JP6123217B2

JP6123217B2 - Piezoelectric vibrating piece

Info

Publication number: JP6123217B2
Application number: JP2012227195A
Authority: JP
Inventors: 和靖阪本; 賢周森本
Original assignee: Daishinku Corp
Current assignee: Daishinku Corp
Priority date: 2012-10-12
Filing date: 2012-10-12
Publication date: 2017-05-10
Anticipated expiration: 2032-10-12
Also published as: JP2014082538A

Description

本発明は、電子機器などに用いられる圧電振動片に関する。 The present invention relates to a piezoelectric vibrating piece used in an electronic device or the like.

圧電振動子に代表される圧電振動デバイスは、携帯電話などの移動体通信機などに広く用いられている。圧電振動子に用いられる圧電振動片の一つとして水晶振動片がある。水晶振動片は、表裏主面に励振電極とこれらの励振電極を水晶振動片の端部に延出するための引出電極などが形成されている。このような水晶振動片は、上部が開口した箱状のパッケージ内部に形成された端子電極と、水晶振動片の引出電極の端部に形成された接合部（接続電極）とを導電性接合材を介して接合され、前記開口部分を蓋で気密封止することで表面実装型の水晶振動子が構成される。 Piezoelectric vibration devices represented by piezoelectric vibrators are widely used in mobile communication devices such as mobile phones. There is a crystal vibrating piece as one of the piezoelectric vibrating pieces used in the piezoelectric vibrator. The quartz crystal resonator element is formed with excitation electrodes and lead electrodes for extending these excitation electrodes at the ends of the quartz crystal resonator element on the front and back main surfaces. Such a crystal vibrating piece is a conductive bonding material in which a terminal electrode formed inside a box-shaped package having an open top and a joint (connection electrode) formed at an end of the extraction electrode of the crystal vibrating piece The surface-mount type crystal resonator is configured by airtightly sealing the opening portion with a lid.

例えば特許文献１に示す水晶振動子では、水晶振動片とパッケージとを金属バンプなどの導電性接合材で電気機械的に接合しており、相互の接合強度を向上させるために、水晶振動片に形成される励振電極と接続電極とに関して、下地電極の材料と電極形成方法とを異ならせたものが開示されている。 For example, in the crystal resonator shown in Patent Document 1, the crystal vibrating piece and the package are electromechanically bonded with a conductive bonding material such as a metal bump. In order to improve the mutual bonding strength, With respect to the excitation electrode and the connection electrode to be formed, the base electrode material and the electrode formation method are disclosed differently.

特開２００４−１０４７１９号公報JP 2004-104719 A

しかしながら、特許文献１の構成では、電極形成のための製造工程が増えるだけでなく、電極構造も複雑なものとなる。結果としてコスト高となるだけでなく、より簡易な構成が望ましい小型化された圧電振動子には不向きな構成であった。 However, in the configuration of Patent Document 1, not only the number of manufacturing steps for electrode formation increases, but also the electrode structure becomes complicated. As a result, not only is the cost high, but the configuration is unsuitable for a miniaturized piezoelectric vibrator in which a simpler configuration is desirable.

本発明は、かかる点に鑑みてなされたものであり、安価で、小型化に有利で、かつ、接合強度を高めた圧電振動片を提供することを目的とするものである。 The present invention has been made in view of such points, and an object of the present invention is to provide a piezoelectric vibrating piece that is inexpensive, is advantageous for downsizing, and has increased bonding strength.

上記の目的を達成するため、本発明にかかる圧電振動片は、一対の励振電極と、前記一対の励振電極からそれぞれ引き出された一対の引出電極と、が少なくとも形成され、前記一対の引出電極各々の先端部は、外部電極に接合するための接続電極となり、前記接続電極各々の上面には、バンプが少なくとも形成され、前記バンプは、前記接続電極側に向く第１面と、外部電極との接合面となる第２面とを少なくとも有し、前記第１面が前記第２面より小さく、前記バンプの外形は、前記第１面と、前記第２面と、前記第１面と前記第２面とを繋ぐ側面とから構成され、前記側面は曲面形成されたことを特徴とする。 In order to achieve the above object, a piezoelectric vibrating piece according to the present invention includes at least a pair of excitation electrodes and a pair of extraction electrodes respectively extracted from the pair of excitation electrodes, and each of the pair of extraction electrodes The tip of each of the connection electrodes serves as a connection electrode for bonding to an external electrode, and at least a bump is formed on the upper surface of each of the connection electrodes, and the bump includes a first surface facing the connection electrode and an external electrode. and a second surface as a bonding surface at least, the first surface is rather smaller than the second surface, the outer shape of the bump, the said first surface, said second surface, said first surface and It is comprised from the side surface which connects a 2nd surface, The said side surface was formed in the curved surface, It is characterized by the above-mentioned .

本発明によれば、安価で、小型化に有利で、かつ、接合強度を高めることが可能となる。具体的には、前記接続電極各々の上面に前記バンプが少なくとも形成され、前記バンプの前記第１面が前記第２面より小さいので、前記バンプの前記第２面を実質大きくとることが可能となる。そのため、当該圧電振動片の基板が小さくなり、その結果、前記接続電極が小さくなったとしても、外部電極に接する前記第２面を小さくすることなく、接合強度を保つことが可能となる。その結果、当該圧電振動片を小型化すると、小型化に比例して外部電極に接続する接合箇所も小さくなるが、本発明では接合箇所（前記第２面）を小さくするのを抑制することができ、結果として小型化しても接合強度を高めることが可能となる。また、前記側面が曲面形成されているので、前記側面が平坦面に形成される形態に比べて第２面の周縁の厚みを薄くすることが可能となり、外部電極への接合時に加圧でより均一に拡がって潰し易くなり、また低加圧での接合も可能となる。さらに、前記バンプの厚さを増すことなく容易に前記第２面を大きくすることが可能となり、また前記第２面の周縁を容易に広げることが可能となる。また、前記バンプを形成する際にレジストを用いた場合、レジストの量を少なく（もしくはレジストの厚さを薄く）することが可能となる。 According to the present invention, it is inexpensive, advantageous for downsizing, and it is possible to increase the bonding strength. Specifically, at least the bump is formed on the upper surface of each of the connection electrodes, and the first surface of the bump is smaller than the second surface, so that the second surface of the bump can be made substantially larger. Become. Therefore, board decreases of the piezoelectric vibrating piece, as a result, even as the connecting electrode is reduced, without reducing the second surface in contact with the external electrodes, it is possible to maintain the bonding strength. As a result, when the piezoelectric vibrating piece is miniaturized, the joint location connected to the external electrode is also reduced in proportion to the miniaturization. However, in the present invention, it is possible to suppress the joint location (the second surface) from being reduced. As a result, even if the size is reduced, the bonding strength can be increased. In addition, since the side surface is formed in a curved surface, it is possible to reduce the thickness of the peripheral edge of the second surface as compared with a form in which the side surface is formed as a flat surface, and more pressure is applied during bonding to the external electrode. It spreads uniformly and is easily crushed, and can be joined at a low pressure. Furthermore, the second surface can be easily enlarged without increasing the thickness of the bump, and the periphery of the second surface can be easily widened. In addition, when a resist is used when forming the bumps, the amount of resist can be reduced (or the resist thickness can be reduced).

また、前記バンプの外形が、前記第１面と、前記第２面と、前記第１面と前記第２面とを繋ぐ側面とから構成され、前記バンプの形成工程においてフォトリソ工法を用いた場合、前記接続電極側に向く第１面が、外部電極との接合面となる第２面より小さいので、前記第１面に接する部位（前記基板側の部材で例えば接続電極）と前記側面との頂角が鋭角になる。そのため、露出時に頂角部分に遮られて感光することがなく、この頂角部分にレジストが溜まることになるが、このレジストはレジスト除去の際に取り除くことができるので、レジストが残留することはない。その結果、レジスト残留による接合強度の劣化や、ガスの発生等は生じない。 Further, when the outer shape of the bump is composed of the first surface, the second surface, and a side surface connecting the first surface and the second surface, and a photolithography method is used in the bump forming step Since the first surface facing the connection electrode side is smaller than the second surface serving as a joint surface with the external electrode, a portion (contact electrode, for example, a connection electrode on the substrate side) that contacts the first surface and the side surface The apex angle becomes acute. Therefore, the vertical angle portion is not exposed to exposure during exposure, and the resist accumulates in this vertical angle portion, but since this resist can be removed at the time of resist removal, the resist remains. Absent. As a result, there is no deterioration in bonding strength or gas generation due to residual resist.

前記構成において、前記バンプは、接合部材を介して前記接続電極上に形成されてもよい。 The said structure WHEREIN: The said bump may be formed on the said connection electrode through a joining member.

この場合、前記バンプは前記接合部材を介して前記接続電極上に形成されるので、外部電極に前記バンプを介して前記接続電極を接合した際に前記バンプを全て潰す圧力を加えた場合であっても前記接合部材が存在することで、前記バンプよりも前記接合部材の方が潰れ難くなる。また、前記バンプのみを潰す場合、低圧力で潰すことが可能となり、本構成によれば、前記接合部材を潰さずに前記バンプのみを潰すことが可能となる。その結果、接合部材の形状や形態を可変させることなく、概ね維持することが可能となり、前記接合部材の上面の前記バンプはより潰し易い。すなわち、前記バンプが低荷重で均一に潰し易くなる。そのため、安定した外部電極と前記接続電極との接合を行うことが可能となる。 In this case, since the bump is formed on the connection electrode via the bonding member, when the connection electrode is bonded to the external electrode via the bump, a pressure for crushing the bump is applied. However, the presence of the bonding member makes the bonding member less likely to be crushed than the bump. Further, when only the bumps are crushed, it is possible to squeeze them with a low pressure, and according to this configuration, it is possible to crush only the bumps without crushing the bonding member. As a result, it is possible to maintain the joining member without changing the shape and form thereof, and the bumps on the upper surface of the joining member are more easily crushed. That is, the bumps can be easily crushed with a low load. Therefore, it becomes possible to perform a stable joining of the external electrode and the connection electrode.

前記構成において、前記接続電極各々の上には、前記バンプが複数形成されてもよい。 In the above configuration, a plurality of the bumps may be formed on each connection electrode.

この場合、前記接続電極各々の上に前記バンプが複数形成されるので、前記接続電極各々の上に前記バンプが１つ形成される形態に比べて、外部電極との接合面となる前記第２面に対して前記バンプがより均一に広がって潰れ易くなり、接合強度のばらつきが生じにくい。その結果、接合強度の安定化につながる。 In this case, a plurality of the bumps are formed on each of the connection electrodes, so that the second surface serving as a joint surface with the external electrode is compared with a form in which one of the bumps is formed on each of the connection electrodes. The bumps spread more uniformly with respect to the surface and are easily crushed, and variations in bonding strength are less likely to occur. As a result, the joint strength is stabilized.

前記構成において、前記接続電極各々の上に形成された複数の前記バンプのうち、当該圧電振動片の側面（当該圧電振動片の基板の端）に近い側に形成された前記バンプの前記第２面が、前記側面から遠い側に形成された前記バンプの前記第２面よりも大きくてもよい。 In the configuration, the second of the bumps formed on the side closer to the side surface of the piezoelectric vibrating piece (the substrate end of the piezoelectric vibrating piece) among the plurality of bumps formed on each of the connection electrodes. surface may be larger than the second surface of the bumps formed on the side farther from the side surface.

この場合、前記接続電極各々の上に形成された複数の前記バンプのうち、当該圧電振動片の側面に近い側に形成されたバンプの第２面が、前記側面から遠い側に形成されたバンプの第２面よりも大きいので、バンプを潰す際に、小さいバンプの方向にバンプが広がり、接合面のうち当該圧電振動片の中央領域に向かってより均一に広がって潰れ易くなり、当該圧電振動片の中央領域の強度向上を図ることが可能となる。また電極の短絡を確実に防止することも可能となる。また、前記側面に近い側に形成された前記バンプの接合領域を拡げることが可能となる。つまり、前記側面から遠い側に形成された前記バンプの前記第２面は、前記側面に近い側に形成された前記バンプの前記第２面よりも小さくなるので、接合の際に、接合部材外に前記バンプが出るのを防ぐことが可能となる。 In this case, among the plurality of bumps formed on each of the connection electrodes, the second surface of the bump formed on the side close to the side surface of the piezoelectric vibrating piece is the bump formed on the side far from the side surface. because of larger than the second surface, when collapsing the bump, bump spreads in the direction of small bumps, easily collapsed spread more evenly toward the central region of the piezoelectric vibrating piece of the joint surface, the piezoelectric vibrating It is possible to improve the strength of the central region of the piece . It is also possible to reliably prevent short-circuiting of the electrodes. Further, it is possible to expand the bonding area of the bumps formed on the side closer to the side surface. In other words, the second surface of the bumps formed on the side farther from the side surface, becomes smaller than the second surface of the bumps formed on the side closer to the side, at the time of bonding, the bonding member outer It is possible to prevent the bumps from coming out.

ここで、バンプの側面が曲面形成された構成の代わりに、バンプの側面が断面視で直線に形成された構成を採用してもよい。具体的には、前記バンプの外形は、前記第１面と、前記第２面と、前記第１面と前記第２面とを繋ぐ側面とから構成され、前記側面は断面視で直線に形成されてもよい。Here, instead of the configuration in which the side surface of the bump is formed into a curved surface, a configuration in which the side surface of the bump is formed in a straight line in a sectional view may be adopted. Specifically, the outer shape of the bump is composed of the first surface, the second surface, and a side surface connecting the first surface and the second surface, and the side surface is formed in a straight line in a sectional view. May be.

前記構成において、前記第２面が平坦面に形成されてもよい。The said structure WHEREIN: The said 2nd surface may be formed in a flat surface.

前記構成において、前記第２面が曲面形成されてもよい。 In the above configuration, the second surface may be formed as a curved surface.

この場合、前記第２面が曲面形成されるので、前記第２面が平坦面形成される形態に比べて、前記バンプがより均一に広がって潰れ易くなり、より小さな加圧力で確実に潰れて接合強度も高まる。また、前記バンプの高さに多少のばらつきが生じても、前記曲面の部分で高さのばらつきを吸収することが可能となる。その結果、より安定した接合を行うことが可能となる。 In this case, since the second surface is formed as a curved surface, the bumps are more uniformly spread and crushed more easily than in the case where the second surface is formed as a flat surface, and reliably crushed with a smaller pressure. Bonding strength is also increased. In addition, even if some variation occurs in the height of the bump, the variation in height can be absorbed by the curved portion. As a result, more stable joining can be performed.

以上のように、本発明によれば、安価で、小型化に有利で、かつ、接合強度を高めることができる。 As described above, according to the present invention, it is inexpensive, advantageous for downsizing, and the bonding strength can be increased.

図１は、本発明の実施の形態を示す音叉型水晶振動子の模式図であり、音叉型水晶振動片を図２に示すＢ−Ｂ線で切断した状態の概略端面図である。FIG. 1 is a schematic diagram of a tuning fork type crystal resonator showing an embodiment of the present invention, and is a schematic end view of a state in which a tuning fork type crystal vibrating piece is cut along line BB shown in FIG. 図２は、本発明の実施の形態を示す音叉型水晶振動片の一主面側の平面図である。FIG. 2 is a plan view of one main surface side of the tuning-fork type crystal vibrating piece showing the embodiment of the present invention. 図３は、図２のＡ−Ａ線端面図である。3 is an end view taken along line AA in FIG. 図４は、他の実施の形態を示すバンプを拡大した概略拡大断面図である。FIG. 4 is a schematic enlarged cross-sectional view showing an enlarged bump showing another embodiment. 図５は、他の実施の形態を示すバンプを拡大した概略拡大断面図である。FIG. 5 is a schematic enlarged cross-sectional view of an enlarged bump showing another embodiment. 図６は、他の実施の形態を示すバンプを拡大した概略拡大断面図である。FIG. 6 is a schematic enlarged cross-sectional view of an enlarged bump showing another embodiment. 図７は、他の実施の形態を示すバンプを拡大した概略拡大平面図である。FIG. 7 is a schematic enlarged plan view of an enlarged bump showing another embodiment. 図８は、他の実施の形態を示すバンプを拡大した概略拡大平面図である。FIG. 8 is a schematic enlarged plan view of an enlarged bump showing another embodiment. 図９は、他の実施の形態を示すバンプを拡大した概略拡大平面図である。FIG. 9 is a schematic enlarged plan view of an enlarged bump showing another embodiment.

以下、圧電振動片として音叉型水晶振動子を例に挙げて図面とともに説明する。本実施の形態で使用される音叉型水晶振動子１では、ベース３と図示しない蓋とが封止部材Ｈを介して接合されて筐体が構成される。具体的には、上部が開口したベース３の電極パッド３２上に音叉型水晶振動片２が接合部材７を介して接合され、ベース３の開口部（開口）を封止するように、封止部材Ｈを介して開口の端面に板状の蓋を接合した構成となっている。ここで、本実施の形態では音叉型水晶振動子１の公称周波数は３２．７６８ｋＨｚとなっている。なお、公称周波数は一例であり、他の周波数にも適用可能である。 Hereinafter, a tuning fork type crystal resonator will be described as an example of the piezoelectric vibrating piece with reference to the drawings. In the tuning fork type crystal resonator 1 used in the present embodiment, a base 3 and a lid (not shown) are joined via a sealing member H to form a casing. Specifically, the tuning fork type crystal vibrating piece 2 is bonded to the electrode pad 32 of the base 3 having an opening at the top via the bonding member 7, and sealing is performed so as to seal the opening (opening) of the base 3. A plate-like lid is joined to the end face of the opening via the member H. Here, in this embodiment, the nominal frequency of the tuning fork type crystal resonator 1 is 32.768 kHz. The nominal frequency is an example and can be applied to other frequencies.

ベース３は、セラミック材料やガラス材料からなる絶縁容器体である。本実施の形態では例えば、ベース３は、セラミック材料からなり、焼成によって形成されている。ベース３は、周囲に堤部３０を有し、かつ、上部が開口した断面視凹形状で、ベース３の内部（収納部）には音叉型水晶振動片２を搭載するための段差部３１が形成されている。そして段差部３１の上面には、一対の電極パッド３２（図１では一方の電極パッド３２のみ図示）が形成されている。一対の電極パッド３２はベース３の内部に形成された図示しない配線パターンを介してベース３の底面（裏面）に形成されている２つ以上の端子電極３３に電気的に接続されている。ベース３の堤部３０の周囲にはメタライズ層３４（封止部材Ｈの一部を構成）が周状に形成されている。電極パッド３２や端子電極３３、メタライズ層３４は例えば３層から構成されており、下からタングステン、ニッケル、金の順で積層されている。タングステンはメタライズ技術により、セラミック焼成時に一体的に形成され、ニッケル、金の各層はメッキ技術により形成される。なお、タングステンの層にモリブデンを使用してもよい。 The base 3 is an insulating container made of a ceramic material or a glass material. In the present embodiment, for example, the base 3 is made of a ceramic material and formed by firing. The base 3 has a bank portion 30 around it, and has a concave shape in cross section with an upper opening. A step 31 for mounting the tuning fork type crystal vibrating piece 2 is provided inside the base 3 (storage portion). Is formed. A pair of electrode pads 32 (only one electrode pad 32 is shown in FIG. 1) is formed on the upper surface of the step portion 31. The pair of electrode pads 32 are electrically connected to two or more terminal electrodes 33 formed on the bottom surface (back surface) of the base 3 through a wiring pattern (not shown) formed inside the base 3. A metallized layer 34 (constituting a part of the sealing member H) is formed around the bank portion 30 of the base 3 in a circumferential shape. The electrode pad 32, the terminal electrode 33, and the metallized layer 34 are composed of, for example, three layers, and are laminated in the order of tungsten, nickel, and gold from the bottom. Tungsten is integrally formed during ceramic firing by metallization technology, and the nickel and gold layers are formed by plating technology. Note that molybdenum may be used for the tungsten layer.

図示しない蓋は、例えば金属材料やセラミック材料、ガラス材料などからなり、平面視矩形状の一枚板に成形されている。この蓋の下面には封止材（封止部材Ｈの一部を構成）が形成されている。この蓋はシーム溶接やビーム溶接、加熱溶融接合などの手法により封止材を介してベース３に接合されて、蓋とベース３とによる水晶振動子１の筐体が構成される。 The lid (not shown) is made of, for example, a metal material, a ceramic material, or a glass material, and is formed into a single plate having a rectangular shape in plan view. A sealing material (constituting a part of the sealing member H) is formed on the lower surface of the lid. The lid is joined to the base 3 through a sealing material by a technique such as seam welding, beam welding, and heat-melt joining, so that the casing of the crystal unit 1 is configured by the lid and the base 3.

音叉型水晶振動片２は、Ｘ軸方向、Ｙ軸方向、およびＺ’軸方向の結晶方向を有する異方性材料の水晶Ｚ板からなる１枚の水晶ウェハ（図示省略）から成形される。音叉型水晶振動片２の基板外形は、フォトリソグラフィ技術（フォトリソ工法）を用いて、レジストまたは金属膜をマスクとして例えばウェットエッチングによって一括的に成形されている。 The tuning fork type crystal vibrating piece 2 is formed from a single crystal wafer (not shown) made of a crystal Z plate made of an anisotropic material having crystal directions in the X-axis direction, the Y-axis direction, and the Z′-axis direction. The substrate outer shape of the tuning-fork type crystal vibrating piece 2 is collectively formed by, for example, wet etching using a resist or a metal film as a mask, using a photolithography technique (a photolithography method).

音叉型水晶振動片２の基板は、図２に示すように、振動部である２本の第１脚部２１および第２脚部２２と、外部電極（本実施の形態ではベース３の電極パッド３２）に接合する接合部２３と、これら第１脚部２１および第２脚部２２と接合部２３とを突出して設けた基部２５と、から構成された外形からなる。 As shown in FIG. 2, the substrate of the tuning-fork type crystal vibrating piece 2 includes two first leg portions 21 and second leg portions 22 which are vibrating portions, and external electrodes (in this embodiment, electrode pads of the base 3). 32) and a base portion 25 provided by projecting the first leg portion 21, the second leg portion 22, and the joint portion 23.

基部２５は、平面視左右対称形状とされ、図２に示すように、振動部（第１脚部２１，第２脚部２２）より幅広に形成されている。また、基部２５の他端面２５２付近が、一端面２５１から他端面２５２にかけて幅狭になるように漸次段差形成されている。このため振動部である第１脚部２１および第２脚部２２の振動により発生した漏れ振動を他端面２５２により減衰させることができ、接合部２３へ漏れ振動が伝わるのを抑制することができ、音響リーク（振動漏れ）を更に低減するのに好ましい。なお、基部２５の他端面２５２付近における漸次幅狭になる構成としては段差形状に限らずテーパ状や、曲面状としてもよい。 The base portion 25 has a left-right symmetric shape in plan view, and is formed wider than the vibrating portions (the first leg portion 21 and the second leg portion 22) as shown in FIG. Further, a step is gradually formed in the vicinity of the other end surface 252 of the base portion 25 so as to become narrower from the one end surface 251 to the other end surface 252. For this reason, the leakage vibration generated by the vibration of the first leg portion 21 and the second leg portion 22 that are the vibration portions can be attenuated by the other end surface 252, and the transmission of the leakage vibration to the joint portion 23 can be suppressed. It is preferable for further reducing acoustic leakage (vibration leakage). The configuration in which the width gradually decreases in the vicinity of the other end surface 252 of the base portion 25 is not limited to the step shape, and may be a tapered shape or a curved surface shape.

２本の第１脚部２１および第２脚部２２は、図２に示すように、基部２５の一端面２５１から突出して隙間部２５３を介して並設されている。なお、ここでいう隙間部２５３は、一端面２５１の幅方向の中央位置（中央領域）に設けられている。これら第１脚部２１および第２脚部２２の先端部２１１，２２１は、第１脚部２１および第２脚部２２の他の部位（第１脚部２１および第２脚部２２の基部２５側の部位を除く）に比べて突出方向に対して直交する方向に幅広に成形され（以下、脚部の幅広領域と称する）、さらにそれぞれ隅部は曲面形成されている。このように先端部２１１，２２１を幅広に成形することで、先端部２１１，２２１（先端領域）を有効に利用することができ、音叉型水晶振動片２の小型化に有用であり、低周波数化にも有用である。また、それぞれ先端部２１１，２２１の隅部を曲面形成することで、外力を受けた時などに堤部などに接触するのを防止することができる。 As shown in FIG. 2, the two first leg portions 21 and the second leg portions 22 protrude from one end surface 251 of the base portion 25 and are arranged in parallel via a gap portion 253. In addition, the gap part 253 here is provided in the center position (central area | region) of the width direction of the one end surface 251. FIG. The distal end portions 211 and 221 of the first leg portion 21 and the second leg portion 22 are other parts of the first leg portion 21 and the second leg portion 22 (the base portion 25 of the first leg portion 21 and the second leg portion 22). (Excluding the portion on the side) in a direction wider than the protruding direction (hereinafter referred to as a wide region of the leg), and each corner is curved. By forming the tip portions 211 and 221 wide in this way, the tip portions 211 and 221 (tip regions) can be used effectively, which is useful for downsizing the tuning-fork type crystal vibrating piece 2 and has a low frequency. It is also useful for conversion. In addition, by forming the corners of the tip portions 211 and 221 as curved surfaces, it is possible to prevent contact with a bank portion or the like when receiving an external force.

２つの第１脚部２１および第２脚部２２の一主面２６１と他主面２６２には、音叉型水晶振動片２の小型化により劣化する直列共振抵抗値（本実施の形態ではＣＩ値、以下同様）を改善させるために、溝部２７がそれぞれ形成されている。また、音叉型水晶振動片２の外形のうち側面２８の一部は一主面２６１と他主面２６２とに対して傾斜して成形されている。これは、音叉型水晶振動片２を湿式でエッチング成形する際に基板材料の結晶方向（図２に示すＸ，Ｙ方向）へのエッチングスピードが異なることに起因している。 The first main surface 261 and the other main surface 262 of the two first leg portions 21 and the second leg portion 22 have a series resonance resistance value (CI value in the present embodiment) that deteriorates due to downsizing of the tuning-fork type crystal vibrating piece 2. In order to improve the same, the groove portions 27 are respectively formed. In addition, a part of the side surface 28 of the outer shape of the tuning-fork type crystal vibrating piece 2 is formed to be inclined with respect to the one main surface 261 and the other main surface 262. This is because the etching speed in the crystal direction of the substrate material (X and Y directions shown in FIG. 2) is different when the tuning fork type crystal vibrating piece 2 is formed by wet etching.

接合部２３は、図２に示すように、下記する引出電極２９３，２９４を外部電極（本実施の形態ではベース３の電極パッド３２）に電気機械的に接合するためのものである。具体的に、接合部２３は、２本の第１脚部２１および第２脚部２２が突出した基部２５の一端面２５１と対向する他端面２５２の幅方向の中央位置（中央領域）から突出形成されている。すなわち、２本の第１脚部２１と第２脚部２２との間に配された隙間部２５３と正対向する位置に、接合部２３が−ｚ‘軸方向に沿って突出形成されている。 As shown in FIG. 2, the bonding portion 23 is for electromechanically bonding the following extraction electrodes 293 and 294 to external electrodes (in this embodiment, the electrode pads 32 of the base 3). Specifically, the joint portion 23 protrudes from the center position (central region) in the width direction of the other end surface 252 facing the one end surface 251 of the base portion 25 from which the two first leg portions 21 and the second leg portions 22 protrude. Is formed. That is, the joint portion 23 is formed to protrude along the −z′-axis direction at a position facing the gap portion 253 disposed between the two first leg portions 21 and the second leg portion 22. .

接合部２３は、基部２５の他端面２５２に対して平面視垂直方向に突出した他端面２５２よりも幅狭な短辺部２３１と、短辺部２３１の先端部と連なり基部２５の幅方向に延出する長辺部２３２とから構成され、接合部２３の先端部２３３は基部２５の幅方向に向いている。すなわち、接合部２３は、短辺部２３１の先端部において平面視直角に折曲された形状からなり、平面視Ｌ字状に成形される。このように、平面視Ｌ字状に成形された折曲箇所である折曲部２３４が短辺部２３１の先端部に対応する。また、基部２５の他端面２５２よりも短辺部２３１が幅狭な状態で形成され、この幅狭形成により振動漏れのさらなる抑制の効果が高まる。 The joining portion 23 is connected to the short side portion 231 narrower than the other end surface 252 protruding in the vertical direction in plan view with respect to the other end surface 252 of the base portion 25, and is connected to the tip portion of the short side portion 231 in the width direction of the base portion 25. The long side portion 232 extends and the distal end portion 233 of the joint portion 23 faces the width direction of the base portion 25. That is, the joint portion 23 has a shape that is bent at a right angle in a plan view at the distal end portion of the short side portion 231 and is formed in an L shape in a plan view. In this way, the bent portion 234 that is a bent portion formed in an L shape in plan view corresponds to the tip portion of the short side portion 231. Moreover, the short side part 231 is formed in a narrower state than the other end face 252 of the base part 25, and the effect of further suppressing vibration leakage is enhanced by this narrow formation.

本実施の形態では、接合部２３の基端部にあたる短辺部２３１の折曲部２３４が、外部電極に接合する接合領域とされ、また、接合部２３の先端部２３３にあたる長辺部２３２の先端部が、外部電極に接合する接合領域とされる。そして、接合部２３の基端部である短辺部２３１には下記する第２励振電極２９２から短辺部２３１の端部（一端部へ）引き出された引出電極２９４（本発明でいう接続電極）が形成され、接合部の先端部である長辺部２３２に、下記する第１励振電極２９１から長辺部２３２の端部（一端部へ）引き出された引出電極２９３（本発明でいう接続電極）が形成されている。 In the present embodiment, the bent part 234 of the short side part 231 corresponding to the base end part of the joint part 23 is a joining region joined to the external electrode, and the long side part 232 corresponding to the distal end part 233 of the joint part 23 is formed. The tip portion is a bonding region that is bonded to the external electrode. A short side portion 231 that is a base end portion of the joint portion 23 is an extraction electrode 294 (a connection electrode referred to in the present invention) drawn from an end portion (to one end portion) of the short side portion 231 from a second excitation electrode 292 described below. ) Is formed, and the extraction electrode 293 (the connection in the present invention) is drawn from the first excitation electrode 291 described below to the end (to one end) of the long side 232 on the long side 232 which is the tip of the joint. Electrode).

本実施の形態にかかる音叉型水晶振動片２には、異電位で構成された２つの第１励振電極２９１および第２励振電極２９２と、これら第１励振電極２９１および第２励振電極２９２を電極パッド３２に電気的に接続させるためにこれら第１励振電極２９１および第２励振電極２９２から引き出された引出電極２９３，２９４が一体的に同時形成され、一対の引出電極２９３，２９４各々の先端部は、音叉型水晶振動片２の一主面２３５の一端部近傍に引き出された接続電極２９５，２９６となる。また、接続電極２９５，２９６各々の上面には、下記する接合部材７とバンプ６とが形成されている。なお、さらに詳説すると、本実施の形態でいう２つの引出電極２９３，２９４は、２つの第１励振電極２９１および第２励振電極２９２からそれぞれ引き出された電極パターンのことをいい、接続電極２９５，２９６は、引出電極２９３，２９４の先端部分のうち、ベース３との接合部位に形成された箇所のことをいう。 The tuning-fork type crystal vibrating piece 2 according to the present embodiment includes two first excitation electrodes 291 and 292 that are configured with different potentials, and the first excitation electrode 291 and the second excitation electrode 292 that are electrodes. Extraction electrodes 293 and 294 extracted from the first excitation electrode 291 and the second excitation electrode 292 to be electrically connected to the pad 32 are integrally formed at the same time, and tip portions of the pair of extraction electrodes 293 and 294 are respectively formed. Are the connection electrodes 295 and 296 drawn near one end of the main surface 235 of the tuning-fork type crystal vibrating piece 2. Further, the following bonding members 7 and bumps 6 are formed on the upper surfaces of the connection electrodes 295 and 296, respectively. In more detail, the two extraction electrodes 293 and 294 referred to in the present embodiment are electrode patterns extracted from the two first excitation electrodes 291 and the second excitation electrodes 292, respectively. Reference numeral 296 denotes a portion formed at the joint portion with the base 3 among the tip portions of the extraction electrodes 293 and 294.

２つの第１励振電極２９１および第２励振電極２９２の一部は、溝部２７の内部に形成されている。このため、音叉型水晶振動片２を小型化しても第１脚部２１および第２脚部２２の振動損失が抑制され、ＣＩ値を低く抑えることができる。 A part of the two first excitation electrodes 291 and the second excitation electrode 292 is formed inside the groove 27. For this reason, even if the tuning fork type crystal vibrating piece 2 is downsized, the vibration loss of the first leg portion 21 and the second leg portion 22 is suppressed, and the CI value can be suppressed low.

第１励振電極２９１は、第１脚部２１の両主面（一主面２６１と他主面２６２）と第２脚部２２の両側面２８に形成されている。同様に、第２励振電極２９２は、第２脚部２２の両主面（一主面２６１と他主面２６２）と第１脚部２１の両側面２８に形成されている。 The first excitation electrode 291 is formed on both main surfaces (one main surface 261 and the other main surface 262) of the first leg portion 21 and both side surfaces 28 of the second leg portion 22. Similarly, the second excitation electrode 292 is formed on both main surfaces (one main surface 261 and the other main surface 262) of the second leg portion 22 and both side surfaces 28 of the first leg portion 21.

また、接続電極２９５，２９６各々の上面には、接合部材７を介して６つのバンプ６が夫々形成されている。 In addition, six bumps 6 are formed on the upper surfaces of the connection electrodes 295 and 296 via the bonding members 7 respectively.

バンプ６は、金メッキ等からなり、外部電極（電極パッド３２）に接合するためのものであり、バンプ６の接続電極２９５，２９６側に向く第１面６１と、が、第１面６１に対面し外方に向き外部電極（電極パッド３２）との接合面となる第２面６２とを有し、第１面６１は、第２面６２より小さい。 The bump 6 is made of gold plating or the like, and is used for bonding to an external electrode (electrode pad 32). The first surface 61 facing the connection electrodes 295 and 296 of the bump 6 faces the first surface 61. The first surface 61 is smaller than the second surface 62 and has a second surface 62 that faces outward and serves as a joint surface with the external electrode (electrode pad 32).

また、バンプ６の外形は、平坦面となる第１面６１と、平坦面となる第２面６２と、第１面６１と第２面６２とを繋ぐ側面６３とから構成された円錐台となる。すなわち、本実施の形態にかかるバンプ６は、図１，３に示すように逆テーパを有する端面視（断面視）台形となり、Ｙ軸方向の断面視や端面視では、側面が直線となる。なお、バンプ６の第１面６１および第２面６２は、接続電極２９５，２９６より粗面である。 The outer shape of the bump 6 is a truncated cone composed of a first surface 61 that is a flat surface, a second surface 62 that is a flat surface, and a side surface 63 that connects the first surface 61 and the second surface 62. Become. That is, as shown in FIGS. 1 and 3, the bump 6 according to the present embodiment has a trapezoidal shape in an end view (cross-sectional view) having a reverse taper, and a side surface is a straight line in a cross-sectional view and an end view in the Y-axis direction. The first surface 61 and the second surface 62 of the bump 6 are rougher than the connection electrodes 295 and 296.

また、接続電極２９５，２９６各々の上に形成された６つのバンプ６に関して、少なくとも、基板の端（本実施の形態では、音叉型水晶振動片２の側面）に近い側に形成されたバンプ６（６０１）の第２面６２が、基板の端（本実施の形態では、音叉型水晶振動片２の側面）から遠い側に形成されたバンプ６（６０２）の第２面６２よりも大きい。すなわち、本実施の形態では、バンプ６０１が接合部２３の先端部に形成され、バンプ６０が折曲部２３４に形成され、バンプ６０１の第２面６２が、バンプ６０２の第２面６２よりも大きい。 Further, regarding the six bumps 6 formed on each of the connection electrodes 295 and 296, at least the bumps 6 formed on the side close to the end of the substrate (in this embodiment, the side surface of the tuning-fork type crystal vibrating piece 2). The second surface 62 of (601) is larger than the second surface 62 of the bump 6 (602) formed on the side far from the end of the substrate (in this embodiment, the side surface of the tuning-fork type crystal vibrating piece 2). That is, in the present embodiment, the bump 601 is formed at the tip end portion of the joint portion 23, the bump 60 is formed at the bent portion 234, and the second surface 62 of the bump 601 is more than the second surface 62 of the bump 602. large.

接合部材７は、金メッキ等からなり、図２に示すように、Ｘ軸方向が長辺方向となりＺ’軸方向が短辺方向となる平面視楕円形状となる。本実施の形態では、接合部材７の表面全体を効率よく接合するためにバンプ６を積極的に用いる。 The joining member 7 is made of gold plating or the like and has an elliptical shape in plan view in which the X-axis direction is the long side direction and the Z′-axis direction is the short side direction, as shown in FIG. In the present embodiment, the bumps 6 are positively used to efficiently join the entire surface of the joining member 7.

次に、音叉型水晶振動片２の製造方法について説明する。 Next, a method for manufacturing the tuning fork type crystal vibrating piece 2 will be described.

Ｘ軸方向、Ｙ軸方向、およびＺ’軸方向の結晶方向を有する異方性材料の水晶Ｚ板からなる１枚の水晶ウェハを用い、水晶ウエハから、多数個の音叉型水晶振動片２をマトリックス状に一括形成する。この時、音叉型水晶振動片２の外形は、フォトリソグラフィ技術を用いて、レジストまたは金属膜をマスクとして例えばウェットエッチングによって一括的に成形する。 A single crystal wafer made of a crystal Z plate made of an anisotropic material having crystal directions in the X-axis direction, the Y-axis direction, and the Z′-axis direction is used, and a large number of tuning-fork type crystal vibrating pieces 2 are formed from the crystal wafer. Collectively form a matrix. At this time, the outer shape of the tuning fork type crystal vibrating piece 2 is collectively formed by, for example, wet etching using a resist or a metal film as a mask by using a photolithography technique.

そして、音叉型水晶振動片２の外形の成形と同時に、第１励振電極２９１および第２励振電極２９２や引出電極２９３，２９４、接続電極２９５，２９６を形成する。本実施の形態では、第１励振電極２９１および第２励振電極２９２や引出電極２９３，２９４（接続電極２９５，２９６）を、下記の第１工程，第２工程，第３工程を順に経て形成する。 The first excitation electrode 291 and the second excitation electrode 292, the extraction electrodes 293 and 294, and the connection electrodes 295 and 296 are formed simultaneously with the shaping of the outer shape of the tuning fork type crystal vibrating piece 2. In the present embodiment, the first excitation electrode 291 and the second excitation electrode 292 and the extraction electrodes 293 and 294 (connection electrodes 295 and 296) are formed through the following first step, second step, and third step in order. .

―第１工程―
上記した音叉型水晶振動片２の第１励振電極２９１および第２励振電極２９２や引出電極２９３，２９４、接続電極２９５，２９６は、金属蒸着によって各第１脚部２１および第２脚部２２上にクロム（Ｃｒ）層を形成し、このクロム層上に金（Ａｕ）層を形成して構成される薄膜である。この薄膜は、真空蒸着法やスパッタリング法などの手法により基板全面に形成した後、フォトリソグラフィ技術によりメタルエッチングして所望の形状に形成することで、一体的に同時形成する。なお、第１励振電極２９１，第２励振電極２９２および引出電極２９３，２９４はクロム（Ｃｒ），金（Ａｕ）の順に形成してなるが、例えば、クロム（Ｃｒ），銀（Ａｇ）の順や，クロム（Ｃｒ），金（Ａｕ），クロム（Ｃｒ）の順や，クロム（Ｃｒ），銀（Ａｇ），クロム（Ｃｒ）の順などであってもよい。またクロム（Ｃｒ），金（Ａｕ），クロム（Ｃｒ），金（Ａｕ）等の複数の膜が積層されたものであってもよい。下地のクロム（Ｃｒ）は、ニッケル（Ｎｉ），チタン（Ｔｉ），クロム（Ｃｒ）とニッケル（Ｎｉ）との合金からなるニクロムなどであってもよい。 ―First step―
The first excitation electrode 291 and the second excitation electrode 292, the extraction electrodes 293 and 294, and the connection electrodes 295 and 296 of the tuning fork type crystal vibrating piece 2 are formed on the first leg portion 21 and the second leg portion 22 by metal deposition. The thin film is formed by forming a chromium (Cr) layer on the chromium layer and forming a gold (Au) layer on the chromium layer. This thin film is formed on the entire surface of the substrate by a technique such as vacuum vapor deposition or sputtering, and then formed into a desired shape by metal etching using a photolithography technique, so that they are integrally formed simultaneously. The first excitation electrode 291, the second excitation electrode 292, and the extraction electrodes 293 and 294 are formed in the order of chromium (Cr) and gold (Au). For example, the order of chromium (Cr) and silver (Ag) is formed. Alternatively, the order may be chromium (Cr), gold (Au), chromium (Cr), chromium (Cr), silver (Ag), chromium (Cr). A plurality of films such as chromium (Cr), gold (Au), chromium (Cr), and gold (Au) may be laminated. The underlying chromium (Cr) may be nickel (Ni), titanium (Ti), nichrome made of an alloy of chromium (Cr) and nickel (Ni), or the like.

各第１脚部２１および第２脚部２２の先端部２１１，２２１の一主面２６１と他主面２６２には、上記した第１脚部２１および第２脚部２２の幅広領域に対してほぼ全面に引出電極２９３，２９４をそれぞれ形成する。 The first main surface 261 and the other main surface 262 of the distal end portions 211 and 221 of the first leg portion 21 and the second leg portion 22 have a wide area of the first leg portion 21 and the second leg portion 22 described above. Lead electrodes 293 and 294 are formed on almost the entire surface.

また、接合部２３の一主面２３５に形成された引出電極２９３，２９４の上面におけるベース３との接合部位になる箇所には、接合部材７を形成し、接合部材７上に外部電極に接合するためのバンプ６を形成する。 In addition, a bonding member 7 is formed at a position to be a bonding portion with the base 3 on the upper surface of the extraction electrodes 293 and 294 formed on one main surface 235 of the bonding portion 23 and bonded to an external electrode on the bonding member 7. Bumps 6 are formed for this purpose.

―第２工程―
接合部２３への接合部材７およびバンプ６の形成に関して、接合部２３の各領域（接続電極２９５，２９６の上面）に図示しない接合部材７の形成部（接続電極２９５，２９６より面積の小さい窓部を有するマスク）をフォトリソグラフィ技術により所望の形状（本実施の形態では楕円形状の窓部）に形成して、接合部材７の形成部に接合部材７を電解メッキ法などの手法によりメッキ形成する。 -Second step-
Regarding the formation of the bonding member 7 and the bump 6 on the bonding portion 23, a window having a smaller area than the formation portion (connection electrode 295, 296) of the bonding member 7 not shown in each region of the bonding portion 23 (upper surface of the connection electrodes 295, 296) A mask having a portion) is formed into a desired shape (in this embodiment, an elliptical window portion) by a photolithography technique, and the joining member 7 is plated by a technique such as electrolytic plating on the forming portion of the joining member 7 To do.

―第３工程―
接合部材７の各領域（接合部材７の上面）に図示しないバンプ６の形成部（接続電極２９５，２９６より面積の小さく、バンプ６より面積の大きい窓部を有するマスク）をフォトリソグラフィ技術により所望の形状（本実施の形態では円形状の窓部）に形成して、バンプ６の形成部にバンプ６を電解メッキ法などの手法によりメッキ形成する。その後、アニール処理を行ってもよい。 -Third step-
Bump 6 formation portions (masks having a window area smaller than the connection electrodes 295 and 296 and larger in area than the bumps 6) are desired in each region of the bonding member 7 (upper surface of the bonding member 7) by a photolithography technique. (In this embodiment, a circular window portion), and bumps 6 are formed on the bump 6 formation portions by a method such as electrolytic plating. Thereafter, an annealing treatment may be performed.

また、第１脚部２１および第２脚部２２の一主面２６１に配された幅広領域に形成された引出電極２９３，２９４の上面には、図２に示すように、レーザービームなどのビーム照射によって金属膜の質量削減を行うことで音叉型水晶振動片２の周波数を調整してなる調整用金属膜（周波数調整用錘）Ｍ３が引出電極２９３，２９４に対して若干小さな面積で一体形成されている。調整用金属膜Ｍ３は、例えば、各幅広領域に形成された引出電極２９３，２９４に対して、調整用金属膜Ｍ３の形成部（所望の形状）をフォトリソグラフィ技術により形成して、調整用金属膜Ｍ３の形成部に調整用金属膜Ｍ３を電解メッキ法などの手法によりメッキ形成する。また、このメッキ形成後、アニール処理を行ってもよい。これら調整用金属膜Ｍ３などの金属膜をメッキ形成する際には、上記した接合部材７あるいはバンプ６の少なくとも１つ以上と同じ工程で同時に構成すると実用上より望ましい。接合部材７（Ｍ１１，Ｍ１２）、バンプ６、調整用金属膜Ｍ３は、同材質のもので構成されており例えば金（Ａｕ）からなる。 Further, as shown in FIG. 2, a beam such as a laser beam is formed on the upper surfaces of the extraction electrodes 293 and 294 formed in the wide region disposed on the one main surface 261 of the first leg portion 21 and the second leg portion 22. An adjustment metal film (frequency adjustment weight) M3 formed by adjusting the frequency of the tuning-fork type crystal vibrating piece 2 by reducing the mass of the metal film by irradiation is formed integrally with the extraction electrodes 293 and 294 in a slightly small area. Has been. For example, the adjustment metal film M3 is formed by forming a formation portion (desired shape) of the adjustment metal film M3 on the lead electrodes 293 and 294 formed in each wide region by a photolithography technique. The adjustment metal film M3 is formed by plating on the formation part of the film M3 by a technique such as electrolytic plating. Further, an annealing treatment may be performed after the plating is formed. When the metal film such as the adjustment metal film M3 is formed by plating, it is more practically preferable to form it simultaneously in the same process as at least one of the above-described bonding member 7 or bump 6. The joining members 7 (M11, M12), the bumps 6, and the adjustment metal film M3 are made of the same material and are made of, for example, gold (Au).

以上のように構成された音叉型水晶振動片２は、上記ウェハの状態の際に各々の音叉型水晶振動片２の周波数を計測した後、各々の音叉型水晶振動片２の調整用金属膜Ｍ３をビーム照射などで減少させたり、パーシャル蒸着により増加させたりすることで、周波数の粗調整を行っている。 The tuning fork type crystal vibrating piece 2 configured as described above measures the frequency of each tuning fork type crystal vibrating piece 2 in the state of the wafer, and then adjusts the metal film for adjustment of each tuning fork type crystal vibrating piece 2. The frequency is roughly adjusted by decreasing M3 by beam irradiation or increasing it by partial vapor deposition.

周波数粗調整を施し、その後ウェハから取り出した個片の音叉型水晶振動片２は、その一主面２６１側の接続電極２９５，２９６の上面に形成されたバンプ６（接合部材７を含む）とベース３の電極パッド３２とをＦＣＢ法により超音波接合し、ベース３に音叉型水晶振動片２を搭載する。なお、音叉型水晶振動片２をベース３に搭載する際、ベース３の搭載部などに対してアッシングを行い音叉型水晶振動片２とベース３の接合界面（バンプ６など）の活性化を行う。なお、アッシング処理についてはウェハの状態で実施してもよい。そして、接合箇所の活性化を行った状態で、バンプ６の一部分もしくは全てが潰れる加圧によりベース３に音叉型水晶振動片２を接合する。この時、ベース３の筐体の内部の底面に対して、音叉型水晶振動片２の主面が同一方向に向く、もしくは、音叉型水晶振動片２の主面が傾くように配する。このように、バンプ６を潰すのみの加圧を行うことで、接合によってバンプ６や接合部材７を構成する材料が過剰に拡散するのを抑制することができる。なお、このような効果は、バンプ６や接合部材７などの金属膜がメッキ形成されていることに関係しており、バンプ６を潰すのみの加圧接合により、接合部材７に接している接続電極２９５，２９６の金属膜に生じる過剰拡散やダメージを減らし、その結果、当該水晶振動子１を落下させた際などの衝撃時の金属膜の膜剥がれを抑えることができる。また、この膜形成の製造方法によれば、メッキ形成された金属膜であっても安定した潰れを得ることができる。 The individual tuning-fork type crystal vibrating piece 2 subjected to coarse frequency adjustment and then taken out from the wafer is provided with bumps 6 (including the bonding member 7) formed on the upper surfaces of the connection electrodes 295 and 296 on the one main surface 261 side. The electrode pad 32 of the base 3 is ultrasonically bonded by the FCB method, and the tuning fork type crystal vibrating piece 2 is mounted on the base 3. When the tuning fork type crystal vibrating piece 2 is mounted on the base 3, ashing is performed on the mounting portion of the base 3 to activate the bonding interface (such as the bump 6) between the tuning fork type crystal vibrating piece 2 and the base 3. . The ashing process may be performed in a wafer state. Then, the tuning-fork type crystal vibrating piece 2 is joined to the base 3 by pressurizing the bump 6 so that a part or all of the bump 6 is crushed in a state where the joining portion is activated. At this time, the tuning fork type crystal vibrating piece 2 is arranged so that the main surface of the tuning fork type crystal vibrating piece 2 faces in the same direction or the main surface of the tuning fork type crystal vibrating piece 2 is inclined with respect to the bottom surface inside the casing of the base 3. Thus, by performing pressurization that only crushes the bumps 6, it is possible to suppress excessive diffusion of materials constituting the bumps 6 and the bonding member 7 by bonding. Such an effect is related to the fact that a metal film such as the bump 6 or the bonding member 7 is formed by plating, and the connection in contact with the bonding member 7 by pressure bonding that only crushes the bump 6. Excess diffusion and damage generated in the metal film of the electrodes 295 and 296 can be reduced, and as a result, film peeling of the metal film at the time of impact such as when the crystal unit 1 is dropped can be suppressed. Moreover, according to this film formation manufacturing method, stable crushing can be obtained even with a metal film formed by plating.

ベース３に搭載された音叉型水晶振動片２に対して周波数を再計測した後、測定結果に基づいて音叉型水晶振動片２の調整用金属膜Ｍ３をビーム照射やイオンミーリングなどで減少させることで、周波数の微調整を行う最終の周波数調整を行っている。 After re-measuring the frequency of the tuning-fork type crystal vibrating piece 2 mounted on the base 3, the metal film M3 for adjustment of the tuning-fork type crystal vibrating piece 2 is reduced by beam irradiation or ion milling based on the measurement result. Thus, the final frequency adjustment for finely adjusting the frequency is performed.

その後、最終の周波数調整が行われた音叉型水晶振動片２が搭載されたベース３に対して、図示しない蓋を加熱溶融接合などの手法により封止部材Ｈを介して接合し、音叉型水晶振動片２をベース３と図示しない蓋とで構成された筐体の内部に気密封止する。なお、上述の気密封止の手法として、シーム溶接、ビーム溶接、雰囲気加熱などの手法をあげることができる。 Thereafter, a lid (not shown) is joined to the base 3 on which the tuning-fork type crystal vibrating piece 2 having been subjected to the final frequency adjustment is mounted via a sealing member H by a technique such as heating and melting, and the tuning-fork type crystal. The resonator element 2 is hermetically sealed inside a housing constituted by a base 3 and a lid (not shown). Examples of the above-described hermetic sealing methods include seam welding, beam welding, and atmosphere heating.

本実施の形態にかかる音叉型水晶振動片２および音叉型水晶振動子１によれば、安価で、小型化に有利で、かつ、接合強度を高めることができる。具体的には、接続電極２９５，２９６各々の上面にバンプ６が少なくとも形成され、バンプ６の第１面６１が第２面６２より小さいので、バンプ６の第２面６２を実質大きくとることができる。そのため、音叉型水晶振動片２の基板が小さくなり、その結果、接続電極２９５，２９６が小さくなったとしても、外部電極（電極パッド３２）に接する第２面６２を小さくすることなく、接合強度を保つことができる。その結果、音叉型水晶振動片２を小型化すると、小型化に比例して外部電極（電極パッド３２）に接続する接合箇所も小さくなるが、本実施の形態によれば接合箇所（第２面６２）を実質小さくするのを抑制することができ、結果として小型化しても接合強度を高めることができる。 According to the tuning-fork type crystal vibrating piece 2 and the tuning-fork type crystal resonator 1 according to the present embodiment, it is inexpensive, advantageous for downsizing, and can increase the bonding strength. Specifically, at least the bump 6 is formed on the upper surface of each of the connection electrodes 295 and 296, and the first surface 61 of the bump 6 is smaller than the second surface 62, so that the second surface 62 of the bump 6 can be made substantially larger. it can. Therefore, even if the substrate of the tuning-fork type crystal vibrating piece 2 is reduced and, as a result, the connection electrodes 295 and 296 are reduced, the bonding strength is reduced without reducing the second surface 62 in contact with the external electrode (electrode pad 32). Can keep. As a result, when the tuning-fork type crystal vibrating piece 2 is reduced in size, the joint location connected to the external electrode (electrode pad 32) is also reduced in proportion to the miniaturization. However, according to the present embodiment, the joint location (second surface) is reduced. 62) can be substantially reduced, and as a result, the bonding strength can be increased even if the size is reduced.

また、第１面６１と第２面６２と側面６３とから構成されたバンプ６の製造工程においてフォトリソ工法を用いた場合、接続電極２９５，２９６側に向く第１面６１が、外部電極（電極パッド３２）との接合面となる第２面６２より小さいので、第１面６１に接する部位（基板側の部材で例えば接続電極２９５，２９６）と側面６３との頂角が鋭角になる。そのため、露出時に頂角部分に遮られて感光することがなく、この頂角部分にレジストが溜まることになるが、このレジストはレジスト除去の際に取り除くことができるので、レジストが残留することはない。その結果、レジスト残留による接合強度の劣化は生じない。 Further, when the photolithography method is used in the manufacturing process of the bump 6 constituted by the first surface 61, the second surface 62, and the side surface 63, the first surface 61 facing the connection electrodes 295, 296 side is an external electrode (electrode Since the second surface 62 is smaller than the second surface 62 serving as a bonding surface with the pad 32), the apex angle between the portion that contacts the first surface 61 (for example, the connection electrodes 295 and 296 as members on the substrate side) and the side surface 63 becomes an acute angle. Therefore, the vertical angle portion is not exposed to exposure during exposure, and the resist accumulates in this vertical angle portion, but since this resist can be removed at the time of resist removal, the resist remains. Absent. As a result, the bonding strength does not deteriorate due to the resist residue.

また、バンプ６は接合部材７を介して接続電極２９５，２９６上に形成されるので、外部電極（電極パッド３２）にバンプ６を介して接続電極２９５，２９６を接合した際にバンプ６を全て潰す圧力を加えた場合であっても接合部材７が存在することで、バンプ６よりも接合部材７の方が潰れ難くなる。また、バンプ６のみを潰す場合、低圧力で潰すことができ、本実施の形態によれば、接合部材７を潰さずにバンプ６のみを潰すことができる。その結果、接合部材７の形状や形態を可変させることなく、概ね維持することができ、接合部材７の上面のバンプ６はより潰し易い。すなわち、バンプ６が低荷重で均一に潰し易くなる。そのため、安定した外部電極（電極パッド３２）と接続電極２９５，２９６との接合を行うことができる。 Further, since the bump 6 is formed on the connection electrodes 295 and 296 via the bonding member 7, all the bumps 6 are bonded when the connection electrodes 295 and 296 are bonded to the external electrode (electrode pad 32) via the bump 6. Even when the crushing pressure is applied, the joining member 7 is less likely to be crushed than the bump 6 due to the presence of the joining member 7. Further, when only the bump 6 is crushed, it can be crushed with a low pressure, and according to the present embodiment, only the bump 6 can be crushed without crushing the bonding member 7. As a result, the shape and form of the bonding member 7 can be generally maintained without being changed, and the bumps 6 on the upper surface of the bonding member 7 are more easily crushed. That is, the bumps 6 are easily crushed uniformly with a low load. Therefore, the stable connection between the external electrode (electrode pad 32) and the connection electrodes 295 and 296 can be performed.

また、接続電極２９５，２９６各々の上にバンプ６が複数（本実施の形態では６つ）形成されるので、接続電極２９５，２９６各々の上にバンプ６が１つ形成される形態に比べて接合強度向上を図ることができる。 In addition, since a plurality of bumps 6 (six in this embodiment) are formed on each of the connection electrodes 295 and 296, compared with a mode in which one bump 6 is formed on each of the connection electrodes 295 and 296. Bonding strength can be improved.

また、接続電極２９５，２９６各々の上に形成された６つのバンプ６のうち、基板の端に近い側に形成されたバンプ６の第２面６２（図２，３に示す６０１参照）が、基板の端から遠い側に形成されたバンプ６（図２，３に示す６０２参照）の第２面６２よりも大きいので、バンプ６を潰す際に、小さいバンプ６（６０２）の方向にバンプが広がり、接合面（第２面６２）のうち基板（接合部２３）の中央領域に向かってより均一に広がって潰れ易くなり、基板（接合部２３）の中央領域の強度向上を図ることができる。また電極の短絡を確実に防止することもできる。また、基板の端に近い側に形成されたバンプ６（６０１）の接合領域を拡げることができる。つまり、基板の端から遠い側に形成されたバンプ６（６０２）の第２面６２は、基板の端に近い側に形成されたバンプ６（６０１）の第２面６２よりも小さくなるので、接合の際に、接合部材７外にバンプ６が出るのを防ぐことができる。 Of the six bumps 6 formed on each of the connection electrodes 295 and 296, the second surface 62 (see 601 shown in FIGS. 2 and 3) of the bump 6 formed on the side close to the end of the substrate is Since it is larger than the second surface 62 of the bump 6 (see 602 shown in FIGS. 2 and 3) formed on the side far from the end of the substrate, when the bump 6 is crushed, the bump is directed in the direction of the small bump 6 (602). It spreads and spreads more uniformly toward the central region of the substrate (bonding portion 23) in the bonding surface (second surface 62), and is easily crushed, so that the strength of the central region of the substrate (bonding portion 23) can be improved. . Moreover, it is possible to reliably prevent short-circuiting of the electrodes. In addition, the bonding region of the bump 6 (601) formed on the side close to the end of the substrate can be expanded. That is, the second surface 62 of the bump 6 (602) formed on the side far from the end of the substrate is smaller than the second surface 62 of the bump 6 (601) formed on the side close to the end of the substrate. It is possible to prevent the bumps 6 from coming out of the bonding member 7 during bonding.

なお、本実施の形態では、屈曲振動してなる音叉型圧電振動片に限らず、ＡＴカットなどの厚みすべり振動系や他の振動モードの圧電振動片、あるいは平板形状や逆メサ形状などの他の形状の圧電振動片にも適用できる。 In the present embodiment, the present invention is not limited to a tuning-fork type piezoelectric vibrating piece formed by bending vibration, but a thickness-slip vibration system such as an AT cut, a piezoelectric vibrating piece of another vibration mode, a flat plate shape, an inverted mesa shape, or the like. It can also be applied to a piezoelectric vibrating piece of the shape

また、本実施の形態では、バンプ６が第１面６１と第２面６２とが対面する円錐台となっているが、これに限定されるものではなく、第１面６１と第２面６２とが厳密に対面していなくても同様の作用効果が生じる。ただし、第１面６１と第２面６２とが対面する形態が好ましい。 In the present embodiment, the bump 6 is a truncated cone in which the first surface 61 and the second surface 62 face each other. However, the present invention is not limited to this, and the first surface 61 and the second surface 62 are not limited thereto. Even if they are not strictly facing each other, the same effect is produced. However, a form in which the first surface 61 and the second surface 62 face each other is preferable.

また、本実施の形態では、バンプ６の側面６３（Ｙ軸方向の断面視や端面視）が直線となっているが、これに限定されるものではなく、図４，６に示すように、曲面形成されてもよい。 Further, in the present embodiment, the side surfaces 63 (the Y-axis direction cross-sectional view and end face view) of the bump 6 are straight lines, but the present invention is not limited to this, and as shown in FIGS. A curved surface may be formed.

この場合、バンプ６の側面６３が曲面形成されているので、側面６３が平坦面に形成される形態に比べて第２面６２の周縁の厚みを薄くすることができ、外部電極（電極パッド３２）への接合時に加圧で潰し易くなる。 In this case, since the side surface 63 of the bump 6 is formed in a curved surface, the peripheral edge of the second surface 62 can be made thinner than in the form in which the side surface 63 is formed as a flat surface. ) Is easily crushed by pressurization.

また、本実施の形態では、バンプ６の第２面６２が平面となっているが、これに限定されるものではなく、図５，６に示すように、曲面形成されてもよい。 In the present embodiment, the second surface 62 of the bump 6 is a flat surface. However, the present invention is not limited to this, and a curved surface may be formed as shown in FIGS.

この場合、バンプ６の第２面６２が曲面形成されるので、第２面６２が平坦面形成される形態に比べて、外部電極への接合領域を大きくすることができ、より安定した接合を行うことが可能となる。 In this case, since the second surface 62 of the bump 6 is formed as a curved surface, the bonding area to the external electrode can be increased as compared with the form in which the second surface 62 is formed as a flat surface, and more stable bonding can be achieved. Can be done.

また、本実施の形態では、接続電極２９５，２９６各々の上に、バンプ６を６つずつ形成しているが、数は限定されるものではなく、１つでもよい。しかしながら、接合強度の点から、複数のバンプが形成されることが好ましい。また、バンプ６の数も６つに限定されるものではなく、図７，８，９に示すような２つ，４つや、８つ（図示省略）など他の任意の数であってもよく、奇数の５つ（図示省略）であってもよい。 In the present embodiment, six bumps 6 are formed on each of the connection electrodes 295 and 296, but the number is not limited, and one bump may be used. However, it is preferable that a plurality of bumps are formed from the viewpoint of bonding strength. The number of bumps 6 is not limited to six, and may be any other number such as two, four, or eight (not shown) as shown in FIGS. , An odd number of five (not shown) may be used.

また、本実施の形態では、接合部材７を介してバンプ６を接続電極２９５，２９６上に形成しているが、これに限定されるものではなく、図７に示すように、接続電極２９５，２９６上に直接バンプ６を形成してもよい。 In the present embodiment, the bumps 6 are formed on the connection electrodes 295 and 296 via the bonding member 7. However, the present invention is not limited to this, and as shown in FIG. Bumps 6 may be formed directly on 296.

また、本実施の形態では、図２に示すように、平面視形状が楕円形状となっているが、これに限定されるものではなく、図８に示すように緩やかな曲線を描く窪み部５を有してもよい。この場合、窪み部５に関して短いライン領域が連続する領域と略視することができる。このため、音叉型水晶振動片２のＺ’軸方向だけでなく、Ｚ’軸からＸ軸方向へ傾斜した軸方向の振動が発生した時（例えば、Ｚ’軸からＸ軸方向へ傾斜した軸方向を落下方向として落とした時など）でも、その振動をメッキバンプとして作用する接合部材７（Ｍ１１，Ｍ１２）の端縁である窪み部５の端縁箇所（窪み部５の外形を成形するラインのいずれかのポイント）で受けることができ、当該メッキバンプを介在したベース３と音叉型水晶振動片２との接合部の厚み方向（Ｙ軸方向）に生じるダメージを分散させることができる。その結果、ベース３への音叉型水晶振動片２の接合状態の安定を図ることができる。 Further, in the present embodiment, as shown in FIG. 2, the planar view shape is an elliptical shape. However, the shape is not limited to this, and the hollow portion 5 that draws a gentle curve as shown in FIG. You may have. In this case, it can be roughly regarded as a region where short line regions are continuous with respect to the recessed portion 5. Therefore, not only when the tuning-fork type quartz vibrating piece 2 is vibrated in the axial direction inclined from the Z ′ axis to the X axis direction but also in the Z ′ axis direction (for example, the axis inclined from the Z ′ axis to the X axis direction). Even when the direction is dropped as a falling direction, etc.), the edge portion of the recess portion 5 (the outer shape of the recess portion 5) that forms the edge of the joining member 7 (M11, M12) that acts as a plating bump. Any of these points) can be received, and damage generated in the thickness direction (Y-axis direction) of the joint portion between the base 3 and the tuning-fork type crystal vibrating piece 2 with the plated bump interposed therebetween can be dispersed. As a result, it is possible to stabilize the bonding state of the tuning fork type crystal vibrating piece 2 to the base 3.

また、本実施の形態では、図２に示すように、平面視形状が楕円形状となっているが、これに限定されるものではなく、図９に示すように角を丸くした平面視矩形状や、平面視矩形状、他の多角形状などであってもよい。なお、図９に示すバンプ６では、基板の端に近い側に形成されたバンプ６の第２面６２（図２，３に示す６０１参照）と、基板の端から遠い側に形成されたバンプ６（図２，３に示す６０２参照）の第２面６２とが同じ大きさとなっており、この場合であってもその他の構成は、本実施の形態にかかる構成と同じになるので、本実施の形態による作用効果は有する。しかしながら、より好ましい形態は、上記の基板の端に近い側に形成されたバンプ６の第２面６２（６０１）が、基板の端から遠い側に形成されたバンプ６（６０２）の第２面６２より大きい形態である。 Further, in the present embodiment, as shown in FIG. 2, the shape in plan view is an elliptical shape. However, the shape is not limited to this, and a rectangular shape in plan view with rounded corners as shown in FIG. Alternatively, the shape may be a rectangular shape in plan view or another polygonal shape. In the bump 6 shown in FIG. 9, the second surface 62 (see 601 shown in FIGS. 2 and 3) of the bump 6 formed on the side close to the end of the substrate and the bump formed on the side far from the end of the substrate. 6 (see 602 shown in FIGS. 2 and 3) has the same size as the second surface 62. Even in this case, the other configuration is the same as the configuration according to the present embodiment. The effect by embodiment has it. However, in a more preferable form, the second surface 62 (601) of the bump 6 formed on the side close to the end of the substrate is the second surface of the bump 6 (602) formed on the side far from the end of the substrate. It is a form larger than 62.

なお、本発明は、その精神または主要な特徴から逸脱することなく、他のいろいろな形で実施することができる。そのため、上述の実施の形態はあらゆる点で単なる例示にすぎず、限定的に解釈してはならない。本発明の範囲は特許請求の範囲によって示すものであって、明細書本文には、なんら拘束されない。さらに、特許請求の範囲の均等範囲に属する変形や変更は、全て本発明の範囲内のものである。 The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

本発明は、水晶振動子などの圧電振動デバイスに適用できる。 The present invention can be applied to a piezoelectric vibration device such as a crystal resonator.

１音叉型水晶振動子
２音叉型水晶振動片
２１第１脚部
２１１先端部
２２第２脚部
２２１先端部
２３接合部
２３１短辺部
２３２長辺部
２３３先端部
２３４折曲部
２３５一主面
２５基部
２５１一端面
２５２他端面
２５３隙間部
２６１第１脚部および第２脚部の一主面
２６２第１脚部および第２脚部の他主面
２７溝部
２８側面
２９１第１励振電極
２９２第２励振電極
２９３，２９４引出電極
２９５，２９６接続電極
３ベース
３０堤部
３１段差部
３２電極パッド
３３端子電極
３４メタライズ層
４水晶振動板
４９５，４９６接続電極
５窪み部
６，６０１，６０２バンプ
６１第１面
６２第２面
６３側面
７接合部材
Ｈ封止部材
Ｍ３調整用金属膜（周波数調整用錘） DESCRIPTION OF SYMBOLS 1 Tuning fork type crystal resonator 2 Tuning fork type crystal resonator element 21 First leg portion 211 Tip portion 22 Second leg portion 221 Tip portion 23 Joint portion 231 Short side portion 232 Long side portion 233 Tip portion 234 Bending portion 235 One main surface 25 Base portion 251 One end surface 252 Other end surface 253 Gap portion 261 One main surface 262 of the first leg portion and the second leg portion The other main surface 27 of the first leg portion and the second leg portion 27 Groove portion 28 Side surface 291 First excitation electrode 292 First 2 Excitation electrodes 293 and 294 Extraction electrodes 295 and 296 Connection electrode 3 Base 30 Bank portion 31 Step portion 32 Electrode pad 33 Terminal electrode 34 Metallized layer 4 Crystal diaphragm 495 and 496 Connection electrode 5 Recessed portion 6, 601 and 602 Bump 61 1 surface 62 2nd surface 63 Side surface 7 Joining member H Sealing member M3 Metal film for adjustment (weight for frequency adjustment)

Claims

In the piezoelectric vibrating piece,
A pair of excitation electrodes and a pair of extraction electrodes respectively extracted from the pair of excitation electrodes are formed at least,
The tip of each of the pair of extraction electrodes serves as a connection electrode for bonding to an external electrode,
At least a bump is formed on the upper surface of each of the connection electrodes,
The bump has at least a first surface facing the connection electrode and a second surface serving as a bonding surface with an external electrode, and the first surface is smaller than the second surface,
The outer shape of the bump is composed of the first surface, the second surface, and a side surface connecting the first surface and the second surface,
The piezoelectric vibrating piece according to claim 1, wherein the side surface is curved.

In the piezoelectric vibrating piece,
A pair of excitation electrodes and a pair of extraction electrodes respectively extracted from the pair of excitation electrodes are formed at least,
The tip of each of the pair of extraction electrodes serves as a connection electrode for bonding to an external electrode,
At least a bump is formed on the upper surface of each of the connection electrodes,
The bump has at least a first surface facing the connection electrode and a second surface serving as a bonding surface with an external electrode, and the first surface is smaller than the second surface,
The outer shape of the bump is composed of the first surface, the second surface, and a side surface connecting the first surface and the second surface,
The piezoelectric vibrating piece according to claim 1, wherein the side surface is formed in a straight line in a sectional view.

The piezoelectric vibrating piece according to claim 1 or 2,
The piezoelectric vibrating piece according to claim 1, wherein the bump is formed on the connection electrode via a bonding member.

In the piezoelectric vibrating piece according to any one of claims 1 to 3,
A piezoelectric vibrating piece in which a plurality of the bumps are formed on each of the connection electrodes.

The piezoelectric vibrating piece according to claim 4,
Of the plurality of bumps formed on each of the connection electrodes, the bump formed on the side far from the side surface of the bump formed on the side close to the side surface of the piezoelectric vibrating piece. The piezoelectric vibrating piece is larger than the second surface.

In the piezoelectric vibrating piece according to any one of claims 1 to 5,
A piezoelectric vibrating piece, wherein the second surface is formed into a curved surface.

In the piezoelectric vibrating piece according to any one of claims 1 to 5,
The piezoelectric vibrating piece according to claim 1, wherein the second surface is a flat surface.