JPH0122260Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a piezoelectric resonator such as a crystal resonator.

With the miniaturization of electronic devices, there is an increasing demand for miniaturization of the individual electronic components used.Recently, so-called chip components have been widely used and are greatly contributing to the miniaturization of electronic devices. However, piezoelectric resonators such as crystal resonators generally require high stability and are housed in a package hermetically sealed in an inert gas or vacuum atmosphere, which has delayed the development of chip components. ing. That is, in chip parts, as shown in FIG. 1, in general, solder is directly attached to the electrode parts 12 attached to both ends of the main body 11, so the temperature of the main body 11 rises to around the melting point of the solder. Direct heating in this manner is not preferable for products such as piezoelectric vibrators that require stricter performance than general parts. A chip-shaped piezoelectric vibrator that is currently generally considered has a structure as shown in FIG. That is, the conductive lead 2 is placed on the insulating substrate 21.
2 is metallized, and a piezoelectric substrate 24 is placed on top of this via a metal spacer 23 with a conductive adhesive 2.
Fixed at 5. Further, a can 26 made of metal is bonded to the substrate 21, but this is achieved by providing an insulating layer 27 on the lead-out lead 22, and further providing a metal layer 28 on the insulating layer by metallization. and the can 26 are joined by high-temperature solder in an inert gas or vacuum atmosphere.
However, in such a chip-type vibrator, since both ends of the lead 22 on the substrate 21 are directly heated, the entire temperature rises to approximately the same temperature, and the lead 22, the insulating layer 27, Since the metal layer 28 is successively baked at a high temperature, the cost increases and becomes expensive. Further, it is actually difficult to uniformly adhere the flange portion 26a of the metal can 26 to the metal layer 28 over the entire surface without causing pinholes or the like.

The present invention was devised in view of these circumstances, and its purpose is to provide a chip-shaped piezoelectric vibrator that is inexpensive and has excellent heat resistance.

In order to achieve such an objective, the present invention provides a piezoelectric vibrator in which a terminal for external extraction is installed perpendicularly to the bottom surface, and a through-hole that is perpendicular to the plate surface and a through-hole connected to the through-hole. An insulating plate having a groove extending on the plate surface is provided, and after the terminal is passed through the through hole, the tip is bent to extend into the groove.

A piezoelectric vibrator generally uses a case having a structure in which terminals 31 are installed in a direction perpendicular to a bottom surface 32, as shown in FIG. Conventionally, the base portion constituting such a case uses what is called a hermetic terminal using glass, but this is expensive. Hereinafter, the present invention will be explained in detail using the illustrated embodiments. Here, an example using an inexpensive case in which a metal can is sealed in an insulating substrate such as ceramic or epoxy resin will be taken up.

FIG. 4 is a sectional view showing such a piezoelectric vibrator. In the figure, an insulating substrate 41 as described above has terminals 42 for external extraction installed substantially perpendicularly to the bottom surface thereof. This terminal 42 has a melting point in a metal layer 43 formed by metallization process surrounding the terminal 42 on the upper surface of the substrate 41.
It is bonded using high temperature solder of over 300℃.
A piezoelectric substrate 45 having electrodes 44 on its upper and lower surfaces is fixed to the head of the terminal 42 with a conductive adhesive at both ends where the electrodes 44 are drawn out.
These are covered with a metal can 46 and sealed at the periphery, but the sealing between the metal can 46 and the substrate 41 is achieved by using a metal layer formed on the periphery of the substrate 41 by a metallization process and a metal can 46 This is done by joining the inner side of the wafer with high melting point solder 47. Here, reference numeral 48 denotes an insulating member which is brought into contact with the bottom surface of the board 41 by passing the terminal 42 through its through hole in advance, and prevents the solder 47 from flowing to the terminal 42 during the sealing process. By limiting the area in which the solder 47 flows, the reliability of soldering is improved. Therefore, if a chip-shaped piezoelectric vibrator can be made using such a case, it can be made at low cost and with good reliability.
To make the terminal 42 into a chip shape, it is necessary to bend the terminal 42 horizontally, that is, along the plate surface of the insulating member 48, but if it is simply bent in the state shown in FIG. I come into contact with it.

Therefore, in the present invention, an insulating plate 51 as shown in FIG. 5 is used. This is done by providing an insulating and heat-resistant plate such as epoxy or phenolic resin with a hole 52 penetrating from the upper surface shown in the figure a to the lower surface shown in the same figure b, and the through hole 5 in the lower surface.
A groove 53 is continuously provided at the end of the groove 2.
This is brought into contact with the bottom surface of the insulating member 48 shown in FIG. 4 so that the terminal 42 passes through the through hole 52, and the tip 42a of the terminal 42 protruding from the bottom surface is bent as shown in FIG. It extends into the groove 53.

FIG. 7 shows the cross-sectional structure of the piezoelectric vibrator constructed in this manner. The groove 5 is cut so that the lower side of the bent terminal 42 is almost flush with the lower surface of the insulating plate 51.
3 depth is selected in advance. This is to ensure stable attachment when mounting this chip-type piezoelectric vibrator on a printed circuit board for an apparatus. In such a configuration, soldering during installation is performed via the terminal 42, which is advantageous in preventing deterioration of the characteristics of the vibrator due to heating during installation, compared to the conventionally considered structure shown in FIG. It is. Although the thickness of the vibrator increases slightly due to the use of the insulating plate 51, in this example, the length was 8 mm and the width was 3 mm, but the thickness could be suppressed to 3.3 mm. Also,
In the case where a base made of an insulating substrate 41 is used as in this embodiment, the insulating plate 51 can be molded integrally with the insulating substrate 41 by using a resin such as phenol, and an increase in price can be suppressed. .

Since the substrate 51 has a structure in which the terminal 42 made of a lead wire with a thickness of 1.0 mm and a diameter of 0.5 mm is bent into the groove 53, the distance between the upper side of the terminal 42 and the metal ring 46 is 0.5 mm. It is only about mm. Therefore,
During mounting, solder may adhere in the form of a bridge between the terminal 42 and the metal can 46, causing a short circuit therebetween. A solution to this problem is to extend the end 51a of the substrate 51 outward by about 1.0 mm beyond the side surface of the metal can 46, as shown in FIG. As shown in the figure, it is effective to form an upwardly folded portion 51b at the end of the substrate 51. In this way, it is possible to almost certainly prevent solder from adhering to the metal can part. As a simple method, use a metal can 4
It is also effective to apply insulating paint to 6.

The above explanation has been made using as an example a piezoelectric vibrator having a structure in which a metal can is sealed in an insulating substrate made of ceramic or epoxy resin, but the present invention is not limited to this. Although this advantage is somewhat reduced, piezoelectric vibrators equipped with so-called hermetic terminals made of glass can also be applied in the same way to be made into chip components.

As explained above, according to the present invention, an insulating plate having a through hole perpendicular to the plate surface and a groove continuous to the through hole is used for a piezoelectric vibrator in which a terminal for external extraction is installed perpendicularly to the bottom surface. The piezoelectric vibrator can be made into a chip component at low cost by an extremely simple structure in which the terminal is passed through the through hole and the tip is bent to extend into the groove. Moreover, the piezoelectric vibrator can be mounted on a printed circuit board for the device through the terminals in the groove, and the characteristics of the piezoelectric vibrator will not be deteriorated by the heat caused by soldering, thus providing extremely high practicality.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an example of the configuration of a general chip-shaped electronic component, Figure 2 is a cross-sectional view showing a conventional chip structure of a piezoelectric vibrator, and Figure 3 is a general view of a piezoelectric vibrator. FIG. 4 is a sectional view showing an example of the structure of a piezoelectric vibrator having a base portion made of resin, etc. FIGS. 5 a and b show the structure of an insulating plate used in an embodiment of the present invention. 6 is a perspective view showing an embodiment of the present invention using the insulating plate of FIG. 5, FIG. 7 is a sectional view, and FIGS.
The figures are front views showing other embodiments of the present invention. 42... External lead-out terminal, 45... Piezoelectric substrate,
48... Insulating member (bottom), 51... Insulating plate, 5
2...Through hole, 53...Groove.

Claims (1)

[Scope of utility model registration request] A piezoelectric vibrator equipped with an external extraction terminal installed almost perpendicularly to the bottom surface, including a through hole that is almost perpendicular to the plate surface and a groove that extends continuously to the plate surface at the end of the through hole. The insulating plate is brought into contact with the bottom surface so that the external lead-out terminal passes through the through-hole, and the tip of the external lead-out terminal protruding from the plate surface of the insulating plate is bent at the end of the through-hole. A piezoelectric vibrator characterized by extending into a groove.