JP2007189378A - Piezoelectric device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric device which can be miniaturized, and to provide a method of manufacturing the piezoelectric device. <P>SOLUTION: The piezoelectric device is provided with a crystal resonator package 10 in which a crystal resonation piece 12 is housed in the inside of a ceramic package 11 and its inside if hermetically sealed with a lid 15, and an integrated circuit element 20 connected to the external surface of the crystal resonator package 10. An electrode pad 16 formed on the external surface of the crystal resonator package 10 is connected to bumps 21 formed on an active surface 24 as one surface of the integrated circuit element 20, and an external connection terminal 23 is formed on the rear surface of the integrated circuit element 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface-mount type piezoelectric device used for electronic equipment or communication equipment, and a method for manufacturing the piezoelectric device.

In recent years, downsizing of devices is rapidly progressing due to demands for improving portability of electronic devices and communication devices. For this reason, piezoelectric devices such as crystal oscillators used in these devices are required to be further reduced in size and height.
As an example corresponding to the reduction in size and height of the piezoelectric device, a structure as shown in Patent Document 1 is known. In Patent Document 1, a piezoelectric element is hermetically sealed in a ceramic package (container), and an IC (integrated circuit element) is face-down bonded to the lower surface of the ceramic package. Furthermore, solder balls are formed on the same surface as the IC mounting surface of the ceramic package for connection to an external substrate or the like, and these solder balls are used as external connection terminals.

Japanese Patent Laying-Open No. 2005-151116 (FIG. 2)

  However, in the conventional piezoelectric device structure, if the size of the IC is not changed in order to further reduce the size of the piezoelectric device, the size of the IC occupies a relatively large proportion of the area of the ceramic package. As a result, there is a problem that a space for providing solder balls (external connection terminals) cannot be secured. For this reason, the conventional structure has a limit to miniaturization of the piezoelectric device.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a piezoelectric device and a method for manufacturing the piezoelectric device, which can reduce the size of the piezoelectric device.

  In order to solve the above-described problems, a piezoelectric device according to the present invention is connected to a piezoelectric element package in which a piezoelectric element is housed and hermetically sealed, and an outer surface of the piezoelectric element package. An integrated circuit element, and an electrode pad formed on the outer surface of the piezoelectric element package and a connection terminal formed on an active surface, which is one surface of the integrated circuit element, are connected to each other. An external connection terminal is formed on the other surface.

  According to this configuration, one surface (active surface) of the integrated circuit element is connected to the piezoelectric element package, and the external connection terminal is provided on the other surface. Therefore, even if the piezoelectric element package is small and the proportion of the area occupied by the integrated circuit element is relatively large, it is not necessary to provide an external connection terminal on the piezoelectric element package, and the external surface is not provided on the other surface of the integrated circuit element A space for arranging the connection terminals can be easily secured. Therefore, the external connection terminals can be formed without being influenced by the size of the integrated circuit element, and the piezoelectric device can be miniaturized.

  In the piezoelectric device of the present invention, it is desirable that the size of the integrated circuit element in a plan view is substantially the same as the size of the piezoelectric element package in a plan view.

  Thus, if an integrated circuit element having a size substantially equal to that of the piezoelectric element package is used, the circuit element can be formed by effectively using the area of the piezoelectric element package.

  In the piezoelectric device of the present invention, it is preferable that an adjustment terminal capable of controlling a circuit in the integrated circuit element is provided on the other surface of the integrated circuit element in addition to the external connection terminal.

  Among piezoelectric devices, in a temperature-compensated piezoelectric oscillator with a built-in temperature compensation circuit, a PLL piezoelectric oscillator with a built-in PLL circuit, etc., it is necessary to write data to the memory circuit of the integrated circuit element. Data can be written into a memory circuit or the like of the integrated circuit element by using the adjustment terminal formed in (1).

  In the piezoelectric device of the present invention, it is preferable that a side surface of the piezoelectric element package is provided with an adjustment terminal that is electrically connected to the integrated circuit element and can control a circuit in the integrated circuit element.

  Among piezoelectric devices, in a temperature-compensated piezoelectric oscillator with a built-in temperature compensation circuit or a PLL piezoelectric oscillator with a built-in PLL circuit, it is necessary to write data to the memory circuit of the integrated circuit element, which is formed on the side surface of the piezoelectric element package. Data can be written into a memory circuit or the like of the integrated circuit element using the adjustment terminal.

  Further, the piezoelectric device manufacturing method of the present invention connects the electrode pad formed on the outer surface of the piezoelectric element package containing the piezoelectric element and the connection terminal formed on the active surface which is one surface of the integrated circuit element, A method of manufacturing a piezoelectric device in which an external connection terminal is provided on the other surface of the integrated circuit element, wherein the piezoelectric element package is larger than the planar projection shape and extends from the planar projection shape of the piezoelectric element package. Connecting the integrated circuit element provided with an adjustment terminal to an extension part, controlling a memory circuit in the integrated circuit element from the adjustment terminal, and then separating the adjustment extension part of the integrated circuit element; It is characterized by.

  According to this method for manufacturing a piezoelectric device, data can be written to the storage circuit in the integrated circuit element from the adjustment terminal formed on the adjustment extension extending from the projected shape of the piezoelectric element package. Thereafter, the adjustment extension portion of the integrated circuit element is separated to obtain a miniaturized piezoelectric device. As described above, according to the piezoelectric device manufacturing method of the present invention, the piezoelectric device can be easily adjusted when the piezoelectric device is downsized and the adjustment terminal cannot be provided on the piezoelectric device, or when adjustment work is difficult. A method of manufacturing a piezoelectric device capable of performing work can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. In the following embodiments, a crystal oscillator will be described as an example of a piezoelectric device.
(First embodiment)

1A and 1B show a configuration of a crystal oscillator according to the first embodiment. FIG. 1A is a schematic plan view, FIG. 1B is a schematic partial sectional view, and FIG. 1C is a schematic bottom view.
The crystal oscillator 1 includes a crystal resonator package 10 that houses a crystal vibrating piece 12 as a piezoelectric element and an integrated circuit element 20.
In the crystal resonator package 10, a crystal vibrating piece 12 is accommodated in a concave portion of a ceramic package 11 serving as a container, and is fixed by a conductive adhesive 14 such as an Ag paste. In addition, a plurality of electrode pads 16 are provided on the bottom surface of the ceramic package 11, and predetermined electrode pads 16 among these are connected via the conductive adhesive 14 described above by wiring (not shown) in the ceramic package 11. Thus, it is configured to be electrically connected to the excitation electrode 13 formed on the crystal vibrating piece 12. Further, a lid 15 is provided on the upper portion of the ceramic package 11 and is hermetically sealed while maintaining the space of the concave portion in which the crystal vibrating piece 12 is accommodated in a reduced pressure atmosphere or an inert gas atmosphere.

The integrated circuit element 20 such as an IC is formed substantially equal to the size (projected area) of the crystal resonator package 10 in plan view. A circuit element is formed on one surface of the integrated circuit element 20, and this surface is used as an active surface 24. An electrode pad (not shown) is formed on the active surface 24 of the integrated circuit element 20, and a bump 21 made of a metal such as Au is formed as a connection terminal on the electrode pad. The bumps 21 and the electrode pads 16 of the crystal resonator package 10 are connected, and the integrated circuit element 20 is so-called face-down bonded to the bottom surface of the crystal resonator package 10.
The integrated circuit element 20 includes an oscillation circuit that excites the crystal resonator element 12, and a PLL circuit, a temperature compensation circuit, a memory circuit, and the like depending on circumstances.
Further, as electrode pads formed on the active surface 24 of the integrated circuit element 20, a plurality of ground terminals or dummy terminals are arranged to increase the number of terminals, thereby increasing the bonding strength between the crystal resonator package 10 and the integrated circuit element 20. It may be improved.

  Further, an external connection terminal 23 connected to an external substrate or the like is formed on the back surface 25 which is the other surface of the active surface 24 in the integrated circuit element 20. The external connection terminal 23 is configured to be connected to the wiring of the active surface 24 through the through hole 22 opened from the active surface 24 of the integrated circuit element 20.

  In the crystal oscillator 1 having the above configuration, the crystal resonator element 12 is excited by the oscillation circuit provided in the integrated circuit element 20 and outputs a desired frequency signal from a predetermined external connection terminal 23.

According to the crystal oscillator 1 of the first embodiment, the active surface 24 of the integrated circuit element 20 is connected to the crystal resonator package 10, and the external connection terminal 23 is provided on the back surface 25 of the integrated circuit element 20. . Therefore, even if the crystal resonator package 10 is small and the proportion of the area occupied by the integrated circuit element 20 is relatively large, it is not necessary to provide an external connection terminal in the crystal resonator package 10, and the integrated circuit element 20 It is possible to easily secure a space for arranging the external connection terminals 23 on the back surface 25 of the. Therefore, the external connection terminal 23 can be formed regardless of the size of the integrated circuit element 20, and the crystal oscillator 1 can be downsized.
Further, if the integrated circuit element 20 having a size substantially equal to that of the crystal resonator package 10 is used, the circuit element can be formed by effectively using the area of the crystal resonator package 10.
(Second Embodiment)

Next, as a second embodiment of the present invention, a temperature-compensated crystal oscillator that enables adjustment such as writing temperature compensation data in an integrated circuit element will be described.
2A and 2B show a configuration of a crystal oscillator according to the second embodiment, in which FIG. 2A is a schematic plan view, FIG. 2B is a schematic partial sectional view, and FIG. 2C is a schematic bottom view.
The crystal oscillator 2 of the second embodiment includes a crystal resonator package 10 and an integrated circuit element 30. Since the crystal resonator package 10 has the same configuration as that of the first embodiment, the same reference numerals are given. Description is omitted.

The integrated circuit element 30 such as an IC is formed substantially equal to the size (projected area) of the crystal resonator package 10 in plan view. A circuit element is formed on one surface of the integrated circuit element 30, and this surface serves as an active surface 34. An electrode pad (not shown) is formed on the active surface 34 of the integrated circuit element 30, and a bump 31 made of a metal such as Au is formed on the electrode pad. The bumps 31 and the electrode pads 16 of the crystal resonator package 10 are connected, and the integrated circuit element 30 is so-called face-down bonded to the bottom surface of the crystal resonator package 10.
The integrated circuit element 30 includes an oscillation circuit that excites the quartz crystal vibrating piece 12, a temperature compensation circuit, a memory circuit, and the like.

An external connection terminal 33 connected to an external substrate or the like is formed on the back surface 35 of the integrated circuit element 30. The external connection terminal 33 is configured to be connected to the wiring of the active surface 34 through the through hole 32 opened from the active surface 34 of the integrated circuit element 30.
Further, an adjustment terminal 37 is formed on the back surface 35 of the integrated circuit element 30. The adjustment terminal 37 is configured to be connected to a memory circuit on the active surface 34 through a through hole 36 opened from the active surface 34 of the integrated circuit element 30.

As described above, in the crystal oscillator 2 of the present embodiment, the adjustment terminal 37 is formed on the back surface 35 of the integrated circuit element 30, and therefore the temperature compensation data is stored in the storage circuit of the integrated circuit element 30 using the adjustment terminal 37. Can be written.
Further, since the adjustment terminal 37 is arranged in the same direction as the external connection terminal 33, a contact such as a contact probe can be brought into contact from one direction at the time of adjustment such as data writing, thereby facilitating the adjustment work. it can.
As described above, according to the temperature-compensated crystal oscillator 2 of the present embodiment, it is possible to provide a miniaturized crystal oscillator 2 that can control the storage circuit of the integrated circuit element in adjustment work such as data writing. .
Even in a PLL oscillator in which an oscillation circuit and a PLL circuit are incorporated in an integrated circuit element, the frequency data can be written from the adjustment terminal by using the above configuration, and a downsized PLL crystal oscillator is provided. be able to.
(Third embodiment)

Next, as a third embodiment of the present invention, another embodiment of a temperature-compensated crystal oscillator that enables adjustment such as writing of temperature compensation data to an integrated circuit element will be described.
3A and 3B show the configuration of the crystal oscillator according to the third embodiment. FIG. 3A is a schematic plan view, FIG. 3B is a schematic partial sectional view, and FIG. 3C is a schematic bottom view.
The crystal oscillator 3 of the third embodiment includes a crystal resonator package 40 and an integrated circuit element 20, and since the integrated circuit element 20 has the same configuration as that of the first embodiment, the same reference numerals are used for description. Is omitted.

  In the crystal resonator package 40, the crystal vibrating piece 12 is accommodated in a recess of a ceramic package 41 as a container, and is fixed by a conductive adhesive 14 such as an Ag paste. In addition, a plurality of electrode pads 46 are provided on the bottom surface of the ceramic package 41, and the predetermined electrode pads 46 among these are provided via the conductive adhesive 14 described above by wiring (not shown) in the ceramic package 41. Thus, it is configured to be electrically connected to the excitation electrode 13 formed on the crystal vibrating piece 12. Further, the predetermined electrode pad 46 is connected to an adjustment terminal 48 provided on each of the opposing side surfaces of the ceramic package 41 via a wiring 47 in the ceramic package 41. A lid 15 is provided on the upper portion of the ceramic package 41, and is hermetically sealed while maintaining the space of the recess in which the crystal vibrating piece 12 is accommodated in a reduced pressure atmosphere or an inert gas atmosphere.

Further, the bumps 21 provided on the integrated circuit element 20 are connected to the electrode pads 46 of the crystal resonator package 40, and the integrated circuit element 20 is so-called face-down bonded to the bottom surface of the crystal resonator package 40. The integrated circuit element 20 includes an oscillation circuit that excites the quartz crystal resonator element 12, a temperature compensation circuit, a memory circuit, and the like.
In this way, the adjustment terminal 48 is connected to the predetermined electrode pad 46 through the wiring 47 in the ceramic package 41, and is connected to the memory circuit built in the integrated circuit element 20 from the bump 21 of the integrated circuit element 20. It is configured.

As described above, in the crystal oscillator 3 of the present embodiment, the adjustment terminals 48 are formed on the opposing side surfaces of the ceramic package 41, respectively. Compensation data can be written.
Further, by providing the adjustment terminal 48 on the opposing side surface of the ceramic package 41, a contact such as a contact probe that contacts when writing data can be held between the crystal oscillator 3 from both sides, and stable contact can be maintained.
As described above, according to the temperature-compensated crystal oscillator 3 of the present embodiment, it is possible to provide a miniaturized crystal oscillator 3 that can control the storage circuit of the integrated circuit element in adjustment work such as data writing. .
Even in a PLL oscillator in which an oscillation circuit and a PLL circuit are incorporated in an integrated circuit element, the frequency data can be written from the adjustment terminal by using the above configuration, and a downsized PLL crystal oscillator is provided. be able to.
(Fourth embodiment)

Next, as a fourth embodiment, a method for manufacturing a temperature compensated crystal oscillator having the configuration shown in the first embodiment will be described.
FIG. 4 is a flowchart for explaining the steps of the method for manufacturing the temperature compensated crystal oscillator.
FIG. 5 shows a configuration of a crystal oscillator before temperature compensation data is written. FIG. 5 (a) is a schematic plan view, FIG. 5 (b) is a schematic partial sectional view, and FIG. 5 (c) is a schematic bottom view. .

A description will be given with reference to the configuration diagram of FIG. 5 according to the flowchart of FIG.
First, the crystal vibrating piece 12 is fixed to the concave portion of the ceramic package 11 with the conductive adhesive 14, and the crystal vibrating piece 12 is accommodated in the ceramic package 11 (step S1).
Next, the frequency of the crystal vibrating piece 12 is adjusted by adding a weight to the excitation electrode 13 formed on the crystal vibrating piece 12 or removing a part of the excitation electrode 13 (step S2).
Subsequently, the upper portion of the ceramic package 11 is sealed with a lid 15 and hermetically sealed by keeping the space of the concave portion in which the crystal vibrating piece 12 is accommodated by seam welding or the like in a reduced pressure atmosphere or an inert gas atmosphere (step S3). . In this way, the crystal resonator package 10 is manufactured.

Next, the electrode pads 16 of the crystal resonator package 10 and the bumps 51 formed on the active surface 54 of the integrated circuit element 50 are bonded (step S4). As a result, as shown in FIG. 5, the integrated circuit element 50 and the crystal unit package 10 are integrated.
Here, the integrated circuit element 50 includes an oscillation circuit, a temperature compensation circuit, a storage circuit, and the like that excite the crystal resonator element 12. Further, the integrated circuit element 50 includes an adjustment extension 56 extending from the planar projection shape of the crystal resonator package 10 to the left and right sides in the drawing (FIG. 5). An adjustment terminal 57 is provided on the adjustment extension 56 on the active surface 54 side of the integrated circuit element 50, and is connected to a memory circuit built in the integrated circuit element 50.
Furthermore, an external connection terminal 53 connected to an external substrate or the like is formed on the back surface 55 of the integrated circuit element 50. The external connection terminal 53 is configured to be connected to a wiring on the active surface 54 through a through hole 52 opened from the active surface 54 of the integrated circuit element 50.

Next, a contact such as a contact probe is applied to the adjustment terminal 57 disposed in the adjustment extension 56 of the integrated circuit element 50, and temperature compensation data is written in the storage circuit of the integrated circuit element 50 (step S5).
Thereafter, the adjustment extension 56 of the integrated circuit element 50 is cut and separated along the cutting lines C and D shown in FIG. 5 (step S6).
In this way, a temperature compensated crystal oscillator having the same configuration as that of the first embodiment can be obtained.

As described above, according to the method for manufacturing the temperature-compensated crystal oscillator, the adjustment terminal 57 formed on the adjustment extension 56 extending from the planar projection shape of the crystal resonator package 10 is connected to the memory circuit in the integrated circuit element 50. Data can be written. Thereafter, by separating the adjustment extension 56 of the integrated circuit element 50, a miniaturized crystal oscillator can be obtained.
As described above, according to the crystal oscillator manufacturing method of the present embodiment, when the crystal oscillator is downsized, the adjustment terminal cannot be provided in the crystal oscillator, or the adjustment work is difficult. In addition, it is possible to provide a method for manufacturing a crystal oscillator that can be easily adjusted.
Further, since the adjustment terminals 57 are provided on both sides of the integrated circuit element 50, a contact such as a contact probe that contacts when writing data can maintain a stable contact.
Furthermore, you may provide further the terminal connected with the external connection terminal 53 in the surface in which the adjustment terminal 57 of the extension part 56 for adjustment was formed. In this way, a contact such as a contact probe can be brought into contact from one direction at the time of adjustment such as data writing, productivity can be improved, and in addition, production equipment can be simplified.

In the first to fourth embodiments, a metal ball such as a solder ball may be added to the external connection terminal provided in the integrated circuit element to serve as an external connection terminal.
In the above embodiment, the connection from the active surface of the integrated circuit element to the external connection terminal on the back surface is made through a through-hole penetrating the integrated circuit element. You may connect to a connection terminal.
In addition, after connecting the integrated circuit element and the crystal resonator package, the gap between them is filled with an underfill (insulating resin) and cured by heating to improve the connection strength between the integrated circuit element and the crystal resonator package. The integrated circuit element may be protected.

As described above, in the above-described embodiment, the crystal oscillator using the crystal resonator as the piezoelectric device has been described as an example. However, the piezoelectric element material is not limited to quartz, and piezoelectric materials such as lithium tantalate and lithium niobate are used. The piezoelectric vibrator used may be used.
Further, the present invention can also be used in a SAW oscillator, a vibration gyro sensor, and the like using a SAW (surface acoustic wave) element, a vibration gyro element, or the like as a piezoelectric element instead of a crystal vibrating piece, and can enjoy the same effect.

The structure of the crystal oscillator in 1st Embodiment is shown, (a) is a schematic plan view, (b) is a schematic fragmentary sectional view, (c) is a schematic bottom view. The structure of the crystal oscillator in 2nd Embodiment is shown, (a) is a schematic plan view, (b) is a schematic fragmentary sectional view, (c) is a schematic bottom view. The structure of the crystal oscillator in 3rd Embodiment is shown, (a) is a schematic plan view, (b) is a schematic fragmentary sectional view, (c) is a schematic bottom view. 9 is a flowchart showing a process sequence of a method for manufacturing a crystal oscillator according to a fourth embodiment. It is explanatory drawing explaining the manufacturing method of the crystal oscillator in 4th Embodiment, (a) is a schematic plan view, (b) is a schematic fragmentary sectional view, (c) is a schematic bottom view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2, 3 ... Crystal oscillator as a piezoelectric device, 10 ... Crystal oscillator package as a piezoelectric element package, 11 ... Ceramic package as a container, 12 ... Crystal vibrating piece as a piezoelectric element, 15 ... Cover, 16 DESCRIPTION OF SYMBOLS ... Electrode pad, 20 ... Integrated circuit element, 21 ... Bump as connection terminal, 22 ... Through hole, 23 ... External connection terminal, 24 ... Active surface of integrated circuit element, 25 ... Back surface of integrated circuit element, 30 ... Integrated circuit Elements 33 ... external connection terminals 37 ... adjustment terminals 40 ... crystal oscillator package as piezoelectric element package 48 ... adjustment terminals 50 ... integrated circuit elements 53 ... external connection terminals 56 ... extension parts for adjustment, 57: Adjustment terminal.

Claims (5)

A piezoelectric element package in which a piezoelectric element is housed and hermetically sealed; and
An integrated circuit element connected to the outer surface of the piezoelectric element package,
An electrode pad formed on the outer surface of the piezoelectric element package and a connection terminal formed on an active surface which is one surface of the integrated circuit element are connected, and an external connection terminal is connected to the other surface of the integrated circuit element. A piezoelectric device characterized in that is formed. The piezoelectric device according to claim 1.
A size of the integrated circuit element in plan view is approximately equal to a size of the piezoelectric element package in plan view. The piezoelectric device according to claim 1 or 2,
A piezoelectric device, wherein an adjustment terminal capable of controlling a circuit in the integrated circuit element is provided on the other surface of the integrated circuit element in addition to the external connection terminal. The piezoelectric device according to claim 1 or 2,
A piezoelectric device comprising an adjustment terminal that is electrically connected to the integrated circuit element and capable of controlling a circuit in the integrated circuit element on a side surface of the piezoelectric element package. An electrode pad formed on the outer surface of a piezoelectric element package containing a piezoelectric element is connected to a connection terminal formed on an active surface which is one surface of the integrated circuit element, and an external connection terminal is connected to the other surface of the integrated circuit element. A method of manufacturing a piezoelectric device provided with
Connecting to the piezoelectric element package the integrated circuit element provided with an adjustment terminal at an adjustment extension extending from the planar projection shape of the piezoelectric element package larger than the planar projection shape;
A method for manufacturing a piezoelectric device, comprising: controlling a memory circuit in the integrated circuit element from the adjustment terminal; and then separating the adjustment extending portion of the integrated circuit element.

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