JPS6150413A - Manufacture of piezoelectric vibrator - Google Patents

Abstract

PURPOSE:To manufacture a piezoelectric vibrator with a small height and high quality by holding a piezoelectric chip connected at leat with a couple of leads in a space between a set of covers applied with molten glass on a frame upper face, bonding incorporatedly frame upper faces to form a package and leading the lead from the side face of the package externally to mount directly the main body without requiring any terminal hole to the circuit board. CONSTITUTION:A peripheral of both ends of a crystal chip 11 is faced to a holding arm 18 of a lead frame 15, they are connected electrically mechanically by a conductive adhesives to form a crystal chip 21 with frame. All convers 7a, 7b or a sintered glass applied to the upper face of a frame 8 are heated by a heater to transform one set of covers 7a, 7b into molten glass, said crystal chip 21 with a frame is fixed in a space by holding both short sides of the frame 14 by a holder, each outer surface of one set of covers 7a, 7b is applied with a weight in the plate face direction of the crystal chip 11 shown in the arrow (p) of one set of the covers 7a, 7b to bond the frame upper face of the covers 7a, 7b and to seal them thereby forming a package 24.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a piezoelectric vibrator in which a piezoelectric piece is enclosed in a container consisting of a set of lids, and is particularly applicable to communication equipment, etc. The present invention relates to a method for manufacturing a piezoelectric vibrator that is suitable for automated production of electronic devices, can be directly mounted on a circuit board (referred to as surface mount), and has a small height dimension.

(Prior art) In general, piezoelectric resonators made of single crystals, especially crystal resonators, have an extremely high Q value that roughly determines their resonance characteristics.
It has traditionally been used as an oscillator or resonator in communication equipment. FIG. 2 shows the structure of this type of crystal resonator, and is a sectional view of a conventional example in which a metal cover for maintaining airtightness is removed. In the figure, 1 is a disk-shaped AT-cut crystal piece on which electrodes 2 are formed extending from the center of both main surfaces to both ends, and 3 is a pair of lead terminals 4 insulated by glass 5 that penetrate through the main surfaces. A metal base 6 is a clip member that is connected to one end of the lead terminal 4 by spot welding or the like, and holds the crystal piece 2 at its tip wound into a coil.

(Problems and Background of the Prior Art) In recent years, crystal oscillators have been widely used not only in the above-mentioned communication devices, but also in various consumer electronic devices such as watches, which require a reference time source. In addition to the trend toward miniaturization, these various electronic devices are also becoming more compact, with each component placed in a higher density using automatic component inserters, etc., in order to provide other functions to the model, and automated production, which reduces production costs and increases efficiency. Measuring quality. For this reason, it is desired that not only each component be of high quality, but also chip-shaped components such as resistor capacitors and Cs that are suitable for automatic production and miniaturization. However, the crystal oscillator can be said to be the heart of the device, and its performance must never be compromised, and the old-fashioned method is still used, as mentioned above, by enclosing a crystal holder inside the container that serves as the metal base 3 and metal cover to ensure an airtight seal. The mainstream is one with a configuration that maintains this characteristic. Therefore, when this crystal resonator is mounted on a circuit board (not shown), terminal holes are required, so the height dimension is large due to the length of the lead wire, and the circuit board cannot be used effectively. It is unsuitable as a component of equipment. For this reason, for example, a crystal piece may be sealed in a flat container made of an insulator, and lead wires may be led out from the side of the container, or metallized electrodes may be formed on the surface of the container to attach the crystal to the circuit board. Container 1 A flat piezoelectric vibrator that can be attached directly to the main body and is suitable for automation is being developed and researched. However, when forming an insulating container, for example, when applying sintered glass to the sealing part and heating it to seal it, the inside of the container (the enclosed crystal piece is not affected by this heat). For example, when heat above the Curie temperature of 573° C. is applied, the piezoelectric effect of the crystal piece is impaired due to crystal transition, leading to a decline in its quality.

(Object of the Invention) Therefore, the present invention provides a method for manufacturing a piezoelectric vibrator, which allows the main body to be directly attached to a circuit board without requiring terminal holes, and which can manufacture a piezoelectric vibrator with a small height dimension and high quality. It is.

(Characteristics of the Solution Means of the Invention) The present invention provides a piezoelectric piece to which at least one pair of lead wires are connected, and a piezoelectric piece connected to at least one pair of lead wires, which is coated with molten glass on the upper surface of a frame formed around a plate surface, and which is placed between a pair of opposing lid bodies. A container is formed by integrally joining the top surfaces of the frames of the pair of lids in a hollow shape, and at the same time, the piezoelectric piece is enclosed in the container, and the lead wire is inserted from the side surface of the container. is characterized in that it is derived to the outside.

(Detailed Description of the Invention) FIG. 1 is a diagram showing an outline of an embodiment of the piezoelectric vibrator manufacturing method of the present invention, in which a pair of lid bodies 7a having a frame 8 around a plate surface and facing each other are shown. , 7b, the crystal piece 2 with lead frame
1 is held in a hollow shape, and the upper surfaces of the frame 8 heated from the screen surface side of the crystal piece 11 are brought close to each other and joined to form a piezoelectric vibrator integrally.

(Embodiment of the Invention) Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. 3 and subsequent figures. Note that FIG. 1 and FIG. 4(c) described above are the same drawing, and are shown redundantly for convenience of explanation.

First, the components of the present invention will be explained with reference to FIG. FIG. 3(a) shows a container 2 formed by the method described later.
This lid body 7a + 7b is made of an insulator such as ceramic, and has a frame 8 formed around the plate surface, and one opposing frame. Each of the upper surfaces is provided with a pair of grooves 9. In the figure, the black dots indicate the sintered glass 10 applied to the upper surface of the frame 8, which serves as a sealing material when forming the container U.

FIG. 3 (can) is a diagram of an AT-cut disc-shaped crystal piece 11 enclosed in a container U, in which folded electrodes 12 are formed at both ends extending from the center of both main surfaces. Figure 3 (
C) holds the crystal piece 11 and connects the pair of lead wires 13a and 13b led out from the side of the container to the frame 14.
A lead frame 15 is shown disposed between the short sides of the lead frame 15, and this lead frame 15 is formed by, for example, press working. And the lead wire 13a.

13b, a holding arm 18 is formed in the frame 14 to electrically and mechanically connect the outer periphery of both ends of the crystal piece 11 from the center of the opposing U-shaped internal lead wires 16 via a protrusion 17. Bent parts 19 are formed at both ends of the U-shaped connection part in consideration of thermal and mechanical shock, and external terminals connected in an engineering manner are formed from both ends of the U-shape.

A method of manufacturing a piezoelectric vibrator using the above-mentioned components will be described below. First, as shown in FIG. 4(a), the outer circumferences of both ends of the crystal piece 11 are made to face the holding arms 18 of the lead frame 15, and are connected electrically and mechanically with a conductive adhesive (not shown) to form a frame. The attached crystal piece 21 is formed. At this time, a conductive adhesive is applied to the expanding areas n provided at both ends of the holding arm, so that the conductive adhesive is applied not only to the opposing surface of the crystal piece 11 but also to the side and main surfaces. . Next, as shown in FIG. 4(b), the respective outer surfaces are suctioned using, for example, a vacuum suction machine (not shown), and the upper surfaces of the frames corresponding to the positions of the grooves 9 are made to face each other and separated from each other. Then, using, for example, a heater (not shown), heat is applied to the sintered glass 10 applied to the entire lids 7a, 7b or directly to the upper surface of the frame 8 to form molten glass 23. Next, as shown in FIG. 4(c), the frame-equipped crystal piece 21 is held at both short sides (not shown) of the frame 14 between a pair of lids 7a and 7b facing each other and separated from each other. Hold it in a hollow shape with a container and fix it. At this time, the opposite U-shaped internal lead wires 16 connecting the crystal piece 11 to the holding arm 18 of the frame-attached crystal piece 21 are connected to such an extent that their outer peripheries do not touch the inner peripheral walls of the lids 7a and 7b. The external terminals 20 are located close to each other and are arranged so that the engineered coupling portions of the external terminals 20 fit into the respective grooves 9. Next, Figure 4 (d
), the outer surfaces of the pair of lids 7a and 7b positioned on the screen side of the crystal blank 11 are loaded in the direction of the plate surface of the crystal blank 11 as indicated by the arrow p, and a pair of lids 7a, 7
The upper surface of the frame b is joined and sealed to form the container 24. At the same time, the crystal piece 11 is sealed inside the container U, and the external terminal 20 is led out from one opposing side surface while being connected to the frame 14 that goes around the outer periphery of the container. In addition, when forming the container 24, the molten glass 23 on the top surface of the frame may flow into and out of the container, causing errors in the external dimensions,
In addition, in order to prevent it from adhering to the crystal piece 11 and adversely affecting the vibration characteristics, for example, as shown in FIG. Alternatively, a stepped surface 26 may be formed. And finally, the fourth
As shown in the side view of Figure (e), only the frame 14 that goes around the container 24 once is cut and separated from the external terminal 20, and, for example, a notch 2 is formed on the tip side of the external terminal 2o.
Step 5, the crystal resonator is bent from both sides to one main surface to complete a flat crystal resonator.

(Operations and Effects of Embodiment) Therefore, in this embodiment, the molten glass 23 is applied to the upper surface of the frame, and the lid body facing Since the piezoelectric vibrator is integrally formed by holding a hollow crystal piece with a frame formed independently between them, the thermal energy when melting the sintered glass applied to the frame surface is absorbed by the crystal piece. It can be prevented from being transmitted to the piece 11. Also, the top surfaces of the frames are joined together to form a container 2.
4, the external terminal 2o is attached to the crystal blank II.
Since the frame 14 is led out of the container via
The heat beam of the molten glass 23 is
Heat is dissipated to the outside more easily than 4D. Further, in the container, the internal lead 1s16 is formed with a bent portion 9 to lengthen the heat conduction path, so that the thermal energy transmitted to the crystal blank 11 is attenuated. It goes without saying that it would be better if a device for cooling the frame 14 is provided when the container 24 is integrally formed. (However, rapid cooling will actually worsen the adhesion of the molten glass between the top surfaces of the frames and impair the sealing, so sufficient care must be taken.) Therefore, the crystal piece] 1 is placed in a container (sealed in The crystal blank 11 is not adversely affected by the thermal energy when sealing the container, and the piezoelectric action of the crystal blank 11 is not impaired due to a change in crystal structure due to a cue temperature of 573° C. or higher, for example.

(Effects of the Invention) Based on the above configuration, the present invention does not require terminal holes on the circuit board, allows the main body to be directly mounted, and makes it possible to manufacture a piezoelectric vibrator with a small height and high quality.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the manufacturing process of a piezoelectric vibrator showing the main part of the present invention. FIG. 2 is a sectional view showing a conventional example of a piezoelectric vibrator. FIG. 3 is a diagram of components related to the method of manufacturing a piezoelectric vibrator of the present invention, and FIG. 4 is a diagram showing each step of the method of manufacturing a piezoelectric vibrator of the present invention. FIG. 5 is a diagram showing another modification of the set of lids. 7a, 7b... Lid body, 8... Frame, 9... Groove, 10
...Sintered glass, 1J...Crystal piece, 12...Folded electrode, 13a, 13b...Lead wire, 14...
Frame, 15...Lead frame, 16...Internal lead wire, 17...Protrusion, 18...Holding arm, 19...Bending portion, 20...External terminal, 21...・
Crystal piece with frame, 22... Expansion area, 23...
Molten glass, 24... Container, 25... Notch, 2
6...Step surface. Figure 1 3rd neighbor ((1) 2111*41a) Figure 4 (b) Figure 4 (C) Figure 4 (e) jlrs diagram

Claims (1)

[Claims] A piezoelectric piece to which at least one pair of lead wires is connected is held in a hollow state between a pair of opposing lid bodies, each of which has a molten glass applied to the upper surface of a frame formed around the plate surface. A piezoelectric vibrator characterized in that a container is formed by joining the upper surfaces of the frames of the piezoelectric vibrator, and at the same time, the crystal piece is enclosed in the container, and the lead wire is led out from the side surface of the container. Production method.