IC tag and manufacturing method thereof

Abstract

The invention provides an IC tag and a method for manufacturing the same, wherein an antenna can be prevented from being damaged even if the IC tag is repeatedly subjected to external force such as bending. An IC tag according to the present invention is provided with an IC chip (2), an antenna (3) for electrically connecting and receiving information stored in the IC chip (2), a sheet-like substrate (1) for supporting the IC chip (2) and the antenna (3), and a dielectric, i.e., a resin protective layer (4) for covering the IC chip (2) and the antenna (3) between the substrate (1) and the protective layer (4), in which the tensile modulus of the substrate (1) is X-axis and the tensile modulus of the protective layer (4) is Y-axis. The IC tag is disposed such that the tensile modulus [GPa] of the base material (1) and the tensile modulus [GPa] of the protective layer (4) are defined within a region surrounded by five lines represented by formulae (1), (2), (3), (4), and (5). X = 0.8... (1); x = 8... (2); y = 0.03... (3); y = X0.4... (4); y = 0.01 * X2... (5).

Description

Technical Field

[0001] The present invention relates to an IC tag and a method for manufacturing the same. Background Art

[0002] In recent years, as a type of IC tag, a structure has been proposed in which a radio communication antenna pattern and an IC chip are mounted on a substrate made of plastic or paper called an inlet. In addition, the inlet, which is encapsulated with resin, is mounted on or embedded in an object for use in the management of the object. Prior art literature Patent Literature

[0003] Patent Document 1: International Publication No. 2009 / 011041 Summary of the invention Problems to be solved by the invention

[0004] However, the IC tags described above are sometimes used in harsh environments where they are subjected to external forces such as bending, so the resin protecting the antenna may peel off or the antenna may be damaged. If the antenna is damaged, communication performance may be reduced or communication may be impossible. In particular, laundry tags used for clothes or linens need to be durable against repeated washing or drying in a dryer.

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an IC tag capable of preventing the antenna from being damaged even when subjected to repeated external forces such as bending, and a method for manufacturing the same. Means for solving problems

[0006] According to the present invention, an IC tag includes an IC chip, an antenna for electrically connecting to send and receive information stored in the IC chip, a sheet substrate supporting the IC chip and the antenna, and a resin protective layer serving as a dielectric covering the IC chip and the antenna between the substrate and the IC chip, wherein, when the tensile modulus of the substrate is taken as the X-axis and the tensile modulus of the protective layer is taken as the Y-axis, the IC tag is configured so that the tensile modulus [GPa] of the substrate and the tensile modulus [GPa] of the protective layer are limited to an area surrounded by five lines shown in the following formulas (1), (2), (3), (4), and (5). X=0.8…(1) X=8…(2) Y=0.03…(3) Y=X 0.4 …(4) Y = 0.01 × X 2 …(5)

[0007] The manufacturing method of an IC tag of the present invention includes: a step of forming an IC chip and an antenna for electrically connecting to send and receive information stored in the IC chip on a sheet-like substrate; a step of configuring a sheet-like resin material as a dielectric on the substrate in a manner covering the IC chip and the antenna; and a step of forming a protective layer along the IC chip and the antenna on the substrate by pressing the resin material while heating, wherein the substrate and the resin material are selected so that when the tensile modulus of the substrate is the X-axis and the tensile modulus of the protective layer is the Y-axis, the tensile modulus [GPa] of the substrate and the tensile modulus [GPa] of the protective layer are limited to an area surrounded by five lines shown in the following formulas (1), (2), (3), (4), and (5). X=0.8…(1) X=8…(2) Y=0.03…(3) Y=X 0.4 …(4) Y = 0.01 × X 2 …(5) Effects of the Invention

[0008] According to the IC tag and the method for manufacturing the same of the present invention, the flex resistance can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a top view showing one embodiment of the IC tag of the present invention. Figure 2 yes Figure 1 A cross-sectional view of an IC tag. Figure 3 Yes means Figure 1 A cross-sectional view of another example of an IC tag. FIG. 4 is a diagram showing a bend test of an IC tag. Figure 5 This is a graph showing the results of a bending test, with the tensile modulus of the base material as the X-axis and the tensile modulus of the protective layer as the Y-axis. DETAILED DESCRIPTION

[0010] <1. Overview of IC Tags> Hereinafter, one embodiment of the IC tag of the present invention will be described with reference to the drawings. Figure 1 is a top view of the IC tag of this embodiment. Figure 2 yes Figure 1 A cross-sectional view of Figure 1 and Figure 2As shown, the IC tag of this embodiment includes: a sheet-like substrate 1 formed into a rectangular shape, an IC chip 2 and an antenna 3 arranged on the substrate 1, and a rectangular protective layer 4 covering the IC chip 2 and the antenna 3. These components are described in detail below.

[0011] The substrate 1 is formed of a material with a tensile modulus of 0.8 GPa to 8 GPa. If the tensile modulus is 0.8 GPa to 8 GPa, the material constituting the substrate 1 is not particularly limited, and for example, the substrate 1 may be formed of a polyester resin such as polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, or a polyimide resin. In addition, the thickness of the substrate 1 is preferably, for example, 25 to 200 μm, and more preferably 50 to 150 μm.

[0012] In addition, for the sake of convenience, Figure 1 As shown, the longitudinal sides of the substrate 1 and the protective layer 4 are called the first side 101 and the second side 102, and the width sides are called the third side 103 and the fourth side 104. Therefore, these sides are connected in the order of the first side 101, the third side 103, the second side 102 and the fourth side 104.

[0013] The IC chip 2 is a well-known chip having a memory function, and is electrically connected to a dipole antenna 3 formed of a conductor.

[0014] In this embodiment, as an example, the following is used Figure 1 The dipole antenna shown in FIG. That is, the dipole antenna 3 includes: an impedance matching portion 31 arranged near the center in the longitudinal direction of the substrate 1, and a pair of dipole portions 32 extending from the impedance matching portion 31 in the longitudinal direction of the substrate 1. The impedance matching portion 31 is formed into a rectangular frame having a first side to a fourth side. In more detail, the first side 311 of the impedance matching portion 31 is arranged at a position slightly away from the first side 101 of the substrate 1, and the second side 312 is arranged along the second side 102 of the substrate 1. That is, the first side 311, the third side 313, the second side 312 and the fourth side 314 of the impedance matching portion 31 are connected in this order. Furthermore, the IC chip 2 is arranged near the center of the first side 311 of the impedance matching portion 31 or at a position slightly deviated from the center.

[0015] The dipole portion 32 has a bilaterally symmetrical shape, so only Figure 1The dipole portion 32 extends from the first side 311 of the impedance matching portion 31 to the first side 101 of the substrate 1, and extends from there along the first side 101, the third side 103, and the second side 102 of the substrate 1, and then forms a rectangular frame along the third side 313 of the impedance matching portion 31, and then extends in a spiral shape inside. In addition, the thickness of the dipole antenna 3 is not particularly limited, and can be 5 to 20 μm.

[0016] The material constituting the dipole antenna 3 is not particularly limited, and can be formed of, for example, silver, copper, or aluminum. When silver is used, the dipole antenna 3 can be formed by applying a silver paste containing silver on the substrate 1 by screen printing. On the other hand, when copper or aluminum is used, the dipole antenna 3 can be formed by etching. In addition, the IC chip 2 can be fixed to the antenna 3 by an adhesive, or fixed to the antenna 3 by a known flip chip package for electronic components. In addition, the thickness of the IC chip 2 is not particularly limited, and can be 100 to 150 μm.

[0017] By means of the dipole antenna 3 as described above, information stored in the IC chip 2 can be transmitted and received by radio waves of the UHF band, for example.

[0018] In the graph with the tensile modulus [GPa] of the substrate 1 as the X axis and the tensile modulus [GPa] of the protective layer 4 as the Y axis, the tensile modulus of the protective layer 4 is set to be above the line of Y=0.03 and Y=0.01×X 2 The area above the line, and Y = X 0.4 The value of the area below the line. In other words, when the tensile modulus [GPa] of the substrate 1 is taken as the X-axis and the tensile modulus [GPa] of the protective layer 4 is taken as the Y-axis, the tensile modulus of the substrate 1 and the tensile modulus of the protective layer 4 are limited to the area surrounded by the five lines shown in the following formulas (1), (2), (3), (4), and (5). X=0.8…(1) X=8…(2) Y=0.03…(3) Y=X 0.4 …(4) Y = 0.01 × X 2 …(5) Such a protective layer 4 is formed of a resin material serving as a dielectric. The protective layer 4 can be formed of a material having acrylic thermosetting resin, ester thermosetting resin, epoxy thermosetting resin or polyimide thermosetting resin as a main component, for example. For example, in the case of using epoxy thermosetting resin, phenolic epoxy resin (Novolac Epoxy), bisphenol epoxy resin, biphenyl epoxy resin, alicyclic epoxy resin, cyclopentadiene epoxy resin, etc. can be used. Even in the case of using other acrylic thermosetting resins, ester thermosetting resins, and polyimide thermosetting resins, there is no particular limitation, and various materials can be used. In addition, the protective layer 4 only needs to be able to cover the dipole antenna 3 and the IC chip 2, but the thickness from the substrate 1 is preferably 25 to 150 μm, and more preferably 50 to 100 μm. In addition, the tensile modulus can be measured using IPC-TM-650.

[0019] <2. Method for manufacturing IC tag> The IC tag constructed as described above can be formed by various methods, for example, by the following method. First, a dipole antenna 3 is formed on a substrate 1 by the above-mentioned screen printing or etching method. Then, the IC chip 2 is fixed to the dipole antenna 3 by the above-mentioned method. Next, a sheet of resin material is arranged on the substrate 1 to form a protective layer 4 in a manner that covers the dipole antenna 3 and the IC chip 2 in the same size as the substrate 1. Next, the resin material is pressed while being heated by a plate. As a result, the resin material is deformed along the shape of the dipole antenna 3 and the IC chip 2, and is bonded to the substrate 1 in a manner that covers the dipole antenna 3 and the IC chip 2. In this way, the IC tag is completed.

[0020] <3. Features> As described above, according to the present embodiment, the dipole antenna 3 is formed on the substrate 1 having a tensile modulus of 0.8 GPa to 8 GPa, and the IC chip 2 is fixed to the dipole antenna 3. If the tensile modulus of the substrate 1 is too small, the substrate 1 becomes too soft, and the dipole antenna 3 is easily disconnected or peeled off from the substrate 1 due to bending. Therefore, in the present embodiment, in order to prevent such disconnection or peeling of the dipole antenna 3, the tensile modulus of the substrate 1 is set to 0.8 GPa or more. On the other hand, if the tensile modulus of the substrate 1 is too large, the substrate 1 becomes too hard and is easily cracked when subjected to bending. Therefore, in the present embodiment, in order to prevent such cracking, the tensile modulus of the substrate 1 is set to 8 GPa or less. Furthermore, according to the present embodiment, in a graph with the tensile modulus [GPa] of the substrate 1 as the X-axis and the tensile modulus [GPa] of the protective layer 4 as the Y-axis, the tensile modulus [GPa] of the protective layer 4 is set to be above the line where Y=0.03, and Y=0.01×X 2 The area above the line, and Y = X0.4 It can be seen that the tensile modulus of the protective layer 4 is smaller than the tensile modulus of the substrate 1. When the tensile modulus of the protective layer 4 is less than Y=0.01×X 2 When the line is bent repeatedly, it is easy to peel off at the interface between the substrate 1 and the protective layer 4. In addition, it can be seen that the tensile modulus of the protective layer 4 is larger than the tensile modulus of the substrate 1. 0.4 In the case of a line, it is also easy to peel off at the interface between the substrate 1 and the protective layer 4 due to repeated bending. With respect to the tensile modulus of the substrate 1, the tensile modulus of the protective layer 4 is set to Y = 0.01 × X 2 Above the line and Y = X 0.4 The line is set below , thereby preventing the interface between the substrate 1 and the protective layer 4 from being peeled off due to repeated bending, and preventing the dipole antenna 3 from being damaged.

[0021] <4. Modifications> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. Furthermore, the plurality of modified examples shown below can be combined as appropriate.

[0022] <4-1> In the above embodiment, only the dipole antenna 3 and the IC chip 2 are covered with the protective layer 4, but Figure 3 As shown, a sheet-shaped cover 5 may be further provided on the protective layer 4. Such a cover 5 may be formed of the same material as the substrate 1, for example. In addition, the tensile modulus of the cover 5 is, for example, 0.8 GPa to 8 GPa, and the thickness is, for example, preferably 25 to 200 μm, and more preferably 50 to 150 μm. Here, if the tensile modulus of the cover 5 is greater than 8 GPa, it is possible to crack when bent, and if it is less than 0.8 GPa, the effect of suppressing the deformation of the protective layer 4 becomes smaller. In addition, similar to the interface between the substrate 1 and the protective layer 4, the peeling of the interface between the protective layer 4 and the cover 5 is also suppressed.

[0023] The cover 5 can be provided, for example, as follows. First, the dipole antenna 3 and the IC chip 2 are formed on the substrate 1, and the resin material for the protective layer 4 and the resin material for the cover 5 are sequentially stacked thereon. Then, the resin material for the cover 5 is pressed while being heated by a plate. Thus, heat and pressure act on the resin material for the protective layer 4, so that the resin material deforms along the shapes of the dipole antenna 3 and the IC chip 2 while being bonded to the substrate 1 in a manner covering them. Furthermore, the resin material for the cover 5 is bonded to the protective layer 4. In this way, Figure 3The IC tag shown is completed. If such a cover 5 is provided, since the protective layer 4 is covered, the stress received by the protective layer 4 during bending can be dispersed to the cover 5. As a result, the bending resistance of the IC tag can be improved.

[0024] <4-2> The shape of the dipole antenna 3 is an example, and various shapes can be used. In addition, there is no particular limitation on the position of the IC chip 2 on the antenna 3. Furthermore, various antennas can be used as the antenna 3. In addition to the dipole antenna, a patch antenna can also be used. That is, the shape of the antenna 3 is not particularly limited, and various forms can be used.

[0025] <4-3> The shape of the IC tag, i.e., the shapes of the substrate 1, the protective layer 4 and the cover 5, is not particularly limited, and in addition to the above-mentioned long-size shape, it can also be made into various shapes such as rectangular, circular, polygonal, etc. according to the purpose. In addition, the substrate 1, the protective layer 4 and the cover 5 can also be of different shapes. Example

[0026] Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples.

[0027] <1. Sample preparation> As described below, IC tags of samples 1 to 50 were prepared. Table 1 shows the material, tensile modulus, and thickness of the substrate used to make samples 1 to 50. Table 2 shows the material, tensile modulus, and thickness of the protective layer used to make samples 1 to 50. Samples 1 to 50 shown in Table 3 were prepared by changing the combination of the substrate and the protective layer. In samples 1 to 50, the size of the substrate, IC chip, and dipole antenna were the same. That is, on a 33.5 mm × 7.5 mm rectangular substrate of the material shown in Table 1, as shown in Figure 1 As shown in Table 2, a silver paste antenna with a thickness of 10 μm was formed, and an IC chip was fixed by an adhesive. Then, the antenna and the IC chip were covered with a protective layer of the material shown in Table 2.

[0028] Table 1

[0029] Table 2

[0030] Table 3

[0031] <2. Bending test> The IC tag was held at both sides in the longitudinal direction, and bent 1000 times in a manner such that the chip side became convex, as shown in FIG4(a). Furthermore, as shown in FIG4(b), the chip side was bent 1000 times in a manner such that the chip side became concave. In addition, the evaluation of no peeling between the substrate and the protective layer was A, and the evaluation of peeling between the substrate and the protective layer was B. The results are shown in Table 3.

[0032] Figure 5 This is a graph showing the bending test results with the tensile modulus [GPa] of the substrate as the X-axis and the tensile modulus [GPa] of the protective layer as the Y-axis. The X-axis represents the tensile modulus [GPa] of the substrate in logarithmic terms, and the Y-axis represents the tensile modulus [GPa] of the protective layer in logarithmic terms, and the bending test results of samples 1 to 50 are plotted. For both the case of 1000 bends on the convex side of the chip and the case of 1000 bends on the concave side of the chip, the case where no peeling occurred between the substrate and the protective layer and the evaluation was A is plotted with ○, and for the case where peeling occurred between the substrate and the protective layer and the evaluation was B in at least one of the case of 1000 bends on the convex side of the chip and the concave side of the chip, the case is plotted with ×. In the sample in which the tensile modulus [GPa] of the substrate and the tensile modulus [GPa] of the protective layer were limited to the area enclosed by the five straight lines shown in the following equations (1), (2), (3), (4), and (5), no peeling was confirmed between the substrate and the protective layer in both cases where the chip was bent 1000 times on the convex side and 1000 times on the concave side, indicating that the bending resistance when repeatedly bent was high. X=0.8…(1) X=8…(2) Y=0.03…(3) Y=X 0.4 …(4) Y = 0.01 × X 2 …(5)

[0033] The IC tag of the present invention has high bending resistance when repeatedly bent, and is therefore particularly suitable for laundry tags for clothes or linen that need to be durable against repeated washing or drying in a dryer. It is also suitable for rental mats and mops that are exposed to repeated washing or chemical treatment. Description of Reference Numerals

[0034] 1: Base material; 2: IC chip; 3: Antenna (dipole antenna); 4: Protective layer; 5: Cover.

Claims

1. An IC tag, comprising: IC chips; an antenna electrically connected to transmit and receive information stored in the IC chip; A sheet-like substrate supporting the IC chip and the antenna; as well as The resin protective layer is a dielectric layer covering the IC chip and the antenna between the resin protective layer and the substrate. Wherein, when the tensile modulus of the substrate is taken as the X-axis and the tensile modulus of the protective layer is taken as the Y-axis, the IC tag is configured so that the tensile modulus [GPa] of the substrate and the tensile modulus [GPa] of the protective layer are limited to a region surrounded by five lines represented by the following formulas (1), (2), (3), (4), and (5): X＝0.8…(1) X＝8…(2) Y＝0.03…(3) Y=X 0.4 …(4) Y=0.01×X 2 …(5)。 2. A method for manufacturing an IC tag, comprising: The step of forming an IC chip and an antenna for electrically connecting to send and receive information stored in the IC chip on a sheet-like substrate; a step of disposing a sheet-shaped resin material as a dielectric on the substrate so as to cover the IC chip and the antenna; as well as forming a protective layer along the IC chip and the antenna on the substrate by pressing the resin material while heating, The substrate and the resin material are selected so that when the tensile modulus of the substrate is the X-axis and the tensile modulus of the protective layer is the Y-axis, the tensile modulus [GPa] of the substrate and the tensile modulus [GPa] of the protective layer are limited to the area surrounded by the five lines shown in the following formulas (1), (2), (3), (4), and (5): X＝0.8…(1) X＝8 … (2) Y＝0.03 … (3) Y=X 0.4 … (4) Y=0.01×X 2 … (5)。

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