JP3956614B2 - Piezoelectric oscillator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oscillator, and more particularly to a small voltage-controlled oscillator.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a small crystal oscillator, 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 shows a perspective configuration diagram of a conventional crystal oscillator, and FIG. 3B shows a sectional configuration diagram of the AA ′ portion.
As shown in the figure, a crystal oscillator 100 has an electronic component 103 such as a crystal resonator and an amplifier circuit mounted directly on a land pattern 102 of a flexible wiring board 101, and a metal case 104 so as to cover the upper surface of the electronic component 103. Is installed.
[0003]
At this time, a metal frame 105 using a conductive wiring material is embedded in the outer peripheral edge of the flexible wiring board 101 to prevent the flatness of the board from being damaged due to the bending of the board. The rigidity of the flexible wiring board 101 is obtained.
[0004]
[Problems to be solved by the present invention]
However, in the case of the crystal oscillator 100 having the above-described configuration, it is inevitable that the flexible wiring board 101 is widened only by the range of the metal frame 105 provided on the outer periphery of the component mounting area. In some cases, there is a problem that the demerit of the enlargement of the crystal oscillator 100 accompanying the increase in area is greater than the advantage of lowering the height.
[0005]
Further, in order to obtain the flatness of the flexible wiring board 101, the case 104 and the flexible wiring board 101 are fixed so that the fixing force between the case 104 and the flexible wiring board 101 is uniformly generated on the entire edge of the flexible wiring board 101. In general, it is necessary that the edges have almost the same height. However, in the case 104 formed by the die-cutting method, it is generally easy to generate a case where the edge of the case 104 is not uniform although it is inexpensive. On the other hand, it is possible to keep the edges of the case uniform even in a case constructed by welding a plurality of metal materials, but it is expensive, and it is impossible to achieve both miniaturization and cost reduction of the crystal oscillator. There was a case that the problem occurred.
[0006]
The present invention has been made to solve the above-described problems of piezoelectric oscillators, and even when a flexible wiring board is used as a mounting board, the mounting range of the crystal oscillator is narrow, and the terminals The object is to provide a piezoelectric oscillator with excellent flatness at low cost.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention includes a piezoelectric vibrator in which a piezoelectric vibrating piece is housed in a ceramic package, a flexible wiring board having rigidity lower than that of the ceramic package, An electronic component mounted on the upper surface of the flexible wiring board, the lower surface of the ceramic package is smooth, and has a surface-mounting terminal on the lower surface, and a plurality of surroundings around the flexible wiring substrate. A columnar terminal is mounted, the piezoelectric vibrator is mounted so as to cover the upper surface of the electronic component, and the surface-mounted terminal and the plurality of columnar terminals are fixed to reinforce the flexible substrate. It is characterized by comprising.
[0008]
The invention according to claim 2 is characterized in that, in addition to the invention according to claim 1, the substrate of the flexible wiring board has a structure that is thinner than the thickness of the ceramic package.
[0009]
According to a third aspect of the present invention, in addition to the first aspect of the invention, the plurality of columnar terminals are metal balls.
[0010]
According to a fourth aspect of the invention, in addition to the third aspect of the invention, a gap between the lower surface of the ceramic package and the flexible wiring board is fixed so as to fix the lower surface of the ceramic package and the flexible wiring board. An adhesive is interposed between the flexible substrate and the flatness of the flexible substrate.
[0011]
[Embodiments of the Invention]
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, in which FIG. 1 (a) shows a side configuration diagram, and FIG. 1 (b) shows a perspective configuration diagram in an exploded state of the piezoelectric oscillator.
[0012]
In the crystal oscillator 1 shown in the figure, an electronic component 3 is mounted directly on a land pattern on one side of a flexible wiring board 2, and metal balls 5 are placed on a land pattern 4 provided on the outer peripheral edge of the flexible wiring board 2. Further, a surface of a crystal resonator 6 having a plane shape substantially equal to that of the flexible wiring board 2 is provided on the bottom surface of the ceramic package 7 of the crystal resonator 6 via the metal ball 5 while covering the upper surface of the electronic component 3. The mounting terminal 8 and the land pattern 4 are mounted so as to be conductive.
[0013]
In this case, the outer peripheral edge of the flexible wiring board 2 is not provided with a metal frame made of an annular wiring which has been conventionally used for reinforcing the flexible wiring board, and the crystal resonator 7 is overlapped with other electronic components 3. With the arrangement structure, the flexible wiring board 2 can be reduced in size to almost the same as the planar shape of the crystal resonator 7.
Furthermore, the ceramic package 7 can be easily formed by a general firing process and the bottom surface thereof is smooth even with the miniaturization of the flexible wiring board 2 without the conventional annular metal frame. Even if only the ceramic package 7 is used as a reinforcing frame, the crystal oscillator 1 having excellent substrate flatness (terminal flatness) of the flexible wiring board 2 can be reliably obtained at a lower cost than the case of using a conventional metal case as a reinforcing frame. Can do.
[0014]
Further, since the crystal resonator 6 is provided with a metal lid 9 on the upper surface thereof, the metal lid 9 is used as a shield case for the entire crystal oscillator 1 so that a conventionally used metal case for the crystal oscillator is necessary. However, although the metal case is omitted, the crystal oscillator 6 is arranged on the part, but the height of the crystal oscillator can be suppressed to be equal to or lower than the conventional one.
As the pillar member to conduct the surface mounting terminal 8 and the land pattern 4 instead may be a column member in addition to prismatic metal ball Lumpur 5, in this case, the pillar member is a length of the prismatic one metal rods example It is cut and formed.
[0015]
However, prismatic cylinders, cylinders, and elliptical column members vary in size due to variations in cutting accuracy during formation and variations in the thickness of metal rods. After being cut into pieces, it is polished so as to correct the variation in length between the individual pieces, and then mounted on the flexible wiring board 2. In this case, it is necessary to check the corrected direction. It may be difficult to obtain assembly work.
[0016]
In this regard, the metal ball column member is originally spherical, so the mounting direction is not limited, and even when the ball diameter varies, for example, the ball is sandwiched between two polishing plates and polished. Therefore, it is possible to compensate for the variation in diameter uniformly. For this reason, since the diameter is almost uniform when mounted on the flexible wiring board 2, the mounting direction is a concern as in the case of a prism. There is an advantage that an efficient assembling work can be easily obtained without doing so.
Further, although the present invention has been described using the configuration in which the crystal unit 6 and the flexible wiring board 2 are connected only through the metal balls 5, the top surface of the electronic component 3 and the bottom surface of the ceramic package 7 are non-conductive. The flexible wiring board 2 can be more firmly restrained by using an adhesive, and the flatness of the board can be maintained with high accuracy.
[0017]
In addition to the flexible wiring board 2, the component mounting board and the column member are separated, so that the component mounting board surface is in a flat state, and the land on which the electronic component 3 is mounted and the land pattern 4. Solder can be easily screened on.
Furthermore, although the present invention has been described using a structure in which the crystal resonator 6 and the column member 5 are separate, the present invention is not limited to this, and the column member 5 is made of a crystal as shown in FIG. It may be provided integrally with the ceramic package 7 of the vibrator 6.
[0018]
That is, FIG. 2 shows another embodiment based on the present invention. The bottom surface of the ceramic package 7 of the crystal unit 6 is provided with a column member 5 provided in a laminated configuration. The bottom surface is provided with surface mount terminals 8 for fixing to the land pattern 4 of the flexible wiring board 2, and the land pattern 4 and the surface mount terminals 8 are electrically connected to each other so that the crystal vibrating piece in the ceramic package 7 is connected to the electronic component. 3 is connected to form a crystal oscillator circuit.
In the above description, the present invention has been described using the crystal resonator 7 as the piezoelectric vibrator. However, the present invention is not limited to this, and the present invention is also applicable to a piezoelectric vibrator using a surface acoustic wave resonator and other piezoelectric materials. Needless to say, it is possible.
[0019]
【The invention's effect】
As described above, the piezoelectric oscillator according to the present invention includes 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, a piezoelectric vibrator, and an electronic component. And mounting the electronic component on one side of the flexible wiring substrate, and the piezoelectric vibrator on the flexible wiring substrate via a plurality of pillar members so as to cover the top of the electronic component. 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 the metal frame that has been used in the past. It is possible to realize.
[Brief description of the drawings]
FIG. 1A is a side view of a configuration of an embodiment of a crystal oscillator according to the present invention.
(B) The exploded block diagram of one Example of the crystal oscillator based on this invention is shown.
FIG. 2 is an exploded configuration diagram of another embodiment of a crystal oscillator according to the present invention.
FIG. 3A is a plan view of a conventional crystal oscillator.
(B) A sectional side view of a conventional crystal oscillator is shown.
[Explanation of symbols]
1 crystal oscillator, 2 flexible wiring board, 3 electronic components, 4 land pattern, 5 metal ball (column member), 6 crystal resonator, 7 ceramic package, 8 surface mounting terminal, 9 metal lid, 100 crystal oscillator, 101 flexible wiring Substrate, 102 land pattern, 103 electronic components, 104 metal case, 105 metal frame

Claims (4)

A piezoelectric vibrator having a piezoelectric vibrating piece housed in a ceramic package; a flexible wiring board having rigidity lower than that of the ceramic package; and an electronic component mounted on an upper surface of the flexible wiring board. The piezoelectric vibrator has a smooth bottom surface, surface mounting terminals on the bottom surface, a plurality of columnar terminals mounted around the flexible wiring board, and covers the top surface of the electronic component. The piezoelectric oscillator is configured to reinforce the flexible substrate by mounting the surface mount terminal and the plurality of columnar terminals. 2. The piezoelectric oscillator according to claim 1, wherein a thickness of the flexible wiring board is thinner than a thickness of the ceramic package. The piezoelectric oscillator according to claim 1, wherein the plurality of columnar terminals are metal balls. An adhesive is interposed between the lower surface of the ceramic package and the flexible wiring substrate so as to fix the lower surface of the ceramic package and the flexible wiring substrate so that the flatness of the flexible substrate is increased. The piezoelectric oscillator according to claim 1, wherein the piezoelectric oscillator is configured to be maintained.

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