JP6457736B2 - Method for manufacturing crystal resonator element - Google Patents

Description

  The present invention relates to a technique for manufacturing a quartz crystal vibrating element such as a thickness shear vibrating element, and more particularly to a frequency adjusting method for a quartz crystal vibrating element performed at a stage of a quartz wafer.

  There are various modes of oscillation in the crystal resonator element depending on the cut angle of the crystal. Here, as an example of a quartz crystal vibration element, a thickness shear vibration element made of an AT cut plate will be described. In this crystal resonator element, electrodes are formed on the front and back surfaces of a crystal piece, the polarization direction is parallel to the plate surface, and a voltage is applied in the plate thickness direction.

  The oscillation frequency of the crystal resonator element is mainly determined by the thickness of the crystal piece and the thickness of the electrode film. That is, since the oscillation frequency is inversely proportional to the thickness of the crystal piece, it decreases as the thickness increases, and decreases as the mass of deposits on the crystal piece increases. Therefore, the oscillation frequency decreases as the electrode film increases.

  FIG. 8 is a process diagram showing a general method for manufacturing a crystal resonator element. Hereinafter, description will be given based on this drawing.

  A general method for manufacturing a crystal resonator element includes the following steps. A crystal wafer polishing step 201 for uniformizing the thickness between crystal wafers and in crystal wafers by polishing the crystal wafers. A wet etching step 202 for processing the polished crystal wafer into a shape in which a large number of crystal pieces are connected to a frame by wet etching. An electrode forming step 203 for obtaining a crystal resonator element by forming electrodes on both sides of each crystal piece. A package mounting step 204 in which each crystal resonator element is separated from the frame and mounted on the package one by one. A frequency adjustment step 205 for adjusting the oscillation frequency of each crystal resonator element one by one after packaging.

  In the frequency adjustment step 205, the oscillation frequency of the crystal resonator element is measured one by one, and depending on the difference from the target frequency, for example, a part of the electrode film is shaved with a laser beam or an ion beam, or the electrode film is removed by vapor deposition or the like. Or add it partially.

  In addition, there are a method of adjusting the oscillation frequency before separating from the frame, and a method of adjusting the oscillation frequency in two steps, coarse adjustment and fine adjustment. Both methods measure the oscillation frequency of the crystal resonator element one by one. Thus, there is no change in the adjustment (see, for example, Patent Document 1).

JP2011-250226A (FIG. 9 etc.) JP 2006-101317 A (paragraph 0005 and the like)

  However, in the conventional frequency adjustment method, the oscillation frequency is measured one by one for each crystal resonator element, and a part of the electrode film is scraped off by, for example, laser light, so that the frequency adjustment of all the crystal resonator elements is completed. It took a considerable amount of time.

  Accordingly, an object of the present invention is to provide a frequency adjustment method for a crystal resonator element that can shorten the time required for frequency adjustment of the crystal resonator element.

The method for manufacturing a quartz crystal resonator element according to the present invention includes
The method of manufacturing a water crystal vibrating element you preparing a plurality of the quartz element from a single crystal wafer,
A quartz wafer polishing step for polishing the quartz wafer;
A wet etching step of processing the polished crystal wafer into a shape in which a large number of crystal pieces are connected to a frame by wet etching;
Forming an electrode film on both sides of each crystal piece to obtain the crystal resonator element; and
A dry etching step of removing a part of the electrode film in the opening by performing dry etching on the crystal wafer using a mask having an opening;
A package mounting step of separating the crystal resonator element from the frame and mounting the crystal resonator elements one by one on a package,
A frequency adjustment step of adjusting the oscillation frequency of the crystal resonator element mounted on the package one by one,
The mask is prepared by examining in advance a frequency reduction region in which the oscillation frequency is lowered in the crystal wafer, with respect to the crystal resonator manufactured under the same device and conditions as those used in the respective steps. The opening is formed at a position where
It is characterized by that.

  According to the present invention, since a part of the crystal wafer is collectively removed by dry etching with respect to the frequency lowering region in the crystal wafer, the frequency in the process of adjusting the frequency of the crystal resonator elements one by one later Adjustment amount can be reduced. In other words, prior to the step of adjusting the frequency individually for each crystal resonator element (fine adjustment), the frequency of all crystal resonator elements is adjusted collectively (coarse adjustment). The time required for frequency adjustment can be shortened.

FIG. 5 is a process diagram illustrating a method for manufacturing a crystal resonator element using the frequency adjustment method according to the first embodiment. FIG. 2A is a plan view showing a quartz wafer, FIG. 2B is a cross-sectional view taken along line IIb-IIb in FIG. 2A, and FIG. ] Is a plan view showing a mask. FIG. 3A is a schematic diagram showing a dry etching apparatus, FIG. 3B is a plan view showing a state in which a mask is overlaid on a crystal wafer, and FIG. C] is a sectional view taken along line IIIc-IIIc in FIG. 3B. 6 is a graph showing the effect of the frequency adjustment method of the first embodiment. FIG. 5A shows a plan view of a quartz wafer, FIG. 5B is a cross-sectional view taken along the line Vb-Vb in FIG. 5A, and FIG. ] Is a plan view showing a mask. FIG. 10 is a process diagram illustrating a method for manufacturing a crystal resonator element using the frequency adjustment method according to the third embodiment. FIGS. 7A and 7B are plan views showing a crystal wafer, FIG. 7B is a sectional view taken along line VIIb-VIIb in FIG. 7A, and FIG. ] Is a plan view showing a mask. It is process drawing which shows the manufacturing method of a general crystal oscillation element.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the accompanying drawings. In the present specification and drawings, the same reference numerals are used for substantially the same components. The shapes depicted in the drawings are drawn so as to be easily understood by those skilled in the art, and thus do not necessarily match the actual dimensions and ratios.

  FIG. 1 is a process diagram illustrating a method for manufacturing a crystal resonator element using the frequency adjustment method according to the first embodiment. Hereinafter, description will be given based on this drawing.

  The manufacturing method of the crystal resonator element includes the following steps. A crystal wafer polishing step 201 for uniformizing the thickness between crystal wafers and in crystal wafers by polishing the crystal wafers. A wet etching step 202 for processing the polished crystal wafer into a shape in which a large number of crystal pieces are connected to a frame by wet etching. An electrode forming step 203 for obtaining a crystal resonator element by forming electrodes on both sides of each crystal piece. Mask manufacturing process 101 and dry etching process 102 (described later). A package mounting step 204 in which each crystal resonator element is separated from the frame and mounted on the package one by one. A frequency adjustment step 205 for adjusting the oscillation frequency of each crystal resonator element one by one after packaging. The frequency adjustment method 100 according to the first embodiment includes a mask manufacturing process 101 and a dry etching process 102.

  Next, the mask manufacturing process 101 will be described. FIG. 2 shows a mask manufacturing process in the frequency adjustment method of the first embodiment, FIG. 2 [A] is a plan view showing a quartz wafer, FIG. 2 [B] is a plan view showing a mask, and FIG. 2 [C] is a quartz wafer. It is sectional drawing which expands and shows a part of. Hereinafter, a description will be given based on FIG. 1 and FIG.

  In the mask manufacturing step 101, the frequency reduction region 11 where the oscillation frequency is lowered in the crystal wafer 10 is examined in advance, and the mask 20 having the opening 21 corresponding to the frequency reduction region 11 is prepared. An electrode film 12 is formed on the quartz wafer 10.

  The quartz wafer 10 is made of an AT cut plate and has a circular plane. An orientation flat 13 is formed on the −X surface at the periphery of the quartz wafer 10. The diameter of the crystal wafer is, for example, 25.4 to 50.8 mm (1 to 2 inches), and the thickness of the crystal wafer 10 is, for example, 50 μm.

  In addition, the crystal wafer 10 is formed with a plurality of crystal resonator elements 14 and a frame 15 connecting the plurality of crystal resonator elements 14. Each crystal resonator element 14 is formed with an electrode film 12. The material of the mask 20 is glass, for example.

  In the first embodiment, the frequency reduction region 11 is formed in a band shape parallel to the orientation flat 13 and passing through the center of the crystal wafer 10. Therefore, the opening 21 corresponding to the frequency lowering region 11 is also in a band shape passing through the center of the mask 20.

  Here, a process until the electrode film 12 is formed on the quartz wafer 10 will be described.

  In the crystal wafer polishing step 201, the crystal wafer 10 cut out from the crystal ingot is polished to a predetermined thickness using, for example, a double-side polishing apparatus including a planetary gear mechanism. However, since any polishing apparatus has so-called unevenness of wrinkles, the thickness of the crystal wafer 10 varies regularly. For example, the thickness of the crystal wafer 10 is non-uniform so that the peripheral side of the crystal wafer 10 is thin and becomes thicker toward the center of the crystal wafer 10. Such variation in the thickness of the crystal wafer 10 leads to the frequency distribution of the crystal resonator element 14 in the crystal wafer 10. That is, the oscillation frequency of the crystal resonator element 14 formed in the region where the thickness of the quartz wafer 10 is thick decreases, and conversely, the oscillation frequency of the crystal resonator element 14 formed in the region where the thickness of the crystal wafer 10 is thin increases.

  In the wet etching step 202, the crystal wafer 10 on which the corrosion-resistant film pattern is formed is immersed in an etching solution such as hydrofluoric acid, thereby wet etching the crystal wafer 10. The corrosion resistant film is a two-layer film in which gold is formed on, for example, chromium. As a result, the portion of the crystal wafer 10 that is not covered with the corrosion-resistant film is removed, and the crystal wafer 10 is processed into a shape in which a large number of crystal pieces are connected to the frame 15. Although simplified in the drawing, the crystal piece that becomes the crystal resonator element 14 has a size of about 1 mm × 0.8 mm, for example, and is separated from the frame 15 except for the connecting portion for folding, and the vibration surface Is as thin as about 10 to 15 μm.

  In the electrode forming step 203, the electrode film 12 such as gold is formed on both surfaces of the crystal wafer 10 using a film forming apparatus such as a sputtering apparatus or a vapor deposition apparatus. However, since any film forming apparatus has an uneven film formation, a so-called “wrinkle”, the thickness of the electrode film 12 varies regularly. For example, the thickness of the electrode film 12 is non-uniform so that the peripheral side of the crystal wafer 10 is thin and becomes thicker toward the center of the crystal wafer 10. Such variation in the thickness of the electrode film 12 leads to the frequency distribution of the crystal resonator element 14 in the crystal wafer 10. In other words, the crystal oscillation element 14 formed in the region where the electrode film 12 is thick has a low oscillation frequency, and conversely, the crystal oscillation element 14 formed in the region where the electrode film 12 is thin has a high oscillation frequency. Although simplified in the drawing, the electrode film 12 is processed into a predetermined pattern such as an excitation electrode, a pad electrode, and a wiring by photolithography and etching.

  Thus, the position where the frequency drop region 11 occurs in the crystal wafer 10 becomes clear by, for example, statistically examining the “waist” of the polishing apparatus or the film forming apparatus. That is, if the crystal resonator element 14 is manufactured with the same apparatus and the same conditions, the frequency lowering region 11 is generated at the same position on any crystal wafer 10. If the position becomes clear, the position corresponding to the frequency lowering region 11 is obtained. The mask 20 is obtained by forming the opening 21 in the substrate. The mask 20 can be produced by, for example, subjecting a glass plate to wet etching with photolithography and hydrofluoric acid, and can be used any number of times until the lifetime is reached.

  Next, the dry etching process 102 will be described. FIG. 3 shows a dry etching process in the frequency adjustment method of the first embodiment, FIG. 3 [A] is a schematic view showing a dry etching apparatus, and FIG. 3 [B] is a plan view showing a state in which a mask is overlaid on a crystal wafer. FIG. 3C is a sectional view taken along line IIIc-IIIc in FIG. 3B. Hereinafter, description will be given with reference to FIGS.

  In the dry etching step 102, a part of the crystal wafer 10 in the frequency lowering region 11 is removed by performing dry etching on the crystal wafer 10 using the mask 20. At this time, a part of the electrode film 12 is scraped off as a part of the crystal wafer 10.

  The dry etching apparatus 30 shown as an example in FIG. 3A is a general parallel plate type plasma etching apparatus including a vacuum chamber 31, a high-frequency power source 32, an upper electrode 33, a lower electrode 34, and the like. It is what is called. The dry etching apparatus 30 operates as follows. First, the crystal wafer 10 is placed on the lower electrode 34 in the vacuum chamber 31, and the mask 20 is placed thereon. That is, as shown in FIGS. 3B and 3C, these are fixed on the lower electrode 34 in a state where the mask 20 is superimposed on the crystal wafer 10. Subsequently, when the vacuum chamber 31 is evacuated to a predetermined degree of vacuum, argon gas 35 is introduced into the vacuum chamber 31 and high-frequency power is supplied from the high-frequency power source 32 between the upper electrode 33 and the lower electrode 34. To do. Then, a plasma 36 of argon gas 35 is generated in the space between the upper electrode 33 and the lower electrode 34. As a result, the ionized argon gas 35 is attracted to the lower electrode 34, hits the crystal wafer 10 through the opening 21 of the mask 20, and blows off the metal particles constituting the electrode film 12.

  As a result, the electrode film 12 is etched. At this time, the larger the difference between the oscillation frequency of the frequency lowering region 11 and the target frequency, the larger the etching amount. The etching amount is adjusted by, for example, the etching time. This is because the etching amount increases as the etching time increases.

  In the dry etching step 102, only the electrode film 12 on one side is etched, but the electrode film 12 on both sides may be etched by turning the quartz wafer 10 upside down, for example. In that case, an increase in the crystal impedance value due to an increase in the electrical resistance of only the electrode film 12 on one side can be suppressed.

  In FIG. 1, the frequency adjustment method 100 according to the first embodiment is inserted between the electrode formation step 203 and the package mounting step 204, but between the crystal wafer polishing step 201 and the wet etching step 202, Alternatively, it may be inserted between the wet etching process 202 and the electrode forming process 203. In that case, in the dry etching step 102, not the electrode film 12 but the crystal is etched. Further, the frequency adjustment method 100 of the first embodiment may be inserted between the film formation and the patterning in the electrode formation step 203.

  Next, the operation and effect of the frequency adjustment method of the first embodiment will be described.

  (1) Since a part of the crystal wafer 10 is collectively removed by dry etching with respect to the frequency lowering region 11 in the crystal wafer 10, a frequency adjustment step of adjusting the frequency of the crystal resonator element 14 one by one later The amount of frequency adjustment at 205 can be reduced. In other words, prior to the frequency adjustment step 205 (fine adjustment) for individually adjusting the frequency for each crystal resonator element 14, the frequency is adjusted (coarsely adjusted) for all the crystal resonator elements 14 at once. The time required for frequency adjustment of the crystal resonator element 14 can be shortened, and the frequency adjustment step 205 can be omitted in some cases. In recent years, as the size of the crystal resonator element 14 and the size of the crystal wafer 10 have increased, the number of crystal resonator elements 14 formed on one crystal wafer 10 has increased. The effect of Form 1 becomes more prominent.

  (2) It is known that the characteristics of the crystal resonator element 14 deteriorate due to laser light, ion beam, or the like in the frequency adjusting step 205 (see, for example, Patent Document 2). That is, since unevenness is formed on the surface of the electrode film 12 by laser light, ion beam, or the like, the thickness and mass distribution of the electrode film 12 as a whole becomes non-uniform. As a result, for example, the crystal impedance (CI) value of the main vibration changes, and the spurious (SP) ratio deteriorates. According to the first embodiment, since the amount of frequency adjustment in the frequency adjustment step 205 can be reduced, deterioration of the crystal resonator element 14 can also be suppressed. In the dry etching step 102, the entire electrode film 12 of one crystal resonator element 14 is evenly cut, so that no irregularities are formed on the surface of the electrode film 12.

  (3) In the mask manufacturing process 101, the frequency reduction region 11 is examined for the crystal wafer 10 on which the electrode film 12 is formed, and in the dry etching process 102, a part of the electrode film 12 is scraped off as a part of the crystal wafer 10. In this case, since the variation in the oscillation frequency due to the variation in the thickness of the electrode film 12 added to the variation in the thickness of the crystal wafer 10 can be adjusted, the variation in the oscillation frequency can be adjusted more accurately. Further, damage to the crystal due to dry etching on the crystal can be avoided.

  (4) The graph of FIG. 4 shows an example of the effect of the frequency adjustment method of the first embodiment by the cumulative frequency of the oscillation frequency. In FIG. 4, the horizontal axis represents the oscillation frequency [MHz], and the vertical axis represents the percentage [%]. With respect to all the crystal resonator elements 14 obtained from one crystal wafer 10, the oscillation frequency before adjustment using the frequency adjustment method of the first embodiment (before adjustment) is set to ◯, and the frequency adjustment method of the first embodiment The oscillation frequency after adjustment (after adjustment) is plotted with □. As is apparent from FIG. 4, the crystal resonator element 14 having a high oscillation frequency before adjustment does not change after adjustment, whereas the crystal resonator element 14 having a low oscillation frequency before adjustment has a high oscillation frequency after adjustment. Yes. As a result, the difference between the maximum value and the minimum value of the oscillation frequency was 10800 ppm before the adjustment, but decreased to 6600 ppm after the adjustment. Thus, the effect of the first embodiment was confirmed experimentally.

  Next, a frequency adjustment method according to the second embodiment will be described. 5 shows a mask manufacturing process in the frequency adjustment method of Embodiment 2, FIG. 5A is a plan view showing a quartz wafer, FIG. 5B is a cross-sectional view taken along the line Vb-Vb in FIG. FIG. 5C is a plan view showing the mask. Hereinafter, description will be given based on this drawing.

  In the mask manufacturing process according to the second embodiment, a frequency reduction region 41 where the oscillation frequency is lowered in the quartz wafer 40 is examined in advance, and a mask 50 having an opening 51 corresponding to the frequency reduction region 41 is prepared. An electrode film 12 is formed on the crystal wafer 40.

  In the second embodiment, a frequency reduction region 41 is generated on the peripheral side of the crystal wafer 40. Therefore, the opening 51 corresponding to the frequency lowering region 41 is also in an annular shape surrounding the center of the mask 50.

  Other configurations, operations, and effects of the second embodiment are the same as those of the first embodiment.

  Next, the frequency adjustment method of Embodiment 3 will be described. FIG. 6 is a process diagram illustrating a method for manufacturing a crystal resonator element using the frequency adjustment method according to the third embodiment. 7 shows a mask manufacturing process in the frequency adjustment method of Embodiment 3, FIG. 7A is a plan view showing a quartz wafer, FIG. 7B is a sectional view taken along line VIIb-VIIb in FIG. FIG. 7C is a plan view showing the mask. Hereinafter, these drawings will be described with reference to FIGS.

  As shown in FIG. 6, the frequency adjustment method 110 according to the third embodiment includes mask manufacturing steps 101 and 111 and dry etching steps 102 and 112.

  The frequency lowering region 11, the opening 21, and the mask 20 described below are shown in FIG. 2, and the frequency lowering region 61, the opening 71, and the mask 70 are shown in FIG. The oscillation frequency fa of each crystal resonator element 14 in the frequency reduction region 11 is f1 ≦ fa <f2, and the oscillation frequency fb of each crystal resonator element 14 in the frequency decrease region 61 (excluding the frequency decrease region 11) is f2. ≦ fb <f3.

  In the mask manufacturing steps 101 and 111, a plurality of frequency lowering regions 11 and 61 corresponding to the degree to which the oscillation frequency is lowered in the quartz wafer 10 are examined in advance, and openings corresponding to the plurality of frequency lowering regions 11 and 61, respectively. A plurality of masks 20 and 70 having 21 and 71 are prepared. In other words, in the mask manufacturing step 101, as shown in FIG. 2, a frequency reduction region 11 where the oscillation frequency is lowered in the crystal wafer 10 is examined in advance, and a mask 20 having an opening 21 corresponding to the frequency reduction region 11 is manufactured. Keep it. In the mask manufacturing step 111, as shown in FIG. 7, the frequency reduction region 61 where the oscillation frequency is lowered in the crystal wafer 10 is examined in advance, and a mask 70 having an opening 71 corresponding to the frequency reduction region 61 is prepared. .

  In the third embodiment, the two frequency reduction regions 11 and 61 are examined, and two masks 20 and 70 are produced. The frequency reduction region 11 is a region where the oscillation frequency is most reduced. The frequency decrease region 61 (excluding the frequency decrease region 11) is a region where the oscillation frequency decreases next. The frequency reduction region 61 includes a band-shaped frequency reduction region 11 that is parallel to the orientation flat 13 and passes through the center of the crystal wafer 10, and has a wide band shape that sandwiches the frequency reduction region 11. The opening 71 corresponding to the frequency lowering region 61 also includes the band-shaped opening 21 and has a wide band shape that sandwiches the opening 21.

  In the dry etching steps 102 and 112, the quartz wafer 10 is partially etched by sequentially using the plurality of masks 20 and 70, thereby removing a part of the quartz wafer 10 in the plurality of frequency reduction regions 11 and 61. At this time, a part of the electrode film 12 is scraped off as a part of the crystal wafer 10. In other words, in the dry etching step 102, the quartz wafer 10 in the frequency lowering region 11 is partly scraped off by performing dry etching on the quartz wafer 10 using the mask 20. In the dry etching step 112, a part of the crystal wafer 10 in the frequency lowering region 61 is scraped off by performing dry etching on the crystal wafer 10 using the mask 70.

  Since the opening 71 of the mask 70 has a shape including the opening 21 of the mask 20, the frequency reduction region 11 is etched twice in the dry etching steps 102 and 112, and the frequency reduction region 61 (the frequency reduction region 11 is changed). Is removed once in the dry etching step 112. That is, since the frequency reduction region 11 is a region where the oscillation frequency is the lowest, the etching amount is the largest. Since the frequency decrease region 61 (excluding the frequency decrease region 11) is the region where the oscillation frequency decreases next, the etching amount is the next largest.

  In the third embodiment, dry etching is first performed using the mask 20, and then dry etching is performed using the mask 70. On the contrary, dry etching is performed using the mask 70 first. Subsequently, dry etching may be performed using the mask 20.

  Next, the operation and effect of the frequency adjustment method of the third embodiment will be described.

  A frequency lowering region 61 in which a part of the crystal wafer 10 is scraped off by dry etching twice with respect to the frequency lowering region 11 in the crystal wafer 10 where the oscillation frequency is lowest, and the oscillation frequency is next lowered in the crystal wafer 10. Since part of the crystal wafer 10 is scraped off by one dry etching (excluding the frequency reduction region 11), the frequency adjustment amount in the subsequent frequency adjustment step 205 can be further reduced. That is, in order to adjust (roughly adjust) the frequency in two stages for all the crystal resonator elements 14 prior to the frequency adjustment step 205 (fine adjustment) for adjusting the frequency individually for each crystal resonator element 14. Further, the time required for frequency adjustment of the crystal resonator element 14 can be further shortened, and in some cases, the frequency adjustment step 205 can be omitted. In recent years, as the size of the crystal resonator element 14 and the size of the crystal wafer 10 have increased, the number of crystal resonator elements 14 formed on one crystal wafer 10 has increased. The effect of form 3 becomes even more pronounced.

  Other configurations, operations, and effects of the third embodiment are the same as those of the first embodiment. In the third embodiment, the two frequency lowering regions 11 and 61 are examined, two masks 20 and 70 are manufactured, and dry etching is performed twice. However, three or more frequency lowering regions are examined. Three or more masks may be produced and dry etching may be performed three or more times.

  Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. For example, in each of the embodiments described above, the manufacturing process of the thickness shear vibration element is taken up, but the present invention is also applicable to the manufacturing process of other crystal vibration elements such as a tuning fork type bending vibration element and a contour sliding vibration element. Further, the present invention includes a combination of some or all of the configurations of the above-described embodiments as appropriate.

DESCRIPTION OF SYMBOLS 10 Crystal wafer 11 Frequency fall area | region 12 Electrode film 13 Orientation flat 14 Crystal oscillator 15 Frame 20 Mask 21 Opening 30 Dry etching apparatus 31 Vacuum chamber 32 High frequency power supply 33 Upper electrode 34 Lower electrode 35 Argon gas 36 Plasma 100 Frequency adjustment method 101 Mask manufacturing process 102 Dry etching process 201 Crystal wafer polishing process 202 Wet etching process 203 Electrode formation process 204 Package mounting process 205 Frequency adjustment process 40 Crystal wafer 41 Frequency reduction region 50 Mask 51 Opening 61 Frequency reduction region 70 Mask 71 Opening 110 Frequency adjustment method 111 Mask manufacturing process 112 Dry etching process

Claims (2)

The method of manufacturing a water crystal vibrating element you preparing a plurality of the quartz element from a single crystal wafer,
A quartz wafer polishing step for polishing the quartz wafer;
A wet etching step of processing the polished crystal wafer into a shape in which a large number of crystal pieces are connected to a frame by wet etching;
Forming an electrode film on both sides of each crystal piece to obtain the crystal resonator element; and
A dry etching step of removing a part of the electrode film in the opening by performing dry etching on the crystal wafer using a mask having an opening;
A package mounting step of separating the crystal resonator element from the frame and mounting the crystal resonator elements one by one on a package,
A frequency adjustment step of adjusting the oscillation frequency of the crystal resonator element mounted on the package one by one,
The mask is prepared by examining in advance a frequency reduction region in which the oscillation frequency is lowered in the crystal wafer, with respect to the crystal resonator manufactured under the same device and conditions as those used in the respective steps. The opening is formed at a position where
A method for manufacturing a quartz crystal resonator element. The mask examines a plurality of frequency reduction region corresponding to the extent that lower the oscillation frequency within the crystal wafer preliminarily prepare a plurality having openings respectively corresponding to the plurality of frequency reduction region,
In the dry etching step, by performing dry etching using the plurality of masks sequentially with respect to the crystal wafer, a part of the crystal wafer in the plurality of frequency reduction regions is scraped off,
A method for manufacturing a crystal resonator element according to claim 1 .

Images