JP2007142869A - Temperature compensated crystal oscillator for surface mounting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature compensated crystal oscillator for surface mounting, compatible with size reduction, on side faces of which crystal inspection terminals and write surface terminals are provided, and on both principal sides of which recessed parts are provided. <P>SOLUTION: The temperature compensated crystal for surface mounting, provided with a rectangular package body, wherein the recessed part, is formed on the upper and lower sides made of a laminated ceramic, comprising a flat plate like center layer, and upper lower frame layers with openings, a crystal chip is contained in the recessed part of the upper side and is hermetically sealed, and an IC chip is contained in the recessed part of the lower side; mounting terminals, each comprising at least a bottom-side electrode located on the surface of each of square parts in the lower frame layer of the package body; the write surface terminals for temperature compensated data, electrically connected to the IC chip located on the side face of the package body; and a pair of the crystal inspection terminals connected electrically to the crystal chip located on one of the outer surfaces of the package body, is configured, such that the IC chip adopts an IC chip that uses two sets of the write surface terminals, and a pair of the crystal inspection terminals are formed on the side face of the package body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a surface-mounted temperature compensated crystal oscillator (hereinafter referred to as a temperature compensated oscillator) having a writing surface terminal and a crystal inspection terminal using a container body (H-shaped cross section) having recesses on both main surfaces. In particular, the present invention relates to a temperature compensated oscillator corresponding to miniaturization.

  A surface-mounted temperature-compensated oscillator is small and lightweight and has high frequency stability with respect to temperature. Therefore, the surface-compensated oscillator is applied to a portable electronic device including a mobile phone as a reference source for frequency and time. In recent years, further miniaturization has progressed, and temperature compensated oscillators are required to have further miniaturization and reliability in performance and the like.

(Example of conventional technology)
FIG. 5 is a view of a temperature compensated oscillator for explaining a conventional example. FIG. 5 (a) is a front view including a partial cross section, and FIG. 5 (b) is a bottom view.

  The temperature compensated oscillator basically comprises a container body 1, a crystal piece 2 and an IC chip 3. The container body 1 is made of a laminated ceramic having concave portions on the upper and lower surfaces (both main surfaces), and has a flat plate-shaped central layer 1a and an upper and lower frame layer 1 (bc) having an opening. The crystal piece 2 is accommodated in the recess on the upper surface and hermetically sealed, and the IC chip 3 is accommodated in the recess on the lower surface. In the figure, the central layer 1a and the upper and lower frame layers 1 (bc) are shown as a single layer for convenience, but each has a plurality of layers.

  The crystal piece 2 has a pair of excitation electrodes (not shown) on both main surfaces, and extends, for example, extraction electrodes to the outer peripheral portions on both sides of one end portion. Then, both ends of the extended end portion of the extraction electrode are fixed to the pair of crystal holding terminals 4 provided on the bottom surface of the concave portion by the conductive adhesive 5. A metal ring (not shown) or the like is provided on the upper surface of the upper frame layer 1b, and the crystal cover 2 is hermetically sealed by joining the metal cover 6 by seam welding or the like.

  The IC chip 3 integrates an oscillation circuit and a temperature compensation mechanism (not shown) and has various IC terminals on the circuit function side. The IC terminal includes a pair of crystal IC terminals, a power source, an output, a ground, an automatic frequency control (AFC), and four write IC terminals. For example, model name AN28518 manufactured by Matsushita Electric Industrial Co., Ltd. is applied. And it adheres to each circuit terminal 7 provided in the recessed part bottom face of the lower surface by ultrasonic thermocompression using the bump 8.

  At the four corners of the lower frame layer 1c of the container body 1, there are mounting terminals 9 for the set substrate. The mounting terminal 9 includes a bottom electrode 9a that is the top surface of the four corners of the lower frame layer 1c, and side electrodes 9b that are both ends of each side surface in the long side direction of the container body 1. The side electrode 9b is provided on a through-hole surface penetrating the thickness direction of the container body 1, and the uppermost layer of the laminated ceramic is an electrodeless layer to prevent an electrical short circuit with the metal cover 6. These mounting terminals 9 are electrically connected to a power source, an output, a ground, and an automatic frequency control (AFC) terminal among the IC terminals by a conductive path (not shown).

  A total of four writing surface terminals 10 are provided between the side electrodes 9b on both ends in the long side direction of the container body 1 in correspondence with the writing IC terminals of the IC chip 3, two in total. . Each writing surface terminal 10 is provided on a through-hole surface penetrating the thickness direction, and the uppermost layer and the lowermost layer of the multilayer ceramic are electrodeless layers. In addition, crystal inspection terminals X 1 and X 2 connected to the crystal holding terminal 4 are provided on the bottom surface of the concave portion on the lower surface, separately from the pair of crystal circuit terminals 7 a in the circuit terminal 7. The crystal holding terminal 4, the crystal inspection terminals X1, X2 and the crystal circuit terminal 7a are connected in parallel or in series.

  In such a case, after the crystal cover is formed by bonding the metal cover 6 to the concave portion on the upper surface of the container body 1 in which the crystal piece 2 is accommodated, the crystal inspection terminals X1 and X2 on the bottom surface of the concave portion on the lower surface are not shown. Contact the probe from the measuring instrument to measure the vibration characteristics of the crystal unit. Then, if there is an abnormality in the vibration characteristics of the crystal unit alone, such as crystal impedance (CI) or temperature characteristics, it is discarded.

  Next, when there is no abnormality in these vibration characteristics and the product is good, the IC chip 3 is mounted and, for example, a protective resin (not shown) is applied (underfill). Then, the temperature compensation data is written to the temperature compensation mechanism of the IC chip 3 by bringing the probe into contact with the writing surface terminal 10 on the side surface. Finally, the probe is brought into contact with the side electrode 9b in the mounting terminal 9 to confirm the oscillation characteristics of the temperature compensated oscillator. Since the through-hole surfaces of the side electrode 9b and the writing surface terminal 10 penetrate the thickness direction, there are no protrusions above and below, and the probe can be easily brought into contact.

  The side electrode 9b of the mounting terminal 9 is basically intended to form a solder fillet when mounted on a set substrate, but here also serves as a terminal for measuring oscillation characteristics. This is because the probe can be brought into contact with either the bottom surface or the side surface due to the relationship of jigs and the like, and measurement is easy. Further, even after mounting on the set substrate, the oscillation characteristics can be confirmed using the side electrode 9b.

(Problems of conventional technology)
However, in the temperature compensated oscillator having the above-described configuration, the crystal inspection terminals X1 and X2 provided on the bottom surface of the concave portion are covered with the IC chip 3, and particularly after being commercialized with an underfill, the vibration characteristics of the crystal unit alone. There was a problem that could not be measured. In this case, for example, if there is an accident that causes an oscillation failure after product shipment, the crystal resonator cannot be analyzed, making it difficult to determine the true cause of the oscillation failure.

  In addition, as the temperature compensated oscillator becomes smaller, for example, the planar outer shape becomes 3.2 × 2.5 mm or less, the bottom surface of the concave portion of the container body 1 becomes smaller, and it becomes difficult to form crystal inspection terminals X1 and X2 having sufficient sizes. The crystal inspection terminals X1 and X2 require, for example, 0.6 × 0.6 mm or more because of the relationship with the probe from the measuring instrument, but in this case, it becomes less than this, making reliable measurement difficult.

  From this, for example, as shown in FIG. 6, as is well known in a one-room type temperature compensated oscillator in which the IC chip 3 is fixed to the bottom of the concave portion of the container body 1 and the crystal piece 2 is fixed to the inner wall step portion, It was considered that crystal inspection terminals X1 and X2 were arranged on the side surface of the container body 1. In this case, when four of the writing surface terminals 10 are taken into consideration, a new surface terminal cannot be formed on the side surface in the long side direction.

  Therefore, through-hole surfaces penetrating in the thickness direction are provided on both short sides to form the crystal inspection terminals X1 and X2. However, it is necessary to increase the frame width to compensate for a decrease in strength or the like due to the through-hole surface. . In this case, if it is going to maintain the external dimension of the container main body 1, the internal diameter of a long side direction will become small and the inner product will also reduce.

  Even if both short sides are used, if four of the side electrodes 9b of the mounting terminal 9 are added to a total of six of the writing surface terminal 10 and the crystal inspection terminals X1 and X2, a total of 10 side surfaces are added. A terminal is required. Therefore, there is a problem that it cannot be applied to further downsizing, for example, 2.0 × 1.6 mm. Further, when the circuit terminals 7 are formed with a narrower interval between the IC terminals of the IC chip 3, the crystal inspection terminals X1 and X2 cannot be formed on the bottom surface of the concave portion on the lower surface, which hinders downsizing.

(Object of invention)
An object of the present invention is to provide a temperature-compensated oscillator for surface mounting which has a crystal inspection terminal of a crystal resonator and a writing surface terminal for writing temperature compensation data on a side surface and has concave portions on both main surfaces corresponding to miniaturization. And

  According to the present invention, as shown in the claims (Claim 1), a concave portion is formed on the upper and lower surfaces from a laminated ceramic of a flat central layer and an upper and lower frame layer having an opening, and the upper surface concave portion Includes a rectangular piece of a container body that accommodates an IC chip in the recess on the lower surface, and at least a bottom electrode on the surface of the four corners of the lower frame layer of the container body A mounting surface terminal, a temperature compensation data writing surface terminal electrically connected to the IC chip on a side surface of the container body, and a crystal piece on one of the outer surfaces of the container body In the surface-mounted temperature compensated oscillator having a pair of crystal inspection terminals electrically connected to the IC chip, an IC chip having two write surface terminals is applied as the IC chip, and the pair of crystal inspection terminals are Formed on the side of the container body And configuration.

With such a configuration, since there are two writing surface terminals, even if miniaturization progresses, a pair of crystal inspection terminals are excluded from the bottom surface of the concave portion on the lower surface, and the container body has concave portions on the upper and lower surfaces. Can be formed on the side of Thereby, even after the product is shipped, the crystal inspection terminal is exposed on the side surface, so that the vibration characteristics of the crystal resonator can be analyzed. And since there are only two writing surface terminals and only the circuit terminal to which the IC chip is fixed on the bottom surface of the recess on the lower surface, the temperature compensated oscillator having the writing surface terminal and the crystal inspection terminal on the side surface can be downsized. Can be promoted.
(Embodiment of the Invention)

  According to a second aspect of the present invention, the writing surface terminal and the crystal inspection terminal according to the first aspect are formed on a through-hole surface penetrating the thickness direction of the container body, and the uppermost layer and the lowermost layer of the multilayer ceramic are provided. It is formed in the central region of the thickness direction except. This makes it easier for the writing or measuring probe to come into contact with the writing surface terminal or the crystal inspection terminal.

  In the third aspect of the present invention, a total of four of the writing surface terminal and the crystal inspection terminal of the first aspect are provided on both side surfaces in the long side direction of the container body. Thereby, since it is not necessary to form a through-hole surface for forming a writing surface terminal and a crystal inspection terminal on each side surface along the short side direction, the inner product can be increased while keeping the frame width small.

  In the fourth aspect, a total of four of the writing surface terminal and the crystal inspection terminal of the first aspect are provided on each side surface of the container body. Thereby, it can respond to progress of further miniaturization.

  In the fifth aspect, the mounting terminal according to the first aspect has side electrodes on both end sides on both side surfaces in the long side direction extending from the bottom electrode at the four corners, and the side electrodes are formed on the container body. It is formed on the through-hole surface that penetrates the thickness direction, and is formed over half or more of the thickness direction of the container body excluding the uppermost layer of the multilayer ceramic. Thus, the side electrode can be used not only for the solder fillet but also as an inspection terminal for oscillation characteristics.

  In the sixth aspect, the mounting terminal according to the first aspect has side electrodes on both ends on both side surfaces in the long side direction extending from the bottom electrode at the four corners, and the side electrodes are formed on the container body. The writing surface terminal or the crystal inspection terminal is formed on the through hole surface which is formed near the lowest layer of the through hole surface penetrating through the thickness direction and above the side surface electrode. In this case, since the solder fillet and the writing surface terminal or the crystal inspection terminal are formed on the same through hole surface, the number of through holes can be reduced.

  In claim 7, the mounting terminal of claim 1 consists of only the bottom surface electrode of the four corners, and either the writing surface terminal or the crystal inspection terminal is formed on a side surface of the four corners, The writing surface terminal and the crystal inspection terminal are formed in a through-hole surface penetrating the thickness direction of the container body, and are formed in a central region in the thickness direction excluding the uppermost layer and the lowermost layer of the multilayer ceramic. Thereby, even if miniaturization progresses, a total of four writing surface terminals or crystal inspection terminals can be formed on the side surface. Further, since the mounting terminal is composed only of the bottom electrode and the side electrode for the solder fillet is removed, high-density mounting is possible when mounting on the set substrate.

  In the eighth aspect, the mounting terminal according to the first aspect includes only the bottom surface electrode at the four corners, and the writing surface terminal or the crystal inspection terminal is provided at a central portion of a side surface of each side of the container body. The writing surface terminal and the crystal inspection terminal are formed in a through hole surface penetrating the thickness direction of the container body, and are formed in a central region in the thickness direction excluding the uppermost layer and the lowermost layer of the multilayer ceramic. As a result, even if miniaturization proceeds, a total of four writing surface terminals or crystal inspection terminals can be formed on the side surface, and high-density mounting is possible when mounted on a set substrate.

(Corresponding to the first embodiment, claims 1 to 5)
FIG. 1 is a diagram of a temperature compensated oscillator for explaining a first embodiment of the present invention. FIG. 1 (a) is a front view including a partial cross section, and FIG. 1 (b) is a bottom view. 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 temperature-compensated oscillator includes a container body 1 having a recess on the upper and lower surfaces having a flat central layer 1a and an upper and lower frame layer 1 (bc) having an opening, and a crystal holding terminal on the bottom surface of the recess. 4 includes a crystal piece 2 in which an outer peripheral portion on both sides of an extended end of the extraction electrode is fixed and hermetically sealed, and an IC chip 3 in which an IC terminal is fixed to a circuit terminal 7 on a bottom surface of a recess. The mounting terminal 9 includes a bottom electrode 9a at the four corners of the lower frame layer 1c that forms a recess on the lower surface, and side electrodes 9b at both ends in the long side direction.

  In this embodiment, the IC chip 3 has, for example, a model name AK2131 made by Asahi Kasei Microsystem with two write IC terminals. The two writing surface terminals 10 electrically connected to each writing IC terminal are provided between the side surface electrodes 9b on both sides on one side surface in the length direction, for example. Crystal inspection terminals X1, X2 electrically connected to the crystal piece 2 are provided between the side electrodes 9b on the other side. Note that one writing surface terminal 10 and one of the crystal inspection terminals X1 and X2 may be provided on each side surface in the long side direction due to the relationship between jigs and the like.

  These writing surface terminal 10 and crystal inspection terminals X1 and X2 are all formed in a through-hole surface penetrating in the thickness direction, and are formed in a central region where the uppermost layer and the lowermost layer of the multilayer ceramic are electrodeless layers. The The crystal holding terminal 4 and the crystal inspection terminals X1 and X2, and the write IC terminal and the write surface terminal 10 are connected through a laminated surface by a conductive path (not shown).

  In such a configuration, since the IC chip 3 having two write IC terminals is applied, the number of the outer surface terminals is four, including the pair (two) of crystal inspection terminals X1 and X2. Therefore, with the side electrode 9b of the mounting terminal 9 left, for example, the writing surface terminal 10 is placed between the side electrodes 9b on one side along the long side direction, and the crystal inspection terminal X1, between the side electrodes 9b on the other side. X2 can be formed.

  As a result, the crystal inspection terminals X1 and X2 are removed from the bottom surface of the recess on the lower surface of the container body 1 and exposed to the side surface, so that the vibration characteristics of the crystal unit alone can be inspected even after shipment. Therefore, the analysis result of defective products after shipment becomes clear, which leads to subsequent quality improvement. Further, since neither the writing surface terminal 10 nor the crystal inspection terminals X1 and X2 are formed on the side surface in the short side direction, the inner product can be increased while keeping the frame width small.

  Since the mounting terminal 9 has the side electrode 9b, it can be used as an inspection terminal for oscillation characteristics as in the prior art. In addition, since the writing surface terminal 10 and the crystal inspection terminals X1 and X2 are both formed in the central region of the through-hole surface that penetrates the thickness direction, probes for writing temperature compensation data and measuring vibration characteristics are used. It becomes easy to contact. Of course, it is possible to confirm the melting of the solder by forming a solder fillet.

(Corresponding to the second embodiment, claims 1 to 3 and 6)
FIG. 2 is a diagram of a temperature compensated oscillator for explaining a second embodiment of the present invention. FIG. 2 (a) is a front view including a partial cross section, and FIG. 2 (b) is a bottom view excluding side electrodes. In the following embodiments, the description of the same parts as in the previous embodiment is omitted or simplified.

  In the second embodiment, similarly to the first embodiment, the IC chip 3 having two write IC terminals is applied, and the side surface terminal is composed of two each of the write surface terminal 10 and the crystal inspection terminals X1 and X2. A total of four are formed on the side surface of the container body 1. Here, the side surface electrodes 9b of the respective mounting terminals 9 at the four corners are divided so as to be close to the lowest layer, for example, only the lowest layer. The side electrode 9b is used as the writing surface terminal 10 and the crystal inspection terminals X1 and X2 above the electrodeless electrode layer. Even in this case, a through-hole surface penetrating in the thickness direction is used, and the uppermost layer is an electrodeless layer.

  With such a configuration, even when the length dimension of the container body 1 is reduced as compared with the first embodiment, for example, even if the outer dimension becomes 2.0 × 1.6 mm, each side surface in the long side direction is provided. The writing surface terminal 10 and the crystal inspection terminals X1, X2 can be formed. As in the first embodiment, the crystal inspection terminals X1 and X2 are removed from the bottom surface of the recess on the lower surface of the container body 1 and exposed to the side surface, so that the vibration characteristics of the crystal unit alone can be inspected even after shipment. Since there are no crystal inspection terminals X1 and X2 on the bottom surface of the concave portion on the lower surface, the circuit terminal 7 can be formed even if the IC chip 3 is reduced and the IC terminal interval is reduced.

  Further, since neither the writing surface terminal 10 nor the crystal inspection terminals X1 and X2 are formed on the side surface in the short side direction, the inner product can be increased while keeping the frame width small. Then, the side electrode 9b of the mounting terminal 9 and the writing surface terminal 10 or the crystal inspection terminals X1, X2 are formed by being divided into the same through-hole surface. Therefore, the through-hole surface can be halved as compared with the case where these are formed on individual through-hole surfaces. Thereby, for example, the strength of the frame can be increased.

(Corresponding to the third embodiment, claims 1 to 3 and 7)
FIG. 3 is a diagram of a temperature compensated oscillator for explaining a third embodiment of the present invention. FIG. 3 (a) is a front view including a partial cross section, and FIG. 3 (b) is a bottom view excluding side electrodes.

  In the third embodiment, similarly to the second embodiment, two writing surface terminals 10 and a pair of crystal inspection terminals X1, X2 are formed on both end sides of each side surface in the length direction of the container body 1. Here, the side electrode 9b of the mounting terminal 9 is removed, and the lowest layer of the multilayer ceramic is made an electrodeless layer. In short, the mounting electrode 9 is only the bottom electrode 9a, and the writing surface terminal 10 and the pair of crystal inspection terminals X1, X2 are electrically independent by the lowest electrodeless layer.

  Even in such a configuration, the writing surface terminal 10 and the crystal inspection terminals X1 and X2 are formed on the side surfaces in the long side direction even when the length of the container body 1 is reduced, as in the second embodiment. it can. Even after shipment, the vibration characteristics of the crystal unit alone can be inspected. In addition, the inner width is increased by reducing the frame width in the short side direction.

  Here, since the side electrode 9b of the mounting terminal 9 is removed, a solder fillet is not formed during mounting on the set substrate. Therefore, the melting of the solder cannot be confirmed directly when mounted on the set substrate, but in this case, the area of the circuit terminals of the set substrate can be reduced, so that the mounting density can be increased.

  Although a solder fillet cannot be formed, it is guaranteed that the solder fillet is fixed by strict management of the heating temperature and time during manufacturing. However, if necessary, a side electrode for forming a solder fillet having a narrow width may be formed on the side surface of the short side adjacent to the writing surface terminal 10 and the crystal inspection terminals X1 and X2.

(Other matters, corresponding to claims 4 and 8)
In the above embodiment, the writing surface terminal 10 and the crystal inspection terminals X1 and X2 are provided on the respective side surfaces in the long side direction of the container body 1. For example, as shown in FIG. One piece may be provided on each side. In this case, since one is disposed on each side, further miniaturization can be accommodated. In the figure, the mounting terminal 9 is only the bottom electrode 9a, but a side electrode 9b for forming a solder fillet may be provided. The side electrode 9b may be narrow or corner.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure of the temperature compensation oscillator explaining 1st Embodiment of this invention, The figure (a) is a front view including a partial cross section, The figure (b) is a bottom view. It is a figure of the temperature compensation oscillator explaining 2nd Embodiment of this invention, The figure (a) is a front view including a partial cross section, The figure (b) is a bottom view. It is a figure of the temperature compensation oscillator explaining 3rd Embodiment of this invention, The figure (a) is a front view including a partial cross section, The figure (b) is a bottom view. It is a bottom view of the temperature compensation oscillator explaining other embodiment of the present invention. It is a figure of the temperature compensation oscillator explaining a prior art example, the figure (a) is a front view including a partial cross section, and the figure (b) is a bottom view. It is a figure of the temperature compensation oscillator explaining another prior art example, the figure (a) is a front view including a partial cross section, and the figure (b) is a bottom view.

Explanation of symbols

  1 Container body, 2 Crystal piece, 3 IC chip, 4 Crystal holding terminal, 5 Conductive adhesive, 6 Metal cover, 7 Circuit terminal, 8 Bump, 9 Mounting terminal, 10 Writing surface terminal, X1, X2 Crystal inspection terminal .

Claims (8)

  A concave portion is formed on the upper and lower surfaces from a laminated ceramic of a flat central layer and an upper and lower frame layer having an opening, a crystal piece is accommodated in the concave portion on the upper surface and hermetically sealed, and an IC is formed on the concave portion on the lower surface. A rectangular container body that accommodates the chip, and has a mounting terminal including at least a bottom electrode on the surface of the four corners of the lower frame layer of the container body; Temperature compensation data for surface mounting, having a surface terminal for writing temperature compensation data to be connected electrically, and a pair of crystal inspection terminals electrically connected to the crystal piece on one of the outer surfaces of the container body In the crystal oscillator, an IC chip having two write surface terminals is applied as the IC chip, and the pair of crystal inspection terminals are formed on a side surface of the container body. Compensated crystal Vessel.   2. The writing surface terminal and the crystal inspection terminal according to claim 1, wherein the writing surface terminal and the crystal inspection terminal are formed in a through-hole surface penetrating the thickness direction of the container body, and are formed in a central region in the thickness direction excluding the uppermost layer and the lowermost layer of the multilayer ceramic. A surface-compensated crystal oscillator for surface mounting.   2. The temperature-compensated crystal oscillator for surface mounting according to claim 1, wherein a total of four of the writing surface terminal and the crystal inspection terminal are provided on each side surface in the long side direction of the container body.   2. The surface mount temperature compensated crystal oscillator according to claim 1, wherein a total of four of the writing surface terminal and the crystal inspection terminal are provided on each side surface of the container body.   In Claim 1, the said mounting terminal has the side electrode of the both ends in the both sides of the long side direction extended from the said bottom face electrode of the said 4 corner | angular part, and the said side electrode penetrated the thickness direction of the said container main body. A temperature-compensated crystal oscillator for surface mounting, which is formed on a through-hole surface and formed over a half of the thickness direction of the container body excluding the uppermost layer of the multilayer ceramic.   In Claim 1, the said mounting terminal has the side electrode of the both ends in the both sides of the long side direction extended from the said bottom face electrode of the said 4 corner | angular part, and the said side electrode penetrated the thickness direction of the said container main body. A temperature-compensated crystal oscillator for surface mounting, wherein the write surface terminal or the crystal inspection terminal is formed on the through hole surface formed near the lowest layer of the through hole surface and above the side electrode.   2. The writing terminal according to claim 1, wherein the mounting terminal includes only the bottom surface electrode of the four corners, and the writing surface terminal or the crystal inspection terminal is formed on a side surface of the four corners, And a temperature-compensated crystal for surface mounting formed in a central region in the thickness direction excluding the uppermost layer and the lowermost layer of the multilayer ceramic, formed in a through-hole surface penetrating the thickness direction of the container body. Oscillator. 2. The writing terminal according to claim 1, wherein the mounting terminal includes only the bottom surface electrode of the four corners, and the writing surface terminal or the crystal inspection terminal is provided at a central portion of a side surface of each side of the container body. 2. The surface mounting according to claim 1, wherein the terminal and the crystal inspection terminal are formed in a through-hole surface penetrating the thickness direction of the container body and formed in a central region in the thickness direction excluding the uppermost layer and the lowermost layer of the multilayer ceramic. Temperature-compensated crystal oscillator.

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