A. It is a critical surface tension according to the definition of Zisman, as long as the surface tensions of the adhesive forming layer and the back layer are obtained by the same method. In the configuration of the separator base material, a two-layer configuration including a layer forming an adhesive layer and a back layer can be formed at low cost, but is not particularly limited.

  Next, as the adhesive as the connecting member, a material that exhibits curability by heat or light can be widely applied. Since these are excellent in heat resistance and moisture resistance after connection, it is preferable to use a crosslinkable material. Among these, an epoxy adhesive is preferable because it can be cured in a short time, has good connection workability, and has excellent molecular adhesion. Epoxy adhesives are mainly composed of epoxy modified with high molecular weight epoxy, solid epoxy and liquid epoxy, urethane, polyester, acrylic rubber, NBR, nylon, etc., and include curing agents, catalysts, coupling agents, fillers, etc. What is added is common. As the conductive particles used as the conductive material in the connection member, there are metal particles such as Au, Ag, Pt, Ni, Cu, W, Sb, Sn, and solder, carbon, and the like. Alternatively, a core layer made of a polymer such as non-conductive glass, ceramic, or plastic may be coated with a conductive layer made of the above-described material. Furthermore, it is possible to apply insulating coating particles formed by coating a conductive material with an insulating layer, or a combination of conductive electrons and insulating particles. The upper limit of the particle size is preferably a small particle size for application to a fine electrode, and is 15 μm or less, more preferably 7 μm or less. The lower limit of the particle diameter should be 0.5 μm or more, preferably 1 μm or more in order to be able to cope with the cohesiveness of the particles and the irregularities on the negative electrode surface.

  Hereinafter, although an Example demonstrates in detail, this invention is not limited to this.

Example 1
As a film forming material, a ratio of a liquid epoxy resin (epoxy equivalent 185) containing a phenoxy resin (high molecular weight epoxy resin) and a microcapsule type latent curing agent was 20/80, and a 30% solution of ethyl acetate was obtained. To this solution, 5% by volume of conductive particles having a Ni / Au thickness of 0.2 / 0.02 μm formed on polystyrene particles having a particle diameter of 5 μm were added and mixed and dispersed. This dispersion is continuously applied to the polyethylene material side of the separator substrate (polypropylene 20 μm, polyethylene 20 μm) using a roll coater, dried at 100 ° C. for 10 minutes, and then an adhesive layer having a thickness of 20 μm is applied. Thus, a rolled body of the separator base material was obtained. Furthermore, this wound body was slit in the winding direction to obtain a wound body having a width of 2.5 mm and a width of 0.8 mm.

Example 2
The same dispersion as in Example 1 was continuously applied to the polyvinyl fluoride material side of the separator substrate (two-layer structure of polytetrafluoroethylene 20 μm and polyvinyl fluoride 20 μm) using a roll coater, and 100 ° C. for 10 minutes. After drying, a roll of separator base material coated with a 20 μm thick adhesive layer was obtained. Furthermore, this wound body was slit in the winding direction to obtain a wound body having a width of 2.5 mm and a width of 0.8 mm.

Comparative Example The same dispersion as in Example 1 and Example 2 was applied to a separator substrate that had been used in the past (by applying a silicon treatment liquid on the front and back of a polyethylene terephthalate film with a thickness of 40 μm, the difference in surface tension was The surface was coated with a roll coater on the low surface tension side, dried at 100 ° C. for 10 minutes, and then a separator substrate roll coated with a 20 μm thick adhesive layer was obtained. Furthermore, this wound body was slit in the winding direction to obtain a wound body having a width of 2.5 mm and a width of 0.8 mm.

Evaluation 1
A thin film of indium oxide (thickness 0.2 μm, surface resistance 20Ω / □) is formed on a glass substrate (thickness 1.1 mm) using the roll of 2.5 mm width obtained in Examples 1 and 2 and Comparative Example. It affixed on the plane electrode which has a circuit. The pasting was performed by heating and pressing at 80 ° C.-10 kgf / cm ² -3s. As the evaluation method, the peel strength of the separator substrate was measured using a tensile tester under the conditions of a pulling speed of 50 mm / min and a pulling direction of 90 °. The obtained results are shown in Table 1. As is clear from this result, when the separator base material of the present invention is used, a separator base material that has been used conventionally (by applying a silicon-based treatment liquid to the front and back of a polyethylene terephthalate film having a thickness of 40 μm) It was found that stable releasability can be obtained as compared with the case where the surface tension is different.

Evaluation 2
Examples 1, 2 and a wound body having a width of 2.5 mm and a width of 0.8 mm obtained in the comparative example were left in a constant temperature bath at 40 ° C. for 1 day, 3 days, and 5 days, and then pulled at a speed of 30 cm / sec. The separator base material to which the adhesive layer was applied was pulled out, and it was confirmed whether or not it was transferred to the separator base material facing the adhesive layer (hereinafter referred to as a blocking test). The obtained results are shown in Tables 2 and 3. A separator base material that has been used conventionally (a difference in surface tension was obtained by applying a silicon-based treatment liquid to the front and back surfaces of a polyethylene terephthalate film having a thickness of 40 μm) was defective in a blocking test. This phenomenon tended to be noticeable when the width was narrow. The cause of the failure in the blocking test is due to the adhesive layer flowing when left at high temperature and adhered to the end face of the separator base material that has not been surface-treated by the silicon-based treatment liquid. In particular, when the width ratio of the end surface in the surface area of the separator substrate is increased, the peelability at the end surface cannot be maintained when the width is narrow, and the above-described problem appears remarkably. On the other hand, when the separator base material of the present invention was used, good results were obtained and it was satisfactory.

(A) (b) (c) The conceptual diagram which shows the usage example of the separator base material in which the connection member was formed. Sectional drawing which shows the example in which the connection member was formed on the separator base material of this invention. Sectional drawing which shows the example in which the connection member was formed on the conventional separator base material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Circuit electrode 3 Separator base material in which the connection member was formed 4 Pressure heating head 5 Separator base material 6 Connection member 7 High surface tension layer 8 Low surface tension layer 9 Silicon processing surface (maximum processing)
10 Silicon processing surface (minimum processing)

Claims (2)

A material having a superior difference in surface tension between the front and back surfaces is a separator base material, and a wound body in which an adhesive layer is formed on one side,
The separator substrate comprises at least two layers,
Make the surface tension of the adhesive-forming surface larger than the surface tension of the back layer (except when applying a silicone treatment liquid)
Width Ri der less than 3mm,
The winding body , wherein the separator base material is composed of only two layers of the adhesive-forming surface side and the back layer . The wound body according to claim 1, wherein the adhesive layer contains conductive fine particles having an average particle diameter of 1 to 20 µm.

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