JP2008263564A - Temperature-compensated piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature-compensated piezoelectric oscillator capable of temperature compensation with high accuracy, by eliminating the difference between the ambient temperature of a piezoelectric vibrating element and the temperature sensed by a temperature sensor element. <P>SOLUTION: The temperature compensated piezoelectric oscillator is provided with a container body constituted of a substrate, a first frame which is integrally provided on one principal surface of the substrate and forms a first recessed part, and a second frame which is integrally provided on another principal surface of the substrate and forms a second recessed part; a piezoelectric vibrating element mounted in the first recessed part; a first integrated circuit element; a second integrated circuit element mounted in the second recessed part; and a cover which air-tightly seals the first recessed part, wherein the first integrated circuit element comprises a temperature sensor and an oscillation circuit, and the second integrated circuit element comprises a temperature compensation circuit. Furthermore, the temperature compensated piezoelectric oscillator has a step which is provided to the substrate, within the first recessed part, and the first integrated circuit element is mounted in the step. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a temperature compensated piezoelectric oscillator used in electronic equipment such as portable communication equipment.

Conventionally, a temperature compensated piezoelectric oscillator 119 has been used in electronic devices such as portable communication devices. For example, as shown in FIG. 3, a conventional temperature compensated piezoelectric oscillator 119 has a piezoelectric vibration element 111 mounted on a substrate body 102 and an integrated circuit element 116 mounted on the lower surface of the substrate body 102 (for example, a patent). Reference 1). A frame-shaped first frame body 103 is formed on the upper surface of the substrate body 102 made of ceramic, which is a constituent part of the container body 101, and the upper surface of the substrate body 102 is formed inside the first frame body 103. A piezoelectric vibration element 111 is disposed. The piezoelectric vibration element 111 is fixed to a wiring pattern formed on one surface of the substrate body 102 via the conductive adhesive 13 and is electrically and mechanically held. A lid 104 is joined to the upper surface of the first frame 103 by seam welding or the like to hermetically seal the piezoelectric vibration element 111. In addition, a component mounting pad (not shown, the same applies hereinafter) is provided on the lower surface of the substrate body 102 and is surrounded by the ceramic second frame body 105, and an integrated circuit element 116 for oscillation is mounted on the component mounting pad 115. Has been. Further, four external terminal electrodes 106 are formed at the four corners of the lower surface of the second frame 105. The external terminal electrode 106 is used as, for example, an input / output terminal connected from the integrated circuit element 116 through the lead wiring 114 inside the ceramic.
JP 2003-46251 A

  In addition to the prior art documents specified by the prior art document information described above, no prior art documents related to the present invention have been found by the time of filing of the present application.

  However, the above-described conventional temperature-compensated piezoelectric oscillator includes an integrated circuit in which a piezoelectric element is provided in a first recess and a temperature sensor element is provided in a second recess that is divided by a substrate in the container. Therefore, there is a possibility that temperature compensation with high accuracy cannot be performed due to this temperature difference. In other words, since both the piezoelectric vibration element and the integrated circuit element are not disposed in the same sealed container, the temperature around the piezoelectric vibration element and the integrated circuit disposed in a space different from the space where the piezoelectric vibration element is disposed. There is a difference between the temperature sensed by the temperature sensor provided inside the circuit element. As a result, it has been difficult to improve the temperature compensation accuracy of the temperature compensated piezoelectric oscillator.

  The present invention has been conceived in view of the above-described problems, and therefore the object of the present invention is to provide temperature compensation capable of highly accurate temperature compensation without any difference between the temperature around the piezoelectric vibration element and the temperature sensed by the temperature sensor element. It is to provide a piezoelectric oscillator.

  The temperature-compensated piezoelectric oscillator of the present invention includes a substrate body, a first frame body integrally formed on one principal surface of the substrate body to form a first recess, and the other principal surface of the substrate body. A container body formed of a second frame body that is provided integrally with the first recess portion, a piezoelectric vibration element mounted in the first recess portion, a first integrated circuit element, and the first A second integrated circuit element mounted in the second recess, and a lid for hermetically sealing the first recess, wherein the first integrated circuit element includes a temperature sensor and an oscillation circuit, The second integrated circuit element includes a temperature compensation circuit.

  The temperature compensated piezoelectric oscillator of the present invention has a step portion provided in the substrate body in the first recess, and the first integrated circuit element is mounted in the step portion. It is characterized by.

  According to the temperature-compensated piezoelectric oscillator of the present invention, the first integrated circuit element in which the temperature sensor element and the oscillation circuit are provided is housed in the same sealed concave container as the piezoelectric vibration element, and the temperature compensation circuit is provided. Since the second integrated circuit is mounted in a recess different from the recess in which the piezoelectric vibration element is accommodated, the temperature difference between the temperature of the piezoelectric vibration element and the temperature sensor provided inside the integrated circuit element is detected. The temperature change of the crystal can be reduced by making the heat generation from the temperature compensation circuit and the memory element in the second integrated circuit different from the space in which the piezoelectric vibration element is accommodated. As a result, a temperature compensated piezoelectric oscillator structure with improved temperature compensation accuracy can be obtained.

  Further, according to the temperature compensated piezoelectric oscillator of the present invention, the temperature compensated accuracy is improved, and a small temperature compensated piezoelectric oscillator in which the piezoelectric vibration element and the first integrated circuit are spatially stacked in the same space. Can be obtained.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol in each figure shall show the same object.

  FIG. 1 is a schematic sectional view of a temperature compensated piezoelectric oscillator 19 according to an embodiment of the present invention, and FIG. 2 is a bottom view of the temperature compensated piezoelectric oscillator 19. A temperature-compensated piezoelectric oscillator 19 shown in FIG. 1 mainly includes a container body 1, a piezoelectric vibration element 11, a first integrated circuit element 12, a second integrated circuit element 16, and a resin 17. In the temperature compensated piezoelectric oscillator 19 shown in FIG. 1, the piezoelectric vibration element 11 and the first integrated circuit element 12 are accommodated in the first recess 7. A step portion 8 provided in the substrate body 2 is provided in the first recess 7, the first integrated circuit element 12 is mounted on the lower side plane of the step portion 8, and the piezoelectric vibration element 11 is provided on the step portion 8. It is mounted on the upper plane. The second integrated circuit element 16 is accommodated in the second recess 18 of the container body 1. As shown in FIG. 2, external terminal electrodes 6 are arranged at the four corners of the lower surface of the second frame 5 and at the center of the long side of the second frame 5. Further, the second integrated circuit element 16 is mounted on the lower surface of the substrate body 2 surrounded by the second frame body 5, and the second integrated circuit element 16 and the inside of the second frame body 5 are made of resin 17. It is covered with. The external terminal electrodes 6 at the four corners of the external terminal electrode 6 serve as operation terminals for the oscillation function of the temperature compensated piezoelectric oscillator 19 and are external terminal electrodes provided at the center of the long side of the second frame 5. 6 is a function of the piezoelectric vibrating base plate used as an operation terminal.

  The container body 1 includes a substrate body 2 made of a ceramic material such as glass-ceramic and alumina ceramic, and a first frame body 3 and a second frame body 5 made of a ceramic material similar to the substrate body 2. . On the first frame 3, a lid 4 made of 42 alloy, Kovar, phosphor bronze or the like is joined by seam welding or the like. The first frame 3 is attached to the upper surface of the substrate body 2, the second frame 5 is attached to the lower surface, and the lid 4 is placed and fixed on the upper surface of the first frame 3. A body 1 is constructed. The piezoelectric vibration element 11 and the first integrated circuit element 12 are mounted on the upper surface of the substrate body 2 located inside the first frame 3 via the conductive adhesive 13. The container body 1 has a piezoelectric vibration element in the inside thereof, specifically, in a first recess 7 surrounded by an upper surface of the substrate body 2, an inner surface of the first frame body 3, and a lower surface of the lid body 4. 11 and the first integrated circuit element 12 are accommodated and hermetically sealed.

  On the other hand, the piezoelectric vibration element 11 accommodated in the first recess 7 of the container body 1 is formed by attaching and forming a pair of vibration electrodes on both main surfaces of a piezoelectric piece cut along a predetermined crystal axis. When an externally varying voltage is applied to the piezoelectric vibration element 11 via a pair of vibration electrodes, thickness shear vibration is caused at a predetermined frequency.

  On the other hand, as shown in FIGS. 1 and 2, the second frame body 5 is attached and formed on the lower surface of the substrate body 2 described above, and the substrate body 2 inside the second frame body 5. A rectangular flip-chip type second integrated circuit element 16 is mounted on the lower surface of the substrate. The second integrated circuit element 16 is connected to the substrate body 2 via the conductive adhesive 13. The second integrated circuit element 16 and the inside of the second frame 5 are covered with a resin 17, and the second integrated circuit element 16 is protected by the resin 17.

  The first integrated circuit element 12 includes a temperature sensor for detecting the ambient temperature state and an oscillation circuit on the circuit formation surface. The second integrated circuit element 16 stores temperature compensation data for compensating the temperature characteristics of the piezoelectric vibration element 11, and the vibration characteristics of the piezoelectric vibration element 11 are corrected according to the temperature change based on the temperature compensation data. A temperature compensation circuit is provided. The oscillation output generated by the oscillation circuit of the first integrated circuit element 12 is output to the outside of the temperature compensated piezoelectric oscillator 19 and then used as a reference signal such as a clock signal. Here, the piezoelectric vibration element 11, the first integrated circuit element 12, and the second integrated circuit element 16 are connected by a lead wire 14 provided in the inner layer of the substrate body 2 shown in FIG. 1.

  As shown in FIG. 1, the characteristic part of the present invention is that a first integrated circuit element 12 having a function of a temperature sensor or an oscillation circuit is disposed in a first recess 7 in which the piezoelectric vibration element 11 is accommodated. A second integrated circuit element 16 having a temperature compensation circuit, a memory element, and the like is fixed and accommodated in the second recess 18, and the first recess 7 and the second recess 18 are respectively placed above and below the substrate body 2. This is that the concave opening has a one-piece structure in the opposite direction. As described above, the first integrated circuit element 12 having the temperature sensor function is disposed in the first recess 7 sealed in the vicinity of the piezoelectric vibration element 11, so that the piezoelectric vibration element 11 and the temperature sensor sense. Since the temperature difference in temperature can be reduced, highly accurate temperature compensation is possible, and the temperature compensated piezoelectric oscillator 19 with improved temperature compensation accuracy can be obtained.

  Further, according to the temperature compensated piezoelectric oscillator 19 of the present invention, the step portion 8 is provided in the first recess 7 so that the piezoelectric vibration element 11 and the first integrated circuit element 12 are spatially overlapped in the vertical direction. Since the piezoelectric vibration element 11 and the first integrated circuit element 12 are arranged in parallel on the same plane, the mounting area of the temperature compensated piezoelectric oscillator 19 on the mounting board is reduced. It becomes possible to reduce.

  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, as illustrated in FIG. 1, the piezoelectric vibration element 11 and the first integrated circuit element 12 are mounted on the substrate body 2, and the second integrated circuit element 16 is disposed below the substrate body 2. However, the container body in which the piezoelectric vibration element 11 and the first integrated circuit element 12 are mounted and the container body in which the second integrated circuit element 16 is mounted can be stacked.

  In the above-described embodiment, only the piezoelectric vibration element 11 and the first integrated circuit element 12 are accommodated in the first recess 7, but the function of the first integrated circuit element 12 is further divided. For example, a third integrated circuit element such as a protection circuit in which constants such as capacitors and resistors not related to the oscillation circuit function and the temperature sensor function are integrated may be accommodated. Similarly, only one second integrated circuit element 16 is mounted in the second recess 18, but an integrated circuit element in which the functions of another second integrated circuit element 16 are divided is accommodated. I can do it.

1 is a schematic cross-sectional view of a temperature compensated piezoelectric oscillator according to an embodiment of the present invention. It is a schematic bottom view of the temperature compensated piezoelectric oscillator of the present invention. It is a schematic sectional view of a conventional temperature compensated piezoelectric oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container body 2 ... Substrate body 3 ... 1st frame 4 ... Lid 5 ... 2nd frame 6 ... External terminal electrode 7 ... 1st Concave part 8 ... Step part 11 ... Piezoelectric vibration element 12 ... First integrated circuit element 13 ... Conductive adhesive 14 ... Lead-out wiring 16 ... Second integrated circuit element 17 ..Resin 18 ... second recess 19 ... temperature compensated piezoelectric oscillator

Claims (2)

A substrate body and a first frame body integrally formed on one main surface of the substrate body to form a first recess, and a second recess portion integrally formed on the other main surface of the substrate body A container body comprising a second frame body to be formed;
A piezoelectric vibration element and a first integrated circuit element mounted in the first recess;
A second integrated circuit element mounted in the second recess;
A lid for hermetically sealing the first recess,
The first integrated circuit element includes a temperature sensor and an oscillation circuit;
The temperature-compensated piezoelectric oscillator, wherein the second integrated circuit element includes a temperature compensation circuit.
A step portion provided in the substrate body in the first recess,
2. The temperature compensated piezoelectric oscillator according to claim 1, wherein the first integrated circuit element is mounted in the stepped portion.

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