JPH0321073Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ultrasonic delay element, particularly an ultrasonic delay element using a thin plate-like ultrasonic delay medium such as glass.

Many ultrasonic delay elements are equipped with an input/output transducer for a delay medium such as glass, but in recent years there has been a great desire for miniaturization, and the container housing this delay medium has also become smaller. It is desired that

This container body consists of a box-shaped bottom member 2 on which a delay medium 1 is placed as shown in FIG. 1, and a lid-shaped upper member 3 that covers the delay medium. The top member 3 has at least one protrusion 4 on its side surface, and a hole 5 is formed in the side surface of the top member 3 corresponding to the protrusion on the bottom member. Ultrasonic delay elements that engage and integrate into holes are well known. Since the bottom member of such an ultrasonic delay element is a mold for molding, a groove 6 having a width equal to or wider than the protrusion is formed below the protrusion 4.

This kind of container did not pose much of a problem when the container was large, but as the container became smaller, the height H of the bottom member when attached to the circuit board became lower, and the height H of the bottom member before the soldering process became smaller. In the flux process, flux tends to creep up along the grooves 6 on the side surface of the bottom member 2, enter the inside of the container through the gap between the bottom member and the top member, and adhere to the retardation medium, degrading performance. Summer.

In order to prevent this, as shown in FIG. 2 (perspective view), a groove extending downward from the protruding portion 4 of the bottom member 2 is formed in two stages 6A, 6 so that the lower side of the groove is deeper.
By forming B, the rise of flux was also prevented by the steps of the groove, which was more effective than the example shown in Figure 1, but as miniaturization progressed further, the surface tension of the flux The flux rose along the corners 7 at both ends of the bottom of the groove, which was insufficient as a measure to prevent flux from entering.

3 and 4 show a partial side view and a partial bottom view of the example of FIG. 2, respectively, and show that the lower groove 6B is
This shows a part that is deeper than the upper groove 6A, and although this level difference considerably prevents the flux from rising, it is insufficient as described above.

The present invention can prevent such drawbacks and prevent flux from entering, and is composed of a delay medium, a box-shaped bottom member on which the delay medium is placed, and a lid-shaped upper member that covers the delay medium. , the bottom member has at least one protrusion on at least one side, a hole is formed in a side of the upper member corresponding to the protrusion on the bottom member, and the protrusion on the bottom member is connected to the protrusion. In an ultrasonic delay element that engages and integrates with a hole in a top member, a groove extending downward from the protruding portion of the bottom member is formed in two stages so that the lower side of the groove is deeper; This ultrasonic delay element is characterized in that the lower groove is formed in a concave shape with rounded corners at both ends of the groove bottom in a cross section perpendicular to the height direction.

Since the ultrasonic delay element of the present invention has such a configuration, flux hardly enters the inside of the container and does not deteriorate the characteristics of the delay medium.

Next, the ultrasonic delay element of the present invention will be explained with reference to the drawings.

FIG. 5 shows a box-shaped bottom member 12 according to an embodiment of the present invention.
FIG. 6 and FIG. 2 show a partial side view and a partial bottom view of the bottom member 12, and the groove is two-staged as in the example of FIG. 2. , the upper groove 16A is the same as in the example of FIG.
As is clear from the figure, in a cross section perpendicular to the height direction, the corners 17 at both ends of the groove bottom are formed into a rounded concave shape, and the corners 17 at both ends have a curvature of 0.5 to 2R. It is preferable to form it so that it forms part of a certain circular arc. If the curvature is smaller than 0.5R, the flux will rise up the bottom member due to surface tension, which is undesirable.If the curvature is larger than 2R, the width of the groove will become large, which may weaken the bottom member in terms of strength.
The terminal provided on the bottom member protrudes into the corner 17, making it unsuitable for miniaturizing the device.

As shown in this example, the lower groove 16B is deeper than the upper groove 16A and has a complete step, that is, the width of the lower groove 16B is equal to the width of the upper groove 16A.
6A, and the corners of both ends of the bottom of the upper groove 16A are preferably not in line with the corners of both ends of the bottom of the lower groove 16B, from the viewpoint of preventing flux from rising.

The bottom member 12 has a box-like interior and may have a shape that allows the delay medium 11 to be inserted therein, has at least one protrusion 14 on at least one side thereof, and has an upper member 13. It is sufficient that the bottom member can be integrated by engaging with the hole 15 in the side surface of the bottom member corresponding to the protrusion of the bottom member. Note that it is preferable to form at least one protrusion on each of the two opposite side surfaces as in this example to ensure a strong engagement.

This bottom member 12 may be provided with other features other than those described above, such as providing connection pins for connection to an external circuit, mounting means for attaching to a circuit board, and parts of circuit components on its surface or inner surface. may be equal.

The upper member 13 of the present invention may have the same structure as the conventional one, as shown in FIG.

This upper member 13 has a hole 15 formed on its side surface in a portion corresponding to the protrusion 14 of the bottom member 12, and the protrusion of the bottom member is engaged with the hole of the upper member.
That is, in the example shown in FIG. 5, the upper member 13 is lowered onto the bottom member 12, and the protrusion 14 fits into the hole 15, thereby integrating the upper member and the bottom member. This hole may be a through hole, as in the example shown in FIG. 5, or a recess, but it is preferable to use a through hole because it is easy to manufacture the upper member.

The delay medium of the present invention can be a normal delay medium, such as a glass plate equipped with an input/output transducer, and can have a known shape such as a square, pentagon, or hexagon. It is sufficient that one or more than one can be accommodated.

Note that the present invention is not limited to this example, and can also be used upside down with a structure in which a pin is attached to the upper member, or a horizontal container in which the delay medium is placed on its side. It is also possible to house circuit components such as inductors, resistors, capacitors, and ICs inside, and it is also possible to form connection terminals with external circuits other than pins.

As described above, the present invention is excellent in that it can prevent flux from entering the delay medium, which would have a negative effect on the delay medium, and it can miniaturize the ultrasonic delay element itself.
Various applications are possible in the future.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional ultrasonic delay element with an upper member and a bottom member separated. FIG. 2 is a perspective view of a bottom member of another conventional example of an ultrasonic delay element. Third
4 are a partial side view and a partial bottom view of the bottom member of the ultrasonic delay element of FIG. 2. FIG. 5 is a perspective view of the ultrasonic delay element according to the embodiment of the present invention, with the top member and bottom member separated. 6 and 7 are a partial side view and a partial bottom view of the bottom member of the ultrasonic delay element of FIG. 5; FIG. Delay medium: 1, 11, Bottom member: 2, 12, Top member: 3, 13, Protrusion: 4, 14, Hole: 5, 1
5. Groove: 6, 16A, 16B.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of a delay medium, a box-shaped bottom member on which the delay medium is placed, and a lid-shaped upper member that covers the delay medium, at least one side of the bottom member. has at least one protrusion, and a hole is formed in a side surface of the upper member corresponding to the protrusion of the bottom member, and the protrusion of the bottom member is engaged with the hole of the upper member. In the ultrasonic delay element that is integrated with the bottom member, a groove extending downward from the protruding portion of the bottom member is formed in two stages so that the lower side of the groove is deeper, and the lower groove is deeper in the height direction. An ultrasonic delay element characterized in that, in a cross section perpendicular to , the corners at both ends of the groove bottom are formed into a rounded concave shape. (2) The ultrasonic delay element according to claim 1, wherein the curvature of the corners of both ends of the lower groove bottom in a cross section perpendicular to the height direction is 0.5 to 2R.