JP4795697B2 - Vibrator package - Google Patents

Description

  The present invention relates to a vibrator package in which both surfaces are covered and sealed with a cover made of glass or the like.

  Piezoelectric elements (piezoelectric vibrators) such as quartz filters and quartz vibrators are damaged by changes in ambient temperature and humidity, or by fine foreign substances, and they are damaged by mechanical vibrations and shocks. Cheap. For this reason, the element mentioned above is sealed for use in a package. The package system is divided into a hermetic sealing system and a simple sealing system using a resin. In the SMD (Surface Mounted Device) type hermetic sealing system, materials such as ceramics and metals are mainly used. Further, as a cheaper hermetic sealing method, a hermetic sealing plastic package using plastic has also been realized.

  In the above-described package, the package is formed individually for each element. On the other hand, after being sealed at the wafer level where a plurality of elements are simultaneously formed, the package is cut into individual elements (chips). There is also proposed a technique for forming a packaged chip (see Patent Document 1). In this technique, as shown in FIG. 6, glass wafers 602 and 603 are bonded to a quartz wafer 601 on which a plurality of quartz vibrator bodies are formed, and the quartz vibrator body is sealed.

  As shown in FIG. 7, the plurality of chip portions formed on the quartz wafer 601 includes a frame portion 610 and a quartz resonator element 611 formed by hollowing out the periphery. Here, FIG. 7B is a cross-sectional view schematically showing a cross section taken along line BB ′ in FIG. 7A, and FIG. 7C is a cross section taken along line CC ′ in FIG. It is sectional drawing which showed typically. As shown in each sectional view, covers 615 and 616 are fixed to the frame portion 610, and a sealed space is formed in the region of the crystal resonator element 611. The cover 615 is provided on the surface side shown in FIG. 7A, and the cover 616 is provided on the surface side not shown in FIG. 7A. The covers 615 and 616 are fixed to the frame portion 610 by, for example, anodic bonding.

  The crystal resonator piece 611 is fixed to the frame portion 610 by connecting portions 613 and 614, and electrodes 612 are formed on both surfaces of the crystal resonator piece 611. The electrode 612 provided on one surface shown in the plan view of FIG. 7A is connected to the wiring 631 drawn out to the frame portion 610 through the connecting portion 613. The wiring 631 provided on one surface of the frame part 610 is drawn to the lower left of the frame part 610 in FIG. 7A and provided on the side part of the cover 615 as shown in FIG. 7C. The wiring 632 is connected to a terminal 633 provided on the outer plane of the cover 615.

  On the other hand, the electrode 612 provided on the other surface (the surface on the cover 616 side) of the crystal resonator element 611 is connected to the wiring 641 led out to the frame portion 610 through the connecting portion 614. The wiring 641 provided on the other surface of the frame part 610 is drawn out to the right center part of the frame part 610 in FIG. 7A and provided in the frame part 610 as shown in FIG. 7B. It is connected to the plug 642 in the through hole. The plug 642 is connected to a wiring 643 provided on one surface of the frame portion 610, and the wiring 643 is pulled out to the lower right of the frame portion 610. As shown in FIG. Is connected to a terminal 646 provided on the outer plane of the cover 615 via a wiring 645 provided on the cover 615.

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
JP 2003-188436 A

  In the conventional technique described above, the electrode 612 on the other surface of the crystal resonator element 611 is connected to the plug 642 in the through hole of the frame 610 so that the terminal 633 and the terminal 646 are arranged on the same side. To be connected to the terminal 646. In other words, in order to arrange the terminal 633 and the terminal 646 on the same side, the frame portion 610 needs a through hole. Here, as is well known, in order to improve the characteristics of the vibrator, the crystal vibrator piece 611 is preferably formed in a wider area. While a smaller chip is required, in order to make the crystal resonator element 611 larger, the frame portion 610 is formed as narrow as possible. However, since the conventional technique requires a through-hole as described above, the frame portion 610 is formed to have a wider width corresponding to the area of the through-hole, and the expansion of the crystal resonator element 611 is limited. there were.

  The present invention has been made to solve the above problems, and realizes a state in which two terminals provided outside are arranged on the same side without providing a through hole in the frame portion, It is an object of the present invention to make the vibrator piece made of a piezoelectric material such as quartz smaller by making the frame portion smaller.

The vibrator package according to the present invention includes a substantially rectangular piezoelectric substrate in which a frame portion and a piezoelectric vibrating piece disposed inside thereof are integrally formed, and a first electrode formed on the first surface side of the piezoelectric vibrating piece. A second electrode formed on the second surface side opposite to the first surface of the piezoelectric vibrating piece, a first metal layer connected to the first electrode and formed on the frame portion on the first surface side, A second metal layer connected to the second electrode and formed on the frame on the second surface side; a first cover provided on the first surface side piezoelectric substrate bonded to the first metal layer by anodic bonding ; one end of the second cover and the outer surface of the first cover disposed on the second surface side of the piezoelectric substrate are bonded by anodic bonding to the second metal layer, one side portion of the first cover, the over one end of the frame protruding from the first cover and the second cover, one side portion of the second cover, and one end portion of the outer surface of the second cover A first terminal disposed, the other end of the outer surface of the first cover, the other side portion of the first cover, the other end of the frame portion which protrudes from the first cover and the second cover, the second the other side portion of the cover, and at least a second terminal disposed over the other end of the outer surface of the second cover, one side and the other side of the first cover of the first cover The first metal layer is disposed on one side of the frame portion on the first surface side. The one side portion of the second cover and the other side portion of the second cover are disposed opposite to each other. A first external connection layer extending to the end portion ; a second metal layer including a second external connection layer extending to the other end portion of the frame portion on the second surface side; 1 is connected to the external connection layer, and the second terminal is connected to the second external connection layer.

  Therefore, in the piezoelectric vibrator piece, the first electrode and the second electrode formed on the front surface and the back surface are connected to the first terminal and the second terminal on the same surface outside the package.

As described above, in the present invention, firstly, a first terminal, one end of the outer surface of the first cover, one side portion of the first cover, a frame portion which protrudes from the first cover and the second cover one end of one side portion of the second cover, and the second is disposed over the one end portion of the outer surface of the cover, a second terminal, the other end portion of the outer surface of the first cover the other side portion of the first cover, the other end of the frame portion which protrudes from the first cover and the second cover, the other side portion of the second cover, and the other end portion of the outer surface of the second cover Arranged. In addition, the first terminal is connected to the first external connection layer, and the second terminal is connected to the second external connection layer. As a result, according to the present invention, the state in which the two terminals provided on the outside are arranged on the same side is realized without providing a through hole in the frame part, and the piezoelectric element piece is further reduced by making the frame part smaller. An excellent effect of being able to increase the size is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1, FIG. 2, FIG. 3, and FIG. 4 show an example of a method for manufacturing a vibrator package according to an embodiment of the present invention, and schematically show states in each step. FIG. 1 is a plan view, and FIG. 1 (a) shows one surface, and the other surface on the opposite side is shown in FIG. 1 (b). 2 is a perspective view, and FIGS. 3 and 4 are cross-sectional views.

  First, as shown in FIG. 1A, a plurality of frame portions 110 and crystal resonator elements 111 are formed on a crystal wafer 101, and openings 102 are formed in regions corresponding to the four corners of the frame portion 110. It is assumed that it is formed. Each of these chip portions is arranged substantially squarely via the cutting region 103. Further, in each chip part, the crystal resonator element 111 is disposed inside the frame part 110 and is fixed by the connecting part 113 and the connecting part 114. Accordingly, the frame portion 110 and the crystal resonator element 111 are integrally formed as a substantially rectangular crystal substrate.

  The opening 102 is formed such that the four corners 110 a, 110 b, 110 c, and 110 d of the frame 110 protrude to the inside of the opening 102. These can be formed by processing the quartz wafer 101 by a known photolithography technique and etching technique.

  Next, as shown in FIG. 1A, on one surface side of the crystal wafer 101, the wiring 122 passing through the connecting portion 113, the metal layer 123 disposed in the frame portion 110, and the metal layer 123 are connected. Assume that the external connection layers 124 disposed in the corner portions 110a and 110b are formed. In these methods, for example, an aluminum film is formed on the entire surface of one surface of the quartz wafer 101 by sputtering or vacuum deposition, and the formed aluminum film is patterned by a known photolithography technique and etching technique. Can be formed. Here, the metal layer 123 is continuously arranged in the circumferential direction of the frame portion 110. Further, the wiring 122, the metal layer 123, and the external connection layer 124 are formed from the same metal layer, and there is no step from the frame portion 110 to the cutting region 103. Note that an insulating region 123 a in which the metal layer 123 is not formed is formed at the boundary portion between the chip portion on the side where the external connection layer 124 is not provided and the cutting region 103. By providing the insulating region 123a, the insulation separation between the terminal 162 and the metal layer 123, which will be described later, becomes more reliable.

  Similarly, as shown in FIG. 1B, the other surface side of the crystal wafer 101 is connected to the wiring 132 passing through the connecting portion 114, the metal layer 133 disposed in the frame portion 110, and the metal layer 133. Assume that the external connection layer 134 disposed in the corner portion 110c and the corner portion 110d is formed. Here, the metal layer 133 is continuously arranged in the circumferential direction of the frame portion 110. Further, the wiring 132, the metal layer 133, and the external connection layer 134 are formed from the same metal layer, and there is no step from the frame portion 110 to the cutting region 103. Note that an insulating region 133a in which the metal layer 133 is not formed is formed at the boundary portion between the chip portion on the side where the external connection layer 134 is not provided and the cutting region 103. By providing the insulating region 133a, the insulation separation between the terminal 161 and the metal layer 133, which will be described later, becomes more reliable.

  Further, it is assumed that the electrode 121 is formed on one surface of the crystal resonator element 111 and the electrode 131 is formed on the other surface. For example, a metal film having a two-layer structure of a Cr film formed by, for example, a vapor deposition method or a sputtering method and an Au film laminated thereon is formed on both surfaces of the quartz wafer 101 by a sputtering method or a vacuum vapor deposition method, The electrode 121 and the electrode 131 can be formed by patterning the formed metal film using a known photolithography technique and etching technique. Note that the electrode 121 is connected to the wiring 122 and the electrode 131 is connected to the wiring 132.

  Next, as shown in the perspective view of FIG. 2A, a glass wafer 140a having a plurality of circular openings 102a and a glass wafer 150a having a plurality of circular openings 102b are prepared. . The glass wafer 150a has a plurality of recesses 150b. Although not shown in FIG. 2, the glass wafer 140a is similarly formed with a plurality of recesses. The openings 102 a and 102 b are formed in the same arrangement as the openings 102 provided in the crystal wafer 101. For example, when the glass wafer 140a and the quartz wafer 101 are bonded together, the center of the opening 102 overlaps the center of the opening 102b as shown in the plan view of FIG. In addition, the corner 110a, the corner 110b, the corner 110c, and the corner 110d protruding inside the opening 102 are exposed in the opening of the circular opening 102b. In addition, not only glass but other wafers such as quartz may be used.

  The glass wafer 140a thus formed is anodically bonded to the bonding film made of the metal layer 123, and the glass wafer 150a is bonded to the bonding film made of the metal layer 133, whereby the glass wafer 140a and the glass wafer 150a are bonded. Then, a state of being bonded to the frame portion 110 (the quartz wafer 101) is obtained. For example, if the glass wafer 140a, the crystal wafer 101, and the glass wafer 150a are stacked in this order, and the same potential is applied to the metal layer 123 and the metal layer 133 and anodic bonding is performed, the three wafers are bonded simultaneously. it can.

  As a result of the above-described bonding, as shown in the cross-sectional view of FIG. It will be in the state sealed in the space formed by 150b. In the bonded state, the openings 102a, the openings 102, and the openings 102b are in communication with each other, and the corners 110a, 110b, 110c, and 110d Protruding state. FIG. 3 shows a cross section taken along the line BB ′ of FIG. 1. In FIG. 3, the corner portion 110 b and the corner portion 110 d are shown. Further, the external connection layer 124 and the external connection layer 134 are exposed to the outside in the communicating holes.

  As described above, after each wafer is bonded, by cutting into individual chips from the bonded glass wafer 140a, crystal wafer 101, and glass wafer 150a, as shown in the cross-sectional view of FIG. Assume that individual chip portions are formed. For example, if the lattice-shaped cutting region 103 (FIG. 1) passing through each opening 102 is cut out by a dicing technique using a diamond blade or the like, a state in which individual chip portions are formed can be obtained. As a result, the crystal resonator element 111 is sealed in the space formed by the frame 110 of the crystal substrate (piezoelectric substrate) 101a, the recess 140b of the cover 140, and the recess 150b of the cover 150. A vibrator package is obtained.

  Next, a metal film is formed on the outer surface of the chip, and terminals 161 and 162 are formed by the formed metal film as shown in the cross-sectional view of FIG. 4 and the perspective view of FIG. The terminal 161 is located on one end of the chip from the top of the cover 140 (outer side) to the side of the cover 140, the side of the frame 110 (crystal substrate 101a), the side of the cover 150, and the top of the cover 150. (Outside surface) is arranged. Similarly, the terminal 162 is disposed on the other end of the chip from the top of the cover 140 to the side of the cover 140, the side of the frame 110, the side of the cover 150, and the cover 150. .

  As the metal film constituting the terminal 161 and the terminal 162, for example, a two-layer film including a Cr film formed by a vapor deposition method or a sputtering method and an Au film stacked thereon may be used. For example, the terminal 161 and the terminal 162 can be formed by using a mask at the time of forming the film so that the metal film is formed on both surfaces including the side portions at both ends of the chip. As shown in FIG. 4, the terminal 161 formed to extend to the side portion is connected to the external connection layer 124, and the terminal 162 is connected to the external connection layer 134. Therefore, the terminal 161 is connected to the electrode 121 via the external connection layer 124 -metal layer 123 -wiring 122, and the terminal 162 is connected to the electrode 131 via the external connection layer 134 -metal layer 133 -wiring 132. It becomes.

  Further, since there is no external connection layer connected to the metal layer 133 on the side where the terminal 161 is formed, the terminal 161 and the metal layer 133 are insulated and separated, and thus the terminal 161 and the electrode 131 are connected. It has not been. Similarly, on the side where the terminal 162 is formed, since there is no external connection layer connected to the metal layer 123, the terminal 162 and the metal layer 123 are insulated and separated, so that the terminal 162 and the electrode 121 are separated from each other. Not connected. Although not shown in FIG. 4, an insulating region 123a is formed at the boundary between the chip portion on the side where the external connection layer 124 is not provided and the cutting region 103, so that the terminal 162 is formed. In the region, the terminal and the metal layer 123 are reliably insulated and separated. Similarly, since an insulating region 133a is formed at the boundary portion between the chip portion where the external connection layer 134 is not provided and the cutting region 103, the terminal and the metal layer are formed in the region where the terminal 161 is formed. 133 is surely insulated and separated.

  According to the transducer package (chip) shown in FIGS. 4 and 5 formed as described above, two terminals are provided on the outer surfaces of both covers. By doing so, the vibrator package (chip) can be used without distinguishing between the front and back surfaces. As a result, it is easy to align a plurality of chips in the characteristic inspection, and it is possible to easily pack without distinguishing between the back and back surfaces of both sides, and it is possible to mount on either side. Moreover, since the structure of the terminal described above is formed without providing a through hole in the frame part 110, it is easy to reduce the area of the frame part 110. As a result, a smaller chip can be formed without reducing the area of the crystal resonator element 111 so much.

  By the way, in the above description, the corner portion of the cover is provided with a notch so that the corner portion of the frame portion protrudes, and the external connection layer is provided in this portion. However, the present invention is not limited to this. . Any shape may be used as long as the corner of the frame protrudes outward (side direction) with respect to the corner of the cover. For example, the corner portion of the frame portion and the corner portion of the cover may both have the shape of an arc protruding outward. In addition, at the bonding interface between the frame portion and the cover, the metal layer 123 extends to the outermost periphery on one side of the chip, and the metal layer 133 extends to the outermost periphery on the other side of the chip, The end of the metal layer 123 may be connected to the terminal 161, and the end of the metal layer 133 may be connected to the terminal 162.

  In the above description, quartz has been described as an example. However, the present invention is not limited to this, and other piezoelectric materials such as crystals or ceramics having piezoelectricity may be used. In the above description, the cover is provided with a recess to form a sealed space in which the crystal resonator element is disposed. However, the present invention is not limited to this. For example, if the frame portion is formed thicker than the piezoelectric vibrator piece portion, even if the cover is a plate-like cover in which no recess is formed, there is a space in which the crystal vibrator piece can be operated by the cover and the frame portion. Can be formed. In this case, a recess is formed in the piezoelectric substrate. Here, the depth of the concave portion described above may be as long as a space in which the piezoelectric vibrator piece can vibrate is formed.

It is a top view which shows typically the state of each process in an example of the manufacturing method of the vibrator package in embodiment of this invention. It is a perspective view which shows typically the state of each process in an example of the manufacturing method of the vibrator package in embodiment of this invention. It is sectional drawing which shows typically the state of each process in an example of the manufacturing method of the vibrator package in embodiment of this invention. It is sectional drawing which shows typically the state of each process in an example of the manufacturing method of the vibrator package in embodiment of this invention. It is a perspective view which shows the structural example of the vibrator package in this Embodiment. It is a perspective view which shows the structure of the conventional vibrator package. It is the top view (a) and sectional drawing (b), (c) which show the structure of the conventional vibrator package.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Quartz wafer, 102, 102a, 102b, ... Opening part, 103 ... Cutting area, 110 ... Frame part, 110a, 110b, 110c, 110d ... Corner | angular part, 111 ... Crystal oscillator piece, 113, 114 ... Connection part, DESCRIPTION OF SYMBOLS 121 ... Electrode, 122 ... Wiring, 123 ... Metal layer, 124 ... External connection layer, 131 ... Electrode, 132 ... Wiring, 133 ... Metal layer, 134 ... External connection layer, 140, 150 ... Cover, 140a, 150a ... Glass wafer , 140b, 150b... Recesses, 161, 162.

Claims (1)

A substantially rectangular piezoelectric substrate in which a frame portion and a piezoelectric vibrating piece disposed inside the frame portion are integrally formed;
A first electrode formed on the first surface side of the piezoelectric vibrating piece;
A second electrode formed on the second surface side opposite to the first surface of the piezoelectric vibrating piece;
A first metal layer connected to the first electrode and formed on the frame portion on the first surface side;
A second metal layer connected to the second electrode and formed on the frame portion on the second surface side;
A first cover which is bonded to the first metal layer by anodic bonding and is provided on the piezoelectric substrate on the first surface side;
A second cover that is bonded to the second metal layer by anodic bonding and provided on the piezoelectric substrate on the second surface side;
One end portion of the first cover of the outer surface, the one side portion of the first cover, one end of said frame portion which protrudes from the first cover and the second cover, one of said second cover a first terminal disposed side portions, and over the one end portion of the second cover of the outer surface of,
The other end portion of the first cover of the outer surface, the other side portion of the first cover, the other end portion of the first cover and said frame portion which protrudes from the second cover, the other of the second cover side portion, and includes at least a second terminal disposed over the other end portion of the second cover of the outer surface of,
One side of the first cover and the other side of the first cover are arranged to face each other,
One side of the second cover and the other side of the second cover are arranged to face each other,
The first metal layer includes a first outer connecting layer extending to said one end of the frame portion of the first surface side,
The second metal layer includes a second outer connection layer extending to the other end of the frame portion of the second surface side,
The first terminal is connected to the first external connection layer;
The vibrator package, wherein the second terminal is connected to the second external connection layer.

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