JP2016011945A - Wireless temperature sensor and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless temperature sensor that is easily manufactured, and has improved reliability.SOLUTION: A method for manufacturing a wireless temperature sensor 1 includes the steps of: preparing a first structure including an insulating substrate 12 and a second structure; disposing an antenna electrode 11 and a GND electrode 13 on the first structure including the insulating substrate 12 to form an antenna; fixing a temperature detection element 30 to the first structure so that the temperature detection element 30 is electrically connected to the antenna electrode 11 and the GND electrode 13; and joining and assembling the first structure and the second structure so that the second structure is disposed on a side wall 31a side of the temperature detection element 30.

Description

  The present invention relates to a wireless temperature sensor and a manufacturing method thereof.

  There are several methods for measuring temperature using a wired cable. Examples include temperature-resistance characteristics and thermoelectromotive force using a thermistor or thermocouple, radiation thermometers that measure temperature from infrared rays emitted from objects, and physical characteristics of piezoelectric elements and surface acoustic wave elements depending on temperature. There is a method using a changing principle.

  However, for example, when measuring the temperature of a wafer in a chamber in a semiconductor process, the arrangement of a wired cable connected for output to the outside from a measurement unit arranged in the chamber is limited by the chamber and associated devices. I will receive it. As a solution to this problem, a wireless temperature sensor is known in which a unit provided with a transmission / reception antenna in a surface acoustic wave element operates in response to a signal transmitted from an external antenna and returns a response signal including measurement information. . (For example, see Patent Document 1)

  FIG. 27A is a plan view of the container body 101 of the temperature sensor in the first specific example described in Patent Document 1, and FIG. 27B is a plan view of the lid 107. As shown in FIG. 27A, the electrodes attached to the diaphragm 104 and the external terminals 102 and 103 attached to the container body 101 are connected by lead wires 105 and 106, respectively. As shown in FIG. 27B, both ends of the coil 108 formed on the lid 107 and the external terminals 102 and 103 shown in FIG. 27A are connected by lead wires (not shown).

  FIG. 27C is a cross-sectional view of the temperature sensor in the second specific example described in the patent document, and is a cross-sectional view before the lid 125 is hermetically sealed to the container main body 121. The diaphragm 123 includes a groove 130 and is attached to the container main body 121. A coil 126 is formed on the lid 125. The diaphragm 123 is attached to the container main body 121 and connected to the external terminal 122 by the lead wire 124. After the external terminal 122 and the coil 126 are connected by the lead wire 128, the container main body 121 and the lid 125 are hermetically sealed. Is done.

  In both of the first and second specific examples, the coil (108 or 126) provided on the lid (107 or 125) and the diaphragm (104 or 123) provided on the container body (101 or 121). ) Is connected by a lead wire.

Japanese Patent No. 5341381

  However, in the manufacturing method in which the lid is mounted on the container body so that the lead wire is stored in the container after the lid prepared separately and the container body are connected with the lead wire, the lead wire is bent at the time of mounting. In some cases, the wire may be disconnected, or after mounting, the bent lead wire may contact the diaphragm and cause malfunction.

  An object of the present invention is to solve the above-described problems, and to provide a wireless temperature sensor that is easy to manufacture and has improved reliability.

  A method for manufacturing a wireless temperature sensor according to the present invention includes a step of preparing a first structure and a second structure including an insulating substrate, and disposing an antenna electrode and a GND electrode on the first structure including the insulating substrate. Forming the antenna, fixing the temperature detecting element to the first structure so that the temperature detecting element is electrically connected to the antenna electrode and the GND electrode, and the second structure A step of joining and assembling the first structure and the second structure so as to be arranged on the side wall side of the detection element.

  With the above configuration, since the temperature detection element is fixed to the first structure in which the antenna electrode and the GND electrode are provided on the insulating substrate, a wireless temperature sensor that is easy to manufacture and has improved reliability is manufactured. can do.

  In the method for manufacturing a wireless temperature sensor, the step of joining and assembling the first structure and the second structure is such that the temperature detection element further contacts the inside of the second structure constituting the container. It may include joining and assembling the first structure and the second structure.

  With the above configuration, it is possible to manufacture a wireless temperature sensor with further improved temperature measurement responsiveness.

  In the manufacturing method of the wireless temperature sensor, the second structure may have an opening on the side opposite to the side bonded to the first structure.

  With the above configuration, it is possible to manufacture a wireless temperature sensor with further improved temperature measurement responsiveness.

  In the method for manufacturing a wireless temperature sensor, the step of joining and assembling the first structure and the second structure may further include disposing a heat conductor between the second structure and the temperature detection element. , And joining and assembling the first structure and the second structure.

  With the above configuration, it is possible to manufacture a wireless temperature sensor with further improved temperature measurement responsiveness.

  In the method for manufacturing the wireless temperature sensor, the second structure may have a porous structure or a mesh structure.

  With the above configuration, it is possible to measure the environmental temperature (atmosphere temperature) more accurately.

  In the method of manufacturing a wireless temperature sensor, the step of forming the antenna further includes disposing a conductor pattern serving as an antenna electrode on one surface of the insulating substrate, and disposing a conductor pattern serving as a GND electrode on the inner layer of the insulating substrate. A first via hole that is electrically connected to the antenna electrode and a second via hole that is electrically connected to the GND electrode are formed on the insulating substrate, and the first electrode pad and the second electrode hole electrically connected to the first via hole are formed on the other surface of the insulating substrate. The method may include forming a second electrode pad that is electrically connected to the second via hole.

  With the above configuration, since a patch antenna having an excellent transmission / reception function is configured by the antenna electrode formed on the insulating substrate and the GND electrode formed in the insulating substrate, a wireless temperature sensor with improved antenna characteristics is manufactured. Can do.

  In the method for manufacturing a wireless temperature sensor, the step of forming the antenna further includes a step of electrically connecting the second electrode pad on the other surface of the insulating substrate, and thermally connecting the temperature detection element and the second structure. It may include forming a thermally conductive layer to be connected.

  With the above configuration, the heat transmitted through the second structure is efficiently transmitted to the temperature detection element via the heat conductive layer, so that it is possible to manufacture a wireless temperature sensor with improved temperature measurement response and tracking.

  In the method for manufacturing a wireless temperature sensor, the step of fixing the temperature detection element to the first structure may further include fixing the temperature detection element on the second via hole on the heat conductive layer.

  With the above configuration, it is possible to reduce the amount of heat transferred to the inside of the lid by the via hole, so that a wireless temperature sensor with improved temperature measurement responsiveness and reduced variation in antenna characteristics due to the influence of heat is provided. Can be manufactured.

  In the wireless temperature sensor according to the present invention, a first structure having an antenna in which an antenna electrode and a GND electrode are disposed on an insulating substrate, and a surface on which the antenna electrode of the first structure is disposed are fixed on the back surface side. And a second structure body disposed on the side wall side of the temperature detection element and joined to the first structure body, wherein the temperature detection element is connected to the antenna electrode and the GND electrode. It is fixed to the first structure body so as to be electrically connected.

  With the above configuration, since the temperature detection element is fixed to the first structure in which the antenna electrode and the GND electrode are provided on the insulating substrate, a wireless temperature sensor that is easy to manufacture and has improved reliability is provided. can do.

  In the wireless temperature sensor, the temperature detection element may be fixed inside the container so as to contact the inside of the second structure.

  With the above configuration, it is possible to provide a wireless temperature sensor with further improved temperature measurement responsiveness.

  In the wireless temperature sensor, the second structure may have an opening on the side opposite to the side bonded to the first structure.

  With the above configuration, it is possible to provide a wireless temperature sensor with further improved temperature measurement responsiveness.

  The wireless temperature sensor may further include a heat conductor disposed between the second structure and the temperature detection element.

  With the above configuration, it is possible to provide a wireless temperature sensor with further improved temperature measurement responsiveness.

  In the wireless temperature sensor, the second structure may have a porous structure or a mesh structure.

  With the above configuration, it is possible to measure the environmental temperature (atmosphere temperature) more accurately.

  The wireless temperature sensor may further include a heat conductive layer formed on the insulating substrate and thermally connected to the temperature detection element and the second structure.

  With the above configuration, the heat transmitted through the second structure is efficiently transmitted to the temperature detection element via the heat conductive layer, so that it is possible to provide a wireless temperature sensor with improved temperature measurement responsiveness and followability.

  The wireless temperature sensor may further include a via hole formed in the insulating substrate and electrically connected to the GND electrode and the heat conductive layer, and the temperature detection element may be fixed on the via hole on the heat conductive layer.

  With the above configuration, it is possible to reduce the amount of heat transferred to the inside of the lid by the via hole, so that a wireless temperature sensor with improved temperature measurement responsiveness and reduced variation in antenna characteristics due to the influence of heat is provided. Can be manufactured.

  According to the present invention, since the temperature detection element is fixed to the first structure in which the antenna electrode and the GND electrode are provided on the insulating substrate, the wireless temperature sensor that is easy to manufacture and has improved reliability can be obtained. Can be provided.

2 is a diagram for explaining the structure of a wireless temperature sensor 1; FIG. (A) is a top view of the temperature detection element 30, (b) is sectional drawing along CC line shown to Fig.2 (a) of the temperature detection element 30, (c) is the temperature detection element 30. FIG. It is sectional drawing along the DD line | wire shown to Fig.2 (a). FIG. 2 is a plan view of the wireless temperature sensor 1, and (b) is a side view of the wireless temperature sensor 1. FIG. It is sectional drawing along the BB line shown in FIG.3 (b) of the wireless temperature sensor 1. FIG. It is a figure for demonstrating the temperature detection method by the wireless temperature sensor. It is a graph which shows the time change of reflective surface acoustic wave intensity | strength Rwp in a surface acoustic wave element. It is a figure for demonstrating the structure of the temperature measurement system using the wireless temperature sensor. 4 is a flowchart showing an outline of a manufacturing process of the wireless temperature sensor 1. It is a figure for demonstrating the 1st structure assembly process of the wireless temperature sensor. It is a figure for demonstrating the temperature detection element mounting process of the wireless temperature sensor. It is a figure for demonstrating the container assembly process of the wireless temperature sensor. It is a figure for demonstrating the structure of the other wireless temperature sensor. FIG. 5 is a diagram for explaining a first structure assembly process of the wireless temperature sensor 2. It is a figure for demonstrating the structure of the another wireless temperature sensor 3. FIG. (A) is sectional drawing which represented typically the propagation | transmission path | route of the heat from the measuring object (not shown) of the wireless temperature sensor 2, (b) is propagation of the heat from the measuring object (not shown) of the wireless temperature sensor 3. It is sectional drawing which represented the path | route typically. It is a figure for demonstrating the structure of the another wireless temperature sensor 4. FIG. It is a figure for demonstrating the manufacturing method of the wireless temperature sensor. It is a figure for demonstrating the structure of the another wireless temperature sensor 5. FIG. It is a figure for demonstrating the temperature detection element mounting process of the wireless temperature sensor. It is a figure for demonstrating the structure of the other wireless temperature sensor 6. FIG. It is the figure which looked at the wireless temperature sensor 6 from the direction 6D of FIG. It is a figure for demonstrating the structure of another wireless temperature sensor. It is the figure which looked at the wireless temperature sensor 7 from the direction 7D of FIG. It is a figure for demonstrating the structure of the another wireless temperature sensor 8. FIG. It is a figure for demonstrating the temperature detection element mounting of the wireless temperature sensor 8, and the whole assembly process. It is a figure for demonstrating the structure of the another wireless temperature sensor 9. FIG. It is a top view which shows the piezoelectric vibrator, temperature sensor, and temperature measurement method of a prior art example.

  Hereinafter, embodiments of a wireless temperature sensor according to the present invention will be described in detail with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof. Note that the dimensions of each drawing do not reflect the exact dimensions, and the size of parts may be exaggerated for explanation, and some parts may be omitted for explanation. The same numbers are assigned to the same elements, and duplicate descriptions are omitted.

  FIG. 1 is a diagram for explaining the structure of the wireless temperature sensor 1. In addition, the figure shown in FIG. 1 is sectional drawing along the AA line shown to Fig.3 (a) of the wireless temperature sensor 1. FIG.

  As shown in FIG. 1, the wireless temperature sensor 1 includes a container 50 including a lid 10 and a container main body 20, and a temperature detection element 30 fixed inside the container 50. The temperature detection element 30 is mounted on the lid 10.

  The lid 10 is a first structure, and is a microstrip antenna (hereinafter referred to as an antenna) formed by laminating an antenna electrode layer 11 and a GND electrode layer 13 on an insulating substrate 12. The microstrip antenna is also referred to as a planar antenna or a patch antenna, and is an antenna having high directivity, narrow bandwidth, and wide directivity while being small and thin.

The insulating substrate 12 has a thickness of about 1 mm and is formed of CaO—Al ₂ O ₃ —SiO ₂ —B ₂ O ₃ , which is a low-temperature fired ceramic material generally known as LTCC (Low Temperature Coated Ceramics). The However, the present invention is not limited to this, and the insulating substrate 12 may be formed using other LTCC. Other LTCCs include BaO—Al ₂ O ₃ —SiO ₂ —Bi ₂ O ₃ , BaOTiO ₂ —ZnO, and BaO—Nd ₂ O ₃ —Bi ₂ O ₃ —TiO ₂ , BaO—R ₂ O ₃ —TiO _{2. 2} (R is an alkali metal) and the like.

  The thickness of the insulating substrate 12 is not limited to approximately 1 mm, and varies depending on the ceramic material used, but may be a thickness sufficient to ensure the characteristics as an antenna.

The insulating substrate 12 may be formed using a high-temperature fired ceramic material having a high thermal conductivity, generally known as HTCC (High Temperature Coated Ceramics). HTCC includes, for example, aluminum oxide (Al ₂ O ₃ ) and aluminum nitride (AlN).

  The antenna electrode layer 11 is an electrode layer made of Cu and having a thickness of about 10 to 15 μm. The antenna electrode layer 11 may have other thicknesses. The antenna electrode layer 11 is electrically connected to the antenna connection pad 15a which is the first electrode pad provided on the lid mounting surface 15m of the insulating substrate 12 through the antenna via hole 11h which is the first via hole penetrating the insulating substrate 12. It is connected to the. The antenna via hole 11h and the antenna connection pad 15a are made of Cu.

  The GND electrode layer 13 is an electrode layer made of Cu and having a thickness of about 10 to 15 μm. The GND electrode layer 13 may have another thickness. The GND electrode layer 13 is electrically connected to the GND connection pad 15b which is the second electrode pad provided on the lid mounting surface 15m of the insulating substrate 12 through the GND via hole 13h which is the second via hole provided in the insulating substrate 12. Connected. The GND electrode layer 13 includes a GND pattern opening 13w for penetrating the antenna via hole 11h. The GND pattern opening 13w may be filled with a ceramic material that forms the insulating substrate 12. The GND via hole 13h and the GND connection pad 15b are made of Cu.

  The conductor patterns (that is, the antenna electrode layer 11, the antenna via hole 11h, and the antenna connection pad 15a, and the GND electrode layer 13, the GND via hole 13h, and the GND connection pad 15b) are formed using Cu. Other metals may be used. It is preferable to use Ag or Cu having high electrical conductivity for the conductor pattern. In particular, when LTCC is used for the insulating substrate 12 of the lid 10, efficient antenna characteristics can be obtained by using Ag or Cu having high electrical conductivity.

The container body 20 is a second structure and is made of Al ₂ O ₃ which is a high-temperature fired ceramic material generally known as HTCC. A body cavity 20c is formed in the container body 20 by a method described later. The container body 20 is not limited to Al ₂ O ₃ , and other HTCC such as aluminum nitride (AlN) can also be used.

  Furthermore, the container body 20 is not limited to the HTCC, and may be formed of other ceramic materials such as the above-described LTCC, a rigid substrate having a high relative dielectric constant, a polymer material such as polyimide, and a metal having an oxide film. .

  The temperature detection element 30 is mounted on the lid mounting surface 15 m of the insulating substrate 12 of the lid 10. The temperature detection element 30 has element bonding pads 34a and 34b. The element bonding pad 34a is connected to the antenna connection pad 15a which is the first electrode pad by a bonding wire 35a. The element bonding pad 34b is connected to the GND connection pad 15b which is the second electrode pad by a bonding wire 35b. Therefore, the element bonding pad 34a is electrically connected to the antenna electrode layer 11, and the element bonding pad 34b is electrically connected to the GND electrode layer 13.

  2A is a plan view of the temperature detection element 30, and FIG. 2B is a cross-sectional view of the temperature detection element 30 taken along the line CC shown in FIG. 2A. ) Is a cross-sectional view of the temperature detection element 30 taken along line DD shown in FIG.

  In FIG. 2A, the temperature detection element 30 is a surface acoustic wave element, and includes a surface acoustic wave element substrate 31, comb-shaped electrodes 32 a and 32 b provided on the surface of the surface acoustic wave element substrate 31, and a reflector 33. . An element bonding pad 34a is formed at the end of the comb-shaped electrode 32a, and an element bonding pad 34b is formed at the end of the comb-shaped electrode 32b. The surface acoustic wave element substrate 31 has a side wall 31a composed of four surfaces substantially perpendicular to the surface on which the comb-shaped electrodes 32a and 32b and the reflector 33 are provided.

The surface acoustic wave element substrate 31 is formed of a single crystal of lithium niobate (LiNbO ₃ ) and has a rectangular plate shape having a plan view size of about 10 mm × 10 mm and a thickness of about 2 mm. The surface acoustic wave element substrate 31 is not limited to this, and a single crystal substrate of a piezoelectric material, a substrate in which a thin film of a piezoelectric material is formed on a glass substrate or a Si substrate, or the like may be used. The piezoelectric material, for example, lithium tantalate (LiTaO _3), quartz (SiO _2), langasite _{(La 3 Ga 5 SiO 14)} , including but such Rangateito _{(La 3 Ta 0.5 Ga 5.5 O} 14), It is not limited to these.

  The comb-shaped electrode 32 a and the comb-shaped electrode 32 b are formed on one surface of the surface acoustic wave element substrate 31 so that two pairs of electrodes are alternately arranged. The comb-shaped electrode 32a and the comb-shaped electrode 32b are formed by sputtering using Cu. However, the comb electrodes 32a and 32b may be formed using an electrode material other than Cu, such as Au, Ti, Ni, chromium (Cr), aluminum (Al), or by a film forming method other than sputtering. It may be formed.

  The inter-electrode distance d between the comb-shaped electrode 32a and the comb-shaped electrode 32b needs a value corresponding to the wavelength of the surface acoustic wave excited by the surface acoustic wave element. When the propagation velocity of the surface acoustic wave is v, the wavelength is λ, and the excitation frequency of the comb electrode is f, there is a relationship of v = f × λ and d = λ / 2. For example, in the case of lithium niobate, when the excitation frequency is 2.45 GHz, the inter-electrode distance d needs to be about 0.8 μm.

  It is preferable that the electrode widths and distances between the adjacent comb electrodes 32a and 32b are equally spaced. In the above case, the width of each electrode is more preferably about 0.4 μm, which is half of the interelectrode distance d. Since the propagation velocity v varies depending on the material of the surface acoustic wave element substrate 31 that generates the surface acoustic wave, the inter-electrode distance d can be appropriately selected depending on an arbitrary material and frequency.

  The reflector 33 is formed on the surface of the surface acoustic wave element substrate 31 on which the comb-shaped electrodes 32a and 32b are formed to have substantially the same dimensions as the comb-shaped electrode 32a and the comb-shaped electrode 32b. The reflector 33 is formed by sputtering using Cu in the same manner as the comb electrodes 32a and 32b. However, the reflector 33 may be formed using an electrode material other than Cu, such as Au, Ti, Ni, chromium (Cr), and aluminum (Al), or formed by a film forming method other than sputtering. May be.

  The reflector 33 reflects the surface acoustic wave induced on the surface of the surface acoustic wave element substrate 31 by the high-frequency signal applied to the comb-shaped electrodes 32a and 32b, and again returns measurement information to the outside through the comb-shaped electrode 32a and the comb-shaped electrode 32b. Is provided to transmit a response signal. The principle of temperature measurement using a surface acoustic wave element will be described later.

  FIG. 3A is a plan view of the wireless temperature sensor 1, and FIG. 3B is a side view of the wireless temperature sensor 1.

  As shown in FIG. 3A, an antenna electrode layer 11 having a size of about 20 mm × 20 mm is provided on the upper surface of the wireless temperature sensor 1 of about 30 mm × 30 mm, that is, the surface of the lid 10. The external dimension of the wireless temperature sensor 1 is not limited to approximately 30 mm × 30 mm, and may be a size sufficient to mount the elastic surface element. Although the suitable outer dimensions of the antenna electrode layer 11 vary depending on the dielectric constant of the lid 10, the above dimensions (approximately 20 mm × 20 mm) are suitable when the relative dielectric constant of the lid 10 is about 9.8, for example. However, the dimensions of the antenna electrode layer 11 are not limited to this.

  As shown in FIG. 3B, the container 50 of the wireless temperature sensor 1 includes a lid 10 and a container body 20. The total thickness of the wireless temperature sensor 1 is approximately 8 mm, but is not limited to this and can be arbitrarily set.

  FIG. 4 is a cross-sectional view of the wireless temperature sensor 1 taken along line BB shown in FIG. In addition, in order to make it easy to understand the position of the BB cross section, the same reference numerals BB are also given in FIG.

  As shown in FIG. 4, the GND electrode layer 13 is provided in the inner layer of the insulating substrate 12, and the GND pattern opening 13w is provided in the center left of the GND electrode layer 13 so as to penetrate the antenna via hole 11h. The external dimensions of the GND electrode layer 13 are approximately 25 mm × 25 mm, but are not limited thereto. In order to further improve the high-frequency characteristics, it is preferable to make the shape of the GND electrode layer 13 larger.

  FIG. 5 is a diagram for explaining a temperature detection method by the wireless temperature sensor 1.

  The temperature detection method using the wireless temperature sensor 1 is based on the principle that the propagation speed of the surface acoustic wave propagating through the surface acoustic wave element substrate 31 depends on the temperature. In other words, the fact that the propagation time of the excitation surface acoustic wave Tw and the reflected surface acoustic wave Rw depends on the temperature of the surface acoustic wave element substrate 31 is utilized. Therefore, a calibration table of “propagation time versus surface acoustic wave element substrate temperature” is prepared in advance.

  First, an external device (not shown) transmits a high-frequency signal including an excitation frequency unique to the above-described antenna (a microstrip antenna including the antenna electrode layer 11, the insulating substrate 12, and the GND electrode layer 13). As shown in FIG. 5, the high-frequency signal received by the antenna is applied to the comb-shaped electrode 32 a and the comb-shaped electrode 32 b through the bonding wires 35 a and 35 b to bring about an electro-mechanical conversion effect on the surface acoustic wave element substrate 31. That is, an excitation surface acoustic wave Tw determined by the inter-electrode distance d of the comb-shaped electrode is generated on the surface of the surface acoustic wave element substrate 31.

  The excitation surface acoustic wave Tw propagates on the surface of the surface acoustic wave element substrate 31, is reflected by the reflector 33, and returns to the comb electrode 32a and the comb electrode 32b as a reflected surface acoustic wave Rw. Next, part of the reflected surface acoustic wave Rw has a mechanical-electrical conversion effect on the surface acoustic wave element substrate 31 and is converted into a high-frequency signal, and a response signal is transmitted to the outside by the antenna. On the other hand, a part of the reflected surface acoustic wave Rw that has not been converted into a high-frequency signal is reflected by the comb-shaped electrode 32a and the comb-shaped electrode 32b, and travels on the surface acoustic wave element 31 toward the reflector 33 again. Hereinafter, the reflected surface acoustic wave Rw travels between the reflector 33 and the comb electrodes 32a and 32b on the surface acoustic wave element substrate 31, and a part thereof is gradually converted into a high-frequency signal by the comb electrodes 32a and 32b. As it is being attenuated.

  When the response signal transmitted by the antenna reaches the external device and the external device receives the response signal, the external device measures the time from when the high-frequency signal is transmitted until the response signal is received.

  After measuring the time from when the high frequency signal is transmitted until the response signal is received, the propagation time of the surface acoustic wave in the surface acoustic wave element is calculated from the time from when the high frequency signal is transmitted until the response signal is received. . The temperature of the surface acoustic wave element substrate 31 is obtained from the calculated propagation time based on a calibration table of “propagation time versus surface acoustic wave element substrate temperature” prepared in advance. Then, based on the temperature of the surface acoustic wave element substrate 31, the measurement temperature of the object on which the surface acoustic wave element substrate 31 is mounted is determined.

  FIG. 6 is a graph showing temporal changes in the reflected surface acoustic wave intensity Rwp in the surface acoustic wave element.

  In the graph shown in FIG. 6, the vertical axis indicates the intensity Rwp of the reflected surface acoustic wave Rw, and the horizontal axis indicates the propagation time T of the surface acoustic wave. Since the reflected surface acoustic wave Rw is repeatedly reflected between the comb electrode 32a and the comb electrode 32b and the reflector 33, the reflected surface acoustic wave Rw is observed at a plurality of times from time T1 to time T3. The intensity Rwp of the reflected surface acoustic wave Rw is advantageous in measurement because Rw1 at time T1, that is, the intensity of the reflected surface acoustic wave Rw detected first is the largest.

  FIG. 7 is a diagram for explaining a configuration of a temperature measurement system using the wireless temperature sensor 1.

  The temperature display device 40 transmits a high-frequency signal for temperature measurement to each of the plurality of wireless temperature sensors, receives a response signal of each wireless temperature sensor, and based on the calibration table, The measurement temperature is displayed.

  In the example illustrated in FIG. 7, the temperature display device 40 has one measurement temperature display unit, and the display unit detects a predetermined wireless temperature sensor selected from a plurality of wireless temperature sensors by a switch or the like. Display temperature. However, an individual display unit corresponding to each of the plurality of wireless temperature sensors may be provided in the temperature display device 40.

  In the example shown in FIG. 7, three wireless temperature sensors 1 </ b> A to 1 </ b> C are used, and the surface acoustic wave propagation distance L is designed to be different. Each wireless temperature sensor has a configuration table of “propagation time versus surface acoustic wave element substrate temperature”.

  A high frequency signal including an excitation frequency specific to each wireless temperature sensor is transmitted from the temperature display device 40. A response signal delayed by the propagation time of the surface acoustic wave is generated from each wireless temperature sensor. The wireless temperature sensors 1A to 1C are preferably attached in close contact with the measurement target so as not to generate a thermal gradient with the measurement target (not shown).

  By changing the surface acoustic wave propagation distance L, each wireless temperature sensor reciprocates the reflector 33 from the comb-shaped electrodes 32a and 32b over different propagation times. The wireless temperature sensors 1A to 1C can be distinguished from the difference in propagation time. Furthermore, the temperature of the measurement object (not shown) can be measured from the calibration table of “propagation time versus surface acoustic wave element substrate temperature” corresponding to each wireless temperature sensor from this propagation time.

  As described above, in addition to the method of designing the surface acoustic wave propagation distance L of each wireless temperature sensor to be different, the wireless frequency sensors may be designed to have different operating frequencies. This can be realized, for example, by changing the inter-electrode distance d of the comb electrodes 32a and 32b. By changing the inter-electrode distance d of the comb electrodes, each wireless temperature sensor is excited only by the unique high frequency signal f1 to high frequency signal f3. Therefore, by providing the temperature display device 40 with a frequency sweep function (not shown), the high-frequency signal f1 to the high-frequency signal f3 can be sequentially transmitted and received, and the temperature of the measurement object (not shown) can be measured.

  The method of using the temperature characteristics of the surface acoustic wave propagation time of the surface acoustic wave element substrate 31 for temperature measurement has been described above. However, an impedance modulation function according to temperature is provided in the reflector 33, and a temperature is measured based on the absolute value of the intensity Rwp of the reflected surface acoustic wave, or a resonance circuit is formed by forming a resonance circuit with a piezoelectric element or a ferroelectric element. A method using temperature characteristics is also effective.

  FIG. 8 is a flowchart showing an outline of the manufacturing process of the wireless temperature sensor 1.

  As shown in FIG. 8, the manufacturing process of the wireless temperature sensor 1 includes a first structure assembly process ST1, a temperature detection element mounting process ST2, and a container assembly process ST3.

  In the first structure assembly step ST1, the antenna 10 is formed by preparing the lid 10 which is the first structure including the insulating substrate 12, and arranging the antenna electrode 11 and the GND electrode 13 on the first structure. It is a process. The temperature detection element mounting step ST2 is a process of fixing the temperature detection element 30 to the first structure so that the temperature detection element 30 is electrically connected to the antenna electrode 11 and the GND electrode 13. In the container assembly step ST3, the container body 20 as the second structure is prepared, and the first structure and the second structure are arranged so that the second structure is disposed on the side wall 31a side of the temperature detection element 30. This is a process of joining and assembling the structures.

  FIG. 9 is a diagram for explaining the first structure assembly step ST1 of the wireless temperature sensor 1. FIG.

  First, as shown in FIG. 9A, a first collective insulating substrate 12b is formed using an LTCC ceramic green sheet, and a plurality of antenna via holes 11h are provided using Cu.

  Next, as shown in FIG. 9B, as the antenna electrode forming step, the antenna electrode layer 11 that is a plurality of conductor patterns using Cu is formed on the first collective insulating substrate 12b produced in FIG. 9A. Each antenna electrode layer 11 is connected to each antenna via hole 11h by printing.

  Next, as shown in FIG. 9C, a second collective insulating substrate 12c is formed using a ceramic green sheet of LTCC. Furthermore, as a via hole forming step, a plurality of antenna via holes 11h for connecting to the antenna electrode layer 11 and a plurality of GND via holes 13h for connecting to the GND electrode layer 13 are formed on the second collective insulating substrate 12c using Cu. Form.

  Next, as shown in FIG. 9D, as the GND electrode forming step, the GND electrode layer 13 which is a plurality of conductor patterns using Cu is printed and formed on the produced second collective insulating substrate 12c. A GND pattern opening 13w is provided in a portion of the GND electrode layer 13 extending over the antenna via hole 11h, and the antenna via hole 11h is formed in the GND pattern opening 13w. Furthermore, each GND electrode layer 13 and each GND via hole 13h are connected.

  Next, as shown in FIG. 9E, the first collective insulating substrate 12b is overlaid on the second collective insulating substrate 12c, and the antenna via holes 11h are connected. Next, an electrode pad forming process is performed for forming the antenna connection pads 15a using Cu in the antenna via holes 11h and the GND connection pads 15b using Cu in the GND via holes 13h. Then, baking is performed at about 890 ° C. suitable for the first collective insulating substrate 12b and the second collective insulating substrate 12c.

  The formation order of the first collective insulating substrate and the second collective insulating substrate may be reversed. That is, after printing with each side turned upside down, the second collective insulating substrate 12c may be stacked on the first collective insulating substrate 12b and fired.

  After firing, a collective lid 10b as the first structure is obtained as shown in FIG. 9 (f). Here, each antenna electrode layer 11, each antenna via hole 11h, and each antenna connection pad 15a are integrated and connected, and each GND electrode layer 13, each GND via hole 13h, and each GND connection pad 15b are integrated. Conducted. The first collective insulating substrate 12b and the second collective insulating substrate 12c are integrated to form the collective insulating substrate 12a.

  The conductor patterns in the collective lid 10b described above are all formed of Cu, but may be formed of Ag instead of Cu.

  At the firing temperature (about 890 ° C.) described above, neither Ag nor Cu changes so as to substantially affect the antenna characteristics of the wireless temperature sensor.

  FIG. 10 is a diagram for explaining the temperature detection element mounting step ST2 of the wireless temperature sensor 1. FIG.

  First, as shown in FIG. 10A, a plurality of temperature detecting elements 30 are mounted on the cover mounting surface 15m of the collective cover 10b by a metal brazing method using an alloy of titanium (Ti) and nickel (Ni). To do. In addition, the metal used for the metal brazing method is not limited to these, and a combination of other metals may be used.

  Next, as shown in FIG. 10B, the element bonding pad 34a of each temperature detection element 30 and the antenna connection pad 15a of the collective lid 10b are connected by a bonding wire 35a. Similarly, the element bonding pad 34b of each temperature detection element 30 and the GND connection pad 15b of the collective lid 10b are connected by a bonding wire 35b.

  FIG. 10C is a cross-sectional view showing another method for joining the temperature detection element 30 to the collective lid 10b. As shown in FIG. 10C, gold bumps 36a and 36b are provided on the mounting surface of the temperature detection element 30f.

  More specifically, the element bonding pad 34a is connected to the gold bump 36a on the mounting surface, and the element bonding pad 34b is connected to the gold bump 36b on the mounting surface by via holes (not shown) provided inside the temperature detection element 30f. The gold bump 36a is welded to the antenna connection pad 15a on the mounting surface 15m, and the gold bump 36b is welded to the GND connection pad 15b on the mounting surface 15m, respectively, using an ultrasonic method or a pressure method. The manufacturing process by these other methods and the product thereof are also included in the technical scope of the present invention.

  FIG. 10D is a cross-sectional view showing still another method of joining the temperature detection element 30 to the collective lid 10b. The surface of the temperature detecting element 30 on which the element bonding pads 34a and 34b are formed faces the collective lid 10b. The temperature detection element 30 is flipped to the collective lid 10b so that the element bonding pad 34a is connected to the antenna connection pad 15a by the gold bump 36a and the element bonding pad 34b is connected to the antenna connection pad 15b by the gold bump 36b. Chip mounted. The configuration of the flip chip mounting will be described later.

  FIG. 11 is a diagram for explaining the container assembly process ST3 of the wireless temperature sensor 1. FIG.

  First, as shown in FIG. 11A, a ceramic material, a glass filler, a binder, a solvent, and the like are mixed and stirred, and a main body bottom aggregate substrate 21b is formed using the produced HTCC ceramic green sheet.

  Next, as shown in FIG. 11B, the main body side aggregate substrate 22b is formed using an HTCC ceramic green sheet, and the main body side aggregate substrate 22b is provided with a plurality of main body cavities 20c.

  Next, as shown in FIG. 11C, the main body bottom aggregate substrate 21b and the main body side aggregate substrate 22b are stacked and fired at a high temperature at about 1610 ° C. After firing, a collective container body 20b shown in FIG. 11 (d) is obtained.

  Next, as shown in FIGS. 11 (e) and 11 (f), the collective container body 20 b and the collective lid 10 b mounted with the temperature detection element 30 are placed so that the main body cavity 20 c is aligned with the position of the temperature detection element 30. By overlapping and joining, the collective wireless temperature sensor 1b is obtained. Thereby, the collection container main body 20b which is a 2nd structure is arrange | positioned at the side wall 31a side of the temperature detection element 30. FIG.

  The collective container body 20b and the collective lid 10b are formed by, for example, forming gold (Au) and tin (Sn) on the bonding surface and performing eutectic bonding. Since Au and Sn have high thermal conductivity, the collective container body 20b and the collective lid 10b are thermally connected. Thereby, the heat obtained by the collective container main body 20b (container main body 20) can be transmitted to each temperature detection element 30 via the collective lid 10b (lid 10). In addition, the material and joining method for joining the collecting container main body 20b and the collecting lid 10b are not limited to this, such as a metal brazing method and a solid phase joining method in which materials are pressure-fused at a high temperature. Other joining methods can also be used.

  As shown in FIG. 11 (f), the assembled collective wireless temperature sensor 1 b is divided along the cutting line dc to obtain the separated wireless temperature sensor 1 shown in FIG. 11 (g). In the above example, the method of manufacturing three wireless temperature sensors at a time has been described. However, the number of wireless temperature sensors manufactured at a time can be further increased.

  In the wireless temperature sensor 1, the temperature detection element 30 is mounted on an antenna (lid 10) formed by laminating the antenna electrode layer 11 and the GND electrode layer 13 on the insulating substrate 12. Therefore, it is possible to provide a wireless temperature sensor that is easy to manufacture and has improved reliability.

  FIG. 12 is a diagram for explaining the structure of another wireless temperature sensor 2.

  The wireless temperature sensor 2 is a modification of the wireless temperature sensor 1 described above. In the following, the wireless temperature sensor 2 will be described with respect to differences from the wireless temperature sensor 1, and description of points similar to the wireless temperature sensor 1 will be omitted as appropriate.

  The difference between the wireless temperature sensor 2 shown in FIG. 12 and the wireless temperature sensor 1 shown in FIG. 1 is the presence or absence of a heat conductive layer provided on the insulating substrate, and the others are the same.

  As shown in FIG. 12, the wireless temperature sensor 2 further includes a heat conductive layer 17 provided under the insulating substrate 12. The heat conductive layer 17 has a size of approximately 25 mm × 25 mm, and is thermally connected to the container body 20 at the end. A heat conduction layer opening 17w is provided at a position where the antenna connection pad 15a of the heat conduction layer 17 is formed. However, the shape and size of the heat conductive layer 17 can be arbitrarily designed as long as it can be thermally connected to the container body 20.

  The heat conductive layer 17 is formed using Cu, but other metals may be used. The heat conductive layer 17 is electrically connected to the GND connection pad 15b. The heat conductive layer 17 and the GND connection pad 15b may be integrally formed of the same material. In FIG. 12, the heat conductive layer 17 may be electrically connected to the antenna connection pad 15a instead of the GND connection pad 15b.

  The temperature detecting element 30 is metal brazed on the heat conductive layer 17. The element bonding pad 34a of the temperature detection element 30 is electrically connected to the antenna connection pad 15a via the bonding wire 35a. The element bonding pad 34b of the temperature detection element 30 is electrically connected to the GND connection pad 15b (or the heat conduction layer 17) via the bonding wire 35b.

  A first structure assembly process of the wireless temperature sensor 2 will be described with reference to FIG. In addition, since other processes (temperature detection element mounting process and container assembly process) in the manufacturing method of the wireless temperature sensor 2 are the same as those of the wireless temperature sensor 1, the description thereof is omitted.

  First, as shown in FIG. 13A, a first collective insulating substrate 12b is formed. Since the formation of the first collective insulating substrate 12b is the same as that of the wireless temperature sensor 1, description thereof is omitted.

  Next, as shown in FIG. 13B, a plurality of antenna connection pads 15a and GND connection pads 15b (thermal conductive layers 17) are formed using Cu. Each heat conduction layer 17 is provided with a heat conduction layer opening 17w.

  Next, as shown in FIG. 13C, the antenna connection pad 15a and the GND connection pad 15b (heat conduction) shown in FIG. 13B are formed on the LTCC ceramic green sheet in which the antenna via hole 11h and the GND via hole 13h are formed. Apply layer 17). At this time, the thermal conductive layer opening 17w is attached so as to match the position of the antenna via hole 11h. Further, the antenna connection pad 15a and the GND connection pad 15b (thermal conductive layer 17) are connected to the antenna via hole 11h and the GND via hole 13h, respectively, thereby obtaining the second collective insulating substrate 12d.

  Next, as shown in FIG. 13 (d), the GND electrode layer 13 is printed and formed on the created second collective insulating substrate 12d using Cu, and the GND electrode layer 13 is connected to the GND via hole 13h. The GND electrode layer 13 is provided with a GND pattern opening 13w, and an antenna via hole 11h is formed in the GND pattern opening 13w.

  Next, as shown in FIG. 13E, the first collective insulating substrate 12b is overlaid on the second collective insulating substrate 12d shown in FIG. 13D, and the antenna via hole 11h and the GND via hole 13h are connected to each other. To do. Furthermore, this is baked at about 890 degreeC, and collective cover 10Ab shown in FIG.13 (f) is obtained.

  The wireless temperature sensor 2 includes a heat conductive layer 17 provided below the insulating substrate 12, and the heat conductive layer 17 is thermally connected to each of the container body 20 and the temperature detection element 30. Therefore, the heat of the measurement object transmitted to the container body 20 can be transmitted from the container body 20 to the temperature detection element 30 via the heat conductive layer 17. Therefore, heat is prevented from being dissipated in the lid 10A, and the thermal responsiveness as the wireless temperature sensor 2 is further improved.

  In the wireless temperature sensor 2, since the temperature detection element 30 is connected to the GND connection pad 15b, noise resistance is improved, and characteristics and reliability as a temperature sensor are improved.

  FIG. 14 is a diagram for explaining the structure of still another wireless temperature sensor 3.

  The wireless temperature sensor 3 is a modification of the wireless temperature sensor 2 described above. In the following, the wireless temperature sensor 3 will be described with respect to points different from the wireless temperature sensor 2, and description of points similar to the wireless temperature sensor 2 will be omitted as appropriate.

  The difference between the wireless temperature sensor 3 shown in FIG. 14 and the wireless temperature sensor 2 shown in FIG. 12 is the position of the GND via hole, and the others are the same.

  As shown in FIG. 14, in the wireless temperature sensor 3, the temperature detection element 30 is fixed on the GND via hole 13h. Here, “fixed on the GND via hole 13h” includes the case where the position of the approximate center of the temperature detection element 30 is equal to the position of the approximate center of the GND via hole 13h, as shown in FIG. Not limited to this. For example, the case where the position of the approximate center of the GND via hole 13h is included in the region of the temperature detection element 30 and the case where the region of the GND via hole 13h is included in the region of the temperature detection element 30 are also included.

  The position of the GND via hole 13h is not limited to the vicinity of the approximate center of the lid 10A, but can be arbitrarily arranged. The temperature detection element 30 can be “fixed on the GND via hole 13h” in accordance with the position of the GND via hole 13h.

  FIG. 15A is a cross-sectional view schematically showing a propagation path of heat from a measurement object (not shown) of the wireless temperature sensor 2. FIG. 15B is a cross-sectional view schematically showing a propagation path of heat from a measurement object (not shown) of the wireless temperature sensor 3. In FIG. 15A and FIG. 15B, hatching representing a cross section is omitted for the sake of explanation.

  As shown in FIG. 15A, in the wireless temperature sensor 2, as indicated by H, heat transferred from the measurement object (not shown) to the container body 20 moves through the container body 20, and eventually the heat conduction layer 17. It is transmitted to. The heat transferred to the heat conduction layer 17 moves inside the heat conduction layer 17 toward the temperature detecting element 30, but a part of the heat moves to the insulating substrate 12 through the GND via hole 13h as indicated by H1. To do. This is because the thermal resistance of the GND via hole 13h made of Cu is low.

  As shown in FIG. 15B, in the wireless temperature sensor 3, as indicated by H, heat transferred from the measurement object (not shown) to the container body 20 moves through the container body 20, and eventually the heat conduction layer 17. It is transmitted to. The heat transferred to the heat conductive layer 17 moves inside the heat conductive layer 17 toward the temperature detection element 30 as indicated by H2. At this time, since there is no GND via hole 13 h having a low thermal resistance in the middle of the path to the temperature detection element 30, most of the heat flows into the temperature detection element 30 via the heat conductive layer 17.

  As described above, in the wireless temperature sensor 3, since the temperature detection element 30 is fixed on the GND via hole 13h, it is possible to reduce the amount of heat that moves to the inside of the lid 10 by the via hole. Therefore, in the wireless temperature sensor 3, the responsiveness of the temperature measurement is improved and the fluctuation of the antenna characteristics due to the influence of heat is reduced.

  FIG. 16 is a diagram for explaining the structure of still another wireless temperature sensor 4.

  The wireless temperature sensor 4 is a modification of the wireless temperature sensor 1 described above. Hereinafter, the wireless temperature sensor 4 will be described with respect to points different from the wireless temperature sensor 1, and description of points similar to the wireless temperature sensor 1 will be omitted as appropriate.

  The difference between the wireless temperature sensor 4 shown in FIG. 16 and the wireless temperature sensor 1 shown in FIG. 1 is the shape of the first structure and the second structure, and the others are the same.

  As shown in FIG. 16, the insulating substrate 12 of the container main body 10 </ b> B that is the first structure of the wireless temperature sensor 4 has a container shape including the container main body side portion 23 s, and is a lid that is the second structure. 25 forms a lid shape.

  A manufacturing method of the wireless temperature sensor 4 will be described with reference to FIG. In addition, about the process similar to the wireless temperature sensor 1, description is abbreviate | omitted suitably.

  First, as shown in FIG. 17A, a first collective insulating substrate 12b and a second collective insulating substrate 12c are formed, and the first collective insulating substrate 12b is overlaid on the second collective insulating substrate 12c. . In addition, since the said process is the same as the process demonstrated using Fig.8 (a)-(e), description is abbreviate | omitted.

  Next, as shown in FIG. 17B, a third collective insulating substrate 12e is formed using an LTCC ceramic green sheet, and a plurality of body cavities 20c are provided in the third collective insulating substrate 12e.

  Next, as shown in FIG. 17C, the third collective insulating substrate 12e, the first collective insulating substrate 12b, and the second collective insulating substrate 12c are stacked and baked at about 890 ° C. By firing, a collective container body 10Bb in which the first collective insulating substrate 12b, the second collective insulating substrate 12c, and the third collective insulating substrate 12e are integrated as shown in FIG. 17D is obtained.

  Next, as shown in FIG. 17 (e), the temperature detection element 30 is mounted in each main body cavity 20c of the collecting container main body 10Bb, and the antenna connection pad 15a and the GND connection pad 15b are connected by the bonding wire 35a and the bonding wire 35b. Each is connected to complete the assembly of the collection container body 10Bb.

  Next, as shown in FIG. 17 (f), a body bottom aggregate substrate 25c is formed using a ceramic green sheet of HTCC material, and the body bottom aggregate substrate 25c and the assembly container body 10Bb are made of Au or Sn. Eutectic bonding is performed to form the aggregate wireless temperature sensor 4b. Further, the collective wireless temperature sensor 4b is divided into pieces along a cutting line dc indicated by a one-dot chain line. A perspective view of the separated wireless temperature sensor 4 is shown in the lower part of FIG.

  In the wireless temperature sensor 4, the material can be selected more widely by making the first structure into a container shape and the second structure into a lid shape, that is, a plate shape. For example, when this wireless temperature sensor is used for higher-precision temperature measurement, a response is made by using a thin metal plate as the lid 25 (an oxide film can be provided on the surface as an insulating substrate if necessary). It is possible to improve the property. Further, by forming the lid 25 from a polymer material and adhering it to the container body 10B, it is possible to reduce the firing process and increase the production efficiency.

  FIG. 18 is a diagram for explaining the structure of still another wireless temperature sensor 5.

  The wireless temperature sensor 5 is a modification of the wireless temperature sensor 1 described above. Hereinafter, the wireless temperature sensor 5 will be described with respect to differences from the wireless temperature sensor 1, and description of points similar to the wireless temperature sensor 5 will be omitted as appropriate.

  The difference between the wireless temperature sensor 5 shown in FIG. 18 and the wireless temperature sensor 1 shown in FIG. 1 is the point of the mounting method of the temperature detection element and the point of contact between the temperature detection element and the container body. It is.

  As shown in FIG. 18, the temperature detection element 30 is flip-chip mounted on the lid 10 with the surface on which the comb-shaped electrodes 32 a and 32 b and the reflector 33 are provided facing the lid 10. The element bonding pad 34a is connected to the antenna connection pad 15a via the gold bump 36a, and the element bonding pad 34b is connected to the GND connection pad 15b via the gold bump 36b.

  As shown in FIG. 18, in the wireless temperature sensor 5, the surface opposite to the surface facing the lid 10 of the temperature detection element 30 is in contact with the container body 20. However, even if the temperature detection element 30 and the container body 20 are not in contact with each other, they may be close to each other to the extent that direct heat conduction occurs between them. The location of the temperature detection element 30 in contact with or close to the container body 20 and the distance between the temperature detection element 30 and the container body 20 in the case of proximity are arbitrarily designed as long as direct heat conduction occurs between them. can do.

  Hereinafter, the temperature detection element mounting process of the wireless temperature sensor 5 will be described with reference to FIG. The other steps of the manufacturing method of the wireless temperature sensor 5 (first structure assembly nationalization and container assembly step) are the same as those of the wireless temperature sensor 1, and thus the description thereof is omitted. Note that the thickness of the space inside the container body 20 is set to a length corresponding to the height from the mounting surface 15 m to the surface opposite to the lid 10 of the temperature detection element 30. Although the manufacturing process of one wireless temperature sensor will be described below for convenience of explanation, it is also possible to use a manufacturing method in which a plurality of wireless temperature sensors are formed at the same time and then separated.

  First, as shown in FIG. 19A, a gold bump 36 a is formed on the element bonding pad 34 a of the temperature detection element 30, and a gold bump 36 b is formed on the element bonding pad 34 b of the temperature detection element 30.

  Next, as shown in FIG. 19B, the temperature detection element 30 is inverted and the temperature detection is performed so that the gold bump 36a contacts the antenna connection pad 15a and the gold bump 36b contacts the GND connection pad 15b. The element 30 is placed on the lid mounting surface 15m.

  Next, by bonding and bonding the bonding pads (15a, 15b, 34a, 34b) and the gold bumps 36a, 36b by ultrasonic vibration, as shown in FIG. Is mounted on the lid 10. Thus, the temperature detection element mounting process in the wireless temperature sensor 5 is completed.

  In the wireless temperature sensor 5, the temperature detection element 30 and the container body 20 are in contact with each other or close to each other to the extent that direct heat conduction occurs between them. Therefore, the heat transferred from the measurement object to the container main body 20 can directly move from the container main body 20 to the temperature detection element 30 as indicated by H3 in FIG. Therefore, the responsiveness of temperature measurement in the wireless temperature sensor is improved.

  FIG. 20 is a view for explaining the structure of still another wireless temperature sensor 6, and FIG. 21 is a view of the wireless temperature sensor 6 as viewed from the direction 6D in FIG.

  The wireless temperature sensor 6 is a modification of the above-described wireless temperature sensor 5. Hereinafter, the wireless temperature sensor 6 will be described with respect to points different from the wireless temperature sensor 5, and description of points similar to the wireless temperature sensor 5 will be omitted as appropriate.

  The difference between the wireless temperature sensor 6 shown in FIG. 20 and the wireless temperature sensor 5 shown in FIG. 18 is the presence or absence of an opening provided on the side opposite to the side to be joined to the lid of the container body. It is.

  The container main body 20 </ b> A of the wireless temperature sensor 6 has an opening 20 </ b> AW on the side opposite to the surface facing the lid 10. Therefore, as shown in FIG. 21, the temperature detection element 30 is exposed to the outside.

  The shape of the opening 20AW is not limited to a rectangular shape, and may be an arbitrary shape such as a circular shape, a polygonal shape, or an irregular shape. The container body 20A can be obtained, for example, by creating the container body without using the body bottom aggregate substrate 21b described with reference to FIG. 11A, but can also be created by other methods. .

  A sealing resin 70 is provided at an edge of the temperature detection element 30 so as to fill a space between the temperature detection element 30 and the lid 10, and hermetic sealing is performed by the lid 10, the temperature detection element 30, and the sealing resin 70. The formed space 6S is formed. The space 6S includes comb electrodes 32a and 32b and a reflector 33 therein.

  In the wireless temperature sensor 6, the opening 20 </ b> AW is provided on the side opposite to the side of the container body 20 </ b> A that is joined to the lid 10, and the temperature detection element 30 is exposed to the outside. It becomes possible to arrange | position near the measurement object. Therefore, the heat of the measurement object is easily transmitted to the temperature detection element 30, and the thermal responsiveness of the wireless temperature sensor is improved.

  In the wireless temperature sensor 6, the comb-shaped electrodes 32 a and 32 b and the reflector 33 are included in the space 6 </ b> S hermetically sealed with the sealing resin 70, so that an external gas or fluid cannot enter the space 6 </ b> S. Therefore, the stability of the antenna characteristics of the wireless temperature sensor is improved. The space 6S may be a vacuum, and when the space 6S is a vacuum, the stability of the antenna characteristics of the wireless temperature sensor is further improved.

  22 is a view for explaining the structure of still another wireless temperature sensor 7, and FIG. 23 is a view of the wireless temperature sensor 7 as viewed from a direction 7D in FIG.

  The wireless temperature sensor 7 is a modification of the wireless temperature sensor 6 described above. In the following, the wireless temperature sensor 7 will be described with respect to differences from the wireless temperature sensor 6, and description of points similar to the wireless temperature sensor 6 will be omitted as appropriate.

  As shown in FIG. 22, the wireless temperature sensor 7 does not have the container body 20A itself, and instead, the sealing resin 71 becomes the second structure. The sealing resin 71 is formed so as to cover the side wall 31 a of the temperature detection element 30 and is disposed on the side wall 31 a side of the temperature detection element 30.

  Since the wireless temperature sensor 7 does not have a container body, it is easy to directly attach the temperature detection element 30 to the measurement object, and the thermal responsiveness of the wireless temperature sensor is further improved.

  FIG. 24 is a diagram for explaining the structure of still another wireless temperature sensor 8.

  The wireless temperature sensor 8 is a modification of the above-described wireless temperature sensor 5. Hereinafter, the wireless temperature sensor 8 will be described with respect to points different from the wireless temperature sensor 5, and description of points similar to the wireless temperature sensor 5 will be omitted as appropriate.

  The difference between the wireless temperature sensor 8 shown in FIG. 24 and the wireless temperature sensor 5 shown in FIG. 18 is the presence or absence of a heat conductor, and the others are the same.

  As shown in FIG. 24, the wireless temperature sensor 8 further includes a heat conductor 60 disposed between the temperature detection element 30 and the container body 20. The heat conductor 60 is thermally connected to both the temperature detection element 30 and the container body 20, and is bonded by, for example, a highly heat conductive resin. Alternatively, the heat conductor 60 may be sandwiched between the temperature detection element 30 and the container body 20 even if it is not bonded to the temperature detection element 30 and the container body 20.

  The thermal conductor 60 is formed of a silver paste having a high thermal conductivity. However, the heat conductor 60 is not limited to the silver paste, and may be formed of a material having high thermal conductivity such as an epoxy resin, a silicon resin, a ceramic material, a metal, and a heat resistant resin.

  Furthermore, it is preferable that the thermal conductor 60 has a small coefficient of thermal expansion in order to maintain the airtightness of the lid 10 and the container body 20.

  Hereinafter, the temperature detection element mounting and the entire assembly process of the wireless temperature sensor 8 will be described with reference to FIG. In addition, since the 1st structure assembly process of the wireless temperature sensor 8 is the same as that of the wireless temperature sensor 1, description is abbreviate | omitted.

  First, as shown in FIG. 25A, the temperature detecting element 30 is flip-chip mounted on the lid 10. In addition, since the said process is the same as the process mentioned above using Fig.19 (a)-(d), description is abbreviate | omitted.

  Next, as shown in FIG. 25 (b), the heat conductor 60, which is a silver paste formed by firing silver binder mixed in the surface opposite to the lid 10 of the temperature detection element 30. Are bonded using a highly heat conductive resin.

  Next, as shown in FIG. 25C, the container body 20 is overlapped and joined to the lid 10 on which the temperature detection element 30 is mounted so that the body cavity 20c is aligned with the position of the temperature detection element 30. The wireless temperature sensor 8 shown in FIG. Note that the bonding method is the same as the method described above with reference to FIGS.

  Unlike the above-described method, after bonding the heat conductor 60 to the bottom of the container body 20, the lid 10 and the container body 20 are overlapped and bonded so that the heat conductor 60 contacts the temperature detection element 30, A wireless temperature sensor 8 may be obtained.

  In the wireless temperature sensor 8, since the heat conductor 60 is disposed between the temperature detection element 30 and the container body 20, the heat of the measurement object transmitted to the container body 20 is detected via the heat conductor 60. It is transmitted to the element 30. Therefore, the heat of the measurement object is easily transmitted to the temperature detection element 30, and the thermal responsiveness of the wireless temperature sensor is improved.

  FIG. 26 is a diagram for explaining the structure of still another wireless temperature sensor 9.

  The wireless temperature sensor 9 is a modification of the above-described wireless temperature sensor 5. In the following, the wireless temperature sensor 9 will be described with respect to points different from the wireless temperature sensor 5, and description of points similar to the wireless temperature sensor 5 will be omitted as appropriate.

  The difference between the wireless temperature sensor 9 shown in FIG. 26 and the wireless temperature sensor 5 shown in FIG. 17 is the point of the structure of the container body, and the others are the same.

Similar to the container body 20 of the wireless temperature sensor 1, the container body 20B of the wireless temperature sensor 9 is formed of Al ₂ O ₃ which is HTCC. However, unlike the container body 20, the container body 20 </ b> B has a porous structure that is a structure that allows gas or fluid to pass through. For example, when the container main body 20B is formed of metal, a mesh structure may be adopted as a structure through which gas or fluid can pass. Thus, as a structure of the container main body 20B, a structure capable of allowing a gas or a fluid to pass can be designed according to the substance forming the container main body 20B.

  A sealing resin 70 is provided on the edge of the temperature detection element 30 of the wireless temperature sensor 9 so as to fill the space between the temperature detection element 30 and the lid 10. The lid 10, the temperature detection element 30, and the sealing resin A space 9S hermetically sealed by 70 is formed. The space 9S includes comb electrodes 32a and 32b and a reflector 33 therein.

  The wireless temperature sensor 9 has a structure in which the container body 20B allows gas or fluid to pass through. Therefore, as shown at H4 in FIG. 26, the gas or fluid around the wireless temperature sensor 9 passes through the container body 20B and enters and exits the space surrounded by the lid 10 and the container body 20B (excluding the space 9S). It becomes possible to do. Therefore, since the temperature detection element 30 can directly detect the temperature of the gas or fluid, the wireless temperature sensor 9 can more accurately measure the environmental temperature (atmosphere temperature).

  In the wireless temperature sensor 9, the comb electrodes 32 a and 32 b and the reflector 33 are included in a space 9 </ b> S hermetically sealed with a sealing resin 70. Therefore, the gas or fluid that passes through the container body 20B and flows into the space surrounded by the lid 10 and the container body 20B cannot enter the space 9S. Therefore, the stability of the antenna characteristics of the wireless temperature sensor is improved. The space 9S may be a vacuum, and when the space 9S is a vacuum, the stability of the antenna characteristics of the wireless temperature sensor is further improved.

  The above-described wireless temperature sensors 1 to 9 can be applied to devices that require remote sensing of temperature measurement.

  It should be understood by those skilled in the art that various changes, substitutions, and modifications can be made thereto without departing from the spirit and scope of the present invention, and the embodiments may be appropriately combined.

1, 1A-1C, 2, 3, 4, 5, 6, 7, 8, 9 Wireless temperature sensor 1b Collective wireless temperature sensor 10, 10A, 25 Lid 10b, 10Ab, 10Bb Collective lid 11 Antenna electrode 11h Antenna via hole 12 Insulation Substrate 12b First collective insulating substrate 12c, 12d Second collective insulating substrate 12e Third collective insulating substrate 13 GND electrode 13h GND via hole 13w GND pattern opening 15a Antenna connection pad 15b GND connection pad 15m, 15ma Cover mounting surface 17 Thermal conduction layer 17w Thermal conduction layer opening 20, 10B Container body 20b Collecting container body 20c Main body cavity 21b, 25c Main body bottom assembly board 22b Main body side assembly board 23s Container body side section 30, 30f Temperature detection element 31 Surface acoustic wave element Substrate 31a Side wall 32 , 32b Comb electrode 33 Reflector 34a, 34b Element bonding pad 35 Bonding wire 36a, 36b Gold bump 40 Temperature display device 50, 50A, 50B, 50C, 50D Container 70, 71 Sealing resin 101, 121 Container body 107, 125 Lid 104, 123 Diaphragm 130 Groove 102, 103, 122 External terminal 105, 106, 124, 128 Lead wire 108, 126 Coil Tw Excited surface acoustic wave Rw Reflected surface acoustic wave Rwp (reflected surface acoustic wave) intensity T, T1, T2, T3 Time d, d1, d2, d3 Interelectrode distance f1, f2, f3 High frequency signal t Propagation time ST1 First structure assembly process ST2 Temperature detection element mounting process ST3 Container assembly process dc Cutting line

Claims (15)

Providing a first structure and a second structure including an insulating substrate;
Forming an antenna by disposing an antenna electrode and a GND electrode on the first structure including the insulating substrate; and
Fixing the temperature detection element to the first structure so that the temperature detection element is electrically connected to the antenna electrode and the GND electrode;
Bonding and assembling the first structure and the second structure such that a second structure is disposed on the side wall of the temperature detection element;
A method for manufacturing a wireless temperature sensor.   The step of joining and assembling the first structure and the second structure further includes the first structure and the second structure so that the temperature detection element contacts the inside of the second structure. The method of manufacturing a wireless temperature sensor according to claim 1, comprising joining and assembling the second structure.   2. The method of manufacturing a wireless temperature sensor according to claim 1, wherein the second structure has an opening on a side opposite to a side bonded to the first structure.   The step of joining and assembling the first structure and the second structure further includes the step of arranging the heat conductor between the second structure and the temperature detecting element. The method of manufacturing a wireless temperature sensor according to claim 1, comprising joining and assembling the structure of the second structure and the second structure.   The method for manufacturing a wireless temperature sensor according to claim 1, wherein the second structure has a porous structure or a mesh structure. The step of forming the antenna further comprises:
A conductor pattern to be the antenna electrode is disposed on one surface of the insulating substrate,
A conductor pattern to be the GND electrode is disposed on the inner layer of the insulating substrate,
Forming a first via hole in conduction with the antenna electrode and a second via hole in conduction with the GND electrode on the insulating substrate;
6. The method according to claim 1, further comprising: forming a first electrode pad electrically connected to the first via hole and a second electrode pad electrically connected to the second via hole on the other surface of the insulating substrate. The manufacturing method of the wireless temperature sensor as described in any one.   The step of forming the antenna is further electrically connected to the second electrode pad on the other surface of the insulating substrate and thermally connected to the temperature detection element and the second structure. The method of manufacturing a wireless temperature sensor according to claim 6, comprising forming a heat conductive layer.   The step of fixing the temperature detection element to the first structure further includes fixing the temperature detection element on the second via hole on the heat conductive layer. Manufacturing method for wireless temperature sensor. A first structure having an antenna in which an antenna electrode and a GND electrode are disposed on an insulating substrate;
A surface on which the antenna electrode of the first structure is disposed is a temperature detection element fixed to a back surface side;
A second structure disposed on the side wall of the temperature detection element and joined to the first structure, and
The wireless temperature sensor, wherein the temperature detection element is fixed to the first structure so that the temperature detection element is electrically connected to the antenna electrode and the GND electrode.   The wireless temperature sensor according to claim 9, wherein the temperature detection element is fixed so as to contact the inside of the second structure.   The wireless temperature sensor according to claim 9, wherein the second structure has an opening on a side opposite to a side bonded to the first structure.   The wireless temperature sensor according to claim 9, further comprising a heat conductor disposed between the second structure and the temperature detection element.   The wireless temperature sensor according to claim 9, wherein the second structure has a porous structure or a mesh structure.   The wireless temperature sensor according to claim 9, further comprising a heat conductive layer formed on the insulating substrate and thermally connected to the temperature detection element and the second structure. A via hole formed in the insulating substrate and electrically connected to the GND electrode and the heat conductive layer;
The wireless temperature sensor according to claim 14, wherein the temperature detection element is fixed on the via hole on the heat conductive layer.

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