JP5955024B2 - MEMS module and manufacturing method thereof - Google Patents

Description

  The present invention relates to a MEMS module having a plurality of MEMS elements and a manufacturing method thereof.

  In recent years, a MEMS package for sealing a MEMS element is known. For example, a MEMS package in which a MEMS assembly formed of a MEMS element having a movable part and a cap chip that seals at least the movable part of the MEMS element is fixed to a wiring board or a circuit board is known.

  In this MEMS package, the MEMS element and the circuit board, and the circuit board and the wiring board are each connected by wiring, and the circuit board, the wiring, and the MEMS assembly on the wiring board are sealed with a resin member. Further, at least the MEMS element side surface and the cap chip side surface of the MEMS assembly are formed by a wet etching surface.

JP 2008-91845 A

  However, it is difficult to cope with the thinning in the structure of the MEMS package. In particular, when realizing a MEMS module having a plurality of MEMS elements, it is difficult to cope with a reduction in thickness.

  This invention is made | formed in view of said point, and makes it a subject to provide the MEMS module which can be reduced in thickness, and its manufacturing method.

This MEMS modules are first substrate having a first wiring to the detection portion and the one surface to detect a predetermined physical quantity, and, before Symbol the detection portion and the one surface of the first substrate A first MEMS element having a second substrate, the second substrate having a second wiring provided on a surface opposite to the first substrate, the first MEMS element being stacked to cover the first wiring; A second MEMS element mounted on the second wiring opposite to the first substrate; and the second MEMS element on a surface of the second substrate opposite to the first substrate. A sealing substrate that forms a first sealing space that seals the second MEMS element, the second MEMS element via the second wiring and the first wiring. It is a requirement to be electrically connected to an external connection terminal formed in a region exposed from the sealing substrate.

  According to the disclosed technology, it is possible to provide a MEMS module capable of being thinned and a method for manufacturing the same.

It is a figure which illustrates the MEMS module which concerns on 1st Embodiment. It is a figure which illustrates a part of MEMS module which concerns on 1st Embodiment. FIG. 3 is a diagram (part 1) illustrating a manufacturing process of the MEMS module according to the first embodiment; FIG. 6 is a diagram (No. 2) for exemplifying the manufacturing process for the MEMS module according to the first embodiment; FIG. 6 is a diagram (No. 3) for exemplifying the manufacturing process for the MEMS module according to the first embodiment; FIG. 6 is a diagram (No. 4) for exemplifying the manufacturing process for the MEMS module according to the first embodiment; FIG. 6 is a diagram (No. 5) for exemplifying the manufacturing process for the MEMS module according to the first embodiment; It is a figure which illustrates the MEMS module which concerns on the modification 1 of 1st Embodiment. It is a figure which illustrates the MEMS module which concerns on the modification 2 of 1st Embodiment.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and the overlapping description may be abbreviate | omitted. Further, for convenience, hatching corresponding to a cross-sectional view may be given in a plan view or the like.

<First Embodiment>
[Structure of MEMS Module According to First Embodiment]
First, the structure of the MEMS module according to the first embodiment will be described. FIG. 1 is a diagram illustrating the MEMS module according to the first embodiment, in which (b) is a plan view and (a) is a cross-sectional view taken along line AA in (b). FIG. 2 is a diagram illustrating a part of FIG. 1A, where FIG. 2A is a perspective view of the second substrate 40, and FIG. 2B is a perspective view of the first substrate 30.

  Referring to FIGS. 1 and 2, the MEMS module 10 is roughly composed of a first MEMS element 20, a second MEMS element 60, a sealing substrate 70, a control integrated circuit 80, and a bonding wire 90. And have.

  The first MEMS element 20 is an element manufactured by MEMS (Micro Electro Mechanical Systems) technology, and is a sensor that detects mechanical quantities such as acceleration and angular velocity. In the present embodiment, the following description is given by taking as an example the case where the first MEMS element 20 is an acceleration sensor that detects acceleration, which is a mechanical quantity.

  The first MEMS element 20 includes a first substrate 30, a second substrate 40, and a third substrate 50. The first substrate 30 is a main part of the acceleration sensor, and includes a fixed part 31, a movable part 32, a support part 33, and a first wiring 34. The fixed part 31 is a non-movable part. The planar shape of the fixing portion 31 is formed in a frame shape having an opening 30x penetrating the first substrate 30 in the vicinity of the center portion.

  The movable portion 32 is disposed in the opening 30x and is supported by the fixed portion 31 in a movable state by a flexible support portion 33 formed at four outer edge portions. Each support portion 33 is formed with, for example, a piezoresistive element (not shown). When acceleration is applied to the first MEMS element 20 from the outside, the movable portion 32 is displaced with respect to the fixed portion 31, and at this time, each support portion 33 is deformed (distorted). Thereby, since the resistance value of each piezoresistive element (not shown) formed in each support part 33 changes, acceleration can be detected by monitoring the change in resistance value.

  Thus, the movable part 32 and the support part 33 (including the piezoresistive element) function as a detection part that detects acceleration. Hereinafter, the movable part 32 and the support part 33 (including the piezoresistive element) may be simply referred to as a detection part.

A first wiring 34 is formed in the fixing portion 31. The first wiring 34 is a low resistance region formed by diffusing impurities such as boron and phosphorus in the first substrate 30. The first wiring 34 includes pads 34 a _{1 to} 34 a ₆ and a wiring pattern 34 b formed in a region near the surface of the fixing portion 31. Thus, the first wiring 34 is formed in a region near the surface of the fixing portion 31 and does not protrude from the surface of the fixing portion 31.

Pads 34a ₁ and 34a ₂ via a wiring pattern 34b corresponding to each, and is electrically connected to the pads 34a ₃ and 34a _4. Pads 34a ₃ and 34a ₄ are connected later via interconnects 42c and electrically corresponding to each. The pads 34a ₅ and 34a ₆ are electrically connected to a piezoresistive element (not shown) or the like by a wiring pattern (not shown) and to a via wiring 42c described later corresponding to each. . For convenience, only representative pads are shown, but there are actually a large number of pads.

  As a material for the fixed portion 31, the movable portion 32, and the support portion 33, for example, silicon can be used. The thickness of each of the fixed part 31, the movable part 32, and the support part 33 can be, for example, about several tens to several hundreds of micrometers. In the present embodiment, the movable portion 32 is formed thinner than the fixed portion 31 in order to make the movable portion 32 easy to move. That is, the thicknesses of the fixed portion 31, the movable portion 32, and the support portion 33 may not be the same.

  The second substrate 40 is laminated on the upper surface (one surface) of the first substrate 30 so as to cover the detection unit. That is, the lower surface of the second substrate 40 is bonded to the upper surface of the first substrate 30. The second substrate 40 includes a substrate body 41, second wiring 42, and external connection terminals 43.

  The second substrate 40 forms a sealing space (hereinafter referred to as a first sealing space) for sealing the second MEMS element 60 between the second substrate 40 and the sealing substrate 70. A first via hole 40 x penetrating the substrate body 41 of the second substrate 40 is formed in a region forming the first sealing space of the second substrate 40. In a region exposed from the sealing substrate 70 of the second substrate 40, a second via hole 40y penetrating the substrate body 41 of the second substrate 40 is formed.

The second wiring 42 includes pads 42a ₁ and 42a ₂ formed on the upper surface of the substrate body 41, a wiring pattern 42b formed on the upper surface of the substrate body 41, and the first via hole 40x and the second via hole 40y. Via wiring 42c formed on the inner wall of the. However, the via wiring 42c may fill the first via hole 40x and the second via hole 40y. Incidentally, the pad 42a ₁ and 42a ₂ are formed in the first sealing space.

The external connection terminals 43 ₁ to 434 ₄ are formed on the upper surface of the substrate body 41. The external connection terminal referred to here is a terminal that is disposed outside the sealing substrate 70 and is used when the first MEMS element 20 and the second MEMS element 60 are electrically connected to the control integrated circuit 80 and the like. Means. Note that the external connection terminals 43 ₁ to 43 ₄ may be referred to as the external connection terminals 43 when the distinction is not particularly required.

  The external connection terminal 43 is not included in the second wiring 42 for convenience, but is actually formed integrally with the second wiring 42. The second wiring 42 and the external connection terminal 43 can be formed from, for example, copper (Cu). The second wiring 42 and the external connection terminal 43 may be formed by stacking a plurality of metals.

A part of the second wiring 42 is electrically connected to a part of the first wiring 34 through the first via hole 40x. A part of the first wiring 34 via the second via holes 40y, is another part electrically connected to the second wiring 42, further electrically connected to an external connection terminal 43 ₁ and 43 ₂ Has been.

More specifically, the pads 42a ₁ and 42a ₂ via a wiring pattern 42b and the via wiring 42c for each, are electrically connected to the pads 34a ₁ and 34a _2. The pads 34a ₁ and 34a ₂ are electrically connected to the pads 34a ₃ and 34a ₄ through the wiring pattern 34b, further through a via wiring 42c and the wiring patterns 42b corresponding to the pads 34a ₃ and 34a _4, external and it is electrically connected to the connection terminals 43 ₁ and 43 _2.

As described below, the second MEMS element 60 is electrically connected to pads 42a ₁ and 42a _2. In other words, the second MEMS element 60 via the second wiring 42 and the first wiring 34 is connected to the external connection terminals 43 ₁ and 43 ₂ and electrically.

The external connection terminals 43 ₃ and 43 ₄ are electrically connected to the pads 34a ₅ and 34a ₆ via the wiring patterns 42b and via wirings 42c corresponding to the external connection terminals 43 ₃ and 43 ₄ respectively. In other words, the external connection terminal 43 ₃ and 43 ₄ through the second wiring 42 and the first wiring 34, the piezoresistive element (not shown) or the like and are electrically connected.

  The third substrate 50 is laminated on the lower surface (the other surface) of the first substrate 30 so as to cover the detection unit. That is, the upper surface of the third substrate 50 is bonded to the lower surface of the first substrate 30. The third substrate 50 is a flat substrate on which no wiring, via holes or the like are formed, and the upper surface and the lower surface are flat surfaces.

  The upper side of the opening 30 x of the first substrate 30 is closed by the lower surface of the second substrate 40, and the lower side of the opening 30 x is closed by the upper surface of the third substrate 50. That is, the detection unit including the movable unit 32 is configured such that the inner wall surface of the opening 30x, the surface of the second substrate 40 and the third substrate 50 facing each other through the first substrate 30 (the lower surface of the second substrate 40). And the upper surface of the third substrate 50) are hermetically sealed in a space (hereinafter referred to as a second sealing space). The second sealed space can be a vacuum, for example. The second sealed space may be filled with argon gas, nitrogen gas, or the like.

  When the first substrate 30 has silicon as a main component and the second substrate 40 and the third substrate 50 have glass (for example, borosilicate glass) as a main component, the first substrate 30 and the second substrate 30 The substrate 40 and the third substrate 50 can be joined by anodic bonding. When materials other than glass (silicon, ceramic, etc.) are used as the second substrate 40 and the third substrate 50, for example, an adhesive is formed in a frame shape on the outer edge portions of both surfaces of the first substrate 30, for example. Alternatively, the second substrate 40 and the third substrate 50 may be bonded via an adhesive. Note that the adhesive herein includes an organic adhesive, an inorganic adhesive, a conductive paste, solder, and the like.

  The second MEMS element 60 is an element manufactured by MEMS (Micro Electro Mechanical Systems) technology, and is, for example, a gyro sensor (angular velocity sensor). The gyro sensor is, for example, a sensor that has a disk-like movable part supported in a movable state via a plurality of support parts in an annular fixed part, and detects angular velocity from the displacement of the disk-like movable part. is there. In the present embodiment, the following description is given by taking the case where the second MEMS element 60 is a gyro sensor as an example.

The second MEMS element 60 is mounted on the upper surface (the surface opposite to the first substrate) of the second substrate 40 of the first MEMS element 20. The second MEMS element 60 has, for example, two electrodes (not shown), and a bump 61 is formed on each electrode. Each bump 61 is, for example, via a solder (not shown) or the like, and is electrically connected to the pads 42a ₁ and 42a ₂ of the second substrate 40.

The sealing substrate 70 is a substrate in which a concave portion 70x and a cutout portion 70y are provided in a member having a substantially rectangular planar shape, and can be formed from, for example, a material mainly composed of silicon. The sealing substrate 70 is laminated on the upper surface (the surface opposite to the first substrate) of the second substrate 40 of the first MEMS element 20. Recess 70x is provided in order to accommodate the second MEMS element 60, notches 70y is provided in order to expose the external connection terminals ₄₃ 1 to 43 ₄ from the sealing substrate 70.

  The sealing substrate 70 forms a first sealing space for sealing the second MEMS element 60 between the inner wall surface of the recess 70 x and the second substrate 40. That is, the second MEMS element 60 is hermetically sealed by the sealing substrate 70 and the second substrate 40. The first sealed space can be a vacuum, for example. The first sealed space may be filled with argon gas, nitrogen gas, or the like.

  When the sealing substrate 70 has silicon as a main component and the second substrate 40 has glass as a main component, the sealing substrate 70 and the second substrate 40 can be bonded by anodic bonding. Further, even when the sealing substrate 70 is mainly composed of glass and the second substrate 40 is mainly composed of silicon, the sealing substrate 70 and the second substrate 40 can be bonded by anodic bonding. When the sealing substrate 70 and the second substrate 40 are a combination of other materials, for example, an adhesive is formed around the recess 70x on the lower surface of the sealing substrate 70, and the adhesive is interposed therebetween. And can be bonded to the second substrate 40.

The structure including the first MEMS element 20, the second MEMS element 60, and the sealing substrate 70 is mounted on the control integrated circuit 80 via an adhesive (not shown) or the like. The control integrated circuit 80 includes a substrate body 81 and a plurality of pads 82. A semiconductor integrated circuit (not shown) is formed on the substrate body 81. A semiconductor integrated circuit (not shown) formed on the substrate body 81 has functions such as CPU, ROM, RAM, and signal processing, for example. Each pad 82, each via a bonding wire 90 and is connected to the outer connection terminals ₄₃ 1 to 43 ₄ electrically.

[Method for Manufacturing MEMS Module According to First Embodiment]
Next, a method for manufacturing the MEMS module according to the first embodiment will be described. 3 to 7 are diagrams illustrating the manufacturing process of the MEMS module according to the first embodiment. In each figure, C indicates a cutting position when finally producing a plurality of MEMS modules 10 by dividing into pieces. That is, each region surrounded by the cutting position C is finally separated into a plurality of MEMS modules 10. Actually, a scribe region (not shown) having a predetermined width exists, and a substantially central portion of the scribe region (not shown) is the cutting position C.

  Silicon, glass, or the like can be used for each of the first substrate 30, the second substrate 40, the third substrate 50, and the sealing substrate 70. Here, silicon is used for the first substrate 30 and the sealing substrate 70, The following description will be given by taking the case where glass is used for the second substrate 40 and the third substrate 50 as an example.

  First, in the step shown in FIG. 3 ((b) is a plan view, (a) is a cross-sectional view taken along line BB in (b)), for example, 6 inches (about 150 mm), 8 inches (about 200 mm), 12 A glass wafer 400 such as an inch (about 300 mm) is prepared. Then, a first via hole 40x and a second via hole 40y are formed in each region surrounded by the cutting position C of the glass wafer 400 (a region finally formed into each second substrate 40). To do. As a material of the glass wafer 400, for example, borosilicate glass or the like can be used.

  The thickness of the glass wafer 400 is, for example, 0.625 mm (in the case of 6 inches), 0.725 mm (in the case of 8 inches), 0.775 mm (in the case of 12 inches), or the like. Can be The first via hole 40x and the second via hole 40y form, for example, a resist layer that opens a position where the first via hole 40x and the second via hole 40y are formed on one surface of the glass wafer 400. And it can form by performing a blast process to the glass wafer 400 by using a resist layer as a mask. Instead of the blast treatment, the first via hole 40x and the second via hole 40y may be formed by laser light irradiation, dry etching, wet etching, or the like. Glass wafer 400 is a typical example of the second wafer according to the present invention.

  Next, in the process shown in FIG. 4 ((b) is a plan view, (a) is a cross-sectional view taken along the line DD in (b)), for example, 6 inches (about 150 mm), 8 inches (about 200 mm), A silicon wafer 300 of 12 inches (about 300 mm) or the like is prepared. Then, each of the regions surrounded by the cutting position C of the silicon wafer 300 (regions that are finally separated into individual first substrates 30) are each formed with an opening 30x to form a fixed portion 31 and a movable portion. 32 and the support part 33 are formed.

  The thickness of the silicon wafer 300 is, for example, 0.625 mm (in the case of 6 inches), 0.725 mm (in the case of 8 inches), 0.775 mm (in the case of 12 inches), or the like. Can be

  In order to form the fixed part 31, the movable part 32, and the support part 33, for example, the area where the fixed part 31, the movable part 32, and the support part 33 are formed is covered on one surface and the other surface of the silicon wafer 300. A resist layer is formed. Then, using the resist layer as a mask, the silicon wafer 300 is dry etched or wet etched to form the opening 30x. Further, after removing the resist layer, the portion that becomes the movable portion 32 is made thinner than the fixed portion 31. The silicon wafer 300 is a typical example of the first wafer according to the present invention.

Next, in the step shown in FIG. 5 ((b) is a plan view, (a) is a cross-sectional view taken along the line EE of (b)), each region (final) surrounded by the cutting position C of the silicon wafer 300 is shown. Thus, first wirings 34 are formed in the respective regions) that are separated into individual pieces to become the first substrates 30. As shown in FIG. 2B, the first wiring 34 in each region is formed so as to include pads 34 a _{1 to} 34 a ₆ and a wiring pattern 34 b formed in a region near the surface of the fixing portion 31.

  The first wiring 34 can be formed by diffusing impurities such as boron and phosphorus into a predetermined region of the silicon wafer 300 to reduce the resistance of the predetermined region. The first wiring 34 may be formed by ion-implanting impurities such as boron and phosphorus into a predetermined region of the silicon wafer 300 to reduce the resistance of the predetermined region. A piezoresistive element (not shown) formed in each support portion 33 for detecting acceleration can be formed simultaneously with the first wiring 34 by diffusion or ion implantation.

  Next, in the step shown in FIG. 6A, for example, a glass wafer 500 having the same shape as the glass wafer 400 is prepared (the thickness of the glass wafer 500 may not be the same as that of the glass wafer 400). Then, by aligning the positions of the respective cutting positions C, the glass wafer 400 is laminated on one surface of the silicon wafer 300 so as to cover the detection portion, and the glass wafer 500 is covered on the other surface of the silicon wafer 300. Laminate as follows. Then, the glass wafer 400 is bonded to one surface of the silicon wafer 300 and the glass wafer 500 is bonded to the other surface by anodic bonding or the like.

  The first wiring 34 is formed in a region near the surface of the silicon wafer 300 and does not protrude from the surface of the silicon wafer 300. Therefore, the surface of the silicon wafer 300 on which the first wiring 34 is formed can be anodically bonded to the glass wafer 400.

  In the case of performing anodic bonding, specifically, the glass wafer 400 and the glass wafer 500 are brought into contact with each other above and below the silicon wafer 300 in a high temperature environment of about 250 ° C. to 400 ° C., for example. Then, a high voltage of about 500 to 1000 V, for example, is applied from a DC power supply so that the silicon wafer 300 has a high potential with respect to the glass wafer 400 and the glass wafer 500.

Thus, sodium oxide contained in the glass wafer 400 and the glass wafer 500 _(Na 2 O) is ionized to Na ⁺ and ^{O 2-} and, Na ⁺ glass wafer 400 and the glass wafer 500 middle of DC power - on the side Moving. O ²⁻ moves through the glass wafer 400 and the glass wafer 500 to the silicon wafer 300 side. On the other hand, silicon (Si) contained in the silicon wafer 300 becomes positively charged Si ⁴⁺ and moves in the silicon wafer 300 toward the glass wafer 400 and the glass wafer 500.

Thereby, electrostatic attracting force is generated and Si ⁴⁺ having a positive charge on the silicon wafer 300 and O ^{2 −} having a negative charge on the glass wafer 400 and the glass wafer 500 are converted into the silicon wafer 300, the glass wafer 400 and the glass wafer. Chemical bonds at each interface with 500. As a result, the glass wafer 400 and the glass wafer 500 are bonded to the top and bottom of the silicon wafer 300, respectively. A thin film (not shown) of silicon dioxide (SiO ₂ ) is formed at each interface between the silicon wafer 300, the glass wafer 400, and the glass wafer 500.

  In addition, for example, an adhesive is formed in a frame shape on each outer edge portion (a portion in the vicinity of the cutting position C) surrounded by the cutting position C on both surfaces of the silicon wafer 300, and the glass wafer 400 and the The glass wafer 500 may be bonded. Glass wafer 500 is a typical example of the fourth wafer according to the present invention.

Next, in the process shown in FIG. 6B, the first region is formed in each region (region finally divided into the second substrate 40) surrounded by the cutting position C of the glass wafer 400. A second wiring 42 and an external connection terminal 43 that are electrically connected to the wiring 34 are formed. As shown in FIG. 2A, the second wiring 42 in each region includes the pads 42a _{1 to} 42a ₆ and the wiring pattern 42b formed on the glass wafer 400, the first via hole 40x and the second wiring 42b. It is formed so as to include a via wiring 42c formed on the inner wall of the via hole 40y. The external connection terminal 43 is formed so as to include the external connection terminals 43 ₁ to 43 ₄ . The via wiring 42c may fill the first via hole 40x and the second via hole 40y.

  The second wiring 42 and the external connection terminal 43 can be formed by various wiring forming methods such as a semi-additive method and a subtractive method. As a material of the second wiring 42 and the external connection terminal 43, for example, copper (Cu) or the like can be used. The second wiring 42 and the external connection terminal 43 may be formed by stacking a plurality of metals. In each region surrounded by the cutting position C of the structure shown in FIG. 6B, a portion to be the first MEMS element 20 is formed.

Next, in the step shown in FIG. 6C, for example, a second MEMS element 60 having two electrodes (not shown) and having bumps 61 formed on each electrode is prepared. Then, a second MEMS is formed on the surface of each region surrounded by the cutting position C of the glass wafer 400 (a region finally divided into each second substrate 40) opposite to the silicon wafer 300. The element 60 is mounted. Specifically, the second bump 61 of the MEMS device 60 of each example, the solder via a (not shown) or the like, of each region surrounded by the cutting position C of the glass wafer 400 pads 42a ₁ and 42a ₂ is electrically connected.

  Next, in the step shown in FIG. 7 ((b) is a plan view, (a) is a cross-sectional view taken along line FF in (b)), for example, a silicon wafer 700 having the same shape as the silicon wafer 300 is prepared ( The thickness of the silicon wafer 700 may not be the same as that of the silicon wafer 300). Then, a recess 70x and a notch 70y are respectively formed in each region (region finally divided into individual sealing substrates 70) surrounded by the cutting position C of the silicon wafer 700. The recess 70x and the notch 70y can be formed by, for example, dry etching or wet etching.

  Thereafter, the positions of the respective cutting positions C are aligned, and the silicon wafer 700 is laminated on one surface of the glass wafer 400 so as to seal the second MEMS element 60. Then, the silicon wafer 700 is bonded to one surface of the glass wafer 400 by anodic bonding or the like. Instead of anodic bonding, for example, an adhesive is formed in a frame shape around each recess 70x in each region surrounded by the cutting position C on the lower surface of the silicon wafer 700, and bonded to the glass wafer 400 via the adhesive. May be.

In this step, a first sealing space for sealing each second MEMS element 60 is formed between each recess 70x of the silicon wafer 700 and the glass wafer 400, and each second MEMS element 60 is Each of the first sealing spaces is hermetically sealed. Further, it exposed from the cutout portion 70y external connection terminals ₄₃ 1 to 43 ₄ and the via wirings 42c of each region surrounded by the cutting position C of the glass wafer 400. That is, the second MEMS element 60 is electrically connected to the external connection terminal 43 disposed outside the portion to be the sealing substrate 70 via the second wiring 42 and the first wiring 34. Silicon wafer 700 is a typical example of the third wafer according to the present invention.

After the step shown in FIG. 7, the structure shown in FIG. 7 is cut into pieces by cutting at a cutting position C using a dicing blade or the like. As a result, a plurality of structures including the first MEMS element 20, the second MEMS element 60, and the sealing substrate 70 are manufactured. Thereafter, each of the separated structures is mounted on the control integrated circuit 80 via an adhesive (not shown) or the like, and each pad 82 of the control integrated circuit 80 is externally connected via a bonding wire 90. electrically connected to the connecting terminals ₄₃ 1 to 43 _4. As a result, a plurality of MEMS modules 10 shown in FIGS. 1 and 2 are completed.

  As described above, in the MEMS module 10 according to the first embodiment, the second MEMS element 60 is stacked on the second substrate 40 constituting the first MEMS element 20 and sealed with the second substrate 40. The second MEMS element 60 is sealed with the stop substrate 70. Since the second substrate 40 is a rigid substrate formed of glass, silicon, or the like, the second MEMS element 60 can be easily stacked. In addition, since the second substrate 40 is used as a part of the member for sealing the second MEMS element 60, a component different from the component of the first MEMS element 20 is prepared, and the sealing substrate 70 As compared with the case where the second MEMS element 60 is sealed between, the MEMS module 10 can be thinned.

The second MEMS element 60 via the second wiring 42 and the first wiring 34, is arranged connected external connection terminals 43 ₁ and 43 ₂ and the electrical outside of the sealing substrate 70 Yes. Thus, by passing through the first wiring 34 of the first MEMS element 20, the second MEMS element 60 disposed in the hermetically sealed space and the outside of the hermetically sealed space are disposed. It has been and external connection terminals 43 ₁ and 43 ₂ can be easily electrically connected.

  Moreover, since the 1st MEMS element 20 and the sealing substrate 70 can be manufactured at a wafer level, and the 2nd MEMS element 60 can be sealed at a wafer level, the manufacturing process of the MEMS module 10 can be made efficient.

<Variation 1 of the first embodiment>
In the first modification of the first embodiment, an example in which external connection terminals are provided at positions different from those in the first embodiment will be described. In the first modification of the first embodiment, the description of the same components as those of the already described embodiment is omitted.

  8A and 8B are diagrams illustrating a MEMS module according to Modification 1 of the first embodiment, where FIG. 8B is a plan view and FIG. 8A is a cross-sectional view taken along line GG in FIG. . Referring to FIG. 8, the MEMS module 10 </ b> A is different in that the first MEMS element 20 and the sealing substrate 70 are replaced with the first MEMS element 20 </ b> A and the sealing substrate 70 </ b> A, respectively. 2).

  The first MEMS element 20A includes a first substrate 30A, a second substrate 40A, and a third substrate 50A. The first substrate 30A is different from the first substrate 30 (see FIGS. 1 and 2) in that the first wiring 34 is replaced with the first wiring 34A and the third via hole 30y is added. Is different. The first wiring 34 </ b> A is filled in the third via hole 30 y that penetrates the fixing portion 31. As a material of the first wiring 34A, for example, copper (Cu) or the like can be used.

  The second substrate 40A is the second substrate 40 (FIGS. 1 and 2) in that the second via hole 40y, the via wiring 42c formed on the inner wall of the second via hole 40y, and the external connection terminal 43 are removed. Different from reference).

  The third substrate 50A is different from the third substrate 50 (see FIGS. 1 and 2) in that a substrate body 51, a via wiring 52, an external connection terminal 53, and a fourth via hole 50x are added. The substrate body 51 is formed with a fourth via hole 50x penetrating the substrate body 51, and a via wiring 52 is formed on the inner wall of the fourth via hole 50x. The via wiring 52 is electrically connected to the external connection terminal 53 via a wiring pattern (not shown).

A plurality of external connection terminals 53 are formed on the lower surface of the third substrate 50A (the surface opposite to the first substrate 30A). The external connection terminals 53, which corresponds to the external connection terminals ₄₃ 1 to 43 ₄ of the MEMS module 10 functions similarly to the external connection terminals ₄₃ 1 to 43 _4. Each external connection terminal 53 is electrically connected to each pad 82 of the control integrated circuit 80 through bumps 95 such as solder. As materials of the via wiring 52 and the external connection terminal 53, for example, copper (Cu) or the like can be used.

  In the first substrate 30A, the second substrate 40A, and the third substrate 50A, one end of the first wiring 34A is electrically connected to the via wiring 42c formed on the inner wall of the first via hole 40x. Yes. The other end of the first wiring 34A is electrically connected to the external connection terminal 53 via a via wiring 52 formed on the inner wall of the fourth via hole 50x. That is, the second MEMS element 60 is electrically connected to the external connection terminal 53 via the second wiring 42, the first wiring 34 </ b> A, and the via wiring 52.

  The sealing substrate 70A is different from the sealing substrate 70 (see FIGS. 1 and 2) in that the notch 70y is not formed. The reason why the notch 70y is not formed is that the external connection terminal 53 is formed on the lower surface of the third substrate 50A.

  In order to manufacture the MEMS module 10A, the steps of the first embodiment may be changed as follows. First, in the process shown in FIG. 3, a glass wafer 400 is prepared, and first via holes 40 x are formed in each region surrounded by the cutting position C of the glass wafer 400. However, the second via hole 40y is not formed.

  Next, in the process shown in FIG. 4, a silicon wafer 300 is prepared, and an opening 30 x is formed in each region surrounded by the cutting position C of the silicon wafer 300 to fix the fixed portion 31, the movable portion 32, and The support part 33 is formed. A third via hole 30y is formed in each region surrounded by the cutting position C of the silicon wafer 300.

  Next, in the process shown in FIG. 5, first wirings 34 </ b> A filling the third via holes 30 y are formed in the respective regions surrounded by the cutting position C of the silicon wafer 300. That is, the first wiring 34 </ b> A that penetrates the silicon wafer 300 is formed in each region surrounded by the cutting position C of the silicon wafer 300.

  Next, in the step shown in FIG. 6A, for example, a glass wafer 500 having the same shape as the glass wafer 400 is prepared, and the fourth via holes 50x are respectively formed in the respective regions surrounded by the cutting position C of the glass wafer 500. Form. Then, by aligning the positions of the respective cutting positions C, the glass wafer 400 is laminated on one surface of the silicon wafer 300 so as to cover the detection portion, and the glass wafer 500 is covered on the other surface of the silicon wafer 300. Laminate as follows. Then, the glass wafer 400 is bonded to one surface of the silicon wafer 300 and the glass wafer 500 is bonded to the other surface by anodic bonding or the like.

Next, in the step shown in FIG. 6B, the second wiring 42 electrically connected to the first wiring 34A is formed in each region surrounded by the cutting position C of the glass wafer 400. However, the external connection terminal 43 is not formed. Second wiring 42 in each region is formed to include pads 42a ₁ and 42a ₂ are formed on the glass wafer 400, the wiring pattern 42b, and a via wiring 42c formed on the inner wall of the first via hole 40x . The via wiring 42c may be filled with the first via hole 40x.

  In addition, a via wiring 52 electrically connected to the first wiring 34A is formed in the fourth via hole 50x in each region surrounded by the cutting position C of the glass wafer 500. That is, the via wiring 52 penetrating the glass wafer 500 is formed in each region surrounded by the cutting position C of the glass wafer 500. Further, external connection terminals 53 are formed on the surface of each region surrounded by the cutting position C of the glass wafer 500 on the side opposite to the silicon wafer 300. In each region surrounded by the cutting position C of the structure shown in FIG. 6B, a portion to be the first MEMS element 20A is formed.

  Next, in the step shown in FIG. 6C, the second MEMS element 60 is prepared, and the second surface of each region surrounded by the cutting position C of the glass wafer 400 is formed on the surface opposite to the silicon wafer 300. The MEMS element 60 is mounted. As a result, the second MEMS element 60 is electrically connected to the external connection terminal 53 via the second wiring 42, the first wiring 34 </ b> A, and the via 52.

  Next, in the process shown in FIG. 7, a silicon wafer 700 having the same shape as the silicon wafer 300 is prepared, and a recess 70 x is formed in each region surrounded by the cutting position C of the silicon wafer 700. However, the notch 70y is not formed. Thereafter, the positions of the respective cutting positions C are aligned, and the silicon wafer 700 is laminated on one surface of the glass wafer 400 so as to seal the second MEMS element 60. Then, the silicon wafer 700 is bonded to one surface of the glass wafer 400 by anodic bonding or the like. Instead of anodic bonding, for example, an adhesive is formed in a frame shape around each recess 70x in each region surrounded by the cutting position C on the lower surface of the silicon wafer 700, and bonded to the glass wafer 400 via the adhesive. May be.

  After the step shown in FIG. 7, the structure shown in FIG. 7 is cut into pieces by cutting at a cutting position C using a dicing blade or the like. Thereby, a plurality of structures including the first MEMS element 20A, the second MEMS element 60, and the sealing substrate 70A are manufactured. Thereafter, each separated structure is mounted on the control integrated circuit 80 via an adhesive (not shown) or the like, and each pad 82 of the control integrated circuit 80 is connected via a bump 95 such as solder. Are electrically connected to the external connection terminal 53. Thereby, a plurality of MEMS modules 10A shown in FIG. 8 are completed.

  As described above, the external connection terminal can be provided at an arbitrary position outside the sealing substrate as long as it can be used to electrically connect the first MEMS element, the second MEMS element, and the control integrated circuit. Good. Further, the first wiring may be formed in a region near the surface of the fixed portion, or may be formed so as to penetrate the fixed portion.

<Modification 2 of the first embodiment>
In the second modification of the first embodiment, an example in which a recess is provided in each of the second substrate and the third substrate will be described. In the second modification of the first embodiment, the description of the same components as those of the already described embodiment is omitted.

  FIGS. 9A and 9B are diagrams illustrating a MEMS module according to Modification 2 of the first embodiment, where FIG. 9B is a plan view and FIG. 9A is a cross-sectional view taken along line HH in FIG. . Referring to FIG. 9, the MEMS module 10B is different from the MEMS module 10 (see FIGS. 1 and 2) in that the first MEMS element 20 is replaced with the first MEMS element 20B. The first MEMS element 20B includes a first substrate 30B, a second substrate 40B, and a third substrate 50B.

  In the first substrate 30 of the MEMS module 10, the movable portion 32 is formed thinner than the fixed portion 31. That is, by increasing the thickness of the fixed portion 31, a gap between the movable portion 32 and the second substrate 40 and the third substrate 50 is secured, and the movable portion 32 can be operated.

  On the other hand, in the first substrate 30B of the MEMS module 10B, the fixed portion 31B and the movable portion 32 have the same thickness. In order to enable the operation of the movable part 32, the movable part 31 and the support part 33 on the side facing each other through the second substrate 40B and the first substrate 30B of the third substrate 50B overlap. Recesses 40z and 50z are respectively formed at the positions.

  As described above, the fixed portion 31B and the movable portion 32 have the same thickness, and the concave portions 40z and 50z are formed in the second substrate 40B and the third substrate 50B, respectively, to secure a space that enables the movable portion 32 to operate. May be. In this case, in addition to the effect of the first embodiment, the MEMS module 10B can be made thinner than the MEMS module 10.

  The preferred embodiment and its modification have been described in detail above, but the present invention is not limited to the above-described embodiment and its modification, and the above-described implementation is performed without departing from the scope described in the claims. Various modifications and substitutions can be added to the embodiment and its modifications.

  For example, the MEMS element that can be mounted on the MEMS module according to the present invention may be other than an acceleration sensor or a gyro sensor.

10, 10A, 10B MEMS module 20, 20A, 20B First MEMS element 30, 30A, 30B First substrate 30x Opening 30y Third via hole 31, 31B Fixed portion 32 Movable portion 33 Support portion 34, 34A First Wiring 34a _{1 to} 34a ₆ , 42a ₁ , 42a ₂ , 82 pad 34b, 42b wiring pattern 40, 40A, 40B second substrate 40x first via hole 40y second via hole 40z, 50z, 70x recess 41 substrate body 42 second wiring 42c, 52 via wiring 43 and 43 ₁ to 43 _4, 53 external connection terminals 50, 50A, 50B third substrate 50x fourth via holes 51, 81 substrate body 60 second MEMS element 61,95 bumps 70, 70A Sealing substrate 70y Notch 80 Control integrated circuit 0 bonding wires 300 and 700 a silicon wafer 400, 500 glass wafer C cutting position

Claims (13)

A first substrate having a first wiring to the detection portion and the one surface to detect a predetermined physical quantity, as well as, covering the pre-Symbol the detection portion and the first wiring on one surface of a first substrate A first MEMS element having a second substrate provided with a second wiring on a surface opposite to the first substrate,
A second MEMS element mounted on the second wiring on the opposite side of the second substrate from the first substrate;
A sealing substrate that forms a first sealing space for sealing the second MEMS element on a surface of the second substrate opposite to the first substrate;
The second MEMS element is electrically connected to an external connection terminal formed in a region exposed from the sealing substrate of the second substrate via the second wiring and the first wiring. MEMS module. A first via hole penetrating the second substrate is formed in a region of the second substrate forming the first sealing space;
The MEMS module according to claim 1, wherein the second wiring is electrically connected to the first wiring via the first via hole. A second via hole penetrating the second substrate is formed in a region of the second substrate exposed from the sealing substrate;
The MEMS module according to claim 2, wherein the first wiring is electrically connected to the external connection terminal through the second via hole.   The MEMS module according to claim 3, wherein a cutout portion is formed in the sealing substrate, and the external connection terminal is formed in a region exposed from the cutout portion of the second substrate. The first MEMS element includes a third substrate laminated on the other surface of the first substrate so as to cover the detection unit,
The detector is supported in a movable state in an opening that penetrates the first substrate,
The detection unit is sealed in a second sealing space formed by an inner wall surface of the opening and a surface of the second substrate and the third substrate facing each other through the first substrate. The MEMS module according to any one of claims 1 to 4, wherein: A first substrate provided with the sensing portion and the first wiring for detecting a predetermined physical quantity, are stacked before SL to cover the sensing portion and said first wiring on one surface of the first substrate, the A second substrate having a second wiring on a surface opposite to the first substrate, and a third substrate laminated on the other surface of the first substrate so as to cover the detection unit, A first MEMS device having:
A second MEMS element mounted on the second wiring on the opposite side of the second substrate from the first substrate;
A sealing substrate that forms a first sealing space for sealing the second MEMS element on a surface of the second substrate opposite to the first substrate;
A first via hole penetrating the second substrate is formed in a region of the second substrate forming the first sealing space, and the second wiring is formed in the first via hole. ,
A third via hole penetrating the first substrate is formed in the first substrate, and the first wiring is formed in the third via hole;
A fourth via hole penetrating the third substrate is formed in the third substrate, and a via wiring is formed in the fourth via hole;
The second MEMS element is externally formed on the surface of the third substrate opposite to the first substrate through the second wiring, the first wiring, and the via wiring. A MEMS module that is electrically connected to a connection terminal. The detector is supported in a movable state in an opening that penetrates the first substrate,
The detection unit is sealed in a second sealing space formed by an inner wall surface of the opening and a surface of the second substrate and the third substrate facing each other through the first substrate. The MEMS module according to claim 6.   The recessed part is each formed in the position which overlaps with the said detection part of the surface side which mutually opposes via the said 1st board | substrate of the said 2nd board | substrate and the said 3rd board | substrate. The MEMS module according to claim 1. The sealing substrate has a recess;
The MEMS module according to claim 1, wherein the first sealing space is formed by an inner wall surface of the concave portion and the second substrate.   The MEMS module according to claim 1, wherein the first wiring is formed so as not to protrude from a surface of the first substrate. Forming a detection unit for detecting a predetermined mechanical quantity in each of the regions of the first wafer having a plurality of regions;
Forming a first wiring in each of the regions of the first wafer;
Stacking and bonding a second wafer having a plurality of regions corresponding to the first wafer so as to cover the detection unit on one surface of the first wafer;
Forming a second wiring electrically connected to the first wiring in each of the regions of the second wafer, and each of the regions of the first wafer and each of the second wafers; Forming a first MEMS element in the region;
Mounting a second MEMS element on a surface of each of the second wafers opposite to the first wafer in the region;
A third wafer having a plurality of regions corresponding to the first wafer is laminated and bonded to a surface of the second wafer opposite to the first wafer, and is bonded to the second wafer. Forming a first sealing space for sealing each of the second MEMS elements,
In the step of forming the first sealing space, the second MEMS element is exposed from the third wafer of the second wafer via the second wiring and the first wiring. A manufacturing method of a MEMS module electrically connected to an external connection terminal formed in a region. Forming a detection unit for detecting a predetermined mechanical quantity in each of the regions of the first wafer having a plurality of regions;
Forming a first wiring penetrating the first wafer in the region of each of the first wafers;
Stacking and bonding a second wafer having a plurality of regions corresponding to the first wafer so as to cover the detection unit on one surface of the first wafer;
Stacking and bonding a fourth wafer having a plurality of regions corresponding to the first wafer so as to cover the detection unit on the other surface of the first wafer;
Forming a second wiring electrically connected to the first wiring in the region of each of the second wafers;
Forming a via wiring penetrating through the fourth wafer and electrically connected to the first wiring in each of the regions of the fourth wafer; and each region of the first wafer; Forming a first MEMS element in each of the regions of the second wafer and in each of the regions of the fourth wafer;
Mounting a second MEMS element on a surface of each of the second wafers opposite to the first wafer in the region;
A third wafer having a plurality of regions corresponding to the first wafer is laminated and bonded to a surface of the second wafer opposite to the first wafer, and is bonded to the second wafer. Forming a first sealing space for sealing each of the second MEMS elements,
In the step of forming the first MEMS element, an external connection terminal is formed on the surface of the fourth wafer opposite to the first wafer in the region,
In the step of mounting the second MEMS element, the second MEMS element is electrically connected to the external connection terminal via the second wiring, the first wiring, and the via wiring. A manufacturing method of a MEMS module. In the step of laminating and bonding the fourth wafer to the other surface of the first wafer,
Preparing a silicon wafer as the first wafer;
Preparing a glass wafer as the fourth wafer;
The method of manufacturing a MEMS module according to claim 12, wherein the glass wafer is anodically bonded to the other surface of the silicon wafer.