JPH04212510A - Ultrasonic delay line - Google Patents

Abstract

PURPOSE:To efficiently apply an ultrasonic absorbing member with high accuracy by forming the groove of prescribed depth at a prescribed position on the side face of an ultrasonic delay medium. CONSTITUTION:On a transducer adhering face 2 provided by notching one side face of an ultrasonic delay medium 10 at 45 deg., an input transducer 4 and an output transducer 5 are respectively joined. On the input transducer 4 and the output transducer 5, elliptical electrodes 14 are respectively provided, and a ground electrode 13 separated at the center is formed on the adhering face 2. At the parts of side faces 60A, 60B and 60C excepting for a regular reflection area, grooves 17, 17,... of the prescribed depth are formed parallelly to the thickness direction of the ultrasonic medium 10. Since ultrasonic absorbing members 16, 16,... are applied into these groove parts 17, 17,..., the ultrasonic absorbing members can efficiently be applied with high accuracy.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to improvements in ultrasonic delay lines.

0002

[Prior Art] The bulk wave type ultrasonic delay line that is currently widely used is a multi-reflection type ultrasonic delay line that uses a rectangular ultrasonic delay medium in order to obtain a relatively long delay time while being compact. Lines are the norm. The ultrasonic delay line 40 shown in FIG. 8 is a multi-reflection type ultrasonic delay line, and has a thickness of d
The main component is an ultrasonic delay medium 20 having a cutout surface (transducer adhesion surface) 2 with one side cut out at an angle of 45° along the center line.

On the transducer bonding surface 2, ground electrodes 3, 3 separated at the center are provided, and on top of the ground electrodes 4, an input transducer 4 and an output transducer 5 each having signal electrodes 14, 14 bonded to the upper surface are provided. Each electrode 3, 3, 14, 14 is connected to a lead wire 24, 24, 234, 34 using a conductive adhesive A, A, . . . , A, respectively, as shown in the figure. .

[0004] Also, the main surface 50 of this ultrasonic delay medium 20
, 50 are formed with holes 18, 18, . . . , 18 having bottom surfaces in order to remove spurious signals, and the inner peripheral surface of each hole 18, 18, . Ultrasonic absorber (silver (lead)) to absorb spurious signals
epoxy resin) 19, 19,..., 19 is applied.

On the other hand, ultrasonic absorbing materials 16, 16, . , 16 are applied.

[0006]

[Problem to be Solved] In the case of this type of ultrasonic delay line 40, the ultrasonic absorbing material 16,
The more 16, . . . , 16 is applied, the more the effects of spurious signals can be removed. Conversely, if the ultrasonic absorbing material 16, 16, . . . , 16 is applied to the regular signal reflection area, the regular signal will be greatly attenuated, making it impossible to satisfy the product characteristics. However, since the thickness d of the ultrasonic delay medium 20 of this ultrasonic delay line 40 is as thin as about 3 [mm], the side surfaces 60A, 60B,
Applying (printing) the ultrasonic absorbing materials 16, 16, . . . , 16 to predetermined positions on the 60C with high precision requires skill, and there is an inconvenience that work efficiency is extremely low.

[0007]

OBJECTS OF THE INVENTION The present invention improves the disadvantages of the conventional example and provides an ultrasonic delay line in which an ultrasonic absorbing material is efficiently and precisely applied to a predetermined position on the side surface of an ultrasonic delay medium. Its purpose is to provide.

[0008]

[Means for Solving the Problems] Accordingly, in the present invention, one side of a rectangular ultrasonic delay medium is cut at 45 degrees to form a transducer joint surface, and input/output transducers are bonded to this transducer joint surface. In the ultrasonic delay line, a groove portion of a predetermined depth is formed in the thickness direction of the delay medium in a portion other than the regular signal reflection area on each side surface of the ultrasonic delay medium excluding the transducer joint surface, and a groove portion is formed in the thickness direction of the delay medium. A structure is adopted in which an ultrasonic absorbing material is applied to each of them, thereby attempting to achieve the above object.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

[0010] Here, the same reference numerals are given to the same constituent members as in the above conventional example.

The bulk wave type ultrasonic delay line 1 shown in FIG.
An ultrasonic delay medium 10 is formed with a transducer adhesive surface 2 formed by cutting out the transducer adhesive surface 2. On this transducer adhesive surface 2, an input transducer 4,
Output transducers 5 are connected respectively.

On this transducer adhesive surface 2, earthing electrodes 3, 3 are formed separated at the center, and on each electrode 3, 3, an elliptical electrode 14, 14 is formed on the upper surface.
An input transducer 4 and an output transducer 5 are bonded together using a conductive adhesive (not shown). In addition, the grounding electrodes 3, 3 and the electrodes 14, 1
4, conductive adhesives A, A,
..., A are used to connect the lead wires 24, 24, 34, 34.

Further, holes 18, 18, . . . , 18 are provided in the main surfaces 50, 50 in areas other than the regular signal passages, and the inner circumferential surface of each hole 18, 18, . Material (silver)
Epoxy resin containing lead) 19 is applied.

On the other hand, grooves 17, 17, .
is formed, and ultrasonic absorbing materials 16, 16,..., are formed inside it.
16 is applied.

A method of manufacturing the ultrasonic delay line 1 constructed as described above will now be described with reference to FIGS. 2 to 7.

A. As shown in Figure 2, cut out the corner at 45° along the center line to form the notched surface (transducer adhesive surface).
A prismatic ultrasonic delay medium block 11 formed by forming 2
, and a delay medium block 1 adjacent to this cutout surface 2
A central portion 12 is provided on the top surface 1B and side surface 1C of 1 as shown in the figure.
Then, ground electrodes 3, 3 having non-electrode forming portions are formed.

B. The transducers 4, 5 are then glued with conductive adhesive on the electrodes 3, 3 of the transducer adhesive surface 2 of this delay medium block 11 with electrodes 29, 29 provided on their own lower surfaces 4A, 5A (not shown). Use to adhere. In this case, a plurality of elliptical electrodes 14, 14, . . . , 14 may be provided in advance on the upper surfaces 4A, 5A at predetermined intervals along the thickness direction of the delay medium block 11.

C. And as shown in FIG. 4, the side surface 60A
, 60B, 60C other than the regular signal reflection area,
Grooves 17, 17, ..., 17 of a predetermined depth are formed parallel to the thickness direction of the ultrasonic delay medium 10, and ultrasonic absorbing materials 16, 16, ..., 16 are applied inside the grooves (see FIG. 5). ). Note that the depth of the groove portion 17 is 1 [mm] or less, and is 0.3 mm.
~0.5 [mm] is sufficient.

D. Next, this delay medium block 11 is shown in FIG.
As shown in FIG.
3 [mm]) to produce a plurality of unfinished ultrasonic delay lines 11, 11, . . . , 11 at the same time.

E. Subsequently, each unfinished ultrasonic delay line 11,
Elliptical electrodes 14, 14 are provided on the transducers 4, 5 of 11, . . . , 11, respectively, as shown in FIG.
Depth D [m] from one main surface 50 to the other main surface 50
m] holes 18, 18, ..., 18 are provided, and each hole 18, 18,
..., 18, an ultrasonic absorbing material (epoxy resin containing silver (lead)) 19 is applied.

F. Next, after connecting the lead wires 24, 24, 34, 34 on each electrode 3, 3, 14, 14 using conductive adhesive A, the time adjustment surface (side surface) 60A (Fig. 1) is polished. The delay time is finely adjusted and the excess portion of the ultrasonic absorbing material 16 is removed. Note that the holes 18, 18, . . . , 18 may be through holes.

[0022]

[Effects of the Invention] Since the present invention is constructed as described above, it provides an ultrasonic delay line in which an ultrasonic absorbing material is efficiently and precisely applied to a predetermined position on the side surface of an ultrasonic delay medium. can.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a bulk wave type ultrasonic delay line according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the manufacturing process of a bulk wave type ultrasonic delay line according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of the manufacturing process of a bulk wave type ultrasonic delay line according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of the manufacturing process of a bulk wave type ultrasonic delay line according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of the manufacturing process of a bulk wave type ultrasonic delay line according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of the manufacturing process of a bulk wave type ultrasonic delay line according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram of the manufacturing process of a bulk wave type ultrasonic delay line according to an embodiment of the present invention.

[Figure 8] Perspective view of conventional ultrasonic delay line

[Explanation of symbols]

1……Bulk wave type ultrasonic delay line 2...Transducer adhesive surface 3......Earth electrode 4……Input transducer 5……Output transducer 10...Ultrasonic delay medium block 14...Signal electrode 16... Ultrasonic absorber 17...Groove 18...hole 24, 34...Lead wire A... Conductive adhesive

Claims (1)

[Claims] Claim 1: One side of a rectangular ultrasonic delay medium is set at 45°.
In an ultrasonic delay line formed by cutting out a transducer joint surface to form a transducer joint surface, and gluing an input/output transducer to this transducer joint surface, a portion other than the normal signal reflection area on each side of the ultrasonic delay medium except for the transducer joint surface. An ultrasonic delay line characterized in that a groove portion having a predetermined depth is formed in the thickness direction of the delay medium in the portion, and an ultrasonic absorbing material is applied to each groove portion.