JPH01126008A - Thin profile crystal vibrator - Google Patents

Abstract

PURPOSE:To improve the shock and vibration resistance by providing a weight of a vibrator to a side opposed to a bottom face of a case. CONSTITUTION:A laser beam is radiated from a rear face of a crystal vibrator 3 having a weight 4. A crystal is transparent and a border face between the crystal vibrator 3 and the weight 4 is formed as a mirror face, the laser is not scattered at the border face and trimmed efficiently to prevent the weight 4 from being scattered to the surrounding. Then the scattered and removed weight is adhered onto the opposed case bottom part 5 to be an adhered metal 5'. Then the sintered surface of a ceramic case 1 forms a random coarse face, the adhered force is strong and the adhered metal 5' is not fallen off due to mechanical shock and vibration.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention contributes to high-density packaging, which has seen remarkable progress in the electronics industry, and is mainly supplied as parts for high-density surface mounting. This relates to the arrangement within the case of a flat type crystal resonator.

[Summary of the invention]

The purpose of the present invention is to stably maintain the accuracy of the oscillation frequency, which is the most important basic characteristic of a crystal resonator, and to stabilize the removed weight when adjusting the frequency by removing the weight of the resonator. The removed metal is brought into close contact with the random rough surfaces of the ceramic, resulting in a highly reliable crystal resonator that is particularly resistant to mechanical shock and vibration. It is.

[Conventional technology]

FIG. 2 is a cross-sectional structural diagram of a conventional thin crystal resonator before and after frequency adjustment and sealing, where (a) shows the state before sealing and (b) shows the state after sealing. 1 is a case, 2 is a cap, and 3 is a vibrator. One end of the vibrator is attached to the case and is electrically connected to the case. A weight 4 usually metal plated for frequency adjustment is provided on the other end of the vibrator, which is not facing the case, and frequency adjustment is usually done by irradiating the weight with a laser beam and instantaneously heating the weight using the laser trimming method. The value has been brought to the specified value by dissolving and removing scattering.

In case (a), the cap is then washed and dried, and the cap is welded and sealed integrally with the case. In the case of (b), the cap 2 integrally formed with the case is made of transparent glass, and it is a known fact that the weight of the vibrator is removed and the frequency is adjusted by laser trimming through the glass.

[Problem that the invention seeks to solve]

However, such conventional thin crystal resonators have the disadvantage that, in the case shown in Figure 2 (a), some of the weight scattered during laser trimming adheres to the area around the resonator, and the frequency deviates from the predetermined frequency after cleaning and drying. be.

In the case of (b), the scattered weight adheres to the inner surface 6 of the glass cap, and when a load such as mechanical shock or mechanical vibration is applied, it re-adheres to the vibrator surface and falls off, resulting in a weight effect. The disadvantage is that frequency variations occur. This falling off from the 6° inner surface of the glass cap was a major drawback because its surface structure was a flat wetted surface, and therefore the adhesion of the scattered electrical layer material was weak.

[Means for solving problems]

The present invention has been made to solve the above problems, and as shown in FIGS. The 0 frequency is adjusted by the laser trimming method through the transparent vibrator.

[Effect]

As mentioned above, when the weight on the vibrator surface is set on the side facing the case and the laser beam is passed through the transparent vibrator to trim the weight, the scattered and removed weight becomes a metal layer 5 attached to the bottom surface 5 of the case. However, the state of the adhesion is close to that of vapor deposition, and it is tightly adhered to the bottom of the case. This is because the sintered surface structure of the ceramic forms a random rough surface,
Therefore, the adhesion is strong. Note that the laser beam is irradiated onto the interface between the transparent vibrator and the weight, and since the interface is a mirror surface, there is little scattering of the laser and efficient trimming prevents the weight from scattering around.

As described above, the present invention provides a thin crystal resonator which is highly accurate and has excellent accuracy and has very little influence from weight-scattered particles and very little variation in frequency due to mechanical shock or mechanical vibration.

〔Example〕

The present invention will be explained in detail below based on examples. Third
The figure shows a ceramic case 1, a 32KHz tuning fork crystal oscillator 3, and a glass cap 2.The oscillator has a weight ^U plating part 4 and the adhesive part between the case ^U plating 1
5 are formed on the same surface.

As an assembly procedure, a vibrator adhesive portion 6 is provided at one end of the inner surface of the case, and the vibrator Au plating 15 is firmly bonded to the adhesive portion 6 using a conductive adhesive. That is, the vibrator weight plated portion 4 is disposed facing the ceramic case bottom portion 5. At this stage, when the frequency is adjusted by the laser trimming method, the state shown in Figure 1 (a) is obtained, and the weight is removed and the scattered ^U is firmly deposited on the bottom of the ceramic case, and the attached metal becomes 5 degrees, and scattering to the surrounding area is extremely difficult. Thereafter, the glass cap 2 is sealed with a solder sealant through a washing and drying process.

Comparing the thin crystal resonator of the present invention manufactured through the above process with the conventional thin crystal resonator manufactured through the process shown in Figure 2 (a), the standard frequency value is 32.768 KHz.
The crystal resonator of the present invention is 100% satisfied with ±10 ppm, but the frequency of the crystal resonator made by the conventional method is 32
．． The present invention can provide a thin crystal resonator with good precision and no frequency shift, and is highly effective. it is obvious.

As another embodiment, the glass cap 2 is similarly sealed with a solder sealing material after the process of joining the crystal resonator of the above embodiment with the case, and then the frequency is adjusted by laser trimming. The effects of shaped resonators will be explained.

〔Effect of the invention〕

FIG. 4 is a graph explaining the present invention in detail. FIG. 4 (b) shows the mechanical impact strength of the conventional thin crystal resonator, and FIG. 4 (a) shows the mechanical impact strength of the thin crystal resonator of the present invention. This shows the frequency fluctuations for .

Initial frequency values are all 32.768KHz±5ppm
The mechanical impact strength is 5000
G and 10000 G were added respectively. As is clear from Fig. 4, the conventional thin crystal resonator has an acceleration rate of %[5000
G.

±15ppm and ±40p for 10000G, respectively
The variation in p rn is increasing. On the other hand, the thin crystal resonator of the present invention does not change at 5000 G,
At 10,000 G, the variation is extremely small at ±7 ppm.

From the above, it is clear that the present invention has a great effect on mechanical reliability and frequency stability.

To summarize the effects of the present invention as described above, by minimizing the influence of scattering weights during frequency adjustment, a thin piezoelectric vibrator with good frequency accuracy and excellent mechanical reliability can be manufactured by a simple method. It is clear that the industrial value is great.

Note that the present invention is not limited to a tuning fork type crystal resonator, but can be applied to any transparent resonator such as a longitudinal vibrating type crystal resonator or a CT cut type crystal resonator.

[Brief explanation of the drawing]

FIGS. 1A and 1B are cross-sectional views of the thin crystal resonator of the present invention, in which the weight portion 4 is disposed facing the bottom surface of the case 5. FIG. FIGS. 2A and 2B are cross-sectional views of a conventional thin crystal resonator, in which the weight portion 4 is provided on the surface of the resonator opposite to the case 5. FIG. FIG. 3 is an exploded view of the thin tuning fork crystal resonator of the present invention, in which the tuning fork weight 4 is attached to the ceramic case 1.
It is placed opposite. FIG. 4 shows the frequency variation of the mechanical shock test, in which (a) is a characteristic diagram of the present invention and (b) is a characteristic diagram of a conventional thin crystal resonator. 1...Ceramic case 2...Glass cap 3...Crystal oscillator 4...Weight plated part 5...Case bottom 5"...More than attached metal Applicant: Seiko Electronic Components Co., Ltd. Oscillator bamboo 4 gomon

Claims (1)

[Claims] A crystal resonator housed in a ceramic case, in which a frequency adjustment weight is provided on one surface of the crystal resonator, and the crystal resonator is arranged in a space between the ceramic case and a cap made of a transparent glass plate. . A thin crystal resonator, characterized in that the frequency adjustment weight of the crystal resonator is disposed facing the bottom of the ceramic case.