JP2007103994A - Piezoelectric oscillator - Google Patents

Abstract

An object of the present invention is to ensure that control signals can be input and output to an integrated circuit element even when a piezoelectric oscillator is miniaturized, and adjacent external connection electrode terminals cause electrical interference. It is an object of the present invention to provide a piezoelectric oscillator without any problems.
A first side wall portion is formed on one main surface of the substrate, and a piezoelectric vibration element is mounted in a first recess space surrounded by the first side wall portion. A second side wall portion is formed on the other main surface of the substrate, and an integrated circuit element is mounted in the second recess space surrounded by the second side wall portion. In the piezoelectric oscillator in which external connection electrode terminals are formed at the four corners of the second recess space 17 opening side top surface, the second recess space opening side top surface between the external connection electrode terminals In addition, a piezoelectric oscillator in which a data write electrode pad is used for input / output of a control signal to an integrated circuit element and used as a ground terminal when the piezoelectric oscillator is mounted.
[Selection] Figure 1

Description

  The present invention relates to a piezoelectric oscillator used in an electronic device such as a portable communication device, and more particularly to a piezoelectric oscillator having a so-called H-shaped cross section perpendicular to the main surface of a container body.

  2. Description of the Related Art Conventionally, in some electronic devices such as portable communication devices, a piezoelectric oscillator is used as one of the electronic components that constitute the electronic device.

  As such a conventional piezoelectric oscillator, for example, as shown in FIG. 5, a first recessed space 57 surrounded by an upper surface of a substrate 52 and a first side wall portion 53, a lower surface of the substrate 52, and a second side wall portion. 55, the piezoelectric resonator element 60 is mounted and hermetically sealed on the inner bottom surface of the first recess space 57 of the container body 51 having the second recess space 58 surrounded by the second recess space 58, and the second recess A temperature-compensated piezoelectric oscillator in which an integrated circuit element 64 for performing temperature compensation of the piezoelectric vibration element 60 is accommodated in a space 58, and the integrated circuit element 64 is disposed in the second recess space 58. A piezoelectric oscillator filled with a resin 65 for protection is disclosed. A data writing electrode pad 56 for writing temperature compensation data to the integrated circuit element 64 is formed on the outer surface of the substrate 52. Further, external connection electrode terminals 59 are formed at the four corners on the top surface of the second recess space 58 opening side (mounting side) of the second side wall 55 forming the second recess space 58. The piezoelectric oscillator is mounted on the external circuit mother board by bonding the external connection electrode terminal 59 to the wiring or electrode pad of the external circuit mother board with solder or the like.

  The advantage of the container structure as described above is that the piezoelectric vibration element 60 is mounted in the first recessed space 57 of the container body 51, and the integrated circuit element is formed on the bottom surface in the second recessed space 58 facing the substrate 52. Since 64 is mounted, a small piezoelectric oscillator with a small mounting area can be obtained. Further, since the piezoelectric vibration element 60 and the integrated circuit element 64 can be accommodated in completely different spatial regions, the oscillation operation of the piezoelectric vibration element 60 can be stabilized over a long period of time. In addition, since a defect in the oscillation characteristics of the piezoelectric vibration element 60 can be easily detected during the manufacturing process before the integrated circuit element is mounted, an inexpensive piezoelectric oscillator can be obtained by wasting the integrated circuit element 64 and not performing the useless manufacturing process. Can provide. In addition, since the integrated circuit element 64 is mounted in the second recessed space 58 after the piezoelectric vibrating element 60 is mounted in the first recessed space 57 of the container body 51, the frequency stabilization is achieved after mounting the piezoelectric vibrating element 60. Thus, the heat treatment performed for the purpose is not applied to the integrated circuit element 64, and the operation reliability and connection reliability of the integrated circuit element 64 can be improved.

The piezoelectric vibrator and the piezoelectric oscillator as described above are disclosed in the following prior art documents.
JP 2005-94514 A

  In addition, the applicant has not found any prior art documents related to the present invention by the time of filing of the present application other than the prior art documents specified by the above prior art document information.

  However, when the above-described conventional piezoelectric oscillator is formed, the space on the outer surface of the container body for forming the data writing electrode pad is remarkably reduced as the piezoelectric oscillator is further reduced in size and thickness. It becomes difficult to form an electrode pad for data writing or it becomes an extremely small electrode pad for data writing, and a data writing jig for inputting temperature compensation data is used as an electrode pad for data writing. It is difficult to make sure that it is in contact.

  Furthermore, due to the miniaturization of the piezoelectric oscillator, the external connection electrode terminals formed at the four corners of the top surface on the second concave space opening side of the container body are formed close to each other. There is a possibility that the electrode terminals for electric use are likely to interfere with each other electrically.

  The present invention has been conceived in view of the above disadvantages, and has a data writing electrode pad having a size that allows the data writing jig to reliably contact even when the piezoelectric oscillator is reduced in size and thickness. Another object of the present invention is to provide a piezoelectric oscillator structure in which adjacent external connection electrode terminals do not cause electrical interference.

In the piezoelectric oscillator of the present invention, an upright first side wall portion is formed on an edge portion of one main surface of a substrate having a rectangular main surface shape and a flat outer shape. A piezoelectric vibration element is mounted in the first recess space surrounded by the side wall and the main surface, and the first recess space is arranged and fixed so as to cover the opening of the first recess space. Further, an integrated circuit element electrically connected to the piezoelectric vibration element is disposed and fixed on the other main surface of the substrate, and the other main surface of the substrate is further sealed. A second side wall portion is formed upright at the edge of the surface, and at least an integrated circuit element is mounted in the second concave portion space surrounded by the second side wall portion and the main surface. In addition, electrode terminals for external connection are respectively formed at four corners of the top surface on the second recess space opening side of the second side wall portion. In the piezoelectric oscillator,
Electrically connecting to the integrated circuit element and inputting / outputting a control signal to / from the integrated circuit element on a top surface of the second recess space between the external connection electrode terminals in the second side wall part; and When the piezoelectric oscillator is mounted, an electrode pad used for conduction and fixation of the piezoelectric oscillator to an external substrate is formed as a ground terminal.

  In the piezoelectric oscillator of the present invention, the electrode pad is a temperature compensation data writing electrode pad.

  According to the piezoelectric oscillator of the present invention, a control signal is input to the integrated circuit element by electrically connecting to the integrated circuit element on the top surface of the second recess space opening between the external connection electrode terminals on the second side wall. When the piezoelectric oscillator is mounted, an electrode pad used for conduction and fixing to the external substrate of the piezoelectric oscillator is formed as a grounding terminal. Therefore, for temperature compensation formed on the outer surface of the conventional container body Compared to an electrode pad for inputting / outputting a control signal such as data, an electrode pad having a large formation area can be formed.

  In addition, when the piezoelectric oscillator is mounted, the electrode pad is electrically and mechanically connected to the ground terminal of the external substrate, so that the four corners on the top surface of the second recess space opening side of the second side wall portion. It is possible to block the electrical interference between the external connection electrode terminals formed on the ground by the grounded electrode pad.

  As a result, it is possible to provide a small and thin piezoelectric oscillator that is easy to manufacture and highly reliable.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an external perspective view of a piezoelectric oscillator according to an embodiment of the present invention as seen from the mounting surface side (integrated circuit element mounting side). FIG. 2 is a sectional view taken along the virtual cutting line A1-A2 shown in FIG. FIG. 3 is an external perspective view showing a form in which the piezoelectric oscillator disclosed in FIG. 1 is mounted on an external substrate. FIG. 4 is an external perspective view of a piezoelectric oscillator according to another embodiment of the present invention as seen from the mounting surface side (integrated circuit element mounting side).
In each drawing, the same reference numerals indicate the same object, and for the sake of clarity, a part of the structure that does not need to be described is not shown, and the dimensions of each structure are partially exaggerated. In particular, the thickness dimension of each structure is greatly exaggerated.

In general, the piezoelectric oscillator shown in each figure is a container body 1 composed of a substrate 2, a first side wall portion 3 and a second side wall portion 5, a piezoelectric vibration element 12, an integrated circuit element 14, a resin 16. It consists of and.
Each of the piezoelectric oscillators shown in the drawings accommodates a piezoelectric vibration element 12 in a first recessed space 10 surrounded by a substrate 2 and a first side wall 3, and has four corners on the mounting side top surface of the second side wall 5. An external connection electrode terminal 9 is provided in the part. The electrode terminal 9 for external connection is an integrated circuit element mounted in the second recessed space 17 surrounded by the substrate 2 and the second side wall 5 via the conductive wiring in the second side wall 5. It is electrically connected to 14 predetermined electrode terminals. A resin material 16 is filled between the surface of the integrated circuit element 14 and the inner surface of the second recessed space 17 facing the surface. Further, between the adjacent external connection electrode terminals 9 formed at the four corners of the mounting side top surface of the second side wall 5, data electrically connected to the temperature compensation data write terminal of the integrated circuit element 14. Write electrode pads 6 are arranged.

  FIG. 1 shows the positional relationship of the data writing electrode pads 6 arranged between the external connection electrode terminals 9 formed at the four corners of the mounting side top surface of the second side wall 5. As shown in FIG. 1, the data writing electrode pad 6 is formed at a position approximately in the middle between the external connection electrode terminals 9 formed at the four corners of the mounting side top surface of the second side wall 5. Yes.

  For example, the container body 1 includes a substrate 2 made of a ceramic material such as glass-ceramic and alumina ceramic, and a first side wall portion 3 and a second side wall portion 5 made of a ceramic material similar to the substrate 2, by firing. It is configured as follows. A piezoelectric vibrating element 12 is mounted on the surface of the substrate 2 located inside the first side wall portion 3 via a conductive adhesive 13. One purpose of use of the container body 1 is, specifically, in the first recessed space 10 surrounded by the upper surface of the substrate 2, the inner surface of the first side wall 3, and the lower surface of the lid 4. The lid 4 is made of 42 alloy, copal, phosphor bronze, or the like, and the top of the first side wall 3 on the first concave space opening side. The first recess space is hermetically sealed by placing and fixing the lid body 4 to the top.

  In addition, quartz is mainly used as the material of the piezoelectric vibration element 12 accommodated in the first concave space 10 of the container body 1, and outer shape polishing is performed on a crystal base plate cut at a predetermined angle from the crystal axis from the artificial crystal. And a pair of vibrating electrodes is deposited and formed on both main surfaces to form a piezoelectric (quartz) diaphragm. When a fluctuating voltage is applied to this piezoelectric (quartz) diaphragm from the outside via a pair of vibrating electrodes, it vibrates in a predetermined mode at a predetermined frequency.

  On the other hand, as shown in FIGS. 1 and 2, the second side wall 5 is formed on the lower surface of the substrate 2 described above, and external connection electrode terminals 9 are formed at the four corners of the second side wall 5. Deposited and formed. A flip chip type integrated circuit element 14 formed in a rectangular shape is mounted on the lower surface of the substrate 2 located between the second side wall portions 5, and the integrated circuit element 14 is interposed via a conductive bonding material 18. Are connected to the substrate 2.

  The integrated circuit element 14 has, on its circuit forming surface, a temperature-sensitive element that detects the ambient temperature state, and temperature compensation data that compensates for the temperature characteristics of the piezoelectric vibration element 12, and the piezoelectric vibration element 12 is based on the temperature compensation data. Is provided with a temperature compensation circuit that corrects the vibration characteristics according to temperature changes, an oscillation circuit that is connected to the temperature compensation circuit and generates a predetermined oscillation output, and the oscillation output generated by the oscillation circuit is externally provided. After being output, it is used as a reference signal such as a clock signal. Here, the piezoelectric vibration element 12 and the integrated circuit element 14 are electrically connected by a metallized wiring 15 provided in the inner layer of the substrate 2 shown in FIG. The integrated circuit element 14 and the data writing electrode pad 6 are also electrically connected by a metallized wiring (not shown) provided in the inner layer of the substrate 2, and the temperature compensation data is based on the temperature compensation data. After the integrated circuit element 14 having the temperature compensation circuit for correcting the vibration characteristics of the piezoelectric vibration element 12 according to the temperature change is mounted in the second recess space 17, the specification of the piezoelectric oscillator becomes a desired numerical value. As described above, the bit data is written into the integrated circuit element 14 from the data writing electrode pad 6.

  Here, as shown in FIG. 3, the characteristic part of the present invention is disposed on the mounting side top surface of the second side wall 5 and is used for writing temperature compensation data. Are electrically and mechanically connected to the ground terminal 31 of the external substrate 30, so that adjacent external connections formed at the four corners of the top surface of the second recess space 20 opening side of the second side wall 5. It is possible to block electrical interference between the electrode terminals 9 for use by the electrode pads 6. Thus, even if the piezoelectric oscillator is downsized, the external connection electrode terminals 9 arranged at the four corners of the mounting side top surface of the second side wall 5 have stable electrical characteristics without interference between adjacent terminals. Can be obtained.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the electrode pads 6 are formed at two locations between the external connection electrode terminals 9 at the four corners of the mounting side top surface of the second side wall portion 5, but as shown in FIG. The data writing electrode pads 6 may be arranged at two positions between the external connection electrode terminals 9. Needless to say, this case is also included in the technical scope of the present invention.

FIG. 1 is an external perspective view of a piezoelectric oscillator according to an embodiment of the present invention as seen from the mounting surface side (integrated circuit element mounting side). 2 is a cross-sectional view taken along the virtual cutting line A1-A2 shown in FIG. FIG. 3 is an external perspective view showing a form in which the piezoelectric oscillator disclosed in FIG. 1 is mounted on an external substrate. FIG. 4 is an external perspective view of a piezoelectric oscillator according to another embodiment of the present invention as seen from the mounting surface side (integrated circuit element mounting side). FIG. 5 is a cross-sectional view of a conventional piezoelectric oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container body 2 ... Board | substrate 3 ... 1st side wall part 4 ... Lid body 5 ... 2nd side wall part 6 ... Electrode pad for data writing 9 ... External Connecting electrode terminal 10 ... first recess space 12 ... piezoelectric vibration element 13 ... conductive adhesive 14 ... integrated circuit element 15 ... metallized wiring 16 ... resin material 17 ...・ Second recess space 18 ... conductive bonding material

Claims (2)

A first side wall portion that is upright is formed on the edge portion of one main surface of the substrate having a rectangular main surface shape and a flat outer shape, and the first side wall portion and the main surface are A piezoelectric vibration element is mounted in the enclosed first recess space, and the first recess space is hermetically sealed by a lid that is disposed and fixed so as to cover the opening of the first recess space. Further, an integrated circuit element electrically connected to the piezoelectric vibration element is disposed and fixed on the other main surface of the substrate, and further, on the edge of the other main surface of the substrate. An upstanding second side wall is formed, and at least an integrated circuit element is mounted in the second recess space surrounded by the second side wall and the main surface, and the second side wall In the piezoelectric oscillator in which external connection electrode terminals are respectively formed at the four corners of the top surface of the second recess space opening side of the part,
Electrically connecting to the integrated circuit element and inputting / outputting a control signal to / from the integrated circuit element on a top surface of the second recess space between the external connection electrode terminals in the second side wall part; and A piezoelectric oscillator characterized in that when the piezoelectric oscillator is mounted, an electrode pad is formed which is electrically connected to a ground terminal of an external substrate and used for fixing the piezoelectric oscillator to the external substrate.   2. The piezoelectric oscillator according to claim 1, wherein the electrode pad is an electrode pad for writing temperature compensation data.

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