JP5599057B2 - Package and piezoelectric vibrator - Google Patents

Description

  The present invention relates to a package and a piezoelectric vibrator.

  For example, a cellular phone or a portable information terminal uses a piezoelectric vibrator using crystal or the like as a time source, a timing source such as a control signal, or a reference signal source. Various types of piezoelectric vibrators of this type are known. One of them is a two-layer structure type surface-mount package.

  As one of such two-layer structure type packages, a lid having a plate-like base member (corresponding to the “base substrate” of the present application) and a cavity, and joining the base member to make the cavity a sealed space There is known a crystal device comprising a member (corresponding to the “lid substrate” of the present application) and a quartz plate (corresponding to the “piezoelectric vibrator” of the present application) mounted on a base member (see Patent Document 1). .

  The base member of this quartz crystal device has an extraction electrode (corresponding to the “leading electrode” in the present application) formed on the upper surface and an external terminal (corresponding to the “external electrode” in the present application) formed on the lower surface. The lead electrode and the external terminal are electrically connected by a through electrode made of a metal pin embedded through the base member.

  Here, when the electrode in the package is routed facing the piezoelectric vibrating piece, capacitance is generated in the gap between the electrode formed on the main surface of the piezoelectric vibrating piece and the electrode in the package. It is known that so-called capacitive coupling occurs. When capacitive coupling occurs, the piezoelectric vibrating piece is not able to oscillate normally due to the influence of capacitance. Thereby, there exists a possibility that the electrical property of a piezoelectric vibrator may deteriorate.

  For this reason, for example, in Patent Document 1, the extraction electrode 33 is routed along the outer shape of the piezoelectric vibrating piece in a plan view so as to avoid a portion facing the piezoelectric vibrating piece on the base substrate (Patent Document 1). FIG. 2). By arranging the electrodes in the package in this manner, the excitation electrode of the piezoelectric vibrating piece and the electrode in the package are prevented from facing each other to prevent the occurrence of capacitive coupling, and the piezoelectric vibrator has good electrical characteristics. Trying to maintain the characteristics.

JP 2010-129646 A

By the way, with recent miniaturization of electronic devices, miniaturization of packages and electronic components mounted in the packages is required.
However, as in Patent Document 1, when the lead electrode in the package is routed along the outer shape of the piezoelectric vibrating piece in plan view, there is a space for routing the electrode in the package around the piezoelectric vibrating piece. Necessary. Since the area of the base substrate is increased by securing a space for wiring the electrodes in the package, this is an obstacle to miniaturization of the package.

  Further, it is known that when the piezoelectric vibrating piece itself is downsized, the CI value (Crystal Impedance) of the piezoelectric vibrator generally increases. Therefore, there is a possibility that good electrical characteristics of the piezoelectric vibrator cannot be maintained.

  Accordingly, an object of the present invention is to provide a package and a piezoelectric vibrator that can be reduced in size while maintaining good electrical characteristics.

In order to solve the above problems, a package of the present invention has a plurality of substrates capable of forming a cavity for enclosing an electronic component, and a recess for the cavity is formed in a first substrate among the plurality of substrates. A package provided with a plurality of through electrodes penetrating between the concave portion and the outer surface side of the first substrate, wherein the electronic component and the through electrode are electrically connected to a side wall of the concave portion. A routing electrode for connection is routed , and one end of the through electrode is formed so as to protrude from the side wall of the recess .

  According to the present invention, since the routing electrode is arranged on the side wall of the cavity recess, it is possible to prevent the electrode of the electronic component and the routing electrode from facing each other. As a result, it is possible to prevent the capacitive coupling between the electronic component and the lead-out electrode and maintain the good electrical characteristics of the package. Further, since the routing electrode is routed on the side wall of the recess, a space for routing the routing electrode on the bottom surface of the recess is not required, and the package can be reduced in size. Therefore, it is possible to provide a package that can be reduced in size while maintaining good electrical characteristics.

Moreover, it is desirable that the one end of at least one of the plurality of through electrodes and the lead-out electrode are electrically connected to the side wall of the recess.
According to the present invention, a space for electrically connecting the through electrode and the lead-out electrode on the bottom surface of the concave portion is not necessary, so that the package can be further reduced in size.

The other end of the at least one through electrode is led out to the lower surface side of the first substrate, and the shape of the at least one through electrode projected onto any one side surface of the first substrate is from the recess to the lower surface. It is desirable that it be formed obliquely so as to move away from the outer wall of the first substrate as it goes to.
According to the present invention, the thickness between the outer wall and the through electrode can be increased as the through electrode moves away from the outer wall of the first substrate toward the bottom surface of the first substrate. Therefore, the strength of the first substrate around the through electrode can be ensured.

When the angle between the bottom surface of the recess and the side wall of the recess is θ,
The angle θ is
95 ° ≦ θ ≦ 140 °
It is desirable to set so as to satisfy.
According to the present invention, each side wall of the recess is not undercut when viewed from the opening side of the recess. Therefore, it is possible to easily perform the formation of the lead electrode, the processing by photolithography, and the like on each side wall of the recess.

The piezoelectric vibrator of the present invention is a piezoelectric vibrator using the package, wherein the plurality of substrates are formed of glass, and a piezoelectric vibrating piece is enclosed as the electronic component inside the recess. Features.
ADVANTAGE OF THE INVENTION According to this invention, the piezoelectric vibrator which can be reduced in size can be provided, maintaining a favorable electrical property.

  According to the present invention, since the routing electrode is arranged on the side wall of the cavity recess, it is possible to prevent the electrode of the electronic component and the routing electrode from facing each other. As a result, it is possible to prevent the capacitive coupling between the electronic component and the lead-out electrode and maintain the good electrical characteristics of the package. Further, according to the present invention, since the routing electrode is routed on the side wall of the recess, a space for routing the routing electrode on the bottom surface of the recess is not required, and the package can be reduced in size. Therefore, it is possible to provide a package that can be reduced in size while maintaining good electrical characteristics.

It is an external perspective view of a piezoelectric vibrator. It is sectional drawing which follows the AA line of FIG. FIG. 2 is an internal configuration diagram of the piezoelectric vibrator shown in FIG. 1, and is a plan view with a lid substrate removed. FIG. 2 is an exploded perspective view of the piezoelectric vibrator shown in FIG. 1. It is a flowchart of the manufacturing method of a piezoelectric vibrator. It is a figure which shows the state which formed the several recessed part in the wafer for base substrates. It is a figure which shows the state which was drawn around the upper surface of the wafer for base substrates, and patterned the electrode. It is the elements on larger scale of FIG. It is a disassembled perspective view of a wafer body. It is sectional drawing along the AA line of the piezoelectric vibrator in the modification of 1st Embodiment. It is explanatory drawing of the recessed part formation process of 2nd reference form , FIG.11 (a) is explanatory drawing before a press, FIG.11 (b) is explanatory drawing after a press, FIG.11 (c) is a penetration electrode. It is explanatory drawing when the front-end | tip is removed.

(First embodiment)
Hereinafter, a piezoelectric vibrating piece, a piezoelectric vibrator, and a method of manufacturing the piezoelectric vibrator according to the first embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 4, in the piezoelectric vibrator 1 of this embodiment, the base substrate 2 (first substrate) and the lid substrate 3 (second substrate) are anodically bonded via the bonding film 23, and the recess 16 1 is a surface-mounting type piezoelectric vibrator 1 including a piezoelectric vibrating piece 4 housed in the housing.

(Piezoelectric vibrating piece)
The piezoelectric vibrating piece 4 is an AT-cut type vibrating piece formed of a quartz piezoelectric material, and vibrates when a predetermined voltage is applied.
The piezoelectric vibrating reed 4 includes a quartz plate 17 processed into a plate having a substantially rectangular shape in plan view and a uniform thickness, and a pair of excitation electrodes 5 and 6 disposed at positions facing both surfaces of the quartz plate 17; There are lead electrodes 19 and 20 electrically connected to the excitation electrodes 5 and 6, and mount electrodes 7 and 8 electrically connected to the lead electrodes 19 and 20.

  The excitation electrodes 5 and 6, the extraction electrodes 19 and 20, the mount electrodes 7 and 8, and the side electrode 15 are formed of, for example, a gold (Au) film. Note that these films are formed of a conductive film such as chromium (Cr), nickel (Ni), aluminum (Al), or titanium (Ti), or a laminated film combining some of these conductive films. May be.

  The piezoelectric vibrating reed 4 configured in this manner is bonded to the bottom surface 16e of the recess 16 formed on the top surface U of the base substrate 2 by flip chip bonding using the bumps 11 and 12 made of gold or the like. . Specifically, bumps 11 and 12 are formed on routing electrodes 9 and 10 (described later) patterned in the recess 16 of the base substrate 2, and a pair of mount electrodes 7 and 8 are in contact with the bumps 11 and 12, respectively. In this state, they are joined by flip chip bonding. Accordingly, the piezoelectric vibrating reed 4 is supported in a state where it floats from the bottom surface 16e of the concave portion 16 of the base substrate 2 by the thickness of the bumps 11 and 12, and the mount electrodes 7 and 8 and the routing electrodes 9 and 10 are connected. Each is electrically connected.

(Piezoelectric vibrator)
The lid substrate 3 is a substrate capable of anodic bonding made of a glass material, for example, soda-lime glass, and is formed in a substantially flat plate shape. A bonding film 23 for anodic bonding is patterned on the bonding surface side of the lid substrate 3 with the base substrate 2 using a conductive material such as aluminum (Al) or silicon (Si). The bonding film 23 is formed along the shape of the upper surface U of the base substrate 2 so as to surround the periphery of the recess 16 formed in the base substrate 2.

  The base substrate 2 is a substrate made of a glass material, for example, soda lime glass, and is formed in a substantially plate shape with the same outer shape as the lid substrate 3. On the upper surface U of the base substrate 2, a recess 16 (a cavity recess) for accommodating the piezoelectric vibrating reed 4 is formed.

  The recess 16 is disposed on the bottom surface 16e, the first side wall 16a disposed on one side in the width direction of the piezoelectric vibrating piece 4 (right side in FIG. 3), and the other side in the width direction (left side in FIG. 3). The second side wall 16b, the third side wall 16c disposed on the base end side (lower side in FIG. 3) of the piezoelectric vibrating piece 4, and the fourth side disposed on the distal end side (upper side in FIG. 3) of the piezoelectric vibrating piece 4. And a side wall 16d.

The depth from the upper surface U to the bottom surface 16e of the concave portion 16 is set to be deeper than the combined thickness of the piezoelectric vibrating reed 4 and the thickness of the bumps 11 and 12.
Here, the angle θ (see FIG. 2) between the bottom surface 16e of the recess 16 and the side walls 16a, 16b, 16c, 16d of the recess 16 is
95 ° ≦ θ ≦ 140 ° (1)
It is set to satisfy.
That is, it is formed so that the opening side is wider than the bottom surface 16 e of the recess 16. The angle θ is set so as to satisfy the expression (1) because when the lead-out electrodes 9 and 10 are formed on the side walls 16a, 16b, 16c, and 16d, film formation by a sputtering method, a vacuum evaporation method, or the like, or photolithography is performed. This is to facilitate the processing.

Generally, when forming a film from the opening side of the recess 16, the film thickness formed on each of the side walls 16a, 16b, 16c, and 16d is 1 / tan (180-θ) of the film thickness formed on the bottom surface 16e. Become. Here, for example, when tan (180−θ) ≧ 10, the film is formed on the bottom surface 16e with a thickness 10 times as large as the film thickness desired to be formed on each of the side walls 16a, 16b, 16c, and 16d. Photolithography and etching become difficult. Therefore, in order to suppress the film thickness difference between the bottom surface 16e and the side walls 16a, 16b, 16c, and 16d within 10 times, arctan (10) ≈85 °, so θ ≧ 180 ° −85 °, that is, θ is It is desirable that the angle is 95 ° or more. The reason why θ is set to 140 ° or less is that the maximum value of θ is generally about 130 ° to 140 ° when the side walls 16a, 16b, 16c, and 16d are formed by etching.
The base substrate 2 is anodically bonded to the lid substrate 3 with the recess 16 facing the lid substrate 3 side.

(Ground electrode)
A pair of lead-out electrodes 9 and 10 are patterned in the recess 16 of the base substrate 2. The pair of lead-out electrodes 9 and 10 electrically connect one through-electrode 13 and one mount electrode 7 of the piezoelectric vibrating reed 4 among through-electrodes 13 and 14 to be described later, The piezoelectric vibrating piece 4 is patterned so as to be electrically connected to the other mount electrode 8.

One lead-out electrode 9 is formed in a substantially rectangular shape in plan view so as to straddle the bottom surface 16e of the recess 16 and the first side wall 16a on the mount electrodes 7 and 8 side of the piezoelectric vibrating reed 4. Specifically, one lead-out electrode 9 includes a bottom electrode 9 a formed on the bottom surface 16 e of the recess 16 and a side wall electrode 9 b formed on the first side wall 16 a of the recess 16.
Bumps 11 are formed on the bottom electrode 9a. The side wall electrode 9b is connected to a through electrode 13 described later.

  The other routing electrode 10 is routed on the second side wall 16b along the outer shape of the piezoelectric vibrating reed 4 from a position adjacent to the one routing electrode 9, and is formed in an approximately L shape in plan view. Yes. Specifically, the other routing electrode 10 is formed from the base end side to the tip end side of the piezoelectric vibrating reed 4 on the bottom electrode 10 a formed on the bottom surface 16 e of the recess 16 and the second side wall 16 b of the recess 16. The side wall electrode 10b and the connection electrode 10c formed on the distal end side of the piezoelectric vibrating reed 4 on the second side wall 16b are configured.

  Bumps 12 are formed on the bottom electrode 10a. The connection electrode 10c is connected to a through electrode 14 described later. The sidewall electrode 10b electrically connects the bottom electrode 10a and the through electrode 14.

  The mount electrodes 7 and 8 of the piezoelectric vibrating reed 4 are mounted by flip chip bonding using the bumps 11 and 12 on the pair of lead-out electrodes 9 and 10. As a result, one mount electrode 7 of the piezoelectric vibrating reed 4 is electrically connected to one through electrode 13 through one routing electrode 9, and the other mount electrode 8 is passed through the other routing electrode 10 to the other penetration electrode. The electrode 14 is electrically connected.

(Penetration electrode)
A pair of through electrodes 13 and 14 are formed on the base substrate 2. The through electrodes 13 and 14 are conductive rod-shaped members formed of a metal material such as gold (Au), platinum (Pt), nickel (Ni) alloy, Hastelloy (registered trademark), or the like. As the raw material for the through electrodes 13 and 14, a metal having a small difference in linear expansion coefficient from the glass member that is the material of the base substrate 2 is preferably used. In particular, it is desirable to form an alloy (42 alloy) containing 58 weight percent iron (Fe) and 42 weight percent nickel (Ni).

The through electrodes 13 and 14 are disposed so as to be substantially perpendicular to the bottom surface 16 e of the recess 16 of the base substrate 2.
One through electrode 13 is disposed on the first side wall 16a side (the right side in FIG. 3) of the base substrate 2 and on the base end side (the lower side in FIG. 3) of the piezoelectric vibrating piece 4. The side is exposed from the first side wall 16a, and the other end side is exposed from the lower surface L.
On the other hand, the other through electrode 14 is disposed on the second side wall 16b side (left side in FIG. 3) of the base substrate 2 and on the tip side (upper side in FIG. 3) of the piezoelectric vibrating piece 4. One end side is exposed from the second side wall 16b, and the other end side is exposed from the lower surface L.

  On the lower surface L of the base substrate 2, external electrodes 21 and 22 that are electrically connected to the pair of through electrodes 13 and 14, respectively, are formed. That is, one external electrode 21 is electrically connected to the first excitation electrode 5 of the piezoelectric vibrating reed 4 via one through electrode 13 and one routing electrode 9. The other external electrode 22 is electrically connected to the second excitation electrode 6 of the piezoelectric vibrating reed 4 via the other through electrode 14 and the other routing electrode 10.

  When the piezoelectric vibrator 1 configured as described above is operated, a predetermined drive voltage is applied to the external electrodes 21 and 22 formed on the base substrate 2. As a result, a current can be passed through the excitation electrode including the first excitation electrode 5 and the second excitation electrode 6 of the piezoelectric vibrating piece 4 and can be vibrated at a predetermined frequency. The vibration can be used as a control signal timing source, a reference signal source, or the like.

(Piezoelectric vibrator manufacturing method)
Next, a method for manufacturing the above-described piezoelectric vibrator will be described with reference to a flowchart.
FIG. 5 is a flowchart of a method for manufacturing a piezoelectric vibrator.
FIG. 6 is a diagram showing a state in which a plurality of recesses 16 are formed in the base substrate wafer.
FIG. 7 is a view showing a state in which the bonding film and the routing electrode are patterned on the upper surface of the base substrate wafer.
FIG. 8 is a partially enlarged view of FIG.
FIG. 9 is an exploded perspective view of the wafer body.
Here, the dotted lines shown in FIG. 7 to FIG. 9 illustrate the cutting line M to be cut in the cutting process to be performed later.
The piezoelectric vibrator manufacturing method according to the present embodiment mainly includes a piezoelectric vibrating piece manufacturing step S10, a lid substrate wafer manufacturing step S20, a base substrate wafer manufacturing step S30, and an assembly step (S50 and subsequent steps). doing. Among them, the piezoelectric vibrating piece producing step S10, the lid substrate wafer producing step S20, and the base substrate wafer producing step S30 can be performed in parallel.

(Piezoelectric vibrating piece manufacturing step S10)
In the piezoelectric vibrating piece producing step S10, the piezoelectric vibrating piece 4 shown in FIGS. 2 to 4 is produced. Specifically, a quartz Lambert rough is first sliced at a predetermined angle to obtain a wafer having a constant thickness. Subsequently, the wafer is lapped and rough processed, and then mirror polishing such as polishing is performed to obtain a wafer having a constant thickness. Subsequently, after appropriate processing such as cleaning is performed on the wafer, a metal film is formed and patterned by photolithography, and the excitation electrodes 5 and 6, the extraction electrodes 19 and 20, and the mount electrode 7 are formed. , 8 and the side electrode 15 are formed. Thereby, a plurality of piezoelectric vibrating reeds 4 are produced.

(Lid substrate wafer manufacturing step S20)
In the lid substrate wafer manufacturing step S20, the disk-shaped lid substrate wafer 50 made of soda-lime glass is polished and washed to a predetermined thickness, and then the outermost processed layer is removed by etching or the like ( S21). Next, a bonding film forming step S <b> 22 is performed in which a conductive material is patterned on the mating surface of the lid substrate wafer 50 with the base substrate wafer 40 to form the bonding film 23 (see FIG. 1). In the present embodiment, the bonding film 23 is formed on the lid substrate wafer 50, but may be formed on the base substrate wafer 40.

(Base substrate wafer manufacturing step S30)
The base substrate wafer manufacturing step S30 mainly includes a through electrode press-fitting step S33 for press-fitting the through electrodes 13 and 14 into the base substrate wafer 40, a recess forming step S35 for forming the recess 16 in the base substrate wafer 40, and a base A routing electrode forming step S37 for forming a routing electrode on the substrate wafer 40;
In the base substrate wafer manufacturing step S30, as shown in FIG. 6, a base substrate wafer 40 that will later become the base substrate 2 is manufactured. First, the disc-shaped base substrate wafer 40 made of soda-lime glass is polished and washed to a predetermined thickness, and then the work-affected layer on the outermost surface is removed by etching or the like (S31).

(Penetration electrode press-fitting step S33)
Next, a through electrode press-fitting step S33 for press-fitting the through electrodes 13 and 14 into the base substrate wafer 40 is performed. In the penetration electrode press-fitting step S33, the base substrate wafer 40 is heated in advance to be in a softened state. Then, the through electrode 13 is pressed into a position corresponding to the first side wall 16 a of the rear recess 16, and the through electrode 14 is pressed into a position corresponding to the second side wall 16 b of the rear recess 16.

(Recess formation step S35)
Next, in the recess forming step S <b> 35, a plurality of recesses 16 are formed on the upper surface U of the base substrate wafer 40. The concave portion 16 is formed by, for example, etching.
As a specific recess forming step S35, first, a film made of gold or the like is formed on the surface of the base substrate wafer 40, and then a portion corresponding to the recess 16 is washed with a potassium iodide aqueous solution or aqua regia (hydrochloric acid and nitric acid). And a mask for etching the recess 16 is formed. Subsequently, the base substrate wafer 40 is etched using an aqueous solution made of hydrofluoric acid or the like. As described above, a plurality of concave portions 16 each including the bottom surface 16e and the side walls 16a, 16b, 16c, and 16d are formed on the upper surface U of the base substrate wafer 40.

(Leading electrode forming step S37)
Next, a lead electrode forming step S37 is performed in which a plurality of lead electrodes 9 and 10 (see FIG. 8) electrically connected to the through electrodes 13 and 14 are formed. The routing electrode 9 is formed on the bottom surface 16 e of the recess 16 and the first side wall 16 a, and the side wall electrode 9 b formed on the first side wall 16 a is formed so as to cover the through electrode 13. The routing electrode 10 is formed on the bottom surface 16e of the recess 16 and the second side wall 16b, and the connection electrode 10c formed on the second side wall 16b is formed so as to cover the through electrode 14. The routing electrodes 9 and 10 are formed by patterning a film formed by a sputtering method, a vacuum deposition method, or the like by a photolithography technique. In addition, since each routing electrode 9 and 10 is formed with the same material, each routing electrode 9 and 10 can be formed simultaneously.
Then, bumps 11 and 12 (see FIG. 4) made of gold or the like are formed on the bottom electrodes 9a and 10a of the routing electrodes 9 and 10, respectively. In FIG. 7 to FIG. 9, the illustration of the bumps is omitted for easy viewing of the drawings.

(External electrode forming step S40)
Next, a conductive material is patterned on the lower surface L of the base substrate wafer 40 to form a pair of external electrodes 21 and 22 (see FIG. 1) electrically connected to the pair of through electrodes 13 and 14, respectively. An external electrode forming step S40 is performed. Through this process, the piezoelectric vibrating reed 4 is electrically connected to the external electrodes 21 and 22 through the through electrodes 13 and 14.
When the external electrodes 21 and 22 are formed, the base substrate wafer manufacturing step S30 ends.

(Piezoelectric vibrator assembly process after mounting process S50)
Next, a mounting step S50 is performed in which the piezoelectric vibrating reed 4 is bonded onto the routing electrodes 9 and 10 of the base substrate wafer 40 via the bumps 11 and 12. Specifically, the piezoelectric vibrating reed 4 is picked by a bonding head (not shown) of a flip chip bonder, the bonding head is vibrated while heating the bumps 11 and 12 to a predetermined temperature, and the piezoelectric vibrating reed 4 is bumped by the bumps 11 and 12. Press on. Thus, the mount electrodes 7 and 8 are flip-chip bonded to the bumps 11 and 12 in a state where the crystal plate 17 of the piezoelectric vibrating reed 4 is lifted from the bottom surface 16 e of the recess 16 of the base substrate wafer 40.

  After the mounting of the piezoelectric vibrating reed 4 is completed, an overlaying step S60 for overlaying the lid substrate wafer 50 on the base substrate wafer 40 is performed. Specifically, both wafers 40 and 50 are aligned at the correct position while using a reference mark (not shown) as an index. As a result, the piezoelectric vibrating reed 4 mounted in the recess 16 of the base substrate wafer 40 is accommodated in the lid substrate wafer 50 and the base substrate wafer 40.

  After the superposition step S60, the superposed wafers 40 and 50 are put into an anodic bonding apparatus (not shown), and a bonding step S70 is performed in which a predetermined voltage is applied in a predetermined temperature atmosphere to perform anodic bonding. Specifically, a predetermined voltage is applied between the bonding film 23 and the base substrate wafer 40. As a result, an electrochemical reaction occurs at the interface between the bonding film 23 and the base substrate wafer 40, and the two are firmly bonded and anodically bonded.

  Next, a cutting step S80 is performed in which the bonded wafer body 70 is cut along a cutting line M (see FIG. 9) to make pieces. As a result, the piezoelectric vibration piece 4 is sealed in the recess 16 formed between the base substrate 2 and the lid substrate 3 that are anodically bonded to each other, and the two-layer structure surface mount type piezoelectric vibration shown in FIG. A plurality of children 1 can be manufactured at a time.

  Thereafter, an internal electrical characteristic inspection S90 is performed. That is, the resonance frequency, resonance resistance value, drive level characteristic (excitation power dependence of resonance frequency and resonance resistance value), etc. of the piezoelectric vibrating reed 4 are measured and checked. Also check the insulation resistance characteristics. Then, an external appearance inspection of the piezoelectric vibrator 1 is performed to check dimensions and quality. When all the checks are completed, the manufacture of the piezoelectric vibrator 1 is finished.

(effect)
According to the first embodiment, the routing electrodes 9 and 10 are arranged on the first side wall 16 a and the second side wall 16 b of the recess 16, so that the electrodes such as the excitation electrodes 5 and 6 of the piezoelectric vibrating piece 4 and the routing electrodes are arranged. It can avoid facing 9,10. As a result, the capacitive coupling between the piezoelectric vibrating reed 4 and the routing electrodes 9 and 10 can be prevented, and good electrical characteristics of the piezoelectric vibrator 1 can be maintained. Further, according to the present invention, since the routing electrodes 9 and 10 are routed on the first side wall 16a and the second side wall 16b of the recess 16, the routing electrodes 9 and 10 are routed on the bottom surface 16e of the recess 16. Space is not required, and the piezoelectric vibrator 1 can be miniaturized. Therefore, it is possible to provide the piezoelectric vibrator 1 that can be reduced in size while maintaining good electrical characteristics.

  In addition, according to the first embodiment, the first side wall 16a and the second side wall 16b of the recess 16 electrically connect the one end of the through electrodes 13 and 14 and the routing electrodes 9 and 10, so A space for electrically connecting the through electrodes 13 and 14 and the lead-out electrodes 9 and 10 to the bottom surface 16e becomes unnecessary, and the piezoelectric vibrator 1 can be further downsized.

( First reference form , deletion of the through electrode protruding into the recess)
Next, the first reference embodiment will be described.
In the first embodiment described above, the end portions of the through electrodes 13 and 14 protrude from the side walls 16a and 16b of the recess 16 as shown in FIG. However, the first reference embodiment is different in that the end portions of the through electrodes 13 and 14 are formed to be flush with the side walls 16a and 16b.

In the first reference embodiment , after the recess forming step S35, the end portions of the through electrodes 13 and 14 protruding from the side walls 16a and 16b of the recess 16 are removed. Specifically, the end portions of the through electrodes 13 and 14 are etched with an aqueous solution of potassium iodide or aqua regia (mixed solution of hydrochloric acid and nitric acid). Thereby, the edge part of the penetration electrodes 13 and 14 and each side wall 16a, 16b can be made substantially flush, without the edge part of the penetration electrodes 13 and 14 projecting from each side wall 16a, 16b.

(effect)
According to the first reference embodiment , since the end portions of the through electrodes 13 and 14 and the side walls 16a and 16b are formed substantially flush with each other, it is easy to form the side wall electrodes 9b and 10b of the routing electrodes 9 and 10. Can be formed. Therefore, the through electrodes 13 and 14 and the routing electrodes 9 and 10 can be easily connected.

( Modification of the first embodiment, inclined through electrode)
Next, a modification of the first embodiment will be described.
FIG. 10 is a cross-sectional view taken along the line AA of the piezoelectric vibrator 1 in a modification of the first embodiment.
In the first embodiment described above, the through electrodes 13 and 14 are disposed so as to be substantially perpendicular to the bottom surface 16e of the recess 16 as shown in FIG. However, the modification of the first embodiment is different in that the through electrodes 13 and 14 are arranged to be inclined with respect to the vertical direction of the bottom surface 16e. In addition, since the penetration electrode 13 and the penetration electrode 14 of a modification are the same structures, below, only the penetration electrode 13 is demonstrated and description of the penetration electrode 14 is abbreviate | omitted. Further, since the configuration other than the through electrodes 13 and 14 is the same as that of the above-described embodiment, the detailed description is omitted.

As shown in FIG. 10, the through electrode 13 is arranged so as to be away from the outer wall 2 a of the base substrate 2 from the recess 16 to the lower surface L of the base substrate 2. The distance between the outer peripheral surface of the through electrode 13 and the outer wall 2 a of the base substrate 2 is wider outside the base substrate 2 than inside the base substrate 2. That is, the through electrode 13 is arranged so that the thickness between the through electrode 13 and the outer wall 2 a of the base substrate 2 is thicker on the outer side of the base substrate 2. Therefore, according to the modification of the first embodiment, the strength of the base substrate 2 around the through electrodes 13 and 14 can be ensured.

( 2nd reference form , recessed part formation process S35)
Next, the second reference embodiment will be described.
FIG. 11 is an explanatory diagram of the recess forming step S35 of the second reference embodiment , FIG. 11 (a) is an explanatory diagram before pressing, FIG. 11 (b) is an explanatory diagram after pressing, and FIG. c) Through electrode 1
It is explanatory drawing when the front-end | tip of 3 and 14 is removed.
In the recess forming step S35 of the first embodiment, the recess 16 was formed by etching.
However, the recess forming step S35 of the second reference embodiment is different from the first embodiment in that the recess 16 is formed by pressing. Below, recessed part formation process S35 of a 2nd reference form is demonstrated. Detailed descriptions of the same contents as those in the first embodiment are omitted. Also,
The process is described by taking a cross-sectional view including the through electrode 13 as an example, but the same applies to the relationship with the through electrode 14.

As shown in FIG. 11, the recess forming step S35 of the second reference embodiment includes a receiving die 80 having a receiving portion 80a into which the base substrate wafer 40 can be inserted, and a base substrate wafer 40 inserted into the receiving portion 80a. This is performed using a pressing mold 85 that presses.
The pressurizing die 85 presses against the base substrate wafer 40 into which the through electrode 13 has been previously press-fitted. The pressing mold 85 is provided with a convex portion 85 a for forming the concave portion 16. Further, a relief portion 85b is formed at a position corresponding to the through electrode 13 of the convex portion 85a. The reason why the escape portion 85b is provided is to prevent the through electrode 13 and the pressurizing die 85 from interfering with each other when the end of the through electrode protrudes from the inclined first side wall 16a during pressing. .

The recess forming step S35 of the second reference form is performed according to the following procedure.
First, as shown in FIG. 11A, the base substrate wafer 40 is placed on the receiving portion 80 a of the receiving mold 80.
And the receiving die 80 is placed in a heating furnace (not shown) together with the base substrate wafer 40.
And a heating furnace is heated so that it may become predetermined temperature.

  Subsequently, the base substrate wafer 40 is pressed by the pressing die 85 using a press machine (not shown) or the like. As a result, as shown in FIG. 11B, the base substrate wafer 40 is buckled and deformed, and the recess 16 is formed while avoiding interference between the pressurizing die 85 and the through electrode 13. At this time, the recess 16 side of the through electrode 13 protrudes from the first side wall 16 a and the surface is covered with the glass material of the base substrate wafer 40.

  Finally, as shown in FIG. 11C, the penetrating electrode 13 protrudes from the first side wall 16a by etching with iodine iodide solution, aqua regia (mixed solution of hydrochloric acid and nitric acid), sandblasting, or the like. The portion is removed to expose the surface of the through electrode 13 from the first side wall 16a. Thus, the recess forming step S35 is completed.

(effect)
According to the second reference embodiment , the concave portion 16 can be easily and accurately formed by hot pressing. In particular, when the base substrate wafer 40 is formed of a glass member, it is effective to form the recess 16 by hot pressing.

The present invention is not limited to the embodiment described above.
In the first embodiment and the second reference embodiment , the piezoelectric vibrator 1 in which the AT-cut type piezoelectric vibrating piece 4 is enclosed in the package has been described as an example. However, the present invention is not limited to this, and a tuning fork type piezoelectric vibrating piece may be enclosed inside the package. Further, an element other than the piezoelectric vibrating piece may be enclosed.

In the first embodiment and the second reference embodiment , the bar-shaped through electrodes 13 and 14 are press-fitted and arranged in the base substrate wafer 40. However, for example, by forming recesses in the base substrate wafer 40, inserting the through electrodes 13 and 14 into the recesses, filling the glass frit and firing, the through electrodes 13 and 14 are then applied to the base substrate wafer 40. You may arrange. However, it is necessary to polish the base substrate wafer 40 and expose the through electrodes 13 and 14 from the first side wall 16 a and the second side wall 16 b of the recess 16 and the lower surface L of the base substrate 2. Therefore, this embodiment is superior in terms of work efficiency.

In the first embodiment and the second reference embodiment , the recess 16 is formed after the through electrodes 13 and 14 are press-fitted into the base substrate wafer 40. However, the through electrodes 13 and 14 may be press-fitted after the cavity is formed.

In the first embodiment and the second reference embodiment , the through electrodes 13 and 14 are formed on the first side wall 16a and the second side wall 16b. However, only one of the through electrode 13 and the through electrode 14 may be formed on either the first side wall 16a or the second side wall 16b. The package size can be reduced by forming at least one through electrode on the side wall.

  In the first embodiment, the recess 16 is formed in the base substrate wafer 40 by etching. However, for example, the recess 16 may be formed by sandblasting.

In the modification of the first embodiment, the through electrodes 13 and 14 are formed obliquely so as to be away from the outer walls 2a and 2b, respectively. However, only one of the through electrode 13 and the through electrode 14 may be formed obliquely so as to be away from the outer walls 2a and 2b. By forming the at least one penetrating electrode obliquely so as to move away from the outer wall, the package strength can be improved.

In the modification of the first embodiment, the through electrodes 13 and 14 are press-fitted into the base substrate wafer 40 to be formed obliquely so as to be away from the outer walls 2a and 2b. However, for example, when the hot pressing is performed as in the second reference embodiment , the through electrodes 13 and 14 may be inclined using the pressure when the base substrate wafer 40 is pressed.

In the second reference embodiment , the recessed portion 16 is formed by pressing after the through electrode 13 is press-fitted and disposed in the base substrate wafer 40 in advance. However, the through electrode 13 may be press-fitted and disposed after the recess 16 is formed.

In the second reference embodiment , the through electrode 13 is formed in a rod shape, and after the recess 16 is formed, the through electrode 13 protruding from the first side wall 16a is removed. However, for example, the end portion of the through electrode 13 on the concave portion 16 side may be formed obliquely so as to be along the first side wall 16a. As a result, it is not necessary to form the relief portion 85b in the pressurizing mold 85, so that the life of the pressurizing mold 85 is improved. However, the second reference embodiment is superior in that the through electrode 13 can be easily formed.

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric vibrator (package) 2 ... Base board | substrate (1st board | substrate) 2a, 2b ... Outer wall 4 ... Piezoelectric vibration piece (electronic component) 9, 10 ... Lead-out electrode 13, 14 ... Through electrode 16 ... Recess 16a, 16b, 16c, 16d ... Side wall 16e ... Bottom

Claims (5)

A plurality of substrates capable of forming cavities for enclosing electronic components;
The first substrate among the plurality of substrates is formed with a recess for the cavity and provided with a plurality of through electrodes penetrating between the recess and the outer surface side of the first substrate,
A routing electrode for electrically connecting the electronic component and the through electrode is arranged on the side wall of the recess ,
A package , wherein one end of the through electrode protrudes from the side wall of the recess . The package of claim 1,
A package, wherein one end of at least one through electrode among the plurality of through electrodes and the lead-out electrode are electrically connected to the side wall of the recess. A package according to claim 2, wherein
The other end of the at least one through electrode is led out to the lower surface side of the first substrate,
The at least one through electrode is formed obliquely so that the shape projected on an arbitrary side surface of the first substrate is away from the outer wall of the first substrate as it goes from the recess to the lower surface. Package characterized by being. The package according to any one of claims 1 to 3,
When the angle between the bottom surface of the recess and the side wall of the recess is θ,
The angle θ is
95 ° ≦ θ ≦ 140 °
A package characterized by being set to satisfy. A piezoelectric vibrator using the package according to any one of claims 1 to 4,
Forming the plurality of substrates with glass;
A piezoelectric vibrator comprising a piezoelectric vibrating piece sealed as the electronic component inside the recess.

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