temperature recorder

Abstract

A temperature recorder capable of accurately measuring and recording the temperature of a measured object is provided. A temperature recorder, provided with a circuit device and a package body that houses the circuit device, the circuit device having a time counting circuit that counts time and generates time data, a temperature sensor that detects temperature and outputs a temperature signal corresponding to the detected temperature, and a memory circuit that stores time information based on the time data and temperature information based on the temperature signal in correspondence with each other, the temperature recorder having a heat capacity of 0.4 J / K or less.

Description

Technical Field

[0001] This invention relates to temperature recorders. Background Technology

[0002] Patent document 1 discloses a real-time clock module comprising: a timing circuit for outputting time data; a selection circuit for selecting at least one of a variety of event data as object event data to be stored, and selecting object time data corresponding to at least a portion of the time bits of the time data as a storage object; and a memory circuit for storing the object time data and the object event data.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-161717

[0004] In a temperature recorder that stores time and temperature information in a memory, it is required to measure the temperature of the object being measured as accurately as possible. When the temperature recorder is installed on or near the object being measured, there is a concern about temperature fluctuations of the object being measured, but Patent Document 1 does not disclose any issue regarding reducing temperature fluctuations of the object being measured. Summary of the Invention

[0005] One embodiment of the temperature recorder according to the present invention comprises: a circuit device; and a package housing the circuit device, the circuit device having: a timing circuit for timing and generating time data; a temperature sensor for detecting temperature and outputting a temperature signal corresponding to the detected temperature; and a memory circuit for storing time information based on the time data and temperature information based on the temperature signal, wherein the heat capacity of the temperature recorder is less than 0.4 [J / K]. Attached Figure Description

[0006] Figure 1 This is a diagram illustrating a structural example of a system including a temperature recorder.

[0007] Figure 2 This is a functional block diagram of the temperature recorder in the first embodiment.

[0008] Figure 3 This is a diagram showing an example of temperature information stored in relation to time information.

[0009] Figure 4 This is a perspective view of the temperature recorder according to the first embodiment.

[0010] Figure 5 This is a top view of the temperature recorder according to the first embodiment.

[0011] Figure 6 yes Figure 4 and Figure 5 AA section diagram.

[0012] Figure 7 This is a graph showing an example of the temperature of the measured object over time.

[0013] Figure 8 This is a functional block diagram of the temperature recorder in the second embodiment.

[0014] Figure 9 This is a top view of the temperature recorder according to the second embodiment.

[0015] Figure 10 yes Figure 9 BB cross-sectional view.

[0016] Figure 11 This is a functional block diagram of the temperature recorder in the third embodiment.

[0017] Figure 12 This is a top view of the temperature recorder according to the third embodiment.

[0018] Figure 13 yes Figure 12 CC section view.

[0019] Figure 14 This is a cross-sectional view of a modified temperature recorder.

[0020] Figure 15 This is a cross-sectional view of a temperature recorder in other variations.

[0021] Explanation of reference numerals in the attached figures

[0022] 1: Temperature recorder; 2: Vibrating plate; 3: Circuit device; 4: Battery; 5: Main unit; 6: Sensor; 6X, 6Y, 6Z: Detection elements; 7: Electronic components; 10: Oscillation circuit; 11: Frequency divider circuit; 12: Timing circuit; 13: Event triggering circuit; 14: Processor; 15: Non-volatile memory; 16: Memory circuit; 17: Register set; 18: Interface circuit; 19: Temperature sensor; 20: Oscillation monitoring circuit ; 21: Power supply voltage monitoring circuit; 22: Power supply circuit; 23: Interrupt generation circuit; 24: Detection circuit; 31: Gasket; 40: Package; 40a: Substrate; 40b, 40c: Frame-shaped sidewalls; 40U, 40Ua, 40Ub: Recesses; 41: Electrode; 42: Bonding wire; 43: Electrode; 44: Bonding component; 45: Electrode; 50: Cover; 61: Gasket; 70: Substrate; 80: Molding resin; 151: Command group. Detailed Implementation

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are not intended to unduly limit the scope of the invention as defined in the claims. Furthermore, not all structures described below are essential structural elements of the present invention.

[0024] 1. First Implementation Method

[0025] 1-1. Overview of Temperature Recorders

[0026] Figure 1 This is a diagram illustrating a structural example of a system including the temperature recorder 1 of this embodiment. (See diagram for details.) Figure 1 As shown, Figure 1 The system shown includes multiple temperature recorders 1, a battery 4, and a host device 5. The battery 4, such as a coin cell battery, supplies power to each of the multiple temperature recorders 1. Specifically, each of the multiple temperature recorders 1 operates by being supplied with a power supply voltage VDD by the battery 4. Furthermore, each of the multiple temperature recorders 1 is connected to the host device 5. It should be noted that... Figure 1 The system shown can also have only one temperature recorder 1.

[0027] Temperature recorder 1 acquires temperature information while continuously timing, and records the acquired temperature information corresponding to the time. Then, temperature recorder 1 sends the recorded information to host device 5. For example, host device 5 acts as the master and temperature recorder 1 as the slave, connected via I... 2 Communication is achieved via the C bus. 2 C is short for Inter-Integrated Circuit. The host device 5 is implemented, for example, through an MCU or MPU. MCU stands for Micro Controller Unit, and MPU stands for Micro Processor Unit. The temperature recorder 1 can acquire and record temperature information at each time interval indicated by the host device 5, or it can acquire and record temperature information at a predetermined period.

[0028] 1-2. Functional Structure of Temperature Recorder

[0029] Figure 2 This is a functional block diagram of the temperature recorder 1 according to the first embodiment. For example... Figure 2As shown, the temperature recorder 1 has multiple external terminals, including external terminals Ta to Th. External terminal Ta is connected to the battery 4, and a power supply voltage VDD is supplied to the temperature recorder 1 from the battery 4 via external terminal Ta. Additionally, external terminal Tb is grounded, and a ground voltage GND is supplied to the temperature recorder 1 via external terminal Tb. Furthermore, external terminals Tc to Th are connected to the host device 5, and the temperature recorder 1 communicates with the host device 5 via external terminals Tc to Th.

[0030] like Figure 2 As shown, the temperature recorder 1 includes a vibrating plate 2 and a circuit device 3.

[0031] Vibrating plate 2 can be a tuning fork-type crystal vibrating plate, an AT-cut crystal vibrating plate, an SC-cut crystal vibrating plate, etc., or it can be a piezoelectric vibrating plate other than a SAW resonator or a crystal vibrating plate. SAW is short for Surface Acoustic Wave. Alternatively, vibrating plate 2 can also be a MEMS vibrating plate made of silicon semiconductor material. MEMS is short for MicroElectroMechanical Systems. For example, vibrating plate 2 can also be an electrostatically driven MEMS vibrating plate using Coulomb force.

[0032] like Figure 2 As shown, the circuit device 3 has multiple terminals including terminals Pa to Pj. Terminals Pa to Ph are respectively connected to external terminals Ta to Th, and terminals Pi and Pj are connected to the vibrating plate 2.

[0033] like Figure 2 As shown, the circuit device 3 includes an oscillation circuit 10, a frequency divider circuit 11, a timing circuit 12, an event triggering circuit 13, a processor 14, a non-volatile memory 15, a memory circuit 16, a register set 17, an interface circuit 18, a temperature sensor 19, an oscillation monitoring circuit 20, a power supply voltage monitoring circuit 21, a power supply circuit 22, and an interrupt generation circuit 23. However, the circuit device 3 may also be a structure that omits or modifies some of these elements, or adds other elements. In this embodiment, the circuit device 3 is a single-chip integrated circuit, but it may also be composed of multiple integrated circuits, or at least a portion of it may be composed of discrete components.

[0034] The power supply voltage monitoring circuit 21 monitors the power supply voltage VDD, determines whether the power supply voltage VDD is below a specified voltage value VT, and outputs a power supply voltage drop signal VDDLOW. In this embodiment, when the power supply voltage VDD is determined to be below the voltage value VT, the power supply voltage monitoring circuit 21 outputs a high-level power supply voltage drop signal VDDLOW; when the power supply voltage VDD is determined to be above the voltage value VT, it outputs a low-level power supply voltage drop signal VDDLOW. Thus, the power supply voltage monitoring circuit 21 monitors the power supply voltage VDD and generates the power supply voltage drop signal VDDLOW as power supply voltage monitoring data.

[0035] Power supply circuit 22 is connected to terminals Pa and Pb, and is supplied with power supply voltage VDD and ground voltage GND through terminals Pa and Pb. Then, based on the power supply voltage VDD and ground voltage GND, power supply circuit 22 generates a stable power supply voltage VOSC and a power supply voltage VLOGIC with constant voltage values. Power supply circuit 22 is implemented, for example, by a regulator. It should be noted that, although not shown in the figure, ground voltage GND is also supplied to all parts of circuit device 3 except power supply circuit 22, serving as the reference voltage for the operation of each part.

[0036] The power supply voltage VOSC is supplied to the oscillation circuit 10. In addition, the power supply voltage VLOGIC is supplied to the frequency divider circuit 11, the timing circuit 12, the event triggering circuit 13, the processor 14, the non-volatile memory 15, the memory circuit 16, the register group 17, the interface circuit 18, the temperature sensor 19, the oscillation monitoring circuit 20, the power supply voltage monitoring circuit 21, and the interrupt generation circuit 23.

[0037] Temperature sensor 19 detects the temperature and outputs a temperature signal VTMP corresponding to the detected temperature. The temperature signal VTMP can be a digital signal or an analog signal.

[0038] The oscillation circuit 10 causes the vibrating plate 2 to vibrate, generating a first clock signal CK1. Specifically, the oscillation circuit 10 is electrically connected to both ends of the vibrating plate 2 via terminals Pi and Pj. By amplifying and feeding back the output signal of the vibrating plate 2, it causes the vibrating plate 2 to vibrate, thereby outputting the first clock signal CK1. Furthermore, the oscillation circuit 10 incorporates a temperature compensation circuit. This temperature compensation circuit controls the frequency of the first clock signal CK1 to vary according to the temperature signal VTMP output from the temperature sensor 19, ensuring that the frequency of the first clock signal CK1 remains constant regardless of temperature. In this embodiment, the frequency of the first clock signal CK1 is 32.768 kHz. However, the frequency of the first clock signal CK1 is not particularly limited.

[0039] The oscillation monitoring circuit 20 monitors the first clock signal CK1, determines whether the oscillation circuit 10 has stopped oscillating, and outputs an oscillation stop signal FST. For example, if the logic level of the first clock signal CK1 does not reverse for a specified time, the oscillation monitoring circuit 20 determines that the oscillation circuit 10 has stopped oscillating and outputs a high-level oscillation stop signal FST. Conversely, if the logic level of the first clock signal CK1 reverses within a specified time, the oscillation monitoring circuit 20 determines that the oscillation circuit 10 has not stopped oscillating and outputs a low-level oscillation stop signal FST. In this way, the oscillation monitoring circuit 20 monitors the first clock signal CK1 and generates the oscillation stop signal FST as oscillation monitoring data.

[0040] Frequency divider circuit 11 divides the first clock signal CK1 to generate a second clock signal CK2 with the desired frequency. In this embodiment, the division ratio of frequency divider circuit 11 is 32, and the frequency of the second clock signal CK2 is 1.024kHz. However, the division ratio of frequency divider circuit 11 and the frequency of the second clock signal CK2 are not particularly limited.

[0041] The timing circuit 12 performs timing based on the second clock signal CK2 and generates time data TM. In this embodiment, the time data TM has 1 / 1024 second, second, minute, hour, day, month, and year as time bits. Specifically, the time data TM consists of sub-second data in binary form representing 1 / 1024 second units (0-1023), second data in BCD form representing seconds (0-59), minute data in BCD form representing minutes (0-59), hour data in BCD form representing hours (0-23), day data in BCD form representing days (1-31), month data in BCD form representing months (1-12), and year data in BCD form representing years (0-9999). BCD is short for Binary Coded Decimal.

[0042] The host device 5 inputs a first event signal EVIN1, a second event signal EVIN2, and a third event signal EVIN3 to the event triggering circuit 13 via terminals Pe, Pf, and Pg, respectively. Additionally, the event command detection signal WRCom, output from the interface circuit 18, is input to the event triggering circuit 13. Furthermore, the power supply voltage drop signal VDDLOW, output from the power supply voltage monitoring circuit 21, is input to the event triggering circuit 13. Additionally, the oscillation stop signal FST, output from the oscillation monitoring circuit 20, is input to the event triggering circuit 13. Then, when the rising edge of at least one of the event command detection signal WRCom, the power supply voltage drop signal VDDLOW, and the oscillation stop signal FST is generated, the event triggering circuit 13 outputs a high-pulse event trigger signal TRG. Furthermore, when at least one of the specified edges of the first event signal EVIN1, the second event signal EVIN2, and the third event signal EVIN3 is generated, the event triggering circuit 13 also outputs a high-pulse event trigger signal TRG. The edges of the first event signal EVIN1, the second event signal EVIN2, and the third event signal EVIN3 that generate the event trigger signal TRG can be specified as rising edge, falling edge, or both edges respectively through the event control register included in register group 17.

[0043] The processor 14 generates capture data CPDT that corresponds to the time information based on the time data TM generated by the timing circuit 12 and the temperature information based on the temperature signal VTMP output from the temperature sensor 19, and stores the generated capture data CPDT in the memory circuit 16. Therefore, the memory circuit 16 stores the time information and temperature information in correspondence.

[0044] For example, the time information can be data corresponding to at least a portion of the time bits of the time data TM. The time information can be, for example, data corresponding to each bit of the year, month, day, hour, minute, and second. Additionally, if the temperature signal VTMP is an analog signal, the temperature information can be, for example, the digital value converted from the voltage of the temperature signal VTMP. Alternatively, if the temperature signal VTMP is a digital signal, the temperature information can be, for example, the digital value itself. For example, the processor 14 can also generate capture data CPDT at a predetermined period set in a register included in register group 17 and sequentially store it in memory circuit 16.

[0045] Furthermore, based on the event trigger signal TRG output from the event trigger circuit 13, the processor 14 selects at least one of various event data as the object event data to be stored, generates capture data CPDT that corresponds to the time information based on time data TM and the selected object event data, and stores the generated capture data CPDT in the memory circuit 16. That is, the processor 14 performs timestamp processing to store the time information corresponding to the object event data in the memory circuit 16 based on the event trigger signal TRG.

[0046] The event data may also include the power supply voltage drop signal VDDLOW, generated by the power supply voltage monitoring circuit 21 as power supply voltage monitoring data. Additionally, the event data may include the oscillation stop signal FST, generated by the oscillation monitoring circuit 20 as oscillation monitoring data. Furthermore, the event data may also include data corresponding to external input signals from the temperature recorder 1. For example, this external input signal may be an event generation command that generates the first event signal EVIN1, the second event signal EVIN2, the third event signal EVIN3, and the event; the data corresponding to this external input signal may be the first event signal EVIN1, the second event signal EVIN2, the third event signal EVIN3, and the event command detection signal WRCom.

[0047] The non-volatile memory 15 stores a command group 151 containing specified object event data. The processor 14, synchronized with the first clock signal CK1, selects the object event data based on the command group 151 and stores the corresponding time information in the memory circuit 16. That is, the command group 151 consists of multiple command codes required by the processor 14 for timestamp processing. The non-volatile memory 15 can be a non-electrically writable ROM such as a mask ROM, or an electrically writable ROM such as an EEPROM. EEPROM is short for Electrically Erasable Programmable Read Only Memory.

[0048] It should be noted that command group 151 may also include command code with a specified period, which is the period during which processor 14 stores time information and temperature information in memory circuit 16. Processor 14 sets the period in the specified registers contained in register group 17 by executing the command code.

[0049] When the timestamp processing based on the event trigger signal TRG is finished, the processor 14 outputs a timestamp end signal TSEND to the interrupt generation circuit 23.

[0050] Interrupt generation circuit 23 generates an interrupt signal INT based on the timestamp end signal TSEND, and outputs the interrupt signal INT to the host device 5 via terminal Ph of circuit device 3. Upon receiving the interrupt signal INT, host device 5 performs prescribed interrupt processing. For example, host device 5 sends a command to temperature recorder 1 requesting the reading of timestamp data, and receives the captured data CPDT stored in memory circuit 16 from temperature recorder 1.

[0051] It should be noted that, in order to reduce the overall power consumption of the system, the host device 5 enters a sleep state when not processing. When it receives an interrupt signal INT in the sleep state, it resumes from the sleep state and reads the timestamp data. When the required processing is finished, it enters a sleep state again.

[0052] Interface circuit 18 is the interface circuit for communication between temperature recorder 1 and host device 5. In communication based on interface circuit 18, host device 5 is the master and temperature recorder 1 is the slave. That is, interface circuit 18 functions as a slave interface relative to host device 5. In this embodiment, interface circuit 18 is connected to I... 2 The interface circuit corresponding to the C bus communicates with the host device 5 based on the serial clock signal SCL input via terminal Pc of circuit device 3 and the serial data signal SDA input / output via terminal Pd of circuit device 3. However, the interface circuit 18 can be an interface circuit corresponding to other serial buses such as SPI, or an interface circuit corresponding to a parallel bus. SPI is short for Serial Peripheral Interface.

[0053] Memory circuit 16 is a semiconductor memory, which can be SRAM, DRAM, or EEPROM, or other electrically writable non-volatile memory. SRAM is short for Static Random Access Memory, and DRAM is short for Dynamic Random Access Memory. Memory circuit 16 functions as an N-level FIFO capable of storing N capture data CPDTs. FIFO stands for First In First Out. That is, memory circuit 16 can simultaneously store N capture data CPDTs. Therefore, for example, as... Figure 3 As shown, the memory circuit 16 simultaneously stores multiple capture data CPDTs that correspond time information and temperature information.

[0054] It should be noted that the captured data CPDT can be stored in the memory circuit 16, or it can be sent to the host device 5 via the interface circuit 18 without being stored in the memory circuit 16.

[0055] 1-3. Construction of a temperature recorder

[0056] Figures 4-6 This is a diagram showing an example of the construction of temperature recorder 1. Figure 4 This is a 3D view of temperature recorder 1. Figure 5 This is a top view of temperature recorder 1. Figure 6 yes Figure 4 and Figure 5 AA section diagram. Figures 4-6 The diagram shows the mutually orthogonal X, Y, and Z directions to help understand the relationship between their orientations.

[0057] like Figures 4-6 As shown, the temperature recorder 1 includes a vibrating plate 2, a circuit device 3, a package 40, and a cover 50. It should be noted that... Figure 5 This is a diagram showing the temperature recorder 1 viewed from the top surface with the cover 50 removed.

[0058] The temperature recorder 1 has a single-seal structure, and the package 40 is a container that houses the vibrating element 2 and the circuit device 3 within the same space. The package 40 is composed of a substrate 40a, a frame-shaped sidewall 40b joined to the substrate 40a, and a frame-shaped sidewall 40c joined to the frame-shaped sidewall 40b. A recess 40U is formed by the substrate 40a and the frame-shaped sidewalls 40b and 40c. The vibrating element 2 and the circuit device 3 are then housed within an airtight internal space formed by covering the recess 40U with a cover 50. This protects the vibrating element 2 and the circuit device 3 from impacts, external environmental factors, especially dust, moisture, and humidity. It should be noted that there are no particular limitations, but the package 40 can be made of ceramic such as alumina, and the cover 50 can be made of a metallic material such as Kovar alloy.

[0059] The atmosphere of the internal space is not particularly limited; for example, it is preferably replaced with inert gases such as nitrogen or argon, and is in a depressurized state relative to atmospheric pressure. Furthermore, it is preferable to be in a state closer to a vacuum. This reduces viscous resistance, effectively increasing the Q value of the vibrator 2 and improving its oscillation characteristics. However, the atmosphere of the internal space is not limited to this; it can also be atmospheric pressure or a pressurized state.

[0060] The recess 40U has a height difference and is composed of recess 40Ua and recess 40Ub. Recess 40Ua is formed by a substrate 40a and a frame-shaped sidewall 40b, while recess 40Ub is formed by frame-shaped sidewalls 40b and 40c, and its opening is smaller than that of recess 40Ua. Multiple electrodes 45 are provided on the bottom surface of the substrate 40a, i.e., the bottom surface of the package 40. Additionally, multiple electrodes 41 and two electrodes 43 are provided on the bottom surface of the recess 40Ub, i.e., the upper surface of the frame-shaped sidewall 40b. Each of the two electrodes 43 is electrically connected to the two electrodes 41 closest to the vibrating element 2 via wiring (not shown) provided in the package 40. Furthermore, multiple electrodes 41, excluding the two electrodes 41, are each connected to multiple electrodes 45 via wiring (not shown) provided in the package 40. The multiple electrodes 45 correspond to... Figure 2 The external terminals Ta~Th are shown as multiple terminals.

[0061] exist Figures 4-6 In this design, the vibrator 2 is a tuning fork type crystal vibrator, and each of the two support arms of the vibrator 2 is connected to one of the two electrodes 43 via a conductive connecting component 44. That is, each support arm of the vibrator 2 is fixed to and electrically connected to each electrode 43. As for the connecting component 44, it is not particularly limited as long as it has both conductivity and bonding properties. For example, conductive adhesives that disperse conductive fillers such as silver fillers in various metal bumps such as gold bumps, silver bumps, copper bumps, and solder bumps, as well as various adhesives such as polyimide-based, epoxy-based, silicone-based, and acrylic-based adhesives, can be used.

[0062] Electrode patterns (not shown) are formed on the two support arms and two vibrating arms of the vibrating plate 2, respectively. Then, the signal generated by one electrode pattern is supplied from one electrode 43 to the Pj terminal of the circuit device 3. The oscillation circuit 10 of the circuit device 3 amplifies the signal and supplies the amplified signal from the Pi terminal to the vibrating plate 2 via the other electrode 43, so that the two vibrating arms of the vibrating plate 2 vibrate continuously like a tuning fork.

[0063] The circuit device 3 is a single-chip integrated circuit, fixed to the bottom surface of the recess 40Ua, i.e., the upper surface of the substrate 40a, by means of an adhesive, with the surface having multiple pads 31 forming the upper surface. Each of the multiple pads 31 is connected to multiple electrodes 41 via bonding wires 42. The multiple pads 31 correspond to... Figure 2 The terminals Pa~Pj shown are multiple terminals.

[0064] It should be noted that, in Figures 4-6 In this context, the vibrator 2 is a tuning fork type crystal vibrator, but it is not limited to this; it can also be an AT-cut crystal vibrator, an SC-cut crystal vibrator, a BT-cut crystal vibrator, an elastic surface wave resonator, other piezoelectric vibrators, electrostatically driven MEMS vibrators, etc. Additionally, in... Figures 4-6 In this circuit, circuit device 3 is a single-chip integrated circuit, but it can also be at least partially composed of discrete components. Additionally, in Figures 4-6 In this embodiment, the circuit device 3 is mounted using wire bonding, but it can also be mounted using flip chip bonding (FCB). Wire bonding allows for visual confirmation of the connection between the pad 31 and the electrode 41, simplifying inspection during manufacturing and ensuring high reliability. On the other hand, FCB mounting eliminates the need for bonding wires 42, thus facilitating a smaller and more compact package 40.

[0065] In this temperature recorder 1, a small and inexpensive package 40 can be used. For example... Figure 4 As shown, the package 40 is approximately cuboid in shape, and its dimensions, when the lengths of the three sides of the approximately cuboid are defined as D[mm], W[mm], and H[mm], are expressed as D[mm]×W[mm]×H[mm]. Additionally, the package 40 is approximately rectangular in shape when viewed from above, and its dimensions are expressed as D[mm]×W[mm]. For example, the dimensions of the package 40 when viewed from above can be 7mm×5mm, 5mm×3.2mm, or 3.2mm×2.5mm. Currently, packages with dimensions of 7mm×5mm, 5mm×3.2mm, or 3.2mm×2.5mm are widely used; by making the package 40 any of these dimensions, convenience and versatility can be improved.

[0066] in the case of Figure 2 The circuit device 3 shown can be housed together with the vibrating plate 2 in a package 40 of, for example, 3.2mm × 2.5mm × 2.1mm. Furthermore, if the circuit device 3 has various functions other than recording temperature information and event data, or if the temperature recorder 1 has various sensors, the size of the package 40 may increase. However, in such cases, a smaller package 40, such as 5mm × 3.2mm × 2.8mm or 7mm × 5mm × 3.3mm, can also be used.

[0067] 1-4. Thermal capacity of the temperature recorder

[0068] To maintain the quality of transported goods, there are situations where strict temperature management of the space containing the goods is required during transport. If the quality of the transported goods deteriorates, inappropriate temperature management during transport is suspected as the cause. A temperature recorder 1 is used to determine whether the temperature management during transport is appropriate. In the event of deterioration in the quality of the transported goods, the transport client who commissioned the transport can determine whether the temperature management during transport was appropriate by analyzing the temperature information stored in the temperature recorder 1 in a time-series format corresponding to the time information. On the other hand, the transporter can effectively utilize the time-series temperature information stored in the temperature recorder 1 as evidence of appropriate temperature management and can differentiate themselves from other transporters by demonstrating high transport quality.

[0069] Furthermore, the temperature recorder 1 in this embodiment is small and inexpensive, so, for example, when transporting multiple goods, multiple temperature recorders 1 can be installed on each of the goods for transport. In this way, the transport client and the transporter can determine whether the temperature management of each goods has been properly carried out during transport based on the time series of temperature information stored in each temperature recorder 1.

[0070] Thus, the temperature recorder 1 of this embodiment brings various advantages to both the consignor and the consignor. However, when the temperature recorder 1 is installed on the goods, there is a situation where the temperature management of the goods becomes difficult due to changes in the temperature of the goods as recorded by the temperature recorder 1.

[0071] When the temperature of the object being measured, such as the commodity, is constant, the mass, specific heat, and initial temperature of the object being measured are set as m1, c1, and t1, respectively. The mass, specific heat, and initial temperature of the temperature recorder 1 are set as m2, c2, and t2, respectively. When the equilibrium temperature after the object being measured comes into contact with the temperature recorder 1 is set as t, according to the principle of heat preservation, equation (1) is obtained.

[0072] [Mathematical Expression 1]

[0073] In equation (1), m1·c1 is the heat capacity C1 of the measured object, and m2·c2 is the heat capacity C2 of the temperature recorder 1. Therefore, according to equation (1), equation (2) is obtained.

[0074] [Mathematical Expression 2]

[0075] In equation (2), t1-t is the temperature change Δt1 of the measured object. Therefore, equation (3) can be obtained from equation (2).

[0076] [Mathematical Expression 3]

[0077] According to equation (3), when the heat capacity C2 of temperature recorder 1 is large relative to the heat capacity C1 of the object being measured, the temperature of the object being measured will change simply by installing temperature recorder 1 on the object. Therefore, if the heat capacity C2 is large, temperature recorder 1 cannot accurately measure the temperature of the object being measured, so it is preferable that the heat capacity C2 is as small as possible. It should be noted that, according to equation (3), if the temperature t2 of temperature recorder 1 is made close to the temperature t1 of the object being measured in advance, then it is not necessary to set a constraint on heat capacity C2. However, at the time when temperature recorder 1 is installed on the object being measured, the temperature t1 is unknown, and it is difficult to make the temperature t2 close to the temperature t1 in advance.

[0078] On the other hand, when the temperature of the measured object changes due to heat dissipation or heat absorption, the temperature Ts of the measured object, for example, Figure 7 As shown, it progresses with the passage of time t, as represented by equation (4). In Figure 7 In equation (4), T s0 T is the initial temperature of the sample being measured. w This is the equilibrium temperature after the measured object comes into contact with temperature recorder 1. Additionally, R is the thermal resistance, and C... s It is the heat capacity. The thermal resistance R changes due to factors such as the contact state between the measured object and the temperature recorder 1.

[0079] [Mathematical Expression 4]

[0080] According to equation (4), the heat capacity C s The larger the value, the greater the time constant τ=RC. s The larger the value, the lower the temperature tracking accuracy. For example, in situations where the temperature change is large due to rapid heating and cooling, such as measuring the temperature shift of a resin mold, the heat capacity C needs to be reduced in order for the temperature recorder 1 to accurately measure and record the temperature shift. s .

[0081] In contrast, in the temperature recorder 1 of this embodiment, as mentioned above, small packages 40 such as 3.2mm×2.5mm×2.1mm, 5mm×3.2mm×2.8mm, and 7mm×5mm×3.3mm can be used, thus reducing the mass and heat capacity of the temperature recorder 1. The inventors of this application estimated the heat capacity of the temperature recorder 1 when using the largest package 40, 7mm×5mm×3.3mm, and the result was approximately 0.2 [J / K]. Considering calculation errors and manufacturing deviations of the temperature recorder 1, the heat capacity of the temperature recorder 1 is less than or equal to 0.4 [J / K], which is twice the value of 0.2 [J / K].

[0082] Additionally, the package 40, measuring 7mm × 5mm × 3.3mm, has a volume of 115.5mm². 3 The package 40, measuring 5mm × 3.2mm × 2.8mm, has a volume of 44.5mm². 3 Therefore, the heat capacity of the temperature recorder 1, which uses a 5mm × 3.2mm × 2.8mm package 40, is approximately 0.08 [J / K] (≈0.2 [J / K] × 44.5 / 115.5). Thus, considering calculation errors and manufacturing deviations of the temperature recorder 1, the heat capacity of the temperature recorder 1 could also be less than 0.16 [J / K], which is twice 0.08 [J / K].

[0083] Additionally, the volume of a 3.2mm × 2.5mm × 2.1mm sample is 17.1mm. 3 Therefore, the thermal capacity of the temperature recorder 1, which uses a 3.2mm × 2.5mm × 2.1mm package 40, is approximately 0.03 [J / K] (≈0.2 [J / K] × 17.1 / 115.5). Thus, considering calculation errors and manufacturing deviations of the temperature recorder 1, the thermal capacity of the temperature recorder 1 could also be less than 0.06 [J / K], which is twice 0.03 [J / K].

[0084] Here, considering the desire to ensure a temperature measurement accuracy of ±1% for temperature recorder 1, according to equation (3), it is preferable that the heat capacity of temperature recorder 1 is less than or equal to 1 / 100 of the heat capacity of the object being measured. For example, if the heat capacity of temperature recorder 1 is less than or equal to 0.4 [J / K], then as long as the heat capacity of the object being measured is 40 [J / K] or more, the temperature measurement accuracy of temperature recorder 1 can be guaranteed to be ±1%. Furthermore, for example, if the heat capacity of temperature recorder 1 is less than or equal to 0.16 [J / K], then as long as the heat capacity of the object being measured is 16 [J / K] or more, the temperature measurement accuracy of temperature recorder 1 can be guaranteed to be ±1%. Additionally, for example, if the heat capacity of temperature recorder 1 is less than or equal to 0.06 [J / K], then as long as the heat capacity of the object being measured is 6 [J / K] or more, the temperature measurement accuracy of temperature recorder 1 can be guaranteed to be ±1%.

[0085] 1-5. Effects

[0086] As explained above, the temperature recorder 1 of the first embodiment has a heat capacity of 0.4 [J / K] or less, which is extremely small. Therefore, even when the object being measured is installed at a certain temperature, the temperature fluctuation of the object being measured is small. Furthermore, even when installed on an object being measured where the temperature changes rapidly, it does not hinder the temperature tracking of the object being measured. Therefore, the temperature recorder 1 according to the first embodiment can accurately measure and record the temperature of the object being measured. In addition, according to the temperature recorder 1 of the first embodiment, by setting the heat capacity to 0.16 [J / K] or less, the temperature of the object being measured can be measured and recorded even more accurately. Furthermore, according to the temperature recorder 1 of the first embodiment, by setting the heat capacity to 0.06 [J / K] or less, the temperature of the object being measured can be measured and recorded even more accurately.

[0087] Furthermore, according to the temperature recorder 1 of the first embodiment, by setting the heat capacity to 1 / 100 or less of the heat capacity of the object to be measured, the temperature of the object to be measured can be accurately measured and recorded with an error of ±1% or less.

[0088] Furthermore, according to the temperature recorder 1 of the first embodiment, by setting the time information stored in relation to the temperature information to the minimum required number of bits, the amount of data stored in the memory circuit 16 can be reduced.

[0089] Furthermore, according to the first embodiment, by using a ceramic package as the package body 40, the outer casing is extremely rigid and robust. Therefore, for example, a robust temperature recorder 1 can be provided that is not easily damaged or malfunctioned even when subjected to impact during transportation. In addition, wiring can pass through the interior of the package body 40, thus eliminating the need for a printed circuit board or the like. Furthermore, the package body 40 can achieve an airtight seal, thus eliminating the need for a packaged vibrating element 2 and circuitry 3. As a result, the temperature recorder 1 can be miniaturized, and resources can be reduced, thereby achieving cost reduction.

[0090] 2. Second Implementation Method

[0091] Regarding the temperature recorder 1 of the second embodiment, the same reference numerals are used for structural elements that are the same as those in the first embodiment, and descriptions that are repeated in the first embodiment are omitted or simplified. The descriptions mainly focus on the differences from the first embodiment.

[0092] Figure 8 This is a functional block diagram of the temperature recorder 1 according to the second embodiment. The perspective view of the temperature recorder 1 according to the second embodiment is also shown. Figure 4 Since they are the same, their illustrations are omitted. Figure 9 This is a top view of the temperature recorder 1 according to the second embodiment. Figure 10 yes Figure 9 The BB cross-sectional view. It should be noted that... Figure 9This is a diagram showing the temperature recorder 1 viewed from the top surface with the cover 50 removed. Figure 9 and Figure 10 The diagram illustrates the mutually orthogonal X, Y, and Z directions to help understand the relationship between their orientations.

[0093] like Figures 8-10 As shown, the temperature recorder 1 of the second embodiment includes a battery 4 that supplies power to the circuit device 3, and the battery 4 is housed in a package 40. That is, the package 40 houses the vibrating plate 2, the circuit device 3, and the battery 4 in the same space. The battery 4 is, for example, a solid-state battery, such as... Figure 10 As shown, it is fixed to the bottom surface of the recess 40Ua, i.e. the upper surface of the substrate 40a, by an adhesive or the like.

[0094] The other structures and functions of the temperature recorder 1 in the second embodiment are the same as those in the temperature recorder 1 in the first embodiment, so their description is omitted.

[0095] The temperature recorder 1 according to the second embodiment described above can achieve the same effect as the temperature recorder 1 according to the first embodiment. Furthermore, according to the temperature recorder 1 of the second embodiment, the user does not need to prepare the battery 4, thus improving convenience.

[0096] 3. Third Implementation Method

[0097] Regarding the temperature recorder 1 of the third embodiment, the same reference numerals are used for structural elements that are the same as those in the first or second embodiment, and descriptions that are repeated in the first or second embodiment are omitted or simplified. The description mainly focuses on the contents that are different from the first and second embodiments.

[0098] Figure 11 This is a functional block diagram of the temperature recorder 1 according to the third embodiment. A perspective view of the temperature recorder 1 according to the third embodiment is also shown. Figure 4 Since they are the same, their illustrations are omitted. Figure 12 This is a top view of the temperature recorder 1 according to the third embodiment. Figure 13 yes Figure 12 The CC section diagram. It should be noted that... Figure 12 This is a diagram showing the temperature recorder 1 viewed from the top surface with the cover 50 removed. Figure 12 and Figure 13 The diagram illustrates the mutually orthogonal X, Y, and Z directions to help understand the relationship between their orientations.

[0099] like Figures 11-13 As shown, the temperature recorder 1 of the third embodiment includes a sensor 6 in addition to the vibrating plate 2 and the circuit device 3. (As shown...) Figure 12 and Figure 13As shown, the sensor 6 is bonded to the upper surface of the circuit device 3 via an adhesive or the like, with the surface on which a plurality of pads 61 are formed as the upper surface. Each of the plurality of pads 61 is connected to a pad 31 formed in part of the circuit device 3 via a bonding line.

[0100] like Figure 11 As shown, sensor 6 is a triaxial accelerometer with three sensing elements 6X, 6Y, and 6Z. Sensing element 6X detects acceleration in the X direction and outputs an acceleration signal Ax. Sensing element 6Y detects acceleration in the Y direction and outputs an acceleration signal Ay. Sensing element 6Z detects acceleration in the Z direction and outputs an acceleration signal Az. The acceleration signals Ax, Ay, and Az are, for example, analog signals such as charge, current, or voltage.

[0101] Although the illustrations are omitted, detection elements 6X, 6Y, and 6Z are, for example, MEMS elements, each including: a comb-shaped fixed electrode fixed to a support substrate; a movable part configured to move relative to the support substrate; and a comb-shaped movable electrode fixed to the movable part. In detection element 6X, the comb teeth of the fixed electrode and the comb teeth of the movable electrode are arranged opposite each other in the X direction. When an acceleration in the X direction is applied to detection element 6X, the movable part moves in the X direction, and the distance between the comb teeth changes, thus changing the electrostatic capacitance between the comb teeth. In detection element 6Y, the comb teeth of the fixed electrode and the comb teeth of the movable electrode are arranged opposite each other in the Y direction. When an acceleration in the Y direction is applied to detection element 6Y, the movable part moves in the Y direction, and the distance between the comb teeth changes, thus changing the electrostatic capacitance between the comb teeth. In the detection element 6Z, the comb teeth of the fixed electrode and the comb teeth of the movable electrode are arranged opposite each other in the Z direction. When an acceleration in the Z direction is applied to the detection element 6Z, the movable part moves in the Z direction, and the distance between the comb teeth changes, thus changing the electrostatic capacitance between the comb teeth. The detection elements 6X, 6Y, and 6Z output acceleration signals Ax, Ay, and Az, respectively, corresponding to the change in electrostatic capacitance between the comb teeth.

[0102] It should be noted that, in Figure 12 and Figure 13 In this embodiment, the detection elements 6X, 6Y, and 6Z are housed within a package to form sensor 6. However, sensor 6 may also be without a package, with the detection elements 6X, 6Y, and 6Z exposed within the internal space of the package 40. Furthermore, sensor 6 can also be a single-axis or dual-axis accelerometer.

[0103] like Figure 11As shown, the circuit device 3 includes a detection circuit 24. The detection circuit 24 detects and processes the acceleration signals Ax, Ay, and Az output from the detection elements 6X, 6Y, and 6Z of the sensor 6, respectively, generating triaxial acceleration data (ADT), and outputting it to the processor 14. The detection circuit 24 may, for example, include an A / D conversion circuit that performs A / D conversion on the acceleration signals Ax, Ay, and Az respectively. Alternatively, the detection circuit 24 may include an amplifier circuit that amplifies the acceleration signals Ax, Ay, and Az respectively, and an A / D conversion circuit that performs A / D conversion on the output signal of the amplifier circuit. Alternatively, if the acceleration signals Ax, Ay, and Az respectively include a carrier signal and a detection signal, the detection circuit 24 may also include a detection circuit that detects the detection signal from the acceleration signals Ax, Ay, and Az respectively, and an A / D conversion circuit that performs A / D conversion on the detected detection signal.

[0104] Processor 14 generates capture data CPDT that corresponds to the timing information based on the timing data TM generated by timing circuit 12 and the acceleration information based on the triaxial acceleration data ADT output from detection circuit 24, and stores the generated capture data CPDT in memory circuit 16. Therefore, memory circuit 16 stores timing information and acceleration information correspondingly. Alternatively, processor 14 can also generate capture data CPDT that corresponds to the timing information based on timing data TM, the temperature information based on temperature signal VTMP, and the acceleration information based on triaxial acceleration data ADT, and store the generated capture data CPDT in memory circuit 16. That is, memory circuit 16 can also store timing information, temperature information, and acceleration information correspondingly. If the value of the triaxial acceleration data ADT exceeds a predetermined threshold, processor 14 can store only the capture data CPDT for a predetermined period before and after it in memory circuit 16. This reduces the capacity of memory circuit 16.

[0105] For example, if the transported goods are damaged or malfunction, the cause may be a large impact applied to the goods during transport. To determine whether a large impact was applied to the transported goods, the temperature recorder 1 of this embodiment is used. In the event of damage or malfunction, the transport client who commissioned the transport can determine whether a large impact was applied to the transported goods from the acceleration information stored in the temperature recorder 1 in a time sequence corresponding to the time information. Furthermore, the transport client can clearly identify the date and time of the damage or malfunction, the cause of the damage or malfunction, and the point of responsibility, facilitating subsequent responses to the transporter. Furthermore, by confirming the impact applied to the transported goods, the transport client can re-evaluate the mechanical design of the goods and improve it to make them less prone to malfunction. Additionally, the transport client can re-evaluate the shape and size of the cushioning material used to protect the goods from impact; for example, if the cushioning material can be reduced in size as a result of the re-evaluation, the cost of the goods and the transport cost can be reduced accordingly.

[0106] On the other hand, the transporter can effectively utilize the time series of acceleration information stored in the temperature recorder 1 as evidence that the damage or malfunction of the goods did not occur during transport. In addition, the transporter can also use the temperature recorder 1 to demonstrate that the impact applied during transport is much less than that of its competitors, thereby demonstrating high transport quality and differentiating itself from other transporters.

[0107] Furthermore, the temperature recorder 1 in this embodiment is small and inexpensive; therefore, for example, when transporting multiple goods, multiple temperature recorders 1 can be installed on each of the goods for transport. In this way, the transport client and the transporter can individually determine the magnitude of the impact applied to each goods during transport from the time series of acceleration information stored in each temperature recorder 1. Thus, the temperature recorder 1 in this embodiment brings various advantages to both the transport client and the transporter.

[0108] The temperature recorder 1 of the third embodiment has the same other structure and function as the temperature recorder 1 of the first embodiment, so its description is omitted. It should be noted that the sensor 6 and the detection circuit 24 can also be packaged together and disposed outside the temperature recorder 1. In addition, the temperature recorder 1 can also have the battery 4 built in, just like in the second embodiment.

[0109] The temperature recorder 1 according to the third embodiment described above can achieve the same effect as the temperature recorder 1 of the first or second embodiment. Furthermore, the temperature recorder 1 according to the third embodiment can record time information in correspondence with acceleration information, so that, for example, in the event of damage or malfunction of the object being measured, the user can determine whether an impact has been applied to the object being measured, and further, in the event of an impact, the time of that impact can be determined.

[0110] 4. Variations

[0111] This invention is not limited to this embodiment, and various modifications can be implemented within the scope of the spirit of this invention.

[0112] For example, in the above embodiments, the vibrating plate 2 and the circuit device 3 are each housed as an electronic component in the package 40, but the vibrating plate 2 and the circuit device 3 may not be electronic components. The circuit device 3 is a single-chip integrated circuit, but it may be composed of multiple chip integrated circuits, or at least part of it may be composed of discrete components. Figure 14 This is a cross-sectional view showing an example of the structure of the temperature recorder 1 in this modified example. Figure 14 In the example, a plurality of electronic components 7 are mounted on the substrate 40a of the package 40, and these multiple electronic components 7 are housed within the package 40. The functions implemented by the vibrating plate 2 and the circuit device 3 in the above embodiments are implemented by the multiple electronic components 7. For example, the electronic components 7 may include the vibrating plate 2 and an integrated circuit having the functions of an oscillation circuit 10, a frequency divider circuit 11, and a timing circuit 12. Additionally, other electronic components 7 may also include a temperature sensor 19. Furthermore, other electronic components 7 may include an integrated circuit having the function of a processor 14, or an integrated circuit having the function of a memory circuit 16. Additionally, other electronic components 7 may be a battery 4 or a sensor 6.

[0113] According to this modified example, similar to the embodiments described above, by using a ceramic package as the package body 40, the outer casing is extremely rigid and robust. Therefore, for example, a robust temperature recorder 1 can be provided that is not easily damaged or malfunctioned even when subjected to impact during transportation. In addition, wiring can pass through the interior of the package body 40, thus eliminating the need for printed circuit boards, etc. Furthermore, hermetic sealing can be achieved through the package body 40, thus eliminating the need to package individual electronic components 7. As a result, the temperature recorder 1 can be miniaturized, and resources can be reduced, thereby achieving cost reduction.

[0114] exist Figure 14 In the example, multiple electronic components 7 are housed in a package 40 such as a ceramic package, but they can also be housed in a molded package. Figure 15 This is a cross-sectional view showing an example of the structure of the temperature recorder 1 in this modified example. Figure 15 In this example, a plurality of electronic components 7 are mounted on the substrate 70, and these electronic components 7 are fixed by molding resin 80. For example, the substrate 70 can also be made of ceramic. Alternatively, the substrate 70 can also be a PCB substrate. PCB is short for Printed Circuit Board.

[0115] According to this modified example, multiple electronic components 7 are fixed by molding resin 80, thus forming a solid structure, which can improve the resonant frequency. Furthermore, since ceramic is extremely hard, by making the substrate 70 a ceramic material, the resonant frequency of the external component can be improved. Additionally, by making the substrate 70 a PCB substrate, the temperature recorder 1 can be manufactured inexpensively.

[0116] The above embodiments and modifications are merely examples and are not intended to limit the scope. For instance, the embodiments and modifications can be appropriately combined.

[0117] This invention includes structures that are substantially the same as those described in the embodiments (e.g., structures with the same function, method, and result, or structures with the same purpose and effect). Additionally, this invention includes structures that replace non-essential parts of the structures described in the embodiments. Furthermore, this invention includes structures that can achieve the same effect as the structures described in the embodiments or achieve the same purpose. Additionally, this invention includes structures incorporating known techniques into the structures described in the embodiments.

[0118] The following content is derived from the above implementation methods and variations.

[0119] One embodiment of a temperature recorder includes: a circuit device; and a package housing the circuit device, the circuit device comprising: a timing circuit for timing and generating time data; a temperature sensor for detecting temperature and outputting a temperature signal corresponding to the detected temperature; and a memory circuit for storing time information based on the time data and temperature information based on the temperature signal, wherein the thermal capacity of the temperature recorder is below 0.4 [J / K].

[0120] This temperature recorder has a very small heat capacity, so even when installed on an object being measured at a certain temperature, the temperature change of the object is small. Furthermore, it does not impede the temperature tracking of the object being measured when installed on an object experiencing rapid temperature changes. Therefore, this temperature recorder can accurately measure and record the temperature of the object being measured.

[0121] In one embodiment of the temperature recorder, the heat capacity may be less than 0.16 [J / K].

[0122] This temperature recorder has a smaller heat capacity, thus enabling more accurate measurement and recording of the temperature of the object being measured.

[0123] In one embodiment of the temperature recorder, the heat capacity may be less than 0.06 [J / K].

[0124] This temperature recorder has a smaller heat capacity, thus enabling more accurate measurement and recording of the temperature of the object being measured.

[0125] In one configuration of the temperature recorder, the heat capacity may be less than 1 / 100 of the heat capacity of the object being measured.

[0126] This temperature recorder can accurately measure and record the temperature of the object being measured with an error of less than ±1%.

[0127] In one embodiment of the temperature recorder, the time information may also be data corresponding to at least a portion of the time bits of the time data.

[0128] According to this temperature recorder, the time information can be set to the minimum required number of bits, thus reducing the amount of data stored in the memory circuit.

[0129] Another embodiment of the temperature recorder is that the temperature recorder includes a vibrating plate, the circuit device has an oscillation circuit that causes the vibrating plate to vibrate, and the vibrating plate is housed in the package.

[0130] Alternatively, the temperature recorder may include a battery that supplies power to the circuitry, the battery being housed within the package.

[0131] This temperature recorder eliminates the need for users to prepare batteries, thus improving convenience.

[0132] The temperature recorder can also be configured such that the dimensions of the package, when viewed from above, are 7mm×5mm, 5mm×3.2mm, or 3.2mm×2.5mm.

[0133] The temperature recorder uses a widely available package, thus improving convenience and versatility.

Claims

1. A temperature recorder, characterized in that, have: Circuit devices; and Package housing the circuit device The circuit device has: The timing circuit performs timing and generates time data; A temperature sensor detects temperature and outputs a temperature signal corresponding to the detected temperature; and The memory circuit stores the time information based on the time data and the temperature information based on the temperature signal in a corresponding manner. The heat capacity of the temperature recorder is below 0.4 J / K.

2. The temperature recorder according to claim 1, characterized in that, The heat capacity is below 0.16 J / K.

3. The temperature recorder according to claim 2, characterized in that, The heat capacity is below 0.06 J / K.

4. The temperature recorder according to claim 1, characterized in that, The heat capacity is less than 1 / 100 of the heat capacity of the object being measured.

5. The temperature recorder according to claim 1, characterized in that, The time information is data corresponding to at least a portion of the time bits of the time data.

6. The temperature recorder according to claim 1, characterized in that, The temperature recorder has a vibrating plate. The circuit device has an oscillation circuit that causes the vibrating plate to vibrate. The vibrating plate is housed within the encapsulation.

7. The temperature recorder according to claim 1, characterized in that, The temperature recorder includes a battery that supplies power to the circuitry. The battery is housed within the package.

8. The temperature recorder according to any one of claims 1 to 7, characterized in that, The dimensions of the package when viewed from above are 7mm×5mm, 5mm×3.2mm, or 3.2mm×2.5mm.

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