JP2006238210A - Piezoelectric device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric device comprising the piezoelectric vibrator and an IC chip, wherein the manufacturing cost is reduced by utilizing a versatile piezoelectric vibrator on the market as it is, and the size is made small. <P>SOLUTION: A crystal oscillator 1 comprises a crystal vibrator 2 sealing a crystal vibrating element 7 within a package 6, an IC chip 3 for driving the same, and a frame 4 which has a connecting electrode 17 with the IC chip on its upper surface and is provided with a vertical through-opening 16. The crystal vibrator is housed inside the opening of the frame with its lid 9 downside, the IC chip is fixed thereon, and an electrode pad 15 thereof and the connecting electrode of the crystal vibrator and the frame are connected by wire bonding and are sealed by a mold resin 5 as a whole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a piezoelectric device used in various electronic devices, and in particular, a piezoelectric oscillator including a piezoelectric vibrator and an IC element such as an IC (semiconductor integrated circuit) chip that is an oscillation circuit thereof, and a piezoelectric device such as a real-time clock module. And a manufacturing method thereof.

  Conventionally, piezoelectric devices such as a piezoelectric oscillator and a real-time clock module including a piezoelectric vibrator and an IC chip have been used in various electronic devices. Especially in the field of small information devices such as mobile computers and IC cards, and communication devices such as mobile phones, the miniaturization and high performance of the devices are remarkable, and in response to this, the piezoelectric devices are further miniaturized and thinned. It is requested. Recently, in addition to this, a surface mount type suitable for mounting on a circuit board of an apparatus has been widely adopted.

  In a conventional piezoelectric oscillator, a crystal vibrating piece and its driving IC chip are arranged on a common substrate in a plane and hermetically sealed with a common lid (see, for example, Patent Document 1). Furthermore, there is known a crystal oscillator in which a semiconductor chip is mounted on a common substrate with a crystal resonator and covered with a resin coat (see, for example, Patent Document 2).

  In addition, in order to reduce the planar size of the entire device, the crystal vibrating piece and the IC chip are arranged vertically in a common package, or arranged on the front side and the back side of a common substrate and sealed separately. Is known (see, for example, Patent Documents 3 and 4). Furthermore, in order to reduce the size of the device and reduce the manufacturing cost, a piezoelectric oscillator in which a circuit element (IC chip) is directly mounted on a metal lid for sealing a packaged piezoelectric vibrator and covered with a resin is proposed. (For example, see Patent Document 5).

Japanese Patent Laid-Open No. 9-107186 JP 2000-31324 A Japanese Patent Laid-Open No. 11-186850 JP-A-9-167918 JP 2001-320240 A

  However, as described above, a piezoelectric oscillator having a conventional structure in which an IC chip is directly mounted on a packaged piezoelectric vibrator and integrally sealed with a resin includes an electrode pad for connecting to an electrode of the IC chip and an external electrode pad. Internal wiring and electrodes for drawing out to the surface are formed on the mounting surface of the ceramic package of the piezoelectric vibrator. Therefore, a piezoelectric vibrator having a dedicated package structure corresponding to each required specification of the piezoelectric oscillator is required, and there is a problem that the design is troublesome and the manufacturing cost is increased. Therefore, it would be advantageous if general-purpose piezoelectric vibrators that were conventionally produced in large quantities at low cost can be used as they are.

Therefore, the present invention has been made in view of the above-described conventional problems, and its purpose is to meet the demand for downsizing in a piezoelectric device including a piezoelectric vibrator and an IC chip. A commercially available piezoelectric vibrator having versatility can be used as it is, thereby reducing the manufacturing cost, and more preferably to provide a high-quality piezoelectric device with high frequency accuracy.
It is a further object of the present invention to provide a method for manufacturing such a piezoelectric device easily and at low cost.

  According to the present invention, in order to achieve the above object, a piezoelectric vibrator having a piezoelectric vibrating piece sealed in a package, an IC element for driving the piezoelectric vibrator, and a connection electrode for the IC element on the upper surface thereof. The IC element is fixed on the package of the piezoelectric vibrator, the piezoelectric vibrator is accommodated inside the opening of the frame, the connection electrode of the frame and the IC The electrode pad of the element is connected by wire bonding, and at least fills the gap between the piezoelectric vibrator and the IC element and the frame accommodated in the opening of the frame and covers the connection part of the connection electrode and the electrode pad Thus, a piezoelectric device in which a frame, a piezoelectric vibrator, and an IC element are sealed with a resin is provided.

  In this way, a resin-sealed configuration using a frame provided with an electrode for connection to the outside allows a commercially available piezoelectric vibrator to be used as it is, so that manufacturing costs can be reduced. Further, not only the IC element is superimposed on the piezoelectric vibrator, but also the size and shape of the frame can be selected and designed according to the piezoelectric vibrator to be used, which is particularly advantageous for reducing the planar size of the piezoelectric device.

  In one embodiment, the package of the piezoelectric vibrator is composed of a base on which the piezoelectric vibrating piece is mounted and a lid that is bonded to the base and seals the piezoelectric vibrating piece inside, and is externally provided on a surface opposite to the lid. A piezoelectric vibrator having an electrode is disposed in the opening of the frame with the lid on the lower side, and the external electrode of the piezoelectric vibrator and the corresponding electrode pad of the IC element are connected by wire bonding. In many cases, commercially available surface mount type piezoelectric vibrators have an external electrode disposed on the bottom surface of the base, so that the wire can be easily bonded between the piezoelectric vibrator and the IC element by lowering the lid. In addition, by adjusting the height of the frame to the height of the piezoelectric vibrator, wire bonding between the electrode pad of the IC element and the connection electrode of the frame and the external electrode of the piezoelectric vibrator can be made easier. it can.

  In another embodiment, it is arranged so that the outer surface of the lid of the piezoelectric vibrator is exposed from the sealing surface of the resin at the opening of the frame, whereby the height of the entire device can be further reduced. Further, when the lid of the piezoelectric vibrator is transparent or has a transparent portion, a trimming process is performed in which the electrode film on the surface of the piezoelectric vibrating piece is partially removed by irradiating laser light from the outside through the lid. By doing so, the frequency can be finely adjusted with high accuracy.

  In one embodiment, the frame has an external terminal electrically connected to the connection electrode on the lower surface, thereby obtaining a structure that can be surface-mounted on an external device, a circuit board, or the like when used.

  In another embodiment, the frame has external terminals drawn out from the connection electrodes on the top surface, and is resin-sealed so that the external terminals are exposed. Since there is no need to provide wiring for connecting to the connection electrodes, the structure of the frame itself is simplified and the manufacturing cost can be further reduced.

  In one embodiment, the frame includes two frame portions extending along opposite sides in the longitudinal direction or the transverse direction of the piezoelectric vibrator, and an opening is defined between the frame portions. Thereby, the planar dimension of the whole apparatus can be made smaller.

  In another embodiment, the frame has a complete ring shape extending along the entire circumference of the piezoelectric vibrator, and an opening is defined on the inside thereof, so that the connection electrode is provided on the upper surface of the frame. A larger area is secured. Therefore, even when the number of electrode pads of the IC element is large, there is a high degree of freedom in arrangement and design of connection electrodes connected to the IC element, and there is no possibility that wire bonding is difficult even if the piezoelectric device is downsized.

  According to another aspect of the present invention, a step of preparing a piezoelectric vibrator having a piezoelectric vibrating piece sealed in a package, a step of preparing an IC element for driving the piezoelectric vibrator, and an IC element on the upper surface thereof A step of preparing a frame having connection electrodes and having an opening extending vertically, a step of arranging a piezoelectric vibrator inside the opening of the frame, and fixing an IC element on the package of the piezoelectric vibrator Connecting the connection electrode of the frame and the electrode pad of the IC element by wire bonding, filling at least the gap between the piezoelectric vibrator and the IC element and the frame accommodated in the opening, and connecting the frame There is provided a method of manufacturing a piezoelectric device comprising a step of sealing a frame, a piezoelectric vibrator, and an IC element with a resin so as to cover a connection portion between an electrode and an electrode pad of the IC element.

  With such a manufacturing process, the piezoelectric device of the present invention can be manufactured easily and at low cost using a commercially available piezoelectric vibrator. For the resin sealing, various known resin sealing methods such as a molding method using a mold or potting can be used.

  In one embodiment, the method further includes a step of forming a substrate in which a plurality of frames are continuously arranged in the vertical direction and / or the horizontal direction, and a piezoelectric vibrator is arranged in each opening of each frame of the substrate. In addition, each IC element is fixed on each package, the connection electrode of the corresponding frame and the electrode pad of the IC element are connected by wire bonding, and the corresponding frame, piezoelectric vibrator and IC element of the substrate are sealed with resin. After that, by cutting along the boundary line of each frame and dividing into a plurality of piezoelectric devices, a large number of piezoelectric devices can be efficiently manufactured at the same time. In addition, when sealing with resin by the molding method, the molding die may be a simple one that sandwiches the entire substrate from above and below, and there is no need to prepare individual molding die for each piezoelectric device. It is.

  This substrate is formed of a hard substrate in one embodiment, and is formed of a flexible substrate in another embodiment, and can be appropriately selected according to the specification and size of the target piezoelectric device, the manufacturing process thereof, and the like.

  In another embodiment, the piezoelectric vibrator package includes a base on which the piezoelectric vibrating piece is mounted and a lid that is bonded to the base and seals the piezoelectric vibrating piece inside, and the lid is placed in the opening of the frame. And the outer surface of the lid is exposed from the resin sealing surface at the opening, and after the resin sealing of the frame, the piezoelectric vibrator and the IC element, the laser beam is externally applied through the transparent portion of the lid. , And partially removing the electrode film on the surface of the piezoelectric vibrating piece to adjust its frequency. As a result, the piezoelectric vibrating piece can be finely adjusted with high accuracy, and a high-performance and high-quality piezoelectric device can be obtained.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1A to 1C schematically show the configuration of a crystal oscillator which is a first embodiment of a piezoelectric device according to the present invention. The crystal oscillator 1 includes a crystal resonator 2, an IC chip 3 composed of an oscillation circuit for driving the crystal resonator 2, a frame 4 that defines the outline of the oscillator, and a mold resin 5 that hermetically seals them. .

  The crystal resonator 2 is a commercially available crystal resonator having general versatility. As shown in FIGS. 2A and 2B, a tuning fork type crystal resonator element 7 is mounted in the package 6. The package 6 includes a rectangular box-shaped base 8 in which ceramic sheets 8a and 8b are laminated, and a transparent glass material lid 9 that seals the upper opening thereof. The crystal vibrating piece 7 is fixed substantially horizontally and cantilevered by a conductive adhesive 11 to a connection electrode 10 whose base end portion 7 a is formed inside the base 8. A lid 9 is hermetically bonded to the upper end of the base 8 with a low melting point glass 12, and a pair of external electrodes 13 are formed on the lower surface of the base 8 at both ends in the longitudinal direction.

  As shown in FIG. 1C, the crystal resonator 2 is arranged with the lid 9 on the lower side and the lid exposed from the bottom surface of the mold resin 5. Since there is no mold resin under the crystal unit 2, the height of the crystal unit 1 can be further reduced. Further, since the transparent glass lid 9 is exposed on the outer surface, the frequency is adjusted by partially removing the electrode film on the surface of the crystal vibrating piece 7 by irradiating laser light from the outside through the lid. Can do. The IC chip 3 is directly fixed with an adhesive 14 on the crystal resonator 2, that is, on the surface of the base 8 on which the external electrode 13 is formed. A plurality of electrode pads 15 are provided on the upper surface of the IC chip 3 for connection with the input / output of the oscillation circuit and the crystal resonator 2.

  The frame 4 of the present embodiment has two frame portions 4 a and 4 a extending along each side of the crystal resonator 2 in the longitudinal direction. Between both the frame parts 4a and 4a, the opening part 16 opened to the both sides in the longitudinal direction of the crystal unit 2 and penetrating vertically is defined. Inside the opening 16, the crystal unit 2 is disposed so as to have a gap between the side in the longitudinal direction and each frame portion, and the gap is completely filled with the mold resin 5.

  Each frame portion 4a, 4a has a plurality of connection electrodes 17 formed on its upper surface for connection to the electrode pads 15 of the IC chip 3, and a plurality of external terminals 18 formed on its lower surface for connection to an external device. Has been. A cutout portion 19 having a semicircular cross section is provided on the outer surface of each frame portion 4a, 4a, and each connection electrode 17 and the corresponding external terminal 18 are connected by an electrode film 20 formed on the inner surface thereof. Yes. The lower half of the notch 19 has the mold resin removed and the electrode film 20 exposed, facilitating the formation of a filler fillet when the crystal oscillator 1 is surface-mounted on a circuit board or the like. The notch 19 and the electrode film 20 can be formed, for example, by vertically dividing a through hole formed in the substrate as will be described later.

  The electrode pad 15 of the IC chip 3, the connection electrode 17 of the frame 4, and the external electrode 13 of the crystal resonator 2 are electrically connected by bonding wires 21, respectively. These connecting portions including the bonding wire 21 are completely filled with the mold resin 5.

  Next, each process for manufacturing the crystal oscillator 1 of FIG. 1 will be described in order. FIGS. 3A and 3B show a frame-forming substrate 22 suitable for simultaneously manufacturing a large number of crystal oscillators 1. The substrate 22 of this embodiment is a hard insulating resin substrate made of BT resin or the like generally used for printed wiring boards and the like. A large number of crystal oscillator frames 4 are continuously formed on the substrate 22 in the vertical and horizontal directions.

  A plurality of long grooves 23 extending in the horizontal direction in the figure are formed in the substrate 22 in parallel. The width of the groove 23 is equal to the width of the opening 16 of the frame 4, and the interval between adjacent grooves 23, that is, the width of the substrate portion, is equal to the sum of the widths of the two frame portions 4 a and 4 a. A large number of electrode films 24 for forming the connection electrodes 17 of the frame 4 on the surface thereof and a large number of electrodes for forming the external terminals 18 of the frame 4 on the back surface of the substrate portions on both sides of the grooves 23. The electrode film 25 is formed at a position corresponding to each other. The electrode films 24, 25 are provided so as to form two connection electrodes 17 or external terminals 18, respectively, across the boundary of the frame adjacent to the substrate 22 in the direction orthogonal to the groove 23. The corresponding electrode films 24 and 25 on the front and back sides are electrically connected to each other by an electrode film 27 on the inner surface of the through hole 26 formed in the substrate 22. Each through hole 26 is provided on a boundary line 28 of the adjacent frame.

  First, the adhesive sheet 29 is affixed on the back surface of the substrate 22 so that the bottom of each groove 23 is completely closed and placed horizontally. For the adhesive sheet 29, for example, a commercially available dicing tape made of polyimide resin is used. A reusable metal plate can also be used for the adhesive sheet 29. A large number of crystal resonators 2 are arranged inside the grooves 23 with the lid 9 facing down, and are fixed on the adhesive surface of the adhesive sheet 29 at a predetermined position corresponding to the boundary line 28 in FIG. FIG. 4 (A)). After the IC chip 3 is fixed on each crystal resonator 2 with an adhesive 14, the electrode pads 15 on the upper surface thereof are placed on the substrate 22 inside the corresponding external electrodes 13 and boundary lines 28 of the crystal resonator 2. The adjacent electrode film 24 is connected by wire bonding (FIG. 4B). If the thickness of the substrate 22 is selected according to the height of the crystal unit 2 in advance, wire bonding becomes easy, which is convenient.

  Next, the substrate 22 on which the crystal resonator 2 and the IC chip 3 are arranged and wired in this way is placed in a molding die including the upper die 30a and the lower die 30b. For example, a mold resin 31 made of an epoxy-based thermosetting synthetic resin material is injected into the mold, and the gap between the crystal resonator 2 and the IC element 3 and the substrate 22, the electrode pad 15, the connection electrode 13, and the electrode film. The whole including the connection part with 24 is sealed (FIG. 4C). Of course, various other known materials can be used for the mold resin 31. Further, the molding die of this embodiment may be a simple one that sandwiches the entire substrate 22 from above and below, and it is advantageous because it is not necessary to prepare a separate molding die for each crystal oscillator.

  After the mold resin 31 is completely cured, the upper mold 30a and the lower mold 30b are removed, the substrate 22 is taken out of the mold, and the adhesive sheet 29 is peeled off (FIG. 4D). The substrate 22 thus sealed with resin is cut by dicing or the like along the boundary line 28 in FIG. 3A, and is singulated as shown in FIG. Finally, the lower half of the mold resin 31 filled in each through-hole 26 in the resin sealing step is removed by, for example, sandblasting to expose the electrode film 20. Thereby, the crystal oscillator 1 shown in FIG. 1 is completed. Moreover, the adhesive sheet 29 can also be peeled off individually after being diced together with the substrate 22.

  Furthermore, in the present invention, the frequency of the completed crystal oscillator 1 can be finely adjusted. This is achieved by irradiating laser light from the outside through the transparent glass lid 9 exposed on the mold resin surface on the bottom surface of the crystal oscillator 1 while measuring the frequency through the external terminal 18 of the crystal oscillator 1, thereby producing the crystal vibrating piece 7. This is done by partially removing the electrode film on the surface. Thereby, the frequency of the crystal unit 2 can be adjusted with high accuracy, and a high-performance and highly reliable crystal oscillator 1 can be obtained.

  Further, in the present invention, the frequency of each crystal oscillator can be individually measured in the state of the substrate shown in FIG. 4D before being separated into pieces by dicing. In the state of the substrate 22, the connection electrode 17 of each frame is connected only to the connection electrode sharing the electrode film 24 of another adjacent crystal oscillator, and the entire substrate is not electrically short-circuited. Therefore, the frequency of each crystal oscillator can be adjusted in the substrate state before dicing.

  5A and 5B show a frame creating substrate 32 which is a modification of the frame creating substrate shown in FIG. The substrate 32 of this embodiment is a flexible insulating resin substrate made of a PBT resin or the like generally used for a TAB tape or the like, and is formed in an elongated tape shape as a whole. On the substrate 32, a number of similar crystal oscillator frames 4 are formed continuously in the vertical and horizontal directions.

  A plurality of long grooves 33 extending in the vertical direction in the drawing, that is, the width direction of the tape are formed in the substrate 32 in parallel. The width of the groove 33 is equal to the width of the opening 16 of the frame 4, and the interval between adjacent grooves 33, that is, the width of the substrate portion, is equal to the sum of the widths of the two frame portions 4 a and 4 a. A large number of electrode films 34 for forming the connection electrodes 17 of the frame 4 on the surface thereof and a large number of electrodes for forming the external terminals 18 of the frame 4 on the back surface of the substrate portions on both sides of the grooves 33. The electrode film 35 is formed at a position corresponding to each other. The electrode films 34 and 35 are provided on the substrate 32 so as to form two connection electrodes 17 or external terminals 18 across the boundary between the frames adjacent to each other in the direction orthogonal to the groove 33. The corresponding electrode films 34 and 35 on the front and back are electrically connected to each other by an electrode film 37 on the inner surface of the through hole 36 formed in the substrate 32. Each through hole 36 is provided on a boundary line 38 between the adjacent frames.

  Also for the substrate 32 of this modification, the crystal oscillator 1 can be manufactured according to the process shown in FIG. 4 in the same manner as the substrate 22 of FIG. That is, an adhesive sheet is pasted on the back surface and the substrate 32 with the bottom of each groove 33 completely closed is placed horizontally, and a large number of crystal resonators 2 are placed on the lid 9 on the lower side. After the IC chip 3 is fixed on each crystal resonator 2 and positioned at the position, the external electrode 13 of the crystal resonator 2 corresponding to the electrode pad 15 and the adjacent electrode on the substrate 32 inside the boundary line 38 are disposed. The film 34 is connected by wire bonding. The substrate 32 is placed in a predetermined mold and an appropriate mold resin is injected to seal the whole. After the mold resin is cured, the substrate 32 is taken out from the mold and is taken along a boundary line 38 in FIG. Cut and divide. Finally, by removing the lower half of the mold resin filled in the through hole 36 and exposing the electrode film 37, the crystal oscillator 1 shown in FIG. 1 is similarly completed.

  Furthermore, in this modified example, a carrier tape 39 to which the crystal unit 1 is attached as shown in FIG. 6 can be used in combination with the substrate of FIG. The carrier tape 39 is a TAB tape carrier used for conveying a large number of electronic components in, for example, TAB (tape automatic bonding). On the surface, a plurality of crystal resonators 1 are bonded in advance at predetermined positions corresponding to the grooves 33 and the boundary lines 38 of the substrate 32 with the lid 9 facing down.

  In the manufacturing process of the crystal oscillator 1 using the carrier tape 39, as shown in FIG. 7, first, the carrier tape 39 is horizontally placed with the crystal unit 1 facing upward. A flexible substrate 32 is placed thereon so that each crystal resonator 1 on the carrier tape 39 is disposed inside the groove 33 of the substrate 32. The subsequent steps are the same as the manufacturing steps shown in FIGS. 4B to 4E described above, and the description thereof will be omitted.

  8A to 8E show a modification of the manufacturing process shown in FIGS. 4A to 4E. In this modification, the upper end of each through hole 26 of the substrate 22 is closed with an appropriate plate member 40 in advance. The plate-like member 40 is preferably made of a relatively soft metal material or resin material so that it can be easily cut by subsequent dicing.

  Using this substrate 22, the crystal resonator 2 and the IC chip 3 are arranged and connected by wire bonding 21 in the same manner as in the steps shown in FIGS. 4A to 4E, and are put into molds 30a and 30b and molded resin. 31 is sealed (FIGS. 8A to 8C). At this time, since each through hole 26 is closed by the plate-like member 40, the inside thereof is not filled with the mold resin. Therefore, when the plate member 40 is finally removed from the mold and cut along the boundary line 28 into individual pieces (FIGS. 8D and 8E), the electrode film 20 remains in the through hole 26 as it is. Since it is exposed, the crystal oscillator 1 shown in FIG. 1 is completed. Thereby, the sandblasting in FIG. 4E can be omitted.

  FIGS. 9A to 9C schematically show the configuration of a crystal oscillator which is a second embodiment of the piezoelectric device according to the present invention. As in the first embodiment, the crystal oscillator 41 includes a crystal resonator 2 having a lid 9 on the lower side, an IC chip 3 including an oscillation circuit for driving the crystal resonator 2, and a frame 42 that defines the outline of the oscillator. And a mold resin 5 for hermetically sealing them. The present embodiment is a first embodiment in that the frame 42 has a complete rectangular ring shape extending along the entire circumference of the crystal unit 2 and an opening 43 penetrating vertically is defined inside the frame 42. Different from the example. The crystal unit 2 is arranged inside the opening 43 and with a gap between the crystal unit 2 and the frame 42.

  In FIG. 9B, as in the first embodiment of FIG. 1, the connection electrode 17 to the IC chip 3 is provided only on the upper surface of the portion of the frame 42 that extends along both sides in the longitudinal direction of the crystal unit 2. Is formed. In this embodiment, a connection electrode for the IC chip 3 can be additionally provided on the upper surface of the portion of the frame 42 extending along both lateral sides of the crystal unit 2. Therefore, even when the number of electrode pads of the IC chip 3 is large, the connection electrodes can be arranged on the frame 42 sufficiently apart from each other, the degree of freedom in electrode design is improved, and the formation of electrodes and wire bonding are facilitated. So it is advantageous.

  The crystal oscillator 41 of the second embodiment can be manufactured in large numbers at the same time by using the manufacturing process of the first embodiment shown in FIG. 4 by using the frame forming substrate 44 shown in FIG. The substrate 44 is a hard insulating resin substrate made of BT resin or the like used for a printed wiring board or the like, similar to the substrate 22 of FIG. 3, and a large number of frames 42 are continuously formed in the vertical direction and the horizontal direction. ing. That is, in the substrate 44 of this embodiment, a large number of openings 43 are provided in place of the grooves 23 in FIG. As in the case of the substrate 22 in FIG. 3, a large number of electrode films 24 for forming the connection electrodes 17 of the frame 42 are formed on the surface of the substrate portions on both sides of each opening 43, and each frame 42 is formed on the back surface A plurality of electrode films 25 for forming the external terminals 18 are formed at positions corresponding to each other, and through holes 26 for connecting the electrode films 24 and 25 are respectively provided on the boundary lines 45 of adjacent frames. Yes.

  11A to 11C schematically show the configuration of a crystal oscillator that is a third embodiment of the piezoelectric device according to the present invention. The crystal oscillator 51 includes a crystal resonator 2 having a lid 9 on the lower side, an IC chip 3 composed of an oscillation circuit for driving the crystal resonator 2, and a frame 52 that defines the outline of the oscillator. And a mold resin 53 for hermetically sealing them. As in the first embodiment, the frame 52 has two frame portions 52a and 52a extending along the longitudinal sides of the crystal unit 2, and an opening 54 defined between them. On the inner side, the crystal unit 2 is disposed so as to have a gap between the both sides thereof and the frame portions.

  The present embodiment is different from the above embodiments in the following points. That is, a plurality of electrode films 55 are formed on the upper surfaces of the frame portions 52a and 52a, and the portions on the opening 54 side constitute connection electrodes for connecting to the electrode pads 15 of the IC chip 3, respectively, and Each outer part constitutes an external terminal for connection to an external device. Bumps 56 made of, for example, solder balls are formed on the outer portion of the electrode film 55. Further, the mold resin 53 fills the gap between the crystal resonator 2 and the IC element 3 and the frame 52 and covers the connection portion between the electrode film 55 and the electrode pad 15 of the IC element 3. The outer portion is formed so as to be exposed. Therefore, this embodiment has a feature that, compared to the above embodiments, it is not necessary to provide a separate external terminal on the lower surface of the frame 52 and to form a through hole for connecting to the connection electrode on the upper surface. .

  The crystal oscillator 51 of the third embodiment uses a substrate 57 for frame creation shown in FIGS. 12 (A) and 12 (B), so that a large number of crystal oscillators 51 can be used simultaneously using the manufacturing process of the first embodiment shown in FIG. Can be manufactured. The substrate 57 is a hard insulating resin substrate made of BT resin or the like, similar to the substrate 22 of FIG. 3, and a large number of frames 52 are continuously formed in the vertical direction and the horizontal direction. That is, the substrate 57 of the present embodiment has a plurality of long grooves 58 having the same width as the opening 54 formed in parallel in the horizontal direction in the figure, and the substrate portions on both sides of each groove 58 are formed on the surface thereof. An electrode film 59 for forming the electrode film 55 of the frame 52 is formed. Each electrode film 59 has a bump 56 formed on each side of the border line 60 between adjacent frames.

  FIGS. 13A to 13C schematically show the configuration of a crystal oscillator which is a modification of the third embodiment shown in FIG. The crystal oscillator 51 of this modification is different from the embodiment of FIG. 11 in that each bump 56a formed on the outer portion of the electrode film 55 is formed of a solder ball that is vertically divided. A large number of crystal oscillators 51 can be manufactured at the same time as in the manufacturing process of FIG. 4 by using the frame forming substrate 57 shown in FIGS. 14 (A) and 14 (B). In each electrode film 59 of the substrate 57, solder balls 56 'are formed on the boundary lines 60 of the adjacent frames. In this embodiment, by cutting the substrate 57 along the boundary line, each solder ball 56 'is divided into two bumps 56a at the same time when the crystal oscillator 51 is separated. Compared with the embodiment of FIG. 11, the number of solder balls to be formed can be reduced to almost half, so that the manufacturing process can be simplified.

  FIGS. 15A to 15C schematically show the configuration of a crystal oscillator which is a fourth embodiment of the piezoelectric device according to the present invention. The crystal oscillator 61 includes a crystal resonator 2 having a lid 9 on the lower side, an IC chip 3 composed of an oscillation circuit for driving the crystal resonator 2, and a frame 62 that defines the outline of the oscillator. And a mold resin 63 for hermetically sealing them. As in the first embodiment, the frame 62 has two frame portions 62a and 62a extending along the longitudinal sides of the crystal unit 2, and an opening 64 defined between them. On the inner side, the crystal unit 2 is disposed so as to have a gap between the both sides thereof and the frame portions.

  The crystal oscillator 61 of the present embodiment is different from the first embodiment in the following points where the lid 9 of the crystal resonator 2 is disposed so as not to be exposed on the outer surface of the mold resin 63. Since the crystal unit 2 is completely covered with the mold resin 63 and separated from the bottom surface thereof, it is possible to more effectively eliminate the electromagnetic influence received from them when mounted on an external device or a circuit board. Become.

  Many crystal oscillators 61 according to the fourth embodiment can be manufactured simultaneously according to the steps shown in FIGS. In the present embodiment, the same frame forming substrate 22 as that in the first embodiment shown in FIG. 3 is used. First, the substrate 22 is placed horizontally on the jig 65. On the upper surface of the jig 65, a projection 66 having a flat and constant height is formed at a portion corresponding to the groove 23 of the substrate 22. Inside the groove 23, a large number of crystal resonators 2 are arranged on the protrusions 66 with the lid 9 facing down (FIG. 16A).

  The protrusion 66 is provided with a suction hole 67 that opens on the upper surface thereof. The suction hole 67 is connected to a vacuum device (not shown), and is fixed at a predetermined position in the groove 23 by vacuum suction of the crystal resonator 2. In this state, the IC chip 3 is fixed on each crystal resonator 2 with an adhesive 14, and the electrode pads 15 on the upper surface of the substrate are disposed inside the corresponding external electrodes 13 and boundary lines 28 of the crystal resonator 2. The adjacent electrode film 24 on 22 is connected by wire bonding (FIG. 16B).

  Next, the substrate 22 on which the crystal resonator 2 and the IC chip 3 are thus arranged and wired is removed from the jig 65 and placed in a molding die composed of the upper die 30a and the lower die 30b. The crystal resonator 2 is maintained at substantially the same height even after the IC chip 3 is suspended by the bonding wire 21 and the jig 65 is removed. A mold resin 31 of an appropriate material is injected into the mold, and includes the gap between the crystal resonator 2 and the IC element 3 and the substrate 22 and the connection portion between the electrode pad 15, the connection electrode 13, and the electrode film 24. Is sealed (FIG. 16C).

  In the present embodiment, the gap between the both sides in the longitudinal direction of the crystal unit 2 and the groove 23 is set narrower in the case of the first embodiment shown in FIG. Therefore, when the substrate 22 is removed from the jig 65 and moved into the mold or when the mold resin 31 is injected, the crystal resonator 2 and the IC chip 3 that are suspended by the bonding wires 21 are surely attached to the substrate. It is maintained in the groove, and it can be effectively prevented from greatly deviating from the desired position or jumping out of the groove.

  After the mold resin 31 is cured, the substrate 22 is taken out of the mold (FIG. 16D) and cut into individual pieces by dicing or the like along the boundary line 28 of each frame (FIG. 16E). . Finally, the lower half of the mold resin 31 filled in each through hole 26 is removed by, for example, sand blasting or the like to expose the electrode film 20. Thereby, the crystal oscillator 1 shown in FIG. 15 is completed.

  In addition, according to the present invention, the above embodiments can be implemented in appropriate combinations. For example, a structure in which the lid of the crystal resonator is not exposed from the resin sealing surface as in the fourth embodiment can be used for the crystal oscillators in the second and third embodiments.

  Furthermore, the modifications described above in relation to the first embodiment can be applied to the second to fourth embodiments described above with reference to FIGS. 9, 11, 13, and 15. For example, in the manufacturing steps of the second to fourth embodiments, a flexible substrate similar to that shown in FIG. 5 is used in place of the hard substrate, and a crystal oscillator is manufactured using a carrier tape similar to that shown in FIG. be able to. Further, the manufacturing process shown in FIG. 8 can be similarly applied to the crystal oscillators of the second to fourth embodiments.

  The preferred embodiments of the present invention have been described in detail above. However, as will be apparent to those skilled in the art, the present invention can be carried out with various modifications and changes made to the above embodiments within the technical scope thereof. . For example, in the manufacturing process of each of the above embodiments, resin sealing is performed by a molding method using a mold, but other resin sealing methods such as potting can also be used. In addition, although each of the above embodiments has been described for a crystal oscillator, the present invention is not limited to other piezoelectric oscillators using piezoelectric materials other than quartz, real-time clock modules, and other piezoelectric oscillators incorporating a piezoelectric vibrator and an IC element. The same applies to devices.

(A) is a perspective view showing a first embodiment of a crystal oscillator according to the present invention, (B) is a sectional view taken along line IB-IB, and (C) is a sectional view taken along line IC-IC. (A) is a plan view of a crystal resonator used in the crystal oscillator of FIG. 1, and (B) is a cross-sectional view thereof. FIG. 4A is a plan view of a frame-forming substrate used for manufacturing the crystal oscillator of FIG. 1, and FIG. 4B is a partially enlarged sectional view taken along line III-III. (A) thru | or (E) figure is a fragmentary expanded sectional view similar to FIG. 3 (B) which shows the manufacturing process of the crystal oscillator of FIG. 1 in order. (A) The figure is a fragmentary top view which shows the modification of the board | substrate for frame creation, (B) The figure is the elements on larger scale of the VV line. The fragmentary top view which shows the carrier tape of the crystal oscillator used for the modification of FIG. FIG. 7 is a partially enlarged cross-sectional view showing a procedure for manufacturing a crystal oscillator using the frame forming substrate of FIG. 5 and the carrier tape of FIG. 6. (A) thru | or (E) figure is a partial expanded sectional view which shows the modification of the manufacturing process of a crystal oscillator in order. (A) is a perspective view showing a second embodiment of the crystal oscillator according to the present invention, (B) is a sectional view taken along line IXB-IXB, and (C) is a sectional view taken along line IXC-IXC. The top view of the board | substrate for flame | frame preparation used for manufacture of 2nd Example of a crystal oscillator. (A) is a perspective view showing a third embodiment of the crystal oscillator according to the present invention, (B) is a sectional view taken along line XIB-XIB, and (C) is a sectional view taken along line XIC-XIC. (A) The figure is a top view of the board | substrate for frame preparation used for manufacture of 3rd Example of a crystal oscillator, (B) The figure is the elements on larger scale in the XII-XII line. (A) is a perspective view showing a modification of the third embodiment, (B) is a sectional view taken along line XIIIB-XIIIB, and (C) is a sectional view taken along line XIIIC-XIIIC. (A) The figure is a top view of the board | substrate for flame | frame preparation used for manufacture of the modification of FIG. 13, (B) The figure is the elements on larger scale in the XIV-XIV line. (A) is a perspective view showing a fourth embodiment of a crystal oscillator according to the present invention, (B) is a sectional view taken along line XVB-XVB, and (C) is a sectional view taken along line XVC-XVC. (A) thru | or (E) figure is a partial expanded sectional view which shows the manufacturing process of the crystal oscillator of 4th Example in order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,41,51,61 ... Crystal oscillator, 2 ... Crystal resonator, 3 ... IC chip, 4, 42, 52, 62 ... Frame, 4a, 4a, 52a, 52a, 62a, 62a ... Frame part, 5, 31 , 53, 63 ... Mold resin, 6 ... Package, 7 ... Crystal vibrating piece, 7a ... Base end, 8 ... Base, 8a, 8b ... Ceramic sheet, 9 ... Lid, 10 ... Connection electrode, 11 ... Conductive adhesive , 12 ... low melting point glass, 13 ... external electrode, 14 ... adhesive, 15 ... electrode pad, 16, 43, 54, 64 ... opening, 17 ... connection electrode, 18 ... external terminal, 19 ... notch, 20 24, 25, 27, 34, 35, 37, 55, 59 ... electrode film, 21 ... bonding wire, 22, 32, 44, 57 ... substrate, 23, 33, 58 ... groove, 26, 36 ... through hole, 28, 38, 45, 60 ... Boundary lines, 29 ... pressure-sensitive adhesive sheet, 30a ... upper mold, 30b ... lower mold, 39 ... carrier tape, 40 ... plate-like member, 56 ... bumps 65 ... jig, 66 ... protrusion, 67 ... suction holes.

Claims (12)

  A piezoelectric vibrator in which a piezoelectric vibrating piece is sealed in a package, a semiconductor integrated circuit (IC) element for driving the piezoelectric vibrator, a connection electrode for the IC element on the upper surface thereof, and an opening penetrating vertically And the IC element is fixed on the package of the piezoelectric vibrator, the piezoelectric vibrator is accommodated inside the opening of the frame, and the connection electrode of the frame and the frame The electrode pad of the IC element is connected by wire bonding, and at least fills the gap between the piezoelectric vibrator and the IC element and the frame housed in the opening, and the connection electrode and the electrode pad The piezoelectric device is characterized in that the frame, the piezoelectric vibrator, and the IC element are sealed with a resin so as to cover the connecting portion.   The package of the piezoelectric vibrator includes a base on which the piezoelectric vibrating piece is mounted and a lid that is bonded to the base and seals the piezoelectric vibrating piece inside, and is externally provided on a surface opposite to the lid. The piezoelectric vibrator is disposed in the opening of the frame with the lid on the lower side, and the external electrode of the piezoelectric vibrator and the corresponding electrode pad of the IC element are wire bonded. The piezoelectric device according to claim 1, wherein the piezoelectric devices are connected to each other.   The piezoelectric device according to claim 2, wherein an outer surface of the lid is exposed from a sealing surface of the resin in the opening.   4. The piezoelectric device according to claim 1, wherein the frame has an external terminal electrically connected to the connection electrode on a lower surface thereof. 5.   The said frame has the external terminal pulled out from the said connection electrode on the upper surface, and is resin-sealed so that the said external terminal may be exposed. Piezoelectric device.   The frame includes two frame portions extending along opposite sides in the longitudinal direction or the lateral direction of the piezoelectric vibrator, and the opening is defined between the frame portions. The piezoelectric device according to any one of claims 1 to 5.   6. The frame according to claim 1, wherein the frame has a complete ring shape extending along the entire circumference of the piezoelectric vibrator, and the opening is defined inside the frame. Piezoelectric device.   A step of preparing a piezoelectric vibrator in which a piezoelectric vibrating piece is sealed in a package; a step of preparing an IC element for driving the piezoelectric vibrator; and a connection electrode for the IC element on an upper surface of the piezoelectric vibrator. Preparing a frame provided with an opening therethrough, placing the piezoelectric vibrator inside the opening of the frame, and fixing the IC element on the package of the piezoelectric vibrator; Connecting the connection electrode of the frame and the electrode pad of the IC element by wire bonding, and filling at least a gap between the piezoelectric vibrator and the IC element and the frame housed in the opening. And sealing the frame, the piezoelectric vibrator, and the IC element with a resin so as to cover the connection portion between the connection electrode and the electrode pad. Method for manufacturing a piezoelectric device according to claim.   A step of forming a substrate in which a plurality of the frames are continuously arranged in the vertical direction and / or the horizontal direction, and the piezoelectric vibrators are arranged in the openings of the frames of the substrate, respectively. The IC element is fixed on each package, the connection electrode of the corresponding frame and the electrode pad of the IC element are connected by wire bonding, and the corresponding frame of the substrate, the piezoelectric vibrator, and the IC 9. The method for manufacturing a piezoelectric device according to claim 8, wherein after the element is sealed with a resin, the device is cut into pieces along a boundary line of each frame to be separated into a plurality of piezoelectric devices.   The method for manufacturing a piezoelectric device according to claim 9, wherein the substrate is a hard substrate.   The method for manufacturing a piezoelectric device according to claim 9, wherein the substrate is a flexible substrate.   The package of the piezoelectric vibrator includes a base on which the piezoelectric vibrating piece is mounted and a lid that is bonded to the base and seals the piezoelectric vibrating piece inside, and the lid is placed in the opening of the frame. And the outer surface of the lid is disposed so as to be exposed from the sealing surface of the resin in the opening, and the transparent portion of the lid is sealed after the resin sealing of the frame, the piezoelectric vibrator, and the IC element. 12. The method according to claim 8, further comprising a step of adjusting the frequency by irradiating laser light from the outside through a part of the electrode film on the surface of the piezoelectric vibrating piece and adjusting the frequency thereof. Manufacturing method of the piezoelectric device.

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