1. Technical Field
The present invention relates to a method of manufacturing a vibration device.
2. Related Art
In a process of manufacturing a vibrator on which a quartz crystal vibrator element is mounted, typically, after mounting the quartz crystal vibrator element on a package base, a frequency adjustment process of adjusting a frequency with respect to individual quartz crystal vibrator elements is carried out.
For example, JP-A-2009-44237 discloses a method in which after mounting the vibrator element on a package base, apart of an excitation electrode is etched through ion milling in which the excitation electrode is irradiated with an ion laser and the like, thereby carrying out frequency adjustment of the vibrator.
However, in the frequency adjustment process, even in a vibrator element having no problem in external appearance, there is a problem in that when the vibrator element does not resonate, the vibrator element becomes a defective product, and thus a yield ratio decreases.
An advantage of some aspects of the invention is to provide a method of manufacturing a vibration device capable of improving a yield ratio during manufacturing.
The invention can be implemented as the following forms or application examples.
A method of manufacturing a vibration device according to this application example includes strongly exciting a vibrator element by applying power, which is higher than drive power during use of the vibrator element, to the vibrator element, and adjusting a frequency of the vibrator element after the strongly exciting of the vibrator element.
In the method of manufacturing the vibration device, since the frequency adjustment of the vibrator element is carried out after strongly exciting the vibrator element, as described later, it is possible to reduce an equivalent series resistance value (CI value) of the vibrator element in a frequency adjustment process, and it is possible to improve an oscillation rate. Accordingly, according to the method of manufacturing the vibration device as described above, it is possible to improve a yield ratio during manufacturing of the vibration device.
The method of manufacturing the vibration device according to the application example may further include forming the vibrator element in a substrate before the strongly exciting of the vibrator element.
The method of manufacturing the vibration device as described above includes the forming of the vibrator element in a substrate. Accordingly, it is possible to strongly excite the vibrator element, for example, in a state in which the vibrator element is formed in the substrate. In other words, in the method of manufacturing the vibration device, it is possible to strongly excite the vibrator element before the vibrator element is accommodated in a container.
According to this, in the method of manufacturing the vibration device, it is possible to reduce a possibility that foreign matter, which is attached to the vibrator element, enters the container of the vibration device.
In the method of manufacturing the vibration device according to the application example, the strongly exciting of the vibrator element may include inspecting the vibrator element.
In the method of manufacturing the vibration device as described above, the inspecting is included in the process of strongly exciting the vibrator element, and thus it is possible to reduce transportation of a defective vibrator element that occurs in the strongly exciting process to the subsequent process.
Accordingly, it is possible to realize a reduction in a defective percentage in finished products of the vibration device, and thus it is possible to realize a reduction in the failure cost.
In the method of manufacturing the vibration device according to the application examples, a plurality of the vibrator elements may be formed in the substrate.
In the method of manufacturing the vibration device as described above, the vibrator elements are formed by using a so-called wafer substrate, and the strongly exciting is carried out, and thus it is possible to attain high productivity.
In the method of manufacturing the vibration device according to the application examples, the strongly exciting of the vibrator element may be carried out with respect to the plurality of vibrator elements which are formed in the substrate.
In the method of manufacturing the vibration device as described above, the strongly exciting of the vibrator element is carried out with respect to the plurality of vibrator elements which are formed in the substrate, and thus it is possible to attain high productivity.
The method of manufacturing the vibration device according to the application example may further include joining the base and the vibrator element through a joining member before the strongly exciting of the vibrator element.
The method of manufacturing the vibration device as described above includes the joining of the base and the vibrator element through a joining member before the strongly exciting of the vibrator element, and thus it is possible to improve a yield ratio during manufacturing of the vibration device.
Application Example 9, Application Example 10, Application Example 11, Application Example 12
In the method of manufacturing the vibration device according to the application examples, in the strongly exciting of the vibrator element, power of 2.5 mW or more to 100 mW or less may be applied to the vibrator element.
In the method of manufacturing the vibration device as described above, as described later, it is possible to reduce the CI value of the vibrator element in the frequency adjustment process, and it is possible to improve an oscillation rate.
In the method of manufacturing the vibration device according to the application examples, the vibrator element may include a quartz crystal substrate including a vibration portion that vibrates with thickness shear vibration.
In the method of manufacturing the vibration device as described above, it is possible to improve a yield ratio during manufacturing of the vibrator.
A method of manufacturing a vibration device according to this application example includes forming a vibrator element, joining a base and the vibrator element through a joining member, joining the base and a semiconductor device through a joining member, and applying power, which is higher than drive power during use of the vibrator element, to the vibrator element for strongly exciting before the joining of the semiconductor device.
In the method of manufacturing the vibration device as described above, it is possible to improve a yield ratio during manufacturing of an oscillator. In addition, in the method of manufacturing the oscillator, the vibrator element can also be strongly excited before the vibrator element is accommodated in a container, and thus it is possible to reduce a possibility that foreign matter, which is attached to the vibrator element, enters the container.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In addition, the following embodiments are not intended to limit the contents of the invention which are described in the appended claims. In addition, it cannot be said that all of configurations to be described later are indispensable constitutional requirements of the invention.
First, description will be given of a vibrator that becomes an object for carrying out a method of manufacturing a vibrator (example of a vibration device) according to this embodiment with reference to the drawings.
As illustrated in
As illustrated in
The quartz crystal substrate 5010 is constituted by an AT-cut quartz crystal substrate. Here,
Typically, a piezoelectric material such as quartz crystal is a trigonal system, and has crystal axes (X, Y, Z) as illustrated in
As illustrated in
In addition, the quartz crystal substrate 5010 is not limited to the AT-cut quartz crystal substrate 5101, and may be an SC-cut quartz crystal substrate in which thickness shear vibration is excited, and a piezoelectric substrate such as a BT-cut quartz crystal substrate that vibrates with different thickness shear vibration.
For example, the quartz crystal substrate 5010 has a rectangular shape in which the Y′ axis direction is set as a thickness direction, and the X axis direction is set as a long side and the Z′ axis direction is set as a short side in a plan view from the Y′ axis direction (hereinafter, simply referred to as “in a plan view”). The quartz crystal substrate 5010 includes a peripheral portion 5012 and a vibration portion 5014.
The peripheral portion 5012 is provided at the periphery of the vibration portion 5014. The peripheral portion 5012 is provided along an outer edge of the vibration portion 5014. The peripheral portion 5012 has a thickness smaller than that of the vibration portion 5014.
The vibration portion 5014 is surrounded by the peripheral portion 5012 in a plan view, and has a thickness larger than that of the peripheral portion 5012. The vibration portion 5014 has a side along the X axis, and a side along the Z′ axis. Specifically, in a plan view, the vibration portion 5014 has a rectangular shape in which the X axis direction is set as the long side, and the Z′ axis direction is set as the short side. The vibration portion 5014 includes a first portion 5015 and a second portion 5016.
The first portion 5015 of the vibration portion 5014 has a thickness larger than that of the second portion 5016. In an example illustrated, the first portion 5015 is a portion having a thickness t1. In a plan view, the first portion 5015 has a square shape.
The second portion 5016 of the vibration portion 5014 has a thickness smaller than that of the first portion 5015. In the example illustrated, the second portion 5016 is a portion having a thickness t2. The second portion 5016 is provided in the +X axis direction and the −X axis direction of the first portion 5015, respectively. That is, the first portion 5015 is interposed between the second portions 5016 in the X axis direction. As described above, the vibration portion 5014 includes two kinds of portions 5015 and 5016 which have thicknesses different from each other, and the vibrator element 5102 has a two-step type mesa structure.
The vibration portion 5014 can vibrate in a state in which the thickness shear vibration is set as main vibration. Since the vibration portion 5014 has the two-step type mesa structure, the vibrator element 5102 can have an energy confinement effect. In addition, the “thickness shear vibration” represents vibration in which a displacement direction of the quartz crystal substrate is parallel to the main surface of the quartz crystal substrate (in the example illustrated, the displacement direction of the quartz crystal substrate is the X axis direction), and a propagation direction of waves is a plate thickness direction.
The vibration portion 5014 includes a first convex portion 5017 that further protrudes in the +Y′ axis direction in comparison to the peripheral portion 5012, and a second convex portion 5018 that further protrudes in the −Y′ axis direction in comparison to the peripheral portion 5012. For example, the convex portions 5017 and 5018 have the same shape and the same size. The convex portions 5017 and 5018 include the first portion 5015 and the second portion 5016.
For example, as illustrated in
For example, as illustrated in
For example, as illustrated in
For example, in a case where the AT-cut quartz crystal substrate is etched by using a solution containing a hydrofluoric acid as an etchant, an m-plane of a quartz crystal is exposed, and thus the lateral surface 5017d of the first convex portion 5017 and the lateral surface 5018c of the second convex portion 5018 become surfaces which are inclined to the plane including the X axis and the Z′ axis. In addition, although not illustrated, a lateral surface of the quartz crystal substrate 5010 in the −Z′ direction other than the lateral surfaces 5017d and 5018c may be surfaces which are inclined with respect to the plane including the X axis and the Z′ axis through exposure of the m plane of the quartz crystal.
In addition, as illustrated in
The first excitation electrode 5020a and the second excitation electrode 5020b are provided to overlap the vibration portion 5014 in a plan view. In the example illustrated, the excitation electrodes 5020a and 5020b are also further provided to the peripheral portion 5012. For example, a planar shape (shape when seen in the Y′ axis direction) of the excitation electrodes 5020a and 5020b is a rectangular shape. The vibration portion 5014 is provided on an inner side of the outer edge of the excitation electrodes 5020a and 5020b in a plan view. That is, the area of the excitation electrodes 5020a and 5020b in a plan view is larger than that of the vibration portion 5014. The excitation electrodes 5020a and 5020b are electrodes configured to apply a voltage to the vibration portion 5014.
The first excitation electrode 5020a is connected to a first electrode pad 5024a through a first lead-out electrode 5022a. The second excitation electrode 5020b is connected to a second electrode pad 5024b through a second lead-out electrode 5022b. The electrode pads 5024a and 5024b are provided in the +X axis direction of the peripheral portion 5012. As the excitation electrodes 5020a and 5020b, the lead-out electrodes 5022a and 5022b, and the electrode pads 5024a and 5024b, for example, electrodes, which are obtained by stacking chromium and gold from a quartz crystal substrate 5010 side in this order, may be used.
In addition, description has been given of an example in which the area of the excitation electrodes 5020a and 5020b is larger than that of the vibration portion 5014, but the area of the excitation electrodes 5020a and 5020b in a plan view may be smaller than that of the vibration portion 5014. In this case, the excitation electrodes 5020a and 5020b are provided on an inner side of the outer edge of the vibration portion 5014 in a plan view.
In addition, description has been given of the two-step type mesa structure in which the vibration portion 5014 includes two kinds of portions 5015 and 5016 which have thicknesses different from each other, but the number of steps of the mesa structure of the vibrator element 5102 is not particularly limited. For example, the vibrator element 5102 may be a three-step type mesa structure in which the vibration portion includes three kinds of portions which have thicknesses different from each other, or a one-step type mesa structure in which the vibration portion does not include portions having a different thickness. In addition, the vibrator element 5102 is not limited to the mesa type. For example, the quartz crystal substrate 5010 may have a uniform thickness, or may have a bevel structure or a convex structure.
In addition, description has been given of an example in which the lateral surfaces 5017c and 5017d of the first convex portion 5017, and the lateral surfaces 5018c and 5018d of the second convex portion 5018 are not provided with a step difference due to a difference between the thickness of the first portion 5015 and the thickness of the second portion 5016. However, in the vibrator element 5102, a step difference may be provided in the lateral surfaces 5017c, 5017d, 5018c, and 5018d.
In addition, description has been given of an example in which the first convex portion 5017 that further protrudes in the +Y′ axis direction in comparison to the peripheral portion 5012, and the second convex portion 5018 that further protrudes in the −Y′ axis direction in comparison to the peripheral portion 5012 are provided, but the vibrator element 5102 may include any one of the convex portions.
As illustrated in
The package 5110 has an accommodation space that is formed when the concave portion 5111 is covered with the lead 5114, and the vibrator element 5102 is air-tightly accommodated and provided in the accommodation space. That is, the vibrator element 5102 is accommodated in the package 5110.
In addition, for example, the inside of the accommodation space (the concave portion 5111), in which the vibrator element 5102 is accommodated, may be set to a decompressed state (vacuum state), or an inert gas such as nitrogen, helium, and argon may be sealed in the accommodation space. According to this, vibration characteristics of the vibrator element 5102 are improved.
For example, the material of the base 5112 may be various kinds of ceramic such as an aluminum oxide. For example, the material of the lead 5114 is a material having approximately the same linear expansion coefficient as that of the material of the base 5112. Specifically, in a case where the material of the base 5112 is ceramic, the material of the lead 5114 is an alloy such as Kovar.
A first connection terminal 5130 and a second connection terminal 5132 are provided on the bottom surface of the concave portion 5111 of the package 5110. The first connection terminal 5130 is provided to face the first electrode pad 5024a of the vibrator element 5102. The second connection terminal 5132 is provided to face the second electrode pad 5024b of the vibrator element 5102. The connection terminals 5130 and 5132 are electrically connected to the electrode pads 5024a and 5024b, respectively, through a conductive fixing member 5134.
A first external terminal 5140 and a second external terminal 5142 are provided on the bottom surface of the package 5110. For example, the first external terminal 5140 is provided at a position that overlaps the first connection terminal 5130 in a plan view. For example, the second external terminal 5142 is provided at a position that overlaps the second connection terminal 5132 in a plan view. The first external terminal 5140 is electrically connected to the first connection terminal 5130 through a via (not illustrated). The second external terminal 5142 is electrically connected to the second connection terminal 5132 through a via (not illustrated).
As the connection terminals 5130 and 5132, and the external terminals 5140 and 5142, for example, a metal film, in which respective films of nickel (Ni), gold (Au), silver (Ag), and copper (Cu) are stacked on a metallized layer (base layer) of chromium (Cr) and tungsten (W), is used. As the conductive fixing member 5134, for example, solder, silver paste, a conductive adhesive (adhesive in which conductive filler such as a metal particle is dispersed in a resin material), and the like are used.
Next, description will be given of a method of adjusting a frequency of the vibrator according to this embodiment and a method of manufacturing the vibrator.
The method of manufacturing the vibrator according to this embodiment includes the method of adjusting the frequency of the vibrator according to this embodiment. The method of manufacturing the vibrator according to this embodiment in
First, as illustrated in
Specifically, the vibrator element 5102 is fixed (joined) onto the connection terminals 5130 and 5132 which are provided to the base 5112 by using the conductive adhesive (joining member) 5134a.
Then, the conductive adhesive 5134a is dried in a temperature atmosphere of a predetermined temperature (approximately 180° C.), thereby vaporizing a solvent of the conductive adhesive 5134a.
Next, the conductive adhesive 5134a is subjected to a heating treatment (first annealing process S2).
For example, the base 5112 on which the vibrator element 5102 is mounted is introduced into an annealing furnace (not illustrated), and annealing of the conductive adhesive 5134a is carried out at a peak heating temperature of approximately 200° C. to 300° C. In the first annealing process S2, for example, annealing for 4 hours, which includes heating for 2 hours at the peak heating temperature, is carried out. In the first annealing process S2, the conductive fixing member 5134 can be formed by curing the conductive adhesive 5134a.
Here, in the first annealing process S2, annealing may be carried out in a vacuum atmosphere. When annealing is carried out in the vacuum atmosphere, it is possible to reduce the degree of oxidation of the excitation electrodes 5020a and 5020b. According to this, it is possible to suppress deterioration in aging characteristics. This is also true of a second annealing process S4 and a third annealing process S6 to be described later.
Next, the vibrator element 5102 and the conductive fixing member 5134 are cooled down to a predetermined temperature, and the annealing furnace is opened and ventilated (ventilation process S3).
Next, the conductive fixing member 5134 and the vibrator element 5102 are subjected to a heating treatment (second annealing process S4).
For example, the base 5112 on which the vibrator element 5102 is mounted is introduced into the annealing furnace, and a heating treatment is carried out with respect to the vibrator element 5102 and the conductive fixing member 5134. For example, the second annealing process S4 is carried out under the same temperature conditions and the same time conditions as in the first annealing process S2. In the second annealing process S4, discharging of an out-gas component in the conductive fixing member 5134 which is not sufficiently removed with the first annealing process S2, and removal of the out-gas component that is attached to the vibrator element 5102 are carried out, and stress distortion of the vibrator element 5102, which is not completely solved in the first annealing process S2, can be reduced.
Next, power that is higher than drive power during use of the vibrator element 5102 is applied to the vibrator element 5102 so as to strongly excite the vibrator element 5102 (strong excitation process S5-1).
Specifically, as illustrated in
Here, a drive level is power for oscillating the vibrator element 5102, and is expressed by P=I2×Re. In addition, I represents a current (effective value) that flows to the vibrator element, and Re represents equivalent series resistance of the vibrator element. The current I, which flows to the vibrator element, can be obtained by acquiring a waveform of a current flowing to the vibrator element by using an oscilloscope, and the like over the oscillation circuit.
Next, frequency adjustment of the vibrator element 5102 (vibrator 5100) is carried out (frequency adjustment process S5-2).
For example, although not illustrated, a probe of a measurement device is brought into contact with the external terminals 5140 and 5142 which are electrically connected to the excitation electrodes 5020a and 5020b, a monitor electrode (not illustrated), and the like to excite the vibrator element 5102, and an output frequency is measured. A drive level at this time is a drive level during typical use of the vibrator element. In addition, in a case where a frequency difference exists between an actual frequency that is measured, and a predetermined frequency, a part of the excitation electrodes 5020a and 5020b is etched (ion-milled) by irradiating the excitation electrodes 5020a and 5020b with an ion laser and the like to reduce a mass, thereby carrying out the frequency adjustment. In addition, the frequency adjustment may be carried out by forming a film on the excitation electrodes 5020a and 5020b so as to increase a mass.
Next, the conductive fixing member 5134 and the vibrator element 5102 are subjected to a heating treatment (third annealing process S6).
For example, the base 5112 on which the vibrator element 5102 is mounted is introduced into an annealing furnace, and a heating treatment is carried out with respect to the vibrator element 5102 and the conductive fixing member 5134. For example, in the third annealing process S6, annealing including heating for 45 minutes at a peak heating temperature of approximately 200° C. to 300° C. is carried out.
According to the third annealing process S6, discharging of the out-gas component in the conductive fixing member 5134 which is not sufficiently removed with the first annealing process S2 and the second annealing process S4, and removal of the out-gas component that is attached to the vibrator element 5102 are carried out, and stress distortion of the vibrator element 5102, which is not completely solved in the first annealing process S2 and the second annealing process S4, can be reduced. In addition, it is possible to reduce stress distortion of the vibrator element 5102 which is newly added in the frequency adjustment process S5-2.
In addition, the third annealing process S6 may not be carried out.
Next, as illustrated in
Next, characteristics of the vibrator 5100 are inspected (inspection process S8).
For example, although not illustrated, characteristics (drive level dependence (DLD) characteristics and the like) of the vibrator 5100 are measured by bringing a probe of a measurement device into contact with the external terminals 5140 and 5142 which are electrically connected to the excitation electrodes 5020a and 5020b, a monitor electrode (not illustrated), and the like.
Through the above-described processes, it is possible to manufacture the vibrator 5100.
For example, the method of adjusting the frequency of the vibrator 5100 according to this embodiment has the following characteristics.
The method of adjusting the frequency of the vibrator 5100 according to this embodiment includes the process S5-1 of strongly exciting the vibrator element 5102 by applying power that is higher than drive power during use of the vibrator element 5102 to the vibrator element 5102, and the process S5-2 of adjusting the frequency of the vibrator element 5102 after the process S5-1 of strongly exciting the vibrator element 5102. According to this, it is possible to reduce the CI value of the vibrator element 5102, and thus it is possible to improve the oscillation rate in the frequency adjustment process S5-2 (refer to “3. Experimental Example” to be described later). Accordingly, it is possible to improve a yield ratio during manufacturing of the vibrator 5100.
In the method of adjusting the frequency of the vibrator 5100 according to this embodiment, in the process S5-1 of strongly exciting the vibrator element 5102, power of 2.5 mW or more to 100 mW or less is applied to the vibrator element 5102. According to this, it is possible to reduce the CI value of the vibrator element 5102, and thus it is possible to improve the oscillation rate (refer to “3. Experimental Example” to be described later).
In the method of adjusting the frequency of the vibrator 5100 according to this embodiment, in the process S5-1 of strongly exciting the vibrator element 5102, power of 10 mW or more to 100 mW or less is applied to the vibrator element 5102. According to this, it is possible to further reduce the CI value of the vibrator element 5102, and thus it is possible to further improve the oscillation rate (refer to “3. Experimental Example” to be described later).
The method of manufacturing the vibrator 5100 according to this embodiment includes the method of adjusting the frequency of the vibrator 5100 according to this embodiment, and thus it is possible to improve a yield ratio during manufacturing.
Hereinafter, an experimental example will be described, and the invention will be described in more detail. In addition, the invention is not particularly limited by the following experimental example.
With regard to the method of manufacturing the vibrator 5100 described above, an experiment was carried out to investigate a relationship between the drive level during over-drive, and a variation ratio of the CI value before and after the over-drive.
Specifically, in the method of manufacturing the vibrator 5100 described above, the CI value before and after the over-drive was measured with respect to cases where the drive level DL during the over-drive in the strong excitation process S5-1 was 0.1 mW, 0.5 mW, 2.5 mW, 10 mW, and 100 mW, respectively. In addition, the vibrator was set to the AT-cut type vibrator, and an oscillation frequency was set to 16 MHz.
A method of obtaining the variation ratio of the CI value before and after the over-drive will be described in more detail. Here, description will be given of a case where DL is 0.1 mW as an example. First, in the method of manufacturing the vibrator 5100 as described above, a drive level DL of 0.01 mW during typical use was applied to the vibrator element before the strong excitation process S5-1 so as to measure the CI value. Next, in the strong excitation process S5-1, power in a drive level DL of 0.1 mW was applied for 1 second to 30 seconds, thereby strongly exciting the vibrator 5100 (over-drive). Next, a drive level DL of 0.01 mW during typical use was applied again to the vibrator element so as to measure the CI value. In this manner, a variation ratio of the CI value before and after the over-drive was obtained with respect to the case where DL was set to 0.1 mW.
The CI value before and after the over-drive was also measured with respect to other cases where the drive level DL was set to 0.5 mW, 2.5 mW, 10 mW, and 100 mW, respectively by the same method so as to obtain the variation ratio of the CI value before and after the over-drive.
In addition, for reference, the CI value was also measured with respect to a case where the drive level DL in the strong excitation process S5-1 was set to 0.01 mW, that is, a case where a drive level during typical use was applied without the strong excitation.
As illustrated in
Next, in the method of manufacturing the vibrator 5100 as described above, an experiment of investigating a relationship between the drive level during the over-drive and an oscillation rate after the over-drive was carried out.
Specifically, as is the case with the above-described first experimental example, an oscillation rate was measured with respect to cases where the drive level DL during the over-drive in the strong excitation process S5-1 was set to 0.1 mW, 0.5 mW, 2.5 mW, 10 mW, and 100 mW, respectively. In addition, the vibrator was set to an AT-cut type vibrator, and an oscillation frequency was set to 16 MHz.
In addition, the oscillation rate represents a ratio of normally oscillating vibrator elements to the total measurement number. In addition, the normally oscillating vibrator elements represent vibrator elements in which the CI value at DL of 0.01 mW satisfies negative resistance of an oscillation circuit. Here, an investigation was made whether or not 1000 vibrator elements normally oscillate for each drive level DL.
As illustrated in
In addition, in the over-drive in which a drive level DL of 100 mW was applied to the vibrator element, as described above, the CI value was reduced by 50%, and the oscillation rate became 100%, and thus a sufficient effect was obtained. According to this, it is preferable that the over-drive is carried out in a drive level of 100 mW or less so as to realize low power consumption.
In addition, when the method of manufacturing the vibrator as described above includes a vibrator formation process of forming the vibrator element 5102 before the vibrator element mounting process S1, and a joining process of connecting a semiconductor device 700 to be described later to the base 5112 at a position not interfering with the vibrator element 5102 through a joining member 510 to be described later before the sealing process S7, the above-described method becomes a method of manufacturing an oscillator.
According to this, the method of manufacturing the oscillator as described above includes a vibrator element formation process of forming the vibrator element 5102, a joining process of joining the base 5112 and the vibrator element 5102 through a joining member (conductive adhesive 5134a) (vibrator element mounting process S1), a strong excitation process of applying power, which is higher than drive power during use of the vibrator element 5102, to the vibrator element 5102 (strong excitation process S5-1), and a joining process of connecting the semiconductor device 700 to the base 5112 through the joining member 510.
In the method of manufacturing the oscillator as described above, as is the case with the method of manufacturing the vibrator, it is possible to reduce the CI value of the vibrator element 5102, and thus it is possible to improve a yield ratio during manufacturing.
As illustrated in
The vibrator element 100 includes a piezoelectric element 10, a first electrode 21 that is formed on a first main surface 10a of the piezoelectric element 10, and a second electrode 22 that is formed on a second main surface 10b of the piezoelectric element 10. With regard to the piezoelectric element 10, there is no particular limitation as long as the piezoelectric element 10 is formed from a material such as quartz crystal, ceramic, and PZT which have piezoelectric properties, and in this embodiment, description will be made with reference to the quartz crystal. Hereinafter, the piezoelectric element 10 is referred to as a quartz crystal element 10.
As illustrated in
The package 200 has insulating properties. For example, the package 200 is formed from ceramic, a resin, glass, and the like. Connection electrodes 610 are formed on the bottom 200b of the concave portion space 200a of the package 200, and external connection electrodes 620a and 620b, which are electrically connected to the connection electrodes 610 through an interconnection (not illustrated) formed on an inner side of the package 200, are formed on an external bottom surface 200c of the package 200.
In the vibrator element 100, the connection electrodes 21b and 22b are arranged in the concave portion space 200a of the package 200 to face the connection electrodes 610 and are connected thereto by a joining member 500 having conductivity. In addition, the lead 300 is fixed to an upper end surface 200d having a frame-shaped planar shape on an opening side of the concave portion space 200a of the package 200 through the seal member 400, and thus the concave portion space 200a is air-tightly sealed. In addition, for example, it is preferable that the concave portion space 200a is, for example, vacuum-sealed or filled with an inert gas, and is air-tightly sealed.
As described above, as the vibrator element 100 that is provided to the vibrator 1000 according to this embodiment, as illustrated in
As illustrated in
As illustrated in
As illustrated in
The vibrator element forming process (S10) is carried out to obtain a first vibrator element wafer 2020 including a plurality of first vibrator element portions 2110. In the vibrator element forming process (S10), a conductive metal film is formed on a surface of the vibration element wafer 2010 through deposition or sputtering, and as illustrated in
As illustrated in
First, as illustrated in
After applying the predetermined large power is applied to the first vibrator element portion 2110 for predetermined time, the connection terminals 3200a and 3200b are separated from the connection electrodes 21b and 22b. According to this, the power application process (S21) with respect to the first vibrator element portion 2110 is terminated, and a second vibrator element portion 2120 is formed. Then, the connection terminals 3200a and 3200b are moved to a next one of the first vibrator element portions 2110, and the power application process (S21) is carried out. In this manner, the power application process (S21) is sequentially carried out with respect to the entirety of the first vibrator element portions 2110 which are provided to the first vibrator element wafer 2020, thereby obtaining a second vibrator element wafer 2021 including a plurality of the second vibrator element portions 2120. Then, the process transitions to the inspection process (S22).
Since occurrence of breakage is predicted in a part of the second vibrator element portion 2120 due to application of power, which is higher than predetermined operation power of the second vibrator element portions 2120, in the power application process (S21), the inspection process (S22) inspects whether or not a predetermined operation is obtained. Although not illustrated, in the inspection process (S22), inspection terminals, which are connected to an inspection device, are brought into contact with the connection electrodes 21b and 22b to apply predetermined power to the connection electrodes 21b and 22b, thereby causing excitation. From an oscillation signal that is obtained, a predetermined quality, for example, a frequency equivalent series resistance value and the like are detected to determine whether or not the quality is good or bad.
The second vibrator element wafer 2021, of which the individual second vibrator element portions 2120 are subjected to the quality determination in the inspection process (S22), is subjected to the defective product removal process (S23). As illustrated in
As described above, the strong excitation process (S20) including the power application process (S21), the inspection process (S22), and the defective product removal process (S23) is carried out, and a second vibrator element wafer 2022, in which a plurality of the second vibrator element portions 2120 with a good quality are formed, is subjected to the subsequent individual piece division process (S30).
As is the case with the above-described defective product removal process (S23), the individual piece division process (S30) is a process of applying a pressing force F to each of the second vibrator element portions 2120 to fracture the cut-out portion 2010c from the second vibrator element wafer 2022 including the second vibrator element portions 2120 with a good quality, thereby taking out individual pieces of the vibrator elements 100. Each of the vibrator elements 100, which are divided into individual pieces in the individual piece division process (S30), is subjected to the accommodation process (S40). In addition, in a case where a mark that is recognizable with an image recognition method is formed on the surface of the detective vibrator element portion 2120F by using ink, a laser, and the like in the defective product removal process (S23), image recognition is carried out in the process of division into individual pieces, and the defective vibrator element portion 2120F is not taken out.
The accommodation process (S40) is a process of obtaining the vibrator 1000 (refer to
In the accommodation process (S40), first, mounting process (S41) is carried out. As illustrated in
When the vibrator element 100 is mounted in the concave portion space 200a of the package 200 through the mounting process (S41), the process transitions to the frequency adjustment process (S42). As illustrated in
The package 200, on which the vibrator element 100 adjusted to a predetermined frequency through the frequency adjustment process (S42) is mounted, is subjected to the sealing process (S43). As illustrated in
In addition, in a processing room (chamber) (not illustrated) which is maintained to a vacuum environment or an inert gas atmosphere environment, the lead 300 and the package 200 are air-tightly joined by a joining method such as seam welding. In this state, the sealing process (S43) is terminated, the accommodation process (S40) is terminated, and the vibrator 1000 is obtained. Then, the process transitions to the inspection process (S50).
In the inspection process (S50), inspection is carried out on the basis of predetermined specifications of the vibrator 1000 as a finished product. Although not illustrated, in the inspection process (S50), predetermined functional quality inspection, which is carried out by bringing terminals provided to an inspection device into contact with the external connection electrodes 620a and 620b, external appearance inspection with the naked eye or a microscope, and the like are carried out for quality determination.
With regard to a vibrator in the related art, there is also known a method of carrying out strong excitation, that is, so-called over-drive to improve adhesiveness between an excitation electrode and an element piece, but the strong excitation is typically carried out after sealing a vibrator element in a package. According to this method in the related art, foreign matter adhered to the vibrator element are shaken off into a sealed package inner space due to strong excitation, and thus the foreign matter collected in the package inner space are repetitively adhered to and detached from the vibrator element. Therefore, the repetitive adhesion and detachment become a cause for a variation in vibration characteristics of the vibrator element.
However, in the method of manufacturing the vibrator 1000 according to the second embodiment, the strong excitation process (S20) is carried out in a state of the vibrator element wafer 2020, and thus at least a part of foreign matter adhered to the vibrator element 100 is shaken off. According to this, it is possible to reduce a possibility that the foreign matter adhered to the vibrator element 100 are introduced into the package 200. Accordingly, it is possible to obtain the vibrator 1000 having stable vibration characteristics. In addition, when the strong excitation process (S20) of the second embodiment is carried out under the same conditions as in the strong excitation process (S5-1) of the first embodiment, the same effect as in the first embodiment is obtained.
As illustrated in
The IC 700 includes an external electrode 700b which is formed on one surface 700a of the IC 700 and is electrically connected to an electronic circuit (not illustrated) that is formed inside the IC 700. The external electrode 700b is disposed over an IC connection electrode 612, which is formed on the bottom 210d of the first concave portion space 210a of the package 210, to face the external electrode 700b of the IC 700, and is joined to the external electrode 700b through a joining member 510 having conductivity. According to this, the IC 700 is accommodated in the first concave portion space 210a of the package 210.
With regard to the vibrator element 100, each of connection electrodes 21b and 22b is arranged to face each of connection electrodes 611 which are formed on a stepped portion 210c that becomes the bottom of the second concave portion space 210b of the package 210, and is fixed and arranged by the joining member 500 having conductivity. In addition, the connection electrode 611 and the IC connection electrode 612 are electrically connected through an arrangement interconnection (not illustrated) that is formed inside the package 210. In addition, the IC connection electrode 612 is electrically connected to external connection electrodes 620a and 620b, which are formed on an external bottom surface 210e of the package 210, through an arrangement interconnection (not illustrated) that is formed inside the package 210.
Next, description will be given of a method of manufacturing the oscillator 1100. The method of manufacturing the oscillator 1100 according to this embodiment includes the same processes in the method of manufacturing the vibrator 1000 according to the second embodiment, that is, the same processes as in the flowchart illustrated in
The oscillator 1100, which is obtained by the manufacturing method according to this embodiment, includes the vibrator element 100 that is provided to the vibrator 1000 that is obtained by the manufacturing method according to the second embodiment. Accordingly, processes from the vibrator element forming process (S10) to the individual piece division process (S30) are the same between the second embodiment and the third embodiment illustrated in
An accommodation process (S40) is a process of obtaining the oscillator 1100 (refer to
In the mounting process (S41), first, the IC mounting process (S411) is carried out. As illustrated in
After the IC mounting process (S411), the process transitions to the vibrator element mounting process (S412). As illustrated in
After carrying out the mounting process (S41) including the IC mounting process (S411) and the vibrator element mounting process (S412), the process transitions to the frequency adjustment process (S42).
The frequency adjustment process (S42) and the sealing process (S43) are the same as in the method of manufacturing the vibrator 1000 according to the second embodiment. As illustrated in
After the frequency adjustment process (S42), the process transitions to the sealing process (S43). As illustrated in
After the accommodation process (S40) including the mounting process (S41), the frequency adjustment process (S42), and the sealing process (S43), the process transitions to the inspection process (S50). In the inspection process (S50), inspection is carried out on the basis of predetermined specifications of the oscillator 1100 as a finished product. Although not illustrated, in the inspection process (S50), predetermined functional quality inspection, which is carried out by bringing terminals provided to an inspection device into contact with the external connection electrodes 620a and 620b, external appearance inspection with the naked eye or a microscope, and the like are carried out for quality determination.
In the method of manufacturing the oscillator 1100 according to the third embodiment as described above, the strong excitation process (S20) is carried out in a state of the vibrator element wafer 2020, and thus at least a part of foreign matter adhered to the vibrator element 100 is shaken off. According to this, it is possible to reduce a possibility that the foreign matter adhered to the vibrator element 100 are introduced into the package 210. Accordingly, it is possible to obtain the oscillator 1100 having stable vibration characteristics.
In addition, in the related art, in a case of an oscillator in which the strong excitation is typically carried out after sealing a semiconductor device (IC) and a vibrator element in a package, large power for strong excitation also flows to the semiconductor device, and thus there is a concern that the semiconductor device may be broken. However, in the method of manufacturing the oscillator 1100 according to this embodiment, the strong excitation process (S20) is carried out at a part stage of the vibrator element 100, and thus it is possible to obtain a stable-quality oscillator 1100 in which the IC 700 to be mounted in the accommodation process (S40) after the strong excitation process (S20) is not affected by the strong excitation at all. In addition, when the strong excitation process (S20) of the third embodiment is carried out under the same conditions as in the strong excitation process (S5-1) of the first embodiment, the same effect as in the first embodiment is obtained.
In addition, in the method of manufacturing the vibrator 1000 according to the second embodiment, and in the method of manufacturing the oscillator 1100 according to the third embodiment, large power for the strong excitation is applied to the first vibrator element portion 2110 in a type of the vibrator element wafer 2020 (refer to
That is, as disclosed in the related art (for example, JP-A-2004-297737), in a type in which a vibrator element, or the vibrator element and an IC chip are disposed in a cavity, and the vibrator element is strongly excited, in a case where the vibrator element or the IC chip malfunctions due to the strong excitation, a defective loss is added to the cost of the vibrator element, thereby leading a large loss cost including the part cost of the package, the IC, and the like other than the vibrator element, and the number of processing processes (processing cost). However, according to the above-described manufacturing methods, it is possible to avoid the loss cost.
The above-described embodiments are illustrative only, and various modifications can be made without limitation thereto. For example, in the above-described embodiments, as an example of the substrate, the quartz crystal is used as a material having piezoelectric properties, but a silicon semiconductor substrate may be used without limitation thereto. In a case of using the silicon semiconductor substrate as the substrate, electrostatic operation with Coulomb's force may be used as excitation means.
The invention includes a configuration (for example, a configuration in which a function, a method, and a result are the same, or a configuration in which an object and an effect are the same) that is substantially the same as the configuration described in the embodiments. In addition, the invention includes a configuration in which non-essential portions of the configuration described in the embodiments are substituted with other portions. In addition, the invention includes a configuration capable of exhibiting the same operational effect as in the configuration described in the embodiments, and a configuration capable of accomplishing the same object. In addition, the invention includes a configuration in which a technology of the related art is added to the configuration described in the embodiments.
The entire disclosure of Japanese Patent Application Nos. 2015-019619, filed Feb. 3, 2015 and 2015-055792, filed Mar. 19, 2015 are expressly incorporated by reference herein.
Number | Date | Country | Kind |
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2015-019619 | Feb 2015 | JP | national |
2015-055792 | Mar 2015 | JP | national |