JP2010228029A - Mounting structure of mems device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure of a MEMS device which accurately has a gap of a desired value less varying even if a driving force is applied to a substrate when driven in a driving region. <P>SOLUTION: This mounting structure of a MEMS device includes a driving substrate 20 having a driving region 21, an electrode substrate 30 which has an electrode pad 31 and on which the driving substrate is placed, a distance adjusting part 60 having a height for holding the distance between the driving region and the electrode pad to a desired one, and an interference avoiding part 70 formed between the driving substrate and the electrode substrate. The distance adjusting part 60 includes bumps 60c and joint films 60a which are formed on the bumps and have joint surfaces. The area obtained by summing up the areas of the joint surfaces of all joint films is smaller than the project area of either the driving substrate or the electrode substrate which are joined to each other on the joint surfaces. At least one bump is disposed near the outer peripheral edge of the driving region so that the joint surface is not interfered with the electrode pad, or disposed near the outer peripheral edge of the electrode pad so that the joint surface is not interfered with the driving region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a driving substrate provided with a driving region having an optical function and a drivable driving region, and an electrode substrate using, for example, solid phase diffusion bonding such as surface activated bonding. The present invention relates to a mounting structure of a MEMS device that maintains a desired distance from an electrode substrate.

  In recent years, by adding optical functions such as lenses and mirrors to chips or substrates mounted on optical products such as optical communication devices and microscopes, the number of parts used, product size reduction, or high functionality can be achieved. Development with the goal of making it happen is actively underway. As a bonding technique used when these Micro Electro Mechanical Systems (hereinafter, MEMS) devices are mounted (bonded) on an electronic device, for example, there is surface activated bonding (hereinafter, SAB).

  SAB removes bonding obstructions such as surface oxides and organic substances adhering to the bonding surface of the adherend by plasma cleaning, and after activating the bonding surfaces, the bonding surfaces are brought into close contact with each other, thereby allowing atomic force bonding. The adherends are bonded by solid phase diffusion bonding.

For example, Patent Document 1 discloses a technique for joining adherends using SAB.
In Patent Document 1, wafers 208a and 208b are irradiated with an inert gas ion beam or an inert gas fast atom beam by beam irradiation devices 211a and 211b. As a result, bonding obstructions adhering to the bonding surfaces of the wafers 208a and 208b are removed. The bonding inhibitor is a surface oxide film, an organic substance, moisture, or the like.

  Thereafter, the wafers 208a and 208b come into contact with each other in the vacuum chamber 202 in which the internal pressure is maintained at a degree of vacuum of about 0.133 Pa or higher, and are firmly bonded by Si atomic force coupling of the wafers 208a and 208b.

  In addition, since the wafers 208a and 208b do not require pressing or heat treatment with a load, damage during bonding is reduced.

Japanese Patent No. 2791429

  In general, unlike a technique in which a liquid phase bonding material such as a brazing material or an adhesive is filled in a bonded portion of an adherend and then cured, in order to enable SAB, the bonding surfaces are mutually connected. It is necessary to approach (adhere) to a state where atomic force bonding is possible. When the bonding area of the bonding surfaces is large, the bonding between the bonding surfaces becomes difficult, so that SAB becomes difficult.

  When the entire surfaces of the wafers 208a and 208b are bonded as in the bonding method disclosed in Patent Document 1 described above, there is a high possibility that an unintended bonding region (hereinafter referred to as a non-bonded portion) will occur as a result. Become. This non-bonded portion is an unintended gap existing between the wafer 208a and the wafer 208b, and it is difficult to hold the distance (interval) between the wafer 208a and the wafer 208b so as to be exactly a desired value. Will be a factor.

  Therefore, in the case of the electrostatic drive method, a distance (hereinafter referred to as a gap) between a drive region that affects the drive force of the device in a square and an electrode to which a drive voltage for driving the drive region is applied is desired. It cannot be controlled to be a value. Therefore, there is a possibility that a failure occurs in a device driven with desired characteristics.

  Further, the gap can be a factor that causes an external force generated when the device is driven to deform the wafer. However, it is considered that the non-bonded portion occurs at an unintended irregular portion. For this reason, for example, when a non-bonded portion occurs in the vicinity of the drive region, the moment that the drive force tries to deform the substrate increases, so that the amount of deformation of the substrate during device driving also increases.

  In addition, the closer the non-bonded portion is generated to the drive region (mirror), the greater the influence on the gap. Therefore, the mounting structure of the MEMS device in which an unintentional non-joint portion is generated unintentionally adversely affects the driving characteristics of the MEMS device during driving.

  The present invention has been made in view of these circumstances, and has a gap with a desired value accurately at the time of mounting, and even if a driving force is applied to the substrate at the time of driving the driving region, the MEMS device has a small gap variation. The purpose is to provide a mounting structure.

  In order to achieve the object, the present invention is configured so that a drive substrate having a drive region and a frame for holding the drive region, and an electrode pad to which a drive voltage for driving the drive region can be applied are opposed to the drive region. And an electrode substrate on which the driving substrate is stacked, and a height for interposing between the driving substrate and the electrode substrate, and for maintaining a desired distance between the driving region and the electrode pad. And a distance avoiding unit formed between the drive substrate and the electrode substrate so that the distance adjusting unit does not interfere with the drive region when the drive region is driven. The distance adjusting unit includes a plurality of bumps arranged in a dispersed manner on at least one of the drive substrate and the electrode substrate, and a film formed on each of the bumps, and the distance between the drive substrate and the electrode substrate. Join with the other And a bonding film that is a film on the surface of the distance adjusting unit, and the total area of the bonding surfaces of all the bonding films is the driving substrate to which the bonding surfaces are bonded and the bonding substrate The at least one bump is smaller than the other projected area with the electrode substrate, the bump is disposed in the vicinity of the outer peripheral edge of the drive region, and the bonding surface is non-interfering with the electrode pad, or the electrode Provided is a mounting structure for a MEMS device, which is disposed in the vicinity of an outer peripheral edge of a pad and is disposed so that the bonding surface does not interfere with the driving region.

  According to the present invention, it is possible to provide a mounting structure for a MEMS device that has a gap of a desired value accurately at the time of mounting and has little fluctuation in the gap even when a driving force is applied to the substrate during driving of the driving region.

FIG. 1 is a plan view of the mounting structure of the MEMS device according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view after bonding of the mounting structure of the MEMS device taken along line AA in FIG. FIG. 3 is an enlarged cross-sectional view of the vicinity of the distance adjusting unit shown in FIG. FIG. 4 is a plan view showing the relationship between the total area of the joint surfaces in the mounting structure of the MEMS device and the projected area of the frame. FIG. 5A is a modification of the distance adjustment unit. FIG. 5B is a cross-sectional view of the mounting structure of the MEMS device including the distance adjusting unit disposed on the driving substrate. FIG. 5C is an enlarged cross-sectional view of the vicinity of the distance adjustment unit shown in FIG. 5B. FIG. 5D is a modification of the distance adjustment unit shown in FIG. 5B. FIG. 5E is a cross-sectional view of a mounting structure of a MEMS device including a distance adjusting unit disposed on a drive substrate and an electrode substrate. FIG. 6 is a plan view of the mounting structure of the MEMS device according to the second embodiment of the present invention. 7A is a cross-sectional view after bonding of the mounting structure of the MEMS device taken along line BB in FIG. FIG. 7B is an enlarged cross-sectional view of the vicinity of the distance adjustment portion on the surface side of the spacer member shown in FIG. 7A. FIG. 7C is an enlarged cross-sectional view of the vicinity of the distance adjustment portion on the back surface side of the spacer member shown in FIG. 7A. FIG. 8A is a modification of the distance adjusting portion on the surface side of the spacer member shown in FIG. 7A. FIG. 8B is a modification of the distance adjusting portion on the back surface side of the spacer member shown in FIG. 7A. FIG. 9A is a plan view of the mounting structure of the MEMS device including bumps disposed on the surface of the spacer member. FIG. 9B is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the driving substrate and the surface of the spacer member. FIG. 9C is a plan view of the mounting structure of the MEMS device including bumps disposed on the surface of the spacer member and the surface of the electrode substrate. FIG. 9D is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the drive substrate, the front surface of the spacer member, and the back surface of the spacer member. FIG. 9E is a plan view of a mounting structure of a MEMS device including bumps disposed on the front surface of the spacer member, the back surface of the spacer member, and the front surface of the electrode substrate. FIG. 9F is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the drive substrate, the surface of the spacer member, the back surface of the spacer member, and the surface of the electrode substrate. FIG. 9G is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the spacer member. FIG. 9H is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the drive substrate and the back surface of the spacer member. FIG. 9I is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the spacer member and the surface of the electrode substrate. FIG. 9J is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the drive substrate, the back surface of the spacer member, and the surface of the electrode substrate. FIG. 9K is a plan view of the mounting structure of the MEMS device including bumps disposed on the back surface of the driving substrate. FIG. 9L is a plan view of a mounting structure of a MEMS device including bumps disposed on the back surface of the drive substrate and the front surface of the electrode substrate. FIG. 9M is a plan view of the mounting structure of the MEMS device including bumps disposed on the surface of the electrode substrate. FIG. 10A is a plan view of the mounting structure of the MEMS device according to the second embodiment of this invention. 10B is a cross-sectional view after bonding of the mounting structure of the MEMS device taken along line CC in FIG. 10A. FIG. 11A is a plan view of a mounting structure of a MEMS device according to a third embodiment of the present invention. FIG. 11B is a cross-sectional view after joining the mounting structure of the MEMS device taken along line DD in FIG. 11A. FIG. 11C is a diagram illustrating a modification of the mounting structure of the MEMS device. FIG. 12A is a plan view of the mounting structure of the MEMS device according to the fourth embodiment of the present invention. 12B is a cross-sectional view after bonding of the mounting structure of the MEMS device taken along line EE in FIG. 12A. FIG. 13A is a plan view of a mounting structure of a MEMS device having a joint protrusion. 13B is an exploded view of the mounting structure of the MEMS device taken along line FF in FIG. 13A, and is a cross-sectional view before joining the mounting structure of the MEMS device. FIG. 13C is an enlarged cross-sectional view of the vicinity of the joint protrusion shown in FIG. 13B before joining. FIG. 14A is a plan view of a mounting structure of a MEMS device including a joint convex portion disposed on a drive substrate. FIG. 14B is an enlarged cross-sectional view of the vicinity of the joint protrusion shown in FIG. 14A. FIG. 14C is a plan view of the mounting structure of the MEMS device including the joint protrusions disposed on the drive substrate and the electrode substrate. FIG. 15A is an exploded view of the mounting structure of the MEMS device in which the joint convex portion is integrally provided with the spacer member. FIG. 15B is an enlarged cross-sectional view of the vicinity of the joint convex portion shown in FIG. 15A. FIG. 16A is an exploded view of the mounting structure of the MEMS device in which the joint protrusion is provided separately from the spacer member. FIG. 16B is an enlarged cross-sectional view of a bonding projection having only a bonding film and a base member. FIG. 16C is an enlarged cross-sectional view of the joint protrusion shown in FIG. 16B arranged on the drive substrate. FIG. 16D is an enlarged cross-sectional view of the bonding convex portion shown in FIG. 16B arranged on the electrode substrate. FIG. 17 is an enlarged cross-sectional view of the distance adjusting unit in which the base member is disposed between the bonding film and the bump. FIG. 18 is a diagram showing a configuration of a conventional mounting structure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The first embodiment will be described with reference to FIGS. 1 to 4 and FIGS. 5A to 5E. 5B and 5E simplify the illustration of the distance adjusting unit 60, and details of the distance adjusting unit 60 are shown in FIGS. 3, 5A, 5C, and 5D, for example.

  As shown in FIG. 1 and FIG. 2, the MEMS device mounting structure 1 includes a drive substrate 20, an electrode substrate 30 on which the drive substrate 20 is laminated, and the drive substrate 20 and the electrode substrate 30. A distance adjusting unit 60 having a height for holding a distance between a driving region 21 described later and an electrode pad 31 described later of the electrode substrate 30 as desired, and a distance adjusting unit when the driving region 21 is driven. An interference avoidance unit 70 formed between the drive substrate 20 and the electrode substrate 30 is provided so that 60 does not interfere with the drive region 21. Such a MEMS device mounting structure 1 is, for example, a Micro Electro Mechanical Systems (hereinafter, MEMS) device in a semiconductor device.

  The drive substrate 20 and the electrode substrate 30 are stacked in the thickness direction and stacked and joined to each other. The drive substrate 20 and the electrode substrate 30 are bonded to each other between the drive substrate 20 and the electrode substrate 30 (more specifically, between the drive region 21 and the electrode pad 31) by the distance adjusting unit 60 after bonding. They are joined to each other so that a distance (hereinafter referred to as gap 2) can be formed. In the drive substrate 20 and the electrode substrate 30, the back surface 20a of the drive substrate 20 and the front surface 30a of the electrode substrate 30, which are surfaces facing each other, are planes. Further, the back surface 20a and the front surface 30a face the interference avoiding unit 70.

  The drive substrate 20 is substantially flat and has, for example, a rectangular shape. The drive substrate 20 is formed on the back surface 20a facing the electrode substrate 30 (interference avoiding unit 70), a drive region 21 that is, for example, a mirror having an optical function, a frame 22 that holds the drive region 21, and the electrode substrate 30 (interference avoiding unit 70). And a bonding film 23.

  The drive region 21 is driven (deformed or deflected) by electrostatic attraction described later. The frame 22 is, for example, a Si substrate that is not etched. The drive region 21 is a thin film portion of the frame 22 in which the central portion of the frame 22 is etched into a circular shape. That is, the drive region 21 is a part of the frame 22 and is made of Si. The drive region 21 is disposed at the center of the drive substrate 20.

  The bonding film 23 is a driving substrate side bonding film bonded to a bonding surface 60d described later. The bonding film 23 is, for example, gold. The back surface 20 a and the front surface 20 b of the drive substrate 20 are also the back surface and the front surface of the frame 22. That is, the bonding film 23 is a film formed on the back surface of the frame 22. Further, between the bonding film 23 and the back surface 20a, a Cr film or a Ti film as an adhesion layer capable of increasing the adhesion strength between the bonding film 23 and the back surface 20a is formed below the bonding film 23. May be.

  The electrode substrate 30 is substantially flat and has, for example, a rectangular shape. The electrode substrate 30 preferably has the same linear expansion coefficient as that of the drive substrate 20 from the viewpoint of reliability. Therefore, the electrode substrate 30 is preferably made of Si, which is the same material as the drive substrate 20, or borosilicate glass having a linear expansion coefficient relatively close to that of the drive substrate 20. The electrode substrate 30 has an electrode pad 31 to which a drive voltage for driving the drive region 21 can be applied so as to face the drive region 21.

  The electrode pad 31 generates an electrostatic attractive force when a drive voltage is applied, and drives the drive region 21 by this electrostatic attractive force (deforms the electrode into a desired shape or deflects it to a desired angle). Since the electrode pad 31 faces the drive region 21, the electrode pad 31 is disposed at the center of the electrode substrate 30.

  In this embodiment, the distance adjusting unit 60 is disposed on the electrode substrate 30 between the outer peripheral edge 31 a of the electrode pad 31 and the outer peripheral edge 30 b of the electrode substrate 30. The distance adjustment unit 60 is arranged symmetrically with respect to the center line in the planar direction of the electrode pad 31 so as not to overlap the electrode pad 31.

  The distance adjustment unit 60 is a spacer member interposed between the drive substrate 20 and the electrode substrate 30. After the drive substrate 20 and the electrode substrate 30 are mounted, the distance adjusting unit 60 has a height for holding the gap 2 as desired as described above. The height of the distance adjusting unit 60 is the same as the desired gap 2. That is, in the present embodiment, the height of the distance adjustment unit 60 (more specifically, a bump 60c described later) is the gap 2.

  As shown in FIG. 3, the distance adjusting unit 60 includes a plurality of bumps 60 c dispersed on the electrode substrate 30, and a bonding film that is formed on each bump 60 c and is a film on the surface of the distance adjusting unit 60. 60a.

  The bonding film 60 a has a bonding surface 60 d that comes into contact with the bonding film 23. The bonding surface 60d is a surface where the drive substrate 20 is bonded to the distance adjusting unit 60, and is a surface including the apex of the bonding film 60a. As shown in FIG. 4, the total area S1 of the bonding surfaces 60d of all the bonding films 60a is smaller than the projected area S2 of the frame 22 to which the bonding surfaces 60d are bonded. The bonding film 60a contacts the bonding film 23 evenly on the bonding surface 60d, and is solid-phase diffusion bonded to the bonding film 23. This solid phase diffusion bonding is, for example, surface activated bonding (hereinafter referred to as SAB). The bonding film 60a is, for example, gold.

Further, as shown in FIG. 3, the bump 60 c is formed on the electrode substrate 30.
The bumps 60c are, for example, convex portions in the electrode substrate 30 that are manufactured by removing a part of the surface 30a of the electrode substrate 30 that has been previously polished to a desired thickness. At this time, the height of each bump 60c is uniform. The processing for removing a part of the electrode substrate 30 is any one of blasting, etching, and laser processing.
As described above, in the present embodiment, each bump 60 c is manufactured by removing a part of the surface 30 a of the electrode substrate 30, is integrated with the manufactured electrode substrate 30, and is formed by the same member as the electrode substrate 30. Are formed on the electrode substrate 30 so as to have a uniform height.

  The bump 60c joins the driving substrate 20 and the electrode substrate 30 on which the bump 60c is formed. Thereby, the distance adjusting unit 60 holds the distance between the drive region 21 and the electrode pad 31 in the gap 2. That is, the bump 60c has a height for holding the gap 2 as desired.

  Further, at least one bump 60 c is disposed in the vicinity of the outer peripheral edge 31 a of the electrode pad 31, and is disposed on the electrode substrate 30 so that the bonding surface 60 d does not interfere with the drive region 21.

  The bump 60c is disposed between the outer peripheral edge 21a of the driving region 21 and the outer peripheral edge 20c of the driving substrate 20, and is rotationally symmetric in the plane direction with respect to the center point 21b of the driving region 21, or based on a desired center line. Thus, they are arranged in line symmetry in the plane direction.

  Between the bonding film 60a and the bump 60c, a Cr film or a Ti film as an adhesion layer capable of increasing the adhesion strength between the bonding film 60a and the bump 60c is formed below the bonding film 60a. Also good.

  As shown in FIG. 5A, the bump 60c may be separate from the electrode substrate 30, for example. In this case, stud bumps are formed on the electrode substrate 30 and leveling is performed. As a result, each bump 60c is formed on the electrode substrate 30 so as to have a uniform height and a height for holding the gap 2 as desired even if it is separate from the electrode substrate 30.

  Moreover, although the distance adjustment part 60 is arrange | positioned at the electrode substrate 30, it is not necessary to limit to this. The distance adjusting unit 60 may be disposed on the drive substrate 20 as shown in FIGS. 5B and 5C as long as it is interposed between the drive substrate 20 and the electrode substrate 30.

  In this case, the bumps 60c are formed in a plurality of dispersed manner on the frame 22 (specifically, the back surface 20a). The bonding surface 60d is bonded to the electrode substrate 30.

  The bump 60 c is a convex portion in the frame 22 that is manufactured by removing a part of the back surface 20 a of the frame 22. That is, the bump 60 c is integral with the frame 22 and is formed of the same member as the frame 22. The processing for removing a part of the frame 22 is any one of blasting, etching, and laser processing.

  That is, in this case, each bump 60c is produced by removing a part of the back surface 20a of the drive substrate 20, and is integrated with the produced drive substrate 20, and is formed by the same member as the drive substrate 20. The driving substrate 20 is formed to have a uniform height.

  The bump 60c joins the drive substrate 20 on which the bump 60c is formed and the electrode substrate 30 to each other. Thereby, the distance adjusting unit 60 holds the distance between the drive region 21 and the electrode pad 31 in the gap 2. That is, the bump 60c has a height for holding the gap 2 as desired.

  Further, at least one bump 60 c is disposed in the vicinity of the outer peripheral edge 21 a of the drive region 21, and is disposed on the drive substrate 20 so that the bonding surface 60 d does not interfere with the electrode pad 31.

  The bump 60c is disposed between the outer peripheral edge 31a and the outer peripheral edge 30b of the electrode substrate 30, and is rotationally symmetric in the plane direction with respect to the center point 21b, or line symmetric in the plane direction with reference to a desired center line. It is arranged.

  The total area S1 of the bonding surfaces 60d of all the bonding films 60a is smaller than the projected area of the electrode substrate 30 to which the bonding surfaces 60d are bonded.

  In this case, on the surface 30a, the bonding film 32, which is gold like the bonding film 23 and is an electrode substrate side bonding film that comes into contact with the bonding surface 60d, is formed.

  Further, as shown in FIG. 5D, the bump 60c may be separate from the frame 22, for example. In this case, stud bumps are formed on the frame 22 and subjected to leveling. As a result, each bump 60c is formed on the drive substrate 20 so as to have a uniform height and a height for holding the gap 2 as desired even if it is separate from the frame 22.

  In addition, the distance adjusting unit 60 may be disposed on at least one of the drive substrate 20 (frame 22) and the electrode substrate 30 by combining the above, as shown in FIGS. 2, 5A, and 5E. In this case, a plurality of bumps 60c are distributed and disposed on at least one of, for example, the drive substrate 20 and the electrode substrate 30 (specifically, the back surface 20a and the front surface 30a). The bonding film 60 a is bonded to the other of the drive substrate 20 and the electrode substrate 30.

  In the present embodiment, the drive substrate 20 (specifically, the frame 22) and the electrode substrate 30 are, for example, a Si substrate or borosilicate glass. The bump 60c is formed of the same member as the electrode substrate 30 and the drive substrate 20. Therefore, the bump 60 c is, for example, a Si substrate or borosilicate glass, like the drive substrate 20 and the electrode substrate 30.

  The interference avoiding unit 70 is formed between the drive substrate 20 and the electrode substrate 30, more specifically, between the drive region 21 and the electrode pad 31. The interference avoidance unit 70 is a space for avoiding interference between the drive substrate 20 and the electrode substrate 30.

  The drive substrate 20 and the electrode substrate 30 are provided with alignment marks (not shown) that can recognize relative positions of each other. The alignment mark serves as an index for adjusting the relative position of the drive substrate 20 and the electrode substrate 30 when the drive substrate 20 and the electrode substrate 30 are aligned by a positioning device (not shown).

Next, the operation of this embodiment will be described with reference to FIGS.
(Step 1)
The bonding film 23 and the bonding film 60a are cleaned by Ar plasma, for example. As a result, an unillustrated bonding inhibitor adhering to the bonding film 23 and the bonding film 60a is removed by the plasma. The bonding inhibitor is, for example, a surface oxide, an organic substance, water, or the like.

(Step 2)
The drive substrate 20 and the electrode substrate 30 are positioned at desired positions by a mounting device (not shown). More specifically, the drive substrate 20 and the electrode substrate 30 are positioned by the alignment mark so that the center point 21b and a center point (not shown) of the electrode pad 31 are located on the same axis.
The drive substrate 20 and the electrode substrate 30 are heated by a bonding head (not shown). As a result, the bonding film 23 is heated through the driving substrate 20, and the distance adjusting unit 60 is also heated through the electrode substrate 30. Note that the bonding film 60a and the bump 60c are also heated by heating the distance adjusting unit 60. At this time, the bonding surfaces of the bonding film 23 and the bonding film 60a (bonding surface 60d) are solid-phase diffusion bonded.

(Step 3)
The height of the distance adjusting unit 60 (bump 60c) is the same as the gap 2. Therefore, after the drive substrate 20 and the electrode substrate 30 are joined, the drive substrate 20 and the electrode substrate 30 are joined with the gap 2 formed between the drive substrate 20 and the electrode substrate 30. At this time, the gap 2 becomes uniform, and a desired value is maintained and maintained by the distance adjusting unit 60. Therefore, the driving force of the driving region 21 maintains a desired value.

(Step 4)
In Step 2, the bonding stress (σ) at the time of mounting = mounting load (F) / the area S1 obtained by totaling the bonding surfaces 60d of all the bonding films 60a.
As described above, the total area S1 of the bonding surfaces 60d of all the bonding films 60a is smaller than the projected area S2 of the frame 22. Therefore, joining with a desired portion of the back surface 20a of the frame 22 can obtain a larger joining stress (σ) than joining with the entire back surface 20a of the frame 22.
Therefore, the bonding film 23 and the bonding film 60a are more closely attached and are easily bonded by atomic force. As a result, the joining surface 60d, which is a desired joining surface, is reliably joined to the back surface 20a of the frame 22 by SAB, and an unintended gap (non-joined portion) is generated between the drive substrate 20 and the bump 60c. Is prevented.

(Step 5)
As described above, S1 is smaller than S2. Therefore, the bonding film 60a is bonded to a desired portion of the back surface 20a of the frame 22 than the bonding film 60a is bonded to all of the back surface 20a of the frame 22. ) Is sandwiched between the bonding film 23 and the bonding film 60a, and the probability of occurrence of a problem that prevents the adhesion between the bonding film 23 and the bonding film 60a is reduced.

  Therefore, it is possible to prevent an unintended gap (non-joined portion) from being generated between the drive substrate 20 and the bump 60c.

  This also applies to the states shown in FIGS. 5A to 5E.

  Thus, in this embodiment, it is possible to prevent an unintended gap from being generated between the drive substrate 20 and the bump 60c and between the electrode substrate 30 and the bump 60c. Since this gap becomes a fluctuation factor of the gap 2 when the drive region 21 is driven, fluctuation of the gap 2 can be reduced by preventing the gap from being generated.

  Accordingly, in the present embodiment, the MEMS device mounting structure 1 has a gap 2 with a desired value accurately at the time of mounting, and even when a driving force is applied to the driving substrate 20 at the time of driving the driving region 21, the gap 2 is less varied. Can be provided.

  In the present embodiment, in solid phase diffusion bonding such as SAB, a limited bondable area is provided, and a non-bonded portion (gap) is generated in the vicinity of the drive region 21 even when mounted with a low load. Therefore, it is possible to reliably join a desired joint.

  In the present embodiment, the distance adjusting unit 60 (bump 60c) has a height for holding the gap 2 as desired. Therefore, in the present embodiment, when the driving substrate 20 and the electrode substrate 30 are bonded, the bonding reliability can be improved in a state where the gap 2 is uniformly held so as to have a desired value. Thereby, in this embodiment, the mounting structure 1 of the MEMS device which can exhibit a desired drive characteristic can be provided.

  Further, in the present embodiment, since a desired portion of the drive substrate 20 and the electrode substrate 30 is reliably bonded by the distance adjusting unit 60 using SAB, the electrode substrate 30, between the bonding film 23 and the distance adjusting unit 60, and It is possible to prevent the occurrence of a gap that is an unintended portion between the distance adjusting unit 60 and the unintended portion.

  In this embodiment, for example, the bump 60c is integrated with or driven by the electrode substrate 30 by removing a part of the front surface 30a of the electrode substrate 30 or a part of the back surface 20a of the driving substrate 20 that has been polished to a desired thickness in advance. It can be manufactured integrally with the substrate 20. As a result, in the present embodiment, the bumps 60c can be more easily produced than arranging the bumps 60c on a part of the electrode substrate 30 or a part of the drive substrate 20, respectively, and the bumps 60c having a uniform height are produced. Can do. In addition, according to this embodiment, it is possible to prevent the generation of a gap due to the variation in the height of the bump 60c.

  In the present embodiment, the bonding method of the bonding film 23 and the bonding film 60a may be solid phase diffusion bonding, for example, Au—Au thermocompression bonding. Further, the bonding method between the bonding film 23 and the bonding film 60a need not be limited to SAB.

  Further, in the present embodiment, by making S1 smaller than S2, it is possible to prevent an unintended gap (non-joined part) from being generated between the drive substrate 20 and the bump 60c, and fluctuation of the gap 2 can be prevented. Can be reduced. Further, in the present embodiment, by making S1 smaller than S2, the drive substrate 20 and the electrode substrate 30 can be reliably bonded at a desired site.

  In the present embodiment, the bumps 60c are rotationally symmetric in the plane direction with respect to the center point 21b of the drive region 21, or are arranged in line symmetry in the plane direction with reference to the desired center line. The electrode substrate 30 can be firmly bonded.

  In the present embodiment, the bumps 60c are integrated with the electrode substrate 30, and all the bumps 60c are produced by removing a part of the surface 30a of the electrode substrate 30, whereby the bumps 60c are respectively disposed on the electrode substrate 30. It is possible to save the trouble of processing. In this regard, the same effect can be obtained even if the bump 60c is integrated with the drive substrate 20.

  Further, in this embodiment, the height of the distance adjusting unit 60 can be prevented from varying, and the bump 60c having a uniform height can be produced. As a result, the gap 2 can be held as desired anywhere between the electrode substrate 30 and the drive substrate 20. Further, in the present embodiment, since the distance between the drive region 21 and the electrode pad 31 can always be the gap 2, it is possible to provide the MEMS device mounting structure 1 having desired optical characteristics.

  Next, the second embodiment will be described with reference to FIGS. 6, 7A to 7C, 8A, 8B, and 9A to 9M. The same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. For simplification of illustration, for example, a part of the constituent members is omitted in some drawings so that the bonding film 60a is omitted in FIG. 7A.

  As shown in FIGS. 7A to 7C, the distance adjusting unit 60 of the present embodiment includes a spacer member 61 a having a thickness for holding the gap 2 as desired, and a spacer 62 on the surface 62 b of the spacer member 61 a facing the back surface 20 a. A bump 61b formed integrally with the member 61a, a bump 61c formed integrally with the spacer member 61a on the back surface 62c of the spacer member 61a facing the front surface 30a, and a surface covering the bumps 61b and 61c And a bonding film 60a which is a film of the above.

  In the present embodiment, the height of the distance adjusting unit 60 (the sum of the thickness of the spacer member 61a and the height of the bumps 61b and 61c) is the gap 2. Thus, the spacer member 61a has a thickness for holding the gap 2 as desired together with the bumps 61b and 61c.

  The spacer member 61a is substantially flat and has, for example, a rectangular shape. The spacer member 61 a has the same area as the drive substrate 20. The spacer member 61a is, for example, a Si substrate or borosilicate glass.

  The spacer member 61 a is provided with an interference avoidance portion 70 that is a through hole formed so as to face the drive region 21 and the electrode pad 31. The shape of the interference avoidance unit 70 is the same as the shape of the electrode pad 31 and the drive region 21. The interference avoiding unit 70 has a shape that does not hinder the shape of the drive region 21 that is driven (deformed or deflected) after mounting, and penetrates the spacer member 61a in the thickness direction of the spacer member 61a.

  In addition, when the driving substrate 20, the spacer member 61a, and the electrode substrate 30 are stacked, the driving region 21, the interference avoidance unit 70, and the electrode pad 31 are positioned on the same straight line in the thickness direction of the mounting structure 1 of the MEMS device. It will be.

  The bumps 61b and 61c are substantially the same as the bump 60c. The bumps 61b and 61c of this embodiment are used for joining the drive substrate 20, the spacer member 61a on which the bumps 61b and 61c are disposed, and the electrode substrate 30 by SAB.

As shown in FIGS. 7B and 7C, the bumps 61b and 61c are formed on the spacer member 61a. More specifically, the bumps 61b and 61c are convex portions in the spacer member 61a produced by a process of removing a part of the spacer member 61a (more specifically, a part of the front surface 62b and the back surface 62c). At this time, the heights of the bumps 61b and 61c are uniform. The processing for removing a part of the spacer member 61a is any one of blasting, etching, and laser processing.
Thus, in the present embodiment, each of the bumps 61b and 61c is manufactured by removing a part of the spacer member 61a, is integrated with the manufactured spacer member 61a, and is formed of the same member as the spacer member 61a. Each spacer member 61a is formed to have a uniform height.

  As described above, the bumps 61b and 61c are convex portions of the spacer member 61a that are manufactured by removing a part of the spacer member 61a. The bumps 61b and 61c are integrated with the spacer member 61a and are formed of the same member as the spacer member 61a. Has been. Therefore, the bumps 61b and 61c are, for example, a Si substrate or borosilicate glass, like the spacer member 61a.

  Further, at least one bump 61b is disposed in the vicinity of the outer peripheral edge 21a (the outer peripheral edge 71a of the interference avoiding unit 70), and is disposed on the surface 62b so that the bonding surface 60d does not interfere with the drive region 21. Yes.

  Further, at least one bump 61c is disposed in the vicinity of the outer peripheral edge 31a (the outer peripheral edge 71a of the interference avoiding portion 70), and is disposed on the back surface 62c so that the bonding surface 60d does not interfere with the electrode pad 31. Yes.

  The bumps 61b and 61c are arranged rotationally symmetrical in the plane direction with respect to the center point 21b, or line-symmetrically in the plane direction with reference to a desired center line.

  That is, the bumps 61b and 61c are formed on the spacer member 61a so as not to overlap the electrode pad 31 and the drive region 21 between the outer peripheral edge 71a that is the inner peripheral edge of the spacer member 61a and the outer peripheral edge 63 of the spacer member 61a. It is arranged.

In the bump 61b, the total area S1 of the bonding surfaces 60d of all the bonding films 60a is smaller than the projected area S2 of the frame 22 to which the bonding surfaces 60d are bonded. In the bump 61c, the total area S1 of the bonding surfaces 60d of all the bonding films 60a is smaller than the projected area of the electrode substrate 30 to which the bonding surfaces 60d are bonded.
Note that the drive substrate 20 and the spacer member 61a are provided with alignment marks (not shown) that can recognize relative positions of each other.

  Further, as shown in FIGS. 8A and 8B, the bumps 61b and 61c may be separate from the spacer member 61a. In this case, stud bumps are formed on the spacer member 61a and subjected to leveling. Thus, even if the bumps 61b and 61c are separate from the spacer member 61a, the bumps 61b and 61c are formed on the spacer member 61a so as to have a uniform height.

  9A to 9M, the bump 61b may be disposed on at least one of the front surface 62b and the back surface 20a, and the bump 61c may be disposed on at least one of the back surface 62c and the front surface 30a. In this case, the spacer member 61a is gold on the front surface 62b and the back surface 62c similarly to the bonding film 23, and has a bonding film 65 that is a spacer member-side bonding film.

When the bump 61b is disposed on the back surface 20a, the bump 61b is substantially the same as the bump 60c in the first embodiment (see, for example, FIGS. 5B to 5E).
When the bump 61c is disposed on the surface 30a, the bump 61c is substantially the same as the bump 60c in the first embodiment (see, for example, FIGS. 1 to 4 and 5A).
Next, the operation of this embodiment will be described with reference to FIG. 6 and FIGS. 7A to 7B.
(Step 11)
The bonding film 60a covering the bump 61c and the bonding film 32 are cleaned by, for example, Ar plasma. As a result, a bonding obstruction (not shown) adhering to the bonding film 60a and the bonding film 32 is removed by plasma.

(Step 12)
The spacer member 61a and the electrode substrate 30 are positioned at desired positions by a mounting device (not shown). More specifically, the spacer member 61a and the electrode substrate 30 are positioned by the alignment mark so that the center of the interference avoiding portion 70 (a center point 71 described later) and the center of the electrode pad 31 are coaxially positioned.
The spacer member 61a and the electrode substrate 30 are heated by a bonding head (not shown). As a result, the bumps 61 c and the bonding film 60 a are heated through the spacer member 61 a, and the bonding film 32 is also heated through the electrode substrate 30. At this time, the bonding surfaces of the bonding film 32 and the bonding film 60a (bonding surface 60d) are bonded by SAB, and the distance adjusting unit 60 and the electrode substrate 30 are bonded to each other.
(Step 13)
The bonding film 60a covering the bump 61b and the bonding film 23 are cleaned by, for example, Ar plasma. As a result, a bonding obstruction (not shown) adhering to the bonding film 60a and the bonding film 23 is removed by the plasma.

(Step 14)
The spacer member 61a and the drive substrate 20 are positioned at desired positions by a mounting device (not shown). More specifically, the spacer member 61a and the drive substrate 20 are positioned by the alignment mark so that the center of the interference avoiding portion 70 and the center point 21b are located on the same axis.
The spacer member 61a and the drive substrate 20 are heated by a bonding head (not shown). As a result, the bumps 61b and the bonding film 60a are heated through the spacer member 61a, and the bonding film 23 is also heated through the drive substrate 20. At this time, the bonding surfaces of the bonding film 23 and the bonding film 60a (bonding surface 60d) are bonded by SAB, and the distance adjusting unit 60 and the drive substrate 20 are bonded to each other.
(Step 15)
Since the distance adjusting unit 60 is the gap 2, the distance between the drive region 21 and the electrode pad 31 is held in the gap 2.

  Thus, in this embodiment, the gap 2 is determined by the sum of the thickness of the spacer member 61a and the heights of the bumps 61b and 61c. Therefore, in the present embodiment, it is possible to provide a MEMS device mounting structure 1 having a wider gap 2 than in the first embodiment. Furthermore, in the present embodiment, it is possible to provide the mounting structure 1 for the MEMS device in which the drive amount (deformation amount or deflection amount) of the drive region 21 is large. Therefore, in this embodiment, the freedom degree of design of the mounting structure 1 of a MEMS device can be expanded.

  Moreover, in this embodiment, the same effect as 1st Embodiment mentioned above can also be acquired.

Next, a third embodiment will be described with reference to FIGS. 10A and 10B. The same parts as those in the first and second embodiments described above are denoted by the same reference numerals, and detailed description thereof is omitted. For simplification of illustration, for example, a part of the constituent members is omitted in some drawings so that the bonding film 60a is omitted in FIG. 10B.
In the present embodiment, the bump 61b has a center point 21b (a center point of the interference avoiding unit 70) in the circumferential direction in the stacking direction of the drive substrate 20 and the electrode substrate 30 (the circumferential direction in the planar direction of the spacer member 61a (surface 62b)). 71) and are arranged at a desired equiangular distance from each other. In other words, the bumps 61b are arranged at equal angles apart from each other around the center point 71 in the planar direction of the surface 62b. That is, the bumps 61b are arranged radially.

  Similarly to the bump 61b, the bumps 61c may be arranged at equal angles apart from each other around the center point 71 in the planar direction of the back surface 62c. In this case, the bumps 61c are also arranged radially.

Next, the operation of this embodiment will be described.
(Step 21)
The operations from Step 11 to Step 15 are performed.

(Step22)
The electrode substrate 30 and the distance adjusting unit 60 are mounted so that the center point 21b and the center point 71 are positioned on the same axis. Therefore, the bumps 61b are arranged symmetrically with respect to the center point 21b (center point 71).
For this reason, when the mounting structure 1 of the MEMS device is driven, a driving force is evenly applied to the driving region 21, so that distortion during driving of the driving region is reduced as compared with the second embodiment.

  As described above, in the present embodiment, it is possible to provide a mounting structure 1 for a MEMS device having superior optical characteristics as compared with the first embodiment and the second embodiment.

  The bumps 61b and 61c need not be limited to the center point 71, and may be arranged symmetrically with respect to a desired center line.

Next, a fourth embodiment will be described with reference to FIGS. 11A and 11B. The same parts as those in the first, second, and third embodiments described above are denoted by the same reference numerals, and detailed description thereof is omitted. For simplification of illustration, for example, a part of the constituent members is omitted in some drawings so that the bonding film 60a is omitted in FIG. 11B.
The bumps 61b are arranged such that the distance between the bumps 61b in the plane direction of the drive region 21 (the radial direction of the interference avoidance unit 70) is closer to the interference avoidance unit 70 (drive region 21). In other words, the interval between the bumps 61b increases from the outer peripheral edge 71a of the interference avoiding unit 70 toward the outer peripheral edge 63 of the spacer member 61a. That is, in the radial direction of the interference avoidance unit 70, the distance between the bumps 61b is closer to the interference avoidance unit 70 (drive region 21), and the distance from the bump avoidance unit 70 (drive region 21) is closer. It arrange | positions so that it may become.

  This also applies to the bump 61c.

Next, the operation of this embodiment will be described.
(Step 31)
The operations from Step 11 to Step 15 are performed.

(Step 32)
The electrode substrate 30 and the distance adjusting unit 60 are mounted so that the center point 21b and the center point 71 are positioned on the same axis. Therefore, the bumps 61b are arranged so as to be denser as they are closer to the center point 21b (center point 71).
When a drive voltage is applied to the electrode pad 31 and the drive region 21 is driven, a moment load is generated on the frame 22. However, the bump 61b is disposed in a region closer to the moment load acting point (drive region 21). Therefore, the bending deformation of the frame 22 is reduced as compared with the first to third embodiments.

  As described above, in this embodiment, it is possible to provide the MEMS device mounting structure 1 in which the fluctuation of the gap 2 is small even when the driving region 21 is driven, as compared with the first to third embodiments.

  As shown in FIG. 11C, the closer to the drive region 21, the closer the bump 61 b is to the drive substrate 20 and the electrode substrate 30 in the circumferential direction in the stacking direction. The space | interval of the mutual circumferential direction of the lamination direction with the electrode substrate 30 may be sparse.

Next, a fifth embodiment will be described with reference to FIGS. 12A and 12B. The same parts as those in the first to fourth embodiments described above are denoted by the same reference numerals, and detailed description thereof is omitted. For simplification of illustration, for example, a part of the constituent members is omitted in some drawings so that the bonding film 60a is omitted in FIG. 12B.
The distance adjusting unit 60 further includes a ring-shaped joining frame 67. The joining frame 67 has a desired width, holds the frame 22, is joined to the frame 22, has an inner diameter substantially the same as the outer diameter of the drive region 21 and the diameter of the interference avoiding portion 70, and is the same as the bump 61b. Has height.

  The inner shape of the joining frame 67 only needs to have a shape similar to the outer shape of the drive region 21. Therefore, if the outer shape of the drive region 21 is, for example, a rectangular shape, the inner shape of the joining frame 67 is also a rectangular shape.

  The joining frame 67 may be arranged on the surface 62b or the frame 22 as long as the inner diameter of the joining frame 67 is arranged in the same straight line as the interference avoiding unit 70 in the stacking direction.

  In the first embodiment, the joining frame 67 may be disposed on the surface 30a.

  At this time, the bonding frame 67 is manufactured by removing the surfaces 20a, 30a, and 62b of the drive substrate 20, the electrode substrate 30, or the spacer member 61a in the same manner as the bumps 60c, 61b, and 61c. It is integral with the electrode substrate 30 or the spacer member 61a. Therefore, the joining frame 67 is a Si substrate or borosilicate glass. A bonding film similar to the bonding film 23 may be disposed on the bonding surface of the bonding frame 67.

  At this time, the bumps 60c, 61b, 61c are formed between the outer peripheral edge 67a of the bonding frame 67 and the outer peripheral edge 20c of the frame 22, and between the outer peripheral edge 67a of the bonding frame 67 and the outer peripheral edge 30b of the electrode substrate 30. A plurality of them are arranged at least on one side and have the same height as the joining frame 67.

Next, the operation of this embodiment will be described.
(Step 41)
The operations from Step 11 to Step 15 are performed.

(Step42)
The electrode substrate 30 and the distance adjusting unit 60 are mounted so that the center point 21b and the center point 71 are positioned on the same axis. Therefore, the joining frame 67 continuously holds the outer periphery of the drive region 21.
When a drive voltage is applied to the electrode pad 31 and the drive region 21 is driven, an external force is applied to the frame 22. However, since the joining frame 67 continuously holds the outer periphery of the drive region 21, bending deformation of the frame 22 due to external force is reduced as compared with the first to fourth embodiments.

  As described above, the present embodiment can provide the MEMS device mounting structure 1 in which the fluctuation of the gap 2 is small even when the drive region 21 is driven, as compared with the first to fourth embodiments.

  In each embodiment described above, as shown in FIGS. 13A and 13B, the distance adjustment unit 60 is interposed between the drive substrate 20 and the electrode substrate 30, abuts on the drive substrate 20 and the electrode substrate 30, You may further have the some joint convex part 40 which has the height for hold | maintaining the distance between the drive area | region 21 and the electrode pad 31 as desired.

  The joint protrusions 40 have the same height, and are disposed on, for example, the electrode substrate 30 and between the outer peripheral edge 31 a of the electrode pad 31 and the outer peripheral edge 30 b of the electrode substrate 30. That is, the bonding convex portion 40 is disposed at a desired position on the electrode substrate 30 so as not to overlap the electrode pad 31.

  The bonding convex portion 40 is a spacer member interposed between the drive substrate 20 and the electrode substrate 30. After the drive substrate 20 and the electrode substrate 30 are mounted, the joint projection 40 has a height for holding the gap 2 as desired. The height of the joint projection 40 is the same as the desired gap 2.

  Further, as shown in FIG. 13C, the bonding convex portion 40 includes a bonding film 40a which is a film on the surface of the bonding convex portion 40, a base member 40b formed under the bonding film 40a, and a base member 40b. And a bump 40c formed.

  The bonding film 40 a has a bonding surface 40 d that comes into contact with the bonding film 23. Similar to the bonding surface 60d, the bonding surface 40d is a surface on which the drive substrate 20 is bonded to the bonding convex portion 40, and includes a vertex of the bonding film 40a. The total area of the bonding surfaces 40 d of all bonding films 40 a and the bonding surfaces 60 d of all bonding films 60 a is smaller than the projected area of the frame 22. The bonding film 40a contacts the bonding film 23 evenly on the bonding surface 40d and is solid-phase bonded to the bonding film 23. This solid-phase bonding is, for example, surface activated bonding (hereinafter referred to as SAB).

  A Cr film or a Ti film as an adhesion layer may be formed under the bonding film 40a. The bonding film 40a is, for example, gold.

  The base member 40b is formed of a material that is more flexible than the material of the bonding film 40a. The term “soft” means that the Young's modulus of the base member 40b is smaller than the Young's modulus of the bonding film 40a. When the bonding film 40a is, for example, gold, for example, aluminum or an aluminum alloy is suitable for the base member 40b. In this case, for example, the Young's modulus of the bonding film 40a made of gold is about 78 Mpa, for example, and the Young's modulus of the base member 40b made of aluminum is about 70 Mpa, for example. As a result, the base member 40b has a more flexible structure than the bonding film 40a.

  The base member 40b is thicker than the bonding film 40a and is formed on the bumps 40c. In the present embodiment, the bonding film 40a and the base member 40b are formed by sputtering so that the bonding film 40a has a thickness of, for example, 0.2 μm, and the base member 40b has a thickness of, for example, 2 μm. .

  The bump 40 c is formed on the electrode substrate 30. More specifically, the bump 40 c is a convex portion in the electrode substrate 30 that is manufactured by removing a part of the electrode substrate 30. That is, in the present embodiment, the bump 40 c is integral with the electrode substrate 30 and is formed of the same member as the electrode substrate 30. The processing for removing a part of the electrode substrate 30 is any one of blasting, etching, and laser processing.

  The bonding convex portion 40 has a height for holding the gap 2 as desired, and the base member 40b is more flexible and thicker than the bonding film 40a, so that it easily deforms. Therefore, in the present embodiment, when the drive substrate 20 and the electrode substrate 30 are joined, the base member 40b is deformed, so that deformation due to the mounting of the drive substrate 20 can be suppressed, and fluctuation of the gap 2 can be suppressed. Can be reliably improved in a state in which is uniformly held so as to have a desired value. Thereby, in this embodiment, the mounting structure 1 of the MEMS device which can exhibit a desired drive characteristic can be provided.

  That is, in the present embodiment, it is possible to provide the MEMS device mounting structure 1 that can improve the adhesion between the drive substrate 20 and the electrode substrate 30 and suppress the variation of the gap 2.

  Moreover, in this embodiment, since the desired site | part in the drive board | substrate 20 and the electrode substrate 30 joins reliably by the junction convex part 40 using SAB, it is not intended unjoined between the junction film 23 and the junction convex part 40. It is possible to prevent the occurrence of a gap that is a part.

  In addition, although the joining convex part 40 is arrange | positioned at the electrode substrate 30, it is not necessary to limit to this. As shown in FIG. 14A and FIG. 14B, the joint convex part 40 may be arrange | positioned, for example in the flame | frame 22 (specifically back surface 20a). In this case, the bump 40c is formed on the frame 22 (specifically, the back surface 20a). More specifically, the bump 40 c is a convex portion in the frame 22 that is manufactured by removing a part of the frame 22. That is, the bump 40 c is integral with the frame 22 and is formed of the same member as the frame 22. The processing for removing a part of the frame 22 is any one of blasting, etching, and laser processing.

  Further, as shown in FIGS. 13A, 14A, and 14C, the joint protrusion 40 may be disposed on at least one of the frame 22 and the electrode substrate 30.

  In this case, the bonding protrusions 40 are arranged symmetrically with respect to the center line in the planar direction of the electrode pad 31 between the outer peripheral edge 31a of the electrode pad 31 and the outer peripheral edge 30b of the electrode substrate 30. Or it arrange | positions axisymmetrically on the basis of the centerline of the planar direction of the drive area | region 21 between the outer periphery 21a of the drive area | region 21, and the outer periphery 20c of the drive board | substrate 20 (frame 22).

  In the present embodiment, the drive substrate 20 (specifically, the frame 22) and the electrode substrate 30 are, for example, a Si substrate or borosilicate glass. As described above, the bump 40 c is a convex portion of the electrode substrate 30 that is manufactured by removing a part of the electrode substrate 30, is integral with the electrode substrate 30, and is formed of the same member as the electrode substrate 30. Yes. Further, the bump 40 c is a convex portion of the frame 22 that is manufactured by removing a part of the frame 22 as described above, and is integrated with the frame 22 and formed of the same member as the frame 22. Therefore, the bump 40 c is, for example, a Si substrate or borosilicate glass, like the drive substrate 20 and the electrode substrate 30.

  Of course, as shown in FIGS. 15A and 15B, the joint protrusion 40 may be disposed on the spacer member 61a in the same manner as the bumps 61b and 61c. Similar to the bumps 61b and 61c shown in FIGS. 9A to 9M, the bonding convex portion 40 may be disposed on at least one of the front surface 62b, the back surface 20a, the back surface 62c, and the front surface 30a.

  As shown in FIGS. 16A, 16B, and 16C, the bonding convex portion 40 includes a bonding film 40a that is a film on the surface of the bonding convex portion 40, and a base member 40b that is formed under the bonding film 40a. You may have only.

  The base member 40b is a thin metal film formed on the spacer member 50 (surface 51a) and is separate from the spacer member 61a. The base member 40b is manufactured by removing a part of a thin metal film formed on the spacer member 61a by sputtering or plating. The processing for removing a part of the thin metal film is any one of blasting, etching, and laser processing.

  16D and FIG. 16E, this point is the same even if the bonding convex portion 40 is disposed on the drive substrate 20 or the electrode substrate 30. FIG.

  Further, the base member 40b may be disposed between the bonding film 60a and the bump 60c as shown in FIG. Of course, the base member 40b may be disposed between the bonding film 60a and the bump 61b or between the bonding film 60a and the bump 61c. In this case, the base member 40b is formed of a material that is more flexible than the material of the bonding film 60a. The term “soft” means that the Young's modulus of the base member 40b is smaller than the Young's modulus of the bonding film 60a. This is the same as described above.

  The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Mounting structure, 2 ... Gap, 20 ... Drive board, 20a ... Back surface, 20b ... Front surface, 20c ... Outer periphery, 21 ... Drive region, 21a ... Outer periphery, 21b ... Center point, 22 ... Frame, 23 ... Bonding film 30 ... Electrode substrate, 30a ... Surface, 30b ... Outer periphery, 31 ... Electrode pad, 31a ... Outer periphery, 32 ... Bonding film, 60 ... Distance adjusting part, 60d ... Bonding surface, 60c ... Bump, 60a ... Bonding film, 61a ... spacer member, 61b, 61c ... bump, 62b ... front surface, 62c ... back surface, 63 ... outer periphery, 65 ... bonding film, 67 ... bonding frame, 67a ... outer periphery, 70 ... interference avoiding part, 71a ... outer periphery, 71: Center point.

Claims (11)

A drive substrate having a drive region and a frame for holding the drive region;
An electrode substrate on which the driving substrate is stacked, the electrode pad having an electrode pad capable of applying a driving voltage for driving the driving region facing the driving region;
A distance adjusting unit interposed between the drive substrate and the electrode substrate and having a height for holding a desired distance between the drive region and the electrode pad;
An interference avoidance unit formed between the drive substrate and the electrode substrate so that the distance adjustment unit does not interfere with the drive region when the drive region is driven;
Comprising
The distance adjusting unit is
Bumps that are dispersed and arranged in at least one of the drive substrate and the electrode substrate;
A bonding film that is formed on each of the bumps, has a bonding surface that is bonded to the other of the drive substrate and the electrode substrate, and is a film on the surface of the distance adjustment unit;
Have
The total area of the bonding surfaces of all the bonding films is smaller than the other projected area of the drive substrate and the electrode substrate to which the bonding surfaces are bonded,
At least one of the bumps is disposed in the vicinity of the outer peripheral edge of the drive region, and the bonding surface is disposed in a non-interference with the electrode pad, or is disposed in the vicinity of the outer peripheral edge of the electrode pad and A mounting structure for a MEMS device, wherein a bonding surface is disposed so as not to interfere with the drive region.   The mounting structure of the MEMS device according to claim 1, wherein the bump has a height for holding the distance as desired.   3. The MEMS according to claim 2, wherein the bumps are rotationally symmetric in a plane direction with respect to a center point of the driving region, or are line-symmetrically in a plane direction with reference to a desired center line. Device mounting structure. The distance adjusting unit further includes a spacer member having a thickness for holding the distance as desired together with the bump,
4. The MEMS device mounting structure according to claim 3, wherein the bump is disposed on at least one of the drive substrate, the electrode substrate, and the spacer member.   5. The bumps are disposed at a desired equiangular distance from each other around a center point of the drive region in a circumferential direction of the drive substrate and the electrode substrate in a stacking direction. A mounting structure of the MEMS device according to claim 1.   The bumps are arranged such that in the plane direction of the driving area, the distance between the bumps becomes closer as the driving area is closer, and the distance between the bumps becomes smaller as the distance from the driving area becomes farther. The mounting structure of the MEMS device according to claim 5.   The closer the bump is to the drive region, the closer the distance between the drive substrate and the electrode substrate in the circumferential direction in the stacking direction, and the closer to the drive region, the closer to the drive region the electrode substrate is stacked in the stacking direction. The mounting structure for a MEMS device according to claim 6, wherein the intervals in the circumferential direction are sparse. The distance adjustment unit further includes a hollow ring-shaped frame having a desired width, holding the frame, joining the frame, and having an inner diameter substantially the same as an outer diameter of the drive region;
The bump is disposed on at least one of an outer peripheral edge of the bonding frame and an outer peripheral edge of the frame, and an outer peripheral edge of the bonding frame and an outer peripheral edge of the electrode pad. The mounting structure of the MEMS device according to claim 7, wherein a plurality of the same heights are arranged.   The bump and the bonding frame are produced by processing to remove the surface of the drive substrate, the electrode substrate, or the spacer member, and are integrated with the produced drive substrate, the electrode substrate, or the spacer member. The mounting structure of the MEMS device according to claim 8. The bump, the spacer member, and the bonding frame are a Si substrate or borosilicate glass,
The mounting structure of the MEMS device according to claim 9, wherein the bonding film is gold. The drive substrate, the electrode substrate, and the spacer member each have a drive substrate side bonding film, an electrode substrate side bonding film, and a spacer member side bonding film that are bonded to the bonding surface,
The mounting structure for a MEMS device according to claim 10, wherein the drive substrate side bonding film, the electrode substrate side bonding film, and the spacer member side bonding film are gold.

Images