JP5220584B2 - Piezoelectric oscillator and manufacturing method thereof - Google Patents

Description

  The present invention relates to a piezoelectric oscillator that is one of electronic components used in an electronic device such as a portable communication device, and a manufacturing method thereof.

Conventionally, piezoelectric oscillators are used as electronic components in electronic devices.
FIG. 5 is a cross-sectional view showing a conventional piezoelectric oscillator.
As shown in FIG. 5, a conventional piezoelectric oscillator 200 mainly includes a container body 210, a piezoelectric vibration element 220, a lid body 230, and an integrated circuit element 240 as an example.
The container body 210 includes a substrate part 210a and a frame part 210b.
The container body 210 is provided with a frame portion 210b on one main surface of the substrate portion 210a to form a recessed space 211.
The frame portion 210b is connected to the sealing conductor film 212 provided so as to surround the outer periphery of one main surface of the substrate portion 210a by brazing or the like.
A pair of piezoelectric vibration element mounting pads 213 are provided on one main surface of the substrate portion 210 a exposed in the concave space 211, and the piezoelectric vibration element 220 is mounted via the conductive adhesive 250.
Further, an integrated circuit element mounting pad 215 is provided on the other main surface of the substrate part 210a, and the integrated circuit element 240 is electrically and mechanically bonded through a conductive bonding material such as solder. This state is called loading.
Also, terminal portion connection electrode terminals 214 are provided at the four corners of the other main surface of the substrate portion 210a, and the terminal portion 260 is electrically and mechanically joined via a conductive joining material such as solder. (For example, refer to Patent Document 1).
In addition, the piezoelectric oscillator 200 includes a conductive bonding material (such as solder) that connects a terminal portion 260 serving as an external connection electrode terminal of the container body 210 and a piezoelectric oscillator mounting pad (not shown) provided on a mother board such as an electronic device. It is surface-mounted by bonding with (not shown).

JP 2004-135091 A

  As a conventional piezoelectric oscillator, a conductive bonding material such as solder is used when it is mounted on a mother board, and the flux contained in the conductive bonding material passes between adjacent terminal portions from the integrated circuit element and the substrate. There was a problem that it entered between the bodies and the frequency fluctuated.

  Further, as a conventional method for manufacturing a piezoelectric oscillator, the piezoelectric oscillator is assembled and manufactured by individually mounting integrated circuit elements on a container body. In that case, it is necessary to mount and hold the integrated circuit elements after mounting the individual container bodies on the mounting jig, and accordingly, the number of manufacturing facilities is increased and the manufacturing process is complicated and manufactured. There was a problem that the time was prolonged.

  The present invention has been made in view of the above problems, and an object thereof is to provide a piezoelectric oscillator capable of preventing frequency fluctuations and a method of manufacturing a piezoelectric oscillator capable of improving productivity. .

  The piezoelectric oscillator of the present invention includes a container body in which a concave space is provided on one main surface of the substrate portion by the substrate portion and the frame portion, and two pieces provided on one main surface of the substrate portion exposed in the concave space. A piezoelectric vibration element mounted on a pair of piezoelectric vibration element mounting pads and provided with an excitation electrode; an integrated circuit element mounted on an integrated circuit element mounting pad provided on the other main surface of the substrate portion; A lid that hermetically seals the recessed space, a rectangular parallelepiped terminal portion that is provided at the four corners of the other main surface of the substrate portion and has a thickness greater than that of the mounted integrated circuit element, and an adjacent terminal portion And an insulative wall portion thinner than the thickness of the terminal portion.

  The insulating wall portion is made of any one of silicon, glass epoxy resin, and glass.

  In the piezoelectric oscillator manufacturing method of the present invention, a piezoelectric vibration element is mounted on one main surface of the substrate portion exposed in the recess space of the container body in which the recess space is formed by the substrate portion and the frame portion. An electrode terminal for connecting a terminal portion is provided at four corners of the main surface, the recessed space is hermetically sealed with a lid, and the terminal portion provided with an insulating wall portion is joined to the terminal portion connecting electrode terminal. A manufacturing method comprising a metal terminal portion wafer having a plurality of through holes larger than a container body, and two rectangular parallelepiped terminal portions facing each other on two parallel sides of the through holes. Insulating wall portion mounting step for providing an insulating wall portion so as to straddle adjacent terminal portions, and terminal portion connecting electrode terminals and terminal portions provided at the four corners of the other main surface of the substrate portion of the container body Terminal that joins one main surface of terminal part of wafer with conductive bonding material Each of the bonding step, the integrated circuit element mounting step of mounting the integrated circuit element on the integrated circuit element mounting pad provided on the other main surface of the substrate portion of the container body, and cutting the terminal portion from the terminal portion wafer, And a cutting and separating step of separating the terminal portion from the terminal portion wafer and simultaneously obtaining a plurality of piezoelectric oscillators.

  According to the piezoelectric oscillator of the present invention, since the insulating wall portion is provided between the adjacent terminal portions, the flux contained in the conductive bonding material such as solder used for mounting on the motherboard is integrated circuit. Intrusion between the element and the substrate portion can be prevented. Therefore, it is possible to prevent the frequency of the piezoelectric oscillator caused by the flux from entering from fluctuating.

  In addition, since the insulating wall portion is made of any one of silicon, glass epoxy resin, and glass, the width of the wall portion can be narrowed while maintaining the strength, rather than integrally forming the container body. Therefore, the integrated circuit element can be arranged up to a portion where the width of the wall portion is narrowed. Therefore, the piezoelectric oscillator can be reduced in size.

  Further, according to the method for manufacturing a piezoelectric oscillator of the present invention, the terminal wafer is mounted on the terminal wall wafer for mounting the insulating wall portion and the integrated circuit element until the cutting and separating step after the integrated circuit element is mounted. It is designed to function as a tool. Therefore, there is no need for a dedicated mounting jig for mounting the insulating wall and a dedicated mounting jig for mounting the integrated circuit element, and it is complicated to mount the container body on the mounting jig. No work is required. This also improves the productivity of the piezoelectric oscillator.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view of a piezoelectric oscillator according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. In addition, the illustrated dimensions are partially exaggerated.

  As shown in FIGS. 1 and 2, the piezoelectric oscillator 100 according to the embodiment of the present invention includes a container body 110, a piezoelectric vibration element 120, a lid body 130, an integrated circuit element 140, a terminal portion T, and an insulating wall portion ZH. It is mainly composed. In the piezoelectric oscillator 100, a piezoelectric vibration element 120 is mounted in a recessed space 111 formed in the container body 110, and an integrated circuit element 140 and a terminal portion T are mounted on the other main surface of the container body 110. An insulating wall portion ZH is provided between the terminal portions T. Further, the recessed space 111 has a structure hermetically sealed by the lid 130.

As shown in FIGS. 1 and 2, the piezoelectric vibration element 120 is formed by adhering an excitation electrode 122 to a crystal element plate 121, and an alternating voltage from the outside passes through the excitation electrode 122. When applied to 121, excitation occurs in a predetermined vibration mode and frequency.
The quartz base plate 121 is a substantially flat plate shape that is cut from an artificial crystalline lens at a predetermined cut angle and is subjected to outer shape processing, and has a planar shape of, for example, a quadrangle.
The excitation electrode 122 is formed by depositing and forming a metal in a predetermined pattern on both the front and back main surfaces of the crystal base plate 121.
Such a piezoelectric vibration element 120 conducts between the lead electrode extending from the excitation electrode 122 attached to both main surfaces thereof and the piezoelectric vibration element mounting pad 113 formed on the bottom surface in the recessed space 111. It mounts in the 1st recessed space 111 by electrically and mechanically connecting through the adhesive 150 (refer FIG. 2). At this time, an end side that is a free end opposite to the side on which the extraction electrode is provided is defined as a tip end portion 123 of the piezoelectric vibration element 120.

As shown in FIGS. 1 and 2, the integrated circuit element 140 is provided with an oscillation circuit or the like for generating an oscillation output from the piezoelectric vibration element 120 on the circuit formation surface, and an output signal generated by the oscillation circuit. Is output to the outside of the piezoelectric oscillator 100 via the terminal portion T, and is used as a reference signal such as a clock signal, for example.
The integrated circuit element 140 has a terminal (not shown) corresponding to the integrated circuit element mounting pad 115.
In addition, in the integrated circuit element 140, in order to compensate the fluctuation of the oscillation frequency of the oscillation circuit due to the temperature change by applying a control voltage according to the ambient temperature to the variable capacitance element, the temperature is controlled by the cubic function generation circuit and the storage element unit. A compensation circuit unit is provided, and a temperature sensor is connected to the cubic function generation circuit.
This temperature sensor is configured to output a temperature data signal (voltage value) generated based on the detected temperature and a voltage value applied to the temperature sensor to a cubic function generation circuit.
The integrated circuit element 140 is mounted on an integrated circuit element mounting pad 115 formed on the other main surface of the substrate portion 110a via a conductive bonding material (not shown) such as solder.

As shown in FIG.1 and FIG.2, the container body 110 is mainly comprised by the board | substrate part 110a and the frame part 110b.
The container body 110 is provided with a frame portion 110b on one main surface of the substrate portion 110a to form a recessed space 111.
In addition, the board | substrate part 110a which comprises this container body 110 is formed by laminating | stacking multiple ceramic materials, such as an alumina ceramic and a glass-ceramic, for example. The substrate unit 110a has a structure in which ceramic materials are stacked.
For the frame part 110b, for example, a seal ring is used. In this case, the frame portion 110b is made of a metal such as 42 alloy or Kovar, and has a frame shape with the center punched out.
The frame portion 110b is connected to the sealing conductor film 112 provided so as to surround the outer periphery of one main surface of the substrate portion 110a by brazing or the like.
A pair of piezoelectric vibration element mounting pads 113 (113a and 113b) are provided on one main surface of the substrate portion 110a exposed in the recessed space 111. A wiring pattern or the like is provided on the inner layer of the substrate unit 110a.
On the other main surface of the substrate portion 110a, a terminal portion connection electrode terminal 114 and a plurality of integrated circuit element mounting pads 115 are provided.

The terminal portion T shown in FIG. 1 is formed of, for example, a metal material such as copper or SUS, and one main surface side of the terminal portion T and the terminal portion connection electrode terminal 114 of the substrate portion 110a are made of a conductive bonding material DS. It is joined.
The terminal portion T has a thickness t1 larger than the thickness t2 of the mounted integrated circuit element 150 and has a rectangular parallelepiped shape.
Further, the terminal portion T is provided with a groove portion D (see FIG. 2) along the surface facing the outside of the terminal portion T. That is, the groove part D is provided so that it may go to the opposite side of the surface from the surface where the adjacent terminal part T faces. The groove portion D is provided with an insulating wall portion ZH described later.
Further, Ni plating, Au is applied to one main surface of the terminal portion T connected to the terminal portion connecting electrode terminal 114 of the container body 110 and the other main surface of the terminal portion T connected to an external electronic circuit such as a mother board. By applying in the order of plating, the bondability of the conductive bonding material (not shown) can be improved.

The insulating wall portion ZH shown in FIG. 1 is formed of, for example, silicon, glass epoxy resin, glass or the like, and is provided between adjacent terminal portions T. That is, the insulating wall portion ZH is provided so as to surround the integrated circuit element 140 along the outer peripheral edge of the other main surface of the substrate portion 110 a of the container body 110.
Further, the insulating wall portion ZH has a thickness t3 that is thinner than the thickness t1 of the terminal portion T, and has a rectangular parallelepiped shape. That is, the insulating wall portion ZH may be of a thickness that protects between the integrated circuit element 140 and the substrate body 110a.

  The lid 130 is made of, for example, an Fe—Ni alloy (42 alloy), an Fe—Ni—Co alloy (Kovar), or the like. Such a lid 130 is hermetically sealed in the recessed space 111 with nitrogen gas or vacuum. Specifically, the lid body 130 is placed on the frame part 110b of the container body 110 in a predetermined atmosphere so that the metal on the surface of the frame part 110b and a part of the metal of the lid body 130 are welded. The seam welding is performed by applying a predetermined current to join the frame portion 110b.

  The conductive adhesive 150 contains conductive powder as a conductive filler in a binder such as silicone resin. As the conductive powder, aluminum (Al), molybdenum (Mo), tungsten (W ), Platinum (Pt), palladium (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or a combination thereof is used. .

  When the container body 110 is made of alumina ceramics, a sealing conductor film 112, a piezoelectric vibration element, and the like are formed on the surface of a ceramic green sheet obtained by adding and mixing a suitable organic solvent to a predetermined ceramic material powder. A through-hole (not shown) previously formed by punching a ceramic green sheet with a conductive paste that becomes the mounting pad 113, the terminal portion connection electrode terminal 114, the integrated circuit element mounting pad 115, etc. It is manufactured by applying a conductor paste to be a via conductor therein by well-known screen printing, laminating a plurality of them and press-molding them, followed by firing at a high temperature.

According to the piezoelectric oscillator of the present invention, the insulating wall portion ZH is provided between the adjacent terminal portions T, so that the flux contained in the conductive bonding material such as solder used for mounting on the motherboard can be obtained. Intrusion between the integrated circuit element 150 and the substrate portion 110a of the container body 110 can be prevented. Therefore, frequency fluctuation of the piezoelectric oscillator 100 caused by flux entering can be prevented.
Further, since the insulating wall portion ZH is provided between the adjacent terminal portions T, the width w of the wall portion can be reduced while maintaining the strength, rather than forming the container body 110 integrally. Therefore, the integrated circuit element 140 can be arranged up to the portion where the wall width w is narrowed. Therefore, the piezoelectric oscillator 100 can be reduced in size.

Next, a method for manufacturing the piezoelectric oscillator of the present invention will be described with reference to FIGS.
Here, FIG. 3A is a cross-sectional view showing the insulating wall mounting step of the piezoelectric oscillator manufacturing method of the present invention, and FIG. 3B is a terminal portion joint of the piezoelectric oscillator manufacturing method of the present invention. FIG. 3C is a cross-sectional view showing an integrated circuit element mounting step of the method for manufacturing a piezoelectric oscillator according to the present invention, and FIG. 3D is a cross-sectional view illustrating the process of the piezoelectric oscillator according to the present invention. It is sectional drawing which shows the cutting-separation process of a manufacturing method. FIG. 4A is a perspective view showing a terminal portion wafer in the insulating wall mounting step of the method for manufacturing a piezoelectric oscillator of the present invention, and FIG. 4B shows the method for manufacturing the piezoelectric oscillator of the present invention. It is a perspective view which shows the terminal part wafer in which the insulating wall part in the insulating wall part mounting process was mounted.

(Insulating wall mounting process)
As shown in FIGS. 3A and 4, the insulating wall portion mounting step has a plurality of through holes larger than the container body, and a rectangular parallelepiped terminal on two side surfaces parallel to the through holes. In this step, an insulating wall portion is provided so as to straddle adjacent terminal portions on a terminal portion wafer made of metal provided so that two portions face each other.

As shown in FIG. 4A, the terminal portion wafer MS has a plurality of through holes K larger than the container body 110, and the rectangular parallelepiped terminal portions T are formed on the two parallel side surfaces of the through holes K. It is made of metal that is provided to face each other.
That is, a plurality of terminal portions T having a rectangular parallelepiped shape having a thickness t1 larger than the thickness t3 of the integrated circuit element 150 are arranged in series in a form in which one surface of the terminal portion T is connected to the terminal portion wafer MS, A configuration in which the surface of the terminal portion T arranged in series and the surface opposite to the surface connected to the terminal portion wafer MS are arranged to face each other with a through hole K provided at a predetermined interval therebetween. is there.
Such a terminal portion wafer MS is formed of, for example, a metal material such as copper or SUS, and is formed by processing a single plate made of this metal material into a predetermined pattern using a well-known photo-etching process. Is done.

As shown in FIG. 4A and FIG. 4B, a groove portion D is provided along the surface facing the outside of the terminal portion T. That is, the groove part D is provided so that it may go to the opposite side of the surface from the surface where the adjacent terminal part T faces.
An insulating wall ZH is provided in the groove D so as to straddle the adjacent terminal portions T.
The insulating wall portion ZH has a side t3 lower than the height t1 of the terminal portion T and has a rectangular parallelepiped shape. That is, the insulating wall portion ZH may be of a thickness that protects between the integrated circuit element 140 and the substrate body 110a.
The insulating wall portion ZH is provided by bonding to the groove portion D with a conductive bonding material (not shown) such as solder. Further, a metal piece (not shown) may be applied to the insulating wall portion ZH, and the metal piece and the terminal portion T may be joined by well-known spot welding. Alternatively, the insulating wall portion ZH may be provided in the groove portion D.

(Terminal part joining process)
As shown in FIG.3 (b), a terminal part joining process is the terminal part connection electrode terminal provided in four corners of the other main surface of the board | substrate part of the said container body, and the said terminal part of the said terminal part wafer. This is a step of joining one main surface with a conductive joining material.
Piezoelectric vibration is applied to the piezoelectric vibration element mounting pad 113 provided on one main surface of the substrate portion 110a exposed in the recess space 111 of the container body 110 in which the recess space 111 is formed by the substrate portion 110a and the frame portion 110b. The element 120 is mounted, and the recessed space 111 is hermetically sealed with a lid 130.
The terminal portion connection electrode terminals 114 provided at the four corners of the other main surface of the substrate portion 110a of the container body 110 and one main surface of the terminal portion T of the terminal portion wafer MS are connected by the conductive bonding material DS. Join. That is, the container body 110 is mounted on the terminal portion T by bonding to one main surface of each terminal portion T by the conductive bonding material DS such as solder or conductive adhesive formed in a lump by a printing unit.
Further, the terminal portion T may protrude from the container body 110. At this time, the insulating wall portion ZH is positioned within the plane of the container body 110.

(Integrated circuit element mounting process)
As shown in FIG. 3C, the integrated circuit element mounting step is a step of mounting the integrated circuit element on the integrated circuit element mounting pad provided on the other main surface of the substrate portion of the container body.
The integrated circuit element 140 is electrically and mechanically connected in a form facing the integrated circuit element mounting pad 115 provided on the other main surface of the container body 110. That is, the integrated circuit element 140 is mounted on the integrated circuit element mounting pad 115 so as to be accommodated in the through hole K of the terminal portion wafer MS.

(Cutting and separation process)
As shown in FIG. 3D, the cutting and separating step is a step of cutting the terminal portions from the terminal portion wafer to separate the terminal portions from the terminal portion wafer to simultaneously obtain a plurality of piezoelectric oscillators. It is.
By cutting the connecting portion between the terminal portion wafer MS and the terminal portion T, each terminal portion T is separated from the terminal portion wafer MS, and a plurality of piezoelectric oscillators 100 are obtained simultaneously. The cutting of the terminal part wafer MS is performed by dicing using a dicer or the like.

According to the method for manufacturing a piezoelectric device of the present invention, the conductive bonding material DS used for bonding the terminal portion connection electrode terminal 114 and the terminal portion T is a terminal formed on the upper surface of the terminal portion wafer MS on the terminal portion wafer MS. Since a mask jig in which holes are formed is placed at a location corresponding to the portion T and can be collectively formed on the plurality of terminal portions T by printing means, individual terminal portions are placed one by one as in the prior art. Since the operation for forming the electrode terminal for connecting the terminal part of the body is not required at all, the productivity of the piezoelectric oscillator 100 is improved.
As described above, the terminal portion wafer MS functions as a mounting jig for mounting the insulating wall portion ZH and the integrated circuit element 140 until the cutting and separating step after the integrated circuit element 140 is mounted. It has become. Therefore, a dedicated mounting jig for mounting the insulating wall portion ZH and a dedicated mounting jig for mounting the integrated circuit element 140 are not necessary, and the container body 110 is mounted on the mounting jig. Such complicated work is not required at all. This also improves the productivity of the piezoelectric oscillator 100.

In addition, this invention is not limited to the said 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 case where quartz is used as the piezoelectric material constituting the piezoelectric vibration element 20 has been described. However, as other piezoelectric materials, lithium niobate, lithium tantalate, or piezoelectric ceramics is used as the piezoelectric material. The piezoelectric vibration element used may be used.

In the above-described embodiment, the case where the seal ring is used for the frame portion has been described. However, it may be formed of a ceramic material in the same manner as the substrate portion 100a.
In this case, an annular sealing conductor pattern is formed on the entire circumference of the opening side top surface of the frame portion, and the lid is disposed and joined on the sealing conductor pattern.
In this case, the lid body is provided with a sealing member at a location facing the sealing conductor pattern provided so as to surround the recessed space of the container body.

1 is an exploded perspective view of a piezoelectric oscillator according to an embodiment of the present invention. It is sectional drawing of AA of FIG. (A) is sectional drawing which shows the insulating wall part mounting process of the manufacturing method of the piezoelectric oscillator of this invention, (b) is sectional drawing which shows the terminal part joining process of the manufacturing method of the piezoelectric oscillator of this invention. (C) is a cross-sectional view showing the integrated circuit element mounting step of the method for manufacturing a piezoelectric oscillator of the present invention, and (d) is a cross-sectional view showing the cutting and separating step of the method for manufacturing a piezoelectric oscillator of the present invention. is there. (A) is a perspective view which shows the terminal part wafer in the insulating wall part mounting process of the manufacturing method of the piezoelectric oscillator of this invention, (b) is the insulating wall part of the manufacturing method of the piezoelectric oscillator of this invention. It is a perspective view which shows the terminal part wafer in which the insulating wall part in the mounting process was mounted. It is a step view showing a conventional piezoelectric oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 ... Container body 110a ... Board | substrate part 110b ... Frame part 111 ... Recessed space 112 ... Conductive film for sealing 113 ... Piezoelectric vibration element mounting pad 114 ... For terminal part connection Electrode terminal 115... Integrated circuit element mounting pad 120... Piezoelectric vibration element 121... Quartz element plate 122... Excitation electrode 123 ... Tip portion 130 ... Lid 140. Circuit element 150 ... Conductive adhesive 100 ... Piezoelectric oscillator T ... Terminal part D ... Groove part DS ... Conductive bonding material ZH ... Insulating wall part MS ... Terminal part wafer K ... through hole

Claims (3)

A container body provided with a recessed space on one main surface of the substrate portion by the substrate portion and the frame portion;
A piezoelectric vibration element mounted on two pairs of piezoelectric vibration element mounting pads provided on one main surface of the substrate portion exposed in the recess space, and provided with excitation electrodes;
An integrated circuit element mounted on an integrated circuit element mounting pad provided on the other main surface of the substrate portion;
A lid for hermetically sealing the recessed space;
A rectangular parallelepiped terminal portion provided at four corners of the other main surface of the substrate portion and having a thickness larger than the mounted integrated circuit element;
A piezoelectric oscillator comprising: an insulating wall provided between adjacent terminal portions and thinner than the thickness of the terminal portion.   2. The piezoelectric oscillator according to claim 1, wherein the insulating wall portion is made of any one of silicon, glass epoxy resin, and glass. A piezoelectric vibration element is mounted on one main surface of the substrate portion exposed in the concave space of the container body in which the concave portion space is formed by the substrate portion and the frame portion, and terminal portions are connected to the four corners of the other main surface. An electrode terminal is provided, wherein the recess space is hermetically sealed with a lid, and a terminal portion provided with an insulating wall portion is joined to a terminal portion connection electrode terminal.
A terminal adjacent to a terminal wafer made of metal having a plurality of through-holes larger than the container body and two rectangular parallelepiped terminal portions facing each other on two parallel sides of the through-holes An insulating wall portion mounting step of providing an insulating wall portion so as to straddle the portion;
Terminal portion bonding for bonding terminal portion connection electrode terminals provided at the four corners of the other main surface of the substrate portion of the container body and one main surface of the terminal portion of the terminal portion wafer with a conductive bonding material. Process,
An integrated circuit element mounting step of mounting an integrated circuit element on an integrated circuit element mounting pad provided on the other main surface of the substrate portion of the container body;
A cutting / separating step of cutting each of the terminal portions from the terminal portion wafer to separate each of the terminal portions from the terminal portion wafer to obtain a plurality of piezoelectric oscillators at the same time. Production method.

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