Electronic component and method for manufacturing an electronic component

Abstract

The present application provides an electronic component and a manufacturing method of the electronic component. The electronic component includes a substrate, a one-side frame wall, a cover, a second-side frame wall, and a metal film. The substrate has a one-side electrode and a second-side electrode on one side and the other side, respectively. The one-side electrode is electrically connected to an electrode of a piezoelectric vibrator. The second-side electrode is electrically connected to an electrode of an integrated circuit chip. The one-side frame wall is provided along a peripheral portion of the substrate on the one side of the substrate to form a first housing space for housing the piezoelectric vibrator. The cover blocks an opening of the one-side frame wall to seal the first housing space. The second-side frame wall is provided along the peripheral portion of the substrate on the other side of the substrate to form a second housing space for housing the integrated circuit chip. The metal film is not electrically connected to the second-side electrode and is provided on the one side of the substrate to suppress warping of the substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to an electronic component including a piezoelectric vibrator and an integrated circuit chip, and a manufacturing method of an electronic component. BACKGROUND

[0002] As an electronic component, a structure in which a crystal vibrator and an integrated circuit (IC) chip are housed in a package is known. At this time, the package sometimes adopts a structure including a substrate (a middle plate), a frame wall for forming a housing space for the crystal vibrator on one surface side of the substrate, and a frame wall for forming a housing space for the IC chip on the other surface side of the substrate, each frame wall being disposed along a peripheral portion of the substrate. In manufacturing the electronic component, the IC chip is mounted on the substrate, for example, by flip chip bonding. For example, Patent Literature 1 shows an electronic component including such a package.

[0003] [PTL 1] Japanese Patent Laid-Open No. 2018-56668

[0004] [PTL 1] Japanese Patent Laid-Open No. 2018-56668

[0005] [PTL 1] Japanese Patent Laid-Open No. 2018-56668 SUMMARY

[0006] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0007] Since detailed description is given in the embodiments of the application, a brief description is given here. In manufacturing the package, a substrate-forming sheet in which a pattern to be an electrode has been formed is overlapped with a frame wall-forming sheet to form a laminate, and a jig is pressed against the laminate to form a groove. The package is manufactured from a single sheet obtained by dividing along the groove. In pressing the jig, stress can be uneven in the formation area of the substrate in the substrate-forming sheet due to the arrangement of the electrode pattern, and warping can occur in the formation area. If warping occurs in this way, the height of each electrode on the other surface side of the mounting substrate of the IC chip can be uneven in performing the flip chip bonding described above, and the bonding can not be performed normally.

[0008] In the Patent Document 1, the problem occurring at the time of bonding of the IC chip is not described. Moreover, as described in the embodiment of the invention, the occurrence of the bonding abnormality is affected by the size of the IC chip, but the IC chip of the Patent Document 1 is small so that the electrodes (first electrode pad and second electrode pad) on one surface side of the substrate are not overlapped, and thus it is difficult to consider that the problem is easily conceived. Moreover, in the electronic component of the Patent Document 1, it is considered that either of the first electrode pad and the second electrode pad provided on one surface side of the substrate is selected as the mounting electrode of the crystal oscillator (crystal oscillator sheet), and the product is manufactured. Therefore, it is naturally configured that the conductive path connecting the first electrode pad and the second electrode pad to the mounting electrode of the IC chip on the other surface side of the substrate is provided, and the structure of the Patent Document 1 is different from the structure of the present invention.

[0009] The present invention has been made in view of the circumstances, and aims to provide an electronic component including a substrate, a housing space of a piezoelectric vibrator on one surface side of the substrate, and a housing space of an integrated circuit chip on the other surface side of the substrate, and the connection of the electrode of the integrated circuit chip and the electrode of the substrate is reliably performed, and the reliability is high.

[0010] [Technical means for solving the problem]

[0011] The electronic component of the present invention includes:

[0012] a substrate having a one surface side electrode and an other surface side electrode on one surface side and the other surface side, respectively, the one surface side electrode being electrically connected to an electrode of a piezoelectric vibrator, and the other surface side electrode being electrically connected to an electrode of an integrated circuit chip,

[0013] a one surface side frame wall provided on one surface side of the substrate along a peripheral portion of the substrate so as to form a first housing space housing the piezoelectric vibrator;

[0014] a cover blocking an opening portion of the one surface side frame wall so as to seal the first housing space;

[0015] an other surface side frame wall provided on the other surface side of the substrate along the peripheral portion of the substrate so as to form a second housing space housing the integrated circuit chip; and

[0016] a metal film not electrically connected to the other surface side electrode, provided on one surface side of the substrate so as to suppress warping of the substrate.

[0017] [Effects of the invention]

[0018] As for the electronic component of the present application including a substrate, a housing space of a piezoelectric vibrator on one side of the substrate, and a housing space of an integrated circuit chip on the other side of the substrate, on the one side of the substrate, a metal film not electrically connected to the electrode on the other side is provided. Thus, the warping of the substrate in the manufacturing process of the electronic component can be suppressed, and the connection of the electrode of the integrated circuit chip and the electrode on the other side of the substrate can be reliably performed. As a result, the reliability of the electronic component can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A longitudinal cross-sectional side view of a crystal oscillator of an embodiment of the electronic component of the present application.

[0020] Figure 2 A cross-sectional top surface view of the crystal oscillator.

[0021] Figure 3 A plan view showing the back surface of a substrate included in the crystal oscillator.

[0022] FIGS. 4(a) and 4(b) are manufacturing process views of the crystal oscillator.

[0023] FIGS. 5(a) and 5(b) are manufacturing process views of the crystal oscillator.

[0024] Figures 6(a) to 6(c) A manufacturing process view of the crystal oscillator.

[0025] Figure 7 A top surface view of a laminate for manufacturing the crystal oscillator.

[0026] Figure 8 A top surface view of a laminate and a jig for manufacturing the crystal oscillator.

[0027] FIGS. 9(a) and 9(b) are manufacturing process views of a crystal oscillator of a comparative example.

[0028] Figure 10 A manufacturing process view of a crystal oscillator of a comparative example.

[0029] Figure 11 A cross-sectional top surface view showing another structural example of a substrate constituting a crystal oscillator.

[0030] Figure 12 A cross-sectional top surface view showing another structural example of a substrate constituting a crystal oscillator.

[0031] Figure 13 A cross-sectional top surface view showing another structural example of a substrate constituting a crystal oscillator.

[0032] Figure 14 A cross-sectional top surface view showing another structural example of a substrate constituting a crystal oscillator.

[0033] [Explanation of symbols]

[0034] 1: crystal oscillator

[0035] 10: lid

[0036] 12: package body

[0037] 13: substrate

[0038] 21, 31 to 33: electrode

[0039] 22: dummy pad

[0040] 4: crystal

[0041] 5: IC chip DETAILED DESCRIPTION

[0042] Figure 1 、 Figure 2 FIGS. 1 and 2 are a longitudinal cross-sectional view and a cross-sectional top surface view, respectively, of a temperature-compensated crystal oscillator 1 according to an embodiment of the electronic component of the present application. The crystal oscillator 1 includes a package (frame) 11, a crystal 4, and an IC chip 5. The package 11 includes a package body 12 made of ceramic, and a lid 10 made of, for example, metal or ceramic.

[0043] The package body 12 includes a substrate (middle plate) 13 that is rectangular in plan view, a one-side frame wall 14 provided on one side of the substrate 13, and a other-side frame wall 15 provided on the other side of the substrate 13, the one-side frame wall 14 and the other-side frame wall 15 being formed along the peripheral edge portion of the substrate 13. Thus, the package body 12 has an H shape in longitudinal cross section. The substrate 13, the one-side frame wall 14, and the other-side frame wall 15 are integrated by firing. As briefly described in the item of the problem to be solved by the invention, the package body 12 is manufactured by dividing a laminate formed by superimposing a plurality of sheets along grooves. The manufacturing process of the crystal oscillator 1 including the manufacturing process of the package body 12 will be described in detail below.

[0044] Hereinafter, the one side of the substrate 13 will be referred to as the upper side, and the other side of the substrate 13 will be referred to as the lower side, for the convenience of explanation of the structure of each portion, but the upper side and the lower side are arbitrary in terms of the orientation in which the crystal oscillator 1 is used. A recess is formed on each of the one side and the other side of the substrate 13 by the one-side frame wall 14 and the other-side frame wall 15. An electrode 19 for mounting the crystal oscillator 1 to a mounting substrate (not shown) is provided on the lower side of the other-side frame wall 15.

[0045] On the upper side of the one-side frame wall 14, the lid 10 described above is provided in a manner to block the recess of the one side to form a sealed housing space 17 via a seal ring 16 provided along the one-side frame wall 14. That is, the lid 10 blocks the opening of the one-side frame wall 14, facing the substrate 13. The crystal oscillator 4 is housed in the housing space (first housing space) 17. Further, the recess of the other side of the substrate 13 forms a housing space (second housing space) 18 that houses the IC chip 5.

[0046] The substrate 13 is further described. On the one side of the substrate 13 that forms the housing space 17, on the left and right of the one end side in the length direction of the substrate 13, a substantially rectangular electrode 21 is formed, respectively. In this example, the electrode 21 as the one-side electrode is provided symmetrically with respect to the center of the left and right. Further, the left and right referred to herein is the width direction orthogonal to the length direction.

[0047] Further, on the left and right of the other end side in the length direction of the substrate 13, a substantially rectangular dummy pad 22 as a metal film is formed, respectively. In this example, the area of the dummy pad 22 is substantially equal to the area of the electrode 21, and the dummy pad 22 and the electrode 21 are disposed at symmetric positions with respect to the center of the length direction of the substrate 13. Therefore, the electrode 21 and the dummy pad 22 are provided in one and the other of the regions obtained by bisecting the substrate 13 in the length direction. In more detail, assuming that the substrate 13 is divided into four by a cross seen from above and the center of the substrate 13 coincides with the center of the cross, the layout in which the electrode 21 or the dummy pad 22 is included in each divided piece is obtained. The function of the dummy pad 22 will be described later.

[0048] Figure 3 The other side of the substrate 13 that forms the housing space 18 is shown. With respect to the other side, an electrode is provided on the left and right, respectively, on the one end side, the center portion, and the other end side in the length direction of the substrate 13. The electrode of the one end side is denoted as 31, the electrode of the center portion is denoted as 32, and the electrode of the other end side is denoted as 33, and these electrodes 31 to 33 are electrodes for mounting the IC chip 5. The electrodes 31 and 33 are caused to protrude toward the corner portion of the substrate 13, and protruding electrodes 34 are formed, respectively. The protruding electrodes 34 are connected to the electrode 19 provided in the lower portion of the other-side frame wall 15 via a not-shown wiring provided in the other-side frame wall 15.

[0049] Further, regarding the electrodes 31, 32, 33, the electrode provided on one side of the left and right is noted with the letter A, and the electrode provided on the other side of the left and right is noted with the letter B. That is, for example, regarding the electrodes 31 provided on the left and right, sometimes indicated as 31A, 31B, distinguished from each other. Hereinafter, in order to prevent errors caused by the description, regarding the electrodes 21, 31 to 33 of the substrate 13, sometimes described as the electrodes 21 for the vibrator, the electrodes 31 to 33 for the IC.

[0050] The respective electrodes 21 for the vibrator are connected to at least any one of the electrodes 31, 32, 33 for the IC via the conductive paths 29 provided in the substrate 13, Figure 1 In the example, indicated in a manner connected to the electrodes 31 for the IC. In this way, in a manner electrically conducted between the crystal oscillator 4, the IC chip 5, and the electrodes 19 of the package body 12, the conductive paths are formed in the package body 12.

[0051] Further, Figure 1 In the example, the thickness of the substrate 13 is indicated as Hl, and the thickness of the package body 12 is indicated as H2. In more detail, the thickness H2 is the thickness from the side end (upper end) of the one-face side frame wall 14 provided with the lid 10 to the surface (lower surface) of the electrodes 19, for example, 0.68 mm. If the thickness Hl of the substrate 13 is small, the strength of the substrate 13 is insufficient, and thus, as described later, warping can occur when the package body 12 is manufactured. As shown in the evaluation test described later, it is confirmed that in the case of Hl / H2 = 0.29, the effect of suppressing warping can be obtained, and thus, it is preferable that Hl / H2 be 0.29 or more, and according to the evaluation test, it is more preferable that Hl / H2 be 0.34 or more.

[0052] Next, the crystal oscillator 4 as the piezoelectric vibrator is described. The crystal oscillator 4 includes, for example, a crystal sheet 41 formed in a rectangular shape in plan view, excitation electrodes 42 provided in the central portions of one face side and the other face side of the crystal sheet 41, respectively, and extension electrodes 43 formed in a manner extending from each of the excitation electrodes 42 toward the same short side of the crystal sheet 41, and further extending to the opposite main surface (one face or the other face) via the side surface of the crystal sheet 41. Each of the extension electrodes 43 is electrically connected to each of the electrodes 21 for the vibrator of the substrate 13 via a conductive adhesive 44. Further, the electrodes 21 for the vibrator are provided at the end portions in the length direction of the substrate 13 as described above, and thus, can be connected to the extension electrodes 43 of the crystal oscillator 4 of various sizes. That is, the electrodes 21 for the vibrator are provided in a manner that the selection range of the usable crystal oscillator 4 is wider.

[0053] Next, the IC chip (integrated circuit chip) 5 as a semiconductor element will be described. The IC chip 5 is, for example, rectangular in plan view, and is disposed in the central portion of the substrate 13 in such a manner that the length direction thereof coincides with the length direction of the substrate 13. The electrodes provided on the main surface of the IC chip 5 will be denoted by 51, and the plurality of electrodes 51 are respectively connected to the IC electrodes 31, 32, 33 of the substrate 13 described above via, for example, bumps 52 including gold. As described in the background art item, the IC chip 5 is mounted on the substrate 13 by flip chip bonding.

[0054] The IC chip 5 includes an oscillation circuit that oscillates the crystal oscillator 4. Furthermore, in addition thereto, a temperature sensor circuit that senses the temperature around the crystal oscillator 1, and a temperature compensation circuit that performs temperature compensation of the crystal oscillator 4 using the output of the temperature sensor circuit are included, whereby a desired frequency signal is extracted from the crystal oscillator 1. The size Ll of the length direction of the IC chip 5 is, for example, 1 mm. Furthermore, between the other surface of the substrate 13 of the housing space 18 and the IC chip 5, a resin layer 53 called an underfill is provided, for the purpose of protecting the other surface of the substrate 13 and improving the mounting strength of the IC chip 5 to the substrate 13.

[0055] Furthermore, as for the electrodes 19, 21, 31 to 33 described above that are provided on the package body 12, the base material thereof includes, for example, tungsten (W), and a coating film including, for example, nickel (Ni) and gold (Au) is formed so as to coat the base material. Furthermore, as for the dummy pad 22, the base material thereof includes, for example, tungsten similarly to the electrode 21. However, unlike the electrode 21, a coating film is not formed on the dummy pad 22, and the base material is exposed. Furthermore, W that is listed as the base material of the respective electrodes and the metal film, and Ni and Au that are listed as the coating film of the respective electrodes are examples, and other kinds of metal can be used. For example, molybdenum can be used as the base material in addition to W.

[0056] In addition, the dummy pad 22 is not electrically connected to the IC electrodes 31 to 33 unlike the electrode 21 for the vibrator. That is, a conductive path that connects the dummy pad 22 and the IC electrodes 31 to 33 is not provided on the substrate 13, and even if the protruding electrode 43 of the crystal oscillator 4 is temporarily connected to the dummy pad 22, the protruding electrode 43 is not made to be in conduction with the electrode 19 of the package body 12. Therefore, the dummy pad 22 is in an electrically floating state when the crystal oscillator 1 is used. The dummy pad 22 has an effect of suppressing the warping of the substrate 13 that can occur in the manufacturing process of the crystal oscillator 1 as described in the problem to be solved by the invention.

[0057] Hereinafter, the case where the crystal oscillator 1 is mounted on the substrate 13 will be described with reference to FIG. 4(a) and FIG. 4(b). Figures 4(b) to 6(a)In FIG. 6(c), the manufacturing process of the crystal resonator 1 and the function of the dummy pad 22 are explained. In the figure, 61 is a sheet material for forming the substrate, 62 is a sheet material for forming the other-side frame wall, and 63 is a sheet material for forming the one-side frame wall. Each of the sheet materials 61 to 63 is ceramic. With respect to each of the sheet materials 61 to 63, the formation region 61A of the substrate 13, the formation region 62A of the other-side frame wall 15, and the formation region 63A of the one-side frame wall 14 are arranged in a matrix shape in plan view, and one package body 12 is manufactured from one formation region 61A to one formation region 63A. An opening portion for forming the accommodation space 18 of the IC chip 5 is formed in the sheet material 62, and an opening portion for forming the accommodation space 17 of the crystal resonator 4 is formed in the sheet material 63.

[0058] For example, with respect to the sheet material 61 in which the conductive paths 29 and the like have been formed inside, a conductive paste such as tungsten (W) is applied to the one-side and the other-side of the formation region 61A of the substrate 13 along a prescribed pattern with a mask interposed therebetween, and a metal pattern 64 is formed. The metal pattern 64 includes patterns that will become the electrode 21 for the resonator and the electrodes 31 to 33 for the IC, and a pattern of the dummy pad 22. That is, the application process of the conductive paste is a process of forming each of the base materials of the electrode 21, the electrodes 31 to 33, and the dummy pad 22 that have been described above. For example, with respect to the sheet material 62 in which the wiring lines have been formed inside, a conductive paste of W is applied to each of the formation regions 62A in the same manner as the formation region 61A, and a metal pattern 65 that will become the electrode 19 is formed. Further, the thickness of the metal pattern 64 and the metal pattern 65 is, for example, 5 μm or more.

[0059] Then, the sheet material 61 as the first sheet material, the sheet material 62 as the third sheet material, and the sheet material 63 as the second sheet material are aligned with the positions of the formation region 61A of the substrate 13, the formation region 62A of the other-side frame wall 15, and the formation region 63A of the one-side frame wall 14, and are laminated and joined by applying a load as shown in FIG. 4(a), and a laminate 60 is formed. Figure 7 The upper surface of the laminate 60 is shown. The joining operation is performed with the outer shapes of the sheet materials 61 to 63 aligned with each other, for example, using a jig. Further, by the joining, the conductive paths of the set of the formation regions 61A, 62A, and 63A that constitute one package body 12 become a state in which they are connected to each other, and between the sets of the formation regions, the conductive paths also become a state in which they are connected to each other.

[0060] Next, the jig 66 as a mold is relatively lowered with respect to the one-side of the laminate 60, and the jig 66 is relatively pressed against the laminate 60 (FIG. 4(b)). As shown in FIG. 4(b), the jig 66 is pressed against the laminate 60, and the laminate 60 is pressed against the jig 66. The laminate 60 is pressed against the jig 66, and the laminate 60 is pressed against the jig 66. Figure 8As shown in a plan view, the jig 66 is a cross shape, and by the pressing, grooves 67 (Fig. 5(a)) are formed along the outer edges of the respective formation regions 61A to 63A.

[0061] The state of the laminate 60 at the time of forming the grooves 67 will be described in detail. For the reasons described above, the resonator electrode 21 of the package body 12 is formed so as to be biased toward one end side in the length direction of the substrate 13. Therefore, in the metal pattern 64 formed in the formation region 61A of the substrate 13, the pattern corresponding to the resonator electrode 21 is formed so as to be biased toward one end side in the length direction of the formation region 61A of the substrate 13.

[0062] On the other hand, when the jig 66 is pressed against the laminate 60 as described above, the metal pattern 64 is affected by the stress generated in the formation region 61A. That is, even if the same or substantially the same load is applied, the stress generated is different between the portion where the metal pattern 64 is formed and the portion where the metal pattern 64 is not formed. Therefore, although this will be exemplified using a drawing below, in the case of the portion where the metal pattern 64 is not formed as a dummy pad 22, even if the same load is applied to the formation region 61A, the stress generated in each portion in the formation region 61A can be greatly different due to the uneven distribution of the metal pattern 64 in the formation region 61A caused by the arrangement of the resonator electrode 21. This can cause a large warpage in the formation region 61A.

[0063] However, as described so far, in the laminate 60, the metal pattern 64 is provided as a dummy pad 22 also on the other end side in the length direction of the formation region 61A, and the formation region 61A is structured so that the uneven distribution of the metal pattern 64 in the length direction thereof is suppressed. Therefore, when the jig 66 is pressed against the laminate 60 in order to form the grooves 67 as described above, the stress unevenness in the length direction of the formation region 61A is suppressed, and the warpage generated in the formation region 61A is suppressed. That is, the flatness of the formation region 61A is maintained even after the grooves 67 are formed.

[0064] Returning to the description of the manufacturing process of the crystal oscillator 1. After the grooves 67 are formed, the laminate 60 is baked at a high temperature to be hardened. Next, the laminate 60 is immersed in a chemical liquid, and the conductive paths in the state of being connected to each other in such a manner that the conductive paths of the respective package bodies 12 are formed later are electrified, and thereby plating is performed on the portions of the conductive paths exposed on the laminate 60, and a film of Ni and Au is formed. Thereby, the respective electrodes 19, 21, 31 to 33 are formed from the metal pattern 64 and the metal pattern 65. On the other hand, as for the dummy pad 22, the film is not formed. In other words, as for the portion of the metal pattern 64 where the conductive path of the package body 12 is not formed, the state where the film is not formed is maintained, and remains as the dummy pad 22.

[0065] Then, the laminated body 60 is divided along the groove 67 to manufacture the package body 12 (Fig. 5(b)). Next, the bumps 52 formed on the electrodes 51 of the IC chip 5 are brought into abutment with the IC electrodes 31 to 33 of the substrate 13 formed by the formation region 61A, a load is applied to the IC chip 5, and, for example, heat and / or ultrasonic waves are applied to the bumps 52 to perform flip-chip bonding (Fig. 6(a)).

[0066] At this time, the substrate 13 formed by the formation region 61A is suppressed from warping, and is high in flatness, so that the heights of the IC electrodes 31 to 33 are aligned with each other, and the load is applied to each of the bumps 52 with high uniformity. Therefore, each of the bumps 52 is flattened with high uniformity to become the same bump diameter, and is press-bonded to the IC electrodes 31 to 33 (Fig. 6(b)). Then, the formation of the resin layer 53 and the mounting of the crystal oscillator 4, the sealing ring 16, and the lid 10 are performed to manufacture the crystal oscillator 1 (Fig. 6(c)).

[0067] To more clearly show the effect of providing the dummy pad 22, the manufacturing process of the crystal oscillator of a comparative example in which the dummy pad 22 is not provided is described with the difference from the manufacturing process of the crystal oscillator 1 as the center, using Figs. 9(a) and 9(b), Figure 10 The description is made. The sheet material 61 for forming the substrate 13 is formed with the metal pattern 64. However, the metal pattern 64 does not include a pattern corresponding to the dummy pad 22. The jig 66 is pressed against the laminated body 60 formed from the sheet material 61 to form the groove 67. At this time, since the metal pattern 64 corresponding to the electrode 21 is formed so as to be biased toward the length direction of the formation region 61A of the substrate 13, the difference in stress generated in the length direction is large, and warping is generated in the formation region 61A (Figs. 9(a) and 9(b)).

[0068] Next, the sheet materials 61 to 63 are integrated by baking the laminated body 60, and the laminated body 60 is divided along the groove 67 to form the package body 12, and then flip-chip bonding of the IC chip 5 is performed. At this time, the substrate 13 formed by the formation region 61A warps, so that the heights of the IC electrodes 31 to 33 are different, the load applied to each of the bumps 52 becomes non-uniform, and the degree of flattening (bump height) of each of the bumps 52 also becomes non-uniform. Figure 10

[0069] ​In this case, with respect to some of the bumps 52, a defective condition can occur in which the electrodes of the substrate 13 are not sufficiently pressed and thus not crimped. In order to prevent this defective condition, it is conceivable to increase the load of the IC chip 5 on the substrate 13, but in this case, a defective condition can occur in which some of the bumps 52 are excessively flattened, resulting in excessive force being applied to the IC chip 5, which can cause the IC chip 5 to break. Also, as described above, there is a concern that unevenness in the diameter of the bumps 52 after crimping can result in a decrease in the reliability of the electrical connection of the IC chip 5 to the substrate 13, a decrease in the bonding strength of the IC chip 5 to the substrate 13, and the like.

[0070] The crystal oscillator 1 provided with the dummy pad 22 eliminates the defective conditions that occur in the crystal oscillator of the comparative example. That is, according to the crystal oscillator 1, when the IC chip 5 is mounted to the substrate 13 that constitutes the package body 12, the warping of the substrate 13 can be suppressed, and the connection of each of the bumps 52 to the IC electrodes 31 to 33 of the substrate 13 can be performed with high uniformity. Thus, the breakage of the IC chip 5 or the defective conduction between the electrodes 51 of the IC chip 5 and the electrodes 31 to 33 of the substrate 13 can be prevented, and the IC chip 5 can be firmly mounted to the substrate 13. Therefore, the defective rate of the crystal oscillator 1 can be suppressed, and the reliability of the crystal oscillator 1 can be improved.

[0071] Further, if the size LI (see FIG. 2) of the IC chip 5 in the length direction is large, Figure 1 If the size LI of the IC chip 5 in the length direction is large, the interval between the IC electrodes 31 to 33 also becomes large in correspondence with the size of the IC chip 5. If the interval between the electrodes is large in this way, when the substrate 13 warps, the height difference between the IC electrodes 31 to 33 also becomes large, and thus there is a tendency to easily produce the defective conditions described in the comparative example. The present technology is particularly effective in order to prevent the occurrence of the defective conditions when the LI is, for example, 0.9 mm or more. Also, if the size of the housing space 18 in the length direction is L2, when the LI is, for example, 0.9 mm or more, it is when the LI / L2 is 0.55 or more. Further, if the LI is relatively large in this way, the IC chip 5 overlaps the vibrator electrode 21 and the dummy pad 22 in plan view.

[0072] Further, the influence of the configuration of the electrode 21 for the vibrator causes unevenness of stress in the formation region 61A of the substrate 13 when the groove 67 is formed. In the formation region 61A, the electrode 21 for the vibrator occupies a relatively large area, and thus, in the case where the dummy pad 22 is not provided, it is conceivable that the unevenness of stress in the formation region 61A becomes large due to the influence of the electrode 21 for the vibrator to a large extent, but the conductive path formed in the substrate 13 also influences the stress in the formation region 61A. Therefore, in order to make the stress of each portion in the formation region 61A uniform when the groove 67 is formed and to suppress warping, it is not limited to making the electrode 21 and the dummy pad 22 of substantially the same size and substantially the same shape.

[0073] Hereinafter, other configuration examples of the dummy pad 22 will be described. Figure 11 In the example shown, as described above in Figure 2 In the example shown in Figure 11 Each dummy pad 22 is formed elongated along the length direction of the substrate 13, and one end side (the electrode 21 for the vibrator side) thereof is located closer to the electrode 21 for the vibrator than the center of the length direction of the substrate 13. Further, if the interval L3 between the electrode 21 for the vibrator and the dummy pad 22 is too small, short circuiting occurs, and thus the interval L3 is set to an interval that does not cause short circuiting. With respect to the interval L3, there is no limitation as long as such short circuiting does not occur.

[0074] As the dummy pad 22, it is not limited to being provided in plurality in the substrate 13, but only one can be provided. Figure 12 In Figure 12 The dummy pad 22 is configured in such a manner that the end portions on the width center side of the substrate 13 of the two dummy pads 22 described in Figure 11 are extended to the width center and are joined to each other, and is in a substantially square shape.

[0075] Further, in the case where the dummy pads 22 are provided on the left and right of the substrate 13, they can be in different shapes from each other, and an example of this is shown in Figure 13 In the example shown in Figure 13 In the example shown in Figure 14 The dummy pad 22 can also be configured in a ring shape. In the example shown in Figure 14 An example in which only the peripheral portion in the region in which the dummy pad 22 is formed in Figure 12 is formed as the dummy pad 22 is shown. Further, the dummy pad 22 of each drawing is an example, and with respect to the shape and size thereof, the example shown in the drawing can be appropriately changed.

[0076] In order to suppress the influence of the vibrator electrode 21 when the load is applied as described above, if the area of the dummy pad 22 is too small, sufficient effects can not be obtained, and thus it is preferable that the area of the dummy pad 22 / the area of the vibrator electrode 21 > 0.7. The area of the vibrator electrode 21 means the total of the areas of the two vibrator electrodes 21 provided as described above. Also, when a plurality of dummy pads 22 are provided as described above, the area of the dummy pad 22 means the total of the areas of the plurality of dummy pads 22.

[0077] Also, although the dummy pad 22 exposes the metal of the base material, plating or the like can be performed, and a film such as one made of Au or the like can be formed on the surface of the dummy pad 22 as with the electrodes. However, as described above, the dummy pad 22 does not function as an electrode, and thus it is advantageous in reducing the manufacturing cost of the resonator 1 when the film is not formed. In addition, the base material of the dummy pad 22 and the base material of the electrodes are not limited to including the same metal, and can be different metals.

[0078] In addition, with respect to the resonator 4, the shape of the crystal sheet 41 and the layout of the electrodes are not limited to those described above. For example, the extension electrode 43 can also be formed so as to extend in the opposite direction of the crystal sheet 41. At this time, for example, the electrode 21 of the substrate 13 can also be provided so as to extend away from the one end portion and the other end portion in the length direction in correspondence with the position of the extension electrode 43. In addition, in this case, the dummy pad 22 can also be provided so as to extend away to the left and right of the central portion in the length direction of the substrate 13. That is, with respect to the layout of the electrode 21 and the dummy pad 22 on the substrate 13, the layout can also be changed in accordance with the structure of the resonator 4.

[0079] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not restrictive. The embodiments can be omitted, replaced, changed, or combined in various embodiments without departing from the scope of the appended claims and the spirit thereof.

[0080] (Evaluation Test)

[0081] An evaluation test 1 concerning the present application will be described. As an evaluation test 1-1, the package body 12 was produced by the procedures described in Figs. 4(a) and 4(b), 5(a) and 5(b). That is, after the metal pattern 64 was formed in a manner to form the dummy pad 22, the package body 12 was produced by forming the groove 67 in the laminate 60. The thickness Hl (= the thickness of the sheet material 61 for forming the substrate 13) of the substrate 13 of the package body 12 was set to 0.20 mm. Ten of the produced package bodies 12 were used as samples, and the height difference of the electrodes 31A, 31B, 32A, 32B, 33B from the height of 33A as the Vcc terminal was measured for the IC electrode of each sample. Further, the maximum value - minimum value of the obtained height difference was calculated as the size of the warpage for each sample, and the average value of the size of the warpage was calculated.

[0082] As evaluation tests 1-2 to 1-4, the package body 12 was produced by the procedures described in Figs. 9(a) and 9(b). That is, the metal pattern 64 was formed without the dummy pad 22, and the production of the package body 12 was performed. In the evaluation test 1-2, 1-3, 1-4, the thickness Hl of the substrate 13 was 0.20 mm, 0.23 mm, 0.25 mm, respectively. Also, as to the evaluation tests 1-2 to 1-4, the height difference of the electrodes and the size of the warpage were calculated for the samples of 10 package bodies 12, as in the evaluation test 1-1. Also, the average value of the size of the warpage was calculated. Further, in the evaluation tests 1-1 to 1-4, the thickness H2 of the package body 12 was 0.68 mm, as in the above-described embodiment. Therefore, as to Hl / H2, it was 0.29 in the evaluation test 1-1, 0.34 in the evaluation test 1-2, 0.34 in the evaluation test 1-3, and 0.37 in the evaluation test 1-4.

[0083] Tables 1 and 2 below show the results of the evaluation test 1, and Table 1 shows the height difference of the electrodes for each sample, and Table 2 shows the size of the warpage and the average value thereof. Further, the unit of the values in each table is μm. As shown in Table 1, in each sample of the evaluation test 1-2, the electrodes 32A, 32B were higher than the electrodes 31A, 31B, 33A, 33B. That is, as to the substrate 13, a tendency was seen that the central portion in the length direction was higher than the both end portions in the length direction. However, such a tendency was not seen in the evaluation test 1-1, and the height difference of each electrode was suppressed as compared with the evaluation test 1-2. Also, as shown in Table 2, as to the average value of the size of the warpage, the evaluation test 1-1 was the smallest among the evaluation tests 1-1 to 1-4. Therefore, the effect of the present application in which the dummy pad 22 is provided was shown from the evaluation test.

[0084] [Table 1]

[0085]

[0086] [Table 2]

[0087]

[0088] Moreover, if the height difference of the electrodes adjacent in the length direction of the substrate 13 is examined, depending on the sample, the case of Evaluation Test 1-3, Evaluation Test 1-4 is sometimes less suppressed than Evaluation Test 1-2. Moreover, if the average value of the size of the warpage is examined, the value of Evaluation Test 1-3 is smaller than that of Evaluation Test 1-2. Regarding this, it can be considered that the thickness of the sheet 61 (= the thickness of the substrate 13) is large and thus the strength is high, and therefore the deformation at the time of application of the load is suppressed. It can be inferred that by increasing the thickness of the substrate 13 on the basis of the provision of the dummy pad 22 as in Evaluation Test 1-3, Evaluation Test 1-4, the warpage of the substrate 13 can be more reliably suppressed, and thus it is preferable that H1 / H2 be 0.34 or more as already described above.

Claims

1. An electronic component, characterized by, including: a substrate provided with a one-side electrode and a back-side electrode on a one-side and a back-side, respectively, the one-side electrode being electrically connected to an electrode of a piezoelectric vibrator, the back-side electrode being electrically connected to an electrode of an integrated circuit chip; a one-side frame wall provided along a peripheral portion of the substrate on the one-side of the substrate for forming a first housing space that houses the piezoelectric vibrator; a cover that plugs an opening portion of the one-side frame wall to seal the first housing space; a back-side frame wall provided along a peripheral portion of the substrate on the back-side of the substrate for forming a second housing space that houses the integrated circuit chip; and a metal film not electrically connected to the back-side electrode, provided on the one-side of the substrate for suppressing warping of the substrate, the substrate, the one-side frame wall, and the back-side frame wall constituting a package body including ceramic that is integrated by firing, if a thickness of the substrate is set as H1, a thickness from a side end of the one-side frame wall on which the cover is provided to a surface of an electrode provided in the back-side frame wall on the opposite side to the side on which the one-side frame wall is provided is set as H2, H1 / H2 is 0.34 or more.

2. The electronic component according to claim 1, wherein the metal film is provided so as to overlap the integrated circuit chip when viewed in plan.

3. The electronic component according to claim 1, wherein the one-side electrode includes a base material and a coating film that coats the base material, the metal film includes the base material that is not provided with the coating film.

4. The electronic component according to claim 2, wherein the one-side electrode includes a base material and a coating film that coats the base material, the metal film includes the base material that is not provided with the coating film.

5. The electronic component according to any one of claims 1 to 4, wherein the substrate is rectangular, and the one-side electrode is provided in one of regions obtained by bisecting the substrate in a length direction, and the metal film is provided in the other region.

6. A method of manufacturing an electronic component that includes: a substrate provided with a one-side electrode and a back-side electrode on a one-side and a back-side, respectively, the one-side electrode being electrically connected to an electrode of a piezoelectric vibrator, the back-side electrode being electrically connected to an electrode of an integrated circuit chip; a one-side frame wall provided along a peripheral portion of the substrate on the one-side of the substrate for forming a first housing space that houses the piezoelectric vibrator; a cover that plugs an opening portion of the one-side frame wall to seal the first housing space; and a back-side frame wall provided along a peripheral portion of the substrate on the back-side of the substrate for forming a second space that houses the integrated circuit chip, the method of manufacturing an electronic component characterized by comprising: a step of The first sheet, the second sheet, and the third sheet are overlapped with each other to form a laminate, the first sheet includes a plurality of formation regions of the substrate, and a metal pattern corresponding to the one-face-side electrode and the other-face-side electrode is formed, the second sheet includes a plurality of formation regions of the one-face-side frame wall, and the third sheet includes a plurality of formation regions of the other-face-side frame wall; a jig is pressed against the laminate to form a groove; and the laminate is divided along the groove to form a plurality of structures including the substrate, the one-face-side frame wall, and the other-face-side frame wall, the metal pattern includes a metal film that is not electrically connected to the other-face-side electrode, is provided on the one-face side of each formation region of the substrate, and is used to suppress warping of the formation region of the substrate when the jig is pressed against the laminate.

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