RFID sensing and recording device and method for making the same

The present invention provides a radio frequency identification and sensing device comprising an antenna module, a RFID sensing module, and battery module. The antenna module has a first flexible substrate having an antenna circuit formed thereon. The RFID sensing module comprises a second flexible substrate, a RFID chip, a sensor formed on the second flexible substrate and a memory module formed on the second flexible substrate, wherein the sensor is utilized to detecting an environmental status for generating a plurality of sensing data, and the memory module is utilized to store the plurality of sensing data. The RFID chip is utilized to transfer the plurality of data to a reading device. The battery module is utilized to provide electrical power for operating the RFID sensing module.

This application claims the benefit of Taiwan Patent Application Serial No. 105142042, filed Dec. 19, 2016, the subject matter of which is incorporated herein by reference.

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention is related to a radio frequency identification technique, and more particularly, to a RFID sensing and recording device having electric power supply capability and formed by connecting the antenna module to circuit substrate through conductive adhesives and pressing process.

2. Description of the Prior Art

Radio frequency identification (RFID) is a wireless communication technology that is an integration of wireless information process technology, read/write module, and RFID device. The RFID device comprises a chip circuit and antenna coil so that contactless reading and/or writing of data to the RFID device through RFID reader can be performed to acquired the information stored in the RFID device. The acquired information can be processed, utilized and applied in various kinds of electrical application such as door access control, and vehicle immobilizer system, for example.

For the past few years, the portable electronic devices, such as smart portable devices and IC card are popular to the public so that the need of radio frequency technology integration is gradually increased. In one application, the RFID device further comprises a substrate module having RFID chipset and passive components, and an antenna module having antenna coil designed according to the frequency range and material.

In addition, the solutions integrating the RFID tag with power supply are also increased with the requirement of product applications. For example, the smart home with intelligent living, transportation, logistics, and medical care in the Internet of Things (IoT) require big data collection, this requirement can be efficiently solved through a combination of RFID tag, sensor and power supply. However, when these components are combined together, the thickness of the combined device will be increased. Accordingly, how to provide a solution that can have thin and light device with the abovementioned components becomes a more important issue in the development of RFID technology.

Conventionally, the substrate module and antenna module are electrically bonded through a reflow process. In order to prevent the substrate module and antenna module from heat damage during the reflow process, the substrate of the substrate module is necessary to be made of the material with high temperature resistant capability. However, such kind of material will increase the cost of making the RFID device, the bulk volume and thickness dimension.

Accordingly, there has a need to provide a radio frequency identification device with sensing, recording, and power supplying capabilities and corresponding manufacturing method to solve the problem of the conventional arts.

SUMMARY OF THE INVENTION

The present invention provides a RFID sensing and recording device, comprising a RFID sensing module having a flexible substrate on which a RFID tag, sensor and storage module are arranged, a battery module for providing electric power, and a flexible antenna module. With the supply of the electric power, integration of sensing and storing capability, the RFID sensing and recording device of the present invention can be applied in various kinds of fields such as internet of things, interface of human-computer interaction, smart living, smart logistics, and medical care.

The present invention provides a method for making RFID sensing and recording device, wherein a flexible antenna module is electrically bonded with a RFID sensing module having RFID chip and passive elements through adhesives and pressing procedure, whereby a reflow process can be eliminated thereby reducing the manufacturing cost, and the RFID sensing and recording device is enabled to become thinner and lighter thereby reducing the weight of the RFID sensing and recording device.

The present invention provides method for making RFID sensing and recording device, wherein the area between electric pads formed on the substrate of the antenna module does not have antenna coil passing therethrough so that the circuit layout of the electrical connection between the substrate module and antenna module can be simplified thereby simplifying the manufacturing process of electrical connection between the substrate module and antenna module.

In one embodiment, a RFID sensing and recording device comprises an antenna module, a RFID sensing module, and a battery module. The antenna module comprises a first flexible substrate, an antenna circuit formed on the first flexible substrate, and a first electric pad and a second electric pad formed on a first surface of the flexible substrate, wherein the first and second electric pads are electrically coupled to the antenna circuit. The RFID sensing module comprises a second flexible substrate, and a pair of third electric pads, a RFID chip, a sensor, and a storage module respectively formed on the second flexible substrate, wherein the pair of third electric pads are electrically coupled to the first and second electric pads, respectively, the sensor is utilized to detect a status information and generate a plurality of status data corresponding to the status information, and the storage module is electrically coupled to the sensor and RFID chip for storing the plurality of status data. The battery module is electrically coupled to the RFID sensing module for providing electric power to the RFID sensing module.

In another embodiment, a method for making a RFID sensing and recording device, comprising steps of providing an antenna module which comprises a first flexible substrate, an antenna circuit formed on the first flexible substrate, and a first electric pad and a second electric pad formed on a first surface of the first flexible substrate, wherein the first and second electric pads are electrically coupled to the antenna circuit, providing a RFID sensing module, comprising a second flexible substrate, and a pair of third electric pads, a RFID chip, a sensor, a pair of electrodes, and a storage module respectively formed on the second flexible substrate, wherein the pair of third electric pads are electrically coupled to the first and second electric pads, respectively, the sensor is utilized to detect a status information and generate a plurality of status data corresponding to the status information, and the storage module is electrically coupled to the sensor and RFID chip for storing the plurality of status data, forming a first conductive adhesive on the first and second electric pads or the pair of third electric pads, electrically connecting the pair of third electric pads to the first and second electric pads, and electrically connecting a battery module to the RFID sensing module.

All these objects achieved by the RFID sensing and recording device and method for making such kind device are described below.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention disclosed herein is directed to a RFID sensing and recording device and method for making the same. In the following description, numerous details are set forth in order to provide a thorough understanding of the present invention. It will be appreciated by one skilled in the art that variations of these specific details are possible while still achieving the results of the present invention. In other instance, well-known components are not described in detail in order not to unnecessarily obscure the present invention.

Please refer toFIG. 1, which illustrates a structure of the radio frequency identification (RFID) device according to the one embodiment of the present invention. The RFID device2comprises an antenna module20, a RFID sensing module22, and a battery module5. The antenna module20comprises a flexible substrate200and an antenna circuit201for receiving high frequency (HF) signal, such as 11-16 MHz, or ultra high frequency (UHF) signal, such as 800-1000 MHz.

The antenna circuit201is formed on surface of the flexible substrate200. In one embodiment, the antenna circuit201has a first antenna202formed on a first surface203of the flexible substrate200. The first antenna202has a specific circuit pattern. In the present embodiment, the pattern is a multi-turn pattern but it is not limited thereto. In one alternative embodiment, the first antenna202has a hollow pattern with a specific shape. This hollow pattern is formed by etching a metal layer formed on the flexible substrate200. InFIGS. 1 and 2A, one end of the first antenna202has a first electric pad204while the other end of the first antenna202is connected to a first relay pad205. The first electric pad204and the first relay pad205can be made of metal material, such as aluminum or copper, for example. The first relay pad205is coupled to a relay circuit206.

In the embodiment shown inFIGS. 1 and 2A, the relay circuit206is formed on a second surface207opposite to the first surface203. The first pad205is electrically connected to a second relay pad208coupled to one end of the relay circuit206through a crimping process. Likewise, the second relay pad208is made of metal material, e.g., copper and aluminum. In one embodiment, the crimping process is operated by press molding wherein a plurality of areas of the first relay pad205are pressed to deform by the mold wherein the deformed metal penetrates through the flexible substrate200and are electrically connected to the second relay pad208. After the crimping process, a plural recess structures corresponding to the plurality of areas209of the first relay pad205are formed.

Likewise, the other end of the relay circuit206is connected to a third relay pad210which is made of electrically conductive metal such as aluminum or copper, for example. The fourth relay pad217is crimped to connect to the third relay pad210formed on the second surface207. In one embodiment, the crimping process is performed by press molding, e.g., hot press molding, such that a plurality of areas212of the fourth relay pad217are pressed to penetrate through the flexible substrate200and are electrically connected to the third relay pad210. After the crimping process, a plurality of recess structures respectively corresponding to the plurality of areas212of the fourth relay pad217are formed. The fourth relay pad217is electrically coupled to the second electric pad211through an antenna segment218.

In addition, it is noted that the pattern design of the antenna circuit201is determined according to the actual need and it is to be understood that the invention is not limited to the specific embodiments shown inFIG. 2A. For example, please refer toFIG. 2B, which illustrates elliptical shape antenna202formed on a surface of the substrate200a. The substrate200acan be, but should not be limited to, a flexible substrate. The substrate200ahas a first electric pad204aand a second electric pad211aelectrically connected to electrical connecting terminals226and227of the RFID sensing module22, respectively. The RFID sensing module22is a chip on board (COB) module having integrated circuit (IC) chip221a, such as RFID chip, and electrical components222, such as passive components, detecting sensors, and/or a storage module, formed on the RFID sensing module22. The passive components can be, but should not be limited to, resistor, capacitor, inductor, or a combination thereof while the detecting sensor can be, but should not be limited to, a temperature sensor or humidity sensor. One end of antenna202is electrically connected to the first electric pad204awhile the other end of antenna202is connected to an electrical terminal215b. The second electrical connecting pad211ais electrically connected to the electrical terminal215athrough an antenna segment214. The electrical terminals215aand215bpenetrate through the substrate200aand are crimped or coupled to each other through a conductive wire216.

It is noted that although the embodiments shown inFIGS. 1 and 2Aillustrate that the crimping process is performed by crimping the first relay pad205to the second relay pad208as well as crimping the fourth relay pad217to the third relay pad210, in an alternative embodiment, it is possible to perform the crimping process by crimping the second relay pad208to the first relay pad206and crimping the third relay pad210to the fourth relay pad217whereby the recess structures of the area209and212respectively shown inFIGS. 1 and 2Awill be formed on the surface of first relay pad205and fourth relay pad217. The crimping process can be performed according to the actual need of the manufacture and can be varied by the one having ordinary skilled in the art according to the actual requirement so that it is to be understood that the invention is not limited to the specific embodiments shown inFIGS. 1 and 2A.

Through the layout design of the antenna circuit shown inFIGS. 1 and 2A, the first and second electric pads204and211of the antenna circuit201can be arranged closely or concentrated in the same area. That is, the antenna circuit201does not pass through the area between the first and second electric pads204and211so that the problem of accidental electrical short circuit with the antenna circuit can be prevented in the subsequent manufacturing process where the substrate module21is electrically coupled to the antenna module20whereby the manufacturing process of bonding the substrate module21and antenna module20can be simplified.

Referring back toFIGS. 1 and 2A, the RFID sensing module22comprises a substrate220, RFID chip221, and at least one passive component222a, sensor222b, and a storage module222c. The substrate220can be a rigid substrate or flexible substrate. The RFID sensing module22is a COB substrate module or FPC module. In the present embodiment, the RFID sensing module22is a FPC module wherein the substrate220is a flexible substrate. The RFID chip221is coupled to the substrate220. The at least one passive component222ais electrically coupled to the substrate220and electrically coupled to the RFID chip221. The passive component222acan be a capacitor, resistor, inductor, or any combination thereof. The user can select appropriate components and arrange those selected components on the substrate220according to the requirement and characteristics of electrical circuit. The RFID chip221can be active RFID chip or passive RFID chip.

The sensor222b, in the present embodiment, can be, but should not be limited to, a temperature sensor, humidity sensor, atmospheric pressure sensor, or gas sensor. The sensor222bis arranged on the substrate220and is electrically coupled to the storage module222c, for transmitting the sensing data to the storage module222cso that the storage module222ccan store the sensing data. In another embodiment, the sensor222bcan be an accelerometer, orientation sensor, magnetometer, for detecting the acceleration information, position information or orientation information. The sensor222b, in the present embodiment, is utilized to detect a status information and generate a plurality of data with respect to the status information. In one embodiment, the status information is environmental information such as temperature, humidity, and/or atmospheric pressure. Alternatively, the status information can also be a motion information such as acceleration or velocity, and/or orientation information. The storage module222cis arranged on the substrate220and is electrically coupled to the RFID chip221, and sensor222bfor storing the plurality of data generated by the sensor222b.

The substrate220further comprises a pair of third electric pads223and224respectively coupled to the first and second electric pads204and211. In the present embodiment, conducive adhesives24is arranged between the first electric pad204and one of third electric pads223, and between the second electric pad211and the other one of the third electric pads224. The first and second electric pads204and211are electrically coupled to the pair of third electric pads223and224through a hot pressing process. It is noted that the way for electrically coupling the electric pads is not limited to the hot press. In addition, the conductive adhesives can be, but should not be limited to, a moisture curing conductive adhesive, UV curing conductive adhesive, heat curing conductive adhesive, or conductive pressure-sensitive adhesives.

In addition, the substrate220further comprises an electrical connector225. In the present embodiment, the electric connector225is a pair of electrodes electrically coupled to positive and negative electrodes of the battery module5. The batter module5, in one embodiment, is a thin film battery module for providing electric power required by the RFID sensing module22. In the present embodiment, the electric connector225is electrically coupled to the battery module5through conductive adhesives and a hot pressing process. It is noted that the way for electrically coupling the electric pads is not limited to the hot press. In addition, the conductive adhesives can be, but should not be limited to, a moisture curing conductive adhesive, UV curing conductive adhesive, heat curing conductive adhesive, or conductive pressure-sensitive adhesives.

The battery module5, RFID sensing module22, and antenna module20can be integrated into a single package so as to become an application device3that can be arranged or stuck on the product for monitoring the status of the product. In one embodiment, the application device3can be an environmental monitoring device which can be arranged in outdoor or indoor for monitoring environmental information of the environment. In one embodiment, the environmental information can be temperature, humidity, and/or Atmospheric particulate matter. The data generated by the sensor222bof the RFID sensing module22can be stored in the storage module222cof the RFID sensing module22. The data stored in the storage module222ccan be access through a reading device4. In addition, the application device3can be stuck on a food product for detecting and recording environmental status such as temperature or humidity, for example. Alternatively, the sensor in the application device3can be accelerometer or a combination of accelerometer and orientation sensor. Accordingly, when the application device3is arranged on the product, the application device3can detect acceleration and orientation with respect to the product. The data of acceleration and orientation can be utilized to reconstruct a motion status or a trace with respect to the product.

Next, a method for making the RFID sensing and recording device is explained below. Please refer toFIG. 3A, the present embodiment, the method comprising steps described below. Firstly, an antenna module20is formed. The antenna module20comprises a flexible substrate200having an antenna circuit201formed thereon. In the present embodiment, the thickness of the flexible substrate200is 20-500 μm. It is noted that the antenna circuit201can be formed on single side or double sides of the flexible substrate200.

Next a method for making the antenna circuit is explained. In one embodiment, taking the antenna circuit shown inFIG. 1as an example, a metal layer is respectively formed on the first surface203and the second surface207of the flexible substrate200. The metal layer can be aluminum foil layer or copper foil layer. Next, a metal etching process, such as aluminum etching or copper etching according to the material of the metal layer, is adapted for etching the metal layer thereby forming the first antenna202of the antenna circuit201, the first electric pad204and the second electric pad211, and the first relay pad205and fourth relay pad217respectively coupled to the first antenna202on the first surface203, and forming the relay circuit206, the second relay pad208and the third relay pad210on the second surface207. It is noted that although the antenna in the present embodiment is a loop type antenna, alternatively, the antenna can be a hollow structure with specific shape formed by metal etching process. After that, a crimping process is utilized to electrically connect the first relay pad205to the second relay pad208, and electrically connect the fourth relay pad217to the third relay pad210.

Since the first antenna202is a multi-turn coil like the pattern shown inFIG. 1, the first and second electric pads204and211can be closely arranged at the same area. That is, there has no antenna circuit passing through the area between the first and second electrical connecting pads204and211so as to simplify circuit layout design of the substrate module whereby short circuit with the antenna circuit in the subsequent manufacturing process can be efficiently prevented. In addition, the crimping process is performed by using a press molding wherein a plurality of areas of the first relay pad205are pressed to deform by the mold so that the deformed metal penetrates through the flexible substrate200and are electrically connected to the second relay pad208, and a plurality of areas of the fourth relay pad217are pressed to deform by the mold so that the deformed metal penetrates through the flexible substrate200and are electrically connected to the third relay pad210.

Please refer toFIG. 3B, after the step of providing antenna module20, a RFID sending module22is provided. The RFID sensing module22comprises a substrate220having a pair of third electric pads223, and224, a RFID chip220, at least one passive elements222a, at least one sensor222b, and a storage module222cwhereby the RFID sensing module22has capability of detection and storing data corresponding to the detection. In one embodiment, the substrate220is a flexible substrate. In alternative embodiment, the substrate220can also be a rigid type substrate, such as printed circuit board (PCB).

Next, please refer toFIG. 3C, a conductive adhesive24is formed on the first and second electrical connecting pads204and211. In the present embodiment, the conductive adhesive24is electrically conductive adhesive that can be utilized in the hot pressing process. The conductive adhesive24can be, but should not limited to, anisotropic conductive film (ACF), anisotropic conductive paste (ACP), or anisotropic conductive adhesive (ACA) or solder anisotropic conductive paste (SACP). In one embodiment, the amount of the conductive adhesive24is less than or equal to 1 mg. In addition, the conductive adhesives24can be, but should not be limited to, a moisture curing conductive adhesive, UV curing conductive adhesive, heat curing conductive adhesive, or conductive pressure-sensitive adhesives.

Next, please refer toFIG. 3D, the pair of third electric pads223and224of RFID sensing module22is respectively electrically coupled to the first and second electric pads204and211of antenna module20through a hot pressing process. In one embodiment, the temperature for operating the hot pressing process is lower than or equal to 200° C., and the pressing time is less than or equal to 20 seconds. After the hot pressing process, the RFID sensing module22and antenna module20is bonded as the structure shown inFIG. 3E. The apparatus for hot pressing process which is well known by the one having ordinary skilled in the art will not be described hereinafter. It is noted that, the conductive adhesive24can also be coated on the third pair of the electric pads223and224. After that, the first and second electric pads204and211are pressed to electrically connect to the third pair of electric pads223and224, respectively.

After connecting the antenna module20to the RFID sensing module22, referring to theFIG. 3F, a battery module5is coupled to the RFID sensing module22. In the present step, conductive adhesive27is coated on the electric connector25on the RFID sensing module22or coated on the electrodes50of the battery module5. After that, the battery module5and RFID sensing module22are connected to each other through a hot pressing process whereby the RFID sensing module22, the battery module5, and the antenna module20are integrated to form the RFID sensing and recording device2. In one embodiment, the battery module5is a thin film battery. Since the battery module5is the thin film battery, the RFID sensing and recording device2can be more compact and light. In addition, with the power supply by the battery module5, the device2can be applied is various kinds of application fields, especially, in the field required long term motoring. It is noted that the positions of the pair of third electric pads223and224, and the electric connector225are not limited to the positions illustrated in the figure of the present embodiment. It is decided according to the need of the user.

Moreover, in one alternative embodiment, a plurality of antenna modules20can be formed on a material roll9in advance. In one embodiment, such as the manufacturing system shown inFIG. 4A, the plurality of antenna modules20is formed on the material roll9, and the RFID sensing and recording device2can be manufactured through a roll-to-roll process. The roll-to-roll transportation module30is utilized to transmit the plurality of antennal modules20from one side to the other side through rotating the material roll9. Each antenna module20, such as the structure shown inFIG. 1orFIG. 2A, has a flexible substrate having antenna circuit on one surface or two opposite surfaces. In the present embodiment, the flexible substrate has a relay circuit formed on one surface and an antenna circuit on the other surface. The thickness of the flexible substrate is less than or equal to 500 μm. It is noted that the roll-to-roll transportation module30comprises a plurality of driving and driven mechanism. In the present embodiment, the roll-to-roll transportation module30comprises a plurality of rollers301,302, and303including at least one driving roller and a plurality of driven rollers, wherein a roller302carries the material roll9, and one end of the material roll9is coupled to the roller303utilized to receive material band of the material roll9passing through the plurality of rollers301.

In the present embodiment, since the surface area of the material band of the material roll9is large, a plurality of crimping apparatuses32can be arranged along the width direction Y of the material roll9, each of which is corresponding to an antenna module20formed on the material roll9. By means of the transportation of the material band of the material roll9through the roll-to-roll transportation module30along the X direction, each crimping apparatus2performs the crimping process toward the antenna module20passing therebelow, thereby making two isolated circuit, i.e., antenna circuit and relay circuit, respectively formed on the two opposite surfaces of the flexible substrate20, electrically connected. Thereafter, the material roll9on the roller303is released and arranged on another roll-to-roll system3a, wherein the roll-to-roll system3acomprises a plurality of first coating units33, a plurality of hot pressing units34, a plurality of second coating units35, and a plurality of combining units36.

The first coating unit33is utilized to coat conductive adhesives on the first and second electric pads204and211so as to form the state shown asFIG. 3C. Then the RFID sensing modules22are respectively arranged on the antenna modules20corresponding to each hot pressing unit34. The RFID sensing module22is electrically coupled to the antenna module20through a hot pressing process performed by the hot pressing unit34. The states are illustrated respectively asFIGS. 3D and 3E. The second coating unit35is utilized to coat a conductive adhesive on the electric connector on the RFID sensing module22. Then the battery modules5are respectively arranged on the RFID sensing modules22corresponding to the combining unit36. Each combining unit36makes the battery module5electrically couple to the RFID sensing module, wherein the electrodes of the battery module5are corresponding to the electric connector of the RFID sensing module22so as to form the structure shown in3F. It is noted that the conductive adhesive24can be, but should not limited to, anisotropic conductive film (ACF), anisotropic conductive paste (ACP), or anisotropic conductive adhesive (ACA) or SACP. In addition, the conductive adhesives can be, but should not be limited to, a moisture curing conductive adhesive, UV curing conductive adhesive, heat curing conductive adhesive, or conductive pressure-sensitive adhesives. In addition, although the systems shown inFIG. 4AandFIG. 4Bare separated manufacturing system, it is noted that the two systems shown inFIGS. 4A and 4Bcan be integrated as single system according to the actual requirement.

According to the abovementioned embodiments, the flexible antenna module is electrically bonded with a RFID sensing module having RFID chip and passive elements through conductive adhesives and pressing procedure without a reflow process. The reflow process can be eliminated thereby reducing the manufacturing cost and the weight of the RFID sensing and recording device can be reduced so as to make the RFID sensing and recording device thinner and lighter.

In addition, the area between electric pads formed on the substrate of the antenna module does not have antenna circuit passing therethrough so that the circuit layout of the electrical connection between the substrate module and antenna module can be simplified thereby simplifying the manufacturing process of connection between the substrate module and antenna module. Moreover, with the power, sensor and storage integrated together, the RFID sensing and recording device of the present invention can be expanded to be applied in various kinds of fields such as internet of things, interface of human-computer interaction, smart living, smart logistics, and medical care.