Silver paste used for manufacturing a printed antenna

Abstract

The present invention provides a silver paste used for manufacturing a printed antenna, a kit of parts including three types of silver paste for manufacturing a printed antenna for an electronic device, the use of the silver paste as via filling ink, a method for manufacturing a printed antenna circuit using the three types of silver paste, a printed antenna for an electronic device obtained using the silver paste, and an electronic device including the printed antenna. The silver paste includes the following: at least one epoxy resin of 2 to 40% by weight; at least one curing agent selected from the group consisting of 0 to 5% by weight of an amino resin, a low-temperature cationic curing agent, an amine or an imidazole capsule curing agent, and combinations thereof; at least one filler mixture containing 40 to 90% by weight of silver flakes and silver particles; 10 to 25% by weight of at least one diluent, or 0 to 20% by weight of at least one curing accelerator; and at least one coupling agent selected from the group consisting of 0 to 5% by weight of a silane coupling agent, a titanium-based coupling agent, an aluminum-based coupling agent, and combinations thereof, where all of the above weight percentages are based on the total weight of the silver paste. The silver paste of the present invention has high reliability and high conductivity, has excellent weather resistance or good abrasion resistance, or has no air bubbles, and the combination of the three types of silver paste can be used very effectively for manufacturing a printed antenna.

Description

Technical Field

[0001] The present invention relates to a silver paste used for manufacturing a printed antenna. In particular, the present invention relates to a silver paste used for manufacturing a printed antenna, a kit of parts for manufacturing a printed antenna for an electronic device including three types of silver paste, the use of the silver paste as via fill ink, a method for manufacturing a printed antenna circuit using three types of silver paste, a printed antenna for an electronic device obtained using the silver paste, and an electronic device including the printed antenna.

Background Art

[0002] As 5G communication technology penetrates into our lives, smartphones and other smart devices are increasingly equipped with more antennas. Conventional LDS and FPC technologies can no longer meet the requirements of antennas. In response to the demands of the times, a new technology PDS (Printed Direct-forming Structure) has been developed. In a PDS antenna, three types of silver paste (surface conductive ink, touch point conductive ink, and via fill conductive ink) are required to provide good conductivity and good RF performance to the antenna.

[0003] Regarding the surface conductive ink, existing ones usually have high electrical resistance and poor aging characteristics. Regarding the touch point conductive ink, existing ones usually have high electrical resistance and low wear resistance. Regarding the via fill conductive ink, existing ones usually have low adhesion strength and air bubbles. Further, usually, when these are used in one application, a mismatch occurs between the surface conductive ink, the touch point conductive ink, and the via fill conductive ink, and this mismatch causes many peeling problems during the aging test.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of the above, it is desirable to provide a silver paste for manufacturing a printed antenna that can overcome at least one of the drawbacks of the prior art described above, and that can be used particularly as a surface conductive ink, a touch point conductive ink, or a via fill conductive ink. Further, it is desirable to provide a combination of three types of silver pastes that can be suitably used for manufacturing a printed antenna and that can be used as a surface conductive ink, a touch point conductive ink, or a via fill conductive ink, respectively.

Means for Solving the Problems

[0005] In a first aspect, the present invention provides a silver paste for use in manufacturing a printed antenna, comprising: At least one epoxy resin in an amount of 2 to 40% by weight; At least one curing agent selected from the group consisting of an amino resin, a low-temperature cationic curing agent, an amine or imidazole capsule curing agent, and combinations thereof, in an amount of 0 to 5% by weight; At least one filler mixture containing silver flakes and silver spheres in an amount of 40 to 90% by weight; At least one diluent in an amount of 10 to 25% by weight, or at least one curing accelerator in an amount of 0 to 20% by weight; and At least one coupling agent selected from the group consisting of a silane coupling agent, a titanium-based coupling agent, an aluminum-based coupling agent, and combinations thereof, in an amount of 0 to 5% by weight, wherein all of the above weight percentages are based on the total weight of the silver paste.

[0006] Particularly, in a preferred embodiment of this aspect (hereinafter referred to as the "first embodiment"), the present invention provides a silver paste comprising: At least one epoxy resin in an amount of 2 to 20% by weight, preferably 2 to 8% by weight, more preferably 4 to 6% by weight, 0 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight of at least one curing agent, which includes an amino resin, 40 to 90% by weight, preferably 50 to 85% by weight, more preferably 70 to 80% by weight of at least one filler mixture, which includes 1 to 40% by weight of silver flakes having a tap density of more than 2 to 7 g / cm 3 and 35 to 88% by weight of silver particles having a tap density of 5 to 7 g / cm 3 and 0.08 to 0.45% by weight of zirconium hydroxide, 5 to 25% by weight, preferably 10 to 23% by weight, more preferably 15 to 20% by weight of at least one diluent, 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof, wherein all of the above weight percentages are based on the total weight of the silver paste.

[0007] In another preferred embodiment of this aspect (hereinafter referred to as the "second embodiment"), the present invention provides a silver paste comprising: 2 to 20% by weight, preferably 2 to 8% by weight, more preferably 4 to 6% by weight of at least one epoxy resin, 0.1 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight of at least one curing agent, which includes an amino resin, 40 to 90% by weight, preferably 50 to 85% by weight, more preferably 70 to 80% by weight of at least one filler mixture, which includes 1 to 30% by weight of silver flakes having a tap density of more than 2 to 7 g / cm 3 and 25 to 75% by weight of silver particles having a tap density of 5 to 7 g / cm 3 and 10 to 40% by weight of wear-resistant powder having a particle size of 3.5 to 10 μm, and 0.08 to 0.45% by weight of zirconium hydroxide, 5 to 25% by weight, preferably 10 to 23% by weight, more preferably 15 to 20% by weight of at least one diluent, 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof, Here, all of the above weight percentages are based on the total weight of the silver paste.

[0008] In a more preferred embodiment of this aspect (hereinafter referred to as "the third embodiment"), the present invention provides a silver paste comprising: 10 to 40% by weight, preferably 11 to 30% by weight, more preferably 12% to 20% by weight of at least one epoxy resin, 0.1 to 3% by weight, preferably 0.2 to 2% by weight, more preferably 0.3 to 1% by weight of at least one curing agent, which includes a low-temperature cationic curing agent or an amine or imidazole capsule curing agent, 50 to 90% by weight, preferably 60 to 88% by weight, more preferably 75 to 85% by weight of at least one filler mixture, which includes 45 to 89% of silver flakes having a tap density of 2 to 7 g / cm 3 and 1 to 45% of silver particles having a tap density of 5 to 7 g / cm 3 is included, 1 to 20% by weight, preferably 2 to 15% by weight, more preferably 3 to 10% by weight of at least one curing accelerator, 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof, Here, all of the above weight percentages are based on the total weight of the silver paste.

[0009] In a second aspect, the present invention provides a kit of parts for preparing a printed antenna for an electronic device, comprising the following packaged separately: · A first container containing the silver paste of the first embodiment, · A second container containing the silver paste of the second embodiment, and · A third container containing the silver paste of the third embodiment.

[0010] In a third aspect, the present invention provides the use of the silver paste of the third embodiment as via fill ink for conductive connection between the surface silver paste and the touch point silver paste.

[0011] In a fourth aspect, the present invention provides a method for manufacturing a printed antenna circuit using the silver paste of the first embodiment, the silver paste of the second embodiment, and the silver paste of the third embodiment.

[0012] In a fifth aspect, the present invention provides a printed antenna for an electronic device obtained using the silver paste of the present invention.

[0013] In a sixth aspect, the present invention provides an electronic device including the printed antenna according to the present invention.

[0014] The silver paste of the present invention can provide a very low electrical resistance (having a sheet resistance of less than 10 mohm / square), high adhesiveness, and good aging characteristics; or the silver paste of the present invention can provide high wear resistance up to 3000 cycles and low electrical resistance; or the silver paste of the present invention can be bubble-free and provide high strength. The kit of parts for manufacturing a printed antenna for an electronic device according to the present invention has no problem of mismatch.

Embodiments for Carrying Out the Invention

[0015] A person skilled in the art should understand that this description is merely an illustration of exemplary embodiments and is not intended to limit the broad aspects of the present invention. Each aspect thus described may be combined with any other aspect unless explicitly stated otherwise. In particular, any feature shown as preferred or advantageous may be combined with any other feature shown as preferred or advantageous.

[0016] Regarding the present invention, unless otherwise stated, the terms used are construed in accordance with the following definitions.

[0017] Unless otherwise specified, as used in this specification, the singular forms "a", "an" and "the" include both singular and plural referents.

[0018] The terms "comprising" and "comprises" as used in this specification are synonymous with "including", "includes" or "containing", "contains", are inclusive or open-ended, and do not exclude additional unrecited members, elements or process steps.

[0019] The term "at least one" used herein to define a component refers to the type of component and not to the absolute number of molecules. For example, "at least one epoxy resin" means one type of "epoxy resin" or a mixture of multiple different epoxy resins.

[0020] All tap density data used in this specification are determined in accordance with ISO 3953:1993. The principle of the specified method is to tap a predetermined amount of powder in a container using a tapping device until the volume of the powder no longer decreases. Dividing the mass of the powder by the volume after the test gives the tap density of the powder.

[0021] All particle size data used in this specification refers to the "D50 particle size", which represents the median diameter in the volume-based particle size distribution curve obtained by measurement with a laser diffraction particle size analyzer. In this technique, the size of particles in a suspension or emulsion is measured using the diffraction of a laser beam based on the application of either the Fraunhofer theory or the Mie theory. In the present invention, the Mie theory or the modified Mie theory for non-spherical particles is applied, and the average particle size or D50 value is related to the scattered light measurement at an angle of 0.02 to 135 degrees with respect to the incident laser beam.

[0022] Unless otherwise specified, the description of numerical endpoints includes not only the recited endpoints but also all numbers and fractions included within each range.

[0023] Unless otherwise defined, all terms used in the disclosure of the present invention, including technical and scientific terms, have the meanings commonly understood by those of ordinary skill in the art to which this invention belongs.

[0024] In one aspect, the present disclosure is directed to a silver paste used for manufacturing a printed antenna, including: At least one epoxy resin of 2 to 40% by weight; 0 to 5% by weight of at least one curing agent selected from the group consisting of amino resins, low-temperature cationic curing agents, amine or imidazole capsule curing agents, and combinations thereof; At least one filler mixture containing silver flakes and silver particles of 40 to 90% by weight; 10 to 25% by weight of at least one diluent, or 0 to 20% by weight of at least one curing accelerator; and, 0 to 5% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof, wherein all of the above weight percentages are based on the total weight of the silver paste.

[0025] <First Embodiment> In the first embodiment of the present invention, the silver paste contains the following: 2 to 20% by weight, preferably 2 to 8% by weight, more preferably 4 to 6% by weight of at least one epoxy resin, 0 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight of at least one curing agent, which includes an amino resin, 40 to 90% by weight, preferably 50 to 85% by weight, more preferably 70 to 80% by weight of at least one filler mixture, the mixture including silver flakes having a tap density of 1 to 40% by weight of 2 to 7 g / cm 3 and silver particles having a tap density of 35 to 88% by weight of 5 to 7 g / cm 3 and including 0.08 to 0.45% by weight of zirconium hydroxide, 5 to 25% by weight, preferably 10 to 23% by weight, more preferably 15 to 20% by weight of at least one diluent, 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof, wherein all of the above weight percentages are based on the total weight of the silver paste.

[0026] In the first embodiment of the present invention, preferably, the epoxy resin is selected from the group consisting of bisphenol-A resin, bisphenol-F resin, and alicyclic epoxy resin; preferably selected from the group consisting of bisphenol-A resin and bisphenol-F resin; more preferably bisphenol-A resin.

[0027] Alternatively or additionally, in the first embodiment of the present invention, preferably, the amino resin is catalyzed by benzenesulfonic acid, where the amino resin is preferably selected from the group consisting of urea formaldehyde resin, melamine formaldehyde resin, and polyamide polyamine epichlorohydrin, more preferably selected from the group consisting of melamine formaldehyde resin; and / or, the benzenesulfonic acid is used in the form of pyridinium p-toluenesulfonate.

[0028] Alternatively or additionally, in the first embodiment of the present invention, preferably, the filler mixture contains silver flakes in an amount of 2 to 35% by weight, preferably 10 to 30% by weight, more preferably 12 to 20% by weight, based on the total weight of the silver paste; and / or, the filler mixture contains silver particles in an amount of 40 to 80% by weight, preferably 50 to 70% by weight, more preferably 55 to 65% by weight, based on the total weight of the silver paste; and / or, the filler mixture contains zirconium hydroxide in an amount of 0.1 to 0.3% by weight, preferably 0.15 to 0.25% by weight, based on the total weight of the silver paste; and / or, the silver flakes have a particle size of 5 to 8 μm; and / or, the silver flakes have a tap density of 3 to 6 g / cm 3 and preferably have a tap density of 3.5 to 5 g / cm 3 ; and / or, the silver particles have a particle size of 0.2 to 5 μm, preferably 0.5 to 2 μm; and / or, the silver particles have a tap density of 5.5 to 6.5 g / cm 3 of.

[0029] Alternatively or additionally, in the first embodiment of the present invention, preferably, the diluent is selected from the group consisting of: ketones and esters; preferably selected from the group consisting of isophorone, acetylacetone, cyclohexyl acetate, ethylene glycol butyl ether acetate, and propylene glycol methyl ether acetate; and it is a mixture of isophorone, acetylacetone, cyclohexyl acetate, ethylene glycol butyl ether acetate, and propylene glycol methyl ether acetate.

[0030] The silver paste of the first embodiment can provide a very low electrical resistance (having a sheet resistance of less than 10 mohm / square), high adhesiveness, and good aging characteristics, so it can be advantageously used as a surface conductive ink.

[0031] <Second Embodiment> In the second embodiment of the present invention, the silver paste contains the following: 2 to 20% by weight, preferably 2 to 8% by weight, more preferably 4 to 6% by weight of at least one epoxy resin, 0.1 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight of at least one curing agent, which contains an amino resin, 40 to 90% by weight, preferably 50 to 85% by weight, more preferably 70 to 80% by weight of at least one filler mixture, which contains 1 to 30% by weight of silver flakes having a tap density of more than 2 to 7 g / cm 3 25 to 75% by weight of silver particles having a tap density of 5 to 7 g / cm 3 10 to 40% by weight of wear-resistant powder having a particle size of 3.5 to 10 μm, and 0.08 to 0.45% by weight of zirconium hydroxide, 5 to 25% by weight, preferably 10 to 23% by weight, more preferably 15 to 20% by weight of at least one diluent, 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight, of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof. Here, all of the above weight percentages are based on the total weight of the silver paste.

[0032] In a second embodiment of the present invention, preferably, the epoxy resin is selected from the group consisting of bisphenol-A resin, bisphenol-F resin, and alicyclic epoxy resin; preferably selected from the group consisting of bisphenol-A resin and bisphenol-F resin; more preferably bisphenol-A resin.

[0033] Alternatively or additionally, in a second embodiment of the present invention, preferably, the amino resin is catalyzed by benzenesulfonic acid, where the amino resin is preferably selected from the group consisting of urea formaldehyde resin, melamine formaldehyde resin, and polyamide polyamine epichlorohydrin, more preferably selected from the group consisting of melamine formaldehyde resin; and / or the benzenesulfonic acid is used in the form of pyridinium p-toluenesulfonate.

[0034] Alternatively or additionally, in a second embodiment of the present invention, preferably, the filler mixture contains 2 to 25% by weight, preferably 3 to 10% by weight, more preferably 4 to 8% by weight of silver flakes based on the total weight of the silver paste; and / or the filler mixture contains 30 to 70% by weight, preferably 40 to 60% by weight, more preferably 45 to 55% by weight of silver particles based on the total weight of the silver paste; and / or the filler mixture contains 12 to 30% by weight, preferably 18 to 25% by weight of wear-resistant powder based on the total weight of the silver paste; and / or the filler mixture contains 0.1 to 0.3% by weight, preferably 0.15 to 0.25% by weight of zirconium hydroxide based on the total weight of the silver paste.

[0035] Alternatively or additionally, in the second embodiment of the present invention, preferably, the silver flakes have a particle size of 5 to 8 μm; and / or, the silver flakes have a tap density of 3 to 6 g / cm 3 , preferably 3.5 to 5 g / cm 3 ; and / or, the silver particles have a particle size of 0.2 to 5 μm, preferably 0.5 to 2 μm; and / or, the silver particles have a tap density of 5.5 to 6.5 g / cm 3 ; and / or, the wear-resistant powder is selected from the group consisting of silicon powder, zirconia powder, alumina powder, and alloy powder, wherein the alloy powder is preferably selected from the group consisting of iron-nickel alloy powder and iron-manganese alloy powder, more preferably iron-nickel alloy powder; and / or, the alloy powder has a particle size of 4 to 8 μm, preferably 4.5 to 7 μm.

[0036] Alternatively or additionally, in the second embodiment of the present invention, preferably, the diluent is selected from the group consisting of ketones and esters; preferably, it is selected from the group consisting of isophorone, acetylacetone, cyclohexyl acetate, ethylene glycol butyl ether acetate, and propylene glycol methyl ether acetate; and it is a mixture of isophorone, acetylacetone, cyclohexyl acetate, ethylene glycol butyl ether acetate, and propylene glycol methyl ether acetate.

[0037] The silver paste of the second embodiment can provide high wear resistance (2000 to 3000 cycles) and relatively low electrical resistance, so it can be advantageously used as a touch point conductive ink.

[0038] <Third Embodiment> In the third embodiment of the present invention, the silver paste contains the following: 10 to 40% by weight, preferably 11 to 30% by weight, more preferably 12% to 20% by weight of at least one epoxy resin, 0.1 to 3% by weight, preferably 0.2 to 2% by weight, more preferably 0.3 to 1% by weight of at least one curing agent, which includes a low-temperature cationic curing agent or an amine or imidazole capsule curing agent. 50 to 90% by weight, preferably 60 to 88% by weight, more preferably 75 to 85% by weight of at least one filler mixture, which is composed of 45 to 89% of silver flakes having a tap density of 2 to 7 g / cm 3 and 1 to 45% of silver particles having a tap density of 5 to 7 g / cm 3 is included. 1 to 20% by weight, preferably 2 to 15% by weight, more preferably 3 to 10% by weight of at least one curing accelerator. 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof. Here, all of the above weight percentages are based on the total weight of the silver paste.

[0039] In the third embodiment of the present invention, preferably, the epoxy resin is selected from the group consisting of bisphenol-A resin, bisphenol-F resin, and alicyclic epoxy resin; preferably, it is selected from the group consisting of bisphenol-F resin and alicyclic epoxy resin; more preferably, it is a combination of bisphenol-F resin and alicyclic epoxy resin.

[0040] Alternatively or additionally, in the third embodiment of the present invention, preferably, the low-temperature cationic curing agent is cured at a temperature of 60 to 90°C, preferably 70 to 80°C; and / or the low-temperature cationic curing agent is hexafluoroantimonate and / or hexafluorophosphate, preferably hexafluoroantimonate; and / or the amine or imidazole capsule curing agent is an imidazole capsule curing agent.

[0041] Alternatively or additionally, in the third embodiment of the present invention, preferably, the filler mixture contains 50 to 85 wt%, preferably 60 to 80 wt%, more preferably 65 to 75 wt% of silver flakes based on the total weight of the silver paste; and / or the filler mixture contains 2 to 35 wt%, preferably 5 to 20 wt%, more preferably 8 to 15 wt% of silver particles based on the total weight of the silver paste; and / or the silver flakes have a particle size of 5 to 20 μm; and / or the silver particles have a particle size of 5 to 20 μm; and / or the silver flakes have a tap density of 3 to 6 g / cm 3 and preferably a tap density of 3.5 to 5 g / cm 3 ; and / or the silver particles have a tap density of 5.5 to 6.5 g / cm 3 .

[0042] Alternatively or additionally, in the third embodiment of the present invention, preferably, the curing accelerator is selected from the group consisting of oxetanes, and preferably is (3-ethyl-3-oxetanyl)methanol.

[0043] The silver paste of the third embodiment can provide high strength and, since there are no air bubbles, can be advantageously used as a via-fill conductive ink.

[0044] The method for manufacturing the silver paste according to the present invention may be any conventional method for manufacturing a silver paste and is not particularly limited as long as such a silver paste is obtained. For example, the method for manufacturing the silver paste may include: stirring at least one epoxy resin and any at least one diluent, adding at least one filler mixture, and stirring the mixture thus obtained, adding any at least one curing agent and at least one coupling agent, stirring the mixture thus obtained, and then grinding the mixture obtained above with a three-roll mill.

[0045] In another aspect, the present disclosure is directed to a kit of parts for manufacturing a printed antenna for an electronic device, including the following packaged separately: · A first container containing the silver paste of the first embodiment, · A second container containing the silver paste of the second embodiment, and · A third container containing the silver paste of the third embodiment.

[0046] The combination of the three types of silver pastes has no mismatch problem and has good aging characteristics.

[0047] In yet another aspect, the present disclosure is directed to the use of the silver paste of the third embodiment as via fill ink for electrically connecting between the surface silver paste and the touch point silver paste, preferably for electrically connecting between the silver paste of the first embodiment and the silver paste of the second embodiment.

[0048] In yet another aspect, the present disclosure is directed to a method for manufacturing a printed antenna circuit including the following steps: i) Applying the silver paste of the third embodiment into the via of the intermediate frame of the mobile phone with a glue dispenser, then curing it at 80 - 90 °C for 0.5 - 2 hours, preferably 0.8 - 1.5 hours, more preferably about 1 hour, and leaving it for 0.5 - 2 hours to obtain a product; ii) Applying the silver paste of the first embodiment to the product obtained in step i) three times with a pad printer, then curing it at 80 - 90 °C for 0.5 - 2 hours, preferably 0.8 - 1.5 hours, more preferably about 1 hour to obtain an Ag film having a thickness of 10 - 20 μm, preferably about 15 μm; and iii) Applying the silver paste of the second embodiment to the Ag film obtained in step ii) five times with a pad printer, and curing it at 80 - 90 °C for 1 - 3 hours, preferably 1.5 - 2.5 hours, more preferably about 2 hours to obtain a printed antenna circuit.

[0049] Preferably, the intermediate frame of the mobile phone is made of PC, LPA, aluminum alloy, ceramic, glass, and / or magnesium alloy.

[0050] In a further aspect, the present invention also provides a printed antenna for an electronic device obtained using the silver paste of the present invention, preferably obtained using the silver paste of the first embodiment, the silver paste of the second embodiment, and / or the silver paste of the third embodiment, more preferably obtained using the kit of parts of the present invention.

[0051] In a further aspect, the present invention provides an electronic device including the printed antenna of the present invention.

[0052] Regarding further preferred embodiments of the kit of parts, the use of the silver paste according to the third embodiment, the method for manufacturing a printed antenna circuit, the printed antenna for an electronic device, and the electronic device including the printed antenna, the content described for the silver paste applies with necessary modifications.

Examples

[0053] The present invention will be further described and illustrated in more detail with reference to the following examples. The examples are intended to help those skilled in the art better understand and practice the present invention, but are not intended to limit the scope of the present invention. All amounts in the examples are based on weight in grams unless otherwise specified.

[0054] <Materials> The following materials were used in the examples: TIFF2025520827000001.tif180164

[0055] <Preparation of Silver Paste> The silver pastes of the examples (hereinafter abbreviated as "EX") and comparative examples (hereinafter abbreviated as "CE") according to the present invention were prepared according to the compositions described in Table 1 below: The epoxy resin and any diluent were stirred until uniform, the filler mixture was added, and the resulting mixture was stirred until uniform; any curing agent or curing accelerator was added, and the resulting mixture was stirred until uniform; then, the mixture obtained above was ground with three rolls.

[0056] <Test method> The properties of the silver pastes of the examples and comparative examples were measured by the following methods.

[0057] (Sheet resistance of silver paste) The silver pastes of the examples and comparative examples were coated on a Mylar substrate with a 2-mil gap. The samples were cured at 80 - 90 °C for 1 hour. Two-point probe measurement was performed as follows: A line about 100 mm long and about 2 mm wide was cut into the film and tested. The resistance was measured using a multimeter. The thickness of the line coating was measured at several places on the line, and the average thickness was calculated. The sheet resistance was obtained by the following formula: [Number]

[0058] The sheet resistance was specific to the silver paste during curing. The lower the sheet resistance value, the better the conductivity. The silver paste of the first embodiment having a sheet resistance of less than 10 mohm / square is acceptable; the silver paste of the second embodiment having a sheet resistance of 30 mohm / square or less is acceptable; and the silver paste of the third embodiment having a sheet resistance of less than 80 mohm / square is acceptable.

[0059] (Adhesion of silver paste) The adhesion of the silver paste was tested as follows: 1) Using a sharp blade, 10×10 1mm *Draw in a specified area of 1 mm, where each line needs to penetrate the ink to the edge of the material; 2) Brush the surface with a lint-free cloth or brush, attach a small mesh with 3M 610 tape and press it flat, squeeze out the air bubbles, apply static pressure for more than 5 minutes, keep the product stationary, and quickly pull up the tape side at an angle of 90°.

[0060] The adhesion of the silver paste used in the manufacture of printed antennas should be at least 4B (the silver layer peels off by less than 5%, and cohesive failure with silver is not allowed).

[0061] (Adhesion of silver paste - Artificial sweat) The adhesion - artificial sweat test of the silver paste was tested as follows: Dip a wiper in artificial sweat with a pH of 4.6, place this on the silver paste sample, then put this in a sealed bag and store it under the conditions of 65 ± 1 °C / 91 - 95% RH for 48 hours, and then conduct the adhesion test as described above.

[0062] The adhesion - artificial sweat of the silver paste used in the manufacture of printed antennas should be at least 4B.

[0063] (Adhesion of silver paste - Boiling) The adhesion - boiling test of the silver paste was tested as follows: Boil the silver paste sample for 30 minutes and 2 hours, during which keep the sample from contacting the wall of the container; Take out the sample and thaw it at room temperature for at least 2 hours; And then conduct the above adhesion test.

[0064] The adhesion boiling of the silver paste used in the manufacture of printed antennas should be at least 4B.

[0065] (RCA wear resistance of silver paste) The RCA wear resistance (175 g) of the silver paste was tested as follows: A silver paste sample was taken out, a load of 175 g was applied, it was worn at 2000 cycles, the appearance was evaluated, and the performance was tested. Here, the RCA wear machine (type: 7-IBB-CC) used was obtained from Norman tool.

[0066] In the production of printed antennas, the RCA wear resistance (175 g) of the silver paste must not expose the substrate.

[0067] (Via hole cross-section of silver paste) The via hole cross-section of the silver paste was tested as follows: The holes were filled with glue, 2 pcs of silver paste products were taken out, and cross-sections were made.

[0068] In the via hole cross-section results of the silver paste used in the production of printed antennas, there must be no bubbles with a diameter exceeding 0.5 mm in the narrowest area.

[0069] The results of the above tests of the silver paste were also described in Table 1.

[0070] (Impedance test of printed antenna made of silver paste) The antennas made of the silver paste of the examples and comparative examples were manufactured in the following steps: i) A step of applying the silver paste of the third embodiment into the vias of the intermediate frame of the mobile phone with a glue dispenser, then curing it at 80 °C for 2 hours, and leaving it for 1 hour to obtain a product; ii) A step of applying the silver paste of the first embodiment to the product obtained in step i) 3 times with a pad printer, then curing this at 80 °C for 2 hours to obtain an Ag film having a thickness of 15 μm; and iii) A step of applying the silver paste of the second embodiment to the Ag film obtained in step ii) 5 times with a pad printer, and curing this at 80 °C for 2 hours to obtain a printed antenna circuit.

[0071] Table 2 shows the specific combinations of the first, second, and third embodiments of the silver paste.

[0072] The impedance of the printed antenna circuit for each combination was measured by applying an amplitude of 1 volt to the antenna terminal and measuring the current. The impedance was calculated by the following formula:

Equation

[0073] When the impedance of the antenna circuit is 1 ohm or less, it is acceptable and described as "qualified", but a resistance exceeding 1 ohm was recorded as "unqualified"; the results of the combinations are also shown in Table 2.

[0074]

Table 1

[0075]

Table 2

[0076] From the above table, it can be seen that the silver paste of the first embodiment has very low electrical resistance (sheet resistance less than 10 mohm / square), high adhesiveness, and good aging characteristics, and thus it can be advantageously used as a surface conductive ink; the silver paste of the second embodiment has high wear resistance (>3000 cycles) and low electrical resistance, and thus it can be advantageously used as a touch point conductive ink; the silver paste of the third embodiment has high strength and no bubbles, and thus it can be advantageously used as a via fill conductive ink. Furthermore, the antenna circuit manufactured using the combination of the three types of silver paste according to the present invention exhibits a satisfactory impedance suitable for electronic applications, while the antenna circuits manufactured using other combinations of silver paste have a mismatch problem and exhibit an impedance that cannot be applied.

[0077] Although several preferred embodiments have been described, many changes and modifications can be made in light of the above teachings. Accordingly, it is understood that the present invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.

Claims

1. A silver paste used for manufacturing a printed antenna, comprising the following: 2 to 40% by weight of at least one epoxy resin; 0 to 5% by weight of at least one curing agent selected from the group consisting of amino resins, low-temperature cationic curing agents, amine or imidazole capsule curing agents, and combinations thereof; 40 to 90% by weight of at least one filler mixture containing silver flakes and silver particles; 10 to 25% by weight of at least one diluent, or 0 to 20% by weight of at least one curing accelerator; and, 0 to 5% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof wherein all of the above weight percentages are based on the total weight of the silver paste, a silver paste.

2. 2 to 20% by weight, preferably 2 to 8% by weight, more preferably 4 to 6% by weight of at least one epoxy resin, 0 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight of at least one curing agent, the curing agent containing an amino resin, 40 to 90% by weight, preferably 50 to 85% by weight, more preferably 70 to 80% by weight of at least one filler mixture, the filler mixture being 1 to 40% by weight of silver flakes having a tap density of greater than 2 to 7 g / cm ３ ³, 35 to 88% by weight of silver particles having a tap density of 5 to 7 g / cm ３ ³, and 0.08 to 0.45% by weight of zirconium hydroxide, 5 to 25% by weight, preferably 10 to 23% by weight, more preferably 15 to 20% by weight of at least one diluent, 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof wherein all of the above weight percentages are based on the total weight of the silver paste, the silver paste according to Claim 1.

3. 2 to 20% by weight, preferably 2 to 8% by weight, more preferably 4 to 6% by weight of at least one epoxy resin, 0.1 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight of at least one curing agent, the curing agent containing an amino resin, 40 to 90% by weight, preferably 50 to 85% by weight, more preferably 70 to 80% by weight of at least one filler mixture, the filler mixture comprising 1 to 30% by weight of silver flakes having a tap density of greater than 2 to 7 g / cm ３ and 25 to 75% by weight of silver particles having a tap density of 5 to 7 g / cm ３ , 10 to 40% by weight of wear-resistant powder having a particle size of 3.5 to 10 µm, and 0.08 to 0.45% by weight of zirconium hydroxide. 5 to 25% by weight, preferably 10 to 23% by weight, more preferably 15 to 20% by weight of at least one diluent,0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof ​ comprising, wherein all of the above weight percentages are based on the total weight of the silver paste, the silver paste according to claim 1.

4. The epoxy resin is selected from the group consisting of bisphenol-A resin, bisphenol-F resin, and alicyclic epoxy resin; preferably selected from the group consisting of bisphenol-A resin and bisphenol-F resin; more preferably bisphenol-A resin, the silver paste according to claim 1.

5. The amino resin is catalyzed by benzenesulfonic acid, wherein the amino resin is preferably selected from the group consisting of urea formaldehyde resin, melamine formaldehyde resin, and polyamide polyamine epichlorohydrin; more preferably selected from the group consisting of melamine formaldehyde resin; and / or the benzenesulfonic acid is used in the form of pyridinium p-toluenesulfonate, the silver paste according to claim 1.

6. The filler mixture contains silver flakes in an amount of 2 to 35% by weight, preferably 10 to 30% by weight, more preferably 12 to 20% by weight, based on the total weight of the silver paste; and / or the filler mixture contains silver particles in an amount of 40 to 80% by weight, preferably 50 to 70% by weight, more preferably 55 to 65% by weight, based on the total weight of the silver paste; and / or the filler mixture contains zirconium hydroxide in an amount of 0.1 to 0.3% by weight, preferably 0.15 to 0.25% by weight, based on the total weight of the silver paste; and / or the silver flakes have a particle size of 5 to 8 μm; and / or the silver flakes have a tap density of 3 to 6 g / cm ３ 3, preferably 3.5 to 5 g / cm ３ 3; and / or the silver particles have a particle size of 0.2 to 5 μm, preferably 0.5 to 2 μm; and / or the silver particles have a tap density of 5.5 to 6.5 g / cm ３ 3, The silver paste according to claim 2, having a tap density of.

7. The filler mixture contains 2 to 25% by weight, preferably 3 to 10% by weight, more preferably 4 to 8% by weight of silver flakes based on the total weight of the silver paste; and / or the filler mixture contains 30 to 70% by weight, preferably 40 to 60% by weight, more preferably 45 to 55% by weight of silver particles based on the total weight of the silver paste; and / or the filler mixture contains 12 to 30% by weight, preferably 18 to 25% by weight of wear-resistant powder based on the total weight of the silver paste; and / or the filler mixture contains 0.1 to 0.3% by weight, preferably 0.15 to 0.25% by weight of zirconium hydroxide based on the total weight of the silver paste, the silver paste according to claim 3.

8. The silver flakes have a particle size of 5 to 8 μm; and / or, the silver flakes have a tap density of 3 to 6 g / cm ３ , preferably a tap density of 3.5 to 5 g / cm ３ ; and / or, the silver particles have a particle size of 0.2 to 5 μm, preferably a particle size of 0.5 to 2 μm; and / or, the silver particles have a tap density of 5.5 to 6.5 g / cm ３ ; and / or the wear-resistant powder is selected from the group consisting of silicon powder, zirconia powder, alumina powder and alloy powder, wherein the alloy powder is preferably selected from the group consisting of iron-nickel alloy powder and iron-manganese alloy powder, more preferably iron-nickel alloy powder; and / or, the alloy powder has a particle size of 4 to 8 μm, preferably a particle size of 4.5 to 7 μm, the silver paste according to claim 3.

9. The diluent is selected from the group consisting of ketones and esters; preferably selected from the group consisting of isophorone, acetylacetone, cyclohexyl acetate, ethylene glycol butyl ether acetate, and propylene glycol methyl ether acetate; and a mixture of isophorone, acetylacetone, cyclohexyl acetate, ethylene glycol butyl ether acetate, and propylene glycol methyl ether acetate, the silver paste according to claim 1.

10. 10 to 40% by weight, preferably 11 to 30% by weight, more preferably 12 to 20% by weight of at least one epoxy resin, 0.1 to 3% by weight, preferably 0.2 to 2% by weight, more preferably 0.3 to 1% by weight of at least one curing agent, which curing agent includes a low-temperature cationic curing agent or an amine or imidazole capsule curing agent, 50 to 90% by weight, preferably 60 to 88% by weight, more preferably 75 to 85% by weight of at least one filler mixture, the filler mixture comprising 45 to 89% by weight of silver flakes having a tap density of 2 to 7 g / cm ３ and 1 to 45% of silver particles having a tap density of 5 to 7 g / cm ３ ​ 1 to 20% by weight, preferably 2 to 15% by weight, more preferably 3 to 10% by weight of at least one curing accelerator, 0 to 5% by weight, preferably 0.3 to 3% by weight, more preferably 1.0 to 2.0% by weight of at least one coupling agent selected from the group consisting of silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and combinations thereof, comprising, wherein all of the above weight percentages are based on the total weight of the silver paste, the silver paste according to claim 1.

11. The epoxy resin is selected from the group consisting of bisphenol-A resin, bisphenol-F resin, and alicyclic epoxy resin; preferably selected from the group consisting of bisphenol-F resin and alicyclic epoxy resin; more preferably a combination of bisphenol-F resin and alicyclic epoxy resin, the silver paste according to claim 10.

12. The low-temperature cationic curing agent cures at a temperature of 60 to 90 °C, preferably 70 to 80 °C; and / or the low-temperature cationic curing agent is hexafluoroantimonate and / or hexafluorophosphate, preferably hexafluoroantimonate; and / or the amine or imidazole capsule curing agent is an imidazole capsule curing agent, the silver paste according to claim 10.

13. The filler mixture contains silver flakes in an amount of 50 to 85% by weight, preferably 60 to 80% by weight, more preferably 65 to 75% by weight based on the total weight of the silver paste; and / or the filler mixture contains silver particles in an amount of 2 to 35% by weight, preferably 5 to 20% by weight, more preferably 8 to 15% by weight based on the total weight of the silver paste; and / or the silver flakes have a particle size of 5 to 20 μm; and / or the silver particles have a particle size of 5 to 20 μm; and / or the silver flakes have a tap density of 3 to 6 g / cm ３ ³, preferably 3.5 to 5 g / cm ３ ³; and / or the silver particles have a tap density of 5.5 to 6.5 g / cm ３ ³, the silver paste according to claim 10

14. The curing accelerator is selected from the group consisting of oxetane, preferably (3-ethyl-3-oxetanyl)methanol, the silver paste according to claim 10.

15. Packaged separately, ・A first container containing the silver paste according to any one of claims 2, 4 to 6, and 9, ・A second container containing the silver paste according to any one of claims 3 to 5 and 7 to 9, and ・A third container containing the silver paste according to any one of claims 10 to 14 comprising, a kit of parts for manufacturing a printed antenna for an electronic device.

16. Use of a silver paste according to any of claims 10 to 14 as via fill ink for conductive connection between a surface silver paste and a touch point silver paste, preferably between a silver paste according to any of claims 2, 4 to 6, and 9 and a silver paste according to any of claims 3 to 5 and 7 to 9.

17. The following steps: i) Applying a silver paste according to any of claims 10 to 14 into the vias of the middle frame of a mobile phone with a glue dispenser, then curing at 80 to 90 °C for 0.5 to 2 hours, preferably 0.8 to 1.5 hours, more preferably about 1 hour, and leaving it for 0.5 to 2 hours to obtain a product; ii) Applying a silver paste according to any of claims 2, 4 to 6, and 9 to the product obtained in step i) three times with a pad printer, then curing this at 80 to 90 °C for 0.5 to 2 hours, preferably 0.8 to 1.5 hours, more preferably about 1 hour to obtain an Ag film having a thickness of 10 to 20 μm, preferably about 15 μm; and iii) Applying a silver paste according to any of claims 3 to 5 and 7 to 9 to the Ag film obtained in step ii) five times with a pad printer, and curing this at 80 to 90 °C for 1 to 3 hours, preferably 1.5 to 2.5 hours, more preferably about 2 hours to obtain a printed antenna circuit A method for manufacturing a printed antenna circuit, comprising:

18. The method according to claim 17, wherein the middle frame of the mobile phone is made of PC, LPA, aluminum alloy, ceramic, glass, and / or magnesium alloy.

19. A printed antenna for an electronic device obtained using a silver paste according to any of claims 1 to 14, preferably a silver paste according to any of claims 2, 4 to 6, and 9, a silver paste according to any of claims 3 to 5 and 7 to 9, and / or a silver paste according to any of claims 10 to 14, more preferably obtained using the kit of parts according to claim 15.

20. An electronic device comprising the printed antenna according to claim 19.