JP5018917B2 - Method for manufacturing piezoelectric oscillator - Google Patents

Description

The present invention relates to a method for manufacturing a piezoelectric oscillator, and in particular, has a configuration in which a piezoelectric vibrator packaged using a pillar member is fixed on an upper part of a wiring board on which electronic components constituting an oscillation circuit and a temperature compensation circuit are mounted. The present invention relates to a method for manufacturing a piezoelectric oscillator.

Due to the rapid progress in price reduction and miniaturization accompanying the popularization of mobile communication devices such as mobile phones,
There is an increasing demand for lower prices, smaller sizes, and thinner thicknesses for piezoelectric oscillators such as crystal oscillators used in these communication devices.
Therefore, conventionally, piezoelectric oscillators packaged using chip components have been manufactured, and the structure is such that a pillar member is provided on the upper part of a wiring board on which electronic components constituting an oscillation circuit and a temperature compensation circuit are mounted. There are many structures that fix the piezoelectric vibrators that are packaged using, and on the land on the wiring board on which the electronic components are mounted, cream solder is screen printed and the chip components are fixed by reflow method, and packaged The occupied area is reduced by three-dimensionally arranging the piezoelectric vibrator thus formed on the pillar member fixed to the wiring board.

FIG. 3 shows a first external structure of a crystal oscillator which is an example of a conventional piezoelectric oscillator.
This figure is a longitudinal cross-sectional view, in which a plurality of electronic components 2 constituting an oscillation circuit and a temperature compensation circuit are mounted on a land 1 on the upper surface, and a flat wiring board 4 having an external electrode 3 and the wiring Substrate 4
And a crystal resonator 6 fixed with a predetermined gap through a column member 5 fixed to the upper surface of the crystal oscillator. Further, the bottom electrode 7 of the column member 5 is electrically and mechanically fixed to a column member fixing pattern 8 formed on the upper surface of the wiring board 4, and the upper electrode 9 of the column member 5 is connected to the bottom electrode 10 of the crystal resonator 6. It is fixed electrically and mechanically. The column member 5 used here is a quadrangular column,
Other polygonal column ceramic block and bottom electrode 7 provided at the bottom of the ceramic block
And an upper electrode 9 provided on the upper part of the ceramic block, and a connection conductor that conducts between both electrodes.

When the pillar member 5 is fixed on the pillar member fixing pattern 8 on the wiring substrate 4, reflow connection is performed using cream solder applied on the pillar member fixing pattern 8 by screen printing. In this screen printing, cream solder is applied to the lands 1 at the same time. After placing the electronic components 2 and the column members 5 on the lands 1 and the column member fixing patterns 8 to which the cream solder is applied, The electronic component 2 and the column member 5 are fixed by simultaneously heating in the reflow furnace and then cooling.
As for the crystal unit 6, the column member 5 may be fixed on the wiring substrate 4, and the bottom electrode 10 may be fixed on the upper electrode 9 of the column member 5 using a conductive adhesive or the like. The connection between the electrode 9 and the bottom electrode 10 may be performed simultaneously with the reflow connection of the electronic component 2 or the like.

FIG. 4 shows a second external structure of a crystal oscillator which is an example of a conventional piezoelectric oscillator.
The difference between this conventional example and FIG. 3 is that a metal ball is used in this conventional example as the material of the column member that electrically and mechanically fixes the wiring board and the crystal resonator. Therefore, FIG. 4 shows an example in which the pillar member fixing pattern 8 on the wiring board 4 and the bottom electrode 10 of the crystal resonator 6 are connected using the pillar member 11 made of a metal ball. The connection between the column member 5 and the column member fixing pattern 8 and the connection method between the column member 5 and the bottom electrode 10 of the crystal resonator 6 may be reflow connection using cream solder, A connection using a conductive adhesive may also be used.

However, the conventional piezoelectric oscillator has the following problems. The crystal oscillator shown in FIG. 3 uses a prismatic column member 5, and when this column member 5 is fixed on the column member fixing pattern 8 of the wiring board 4, it is for column member fixing by screen printing. Reflow connection using cream solder applied on the pattern 8 is performed. Therefore, when placing the column member 5 on the cream solder of the column member fixing pattern 8, it is necessary to always place the column member 5 so that the electrode surface of the column member 5 is correctly in contact with the column member fixing pattern 8 surface. Conventionally, there is a risk that the electrode surface of the column member 5 is erroneously placed in a direction that does not contact the surface of the column member fixing pattern 8.

FIG. 5 shows an external structure when a conventional square column member is attached to a wiring board. Column members are
Electrodes 12 are provided on the upper and lower surfaces of a material such as ceramic, and the electrodes on the upper and lower surfaces are electrically connected by a through hole 13 or the like. When this column member is attached to the wiring board, (a
As shown in (b), the electrode 12 needs to be positioned on the upper surface and the lower surface, and when the electrode 12 is located on both sides of the column member as shown in (b), the crystal oscillator is attached to the column member. In this case, the continuity between the wiring board and the crystal oscillator cannot be obtained.
In addition, there are some manufacturing errors in the dimensions of the column members, and when the crystal unit is fixed using the column members, the height dimensions of the column members vary, and there is a problem in the electromechanical fixing. May occur.

On the other hand, the crystal oscillator shown in FIG. 4 uses a metal ball column member 5, and when this column member 5 is fixed on the column member fixing pattern 8 of the wiring board 4, The connection between the column member fixing pattern 8 and the connection between the column member 5 and the bottom electrode 10 of the crystal resonator 6 are performed by reflow connection using cream solder, respectively. When placed on the wiring board, there is a possibility that it is displaced from the column member fixing pattern 8 provided on the wiring board, which causes a problem that workability is lowered.
The present invention has been made in order to solve the problems that occur during the manufacture of the conventional piezoelectric oscillator as described above, and has improved the column member that electrically and mechanically fixes the wiring board and the piezoelectric vibrator. Accordingly, an object of the present invention is to provide a piezoelectric oscillator having high reliability and excellent work efficiency.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1] At least an electronic component constituting an oscillation circuit is mounted on the top surface, a planar wiring board having an external electrode on the bottom surface, a piezoelectric vibrator, a cut surface on the side surface, and a top surface and a bottom surface, respectively. A method of manufacturing a piezoelectric oscillator that is conductively fixed through a pillar member having metal surfaces that are electrically connected to each other, the step of mounting electronic components on a wiring board base material that is formed by partitioning a plurality of wiring boards; Fixing the pillar member base material in which a plurality of pillar members are partitioned so that the pillar member fixing pattern on the wiring board base material is electrically connected to the metal surface on the bottom surface side of the pillar member; Cutting the substrate base material together with the base material for the column member and dividing the substrate base material into individual pieces for each section.

Application Example 2 The column member base material includes a grid member and a column member extending in a peninsular form from the grid member.

As described above, in the piezoelectric oscillator having the configuration in which the packaged piezoelectric vibrator is fixed on the wiring board as described above, both the wiring board and the piezoelectric vibrator are electrically and mechanically applied in both application examples 1 and 2. As a pillar member to be fixed, a pillar member provided in a pillar member block partitioned and formed on a large-area pillar member base material is used, and this pillar member and a wiring board partitioned and formed on a large-area wiring board base material and As a result, the reliability and production efficiency are improved when the piezoelectric oscillator is assembled.
It is possible to exert a remarkable effect on the cost reduction of the piezoelectric oscillator.

It is the longitudinal cross-sectional view (a) and exploded perspective view (b) about the crystal oscillator which is an example of the piezoelectric oscillator concerning this invention. It is a figure which shows the manufacturing method of a wiring board and a column member, and the joining fixing method of both about the crystal oscillator which is one Example of the piezoelectric oscillator concerning this invention. It is a figure which shows the 1st external appearance structure about the crystal oscillator which is an example of the conventional piezoelectric oscillator. It is a figure which shows the 2nd external appearance structure about the crystal oscillator which is an example of the conventional piezoelectric oscillator. It is a figure which shows the external appearance structure at the time of attaching the conventional square pillar member to a wiring board.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
1A and 1B are a longitudinal sectional view and an exploded perspective view of a crystal oscillator which is an example of a piezoelectric oscillator according to the present invention.
The figure shows a plurality of electronic components 1 constituting an oscillation circuit and a temperature compensation circuit on a land 14 on the upper surface.
5 and a crystal substrate 19 provided with an external electrode 16 and a crystal resonator 19 fixed with a predetermined gap through a pillar member 18 fixed to the upper surface of the circuit board 17. It is. Further, the bottom electrode (bottom side electrode) 20 of the column member 18 is electrically and mechanically fixed to the column member fixing pattern 21 formed on the upper surface of the wiring board 17, and the upper electrode (upper surface side electrode) 22 of the column member 18. Is electrically and mechanically fixed to the bottom electrode 23 of the crystal unit 19. The column member 18 used here will be described in detail later, but is formed by forming a plurality of holes in the same ceramic plate, the thickness of the ceramic plate being the height direction of the column member, and wiring The thickness exceeds the maximum mounting height of the electronic component 15 mounted on the substrate 17. The column member 18 includes a bottom electrode 20 provided on the back surface of the ceramic plate, an upper electrode 22 provided on the surface of the ceramic plate, and a connection conductor that conducts between the electrodes.
For the crystal resonator 19, the column member 18 is fixed on the wiring substrate 17, and then the column member 19.
The bottom electrode 23 is fixed on the upper electrode 22 using a conductive adhesive or the like.

FIG. 2 is a diagram showing a method for manufacturing a wiring board and a column member and a method for joining and fixing the crystal oscillator as an example of the piezoelectric oscillator according to the present invention.
As shown in the figure, the printed circuit board 24 for the wiring board and the ceramic board 25 for the pillar member are divided into the wiring board 17 and the pillar member block 26 which are partitioned and formed on the large-area wiring board base material and the pillar member base material, respectively. Many are provided.
Here, the pillar member block 26 is a lattice-shaped member that indicates a partition by forming a hole in the ceramic plate 25 for the pillar member, and the pillar member 1 that protrudes from the lattice-shaped member into a hole as a peninsular projection piece.
8 are integrally formed. Each column member 18 is arranged in accordance with the position of the column member fixing pattern 21 provided on the wiring board 17. The ceramic plate 25 for column members
The front surface and the back surface are metallized, and through holes or the like are provided at predetermined positions of the column member 18 to make the front surface and the back surface conductive, and constitute a bottom electrode and an upper electrode of the column member 18. Further, the thickness of the pillar member ceramic plate 25 is determined in accordance with the mounting height of the electronic component 15 mounted on the wiring board 17.

Therefore, a description will be given of a method for bonding and fixing a wiring board and a pillar member of a crystal oscillator. First, after manufacturing a printed circuit board 24 for a wiring board having a wiring board formed by partitioning on a large-area wiring board base material, After soldering cream solder on the lands on which the electronic components 15 are mounted by screen printing and placing each electronic component 15, the electronic component 15 is fixed by heating in a reflow furnace and then cooling. Next, the pillar member ceramic plate 25 having the pillar member blocks 26 partitioned by providing predetermined holes on the pillar member base material is manufactured, and the electronic component 15 is mounted and fixed on the wiring. After the conductive adhesive is applied to the column member fixing patterns 21 provided on the respective wiring board blocks 26 of the printed circuit board 24 for the substrate, the column member fixing patterns 21 and the column members 18 are aligned, and wiring is performed. The printed board 24 and the pillar member ceramic board 25 are joined and fixed. Thereafter, the wiring board 17 to which the column member 18 is fixed is separated by cutting with a cutting machine such as a dicing saw at a position illustrated by a dotted line on the printed wiring board 24.

As for the joining procedure of the printed circuit board 24 for the wiring board and the ceramic board 25 for the pillar member, first, the pillar member fixing pattern 21 first provided on the printed wiring board 24 for the wiring board and the pillar provided on the ceramic board 25 for the pillar member. After fixing the bottom electrode of the member 18 with a conductive adhesive or the like, cream solder is applied by screen printing to the lands 14 on which the electronic components 15 provided on the printed circuit board 24 are mounted. After placing 15, the electronic component 15 may be fixed by heating in a reflow furnace and then cooling.

Furthermore, about the joining procedure of the printed board 24 for wiring boards and the ceramic board 25 for pillar members,
By applying cream solder to the lands on which the electronic components 15 provided on the printed circuit board 24 for wiring board are mounted and the column member fixing patterns 21 by screen printing, the respective electronic components 15 are placed. The printed board 24 and the column member ceramic plate 25 are aligned and overlapped, heated in a reflow furnace, and then cooled to fix the electronic component 15 and the column member 18 provided on the column member ceramic plate 25. It may be a method to do.

Therefore, since the pillar member according to the present invention is manufactured by forming a plurality of pillar members on one pillar member ceramic plate, the height of the pillar members is all the same, and when the piezoelectric vibrator is attached, It is possible to prevent a mounting failure due to a defective dimension of the pillar member, and a pillar member block that is partitioned on a large-area column member base material and a wiring that is partitioned and formed on a printed board for a large-area wiring board Since the substrates can be bonded together, efficient production becomes possible.

In addition, by using a pillar member block that is partitioned on a large-area pillar member base material,
There is no need to place the pillar members individually on the pillar member fixing pattern provided on the wiring board, and the vertical positional relationship required when placing the pillar members is always in the same direction, preventing erroneous attachment of the pillar members. In addition, when the pillar member is placed on the cream solder, there is no possibility of deviation from the pillar member fixing pattern provided on the wiring board, and the working efficiency is improved.
Next, when the manufacture of the wiring board 17 to which the column member 18 is fixed is completed, a conductive adhesive is applied to the upper electrode 22 of the column member 18 and adhered to the bottom electrode 23 of the crystal resonator 19.
The crystal oscillator 19 is completed by fixing the crystal resonator 19 to the wiring board 17.

1 .... Land, 2 .... Electronic parts,
3 .... external electrode, 4 .... wiring board,
5 .... Pillar member, 6 .... Quartz crystal,
7 .... Bottom electrode, 8 .... Pattern fixing pattern,
9 .... Upper electrode, 10 .... Bottom electrode,
11 .. Column member, 12 .... Electrode,
13 · Through hole, 14 · Land,
15 .... Electronic parts, 16 .... External electrode,
17 .... Wiring board, 18 .... Pillar member,
19 .. Quartz crystal, 20 .. Bottom electrode,
21 .... Pattern fixing pattern, 22 .... Upper electrode,
23 .. Bottom electrode 24 .. Printed circuit board for wiring board,
25. ・ Ceramic plate for pillar member, 26 ・ ・ Column member block

Claims (2)

A metal surface on which a planar wiring board having at least an electronic circuit that constitutes an oscillation circuit is mounted on the upper surface and an external electrode is mounted on the bottom surface, and a piezoelectric vibrator, and a cut surface on the side surface, and a top surface and a bottom surface, respectively A method of manufacturing a piezoelectric oscillator that is conductively fixed through a pillar member having
A step of mounting electronic components on a wiring board base material formed by partitioning a plurality of wiring boards;
Fixing a pillar member base material in which a plurality of pillar members are partitioned so that the pillar member fixing pattern on the wiring board base material and the metal surface on the bottom surface side of the pillar member are electrically connected;
Cutting the wiring board base material together with the pillar member base material and dividing it into individual pieces for each section. 2. The method of manufacturing a piezoelectric oscillator according to claim 1, wherein the base material for a pillar member is formed by integrally forming a lattice member and a pillar member extending from the lattice member in a peninsular shape.

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