JP4918802B2 - Spherical surface acoustic wave device with electronic components, manufacturing method thereof, and surface acoustic wave propagation information transmitting device - Google Patents

Description

  The present invention relates to a spherical surface acoustic wave device with an electronic component, in which electronic components used for realizing various functions such as excitation and measurement of surface acoustic waves and transmission of measurement results are attached to the spherical surface acoustic wave device, and a method for manufacturing the same. And a surface acoustic wave propagation information transmitting element.

  2. Description of the Related Art In recent years, a spherical surface acoustic wave element is known in which interdigital electrodes are formed on the surface of a spherical piezoelectric crystal base material instead of a flat plate shape (see, for example, Patent Document 1).

  Here, the speed at which the surface acoustic wave multi-circulates changes according to the state of the substrate surface. Similarly, the resonance frequency of the surface acoustic wave changes when the circumference of the annular region becomes an integral multiple of the wavelength of the surface acoustic wave due to adhesion of molecules to the surface of the substrate.

  For this reason, spherical surface acoustic wave devices have been proposed for applications such as detecting the adhesion between molecules attached to the annular region of the substrate surface and the reaction film formed on the annular region with environmental gas, etc. Yes.

  In order to realize various functions such as excitation and measurement of surface acoustic waves and transmission of measurement results in such a spherical surface acoustic wave device, it is common to provide various electronic components by wiring or the like.

The patent literature is as follows.
International Publication No. WO 01/45255

  In this case, the installation position and direction of the various electronic components are generally such that the spherical surface acoustic wave element is spherical and positioning and direction determination are not easy.

  The present invention has been made in consideration of the above circumstances, and the installation position and direction of various electronic components are spherical surfaces with electronic components in which spherical surface acoustic wave elements are spherical and positioning and orientation are accurately performed. It is an object of the present invention to provide a surface acoustic wave propagation information transmitting element produced by using an acoustic wave element and a spherical surface acoustic wave element with an electronic component.

The invention corresponding to claim 1 has a dent in the spherical surface acoustic wave device, the dent is obtained by anisotropic etching, and the surface of the surface acoustic wave in the spherical surface acoustic wave device is in the dent . An electronic component-equipped spherical surface acoustic wave device characterized in that an electronic component for performing excitation, measurement, transmission of measurement results, and the like is installed and connected to the interdigital electrode of the spherical surface acoustic wave device.

The invention corresponding to claim 2 is the spherical surface acoustic wave element with electronic component, characterized in that the connection of the spherical surface acoustic wave element with electronic component according to claim 1 is a physically fixed connection.

An invention corresponding to claim 3 is a spherical surface acoustic wave device with electronic component, wherein the hollow of the surface acoustic wave device with electronic component according to claim 1 or 2 has a shape other than a circle. .

According to a fourth aspect of the present invention, there is provided a method for manufacturing a spherical surface acoustic wave device with an electronic component according to the third aspect , wherein the step of providing the depression by anisotropic etching with respect to the spherical surface acoustic wave element, A method of manufacturing a spherical surface acoustic wave device with an electronic component, comprising the steps of aligning and connecting the electronic component.

The invention corresponding to claim 5 is that the electronic components of the spherical surface acoustic wave element according to any one of claims 1 to 3 are a capacitor and a coil, and the capacitor is connected to the coil so that surface acoustic waves can be excited and measured from an external circuit. The surface acoustic wave propagation information transmitting element is characterized.

The invention corresponding to claim 6 is a surface acoustic wave excitation coil and capacitor as electronic components of the spherical surface acoustic wave device according to any one of claims 1 to 3 , and an electronic circuit for measurement and transmission of measurement results. Is a surface acoustic wave propagation information transmitting element.

The invention corresponding to claim 7 is the surface acoustic wave propagation information transmitting element characterized in that an antenna is attached to the spherical surface acoustic wave element according to any one of claims 1 to 3 .

  As described above, according to the first aspect of the present invention, the installation position and direction of the electronic component are facilitated even when the spherical surface acoustic wave device is spherical.

  According to the second aspect of the present invention, electrical connection with an electronic component can be easily performed even when the spherical surface acoustic wave device is spherical.

  According to the third aspect of the present invention, physical connection with an electronic component can be easily performed even when the spherical surface acoustic wave device is spherical.

  According to the present invention of claim 4, the direction of the electronic component can be easily determined even when the spherical surface acoustic wave device is spherical.

  According to a fifth aspect of the present invention, the hollow of the spherical surface acoustic wave element with an electronic component according to any one of the first to third aspects of the present invention has a shape other than a circle. It has become possible to provide an easy manufacturing method of the attached spherical surface acoustic wave device.

  Further, according to the present invention of claim 6, it is possible to provide a surface acoustic wave propagation information transmitting element having high wiring accuracy, yield, and reliability.

  Further, according to the present invention of claim 7, it is possible to provide a surface acoustic wave propagation information transmitting element with high wiring accuracy, yield, and reliability.

  Further, according to the present invention according to claim 8, it is possible to provide a surface acoustic wave propagation information transmitting element having high wiring accuracy, yield, and reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the spherical surface acoustic wave element 10 forms an interdigital electrode 13 on the surface of a piezoelectric crystal sphere, generates an electric field on the surface of the crystal sphere by applying an electric signal, and generates a surface acoustic wave. This is an electronic device characterized in that at least vibration is caused to circulate in an annular region as the propagation surface 11 and the circulating surface acoustic wave is converted again into an electric signal by the interdigital electrode 13.

  A normal manufacturing method can be manufactured by, for example, forming the crystal sphere 32 and then forming interdigital electrodes bi-directionally on the equator with the orientation of the crystal sphere called the Z-axis or C-axis as the ground axis. Quartz is generally used as the crystal sphere, but a piezoelectric crystal other than quartz can be realized using many piezoelectric crystals.

  As for the etching of the crystal sphere itself, it is known that etching is usually performed at a predetermined place using photolithography in the manufacture of a decorative article.

  By the way, the spherical surface acoustic wave element 10 has a propagation surface 11 which is a path around which the surface acoustic wave circulates in an annular shape with respect to the crystal sphere surface, and the propagation of the surface acoustic wave is inhibited in this region. If there is a structure to be broken or a crystal sphere is missing, the strength rapidly decreases with the orbit, and for example, it is difficult to obtain sensitivity when used as a sensor. Therefore, as shown in FIG. 5 using a mask in a portion other than the propagation path, even if partial etching is performed, the circulation of the surface acoustic wave is not hindered.

  Next, as expected from the fact that the electroacoustic transducer formed on the surface of the spherical surface acoustic wave device is used as an electronic component, the diameter of the device is 5 mm or less. As described above, the element requires at least an annular region having a spherical shape, but other regions do not have much surface acoustic wave energy and are used as a surface for fixing to a substrate or electrode bonding.

  By the way, for example, when trying to connect, since the surface irregularities are usually processed to a smooth surface of 100 microns or less in order to produce the crystal sphere of the present application, for example, using an ultrasonic bonder The anchor effect does not work, the adhesion is very weak, and peeling occurs in an environment where there is a lot of vibration.

  On the other hand, as shown in FIG. 6, the resist 31 is used to etch the crystal ball 32 region other than the surface acoustic wave circulation path and the depression to roughen the surface or form a concave surface (dent 17). For example, the anchor effect due to the unevenness on the surface is unlikely to cause a failure due to electrical disconnection.

  As shown in FIG. 5, by using a cyclized rubber-bisazide resist, a circular window having a diameter of 0.1 mm is opened on the C-axis surface portion of the direct crystal 3.3 mm crystal ball 32, and an appropriate concentration is obtained. An example is shown in which etching is performed using a buffered hydrofluoric acid. It can be seen that after 80 hours, etching is performed in a shape close to a triangle according to the different method of quartz. This direction is known to be the MM axis direction of the crystal.

  Using a separately prepared electronic component for embedding, a large amount is cut out from a silicon wafer using a micromachine technique. FIG. 1 is a diagram in which an IC chip manufactured for RF-ID is embedded.

  There are terminals for antenna connection, and they are connected to antenna wires on the surface of two spherical elements. In order to fix to the sphere surface, a conductive adhesive such as a conductive paste can be used.

  Since the etching is performed on the triangle by anisotropic etching, it is easy to align the orientation of the spherical element when connecting to the antenna line.

  The RF-ID is very small so that it is normally used, and is bonded to the base in advance and connected to a terminal for joining to the antenna electrode.

  FIG. 2 is a view in which the above components are joined to a spherical surface acoustic wave element. In order to use the ID-providing function of the RF-ID chip in the process of liquid-treating the surface of the element before the surface acoustic wave is circulated as an actual spherical surface acoustic wave element using the interdigital electrode, the element of this configuration is used. The RF-ID has an interdigital electrode that serves as an antenna necessary for communication.

  When the interdigital electrode is used, the electrode connected to the RF-ID element is grounded because the ID is damaged.

  3 and 4 show an example in which an IC circuit generally formed on the surface of a silicon substrate is embedded in an element. The interdigital electrode of a spherical surface acoustic wave element usually has a very high impedance and requires a matching circuit when connected to a 50 ohm meter circuit. If a component mounted with a capacitor or the like is mounted on this substrate and bonded to the element, fewer electronic circuits need to be formed outside.

  Actually, in order to excite the surface acoustic wave at a high frequency of 100 MHz or more, for example, a crystal has a fine pattern with a pattern period of several tens of microns or less.

1 is a perspective view of a spherical surface acoustic wave device with an electronic component according to an embodiment of the present invention. It is a perspective enlarged view which shows the part which connected the electronic component of the spherical surface acoustic wave element with an electronic component concerning the embodiment. It is process explanatory drawing which shows the etching process in the middle of manufacture of the spherical surface acoustic wave element with an electronic component concerning embodiment at the time of making an electronic component into an IC circuit. It is a perspective enlarged view which shows the part which connected the electronic component of the spherical surface acoustic wave element with an electronic component concerning the embodiment. It is a perspective view which shows the etching process in the middle of manufacture of the spherical surface acoustic wave element with an electronic component concerning each embodiment above. It is process explanatory drawing which shows the etching process in the middle of manufacture of the spherical surface acoustic wave element with an electronic component concerning embodiment of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Spherical surface acoustic wave element 11 ... Propagation surface 12 ... Spherical member 13 ... Interdigital electrode 14 ... Electrode (hot side)
15 ... Electrode (ground side)
DESCRIPTION OF SYMBOLS 16 ... Conductive paste 17 ... Depression 18 ... RF-ID chip 19 ... Antenna electrode joint terminal 20 ... Embedded base material 21 ... IC circuit 22 ... Silicon base material 23 ... Connection electrode 31 ... Resist 32 ... Crystal ball 33 ... Resistance 34 ... Etching solution

Claims (7)

A spherical surface acoustic wave element has a recess,
The depression is obtained by anisotropic etching,
Characterized in that the excitation and measurement of the surface acoustic wave in the spherical surface acoustic wave device, set up electronic components for performing such transmission measurements, and is connected to the interdigital electrodes of the spherical surface acoustic wave element to the recess A spherical surface acoustic wave device with electronic components.   2. The spherical surface acoustic wave device with electronic component according to claim 1, wherein the connection of the spherical surface acoustic wave device with electronic component is a physical fixed connection. 3. A spherical surface acoustic wave element with an electronic component according to claim 1, wherein the recess of the spherical surface acoustic wave element with an electronic component has a shape other than a circle. 4. The method of manufacturing a spherical surface acoustic wave device with an electronic component according to claim 3, wherein the step of providing the depression with respect to the spherical surface acoustic wave device by anisotropic etching, the spherical surface acoustic wave is aligned according to the shape of the depression. A spherical surface with an electronic component comprising a step of installing an electronic component for performing excitation and measurement of surface acoustic waves in the device, transmitting measurement results, etc., and connecting to the interdigital electrode of the spherical surface acoustic wave device A method of manufacturing an acoustic wave device. Electronic component of claims 1 to 3, one of the spherical surface acoustic wave device is the condenser and the coil, the surface acoustic wave propagation information transmission, characterized in that the condenser can excite measure the surface acoustic wave from an external circuit connected to the coil element. Surface acoustic wave propagation information transmitting device which is a transmission electronic circuit according to claim 1 to 3 or of the spherical surface acoustic wave electronic component as a surface acoustic wave exciting coil and a capacitor and measuring and measurement results of element . Surface acoustic wave propagation information transmitting element antenna of claims 1 to 3 or of the spherical surface acoustic wave device is characterized in that it is included.

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