JPS60102097A - Packaging method of ultrasonic wave vibrator - Google Patents

Abstract

PURPOSE:To attain output of an ultrasonic wave of nearly uniform level from the entire region of an ultrasonic wave output face by bonding the ultrasonic wave vibrator with heating to one face in the lengthwise direction of a back plate and dividing minutely the ultrasonic wave vibrator through the dicing processing. CONSTITUTION:The ultrasonic wave vibrator 1 using a lead zirconate titanate as a raw material is supported to the back plate 4 made of plastic or rubber. Reinforced plates 20, 21 made of an elastic member having a small thermal coefficient are fixed to the side face in the lengthwise direction of the back plate 4. Then plural electrodes 20A, 21A leading out the signal for the use of the ultrasonic wave vibrator 1 as a transmission/reception vibrator are provided to the outer face of the reinforced plates 20, 21. The ultrasonic wave vibrator 1 is bonded with heat to the back plate 4 to which the reinforced plates are fixed and since the thermal distortion of the back plate 4 is suppressed by the action of the reinforced plate, the flat state of the ultrasonic wave vibrator 1 is maintained almost perfectly.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The invention is based on the mounting method θ' (K maintenance) of an ultrasonic transducer, especially the internal structure of an ultrasonic probe used for precision measurement of medical equipment, etc. The present invention relates to a method of loading an ultrasonic transducer.

[Prior art and its problems]

There are various types of vibrators used in ultrasonic probes, such as disk-shaped ones and rectangular ones. On the other hand, ultrasonic probes for medical and precision measurements can be used to measure a wide range of objects. While measuring f m, the changes are often recorded on C) LT or recording paper, so in order to improve the measurement accuracy, it is necessary to have good resolution or approximately equalization from the entire output side It is said that the equipment satisfies the standard of safety v1-, such as having an ultrasonic output of -level [7].

FIGS. 1 to 2 show an example of a conventionally used medical or precision measurement probe.

In this conventional example, a high-frequency vibrator is used to improve the resolution, and a matching layer 3 and an acoustic lens 2 are installed to improve the ultrasonic output and prevent beam dispersion. Furthermore, a back plate 4 as a vibrator holder is fixedly attached to the back side of the vibrator l.

Note that 5 indicates a case.

As shown in FIGS. 3 to 5, the vibrator 1 has electrodes 11 and 12 attached to a piezoelectric element 10 made of lead zirconate titanate, etc., in the shape shown in the figure, and a lead, a JI3 , 14 are generally soldered as shown in each figure. In this case, the grain 1 used is one that has been finely divided by dicing as shown in FIG.

However, each of the transducers 1 iL , I A + . Since the distance S between the lead wires 13 and 13 is a value of 0.02 [mm], some of the adjacent vibrators IA and iA are short-circuited due to the soldering work of the lead wires 13. It has become difficult to use the same amount f of solder for mounting 14 for each vibrator IA.

On the other hand, it is said that the function of the back plate 4vC is to almost completely attenuate the ultrasonic waves propagating from the transducer 1, thereby preventing the generation of false echoes. For this reason, the back plate 4 is often made of plastic or rubber material.

However, this plastic or rubber-based material generally has an essential drawback in that it is easily deformed under the influence of external thermal and mechanical forces.

On the other hand, for adhering the vibrator 1 to the back plate 4, heat adhesion, which has high adhesive strength and durability, is adopted. For this reason, the back plate 4 undergoes thermal deformation as shown in S or Z in FIG. At the same time, the matching layer 3 shown in FIG.
With a thickness of 4 mm, it is impossible to form the ultrasonic wave uniformly over the entire surface, and in this respect, it is difficult to output ultrasonic waves at a uniform level from the entire output surface to the outside.

[Purpose of the invention]

The present invention improves the disadvantages of the prior art,
The object of the present invention is to provide a method of loading an ultrasonic transducer that makes it possible to output an approximately average level of full ultrasonic wave output from the entire area of the ultrasonic output surface, and also to significantly improve productivity and quality. purpose.

[Summary of the invention]

Therefore, the present invention fixes reinforcing plates made of an elastic member with a small coefficient of thermal expansion to both longitudinal sides of a back plate formed in the shape of a rectangular parallelepiped, and then applies ultrasonic waves to one longitudinal side of the back plate. The camera element is heated and bonded, and then the entire ultrasonic transducer is divided into smaller parts, or if necessary, the electrode surface and each reinforcing plate of each of the subdivided transducers are preformed. In order to achieve the above-mentioned object, a technique is employed in which the signal extraction electrode is electrically connected to the signal extraction electrode by wire bonding. [Embodiment of the Invention] Hereinafter, a first embodiment of the present invention will be described based on FIGS. 8 to 11.

In these figures, 1 indicates an ultrasonic transducer as in the case of the conventional example described above, and 4 indicates a back metal plate as a transducer holder. The ultrasonic vibrator 1 is made of a piezoelectric element such as lead zirconate titanate, and the back plate 4 is made of plastic or rubber as the main material, similar to the conventional example described above. has been done. This back plate 4 has both corner portions 4A and 4B of the surface on which the ultrasonic transducer 1 is mounted.
Although it is in a chamfered state as shown in the figure, it may not necessarily be processed in this way.

Furthermore, reinforcing plates 20 and 21 are fixed to both sides of this back plate 4. The reinforcing plates 20 and 21 are made of an elastic member 1 having a small coefficient of thermal expansion, such as a metal oxide. Further, on the outer surface of each reinforcing plate 20.21, a signal extraction electrode 20A is provided for using the ultrasonic transducer 1 as a transmitting/receiving transducer.

20A, . . . , 21A, 21A, . . . are provided at multiple locations.

Then, the reinforcing plates 20 and 21 are brought into contact with and fixed to the back plate 4 as shown by arrows A and A in FIG. It is now possible to do so. Therefore, the thermal deformation of the back plate 4 is caused by the reinforcing plate 20.
．． 21, the ultrasonic transducer 1 maintains an almost completely flat state and is firmly attached to the back plate 4.
It can stick to.

FIG. 9 shows a state in which the ultrasonic transducer 1 is divided into pieces by tying after the ultrasonic transducer 1 is fixed. In this case, each transducer IA.

The dimension l of IA, . . . and the distance S between them are set to be the same as in the conventional case. Each of these oscillators IA
, LA, . . . valley electrode surfaces 319.32 and folded electrode surfaces 31A, 32A are formed in advance as shown in FIG.
The piezoelectric element 10 with 2 A completely formed has its end 10
A, IOB is rounded, thereby significantly strengthening the adhesion strength of the folded electrode surfaces 31A and 32A. Furthermore, since the effective vibration area U of this transducer IA is set at the inner center of the piezoelectric element i o iHB of the transducer IA, the directional beam is always on the center line of the probe. It is set as follows.

FIG. 10 shows the folded electrode surface 31A of each vibrator IA.
, 32A and each signal extraction electrode 2 on the reinforcing plate 20.21
0A, 2OA, . . . are connected and electrically connected by the gold wire bonding method. In this case, in this embodiment, the oscillators IA are divided into blocks into a plurality of groups and are formed so that voltage pulses of a predetermined frequency are applied to the oscillators IA. Each signal extraction electrode 21A, 21 on the reinforcing plate 21 side
A.

The same is true for... When this wire bonding is completed, the lead wire 40
, 40 , ... and 41.41 , ... parts are
A molding member is fixed to the entire structure, thereby protecting each of the lead wires 40, 41.

In this way, in this embodiment, since the lead wires 40 and 41 are connected to each vibrator IA by the wire bonding method, solder and other foreign matter do not adhere to each vibrator IA as in the conventional case, and at the same time Since the lead wires 40° and 41 are fixed under exactly the same conditions, each vibrator IA
The overall vibration conditions are the same, and therefore there is an advantage in that it is possible to output ultrasonic waves with approximately uniform intensity throughout at this point, and at the same time, the working time is significantly shortened, and the quality is further improved. Therefore, there is an advantage that productivity can be sufficiently improved. Other specific configurations are the same as those of the prior art example described above.

FIG. 12 shows a second embodiment. In this embodiment, the lead wires 40 and 41 are all identical signal extraction electrodes 20A or 21A.
[For the plurality of conductive transducers IA, the plurality of transducers IA in the group are brought into contact with a conductive adhesive 421/trowel as shown in the overall diagram. in this case,
The wire bonding of the lead wire 40 may be omitted, for example to two wires as shown in the figure. The other configurations are the same as those of the first embodiment described above.

Even in this case, in addition to having the same functions and effects as the first embodiment described in 1), there is an advantage that the wire bonding work time is further shortened.

〔Effect of the invention〕

As described above, according to the present invention, a reinforcing plate base made of an elastic member having a small coefficient of thermal expansion is fixed to both sides in the longitudinal direction of the back plate formed in the shape of a rectangular parallelepiped, and then We adopted a structure in which the ultrasonic vibrator is heat-bonded to one side and then divided into smaller pieces by tying, so the ultrasonic vibrator can be firmly attached to the back plate without bending. Therefore, each of the subdivided oscillators is fixed to the back plate under exactly the same conditions. Therefore, the sameness of the oscillation conditions of each oscillator is maintained at this point, and each This produces the effect that the entire ultrasonic wave output of approximately the same intensity as the vibrator can be output.

In addition, after the above-mentioned dicing process of the vibrator, the folded electric cedar surface formed in advance on each of the subdivided vibrators and the signal extraction electrodes formed in advance on each of the reinforcing plates are wire-bonded. Since we adopted the method of making the leads more conductive and merging, the formation conditions for each lead part of the vibrator are approximately the same, and at this point, the same vibration state is maintained for each vibrator, resulting in the same strength. In addition to outputting ultrasonic waves, lead wire attachment work is greatly speeded up and attachment errors are greatly reduced, which significantly improves the overall productivity and quality of the ultrasonic probe. It is possible to provide an unprecedented and excellent method of loading an ultrasonic transducer.

[Brief explanation of drawings]

Figure 1 is an external view showing the main parts of an ultrasonic probe according to the prior art, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3
7 to 7 are explanatory diagrams showing conventional examples, FIG. 8 is an exploded perspective view showing the first embodiment of the present invention, and FIG. 9 is a perspective view showing the state of the ultrasonic transducer after tying processing. Figure, 10th
The figure is a perspective view showing how lead wires are attached by wire bonding, FIG. 11 is a perspective view showing the entire subdivided vibrator, and FIG. 12 is a perspective view showing the second embodiment. 1... Ultrasonic transducer, IA... Segmented ultrasonic transducer, 4... Back plate, 2 (1, 21... Reinforcement plate. Patent applicant Tokyo Keiki No. 1) 1 Figure 2!''71 Figure 3 Figure 4 Figure 4 tt Figure 6 Figure 7 Figure 8 Two Figure 9 Figure 10 Figure 12 Figure 2

Claims (2)

[Claims] (1) A reinforcing plate made of an elastic material with a small coefficient of thermal expansion is fixed to both longitudinal sides of a back plate formed in the shape of an M cube, and then ultrasonic vibration is applied to one longitudinal side of the back plate. 1. A method of loading an ultrasonic transducer, comprising: adhering a transducer, and then dividing the ultrasonic transducer into V-shaped pieces by tying. (2) A reinforcing plate made of an elastic member with a small coefficient of thermal expansion is fixed to both longitudinal sides of the back plate formed in the shape of a U-cube, and then ultrasonic vibration is applied to one longitudinal side of the back plate. After that, the ultrasonic transducer is divided into r)+111 parts by tying process, and after this tying process,
An ultrasonic transducer characterized in that a light-reflecting electrode surface formed in advance on each of the subdivided transducers and a signal extraction electrode formed in advance on each of the reinforcing plates are electrically connected by a wire bonding method. How to load.