JP5070975B2 - Environmental change detection sensor, non-contact IC medium, non-contact IC medium manufacturing method, and sensing time adjustment method - Google Patents

Description

  The present invention relates to a non-contact IC medium that can be read in a non-contact manner using, for example, an induction electromagnetic field or radio wave, and in particular, a storage process of an article requiring management of a storage environment, such as food, pharmaceuticals, chemicals, and electronic parts. The present invention relates to an environmental change detection sensor that senses an environmental change during storage and is suitable for a system for confirming storage, a non-contact IC medium equipped with the environmental change detection sensor, a method for manufacturing the non-contact IC medium, and a method for adjusting a sensing time.

  In recent years, with the growing concern about the safety of foodstuffs, pharmaceuticals, etc., it is required to manage the surrounding environment during storage of goods, distribution channels, processing, and the like. A system for managing information on the surrounding environment using a non-contact IC medium that can be read in a non-contact manner using an induction electromagnetic field or a radio wave has been proposed.

  For example, a quality assurance method has been proposed in which an acceleration sensor, a temperature sensor, an impact sensor, a humidity sensor, a pressure sensor, etc. are attached to a data carrier to monitor the environmental change that the article has received in the course of physical distribution and perform quality assurance. (See Patent Document 1). In this quality assurance method, sensor detection information is converted into a digital signal by an AD converter, and data is written into an IC memory by a CPU. For this reason, the battery for operating an AD converter and a sensor is required, and there exists a problem that a data carrier becomes high-cost.

  In order to solve this problem, a non-contact communication responder having a resonance circuit (antenna circuit) set so that the resonance frequency is changed by a temperature change in the surrounding storage environment has been proposed (see Patent Document 2). . This non-contact type communication responder cuts a temperature fuse connected in series or in parallel with a resonance circuit (antenna circuit) by temperature change, and causes a capacitance component (C) or an inductance component (C) of the resonance circuit (antenna circuit). L) is changed to change the resonance frequency so that reading is not possible with a reader communicating at the original resonance frequency. Accordingly, it is said that an abnormal alarm indicating that there has been a temperature change can be detected, and temperature management of fresh food products can be easily and inexpensively performed.

  However, the non-contact type communication responder is such that when the ambient temperature rises above the control limit temperature, the thermal fuse is cut, so that the elapsed time after reaching the control limit temperature is a problem. There is a problem that it is difficult to apply to management. Further, the non-contact type communication responder has a problem that an abnormal alarm is generated even in a necessary action such as taking out from a cool box during transportation.

JP 2000-302111 A JP 2005-157485 A

  In view of the above-described problems, an object of the present invention is to provide an environmental change detection sensor and a non-contact IC medium that can detect being placed in an ambient environment exceeding a set limit for a certain period of time.

The present invention includes changing means that changes irreversibly with time when placed in a predetermined environment, and detection enabling means that makes it possible to detect that the changing means has changed beyond a predetermined state. The detection enabling means is composed of two conductors joined so as to be electrically conductive with each other, and the changing means is provided between the joints of the two conductors, and has a thickness capable of electrical conduction by the tunnel effect. An environmental change detection sensor comprising a metal oxide formed on the substrate, wherein the predetermined state is a state in which the resistance value between the two conductors is increased to a certain level due to oxidation growth of the metal oxide. It is characterized by being.

  The predetermined environment may be an environment where temperature, humidity, atmospheric gas, or a plurality of these are in a predetermined situation.

  According to the present invention, it is possible to sense that a user has been left in a predetermined environment for a certain period of time. Therefore, it is possible to appropriately perform sensing when there is no problem if it is placed in a predetermined environment for a moment and there is a problem if it is placed for a certain time or longer.

Further, by detecting metallic oxides test knowledge enabling means a state in which the resistance value has increased above a certain between two conductors grown oxide, two conductors by oxidation growth of the metal oxide An environmental change detection sensor can be realized by using the increase in resistance value between the two.

As an aspect of the present invention, at least one of the conductors can be made of aluminum, and the metal oxide can be made of aluminum oxide.
Accordingly, it is possible to detect that the aluminum substrate has been placed in an environment at a certain temperature or more for a certain period of time by using the oxidation characteristic of aluminum whose oxidation progress upper limit changes according to the ambient temperature.

  The present invention also includes an antenna circuit that performs non-contact communication and an IC that controls non-contact communication through the antenna circuit, wherein the environmental change detection sensor is connected to the antenna circuit or the IC, and the predetermined state Can be a non-contact IC medium in which the resonance frequency of the antenna circuit is changed more than a certain value due to the change of the changing means or the electrical connection of the environmental change detection sensor portion is cut off.

  Thereby, an environmental change can be sensed by a change in resonance frequency or a disconnection of electrical connection. Therefore, a non-contact IC medium with an environmental change detection function can be manufactured at low cost.

In addition, the present invention can be a non-contact IC medium manufacturing method in which a small-sized substrate on which the environmental change detection sensor and the IC are mounted is mounted on an antenna substrate having an antenna.
Thereby, a non-contact IC medium can be manufactured efficiently.

The present invention can also be a sensing time adjustment method in which at least one conductor in the environmental change detection sensor is processed into a predetermined perforated shape to control the change rate of the metal oxide.
Thereby, sensing time can be easily adjusted according to the environmental conditions to sense.

  According to the present invention, it is possible to provide an environment change detection sensor and a non-contact IC medium that can detect that the device has been placed in an ambient environment exceeding a set limit for a certain period of time.

  An embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view of the IC tag 1 and FIG. 2 is a longitudinal sectional view of the vicinity of the environment change detection sensor 20.

  The IC tag 1 shown in FIG. 1 is an RF-ID tag that performs non-contact communication using 13.56 MHz as a communication frequency. The IC tag 1 has a structure in which a module 30 having a strap substrate 12 on which an IC 11 (pair chip IC 11) is mounted and a terminal portion 15 of a wound coil 14 formed on a resin base material 13 are mechanically fastened. It is. The strap substrate 12 of the module 30 is provided with an environmental change detection sensor 20 whose resistance value increases with time in a limit environment.

  The resin base material 13 is formed in a substantially rectangular shape by a PET (polyethylene terephthalate) film having a thickness of 38 μm.

  The winding coil 14 is a conductor pattern formed in a spiral shape by etching Cu (copper) having a thickness of 9 μm or Al (aluminum) having a thickness of 15 μm.

  A wiring circuit 21a to which one end portion 15a of the winding coil 14 is connected to the strap substrate 12, a wiring circuit 21c to which the other end portion 15c of the winding coil 14 is connected, and the wiring circuit 21a and the wiring circuit 21c. A wiring circuit 21b is provided. One terminal of the IC 11 is connected to the wiring circuit 21a, and the other terminal of the IC 11 is connected to the wiring circuit 21b. Further, the wiring circuit 21b and the wiring circuit 21c are connected by the environment change detection sensor 20. Accordingly, one end portion 15a and the other end portion 15c of the winding coil 14 are connected in this order by the wiring circuit 21a, the IC 11, the wiring circuit 21b, the environment change detection sensor 20, and the wiring circuit 21c. Therefore, the environmental change detection sensor 20 of this embodiment is connected in series.

The wiring circuit 21 (21a, 21b, 21c) is composed of a 35 μm aluminum wiring circuit.
The environmental change detection sensor 20 includes a conductor circuit 22 formed by printing silver ink on the wiring circuit 21, wiring circuits 21 b and 21 c connected to the conductor circuit 22, and the conductor circuit 22 and the wiring. It is comprised by the oxide 23 between the connection parts with the circuits 21b and 21c.

The strap substrate 12 is a small resin substrate on which the IC 11 is mounted. In this embodiment, the strap substrate 12 is composed of a 25 μm PET film substrate.
The module 30 configured in this manner has a structure in which both end portions 15 of the winding coil 14 are connected in such a manner as to straddle the winding coil 14.
Note that an oxide 23 (oxide film) of aluminum exists between the connection portions of the conductor circuit 22 and the wiring circuit 21. For this reason, there is a contact resistance 24 caused by the oxide 23 layer between the two conductor circuit 22 and the wiring circuit 21. The contact resistance 24 changes to a high resistance value as the oxide 23 grows due to temperature, moisture in the atmosphere, and oxidizing gas.

3 and 4 are explanatory views showing the manufacturing process of the IC tag 1.
First, the manufacturing process of the module 30 will be described with reference to FIG.

(Process A)
An Al-PET laminate in which an aluminum foil 31 with a thickness of 35 μm is bonded onto a strap substrate 12 that is a heat-resistant PET film with a thickness of 25 μm is prepared.

(Process B)
Next, a resist mask 32 is printed and formed on the aluminum foil 31 on the laminated material in a required pattern circuit shape.

(Process C)
The wiring circuit 21 (21a, 21b, 21c) is created using an etching method that is a known technique.

(Process D)
Next, the resist mask 32 used in the etching process is peeled off, and the exposed aluminum oxide film on the surface of the wiring circuit 21 is removed. The removal at this time is preferably performed by chemical treatment with alkali or acid in terms of productivity, and is performed by immersing in a sodium hydroxide solution having a concentration of 5% and a temperature of about 50 ° C.

(Process E)
Next, the conductor circuit 22 is formed on the wiring circuits 21b and 21c in such a form as to connect the wiring circuits 21b and 21c (see FIG. 1). This conductor circuit 22 is a method in which conductive ink made of conductive particles such as silver or carbon, a binder such as epoxy resin, and a solvent such as isophorone is printed by screen printing or the like, and heated and dried at 150 ° C. for about 10 minutes. Form.

By the heating and drying process at this time, a few angstroms of aluminum oxide 23 is formed between the conductor circuit 22 and the aluminum wiring circuits 21b and 21c in such a manner as to alienate the contact between the conductor circuit 22 and the wiring circuits 21b and 21c. Is done. The aluminum oxide 23 is an insulator. Normally, when the oxide 23 is several angstroms thick, electricity flows due to a tunnel effect in which electrons pass through a thin insulator. In this step, the conductive ink applied to the surface blocks oxygen from the outside air and the surfaces of the wiring circuits 21b and 21c, so that the growth of the oxide 23 can be suppressed to several angstroms.
Furthermore, the conductor circuit 22 formed at this time is configured as a layer in which the solvent constituting the ink is evaporated by heating and drying, and a large number of pores are interposed therein. For this reason, the oxide 23 grows by being left for a long time at a high temperature or a high humidity with a high oxygen concentration later, and when it has a thickness of several tens of angstroms (several nm), the tunnel effect disappears and becomes an insulator. To do. Since this insulation does not occur at the same time for the entire electrode, but occurs partially, the electrical resistance value between the conductor circuit 22 and the wiring circuits 21b and 21c increases.

(Process F)
A polyolefin-based or polyethylene-based thermoplastic adhesive 33 is applied on the electrodes (on the wiring circuits 21a, 21b) on which the IC 11 is mounted. This application can be applied only to the place where the IC 11 is mounted using a screen printing method or the like, but it may be applied to the entire surface of the substrate using a roll coater or the like with good productivity.
However, applying the thermoplastic adhesive 33 on the conductor circuit 22 suppresses the growth of the oxide 23. For this reason, when applying the thermoplastic adhesive 33 on the conductor circuit 22, it is necessary to consider that the increase rate of an electrical resistance value becomes slow.

(Process G)
Finally, the IC 11 is placed on the thermoplastic adhesive 33 in the previous step and mounted on the wiring circuit using a known method proposed in Japanese Patent Laid-Open No. 2001-156110.
That is, the IC 11 is configured as a so-called surface-mounted component in which a connection electrode (Bump) 11a is protruded from the bottom surface. Ultrasonic vibration is applied to the gold connection electrode 11a protruding from the bottom of the IC 11, the adhesive on the surfaces of the wiring circuits 21a and 21b is mechanically removed by vibration, and further heated by frictional heat due to vibration to melt the metal. Bonding is generated and bonding is performed.

  This mounting method is performed by placing the IC at a predetermined position and then applying ultrasonic vibration with a vibration frequency of 40 KHz for about several seconds under a load pressure of 0.2 kg / mm 2.

However, as a mounting method of the IC 11, a conventionally known ACF (anisotropic conductive paste) or a method using a conductive adhesive can be used.
In addition, you may use heat resistant base materials, such as a polyimide film, a PEN, and a PPS film, as the strap board | substrate 12 used by the present Example.

  Next, the process of connecting the module 30 produced by the above process to the wound coil 14 formed on the resin base material 13 by using the method proposed in Japanese Patent Laid-Open No. 2001-156110 according to FIG. explain.

(Process I)
First, a Cu-PET laminated base material is prepared. As an example, 10 μm-thick Cu (copper) is layered on one side of a resin base material 13 composed of a 38 μm-thick PET film via a urethane adhesive, and this is heated under conditions of 150 ° C. and a pressure of 5 kg / cm 2. Lamination is used for lamination. Thereby, the Cu-PET laminated material in which the Cu foil 51 is bonded to the surface of the resin base material 13 is completed.

(Step J) Next, a coil-shaped etching resist pattern 52 is formed on the surface of the Cu foil 51 of the laminated material. That is, an insulating etching resist ink is applied to the Cu foil 51 by using, for example, a gravure printing method in a coil shape having the number of turns, line width, pitch, and inner and outer circumferences to obtain the L value and Q value necessary as the coil characteristics. Print on top.
As the resist ink at this time, a resist ink that is cured by heat or active energy rays is used. As the active energy ray, ultraviolet rays or electron beams are used. When ultraviolet rays are used, a photopolymerization agent is added to the resist ink.

(Process K)
The portion of the Cu foil 51 exposed from the etching resist pattern 52 formed by the above process is removed by performing a conventionally known etching to form the wound coil 14 that is a spiral conductor pattern. This winding coil 14 functions as an antenna of the IC tag 1.

(Process L)
Next, the wiring circuits 21 a and 21 c of the module 30 are arranged so as to overlap the terminal end 15 that is the connecting end of the winding coil 14. Then, the indenter 53 is pressed for about 0.5 seconds from the upper part of the wiring circuits 21a and 21c of the module 30 while applying an ultrasonic vibration 54 having a load pressure of 0.2 kg / mm 2 and a frequency of 40 kHz. The circuit 21 and the winding coil 14 are connected.

  In this embodiment, the mounting method of the module 30 by the ultrasonic bonding method is exemplified in this step. However, this may be performed by using anisotropic conductive paste, solder, conductive paste or the like.

  When the IC tag 1 manufactured by the above steps is left in an atmosphere having a set limit temperature or a limit humidity or higher, the oxide 23 in the environment change detection sensor 20 grows, and the conductor circuit 22 and the wiring are connected. The connection resistance between the circuits 21 increases. If left in the atmosphere for a certain time or more, the oxide 23 grows more than a certain value, and the resonance frequency changes due to the increase in the resistance value, or the electrical connection between the IC 11 and the winding coil 14 is broken. The IC tag 1 becomes inoperable. Therefore, when data is to be read from the IC tag 1 by a separate reader device, it cannot be read due to a change in resonance frequency or inability to operate, so that a certain time or more in an atmosphere at or above the limit temperature or humidity. It can be detected that it was left unattended.

  Therefore, for example, the IC tag 1 that can perform sensing suitable when the temperature of the food product is controlled so as not to spoil can be provided at a low cost. More specifically, foodstuffs rot when left in an environment at a certain temperature or higher for a certain period of time, but do not rot when left in an atmosphere at a temperature above a certain temperature for a short period of time. For this reason, it is necessary not only to detect whether or not it is placed in an atmosphere at a certain temperature or higher, but also to detect that it has been left in the atmosphere at or above the certain temperature for a certain period of time. The IC tag 1 described above can detect that the IC tag 1 has been left in the atmosphere at a certain temperature or more for a certain time.

  With the IC tag 1 described above, it is possible to detect an abnormal alarm of an environmental change by changing the resonance frequency of the IC tag 1 by a change in the resistance value of the environmental change detection sensor 20. That is, since the oxide 23 that grows irreversibly depending on the relationship between the ambient temperature and the standing time is used for sensing, the resistance value of the environmental change detection sensor 20 indicates that it has been left for a certain period of time in a predetermined constant atmosphere. It can be detected when the resonance frequency has risen above a certain level and the resonance frequency has changed above a certain level or has been disconnected.

Therefore, it is possible to sense whether or not an article such as a food product that is important not only in the atmosphere but also in the leaving time is appropriately managed.
In addition, since it is not necessary to add an electronic device such as a memory for storing that it has been placed in a certain atmosphere for a certain period of time as in the prior art, it can be manufactured at a very low cost.

In addition, since the oxide 23 grows with the passage of time in a state where it is left in a state beyond the limit environment, it is possible to perform sensing by adding the stand-by time to the environmental value.
In addition, the growth of the oxide 23 differs depending not only on temperature and time but also on humidity and ambient atmosphere gas, so that the surrounding abnormal environment that causes metal corrosion, food rot, etc. Can be judged by indicators.

In addition, since the oxide 23 grows with the passage of time even in a normal environment such as room temperature, it can be used as a time passage sensor when the article is stored for a long time.
Further, the environmental change detection sensor 20 according to the present invention can be manufactured at a low cost because it can be manufactured with a simple structure in which the conductor circuit 22 is printed on the wiring circuit 21 and a simple manufacturing method. can do.

  Further, the IC tag 1 has a structure in which a component mounting module (hereinafter referred to as a module) 30 is mounted on the surface of the substrate 13 so as to straddle the antenna circuit 14, so that it is not necessary to separately provide a jumper and can be manufactured at low cost.

  In addition, when the environmental change detection sensor 20 that requires high-temperature heat treatment for circuit printing is formed on an expensive heat-resistant material, it is possible to reduce the necessary use area of the strap substrate 12.

The degree of increase in the electrical resistance value can be adjusted by changing the volume of the pores depending on the material of the resin binder in the conductor circuit 22 and the particle diameter of the conductive particles.
For the conductor circuit 22, as shown in FIG. 5, the connecting portions 22b and 22c connected to the wiring circuits 21b and 21c have a comb shape as shown in the connecting portion 22b, or as shown in the connecting portion 22c. Alternatively, the conductor circuit 22a may be formed in a mesh shape. Thereby, the growth rate of the oxide 23 of the environmental change detection sensor 20a is increased, and the time until the electrical resistance value is increased can be adjusted. In the illustration of FIG. 5, the connection portions 22b and 22c are provided with one mesh shape and one comb shape, but both the connection portions 22b and 22c have the same mesh shape, or both have the same comb shape. It is preferable to do. Thereby, the growth rate of the oxide 23 can be easily adjusted in accordance with a certain time to be detected.

  In the first embodiment, the structural example of the IC tag 1 is described in which the module 30 on which the IC 11 is mounted is mounted so as to straddle the wound winding coil 14 formed on the resin base material 13. As shown in FIG. 6, it can also be used for an IC tag 60 having a structure in which the IC 11 is directly mounted on a winding coil 64 as an antenna.

  In this case, the environmental change detection sensor 20 is preferably formed on the resin base 63. Further, in order to dispose both ends of the winding coil 64 at a position where the IC 11 can be mounted, a jumper wire 62 for straddling the winding coil 64 may be provided.

Also in this case, the same effects as those of the first embodiment can be obtained.
In addition, since the area of the base material which forms the environment change detection sensor 20 only needs to be small compared with Example 2, Example 1 can suppress base material cost.

  Moreover, in each above embodiment, although the environmental change detection sensor 20 was connected in series, you may connect in parallel. In this case, it can be detected that the device has been left in a certain environment for a certain period of time.

In correspondence between the configuration of the present invention and the above-described embodiment,
The non-contact IC medium of the present invention corresponds to the IC tag 1 of the embodiment,
Similarly,
IC corresponds to IC11,
The antenna substrate corresponds to the resin base materials 13 and 63,
The antenna and antenna circuit correspond to the winding coils 14 and 64,
The detection enabling means and the two conductors correspond to the wiring circuit 21 and the conductor circuits 22 and 22a,
The changing means, metal oxide, and aluminum oxide correspond to oxide 23,
The predetermined state corresponds to a state in which the oxide 23 has grown to a certain level or more,
The small board corresponds to the module 30, 30a,
The predetermined perforated shape corresponds to a mesh shape or a comb shape,
The present invention is not limited only to the configuration of the above-described embodiment, and many embodiments can be obtained.

The top view of an IC tag. The longitudinal cross-sectional view around an environmental change detection sensor. Explanatory drawing which shows the manufacturing process of an IC tag. Explanatory drawing of the process of connecting a module to the winding coil on resin-made base materials. The top view of the module provided with the conductor circuit of the other example. FIG. 6 is a plan view of an IC tag according to Embodiment 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... IC tag, 11 ... IC, 13, 63 ... Resin base material, 14, 64 ... Winding coil, 20 ... Environmental change detection sensor, 21 ... Wiring circuit, 22, 22a ... Conductor circuit, 23 ... Oxide, 30, 30a ... module

Claims (5)

Change means that changes irreversibly over time when placed in a predetermined environment;
Detection enabling means for making it possible to detect that the changing means has changed beyond a predetermined state ,
The detection enabling means comprises two conductors joined so as to be electrically conductive with each other,
The changing means is provided between the joint portions of the two conductors, and is composed of a metal oxide formed to a thickness capable of electrical conduction by a tunnel effect,
The environmental change detection sensor , wherein the predetermined state is a state in which the resistance value between the two conductors is increased to a certain level or more due to oxidation growth of the metal oxide . At least one of the conductors is made of aluminum;
The metal oxide environment change detection sensor according to claim 1, wherein constructed in aluminum oxide. An antenna circuit for non-contact communication;
An IC for controlling non-contact communication through the antenna circuit,
The environment change detection sensor according to claim 1 or 2 is connected to the antenna circuit or the IC,
A non-contact IC medium in which the predetermined state is a state in which a resonance frequency of the antenna circuit is changed by a predetermined value or a state in which the environmental change detection sensor portion is disconnected due to a change of the changing means. On the antenna board with the antenna,
A non-contact IC medium manufacturing method for mounting an environmental change detection sensor according to claim 1 or 2 and a small substrate on which an IC is mounted which is smaller than the antenna substrate. A method for adjusting a sensing time in which at least one conductor in the environmental change detection sensor according to claim 1 is processed into a predetermined perforated shape to control a change rate of the metal oxide.

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