TWI632219B - Conductive tape and preparation method thereof - Google Patents

Abstract

The invention relates to a conductive tape, which is sequentially laminated with a release protective layer, an inorganic and organic composite conductive layer, an adhesive layer and a conductive substrate layer, and the adhesive layer is mixed with a plurality of conductive materials in the adhesive. The particles, and the inorganic and organic composite conductive layer have an array of vias, such that a portion of the conductive particles enter the via array with the adhesive. Thereby, the problem of unstable conductivity of the prior art is solved, and the effect of stably improving the conductivity is obtained.

Description

Conductive tape and preparation method thereof

The invention relates to a conductive tape and a preparation method thereof, in particular to an inorganic material and an organic composite conductive layer which are directly contacted with a conductive adhesive, and the inorganic material and the organic composite conductive layer have a through hole array, and the adhesive layer has a part. The conductive particles enter the designer of the via array with the adhesive.

According to the development of the consumer electronics industry, consumer electronics products are becoming more and more compact, lightweight, and thinner. Under this trend, the integration of electronic products is getting higher and smaller, and the volume is getting smaller. The power is getting stronger and stronger; therefore, the trend of high power, high integration, and narrow application space is bringing a series of problems of conduction and radiation interference for consumer electronic products; however, traditional conductive connection schemes such as metal Reeds, wire and cable connections, connectors, etc., because of their large size, require more space, and can not meet the needs of lightweight and use of consumer electronics in a small space.

Sub-press, conductive tape is widely used in the consumer electronics industry because of its light weight, thin thickness, certain bonding ability and corresponding conductivity, to achieve the internal electrostatic grounding and electromagnetic shielding of electronic products; however, Since the conductive tape is electrically conductive, the conductive particles are mixed in the non-conductive pressure-sensitive adhesive, and when the non-conductive pressure-sensitive adhesive is bonded to the conductive material, the conductive particles are in contact with the conductive material and between the conductive particles. The current tunneling effect is realized; however, the conventional conductive tape has randomness due to the probability of contact between the conductive particles on the surface and the conductive object, so that the conductive property of the conventional conductive tape is unstable, and with the use (bonding) area The reduction (high integration) leads to a decrease in the probability of the conductive particles that can be effectively conducted, which limits the use of conventional conductive tapes in highly integrated, high-power consumer electronic products.

The main object of the present invention is to solve the problem of unstable conductivity of the prior art, and to have the effect of stably improving the conductivity.

Another object of the present invention is to have a quick preparation effect.

In order to achieve the above effects, the structural features of the conductive tape of the present invention are sequentially laminated with a release protective layer, an inorganic and organic composite conductive layer, an adhesive layer and a conductive substrate layer, and the adhesive layer is applied to the adhesive. A plurality of conductive particles are mixed, and the inorganic material and the organic composite conductive layer have an array of through holes, so that a part of the conductive particles enter the through hole array with the adhesive.

In addition, the inorganic and organic composite conductive layer is silver paste, copper paste, aluminum silver paste, copper glue, indium tin oxide slurry, tin oxide bismuth slurry, graphite glue, graphite paste, graphene glue or graphene paste. The surface of the release protective layer is formed by gravure printing to a thickness of 2 to 6 μm. The adhesive layer is a polyacrylate pressure-sensitive adhesive layer having a thickness of 20-60 micrometers, and the conductive particles are conductive particles or/and conductive fibers. The conductive particles are selected from the group consisting of pure nickel powder, nickel-coated graphite powder, nickel-coated mica powder, silver powder, silver-plated mica, silver-plated hollow microspheres, graphite powder, graphene or conductive carbon black; Rice silver wire, graphite fiber, graphene fiber, carbon fiber, silver plated glass fiber, nickel-coated carbon fiber or silver-plated carbon fiber. The conductive substrate layer is any one or combination of pure metal foil, metal particles, metal microwires, metal nanowires, graphene or porous fibrous materials having a metal plating layer, and has a thickness of 10 to 200 micrometers. The via array is a circular via array, an elliptical via array, a diamond via array, a square via array, or a star via array. The release protective layer is a PET film coated with a release agent or a surface coated release agent paper having a thickness of 30 to 150 μm.

Furthermore, the method for preparing a conductive tape of the present invention comprises the following steps: Step 1: coating a composite conductive coating of inorganic and organic materials on the surface of the release protective layer, and forming an inorganic substance having a through-hole array on the surface of the release protective layer. After the conductive layer is combined with the organic material and then baked to expel the solvent in the conductive coating, the inorganic and organic composite conductive layer is solidified on the surface of the release protective layer; Step 2: coating the surface of the temporary release protective layer with a plurality of conductive materials After the particles are pasted, the solvent in the adhesive is removed by baking, so that the adhesive is cured on the surface of the temporary release protective layer to form an adhesive layer, and then the adhesive layer is adhered to the other surface of the temporary release protective layer. a conductive substrate layer; and step 3: unloading the temporary release protective layer in the second step of the article, and then applying the adhesive layer to the other surface of the temporary conductive substrate layer and the first step of preparing the inorganic material with the release protective layer The organic composite conductive layer is bonded.

In addition, the inorganic and organic composite conductive layers were produced by gravure printing. The releasing surface of the release protective layer relative to the inorganic material and the organic composite conductive layer is previously coated with a release agent, and the release surface of the temporary release protective layer with respect to the adhesive layer is previously coated with a release agent.

Therefore, since the conductive tape of the present invention increases the inorganic material and the organic composite conductive layer directly contacting the conductive adherend, the inorganic material and the organic composite conductive layer have an array of through holes, so that the adhesive layer is partially conductive. The particles enter the through-hole array with the adhesive, and the conductive particles and the conductive paste are in the original planar contact state, and the inorganic and organic composite conductive layers are evolved to form a body contact type.

First, referring to [Fig. 1] to [Fig. 3], the conductive tape of the present invention is sequentially laminated to include: a release protective layer 10, which can be a surface coated PET film or surface coated with a release agent. The paper material of the release agent has a thickness of 30-150 micrometers; an inorganic material and organic composite conductive layer 20 can be silver paste, copper paste, aluminum silver paste, copper glue, indium tin oxide slurry, tin oxide bismuth slurry, Graphite glue, graphite paste, graphene paste or graphene paste is formed on the surface of the release protective layer 10 by gravure printing and has a through hole array 21 having a thickness of 2-6 micrometers, and the through hole array 21 may be circular a via array (as shown in [Fig. 3]), an elliptical via array, a diamond via array, a square via array (as shown in [Fig. 2]) or a star via array; a paste layer 30, A plurality of conductive particles 31 are mixed in the adhesive, and the conductive particles 31 enter the through-hole array 21 along with the adhesive, and the adhesive layer 30 can be a polyacrylate pressure-sensitive adhesive layer having a thickness of 20-60 micrometers. The conductive particles 31 may be selected from the group consisting of pure nickel powder, nickel-coated graphite powder, nickel-coated mica powder, silver powder, and silver-plated cloud. , silver-plated hollow microspheres, graphite powder, graphene or conductive carbon black conductive particles or / and selected from nano silver wire, graphite fiber, graphene fiber, carbon fiber, silver plated glass fiber, nickel-coated carbon fiber or silver plated a conductive fiber of carbon fiber; and a conductive substrate layer 40, which may be any one or combination of pure metal foil, metal particles, metal microwires, metal nanowires, graphene or porous fibrous materials with metal plating, and has a thickness of 10 -200 microns.

The present invention will be further described in detail below with reference to specific embodiments, but the scope of the present invention is not limited to the scope of the embodiments. The proportions of the embodiments are all percentages by weight, and the conductive substrate and polymer are used. Acrylic resins, solvents, curing agents, conductive particles, conductive fibers, inorganic and organic composite conductive coatings, and release protective materials may be other applicable materials in addition to the materials mentioned.

Example 1 Step 1: Using conductive silver paste as a conductive coating for mixing inorganic and organic materials, the silver paste was subjected to gravure printing according to the pattern of [Fig. 2], with a wire diameter of 0.3 mm and a square through hole of 1 mm× 1mm and a thickness of 3 microns, printed on the surface of a PET film with a release liner (8-12g release force) and a thickness of 75 microns, and a PET film (release coating) after printing silver paste After entering the oven, the baking temperature is 120 ° C, and the baking speed is 200 mm/sec. After baking, the inorganic and organic composite conductive layers having the through-hole array are attached to the release PET film. Step 2: adding a mixture of ethyl acetate, an isocyanate hardener and a plurality of conductive particles as a main component of the polymer acrylic resin, the weight percentage is: polymer acrylic resin 30%-40%, ethyl acetate 44%-54%, isocyanate Hardener 0.5%-1%, conductive particles 5%-15%, stirred at 1000 rpm for 30 minutes to prepare a polyacrylate pressure-sensitive adhesive mixture containing a plurality of conductive particles, and then coating the mixture to 30 μm The thickness of the 75-micron surface is attached to the temporary PET release film of the release eucalyptus oil, and is sent to the oven at a speed of 8 m/min. After baking, the polyacrylate pressure-sensitive adhesive mixture containing a plurality of conductive particles is solidified in the temporary separation. A polyacrylate pressure-sensitive adhesive layer was formed on the surface of the type of protective layer, and then a copper foil substrate (conductive substrate layer) having a thickness of 35 μm was attached to the polyacrylate pressure-sensitive adhesive layer. Step 3: Unload the temporary release protective layer in the second product, and then composite the polyacrylate pressure-sensitive adhesive layer with the inorganic material and the organic material with the release protective layer on the other surface of the copper foil substrate and the first step. The layer is laminated to constitute the conductive tape of the present embodiment.

The resistance values of Example 1 and the conventional conductive tape (excluding inorganic and organic composite conductive layers) were tested using a universal electric meter, and the test results were as follows:  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Surface Resistance (Ohm) </td></tr>< Tr><td> </td><td> Sample 1 </td><td> Sample 2 </td><td> Sample 3 </td><td> Average </td></tr><tr ><td> Example 1 </td><td> 0.3 </td><td> 0.3 </td><td> 0.4 </td><td> 0.3 </td></tr><tr> <td> Conventional Conductive Tape</td><td> Exceeds the maximum measurement value of the universal meter</td><td> Exceeds the maximum measurement value of the universal meter</td><td> Exceeds the universal electricity The maximum measured value of the table </td><td> exceeds the maximum measured value of the universal meter</td></tr></TBODY></TABLE> Test Example 1 and the conventional conductive tape according to the ASTM D3330 standard (The inorganic and organic composite conductive layer is not included) 180 degree peeling is performed, and the test results are as follows  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Peeling force (gf/inch) </td></tr ><tr><td> </td><td> Sample 1 </td><td> Sample 2 </td><td> Sample 3 </td><td> Mean</td></tr> <tr><td> Example 1 </td><td> 853 </td><td> 826 </td><td> 794 </td><td> 824 </td></tr>< Tr><td> Conventional Conductive Tape</td><td> 1312 </td><td> 1360 </td><td> 1285 </td><td> 1319 </td></tr>< /TBODY></TABLE> Test Results: Example 1 effectively improved the conductive properties of the surface of the conductive tape while ensuring sufficient adhesive strength.  

Example 2 Step 1: Using a conductive copper paste as a conductive coating for mixing inorganic and organic materials, the copper paste was subjected to gravure printing according to the pattern of [Fig. 3], with a circular hole diameter of 3 mm and a circular hole pitch of 1 mm. Printing size of 5 micron printing, printing on the surface of PET film with release liner oil (release force 8-12g) and thickness 75 microns, PET film (release layer) after printing silver paste The oven has a baking temperature of 120 ° C and a baking speed of 200 mm/sec. After baking, the inorganic and organic composite conductive layers having the through-hole array are attached to the release PET film. Step 2: adding a mixture of ethyl acetate, an isocyanate hardener and a plurality of conductive particles as a main component of the polymer acrylic resin, the weight percentage is: polymer acrylic resin 30%-40%, ethyl acetate 44%-54%, isocyanate Hardener 0.5%-1%, conductive particles 5%-15%, stirred at 1000 rpm for 30 minutes to prepare a polyacrylate pressure-sensitive adhesive mixture containing a plurality of conductive particles, and then coating the mixture to 30 μm The thickness of the 75-micron surface is attached to the temporary PET release film of the release liner, and is sent to the oven at a speed of 8 m/min. After baking, the polyacrylate pressure-sensitive adhesive mixture containing a plurality of conductive particles is solidified in the temporary separation. A polyacrylate pressure-sensitive adhesive layer was formed on the surface of the type of protective layer, and then a nickel-plated conductive woven fabric (conductive substrate layer) having a thickness of 55 μm was attached to the polyacrylate pressure-sensitive adhesive layer. Step 3: Unloading the temporary release protective layer in the second product, and then compounding the polyacrylate pressure-sensitive adhesive layer with respect to the other surface of the nickel-plated conductive woven fabric and the inorganic matter and the organic material with the release protective layer The conductive layer is bonded to form the conductive tape of this embodiment.

The resistance value of the conventional conductive tape (excluding the inorganic and organic composite conductive layer) of Example 2 was tested using a universal electric meter, and the test results were as follows:  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Surface Resistance (Ohm) </td></tr>< Tr><td> </td><td> Sample 1 </td><td> Sample 2 </td><td> Sample 3 </td><td> Average </td></tr><tr ><td> Example 2 </td><td> 0.5 </td><td> 0.5 </td><td> 0.6 </td><td> 0.5 </td></tr><tr> <td> Conventional Conductive Tape</td><td> Exceeds the maximum measurement value of the universal meter</td><td> Exceeds the maximum measurement value of the universal meter</td><td> Exceeds the universal electricity The maximum measured value of the table </td><td> exceeds the maximum measured value of the universal meter</td></tr></TBODY></TABLE> Test Example 1 and the conventional conductive tape according to the ASTM D3330 standard (The inorganic and organic composite conductive layer is not included) 180 degree peeling is performed, and the test results are as follows  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Peeling force (gf/inch) </td></tr ><tr><td> </td><td> Sample 1 </td><td> Sample 2 </td><td> Sample 3 </td><td> Mean</td></tr> <tr><td> Example 2 </td><td> 926 </td><td> 913 </td><td> 878 </td><td> 905 </td></tr>< Tr><td> Conventional Conductive Tape</td><td> 1312 </td><td> 1360 </td><td> 1285 </td><td> 1319 </td></tr>< /TBODY></TABLE> Test results: Example 2 effectively improved the conductive properties of the surface of the conductive tape while ensuring sufficient adhesive strength.  

Based on the constitution of the foregoing, it can be explained that the present invention can be quickly prepared in three steps by the above two embodiments. When the present invention is pasted on a conductive paste to be electrically connected, the conductive tape is more conventionally added in the present invention. The inorganic and organic composite conductive layer 20 is in direct contact with the electrically conductive adherend, and the inorganic and organic composite conductive layer 20 has a through hole array 21, so that the adhesive layer 30 has a part of the conductive particles 31 entering the adhesive layer. In the via array 21, the conductive particles 31 and the conductive paste are in a planar contact state, and the inorganic and organic composite conductive layers 20 are evolved to form a body contact type, thereby enhancing the relationship between the conductive particles 31 and the conductive adherend. The total contact (direct contact + indirect contact with the organic composite conductive layer 20 by the inorganic material) has an area; therefore, the invention has the advantages of stable conductivity improvement and quick preparation.

To sum up, the technical means disclosed in the present invention have the invention patents such as "novelty", "progressiveness" and "available for industrial use", and pray for the patent to be invented by the bureau. German sense.

The drawings and the descriptions of the present invention are merely preferred embodiments of the present invention, and those skilled in the art, which are subject to the spirit of the present invention, should be included in the scope of the patent application.

10 release protective layer 20 inorganic and organic composite conductive layer 21 through hole array 30 adhesive layer 31 conductive particles 40 conductive substrate layer

Fig. 1 is a cross-sectional view showing the structure of the present invention. 2 is a schematic view of a square via array of a composite conductive layer of an inorganic substance and an organic substance of the present invention. Fig. 3 is a schematic view showing a circular through-hole array of a composite conductive layer of an inorganic substance and an organic substance of the present invention.

Claims (10)

A conductive tape is sequentially laminated with a release protective layer, an inorganic and organic composite conductive layer, an adhesive layer and a conductive substrate layer, wherein the adhesive layer is mixed with a plurality of conductive particles in the adhesive, and The inorganic and organic composite conductive layer has an array of vias such that a portion of the conductive particles enter the via array with the adhesive. The conductive tape according to claim 1, wherein the inorganic and organic composite conductive layer is a silver paste, a copper paste, an aluminum silver paste, a copper paste, an indium tin oxide paste, a tin oxide paste, or a graphite paste. A graphite paste, a graphene paste or a graphene paste is formed on the surface of the release protective layer by gravure printing to a thickness of 2 to 6 μm. The conductive tape according to claim 1 or 2, wherein the adhesive layer is a polyacrylate pressure-sensitive adhesive layer having a thickness of 20 to 60 μm, and the conductive particles are conductive particles or/and conductive fibers. The conductive tape according to claim 3, wherein the conductive particles are selected from the group consisting of pure nickel powder, nickel-coated graphite powder, nickel-coated mica powder, silver powder, silver-plated mica, silver-plated hollow microspheres, and graphite powder. Body, graphene or conductive carbon black; the conductive fiber is selected from the group consisting of nano silver wire, graphite fiber, graphene fiber, carbon fiber, silver plated glass fiber, nickel carbon fiber or silver plated carbon fiber. The conductive tape according to claim 4, wherein the conductive substrate layer is any one of a pure metal foil, a metal particle, a metal microwire, a metal nanowire, a graphene or a porous fiber material having a metal plating layer. Or a combination, the thickness is 10-200 microns. The conductive tape of claim 4, wherein the through hole array is a circular through hole array, an elliptical through hole array, a diamond through hole array, a square through hole array, or a star through hole array. The conductive tape according to claim 4, wherein the release protective layer is a PET film coated with a release agent or a surface coated release agent, and has a thickness of 30 to 150 μm. A method for preparing a conductive tape according to claim 1, comprising the following steps: Step 1: coating a composite conductive coating of inorganic and organic materials on the surface of the release protective layer, and having a surface on the surface of the release protective layer The inorganic layer and the organic composite conductive layer of the through-hole array are baked to expel the solvent in the conductive coating, so that the inorganic and organic composite conductive layer is solidified on the surface of the release protective layer; Step 2: coating the surface of the temporary release protective layer The adhesive containing a plurality of conductive particles is mixed, and then the solvent in the adhesive is removed by baking, so that the adhesive is cured on the surface of the temporary release protective layer to form an adhesive layer, and then the adhesive layer is relatively temporarily separated from the protective layer. The other surface is attached to the conductive substrate layer; and the third step is: unloading the temporary release protective layer in the second step of the product, and then attaching the adhesive layer to the other surface of the temporary conductive substrate layer and the step 1 is made to be separated. The inorganic substance of the protective layer is bonded to the organic composite conductive layer. The method for producing a conductive tape according to claim 8, wherein the inorganic material and the organic composite conductive layer are produced by gravure printing. The method for preparing a conductive tape according to claim 8 or 9, wherein the contact surface of the release protective layer relative to the inorganic material and the organic composite conductive layer is pre-coated with a release agent, and the temporary release protective layer is opposite to the adhesive layer. The contact surface is pre-coated with a release agent.