JP2005167746A - Manufacturing method of ultrasound transducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an ultrasound transducer with no sticking of an adhesive to the side surface of an ultrasound matching layer and that of a case for ultrasonic vibrator, with no close control of the quantity of the adhesive. <P>SOLUTION: A ring-like recess 17 is provided to a case 2 for an ultrasound vibrator, which is positioned outside the part abutting with an acoustic matching layer 1 through an adhesive 9. Since the adhesive 9 protruding from between the acoustic matching layer 1 and the case 2 for the ultrasound vibrator flows into the ring-like recess 17, no adhesive 9 that has protruded stick to the side surface or front surface of the acoustic matching layer 1. So, the ultrasound transducer is efficiently manufactured, and measurement precision and reliability in measuring flow rate with the ultrasound transducer are improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing an ultrasonic transducer (ultrasonic sensor) that transmits and receives ultrasonic pulses.

  Conventionally, this type of ultrasonic transducer includes the following configurations. That is, as shown in FIG. 4, the acoustic matching layer 1 is bonded and fixed to the top outer surface 13 of the ultrasonic transducer case 2 with an adhesive 9, and the top surface 14 of the ultrasonic transducer case 2 is piezoelectric. One electrode surface 12 of the body 3 is bonded and fixed by an adhesive 10. Then, between the other electrode surface 11 of the piezoelectric body 3 and the external electrode terminal 7 of the terminal plate 5, a conductive elastic body (conductor) 4 is sandwiched in a pressurized state for electrical connection. Yes.

Further, the flange portion 15 at one end of the ultrasonic transducer case 2 and the terminal plate 5 are joined by electric welding. A sealed space 16 formed by the ultrasonic vibrator case 2 and the terminal plate 5 is filled with nitrogen gas. The external electrode terminals 7 and 8 provided on the terminal plate 5 are electrically insulated by a glass (insulating portion) 6. As a result, the other electrode surface 11 and the external electrode terminal 7 are electrically connected via the elastic body 4, and the ultrasonic vibrator case 2, the flange portion 15, and the terminal in which the one electrode surface 12 also serves as the external electrode. It is electrically connected to the external electrode terminal 8 through the plate 5 (see, for example, Patent Document 1).
JP 2001-50785 A (page 4-6, FIG. 8)

  However, according to the conventional ultrasonic transducer described above, when the ultrasonic transducer case 2 and the acoustic matching layer 1 are bonded and fixed by the adhesive 9, the adhesive 9 protrudes from the acoustic matching layer 1 at the time of pressure bonding. (Flowing out) and may adhere to the side surface or the surface of the acoustic matching layer 1. When the adhesive 9 adheres to the side surface or the surface of the acoustic matching layer 1 in this way, when the ultrasonic wave transmitted from the piezoelectric body 3 propagates to the gas via the ultrasonic transducer case 2 and the acoustic matching layer 1, Variations in the directivity of ultrasonic waves occur. For example, when flow measurement is performed using a pair of other ultrasonic transducers, the transmission / reception sensitivity of the ultrasonic transducers decreases, and the measurement becomes unstable. Problems arise.

  Further, in order to solve the above problem, the amount of the adhesive 9 is reduced and the joining portion of the ultrasonic transducer case 2 and the acoustic matching layer 1 (the ultrasonic transducer case 2 and the acoustic matching layer 1 are connected to each other). It is conceivable to prevent the adhesive 9 from adhering except for (between). However, if the amount of the adhesive 9 is reduced, the ultrasonic wave transmitted from the piezoelectric body 3 is transmitted to the ultrasonic vibrator when the adhesion between the ultrasonic vibrator case 2 and the acoustic matching layer 1 is insufficient. When propagating to the gas through the case 2 and the acoustic matching layer 1, the directivity of the ultrasonic waves varies as described above.

  Therefore, the adhesive 9 is sufficient to bond and fix the ultrasonic transducer case 2 and the acoustic matching layer 1 and protrudes (flows out). It is conceivable that an appropriate amount is applied so as not to adhere to a surface that is not on the joint portion side of the adhesive. However, applying an appropriate amount in this way, that is, controlling the amount of the adhesive in detail is the manufacturing It was very difficult.

  Therefore, the present invention solves the above-mentioned conventional problems, and when the ultrasonic transducer case and the acoustic matching layer are bonded and fixed, the side surface and the surface of the acoustic matching layer can be applied without finely managing the amount of the adhesive. An object of the present invention is to provide a method for manufacturing an ultrasonic transducer that can prevent adhesion of an adhesive.

  In order to achieve the above-described object, a method of manufacturing an ultrasonic transducer according to claim 1 of the present invention is characterized in that the ultrasonic transducer case and the acoustic matching layer are bonded with an adhesive when the ultrasonic transducer case and the acoustic matching layer are bonded. The ultrasonic vibrator case is provided with a means for preventing the adhesive from protruding, and when the ultrasonic vibrator case and the acoustic matching layer are pressure-bonded to each other, the overflow of the protruding adhesive is prevented by the means for preventing the adhesive from protruding. It is characterized by suppression.

  According to a second aspect of the present invention, there is provided an ultrasonic transducer manufacturing method comprising: a piezoelectric body having a pair of opposed electrode surfaces; and an ultrasonic transducer case electrically connected to the one electrode surface. A terminal plate having two external electrode terminals electrically connected to one end of the ultrasonic vibrator case, a conductor sandwiched between the other electrode surface of the piezoelectric body and the one external electrode terminal; In order to obtain an ultrasonic transducer having an acoustic matching layer facing the piezoelectric body and bonded to the ultrasonic transducer case by an adhesive, the ultrasonic transducer case prevents the adhesive from protruding. Means is provided, and when the ultrasonic transducer case and the acoustic matching layer are pressure-bonded, the protruding adhesive means suppresses the overflow of the protruding adhesive.

Therefore, according to the first and second aspects of the present invention, the excessively applied adhesive can be prevented from flowing out by the protrusion preventing means provided on the ultrasonic vibrator case plate.
According to a third aspect of the present invention, there is provided a method of manufacturing an ultrasonic transducer according to the first or second aspect, wherein the protrusion preventing means provided in the ultrasonic transducer case is provided with an adhesive. It is located outside the portion that contacts the acoustic matching layer.

Therefore, according to the third aspect of the present invention, the adhesive is suppressed by the protrusion preventing means and hardened first, and the outflow of the adhesive from the inside is sealed to prevent the protrusion.
Furthermore, in the method for manufacturing an ultrasonic transducer according to claim 4 of the present invention, in the configuration according to any one of claims 1 to 3, the protrusion preventing means is formed in the ultrasonic transducer case. It is characterized by comprising a ring-shaped recess into which the adhesive flows.

Therefore, according to the fourth aspect of the present invention, the adhesive excessively applied to the surface of the ultrasonic transducer case flows into the recess formed in the ultrasonic transducer case plate.
Moreover, the ultrasonic transducer manufacturing method according to claim 5 of the present invention is characterized in that, in the configuration according to claim 4, the ring-shaped recess of the ultrasonic transducer case is formed by press working. It is what.

  Therefore, according to the invention of claim 5, the ultrasonic vibrator case having a recess into which the excessively applied bonding agent flows is formed by press working.

  According to the first and second aspects of the present invention described above, it is possible to prevent the excessively applied adhesive from flowing out by providing the protrusion preventing means on the surface of the ultrasonic transducer case on the acoustic matching layer side. Therefore, it is possible to provide an ultrasonic wave transmitter / receiver that can be suppressed by the means and that prevents the adhesive from adhering to the side surface or the surface of the acoustic matching layer. As described above, when the ultrasonic transducer case and the acoustic matching layer are bonded and fixed, it is possible to prevent the adhesive from adhering to the side surface or the surface of the acoustic matching layer without finely managing the amount of the adhesive. A stable ultrasonic transducer can be manufactured.

  Therefore, when the ultrasonic wave transmitted from the piezoelectric material propagates to the gas through the ultrasonic transducer case and the acoustic matching layer, the directivity of the ultrasonic wave does not vary. For example, another ultrasonic transducer is set to 1 When flow measurement is performed using a pair, measurement can be performed stably without causing a decrease in transmission / reception sensitivity of the ultrasonic transducer.

  According to the fifth aspect of the present invention described above, since the ring-shaped recess can be processed simultaneously with the trimming process of the flange portion of the ultrasonic transducer case, it can be manufactured at low cost.

The ultrasonic transducer according to the first embodiment of the present invention includes a piezoelectric body having a pair of opposed electrode surfaces, an ultrasonic transducer case electrically connected to one electrode surface, and an ultrasonic vibration. One end of the child case is electrically connected and has a terminal plate having two external electrode terminals, a conductor sandwiched between the other electrode surface of the piezoelectric body and the one external electrode terminal, and the piezoelectric body. In order to obtain an ultrasonic transducer having an acoustic matching layer bonded to an ultrasonic transducer case with an adhesive, a ring-shaped recess is formed in the ultrasonic transducer case to prevent the adhesive from protruding. The ultrasonic transducer case and the acoustic matching layer are configured to suppress the outflow of the protruding adhesive by the protruding prevention means.
[Embodiment 1]
Embodiment 1 of the present invention will be described below with reference to FIGS. In the first embodiment, the same or substantially the same components as those in the conventional example (FIG. 4) described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  That is, in FIGS. 1 and 2, 1 is an acoustic matching layer, 2 is an ultrasonic transducer case, 3 is a piezoelectric body, 4 is an elastic body (conductor), 5 is a terminal plate, 6 is glass, 7 and 8 are External electrode terminals, 9 and 10 are adhesives, 11 is the other electrode surface, 12 is one electrode surface, 13 is the top outer surface, 14 is the top inner surface, 15 is the flange portion, and 16 is the sealed space. In the first embodiment, a ring-shaped recess (an example of a protrusion prevention means) 17 is formed on the top of the ultrasonic transducer case 2. At that time, the concave portion 17 is formed outside the portion in contact with the acoustic matching layer 1 through the adhesive 9.

  In the ultrasonic transducer configured as described in the first embodiment, the adhesive 9 is applied to the top outer surface 13 of the ultrasonic transducer case 2 and the acoustic matching layer 1 is pressure bonded. A thin film of the adhesive 9 is formed between the top outer surface 13 and the acoustic matching layer 1. The adhesive 9 protruding from between the ultrasonic transducer case 2 and the acoustic matching layer 1 during the pressure bonding flows into the recess 17 and suppresses further outflow. 9 does not adhere to the side surface or the surface of the acoustic matching layer 1.

  Further, in the first embodiment, the concave portion 17 serving as a fluid reservoir into which excess adhesive 9 flows is opened outside the contact portion with the acoustic matching layer 1 on the top outer surface 13 of the ultrasonic transducer case 2. Therefore, the adhesive 9 flows in and hardens first, and the outflow from the inside is sealed, thereby preventing the adhesive 9 from protruding.

  According to the first embodiment, when the ultrasonic transducer case 2 and the acoustic matching layer 1 are bonded and fixed, the side surfaces of the acoustic matching layer 1 and the acoustic matching layer 1 can be obtained without finely managing the amount of the adhesive 9. Adhesives can be prevented from adhering to the surface, and a stable ultrasonic transducer can be manufactured.

Therefore, when the ultrasonic wave transmitted from the piezoelectric body 3 propagates to the gas via the ultrasonic transducer case 2 and the acoustic matching layer 1, the directivity of the ultrasonic wave does not vary. For example, other ultrasonic wave transmission / reception waves When a flow rate is measured using a pair of devices, the transmission / reception sensitivity of the ultrasonic transducer is not lowered, and the measurement can always be performed stably.
[Embodiment 2]
Next, a second embodiment of the present invention will be described with reference to FIG.

  In the ultrasonic transducer according to the second embodiment of the present invention, the ring-shaped concave portion 17 of the ultrasonic transducer case 2 is formed by press working. That is, the press device 20 includes a die 21 and a punch 22, and processes the ring-shaped recess 17 simultaneously with the trimming of the flange portion 15 of the ultrasonic vibrator case 2.

  According to the ultrasonic transducer in the second embodiment, the ring-shaped concave portion 17 of the ultrasonic vibrator case 2 which is a means for preventing the adhesive 9 from adhering to the side surface and the surface of the acoustic matching layer 1 is formed by pressing. It can be easily processed by molding.

  In the first and second embodiments described above, a form in which the ring-shaped concave portion 17 is formed by press working on the top of the ultrasonic vibrator case 2 is shown as the protrusion preventing means. The form etc. which shape | molded the ring-shaped recessed part (concave groove) by the cutting process in the top part of the case 2 for children may be sufficient.

  As described above, according to the method for manufacturing an ultrasonic transducer according to the present invention, the adhesive does not adhere to the side surface or the surface of the acoustic matching layer, which greatly contributes to the improvement of the manufacturing efficiency of the ultrasonic transducer. Furthermore, since the accuracy of the fluid flow measurement device equipped with this ultrasonic transducer can be remarkably improved, it can be applied to applications such as gas and liquid fluid flow measurement devices.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows Embodiment 1 of this invention and shows an ultrasonic transducer. The schematic block diagram of the principal part. The schematic block diagram which shows Embodiment 2 of this invention and shows press work. The schematic block diagram which shows a prior art example and shows an ultrasonic transducer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Acoustic matching layer 2 Case for ultrasonic transducers 3 Piezoelectric body 4 Elastic body (conductor)
DESCRIPTION OF SYMBOLS 5 Terminal board 7 External electrode terminal 8 External electrode terminal 9 Adhesive 10 Adhesive 11 The other electrode surface 12 One electrode surface 13 Top part outer surface 14 Top part inner surface 15 Flange part 17 Ring-shaped recessed part (extrusion prevention means)
20 Press equipment

Claims (5)

  When joining the ultrasonic transducer case and the acoustic matching layer with an adhesive, the ultrasonic transducer case is provided with means for preventing the adhesive from protruding, and the ultrasonic transducer case and An ultrasonic transducer manufacturing method, wherein when the acoustic matching layer is pressure-bonded, the overflowing adhesive is prevented from flowing out by a protrusion preventing means.   A piezoelectric body having a pair of opposing electrode surfaces, an ultrasonic transducer case electrically connected to the one electrode surface, and one end of the ultrasonic transducer case electrically connected to each other A terminal plate having external electrode terminals, a conductor sandwiched between the other electrode surface of the piezoelectric body and one external electrode terminal, and the piezoelectric body facing the piezoelectric body and bonded to the ultrasonic transducer case with an adhesive In order to obtain an ultrasonic transducer including the acoustic matching layer, the ultrasonic transducer case is provided with an adhesive protrusion preventing means, and the ultrasonic transducer case and the acoustic matching layer are provided. A method of manufacturing an ultrasonic wave transmitter / receiver characterized in that, when pressure bonding is performed, outflow of the protruding adhesive is suppressed by a protrusion preventing means.   The ultrasonic transmission / reception according to claim 1 or 2, wherein the protrusion preventing means provided in the ultrasonic transducer case is located outside a portion in contact with the acoustic matching layer via an adhesive. A method of manufacturing a waverage.   The ultrasonic transducer according to any one of claims 1 to 3, wherein the protrusion prevention means comprises a ring-shaped recess formed in the ultrasonic transducer case and into which an adhesive flows. Method. The method for manufacturing an ultrasonic transducer according to claim 4, wherein a ring-shaped concave portion of the ultrasonic transducer case is formed by press working.

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