Manufacturing methods for multiple vibration devices

Abstract

A method for manufacturing a vibrating device is provided, which enables manufacturing with fewer steps. The method includes the following steps: preparing a base wafer comprising multiple monolithic regions; arranging a vibrating element on a first side of the base wafer; obtaining a device wafer by bonding a cover wafer to the base wafer, wherein each monolithic region has a housing portion for housing the vibrating element; forming a first groove at the boundary of adjacent monolithic regions of the device wafer, extending from the cover wafer side to a second side further than the junction of the base wafer and the cover wafer; arranging a resin material in the first groove; and forming a second groove at the boundary that penetrates the device wafer and is narrower than the width of the first groove, thereby monolithizing the device wafer according to each monolithic region to obtain multiple vibrating devices.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a vibrating device. Background Technology

[0002] Patent Document 1 describes a piezoelectric vibrator comprising: an encapsulation having a structure in which a cover and a base are joined by a joining member; a vibrating element housed within the internal space of the encapsulation, i.e., a housing portion; and a cover member covering the joint portion between the cover and the base to protect that portion from moisture. The cover member is formed by coating each piezoelectric vibrator with a resin material after monolithically processing the piezoelectric vibrator in wafer form.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2018-117243

[0004] However, in the method of forming a cover component by coating each of the monolithic piezoelectric oscillators with resin material, there is a problem that the manufacturing time of the cover component increases. Summary of the Invention

[0005] The method for manufacturing a vibration device according to the present invention is characterized by comprising the following steps: preparing a base wafer having a first surface and a second surface in a front-back relationship and comprising a plurality of monolithic regions; arranging a vibration element on the first surface side of the base wafer according to each of the monolithic regions; preparing a cover wafer comprising the plurality of monolithic regions, and joining the cover wafer to the first surface of the base wafer to obtain a device wafer, wherein the device wafer has a receiving portion for receiving the vibration element formed according to each of the monolithic regions; forming a first groove at the boundary of adjacent monolithic regions of the device wafer extending from the cover wafer side to the second surface side further than the junction of the base wafer and the cover wafer; distributing resin material in the first groove; and forming a second groove at the boundary that penetrates the device wafer and is narrower than the width of the first groove, thereby monolithizing the device wafer according to each of the monolithic regions to obtain a plurality of vibration devices. Attached Figure Description

[0006] Figure 1 This is a cross-sectional view showing the vibration device of the first embodiment. Figure 2 Sectional view along line AA in the diagram.

[0007] Figure 2 This is a top view showing the upper surface of the base.

[0008] Figure 3 It is a process diagram showing the manufacturing process of a vibrating device.

[0009] Figure 4 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0010] Figure 5 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0011] Figure 6 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0012] Figure 7 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0013] Figure 8 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0014] Figure 9 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0015] Figure 10 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0016] Figure 11 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0017] Figure 12 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0018] Figure 13 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0019] Figure 14 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0020] Figure 15 This is a cross-sectional view showing the vibration device of the second embodiment.

[0021] Figure 16 It is a process diagram showing the manufacturing process of a vibrating device.

[0022] Figure 17 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0023] Figure 18 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0024] Figure 19 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating device.

[0025] Figure 20 This is a cross-sectional view showing the vibration device of the third embodiment.

[0026] Figure 21 This is a cross-sectional view showing the vibration device of the fourth embodiment.

[0027] Label Explanation

[0028] 1: Vibrating device; 1A: Device; 10: Package; 100: Device wafer; 110: First slot; 120: Second slot; 2: Base; 2a: Upper surface; 2b: Lower surface; 2c1: Side surface; 2c2: Side surface; 20: Base wafer; 20a: Upper surface; 20b: Lower surface; 21: Through-hole; 210: Through-electrode; 22: Through-hole; 220: Through-electrode; 25: External terminal; 26: Insulation 27: Membrane; 28: Step; 29: Wiring; 3: Cover; 3a: Upper surface; 3b: Lower surface; 3c: Side; 30: Cover wafer; 30a: Upper surface; 30b: Lower surface; 31: Recess; 4: Vibrating element; 41: Vibrating substrate; 42: Electrode; 421: Excitation electrode; 422: Excitation electrode; 423: Terminal; 424: Terminal; 425: Wiring; 426: Wiring; 6: Integrated circuit ; 6A: Oscillating circuit; 60: Laminated body; 62: Wiring layer; 63: Insulating layer; 64: Passivation film; 65: Terminal layer; 650: Mounting terminal; 651: Wiring; 652: Wiring; 7: Metal layer; 71: First metal layer; 72: Second metal layer; 81: Metal bump; 82: Metal bump; 9: Resin layer; 9c: Side; DB1: Cutting tool; DB2: Cutting tool; DT: Cutting strip; G: Gap; Q: Monolithic area; S: Receiving part; S11: Preparation process; S12: Placement process; S13: Joining process; S14: Groove forming process; S15: Resin layer forming process; S16: Monolithic process; S21: Preparation process; S22: Placement process; S23: Joining process; S24: Groove forming process; S25: Resin layer forming process; S26: Monolithic process; W1: Width; W2: Width. Detailed Implementation

[0029] Hereinafter, a preferred embodiment of the method for manufacturing the vibrating device will be described with reference to the accompanying drawings. Furthermore, for ease of explanation, [the following will be omitted]. Figure 1 , Figures 4 to 15 as well as Figures 17-21 The upper side is also called "upper," and the lower side is also called "lower." In this case, in Figure 2 In the middle, the front side of the paper is "top" and the inside side is "bottom".

[0030] <First Implementation>

[0031] Figure 1 This is a cross-sectional view showing the vibration device of the first embodiment. Figure 2 Sectional view along line AA in the diagram. Figure 2 This is a top view showing the upper surface of the base. Figure 3 It is a process diagram showing the manufacturing process of a vibrating device. Figures 4 to 14 These are cross-sectional views used to illustrate the manufacturing method of the vibrating device.

[0032] Figure 1 The vibration device 1 shown includes: a package 10 having an hermetically sealed housing S; a vibration element 4 housed within the housing S; and a resin layer 9 disposed on a portion of the outer surface of the package 10. Furthermore, the package 10 includes: a base 2 engaged with the vibration element 4 via a pair of metal bumps 81, 82; and a cover 3 covering the vibration element 4 and engaged with the upper surface 2a of the base 2. Additionally, an integrated circuit 6 comprising an oscillation circuit 6A for oscillating the vibration element 4 is formed on the lower surface 2b side of the base 2.

[0033] The base 2 is a silicon substrate. In this embodiment, a P-type silicon substrate is specifically used. Therefore, when the vibrating device 1 is used, the base 2 is connected to ground, which is a constant potential. However, the base 2 is not particularly limited and can also be an N-type silicon substrate. Alternatively, semiconductor substrates other than silicon, such as Ge, GaP, GaAs, InP, etc., can also be used.

[0034] The base 2 is plate-shaped, having an upper surface 2a as a first surface (front and back) and a lower surface 2b as a second surface (back and back). Furthermore, the base 2 has a step 27 midway along its thickness, and the portion of this step 27 on the upper surface 2a side is tapered relative to the portion on the lower surface 2b side. Hereinafter, the side surface on the upper side of the step 27 will be referred to as side surface 2c1, and the lower side surface will be referred to as side surface 2c2.

[0035] Furthermore, an insulating film 26 is formed on the upper surface 2a and the lower surface 2b of the substrate 2. The insulating film 26 is, for example, a silicon oxide film formed by thermal oxidation of the surface of the substrate 2. However, the insulating film 26 is not particularly limited, and for example, it can also be a silicon nitride film. In addition, the method for forming the insulating film 26 is not limited to thermal oxidation, and for example, it can also be CVD (Chemical Vapor Deposition).

[0036] Furthermore, an integrated circuit 6 electrically connected to the vibrating element 4 is formed on the lower surface 2b side of the base 2. Thus, by forming the integrated circuit 6 on the base 2, the base 2 can be utilized effectively. In particular, by forming the integrated circuit 6 on the lower surface 2b side, compared to the case where the integrated circuit 6 is formed on the upper surface 2a side as described in the fourth embodiment later, there is no contact area with the cover 3, thereby correspondingly ensuring a wider forming space for the integrated circuit 6.

[0037] The integrated circuit 6 includes an oscillation circuit 6A that is electrically connected to the vibrating element 4 and causes the vibrating element 4 to oscillate to generate an oscillation signal such as a clock signal. In addition to the oscillation circuit 6A, the integrated circuit 6 may also include other circuits. Examples of such circuits include a processing circuit that processes the output signal from the oscillation circuit 6A, and a PLL circuit is an example of such a processing circuit.

[0038] A laminate 60, consisting of a wiring layer 62, an insulating layer 63, a passivation film 64, and a terminal layer 65, is formed on the lower surface 2b. Furthermore, the wiring included in the wiring layer 62 electrically connects multiple active components (not shown) formed on the lower surface 2b to form an integrated circuit 6. Additionally, the terminal layer 65 has multiple mounting terminals 650 that are electrically connected to the integrated circuit 6. In the vibration device 1, the integrated circuit 6 is connected to an external device via these mounting terminals 650.

[0039] Furthermore, in the illustrated structure, the laminate 60 includes one wiring layer 62, but it is not limited to this; multiple wiring layers 62 may also be stacked with insulating layers 63 in between. That is, wiring layers 62 and insulating layers 63 may be stacked alternately in multiple layers. This, for example, can increase the routing of wiring within the integrated circuit 6 and improve the flexibility in the arrangement of multiple mounting terminals 650.

[0040] Furthermore, a pair of through holes 21 and 22 extending through the base 2 in the thickness direction are formed on the base 2. Conductive materials such as metal are filled into each through hole 21 and 22 to form through electrodes 210 and 220. Additionally, a pair of wirings 28 and 29 electrically connected to the vibrating element 4 are disposed on the upper surface 2a of the base 2. Wiring 28 is electrically connected to the integrated circuit 6 via through electrode 210, and wiring 29 is electrically connected to the integrated circuit 6 via through electrode 220.

[0041] Both the cover 3 and the base 2 are made of silicon substrates. Therefore, the base 2 and the cover 3 have the same coefficient of linear expansion, suppressing the generation of thermal stress caused by thermal expansion, resulting in a vibrating device 1 with excellent vibration characteristics. Furthermore, since the vibrating device 1 can be formed using semiconductor processes, it can be manufactured with high precision and miniaturized. However, the cover 3 is not particularly limited, and semiconductor substrates other than silicon, such as Ge, GaP, GaAs, and InP, can also be used.

[0042] like Figure 1 As shown, the cover 3 is box-shaped, having an upper surface 3a, a lower surface 3b, and a bottomed recess 31 that opens on the lower surface 3b and houses the vibrating element 4. In addition, when viewed from above, the cover 3 is slightly smaller than the base 2, and its side 3c is flush with the side 2c1 of the base 2 that is above the step 27.

[0043] The cover 3 is bonded to the upper surface 2a of the base 2 via a metal layer 7 on its lower surface 3b. By bonding the base 2 and the cover 3 via the metal layer 7, they can be firmly and tightly joined. Therefore, the strength of the package 10 can be improved, and the airtightness of the housing S can be improved. The specific bonding method will be explained in the following description of the manufacturing method.

[0044] Furthermore, the cover 3 is electrically connected to the base 2 via the metal layer 7. As described above, when the vibrating device 1 is in use, the base 2 is grounded, and therefore the cover 3 is also grounded. Therefore, the entire package 10 functions as a shield, reducing the influence of electromagnetic noise from the outside. Thus, the vibrating device 1 becomes highly reliable.

[0045] Furthermore, when viewed from above the package 10, the outer edge of the metal layer 7 is located further inward than the outer edge of the upper surface 2a of the base 2 and the outer edge of the lower surface 3b of the cover 3. Therefore, a concave gap G is formed on the outer side of the metal layer 7, between the upper surface 2a of the base 2 and the lower surface 3b of the cover 3, and faces outward from the package 10. This structure protects the metal layer 7 from the cutting process performed during the manufacture of the vibrating device 1. Therefore, it effectively suppresses the reduction in bonding strength and the airtightness failure of the housing S. This will also be explained later in the manufacturing method of the vibrating device 1.

[0046] The housing S within the package 10 is hermetically sealed and in a depressurized state, preferably closer to a vacuum. This reduces viscous resistance and improves the oscillation characteristics of the vibrating element 4. However, the environment of the housing S is not particularly limited; for example, it can be an environment containing inert gases such as nitrogen or Ar, or it can be in an atmospheric pressure or pressurized state instead of a depressurized state.

[0047] like Figure 2 As shown, the vibrating element 4 has a vibrating substrate 41 and an electrode 42 disposed on the surface of the vibrating substrate 41. The vibrating substrate 41 has a thickness shear vibration mode and is formed from an AT-cut quartz substrate in this embodiment. The AT-cut quartz substrate has a three-dimensional frequency-temperature characteristic, thus making it a vibrating element 4 with excellent temperature characteristics. Furthermore, the electrode 42 has: an excitation electrode 421 disposed on the upper surface; and an excitation electrode 422 disposed on the lower surface opposite to the excitation electrode 421. Additionally, the electrode 42 has: a pair of terminals 423 and 424 disposed on the lower surface of the vibrating substrate 41; a wiring 425 electrically connecting the terminals 423 and the excitation electrode 421; and a wiring 426 electrically connecting the terminals 424 and the excitation electrode 422.

[0048] Furthermore, the structure of the vibrating element 4 is not limited to the structure described above. For example, the vibrating element 4 can be a mesa type where the vibration region sandwiched by the excitation electrodes 421 and 422 protrudes from its surroundings; conversely, it can also be a reverse mesa type where the vibration region is recessed from its surroundings. Additionally, it is also possible to perform bevel machining by grinding around the vibrating substrate 41, or convex machining to make the upper and lower surfaces convex curved surfaces.

[0049] Furthermore, the vibrating element 4 is not limited to an element that vibrates in a thickness shear vibration mode. For example, it can also be an element such as a tuning fork type vibrating element in which multiple vibrating arms bend in the in-plane direction. That is, the vibrating substrate 41 is not limited to a substrate formed of AT-cut quartz substrate, but can also be formed of quartz substrates other than AT-cut quartz substrates (e.g., X-cut quartz substrates, Y-cut quartz substrates, Z-cut quartz substrates, BT-cut quartz substrates, SC-cut quartz substrates, ST-cut quartz substrates, etc.).

[0050] Furthermore, the material constituting the vibrating substrate 41 is not limited to quartz. For example, it can be made of piezoelectric single crystals such as lithium niobate, lithium tantalate, lithium tetraborate, lanthanum gallium silicate, potassium niobate, and gallium phosphate, or other piezoelectric single crystals. Furthermore, the vibrating element 4 is not limited to a piezoelectrically driven vibrator, but can also be an electrostatically driven vibrator using electrostatic force.

[0051] like Figure 2 As shown, the vibrating element 4 is engaged with the upper surface 2a of the base 2 via a pair of metal bumps 81 and 82, and is electrically connected to wirings 28 and 29. The metal bumps 81 and 82 are, for example, cylindrical bumps or plated bumps. The metal bumps 81 and 82 are engaged with wirings 28 and 29, for example, by ultrasonic bonding, or with terminals 423 and 424 by thermoforming. However, the bonding method is not particularly limited. Alternatively, a conductive adhesive may be used instead of the metal bumps 81 and 82 as the bonding component.

[0052] like Figure 1 As shown, resin layer 9 is disposed on the outer surface of package 10. Specifically, resin layer 9 covers the entire upper portion from the step 27 formed on the base 2 of package 10. That is, resin layer 9 covers the step 27 and side 2c1 of base 2, the joint between base 2 and cover 3, and the entire cover 3. In this way, by disposing resin layer 9 on the outer surface of package 10, external forces such as impact during falling and stress applied during pickup can be absorbed and mitigated by resin layer 9, making package 10 less susceptible to external forces. Therefore, damage to package 10, especially cracks or defects, can be effectively suppressed, resulting in a vibration device 1 with excellent mechanical strength.

[0053] The effect of protecting against impacts is particularly significant by covering the corners of the package 10 with resin layer 9. In this embodiment, the corners of the upper surface 3a and side surface 3c of the cover 3, as well as the corners of the side surfaces 3c relative to each other, are covered with resin layer 9. Furthermore, the effect of protecting against stress during pickup is particularly significant by covering the sides of the package 10 with resin layer 9.

[0054] In addition, by configuring a resin layer 9 on the outer surface of the package 10, the coefficient of friction of the surface of the vibrating device 1 is increased compared with the case where the package 10 is exposed, thus making the vibrating device 1 less prone to slipping and easier to pick up.

[0055] Furthermore, the resin layer 9 covers the joint between the cover 3 and the base 2, filling the gap G. This protects the joint. It also further enhances the bonding strength between the cover 3 and the base 2, and improves the airtightness of the housing S. Additionally, this portion acts as an anchor, making it difficult for the resin layer 9 to peel off from the package 10. This resin layer 9 is insulating. Therefore, it prevents conductivity with the package 10 and suppresses electrostatic damage to the integrated circuit 6 caused by external electrostatic discharge or other electrical shocks. As a result, it becomes a highly reliable vibration device 1.

[0056] Furthermore, the side 9c of the resin layer 9 is flush with the side 2c2 of the base 2 that is lower than the step 27. Therefore, the resin layer 9 is less likely to get stuck in the external structure, effectively preventing the resin layer 9 from curling up.

[0057] Furthermore, the resin layer 9 is not particularly limited, and examples include epoxy resin, phenolic resin, urea resin, melamine resin, polyester (unsaturated polyester) resin, polyimide resin, silicone resin, polyurethane resin, etc., and one or more of them can be used. As a result, a resin layer 9 with excellent heat resistance can be obtained.

[0058] The structure of the vibrating device 1 has been described above. Next, the manufacturing method of the vibrating device 1 will be explained. For example... Figure 3 As shown, the manufacturing process of the vibrating device 1 includes a preparation process S11, a mounting process S12, a joining process S13, a groove forming process S14, a resin layer forming process S15, and a monolithic process S16. Each of these processes S11 to S16 will be described in detail below.

[0059] [Preparation Step S11]

[0060] First, such as Figure 4 As shown, a substrate wafer 20 is prepared, having an upper surface 20a and a lower surface 20b in a forward-reverse orientation, and comprising multiple monolithic regions Q, which constitute the substrate 2. The substrate wafer 20 is the base material of the substrate 2, and is a silicon substrate. Next, as... Figure 5As shown, an integrated circuit 6 is formed on the lower surface 20b side of the substrate wafer 20 according to each monolithic region Q. Next, as... Figure 6 As shown, through-holes 21 and 22 are formed from the upper surface of the substrate wafer 20 to the integrated circuit 6 in each monolithic region Q. Next, as... Figure 7 As shown, through electrodes 210, 220, wiring 28, 29, and a first metal layer 71 are formed in each monolithic region Q. In this way, by forming the integrated circuit 6 on the substrate wafer 20, the substrate wafer 20 can be effectively utilized.

[0061] [Placement process S12]

[0062] like Figure 8 As shown, a vibrating element 4 is disposed on the upper surface 20a side of the substrate wafer 20 according to each monolithic region Q. Specifically, the vibrating element 4 is prepared and bonded to the upper surface 20a via metal bumps 81 and 82. In addition, wiring 28 is electrically connected to the terminal 423 of the vibrating element 4 via metal bump 81, and wiring 29 is electrically connected to the terminal 424 via metal bump 82. Thus, the vibrating element 4 is electrically connected to the integrated circuit 6.

[0063] [Jointing process S13]

[0064] First, such as Figure 9 As shown, a cover wafer 30 comprising multiple monolithic regions Q, which together form the cover 3, is prepared. On the cover wafer 30, for each monolithic region Q, a recess 31 with an opening on the lower surface 30b and a second metal layer 72 disposed on the lower surface 30b to surround the recess 31 are formed. Furthermore, the first and second metal layers 71 and 72 can, for example, be configured as a structure formed by stacking a gold (Au) surface layer on a copper (Cu) substrate.

[0065] Next, as Figure 10 As shown, the surfaces of the first and second metal layers 71 and 72 are irradiated with an ion beam or plasma to activate them, causing metal diffusion in the first and second metal layers 71 and 72, thereby bonding the base wafer 20 and the cover wafer 30. A metal layer 7 is formed through the diffusion of the first and second metal layers 71 and 72. This results in a device wafer 100 with a housing portion S for housing a resonating element 4 formed in each monolithic region Q. In the device wafer 100, the base wafer 20 and the cover wafer 30 are electrically connected via the metal layer 7.

[0066] According to this bonding method, the base wafer 20 and the cover wafer 30 can be bonded more firmly and tightly, which can improve the mechanical strength and airtightness of the vibrating device 1. In addition, since the base 2 and the cover 3 can be bonded at room temperature (a temperature lower than the melting point of the first and second metal layers 71 and 72), internal stress is less likely to remain in the package 10, and thermal damage to the vibrating element 4 is also reduced.

[0067] Next, as Figure 11 As shown, a dicing tape DT, prepared as a holding component, is attached to the lower surface 20b side of the device wafer 100. This results in the dicing tape DT holding the device wafer 100 from the lower surface 20b side.

[0068] [Trench Forming Process S14]

[0069] like Figure 12 As shown, a first groove 110 is formed from the cover wafer 30 side at the boundary of adjacent monolithic regions Q. The first groove 110 is a bottomed groove that opens onto the upper surface 30a of the cover wafer 30 and does not extend to the lower surface 20b of the base wafer 20. Furthermore, the first groove 110 reaches closer to the lower surface 20b than the junction of the base wafer 20 and the cover wafer 30, i.e., at the middle of the base wafer 20. Therefore, the junction of the base wafer 20 and the cover wafer 30 faces the first groove 110. Additionally, the cover wafer 30 is monolithized according to each monolithic region Q, and a cover 3 is formed in each monolithic region Q.

[0070] The method for forming the first groove 110 is not particularly limited, but in this embodiment, it is formed by using a cutting tool DB1 to make a half cut from the upper surface 30a side of the cover wafer 30. This allows the first groove 110 to be formed easily. Furthermore, the surface of the first groove 110 has minute irregularities, i.e., it is rough, which improves the adhesion between the package 10 and the resin layer 9.

[0071] Here, when viewed from above the device wafer 100, the outer edge of the metal layer 7 is located further inward than the outer edge of the monolithic region Q. Therefore, when forming the first groove 110 using the cutting tool DB1, contact between the cutting tool DB1 and the metal layer 7 can be avoided, and obstruction of the bottom of the cutting tool DB1 can be prevented. Thus, the reduction in the machining accuracy of the first groove 110 can be suppressed. In addition, damage to the metal layer 7 can be suppressed, and the reduction in the bonding strength between the base wafer 20 and the cover wafer 30, the reduction in the airtightness of the housing S, and airtightness failure can be effectively suppressed.

[0072] [Resin layer formation process S15]

[0073] like Figure 13As shown, a resin layer 9 is formed by depositing a resin material on the surface of the device wafer 100. The resin layer 9 is formed on the upper surface 30a of the cover wafer 30 and within the first groove 110. Furthermore, the resin layer 9 also fills the gap G facing the first groove 110. By filling the gap G with the resin layer 9, the bonding portion between the base wafer 20 and the cover wafer 30 can be protected. Additionally, the bonding strength between the base wafer 20 and the cover wafer 30 can be further improved, and the airtightness of the housing portion S can also be enhanced. Furthermore, this portion acts as an anchor, making it difficult for the resin layer 9 to peel off from the device wafer 100. The resin layer 9 can be formed, for example, by spin coating, spray coating, etc.

[0074] Here, by setting the first groove 110 to have a bottom, the device wafer 100 is not monolithized but is connected via the base wafer 20. Therefore, the device wafer 100 has sufficient rigidity to resist stress generated by the shrinkage of the resin layer 9 during curing, effectively suppressing warping and deflection of the device wafer 100 caused by said stress. Thus, by suppressing warping of the device wafer 100 caused by said stress, the subsequent monolithization process S16 can be performed with higher precision and smoother operation.

[0075] [Single-wafer process S16]

[0076] like Figure 14 As shown, a second groove 120 is formed at the boundary of adjacent monolithic regions Q, penetrating the device wafer 100, and the device wafer 100 is monolithized according to each monolithic region Q. Thus, multiple vibrating devices 1 are formed simultaneously. The method for forming the second groove 120 is not particularly limited, but in this embodiment, it is formed by cutting from the cover wafer 30 side using a cutting tool DB2. Therefore, the second groove 120 can be easily formed. In particular, by cutting from the cover wafer 30 side, it is possible to avoid the cutting tool DB2 cutting the cutting strip DT, ensuring that all monolithized vibrating devices 1 are held by the cutting strip DT. Therefore, it is possible to prevent the multiple vibrating devices 1 from becoming scattered.

[0077] Furthermore, the cutting tool DB2 is thinner than the cutting tool DB1, thus the width W2 of the second groove 120 is narrower than the width W1 of the first groove 110. That is, W2 < W1. Therefore, as Figure 14 As shown, the following vibration device 1 is obtained: after monolithization, resin layer 9 is also left on the side of each package 10, and the entire area of ​​the upper part from step 27 is covered by resin layer 9.

[0078] The manufacturing method of the vibration device 1 has been described above. As described above, the manufacturing method of such a vibration device 1 includes: a preparation step S11, preparing a base wafer 20, the base wafer 20 having an upper surface 20a as a first surface and a lower surface 20b as a second surface in a front-back relationship and including a plurality of monolithic regions Q; a mounting step S12, arranging a vibration element 4 on the upper surface 20a side of the base wafer 20 according to each monolithic region Q; and a bonding step S13, preparing a cover wafer 30 including a plurality of monolithic regions Q, bonding the cover wafer 30 to the upper surface 20a of the base wafer 20, thereby obtaining a device wafer with a housing portion S for housing the vibration element 4 formed according to each monolithic region Q. The device wafer 100 undergoes a following process: a groove forming step S14, in which a first groove 110 is formed at the boundary of adjacent monolithic regions Q of the device wafer 100, extending from the cover wafer 30 side to the side lower than the lower surface 20b of the junction between the base wafer 20 and the cover wafer 30; a resin layer forming step S15, in which resin material is disposed within the first groove 110; and a monolithic step S16, in which a second groove 120 is formed at the boundary of adjacent monolithic regions Q of the device wafer 100, penetrating the device wafer 100 and having a width narrower than the width W1 of the first groove 110. The device wafer 100 is monolithized according to each monolithic region Q to obtain a plurality of vibrating devices 1. According to this manufacturing method, a resin layer 9 can be formed simultaneously on multiple vibrating devices 1, thus reducing the manufacturing time of the vibrating devices. Therefore, the manufacturing of the vibrating devices 1 becomes easier.

[0079] Furthermore, as mentioned above, the first slot 110 has a bottom. This allows for the suppression of warping of the device wafer 100, enabling the monolithic assembly process S16 to be performed with higher precision and smoother operation.

[0080] Furthermore, as described above, in the resin layer formation process S15, the resin material is also deposited on the upper surface 30a of the cover wafer 30, i.e., the surface opposite to the base wafer 20. Therefore, since a larger area is covered by the resin layer 9, the mechanical strength of the vibrating device 1 can be improved.

[0081] Furthermore, as described above, in the bonding process S13 of bonding the cover wafer 30, the base wafer 20 and the cover wafer 30 are bonded via the metal layer 7. Additionally, the outer edge of the metal layer 7 is located closer to the inner edge of the monolithization region Q when viewed from above. This suppresses damage to the metal layer 7 during the formation of the first groove 110, effectively preventing a decrease in the bonding strength between the base wafer 20 and the cover wafer 30, a decrease in the airtightness of the housing S, and airtightness failure.

[0082] Furthermore, as described above, in the resin layer formation process S15, resin material is filled into the gap G between the base wafer 20 and the cover wafer 30, which is formed through the metal layer 7 and faces the first groove 110. This protects the junction between the base wafer 20 and the cover wafer 30. Additionally, it further improves the bonding strength between the base wafer 20 and the cover wafer 30 and enhances the airtightness of the housing portion S. Moreover, this portion acts as an anchor, making it less likely for the resin layer 9 to peel off from the device wafer 100.

[0083] Furthermore, as described above, the process of forming the first groove 110 is performed while the device wafer 100 is held from the lower surface 20b side by the dicing tape DT, which serves as a holding member. As a result, all the monolithized vibrating devices 1 are held on the dicing tape DT, thus preventing the vibrating devices 1 from becoming scattered.

[0084] Furthermore, as described above, the substrate chip 20 is a semiconductor substrate, and an oscillation circuit 6A is disposed in each monolithic region Q of the substrate chip 20. Therefore, the substrate chip 20 can be effectively utilized.

[0085] Furthermore, as described above, the cover wafer 30 is a semiconductor substrate, and it is electrically connected to the base wafer 20 by being bonded to the base wafer 20 in the bonding process S13 of bonding the cover wafer 30. Thus, for example, by grounding the base 2 during use, the package 10 can function as a shield, and the effects of electromagnetic noise can be reduced.

[0086] <Second Implementation Method>

[0087] Figure 15 This is a cross-sectional view showing the vibration device of the second embodiment. Figure 16 It is a process diagram showing the manufacturing process of a vibrating device. Figures 17 to 19 These are cross-sectional views used to illustrate the manufacturing method of the vibrating device.

[0088] This embodiment is the same as the first embodiment described above, except for the shape of the base 2 and the arrangement of the resin layer 9. In the following description, this embodiment will be described primarily for its differences from the previous embodiment, and descriptions of identical items will be omitted. Furthermore, in Figures 15 to 19 In this document, structures identical to those described in the above embodiments are labeled with the same reference numerals.

[0089] like Figure 15 As shown, in the vibration device 1 of this embodiment, no step 27 is formed on the side of the base 2, and the entire side area is covered by the resin layer 9. That is, the resin layer 9 is disposed on all areas of the outer surface of the package 10 except for the lower surface. According to this structure, compared with the first embodiment described above, the portion covered by the resin layer 9 is increased, and therefore the function of the resin layer 9 becomes more significant.

[0090] Next, the manufacturing method of the vibrating device 1 will be described. For example... Figure 16 As shown, the manufacturing process of the vibrating device 1 includes a preparation process S21, a mounting process S22, a joining process S23, a groove forming process S24, a resin layer forming process S25, and a monolithic process S26. Hereinafter, each of these processes S21 to S26 will be described in detail. The process up to the joining process S23 is the same as that up to the joining process S13 in the first embodiment described above. Therefore, the description will begin from the groove forming process S24.

[0091] [Trench Forming Process S24]

[0092] like Figure 17 As shown, the device wafer 100, held on the cutting strip DT, is cut from the cover wafer 30 side, and a first groove 110 is formed through the device wafer 100 at the boundary of adjacent monolithic regions Q. Thus, the device wafer 100 is monolithized according to each monolithic region Q, thereby obtaining multiple devices 1A. These devices 1A are vibrating devices 1 without the resin layer 9 formed.

[0093] Furthermore, the method for forming the first groove 110 is not particularly limited, but in this embodiment, it is formed by cutting from the cover wafer 30 side using a cutting tool DB1. This allows for easy formation of the first groove 110. By cutting from the cover wafer 30 side, the cutting tool DB1 avoids cutting the cutting tape DT, resulting in a monolithic device 1A held by the cutting tape DT. Therefore, it is possible to prevent the device 1A from becoming discrete.

[0094] [Resin layer formation process S25]

[0095] like Figure 18 As shown, a resin layer 9 is formed on the surface of each device 1A. Thus, the vibrating device 1 is obtained. In this embodiment, the resin layer 9 is formed on the upper surface 3a of each cover 3 and within the first groove 110. That is, the resin layer 9 is formed in a manner that covers the upper surface and sides of the package 10. Furthermore, the resin layer 9 is not particularly limited, and can be formed, for example, by spin coating, spraying, etc.

[0096] [Single-wafer process S26]

[0097] exist Figure 18 In the state shown, adjacent vibrating devices 1 are integrated with each other by the resin layer 9 formed within the first groove 110. Therefore, in this process, as Figure 19 As shown, a second groove 120 is formed at the boundary of the adjacent monolithic region Q to penetrate the device wafer 100 (resin layer 9) and thus monolithize the vibrating device 1.

[0098] There is no particular limitation on the method for forming the second groove 120, but in this embodiment, it is formed by cutting from the cover wafer 30 side using a cutting tool DB2. This allows the second groove 120 to be easily formed. By cutting from the cover wafer 30 side, the cutting tool DB2 can avoid cutting the cutting strip DT, ensuring that all the monolithically integrated vibrating devices 1 are held in place by the cutting strip DT.

[0099] Furthermore, the cutting tool DB2 is thinner than the cutting tool DB1, so the width W2 of the second groove 120 is narrower than the width W1 of the first groove 110. That is, W2 < W1. Therefore, after the resin layer 9 is cut off in this process, the resin layer 9 also remains on the side of each package 10, resulting in a vibrating device 1 in which the entire area of ​​the package 10, except for the lower surface, is covered by the resin layer 9.

[0100] As described above, in the manufacturing method of the vibration device 1 in this embodiment, the first groove 110 penetrates the device wafer 100. Thus, by having the first groove 110 penetrate the device wafer 100, for example, compared to the first embodiment described above, a wider area of ​​the package 10 can be covered by the resin layer 9, and therefore the function of the resin layer 9 becomes more significant.

[0101] This second implementation method can achieve the same effect as the first implementation method described above.

[0102] <Third Implementation Method>

[0103] Figure 20 This is a cross-sectional view showing the vibration device of the third embodiment.

[0104] This embodiment is the same as the first embodiment described above, except for the different method of joining the base 2 and the cover 3. In the following description, this embodiment will be described primarily for its differences from the previous embodiment, and descriptions of identical items will be omitted. Furthermore, in Figure 20 In this document, structures identical to those described in the above embodiments are labeled with the same reference numerals.

[0105] like Figure 20 As shown, in the vibration device 1 of this embodiment, the upper surface 2a of the base 2 and the lower surface 3b of the cover 3 are surface-activated bonded. Surface-activated bonding, for example, refers to a bonding method in which the upper surface 2a of the base 2 and the lower surface 3b of the cover 3 are activated by irradiation with an ion beam or plasma, allowing these surfaces to be directly bonded to each other without the aid of other components. According to this bonding method, the cover 3 and the base 2 can be bonded more firmly and tightly, improving the strength of the package 10 and effectively suppressing the hermeticity of the housing S. Furthermore, since no other components are involved, for example, compared to the first embodiment described above, the package 10 can be made thinner, i.e., the vibration device 1 can be miniaturized.

[0106] The manufacturing method of such a vibrating device 1 is the same as that of the first embodiment described above, except that surface activation bonding is performed in the bonding process S13. Furthermore, since surface activation bonding has already been described, the description of the manufacturing method of the vibrating device 1 is omitted in this embodiment.

[0107] As described above, in the manufacturing method of the vibration device 1 of this embodiment, the base wafer 20 and the cover wafer 30 are surface activated and bonded in the bonding step S13 of bonding the cover wafer 30. This allows for a more secure and tighter bond between the base wafer 20 and the cover wafer 30, improving the strength of the vibration device 1 and effectively suppressing airtightness failure of the housing S. Furthermore, since no other components are involved, the vibration device 1 can be made thinner, i.e., miniaturized, compared to the first embodiment described above.

[0108] This third embodiment can achieve the same effect as the first embodiment described above.

[0109] <Fourth Implementation>

[0110] Figure 21 This is a cross-sectional view showing the vibration device of the fourth embodiment.

[0111] This embodiment is the same as the first embodiment described above, except for the configuration of integrated circuit 6. In the following description, this embodiment will be described primarily for its differences from the previous embodiment, and descriptions of identical items will be omitted. Furthermore, in Figure 21 In this document, structures identical to those described in the above embodiments are labeled with the same reference numerals.

[0112] like Figure 21 As shown, in the vibration device 1 of this embodiment, the integrated circuit 6, which includes the oscillation circuit 6A, is disposed on the upper surface 2a side of the base 2 and housed in the housing section S. This structure protects the integrated circuit 6 from moisture and dust, thus improving the reliability of the vibration device 1. In this embodiment, the vibration element 4 is mounted on the integrated circuit 6, and the terminal layer 65 includes wiring 651, 652 electrically connected to the vibration element 4 via metal bumps 81, 82. Furthermore, external terminals 25 electrically connected to the integrated circuit 6 via through electrodes 210, 220 are disposed on the lower surface 2b side of the base 2.

[0113] As described above, in the vibration device 1 of this embodiment, the oscillation circuit 6A is disposed on the upper surface 2a side of the base 2. This protects the oscillation circuit 6A from moisture and dust, thereby improving the reliability of the vibration device 1.

[0114] This fourth embodiment can achieve the same effect as the first embodiment described above.

[0115] The manufacturing method of the vibration device of the present invention has been described above according to the illustrated embodiments. However, the present invention is not limited thereto, and the structure of each part can be replaced with any structure having the same function. Furthermore, other arbitrary structures can be added to the present invention. In addition, the various embodiments can be appropriately combined.

[0116] Furthermore, in the above embodiment, the resin layer 9 is disposed on the upper surface and side surface of the package 10, but the configuration of the resin layer 9 is not particularly limited. For example, the resin layer may be omitted from the upper surface of the package 10.

Claims

1. A method for manufacturing multiple vibrating devices, characterized in that, The manufacturing method of these multiple vibration devices includes the following steps: Prepare a substrate wafer having a first surface and a second surface with surfaces facing each other, and including a plurality of first monolithic regions, with a first boundary portion between adjacent first monolithic regions of the plurality of first monolithic regions; A vibration element is disposed on the first surface side of the base wafer according to each of the plurality of first monolithic regions; The cover wafer is bonded to the first surface of the base wafer via multiple metal layers. The cover wafer has multiple second monolithic regions corresponding to the multiple first monolithic regions. Each of the multiple second monolithic regions has a recess for receiving the vibrating element. A second boundary portion is provided between adjacent second monolithic regions of the multiple second monolithic regions. The first boundary portion is aligned with the second boundary portion. When viewed from above, each of the multiple metal layers surrounds the vibrating element. Gaps are formed between adjacent metal layers of the multiple metal layers and between the ends of the first boundary portion and the ends of the second boundary portion. A first groove is formed at the first boundary portion and the second boundary portion, the first groove completely penetrating the second boundary portion of the cover wafer and penetrating at least a portion of the first boundary portion of the base wafer; The resin material is disposed in the first groove in such a way that the gap and the first groove are filled with resin material; as well as A second groove, narrower than the width of the first groove, is formed along the first boundary portion and the second boundary portion to obtain the plurality of vibration devices.

2. The method for manufacturing a plurality of vibration devices according to claim 1, wherein, The first groove has a bottom.

3. The method for manufacturing a plurality of vibration devices according to claim 1, wherein, The first groove extends through the first boundary portion of the base wafer.

4. A method for manufacturing a plurality of vibration devices according to any one of claims 1 to 3, wherein, In the process of preparing the resin material, the resin material is also prepared on the top surface of the cover wafer opposite to the base wafer.

5. A method for manufacturing a plurality of vibration devices according to any one of claims 1 to 3, wherein, The outer edge of each of the plurality of metal layers is located inside the outer edge of each of the plurality of first monolithic regions when viewed from above.

6. The method for manufacturing a plurality of vibration devices according to claim 5, wherein, After the cover wafer is bonded to the base wafer, and before the first groove is formed, the gap is formed by the base wafer, the cover wafer, and adjacent metal layers of the plurality of metal layers.

7. A method for manufacturing a plurality of vibration devices according to any one of claims 1 to 3, wherein, In the process of bonding the cover wafer, the base wafer and the cover wafer are surface activated and bonded.

8. A method for manufacturing a plurality of vibration devices according to any one of claims 1 to 3, wherein, The first groove is formed while the retaining component holds the second surface of the base wafer.

9. A method for manufacturing a plurality of vibration devices according to any one of claims 1 to 3, wherein, The base chip is a semiconductor substrate. An oscillation circuit is configured in each of the plurality of first monolithic regions of the base wafer.

10. The method for manufacturing a plurality of vibration devices according to claim 9, wherein, The cover wafer is a semiconductor substrate that is electrically connected to the base wafer by being bonded to it during the bonding process.

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