JPH0411385Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a support structure for a small tuning fork type crystal resonator and a corresponding electrode structure.

(Prior art) A structure in which the base of a tuning fork type crystal oscillator is sandwiched and supported by two lead wires embedded in a hermetic seal material is known, for example, as described in Japanese Patent Application No. 59-73550. The wire connection portion is provided at a position offset from the widthwise center of the base, the two lead wires are planted at an interval greater than the thickness of the base and smaller than the width of the base, and the two lead wires are An idea has been devised in which the excitation electrode and the two lead wires are connected in a state where the direction connecting the centers of the base and the width direction of the base cross each other at an acute angle. With this method, without changing the pitch of the lead wire, the lead wire and the crystal piece can be stably held in contact with each other without any gaps, and since the connection points are at the two so-called nodal points, which are the nodes of tuning fork vibration, the vibration Loss caused by the vibration energy of the child leaking to the outside through the lead wires was minimized, making it possible to increase the efficiency of the oscillation circuit.

However, the electrode structure of such a tuning fork crystal resonator has many problems in its manufacturing process. Before connecting the tuning fork type crystal piece with the excitation electrode formed thereon to the two lead wires, the frequency balance of both legs of the tuning fork type crystal piece is inspected and adjusted in the frequency selection and adjustment process as shown in Fig. 4. As shown, chuck 9 at the end of the arm of the frequency separator
1 grabs the tuning fork type crystal piece 1, applies voltage from the current conducting parts 92 located above and below the tuning fork type crystal piece 1 to excite it, and inspects the frequency balance situation. The desired frequency is then adjusted by grinding the tips of the legs according to the balance situation. However, in order to make it easier to grasp the tuning fork-shaped crystal piece 1, the chuck 91 has a wider width.
Also, although it is tapered, this may cause the tuning fork type crystal piece 1 to be held at an angle. In such a case, the current-carrying part 92 does not touch the part 8 shown by the dotted line in FIG. 3 that the current-carrying part 92 should contact, and the conventional electrode structure, that is, the excitation electrode at the base of the tuning fork crystal piece With the electrode structure deviated from the center, there were cases where the current-carrying portion 92 and the electrode of the tuning fork crystal piece 1 did not come into contact with each other. As a result, products that were supposed to be good were sometimes judged to be defective.

(Purpose of the invention) The present invention was made in view of the above circumstances, and it has the advantages of the tuning fork type crystal resonator shown in the conventional example, that is, the crystal piece and the lead wire can be brought into contact with each other without any gaps and can be held stably. The purpose of the present invention is to provide a tuning fork type crystal resonator that prevents vibration energy from leaking to the outside because lead wires are connected at dull points, and also allows accurate frequency selection.

(Structure of the invention) The present invention is based on a tuning fork-shaped crystal piece having excitation electrodes on the main surface (front and back) and side surfaces, with a first excitation electrode formed on most of the surface (a second excitation electrode on the back surface). The electrode) has a structure in which a slit-shaped electrode-free part extends longitudinally from the bottom of the base including the center line that bisects the base in the width direction, and the lead wire connection part of the base electrode is connected to the base electrode. Provided at a position offset from the center in the width direction, two lead wires are planted at an interval greater than the thickness of the base and smaller than the width of the base, and the direction connecting the centers of the two lead wires and the The excitation electrode and the two lead wires are connected with the width directions of the base portions crossing each other at an acute angle.

(Example) Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a perspective view of an embodiment of the present invention, and FIG. 2 shows a plan view thereof.

First and second excitation electrodes 21 and 22 in a predetermined pattern are formed on the entire surface of the tuning fork type crystal piece 1, and are appropriately connected in common. In particular, the surface of the base 11 (first
In the first excitation electrode 21 formed on most of the main surface (as shown in the figure), a slit-shaped electrode-free portion 1 including the center line that bisects the base in the width direction
11 are provided. Note that when viewed from the back surface, the second excitation electrode 22 is the target. As for the connecting end 211 between the lead wire 6 and the excitation electrode, either the left or right excitation electrode may be selected with respect to the electrode-free portion.

Two lead wires 6 and 7 pass through the hermetic sealing material 5 that seals the opening of the cylindrical case 4, and the inward protruding portion and the connection end of the excitation electrode described above are connected by solder 3. This also serves as mechanical support for the tuning fork type crystal piece 1. The distance A between the two lead wires is larger than the thickness t of the base 11 and smaller than the width w of the base 11. As a result, the direction connecting the center lines of the lead wires 6, 7 and the width direction of the base 11 intersect at an acute angle α, and
The lead wires 6 and 7 hold the base 11 of the vibrator in such a state that the side generatrix contacts the front or back surface of the base 11.

In addition, since the electrode non-forming part 111 exists in the center of the base, the solder attached to the connecting end 211 does not flow to the opposing non-connecting end 212.

(Effects, etc.) According to the present invention, as described above, the lead wire and the crystal piece can be brought into contact with each other without any gaps and can be stably held, so that the crystal piece is tilted during soldering and the contact conditions on the bottom surface are changed. Accidents such as fluctuations in the resonant frequency have been eliminated.

In addition, by connecting the lead wires opposite the nodal points, the loss caused by the vibration energy of the vibrator leaking to the outside through the lead wires can be minimized, increasing the efficiency of the oscillation circuit.
It has also become more resistant to front and rear, left and right impacts.

Furthermore, although the tuning fork crystal piece vibrates due to piezoelectric phenomenon, the excitation electrode that excites the vibration has the effect of hindering the vibration of the tuning fork crystal piece due to its mass.

In the present invention, by providing a slit-like electrode-free portion on the base, the above effect can be reduced compared to a structure with electrodes on the entire surface of the base, and the so-called crystal impedance can be lowered, making it possible to reduce the so-called crystal impedance. Electrical performance can be improved.

Furthermore, as described above, since the area of the excitation electrode at the base can be increased, erroneous selection is prevented in the frequency selection and adjustment process, and yield and productivity are improved.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a view showing a conventional electrode structure, and Fig. 4 is a perspective view showing the arm end portion of a frequency selector. be. DESCRIPTION OF SYMBOLS 1... Tuning fork type crystal piece, 111... Non-electrode formation part, 21, 22... Excitation electrode, 5... Hermetic seal material, 6, 7... Lead wire.

Claims (1)

[Scope of utility model registration request] In a structure in which the base of a tuning fork-shaped crystal piece having excitation electrodes on the main surface and side surfaces is sandwiched and supported by two lead wires implanted in a hermetic sealing material, a first The excitation electrode (second excitation electrode on the back side) has a structure in which a slit-shaped electrode-free part is provided that extends in the longitudinal direction from the lowest part of the base including the center line that bisects the base in the width direction, The lead wire connection portion is provided at a position offset from the widthwise center of the base, the two lead wires are planted at an interval greater than the thickness of the base and smaller than the width of the base, and the two leads A tuning fork type crystal resonator characterized in that the excitation electrode and the two lead wires are connected in a state in which a direction connecting the centers of the wires and a width direction of the base cross each other at an acute angle.