JPH04111512A - Oscillatory shutter mechanism and vapor deposition frequency adjusting device provided with the same - Google Patents

Abstract

PURPOSE:To adjust the frequency of a piezoelectric oscillator with a high quality and a high precision by using an oscillatory shutter mechanism to form a vapor- deposition film non-stepwise and controlling the open time interval of the window of a shutter blade to arbitrarily control the vapor deposition speed without degrading the quality of the vapor-deposited film. CONSTITUTION:A shutter blade 1a of a first shutter 1 is oscillated and operated simultaneously with the start of vapor deposition adjustment to put a window 2e of a second shutter 2 and a window 1e of a first shutter in the center of a vapor deposition path; and when the vapor deposition path is opened, gas of a vapor deposition material 4b reaches an electrode face 3b of the mechanism piezoelectric oscillator to form a vapor-deposited film 3d, and as the result, the resonance frequency is adjusted. Consequently, the aperture width of the window 1e and that of the window 2e of the second shutter 2 are preliminarily set to proper values and the oscillation amplitude us properly controlled to uniformly form the cross section of the vapor-deposited film 3d, which is obtained on the piezoelectric oscillator by oscillation of the first shutter 1, to a trapezoid. Thus, the occurrence of spurious of the piezoelectric oscillator is suppressed to adjust the resonance frequency with a high precision.

Description

[Detailed Description of the Invention] (Industrial Application Field) A vibrating shutter that lowers the resonant frequency of a piezoelectric vibrator by depositing a deposit on the electrode film of the piezoelectric vibrator to adjust the frequency to a desired frequency. A mechanism and a deposition frequency adjustment device equipped with the same are provided.

(Prior art) A vapor deposition film (secondary pattern) is deposited on the electrode film (primary pattern) of the piezoelectric vibrator to lower the resonant frequency of the piezoelectric vibrator (
This is called a mass addition effect), and in addition to this, the frequency adjustment means compares it with a reference frequency set in advance for the purpose of adjustment, and closes the shutter mechanism to adjust the evaporation frequency when the reference frequency and the resonance frequency match. However, this is widely practiced in piezoelectric vibrators.

In order to accurately match the resonant frequency of the piezoelectric vibrator with the reference frequency, it is important to increase the operating speed of the shutter mechanism and slow down the deposition rate. The response speed between signal and mechanical conversion can be increased by using a high current density coil with low inductance in the electromagnetic plunger, which is lightweight (made of aluminum, etc.), or the evaporation rate can be lowered by reducing the heater current of the evaporation source as much as possible. Metari, aru1,'
! , tAlso, methods such as narrowing the slit diameter of the evaporation source to reduce the amount of evaporation have been adopted.

In addition, in the system of the evaporation frequency adjustment device (1) adjustment factors such as response delay time of the shutter mechanism are programmed in advance, and the shutter blade is closed within a range where the rate of decrease of the resonance frequency is approximately constant. By controlling the time predictably, the resonance frequency of the piezoelectric vibrator may be adjusted by deposition.

(Problem to be solved by the invention) ζ vapor-deposited film (2
When forming a pattern (see below), it is most ideal to perfectly match the shape and position of both films, but this is extremely difficult in practice, and generally the electrode film is made smaller than the deposited film. It is set up to form a staircase.

However, if this vapor-deposited film is formed in a step-like manner, it may generate new spurious vibrations and change the value of the equivalent circuit constant of the piezoelectric vibrator (the capacitance ratio of the equivalent circuit increases). The diameter cannot be set much smaller than the electrode membrane diameter, and the frequency adjustment amount cannot be set too large.

In addition, reducing the heater current to slow down the deposition rate deteriorates the quality of the deposited film, weakening the adhesion strength, impairing long-term operational reliability, and causing deterioration over time.

In predictive control, if there is an error in the reproducibility of adjustment factors, or if the rate of frequency decrease is not constant, for example, if it is affected by spurious vibrations, frequency adjustment accuracy may be further deteriorated.

The object of the present invention has been made in view of these problems, and is to form a deposited film in a non-stepped manner by using a vibrating shutter mechanism, and to control the opening time density of the window of the shutter blade. The objective is to adjust the frequency of a piezoelectric vibrator with high quality and high precision by arbitrarily controlling the deposition rate without deteriorating the quality of the deposited film.

Another object of the present invention is to provide a deposition frequency adjustment device that adjusts the resonance frequency of a piezoelectric vibrator with high quality and precision by adjusting the deposition frequency using the above-mentioned vibrating shutter mechanism.

(Means for solving the problem) Figure 1(b) shows a cross section along the vapor deposition route in Figure 1(a).
Explain according to the following.

A deposit 4b of, for example, silver, heated in the evaporation source heater 4a is gasified in a vacuum state, passes through the slit 4c, and is formed into a beam shape, which is then applied to the electrode surface 3b of the piezoelectric vibrator to be adjusted.
It flies straight along the deposition path toward the target. Before the vapor deposition adjustment starts, the window 2e is located outside the vapor deposition path so as to close the window 1e in the vapor deposition path, so that the gas of the vapor deposit 4b does not reach the electrode surface 3b. At the same time as the deposition adjustment starts, the shutter blade 1a on the first shutter vibrates,
The window 2e of the second shutter 2 and the gl e of the first shear ivy
is located at the center of the evaporation path and opens the evaporation path, so the gas of the evaporation material 4b reaches the electrode surface 3b of the mechanical piezoelectric vibrator and becomes the evaporation film 3d, and as a result, the resonance frequency is adjusted. Ru.

At the same time, when the arm vibration means 1b of the first shutter 1 is excited and driven to vibrate, for example, a sinusoidal vibration displacement S at the position of the window 1e of the shutter blade lb, the window 1e
Since the opening width W of the window 2e vibrates sinusoidally within the range of vibration displacement ±S, if it does not exceed the opening width t of the window 2e, it will be expanded in the same way as if it were opened within the maximum range (w/2+s). . As a result, the opening time density in the formation of the vapor deposited film 3d on the electrode film 3b is controlled, making it possible to control the evaporation il (thickness) and the rate of vapor deposition of the vapor deposition film 3d.

(Function) According to the probability calculation of sinusoidal vibration, it is known that the position of the maximum vibration amplitude ±S has the highest probability of existence and the lowest near O, so the vibration of the first shutter 1 causes piezoelectric vibration. The cross-sectional shape of the vapor deposited film 3d obtained on the window 1e is
When the opening width W of the second shutter is small, the cross-sectional shape becomes concave as shown in FIG. Vibration amplitude S
By appropriately controlling , it is possible to obtain an ideal trapezoidal cross-sectional shape as shown in FIG. 2(a). 1st
By excitation driving with a relatively high t) natural vibration of the shutter system, the cross-sectional shape of the vapor deposited film 3d can be made uniform into a trapezoidal shape even if the shutter opening time is short.

When no vibrational displacement is applied to the window 1e of the first shutter, the shape of the vapor deposited film 3d becomes a projected figure of the window 1e, which is the same as that obtained by the conventional frequency adjustment method. If the vibration displacement becomes extremely large, it can be seen that the opening of the second shutter 2 is being chopped (or sampled) due to the vibration of the first shutter 1, so the adjustment speed is further reduced. As a device that gives vibrational displacement,
If a wave other than a sine wave, such as a sawtooth wave, a rectangular wave, or a pulse wave thereof, is selected and used, the cross-sectional shape and deposition rate of the deposited film 3d can be controlled more freely.

(Embodiment) FIG. 1(a) is an embodiment of the present invention, and shows a part of a deposition frequency adjustment device in which a vibration shutter mechanism is arranged. When a current is applied to the heater 4a of the evaporation source unit to heat it, the evaporated material 4b therein is easily evaporated in a vacuum state, becomes a gas, and is ejected from the opening of the heater 4a. This is condensed through a slit 4c to form a beam and directed toward the electrode film 3b on the piezoelectric vibrator. The vibrating shutter mechanism of the present invention, which consists of a first shutter and a second shutter 2, is placed in this vapor deposition path, and this is used as a device for adjusting the resonance frequency on the piezoelectric vibrator. It is a vapor deposition frequency adjustment device of the present invention.

FIG. 5 shows an embodiment of the first shutter 1 constituting the vibration shutter mechanism of the present invention. A bimorph piezoelectric diaphragm 1b is installed on the shutter arm lc above the first shutter, and is fixed to a base 1d. A shutter blade 1a is provided on the free end side. When externally excited and driven at the same frequency as the natural frequency of the system on the first shutter, it resonates vertically and gives a vertical vibration displacement S to the window 1e of the shutter blade 1a on the free end side of the shutter arm l. At this time, the vibration displacement S can be controlled by varying the amplitude of the excitation current of the natural frequency, so as shown in FIG. 6, assuming that the opening @W of the window 1e is set appropriately, The vibration amplitude S is 0.Sl,
By changing S2, the rate of frequency reduction of the piezoelectric vibrator can be changed without changing the deposition conditions.

The operation of the vibrating shutter mechanism of the present invention will be explained with reference to FIG. When the window 2e operates and opens the window 1e, the window 1e vibrates with a vibrational displacement S. Since the window 1e is vibrated to the outside of the radius t of the window 2e, the vapor deposited film 3d in FIG. 2(b) Instead of forming a concave surface, the deposited film is formed into an ideal trapezoidal shape. Here, @t of the window 2e is kept constant and changed using the width W and vibration displacement S of the window 1e as parameters. Figure 4(a)
is an exaggerated view of the state of formation of the deposited film 3d when the vibration displacement S is small by setting the radius W of the window 1e to be larger than the radius t of the window 2e. Figure (b) shows the formation state when the vibration displacement S in Figure (a) is increased.

FIG. 5(C) shows the state of formation of the deposited films 5e and 5f when applied to a monolithic crystal element.

In this case, the adjustment is repeated little by little for each electrode film 5b, 5c. This is done by appropriately shifting the vibration displacement center on the first shutter up and down, and
, 5C are switched for adjustment.

For example, when using the bimorph-type arm vibrating means 1b using piezoelectric vibration shown in FIG. 5, this can be easily realized by applying a DC bias voltage for position shift control.

(Effects) The formation speed and cross-sectional shape of the deposited film can be freely controlled while maintaining the optimal deposition conditions, suppressing the generation of spurious waves in the piezoelectric vibrator and adjusting the resonant frequency with high precision. There is little change in circuit constants, and high-quality characteristics can be guaranteed to be maintained over a long period of time. These controls are possible by electrical signal control of the arm vibrating means, and are therefore particularly suitable for automatically controlling the evaporation frequency adjustment device. Furthermore, by individually detecting and controlling the position of the electrode film of the piezoelectric vibrator using a sensor, it is possible to accurately align the deposited film with the electrode film, making it possible to eliminate so-called mask alignment, which has significantly hindered automation. No layer required, offering convenient features and automation.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing a part of the evaporation frequency adjusting device in which the vibration shutter mechanism of the present invention is arranged, and FIG. 1(b) is an explanatory diagram of the operation of FIG. 1(a). Figures 2(a) and 2(b)
) is a cross-sectional view of the shutter blade window and piezoelectric vibrator of the vibrating shutter mechanism of the present invention, and FIG. 3 is a plan view of the shutter blade window and a cross-sectional view of the piezoelectric vibrator. FIGS. 4(a) to 4(c) are cross-sectional views of various piezoelectric vibrators whose deposition has been adjusted by the deposition frequency adjustment apparatus of the present invention. FIG. 5 is a cross-sectional view of the first shutter of the present invention. FIG. 6 is an explanatory diagram of the operation of vapor deposition frequency adjustment according to the present invention. Earth, 2...Shutters 1a, 2a...Shutter blades 1b...Arm vibration means 2b...Arm driving means IC12C...Shutter arm shaft...Piezoelectric vibrator 3b, 3c... Electrode film 3d... Vapor deposited film... Evaporation source 4a... Vapor deposition heater 4b... Vapor deposit 4c... Slit patent application Person Nippon Dempa Kogyo Co., Ltd. 10 (Q) To 1 (G) 2α Nine Zuko (

Claims (2)

[Claims] (1) A shutter arm supported by a base, a windowed shutter blade provided on the free end side of the shutter arm,
a first shutter having arm vibrating means for vibrating and displacing a shutter arm; and a windowed second shutter disposed near the shutter blade to open and close a window of the shutter blade, opening and closing the second shutter. and a vibration operation that varies the vibration displacement of the shutter arm in the natural vibration of the shutter arm of the first shutter, the vibrating shutter mechanism configured to be able to control the opening time density of the window of the shutter blade. (2) The vibration shutter mechanism according to claim (1) is arranged in a vapor deposition path between an evaporation source and a piezoelectric vibrator arranged in a vapor deposition frequency adjustment device, and the opening time density of the window of the shutter blade is provided. A deposition frequency adjustment device configured to be able to adjust the rate of frequency reduction of the piezoelectric vibrator by controlling.