JP2008085962A - Piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator capable of performing the characteristic measurement inspection of a piezoelectric oscillation element easily and reliably, and improving productivity and workability. <P>SOLUTION: A support substrate has the area of a main surface wider than that of an outer bottom surface in the piezoelectric oscillator, and is arranged under the outer bottom surface of the piezoelectric oscillator. An electrode terminal for substrate connection formed on the outer bottom surface in the piezoelectric oscillator is connected onto an oscillator mount pad formed on one main surface of the support substrate electrically and mechanically. When the piezoelectric oscillator is arranged on the support substrate, an electrode terminal for monitoring, which is connected to the piezoelectric oscillation element via a vessel electrically, is provided in the region on one main surface of the support substrate outside the piezoelectric oscillator arrangement region. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

   The present invention relates to a piezoelectric oscillator in which at least a piezoelectric vibration element and an integrated circuit element are mounted on a container body, among piezoelectric oscillators that are one of electronic components used in electronic devices such as portable communication devices.

   Conventionally, in electronic devices such as portable communication devices, piezoelectric oscillators, which are one of electronic components, are used as sources for generating operation reference signals and clock signals of electronic devices mounted on electric devices or electronic devices. Yes.

   Such a conventional piezoelectric oscillator will be described. That is, a rectangular plate-shaped piezoelectric vibration element made of quartz, lithium tantalate, lithium niobate, or piezoelectric ceramics is formed at one short side end portion in a recessed space formed in a container body made of a ceramic material or the like. And an integrated circuit element including an oscillation circuit that is electrically connected to the piezoelectric vibration element is mounted together, and a metal lid is placed and fixed on the container body. Thus, the piezoelectric oscillator is configured by hermetically sealing the recessed space in which the piezoelectric vibration element and the integrated circuit element are mounted. (For example, see Patent Document 1). In addition, this piezoelectric oscillator is provided with a monitor electrode terminal for measuring the electrical characteristics of the piezoelectric vibration element mounted in the recessed space on the outer side wall of the container body. (For example, see Patent Document 2).

The following prior art documents are disclosed about the piezoelectric oscillator of the above-mentioned form.
JP 2004-15441 A JP 2004-215799 A JP 2001-119244 A JP 2002-280835 A

   In addition, the applicant did not come to discover prior art documents related to the present invention by the time of the filing of the application other than the prior art documents specified by the prior art document information described above.

   In the conventional piezoelectric oscillator described above, the electrical characteristics as a piezoelectric oscillator are usually measured by measuring the crystal impedance (hereinafter referred to as CI) characteristics of the piezoelectric vibration element with an electrical characteristic measuring instrument after the assembly of the oscillator is completed. We are going to conduct a pass / fail inspection. For this reason, the monitor electrode terminal is deposited on the outer side surface of the side wall of the container body. However, when the monitor electrode terminal is formed on the piezoelectric oscillator body, the area of the monitor electrode terminal is reduced, and the There is a risk that it will be difficult to contact the contact pin of the characteristic measuring instrument with the monitor electrode terminal easily and securely. Due to poor contact between the contact pin and the monitor electrode terminal, the workability and efficiency of the characteristic inspection will be significantly reduced. There was a problem such as.

   The present invention has been devised in view of the above problems, and its purpose is to easily and reliably perform a characteristic measurement inspection of a piezoelectric vibration element even after assembly, thereby improving productivity and workability. It is an object of the present invention to provide a piezoelectric oscillator that can be used.

The present invention has been made to solve the above-described problems. An element mounting pad is formed on the bottom surface of the concave space of the rectangular container body. The piezoelectric element and the piezoelectric vibrating element and the electric element are mounted on the element mounting pad. An integrated circuit element having a built-in electronic circuit to be connected is mounted, and a rectangular lid that covers the opening of the recessed space is disposed on the top of the side wall of the container body. A piezoelectric oscillator that is at least configured in a form that hermetically seals the piezoelectric vibration element and the integrated circuit element in the container body by fixing the sealing conductor pattern provided on the top,
A support substrate having a major surface area larger than the outer bottom surface area of the piezoelectric oscillator is disposed under the outer bottom surface of the piezoelectric oscillator described above. A substrate connection electrode terminal formed on the outer bottom surface of the piezoelectric oscillator, and a support substrate One main surface of the support substrate that is electrically and mechanically connected to the oscillator mounting pad formed on one main surface and is outside the piezoelectric oscillator arrangement region when the piezoelectric oscillator is arranged on the support substrate This region is provided with a monitor electrode terminal electrically connected to the piezoelectric vibration element through the container body.

   Also, the piezoelectric oscillator according to the preceding paragraph is characterized in that the monitor electrode terminal is constituted by a metal post disposed on a support substrate.

   According to the piezoelectric oscillator of the present invention, a rectangular container body containing an integrated circuit element containing a piezoelectric vibration element and an oscillation circuit that outputs an oscillation signal corresponding to the oscillation frequency of the piezoelectric vibration element in the recess space. A piezoelectric oscillator configured to be fixed on a support substrate, and connected to the piezoelectric vibration element in the recessed space through the container body to a main surface region outside the piezoelectric oscillator arrangement region on the support substrate main surface. Thus, a monitor electrode terminal having a size capable of easily and reliably measuring the electrical characteristics of the piezoelectric vibration element can be provided, and the occurrence of a characteristic measurement failure due to poor contact between the contact pin and the monitor electrode terminal can be provided. And the productivity of the piezoelectric oscillator can be greatly improved.

   Further, according to the piezoelectric oscillator of the present invention, the monitor electrode terminal is constituted by a three-dimensional metal post disposed on the support substrate, so that the contact pin is connected to the monitor electrode from the side surface direction of the piezoelectric oscillator. The terminal can be contacted.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is an exploded perspective view showing a piezoelectric oscillator according to an embodiment of the present invention. FIG. 2 is a schematic sectional view showing a form after the piezoelectric oscillator shown in FIG. 1 is assembled. In each figure, the same reference numerals indicate the same parts, and a part of the structure is not shown for clarity. In addition, some of the illustrated dimensions are exaggerated.

   In these drawings, the piezoelectric oscillator shows a material using a crystal, which is one of piezoelectric materials, as a material of a piezoelectric vibration element mounted therein, and is formed inside a container body 10 having a rectangular main surface shape. In the recessed space 11, the piezoelectric vibration element 20 and an integrated circuit element 30 in which an oscillation circuit and a frequency adjusting circuit electrically connected to the piezoelectric vibration element 20 are housed are housed. In this structure, the recessed space 11 in which the element 20 and the integrated circuit element 30 are mounted is hermetically sealed. The present invention generally has a structure in which the container body 10 constituting such a piezoelectric oscillator is fixed on a support substrate 60.

   The container body 10 is formed, for example, by laminating a plurality of insulating layers made of a ceramic material such as alumina ceramics or glass-ceramic, and the upper main surface of the container body 10 has a rectangular shape in the central region. A ring-shaped sealing conductor pattern 12 is formed on the entire periphery of the recess space 11 opening-side top surface of the side wall portion where the opening of the recess space 11 surrounds the opening of the recess space 11. On the external mounting side main surface (lower main surface) of the container body 10, a plurality of support substrate connection electrode terminals 13 are provided.

   The container body 10 is for mounting the piezoelectric vibration element 20 and the integrated circuit element 30 made of quartz, which is one of the piezoelectric materials, in the recessed space 11 opened on the upper main surface side. In the recessed space 11 of the body 10, an integrated circuit element mounting pad 14 for mounting the integrated circuit element 30, excitation electrodes 21 formed on both the front and back main surfaces of the piezoelectric vibration element 20, and each individual A piezoelectric vibration element mounting pad 15 to be connected is deposited. The integrated circuit element mounting pad 14 is electrically connected to the integrated circuit element 30 and connected to a predetermined electrode terminal of the support substrate connecting electrode terminals 13 via a wiring conductor, a via hole conductor, or the like inside the container body 10. Then, the support substrate connection electrode terminal 13 and the oscillator mounting pad 63 provided on the support substrate 60 are connected by a conductive bonding material, and the other main surface of the support substrate is connected to the support substrate 60 via the wiring conductor and via hole conductor. Are electrically connected to the power supply voltage terminal and the output terminal of the substrate external connection electrode terminals 61 formed on the substrate.

   Further, the piezoelectric vibration element mounting pad 15 is electrically connected to the excitation electrode 21 of the piezoelectric vibration element 20 via the conductive adhesive 40, and via the wiring conductor or via hole conductor inside the container body 10, It is electrically connected to the integrated circuit element 30. The piezoelectric vibration element mounting pad 15 is connected to a predetermined electrode terminal among the support substrate connection electrode terminals 13 via a wiring conductor, a via hole conductor, or the like inside the container body 10, and the support substrate connection electrode terminal 13. And an oscillator mounting pad 63 formed on one main surface of the support substrate 60 are connected by a conductive bonding material. Further, the oscillator mounting pad 63 is connected to a wiring conductor and a via hole conductor inside the support substrate 60. The monitor electrode terminal 62 is also electrically connected.

   Further, the sealing conductor pattern 12 formed on the top surface of the opening side of the recess space 11 in the side wall portion of the container body 10 is made of nickel (Ni) on the surface of a base layer made of tungsten (W), molybdenum (Mo), or the like. ) Layer and a gold (Au) layer are sequentially deposited in a form surrounding the container body 10 in an annular shape, and the conductor pattern 12 for sealing has a lid which will be described later. 50 is bonded to the upper surface of the container body 10 via a sealing member 51 formed on the lid body 50. As described above, the sealing conductor pattern 12 is made of W or Mo. Since the Ni layer and the Au layer are sequentially deposited on the surface of the base layer, the wettability of the sealing member 51 with respect to the sealing conductor pattern 12 is improved, and the hermetic reliability and productivity of the piezoelectric oscillator are improved. The Improve.

   In addition, a via conductor (not shown) having one end connected to the sealing conductor pattern 12 of the container body 10 and the other end connected to the support substrate connection electrode terminal 13 of the container body 10 is provided inside the container body 10. ) Is embedded, and the lid 50 is joined to the sealing conductor pattern 12 via the sealing member 51 on the opening conductor top surface of the side wall of the container body 10. 50 is electrically connected to the ground terminal among the external connection electrode terminals 61 of the support substrate 60 via the support substrate connection electrode terminals 13 formed on the lower surface of the container body 10 through via conductors. In this way, the lid 50 made of a metal material is electrically connected to the ground terminal of the external connection electrode terminal 61 of the support substrate 60 via the support substrate connection electrode terminal 13, so that the piezoelectric oscillator In use, since the lid 50 becomes a ground potential, the electromagnetic shielding action of the lid 50 can satisfactorily protect the piezoelectric vibration element 20 and the integrated circuit element 30 by an unnecessary electrical action from the outside. it can.

   When the container body 10 is made of alumina ceramic, the sealing conductor pattern 12 is connected to the surface of the ceramic green sheet obtained by adding and mixing a suitable organic solvent to a predetermined ceramic material powder. Conductor paste to be used as the electrode terminal 13, the integrated circuit element mounting pad 14, the piezoelectric vibration element mounting pad 15, etc., and via conductors in the through holes previously punched by punching the ceramic green sheet. The conductive paste is applied by conventional well-known screen printing, and a plurality of these are pasted and press-molded, and then fired at a high temperature.

   On the other hand, when the piezoelectric vibration element 20 accommodated in the recessed space 11 of the container body 10 uses, for example, quartz as the material of the piezoelectric material constituting the piezoelectric vibration element 20, the crystal base plate is made from an artificial crystalline lens. The flat plate shape is rectangular with a cut angle of 2 mm, and a pair of excitation electrodes 21 are attached and formed on both the front and back main surfaces of the quartz base plate. When an alternating voltage is applied to the quartz base plate via the excitation electrode 21, excitation occurs in a predetermined vibration mode and frequency. Such a piezoelectric vibration element 20 electrically connects the excitation electrode 21 applied to both main surfaces thereof and the corresponding piezoelectric vibration element mounting pad 15 on the bottom surface of the recessed space 11 through the conductive adhesive 40. It is mounted in the recessed space 11 by connecting mechanically and mechanically.

   An oscillation circuit for generating an oscillation output is provided on the integrated circuit element 30 and the circuit formation surface, and the oscillation output generated by the oscillation circuit is used as a reference signal such as a clock signal, for example.

   The conductive adhesive 40 contains a conductive filler in a silicone resin. Examples of the conductive powder include aluminum (Al), molybdenum (Mo), tungsten (W), and platinum (Pt). , Palladium (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or combinations thereof are used.

   The lid 50 is manufactured by adopting a conventionally known metal processing method and molding a metal such as 42 alloy into a predetermined shape, and a nickel (Ni) layer is formed on the surface of the lid 50. A gold tin (Au—Sn) layer, which is the sealing member 51, is formed at a location corresponding to the sealing conductor pattern 12 on the upper surface of the nickel (Ni) layer. The thickness of the gold tin (Au—Sn) layer is 10 μm to 40 μm. For example, the component ratio is 80% gold and 20% tin. Moreover, such a sealing member 51 can relieve unevenness of the sealing conductor pattern 12 and prevent a decrease in hermeticity. Further, if the sealing member 51 is too thin, the function is not sufficiently exhibited.

   The support substrate 60 is for supporting the container body 10 constituting the piezoelectric oscillator described above on one main surface thereof, and is a resin such as glass cloth base epoxy resin, polycarbonate, epoxy resin, polyimide resin or the like. It is formed so as to have a flat plate shape by a material, a ceramic material such as glass-ceramic, alumina ceramic or the like. Moreover, the main surface area of the support substrate 60 is formed wider than the lower main surface area of the container body 10 to be supported, and a plurality of oscillator mounting pads 63 are provided in the piezoelectric oscillator arrangement region on one main surface. In addition, a plurality of monitor electrode terminals 62 are formed outside the piezoelectric oscillator arrangement region on one main surface.

Further, an external connection electrode terminal 61 is formed on the other main surface of the support substrate 60. The external connection electrode terminal 61 is a power supply voltage terminal, a ground terminal, an oscillation output terminal, an oscillation control terminal as a piezoelectric oscillator. For example, nickel plating or gold plating is predetermined on the surface of the external connection electrode terminal 61 in order to improve the bonding state of solder or the like used for bonding to the external wiring board. Deposited in thickness.
The external connection electrode terminal 61 including such a ground terminal is provided with a conductive bonding material such as solder and metal bumps when wiring the piezoelectric oscillator on an external wiring board such as a mother board. It functions as an electrode terminal for electrical connection.

   The plurality of monitor electrode terminals 62 formed outside the piezoelectric oscillator arrangement region on one main surface of the support substrate 60 have a rectangular main surface shape and are formed in a flat plate shape. Further, the area of the main surface is formed in such a size that a contact pin, which will be described later, can be easily and reliably contacted, and after the assembly of the piezoelectric oscillator is completed, the impedance of the piezoelectric vibration element 20 mounted in the recessed space 11 When the characteristic is measured by the electric characteristic measuring instrument, the contact pin of the electric characteristic measuring instrument comes into contact.

   In addition, as an electrical characteristic measuring instrument used for measuring the impedance characteristics of the piezoelectric vibration element 20, a network analyzer capable of measuring equivalent parameters such as inductance and capacitance in addition to the resonance frequency and crystal impedance of the piezoelectric vibration element 20. The contact pin is composed of a highly conductive pin with gold plating on the surface of an alloy such as copper or silver, and a re-sectorable socket with a spring property that suppresses impact during contact. The measurement is performed by pressing and contacting the electrode terminal 62 for monitoring.

   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, the form of the monitor electrode terminal 62 described in the above-described embodiment is a flat plate shape whose main surface is a rectangle, but in addition, the form of the monitor electrode terminal 62 is as shown in FIGS. By configuring the three-dimensional metal post body 62a disposed on the support substrate 60, the contact pin can be pressed and brought into contact with the side surface side of the piezoelectric oscillator (the side surface side of the metal post body 62a). Become. By adopting such a configuration, it is possible to easily divert the electrical characteristic measuring device used in the conventional piezoelectric oscillator in which the monitor electrode terminal is formed on the outer side surface of the side wall.

   When the support substrate 60 is made of a glass cloth base epoxy resin, the glass cloth base formed by weaving glass yarn is impregnated with a liquid precursor of the epoxy resin and the precursor is polymerized at a high temperature. A metal post body may be formed by forming a base and processing a metal foil such as a copper foil adhered to the surface thereof into a predetermined pattern by using a well-known photo-etching or the like.

FIG. 1 is an exploded perspective view of a piezoelectric oscillator according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view when the piezoelectric oscillator shown in FIG. 1 is assembled and then the piezoelectric oscillator is cut along the virtual cutting line AA ′ shown in FIG. FIG. 3 is an exploded perspective view of a piezoelectric oscillator according to another embodiment of the present invention. FIG. 4 is a schematic cross-sectional view when the piezoelectric oscillator shown in FIG. 3 is assembled and then the piezoelectric oscillator is cut at the position of the virtual cutting line BB ′ shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Container body 11 ... Recessed space 12 ... Conductive pattern for sealing 13 ... Electrode terminal for supporting substrate connection 14 ... Integrated circuit element mounting pad 15 ... Piezoelectric vibration element mounting pad 20 ... Piezoelectric vibration element 21 ... Excitation electrode 30 ... Integrated circuit element 40 ... Conductive adhesive 50 ... Cover body 51 ... Sealing member 60 ... Support substrate 61 .. -External connection electrode terminal 62 ... Monitor electrode terminal 62a ... Metal post body 63 ... Oscillator mounting pad

Claims (2)

An element mounting pad is formed on the bottom surface of the concave space of the rectangular container body, and an integrated circuit element in which the piezoelectric vibration element and an electronic circuit network electrically connected to the piezoelectric vibration element are built in the element mounting pad is mounted. A rectangular lid that covers the opening of the recessed space is disposed on the top of the side wall of the container body, and the lid and the sealing conductor pattern provided on the top of the side wall are fixed, A piezoelectric oscillator configured at least in a form of hermetically sealing the piezoelectric vibration element and the integrated circuit element in the container body,
Under the outer bottom surface of the piezoelectric oscillator, a support substrate having a major surface area wider than the outer bottom surface area of the piezoelectric oscillator is disposed, and the substrate connection electrode terminal formed on the outer bottom surface of the piezoelectric oscillator, and the support An oscillator mounting pad formed on one main surface of the substrate is electrically and mechanically connected, and when the piezoelectric oscillator is arranged on the support substrate, the support substrate outside the piezoelectric oscillator arrangement region One main surface of the piezoelectric oscillator is provided with a monitor electrode terminal electrically connected to the piezoelectric vibration element through the container body.   2. The piezoelectric oscillator according to claim 1, wherein the monitor electrode terminal is constituted by a metal post body disposed on the support substrate.

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