JP2002185254A - Piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact crystal oscillator with improved terminal flatness inexpensively. SOLUTION: A piezoelectric vibrator for accommodating a piezoelectric vibration piece in a ceramic package, electronic components for composing an oscillation circuit with the piezoelectric vibrator, and a flexible wiring board for mounting the piezoelectric vibrator and the electronic components are provided. The electronic components are mounted onto one surface of the flexible wiring board, and the piezoelectric vibrator is arranged on the flexible wiring board via a plurality of columnar members so that the upper portion of the electronic components are covered, thus reducing the area of the flexible wiring board, making flat the flexible wiring board due to the stiffness of the ceramic package even without providing any metal flames that have been adopted conventionally, and hence achieving the compact, inexpensive piezoelectric oscillator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an oscillator, and more particularly to a small voltage controlled oscillator.

[0002]

2. Description of the Related Art Conventionally, as a small crystal oscillator, there is known a structure in which electronic components constituting a crystal oscillator circuit are mounted on a flexible substrate as shown in FIG. That is,
FIG. 3A is a perspective view of a conventional crystal oscillator.
FIG. 3B is a cross-sectional view of the AA ′ portion. As shown in the figure, a crystal oscillator 100 has electronic components 103 such as a crystal oscillator and an amplifier circuit mounted directly on a land pattern 102 of a flexible wiring board 101, and a metal case 104 covering the upper surfaces of these electronic components 103.
It is equipped with.

At this time, in order to prevent the flatness of the substrate from being impaired due to the bending of the substrate, the flexible wiring substrate 101 has a metal frame 1 using a conductive wiring material on the outer peripheral edge thereof.
05 is embedded, and the rigidity of the flexible wiring board 101 is obtained by joining the metal case 104 and the metal frame 105.

[0004]

However, in the case of the crystal oscillator 100 having the above configuration, it is inevitable that the area of the flexible wiring board 101 is increased by the area of the metal frame 105 provided on the outer periphery of the component mounting area. In some cases, however, there is a problem that the disadvantage of increasing the size of the crystal oscillator 100 with the increase in the area is greater than the advantage of reducing the height due to the use of the flexible wiring board 101.

Further, in order to obtain the flatness of the flexible wiring board 101, the case 104 and the flexible wiring board 1 are required.
It is generally necessary that the edges of the case fixed to the flexible printed circuit board 101 have substantially the same height so that the fixing force to the flexible printed circuit board 01 is uniformly generated over the entire edge of the flexible printed circuit board 101. Case 1 formed by construction method
In the case 04, although it is inexpensive but the edge of the case 104 is not likely to be non-uniform, it is easy to occur in general. However, there is a case where a problem arises that the cost is high and the size reduction and the price reduction of the crystal oscillator cannot be achieved at the same time.

The present invention has been made in order to solve the above-mentioned problems of the piezoelectric oscillator. Even when a flexible wiring substrate is used as a mounting substrate, the mounting range of the crystal oscillator is small. Another object of the present invention is to provide an inexpensive piezoelectric oscillator having excellent terminal flatness.

[0007]

According to a first aspect of the present invention, there is provided a piezoelectric vibrator in which a piezoelectric vibrating reed is housed in a ceramic package, and an oscillation circuit together with the piezoelectric vibrator. Electronic component, and a flexible wiring board on which the piezoelectric vibrator and the electronic component are mounted. The electronic component is mounted on one side of the flexible wiring board, and the piezoelectric vibrator is mounted on the electronic circuit. The piezoelectric vibrator is arranged on the flexible wiring board via a plurality of column members so as to cover an upper part of the component, so that the flatness of the flexible wiring board is obtained by the rigidity of the ceramic package. And

According to a second aspect of the present invention, in addition to the first aspect, the column member is integrated with an outer bottom surface of the ceramic package.

The invention according to a third aspect is characterized in that, in addition to the first aspect, the pillar member is a member separate from the ceramic package and the flexible wiring board.

A fourth aspect of the invention is characterized in that, in addition to the third aspect, the column member is a metal ball.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 shows an embodiment of a piezoelectric oscillator according to the present invention. FIG. 1 (a) shows a side view and FIG. 1 (b) shows an exploded perspective view of the piezoelectric oscillator.

A crystal oscillator 1 shown in FIG. 1 has an electronic component 3 mounted directly on a land pattern on one side of a flexible wiring board 2 and a metal pattern on a land pattern 4 provided on an outer peripheral edge of the flexible wiring board 2. Equipped with ball 5,
Furthermore, a crystal resonator 6 having a planar shape substantially equal to that of the flexible wiring board 2 covers the upper surface of the electronic component 3, and a ceramic package 7 of the crystal resonator 6 is provided via the metal ball 5.
Are mounted so that the surface mounting terminals 8 provided on the bottom surface of the above and the land pattern 4 are electrically connected.

In this case, the outer peripheral edge of the flexible wiring board 2 is not provided with a metal frame formed by an annular wiring which has been conventionally used for reinforcing the flexible wiring board. With this configuration, it is possible to reduce the size of the flexible wiring board 2 to approximately the same as the planar shape of the crystal unit 7. Further, the ceramic package 7 can be easily formed by a general firing process, and the lower surface thereof is smooth even if the flexible wiring board 2 is downsized without the conventional annular metal frame. Even if only the ceramic package 7 is used as the reinforcing frame, the crystal oscillator 1 excellent in the flatness (terminal flatness) of the flexible wiring board 2 can be reliably obtained at a lower cost than in the case of using the conventional metal case as the reinforcing frame. Can be.

The quartz oscillator 6 has a metal cover 9 on its upper surface.
Since the metal cover 9 is provided with the crystal oscillator 1
The use of the entire shield case eliminates the need for a metal case dedicated to a crystal oscillator, which has been conventionally used, and the structure in which the crystal unit 6 is disposed on a component because the metal case is omitted. It is possible to keep the height of the crystal oscillator equal to or less than the conventional height. In addition, the pillar member for conducting the surface mounting terminal 8 and the land pattern 4 may be a prismatic pillar member other than the metal burl 5. In this case, the pillar member is, for example, a single metal rod having a length of the prism. It is formed by cutting.

[0015] However, the size of the pillar members such as prisms, cylinders, and elliptic cylinders varies among individuals due to variations in cutting accuracy at the time of formation and variations in the thickness of the metal rods. After being cut to the length of the member, it is polished so as to correct the variation in length between the individual members, and then mounted on the flexible wiring board 2. In this case, it is necessary to confirm the corrected direction. It may be difficult to obtain an efficient assembly operation.

In this regard, the mounting direction of the pillar member of the metal ball is not limited since it is originally spherical, and even if the ball diameter varies, for example, the ball is sandwiched between two polishing plates. If the polishing is performed, it is possible to uniformly correct the variation in the diameter. For this reason, the diameter is substantially uniform when mounted on the flexible wiring board 2, so that the mounting direction is the same as in the case of the prism. There is an advantage that an efficient assembly operation can be easily obtained without worrying about Although the present invention has been described using a configuration in which the crystal unit 6 and the flexible wiring board 2 are connected only through the metal balls 5, the upper surface of the electronic component 3 and the bottom surface of the ceramic package 7 are electrically non-conductive. The flexible wiring board 2 may be more firmly constrained by using a flexible adhesive, and the flatness of the board may be maintained with high precision.

Further, the present invention is not limited to the flexible wiring board 2,
Since the component mounting board and the column member are separated from each other, the component mounting board surface is in a flat state, so that the solder on the land on which the electronic component 3 is mounted and the land pattern 4 can be easily screened. it can. Further, the quartz oscillator 6
Although the present invention has been described using a structure in which the column member 5 and the column member 5 are separate bodies, the present invention is not limited to this. 7 may be provided integrally.

FIG. 2 shows another embodiment according to the present invention, in which a column member 5 provided in a laminated structure is provided on the bottom surface of a ceramic package 7 of a crystal unit 6, and a column member 5 is further provided. The flexible wiring board 2 is provided on the bottom of the member 5.
The land pattern 4 and the surface mounting terminal 8 are fixedly connected to each other. When the land pattern 4 and the surface mounting terminal 8 are electrically connected to each other, the electronic component 3 is electrically connected to the crystal resonator element in the ceramic package 7 and the crystal oscillator is formed. A circuit is configured.
In the above description, the present invention has been described using the crystal resonator 7 as the piezoelectric resonator. However, the present invention is not limited to this, and is applicable to a surface acoustic wave resonator and a piezoelectric resonator using other piezoelectric materials. It goes without saying that it is possible.

[0019]

As described above, the piezoelectric oscillator according to the present invention comprises a piezoelectric vibrator in which a piezoelectric vibrating piece is housed in a ceramic package, an electronic component for forming an oscillation circuit together with the piezoelectric vibrator, and a piezoelectric vibrator. And a flexible wiring board on which the electronic component is mounted, the electronic component is mounted on one side of the flexible wiring board, and the piezoelectric vibrator is interposed through a plurality of column members so as to cover the upper part of the electronic component. By arranging on the flexible wiring board, the flexible wiring board has a small area, and the flatness of the flexible wiring board can be obtained by the rigidity of the ceramic package without providing a metal frame which has been conventionally used. It is possible to realize an inexpensive piezoelectric oscillator.

[Brief description of the drawings]

FIG. 1 (a) shows a side view of a crystal oscillator according to an embodiment of the present invention. FIG. 2B is an exploded view of an embodiment of the crystal oscillator according to the present invention.

FIG. 2 is an exploded view of another embodiment of the crystal oscillator according to the present invention.

FIG. 3A is a plan view of a conventional crystal oscillator. (B) is a sectional side view of a conventional crystal oscillator.

[Description of Signs] 1 crystal oscillator, 2 flexible wiring board, 3 electronic components,
4 land pattern, 5 metal balls (pillar member), 6 crystal oscillator, 7 ceramic package, 8 surface mounting terminals, 9 metal cover, 100 crystal oscillator, 101 flexible wiring board,
102 land pattern, 103 electronic components, 104 metal case, 105 metal frame

Claims (4)

[Claims] 1. A piezoelectric vibrator in which a piezoelectric vibrating piece is housed in a ceramic package, an electronic component for forming an oscillation circuit together with the piezoelectric vibrator, and a flexible wiring on which the piezoelectric vibrator and the electronic component are mounted. A substrate, wherein the electronic component is mounted on one surface of the flexible wiring substrate, and the piezoelectric vibrator is mounted on the flexible wiring substrate via a plurality of column members so as to cover the upper part of the electronic component. A piezoelectric oscillator configured to obtain the flatness of the flexible wiring board by the rigidity of the ceramic package. 2. The piezoelectric oscillator according to claim 1, wherein said column member is integrated with an outer bottom surface of said ceramic package. 3. The piezoelectric oscillator according to claim 1, wherein the column member is a member separate from the ceramic package and the flexible wiring board. 4. The piezoelectric oscillator according to claim 3, wherein said column member is a metal ball.