JP3273995B2 - Surface mount type piezoelectric vibrator and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface on which a two-terminal and four-terminal electrode arrangement can be selected by means of a pedestal formed by a mold having a common shape in accordance with a cut portion of a peripheral portion of a lead frame from a frame portion. The present invention relates to a mounted piezoelectric vibrator and a method for manufacturing the same.

[0002]

2. Description of the Related Art Recently, a piezoelectric vibrator, particularly an inexpensive and high-performance quartz crystal vibrator, is frequently used as a reference for frequency, time and the like in various electronic devices. In such a crystal resonator, for example, a pair of terminals are implanted in a base, and a crystal piece formed in a predetermined shape is held at the tip of the terminal. Then, the base is covered with a metal cover, and the base is hermetically sealed by performing soldering, resistance welding, or the like on the outer peripheral edge of the base.

On the other hand, in recent electronic devices, it is particularly desired that the electronic device be small in size and light in weight, and efforts have been made to automate the assembly process as much as possible. For this reason, active elements such as transistors and ICs and passive elements such as resistors and capacitors are often used in a surface mount type without lead terminals. This type of surface mount component is generally small in shape, and is particularly suitable for automating the assembly process. In such an automated assembly process, parts are automatically arranged at predetermined positions on a printed circuit board using, for example, a parts feeder. Then, after all the components are arranged on the printed circuit board, the components are passed through a reflow furnace or the like to melt the solder applied to the terminals of each component so that the mounting operation can be performed efficiently in a short time.

In this way, electronic components can be efficiently mounted on a printed circuit board in a short period of time, so that, for example, electronic devices can be assembled with almost no human intervention, and productivity can be significantly increased. . For this reason, a surface mount type that can perform surface mounting is more desired than a crystal unit that is housed in a metal container and a lead terminal is led out, which is often used in the related art.

[0005] However, in the case of a quartz oscillator housed in a metal container as described above, since the container has conductivity,
It is extremely difficult to perform surface mounting as it is. For example, if a terminal derived from the base is directly connected to a circuit pattern on the surface of a printed circuit board, an accident such as a short circuit between circuit patterns by a metal container occurs. There is a possibility. For this purpose, for example, it has been considered that the base of the crystal unit is mounted on a pedestal made of an insulating material and the bottom surface of the pedestal is soldered to a circuit pattern on a printed circuit board to perform surface mounting.

That is, FIG. 3 is a bottom view of a surface mount type piezoelectric vibrator using a pedestal. FIG. 3 (a) has four terminals, and FIG. 3 (b) has two terminals. In FIG. 3, reference numeral 1 denotes a pedestal formed in a substantially rectangular shape by a molding material;
It is a metal plate embedded in. Then, the terminal 3 of the piezoelectric vibrator is inserted into the through hole formed in the metal plate 2 and connected by performing soldering, spot welding or the like. Then, a part of the metal plate 2 is formed so as to extend to the bottom surface along the outside of the pedestal.

In the case where the mounting electrodes are provided on two terminals as shown in FIG. 3 (b), the metal plate extends from the longitudinal end of the pedestal and extends to the bottom along the outside of the pedestal. The tip is used as a mounting electrode. In the case where the mounting electrodes are provided at four terminals as shown in FIG. 3 (a), a metal plate is formed so as to extend from the end in the width direction of the pedestal and extend to the bottom along both outer sides of the pedestal. Thus, this tip is used as a mounting electrode. When the arrangement of the mounting electrodes is different as described above, it is necessary to use two types of molds for molding the pedestal, and it is necessary to prepare two types of metal plates. Not.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to selectively mold a pedestal having a two-terminal and four-terminal electrode arrangement using a mold having a common shape. It is an object of the present invention to provide a surface-mount type piezoelectric vibrator capable of streamlining a manufacturing process and standardizing members.

[0009]

According to the present invention, two terminals of a piezoelectric vibrator housed in a metal container are inserted into and held by respective through holes of a pair of metal plates embedded in a mold base. In performing surface mounting by forming a metal plate so as to extend to the bottom surface along the outside of the pedestal, the metal plate includes a pair of first conductive bands and a first conductive band each bridging in a width direction from a frame portion. Second extending from the central portion of the conduction band at right angles to the outside and bridging to the frame portion
And selectively molding between one of the first conductive band or the second conductive band and the frame portion so as to be embedded in a pedestal. And the frame is formed so as to extend along the outside of the pedestal to the bottom surface by cutting between the frame and the frame portion. Further, the present invention is characterized in that the piezoelectric vibrator is a quartz vibrator.

Still further, according to the present invention, two terminals of a piezoelectric vibrator housed in a metal container are inserted into respective through-holes of a pair of metal plates embedded in a pedestal made of a molding material and held, and the metal plates are mounted on the pedestal. A method of manufacturing a surface-mount type piezoelectric vibrator for performing surface mounting by molding so as to extend to the bottom surface along the outside of a pair of first conductive bands bridging a lead frame from a frame portion in a width direction. And a second conductive band extending in a longitudinal direction from a central portion of each of the first conductive bands and bridging the frame portion, and a first conductive band or a second conductive band of the lead frame; Selectively cutting between the frame portion and the lead frame is embedded together with the cut portion so as to surround the center of the first and second conductive bands, and a pedestal molded with a molding material is formed; The terminal of the piezoelectric vibrator is inserted into the through hole formed in the center of The other of the first and second conductive strips and the frame are cut to leave a predetermined length and cut off from the frame, and the cut conductive strip extends to the bottom surface along the outside of the pedestal. It is characterized by being molded into

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the assembly perspective view shown in FIG. In the figure, reference numeral 11 denotes a piezoelectric vibrator housed in a metal container. This piezoelectric vibrator has a well-known structure in which a crystal piece is held at the tip of a pair of terminals implanted in a base, and a metal cover is put on the tip to hermetically seal it. The above quartz piece is obtained by cutting an artificial quartz crystal at a predetermined angle with respect to the crystal axis, shaping it into a plate shape, polishing it to a thickness corresponding to a desired resonance frequency, and forming excitation electrodes on both side plate surfaces. It is.

Reference numeral 12 denotes a mold base, which is formed by filling a mold with a mold material such as epoxy resin into a hollow frame. The pedestal is a substantially rectangular parallelepiped, and has a metal plate 13 embedded therein so as to correspond to a pair of terminals 11 a extending from the base of the piezoelectric vibrator 11. This metal plate 13
For example, as shown in a plan view of the lead frame 14 shown in FIG. 2, a pair of first conductive bands 14b bridging in the width direction from a frame portion 14a on the outer periphery of the lead frame 14, and each first conductive band 1
4b extending outwardly at right angles from the center of 4b
and c. A through hole 14 through which the terminal 11a of the piezoelectric vibrator 11 is inserted is provided at the center of the first conductive band 14b.
d is drilled. Then, the first and second conductive bands 14 are formed.
The base is formed by selectively cutting between one of the b and 14c and the frame portion 14a and molding with the molding material 15 so as to embed the cut portion.

The site to be cut in this way is, for example, as shown in FIG.
In the plan view of FIG. 1, first, a portion shown as A or B in the drawing and overlapping with the molding material 15 is cut, and after the molding operation is completed, the remaining portion shown by the same reference numeral is cut, and this tip portion is mounted on a pedestal. Formed so as to extend to the bottom surface along the outside of. In addition, when the illustration A of the lead frame is cut, it becomes a two-terminal mounting electrode as shown in FIG. 3 (b), and when the illustration B is cut, the four electrodes as shown in FIG.
It becomes the mounting electrode of the terminal. Thus, in the plan view of the lead frame 14 shown in FIG.
A portion indicated by oblique lines in the drawing is molded with a molding material 15 so as to surround the intersection of 4c, so that the pedestal 12 having a void in the center portion with the lead frame 14 embedded therein is formed. Then, the terminal 11a of the piezoelectric vibrator 11 is inserted into the through hole 14d provided in the metal plate 13 and connected by soldering, spot welding or the like. The hollow portion of the pedestal 12 may be filled with an insulating material if necessary.

With such a configuration, a pair of first conductive bands 14b bridging the frame portion 14a of the lead frame 14 in the width direction, and outward from the center of each first conductive band 14b at right angles. A second conductive band 14c extending and bridging the frame portion 14a is provided, and one of the first and second conductive bands 14b and 14c and the frame portion 14a are selectively cut to form a mold. The material 15 is used for molding. Therefore, by selectively cutting the frame portion 14a and one of the conductive bands, the pedestal 12 having two terminals and four terminals can be selectively formed using one mold. In this case, the lead frame 14 can also be used in common for the two types of pedestals 12, and the members can be standardized.

Since the molding material 15 is molded so as to embed the cut portion of the frame portion 14a and one conductive band, the pedestal 12 is framed even when the other conductive band and the frame portion 14a are cut. It can be held in the portion 14a. Therefore, even when cutting the frame portion 14a and the other conductive band so as to leave an appropriate length, and forming the front end portion to extend to the bottom surface along the outside of the pedestal 12, the pedestal 12 can be connected to the lead. Since it can be held in the frame portion 14a of the frame 14, workability is good and there is an advantage suitable for an automatic line.

The piezoelectric vibrator 11 is inserted into the through hole 14d of the conductive band.
After the terminals 11a are inserted and soldered, and the two are joined by spot welding or the like, if the top of the case of the piezoelectric vibrator 11 is strongly pressed, for example, the portion of one of the conductive bands embedded in the molding material 15 is Since it is separated from the mold material 15, it can be separated from the frame portion 14a. Therefore, the electrode arrangement of the two terminals and the four terminals can be selectively realized by the pedestal 12 molded by a common mold, and the metal plate 13 can also be of a common shape. Can be standardized, and the cost of the product can be reduced.

[0017]

As described above in detail, according to the present invention, a pedestal having two types of electrodes can be selectively molded by a common mold, so that a common mold and a holding plate can be used. As a result, the manufacturing process can be rationalized, the members can be standardized, and the quality can be improved and the cost can be reduced.

[0018]

[Brief description of the drawings]

FIG. 1 is an assembled perspective view showing one embodiment of the present invention.

FIG. 2 is a plan view showing a lead frame used for the piezoelectric vibrator of the present invention.

FIGS. 3A and 3B are plan views showing the arrangement of electrodes of a piezoelectric vibrator using a pedestal of a conventional molding material, wherein FIG.
It is a bottom view of a terminal.

──────────────────────────────────────────────────続 き Continued on the front page (58) Surveyed fields (Int.Cl. ⁷ , DB name) H03H 9/02 H03H 3/02 H03H 9/19

Claims (3)

(57) [Claims] 1. A tip of the metal plate is retained with the connecting inserted into each hole of a pair of metal plates of the two terminals embedded in the base made of the molding material of the piezoelectric vibrator housed in a metal container
In those molded part so as to extend to the bottom surface along the outside of the seat, the metal plate is first from a position facing the frame portion of the pair of bridges in the width direction to surround the outer periphery and formed by a lead frame A conductive band, a second conductive band extending outward from a central portion of each first conductive band and bridging with a frame portion; and the piezoelectric vibrator pierced at a central portion of the first conductive band. Insert the terminal of
And one of the first and second conductive bands is a pedestal.
The first and second conductive strips are molded so as to be embedded in
The other side is molded on the pedestal and the tip is to the bottom of the pedestal
A surface mount type piezoelectric vibrator characterized by being formed so as to extend . 2. A surface mounted type piezoelectric vibrator according to claim 1, wherein said piezoelectric vibrator is a quartz crystal vibrator. 3. The two terminals of a piezoelectric vibrator housed in a metal container are inserted into and held by respective through holes of a pair of metal plates embedded in a pedestal made of a molding material, and the metal plates extend along the outside of the pedestal. A method of manufacturing a surface mount type piezoelectric vibrator for performing surface mounting by molding so as to extend to a bottom surface, wherein a pair of first
Forming a second conductive band extending in a longitudinal direction from a central portion of each of the first conductive bands and bridging the frame portion; and a first conductive band or a second conductive band of the lead frame. A step of selectively cutting between the second conductive band and the frame portion, and embedding the lead frame together with the cut portion so as to surround the center portions of the first and second conductive bands and molding with a molding material. Forming a pedestal; inserting and connecting a terminal of a piezoelectric vibrator to a through-hole formed in a central portion of the first conductive band, and holding the piezoelectric vibrator; A step of cutting the other of the conductive band from the frame part while leaving a predetermined length, and a step of forming the leading end of the cut conductive band so as to extend to the bottom along the outside of the pedestal. A method for manufacturing a surface-mount type piezoelectric vibrator, comprising: