JPH052012B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a piezoelectric component, and particularly to a piezoelectric component having a grounding electrode on its outer surface.

(Prior Art) FIG. 3 is a sectional view showing an example of a conventional piezoelectric component, which is the background of the present invention. This piezoelectric component 1
Cap terminals 4 and 5 are formed at both ends of an element body 3 having a piezoelectric element 2 therein, and cap terminals 4 and 5 are formed around the outer surface of the element body 3, and the thickness thereof is thinner than that of the cap terminals 4 and 5. A grounding electrode 6 is formed.

(Problems to be Solved by the Invention) However, in such a piezoelectric component 1, since the thickness of the grounding electrode 6 is thinner than the thickness of the cap terminals 4 and 5, it is difficult to attach the piezoelectric component 1 to, for example, a substrate. At this time, there was a problem in that a gap was created between the grounding electrode 6 and the substrate, making it difficult to connect the grounding electrode 6 and the substrate. Therefore, by increasing the thickness of the grounding electrode 6, the cap terminals 4 and 5
It is conceivable to make the wall thickness the same as that of the ground electrode 6, but since the ground electrode 6 is usually formed by baking silver,
This method would be too expensive.

Therefore, the main object of the present invention is to provide a piezoelectric component whose grounding terminal can be easily and reliably connected to a substrate.

(Means for Solving the Problems) The present invention provides an element body having a piezoelectric element therein, cap terminals formed at both ends of the element body and connected to the piezoelectric element, and cap terminals formed on the outer surface of the element body. In a piezoelectric component including a grounding electrode whose wall thickness is thinner than that of a cap terminal, an auxiliary conductor member is fitted around the grounding electrode, and the thickness of the grounding electrode and the wall thickness of the auxiliary member are This piezoelectric component is characterized in that the total thickness of the cap terminal is approximately the same as the thickness of the cap terminal.

(Function) The side surface of the auxiliary member fitted around the outer surface of the grounding electrode is aligned with the side surface of the cap terminal.

(Effects of the Invention) According to the present invention, since the side surface of the auxiliary member fitted around the outer surface of the grounding electrode is aligned with the side surface of the cap terminal, only the cap terminal is in contact with the board when installed, and the grounding electrode and the board They are both in contact with the substrate without any separation between them. Therefore, the connection between the grounding electrode and the substrate is easy and reliable.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIGS. 1 and 2 show an embodiment of the present invention, with FIG. 1 being a sectional view thereof and FIG. 2 being a perspective view thereof. In the following examples, a case will be explained in which the present invention is applied to a piezoelectric resonator with a cylindrical capacitor, but it should be noted in advance that the present invention can also be applied to general piezoelectric components having a grounding electrode on the outer surface of the element body. Let me point this out.

This piezoelectric component 10 includes a cylindrical dielectric ceramic 12 . This dielectric ceramic 12 has inner surface electrodes 14 and 16 extending from both ends of its inner peripheral surface toward the center. In addition, dielectric porcelain 12
Cap terminals 18 made of metal are installed at both ends of the
and 20 are formed. Furthermore, a ring-shaped grounding electrode 22 is formed around the outer surface of the dielectric ceramic 12. In addition, this grounding electrode 2
The wall thickness of cap terminal 2 is formed thinner than that of cap terminals 18 and 20. And this grounding electrode 22
and electrode 14 are opposed to each other with dielectric ceramic 12 interposed therebetween, and form a first capacitor section. Similarly, the grounding electrode 22 and the electrode 16 each face each other to form a second capacitor section.

On the other hand, a piezoelectric element 24 such as an energy trap type thickness-shear vibration type piezoelectric resonant element is inserted into the hollow part of the dielectric ceramic 12. This piezoelectric element 24 includes a plate-shaped piezoelectric substrate 26, and electrodes 28 and 30 are formed on both main surfaces of this piezoelectric substrate 26.

A conductive bonding member 2 is provided near the portion where the cap terminals 18 and 20 and the piezoelectric element 24 are connected.
1a and 21b are filled, thereby connecting the electrode 28 to the cap terminal 18 and the electrode 30 to the cap terminal 20, respectively. Furthermore, the piezoelectric element 24 is arranged and fixed by the joining members 21a and 21b so as not to come into contact with the inner surface of the dielectric ceramic 12.

Around the grounding electrode 22, an auxiliary member 32 made of, for example, phosphor bronze with tin plating is placed so that its side surface is aligned with the side surface of the cap terminals 18 and 20.
is embedded. This auxiliary member 32 is formed in a ring shape, and has one cutting groove 32 in the width direction.
It has a so-called slotted structure in which a is formed. Therefore, the auxiliary member 32 has this cutting groove 3.
The elastic force generated by 2a presses it onto the grounding electrode 22. Note that this auxiliary member 32 is
For example, it may be soldered to the grounding electrode 22 by reflow soldering.

The piezoelectric component 10 configured in this manner is soldered to a printed circuit board, for example. At this time, since the side surfaces of the cap terminals 18 and 20 and the side surface of the auxiliary member 32 are aligned, the cap terminal 18 and the side surface of the auxiliary member 32 are aligned.
Since both 20 and the auxiliary member 32 are in contact with the printed circuit board, the grounding electrode 22 can be reliably connected to the printed circuit board.

In addition, in this example, the cylindrical dielectric ceramic 1
2 was used, but this may be changed to a dielectric ceramic having a rectangular cylinder shape or other shapes.

In addition, in this embodiment, since the auxiliary member 32 has a so-called slotted structure, the dielectric ceramic 1
Even if there is some variation in the dimensions of 2, it can be inserted and attached with high adhesion.

Incidentally, there is a difference in level between the cap terminals 18 and 20 and the auxiliary member 32, but if this difference in level causes any inconvenience, the difference in level may be eliminated by applying resin coating to the step part, for example. .

[Brief explanation of the drawing]

FIGS. 1 and 2 show an embodiment of the present invention, with FIG. 1 being a sectional view thereof and FIG. 2 being a perspective view thereof. FIG. 3 is a sectional view showing a conventional piezoelectric component, which is the background of this invention. In the figure, 10 is a piezoelectric component, 12 is a dielectric ceramic, 18 and 20 are cap terminals, 22 is a grounding electrode, 24 is a piezoelectric element, and 32 is an auxiliary member.

Claims (1)

[Scope of Claims] 1. An element body including a piezoelectric element therein, cap terminals formed at both ends of the element body and connected to the piezoelectric element, and cap terminals formed on the outer surface of the element body and having a wall thickness thereof. In a piezoelectric component including a grounding electrode formed to be thinner than the wall thickness of the cap terminal, a conductive auxiliary member is fitted around the grounding electrode, and the thickness of the grounding electrode and the wall thickness of the auxiliary member are A piezoelectric component characterized in that the sum of the thicknesses of the cap terminals is approximately the same as the wall thickness of the cap terminal.