JPH0138983Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The shape of the crystal plate that undergoes thickness-shear vibration is generally
A disk-shaped one having a diameter D and a thickness t as shown in the perspective view of the figure is mainly used. However, with the diversification of crystal oscillators, rectangular-shaped crystal plates ABCD, such as the examples shown in Figure 2 a, b, c, d, e, and f, are being used in addition to the disk shape. It is in. Figure 2 a shows a flat plate with a thickness of t ₁ , figure b shows a beveled flat plate with a bevel width α whose edges on two opposing sides are each beveled with a radius of curvature r, and figure c shows a part of a spherical surface with a radius of curvature r. , a planoconvex plate with a flat back surface,
Figure d shows a biconvex plate whose front and back surfaces are both part of a spherical surface with a radius of curvature r. Figure e shows a biconvex plate whose front surface has a radius r.
Part of the cylindrical surface of , a single-sided kamaboko board with a flat back surface, f
The figure is a perspective view of both semi-cylindrical boards whose front and back surfaces are part of a cylindrical surface with a radius r, each having a center thickness t ₁ and an end thickness t ₂ . In addition, there are also shapes that are a combination of the above, such as a front surface bevel and a back surface convex. Generally, the above-mentioned crystal plate goes through a predetermined manufacturing process, and as shown in the perspective view of FIG. 3, terminals 300, 30
A so-called hermetically sealed cage 400 having a
is assembled and covered with a case 100 to form a crystal resonator having external dimensions L×H×W. Inside the case of the vibrator shown in Figure 3, when supporting a crystal plate that vibrates through its thickness, the vibration loss caused by the support (in the following description, the equivalent resistance R in addition to the vibration loss of the crystal plate itself) (I will say ₁ )
In order to minimize this, the support mechanism is fixed to the crystal plate using conductive cement, using the area near the edge of the crystal plate where the vibration energy should be minimized due to the so-called energy entrapment effect. It's structured. Now, the flat plates, beveled plates, planoconvex plates, biconvex plates, single semicircular plates, double semicircular plates shown in Fig. 2 a to f, and rectangular crystal plates having a structure in which these structures are mutually combined (described below) One of the advantages of the rectangular crystal plate (hereinafter simply referred to as a rectangular crystal plate) is that the height H in FIG. 3 can be reduced to a certain extent without significantly increasing the vibration loss R ₁ compared to a circular plate. In other words, when supporting the rectangular crystal plate ABCD at the end in the BC or AD direction (below, BC and AD are parallel and equal, and simply referred to as the BC direction), the AB or AD direction is supported while keeping the BC dimension at a certain size. Even if you reduce the dimension in the CD direction (hereinafter simply referred to as the AB direction, assuming that AB and CD are parallel and equal),
The distance between the support point and the center of vibration does not decrease significantly, and the increase in vibration loss is suppressed to a relatively small value.
However, conventional support structures are generally for disk-shaped quartz plates, and are incomplete in fully satisfying the advantages of the rectangular quartz plates described above. Now, let us talk about the support structures for small hermetically sealed cages that have been widely used in the past.These are broadly divided into coil spring types and leaf spring types. Figures 4a, b, c, and d are perspective views of examples of conventional support structures, and Figure a shows a crystal plate inserted between the respective slits 2 and 2' at the tips of the coil springs 1 and 1'. Structure, Figure b shows the coil spring of Figure A with a lower height, Figure C shows the slits 2, ₂ ' (length of the slit, The structure is such that a crystal plate is inserted between the widths h' ₂ and ω'), and the height of figure d is lower than that of figure c, and the slit is provided in a part of the diagonal rising part.
Common to all a, b, c, and d, the crystal plate is 1,
1' with conductive cement, and is connected to terminals 3 and 3'. 4 is the cage base. Now, when a rectangular crystal plate is held in a holder with a conventional support structure, several problems occur in the vibrator. That is, the support structure shown in FIG. 4a or c is not suitable for reducing the height H shown in FIG. 3 because it is limited by the height of the coil spring or leaf spring. The support structure shown in Fig. 4 b or d uses the B and C corners or their vicinity as support parts, and is somewhat more effective than the above a or c in reducing the height H, but still has some unsatisfactory points. leave. In order to clarify this, a general description will be made below regarding the support of the crystal resonator, and the unsatisfactory points of the support structure b or d will be pointed out. Normally, when the crystal plate is rectangular, as BC/t ₁ (t ₁ is the center thickness) becomes smaller (this is true when the resonator is made smaller or when the vibration frequency is relatively low (for example, the fundamental wave is about 8 MHz). (below)), the energy-containing effect is no longer sufficient, and the slight difference between the adhesion position of the conductive cement on the support part (the distance from the edge to the vibration center (generally the center of the crystal plate) is important) and the adhesion area This significantly affects vibration loss (described later with actual measurement examples shown in FIGS. 7 and 8). The common drawbacks of the support structures shown in Figures 4b and d are (a) When inserting the crystal plate, it is difficult to adjust the left-right symmetry of the figure with respect to the vibration center of the crystal plate, and the above-mentioned If BC/t ₁ is small, the adhesion position of the conductive cement will shift, resulting in increased vibration loss and product variation. (b) Since the crystal plate is supported at two points at or near the B and C corners, it is unstable against mechanical shock.
After being fixed, the conductive cement tends to crack, and there is a risk that the cement may fall off or the crystal plate may fall off or be damaged if subjected to a strong impact. In order to prevent this, if the fixed area of cement is increased, the vibration loss will be significantly increased. The support structure shown in Figure b has the following drawbacks. (c) There is a limit to reducing the diameter of the coil part (the current minimum is 1 mm), and when cementing is done inside the coil as is usually done, it is difficult to adjust the cementing area and it tends to spread. As a result, vibration loss increases and the range of variation increases. The support structure shown in Figure d has the following drawbacks. (d) If the crystal plate is simply inserted during the manufacturing process up to cement fixation, the crystal plate is likely to fall, making it extremely unstable and inconvenient for work. As mentioned above, when supporting a rectangular crystal plate with the conventional support structure, many problems occur, making it difficult to downsize and fully demonstrate performance, especially in terms of vibration loss, its dispersion, and impact resistance. cause problems. Solving this problem is an important technical challenge. The present invention is based on the support structure shown in FIG. 4d and is an improvement on it to solve this technical problem. The explanation will be explained below with reference to the figures. FIG. 5 is a front, plan, and side view of an example of a cage having the support structure of the present invention for supporting a rectangular crystal plate, in which the leaf springs 11 and 11' are horizontal portions parallel to the support direction BC. A bent part of length n ₁ and a bent part of length h ₁ which is bent to the opposite side (externally upward) of the retainer base 41 at a bending angle θ° ₁ , and then further bent internally diagonally upward. Tip part 5
1 and 51', and has a structure in which the concave slits at the ends of the portions 51 and 51' press down the side surface of the crystal plate ABCD. This concave slit is configured so that it abuts against a part of the edge thickness t ₂ (t ₁ in the case of a flat plate) of the quartz plate when the quartz plate is inserted. The dimensions and bending angle of 51 etc. are determined as appropriate to meet the above-mentioned purpose. If m is the distance between terminals 31 and 31', then 11,1
The shortest distance l of 1' is m+2n ₁ , which is selected to be slightly smaller than BC. Also, the plate spring 11 etc.
Slits with lengths h ₂ and n ₂ and width w are provided in the h ₁ and n ₁ parts, respectively, and h ₂ and n ₂ are continuous. slit
n ₂ was provided in consideration of the fact that when it is necessary to push the corner of the crystal plate into the slit h ₂ , w becomes easier to widen slightly, and when the crystal plate is a flat plate, n ₂ is not present. However, there is no particular problem. From the same meaning, the slit _h2 may extend beyond _h1 to the inside of 51, etc. Further, the leaf spring 11 and the like and the terminal 31 and the like may have an integral structure. FIG. 6 shows metal thin film electrodes 61 and 61' deposited on the front and back surfaces of the rectangular flat plate ABCD shown in FIG. 2a, for example, on the cage having the support structure shown in FIG. FIG. 12 is a perspective view of an example in which the electrode 61 and the like are inserted into the plate spring 11 with conductive cement 71 and 71', and are connected to the terminal 31 and assembled. (The hatching in FIG. 6 indicates the electrode film). The other parts of FIG. 6 are the same as FIG. 5. The fact that the present invention shown in FIGS. 5 and 6 exhibits superior effects over the conventional support structure will be explained below in comparison with the above-mentioned items A to D. (1) When inserting the B and C corners into the slit w in Fig. 6, the concave slits at the tips of the leaf springs 11 and 11' eliminate left and right symmetry, and the adhesion position of the conductive cement is made uniform. Therefore, vibration loss and its dispersion are improved. (2) In addition to being supported at two points near the B and C corners, the crystal plate is also auxiliary supported by concave slits at the tips of 11 and 11'. At this time, if necessary, the side surface of the end thickness t ₂ (t ₁ in the case of a flat plate) of the quartz plate and the tip recess can be fixed with a very small amount of conductive cement. The effect of this sticking is relatively small.
When this fixing is performed, a smaller amount of conductive cement at the corners of the support portions B and C is required than in the past, and vibration loss can be reduced. By adding the auxiliary support of the concave slit at the tip, impact resistance in the front and rear, left and right, and top and bottom directions, especially in the front and rear and left and right directions, is significantly improved. (3) The position and area of conductive cement fixation at the B and C corners, which are the main support parts, are made uniform, and vibration loss and its dispersion can be improved. (4) Since it has a four-point support structure of main support and auxiliary support, there is no instability, rattling, or falling off of the crystal plate even during the manufacturing process up to cement fixation. (5) Since the tip portion 51 etc. is bent upward inwardly, it does not become a hindrance when covering the case. Also horizontal part
n ₁ part is provided, so when the crystal plate is inserted, there is little lifting and it can be installed stably. Figures 7 and 8 show the fundamental wave vibration frequency of the so-called AT plate.
In the case of 1843MHz, 32768MHz, 4MHz, and 10MHz, assuming that the main dimensions of the crystal plate are taken as shown in Table 1 below, the vibration loss R ₁ is calculated depending on the position and area of the conductive cement. Although we have actually measured a large change, we will mention it as a reference to clarify the effect of the present invention. In Figure 7, the horizontal axis shows the position at a distance s from B and C in the direction of diagonal lines BD and CA, respectively, and at that position approximately 0.3 mmφ
When a conductive cement of size is fixed
The change in R ₁ is shown on the vertical axis. In Figure 8, let P and Q be the points where the vicinity of the B (or C) corner of the crystal plate intersects with the _h1 section bent outwardly upward, and let x be the length of the perpendicular line from B to PQ. , x≒0.5, BP≒0.6, BQ≒0.9 (unit: mm)
Taking the area S0.5 (≒0.27mm ² ) of the triangle as standard 1,
The horizontal axis shows changes in y=fixed area/S0.5, and the vertical axis shows changes in _R1 . A zero value for s and y means no cement.

[Table] How to select s and y is extremely important in obtaining a high quality vibrator. Tables 2 and 3 show the support structure of the present invention shown in Fig. 5 and the conventional support structure shown in Fig. 4b, 1843MHz of No. 1 in Table 1,
And when applying No. 2 32746MHz resonator
R ₁ , variation rate of R ₁ ΔR ₁ /R ₁ , and on hard wood board
This shows a comparison of the measured average values of 50 samples for each 30cm drop impact test δR ₁ /R ₁ performed three times. For the support structure of this invention, x≒ No. 1
0.08mm y≒1.0 In No. 2, x≒0.4, y=0.5, with the conventional structure, the fixed area of the coil diameter 1.0mm is about 0.7 of the total area inside the coil from the inner corner of the coil.

【table】

[Table] As is clear from Tables 2 and 3, the vibrator with the support structure of the present invention has excellent R ₁ , its variation, and impact resistance compared to conventional ones, and in particular, in R ₁ , it is No. .1 is about 3 times as much, and No.2 is about 3 times as much.
This is a 3.5x improvement. In addition, the conventional one is shown in Figure 4 d.
The support structure of the one in which the crystal plate fell off during the impact test was not subject to evaluation. The device according to the present invention shown in Table 2 has an external dimension of approximately 13 cm (H x L x W) as shown in Figure 3.
The so-called HC-18/U type of ×11 × 4.5 mm ³ , and the one according to the present invention shown in Table 3, has a H × L × W of approximately 8 × 11 × 4.5 mm ³
Although it has a smaller H than the HC-18/U type, in terms of performance such as _R1 , the conventional large size so-called HC-6/U type has a H x L x W of approximately 19 x 19 x 8.8.
mm ³ (normally 100 to 150 Ω in the 1.8 MHz band, 30 to 50 Ω in the 3.2 MHz band), which means that the support structure of the present invention is extremely suitable for rectangular crystal plates. This proves that it is a reliable support structure. 9 is a front view and a plan view of an application example of the present invention shown in FIG. 5. FIG. FIG. 9 shows a bellows-like bent portion 8 at the base of the support structure so that the leaf spring 11, etc. has a particularly spring effect in the direction of the terminal 31, etc., compared to the one shown in FIG.
1,81', and the vibrator of the quartz plate ABCD assembled in this support structure has a better effect against impact in the direction of the terminals.
The other parts are the same as those in FIG. 5, so their explanation will be omitted. As detailed above, conventionally, the performance (especially
There is no suitable cage with a support structure that can fully utilize the advantages of R ₁ ) and shape (smaller external shape in the H direction), which has delayed the spread and development of rectangular crystal plates. By using the structure of the cage and the rectangular crystal plate assembled to this cage, it is possible to obtain a vibrator with excellent resistance to _R1 , its variation, and impact, and at the same time, it is also possible to reduce the size in the H direction. , it becomes possible to respond easily and quickly, and in the case of mass production of the same type of vibrators, it exhibits a remarkable effect on maintaining uniform quality, contributing to improving yield and work efficiency. The industrial value of this invention is high.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a disk-shaped crystal plate, Figure 2, a,
b, c, d, e, f are rectangular crystal plates, respectively.
A perspective view of ABCD's flat plate, bevel flat plate, planoconvex plate, biconvex plate, single semicylindrical plate, and double semicylindrical plate; FIG. 3 is a perspective view showing the external structure of a crystal resonator in a so-called hermetically sealed cage; Figures 4a, b, c, and d are examples of conventional support structures for so-called hermetically sealed cages, including one with a coil spring, one with a low height coil spring, and one with a low height coil spring, respectively.
and those with leaf springs and those with a structure in which the height of the leaf spring is low. Fig. 5 is a front, plan and side view of an example of the cage of the present invention for supporting a rectangular crystal plate, and Fig. 6 is a rectangular flat plate ABCD in the cage of the invention shown in Fig. 5. A perspective view of the assembled product,
Figures 7 and 8 show examples of fundamental wave vibration frequencies of 1.84 MHz, 3.28 MHz, 4 MHz, and 10 MHz of the AT plate vibrator, and when the horizontal axis represents the position and area of fixation by conductive cement, the equivalent FIG. 9, which shows the change in resistance R ₁ on the vertical axis, is an application example of the present invention, in which the base of the support structure has a bellows type spring structure. ABCD……Rectangular crystal plate, 11, 11′……
Leaf spring, 21, 21'...Gap, 51, 51'...
Leaf spring tip, 31, 31'...terminal, 41...
Retainer base, 81, 81'... leaf spring bellows part, 6
1,61'... Quartz plate electrode film.

Claims (1)

[Claims for Utility Model Registration] (1) Two terminals each having a metal plate spring part use the metal plate spring part to connect the front and back sides of a rectangular thick-slide vibrating piezoelectric plate ABCD, which has electrodes on the front and back sides. The electrodes are electrically led out, and the piezoelectric plate is connected to corner portions B and C at both ends of one long side BC.
In a thickness-slip piezoelectric vibrator configured to be supported by penetrating the base of the vibrator holder in the direction of the short sides AB and DC of the piezoelectric plate, the two metal plate spring parts have the following a, b, c, d
A rectangular plate-thickness sliding piezoelectric vibrator characterized by comprising a part. a In the part following the penetration part, keep the plate surface of the leaf spring perpendicular to the plate surface of the piezoelectric plate, cross the long side BC, and extend parallel to the plate surface of the piezoelectric plate and on both sides. A corner retaining portion is provided which extends in the direction in which the leaf springs move away from each other. b Furthermore, in the part following this corner holding part,
The plate surface of the leaf spring is kept perpendicular to the plate surface ABCD of the piezoelectric plate, and is extended parallel to the plate surface of the piezoelectric plate in the direction in which both leaf springs approach each other, and each of the plate springs is extended along the short side of the piezoelectric plate. It has a tip that intersects AB and CD. c. Provide a slit in the corner holding portion and insert each corner into each of the slits. d) A concave slit is provided at the tip, and the short sides AB and CD, that is, the side ends of the piezoelectric plate, are inserted into each of the concave slits. (2) Utility model registration claim 1, characterized in that each of the metal plate springs has a portion parallel to the long side BC between the penetrating portion and the corner holding portion. Rectangular plate thickness sliding piezoelectric vibrator as described in Section 1. (3) The rectangular plate according to claim 2 of the utility model registration claim, wherein each of the metal plate springs has a bellows-shaped bent portion in a portion parallel to the long side BC. Thickness sliding piezoelectric vibrator.