JPH0211079B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an ultrasonic probe used in a medical ultrasonic diagnostic device or the like.

Conventionally, ultrasonic probes that use piezoelectric ceramics as a voltage body have been used, such as array type probes as probes used in medical ultrasonic diagnostic equipment, but the manufacturing method for them has generally already been developed. As shown in FIGS. 1a, b, and c, vibrating elements were assembled into a probe through manufacturing processes such as bonding polarized ceramics to a damper, cutting them, and coating them. That is, as shown in FIG. 2, a damper 4 is bonded to an already polarized piezoelectric ceramic electrode 2 having electrodes (thin metal) 2 and 3 on both sides, and an acoustic matching layer 5 is bonded to the other electrode 3. However, a cutting machine is then used to simultaneously cut the piezoelectric ceramics and the electrode matching layer into appropriate dimensions and shapes such as squares, strips, and rings to produce vibrating elements. Generally, when bonding a damper, coating, or acoustic matching layer 5 to piezoelectric ceramics, it is preferable to use a thermosetting or high-temperature adhesive in order to bond more firmly and to automate bonding such as pressure bonding. When using metal, alumina porcelain, or ceramics as the acoustic matching layer, it is preferable to perform high-temperature treatment such as welding or brazing. However, since the Curie point of piezoelectric ceramics is generally between 100 and several tens of degrees (°C) to several hundred degrees (°C), bonding using such high-temperature treatment will destroy the polarization of piezoelectric ceramics.
Bonding by such high temperature treatment was not possible as a manufacturing method because piezoelectricity would be lost. SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a method for manufacturing an ultrasonic probe by bonding through high-temperature treatment.

Next, the manufacturing method of the present invention will be explained. As shown in FIG. 3, a first electrode 2 is provided on the first surface of the ceramic material 1 before polarization, and a part of the second electrode (back electrode) 3 is connected to the surface through a conductive part 32. Before polarizing one electrode surface of the vibrator, which has a folded electrode 31 on a part of the first surface, a thermosetting or high-temperature adhesive is applied to the damper 4 as shown in FIG. Alternatively, an adhesive layer 6 is formed and bonded by high-temperature treatment such as welding or brazing, and an adhesive layer 7 also treated at high temperature is formed on the other three electrode surfaces of the vibrator to form a coating layer or an acoustic matching layer. Layer 5 is adhered and then cut using a cutting machine in the same manner as described above to produce a probe element as shown at 40 in FIG. 4, after which the probe element is polarized. . In other words, in the past, the ceramic blank was polarized in advance, and then the electrodes were attached, the damper or coating layer, and the acoustic matching layer were attached. After the probe element 40 is fabricated by bonding and cutting the damper and acoustic matching layer on the surface, polarization is applied to the ceramic base plate, so there is no polarization breakdown of the piezoelectric ceramic due to high processing, and strong high-temperature contact is possible. It becomes possible to liberalize adhesion such as differential bonding and pressure bonding. In addition, in the case of an array type probe as shown in Figure 4, it may be cut after adhering to the damper as described above, but if a damper is not used, acoustic matching is not performed except for the process of adhering to the damper. After adhesion of the layers, cutting and polarization may be performed. Furthermore, the resonator is manufactured using the same process as before, that is, electrodes are placed on a polarized ceramic blank plate, the constants of the resonator such as the frequency are measured, the polarization is destroyed, a tamper and a matching layer are attached, and repolarization is performed. Alternatively, electrodes may be provided on a similarly polarized ceramic blank plate, a tamper and a matching layer may be bonded and cut, and then polarization destruction and repolarization may be performed.

Methods for polarization include the room temperature polarization method performed at a room temperature below the Curie point, the high temperature polarization method performed at a temperature as high as possible below the Curie point, the alternating current electric field superimposition method, and other methods. good. Further, in the case of an array type probe as shown in FIG. 4, each probe element can be individually and independently polarized.

As explained above in detail, according to the method for manufacturing a probe according to the present invention, a piezoelectric vibrator is bonded to a damper, an acoustic matching layer, etc., and the piezoelectric ceramic is polarized after cutting, so the piezoelectric ceramic is polarized by high-temperature treatment. Adhesion,
Welding, brazing, etc. are now possible, making it possible to manufacture probes with strong adhesive strength. Furthermore, in the case of array type probes, each probe element can be polarized independently, so the polarization direction between each element can be made different, making it possible to manufacture ultrasonic probes with excellent performance. becomes.

[Brief explanation of drawings]

Figures 1a, b, and c show piezoelectric ceramics that have already been polarized; Figure 2 is a cross-sectional view of the probe;
Figure 3 is a perspective view showing the structure of piezoelectric ceramics;
FIG. 4 is a diagram showing the structure of an array type probe. 1... Piezoelectric ceramics, 2, 3... Electrode, 4
... Damper, 5 ... Coating layer or acoustic matching layer, 6, 7 ... Adhesion, welding, brazing, etc. layer, 40 ... Probe element.

Claims (1)

[Claims] 1. A step of preparing a blank ceramic plate with electrodes provided on both sides, a step of bonding a damper material to one electrode side of the blank plate, and a step of bonding a matching layer to the other electrode side. 1. A method for manufacturing an ultrasonic probe, comprising: a step of polarizing the ceramic blank formed in each of the steps described above. 2. The method of manufacturing an ultrasonic probe according to claim 1, wherein the polarized ceramic blank is processed into an ultrasonic probe and then repolarized. 3. The method for manufacturing an ultrasonic probe according to claim 1, wherein the polarized ceramic blank is cut into an ultrasonic probe and then repolarized. 4. A step of preparing a blank plate with electrodes provided on both sides of the ceramic, a step of bonding a damper material to one electrode side of the blank plate, a step of bonding a matching layer to the other electrode side, and a step of bonding a matching layer to the other electrode side of the ceramic blank. 1. A method for manufacturing an ultrasonic probe, comprising the steps of cutting a blank plate and subjecting the ceramic blank formed in each of the above steps to polarization treatment.