JP2010118958A - Ultrasonic transducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein automation is disturbed by complication in routing of I/O leads in preamplifier modules using ultrasonic transducers for transmission and reception of ultrasonic frequency bands. <P>SOLUTION: The preamplifier modules use the ultrasonic transducers. In the ultrasonic transducers, piezoelectric elements are bonded inside a bottom surface of a bottomed cylindrical case to form unimorph vibrators, and ultrasonic waves are transmitted and received by vibration of the unimorph vibrators. When electronic circuit boards are electrically connected to the ultrasonic transducers, metal terminals buried in housings are provided, and the electronic circuit boards are electrically connected to the ultrasonic transducers via the metal terminals to enable assembly by automatic machines, thus providing preamplifier modules using inexpensive ultrasonic transducers. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a preamplifier module using an ultrasonic transducer that transmits and receives an ultrasonic frequency band.

In an ultrasonic transducer according to a conventional embodiment, when this is embedded in a vehicle bumper or the like and an obstacle around it is detected, the pulse transducer electric signal is input to the ultrasonic transducer to obtain the super An ultrasonic signal corresponding to the input pulse burst electric signal is oscillated from the sonic transducer, and the oscillated ultrasonic signal is reflected by the obstacle after reaching the obstacle, and part of the ultrasonic signal is the same Return to the ultrasonic transducer. The ultrasonic transducer detects an obstacle by receiving the reflected signal.
FIG. 3 is a schematic longitudinal sectional view of a preamplifier module using an ultrasonic transducer according to a conventional embodiment. In FIG. 3, the piezoelectric element 1 is fixed inside the bottomed cylindrical case 2 made of an aluminum material or the like to form a unimorph vibrator. In the piezoelectric element 1, silver electrodes are taken out from the back in a folded structure from the back, and two electrodes are installed on one surface. The I / O leads 5a and 5b are soldered out of these silver electrodes. The input / output lead wires 5a and 5b are respectively soldered to the wire 6 of the connector 7 with the PVC coated wire. A sound absorbing material 3 made of a silicone foam or the like is placed on the upper surface of the piezoelectric element 8, and a sealing agent 4 made of an elastic material such as a silicone material or a urethane material is further filled into the bottomed cylindrical case 2. This is fixed to a housing 9 made of PBT resin or the like with a cushion 10 made of elastic resin. The terminals of the connector 7 are soldered to an appropriate pattern on the board 11 on which the electronic circuit is mounted, and electrically connected. A wire 13 for connecting to the controller is provided, and the preamplifier module is configured by sealing with a sealant 12 made of urethane or the like.
FIG. 4 is a schematic longitudinal sectional view of a preamplifier module using another ultrasonic transducer according to the conventional embodiment. In FIG. 4, the piezoelectric element 1 is fixed inside the bottom surface of the bottomed cylindrical case 2 made of an aluminum material or the like to form a unimorph vibrator. In the piezoelectric element 1, silver electrodes are taken out from the back in a folded structure from the back, and two electrodes are installed on one surface. The I / O leads 5a and 5b are soldered out of these silver electrodes. This is fixed to a housing 9 made of PBT resin or the like with a cushion 10 made of elastic resin. The input / output leads 5a and 5b are soldered to the silver electrodes of the piezoelectric element and taken out. A sound absorbing material 3 made of a silicone foam or the like is installed on the upper surface of the piezoelectric element 1, and a sealing agent 4 made of an elastic material such as a silicone material or a urethane material is further filled in the bottomed cylindrical case 2. The input / output leads 5a and 5b are soldered to an appropriate pattern of the substrate 11 on which the electronic circuit is mounted, and are electrically connected. A wire 13 for connecting to the controller is provided, and the preamplifier module is configured by sealing with a sealant 12 made of urethane or the like.
Conventionally, in an ultrasonic transmitter / receiver, it is necessary to route a long wire as a method of electrical connection between an input / output lead and a board on which an electronic circuit is mounted, which requires manual assembly, but is difficult to automate and reduces costs. It is a hindrance.
Tanikoshi Shinji “Ultrasound and its usage-Ultrasonic transducers and ultrasonic motors” Nikkan Kogyo Shimbun 1994 JP-A-11-345818

  In a preamplifier module using an ultrasonic transducer that transmits and receives ultrasonic frequency bands, a long wire is used as a method of electrical connection between the input / output leads taken out of the ultrasonic transducer and the board on which the electronic circuit is mounted. Must be routed, and manual assembly is required, which is difficult to automate and hinders cost reduction.

 In a preamplifier module using an ultrasonic transducer that forms a unimorph vibrator by laminating a piezoelectric element inside the bottomed cylindrical case to form a unimorph vibrator, and transmits and receives ultrasonic waves by the vibration of the unimorph vibrator. By providing a metal terminal with embedded wiring and making an electrical connection between the electronic circuit board and the ultrasonic transducer via this, it is possible to increase productivity and automate.

  The present invention has an advantage that it is possible to provide a preamplifier module using an ultrasonic transducer that is easy to automate and inexpensive, in a preamplifier module using an ultrasonic transducer.

  When used in in-vehicle corner sensors, etc., it can be embedded in a bumper, etc., and stable obstacle detection up to a short distance can be realized without malfunction and with high reliability and low cost.

FIG. 1 shows a schematic cross-sectional view of a preamplifier module using an ultrasonic transducer according to an embodiment of the present invention at the upper part, and a schematic view from the upper surface through which a substrate 11 on which electronic components are mounted is shown at the lower part. In FIG. 1, a piezoelectric element 1 is fixed inside a bottomed cylindrical case 2 made of an aluminum material or the like to form a unimorph vibrator. In the piezoelectric element 1, silver electrodes are taken out from the back in a folded structure from the back, and two electrodes are installed on one surface. This is fixed to a housing 9 made of PBT resin or the like with a cushion 10 made of elastic resin. The input / output leads 5a and 5b are soldered to the silver electrodes of the piezoelectric element and taken out. These input / output leads are connected to metal terminals 16a and 16b embedded in the housing 9 by soldering or the like. A sound absorbing material 3 made of a silicone foam or the like is placed on the upper surface of the piezoelectric element 8, and a sealing agent 4 made of an elastic material such as a silicone material or a urethane material is further filled into the bottomed cylindrical case 2. A substrate 11 on which an electronic circuit in which a through hole 8 is provided in advance is mounted at the position of embedded metal terminals 16a and 16b provided in the housing and is electrically connected to the part by soldering or the like. The preamplifier module is configured by being provided with a terminal for connection to and sealed with a sealant 12 made of urethane or the like.
FIG. 2 shows a schematic cross-sectional view of a preamplifier module using another ultrasonic transducer according to the embodiment of the present invention at the top, and a bottom view from the top through the substrate 11 on which electronic components are mounted. In FIG. 2, a piezoelectric element 1 is fixed inside the bottom of a bottomed cylindrical case 2 made of an aluminum material or the like to form a unimorph vibrator. In the piezoelectric element 1, silver electrodes are taken out from the back in a folded structure from the back, and two electrodes are installed on one surface. This is fixed to a housing 9 made of PBT resin or the like with a cushion 10 made of elastic resin. The input / output leads 5a and 5b are soldered to the silver electrodes of the piezoelectric element and taken out. These input / output leads are connected to metal terminals 16a and 16b embedded in the housing 9 by soldering or the like. This is filled with, for example, a foaming silicone material, a foaming urethane agent 15, a crushed foam or the like and a sealing agent 14 mixed with an elastic agent. A substrate 11 on which an electronic circuit in which through holes are provided in advance is mounted at the positions of embedded metal terminals 16a and 16b provided in the housing, is electrically connected to the part by soldering or the like, and is connected to the controller by a wire 13 or the like. Terminals for connection are provided, and the preamplifier module is configured by being sealed with a sealant 12 made of urethane or the like.
In the preamplifier module using the ultrasonic transducer according to the conventional embodiment, the electrical connection between the input / output leads of FIGS. 3 and 4 and the board on which the electronic circuit is mounted is not routed or handled in the conventional structure. Although complicated and difficult to automate, the present invention facilitates automation and can provide a preamplifier module using a low-cost ultrasonic transceiver.

  The present invention can be applied not only to a back sensor of a car but also to various fields where a drip-proof ultrasonic transducer is used.

Schematic of bottomed cylindrical case and preamplifier module according to an embodiment of the present invention Schematic of bottomed cylindrical case and preamplifier module according to an embodiment of the present invention Schematic diagram of bottomed cylindrical case and preamplifier module according to the conventional embodiment Schematic diagram of bottomed cylindrical case and preamplifier module according to the conventional embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric element provided with the return electrode 2 Bottomed cylindrical case 3 Sound absorbing material 4 Sealant made of elastic material 5a Input / output lead 5b Input / output lead
6 PVC coated wire 7 Connector with PVC coated wire 8 Through hole provided in electronic circuit board 9 Housing 10 Cushion 11 Electronic circuit board 12 Preamplifier module sealant 13 Preamplifier module wire 14 Crushed foam etc. and elastic agent were mixed Sealant 15 Sealant made of foaming elastic material

Embedded metal terminal provided in 16a housing Embedded metal terminal provided in 16b housing

Claims (1)

In a preamplifier module using an ultrasonic transducer that forms a unimorph vibrator by bonding a piezoelectric element inside the bottom surface of a bottomed cylindrical case and transmits and receives ultrasonic waves by the vibration of the unimorph vibrator, a part of the housing is partly attached to the housing. A preamplifier module using an ultrasonic transducer characterized in that an embedded metal terminal is provided and an electronic circuit board and an ultrasonic transducer are electrically connected through the metal terminal.

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