JP2002050930A - Piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent the complication of solder application work on wiring pattern in a frame body that is the failure caused by the cross-sectional shape of the frame body with H shape, and the deformation such as a shape after baking the frame body which consist of a laminated reversible ceramic sheet, in a surface mounting type piezoelectric oscillator comprising a piezoelectric vibrator, electronic components, a frame body with non-H shape which respectively supports the piezoelec tric vibrator and the electronic components and a wiring board mounting electronic components on the wiring pattern. SOLUTION: The surface mounting type piezoelectric oscillator comprises a piezoelectric virbator 22, electronic components 55 which constitute an oscillator circuit, a frame body 40 which respectively supports the piezoelectric vibrator and the electronic components and a wiring board 50 mounting the electronic components. The frame body is an annular frame which has an upper surface electrode 43 which is connected with external electrode 26 of package external surface on the top surface, and has a step surface 44 and a step surface electrode 45 formed on the step surface on the inside wall of the frame body. The wiring board fitted to the inside of the frame body and is seated and supported on the step surface, and has a bottom electrode 52 which is electrically connected to the step surface electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a piezoelectric oscillator, and more particularly, to a surface mount type piezoelectric oscillator configured by combining a packaged piezoelectric vibrator and electronic components constituting an oscillation circuit and the like.

[0002]

2. Description of the Related Art With the rapid spread of cost reduction and miniaturization accompanying the spread of mobile communication devices such as mobile phones, the price of piezoelectric oscillators such as crystal oscillators used in these communication devices has also been reduced. There is an increasing demand for miniaturization and thinning. In response to such demands, not only are crystal oscillators packaged, but also oscillation circuits including frequency adjustment circuits and frequency temperature compensation circuits are integrated and integrated into ICs to reduce the number of components. FIG. 3 is a longitudinal sectional view showing the internal structure of a crystal oscillator as an example of a conventional piezoelectric oscillator. The crystal oscillator 1 includes a ceramic package body 3 and a metal lid 4.
A quartz resonator 2 accommodating a not-shown quartz resonator element in a package consisting of: a ceramic frame 10 having an H-shaped vertical section fixed to the bottom surface of the package body 3;
Electronic components 14 and the like packaged in an IC are mounted on the wiring patterns 11a and 11b formed on the upper and lower surfaces of the flat plate portion 11 integrated in the frame body 10 by soldering. On the outer bottom surface of the package body 3 of the crystal unit 2, an external electrode 5 that is electrically connected to the excitation electrode of the internal crystal unit is exposed. The crystal vibrating element has a configuration in which an excitation electrode is formed on a quartz crystal plate, and is excited by being supplied with a current of a predetermined frequency via the external electrode 5. An electrode 13 is formed on the upper surface of the outer frame 12 of the frame body 10, and the electrode 13 is connected and fixed to the external electrode 5 provided on the outer bottom surface of the package body 3 by soldering or the like. By fixing the bottom surface of the crystal unit 2 to the top surface of the frame 10, the upper concave portion 15 of the frame unit 10 is closed by the crystal unit 2. The frame body 10 is integrated by laminating and firing a plurality of ceramic plates having a required planar shape, and the flat plate part 1 located between the upper and lower recessed parts 15 and 16.
Wiring patterns 11a and 11b are respectively formed on the upper and lower surfaces of 1 and an electronic component 14 is soldered on each wiring pattern. Each of the wiring patterns 11a and 11b is electrically connected to the electrode 13. Further, a bottom electrode 17 for mounting on a wiring pattern (not shown) on a printed circuit board is formed on the bottom surface of the frame 10, and this bottom electrode 17 is used for power supply, grounding, and the like, and a connection (not shown) It is connected to wiring patterns 11a and 11b and electrodes 13 via conductors. This type of crystal oscillator 1 has a frame 1
Since a structure in which the crystal units 2 are stacked on 0 is provided, there is an advantage that the mounting area is reduced.

[0003]

However, in the above-described conventional crystal oscillator 1, the wiring patterns 11a, 11a on the front and back surfaces of the flat plate portion 11 located in the recesses 15, 16 are provided.
When soldering the electronic component 14 to the electronic component 11b, it is necessary to selectively apply cream solder to a predetermined portion of each wiring pattern in advance, but since the wiring pattern is located in the recessed portion, the outer frame 12 is obstructed. Therefore, solder application by a screen printing method is impossible. For this reason, a coating method using a dispenser having extremely poor workability has to be performed. The ceramic frame 10 is formed by laminating a plurality of laminated reversible ceramic sheets and firing the laminated ceramic sheets. When forming a frame having an H-shaped cross section, the flat plate portion 11 is formed at the stage of lamination before firing.
Is easily bent and deformed by its own weight, so that there is a problem that it is difficult to form the flat plate portion 11 into a desired flat plate shape. The problem to be solved by the present invention is to provide a packaged piezoelectric vibrator, electronic components constituting an oscillation circuit arranged outside the piezoelectric vibrator, and non-supporting piezoelectric vibrators and electronic components, respectively. In a surface-mount type piezoelectric oscillator including an H-shaped frame and a wiring board for mounting the electronic component on a wiring pattern, a defect that occurs due to the H-shaped cross section of the frame. Provided is a piezoelectric oscillator that can effectively prevent the work of applying solder onto a wiring pattern in a certain frame body and the deformation of a shape of a frame body made of a laminated reversible ceramic sheet after firing. is there.

[0004]

In order to solve the above-mentioned problems, a first aspect of the present invention relates to a packaged piezoelectric vibrator and an electronic component constituting an oscillation circuit disposed outside the piezoelectric vibrator. A surface mount type piezoelectric oscillator comprising: a frame body for supporting the piezoelectric vibrator and an electronic component; and a flat wiring board having a wiring pattern for mounting the electronic component. A hermetically seals the piezoelectric vibrating element in a package, and comprises an external electrode connected to an excitation electrode on the piezoelectric vibrating element on an outer bottom surface of the package, wherein the frame is an annular frame, An upper surface electrode connected to an external electrode on an outer surface of the package, an inner wall of the frame body has a step surface and a step surface electrode formed on the step surface, and the wiring board includes the frame. Said fit inside the body While being supported seated on difference surface, and a bottom electrode that is electrically connected to the stepped surface electrode. The invention according to claim 2 is a packaged piezoelectric vibrator, an electronic component constituting an oscillation circuit arranged outside the piezoelectric vibrator, and a frame supporting the piezoelectric vibrator;
Wherein the piezoelectric vibrator hermetically seals the piezoelectric vibrating element in a package, and an external electrode connected to an electrode on the piezoelectric vibrating element on an outer bottom surface of the package. And a wiring pattern for mounting an electronic component, wherein the frame is an annular frame, and has a step surface on its inner wall and a step surface electrode formed on the step surface, and the piezoelectric vibrator has The external electrode on the bottom surface of the package and the step surface electrode are electrically connected, while being fitted into the frame and supported on the step surface.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. FIGS. 1A and 1B are an external perspective view and a partial vertical cross-sectional exploded view illustrating a configuration of a crystal oscillator as a piezoelectric oscillator according to an embodiment of the present invention. The crystal oscillator 21 includes a crystal resonator 22 having a configuration in which a crystal resonator element 25 is housed in a package including a ceramic package main body 23 and a metal lid 24, and a longitudinal sectional shape integrally fixed to a bottom surface of the package main body 23. Are mounted on a non-H type (rectangular annular type) ceramic frame body 40 and wiring patterns 51a and 51b formed respectively on the upper and lower surfaces of a flat wiring board 50 located inside the frame body 40. It has an electronic component 55 or the like packaged in an IC package. The package body 23 and the lid 24 constitute a package. Package body 2 of crystal unit 22
3 is provided with an excitation electrode 2 of the internal quartz vibrating element 25.
The external electrodes 26 that are electrically connected to the external electrodes 7 are exposed. The crystal vibrating element 25 has a configuration in which an excitation electrode 27 is formed on a crystal element plate 26, and is supported on a stepped electrode pad 28 in the package body 23 via a conductive adhesive 29. The quartz vibrating element 25 is excited by being supplied with a current of a predetermined frequency via the external electrode 26.

The upper electrode 4 is provided on the upper surface of the outer frame 42 of the frame 40.
3 is formed, and the upper surface electrode 43 is
Is connected and integrated with an external electrode 26 provided on the outer bottom surface by soldering or the like. Thus, the crystal unit 22 is formed by soldering.
Has its outer bottom surface fixed to the upper surface of the frame body 40. Also,
In this example, the frame body 40 is made of a rectangular annular ceramic whose center is vertically penetrated, and is formed by laminating a plurality of laminated reversible ceramic sheets and firing them. A step surface 44 and a step surface electrode 45 formed on the surface of the step surface 44 are provided on the inner wall of the hollow portion of the frame body 40. The step surface 44 is
Protrusions are continuously or intermittently arranged along the same height position on the inner wall of the frame, and the step surface electrode 45 formed on the flat upper surface thereof is connected to a bottom electrode 46 via a conductor (not shown).
Is electrically connected to The hollow part of the frame is the wiring board 5
The wiring board 50 fitted in the cavity is stably seated on the step surface 44 while the dimensions are set so that 0 can be fitted in an aligned state. The bottom electrode 46 provided on the bottom surface of the frame is a mounting electrode for connecting the crystal oscillator 21 to a wiring pattern on a printed board (not shown) by soldering. The wiring substrate 50 is formed by firing after laminating the ceramic sheets, and laminating a plurality of ceramic sheets on a flat surface and firing in that state, so that the wiring sheets 50 are not bent and deformed by their own weight, The obtained wiring board has a flat plate shape. The wiring board 50 has wiring patterns 51a, 51 formed on the upper and lower surfaces thereof.
b, the bottom electrode 5 is located at a position corresponding to the step surface electrode 45.
2 Bottom electrode 52 and wiring patterns 51a, 51
b is electrically connected.

Accordingly, the wiring board 50 is fitted inside the cavity of the frame body 40 and supported on the surface of the step surface 44, and the bottom electrode 52 is connected to the step surface electrode 45 by a binder such as a conductive adhesive. Both are electrically and mechanically fixed by electrical connection. Since the step surface electrode 45 is connected to the upper electrode 43 via a conductor (not shown), the electronic component 55 is also electrically connected to the excitation electrode 27 of the crystal vibrating element 25. The rectangular annular frame 40 thus configured has a substantially H-shaped vertical cross-sectional shape as a whole when the wiring substrate 50 is assembled, and the flat wiring substrate 50 corresponds to the flat plate portion 11 of the conventional example in FIG.
By mounting the electronic components 55 on both the front and back sides, the size can be reduced and the increase in the flat area can be prevented. In addition, since the work of applying cream solder for connecting electronic components on the wiring patterns 51a and 51b on the wiring board 50 can be performed by using screen printing with good work efficiency, the above-described conventional example is used. Disadvantages can be eliminated. The frame and the wiring board are each mass-produced by batch processing. The wiring board is made by laminating large-area ceramic sheets and sintering it with the thin metal plates to be the wiring pattern arranged on both front and back sides, so that multiple wiring board pieces are connected vertically and horizontally and integrated. A material is formed, and thereafter, the wiring board base material is cut into individual pieces to manufacture the wiring board. The screen printing of the cream solder on the wiring pattern on the wiring board may be performed in such a state of the base material, so that the efficiency of the solder coating operation can be increased. Note that the electronic component 55 in the present embodiment is
For example, an oscillation circuit including a frequency adjustment circuit, a frequency temperature compensation circuit, and the like is integrated and integrated.

FIGS. 2 (a) and 2 (b) show another embodiment of the present invention. In the crystal oscillator 61 of this embodiment, a quartz oscillator 22 is placed in a hollow portion of a rectangular annular frame 62. FIG. The quartz oscillator 22 is fitted and seated and fixed on the step surface 63.
The feature is that the electronic component 55 is mounted on the wiring pattern 30 formed on the bottom surface by soldering. That is, the crystal unit 22 includes a ceramic package body 23 containing the crystal unit 25 shown in FIG.
External electrodes 26 are provided on the bottom surface of the ceramic package body 23.
In addition, a wiring pattern 30 is formed. By applying cream solder on the wiring pattern 30 by screen printing, the electronic component 5 can be easily mounted. The frame body 62 is a rectangular annular body made of a ceramic laminate, and a step 63 is formed on the inner wall of the hollow portion.
Are formed, and a step surface electrode 64 is formed on each of the step surfaces 63. By fixing the crystal unit 22 in the hollow portion and fixing the external electrode 26 and the step surface electrode 64 with a conductive adhesive or the like, the fixing between the frame 62 and the crystal unit 22 and the electrical connection are achieved. Done. The bottom surface electrode (mounting electrode) on the bottom surface of the frame 62 is electrically connected to the step surface electrode 64 via a conductor (not shown). If necessary, the adhesive 6 may be used to increase the mechanical fixing force between the frame 62 and the crystal unit 22.
6 may be used to bond and fix appropriate places of both. In the crystal oscillator of this embodiment, since a frame having an H-shaped cross section is not used, the problem that the flat portion is hardened while the flat portion is deformed during firing of the frame is eliminated. Since the electronic component is mounted on the provided wiring pattern, cream solder can be applied by screen printing, and the mounting work of the electronic component can be made more efficient. As a result, the efficiency of assembling and manufacturing processes of the crystal oscillator can be increased, the productivity can be increased, and the cost can be reduced. In the above embodiment, the crystal oscillator is mainly described, but the present invention can be applied to a piezoelectric oscillator other than the crystal oscillator.

[0009]

As described above, according to the present invention, a packaged piezoelectric vibrator, an electronic component constituting an oscillation circuit disposed outside the piezoelectric vibrator, the piezoelectric vibrator and the electronic component In a surface-mount type piezoelectric oscillator including a non-H-shaped frame body respectively supporting the electronic component and a wiring board for mounting the electronic component on a wiring pattern, the cross-sectional shape of the frame body is H-shaped. It is possible to effectively prevent complication of soldering work on the wiring pattern in the frame body, and deformation of the shape after firing the frame body made of the laminated reversible ceramic sheet, which are problems caused by the above.

[Brief description of the drawings]

1A and 1B are an external perspective view and a longitudinal sectional view of a piezoelectric oscillator according to an embodiment of the present invention.

FIGS. 2A and 2B are an external perspective view and a longitudinal sectional view of a piezoelectric oscillator according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a conventional piezoelectric oscillator.

[Explanation of symbols]

21 crystal oscillator (piezoelectric oscillator), 22 crystal oscillator (piezoelectric oscillator), 23 ceramic package body,
24 metal lid, 25 crystal vibrating element (piezoelectric vibrating element),
26 external electrodes, 27 excitation electrodes, 28 electrode pads,
29 conductive adhesive, 40 frame, 42 outer frame, 43
Top electrode, 44 step surface, 45 step surface electrode, 46 bottom electrode, 50 wiring board, 30, 51a, 51b wiring pattern, 52 bottom electrode, 55 electronic components, 61 crystal oscillator, 62 frame, 63 step surface, 64 step Surface electrode.

Claims (2)

[Claims] A packaged piezoelectric vibrator; electronic components forming an oscillation circuit disposed outside the piezoelectric vibrator; a frame supporting the piezoelectric vibrator and the electronic component; A planar wiring board having a wiring pattern on which components are mounted, wherein the piezoelectric vibrator hermetically seals the piezoelectric vibrating element in a package, and An external electrode connected to an excitation electrode on the element is provided on an outer bottom surface of the package, the frame is an annular frame, and an upper surface of the frame is provided with an upper electrode connected to the external electrode on the outer surface of the package. In addition, a step surface and a step surface electrode formed on the step surface are provided on the inner wall of the frame, and the wiring board is fitted inside the frame and is seated and supported on the step surface. And at the same time, A bottom electrode connected to the piezoelectric oscillator. 2. A surface mount type comprising: a packaged piezoelectric vibrator; an electronic component constituting an oscillation circuit arranged outside the piezoelectric vibrator; and a frame supporting the piezoelectric vibrator. A piezoelectric oscillator, wherein the piezoelectric vibrator hermetically seals a piezoelectric vibrating element in a package, and mounts an external electrode connected to an electrode on the piezoelectric vibrating element and an electronic component on an outer bottom surface of the package. The frame body is an annular frame body, and has a step surface on its inner wall and a step surface electrode formed on the step surface, and the piezoelectric vibrator is provided inside the frame body. And an external electrode on a bottom surface of the package and the step surface electrode are electrically connected to each other.