Abstract:
The purpose of the present disclosure is to provide a piezoelectric device that is less likely to be damaged during the cutting process from a wafer into individual pieces, and can be measured at the wafer without being affected by adjacent piezoelectric devices. The piezoelectric device includes: a first plate which constitutes a part of the package for storing the vibrating portion, having a pair of first edges and second edges situated vertically to the first edges; a second plate bonded to the first plate and constitutes another part of the package for storing the vibrating portion; and an adhesive for bonding the first plate and the second plate together. A pair of castellations is formed on each first edge, situated symmetrical to a straight line that passes through a centerline of the first plate and is parallel to the second edge. The present disclosure also provides methods for manufacturing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Japan Patent Application No. 2011-036700, filed on Feb. 23, 2011, in the Japan Patent Office, the disclosure of which is incorporated herein by reference in its respective entirety. 
     FIELD OF THE INVENTION 
     This disclosure pertains to piezoelectric devices in which a plurality of package lids and package bases are manufactured from a wafer. This disclosure also pertains to methods for manufacturing such devices. 
     BACKGROUND OF THE INVENTION 
     Surface-mountable piezoelectric devices are preferably manufactured by mass-production. In the piezoelectric device disclosed in Japan Unexamined Patent Document No. 2006-148758, a quartz-crystal wafer having a plurality of quartz-crystal vibrating pieces is sandwiched between a lid wafer and a base wafer, wherein all three wafers have the same shape. Also, in the methods for manufacturing piezoelectric devices as disclosed in Japan Unexamined Patent Document No. 2006-148758, through-holes are made on the lid wafer and the base wafer for each corner of a package lid and a package base. An edge wire is formed on each device for electrically connecting the respective excitation electrodes with respective external terminals on each corner of the piezoelectric device. Then, the piezoelectric devices manufactured on the wafer are separated into individual pieces. 
     However, in the method of Japan Unexamined Patent Document No. 2006-148758 for manufacturing piezoelectric devices at a wafer scale, the through-holes are situated on each corner of a piezoelectric device, the adjacent piezoelectric devices remain as one unit. Whenever a piezoelectric device is cut along an edge, load is applied onto the piezoelectric device, and causes damage to the piezoelectric device. Also, the adjacent excitation electrodes of the adjacent piezoelectric devices are electrically connected by edge-surface electrodes formed on the through-holes. Therefore, the vibration frequency produced by individual piezoelectric vibrating pieces on the wafer cannot be measured. 
     In view of the foregoing, the present disclosure provides piezoelectric devices in which each piezoelectric device is less likely to be damaged during the cutting process into individual piezoelectric devices. The vibration frequencies of a plurality of piezoelectric devices on the wafer can be measured without being affected by adjacent piezoelectric devices. The present disclosure also provides methods for manufacturing such piezoelectric devices. 
     SUMMARY OF THE INVENTION 
     A first aspect of the present disclosure pertains to piezoelectric devices. In the first aspect, the piezoelectric devices comprise a vibrating portion that vibrates, whenever electrical voltage is applied. The piezoelectric devices comprise: a first plate having a rectangular profile, wherein the first plate includes a pair of straight first edges and a pair of straight second edges situated vertically to the first edges and constitutes a part of the package for storing the vibrating portion; a second plate having a rectangular profile, wherein the second plate is bonded to the first plate and constitutes the other part of the package for storing the vibrating portion; and adhesive for bonding together the first plate and the second plate. A pair of castellations is formed on each first edge, the castellations being recessed toward a center of the package base, and castellations are situated symmetrically to a straight line that passes through a centerline of the first plate and is parallel to the second edge. 
     A second aspect of the present disclosure pertains to piezoelectric devices. In the second aspect, the first plate comprises a package base for mounting the vibrating portion and forming the piezoelectric device; and the second plate comprises a package lid bonded onto the package base and hermetically seals the vibrating portion. 
     A third aspect of the present disclosure pertains to piezoelectric devices. In the third aspect, the second plate of the piezoelectric devices comprises a piezoelectric frame having the vibrating portion and an outer frame surrounding the vibrating portion thereof for constituting a part of the package; the first plate comprises a package base that is bonded onto a first surface of the frame portion of the piezoelectric frame; and the piezoelectric device further comprises a package lid that is bonded to a second surface of the frame portion of the piezoelectric frame, the package lid constitutes a part of the package for hermetically sealing the vibrating portion. 
     A fourth aspect of the present disclosure pertains to piezoelectric devices. In the fourth aspect, the first plate and the second plate are bonded using an adhesive, and the adhesive is fabricated from a glass material that melts between 350° C. to 410° C. 
     A fifth aspect of the present disclosure pertains to a method for manufacturing a piezoelectric device comprising a vibrating portion that vibrates when electrical voltage is applied. The method comprising the steps of: preparing a first wafer constituting a part of a package for storing the vibrating portion, the first wafer comprises a plurality of first plate having a rectangular profile constituted of a pair of first edges and a pair of second edges situated vertically to the first edges; forming through-holes situated at a cross-point between the first edge and the second edge to a center of the first edge, the through-holes extend through the first wafer depthwise; preparing a second wafer comprising a plurality of second plates having a rectangular profile, the second plates constitute a part of a package for storing the vibrating portion; first bonding step for bonding the first wafer and the second wafer using an adhesive; performing a first cutting step after the first bonding step, the first cutting step comprises a step of cutting the first wafer and the second wafer along the first edge; and performing a second cutting step after the first cutting step, the second cutting step comprises a step of cutting the first wafer and the second wafer along the second edge. 
     A sixth aspect of the present disclosure pertains to a method for manufacturing a piezoelectric device. In the sixth aspect, the first wafer comprises a base wafer having a plurality of package bases where the vibrating portions are mounted; and the second wafer comprises a lid wafer having a plurality of package lids that is bonded to the base wafer for hermetically sealing the vibrating portion. 
     A seventh aspect of the present disclosure pertains to a method for manufacturing a piezoelectric device. In the seventh aspect, the second wafer comprises a piezoelectric wafer; wherein the second wafer comprises a plurality of piezoelectric frames having the vibrating portion and an outer frame that surrounds the vibrating portion and forms a part of the package; the first wafer comprises a base wafer bonded to an entire surface of the piezoelectric wafer and includes a plurality of package bases. The method comprises a step for preparing a lid wafer comprising a plurality of package lids that constitutes the package for hermetically sealing the frame portion, the package base and the vibrating portion; and before the first cutting step, performing a second bonding step for bonding the lid wafer onto the other surface of the piezoelectric wafer using an adhesive. 
     An eighth aspect of the present disclosure pertains to a method for manufacturing a piezoelectric device. In the eighth aspect, during the first wafer preparation step, the length of the first edge is shorter than the length of the second edge. 
     A ninth aspect of the present disclosure pertains to a method for manufacturing a piezoelectric device. In the ninth aspect, during the first cutting step, the through-hole is cut in one-half 
     A tenth aspect of the present disclosure pertains to a method for manufacturing a piezoelectric device. In the tenth aspect, during the cutting step, the cut is made along an edge of the through-hole so as to form at least two through-holes in one piezoelectric device. 
     Effects of Invention 
     According to the present invention, piezoelectric devices are provided in which each piezoelectric device is less likely to be damaged during the cutting process from a wafer into individual pieces. Such piezoelectric devices can be measured at a wafer without being affected by adjacent piezoelectric devices. The present disclosure also provides methods for manufacturing such devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a first quartz-crystal vibrating device  100 . 
         FIG. 2A  is a cross-sectional view of  FIG. 1  taken along A-A line. 
         FIG. 2B  is a plan view of the bottom surface of the first quartz-crystal vibrating device  100 . 
         FIG. 3  is a flow-chart of steps in exemplary processes that may be used in an embodiment of a manufacturing method for a quartz-crystal vibrating device  100  of the first embodiment. 
         FIG. 4  is a plan view of a quartz-crystal wafer  10 W. 
         FIG. 5  is a plan view of a lid wafer  11 W. 
         FIG. 6  is a plan view of a base wafer  12 W. 
         FIG. 7  is a plan view of the bottom surface of a base wafer  12 W. 
         FIG. 8  is an exploded perspective view of a second quartz-crystal vibrating device  200 . 
         FIG. 9  is a plan view of the bottom surface of the second quartz-crystal vibrating device  200 . 
         FIG. 10  is a plan view of a base wafer  22 W. 
         FIG. 11  is a plan view of the bottom surface of the base wafer  22 W. 
         FIG. 12  is an exploded perspective view of a second quartz-crystal vibrating device  300 . 
         FIG. 13  is a plan view of the bottom surface of the second quartz-crystal vibrating device  300 . 
         FIG. 14  is a plan view of the bottom surface of a base wafer  32 W. 
         FIG. 15  is an exploded perspective view of a vibrating device  400 . 
         FIG. 16  is a cross-sectional view along the line B-B in  FIG. 15 . 
         FIG. 17  is a plan view of a base wafer  40 W. 
         FIG. 18A  is a plan view of a quartz-crystal vibrating piece  40 ′ viewed from its +Y′-axis side. 
         FIG. 18B  is a perspective view of the vibrating piece  40 ′ viewed from its +Y′-axis side. 
         FIG. 18C  is a plan view of a package base  42 ′ viewed from its +Y′-axis side. 
         FIG. 18D  is a perspective view of the package base  42 ′ viewed from its +Y′-axis side. 
         FIG. 19  is a cross-sectional view along the line D-D in  FIG. 18B . 
         FIG. 20A  is a plan view of an alternative configuration  400 ′ viewed from its +Y′-axis side. In  FIG. 20A  and  FIG. 20B , the vibrating piece  40 ′ is shown as transparent so that the package base  42 ′ can be viewed.  FIG. 20B  is an exploded view of dotted line E. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the explanation below, an AT-cut quartz-crystal vibrating piece is used as a piezoelectric vibrating piece. An AT-cut quartz-crystal material has a principal surface (in the YZ plane) that is tilted by 35° 15′ about the Y-axis of a crystal-coordinate system (XYZ) in the direction of the Y-axis from the Z-axis around the X-axis. In the following description, new axes tilted with respect to the axial directions of the quartz-crystal material are denoted as the Y′-axis and Z′-axis, respectively. Therefore, in the quartz-crystal device  100 , the longitudinal direction of the piezoelectric device is the X-axis direction, the height direction is the Y′-axis direction, and the direction perpendicular to the X-axis and Y′-axis directions is the Z′-axis direction. 
     First Embodiment 
     &lt;Overall Configuration of the First Quartz-crystal Vibrating Device  100 &gt; 
     Overall configuration of a first quartz-crystal vibrating device  100  is explained with reference to  FIGS. 1 and 2 .  FIG. 1  is an exploded perspective view of the first quartz-crystal vibrating device  100 .  FIG. 2A  is a cross-sectional view of  FIG. 1  taken along A-A line.  FIG. 2B  is a plan view of the bottom surface of the first quartz-crystal vibrating device  100 . In  FIG. 1 , an adhesive low-melting-point glass LG is shown as transparent, so that entire connection electrodes  124   a  and  124   b  can be viewed. 
     As shown in  FIGS. 1 and 2 , the first quartz-crystal vibrating device  100  comprises a package lid  11  defining a lid recess portion  111 , a package base  12  defining a base recess portion  121  and a planar quartz-crystal vibrating piece  10  mounted onto the package base  12 . 
     The quartz-crystal vibrating piece  10  comprises an AT-cut quartz-crystal piece  101  and a pair of respective excitation electrodes  102   a  and  102   b  situated substantially in the center of the quartz-crystal piece  101  on the respective principal surfaces thereof. The excitation electrode  102   a  is connected to a respective extraction electrode  103   a , extending in the −X-axis direction on the bottom surface (+Z′-axis side surface) of the quartz-crystal piece  101 . The excitation electrode  102   b  is connected to a respective extraction electrode  103   b , extending in the +X-axis direction on the bottom surface (surface on the −Z′-axis side) of the quartz-crystal piece  101 . The vibrating piece  10  can be mesa-type or inverted-mesa-type. 
     Each of the excitation electrode  102   a ,  102   b  and the extraction electrode  103   a ,  103   b  comprises a foundation layer of chromium (Cr) overlying with a gold layer. An exemplary thickness of the chromium layer is in the range of 0.05 μm to 0.1 μm, and an exemplary thickness of the gold layer is in the range of 0.2 μm to 2 μm. 
     The package base  12  is fabricated from a glass or piezoelectric material, and comprises a second peripheral surface M 2  on its principal surface (+Y′-side surface), circumscribing a base recess  121 . The package base  12  is rectangular shape, and comprises a pair of first edges L 1  extending in the Z′-axis direction and a pair of second edges L 2  extending in the X-axis direction. Four castellations  122  are formed on the first edge L 1  of the package base  12 . 
     Specifically, two base castellations  122   a , and  122   b  are formed on the first edge L 1  of the package base  12  in the −X-axis direction. The base castellations  122   a ,  122   b  are formed simultaneously with the formation of the base through-holes BH 1  (see  FIGS. 6 and 7 ). The base castellation  122   a  is situated on the +Z-axis side, and the base castellation  122   b  is situated on the −Z-axis side. The base castellations  122   a  and  122   b  are formed on each region which is separated by an axis Ax. The axis Ax extends through a center of the package base  12  and is parallel with the second edge L 2  (bisecting the piezoelectric device). Thus, the base castellations  122   a  and  122   b  are situated symmetrically to an axis Ax and along the Z′-axis direction. 
     Similarly, two base castellations  122   c ,  122   d  are formed on the first edge L 1  in the +X-axis direction, and the base through-holes BH 1  are simultaneously formed (see  FIGS. 6 and 7 ). Two base castellations extend in the Z′-axis direction. Here, the base castellation  122   c  extends in the −Z-axis direction, and the base castellation  122   d  extends in the +Z′-axis direction. The base castellations  122   c  and  122   d  are formed on two regions separated by an axis Ax. The axis Ax extends through a center of the package base  12  and is parallel to the second edge L 2 . Thus, the base castellations  122   c  and  122   d  are situated symmetrically to an axis Ax and along the Z′-axis direction. 
     Preferably, the base castellations  122   a  and  122   c , and the base castellations  122   b  and  122   d  are situated point-symmetrically to the center point of the package base  12 . 
     Respective base edge-surface electrodes  123   a - 123   d  are on the base castellations  122   a - 122   d . The second peripheral surface M 2  of the package base  12  includes a pair of connecting electrodes  124   a ,  124   b . A connecting electrode  124   a  is electrically connected to the base edge-surface electrode  123   a ; similarly, a connecting electrode  124   b  is electrically connected to the base edge-surface electrode  123   c . The base edge-surface electrodes  123   a ,  123   c  are configured oppose to each other and diagonally across the package base  12 . 
     On the mounting surface M 3  of the package base  12  are two pairs of mounting terminals  125   a - 125   d , which are electrically connected to respective base edge-surface electrodes  123   a - 123   d . Of the two pairs of mounting terminals  125   a - 125   d , one pair  125   a ,  125   c  serves as mounting electrodes for external electrodes (hereinafter referred as “external electrodes”) and connected to respective connecting electrodes  124   a ,  124   b  via respective base edge-surface electrodes  123   a ,  123   c . The external electrodes  125   a ,  125   c  are situated diagonally on the package base  12 . Whenever an alternating voltage (voltage that alternates positive and negative) is applied across the external electrodes  125   a ,  125   c , the vibrating device  10  exhibits a thickness-shear vibration mode. 
     Of the two pairs of mounting terminals  125   a - 125   d , the other pair of mounting terminals  125   b ,  125   d  serves as mounting terminals for grounding electrodes (hereinafter referred as “grounding electrodes”)  125   b ,  125   d , used for grounding the base edge-surface electrodes  123   b ,  123   d  as necessary. The grounding electrodes  125   b ,  125   d  are situated along different diagonals (compared to the external electrodes  125   a ,  125   c ). Since the grounding electrodes  125   b ,  125   d  are used for grounding, they also include respective terminals for bonding the quartz-crystal vibrating device  100  to the mounting printed board (not shown) without electrical connections. 
     Referring further to  FIG. 2B , the pair of external electrodes  125   a ,  125   c  and the pair of grounding electrodes  125   b ,  125   d  are situated apart from each other. The external electrode  125   a  and the grounding electrode  125   d  are situated apart from one edge of the package base  12  in the +Z′-axis direction. The grounding electrode  125   b  and the external electrode  125   c  are formed apart from each other in the −Z′-axis direction. A space SP 1  is situated between each external electrode  125   a  and its corresponding grounding electrode  125   b  and between each external electrode  125   c  and its corresponding grounding electrode  125   d  in the Z′-axis direction. The width of the space SP 1  is, for example, 200 μm to 500 μm. Also, a space SP 2  is situated between each external electrode  125   a  and the adjacent edge of the package base  12 , between each grounding electrode  125   d  and the adjacent edge of the package base  12 , between each grounding electrode  125   b  and the adjacent edge of the package base  12 , between each external electrode  125   c  and the adjacent edge of the package base  12 . The space SP 2  is, for example, 0 μm to 100 μm wide in the Z-axis direction. 
     In the first quartz-crystal vibrating device  100 , the quartz-crystal vibrating piece  10  is longer in the X-axis direction than the base recess  121 . Therefore, whenever a quartz-crystal vibrating piece  10  is mounted onto a package base  12  using electrically conductive adhesive  13 , both X-direction edges of the quartz-crystal vibrating piece  10  mount to the second peripheral surface M 2  of the package base  12 , as shown in  FIG. 2A . Thus, the extraction electrodes  103   a ,  103   b  on the quartz-crystal vibrating piece  10  are electrically connected to respective connecting electrodes  124   a ,  124   b  on the package base  12 . Hence, the respective external electrodes  125   a ,  125   c  are connected to respective excitation electrodes  102   a ,  102   b  through the respective base edge-surface electrodes  123   a ,  123   c , the respective connecting electrodes  124   a ,  124   b , the electrically conductive adhesive  13 , and the extraction electrodes  103   a ,  103   b.    
     The package lid  11  comprises a lid recess  111  having a greater area in the XZ′ plane than the base recess  121 . A first peripheral surface M 1  circumscribes the lid recess  111 . Whenever the first peripheral surface M 1  of the package lid  11  and the second peripheral surface M 2  of the package base  12  are bonded together, a cavity CT is defined in which the quartz-crystal vibrating piece  10  is situated. The cavity CT is defined in part by the lid recess  111  and in part by the base recess  121 . The cavity CT is filled with an inert-gas or is under a vacuum. 
     The first peripheral surface M 1  of the package lid  11  and second peripheral surface M 2  of the package base  12  are bonded together using a sealing material (non-electrically conductive adhesive), for example a low-melting-point glass LG. Low-melting-point glass LG is a lead-free vanadium-based glass having an adhesive component that melts at 350° C. to 410° C. Vanadium-based glass can be formulated as a paste mixed with a binder and a solvent. Vanadium-based glass bonds to various materials by melting and solidifying. Low-melting-point glass forms a highly reliable air-tight seal and resists water and humidity. Also, since the coefficient of thermal expansion of a low-melting-point glass can be controlled effectively by controlling its glass structure, this material can adjust to various coefficients of thermal expansion. 
     Regarding the package lid  11 , the lid recess  111  is longer in the X-axis direction than the quartz-crystal vibrating piece  10  in the X-axis direction and the base recess  121  in the X-axis direction. Also, as shown in FIGS.  1  and  2 A- 2 B, the low-melting-point glass LG bonds the package lid  11  and the package base  12  at the second peripheral surface M 2 , having a width of approximately 300 μm. 
     Although the quartz-crystal vibrating piece  10  of this embodiment is mounted inside the package on the second peripheral surface M 2  of the package base  12 , the vibrating piece can be stored inside the base recess  121 . In such an instance, the connecting electrodes are parts of respective base castellations  122   a ,  122   c  and extend to the bottom surface of the base recess  121  via the second peripheral surface M 2 . Alternatively, the package lid can be planar and without a recess. 
     &lt;Method for Manufacturing the First Quartz-crystal Vibrating Device  100 &gt; 
       FIG. 3  is a flow-chart of steps in exemplary processes that may be used in an embodiment of a manufacturing method for a quartz-crystal vibrating device  100  of the first embodiment. In  FIG. 3 , a protocol S 10  for manufacturing the quartz-crystal vibrating piece  10 , a protocol S 11  for manufacturing the package lid  11  and a protocol S 12  for manufacturing the package base  12  can be carried out separately or concurrently.  FIG. 4  is a plan view of a quartz-crystal wafer  10 W in which a plurality of quartz-crystal vibrating pieces  10  can be manufactured simultaneously.  FIG. 5  is a plan view of a lid wafer  11 W in which a plurality of package lids  11  can be manufactured simultaneously.  FIG. 6  is a plan view of a base wafer  12 W in which a plurality of package bases  12  can be manufactured simultaneously.  FIG. 7  is a plan view of the bottom surface of a base wafer  12 W. 
     In protocol S 10 , the quartz-crystal vibrating piece  10  is manufactured. The protocol S 10  includes steps S  101 -S  103 . 
     In step S 101  (see  FIG. 4 ) the profile outlines of multiple quartz-crystal vibrating pieces  10  are formed on the planar surface of the quartz-crystal wafer  10 W by etching. Each quartz-crystal vibrating piece  10  is connected to the quartz-crystal wafer  10 W by a respective joining portion  104 . 
     In step S 102  a layer of chromium is formed, followed by forming an overlying layer of gold, on both main surfaces as well as the edge surfaces of the entire quartz-crystal wafer  10 W by sputtering or vacuum-deposition. Then, a photoresist is applied uniformly on the surface of the metal layer. Using an exposure apparatus (not shown), the profile outlines of the excitation electrodes and of the extraction electrodes are lithographically exposed onto the crystal wafer  10 W. Next, regions of the metal layer exposed by photoresist are denuded by etching. As shown in  FIG. 4 , etching forms the excitation electrodes  102   a ,  102   b  and extraction electrodes  103   a ,  103   b  on both main surfaces and edge surfaces of the quartz-crystal wafer  10 W. 
     In step S 103  the quartz-crystal vibrating pieces  10  on the crystal wafer are cut to separate individual devices. During cutting, cuts are made along cut lines CL (denoted by dot-dash lines in  FIG. 4 ) using a dicing unit such as a laser beam or dicing saw. 
     In protocol S 11 , the package lid  11  is manufactured. As shown in  FIG. 5 , several hundreds to several thousands of lid recesses  111  are formed on a main surface of a lid wafer  11 W, with the latter being a circular, uniformly planar plate of a quartz-crystal material. The lid recesses  111  are formed in the lid wafer  11 W by etching or mechanical processing, leaving the first peripheral surfaces M 1  around the lid recesses  111 . 
     In protocol S 12 , the package base  12  is manufactured. Protocol S 12  includes steps S 121 -S 123 . 
     In step S 121 , as shown in  FIG. 6 , several hundreds to several thousands of base recesses  121  are formed on the base wafer  12 W, the latter being a circular, uniformly planar plate of quartz-crystal material. Multiple base recesses  121  are formed on the base wafer  12 W by etching or mechanical processing, and the second peripheral surfaces M 2  circumscribe the respective base recesses  121 . Two rounded-rectangular base through-holes BH 1  are formed on the pair of first edge L 1  of each package base  12  simultaneously. The base through-holes BH 1  extend depthwise through the base wafer  12 W. Two base through-holes BH 1  are situated symmetrically to an axis Ax and along the Z′-axis direction. Whenever a base through-hole BH 1  is cut in half during dicing, it forms a respective base castellation  122   a - 122   d  ( FIG. 1 ). 
     In step S 122 , a foundation layer of chromium (Cr) is formed, followed by a subsequent formation of an overlying layer of gold (Au) on both main surfaces of the base wafer  12 W by sputtering or etching. Then, as shown in  FIG. 6 , the connecting electrodes  124   a ,  124   b  are formed on the second peripheral surface M 2  by etching. Simultaneously, the base edge-surface electrodes  123   a - 123   d  are formed on the entire surfaces of the base through-holes BH 1  ( FIG. 1 ). 
     A pair of external electrodes  125   a ,  125   c  and a pair of grounding electrodes  125   b ,  125   d  is formed on the bottom surface of the base wafer  12 W simultaneously, as shown in  FIG. 7 . Here, the external electrodes and grounding terminals formed on the package base  12  in adjacent X-axis directions are formed as one unit (electrically connected status). Specific explanations are made using four package bases ( 12 A- 12 D) indicated with surrounding dotted lines. The external electrode  125   a  on the package base  12 B, the grounding electrode  125   d  on the package base  12 C, and the base edge-surface electrodes  123   a ,  123   d  on the base through-holes BH 1  are formed simultaneously. Also, the external electrode  125   c  on the package base  12 B, the grounding electrode  125   b  on the package base  12 A, and the base edge-surface electrodes  123   b ,  123   c  are formed simultaneously. Further, the grounding terminals (including external electrodes and grounding electrodes) on the package base  12 B are formed at a space SP 3  away from the external electrodes and grounding electrodes formed on the package base  12 D. Here, the space SP 3  is in the range of approximately 40 μm to 280 μm. If, for example, the space SP 3  is 40 μm, and if the width of a dicing cut (described later in step S 17 ) is 40 μm, the space SP 2  indicated in  FIG. 2B  would be 0 μm. Consequently, the external electrodes and grounding electrodes formed on the adjacent package bases  12  in the X-axis direction are connected and the external electrodes and grounding electrodes formed on the adjacent package bases  12  in the Z′-axis direction are disconnected. 
     In step S 123 , the low-melting point glass LG is printed on the second peripheral surface M 2  at the corresponding position to the first peripheral surface M 1 . A film of low-melting-point glass is formed on the second peripheral surface M 2  of the base wafer  12 W by preliminary curing. Although the low-melting-point glass LG is formed on the second peripheral surface M 2  of the package base  12  in this embodiment, it can alternatively be formed on the first peripheral surface M 12  of the package base  11 . In this case, the film of low-melting-point glass LG is preferred not to be formed on a position which corresponds to the base through-holes BH 1 . 
     In step S 13 , each quartz-crystal vibrating piece  10  manufactured in protocol S 10  is mounted onto the second peripheral surface M 2  of the package base  12  formed on the base wafer  12 W using electrically conductive adhesive  13 . The quartz-crystal vibrating piece  10  is mounted onto the second peripheral surface M 2  of the package base  12  so as to align the extraction electrodes  103   a ,  103   b  formed on the quartz-crystal vibrating piece  10  with respective connecting electrodes  124   a ,  124   b  formed on the second peripheral surface M 2  of the package base  12 . Thus, several hundreds to several thousands of quartz-crystal vibrating pieces  10  are mounted onto the base wafer  12 W. 
     In step S 14 , a pair of probes PB 1 , PB 2  (refer to  FIG. 7 ) for measuring vibration frequency in brought into contact with a pair of external electrodes  125   a  and  125   c  on the package base  12 . Thus, the vibration frequency of each quartz-crystal vibrating piece  10  is measured. 
     Referring to  FIG. 7 , even if an alternating voltage is applied to the external electrodes  125   a ,  125   c  on the package base  12 B via the probes PB 1 , PB 2 , the external electrodes  125   a ,  125   c  on the package base  12 A,  12 C,  12 D do not electrically connect with each other. Thus, the package base  12 B is not affected by other quartz-crystal vibrating pieces  10  on the package bases  12 A,  12 C,  12 D. This allows the vibration frequency of the quartz-crystal vibrating piece  10  on the package base  12  to be measured accurately, at the wafer, before dicing. Also, in step S 14 , although the probes PB 1 , PB 2  for measuring vibration frequency are brought into contact with the external electrodes  125   a ,  125   c , the probes alternatively contact the connecting electrodes  124   a ,  124   b  or to the base edge-surface electrodes  123   a ,  123   c , for obtaining measurements of the vibration frequency of the quartz-crystal vibrating pieces  10 . 
     In step S 15 , the thickness of the excitation electrode  102   a  on the quartz-crystal vibrating piece  10  is adjusted. The thickness can be adjusted by sputtering a metal onto the excitation electrode  102   a  to increase its mass (and thus to decrease its vibration frequency), or by evaporating some metal from the excitation electrode  102   a  to decrease its mass (and thus to increase its vibration frequency). This method for adjusting vibration frequency is discussed in Japan Unexamined Patent Document 2009-141825, in which the assignee is the same as the assignee of the present disclosure. If the measured vibration frequency is within its pre-specified proper range, then adjustment of vibration frequency is not required. 
     The vibration frequency of one quartz-crystal vibrating piece  10  can be measured in step S 14 , then the vibration frequency of the one quartz-crystal vibrating piece  10  can be adjusted in step S 15 . This step is repeated for all quartz-crystal vibrating pieces  10  situated on the base wafer  12 W. Also, in step S 14 , after measuring the vibration frequencies of all the quartz-crystal vibrating pieces  10  situated on the base wafer  12 W, in step S 15 , the vibration frequency of the quartz-crystal vibrating pieces  10  can be adjusted one-by-one. 
     In step S 16  the low-melting-point glass LG is heated as the lid wafer  11 W and base wafer  12 W are compressed against each other. Thus, the lid wafer  11 W and base wafer  12 W are bonded together by the low-melting-point glass LG. 
     In step S 17  the bonded-together lid wafer  11 W and base wafer  12 W are cut along the Z′-axis direction. This cutting is performed by using a dicing unit such as a laser beam or a dicing saw. In step S 17 , the bonded-together lid wafer  11 W and base wafer  12 W is cut until separated along the scribe line SL, denoted by the dot-dash lines in  FIGS. 5-7 . Thus, the lid wafer  11 W and base wafer  12 W are cut separately along the first edge L 1  which the base through-holes BH 1  are formed. Here, since no load is applied onto the base wafer  12 W whenever the dicing unit passes through the through-hole BH 1 , the duration of the wafers being loaded will be shortened. This prevents damage to the base wafer  12 W, such as the peeling of electrodes. 
     In step S 18  the bonded-together lid wafer  11 W and base wafer  12 W are cut along the X-axis direction. Thus, the bonded-together lid wafer  11 W and base wafer  12 W are cut until separated along the second scribe line SL 2 , denoted by the dot-dash lines in  FIGS. 5-7 . Also, although the through-hole BH 1  is not formed along the second scribe line SL 2 , the duration of the wafers being loaded will be shortened, since the lid wafer  11 W and base wafer  12 W are cut along the Z′-axis direction in step S 17 . This prevents damage to the base wafer  12 W, such as the peeling of electrodes. After going through steps S 17  and S 18 , several hundreds to several thousands of quartz-crystal vibrating devices  100  are produced from the bonded-together lid wafer  11 W and base wafer  12 W. 
     In step S 17  and S 18 , the bonded-together lid wafer  11 W and base wafer  12 W are cut along the first edge L 1 , and the bonded-together lid wafer  11 W and base wafer  12 W are cut along the second edge L 2 . In order to minimize the duration of wafers being loaded during the cutting process, it is preferred to form the first edge L 1  shorter than the second edge L 2 . 
     In step S 19 , the vibration frequency of the separate individual first quartz-crystal vibrating devices  100  is measured. 
     Second Embodiment 
     &lt;Overall Configuration of Second Quartz-crystal Vibrating Device  200 &gt; 
     The overall configuration of the second embodiment of a quartz-crystal vibrating device  200  is described below with reference to  FIGS. 8 and 9 .  FIG. 8  is an exploded perspective view of a second quartz-crystal vibrating device  200 , and  FIG. 9  is a plan view of the bottom surface of the second quartz-crystal vibrating device  200 . In  FIG. 8 , low-melting-point glass LG used as a sealing material is shown as transparent, so that the entire connecting electrodes  124   a  and  124   b  can be viewed. In this embodiment, components that are similar to corresponding components of the first embodiment have the same respective reference numerals and are not described further below. 
     As shown in  FIGS. 8 , the second quartz-crystal vibrating device  200  comprises a package lid  11 , a package base  22 , and a planar quartz-crystal vibrating piece  10  mounted on the package base  22 . 
     The package base  22  is fabricated from a glass or piezoelectric material, and comprises a second peripheral surface M 2  on its principal surface (+Y′-axis side surface), circumscribing a base recess  121 . The package base  22  has a rectangular profile, and comprises a pair of first edges L 1  extending parallel to the Z′-axis direction and a pair of second edges L 2  extending parallel to the X-axis direction. On the first edge L 1  of the package base  22 , a pair of castellations  222   a ,  222   c  is formed. 
     Specifically, a base castellation  222   a  is situated on the +Z′-axis side of the first edge L 1  in the −X-axis direction, which was formed simultaneously with the formation of the base through-holes BH 2  (see  FIGS. 10 and 11 ), and extend in the Z′-axis direction. Thus, the base castellation  222   a  is situated on the +Z′-axis region of the axis Ax. Similarly, a base castellation  222   c  is situated on the −Z′-axis side of the first edge L 1  in the +X-axis direction, which was formed simultaneously with the formation of the base through-holes BH 2  (see  FIGS. 10 and 11 ), and extend in the Z′-axis direction. Thus, the base castellation  222   c  is situated on the −Z′-axis region of the axis Ax. Preferably, the base castellations  222   a  and  222   c , and the base castellations  222   b  and  222   d  are situated point-symmetrically to the center point of the package base  22 . Respective base edge-surface electrodes  223   a ,  223   c  are formed on the base castellations  222   a ,  222   c  (see  FIG. 9 ). 
     As shown in  FIG. 9 , on the mounting surface M 3  of the package base  22  are a pair of external electrodes  225   a ,  225   c  that are electrically connected to the respective base edge-surface electrodes  223   a ,  223   c , and a pair of grounding electrodes  225   b ,  225   d  for grounding. On the package base  22 , the external electrodes  225   a ,  225   c  are electrically connected to the base edge-surface electrodes  223   a ,  223   c  that are formed simultaneously with the base castellations  222   a ,  222   c . Castellations are not formed on the grounding electrodes  225   b  and  225   d.    
     Referring further to  FIG. 9 , the pair of external electrodes  225   a ,  225   c  and the pair of grounding electrodes  225   b ,  225   d  are situated apart from each other. The external electrode  225   a  and the grounding electrode  225   d  are situated apart from the second edge L 2  in the +Z′-axis direction of the package base  22  (see  FIG. 8 ). The grounding electrode  225   b  and the external electrode  225   c  are situated apart from the second edge L 2  in the −Z′-axis direction of the package base  22  (see  FIG. 8 ). 
     In the second embodiment, although a pair of grounding electrodes  225   b ,  225   d  is formed in combination with the pair of external electrodes  225   a ,  225   c , grounding electrodes  225   b ,  225   d  does not need to be formed. 
     &lt;Method for Manufacturing the Second Quartz-crystal Vibrating Device  200 &gt; 
     The method for manufacturing the second embodiment of a quartz-crystal vibrating device  200  essentially follows the flow-chart in  FIG. 3  diagramming the method for manufacturing the first embodiment of a quartz-crystal vibrating device  100 . However, during the formation of the package bases  22  on the base wafer  22 W, the shape of the through-holes BH 2  differ from the previous embodiment.  FIG. 10  is a plan view of a base wafer  22 W, and  FIG. 11  is a plan view of the bottom surface of the base wafer  22 W. 
     As shown in  FIG. 10 , in the second quartz-crystal vibrating device  200 , a pair of through-holes BH 2  are formed along the −Z′-axis side of the first edge L 1  in the +X-axis direction, and along the +Z′-axis side of the first edge L 1  in the −X-axis direction. Thus, the adjacent through-holes BH 2  in the Z′-axis direction are situated alternatively on both sides of the second scribe line SL 2 . 
     Thus, in step S 17  of  FIG. 3 , when the base wafer  22 W is cut along the first scribe line SL 1 , the metal film  226  may form on the first edge L 1  of the package base  22  (see  FIG. 8 ). Specifically, as shown in  FIGS. 8 and 9 , the metal films  226  are formed on the −Z′-axis side of the base castellation  222   a  of the first edge L 1  in the −X-axis direction and on the +Z′-axis side of the base castellation  222   c  of the first edge L 1  in the +X-axis direction, and are connected to the respective grounding electrodes  225   b ,  225   d.    
     As shown in  FIG. 11 , vibration frequencies of individual quartz-crystal vibrating pieces  10  can be measured by contacting a pair of probes PB 1 , PB 2  for measuring vibrating frequency to a pair of external electrodes  225   a ,  225   c  on the package base  22  (see  FIG. 8 ). Measuring method is the same as explained in step S 14  of  FIG. 3 , and further explanations are omitted. 
     Furthermore, during the cutting step for separating the bonded-together lid wafer  11 W and base wafer  22 W into individual second quartz-crystal vibrating devices  200 , cuts are made along the first scribe line SL 1  where the through-holes BH 2  are formed. Then, the bonded-together lid wafer  11 W and base wafer  22 W are cut along the scribe line SL 2  where the through-holes BH 2  are not formed. 
     According to this cutting process, the duration of load onto the lid wafer  11 W and base wafer  22 W during cutting process can be shortened. Accordingly, damage to the base wafer  22 W, such as peeling of electrodes, is prevented. 
     Third Embodiment 
     &lt;Overall Configuration of Third Quartz-crystal Vibrating Device  300 &gt; 
     The overall configuration of the third embodiment of a quartz-crystal vibrating device  300  is described below with reference to  FIGS. 12 and 13 .  FIG. 12  is an exploded perspective view of a third quartz-crystal vibrating device  300 , and  FIG. 13  is a plan view of the bottom surface of the second quartz-crystal vibrating device  300 . In  FIG. 12 , low-melting-point glass LG used as a sealing material is shown as transparent, so that the entire connecting electrodes  324   a  and  324   b  can be viewed. In this embodiment, components that are similar to corresponding components of the first embodiment have the same respective reference numerals and are not described further below. 
     As shown in  FIGS. 12 and 13 , the third quartz-crystal vibrating device  300  comprises a package lid  11 , a package base  32 , and a planar quartz-crystal vibrating piece  30 . The quartz-crystal vibrating piece  30  is mounted to the package base  32 . 
     The quartz-crystal vibrating piece  30  comprises an AT-cut quartz-crystal piece  101 . A pair of excitation electrodes  102   a ,  102   b  is situated substantially in the center of the quartz-crystal piece  101 , in which the electrodes are oppose to each other. The excitation electrode  102   a  is connected to an extraction electrode  303   a , extending in the −X-axis direction, and to the bottom surface (+Z′-axis surface) of the quartz-crystal piece  101 . The excitation electrode  102   b  is connected to an extraction electrode  303   b , extending in the −X-axis direction, to the bottom surface (−Z′-axis side surface) of the quartz-crystal piece  101 . The shape of the extraction electrode on the vibrating piece  30  is different from the shape of the extraction electrode on the vibrating piece  10  in the first embodiment. 
     On the pair of first edges L 1  of the package base  32  extending in the X-axis direction, four base castellations  122   a - 122   d  are situated (see  FIG. 14 ). The base castellations  122   a  and  122   b  are situated symmetrically to the axis Ax that passes through the centerline of the package base and is parallel with the second edge L 2 . Thus, the base castellations  122   a  and  122   b  are situated symmetrically to an axis Ax and along the Z′-axis direction. Similarly, the base castellations  122   c  and  122   d  are situated symmetricallt to the axis Ax that passes through the centerline of the package base and is parallel to the second edge L 2 . Thus, the base castellations  122   c  and  122   d  are situated symmetrically to an axis Ax and along the Z′-axis direction. Also, respective base edge-surface electrodes  323   a - 323   d  are situated on the respective base castellations  122   a - 122   d.    
     Connecting electrodes  324   a ,  324   b , formed on the second peripheral surface M 2 , are connected to the respective base edge-surface electrodes  323   a ,  323   b  on the −X-axis direction of the package base  32 , aligned with the quartz-crystal vibrating piece  30 . A pair of external electrodes  325   a ,  325   b  connected to the respective base edge-surface electrodes  323   a ,  323   b  is formed on the mounting surface M 3  of the package base  32  in the -X-axis direction. Base edge-surface electrodes  323   c ,  323   d  formed on the mounting surface M 3  of the package base  32  in the +X-axis direction are connected to respective grounding electrodes  325   c ,  325   d  situated on the mounting surface M 3  of the package base  32  in the +X-axis direction. 
     As shown in  FIG. 13 , the external electrodes  325   a ,  325   b  and grounding electrodes  325   c ,  325   d  are situated apart from each other. The respective external electrodes  325   a ,  325   b  and the respective grounding electrodes  325   c ,  325   d  are separated by a space SP 1 . The space SP 1  is in the range of 200 μm to 500 μm in the Z′-axis direction, for example. The external electrode  325   a  and the grounding electrode  325   d  are situated apart from the second edge-surface L 2  of the package base  32  in the +Z′-axis direction. Similarly, the external electrode  325   b  and the grounding electrode  325   c  are situated apart from the second edge-surface L 2  of the package base  32  in the −Z′-axis direction. The external electrode  325   a  or the grounding electrode  325   d  and the second edge L 2  of the package base  32  in the +Z-axis direction, and the external electrode  325   b  or the grounding electrode  325   c  and the second edge L 2  of the package base  32  in the −Z-axis direction are separated by a space SP 2 . The space SP 2  is in the range of 0 μm to 100 μm in the Z′-axis direction, for example. 
     &lt;Method for Manufacturing a Third Quartz-crystal Vibrating Device  300 &gt; 
     The method for manufacturing a third quartz-crystal vibrating device  300  essentially follows the exemplary process steps of the flow-chart in  FIG. 3  diagramming the method for manufacturing the first embodiment of a quartz-crystal vibrating device  100 . However, as shown in  FIG. 14 , during the formation of the package bases  32  on the base wafer  32 W, the respective positions of the external electrodes and the grounding electrodes differ from the corresponding positions in the first embodiment. 
       FIG. 14  is a plan view of the bottom surface of a base wafer  32 W, on which a plurality of package bases  32  are manufactured simultaneously. The external electrode  325   a  and the grounding electrode  325   d , formed on adjacent package bases  32 A,  32 B in the X-axis direction, are formed as one unit. Similarly, the external electrode  325   b  and the grounding electrode  325   c  are formed as one unit. The mounting terminals (external electrodes and grounding electrodes) formed in the adjacent Z′-axis directions are formed apart from each other, and the space SP 3  in the Z′-axis direction is in the range of approximately 40 μm to 280 μm. 
     Hence, whenever probes PB 1 , PB 2  for measuring vibration frequency are in contact with the external electrodes  325   a ,  325   b  on the package base  32 A, the vibration frequency of each quartz-crystal vibrating piece  30  is measured. Even if an alternating voltage is applied from the probes PB 1 , PB 2  to the external electrodes  325   a ,  325   b  on the package base  32 A, the external electrodes  325   a ,  325   b  only connect to the grounding electrodes  325   c ,  325   d  on the package base  32 B without making electrical connection to the quartz-crystal vibrating piece  30  on the package base  32 B. Therefore, the vibration frequency of the quartz-crystal vibrating piece  30  on the package base  32  can be measured accurately at the wafer level before dicing. 
     Furthermore, during the cutting step for separating the bonded-together lid wafer  11 W and base wafer  32 W into individual third quartz-crystal vibrating devices  300 , cuts are made along the first scribe line SL 1  where the first through-holes BH 1  are formed. Then, the bonded-together lid wafer  11 W and base wafer  32 W are cut along the second scribe line SL 2  where the second through-holes BH 1  are not formed. 
     According to this cutting process, duration of loading onto the base wafer  32 W during cutting process can be shortened. Accordingly, damage to the base wafer  32 W, such as peeling of electrodes, is prevented. 
     Fourth Embodiment 
     &lt;Overall Configuration of a Fourth Quartz-crystal Vibrating Device  400 &gt; 
     The general configuration of the fourth embodiment of a quartz-crystal vibrating device  400  is described below with reference to  FIGS. 15 and 16 .  FIG. 15  is an exploded perspective view of a vibrating device  400 , and  FIG. 16  is a cross-sectional view along the line B-B in  FIG. 15 . 
     As shown in  FIGS. 15 and 16 , the fourth quartz-crystal vibrating device  400  comprises a package lid  41  (defining a lid recess  411 ), a package base  42  (defining a base recess  421 ), and a quartz-crystal vibrating piece  40  sandwiched between the package lid  41  and the package base  42 . 
     The quartz-crystal vibrating piece  40  comprises a quartz-crystal vibrating portion  401  including respective excitation electrodes  402   a ,  402   b  on each main surface thereof An outer frame  408  surrounds the quartz-crystal vibrating portion  401 . Between the vibrating portion  401  and the outer frame  408  are respective supporting portions  404   a ,  404   b  extending from the vibrating portion  401  along both edges in the X-axis directions. This leaves a pair of L-shaped slots  405   a ,  405   b  situated between the vibrating portion  401  and the outer frame  408 . Rounded-rectangular quartz-crystal castellations  406   a - 406   d  are situated on respective edges of the vibrating piece  40  in respective X-axis directions and extending in the Z′-axis directions. Two castellations are formed on each edge. These castellations were originally formed as rounded-rectangular through-holes CH (refer to  FIG. 17 ). Respective quartz-crystal edge-surface electrodes  407   a - 407   d  is formed on each quartz-crystal castellation  406   a - 406   d.    
     An extraction electrode  403   a  is formed on the first surface Me of the supporting portion  404   a , which connects one edge of the vibrating piece  40  in the-X-axis direction to the quartz-crystal edge-surface electrode  407   a  formed on the other edge in the +Z-axis direction. The quartz-crystal edge-surface electrode  407   a  desirably extends to the second surface Mi of the vibrating piece  40  and connects to the connecting pad  407 M. The connecting pad  407 M is electrically connected to the connecting pads  423 M of the base edge-surface electrode  423   a , which is described later below. Similarly, on the second surface Mi of the joining portion  404   b , an extraction electrode  403   b  connects the respective excitation electrode  402   b  to the quartz-crystal edge-surface electrode  407   c  on the vibrating piece  40  in the +X-axis direction and on the -Z-axis side surface. The extraction electrode  403   b  is electrically connected to the connecting pad  423 M of the base edge-surface electrode  423   c , which is described later below. 
     The package base  42  has a rectangular profile having a pair of first edges L 1  extending in the Z′-axis direction and a pair of second edge L 2  extending in the X-axis direction. The package base  42  is fabricated from glass or a quartz-crystal material, and comprises a second peripheral surface M 2  on its principal surface (+Y′-axis surface) surrounding the base recess  421 . Respective base castellations  422   a - 422   d , two castellations on each edge are formed on both edges of the package base  42  in the X-axis directions. These castellations were originally formed as base through-holes BH 1  ( FIGS. 6 and 7 ). Specifically, the base castellations  422   a ,  422   b  are situated on the -X-axis direction, and the base castellations  422   c ,  422   d  are situated on the +X-axis direction. The base castellations  422   a ,  422   b  and the base castellations  422   c ,  422   d  are situated symmetrically to the axis Ax that passes through the centerline of the package base and are parallel to the second edge L 2 . Preferably, the base castellations  422   a  and  422   c , and the base castellations  422   b  and  422   d  are situated point-symmetrically to the center point of the package base  42 . 
     Respective base edge-surface electrodes  423   a - 423   d  are formed on the base castellations  422   a - 422   d . The base edge-surface electrode  423   a , situated on the package base  42  in the −X-axis direction of the first edge L 1  and on the +Z′-axis side, is connected to the connecting pad  407 M situated on the vibrating piece  40  via the connecting pad  423 M on the second peripheral surface M 2 . Thus, the base edge-surface electrode  423   a  is connected to the extraction electrode  403   a  via the connecting pad  407 M and the quartz-crystal edge-surface electrode  407   a . Also, the base edge-surface electrode  423   c  situated on the package base  42  in the +X-axis side of the first edge L 1  and on the −Z′-axis direction is connected to the extraction electrode  403   b  on the vibrating piece  40 . 
     On the package base  42 , two external electrodes  425   a ,  425   c , and two grounding electrodes  425   b ,  425   d  are configured diagonally from each other on the mounting surface M 3  (see  FIG. 2B ). Each external electrode  425   a ,  425   c  is connected to the respective base edge-surface electrode  423   a ,  423   c  that is connected to the respective extraction electrode  403   a ,  403   b  on the vibrating piece  40 . Each grounding electrode  425   b ,  425   d  is connected to the respective base edge-surface electrodes  423   b ,  423   d.    
     As shown in  FIG. 16 , the package lid  41 , the outer frame  408 , and the package base  42  bonded together define a cavity CT in which the quartz-crystal vibrating piece  40  is situated. The package lid  41 , the vibrating piece  40 , and the package base  42  are sealed together using a sealing material of, for example, low-melting-point glass. 
     The fourth embodiment is similar to the first embodiment in that a pair of external electrodes and a pair of grounding electrodes are situated diagonally from each other on the mounting surface of the vibrating device  400 . The fourth embodiment is also similar to the second embodiment and that a pair of external electrodes and a pair of grounding electrodes are situated on one side. Furthermore, as explained in the second embodiment, the third embodiment may lack castellations corresponding to a pair of grounding electrodes. 
     &lt;Method for Manufacturing a Fourth Quartz-crystal Vibrating Device  400 &gt; 
     This method for manufacturing the fourth embodiment of a quartz-crystal vibrating device  400  essentially follows the exemplary process steps in the flow-chart in  FIG. 3 .  FIG. 17  is a plan view of a base wafer  40 W from which a plurality of quartz-crystal vibrating pieces  40  can be made. 
     In step S 101  ( FIG. 17 ), the profile outlines of a plurality of quartz-crystal vibrating pieces  40  are formed on the planar quartz-crystal wafer  40 W by etching. A quartz-crystal vibrating portion  401 , an outer frame  408 , and a pair of slots  405   a ,  405   b  are thereby formed. On respective edges of each vibrating piece  40  in the X-axis directions, two quartz-crystal through-holes CH are formed simultaneously. The through-holes CH extend depthwise through the wafer  40 W. Whenever the quartz-crystal through-holes CH are cut in half during dicing, they forms the respective castellations  406   a - 406   d  ( FIG. 15 ). 
     In step S 11 , a plurality of package lids  41  is manufactured. Manufacturing method of the package lid  41  is same as described in the first embodiment. 
     In protocol S 12 , multiple package bases  42  are manufactured. Protocol S 12  includes steps S 121 -S 123 . Comparing to the first embodiment, the pair of connecting pads  423 M is formed on the second peripheral surface M 2  (see  FIG. 15 ) instead of the pair of connecting electrodes  124   a ,  124   b  (see  FIG. 6 ). 
     In step S 13 , the quartz-crystal wafer having multiple quartz-crystal vibrating pieces  40  manufactured in step S  10  is bonded to the base wafer having multiple package bases  42  using the low-melting-point glass LG. During the bonding, the connecting pad  407 M on the quartz-crystal wafer  40 W is bonded to the connecting pad  423 M on the base wafer, and the extraction electrode  403   b  on the quartz-crystal wafer  40 W is bonded to the connecting pad  423 M on the base wafer. 
     In step S 14 , probes PB 1 , PB 2  for measuring vibration frequency are contacted to respective external electrodes  425   a ,  425   c  on the same package base  42 . Thus, the vibration frequency of each vibrating portion  401  is measured. Even if an alternating voltage is applied to the external electrodes  425   a ,  425   c , the external electrodes  425   a ,  425   c  only connect to the adjacent grounding electrodes  425   b ,  425   d  on the package base  42  and do not electrically connect to the external electrodes  425   a ,  425   c . Hence, the vibration frequency of the vibrating portion  401  can be measured accurately at the wafer level before dicing. 
     In step S 15 , as shown in the first embodiment, the thickness of the excitation electrode  402   a  of the vibrating portion  401  is adjusted. 
     In step T 16  the applied low-melting-point glass LG is heated as the lid wafer and base wafer are compressed against each other. Thus, the lid wafer and the base wafer are bonded together by the low-melting-point glass LG. 
     In step T 17  the bonded-together lid wafer  41 W, the crystal wafer  40 W (see  FIG. 17 ) and the base wafer  42 W (see  FIGS. 6 and 7 ) is cut up into separate individual pieces along the Z′-axis direction. This cutting is performed by using a dicing unit such as a laser beam or a dicing saw. In step S 17 , the bonded-together lid wafer  41 W, the quartz-crystal wafer  40 W and the base wafer  42 W are cut until separated along the scribe line SL 1 , denoted by dot-dash lines in  FIGS. 5-7  and  17 . Thus, the lid wafer  41 W and base wafer  42 W are cut until separated along the first edge L 1 , which the base through-holes BH 1 , CH are formed. Here, since no load is applied onto the quartz-crystal wafer and base wafer  42 W whenever the dicing unit passes through the through-hole BH 1  CH, the duration of the wafers being loaded will be shortened. Accordingly, damage to the quartz-crystal wafer and base wafer  42 W, such as peeling of electrodes, is prevented. 
     In step S 18  the bonded-together lid wafer  41 W (see  FIG. 5 ), quartz-crystal wafer  40 W (see  FIG. 17 ) and base wafer  42 W (see  FIGS. 6 and 7 ) are cut along the X-axis direction. Thus, the bonded-together lid wafer  41 W, quartz-crystal wafer  40 W and base wafer  42 W are cut until separated along the second scribe line SL 2 , denoted by dot-dash lines in  FIGS. 5-7  and  17 . Also, although the through-holes BH 1 , CH are not formed along the second scribe line SL 2 , the duration of the wafers being loaded will be shortened, since the lid wafer  41 W, quartz-crystal wafer  40 W and base wafer  42 W are cut along the Z′-axis direction in step S 17 . Accordingly, damage to the quartz-crystal wafer  40 W and base wafer  42 W, such as peeling of electrodes, is prevented. After going through steps S 17  and S 18 , several hundreds to several thousands of quartz-crystal vibrating devices  400  are produced from the bonded-together lid wafer  41 W, quartz-crystal wafer  40 W and base wafer  42 W. 
     In step S 19 , vibration frequency of the separate individual first quartz-crystal vibrating devices  400  is measured. 
     In step S 12  of the third embodiment, the base edge-surface electrodes  423   a - 423   d , external electrodes  425   a ,  425   c  and grounding electrodes  425   b ,  425   d  are formed on the package base  42 . Then, in step S 13 , the quartz-crystal wafer and base wafer are bonded together. However, after bonding the quartz-crystal wafer and the base wafer (lacking electrodes) together, respective base edge-surface electrodes  423   a - 423   d , external electrodes  425   a ,  425   c , and grounding electrodes  425   b ,  425   b  can be formed by sputtering. Thus, the connecting pad  423 M on the package base  42 , shown in  FIGS. 15 and 16 , needs not be formed. This manufacturing method can be also applied to the alternative configuration to fourth embodiment, as described below. 
     Alternative Configuration to Fourth Embodiment 
     &lt;Overall Configuration of Fourth Quartz-crystal Vibrating Device  400 ′&gt; 
     The general features of this alternative configuration  400 ′ of the fourth embodiment of a quartz-crystal vibrating device  400  are described with reference to  FIGS. 18-20A .  FIG. 18A  is a plan view of the quartz-crystal vibrating piece  40 ′ viewed from its +Y′-axis side.  FIG. 18B  is a perspective view of the vibrating piece  40 ′ viewed from its +Y′-axis side.  FIG. 18C  is a plan view of the package base  42 ′ viewed from its +Y′-axis side.  FIG. 18D  is a perspective view of the package base  42 ′ viewed from its +Y′-axis side.  FIG. 19  is a cross-sectional view along the line D-D in  FIG. 18B .  FIG. 20A  is a plan view of the alternative configuration  400 ′ viewed from its +Y′-axis side. In  FIG. 20A , the package lid  31  is not shown. Also, in  FIG. 20A and 20B , the vibrating piece  40 ′ is shown as transparent so that the package base  42 ′ can be viewed. 
     As shown in  FIGS. 18A and 18B , the quartz-crystal vibrating piece  40 ′ of the fourth embodiment of a quartz-crystal vibrating device  400 ′ does not have a quartz-crystal castellations. The quartz-crystal vibrating piece  40 ′ comprises a quartz-crystal vibrating portion  401  including respective excitation electrodes  402   a ,  402   b  on both principal surfaces thereof and the outer frame  408  surrounding the quartz-crystal vibrating portion  401 . Between the vibrating portion  401  and the outer frame  408 , a pair of supporting portions  404   a ′,  404   b ′ is situated. The supporting arms extend from the vibrating portion  401  in the −X-axis direction. Thus, between the vibrating portion  401  and the outer frame  408 , a rectangular slot  405   a ′ is defined that extends in the −X-axis direction. Also, between the supporting portion  404   a ′,  404   b ′, a rectangular slot  405   b ′ is defined. 
     In  FIG. 19 , the extraction electrode  403   a ′, formed on the first surface Me of the vibrating piece  40 ′ and connected to the excitation electrode  402   a , extends completely from the first surface Me to the second surface Mi of the vibrating piece  40 ′ via the edge surface M 4  on the slot  405   a′.    
     Returning to  FIGS. 18A and 18B , the extraction electrode  403   a ′ (on the vibrating piece  40 ′ and extending to the second surface Mi) is formed on one corner of the vibrating piece  30 ′ on the +Z′-axis side and in the −X-axis direction. Since multiple quartz-crystal vibrating pieces  40 ′ are manufactured on a wafer, the extraction electrode  403   a ′ is situated with a space SP 1  away from one edge of the vibrating piece  40 ′ in the +Z′-axis side, so as to prevent the extraction electrode  403   a ′ from adversely affecting the adjacent quartz-crystal vibrating piece  40 ′. 
     The extraction electrode  403   b ′ on the second surface Mi of the vibrating piece  40 ′ extends from the quartz-crystal vibrating portion  401  in the −X-axis direction and is formed on one corner of the vibrating piece  40 ′ on the −Z′-axis side and in the +X-axis direction. Since multiple quartz-crystal vibrating pieces  40 ′ are manufactured on a wafer, the extraction electrode  403   b ′ is situated with a space SP 1  away from one edge of the vibrating piece  40 ′ on the −Z′-axis side, so as to prevent the extraction electrode  403   b ′ from adversely affecting the adjacent quartz-crystal vibrating piece  40 ′. 
     Referring now to  FIGS. 18C and 18D , the package base  42 ′ in this alternative configuration is essentially similar to the package base  42  in the third embodiment. However, in this alternative configuration, the base edge-surface electrodes  423   b ,  423   d  (see  FIG. 15 ) connected to the grounding electrodes  425   b ,  425   d  extend to the second peripheral surface M 2  of the package base  42 ′, thus forming the connecting pad  423 M. 
     Also, as shown in  FIG. 20A , the package lid  41  (see  FIG. 15 ), the vibrating piece  40 ′, and the package base  42 ′ are bonded together, which simultaneously bonds the extraction electrodes  403   a ′,  403   b ′ of the vibrating piece  40 ′ to the external electrodes  425   a ,  425   c  of the connecting pad  423 M. Thus, the respective external electrodes  425   a ,  425   c  of the package base  42 ′ are connected to the respective excitation electrodes  402   a ,  402   b  of the vibrating piece  40 ′. 
     Preferably, the extraction electrode  403   b ′ on the second surface Mi (and extending through the outer frame  408 ), and the connecting pad  423 M formed on the second peripheral surface M 2  (and connected to the base castellation  422   b ) are formed being separate from the connecting pad  423 M. This is because, whenever multiple package bases  42 ′ are formed on a wafer, the grounding electrode  425   b  (connected to the base castellation  422   b ) is connected to the external electrode  425   c  of the adjacent package base  42 ′ (see  FIG. 7 ). 
     Therefore, as shown in  FIG. 20B , it is desired to form the extraction electrode  403   b ′ separately from the connecting pad  423 M (connected to the base castellation  422   b  by a space SP 7  in the X-axis direction). The space SP 7  is approximately 10 μm wide. 
     In  FIG. 20A and 20B , although the extraction electrode  403   b ′ and the connecting pad  423 M on the −X-axis direction are placed apart from each other in the X-axis directions, these features do not need to be formed apart. Thus, the space SP 7  in the X-axis direction shown in  FIG. 20A and 20B  need not be formed if the extraction electrode  403   b ′ and the connecting pad  423 M in the −X-axis direction are cut off due to the application of the low-melting-point glass LG in the Y′-axis direction. It is desired to form a joining electrode (not shown) covering a part or the entire external electrode  425   c  (see  FIG. 18D ), the base edge-surface electrode  423   c , and the extraction electrode  403   b ′, so that the extraction electrode  403   b ′ and the connecting pad  423 M in the +X-axis direction are assuredly connected together. Accordingly, the length of the outer frame  408  is minimized and forming a larger quartz-crystal vibrating portion  401  is allowed. 
     &lt;Method for Manufacturing a Fourth Quartz-crystal Vibrating Device  400 ′&gt; 
     The method for manufacturing the alternative configuration of the fourth embodiment of a vibrating device  400 ′ essentially follows the method in the fourth embodiment. Thus, in the alternative configuration of the fourth embodiment, cuts of the bonded together lid wafer  41 W, quartz-crystal wafer  40 W and base wafer  42 W into individual fourth quartz-crystal vibrating devices  400 ′, are made along the first scribe line SL 1  where the through-holes BH 1  are formed. Then, the bonded-together lid wafer  41 W, quartz-crystal wafer  40 W and base wafer  42 W are cut along the scribe line SL 2  where the through-holes BH 1  are not formed. 
     According to this cutting process, duration of load onto the base wafer  42 W during cutting process can be shortened. Accordingly, damage to the base wafer  42 W, such as peeling of electrodes, is prevented. 
     Industrial Applicability 
     Representative embodiments have been described in detail above. As evident to those skilled in the art, the present invention may be changed or modified in various ways within the technical scope of the invention. 
     For example, although the present disclosure was explained within the context of AT-cut quartz-crystal vibrating piece, it can be replaced with a tuning-fork type quartz-crystal vibrating piece. 
     Also, although low-melting-point glass was used for bonding together the base wafer, quartz-crystal wafer, and lid wafer, this bonding material can be replaced with polyimide resin. Whenever polyimide resin is applied, it can be used for screen-printing or exposure after applying a photosensitive polyimide resin on the entire surface. 
     In this specification, although the various embodiments have been described in the context of quartz-crystal vibrating pieces, it will be understood that the embodiments can be applied with equal facility to piezoelectric materials such as lithium tantalite and lithium niobate. Furthermore, the present disclosure can be applied to piezoelectric oscillators that also include an IC configured as an oscillating circuit mounted inside the package on the package base.