JP2012187689A - Method for polishing outer periphery of wafer, method for manufacturing piezoelectric vibrating piece, and piezoelectric vibrating piece, piezoelectric vibrator, oscillator, electronic device, and radio-controlled timepiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for polishing an outer periphery of a wafer that can improve production efficiency and also prevent the occurrence of cracks, chipping and the like to improve production yield, and to provide a method for manufacturing a piezoelectric vibrating piece, and a piezoelectric vibrating piece, a piezoelectric vibrator, an oscillator, an electronic device, and a radio-controlled timepiece.SOLUTION: The method for polishing an outer periphery of a wafer includes: a wafer setting step of holding a wafer W from both surface sides in a thickness direction of the wafer by a pair of cutting tables 205; an abutting step of disposing a polishing member 202 so that a longitudinal direction of the polishing member is arranged along the thickness direction of the wafer W to bring the polishing member into abutment on an outer periphery W1 of the wafer W; and a polishing step of reciprocate the polishing member 202 along the longitudinal direction while rotating the wafer W by the cutting tables 205, to polish the wafer W.

Description

  The present invention relates to a method for polishing a wafer outer peripheral surface, a method for manufacturing a piezoelectric vibrating piece, a piezoelectric vibrating piece, a piezoelectric vibrator, an oscillator, an electronic device, and a radio timepiece.

2. Description of the Related Art In recent years, a piezoelectric vibrator using a crystal or the like is used as a time source, a timing source such as a control signal, a reference signal source or the like in a mobile phone or a portable information terminal device. Various types of piezoelectric vibrators of this type are known. For example, one having a tuning fork type piezoelectric vibrating piece, one having a piezoelectric vibrating piece that vibrates in thickness, and the like are known.
By the way, the above-described piezoelectric vibrating piece is formed by using crystal which is a piezoelectric body. Specifically, the surface of the raw stone made of quartz is first ground by rotary grinding or a grinding wheel, and then the raw stone is cut at a desired cutting angle to produce a wafer having a desired thickness and surface condition. To do. Thereafter, the wafer is washed and dried, and then the outer shape of the piezoelectric vibrating piece is formed using a photolithography technique or the like, and an electrode is formed by patterning a metal film on the wafer. Thus, a plurality of piezoelectric vibrating pieces are produced from one wafer.

By the way, fine chips, cracks, and the like remain on the surface of the rough ore after grinding, and there is a possibility that large chips, cracks, etc. may occur in the wafer starting from these chips and cracks in the subsequent process. Therefore, in the manufacturing process of the piezoelectric vibrating piece, chamfering is performed on the outer peripheral surface of the wafer in order to suppress chipping or cracking of the wafer after cutting.
As such a method, for example, as disclosed in Patent Documents 1 and 2, a plurality of wafers are once laminated via wax or an adhesive, and the outer peripheral surface of the laminated wafer laminate is polished with a rotating brush. It has been known.
A method of polishing the outer peripheral surface of a wafer with a grindstone is also known. Specifically, as shown in FIG. 22, the wafer W is sucked by the suction table 301 and the outer peripheral surface W <b> 1 of the wafer W is brought into contact with a concave groove 303 formed on the outer peripheral surface of the grindstone 302. Then, the outer peripheral surface W1 of the wafer W can be polished following the shape of the inner surface of the concave groove 303 by rotating the wafer W and the grindstone 302 about the axis.

JP-A-6-310479 JP 2006-231486 A

However, among the above-described polishing methods, the method using a rotating brush has a problem that it leads to a decrease in manufacturing efficiency because a process of bonding wafers and the like are added.
In the method using a grindstone, a relatively thick wafer such as a silicon wafer can be polished, but a quartz wafer used for manufacturing a piezoelectric vibrator is very thin (for example, about 100 μm to 200 μm). Therefore, there is a problem that cracks, chips, etc. occur during polishing.

  Therefore, the present invention has been made in view of the above-described problems, and it is possible to improve the manufacturing efficiency and suppress the occurrence of cracks, chips, etc. and improve the yield of the wafer outer peripheral surface, and the manufacture of the piezoelectric vibrating piece. A method, a piezoelectric vibrating piece, a piezoelectric vibrator, an oscillator, an electronic device, and a radio timepiece are provided.

In order to solve the above-described problems, the present invention provides the following means.
A method for polishing an outer peripheral surface of a wafer according to the present invention is a polishing method for an outer peripheral surface of a wafer using a belt-shaped polishing member, and the wafer is formed by a holding means including a pair of rotatable holding members. A wafer setting step of clamping the polishing member from both sides in the thickness direction, an abutting step of bringing the polishing member into contact with the outer peripheral surface of the wafer with the longitudinal direction of the polishing member being along the circumferential direction of the wafer, and the holding A polishing step of polishing the entire circumference of the outer peripheral surface of the wafer using a rotating operation of rotating the wafer by means and a reciprocating operation of reciprocating the polishing member in the longitudinal direction. It is characterized by that.

According to this configuration, unlike the method using the conventional rotating brush described above, it is not necessary to stack the wafers, so that the manufacturing process can be reduced and the manufacturing efficiency can be improved.
In particular, by polishing the outer peripheral surface of the wafer with a band-shaped polishing member, the polishing member can be slidably brought into contact with the outer peripheral shape of the wafer, so that the wafer is chipped or cracked during the polishing process. The outer peripheral surface of the wafer can be polished with high accuracy while suppressing the above.
In addition, polishing is performed with a pair of holding members sandwiching the wafer from both sides in the thickness direction, so that even when a load is applied from the polishing member in the thickness direction of the wafer during the polishing process, It is possible to suppress the occurrence of chipping or cracking of the wafer. Therefore, it is possible to increase the rigidity of the wafer by polishing the outer peripheral surface of the wafer with high accuracy while suppressing the occurrence of wafer hooking and cracking, thereby improving the yield of the wafer and producing a high quality wafer. .

Further, the polishing member is characterized by being wider than the thickness of the wafer.
According to this configuration, the center portion in the width direction of the polishing member is in sliding contact with the outer peripheral surface of the wafer, and both side portions in the width direction of the polishing member that are not in sliding contact with the outer peripheral surface of the wafer are wound around the front surface side and the back surface side of the wafer. Therefore, the curved portion of the polishing member is in sliding contact with the corner portion of the wafer, and the corner portion of the wafer can be chamfered (R chamfering). Therefore, even when a tool or the like comes into contact with the corner portion of the wafer in the subsequent process, the wafer can be reliably prevented from being chipped or cracked.

Further, the holding body is provided with an inclined surface that increases in thickness from a radially outer side to a radially inner side at a peripheral portion of the holding body and has an acute angle with respect to the front and back surfaces of the wafer. Yes.
According to this configuration, since the angle of the curved portion of the wafer is prevented from becoming an acute angle than the inclined surface, the corner portion can be stably chamfered (R chamfering).

In the polishing step, tension is applied to the polishing member.
According to this configuration, since the polishing member can be prevented from loosening and pressed against the outer peripheral surface of the wafer with a substantially constant force, the outer peripheral surface of the wafer can be uniformly and efficiently polished.

A method for manufacturing a piezoelectric vibrating piece according to the present invention is a method for manufacturing a piezoelectric vibrating piece using a wafer polished by the method for polishing an outer peripheral surface of a wafer according to the present invention, wherein the wafer is polished. An outer shape forming step of patterning the outer shape of a plurality of piezoelectric vibrating pieces, and patterning an electrode film on the outer surface of the plurality of piezoelectric vibrating pieces to vibrate the piezoelectric vibrating pieces when a predetermined voltage is applied An electrode forming step of forming an excitation electrode and a mount electrode electrically connected to the excitation electrode via an extraction electrode; and a cutting step of separating the plurality of piezoelectric vibrating pieces from the wafer and solidifying them. It is characterized by having.
According to this configuration, the piezoelectric vibrating piece is manufactured using the high-quality wafer polished by the wafer peripheral surface polishing method of the present invention, thereby suppressing the occurrence of chipping or cracking of the wafer during the manufacturing process. In addition, the yield of the piezoelectric vibrating piece can be improved. As a result, it is possible to manufacture a high-quality piezoelectric vibrating piece with low cost and excellent vibration characteristics.

The piezoelectric vibrating piece according to the present invention is manufactured by using the method for manufacturing a piezoelectric vibrating piece according to the present invention.
According to this configuration, since the piezoelectric vibrating reed manufacturing method of the present invention is used, a high-quality piezoelectric vibrating reed having excellent vibration characteristics can be provided at low cost.

The piezoelectric vibrator according to the present invention is characterized in that the piezoelectric vibrating piece according to the present invention is hermetically sealed in a package.
According to this configuration, since the piezoelectric vibrating piece of the present invention is hermetically sealed in the package, a high-quality piezoelectric vibrator having excellent vibration characteristics can be provided.

  The oscillator of the present invention is characterized in that the piezoelectric vibrator of the present invention is electrically connected to an integrated circuit as an oscillator.

  In addition, the electronic device of the present invention is characterized in that the piezoelectric vibrator of the present invention is electrically connected to a time measuring unit.

  The radio timepiece of the present invention is characterized in that the piezoelectric vibrator of the present invention is electrically connected to a filter portion.

  In the oscillator, the electronic device, and the radio timepiece according to the present invention, the yield is improved, and a high-quality oscillator, electronic device, and radio timepiece can be provided.

According to the method for polishing a wafer outer peripheral surface of the present invention, the production efficiency can be improved, and the yield can be improved by suppressing the occurrence of cracks and chips.
According to the piezoelectric vibrating piece manufacturing method and the piezoelectric vibrating piece of the present invention, it is possible to suppress the occurrence of chipping or cracking of the wafer during the manufacturing process and to improve the yield. A vibrating piece can be provided.
According to the piezoelectric vibrator of the present invention, a high-quality piezoelectric vibrator having excellent vibration characteristics can be provided.
In the oscillator, electronic device, and radio timepiece of the present invention, the yield can be improved, and a high-quality oscillator, electronic device, and radio timepiece can be provided.

1 is an external perspective view showing a piezoelectric vibrator according to an embodiment of the present invention. FIG. 2 is an internal configuration diagram of the piezoelectric vibrator shown in FIG. 1, and is a plan view with a lid substrate removed. It is sectional drawing in the AA of FIG. FIG. 2 is an exploded perspective view of the piezoelectric vibrator shown in FIG. 1. It is a top view of a piezoelectric vibrating piece. It is a bottom view of a piezoelectric vibrating piece. It is sectional drawing in the BB line of FIG. It is a flowchart which shows the manufacturing method of a piezoelectric vibrator. It is a flowchart which shows the manufacturing method of a piezoelectric vibrating piece. It is a disassembled perspective view of a wafer bonded body. It is a schematic block diagram of a grinding | polishing apparatus, and is explanatory drawing for demonstrating an outer peripheral surface grinding | polishing process. 12A and 12B are cross-sectional views taken along the line CC of FIG. 11 showing the wafer in the outer peripheral surface polishing step, where FIG. 11A is a wafer immediately before outer peripheral polishing and FIG. It is a figure which shows the manufacturing process of a piezoelectric vibrating piece, Comprising: It is sectional drawing of a wafer. It is a figure which shows the manufacturing process of a piezoelectric vibrating piece, Comprising: It is a top view of a wafer. It is a figure which shows the manufacturing process of a piezoelectric vibrating piece, Comprising: It is sectional drawing which follows the DD line | wire of FIG. FIG. 16 is a view illustrating a manufacturing process of the piezoelectric vibrating piece and a cross-sectional view corresponding to FIG. 15 of a wafer having both surfaces etched. FIG. 16 is a diagram illustrating a manufacturing process of the piezoelectric vibrating piece and a cross-sectional view corresponding to FIG. 15 of the wafer from which the photoresist film is removed. FIG. 16 is a diagram illustrating a manufacturing process of the piezoelectric vibrating piece and a cross-sectional view corresponding to FIG. 15 of the wafer from which the etching protective film is removed after the etching process. It is a schematic block diagram of the oscillator in embodiment of this invention. It is a schematic block diagram of the portable information device in embodiment of this invention. It is a schematic block diagram of the radio timepiece in the embodiment of the present invention. It is a schematic block diagram (side view) of the conventional grinding | polishing apparatus. FIGS. 13A and 13B are cross-sectional views corresponding to FIG. 12 in a modified example of the embodiment of the present invention, where FIG. It is.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Piezoelectric vibrator)
FIG. 1 is an external perspective view of the piezoelectric vibrator according to the present embodiment as viewed from the lid substrate side. FIG. 2 is an internal configuration diagram of the piezoelectric vibrator, and is a view of the piezoelectric vibrating piece viewed from above with the lid substrate removed. 3 is a cross-sectional view of the piezoelectric vibrator taken along line AA shown in FIG. 2, and FIG. 4 is an exploded perspective view of the piezoelectric vibrator.
As shown in FIGS. 1 to 4, the piezoelectric vibrator 1 according to this embodiment includes a piezoelectric vibrating piece 4 as an electronic component in a cavity C formed between a plurality of substrates 2 and 3 bonded to each other. It is a surface mount type configuration including the package 5 enclosed. The package 5 is formed in a box shape in which the base substrate 2 and the lid substrate 3 are laminated in two layers. In FIG. 4, the excitation electrode 15, the extraction electrodes 19 and 20, the mount electrodes 16 and 17, and the weight metal film 21, which will be described later, are omitted for easy understanding of the drawing.

FIG. 5 is a plan view seen from the upper surface of the piezoelectric vibrating piece, and FIG. 6 is a plan view seen from the lower surface. FIG. 7 is a sectional view taken along line BB in FIG.
As shown in FIG. 5 to FIG. 7, the piezoelectric vibrating piece 4 is a tuning fork type vibrating piece formed of a piezoelectric material such as quartz, lithium tantalate, or lithium niobate, and when a predetermined voltage is applied. It vibrates.

The piezoelectric vibrating reed 4 includes a pair of vibrating arm portions 10 and 11 arranged in parallel, a base portion 12 that integrally fixes the base end sides of the pair of vibrating arm portions 10 and 11, and a pair of vibrating arm portions 10. , 11 formed on the outer surface and configured to vibrate the pair of vibrating arms 10, 11, the excitation electrode 15 including the first excitation electrode 13 and the second excitation electrode 14, and the first excitation electrode 13 electrically And a mount electrode 17 electrically connected to the second excitation electrode 14.
Further, the piezoelectric vibrating reed 4 of the present embodiment includes groove portions 18 formed along the longitudinal direction of the vibrating arm portions 10 and 11 on both main surfaces of the pair of vibrating arm portions 10 and 11. The groove portion 18 is formed from the proximal end side of the vibrating arm portions 10 and 11 to the vicinity of the middle.

  The excitation electrodes 13 and 14 are formed on the main surfaces of the pair of vibrating arm portions 10 and 11 as shown in FIG. The excitation electrodes 13 and 14 are formed of a single-layer conductive film such as chromium (Cr), for example. The excitation electrode 15 composed of the first excitation electrode 13 and the second excitation electrode 14 is an electrode that vibrates the pair of vibrating arm portions 10 and 11 at a predetermined resonance frequency in a direction approaching and separating from each other. The outer surface of the pair of vibrating arm portions 10 and 11 is formed by patterning while being electrically separated from each other. Specifically, the first excitation electrode 13 is mainly formed on the groove portion 18 of one vibration arm portion 10 and on both side surfaces of the other vibration arm portion 11, and the second excitation electrode 14 is formed on one side. Are formed mainly on both side surfaces of the vibrating arm portion 10 and on the groove portion 18 of the other vibrating arm portion 11.

In addition, the first excitation electrode 13 and the second excitation electrode 14 are electrically connected to the mount electrodes 16 and 17 via the extraction electrodes 19 and 20, respectively, on both main surfaces of the base portion 12. A voltage is applied to the piezoelectric vibrating reed 4 via the mount electrodes 16 and 17.
The mount electrodes 16 and 17 and the lead electrodes 19 and 20 are, for example, a laminated film of chromium (Cr) and gold (Au), and are formed on the surface after forming a chromium film having good adhesion with crystal as a base. A gold thin film is applied.

  Further, a weight metal film 21 for adjusting (frequency adjustment) to vibrate its own vibration state within a predetermined frequency range is coated on the tips of the pair of vibrating arm portions 10 and 11. The weight metal film 21 is divided into a coarse adjustment film 21a used when the frequency is roughly adjusted and a fine adjustment film 21b used when the frequency is finely adjusted. By adjusting the frequency using the coarse adjustment film 21a and the fine adjustment film 21b, the frequency of the pair of vibrating arm portions 10 and 11 can be kept within the range of the nominal frequency of the device.

  As shown in FIGS. 3 and 4, the piezoelectric vibrating reed 4 configured as described above is bump-bonded to the inner surface of the base substrate 2 using bumps B such as gold. More specifically, a pair of mount electrodes 16, 17 (on the two bumps B formed on routing electrodes 36, 37 described later patterned on the first surface (upper surface in FIG. 3) of the base substrate 2. 5 and 6) are in bump contact with each other.

  The lid substrate 3 is a transparent insulating substrate made of a glass material, for example, soda-lime glass, and is formed in a plate shape as shown in FIGS. A rectangular recess 3 a in which the piezoelectric vibrating reed 4 is accommodated is formed on the bonding surface side to which the base substrate 2 is bonded. The recess 3 a is a cavity recess that becomes a cavity C that accommodates the piezoelectric vibrating reed 4 when the substrates 2 and 3 are overlapped.

  As shown in FIG. 3, a bonding material 35 for anodic bonding is formed on the bonding surface of the lid substrate 3 with the base substrate 2. The bonding material 35 is made of a conductive material such as aluminum or silicon, and is formed by a film forming method such as sputtering or CVD. The lid substrate 3 is anodically bonded to the base substrate 2 via a bonding material 35 with the recess 3a facing the base substrate 2 side. Thereby, the cavity C is vacuum-sealed.

Similar to the lid substrate 3, the base substrate 2 is a transparent insulating substrate made of a glass material, for example, soda-lime glass, and is formed in a plate shape as shown in FIGS.
As shown in FIG. 3, the base substrate 2 is formed with a pair of through holes 30 and 31 that penetrate the base substrate 2. The through hole 30 is formed in a reverse tapered shape that gradually increases in diameter from the first surface of the base substrate 2 toward the second surface (the lower surface in FIG. 3). As shown in FIG. 2, the through holes 30 and 31 of the present embodiment are formed with one through hole 30 at a position corresponding to the base 12 side of the mounted piezoelectric vibrating reed 4, The other through hole 31 is formed at a position corresponding to the tip side.

  As shown in FIG. 3, a pair of through electrodes 32 and 33 are formed in the pair of through holes 30 and 31 so as to fill the through holes 30 and 31. These through electrodes 32 and 33 penetrate the base substrate 2 in the thickness direction, and conduct the inside of the cavity C of the base electrode 2 and the outside of the piezoelectric vibrator 1. The through electrodes 32 and 33 are formed by the cylindrical body 6 and the core member 7 that are integrally fixed to the through holes 30 and 31 by firing, and completely close the through holes 30 and 31. While maintaining the airtightness in the cavity C, it plays the role which makes the external electrodes 38 and 39 mentioned later and the routing electrodes 36 and 37 conduct | electrically_connect.

  The cylindrical body 6 is obtained by firing a paste-like glass frit described later. The cylindrical body 6 is formed in a cylindrical shape having flat ends and substantially the same thickness as the base substrate 2. And the core part 7 is distribute | arranged to the center of the cylinder 6 so that the cylinder 6 may be penetrated. The cylindrical body 6 and the core member 7 are fired in a state of being embedded in the through holes 30 and 31, and are firmly fixed to the through holes 30 and 31.

  The core material portion 7 is a conductive core material formed in a cylindrical shape with a metal material such as stainless steel, silver, Ni alloy, aluminum, etc., and both ends are flat and the thickness of the base substrate 2 is the same as the cylindrical body 6. And so as to have substantially the same thickness. The core member 7 is located in the center hole 6 c of the cylindrical body 6 and is firmly fixed to the cylindrical body 6 by firing the cylindrical body 6. The through electrodes 32 and 33 are ensured to have electrical conductivity through the conductive core portion 7. Moreover, as a metal material which forms the core part 7, the alloy (42 alloy) which contains 58 weight percent of iron (Fe) and contains 42 weight percent of Ni can also be employ | adopted, for example.

As shown in FIG. 4, the pair of lead-out electrodes 36 and 37 include one of the pair of through-electrodes 32 and 33 and one mount electrode 16 (see FIG. 2) of the piezoelectric vibrating piece 4. While being electrically connected, the other through electrode 33 and the other mount electrode 17 (see FIG. 2) of the piezoelectric vibrating piece 4 are patterned so as to be electrically connected.
More specifically, the one lead-out electrode 36 is formed directly above the one through electrode 32 so as to be positioned directly below the base 12 of the piezoelectric vibrating piece 4. The other routing electrode 37 is routed from the position adjacent to the one routing electrode 36 along the vibrating arm portions 10 and 11 to the distal end side of the vibrating arm portions 10 and 11, and then the other through electrode 33. It is formed to be located directly above.

  Bumps B are formed on the pair of routing electrodes 36 and 37, and the piezoelectric vibrating reed 4 is mounted using the bumps B. Thereby, one mount electrode 16 of the piezoelectric vibrating reed 4 is electrically connected to one through electrode 32 through one routing electrode 36, and the other mount electrode 17 is passed through the other routing electrode 37 to the other penetration electrode. The electrode 33 is electrically connected.

  Further, as shown in FIGS. 1, 3, and 4, external electrodes 38 and 39 that are electrically connected to the pair of through electrodes 32 and 33, respectively, are formed on the outer surface of the base substrate 2. . That is, one external electrode 38 is electrically connected to the first excitation electrode 13 of the piezoelectric vibrating reed 4 via one through electrode 32 and one routing electrode 36. The other external electrode 39 is electrically connected to the second excitation electrode 14 (see FIG. 2) of the piezoelectric vibrating piece 4 via the other through electrode 33 and the other routing electrode 37.

  When the piezoelectric vibrator 1 configured as described above is operated, a predetermined drive voltage is applied to the external electrodes 38 and 39 formed on the base substrate 2. As a result, a voltage is applied to the excitation electrode 15 including the first excitation electrode 13 and the second excitation electrode 14 of the piezoelectric vibrating reed 4 so that the pair of vibrating arm portions 10 and 11 are moved in a predetermined direction in the direction of approaching and separating. Can be vibrated at a frequency of The vibration of the pair of vibrating arm portions 10 and 11 can be used as a time source, a timing source for control signals, a reference signal source, and the like.

(Piezoelectric vibrator manufacturing method)
Next, a method for manufacturing the piezoelectric vibrator 1 will be described with reference to FIGS. FIG. 8 is a flowchart showing a method for manufacturing a piezoelectric vibrator, FIG. 9 is a flowchart showing a piezoelectric vibrating piece manufacturing process, and FIG. 10 is an exploded perspective view of a wafer bonded body.
As shown in FIGS. 8 and 10, in the method of manufacturing the piezoelectric vibrator 1, a gap between a base substrate wafer 40 in which a plurality of base substrates 2 are connected and a lid substrate wafer 50 in which a plurality of lid substrates 3 are connected. Next, a method of simultaneously manufacturing a plurality of piezoelectric vibrators 1 by enclosing a plurality of piezoelectric vibrating pieces 4 to form a wafer bonded body 60 and cutting the wafer bonded body 60 will be described. In addition, the broken line M shown in FIG. 10 shows the cutting line cut | disconnected by a cutting process.

  The manufacturing method of the piezoelectric vibrator 1 in this embodiment mainly includes a piezoelectric vibrating piece manufacturing step (S10), a lid substrate wafer manufacturing step (S20), a base substrate wafer manufacturing step (S30), and an assembly step. (S40 and later). Among these, the piezoelectric vibrating reed manufacturing step (S10), the lid substrate wafer manufacturing step (S20), and the base substrate wafer manufacturing step (S30) can be performed in parallel.

(Piezoelectric vibrating piece manufacturing process)
First, as shown in FIGS. 8 and 9, the piezoelectric vibrating reed manufacturing step (S10) is performed to manufacture the piezoelectric vibrating reed 4 (see FIGS. 5 and 6). Specifically, a quartz Lambert rough stone that has been ground by rotary grinding, a grinding wheel, or the like is sliced at a predetermined angle to obtain a wafer W having a constant thickness (see FIG. 12). Subsequently, the wafer W is lapped and subjected to rough processing, and then the work-affected layer is removed by etching, and then mirror processing such as polishing is performed to obtain a predetermined thickness (S110). As the wafer W of this embodiment, for example, a disk-shaped wafer having a diameter of 3 inches and a thickness of about 80 μm to 200 μm is used.

FIG. 11 is a schematic configuration diagram of the polishing apparatus, and is an explanatory diagram for explaining an outer peripheral surface polishing step for polishing the outer peripheral surface W1 of the wafer W.
As shown in FIG. 11, an outer peripheral surface polishing step for polishing the outer peripheral surface W1 of the wafer W is performed (S120). Here, the polishing apparatus 200 used in the outer periphery polishing step (S120) will be described. The polishing apparatus 200 includes a holding mechanism 201 that holds the wafer W, a polishing member supply mechanism 203 that supplies a belt-shaped polishing member 202, and a coolant supply that supplies coolant between the polishing member 202 and the wafer W. And a mechanism (not shown).

  Still referring to FIG. 12A, the holding mechanism 201 includes holding means 205 including a pair of grinding tables (holding bodies) 205a and 205b that hold the wafer W from both sides in the thickness direction. The grinding tables 205a and 205b can be rotated around the axis J and can be moved in the radial direction and the axis J direction of the wafer W, respectively, and are formed in a disk shape slightly smaller than the diameter of the wafer W. The In other words, the holding means 205 moves in the direction of the axis J so that the center axis of the wafer W and the axis J of the grinding tables 205a and 205b are coaxially arranged, and holds the wafer W from both sides in the thickness direction. In addition, the wafer W can be moved in the radial direction with the wafer W sandwiched therebetween.

  The polishing member supply mechanism 203 includes a supply roller 210 and a winding roller 211 around which the polishing member 202 is wound, and a tensioner 212 disposed between the rollers 210 and 211 in the traveling direction of the polishing member 202. .

  The polishing member 202 has a band shape wider than the thickness dimension of the wafer W, and is formed by fixing abrasive particles with an adhesive or the like on the surface of a belt-like base material rich in flexibility. As a material of the polishing member 202, for example, a material in which diamond particles are attached to a resin base (for example, vinyl, nylon, etc.) having a width of about 2 to 3 cm and a thickness of about 100 μm via a metal bond is preferable. It is used. Moreover, the particle size of the abrasive particles (diamond particles) is preferably about # 600 to # 3000, for example.

  The supply roller 210 includes a reel body 214 that is rotatably supported by the shaft 213, and drive means (not shown) such as a motor that rotates the reel body 214. The reel body 214 includes an unused polishing member. 202 is wound. When the reel body 214 is normally rotated (see T1 in FIG. 11), the polishing member 202 is sequentially drawn out to the downstream side.

  On the other hand, the take-up roller 211 has substantially the same configuration as the supply roller 210 described above, and includes a reel body 222 rotatably supported on the shaft 221 and a drive unit (not shown). The polishing member 202 is bridged between the reel body 222 of the take-up roller 211 and the reel body 214 of the supply roller 210, and the reel body 222 rotates forward (see T1 in FIG. 11). The polishing member 202 supplied from the supply roller 210 is wound up sequentially.

  Between the supply roller 210 and the wafer W, and between the take-up roller 211 and the wafer W, tensioners 212 for preventing the polishing member 202 from loosening are arranged. The tensioner 212 includes a tension roller 223 that rotates following the traveling of the polishing member 202, and an urging means (not shown) that urges the tension roller 223 in a direction in which the polishing member 202 is pressed. The Here, the tension roller 223 also functions as a guide roller for guiding the polishing member 202. In addition, the load by which the polishing member 202 is pressed by the urging means is about several hundred grams.

  The axis J of the grinding tables 205a and 205b is in the radial direction of the wafer W with respect to the line L connecting the axes of the rollers 210 and 211 when the outer peripheral surface W1 of the wafer W is being polished. They are shifted in the direction of separation.

  When polishing the outer peripheral surface of the wafer W using the polishing apparatus 200 configured in this way, in this embodiment, the first polishing step of roughing the wafer W with the polishing member 202 having a coarse grain size (for example, about # 600) And a second polishing step of finely grinding the wafer W with the polishing member 202 having a finer particle size (for example, about # 1000) than the first polishing step.

  First, in the first polishing process, the wafer W is set on the holding means 205 (wafer setting process). Specifically, the wafer W is placed on the lower grinding table 205b with the axis of the wafer W aligned with the axis J of the grinding tables 205a and 205b. Thereafter, the upper grinding table 205a is moved (lowered) in the axis J direction, and the wafer W is sandwiched between the grinding tables 205a and 205b from both sides in the thickness direction. In this case, the pressing force to the wafer W by the grinding tables 205a and 205b is set to about 500N. At this time, since the grinding tables 205a and 205b are formed to be slightly smaller than the wafer W, only the outer peripheral part of the wafer W is slightly outward from the outer peripheral surface of the grinding tables 205a and 205b in the radial direction (for example, It is held in a state protruding to about 5 mm).

  Further, the polishing member 202 is bridged between the rollers 210 and 211, and the holding means 205 is connected to the line L connecting the axes of the rollers 210 and 211 with the polishing member 202 guided by the tension roller 223. Is moved to a position where the outer peripheral surface W1 of the wafer W comes into contact with the polishing surface of the polishing member 202 (contact process). At this time, the polishing member 202 is brought into contact with, for example, about 1/2 to 1/3 of the entire circumference of the outer peripheral surface W1 of the wafer W.

  Further, since the dimension in the width direction of the polishing member 202 is larger than the thickness dimension of the wafer W, and the polishing member 202 has flexibility, the polishing member 202 in contact with the outer peripheral surface W1 of the wafer W is attached. The tension in the direction approaching the line L connecting the rollers 210 and 211 acts, and as a result, both sides in the width direction of the polishing member 202 are directed radially inward of the wafer W as shown in FIG. It is curved so as to wrap around, and its edge becomes an acute angle (for example, about 45 degrees) with respect to the front and back surfaces of the wafer W.

  Next, when the operation of the polishing member supply mechanism 203 is started, the rollers 210 and 211 are rotated back and forth in the forward rotation direction (see T1 in FIG. 11) and the reverse rotation direction (see T2 in FIG. 11). Reciprocate along the thickness direction (see Q in FIG. 11). At this time, the holding means 205 is rotated at a relatively low speed around the axis J (for example, in the direction of the arrow in FIG. 11), and further, coolant is supplied between the wafer W and the polishing member 202. Here, the amplitude in the forward rotation direction of each of the rollers 210 and 211 is set to be larger than the amplitude in the reverse rotation direction, whereby the unused polishing member 202 wound around the supply roller 210 is gradually supplied. It will be.

  Then, as described above, the polishing member 202 is moved so as to follow the outer peripheral surface W1 of the wafer W, whereby the corner portion of the wafer W is formed on the curved portion of the polishing member 202 as shown in FIG. Is polished, and the entire circumference of the outer peripheral surface W1 is polished into a curved surface (R chamfering). Note that the end of polishing is determined by image determination or the like.

  After the first polishing step is completed, the second polishing step is performed by the same method as the first polishing step described above using the fine-grain polishing member 202. As a result, the surface roughness (specularity) of the outer peripheral surface W1 of the wafer W is improved, and scratches and irregularities on the outer peripheral surface W1 are eliminated, so that not only during polishing but also at the corners of the wafer W in the subsequent process. Even in the case of contact, the generation of cracks and cracks is suppressed, and as a result, the rigidity of the wafer W can be increased.

  Next, the wafer W is etched by a photolithographic technique to perform an outer shape forming process for forming the outer shapes of the plurality of piezoelectric vibrating reeds 4 on the wafer W. First, as shown in FIG. 13, an etching protection film 230 is formed on both surfaces of the wafer W to form an outer pattern of the piezoelectric vibrating reed 4 (S130). As the etching protection film 230, for example, chromium (Cr) is formed to a thickness of several μm. Next, a photoresist film (not shown) is patterned on the etching protection film 230 by a photolithography technique. At this time, patterning is performed so as to surround the periphery of the piezoelectric vibrating piece 4 including the pair of vibrating arm portions 10 and 11 and the base portion 12. Then, etching is performed using the photoresist film as a mask, and the unmasked etching protection film 230 is selectively removed. Then, the photoresist film is removed after the etching process.

  Accordingly, as shown in FIGS. 14 and 15, the etching protection film 230 can be patterned along the outer shape of the piezoelectric vibrating piece 4, that is, the outer shapes of the pair of vibrating arm portions 10 and 11 and the base portion 12. . At this time, patterning is performed by the number of the plurality of piezoelectric vibrating reeds 4. FIG. 15 is a cross-sectional view taken along the line DD shown in FIG.

  Next, both surfaces of the wafer W are etched by using the etching protective film 230 patterned in advance as a mask as described above (S140). Thereby, as shown in FIG. 16, the region not masked by the etching protection film 230 can be selectively removed to form the outer shape of the piezoelectric vibrating reed 4.

Subsequently, a groove portion forming step is performed in which the groove portion 18 is formed on the main surfaces of the pair of vibrating arm portions 10 and 11 (S150). Specifically, a photoresist film is formed on the etching protection film 230 in the same manner as in the outer shape formation described above. Then, the photoresist film is patterned so as to open the region of the groove 18 by photolithography. Then, etching is performed using the patterned photoresist film as a mask, and the etching protection film 230 is selectively removed.
Thereafter, by removing the photoresist film, as shown in FIG. 17, the already patterned etching protection film 230 can be further patterned in a state where the region of the groove 18 is left open.

  Next, the wafer W is etched using the patterned etching protective film 230 as a mask, and then the etching protective film 230 used as the mask is removed. Thereby, as shown in FIG. 18, the groove part 18 can be formed on both the main surfaces of a pair of vibration arm parts 10 and 11, respectively. Thus, the outer shape forming process is completed. At this time, the plurality of piezoelectric vibrating reeds 4 are connected to the wafer W via connecting portions (not shown).

  Next, the electrode film is patterned on the outer surfaces of the plurality of piezoelectric vibrating reeds 4 to perform an electrode forming step of forming the excitation electrodes 13 and 14, the extraction electrodes 19 and 20 and the mount electrodes 16 and 17, respectively (S160). . Specifically, an electrode film is formed on the outer surface of the piezoelectric vibrating piece 4 in which the groove portion 18 is formed by a vapor deposition method, a sputtering method, or the like, and thereafter, the electrode film is formed by etching.

  After the electrode formation step (S160) is completed, the weight metal film 21 including the frequency adjustment coarse / fine adjustment film 21a and the fine adjustment film 21b is formed at the tips of the pair of vibrating arms 10 and 11 (weight metal film formation step). , S170). The weight metal film 21 has a laminated structure in which a fine adjustment film 21b is first formed and then a coarse adjustment film 21a is formed thereon. The fine adjustment film 21b has a film thickness of about 1500 mm, for example, while the coarse / fine adjustment film 21a has a film thickness of about 3 μm, for example.

  Subsequently, a coarse adjustment process for coarsely adjusting the frequency is performed on all the vibrating arm portions 10 and 11 formed on the wafer W using a trimming device (not shown) (S180). The fine adjustment step (S80) for adjusting the frequencies of the vibrating arm portions 10 and 11 with higher accuracy is performed after the piezoelectric vibrating reed 4 is sealed in the package 5.

After the coarse adjustment step (S180) is completed, the connection portion that finally connected the wafer W and the piezoelectric vibrating piece 4 is cut, and the plurality of piezoelectric vibrating pieces 4 are separated from the wafer W and separated into individual pieces. A process is performed (S190). Thereby, a plurality of tuning fork type piezoelectric vibrating reeds 4 can be manufactured from one wafer W at a time.
At this point, the manufacturing process of the piezoelectric vibrating piece 4 is finished, and the piezoelectric vibrating piece 4 shown in FIG. 5 can be obtained.

(Wad manufacturing process for lid substrate)
Next, as shown in FIGS. 8 and 10, a lid substrate wafer manufacturing process is performed in which a lid substrate wafer 50 to be the lid substrate 3 later is manufactured up to a state immediately before anodic bonding (S20).
Specifically, after polishing and cleaning soda-lime glass to a predetermined thickness, a disk-shaped lid substrate wafer 50 is formed by removing the outermost work-affected layer by etching or the like (S21).

Next, a recess forming step is performed for forming a plurality of recesses 3a for the cavity C in the matrix direction by etching or the like on the first surface 50a (the lower surface in FIG. 10) of the lid substrate wafer 50 (S22).
Subsequently, a polishing process for polishing at least the first surface 50a side of the lid substrate wafer 50 to be a bonding surface with the base substrate wafer 40 in order to ensure airtightness with the base substrate wafer 40 described later. (S23) is performed, and the first surface 50a is mirror-finished.

Next, a bonding material forming step (S24) for forming the bonding material 35 on the entire first surface 50a of the lid substrate wafer 50 (the bonding surface with the base substrate wafer 40 and the inner surface of the recess 3a) is performed. Thus, by forming the bonding material 35 on the entire first surface 50a of the lid substrate wafer 50, the patterning of the bonding material 35 becomes unnecessary, and the manufacturing cost can be reduced. The bonding material 35 can be formed by a film forming method such as sputtering or CVD. Further, since the bonding surface is polished before the bonding material forming step (S24), the flatness of the surface of the bonding material 35 is ensured, and stable bonding with the base substrate wafer 40 can be realized.
The lid substrate wafer manufacturing step (S20) is thus completed.

(Base substrate wafer manufacturing process)
Next, a base substrate wafer manufacturing step is performed in which the base substrate wafer 40 to be the base substrate 2 later is manufactured up to the state immediately before anodic bonding at the same time as before or after the above-described step (S30).
First, after polishing and washing soda-lime glass to a predetermined thickness, a disk-shaped base substrate wafer 40 is formed by removing the outermost work-affected layer by etching or the like (S31).

  Next, a through-hole forming step for forming a plurality of through-holes 30 and 31 for arranging the pair of through-electrodes 32 and 33 on the base substrate wafer is performed by, for example, pressing (S32). Specifically, after forming a recess from the first surface 40a of the base substrate wafer 40 by pressing or the like, the recess is penetrated by polishing at least from the second surface 40b side of the base substrate wafer 40. Holes 30, 31 can be formed.

Subsequently, a through electrode forming step (S33) for forming the through electrodes 32 and 33 in the through holes 30 and 31 formed in the through hole forming step (S32) is performed.
As a result, in the through holes 30 and 31, the core material portion 7 is held flush with both surfaces 40 a and 40 b (upper and lower surfaces in FIG. 10) of the base substrate wafer 40. Thus, the through electrodes 32 and 33 can be formed.

  Next, a conductive material is patterned on the second surface 40b of the base substrate wafer 40 and routed to perform an electrode forming process (S34). In this way, the base substrate wafer manufacturing step (S30) is completed.

(Assembly process)
Subsequently, the piezoelectric vibrating reed 4 manufactured in the piezoelectric vibrating reed manufacturing step (S10) is respectively formed on the routing electrodes 36 and 37 of the base substrate wafer 40 manufactured in the base substrate wafer manufacturing step (S30). It mounts via bumps B, such as gold (S40).
Then, an overlapping process is performed in which the base substrate wafer 40 and the lid substrate wafer 50 manufactured in the manufacturing process of the wafers 40 and 50 described above are overlapped (S50). Specifically, both wafers 40 and 50 are aligned at the correct positions while using a reference mark (not shown) as an index. As a result, the mounted piezoelectric vibrating reed 4 is housed in the cavity C surrounded by the recess 3 a formed in the lid substrate wafer 50 and the base substrate wafer 40.

  After the superposition process, the two superposed wafers 40 and 50 are put into an anodic bonding apparatus (not shown), and the outer periphery of the wafers 40 and 50 are clamped by a holding mechanism (not shown), and a predetermined voltage is applied in a predetermined temperature atmosphere. Is applied to perform anodic bonding (S60). Specifically, a predetermined voltage is applied between the bonding material 35 and the base substrate wafer 40. As a result, an electrochemical reaction occurs at the interface between the bonding material 35 and the base substrate wafer 40, and the two are firmly adhered to each other and anodic bonded. Thereby, the piezoelectric vibrating reed 4 can be sealed in the cavity C, and the wafer bonded body 60 in which the base substrate wafer 40 and the lid substrate wafer 50 are bonded can be obtained.

  Thereafter, a pair of external electrodes 38 and 39 electrically connected to the pair of through electrodes 32 and 33 are formed (S70), and the frequency of the piezoelectric vibrator 1 is finely adjusted (S80). Then, an individualizing step (S90) is performed for cutting the bonded wafer bonded body 60 along the cutting line M.

In the electrical characteristic inspection step (S100), the resonance frequency, resonance resistance value, drive level characteristic (excitation power dependency of the resonance frequency and resonance resistance value), etc. of the piezoelectric vibrator 1 are measured and checked. In addition, the insulation resistance characteristics are also checked. Finally, an appearance inspection of the piezoelectric vibrator 1 is performed to finally check dimensions, quality, and the like.
Thus, the piezoelectric vibrator 1 is completed.

As described above, in this embodiment, the belt-shaped polishing member 202 is moved along the outer peripheral surface of the wafer W while the wafer W is rotated while the wafer W is sandwiched from both sides in the thickness direction by the grinding tables 205a and 205b. It was made to run, and it was set as the structure which grind | polishes the outer peripheral surface W1 of the wafer W. FIG.
According to this configuration, unlike the conventional method using a rotating brush, it is not necessary to stack the wafers W, so that the number of manufacturing steps can be reduced and the manufacturing efficiency can be improved.
In particular, by polishing the outer peripheral surface W1 of the wafer W using the belt-shaped polishing member 202, the polishing member 202 is brought into sliding contact with the shape of the outer peripheral surface W1 of the wafer W. Thereby, even if it is the thin wafer W for piezoelectric vibrating reeds, the outer peripheral surface W1 of the wafer W can be grind | polished with high precision, after generation | occurrence | production of a chip, a crack, etc. is suppressed.
Moreover, since the rigidity of the wafer W can be increased by performing the polishing while the wafer W is sandwiched from both sides in the thickness direction by the pair of grinding tables 205a and 205b, the polishing member is used during the outer peripheral surface polishing step (S120). Even when a load is applied from 202 along the thickness direction of the wafer W, the wafer W can be prevented from being shaken and the like, so that the occurrence of chipping or cracking of the wafer W can be suppressed.
As a result, the yield of the wafers W can be improved and high quality wafers W can be manufactured.

Further, in the conventional method using a rotating brush, there is a problem that the rotating brush enters between the wafers of the laminated body and the surface of the wafer is polished. In this case, the effective area of the wafer W (the range in which the piezoelectric vibrating reed 4 can be manufactured) may be reduced.
On the other hand, according to the present embodiment, since the surface of the wafer W is not polished, the quality of the wafer W can be further stabilized. Further, since the effective area of the wafer W is not reduced, more piezoelectric vibrating reeds 4 can be taken out from one wafer W. Therefore, the low-cost piezoelectric vibrating piece 4 can be provided.

Further, in the outer peripheral surface polishing step (S120) of the present embodiment, the both sides in the width direction of the polishing member 202 are brought into contact with the surface of the wafer W at an acute angle, thereby chamfering the corners of the wafer W (R chamfering). Therefore, even if a tool or the like is in contact with the corner of the wafer W in the subsequent process, chipping or cracking of the wafer W can be reliably suppressed.
Further, by applying tension to the polishing member 202 by the tensioner 212, the polishing member 202 is prevented from loosening between the rollers 210 and 211, and the polishing member 202 is applied to the outer peripheral surface W1 of the wafer W with a desired force. Can be pressed. Therefore, the outer peripheral surface W1 of the wafer W can be efficiently polished.

Then, by manufacturing the piezoelectric vibrating reed 4 using the high-quality wafer W polished in this way, generation of chipping or cracking of the wafer W during the manufacturing is suppressed, and the yield of the piezoelectric vibrating reed 4 is increased. Can be improved. As a result, the high-quality piezoelectric vibrating reed 4 having excellent vibration characteristics can be manufactured at low cost.
Furthermore, since the piezoelectric vibrating reed 4 is hermetically sealed in the package 5, the high-quality piezoelectric vibrator 1 having excellent vibration characteristics can be provided.

(Oscillator)
Next, an embodiment of an oscillator according to the present invention will be described with reference to FIG.
As shown in FIG. 19, the oscillator 100 according to the present embodiment is configured by configuring the piezoelectric vibrator 1 as an oscillator electrically connected to the integrated circuit 101. The oscillator 100 includes a substrate 103 on which an electronic component 102 such as a capacitor is mounted. The above-described integrated circuit 101 for the oscillator is mounted on the substrate 103, and the piezoelectric vibrating piece 5 of the piezoelectric vibrator 1 is mounted in the vicinity of the integrated circuit 101. The electronic component 102, the integrated circuit 101, and the piezoelectric vibrator 1 are electrically connected by a wiring pattern (not shown). Each component is molded with a resin (not shown).

In the oscillator 100 configured as described above, when a voltage is applied to the piezoelectric vibrator 1, the piezoelectric vibrating piece 5 in the piezoelectric vibrator 1 vibrates. This vibration is converted into an electric signal by the piezoelectric characteristics of the piezoelectric vibrating piece 5 and input to the integrated circuit 101 as an electric signal. The input electrical signal is subjected to various processes by the integrated circuit 101 and is output as a frequency signal.
Thereby, the piezoelectric vibrator 1 functions as an oscillator.
Further, by selectively setting the configuration of the integrated circuit 101, for example, an RTC (real-time clock) module or the like according to a request, the operation date and time of the device and external device in addition to a single-function oscillator for a clock A function for controlling the time, providing a time, a calendar, and the like can be added.

  As described above, according to the oscillator 100 of the present embodiment, since the piezoelectric vibrator 1 described above is provided, it is possible to provide a high-quality oscillator 100 having excellent characteristics and reliability. In addition to this, it is possible to obtain a highly accurate frequency signal that is stable over a long period of time.

(Electronics)
Next, an embodiment of an electronic apparatus according to the present invention will be described with reference to FIG. Note that the portable information device 110 having the above-described piezoelectric vibrator 1 will be described as an example of the electronic device. First, the portable information device 110 according to the present embodiment is represented by, for example, a mobile phone, and is a development and improvement of a wrist watch in the related art. The appearance is similar to that of a wristwatch, and a liquid crystal display is arranged in a portion corresponding to a dial so that the current time and the like can be displayed on this screen. Further, when used as a communication device, it is possible to perform communication similar to that of a conventional mobile phone by using a speaker and a microphone that are removed from the wrist and incorporated in the inner portion of the band. However, it is much smaller and lighter than conventional mobile phones.

(Portable information equipment)
Next, the configuration of the portable information device 110 of this embodiment will be described. As shown in FIG. 20, the portable information device 110 includes the piezoelectric vibrator 1 and a power supply unit 111 for supplying power. The power supply unit 111 is made of, for example, a lithium secondary battery. The power supply unit 111 includes a control unit 112 that performs various controls, a clock unit 113 that counts time, a communication unit 114 that communicates with the outside, a display unit 115 that displays various types of information, A voltage detection unit 116 that detects the voltage of the functional unit is connected in parallel. The power unit 111 supplies power to each functional unit.

  The control unit 112 controls each function unit to control operation of the entire system such as transmission and reception of audio data, measurement and display of the current time, and the like. The control unit 112 includes a ROM in which a program is written in advance, a CPU that reads and executes the program written in the ROM, and a RAM that is used as a work area of the CPU.

  The timer unit 113 includes an integrated circuit including an oscillation circuit, a register circuit, a counter circuit, an interface circuit, and the like, and the piezoelectric vibrator 1. When a voltage is applied to the piezoelectric vibrator 1, the piezoelectric vibrating reed 5 vibrates, and this vibration is converted into an electric signal by the piezoelectric characteristics of the crystal and is input to the oscillation circuit as an electric signal. The output of the oscillation circuit is binarized and counted by a register circuit and a counter circuit. Then, signals are transmitted to and received from the control unit 112 via the interface circuit, and the current time, current date, calendar information, or the like is displayed on the display unit 115.

The communication unit 114 has functions similar to those of a conventional mobile phone, and includes a radio unit 117, a voice processing unit 118, a switching unit 119, an amplification unit 120, a voice input / output unit 121, a telephone number input unit 122, and a ring tone generation unit. 123 and a call control memory unit 124.
The wireless unit 117 exchanges various data such as audio data with the base station via the antenna 125. The audio processing unit 118 encodes and decodes the audio signal input from the radio unit 117 or the amplification unit 120. The amplifying unit 120 amplifies the signal input from the audio processing unit 118 or the audio input / output unit 121 to a predetermined level. The voice input / output unit 121 includes a speaker, a microphone, and the like, and amplifies a ringtone and a received voice or collects a voice.

In addition, the ring tone generator 123 generates a ring tone in response to a call from the base station. The switching unit 119 switches the amplifying unit 120 connected to the voice processing unit 118 to the ringing tone generating unit 123 only when an incoming call is received, so that the ringing tone generated in the ringing tone generating unit 123 is transmitted via the amplifying unit 120. To the audio input / output unit 121.
The call control memory unit 124 stores a program related to incoming / outgoing call control of communication. The telephone number input unit 122 includes, for example, a number key from 0 to 9 and other keys. By pressing these number keys and the like, a telephone number of a call destination is input.

  When the voltage applied to each functional unit such as the control unit 112 by the power supply unit 111 falls below a predetermined value, the voltage detection unit 116 detects the voltage drop and notifies the control unit 112 of the voltage drop. . The predetermined voltage value at this time is a value set in advance as a minimum voltage necessary for stably operating the communication unit 114, and is, for example, about 3V. Upon receiving the voltage drop notification from the voltage detection unit 116, the control unit 112 prohibits the operations of the radio unit 117, the voice processing unit 118, the switching unit 119, and the ring tone generation unit 123. In particular, it is essential to stop the operation of the wireless unit 117 with high power consumption. Further, the display unit 115 displays that the communication unit 114 has become unusable due to insufficient battery power.

That is, the operation of the communication unit 114 can be prohibited by the voltage detection unit 116 and the control unit 112, and that effect can be displayed on the display unit 115. This display may be a text message, but as a more intuitive display, a x (X) mark may be attached to the telephone icon displayed at the top of the display surface of the display unit 115.
In addition, the function of the communication part 114 can be stopped more reliably by providing the power supply cutoff part 126 that can selectively cut off the power of the part related to the function of the communication part 114.

  As described above, according to the portable information device 110 of the present embodiment, since the piezoelectric vibrator 1 described above is provided, the high-quality portable information device 110 having excellent characteristics and reliability can be provided. In addition to this, it is possible to display highly accurate clock information that is stable over a long period of time.

(Radio watch)
Next, an embodiment of a radio timepiece according to the present invention will be described with reference to FIG.
As shown in FIG. 21, the radio timepiece 130 according to the present embodiment includes the piezoelectric vibrator 1 electrically connected to the filter unit 131. The radio timepiece 130 receives a standard radio wave including timepiece information and is accurate. It is a clock with a function of automatically correcting and displaying the correct time.
In Japan, there are transmitting stations (transmitting stations) that transmit standard radio waves in Fukushima Prefecture (40 kHz) and Saga Prefecture (60 kHz), each transmitting standard radio waves. Long waves such as 40 kHz or 60 kHz have the property of propagating the surface of the earth and the property of propagating while reflecting the ionosphere and the surface of the earth, so the propagation range is wide, and the above two transmitting stations cover all of Japan. doing.

Hereinafter, the functional configuration of the radio timepiece 130 will be described in detail.
The antenna 132 receives a long standard wave of 40 kHz or 60 kHz. The long-wave standard radio wave is obtained by subjecting time information called a time code to AM modulation on a 40 kHz or 60 kHz carrier wave. The received long standard wave is amplified by the amplifier 133 and filtered and tuned by the filter unit 131 having the plurality of piezoelectric vibrators 1.
The piezoelectric vibrator 1 in this embodiment includes crystal vibrator portions 138 and 139 having resonance frequencies of 40 kHz and 60 kHz that are the same as the carrier frequency described above.

Further, the filtered signal having a predetermined frequency is detected and demodulated by the detection and rectification circuit 134. Subsequently, the time code is taken out via the waveform shaping circuit 135 and counted by the CPU 136. The CPU 136 reads information such as the current year, accumulated date, day of the week, and time. The read information is reflected in the RTC 137, and accurate time information is displayed.
Since the carrier wave is 40 kHz or 60 kHz, the crystal vibrator units 138 and 139 are preferably vibrators having the tuning fork type structure described above.

  In addition, although the above-mentioned description was shown in the example in Japan, the frequency of the long standard wave is different overseas. For example, in Germany, a standard radio wave of 77.5 KHz is used. Accordingly, when the radio timepiece 130 that can be used overseas is incorporated in a portable device, the piezoelectric vibrator 1 having a frequency different from that in Japan is required.

  As described above, according to the radio timepiece 130 of the present embodiment, since the piezoelectric vibrator 1 described above is provided, a high quality radio timepiece 130 having excellent characteristics and reliability can be provided. In addition to this, it is possible to count time stably and with high accuracy over a long period of time.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the present invention has been described by taking a piezoelectric vibrator using a tuning-fork type piezoelectric vibrating piece as an example. However, the present invention is not limited to this. For example, an AT-cut type piezoelectric vibrating piece (thickness-sliding vibrating piece) The present invention may be applied to a piezoelectric vibrator or the like using

In addition, each polishing condition in the outer peripheral surface polishing step (S120) described above can be appropriately changed.
Furthermore, the design of the method for applying tension to the polishing member 202 can be changed as appropriate. For example, the tensioners 212 may be omitted by configuring the rollers 210 and 211 to be movable and biasing the rollers 210 and 211 with an elastic member or the like.

  In the above-described embodiment, the case where the outer peripheral surface W1 of the wafer W is polished in two stages using the two types of polishing members 202 has been described. However, the present invention is not limited to this. I do not care.

  Furthermore, in the above-described embodiment, the case where the wafer W is sandwiched from both sides in the thickness direction using the grinding tables 205a and 205b of the holding unit 205 has been described as an example. However, the present invention is not limited to this configuration. You may use the vacuum suction pad etc. which can fix the front and back of W by vacuum suction.

  In the above-described embodiment, the case where the outer peripheral surfaces of the grinding tables 205a and 205b are parallel to the thickness direction of the wafer W1 has been described as an example. However, the present invention is not limited to this. As shown in FIG. 23 (a), an inclined surface 205c whose thickness increases from the outer side in the radial direction toward the inner side in the radial direction may be formed on the periphery of the grinding tables 205a and 205b. The inclined surface 205c is formed at an acute angle with respect to the front and back surfaces of the wafer, and is formed over the entire circumference of the grinding tables 205a and 205b. By configuring in this way, as shown in FIG. 23B, the angle of the curved surface portion W2 on the periphery of the wafer W formed by polishing is prevented from becoming more acute than the inclined surface 205c. Therefore, the corners of the periphery of the wafer W can be stably chamfered (R chamfering).

  Furthermore, in the above-described embodiment, when the outer peripheral surface of the wafer W is polished, the case where the holding unit 205 is rotated at a relatively low speed in order to polish the entire outer periphery of the wafer W has been described. The rotation of the means 205 may be rotated at a high speed so as to be actively used for polishing.

DESCRIPTION OF SYMBOLS 1 Piezoelectric vibrator 4 Piezoelectric vibration piece 5 Package 13,14,15 Excitation electrode 16,17 Mount electrode 19,20 Extraction electrode 100 Oscillator 101 Oscillator integrated circuit 110 Portable information device (electronic device)
DESCRIPTION OF SYMBOLS 113 Time measuring part of electronic device 130 Radio wave clock 131 Filter part of radio wave clock 202 Abrasive member 205 Holding means 205a, 205b Grinding table (holding body)
C cavity W wafer W1 outer peripheral surface

Claims (11)

A method for polishing an outer peripheral surface of a wafer by polishing an outer peripheral surface of a wafer using a belt-shaped polishing member,
A wafer setting step of holding the wafer from both sides in the thickness direction by holding means comprising a pair of rotatable holding bodies;
An abutting step of bringing the polishing member into contact with the outer peripheral surface of the wafer along the longitudinal direction of the polishing member along the circumferential direction of the wafer;
A polishing step of polishing the entire circumference of the outer peripheral surface of the wafer using a rotating operation of rotating the wafer by the holding means and a reciprocating operation of reciprocating the polishing member in the longitudinal direction. A method for polishing an outer peripheral surface of a wafer.   2. The method for polishing an outer peripheral surface of a wafer according to claim 1, wherein the polishing member is wider than the thickness of the wafer.   The holding body includes an inclined surface that increases in thickness from a radially outer side to a radially inner side at a peripheral portion of the holding body and has an acute angle with respect to the front and back surfaces of the wafer. Item 3. A method for polishing an outer peripheral surface of a wafer according to Item 2.   4. The method of polishing an outer peripheral surface of a wafer according to claim 1, wherein in the polishing step, the wafer is rotated at a constant speed by the rotation operation. 5.   5. The method for polishing a wafer outer peripheral surface according to claim 1, wherein tension is applied to the polishing member in the polishing step. 6. A method for manufacturing a piezoelectric vibrating piece using a wafer polished by the method for polishing an outer peripheral surface of a wafer according to any one of claims 1 to 5,
An outer shape forming step of patterning outer shapes of a plurality of piezoelectric vibrating reeds on the polished wafer;
An electrode film is patterned on the outer surfaces of the plurality of piezoelectric vibrating pieces, and the excitation electrode that vibrates the piezoelectric vibrating piece when a predetermined voltage is applied, and the excitation electrode electrically through the extraction electrode An electrode forming step for forming each of the mount electrodes to be connected;
And a cutting step of separating the plurality of piezoelectric vibrating pieces from the wafer and solidifying them.   A piezoelectric vibrating piece manufactured using the method for manufacturing a piezoelectric vibrating piece according to claim 6.   A piezoelectric vibrator comprising the piezoelectric vibrating piece according to claim 7 hermetically sealed in a package.   An oscillator, wherein the piezoelectric vibrator according to claim 8 is electrically connected to an integrated circuit as an oscillator.   9. An electronic apparatus, wherein the piezoelectric vibrator according to claim 8 is electrically connected to a time measuring unit.   A radio-controlled timepiece, wherein the piezoelectric vibrator according to claim 8 is electrically connected to a filter portion.

Images