JPH03272207A - Surface mount small sized crystal oscillator - Google Patents

Abstract

PURPOSE:To keep the tight closing performance in an excellent way and to make the oscillator small by arranging a crystal chip and an oscillation circuit element in a package main body and joining a weld ring and a metallic cover provided on a side wall of the package main body with seam welding so as to enclose the package main body. CONSTITUTION:A crystal chip 11 and only a CMOS-IC 12 are sealed in a package 10. Moreover, the IC 12 is formed by integrating an oscillation circuit element except the crystal chip 11, the package 10 consists of a package main body 13 and a cover 14 and a weld ring of the package main body 13 is formed to an upper face of a recessed laminated ceramic 15. Then the weld ring 16 and the cover 14 are joined by seam welding to enclose them and a length L of the entire package is selected to be 7.5mm, the width W is to be 5.1mm and the height H is selected to be 2.0mm.

Description

[Detailed Description of the Invention] (Industrial Application Field) The application field of the present invention is a small crystal oscillator for surface mounting.
In particular, it relates to a structure whose overall shape is the smallest in the world.

(Background of the Invention) Crystal oscillators are widely used in various communication devices and digital control devices because of their excellent electrical characteristics. in recent years,
Surface mount type devices have been developed based on the trend toward miniaturization through high-density mounting.

(Prior Art) FIG. 1 is a sectional view of a crystal oscillator illustrating a conventional example of this type.

The crystal oscillator includes a crystal blank 3, (,
- MOS type (7) IC4, resistor R, and condenser are configured. The container 1 consists of a container body 6 and a metal cover 7. The container body 6 is formed by joining the inner flange of a metal frame 9 to a ceramic substrate 8 by brazing. However, a conductive path (not shown) is formed in the ceramic substrate 8, and is insulated from the inner flange and extends to the outer surface. The metal cover 7 is constructed by joining its flange to the outer flange of the metal frame 9 by resistance welding.

(Problems with the Prior Art) However, in such a device, since each element constituting the inverter oscillation circuit is individually sealed, the number of components is basically large, resulting in a large internal volume. Further, after bonding (not shown) as a pair chip, the IC4 is covered with a protective film made of, for example, resin. and,
Since resistance welding is used to ensure airtightness, the metal cover 7 and metal frame 9 require flanges. Therefore, there was a problem in that the shape had to be large, especially in the plane direction. For example, some products are sealed (bonded) using low-melting point glass, but such products lack reliability in sealing, and because the entire container is made of ceramic, they tend to cause electromagnetic interference (EMI). It's difficult.

(Objective of the Invention) An object of the present invention is to provide an ultra-small crystal oscillator for surface mounting while maintaining good sealing.

(Solution Means) The present invention arranges a crystal piece and an oscillation circuit element in a concave container body made of ceramic, and joins a welding ring provided on the upper surface of the side wall of the container body and a metal cover by seam welding. The solution is to seal it tightly. An embodiment of the present invention will be described below.

(Embodiment) FIG. 1 is a diagram of a crystal oscillator illustrating an embodiment of the present invention. Note that FIG. 5A is an exploded view, and FIG. 2B is a cross-sectional view.

In the crystal oscillator, only a crystal piece 11 and a C-MOS type IC 12 are enclosed in a container 10. The crystal blank 11 has an AT cut that is long in the Z'-axis direction. Specifically, the Y-cut plate is cut by rotating it 35,615 times in two axial directions from the X-axis. Then, the length in the Z' axis direction is 5 mm - the width in the x axis direction is 1.0
-2.5 mm, and the thickness in the y'-axis direction is set to <0.07 to 0.14 mm depending on the oscillation frequency. Note that the width is determined depending on the temperature characteristics. IC12 is crystal piece 10
It is formed by integrating the above-mentioned oscillation circuit elements except for. The container 10 consists of a container body 13 and a cover 14. The container body 13 is formed by forming a weld ring 16 on the upper surface of a concave laminated ceramic 15. Then, the weld ring 16 and the cover 14 are joined by seam welding. That is, a pair of rollers (not shown) are pressed into contact with opposing outer circumferential ridges of the cover 14, respectively. Then, while rotating the rollers, resistance welding is first performed on one set of opposing sides and then on the other set of opposing sides in the same manner.

However, there is a divided step 1 on the inner surface of one side wall of the container body 13.
7'(ab). Then, one end side of the crystal blank 11 is electrically and mechanically connected and held.

The IC 12 is located and fixed in the gap between the crystal piece 11 and the lower surface of the container body 13, and is connected to the conductive path by bonding. Note that no protective resin is applied. Further, on the outer surface of the container body 13, a conductive path (not shown) extends from the ceramic layered surface and is formed as an external terminal. In this embodiment, as shown in FIG. 2, external terminals include a power supply terminal (not shown), a common potential terminal (earth) E, a standby terminal S (not shown), and an output terminal ○. As shown in the circuit diagram, both terminals a and b of the crystal resonator 11 are extended.

With such a configuration, each element (excluding the crystal piece) constituting the inverter oscillation circuit can be integrated into one C-MOS type IC.
Since C20 is integrated, the number of parts is minimized to reduce the area occupied. Furthermore, since the IC 12 remains as a paired chip without applying a protective film, its height dimension is reduced. Further, since the container body 13 and the cover 14 are joined by seam welding, the dimension in the plane direction can be reduced without requiring a flange on the outer periphery. As a result, the length L of the overall shape is 7.5 mm, the width W is 5.1 mm, and the height H is 2.0 mm.
It can be made into the world's smallest size of mm. Furthermore, since seam welding is resistance welding, the degree of airtightness is maintained more reliably than when joining with low melting point glass or the like. Furthermore, since the cover 14 is made of metal, electromagnetic interference (EMI) is prevented more than when the entire container is made of ceramic. Terminals a and b of the crystal resonator are led out separately on the outer surface, so it can also be used as a single crystal resonator.

For example, even if the C-MO3IC of the oscillation circuit fails, it can still operate by providing a backup circuit.

(Other matters) In the above embodiment, the crystal piece 11 and the I
Although only C12 is enclosed, if it is necessary to reduce the feedback resistance value, such as in the case of overtone, the resistor 18 may be placed in parallel in the gap between the crystal piece and the bottom surface (the third cross section in the figure). In addition, the dimensions of the overall shape are length L of 7.5 mm, width W of 5-1 mm, and height H of 2-0 m.
m, but in reality each dimension is ±1 considering errors etc.
0% is allowed, and the present invention does not exclude this. In addition, the overall size is basically 11 crystal pieces.
Although it depends on the size of the oscillator, in the present invention, as clarified in the above explanation, the ultra-compact device that can be put to practical use basically requires seam welding and the adoption of a C-MOS type IC that integrates each oscillation element. This makes it possible to provide surface-mounted crystal oscillators.

(Effects of the Invention) The present invention arranges a crystal piece and an oscillation circuit element in a concave container body made of ceramic, and joins a welding ring provided on the upper surface of the side wall of the container body and a metal cover by seam welding. The length L of the whole shape is 7.5m.
By setting m, @W to 5.1 mm and height H to 2-0 mm, it is possible to provide an ultra-compact surface-mount crystal resonator that ensures airtightness, and the effect it has on the industry is extremely large. be.

[Brief explanation of drawings]

The wt diagram is a diagram of a crystal oscillator illustrating an embodiment of the present invention, where (a) is an exploded view and (b) is a cross-sectional view. FIG. 2 is a circuit diagram of the oscillation circuit of the same embodiment. FIG. 3 is a sectional view of a crystal oscillator illustrating another embodiment of the present invention. FIG. 4(a) is a cross-sectional view of a crystal oscillator explaining a conventional example,
FIG. 3(b) is an oscillation circuit diagram.

Claims (2)

[Claims] (1) A crystal piece and a C-MOS type IC are arranged in a concave container body made of ceramic, and a weld ring provided on the upper surface of the side wall of the container body and a metal cover are joined by seam welding to seal the container. Then, the length L in the overall shape is 7.5
A small crystal oscillator for surface mounting, characterized in that the width W is 5.1 mm, and the height H is 2.0 mm. (2) A crystal piece, a C-MOS type IC, and a resistor are arranged in a concave container body made of ceramic, and a welding ring provided on the upper surface of the side wall of the container body and a metal cover are joined by seam welding. and the length L in the overall shape.
is 7.5mm, width W is 5.1mm, and height H is 2.0mm.
A small crystal oscillator for surface mounting, characterized by the following.