JP2010171475A - Crystal oscillator for surface mounting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface mount crystal oscillator which facilitates abutting of a probe corresponding to miniaturization. <P>SOLUTION: The crystal oscillator for surface mounting includes: a container body 1 having a recessed portion at least on one main surface and composed of laminated ceramics; a crystal piece 2 accommodated in the recessed portion formed on the one main surface; an IC chip 3 accommodated in the container body 1; a metal film 6 formed on the opening end surface of the recessed portion formed on the one main surface on the inner side of the outer periphery of the opening end surface; and a metal cover 4 bonded to the metal film 6 by eutectic alloy, wherein a notch groove 9 is formed on the outer surface of the container body 1 so as to cross a height direction and the notch groove 9 has a communication terminal. In the crystal oscillator, a projected bank of a frame wall 1b is formed on the outer peripheral part of the opening end surface, which is the outside of the metal cover 4 bonded to the opening end surface of the recessed portion formed on the one main surface, the notch groove 9 is formed on the outer surface of the container body 1 so as to include the outer surface of the projected bank of the frame wall 1b and cross the height direction of the outer surface of the container body 1, and the communication terminal is formed on the outer surface of the container body 1 which includes the projected bank of the frame wall 1b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface mount crystal oscillator (hereinafter referred to as a surface mount oscillator), and more particularly to a surface mount oscillator in which a metal cover is bonded with a eutectic alloy.

(Background of the Invention)
Since surface-mounted oscillators are small and lightweight, they are built in as a frequency and time reference source, especially in portable electronic devices. One of these is a case where a metal cover is bonded to the opening end face of a container body containing a crystal piece with a eutectic alloy.

(Example of conventional technology)
Hereinafter, a conventional example will be described with reference to a cross-sectional view, a bottom view, a side view, and a plan view of a crystal piece of the surface mount oscillator shown in FIG. 3 (abc) and FIG.

  The surface-mount oscillator includes a container body 1, a crystal piece 2, an IC chip 3, and a metal cover 4. The container body 1 is made of a laminated ceramic, has a bottom wall 1a and a frame wall 1b, and has a concave shape provided with an inner wall step. Here, for example, there are five layers as indicated by the dividing line on the laminated surface of each ceramic. A crystal holding terminal 5 is mounted on the inner wall step portion of the container body 1, a circuit terminal (not shown) is mounted on the inner bottom surface, a metal film 6 is mounted on the upper surface of the frame wall 1 b serving as the opening end surface, and a corner portion of the outer bottom surface is mounted. The terminal 7 has a crystal inspection terminal 8 on a set of opposed outer surfaces.

  The crystal holding terminal 5 is electrically connected to a crystal terminal (not shown) in the circuit terminals on the inner bottom surface and to a crystal inspection terminal 8 on the outer side by a wiring path (not shown) through a laminated surface or the like. The mounting terminal 7 includes a power source, an output, a ground, an AFC terminal, and the like, and is electrically connected to the corresponding circuit terminals on the inner bottom surface. The metal film 6 is electrically connected to a mounting terminal 7 serving as a ground terminal on the outer bottom surface by a wiring path including a through electrode (not shown) provided on the frame wall 1b.

  The crystal inspection terminal 8 is formed in a notch groove 9 having a rectangular shape in plan view that crosses the container body 1 (multilayer ceramic) in the vertical direction. However, it is provided in an intermediate layer excluding the uppermost layer and the lowermost layer of the container body 1 (multilayer ceramic), and the uppermost layer and the lowermost layer are electrodeless layers. This prevents an electrical short circuit between the metal film 6 on the upper surface of the frame wall and a wiring board (not shown) on which the surface mount oscillator is mounted.

  The crystal piece 2 extends, for example, extraction electrodes 10b on both sides of one end from the excitation electrodes 10a on both main surfaces. The extraction electrodes 10b are formed so as to be folded back on the opposite surfaces. And it adheres to the crystal holding terminal 5 provided on the inner wall step of the container body 1 with the conductive adhesive 11 or the like, and is electrically and mechanically connected.

  The IC chip 3 integrates at least an oscillation circuit (not shown) and has an IC terminal on one main surface serving as a circuit function surface. And it adheres to the circuit terminal provided in the inner bottom face of the container main body 1 by ultrasonic thermocompression using the bump 12 (so-called flip chip bonding), and is electrically and mechanically connected. The metal cover 4 is bonded to the metal film 6 on the opening end face by heating and melting a eutectic alloy 13 such as AuSn, and the crystal piece 2 and the IC chip 3 are hermetically sealed.

  In such a case, since the crystal inspection terminal 8 is provided on the outer surface of the container body 1, for example, even after the crystal piece 2 is hermetically sealed, a probe from a measuring instrument (not shown) is brought into contact with the crystal inspection terminal 8 to provide crystal impedance. Etc. can be measured. In addition, since the vibration characteristics of the crystal resonator change after the metal cover 4 is bonded to the vibration system (holding system), the crystal inspection terminal 8 is necessary.

JP 2007-288268 (FIG. 6)

(Problems of conventional technology)
However, in the surface mount oscillator configured as described above, the uppermost layer of the container body 1 (laminated ceramic) is an electrodeless layer in order to prevent an electrical short circuit with the metal film 6 on the upper surface of the frame wall as described above. In this case, when the height dimension of the surface mount oscillator (container body 1) is large, the height of the crystal inspection terminal 8 is sufficient to facilitate the contact of the probe. However, for example, if the thickness of the IC chip 3 is reduced to promote downsizing (lowering the height) of the container body 1, the height of the crystal inspection terminal 8 is also reduced, which makes it difficult to contact the probe. It was.

(Object of invention)
It is an object of the present invention to provide a surface mount oscillator that facilitates contact of a probe in response to downsizing.

According to the present invention, as shown in the claims (Claim 1), a container body made of a multilayer ceramic having a concave portion on at least one main surface, a crystal piece housed in the concave portion on the one main surface, An IC chip housed in the container body, a metal film provided on the opening end surface of the concave portion of the one main surface, and a metal cover joined to the metal film by a eutectic alloy,
The outer surface of the container body is provided with a set of notch grooves crossing the height direction, and the notch groove has a crystal oscillator for surface mounting having a communication terminal.
A frame wall jetty is provided on the outer peripheral portion of the opening end surface that is the outside of the metal cover joined to the opening end surface of the concave portion of the one main surface,
The notch groove is formed across the height direction on the outer surface of the container body including the outer surface of the frame wall jetty, and the communication terminal is formed on the outer surface of the container body including the frame wall jetty. The formed structure is assumed.

  If it is such a structure, a frame wall jetty will be provided in the outer peripheral part of the opening end surface of a container main body, and a metal cover will be joined to the opening end surface in a frame wall jetty. And a communication terminal is formed in the notch groove provided including the outer side surface of a frame wall jetty. Therefore, even if the communication terminal is formed in the cutout groove of the frame wall jetty, it is possible to prevent an electrical short circuit between the communication terminal and the metal film or eutectic alloy at the opening end face. Thereby, even if the height dimension of the container main body 1 becomes small, the height dimension of a communication terminal can be enlarged.

(Embodiment)
According to a second aspect of the present invention, in the first aspect, the communication terminal is formed excluding at least the lowest layer of the multilayer ceramic. As a result, the height dimension of the communication terminal can be increased by the configuration of claim 1 while preventing an electrical short circuit with the set substrate on which the surface mount oscillator is mounted.

  In the third aspect of the present invention, in the first aspect, the IC chip is accommodated in the concave portion of the one main surface or in the concave portion provided on the other main surface of the container body 1. Thereby, the structure of the container main body in Claim 1 is clarified, and in any case, the same effect as in Claims 1 and 2 can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure of the surface mount oscillator explaining 1st Embodiment of this invention, The figure (a) is sectional drawing, The figure (b) is a side view of a short side direction. It is sectional drawing of the surface mount oscillator explaining 2nd Embodiment of this invention. FIG. 1A is a diagram of a surface-mount oscillator for explaining a conventional example, in which FIG. 1A is a cross-sectional view taken along line AA of FIG. 1B, FIG. 1B is a bottom view, and FIG. It is a side view. It is a top view of the crystal piece explaining a prior art example.

(First embodiment)
The first embodiment of the present invention will be described below with reference to FIG. 1 described above (a cross-sectional view and a side view of a surface-mount oscillator). In addition, the same number is attached | subjected to the same part as a prior art example, and the description is simplified or abbreviate | omitted.

  As described above, the surface-mounted oscillator has one main surface of the IC chip 3 on the inner bottom surface of the container body 1 made of a concave laminated ceramic having the bottom wall 1a and the frame wall 1b, and both ends of the crystal piece 2 on one side. Adheres to the inner wall step. Then, the metal cover 4 is bonded to the metal film 6 on the opening end surface (upper surface of the frame wall) by the eutectic alloy 13 to hermetically enclose the crystal piece 2 and the IC chip. In addition, crystal inspection terminals 8 are provided together with the notch grooves 9 on a pair of opposed outer surfaces.

  In the present embodiment, an annular frame wall jetty 14 is provided on the outer peripheral portion of the upper surface of the frame wall of the container body 1 that is outside the metal cover 4. The metal film 6 on the upper surface of the frame wall is formed to be separated from the outer surface, and is provided inside the frame wall protrusion 14 here. The notch groove 9 provided in the height direction of the pair of opposed outer surfaces is formed across the outer surface including the frame wall protrusion 14. The crystal inspection terminal 8 is formed on the outer surface including the frame wall jetty 14 except for the lowest layer of the container body (multilayer ceramic) 1. The metal cover 4 is bonded to the metal film 6 by the eutectic alloy 13. In this example, the metal cover 4 is in the plane of the frame wall jetty 14.

  If it is such a structure, as described also in the column of the effect of invention, the frame wall jetty 14 is provided in the outer peripheral part of the opening end surface of the container main body 1, and the metal cover 4 is the opening inside the frame wall jetty 14. Join to the end face. Then, the crystal inspection terminal 8 is formed in the cutout groove 9 provided including the outer surface of the frame wall jetty 14 except for the lowest layer.

  Therefore, even if the crystal inspection terminal 8 is formed in the cutout groove 9 of the frame wall jetty 14 which is the uppermost layer of the container body 1, the crystal test terminal 8 and the metal film 6 or eutectic on the opening end face are formed by the frame wall jetty 14. An electrical short circuit with the alloy 13 can be prevented. Thereby, even if the height dimension of the container main body 1 becomes small, the height dimension of the crystal inspection terminal 8 can be enlarged and an area can be ensured. Therefore, the probe can be easily brought into contact with the crystal inspection terminal 8 and the vibration characteristics can be reliably measured.

(Second Embodiment)
The second embodiment of the present invention will be described below with reference to FIG. 2 (cross-sectional view of a surface mount oscillator) described above. In addition, description of the same part as previous embodiment is abbreviate | omitted or simplified.

  In 2nd Embodiment, the container main body 1 which consists of laminated ceramics has the frame walls 1b and 1c in both the main surfaces of the bottom wall 1a, and has a recessed part in both main surfaces. The crystal piece 2 is accommodated in one recess, and the IC chip 3 is accommodated in the other recess. Then, a frame wall jetty 14 is provided on the opening end face of one of the recesses, and a notch groove 9 is formed across the height direction on the outer surface, and the crystal inspection terminal 8 is formed except for the lowest layer. To do. Then, the metal cover 4 is bonded to the metal film 6 on the upper surface of the frame wall, which is the inner side of the frame wall jetty 14, by the eutectic alloy 13, and the crystal piece 2 is hermetically sealed.

  Even in such a configuration, as described above, even if the crystal inspection terminal 8 is formed in the notch groove 9 of the frame wall jetty 14, the crystal inspection terminal 8 and the metal film 6 on the opening end face are formed by the frame wall jetty 14. An electrical short circuit with the eutectic alloy 13 can be prevented. Therefore, the height dimension of the crystal inspection terminal 8 can be increased to secure an area, and the probe can be easily brought into contact with the crystal inspection terminal 8.

(Other matters)
In the above-described embodiment, the crystal inspection terminals 8 are provided on a pair of opposed outer surfaces. However, the present invention can be similarly applied to, for example, a temperature compensation data writing terminal when the surface mount oscillator is a temperature compensation type. . Therefore, in the scope of claims, these are included as communication terminals.

  DESCRIPTION OF SYMBOLS 1 Container body, 2 Crystal piece, 3 IC chip, 4 Metal cover, 5 Crystal holding terminal, 6 Metal film, 7 Mounting terminal, 8 Crystal inspection terminal, 9 Notch groove, 10 Excitation and extraction electrode, 11 Conductive adhesive agent, 12 bumps, 13 eutectic alloy, 14 frame wall jetty.

Claims (3)

A container body made of a multilayer ceramic having a recess on at least one main surface, a crystal piece accommodated in the recess on the one main surface, an IC chip accommodated in the container body, and an open end surface of the recess on the one main surface And a metal cover joined to the metal film with a eutectic alloy,
The outer surface of the container body is provided with a set of notch grooves crossing the height direction, and the notch groove has a crystal oscillator for surface mounting having a communication terminal.
A frame wall jetty is provided on the outer peripheral portion of the opening end surface that is the outside of the metal cover joined to the opening end surface of the concave portion of the one main surface,
The notch groove is formed across the height direction on the outer surface of the container body including the outer surface of the frame wall jetty, and the communication terminal is formed on the outer surface of the container body including the frame wall jetty. A crystal oscillator for surface mounting, characterized by being formed.   2. The surface-mount crystal oscillator according to claim 1, wherein the communication terminal is formed by removing at least the lowest layer of the multilayer ceramic.   2. The surface-mount crystal oscillator according to claim 1, wherein the IC chip is housed in a recess on the one main surface or in a recess provided on the other main surface of the container body.

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