JP2009267863A - Piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator which prevents from shorting out without providing a resin agent in a recessed portion where an integrated circuit element is mounted, and adaptive to size reduction. <P>SOLUTION: The piezoelectric oscillator is characterized in that one container body 110 has two recessed portions 111 and 112 to mount a piezoelectric vibration element 120 in the first recessed portion 111 and the integrated circuit element 130 at least having an oscillation circuit in the second recessed portion 112, and the interval size A between an outer peripheral side surface of the integrated circuit element 130 and an inner side surface of the second recessed portion 112 which is opposed to the outer peripheral side surface is ≥20 μm and ≤100 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a piezoelectric oscillator used in an electronic device.

  2. Description of the Related Art Conventionally, a piezoelectric oscillator that is one of electronic components is mounted on an electronic device such as a portable communication device. This piezoelectric oscillator is used as a reference signal generation source or a clock signal generation source, for example.

FIG. 5 is an exploded perspective view showing one embodiment of a conventional piezoelectric oscillator.
The piezoelectric oscillator 500 mainly includes a piezoelectric vibrator portion 501 mainly composed of a first container body 502, a piezoelectric vibration element (not shown) and a lid body 503, a second container body 511 and an integrated circuit element 512. It is comprised from the circuit part 510 comprised.

  External connection electrode terminals 513 are provided on the outer lower surface of the second container body 511 constituting the circuit unit 510. The second container body 511 is provided with a recess 514 having an opening on the upper surface side, and a plurality of integrated circuit element connection electrode pads are provided on the bottom surface of the recess 514. An integrated circuit element 512 is mounted on the electrode pad for connecting the integrated circuit element by an ultrasonic bonding method. Further, a notch 515 is provided in a part of the side wall that surrounds the recess 514. Furthermore, a piezoelectric vibrator portion connection terminal 516 for mechanically and electrically connecting to a piezoelectric vibrator portion 501 described later is provided at the corner of the top surface of the side wall portion surrounding the concave portion 514, and the second container The external connection electrode terminal 513, the integrated circuit element 512, and the piezoelectric vibrator portion connection terminal 516 are electrically connected by a conductive wiring provided inside or on the surface of the body.

  In addition, an insulating resin agent 517 (hereinafter referred to as a resin agent) is filled as an underfill between the integrated circuit element 512 mounted in the recess 514 and the inner surface of the recess 514 through the notch 515. Yes. By providing this resin agent 517, solder scraps that have entered from the outside come into contact with the circuit forming surface of the integrated circuit element 512 and the electrode pads for connecting the integrated circuit elements, so that no short circuit occurs in the integrated circuit or between the electrode pads. Protect the circuit forming surface and its surroundings. A circuit unit 510 is configured by these components. Solder scrap is generated when a part of the electronic component including the piezoelectric oscillator is separated from the solder when the electronic component is mounted on the external electronic substrate by solder, and has a three-dimensional structure with a minimum diameter of 100 μm or more. .

  A circuit unit connection terminal 504 for mechanically and electrically connecting to the circuit unit 510 is provided on the outer lower surface of the first container body 502 constituting the piezoelectric vibrator unit 501. The first container body 502 is provided with a recess (not shown) having an opening on the upper surface side, and a piezoelectric vibration element is mounted in the recess. The concave portion is hermetically sealed by a lid body 503 that is disposed and bonded to the top surface of the side wall portion of the first container body 502 surrounding the concave portion so as to cover the concave portion opening. A piezoelectric vibrator portion 501 is constituted by these components.

  In the piezoelectric oscillator 500, the piezoelectric vibrator unit 501 is placed on the circuit unit 510 so that the piezoelectric vibrator unit connection terminal 516 of the circuit unit 510 and the circuit unit connection terminal 504 of the piezoelectric vibrator unit 501 are mechanically connected. And it is comprised by connecting electrically (for example, refer patent document 1).

  As another conventional piezoelectric oscillator, in the container body, the first recess is provided so that the opening is provided on one main surface of the container body, and the second recess is the container body. There is a piezoelectric oscillator provided with an opening on the other main surface. The first recess has a piezoelectric vibrator mounted therein and is hermetically sealed by a lid. An integrated circuit element is mounted in the second recess, and a protective resin agent serving as an underfill is injected between the integrated circuit element and the inner surface of the second recess. (For example, refer to Patent Document 2).

JP 2006-211065 A JP 2005-6171 A

  However, in the conventional piezoelectric oscillator described above, it is necessary to provide a resin agent in order to protect the solder scraps from coming into contact with the circuit forming surface of the integrated circuit element and the electrode pad for connecting the integrated circuit element. For that purpose, the process which inject | pours a resin agent between the recessed part of the container body in which an integrated circuit element and an integrated circuit element are mounted is needed. Further, in order to inject the resin agent, a space in which the resin agent can be injected between the integrated circuit element and the concave portion of the container body on which the integrated circuit element is mounted, as in a conventional piezoelectric oscillator. And a structure must be separately provided in the container body, which may reduce the rigidity of the container body and hinder downsizing of the container body.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a piezoelectric oscillator that solves the above-described problems, prevents a short circuit without providing a resin agent in a recess in which an integrated circuit element is mounted, and can cope with downsizing. .

  The piezoelectric oscillator according to the present invention has been made to solve the above-described problem. One container body is provided with two recesses, a piezoelectric vibration element is mounted in the first recess, and the second A piezoelectric oscillator in which an integrated circuit element including at least an oscillation circuit is mounted in the recess of the integrated circuit element, and an outer peripheral side surface of the integrated circuit element and an inner side surface of the second recess facing the outer peripheral side surface. The distance dimension is 20 μm or more and less than 100 μm.

  In the piezoelectric oscillator according to the present invention, the two container bodies each have a recess, and the piezoelectric vibration element is mounted in the recess of the first container body, and in the recess of the second container body. Is a piezoelectric oscillator in which a semiconductor element having at least a built-in oscillation circuit is mounted and the first container body and the second container body are overlapped and mechanically and electrically connected to each other. And the dimension of the space | interval with the inner surface of the recessed part of the 2nd container body facing this outer peripheral side surface is 20 micrometers or more and less than 100 micrometers.

  In the piezoelectric oscillator according to the present invention, the distance between the outer peripheral side surface of the integrated circuit element and the inner side surface of the concave portion on which the integrated circuit element facing the outer peripheral side surface is 20 μm or more and less than 100 μm. With such a structure, the solder scrap which is a three-dimensional structure with a minimum diameter of 100 μm or more enters the gap between the inner side surface of the recess in which the integrated circuit element is mounted and the outer peripheral side surface of the integrated circuit element, and the integrated circuit element The circuit forming surface and the electrode pad for connecting the integrated circuit element cannot be contacted, and a short circuit does not occur in the integrated circuit or between the electrode pads for connecting the integrated circuit element. Therefore, there is no need for the resin agent provided to protect the scraps from coming into contact with the circuit forming surface of the integrated circuit element and the electrode pad for connecting the integrated circuit element, and there is no need for the step of injecting the resin agent. The manufacturing process of the oscillator can be shortened. Further, a space and a structure that need to be separately provided in the container body for injecting the resin agent are not required, the rigidity of the container body is not lowered, and the container body can be downsized.

  Furthermore, since the lower limit of the distance between the inner side surface of the recess in which the integrated circuit element is mounted and the outer peripheral side surface of the integrated circuit element is 20 μm, the integrated circuit element is mounted during the integrated circuit element mounting process. The integrated circuit element comes into contact with the frame surrounding the concave portion to be formed, and the integrated circuit element is not cracked, chipped or mounted, and the integrated circuit element can be reliably mounted.

  Therefore, the present invention has an effect that it is possible to provide a piezoelectric oscillator that can prevent a short circuit without being provided with a resin agent in a recess in which an integrated circuit element is mounted, and that can cope with downsizing.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In each drawing, for clarity of explanation, some of the components are not shown, and the dimensions of the components shown are also exaggerated.

(First embodiment)
FIG. 1 is a schematic cross-sectional view showing a piezoelectric oscillator according to a first embodiment of the present invention. FIG. 2 is a plan view showing the piezoelectric oscillator according to the first embodiment of the present invention from the mounting side.
As shown in FIG. 1, the piezoelectric oscillator 100 according to the first embodiment of the present invention is mainly configured by a container body 110, a piezoelectric vibration element 120, an integrated circuit element 130, and a lid body 140. .

  The container body 110 is configured by providing a frame body 110b on one main surface of a substrate 110a having a rectangular shape in plan view and providing a frame body 110c on the other main surface of the substrate 110a. As a result, a first recess 111 is formed on one main surface of the substrate 110a, and a second recess 112 is formed on the other main surface of the substrate 110a. The substrate 110a and the frames 110b and 110c are made of a ceramic material such as glass-ceramic or alumina ceramic.

  Further, two pairs of piezoelectric vibration element connection electrode pads 113 are provided on one main surface of the substrate 110 a exposed in the first recess 111, and the substrate exposed in the second recess 112. On the other main surface of 110a, a plurality of integrated circuit element connection electrode pads 114 are provided. Furthermore, external connection electrode terminals 115 that are conductively fixed to an external electronic substrate when the piezoelectric oscillator 100 is mounted are provided at the four corners of the side surface surrounding the second recess 112 of the frame 110c.

  The piezoelectric vibration element 120 includes a piezoelectric element plate having a rectangular shape in plan view, an excitation electrode (not shown) provided at the center of both main surfaces of the piezoelectric element plate, and one of the piezoelectric element plates from the excitation electrode. It is mainly composed of an extraction electrode (not shown) extending to the short side end. The piezoelectric vibration element 120 having such a configuration is mounted in the first recess 111 by electrically connecting and fixing the extraction electrode and the piezoelectric vibration element connecting electrode pad 113 with the conductive adhesive 121.

  The lid 140 is a flat plate made of a metal such as 42 alloy, Kovar, or phosphor bronze, and is arranged on the top surface of the frame 110b on the opening side of the first recess 111 so as to cover the opening of the first recess 111. Are joined to the frame 110b. The lid 140 is hermetically sealed in the first recess 111.

  The integrated circuit element 130 is mounted on a plurality of integrated circuit element connection electrode pads 114 provided on the other main surface of the substrate 110 a exposed in the second recess 112. In the integrated circuit element 130, an electronic circuit including an oscillation circuit, a temperature compensation circuit, and the like is provided. The electronic circuit is electrically connected to the piezoelectric vibration element 120 and the external connection electrode terminal 115 provided on the container body 110.

  When the integrated circuit element 130 is mounted in the second recess 112, the interval A between the outer peripheral side surface of the integrated circuit element 130 and the inner side surface of the second recess 112 facing the outer peripheral side surface is 20 μm or more and 100 μm. Less than. With such a structure, the three-dimensional structure solder scrap having a minimum diameter of 100 μm or more cannot enter the gap between the outer peripheral side surface of the integrated circuit element 130 and the inner side surface of the second recess 112 facing the outer peripheral side surface. Therefore, the circuit formation surface of the integrated circuit element 130 and the electrode pad 114 for connecting the integrated circuit element cannot be contacted, and a short circuit does not occur in the integrated circuit or between the electrode pads 114 for connecting the integrated circuit element. Therefore, the resin agent (underfill) conventionally provided for protecting the integrated circuit element 130 from being contacted with solder scraps is not necessary, and the step of injecting the resin agent is not necessary. Thereby, the manufacturing process of the piezoelectric oscillator can be shortened. In addition, unlike the conventional piezoelectric oscillator, there is no need for a space or a structure that must be provided in the container body for injecting the resin agent, and there is no reduction in the rigidity of the container body, and the container body can be downsized. Become.

  In addition, since the lower limit dimension of the distance A between the outer peripheral side surface of the integrated circuit element 130 and the inner side surface of the second recess 112 facing the outer peripheral side surface is 20 μm, the integrated circuit The integrated circuit element 130 comes into contact with the frame 110c surrounding the second recess 112 for mounting the element 130, and the integrated circuit element 130 is reliably broken without being cracked, chipped, or mounted. 110 can be mounted.

(Second embodiment)
FIG. 3 is a schematic cross-sectional view showing a piezoelectric oscillator according to the second embodiment of the present invention. FIG. 4 is a plan view showing a circuit unit constituting the piezoelectric oscillator according to the second embodiment of the present invention from the piezoelectric vibrator unit side.
The piezoelectric oscillator according to the second embodiment of the present invention is different from the first embodiment in the structure of the container body on which the piezoelectric vibration element and the integrated circuit element are mounted.

  As shown in FIG. 3, the piezoelectric oscillator 300 according to the second embodiment of the present invention includes a piezoelectric vibrator section 301 mainly composed of a first container body 302, a piezoelectric vibration element 120, and a lid body 140, It is composed of a second container body 311 and a circuit unit 310 mainly composed of the integrated circuit element 130. Therefore, it differs from the first embodiment in that the piezoelectric vibration element 120 and the integrated circuit element 130 are mounted in different container bodies.

  An external connection electrode terminal 313 is provided on the outer lower surface of the second container body 311 constituting the circuit unit 310. The second container body 311 is provided with a recess 314 having an opening on the upper surface side, and a plurality of integrated circuit element connection electrode pads 315 are provided on the inner bottom surface of the recess 314. An integrated circuit element 130 is mounted on the electrode pad 315 for connecting the integrated circuit element. Furthermore, a piezoelectric vibrator portion connection terminal 316 for mechanically and electrically connecting a piezoelectric vibrator portion 301 to be described later is provided at the corner of the top surface of the side wall portion surrounding the concave portion 314, and the second container The external connection electrode terminal 313, the integrated circuit element 130, and the piezoelectric vibrator portion connection electrode terminal 316 are electrically connected by a conductive wiring provided inside or on the surface of the body 311.

  A circuit unit connection electrode terminal 305 for mechanically and electrically connecting to the circuit unit 310 is provided on the outer lower surface of the first container body 302 constituting the piezoelectric vibrator unit 301. The first container body 302 is provided with a recess 306 having an opening on the upper surface side. Further, two pairs of piezoelectric vibration element connection electrode pads 303 are provided on the bottom surface of the recess 306, and the piezoelectric vibration element 120 is placed on the piezoelectric vibration element connection electrode pad 303 by the conductive adhesive 121. It is installed. The recess 306 is hermetically sealed by a lid 140 that is arranged and bonded to the top surface of the side wall that surrounds the recess 306 so as to cover the opening of the recess 306. The piezoelectric vibrator unit 301 is configured by these components.

  In the piezoelectric oscillator 300, the piezoelectric vibrator unit 301 is disposed on the circuit unit 310, and the piezoelectric vibrator unit connection electrode terminal 316 of the circuit unit 310 and the circuit unit connection electrode terminal 305 of the piezoelectric vibrator unit 301 are arranged. It is configured by connecting mechanically and electrically.

  In the piezoelectric oscillator 300, when the integrated circuit element 130 is mounted in the second container body 311, the distance B between the outer peripheral side surface of the integrated circuit element 130 and the inner side surface of the recess 314 facing the outer peripheral side surface is set. 20 μm or more and less than 100 μm. By adopting such a structure, like the piezoelectric oscillator 100 in the first embodiment, the three-dimensional structure solder scrap having a minimum diameter of 100 μm or more is formed on the outer peripheral side surface of the integrated circuit element 130 and the concave portion facing the outer peripheral side surface. It is impossible to enter the gap between the inner surface of 314 and solder scraps do not come into contact with the circuit forming surface of the integrated circuit element 130 or the electrode pad 315 for connecting the integrated circuit element. Therefore, there is no need for a resin agent that has been conventionally provided to protect the circuit formation surface of the integrated circuit element 130 or the electrode pad 315 for connecting the integrated circuit element from contact with solder scraps, and this resin agent is injected. Since no process is required, the manufacturing process of the piezoelectric oscillator can be shortened. In addition, unlike the conventional piezoelectric oscillator, there is no need for a space or a structure that needs to be provided in the container body for injecting the resin agent, the rigidity of the container body is not reduced, and the container body can be downsized. .

  In addition, since the lower limit of the distance B between the outer peripheral side surface of the integrated circuit element 130 and the inner side surface of the recess 314 facing the outer peripheral side surface is 20 μm, the integrated circuit element 130 is mounted during the mounting process of the integrated circuit element 130. Since the integrated circuit element 130 is not in contact with the second container body 311 to be mounted, the integrated circuit element 130 is not cracked, chipped, or mounted, and the integrated circuit element 130 is securely attached to the second container body. 311 can be mounted.

  In the present invention, since the distance between the outer peripheral side surface of the integrated circuit element and the inner side surface of the recess facing the outer peripheral side surface is less than 100 μm, the integrated circuit element is mounted by using only metal bumps. It is difficult to use a sonic bonding method. Therefore, as a method for mounting an integrated circuit element in the present invention, first, a bump made of a gold bump or the like and solder formed so as to cover the bump are provided on the electrode pad for connecting the integrated circuit element. Then, the integrated circuit element is arranged so that the electrode for connecting the container provided on the circuit forming surface of the integrated circuit element comes into contact with the solder. Thereafter, the container body in which the integrated circuit element 130 is disposed is placed on reflow means or the like to heat and melt the solder, and then solidify by cooling. By this method, the integrated circuit element connection electrode pad and the container body connection electrode pad of the integrated circuit element are electrically and mechanically connected and fixed by solder, and the integrated circuit element is mounted in the recess. In the present invention, the integrated circuit element is mounted on the container body by the method as described above.

  In addition to the above-described embodiments, various changes and improvements can be made without departing from the scope of the present invention. For example, in the piezoelectric oscillator shown in each of the above embodiments, the piezoelectric vibration element of the form in which the excitation electrode and the extraction electrode are provided on the surface of the piezoelectric element plate having a rectangular shape in plan view is shown as the piezoelectric vibration element mounted inside. However, the present invention is not limited to this, for example, a piezoelectric vibration element in which various electrodes are provided on a piezoelectric base plate having a circular or tuning fork shape in plan view, or a surface acoustic wave element is used instead of the piezoelectric vibration element. It doesn't matter.

1 is a schematic cross-sectional view showing a piezoelectric oscillator according to a first embodiment of the present invention. It is the top view which showed the piezoelectric oscillator which concerns on 1st embodiment of this invention from the mounting side. It is a schematic sectional drawing which shows the piezoelectric oscillator which concerns on 2nd embodiment of this invention. It is the top view which showed the circuit part which comprises the piezoelectric oscillator which concerns on 2nd embodiment of this invention from the piezoelectric vibrator part joining side. It is a disassembled perspective view which shows one form of the conventional piezoelectric oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,300 ... Piezoelectric oscillator 110 ... Container body 110a ... Board | substrate 110b, 110c ... Frame part 111 ... 1st recessed part 112 ... 2nd recessed part 113, 303 ... Piezoelectric Electrode pads for connection of vibration elements 114, 315 ... Electrode pads for connection of integrated circuit elements 115, 313 ... Electrode terminals for external connection 120 ... Piezoelectric vibration elements 121 ... Conductive adhesive 130 ... Integration Circuit element 140: Lid 301: Piezoelectric vibrator unit 302 ... First container body 305 ... Circuit unit connection electrode terminal 306, 314 ... Concave part 310 ... Circuit unit 311 ..Second container body 316: Electrode terminal for connecting piezoelectric vibrator part A, B: Distance between the outer peripheral side surface of the integrated circuit element and the inner side surface of the concave portion facing the outer peripheral side surface

Claims (2)

Two recesses are provided in one container body, a piezoelectric vibration element is mounted in the first recess, and a piezoelectric circuit in which an integrated circuit element containing at least an oscillation circuit is mounted in the second recess. An oscillator,
A piezoelectric oscillator, wherein a distance between an outer peripheral side surface of the integrated circuit element and an inner side surface of the second recess facing the outer peripheral side surface is 20 μm or more and less than 100 μm. Each of the two container bodies is provided with a recess, a piezoelectric vibration element is mounted in the recess of the first container body, and an integrated circuit element including at least an oscillation circuit in the recess of the second container body A piezoelectric oscillator in which the first container body and the second container body are stacked and mechanically and electrically connected,
The piezoelectric oscillator, wherein a distance between the outer peripheral side surface of the integrated circuit element and the inner side surface of the concave portion of the second container body facing the outer peripheral side surface is 20 μm or more and less than 100 μm.

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