JPH0832108B2 - Ultrasonic probe manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention reduces the number of grating lobes and increases the transmission / reception efficiency in the production of an electronic scanning ultrasonic probe.
Further, in order to make the manufacturing method easy, a single piezoelectric element is cut into a predetermined thickness, and the front matching layer and the back matching layer or the sound wave absorber are formed as they are.

[Industrial applications]

The present invention relates to a method for manufacturing an electronic scanning ultrasonic probe.

The electronic scanning ultrasonic probe has a structure in which a plurality of strip-shaped piezoelectric elements are arranged on a flat surface or on a curved surface, so that it did not significantly appear in the case of a single-plate piezoelectric element. Grating lobes occur, the sound field is disturbed, and as a result, the resolution tends to decrease. Moreover, since the element area is reduced, the transmission / reception efficiency is reduced. Therefore, there is a need for a manufacturing method in which the element spacing is made as small as possible and is close to the sound field of a single plate.

[Conventional technology]

Since the structure of the electronic scanning ultrasonic probe is complicated, many kinds of manufacturing methods can be considered. However, the common points of the conventional manufacturing methods are as shown in FIG. 3 (a).
As shown in FIG. 3 (b), a single-plate piezoelectric element 1 made of PZT or the like having electrodes 2 and 3 formed on the upper and lower surfaces is adhered and fixed on a back matching layer or a backing 4 such as a sound absorber, and then the third As shown in FIG. 3 (c), it is cut into strips or matrixes, and the matching layer 6 is formed as shown in FIG. Is. After cutting into a matrix shape, a method of filling with resin and bending into a curved surface is also adopted, but basically it can be considered that the element spacing is maintained.

[Problems to be solved by the invention]

Although these conventional manufacturing methods are excellent in that they are stably manufactured, they have a drawback in that the element spacing G is determined by the thickness of a blade when cutting. Blades with a thickness of 10 μm are currently on the market, but for example, 3.
The thickness of the piezoelectric element used for the 5MHz oscillator is about 400μm.
Yes, 50 for stable cutting of piezoelectric elements of this thickness.
It was necessary to use a blade having a thickness of not less than μm, and therefore it was difficult to arrange elements at intervals of not more than 50 μm.

[Means for solving problems]

The method for manufacturing an ultrasonic probe of the present invention includes electrodes 2 on the upper and lower surfaces,
After cutting the single-plate piezoelectric element 1 on which 3 is formed into strips,
After arranging the spacers, the front matching layer having the groove for fitting the strip element is adhered and fixed to one surface of the strip element, and then the back matching layer or the sound absorber is adhered, fixed or formed on the other surface of the strip element. Consists of steps.

〔Example〕

Example 1 Length of 120 mm, width of 11 mm and thickness of 40 with electrodes 20 and 30 formed on both sides
The PZT plate 10 shown in FIG.
Fix it with wax 50 at 0 as shown in Fig. 1 (b) and cut it with a blade of 60μm in thickness at 235μm pitch as shown in Fig. 1 (c). After removing the wax, length 175μm, width 11mm, thickness 400μ
m strip-shaped element was obtained.

Next, as shown in Fig. 1 (d), a strip-shaped element with a thickness of 25 μm and a length
Spacer made of polyimide film with a width of 20 mm and a width of 300 μm
60 are alternately arranged in the recess 70a of the holding jig 20. Then, as shown in FIG. 1 (e), the front matching layer 80 is bonded with an adhesive. If a groove having the same width as the strip element is formed in the matching layer 80, the spacing between the strip elements can be properly maintained. After the adhesive is hardened, it is taken out from the holding jig 70 and bonded to the sound wave absorber 90 as shown in FIG.

FIG. 2 is a diagram showing an embodiment of the present invention. In this embodiment, a spacer 100 higher than the strip-shaped element is used.

Then, as shown in FIG. 2 (a), in the recess 70a of the jig 70,
Epoxy resin in which iron oxide powder is dispersed is poured and cured as it is.

After the epoxy resin has hardened, it is taken out from the holding jig and bonded to the front matching layer 80 with an adhesive.

According to this embodiment, the spacer 100 has a shape in which it is difficult to insert the holding jig, so that it is possible to eliminate interference between adjacent strip-shaped elements.

〔〔The invention's effect〕

This probe having an element pitch of 200 μm and an element gap of 25 μm had a 17% increase in transmission / reception efficiency and a slight decrease in grating lobe, as compared with a probe having an element gap of 50 μm.

In the case of a higher frequency probe, if the element pitch is reduced in order to reduce the occurrence of grating lobes, the transmission / reception efficiency will be significantly reduced if the element gap is large.Therefore, the present invention is more effective at higher frequencies. is there.

[Brief description of drawings]

1 and 2 show an embodiment according to the present invention, and FIG. 3 shows a conventional example. In the figure, 10 is a piezoelectric plate, 2 and 3 are electrodes, 60 is a spacer, 80 is a front matching wave, and 90 is a radio wave absorber.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumihiro Namiki, 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Kazuhiro Watanabe 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Yasuo Iida 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa, Fujitsu Limited (56) References JP-A-52-101070 (JP, A) JP-A-58-120397 (JP, A)

Claims (1)

[Claims] 1. A method for manufacturing an electronic scanning ultrasonic probe having a plurality of piezoelectric elements arranged on a plane or in a curved surface, the single-plate piezoelectric element having electrodes formed on the upper and lower surfaces thereof. Cutting into strips, installing spacers between the strip elements, adhering and fixing a front matching layer having a groove into which the strip elements fit to one surface of the strip elements, and back aligning A method of manufacturing an ultrasonic probe, comprising a step of adhesively fixing or forming a layer or a sound wave absorber on the other surface of the strip element.