JP2010056842A - Piezoelectric device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To let an increase in an electronic-part loadable area on a circuit board and an improvement in reliability on an electro-mechanical connection coexist in a piezoelectric device having a two-storied structure. <P>SOLUTION: The piezoelectric device 10 having the two-storied structure includes a resin 39 coating an IC on the circuit board 22. Through-holes 28 used for electrically connecting internal terminals 24 fitted on one main surface in the circuit board 22 and a rear electrode 44 for a piezoelectric vibrator 40 are formed to the resin 39. Recesses 30 having aperture areas larger than the through-holes 28 are formed at the upper ends of the through-holes 28, and the circuit board 22 and the piezoelectric vibrator 40 are connected electrically and mechanically by a conductive member 38 filled into the through-holes 28 and the recesses 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a piezoelectric device and a manufacturing method of the piezoelectric device, and more particularly to a piezoelectric device of a type in which a circuit board and a piezoelectric vibrator are arranged in a thickness direction and a manufacturing method thereof.

  As a piezoelectric device in which an oscillation circuit and a piezoelectric vibrator are arranged so as to overlap each other in the thickness direction, for example, a device disclosed in Patent Document 1 is known. As shown in FIG. 12, the piezoelectric device disclosed in Patent Document 1 covers a circuit board 3 on which an IC 4 is mounted with a resin sheet 7, and a resin sheet 7 disposed on the upper surface of an internal terminal 5 on the circuit board 3. Is irradiated with a laser to form a funnel-shaped through-hole 8. The through-hole 8 is filled with a conductive member 6 and solidified, and a connecting conductor 6 a is applied to the top of the filled and solidified conductive member 6 to join the piezoelectric vibrator 9.

By having such a structural feature, in a so-called two-story structure type piezoelectric device in which an oscillation circuit and a piezoelectric vibrator are arranged in the thickness direction, underfillless due to a demand for downsizing and thinning, or It is suitable for cavityless and simplification of the manufacturing process can be realized.
JP 2007-96372 A

  It can be said that the piezoelectric device having the above-described configuration is certainly an effective configuration in reducing the size and thickness of a two-story piezoelectric device. However, in the field of piezoelectric devices, in addition to further miniaturization and thinning of devices, higher integration is progressing along with multi-functionality and high functionality.

  In such a current piezoelectric device, between the conductive member that penetrates the resin sheet, the electronic component mounted on the circuit board, the metal wire that connects the electronic component and the pattern arranged on the circuit board, etc. It may not be possible to maintain sufficient clearance. As described above, when the clearance between the conductive members is insufficient, the characteristics are deteriorated and the yield is reduced.

  In order to maintain sufficient clearance between the conductive member penetrating the resin layer and the electronic component, wiring pattern, metal wire, etc. disposed on the circuit board or in the resin layer, the conductive member penetrating the resin layer It can be considered that the occupation area of the area should be reduced. However, in this case, since the bonding surface between the piezoelectric vibrator and the conductive member is also reduced, the electromechanical bonding strength between the piezoelectric vibrator and the circuit board is lowered, leading to a decrease in reliability as a device. Become.

  Therefore, in the present invention, in view of the above-described problems, in a piezoelectric device having a two-story structure, a conductive member penetrating the resin layer, an electronic component disposed on the circuit board or in the resin layer, a wiring pattern, A piezoelectric device that can maintain a sufficient clearance between the piezoelectric vibrator and the circuit board, and that can provide good electrical and mechanical connectivity between the piezoelectric vibrator and the circuit board, and a method for manufacturing the piezoelectric device are provided. The purpose is to do.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
Application Example 1 A piezoelectric device in which an electronic component and a piezoelectric vibrator are stacked on a circuit board, and the electronic component is mounted on one side of the circuit board and is on the one side of the circuit board A resin portion covering the electronic component is formed, and the resin portion is formed with a recess formed on a surface thereof and a through hole penetrating from the bottom surface of the recess to the one surface of the circuit board, A piezoelectric device characterized in that an internal terminal formed on the one surface of the circuit board and a back electrode of the piezoelectric vibrator are electrically connected by a through hole and a conductive member filled in the recess.

  With such a configuration, a sufficient clearance is maintained between the conductive member penetrating the resin portion and the electronic component, wiring pattern, metal wire, or the like disposed on the circuit board or in the resin portion. be able to. Also, the area where electronic components can be mounted on the circuit board can be increased. Furthermore, the electromechanical connectivity between the piezoelectric vibrator and the circuit board can also be improved.

[Application Example 2] The piezoelectric device according to Application Example 1, wherein the concave portion has an external shape similar to the back electrode of the piezoelectric vibrator in plan view.
By making the form of the recess as described above, the connection area between the back electrode and the conductive member filled in the recess can be effectively increased.

Application Example 3 In the piezoelectric device according to Application Example 1, the concave portion is formed by connecting sides located outside the plurality of back surface electrodes provided on the piezoelectric vibrator in plan view. A piezoelectric device characterized in that it is one concave portion having an external shape similar to a square.
By making the shape of the recess as described above, the connection area between the back electrode and the internal terminal on the circuit board can be effectively increased without depending on the shape of the back electrode.

  [Application Example 4] A piezoelectric device according to Application Example 2 or Application Example 3, wherein the concave portion is made wider than the area of the back electrode or the area of the polygon.

  By setting it as such a structure, a back surface electrode will fit in a recessed part. For this reason, a self-alignment effect can be expected when the piezoelectric vibrator is bonded.

の範囲で定めたことを特徴とする圧電デバイス。 Application Example 5 In the piezoelectric device according to any one of Application Examples 1 to 4, the conductive member includes a first member having conductivity and a conductive first member that covers the first member. The first member employs a member having a melting point higher than that of the second member, the height from the internal terminal to the bottom surface of the recess is d, and from the internal terminal to the recess opening. Height D, height A of the first member,

Piezoelectric device characterized in that it is defined in the range.

  With such a configuration, it is possible to prevent the piezoelectric vibrator from sinking extremely by the first member and to fix the bonded state of the piezoelectric vibrator by the second member. For this reason, the height dimension of the mass-produced piezoelectric device can be made uniform stably.

  [Application Example 6] The piezoelectric device according to any one of Application Example 1 to Application Example 5, wherein the bottom surface of the concave portion is provided with an inclination toward the upper end portion of the through hole. .

  By adopting such a configuration, it is possible to prevent the conductive member from overflowing from the recess even when a conductive member for joining the piezoelectric vibrator is added (overcoated).

  Application Example 7 A method of manufacturing a piezoelectric device in which a piezoelectric vibrator is stacked on a circuit board on which electronic components are mounted, the electronic component mounting process for mounting electronic components on the circuit board, and the circuit board A molding step of covering the mounted electronic component with a resin; and a vibrator mounting step of mounting the piezoelectric vibrator on a circuit board molded with the electronic component. In the molding step, the main surface of the circuit board is provided. Using a mold having a pin that makes contact with the surface of the provided internal terminal and a stepped portion having a cross-sectional area larger than that of the pin provided on the base end side of the pin, the pin is connected to the internal terminal The resin is poured into the mold in contact with the mold, and a through hole and a recess having a larger opening area than the through hole are formed on the internal terminal. In the vibrator mounting step, the through hole and The recess filled with a conductive member, melting the conductive member, electrically with the circuit board and the piezoelectric vibrator by solidifying method of a piezoelectric device, characterized in that to achieve a mechanical connection.

  By manufacturing a piezoelectric device by such a method, it is possible to manufacture a piezoelectric device having the above-described characteristics without increasing the number of steps by using a transfer mold method that has been conventionally used. It becomes possible.

Application Example 8 In the method for manufacturing a piezoelectric device according to Application Example 7, the conductive member includes a first member and a second member that covers the first member and has a lower melting point than the first member. A method for manufacturing a piezoelectric device, characterized by employing a conductive member.
By adopting the conductive member having the above structure, it becomes easy to make the height dimension of the piezoelectric device uniform.

Hereinafter, embodiments of a piezoelectric device and a manufacturing method of the piezoelectric device of the present invention will be described in detail with reference to the drawings.
First, a first embodiment according to the piezoelectric device of the present invention will be described with reference to FIG. 1A is a schematic cross-sectional view of a piezoelectric device, and FIG. 1B is a plan view of an oscillation circuit portion in the piezoelectric device.

The piezoelectric device 10 according to the present embodiment is a piezoelectric oscillator, and includes an oscillation circuit unit 20 and a piezoelectric vibrator 40 bonded to the upper part (upper side in the thickness direction).
The oscillation circuit unit 20 includes a circuit board 22, electronic components (IC 34 in this embodiment) mounted on one main surface of the circuit board 22, and a resin part 39.

  The circuit board 22 may be an insulating board made of a resin board such as polyimide or ceramic, and an electrode pattern including an internal terminal 24 on one main surface facing a piezoelectric vibrator 40 described in detail later. (The whole is not shown) is formed. On the other main surface, a mounting electrode 26 for mounting the piezoelectric device (in the case of the present embodiment, a piezoelectric oscillator) 10 on another substrate or the like is formed. The internal terminal 24 and the mounting electrode 26 described above are exclusively composed of Au (gold) or Cu (copper).

  The electronic components include necessary resistors, capacitors and the like in addition to the IC 34 constituting the oscillation circuit (in the case of the present embodiment, only the IC 34 is shown in the drawing). In the case of the present embodiment, the IC 34 is bonded using the adhesive 36 with the back surface facing the circuit board 22, and then the terminal (not shown) on the active surface and one of the circuit boards 22 are joined. The internal terminals 24 arranged on the main surface are bonded (wire bonding) using metal wires 32. Here, even when so-called flip chip bonding is employed in which the active surface is opposed to the circuit board 22 and mounting is performed using metal bumps or the like, the piezoelectric device 10 according to this embodiment is manufactured. There is no hindrance.

  As the resin portion 39, it is desirable to select a resin that can avoid the above-described electronic components such as the IC 34, electrode patterns, and the like from being affected by outside air, particularly moisture. Specific examples include epoxy resins.

  In the resin portion 39, a recess 30 is formed on the upper portion of the internal terminal 24 that is electrically connected to the back electrode 44 of the piezoelectric vibrator 40, which will be described in detail later. A through hole 28 that penetrates to the internal terminal 24 is provided on the bottom surface of the recess 30 (the recess bottom surface 31). In other words, it can be said that the recess 30 having an opening area larger than the opening of the through hole 28 is formed in the upper end opening of the through hole 28. The shape of the recess 30 may be an external shape similar to that of the back electrode 44 of the piezoelectric vibrator 40 described later in detail in plan view. In the present embodiment, the recess 30 has a larger area than the back electrode 44. Yes. With such a configuration, the back electrode 44 can be fitted in the recess 30 and a self-alignment effect can be achieved. For this reason, even when the conductive member 38 that joins the oscillation circuit unit 20 and the piezoelectric vibrator 40 is melted in a reflow process or the like, it is possible to suppress the displacement of the mounting position of the piezoelectric vibrator 40 with respect to the oscillation circuit unit 20. Become. Further, in the case of such a configuration, it is desirable that the diameter of the through hole 28 positioned below the recess 30 is as small as possible if electrical connection with the internal terminal 24 is possible. By adopting such a configuration, it is possible to increase the connection reliability between the piezoelectric vibrator 40 and the oscillation circuit unit 20 while widening the electronic component mounting area on one main surface of the circuit board 22. Because it becomes.

  The piezoelectric vibrator 40 includes a piezoelectric vibrating piece 54 and a package 53 that seals the piezoelectric vibrating piece 54. The piezoelectric vibrating piece 54 includes a piezoelectric element plate and an electrode pattern (not shown) formed on the piezoelectric element plate. The piezoelectric element plate may be any material that can exhibit a piezoelectric effect, such as quartz, lithium tantalate, lithium niobate, and piezoelectric ceramic. In the present embodiment, as the piezoelectric element plate, a crystal having a good standard of frequency change within the operating temperature range, that is, a so-called frequency temperature characteristic is adopted.

  Examples of the electrode pattern applied to the piezoelectric element plate include an excitation electrode, a connection electrode, and a lead electrode (all not shown). The excitation electrode is an electrode for applying a voltage for producing a piezoelectric effect to the piezoelectric element plate, and is formed on the front and back surfaces of the excitation region of the piezoelectric element plate. The connection electrode is an electrode that mounts a piezoelectric vibrating piece on an internal terminal of a package, the details of which will be described later, and exchanges signals with the internal terminal. The extraction electrode is an electrode that electrically connects the excitation electrode and the connection electrode described above.

  In the present embodiment, the package 53 employs a so-called ring cavity structure including a package substrate 42, a seam ring 48, and a lid 52. The package substrate 42 is preferably an insulating member, and specifically includes an aluminum oxide ceramic green sheet. An internal terminal 46 is formed on one main surface of the package substrate 42, and a back electrode 44 for mounting the piezoelectric vibrator 40 is formed on the other main surface. Here, the internal terminal 46 and the back electrode 44 are formed by using W (tungsten) and Ni (nickel) plating as the base and Au (gold) plating on the surface, so that both the fixing property and the conductivity are good. However, the present invention is not limited to this.

  The seam ring 48 is preferably made of a material whose thermal expansion coefficient approximates that of the package substrate 42. For example, when the package substrate 42 is a ceramic green sheet, the package substrate 42 may be composed of Kovar, which is an alloy containing Fe (iron), Ni (nickel), and Co (cobalt) as main components. By adopting such a configuration, it is possible to prevent the package 53 from being greatly warped, the joint portion from being peeled off, and the package 53 from being damaged due to these in a heating process such as a reflow process.

  The lid 52 is a lid that seals the opening of the bowl-shaped box formed by the package substrate 42 and the seam ring 48 described above. For this reason, in order to prevent warpage or breakage of the package 53, it is desirable that the coefficient of thermal expansion of its constituent members approximate that of the package substrate 52 or the seam ring 48. Therefore, when the seam ring 52 is made of Kovar, the constituent member of the lid 52 is preferably made of Kovar or soda glass. When the lid 52 is made of Kovar, the lid 52 can be joined by seam welding using the seam ring 48, and when soda glass is used, the low-melting glass can be used for joining. .

  In the case of the embodiment shown in FIG. 1, when the piezoelectric vibrating piece 54 is mounted on the internal terminal 46 disposed on the package substrate 42 using the conductive adhesive 56 or the like, the mounting form is cantilever. However, there is no problem in configuring the piezoelectric vibrator 40 even when the mounting form is varied depending on the form and specification of the piezoelectric vibrating piece 54. Here, the piezoelectric vibrating piece 54 using quartz as a base material has different vibration forms and characteristics depending on the cut angle. For example, an AT cut piezoelectric vibrating piece, a BT cut piezoelectric vibrating piece, a tuning fork type piezoelectric vibrating piece, and a surface acoustic wave. Various forms and specifications such as element pieces (SAW element pieces) can be given. In addition, as the conductive adhesive 56, a material using a relatively hard resin such as an epoxy resin or a polyimide resin as a binder, or a material using a relatively soft resin of a silicone material as a binder is known. Also contains a metal filler (conductive filler), which is used as a conductive medium.

  In the oscillation circuit unit 20 and the piezoelectric vibrator 40 configured as described above, the conductive member 38 such as solder is filled in the through hole 28 and the recess 30 in the resin portion 39 of the oscillation circuit unit 20. The piezoelectric device 10 is configured by bonding the two by melting the slag and mounting the piezoelectric vibrator 40.

  According to the piezoelectric device 10 having such a configuration, the back surface electrode 44 of the piezoelectric vibrator 40 is fitted into the concave portion 30 of the resin portion 39 and joined, so that a sufficient area of the joint surface can be secured. The mechanical connection strength can be ensured as well as the general connection. Therefore, the connection reliability between the oscillation circuit unit 20 and the piezoelectric vibrator 40 can be improved.

  In addition, since the back electrode 44 of the piezoelectric vibrator 40 is fitted into the recess 30 of the resin portion 39, a self-alignment effect can be obtained and the mounting accuracy of the piezoelectric vibrator 40 can be improved.

  Furthermore, the arrangement part of the conductive member 38 that connects the internal terminal 24 of the circuit board 22 and the back electrode 44 of the piezoelectric vibrator 40 is formed by a through hole 28 having a small diameter and a recess 30 having a large opening area at the upper end of the through hole 28. As a result of the formation, it is possible to increase both the area where electronic components can be mounted on the circuit board 22 and the improvement of the connection reliability of the piezoelectric vibrator 40.

  In the piezoelectric device 10 configured as described above, the circuit board 22 is first manufactured, and the IC 34 is mounted on the circuit board 22. After the IC 34 is mounted, the terminals disposed on the active surface of the IC 34 and the internal terminals 24 disposed on one main surface of the circuit board 22 are electrically connected by wire bonding (electronic component mounting step).

  Next, a molding process for forming the resin portion 39 for sealing the IC 34 mounted on the circuit board 22 or the metal wire 32 for connecting the IC 34 and the circuit board 22 is performed. An example of a method for forming the resin portion 39 is a transfer molding method. Specifically, as shown in FIG. 2, sealing is performed using a mold 78 (upper mold 70, lower mold 76). The upper mold 70 in the mold 78 is provided with a pin 72 for forming the through hole 28, and a stepped portion 74 for forming the recess 30 is formed at the root of the pin 72.

  In the molding process, first, a circuit board on which the IC 34 is mounted is placed on a mold 78, and a solid resin tablet (for example, an epoxy resin tablet) 80 is set in a pot of the mold 78 (see FIG. 2A). . The temperature of the mold 78 is raised to about 170 to 180 ° C. to melt the resin tablet 80. After the resin tablet 80 is melted, a plunger 90 is inserted into the pot, pressure is applied to the resin in the pot, and the resin tablet 80 is poured into a mold having the circuit board 22 (see FIG. 2B). After pressurizing for a predetermined time and the resin is cured, the mold 78 is opened, and the oscillation circuit unit 20 in which the resin unit 39 is formed is completed.

  The piezoelectric vibrator 40 is manufactured in parallel with or before or after the manufacture of the oscillation circuit unit 20 formed as described above. The piezoelectric vibrating piece 54 sealed in the package 53 undergoes processes such as cutting of a piezoelectric element plate, polishing, outer shape formation, and electrode pattern formation. Cutting of the piezoelectric element plate is performed by dicing according to a predetermined cut angle, and polishing is performed by a polishing machine, and the thickness of the piezoelectric element plate is adjusted. Examples of the outer shape formation include dicing or etching using a mask formed by photolithography. In addition, the electrode pattern can also be formed using a photolithography technique.

  The package base 50 forms an electrode pattern on the package substrate 42 by screen printing or the like, and fires it. Thereafter, a seam ring 48 is joined to one main surface of the package substrate 42.

A conductive adhesive 56 is applied to the internal terminal 46 of the package substrate 42 located on the inner bottom surface of the package base 50, and the piezoelectric vibrating piece 54 is mounted.
After mounting the piezoelectric vibrating piece 54, the lid 52 is placed on the opening of the package base 50, that is, the upper end of the seam ring 48, and sealed by seam welding.

  Next, a vibrator mounting step for joining the oscillation circuit unit 20 and the piezoelectric vibrator 40 manufactured as described above is performed. First, a conductive member 38 such as solder is filled in the through hole 28 and the concave portion 30 provided in the resin portion 39 of the oscillation circuit portion 20. Thereafter, the piezoelectric vibrator 40 is disposed and heated so that the back electrode 44 of the piezoelectric vibrator 40 is positioned on the upper portion of the concave portion 30 provided in the resin portion 39, and the conductive material filled in the through hole 38 and the concave portion 30. The member is melted, the back electrode 44 of the piezoelectric vibrator 40 is fitted in the recess 30, the conductive member 38 is cured, and the two are joined.

  According to such a method for manufacturing a piezoelectric device, it is possible to manufacture the above-described piezoelectric device 10 by using a transfer molding method that has been conventionally performed without increasing the number of steps.

  Next, a second embodiment according to the piezoelectric device of the present invention will be described with reference to FIG. Most of the configuration of the piezoelectric device according to this embodiment is the same as that of the piezoelectric device according to the first embodiment described above. Therefore, components having the same function are denoted by reference numerals added with 100 in the drawings, and detailed description thereof is omitted. The difference from the piezoelectric device 10 according to the first embodiment is that the area of the back electrode 144 of the piezoelectric vibrator 140 is larger than the opening area of the recess 130 provided in the resin part 139 of the oscillation circuit part 120. It is. In such a configuration, the self-alignment effect when bonding the piezoelectric vibrator 140 cannot be expected, but the improvement of the bonding area between the oscillation circuit unit 120 and the piezoelectric vibrator 140 by the conductive member 138, and It is possible to improve the connection reliability due to the effect of the through hole 128 and to improve the mountable area of an electronic component or the like on one main surface of the circuit board 122. For this reason, it can be regarded as a part of the piezoelectric device according to the present invention. Note that the case where the clearance between the end of the back electrode 144 of the piezoelectric vibrator 140 and the wall surface of the recess 130 is 0 is also included in the present embodiment.

  Next, a third embodiment according to the piezoelectric device of the present invention will be described with reference to FIG. Most of the configuration of the piezoelectric device according to this embodiment is the same as that of the piezoelectric device according to the first and second embodiments described above. Therefore, components having the same function are denoted by reference numerals obtained by adding 200 to the reference numerals in FIG. 1 and detailed description thereof will be omitted. 4A is a diagram illustrating a cross-sectional configuration of the piezoelectric device, FIG. 4B is a diagram illustrating a planar configuration of the oscillation circuit unit, and FIG. 4C is a piezoelectric vibrator. It is a figure which shows the back surface structure. As a difference from the piezoelectric devices 10 and 110 according to the first and second embodiments, the shape of the concave portion 230 provided in the resin portion 239 of the oscillation circuit portion 220 can be cited. Specifically, in the piezoelectric devices 10 and 110 shown in the first and second embodiments, the concave portions 30 and 130 are shown to be provided for the through holes 28 and 128 (in the above-described embodiments, any Are also provided with four recesses 30,130). On the other hand, the concave portion 230 of the piezoelectric device 210 according to the present embodiment is a polygon formed by connecting sides located outside when the plurality of back surface electrodes 224 provided in the piezoelectric vibrator 240 are viewed in plan (implementation). In the form of a rectangle), a single recess 230 having an external shape similar to 225 is shared by a plurality of through holes 228.

  Even when the shape of the recess 230 is such, a self-alignment effect can be expected by fitting the back electrode 224 inside the recess 230. Further, since there is no change in the configuration in which the concave portion 230 having an opening area larger than that of the through hole 228 is provided at the upper end portion of the through hole 228, the mounting area of electronic components and the like can be improved, and the piezoelectric vibrator 240 and the oscillation circuit portion Each effect such as improvement in connection reliability with 220 can be expected.

Hereinafter, application examples applicable to any of the above embodiments will be described with reference to FIGS. 5 to 11 by taking the piezoelectric device according to the first embodiment as an example.
First, FIGS. 5 and 6 show application forms of the resin portion. In the basic forms according to the first to third embodiments described above, the resin portion is not covered with the piezoelectric vibrator. However, in configuring the piezoelectric device according to the present invention, as in the piezoelectric device 10a shown in FIG. 5, the resin portion 39a is arranged so as to cover the package base 50 in the piezoelectric vibrator 40 or the piezoelectric device shown in FIG. As in the device 10b, the resin portion 39b may cover other than the lid 52 of the piezoelectric vibrator 40. Naturally, even when the entire structure including the lid 52 of the piezoelectric vibrator 40 is molded with resin, it can be regarded as a part of the piezoelectric device according to the present invention. It will be contrary to.

Next, a conductive member that electrically and mechanically joins the oscillation circuit portion and the piezoelectric vibrator will be described with reference to FIGS.
The conductive member 38a shown in FIG. 7 covers a second member (coating material) 37b, which is a conductive member having a melting point lower than that of the first member, around the first member (conductive core material) 37a having a high melting point. For example, the conductive core material 37a may be copper, and the covering material 37b may be solder. As a form, since the conductive core material 37a is formed into a spherical shape and the periphery thereof is covered with solder, it forms a spherical shape as a whole. The conductive member (hereinafter referred to as “copper core ball”) 38 a having such a configuration has a distance (height) from the internal terminal 24 to the bottom surface 31 of the recess on the circuit board 22, and an opening of the recess 30 from the internal terminal 24. It is desirable that the diameter A of the conductive core material 37a is set within the range of Equation 1, where D is the distance (height) up to.

  With such a configuration, as shown in FIG. 8, the conductive core material 37a suppresses the piezoelectric vibrator 40 from sinking extremely, and the height dimension of the mass-produced piezoelectric device 10c is uniformly determined. be able to. Further, by adopting the copper core ball 38a in the piezoelectric device 10c having the above-described configuration, the copper core ball 38a may be disposed in the through hole 28 of the resin portion 39. The copper core ball 38a can be easily handled.

  Further, in the case where a solder (second member) 37b used for bonding is added when the piezoelectric vibrator 40 is bonded to the oscillation circuit section 20, as shown in FIG. In addition, it is preferable to provide an inclined surface 30 a that is a downward slope of an angle θ toward the through hole 28. This is because by adopting such a configuration, the volume of the recess 30 is increased, and it becomes possible to suppress the leakage of solder from the recess 30.

  In the example shown in FIGS. 7 to 9, the conductive member 38a is shown as a spherical shape of the conductive core material 37a. However, in this application example, the shape of the conductive core material 37a is not limited to a spherical shape. For example, as shown in FIG. 10, the conductive core member 37a may be formed in a cylindrical shape or a prism shape, and the conductive member 38b as a whole may be formed in a cylindrical shape or a prism shape. By making the shape of the conductive core material 37a like this, it is not necessary to increase the diameter of the through hole 38 in proportion to the diameter (thickness) of the conductive core material 37a. In addition, when employ | adopting the electroconductive member 38b of such a form, what is necessary is just to make it apply as A in Formula 1 as the height of the electroconductive core material 37a.

  Further, the conductive member 38c filling the through hole 28 and the recess 30 may be a plurality of minute solder balls. With such a configuration, the conductive member 38c can be easily handled. Of course, each of the small solder balls may be a copper core ball.

  Further, in the piezoelectric device manufacturing method shown in the above embodiment, when the resin portion 39 is formed by the transfer molding method, the pin 72 and the stepped portion 74 are provided in the upper mold to form the through hole 28 and the concave portion 30 at a time. As shown. However, in manufacturing the piezoelectric device according to the present invention, only the stepped portion is provided in the upper mold, and only the concave portion 30 is formed in the resin portion 39 in the molding process, and the through hole 28 is formed by the spot laser. Anyway.

  The configuration of the resin portions 39, 139, and 239 in the oscillation circuit portions 20, 120, and 220 of the present invention is not limited to the case where the piezoelectric vibrators 40, 140, and 240 are laminated, and other electronic devices, semiconductor elements, and the like. It is considered that the present invention can also be applied to the case of configuring the above.

It is a figure which shows the structure of the piezoelectric device which concerns on 1st Embodiment. It is a figure which shows the formation process of the resin part in an oscillation circuit part. It is a figure which shows the structure of the piezoelectric device which concerns on 2nd Embodiment. It is a figure which shows the structure of the piezoelectric device which concerns on 3rd Embodiment. It is a figure which is an application form of the piezoelectric device which concerns on embodiment, Comprising: The form which coat | covered the package base to the resin part. It is an application form of the piezoelectric device which concerns on embodiment, Comprising: It is a figure which shows the form which coat | covered except the lid upper surface of the piezoelectric vibrator with the resin part. It is an application form of the piezoelectric device according to the embodiment, and is a diagram showing an example in which a conductive member is a copper core ball. It is a figure which shows the structure of the piezoelectric device joined using the copper core ball | bowl. It is a figure which shows the structure which provided the inclination in the bottom face of the resin part. It is a figure which shows the example at the time of making the electroconductive core material of an electroconductive member into a column shape or a prismatic shape. It is a figure showing an example at the time of making a conductive member into a plurality of minute solder balls. It is a figure which shows the structure of the conventional piezoelectric device.

Explanation of symbols

  10 ......... Piezoelectric device, 20 ......... Oscillator circuit, 22 ......... Circuit board, 24 ......... Internal terminal, 26 ......... Mounting electrode, 28 ...... Through hole, 30 ......... Recess, 32 ......... Metal wire, 34 ......... IC, 36 ......... Adhesive, 38 ......... Conductive member, 40 ......... Piezoelectric vibrator, 42 ......... Package substrate, 44 ......... Back electrode, 46... Internal terminal 48... Seam ring 50... Package base 52... Lid 53 53 Package 54 Piezoelectric vibrating piece 56 Conductive adhesive

Claims (8)

A piezoelectric device in which an electronic component and a piezoelectric vibrator are stacked on a circuit board,
The electronic component is mounted on one surface of the circuit board,
A resin part covering the electronic component is formed on the one surface of the circuit board,
The resin portion has a recess formed on the surface thereof, and a through hole penetrating from the bottom surface of the recess to the one surface of the circuit board,
A piezoelectric device characterized in that an internal terminal formed on the one surface of the circuit board and a back electrode of the piezoelectric vibrator are electrically connected by a conductive member filled in the through hole and the recess. . The piezoelectric device according to claim 1,
The piezoelectric device according to claim 1, wherein the concave portion has an external shape similar to the back electrode of the piezoelectric vibrator in plan view. The piezoelectric device according to claim 1,
The concave portion is a single concave portion having an outer shape similar to a polygon formed by connecting sides located outside the plurality of back electrodes provided on the piezoelectric vibrator in plan view. Piezoelectric device. The piezoelectric device according to claim 2 or 3, wherein
The piezoelectric device, wherein the concave portion is wider than the area of the back electrode or the polygonal area. The piezoelectric device according to any one of claims 1 to 4,
The conductive member includes a first member having conductivity and a second member having conductivity that covers the first member. The first member is a member having a higher melting point than the second member. And
The height from the internal terminal to the bottom surface of the recess is d, the height from the internal terminal to the recess opening is D, the height A of the first member,

Piezoelectric device characterized in that it is defined in the range. The piezoelectric device according to any one of claims 1 to 5,
The piezoelectric device according to claim 1, wherein an inclination toward the upper end of the through hole is provided on the bottom surface of the recess. A method of manufacturing a piezoelectric device in which a piezoelectric vibrator is stacked on an upper part of a circuit board on which electronic components are mounted,
An electronic component mounting process for mounting electronic components on a circuit board;
A molding step of covering an electronic component mounted on a circuit board with a resin;
A vibrator mounting step of mounting the piezoelectric vibrator on a circuit board molded with electronic components,
In the molding step, a pin to be brought into contact with the surface of the internal terminal provided on the main surface of the circuit board, and a stepped portion having a cross-sectional area determined to be larger than the pin provided on the base end side of the pin. Use the mold you have,
The resin is poured into the mold in a state where the pin is in contact with the internal terminal, and a through hole and a recess having a larger opening area than the through hole are formed on the internal terminal.
In the vibrator mounting step, the through hole and the concave portion are filled with a conductive member, and the conductive member is melted and solidified to achieve electrical and mechanical connection between the circuit board and the piezoelectric vibrator. A method for manufacturing a piezoelectric device. A method for manufacturing a piezoelectric device according to claim 7,
A method for manufacturing a piezoelectric device, characterized in that a conductive member comprising a first member and a second member that covers the first member and has a lower melting point than the first member is employed as the conductive member.

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