JP2016139896A - Package for mounting piezoelectric element and piezoelectric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package for mounting a piezoelectric element which eliminates the need for preparing many kinds of packages for mounting piezoelectric elements to deal with several kinds of piezoelectric devices and enables different kinds of piezoelectric elements, such as crystal elements and SAW elements, to be mounted thereon.SOLUTION: A package 110 for mounting a piezoelectric element includes: a rectangular substrate 110a; an electrode pad 111 provided along one side on an upper surface of the substrate 110a; a joint pad 114 provided along one side facing one side of the upper surface of the substrate 110a; and a protruding part 115 provided at a position located between the electrode pad 111 and the joint pad 114 and on the upper surface of the substrate 110a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a piezoelectric element mounting package for mounting a piezoelectric element therein, and a piezoelectric device formed by mounting a piezoelectric element in the package.

  The package for mounting a piezoelectric element is electrically connected to an electrode pad formed on the bottom surface of the recess through a conductive adhesive. There has been proposed a piezoelectric device in which a piezoelectric element is hermetically sealed in a concave portion by bonding with a lid around the concave portion on the upper surface of the frame (see, for example, Patent Document 1 below). In addition, such piezoelectric devices have a very wide range of demands on oscillation frequency characteristics, and in accordance with this, piezoelectric elements having different shapes, dimensions, and arrangement forms of excitation electrodes are mounted. There are an increasing number of types of piezoelectric devices.

JP 2009-141234 A

  The above-described piezoelectric element mounting package prepares many types of piezoelectric element mounting packages corresponding to the types of piezoelectric elements, which may increase the number of components and reduce productivity. was there.

  The present invention has been made in view of the above problems, and it is not necessary to prepare many types of piezoelectric element mounting packages corresponding to the types of piezoelectric devices, and crystal elements or SAW elements that are different types of piezoelectric elements. A package for mounting a piezoelectric element that can be mounted is provided.

  A package for a piezoelectric element according to one aspect of the present invention includes a rectangular substrate, an electrode pad provided along one side of the upper surface of the substrate, and a bonding pad provided along one side facing one side of the upper surface of the substrate. And a convex portion provided on the upper surface of the substrate and between the electrode pad and the bonding pad.

  A package for a piezoelectric element according to one aspect of the present invention includes a rectangular substrate, an electrode pad provided along one side of the upper surface of the substrate, and a bonding pad provided along one side facing one side of the upper surface of the substrate. And a convex portion provided on the upper surface of the substrate and at a position between the electrode pad and the bonding pad. By doing so, a rectangular piezoelectric element plate, excitation electrodes provided on the upper and lower surfaces of the piezoelectric element plate, and a pair of electrodes provided along one side of the piezoelectric element plate with a space between the excitation electrodes. In the case of a quartz crystal element that is one of piezoelectric elements having a lead electrode, it can be mounted on an electrode pad via a conductive adhesive. Also, a piezoelectric element having a rectangular piezoelectric element plate, a comb-shaped electrode provided on the upper surface of the piezoelectric element plate, and an extraction electrode provided along one side of the piezoelectric element plate with a gap between the comb-shaped electrodes. In the case of a SAW element, which is an element, the bonding pad and the extraction electrode can be electrically connected by being mounted on the convex portion with an adhesive. Thus, it is not necessary to prepare many types of packages corresponding to the types of piezoelectric devices, and both crystal elements and SAW elements, which are different types of piezoelectric elements, can be mounted, improving productivity. Can be made.

(A) The top view which looked at the package for piezoelectric element mounting in this embodiment from the upper surface, (b) The top view which looked at the package for piezoelectric element mounting in this embodiment from the lower surface. 1 is an exploded perspective view showing a crystal resonator in which a crystal element is mounted on a piezoelectric element mounting package in the present embodiment. (A) It is sectional drawing in AA of the crystal oscillator shown in FIG. 2, (b) The top view seen from the upper surface in the state which removed the cover body of the crystal oscillator shown in FIG. . It is a disassembled perspective view which shows the SAW resonator which mounted the SAW element in the package for piezoelectric element mounting in this embodiment. (A) It is sectional drawing in BB of the SAW resonator shown by FIG. 4, (b) The top view seen from the upper surface in the state which removed the cover body of the SAW resonator shown by FIG. . It is a disassembled perspective view which shows the crystal oscillator which mounted the crystal element and the integrated circuit element in the package for piezoelectric element mounting in the 1st modification of this embodiment. It is sectional drawing of the crystal oscillator of FIG. It is a disassembled perspective view which shows the SAW oscillator which mounted the SAW element and the integrated circuit element in the package for piezoelectric element mounting in the 1st modification of this embodiment.

(Piezoelectric packaging)
In the piezoelectric element mounting package 110 of the present embodiment, as shown in FIG. 1 or FIG. 5, a first recess K1 surrounded by the upper surface of the substrate 110a and the inner surface of the first frame 110b is formed. ing. The substrate 110a has a rectangular shape and functions as a mounting member for mounting the crystal element 120 mounted on the upper surface. An electrode pad 111 for mounting a crystal element 120 described later is provided along one side of the upper surface of the substrate 110a, and a SAW element 220 described later is electrically connected along one side facing the one side of the substrate 110a. A bonding pad 114 is provided for this purpose. A convex portion 115 is provided between the electrode pad 111 and the bonding pad 114 provided on the substrate 110a, and in the vicinity of the center of the substrate 110a. A first electrode pad 111a and a second electrode pad 111b for mounting the crystal element 120 are provided along one side of the substrate 110a. A first bonding pad 114a and a second bonding pad 114b for electrically connecting a later-described SAW element 220 are provided along one side opposite to one side of the substrate 110a.

  The substrate 110a is made of an insulating layer made of a ceramic material such as alumina ceramic or glass-ceramic. The substrate 110a may be one using an insulating layer or may be a laminate of a plurality of insulating layers. A wiring pattern 113 for electrically connecting the electrode pad 111 provided on the upper surface and the bonding pad 114 is provided on the surface of the substrate 110a. In addition, a conductor portion for electrically connecting the electrode pad 111 or the bonding pad 114 provided on the upper surface of the substrate 110a and the external terminal 112 provided on the lower surface of the substrate 110a on the surface and inner layer of the substrate 110a. 116 and a wiring pattern 113 are provided.

  The first frame 110b is disposed along the outer peripheral edge of the upper surface of the substrate 110a, and is for forming the first recess K1 on the upper surface of the substrate 110a. The first frame 110 is made of a ceramic material such as alumina ceramics or glass-ceramics, and is formed integrally with the substrate 110a.

  As shown in FIG. 1, a pair of electrode pads 111 are provided along one side of the upper surface of the substrate 110. The electrode pad 111 is electrically connected to the electrode pad 111 and the external terminal 112 via a conductor portion 116 provided on the substrate 110. The external terminals 112 are provided along the outer peripheral edge of the substrate 110 at the four corners of the lower surface of the substrate 110a.

  The external terminal 112 is used for electrical connection with a mounting board (not shown) such as an electronic device. The external terminals 112 are provided at the four corners of the lower surface of the substrate 110a. Two of the external terminals 112 are electrically connected to a pair of electrode pads 111 provided on the upper surface of the substrate 110a. The external terminals 112 that are electrically connected to the electrode pads 111 are provided so as to be located diagonally on the lower surface of the substrate 110a. The second external terminal 112b is electrically connected to the sealing conductor pattern 117 via via conductors (not shown) provided in the substrate 110a and the first frame 110b.

  The wiring pattern 113 is for electrically connecting the electrode pad 111 and a bonding pad 114 described later. The first wiring pattern 113a and the second wiring pattern 113b are provided on the upper surface of the substrate 110a, and electrically connect the electrode pad 111 and a bonding pad 114 described later. The length of the first wiring pattern 113a and the length of the second wiring pattern 113b are substantially equal. Here, the substantially equal length means that the difference between the length of the first wiring pattern 113a provided on the upper and lower surfaces of the substrate 110 and the length of the second wiring pattern 113b provided on the upper and lower surfaces of the substrate 110 is 0 to 0. It shall include 200 μm different ones. As for the length of the wiring pattern 113, the length of a straight line passing through the center of each wiring pattern 113 is measured.

  The bonding pad 114 is for electrically connecting to an extraction electrode 224 of the SAW element 220 described later. In addition, the bonding pad 114 is provided along one side facing the one side where the electrode pad 111 is provided on the upper surface of the substrate 110a. The bonding pad 114 is electrically connected to the extraction electrode 224 of the SAW element 220 by the wire portion 142 shown in FIG.

  The electrode pad 111 includes a first electrode pad 111a and a second electrode pad 111b. The external terminal 112 includes a first external terminal 112a, a second external terminal 112b, a third external terminal 112c, and a fourth external terminal 112d. The wiring pattern 113a includes a first wiring pattern 113a, a second wiring pattern 113b, a third wiring pattern 113c, and a fourth wiring pattern 113d. The bonding pad 114 includes a first bonding pad 114a and a second bonding pad 114b. The conductor 116 is composed of a first conductor 116a and a second conductor 116b.

  As shown in FIG. 1, the first electrode pad 111a and the first external terminal 112a are connected by a third wiring pattern 113c and a first conductor portion 116a provided on the substrate 110a. The first electrode pad 111a and the first bonding pad 114a are connected by the first wiring pattern 113a. Therefore, the first bonding pad 114a is electrically connected to the first external terminal 112a. As shown in FIG. 1, the second bonding pad 114b and the third external terminal 112c are connected by a fourth wiring pattern 113d and a second conductor portion 116b provided on the substrate 110a. The second electrode pad 111b and the second bonding pad 114b are connected by the second wiring pattern 113b. Therefore, the second electrode pad 111b is electrically connected to the third external terminal 112c.

  The convex portion 115 is for suppressing a free end of a crystal element 120 described later from coming into direct contact with the substrate 110a. Further, the convex 115 serves as a pedestal for fixing the SAW element 220 described later. The convex 115 is provided near the center of the upper surface of the substrate 110a.

  As shown in FIG. 1, the conductor 116 is provided inside a notch provided at a corner of the substrate 110a. Both ends of the conductor 116 are connected to the wiring pattern 113. In this way, the electrode pad 111 or the bonding pad 114 is electrically connected to the external terminal 112 via the wiring pattern 113 and the conductor portion 116.

  The sealing conductor pattern 117 plays a role of improving the wettability of the bonding member 131 when bonded to the lid 130 via the bonding member 131. The sealing conductor pattern 117 is provided so as to surround the upper surface of the first frame 110b. The sealing conductor pattern 117 is, for example, 10 to 25 μm in thickness by applying nickel plating and gold plating on the surface of the conductor pattern made of tungsten or molybdenum, for example, so as to surround the upper surface of the first frame 110b in an annular shape. Is formed.

  The electrode pad 111, the external terminal 112, and the bonding pad 114 have a shape provided along the substrate 110a. Here, when the package 110 is viewed in plan, the long side dimension is 1.2 to 2.5 mm, and the short side dimension is 1.0 to 2.0 mm. The sizes of the external terminal 112 and the bonding pad 114 will be described. The long sides of the electrode pads 111, the external terminals 112, and the bonding pads 114 are 0.40 to 0.90 mm, and the short sides are 0.30 to 0.60 mm.

  Here, a manufacturing method of the piezoelectric element mounting package 110 will be described. When the substrate 110a and the first frame 110b are made of alumina ceramics, first, a plurality of ceramic green sheets obtained by adding and mixing an appropriate organic solvent or the like to a predetermined ceramic material powder is prepared. In addition, a predetermined conductor paste is applied to the surface of the ceramic green sheet or a through-hole previously punched by punching the ceramic green sheet by screen printing or the like. Further, these green sheets are laminated and press-molded and fired at a high temperature. Finally, nickel plating or gold plating is applied to a predetermined portion of the conductor pattern, specifically, the electrode pad 111, the external terminal 112, the wiring pattern 113, the bonding pad 114, the conductor portion 116, and the sealing conductor pattern 117. It is produced by applying silver palladium or the like. Moreover, the conductor paste is comprised from the sintered compact etc. of metal powders, such as tungsten, molybdenum, copper, silver, or silver palladium, for example.

(Crystal oscillator)
As shown in FIGS. 2 and 3, the crystal resonator includes a piezoelectric element mounting package 110 and a crystal element 120 mounted on the upper surface of the substrate 110a in the first recess K1 of the piezoelectric element mounting package 110. And a lid 130 for hermetically sealing the quartz crystal element 120.

  As shown in FIGS. 1 and 2, the crystal element 120 is bonded onto the electrode pad 111 via a conductive adhesive 140. The crystal element 120 plays a role of oscillating a reference signal of an electronic device or the like by stable mechanical vibration and a piezoelectric effect.

  Further, as shown in FIGS. 2 and 3, the crystal element 120 has a structure in which the excitation electrode 122 and the extraction electrode 123 are attached to the upper surface and the lower surface of the crystal base plate 121, respectively. . The excitation electrode 122 is formed by depositing and forming a metal in a predetermined pattern on each of the upper surface and the lower surface of the quartz base plate 121. The excitation electrode 122 includes a first excitation electrode 122a on the upper surface and a second excitation electrode 122b on the lower surface. The extraction electrode 123 extends from the excitation electrode 122 toward one side of the crystal base plate 121. The extraction electrode 123 includes a first extraction electrode 123a on the upper surface and a second extraction electrode 123b on the lower surface. The first extraction electrode 123 a is extracted from the first excitation electrode 122 a and is provided so as to extend toward one side of the crystal base plate 121. The second extraction electrode 123 b is extracted from the second excitation electrode 122 b and is provided so as to extend toward one side of the crystal base plate 121. That is, the extraction electrode 123 is provided in a shape along the long side or the short side of the quartz base plate 121. In the present embodiment, one end of the crystal element 120 connected to the first electrode pad 111a and the second electrode pad 111b is a fixed end connected to the upper surface of the substrate 110a, and the other end is between the upper surface of the substrate 110a. The quartz crystal element 120 is fixed on the substrate 110 by a cantilevered support structure having a free end with a gap.

  Here, the operation of the crystal element 120 will be described. In the crystal element 120, when an alternating voltage from the outside is applied from the extraction electrode 123 to the crystal base plate 121 via the excitation electrode 122, the crystal base plate 121 is excited in a predetermined vibration mode and frequency. ing.

  Here, a manufacturing method of the crystal element 120 will be described. First, the crystal element 120 is cut from the artificial crystalline lens at a predetermined cut angle to reduce the thickness of the outer periphery of the crystal base plate 121, and the central portion of the crystal base plate 121 is thicker than the outer peripheral portion of the crystal base plate 121. The bevel processing provided is performed. The crystal element 120 is produced by forming the excitation electrode 122 and the extraction electrode 123 by depositing a metal film on both main surfaces of the crystal base plate 121 by a photolithography technique, a vapor deposition technique, or a sputtering technique. Is done.

  A method for bonding the crystal element 120 to the substrate 110a will be described. First, the conductive adhesive 140 is applied onto the first electrode pad 111a and the second electrode pad 111b by a dispenser, for example. The crystal element 120 is transported onto the conductive adhesive 140 and placed on the conductive adhesive 140. The conductive adhesive 140 is cured and contracted by being heated and cured. The crystal element 120 is bonded to the electrode pad 111. That is, the first extraction electrode 123a of the crystal element 120 is bonded to the first electrode pad 111a, and the second extraction electrode 123b is bonded to the second electrode pad 111b. As a result, the second external terminal 112b and the fourth external terminal 112d are electrically connected to the crystal element 120.

  Further, as shown in FIG. 3B, the crystal element 120 is mounted such that the convex portion 115 is disposed at a position facing the free end of the crystal element 120. By doing so, the free end of the crystal element 120 comes into contact with the convex portion 115 even if the crystal element 120 is tilted about the location where the extraction electrode 123 of the crystal element 120 and the electrode pad 111 are joined, so that the substrate 110a. It is possible to prevent the free end of the quartz crystal element 120 from coming into contact with the upper surface of the substrate. If the drop test is performed in a state where the free end of the crystal element 120 is in contact with the substrate 110a, the free end of the crystal element 120 may be lost. By doing in this way, it can reduce that the oscillation frequency of the crystal element 120 fluctuates, suppressing that the free end side of the crystal element 120 is missing.

  The lid 130 has a rectangular shape, and is for hermetically sealing the first recess K1 in a vacuum state or the first recess K1 filled with nitrogen gas or the like. Specifically, the lid 130 is placed on the upper surface of the sealing conductor pattern 117 provided on the first frame 110b in a predetermined atmosphere. When heat is applied to the bonding member 131 provided on the lower surface of the sealing lid 130, the sealing conductor pattern 117 is melt-bonded. The lid 130 is made of an alloy containing at least one of iron, nickel, and cobalt, for example.

  As shown in FIG. 3A, the bonding member 131 is provided from the outer peripheral edge of the lower surface of the lid 130 to the sealing conductor pattern 117 on the first frame 110b. For example, in the case of glass, the bonding member 131 is made of low-melting glass containing, for example, vanadium, which is a lead-free glass that melts at 350 to 400 ° C. Lead-free glass is in the form of a paste with a binder and a solvent added, and after being melted and solidified, it adheres to other members. The joining member 131 is provided by, for example, applying glass frit paste by a screen printing method and drying.

  For example, in the case of an insulating resin, the bonding member 131 is made of an epoxy resin or a polyimide resin. The thickness of the bonding member 131 provided between the lower surface of the lid 130 and the upper surface of the sealing conductor pattern 117 is 30 to 100 μm.

  For example, when the bonding member 131 is gold tin, the thickness of the layer of the bonding member 150 is 10 to 40 μm. For example, the component ratio is 70 to 80% for gold and 20 to 30% for tin. May be used. For example, when the joining member 131 is silver brazing, the thickness of the layer of the joining member 131 is 10 to 40 μm. For example, the component ratio is 70 to 80% for silver and 20 to 30% for copper. May be used.

(SAW resonator)
As shown in FIGS. 4 and 5, the SAW resonator includes the piezoelectric element mounting package 110 and the SAW element 220 mounted on the upper surface of the substrate 110 a in the first recess K 1 of the piezoelectric element mounting package 110. And a lid 130 for hermetically sealing the SAW element 220.

  The SAW element 220 is provided with a comb-shaped electrode 222 provided on the upper surface of the piezoelectric element plate 221, a reflective electrode 223, and an extraction electrode 224. Further, the SAW element 220 has a property that when the voltage is applied to the comb-shaped electrode 222, the upper surface of the piezoelectric element plate 221 and the vicinity of the upper surface of the piezoelectric element plate 221 vibrate at a predetermined frequency. It can obtain vibrations and plays a role of transmitting a reference signal for an electronic machine or the like.

  The piezoelectric element plate 221 is for vibrating the upper surface and the vicinity of the upper surface of the piezoelectric element plate 221 on which the comb electrode 222 is formed at a predetermined frequency when a voltage is applied to the comb electrode 222. The piezoelectric element plate 221 is made of a quartz member and has a rectangular flat plate shape.

  The comb-shaped electrode 222 is provided on the upper surface of the piezoelectric element plate 221 and applies a voltage to the piezoelectric element plate 221. The comb-shaped electrode 222 includes a first comb-shaped electrode 222a and a second comb-shaped electrode 222b, and is provided to face each other in a non-contact state.

  The reflective electrode 223 is for reflecting and amplifying the vibration generated by the voltage applied to the comb-shaped electrode 222. The reflective electrode 223 includes a first reflective electrode 223a and a second reflective electrode 223b. The reflective electrode 223 is provided so as to sandwich the comb-shaped electrode 222 in plan view.

  The extraction electrode 224 is used when a voltage is applied to the comb-shaped electrode 222. The extraction electrode 224 includes a first extraction electrode 224a and a second extraction electrode 224b. The first extraction electrode 224 a is extracted from the first comb electrode 222 a and is provided so as to extend toward one side of the piezoelectric element plate 221. The second extraction electrode 224 b is extracted from the second comb-shaped electrode 222 b and is provided so as to extend toward one side of the piezoelectric element plate 221. That is, the extraction electrode 224 is provided in a shape along the long side or the short side of the piezoelectric element plate 221. In the present embodiment, the first bonding pad 114a and the first extraction electrode 224a are electrically connected by the wire portion 142, and the second bonding pad 114b and the second extraction electrode 224b are connected by the wire portion 142. Is electrically connected.

  The SAW element 220 is fixedly held by an adhesive 141 provided between the lower surface of the piezoelectric element plate 221 and the convex portion 115 and mounted on the piezoelectric element mounting package 110. At this time, the adhesive 141 is provided at a position overlapping the comb electrode 222 in plan view. As a result, the center of the piezoelectric element plate 221 and the adhesive 141 overlap each other in plan view, so even if stress occurs when the adhesive 141 is cured, the SAW element 220 is equally stressed. The fluctuation of the oscillation frequency can be suppressed.

  The adhesive 141 is for fixing and holding the convex 115 and the SAW element 220. The adhesive 141 is provided between the lower surface of the piezoelectric base plate 221 and the upper surface of the convex portion 115. In addition, as the adhesive 141, a thermoplastic adhesive is used, and for example, an epoxy adhesive is used. Such an adhesive 141 is first applied to the upper surface of the convex portion 115, and the applied adhesive 141 is placed between the lower surface of the piezoelectric base plate 221 and the upper surface of the convex portion 115 and cured. Is provided.

  The wire part 142 is for electrically connecting the extraction electrode 224 and the bonding pad 114 by bonding. For example, a gold wire is used for the wire portion 142 and is joined by wire bonding.

  One end of the wire portion 142 is bonded to the extraction electrode 224 of the SAW element 220, the other end is bonded to the bonding pad 114 provided on the substrate 110a, and the extraction electrode 224 and the bonding pad 114 are electrically connected. Connected.

  The piezoelectric element mounting package 110 of the present invention is provided along a rectangular substrate 110a, an electrode pad 111 provided along one side of the upper surface of the substrate 110a, and one side facing one side of the upper surface of the substrate 110a. The bonding pad 114 includes a protrusion 115 provided on the upper surface of the substrate 110 a and between the electrode pad 111 and the bonding pad 114. By doing so, the rectangular crystal base plate 121, the excitation electrodes 122 provided on the upper and lower surfaces of the crystal base plate 121, and the excitation electrode 122 are spaced along the one side of the crystal base plate 121. In the case of the quartz crystal element 120 which is one of the piezoelectric elements having a pair of lead electrodes 123 provided in the manner described above, it can be mounted on the electrode pad 111 via the conductive adhesive 140. In addition, a rectangular piezoelectric element plate 221, a comb-shaped electrode 222 provided on the upper surface of the piezoelectric element plate 221, and an extraction electrode 224 provided along one side of the piezoelectric element plate 221 with a gap between the comb-shaped electrodes 222 In the case of the SAW element 220, which is a piezoelectric element having the above, the adhesive pad 141 is mounted on the convex portion 115, and the bonding pad 114 and the extraction electrode 224 can be electrically connected. Thus, it is not necessary to prepare many types of packages corresponding to the types of piezoelectric devices, and both the crystal element 120 and the SAW element 220, which are different types of piezoelectric elements, can be mounted. Can be improved.

  The piezoelectric device of the present invention includes a rectangular crystal element plate 121, excitation electrodes 122 provided on the upper and lower surfaces of the crystal element plate 121, and the excitation electrode 122, along one side of the crystal element plate 121. A crystal element 120 having a pair of lead electrodes 123 provided on the electrode pad 111 and a lid 130 for hermetically sealing the crystal element 120, and a crystal base plate 121. One side facing one side is provided at a position overlapping the convex portion 115 in plan view. By doing so, the free end of the crystal element 120 comes into contact with the convex portion 115 even if the crystal element 120 is tilted about the location where the extraction electrode 123 of the crystal element 120 and the electrode pad 111 are joined. It is possible to prevent the free end of the quartz crystal element 120 from coming into contact with the upper surface of the substrate. If the drop test is performed with the free end of the crystal element 120 in contact with the substrate 110, the free end of the crystal element 120 may be lost. By doing in this way, it can reduce that the oscillation frequency of the crystal element 120 fluctuates, suppressing that the free end side of the crystal element 120 is missing.

  In addition, the piezoelectric device of the present invention includes a piezoelectric element mounting package 110, a piezoelectric element plate 221 having a shape, a comb electrode 222 provided on the upper surface of the piezoelectric element plate 221, and a piezoelectric element with a gap between the comb electrode 222. A SAW element 220 having an extraction electrode 224 provided along one side of the plate 221, mounted on the convex portion with an adhesive 141, and electrically connecting the bonding pad 114 and the extraction electrode 224. And a lid 130 for hermetically sealing the SAW element 220, and the adhesive 141 is provided at a position overlapping the comb-shaped electrode 222 of the piezoelectric base plate 221 in plan view. As a result, the adhesive 141 overlaps with the center of the piezoelectric base plate 221 in plan view, so even if stress occurs when the adhesive 141 is cured, the SAW element 220 is equally stressed. The fluctuation of the oscillation frequency can be suppressed.

(First modification)
As shown in FIG. 6 or FIG. 8, the crystal oscillator according to the first modification of the present embodiment includes a second frame 210c on the lower surface of the substrate 210a and an integrated circuit element 150 mounted on the lower surface of the substrate 210a. In this respect, it differs from the crystal resonator of this embodiment. As shown in FIGS. 6 and 7, the crystal oscillator includes a piezoelectric element mounting package 210, and a crystal element 120 mounted on the upper surface of the substrate 210a in the first recess K1 of the piezoelectric element mounting package 210. The integrated circuit element 150 mounted on the lower surface of the substrate 210a in the second recess K2 of the piezoelectric element mounting package 210, and the lid 130 for hermetically sealing the crystal element 120 are included. In addition, connection pads 218 for mounting the integrated circuit element 150 are provided on the lower surface of the substrate 210a.

  The 2nd frame 210c is arrange | positioned along the outer periphery of the lower surface of the board | substrate 210a, and is for forming the 2nd recessed part K2 in the lower surface of the board | substrate 210a. The first frame 210b and the second frame 210c are made of a ceramic material such as alumina ceramics or glass-ceramics, and are formed integrally with the substrate 210a. External terminals 212 are provided at the four corners of the lower surface of the second frame 210c.

  The external terminal 212 is for mounting the crystal oscillator on a mounting board such as an electronic device. The external terminals 212 are provided at the four corners of the lower surface of the second frame 210c. The external terminals 212 are electrically connected to four of the six connection pads 215 provided on the lower surface of the substrate 210a. One of the external terminals 212 is connected to a mounting pad connected to a ground potential that is a reference potential on a mounting board of an electronic device or the like. As a result, the lid 130 joined to the sealing conductor pattern 217 is connected to the external terminal 212 that is at the ground potential. Therefore, compared with the case where the lid 130 is connected to the external terminal 212 having the ground potential, the shielding performance in the first recess K1 by the lid 130 is improved. The other one of the external terminals 212 is used as an output terminal, and the other one of the external terminals 212 is used as a power supply voltage terminal.

  The connection pad 218 is used for mounting the integrated circuit element 150. For example, six connection pads 218 are provided, and three connection pads 218 are arranged side by side on the lower surface of the substrate 210a in the second recess K2 formed by the substrate 210a and the second frame 210c. As shown in FIG. 7, the connection terminal 151 of the integrated circuit element 150 and the connection pad 218 are mechanically and electrically bonded via a conductive bonding material 143.

  As the integrated circuit element 150, for example, a rectangular flip-chip type integrated circuit element having a plurality of connection terminals 151 is used, and a circuit formation surface (upper surface) is connected to the crystal element 120 and has a predetermined oscillation. An oscillation circuit unit for generating an output is provided. The output signal generated by the oscillation circuit unit is output to the outside of the crystal oscillator via one of the external terminals 112 of the second frame 210c, and is used as a reference signal such as a clock signal, for example.

  The conductive bonding material 143 is made of, for example, silver paste or lead-free solder. The conductive bonding material 143 contains an added solvent for adjusting the viscosity to be easily applied. The component ratio of the lead-free solder is 95 to 97.5% for tin, 2 to 4% for silver, and 0.5 to 1.0% for copper.

  Even in such a crystal oscillator, the above-described effects can be achieved, and a stable oscillation frequency can be output.

  In addition, it is not limited to this embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. In the above embodiment, the electrode pad 111 and the external terminal 112 are electrically connected by the conductor portion 116 provided in the substrate 110. However, the wiring pattern is provided on the side surface of the substrate, and the electrode pad 111 and the external terminal 112 are externally connected. The terminal 112 may be electrically connected. In the first modification of the above-described embodiment, the case where the crystal element for AT is used as the crystal element has been described. However, two flat plate-like vibrating arms extending in the same direction from the side surface of the base part A tuning-fork type bent quartz element having a portion may be used.

  In addition, the crystal element 120 may be beveled so that the thickness of the outer periphery of the crystal element plate 121 is thin and the central part of the crystal element plate 121 is thicker than the outer periphery of the crystal element plate 121. . A bevel processing method for the crystal element 120 will be described. A polishing material provided with media and abrasive grains having a predetermined particle size and a quartz base plate 121 having a predetermined size are prepared. The abrasive prepared in the cylindrical body and the quartz base plate 121 are placed, and the open end of the cylindrical body is closed with a cover. The quartz base plate 121 that rotates the cylindrical body containing the abrasive and the quartz base plate 121 with the central axis of the cylindrical body as the rotation axis is polished with the abrasive and beveled.

  In the oscillator of the above embodiment, the crystal element 120 is mounted. However, as shown in FIG. 8, a SAW element 220 may be mounted. In the case of the SAW oscillator, the convex portion 215 plays a role of reducing the influence of heat generated when the integrated circuit element 150 operates. The convex portion 215 is provided between the substrate 210 a and the adhesive 141 that holds the SAW element 220 firmly. For this reason, heat generated when the integrated circuit element 150 is operated first moves from the connection pad 218 to the substrate 210a, then moves from the substrate 210a via the convex portion 215 to the adhesive 141, and then the SAW element. It will move to 220. Therefore, by providing the convex portion 215, the speed of heat transfer from the integrated circuit element 150 to the SAW element 220 can be reduced, and the influence of the heat of the SAW element 220 can be reduced.

110a, 210a ... substrate 110b, 210b ... first frame 210c ... second frame 110, 210 ... package for mounting piezoelectric elements 111, 211 ... electrode pads 112, 212 ... External terminals 113, 213 ... wiring patterns 114, 214 ... bonding pads 115, 215 ... convex portions 116 ... conductor portions 117, 217 ... sealing conductor patterns 218 ... connection pads 120 ... Quartz element 220 ... SAW element 121,221 ... Piezoelectric element (crystal element)
122 ... excitation electrode 222 ... comb electrode 123,224 ... extraction electrode 130 ... lid body 131 ... joining member 140 ... conductive adhesive 141 ... adhesive 142 ... Wire portion 143: conductive bonding material 150 ... integrated circuit element K1 ... first recess K2 ... second recess

Claims (3)

A rectangular substrate;
An electrode pad provided along one side of the upper surface of the substrate;
A bonding pad provided along one side facing the one side of the upper surface of the substrate;
A package for mounting a piezoelectric element, comprising: an upper surface of the substrate; and a protrusion provided at a position between the electrode pad and the bonding pad. A package for mounting a piezoelectric element according to claim 1;
A rectangular crystal base plate, excitation electrodes provided on the upper and lower surfaces of the crystal base plate, and a pair of extraction electrodes provided along one side of the crystal base plate with a space between the excitation electrodes; And a crystal element mounted on the electrode pad,
A lid for hermetically sealing the crystal element,
One side facing the one side of the quartz base plate is provided at a position overlapping the convex portion in plan view. A package for mounting a piezoelectric element according to claim 1;
A rectangular piezoelectric element plate, a comb electrode provided on the upper surface of the piezoelectric element plate, and an extraction electrode provided along one side of the piezoelectric element plate with a gap between the comb electrodes, A SAW element mounted on the convex portion with an adhesive, and the bonding pad and the extraction electrode are electrically connected;
A lid for hermetically sealing the SAW element,
The piezoelectric device, wherein the adhesive is provided at a position overlapping the comb shape of the piezoelectric element plate in plan view.

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