JP2017126626A - Electronic device, method for manufacturing the same, electronic equipment, and mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device capable of increasing the bonding strength by keeping the distance h2 between a substrate and a lid constant, and a method for manufacturing the electronic device. An electronic device of the present invention is bonded to a functional element 80 bonded on a substrate 10 to a bonding portion 61 on the substrate 10 via a bonding material 60, and covers the functional element 80 with the substrate 10. It includes a lid 50 forming an internal space between them, and includes a gap member 90 that is in contact with the surface of the base 10 on the lid 50 side and the surface of the lid 50 on the base 10 side. The height of the gap member 90 is larger than the thickness of the bonding material 60. [Selection diagram] Fig. 2

Description

  The present invention relates to an electronic device, an electronic device manufacturing method, an electronic apparatus, and a moving object.

  Conventionally, for example, an electronic device including a functional element that detects a physical quantity using silicon MEMS (Micro Electro Mechanical Systems) technology has been formed from a silicon substrate or the like on a package substrate (substrate) such as a semiconductor substrate or a glass substrate. There are known acceleration sensors and gyro sensors that are provided with functional elements and are hermetically sealed with a sealing material.

  As such an electronic device, for example, in Patent Document 1, a low melting point glass as a sealing material is heated to a pour point or higher in a reduced-pressure atmosphere, and a base substrate and a lid are joined to manufacture a package. It is disclosed. The low-melting glass described in Patent Document 1 includes a gap material, and the gap material allows the gap between the base substrate and the lid to be kept constant so that the low-melting glass is reliably present and bonded. A manufacturing method is disclosed.

JP 2014-38969 A

  However, in the method for manufacturing an electronic device described in Patent Document 1, the content of a component having a bonding function included in the low-melting glass is obtained by adding a gap material that does not have a bonding function to the low-melting glass. There is a risk that the bonding strength between the base substrate and the lid may decrease.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] An electronic device according to this application example is bonded to a bonding portion on the substrate via a substrate, a functional element bonded on the substrate, and a bonding material, and covers the functional element. A lid that forms an internal space with the base, and includes a gap member that is in contact with the lid-side surface of the base and the base-side surface of the lid, The height of the gap member is larger than the thickness of the bonding material.

  According to this configuration, when the base and the lid are joined via the joining material, the distance between the base and the lid is defined by the height of the gap member. As a result, regardless of the amount of the bonding material applied to the bonding portion, the bonding material can be reliably inserted between the base body and the lid body at a certain height (amount).

  Therefore, even when the amount of the bonding material applied to the bonding portion is larger than the specified amount, it is possible to suppress an increase in the distance between the base and the lid. Moreover, even when the amount of the bonding material applied to the bonding portion is smaller than the specified amount, it is possible to suppress the interval between the base body and the lid from becoming small. As a result, since the bonding between the base and the lid can be performed with a constant interval, deterioration of the bonding strength can be reduced and a highly reliable electronic device can be obtained.

  Application Example 2 In the electronic device according to the application example described above, the height of the gap member is substantially the same as the thickness of the functional element.

  According to this configuration, the gap member and the functional element can be easily formed collectively from the same substrate, and the cost can be reduced.

  Application Example 3 The electronic device according to the application example is characterized in that the gap member is formed of the same material as the functional element.

  According to this configuration, since the manufacturing process only for forming the gap member is not required, the gap member can be obtained without increasing the cost.

  Application Example 4 In the electronic device according to the application example, the gap member is disposed so as to surround the functional element.

  According to this configuration, when the base and the lid are joined via the joining material, the gap between the base and the lid is defined by the height of the gap member around the functional element. As a result, regardless of the amount of bonding material applied to the bonding portion, the bonding material can be reliably inserted at a certain height (amount) between the base and the cover body around the functional element. it can. As a result, the base body and the lid can be reliably bonded.

  Application Example 5 In the electronic device according to the application example, the gap member is formed including silicon.

  According to this configuration, it is possible to apply a processing technique used for manufacturing a silicon semiconductor device when forming the gap member. As a result, the gap member can be formed with a fine and high accuracy.

  Application Example 6 In the electronic device according to the application example described above, the lid body includes silicon.

  According to this configuration, it is possible to apply a processing technique used for manufacturing a silicon semiconductor device when forming the lid. As a result, the lid can be formed with a fine and high accuracy.

  Application Example 7 In the electronic device according to the application example described above, the gap member is integrated with the lid.

  According to this configuration, the gap member and the lid can be easily formed collectively from the same substrate, and the cost can be reduced.

  Application Example 8 In the electronic device according to the application example described above, the base is formed including glass.

  According to this configuration, it is not necessary to interpose the insulating film on the base when maintaining the insulating property between the base and the functional element, and the insulation can be easily separated.

  Application Example 9 In the electronic device according to the application example described above, the bonding material is formed including low-melting glass.

  According to this structure, when joining a base | substrate and a cover body, compared with the case where it joins by resin, a metal, soda glass, etc., it can join at low temperature. As a result, exposure of the base body and the lid body to high temperatures can be reduced, and breakage can be suppressed.

  Application Example 10 An electronic device manufacturing method according to this application example includes a first bonding process for bonding functional elements on a substrate, an etching process for forming a gap member, and a flexible bonding material. A second bonding step of bonding a lid to the bonding portion of the base so as to cover the functional element and form an internal space with the base. In the second bonding step, A step of bringing a gap member into contact with the surface of the base on the lid side and the surface of the lid on the base side, wherein the height of the gap member is larger than the thickness of the bonding material; To do.

  According to this method, when the base body and the lid body are joined via the joining material, the distance between the base body and the lid body is defined by the height of the gap member. As a result, regardless of the amount of bonding material applied to the bonding portion, the bonding material can be reliably inserted at a constant height between the base body and the lid.

  Therefore, even when the amount of the bonding material applied to the bonding portion is larger than the specified amount, it is possible to suppress an increase in the distance between the base and the lid. Moreover, even when the amount of the bonding material applied to the bonding portion is less than the specified amount, it is possible to suppress the interval between the base body and the lid body from being reduced. As a result, since the base body and the lid can be reliably bonded, deterioration of the bonding strength can be reduced, and a highly reliable method for manufacturing an electronic device can be provided.

  Application Example 11 An electronic apparatus according to this application example includes the electronic device described above.

  According to such an electronic device, a highly reliable electronic device can be obtained by mounting the above-described electronic device.

  Application Example 12 A moving object according to this application example includes the electronic device described above.

  According to such a moving body, a highly reliable moving body can be obtained by mounting the electronic device described above.

The top view which shows typically schematic structure of the acceleration sensor as an example of an electronic device. FIG. 2 is a front sectional view schematically showing the schematic configuration of the acceleration sensor, taken along line AA in FIG. 1. The front sectional view which expanded the gap member and projection part of Drawing 2. The flowchart which shows the outline of the manufacturing method of the acceleration sensor which concerns on this embodiment. The front sectional view which shows the process flow 1 of the manufacturing method of an acceleration sensor. FIG. 5 is a front sectional view showing process flows 2 and 4 of the method for manufacturing the acceleration sensor. The front sectional view which shows the process flow 3 of the manufacturing method of an acceleration sensor. FIG. 6 is a front sectional view showing a process flow 5 of the method for manufacturing the acceleration sensor. The front sectional view which shows the process flow 6 of the manufacturing method of an acceleration sensor. The front sectional view showing process flow 7 of the manufacturing method of an acceleration sensor. The front sectional view which showed typically the acceleration sensor which concerns on the modification 1, and expanded the gap | interval member and the projection part. FIG. 10 is a schematic plan view showing the arrangement of gap members according to Modification 2. FIG. 10 is a schematic plan view showing the arrangement of gap members according to Modification 3. FIG. 10 is a schematic plan view showing the arrangement of gap members according to Modification 4. FIG. 10 is a schematic plan view showing the arrangement of gap members according to Modification 5. FIG. 10 is a schematic plan view showing the arrangement of gap members according to Modification 6. The perspective view which shows typically the structure of the mobile type (or notebook type) personal computer as an electronic device provided with the electronic device. The perspective view which shows typically the structure of the mobile telephone (PHS is also included) as an electronic device provided with the electronic device. The perspective view which shows typically the structure of the digital still camera as an electronic device provided with the electronic device. The perspective view which shows typically the motor vehicle as an example of the mobile body provided with the electronic device.

  Hereinafter, this embodiment will be described. In addition, this embodiment demonstrated below does not unduly limit the content of this invention described in the claim. In addition, all the configurations described in the present embodiment are not necessarily essential configuration requirements of the present invention. In the following, for convenience of explanation, in each drawing, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other, and the direction parallel to the X axis is referred to as the “X axis direction”, the Y axis. The direction parallel to is called the “Y-axis direction”, and the direction parallel to the Z-axis is called the “Z-axis direction”. The + Z-axis direction side is referred to as “upper”, and the −Z-axis direction side is referred to as “lower”.

<Embodiment>
[Accelerometer]
The structure of the acceleration sensor as the electronic device according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2 schematically show a schematic configuration of an acceleration sensor as an example of an electronic device according to the present embodiment. FIG. 1 is a plan view, and FIG. 2 is a line AA in FIG. It is a front sectional view.

  As shown in FIGS. 1 and 2, the acceleration sensor 100 according to the present embodiment includes a base body 10, a groove portion 15, a wiring 20, an external connection terminal 30, a lid body 50, a bonding material 60, and a functional element. 80 and the gap member 90.

  The acceleration sensor 100 includes groove portions 16 and 17, wirings 22 and 24, external connection terminals 32 and 34, a through hole 58, and a sealing member 70. For convenience, in FIG. 1, the lid 50, the through hole 58, and the sealing member 70 are shown in a transparent manner.

(Substrate)
The substrate 10 is made of glass (borosilicate glass). The material of the base 10 is not limited to glass, but may be, for example, silicon. As shown in FIG. 2, the base 10 has an upper surface (hereinafter referred to as a first surface 11) of the base 10 and a lower surface (referred to as a second surface 12) opposite to the first surface 11. Yes. A recess 14 is provided in the first surface 11.

  The movable portion 86 and the movable electrode portion 87 of the functional element 80 are arranged in the + Z-axis direction of the concave portion 14, and the movable portion 86 and the movable electrode portion 87 are not obstructed by the base body 10 by the concave portion 14 and are in a desired direction. Can be moved to. In the plan view seen from the Z-axis direction, the shape of the recess 14 is not particularly limited, but is rectangular in this embodiment.

  The groove portion 15 is provided on the first surface 11 of the base body 10 and extends from the inside to the outside of the internal space 56 surrounded by the base body 10 and the lid body 50. For example, the groove 15 has a planar shape corresponding to the planar shapes of the wiring 20 and the external connection terminal 30.

  Similarly, the grooves 16 and 17 are provided on the first surface 11 of the base body 10 along the outer periphery of the recess 14. More specifically, the groove 16 extends from the external connection terminal 32 in the −X axis direction, passes along the outer periphery of the recess 14, the + Y axis direction side of the recess 14, the −X axis direction side, and −Y Up to the fixed electrode portion 88 disposed on the most + X-axis direction side on the axial direction side.

  The groove portion 17 extends from the external connection terminal 34 in the −X-axis direction, passes along the outer side of the groove portion 16, the + Y-axis direction side of the concave portion 14, the −X-axis direction side, and the most + X on the −Y-axis direction side. Up to the fixed electrode portion 89 arranged on the axial direction side is provided.

  The depth of the grooves 15, 16, and 17 (size in the Z-axis direction) is larger than the thickness (size in the Z-axis direction) of the wirings 20, 22, and 24 and the external connection terminals 30, 32, and 34. Thereby, it is possible to suppress the wirings 20, 22, 24 and the external connection terminals 30, 32, 34 from protruding in the + Z-axis direction from the first surface 11.

(wiring)
The wiring 20 is provided in the groove 15. Specifically, the wiring 20 is provided on the surface of the base body 10 that defines the bottom surface of the groove 15. The wiring 20 electrically connects the functional element 80 and the external connection terminal 30. The wiring 20 is connected to the fixing portion 81 of the functional element 80 through the contact portion 40 provided in the groove portion 15.

  The wiring 22 is provided in the groove 16. Specifically, the wiring 22 is provided on the surface of the base 10 that defines the bottom surface of the groove 16. The wiring 22 electrically connects the functional element 80 and the external connection terminal 32. The wiring 22 is connected to the fixed electrode portion 88 of the functional element 80 through the contact portion 42.

  The wiring 24 is provided in the groove portion 17. Specifically, the wiring 24 is provided on the surface of the base body 10 that defines the bottom surface of the groove portion 17. The wiring 24 electrically connects the functional element 80 and the external connection terminal 34. The wiring 24 is connected to the fixed electrode portion 89 of the functional element 80 through the contact portion 44.

  The external connection terminal 30 is provided on the wiring 20 in the groove 15. The external connection terminal 30 is disposed outside the internal space 56 and is provided at a position overlapping the terminal hole 55 of the lid 50 in a plan view viewed from the Z-axis direction. The terminal hole 55 is a hole that penetrates the lid 50 in the Z-axis direction in order to connect an external device (not shown) and the external connection terminal 30.

  Similarly, the external connection terminal 32 is provided on the wiring 22 in the groove 16, and the external connection terminal 34 is provided on the wiring 24 in the groove 17. The external connection terminals 32 and 34 are disposed outside the internal space 56. The external connection terminals 30, 32, and 34 are arranged side by side along the Y-axis direction.

  The materials of the wirings 20, 22, 24 and the external connection terminals 30, 32, 34 are, for example, ITO (Indium Tin Oxide), aluminum, gold, platinum, titanium, tungsten, chromium, and the like. The material of the contact portions 40, 42, 44 is, for example, gold, copper, aluminum, platinum, titanium, tungsten, chromium, or the like.

  When the wiring 20, 22, 24 and the external connection terminals 30, 32, 34 are transparent electrode materials such as ITO, when the substrate 10 is transparent, for example, on the wirings 20, 22, 24 or outside Foreign matters present on the connection terminals 30, 32, and 34 can be easily confirmed from the second surface 12 side of the base 10.

  In the above description, the acceleration sensor 100 including the three wirings 20, 22, 24 and the three external connection terminals 30, 32, 34 has been described as an example, but the number of wirings and external connection terminals is the same as that of the functional element 80. It can be appropriately changed depending on the shape and number.

(Lid)
The lid 50 is bonded onto the first surface 11 of the base body 10 via the bonding material 60, covers the functional element 80, and forms an internal space 56 between the base body 10. The lid 50 is made of silicon.

  The lid 50 has an upper surface (hereinafter referred to as a third surface 51) of the lid 50 and a lower surface (referred to as a fourth surface 52) opposite to the third surface 51. The fourth surface 52 is provided with a recess 57. The recess 57 of the lid 50 has a fifth surface 54 that defines an internal space 56 that houses the functional element 80. The internal space 56 is sealed, for example, in an inert gas atmosphere such as nitrogen gas or in a reduced pressure state.

  The protrusion 53 is a portion of the lid 50 that protrudes in the −Z-axis direction, and is provided on the outer periphery of the lid 50.

(Joining material)
The base body 10 and the lid body 50 are joined by a joining material 60 at a joining portion 61. Examples of the bonding material 60 include low-melting glass. The bonding material 60 is not particularly limited, for example, lead silicate (PbO-SiO ₂₎ salt, boric acid (B ₂ O ₃₎ salt, phosphoric acid (P ₂ O ₅₎ salt, germanate acid (GeO ₂₎ Salts, thalamic acid (Tl ₂ O) salt, molybdic acid (MoO ₃ ) salt, telluric acid (TeO ₂ ) salt, vanadate (V ₂ O ₅ ) salt, and the like.

  One of these can be used alone or in combination of two or more, that is, mixed or laminated. What is necessary is just to determine the constituent material of the joining material 60 suitably according to the material of the base | substrate 10 or the cover body 50. FIG.

(Through hole)
The through hole 58 penetrates the lid 50 in the Z-axis direction from the third surface 51 to the fifth surface 54 of the lid 50 and communicates with the internal space 56. The through hole 58 has a tapered shape in which the opening diameter becomes smaller from the third surface 51 toward the fifth surface 54.

  By doing so, it is possible to prevent the solder balls from falling when the solder balls described later are melted. Further, since the opening area becomes narrower from the third surface 51 toward the fifth surface 54, the sealing can be performed more reliably.

  The sealing member 70 is provided in the through hole 58 and closes the through hole 58. The internal space 56 is sealed by the sealing member 70. The material of the sealing member 70 is, for example, an alloy such as AuGe, AuSi, AuSn, SnPb, PbAg, SnAgCu, SnZnBi.

  By providing the through hole 58 and the sealing member 70, the internal space 56 can be made an inert gas atmosphere such as nitrogen gas through the through hole 58. Further, the degree of vacuum of the internal space 56 can be adjusted through the through hole 58.

(Functional element)
The functional element 80 is accommodated in the internal space 56 and joined to the first surface 11 of the base body 10. Hereinafter, a case where the functional element 80 is an acceleration sensor element (capacitive MEMS acceleration sensor element) that detects acceleration in the horizontal direction (X-axis direction) will be described.

  The functional element 80 includes fixed portions 81 and 82, connecting portions 84 and 85, a movable portion 86, a movable electrode portion 87, and fixed electrode portions 88 and 89. The material of the functional element 80 is, for example, silicon imparted with conductivity by doping impurities such as phosphorus and boron.

  The fixing portions 81 and 82 are joined to the first surface 11 of the base body 10. The fixing portions 81 and 82 are provided so as to straddle the outer peripheral edge of the recess 14 in a plan view viewed from the Z-axis direction.

  The connecting portions 84 and 85 connect the movable portion 86 to the fixed portions 81 and 82. The connecting portions 84 and 85 have a desired spring constant and are configured such that the movable portion 86 is displaced in the X-axis direction.

  The connecting portion 84 is configured by two beams 84a and 84b having a shape extending in the X-axis direction while meandering in the Y-axis direction. Similarly, the connecting portion 85 is configured by two beams 85a and 85b having a shape extending in the X-axis direction while meandering in the Y-axis direction.

  The movable portion 86 is provided between the fixed portion 81 and the fixed portion 82. In a plan view viewed from the Z-axis direction, the movable portion 86 is a rectangle having a long side along the X-axis direction.

  The movable portion 86 is displaced in the + X-axis direction or the −X-axis direction while elastically deforming the connecting portions 84 and 85 according to the change in the acceleration in the X-axis direction. With such a displacement, the size of the gap between the movable electrode portion 87 and the fixed electrode portion 88 and the size of the gap between the movable electrode portion 87 and the fixed electrode portion 89 change.

  That is, with such a displacement, the magnitude of the capacitance between the movable electrode portion 87 and the fixed electrode portion 88, and the magnitude of the capacitance between the movable electrode portion 87 and the fixed electrode portion 89. Changes. Based on these changes in capacitance, the functional element 80 can detect acceleration in the X-axis direction.

  The movable electrode portion 87 is connected to the movable portion 86, and a plurality of movable electrode portions 87 are provided. The movable electrode portion 87 protrudes from the movable portion 86 in the + Y-axis direction and the −Y-axis direction, and is arranged along the X-axis direction so as to form a comb shape.

  The fixed electrode portions 88 and 89 are joined to the first surface 11 of the base 10 with one end portion as a fixed end, and the other end portion extends to the movable portion 86 side as a free end. The fixed electrode portion 88 is electrically connected to the wiring 22, and the fixed electrode portion 89 is electrically connected to the wiring 24.

  A plurality of fixed electrode portions 88 and 89 are alternately arranged in the X-axis direction so as to form a comb-teeth shape. The fixed electrode portions 88 and 89 are provided to face the movable electrode portion 87 with a space therebetween, and the fixed electrode portion 88 is disposed on the −X axis direction side of the movable electrode portion 87 and fixed on the + X axis direction side. An electrode portion 89 is disposed.

  The fixed portions 81 and 82, the connecting portions 84 and 85, the movable portion 86, and the movable electrode portion 87 are integrally formed.

  The bonding method of the base 10 and the functional element 80 (fixed portions 81 and 82 and fixed electrode portions 88 and 89) is, for example, that the base 10 is made of glass containing alkali metal ions, and the functional element 80 is made of silicon. In some cases, an anodic bonding method can be applied. In the present embodiment, the base 10 and the functional element 80 are bonded by anodic bonding.

  In the acceleration sensor 100, the capacitance between the movable electrode part 87 and the fixed electrode part 88 can be measured by using the external connection terminals 30 and 32. Further, in the acceleration sensor 100, the capacitance between the movable electrode portion 87 and the fixed electrode portion 89 can be measured by using the external connection terminals 30 and 34.

  As described above, in the acceleration sensor 100, the electrostatic capacitance between the movable electrode portion 87 and the fixed electrode portion 88 and the electrostatic capacitance between the movable electrode portion 87 and the fixed electrode portion 89 are separately measured. Based on the measurement result, acceleration can be detected with high accuracy.

  Although the case where the functional element 80 is an acceleration sensor element that detects acceleration in the X-axis direction has been described above, the functional element 80 may be an acceleration sensor element that detects acceleration in the Y-axis direction. Alternatively, an acceleration sensor element that detects acceleration in the vertical direction (Z-axis direction) may be used.

  The functional element 80 is not limited to an acceleration sensor element, and may be, for example, a gyro sensor element that detects angular velocity or a pressure sensor element that detects pressure. Further, the acceleration sensor 100 may be equipped with a plurality of such functional elements 80, or may be combined with elements having different functions.

(Gap member)
Next, the gap member 90 will be described with reference to FIGS. FIG. 3 is an enlarged front sectional view of the gap member and the protrusion of FIG. As shown in FIGS. 2 and 3, the gap member 90 of the present embodiment has the functional element 80 sandwiched outside the functional element 80 on the first surface 11 of the base 10 in a plan view as viewed from the Z-axis direction. It is disposed at a position facing each other, and is provided in contact with the first surface 11 of the base 10 and the fourth surface 52 of the lid 50.

  The length (hereinafter referred to as height) h1 of the gap member 90 in the Z-axis direction is higher than the height of the bonding material 60, that is, the distance h2 between the base 10 and the lid 50 (h1> h2). The height h3 of the protrusion 53 is lower than the height h1 of the gap member 90 (h1> h3). When the height h2 of the bonding material 60 and the height h3 of the projection 53 are matched, the height h1 of the gap member 90 is matched (h1 = h2 + h3).

  The height (interval between the base 10 and the lid 50) h2 of the bonding material 60 is determined from the viewpoint of the bonding strength between the base 10 and the lid 50. In the present embodiment, the height (the distance between the base body 10 and the lid 50) h2 of the bonding material 60 is about 10 μm.

  Similarly, the height h <b> 3 of the protrusion 53 is determined in consideration of the thickness of the functional element 80. The height h1 of the gap member 90 is determined by the height (interval between the base body 10 and the lid 50) h2 of the bonding material 60 and the height h3 of the protrusion 53.

  At this time, the height h1 of the gap member 90 may be the same as the thickness of the functional element 80. As an example, when the height h2 of the bonding material 60 (the distance between the base body 10 and the lid 50) h2 is 10 μm and the height h3 of the protrusion 53 is 20 μm, the height h1 of the gap member 90 is 30 μm.

  The length W1 in the Y-axis direction of the gap member 90 (hereinafter referred to as the width) is about 50 μm, the width W2 of the bonding material 60 is about 200 μm, and the width W3 of the protrusion 53 is about 200 μm. Is desirable.

  If the width W1 of the gap member 90, the width W2 of the bonding material 60, and the width W3 of the protrusion 53 are too large, the functional element 80 may be contacted, and the detection accuracy may be reduced. On the other hand, if the width W1 of the gap member 90, the width W2 of the bonding material 60, and the width W3 of the protrusion 53 are too small, the height (interval between the base body 10 and the lid 50) h2 of the bonding material 60 is defined. Is difficult.

  Examples of the material of the gap member 90 include glass (borosilicate glass), silicon, and the like. The gap member 90 may be made of the same material as that of the functional element 80, and may be made of, for example, silicon imparted with conductivity by doping impurities such as phosphorus and boron.

[Acceleration sensor manufacturing method]
Next, a method for manufacturing the acceleration sensor 100 as the electronic device according to the present embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing an outline of a method of manufacturing the acceleration sensor according to this embodiment. 5 to 10 are process flow diagrams (a front sectional view schematically showing the acceleration sensor in each process) showing a method for manufacturing the acceleration sensor, FIG. 5 shows a process flow 1, and FIG. 6 shows a process. FIG. 7 shows the process flow 3, FIG. 8 shows the process flow 5, FIG. 9 shows the process flow 6, and FIG. 10 shows the process flow 7. In addition, the cross-sectional position in each figure of FIGS. 5-10 is the same as that of FIG.

  As shown in FIG. 4, the method of manufacturing the acceleration sensor 100 includes a base body preparation process (step S101), a silicon substrate preparation process (step S102), and a lid body preparation process (step S103) as preparation processes. Yes.

  Moreover, the manufacturing method of the acceleration sensor 100 includes a first bonding step (step S104), an etching step (step S105), and a second bonding step (step S106). Furthermore, the method for manufacturing the acceleration sensor 100 may include a sealing step (step S107).

(1) Substrate preparation process (step S101)
As shown in FIG. 5, a base 10 is prepared. A recess 14 and grooves 15, 16, and 17 are formed on the first surface 11 of the base 10 (see FIG. 1). The concave portion 14 and the groove portions 15, 16, and 17 are formed by, for example, a photolithography technique and an etching technique. The base 10 is made of, for example, borosilicate glass having alkali metal ions.

  Wirings 20, 22, and 24 are formed in the grooves 15, 16, and 17, respectively. Next, the external connection terminal 30 and the contact part 40 are formed on the wiring 20 on the first surface 11 side of the base 10 so as to be electrically connected to the wiring 20.

  Similarly, the external connection terminal 32 and the contact portion 42 are formed on the wiring 22 so as to be electrically connected to the wiring 22 (see FIG. 1). Further, the external connection terminal 34 and the contact portion 44 are formed on the wiring 24 so as to be electrically connected to the wiring 24 (see FIG. 1).

  The wirings 20, 22, and 24 are formed by, for example, forming a conductive layer (not shown) by sputtering or CVD (Chemical Vapor Deposition), and then patterning the conductive layer. The patterning is performed by a photolithography technique and an etching technique.

  As another method, a lift-off method can be used in which a conductive film is formed after patterning with a photoresist and an unnecessary film is peeled off at the same time as the photoresist to form wiring. The external connection terminals 30, 32, and 34 and the contact portions 40, 42, and 44 are formed by the same method as the wirings 20, 22, and 24, for example.

  Through the above steps, the base body 10 provided with the concave portion 14, the wirings 20, 22, 24, the external connection terminals 30, 32, 34, the contact portions 40, 42, 44 and the like is prepared.

(2) Silicon substrate preparation process (step S102)
As shown in FIG. 6, a silicon substrate 8 as a base substrate on which the functional element 80 is formed is placed on a base 10 and prepared.

(3) Lid preparation process (step S103)
As shown in FIG. 7, a lid 50 is prepared. As a material of the lid 50, for example, silicon, glass, or the like can be applied. A recess 57 that forms an internal space 56 and a through hole 58 that penetrates from the third surface 51 to the fifth surface 54 are formed between the base body 10 and the lid 50. Photolithography technology and etching technology can be applied to the formation of the recess 57 and the through hole 58.

(4) 1st joining process (step S104)
Further, as shown in FIG. 6, the silicon substrate 8 prepared in the silicon substrate preparation step (step S102) is bonded to the base body 10 by anodic bonding. As conditions for anodic bonding, for example, it is preferable to apply a DC voltage of about 800 V to 1 kV while heating at about 300 ° C.
In addition, the heating temperature in anodic bonding can apply the range of about 250 degreeC to 500 degreeC. Therefore, the base 10 and the region where the silicon substrate 8 is in contact are joined.

  By bonding the base 10 and the silicon substrate 8 (functional element 80) by anodic bonding, the bonding strength can be increased and stable bonding can be performed. As a result, etching or the like can be performed on the silicon substrate 8.

(5) Etching process (step S105)
As shown in FIG. 8, in the first bonding step (step S104), patterning is performed on the silicon substrate 8 that is anodically bonded to the base 10, and the functional element 80 (see FIGS. 1 and 2) and the gap member 90 (see FIGS. 1 and 2). 2).

  For the patterning, a photolithography technique and dry etching or wet etching can be used. Preferably, a dry etching method using a dielectric coupled plasma (ICP (Inductively Coupled Plasma)) technique is used. Note that the silicon substrate 8 may be thinned to a desired thickness before patterning.

(6) Second joining step (step S106)
As shown in FIG. 9, low melting point glass as a bonding material 60 is applied to the lower surface of the protrusion 53 of the lid 50 prepared in the lid preparation step (step S103) using a screen printing method, and the lid 50 is attached. Bonded to the substrate 10.

  Specifically, the lid 50 accommodates the functional element 80 formed in the etching step (step S105) in the internal space 56, and one end of the gap member 90 is the surface of the base body 10 on the lid 50 side. The other end of the gap member 90 is brought into contact with the surface of the lid 50 on the base 10 side. At this time, the height of the gap member 90 is preferably larger than the thickness of the bonding material 60.

  Thereafter, the base 10 and the lid 50 are overlapped with each other through a low melting point glass to perform heat treatment. Thereby, the joining strength of the base body 10 and the lid 50 can be increased and the stable joining can be performed via the low melting point glass. Thereby, the airtight sealing by the lid 50 can be reliably performed.

(7) Sealing step (Step S107)
As shown in FIG. 10, the atmosphere of the internal space 56 is adjusted by the through hole 58, and the internal space 56 is sealed by closing the through hole 58 with the sealing member 70. At this time, for example, the internal space 56 may be in an inert gas (nitrogen gas) atmosphere or may be in a reduced pressure state through the through hole 58.

  For example, when the functional element 80 is an acceleration sensor element, the internal space 56 is desirably in a reduced pressure state. Thereby, it can suppress that the vibration phenomenon of an acceleration sensor element attenuate | damps by air viscosity.

  Specifically, a sealing member 70 is formed by disposing a spherical solder ball (not shown) in the through hole 58 and melting the solder ball by laser light irradiation.

Even if the through hole 58 is not provided, the internal space 56 can be in a reduced pressure state by performing the second bonding step (step S106) in a reduced pressure atmosphere. Thereby, the process can be simplified.
Through the above steps, the acceleration sensor 100 can be manufactured.

  In the above-described embodiment, the method using anodic bonding in the first bonding step (step S104) has been described. However, the method for manufacturing an electronic device according to the present invention can be applied to a manufacturing method in which anodic bonding is performed a plurality of times. It can also be applied to the case where anodic bonding is performed more than twice (three times or more).

  In the above description, the method using anodic bonding in the first bonding step is described. However, the present invention can be applied even when the bonding method is performed without using any other adhesive substance. Specifically, it can also be applied to a direct bonding technique that requires flatness and cleanliness of the bonding surface such as low-temperature plasma activated bonding.

From the above, according to the acceleration sensor 100 according to the present embodiment, the following effects can be obtained.
(1) Since the gap member 90 is brought into contact with the surface 11 of the base 10 on the lid 50 side and the fourth surface 52 of the lid 50 on the base 10 side, the bonding material 60 (low melting point glass) is used. Accordingly, when the base body 10 and the lid body 50 are joined together, the distance h <b> 2 between the base body 10 and the lid body 50 is defined by the height of the gap member 90.
As a result, regardless of the amount of the bonding material 60 applied to the bonding portion 61, the bonding material 60 can be reliably inserted between the base body 10 and the lid body 50 at a certain height (amount). That is, even when the amount of the bonding material 60 applied to the bonding portion 61 is larger than the specified amount, it is possible to suppress an increase in the interval h2 between the base body 10 and the lid body 50.
Further, even when the amount of the bonding material 60 applied to the bonding portion 61 is less than the specified amount, it is possible to suppress the interval h2 between the base body 10 and the lid body 50 from being reduced. As a result, since the space h2 between the base body 10 and the lid 50 can be reliably bonded, the deterioration of the bonding strength can be reduced, and the highly reliable acceleration sensor 100 can be obtained.

  (2) Since the gap member 90 and the functional element 80 are formed of the same material, the gap member 90 can be obtained without increasing the cost by not requiring a manufacturing process only for forming the gap member 90. Can do.

  (3) Since the gap member 90 and the functional element 80 are formed of silicon, the gap member 90 and the functional element 80 can be easily formed collectively from the same substrate, and the cost can be reduced.

(4) Since the gap member 90 is disposed so as to surround the functional element 80, when the base 10 and the lid 50 are joined via the low melting point glass, the functional element is determined by the height h1 of the gap member 90. A distance h <b> 2 between the base body 10 and the lid 50 is defined over the periphery of 80.
As a result, regardless of the amount of the bonding material 60 applied to the bonding portion 61, the bonding material 60 is placed at a constant height (amount) between the base body 10 and the lid 50 around the functional element 80. Can be inserted reliably. As a result, the base body 10 and the lid body 50 can be reliably bonded.

  (5) Since the gap member 90 is formed including silicon, it is possible to apply a processing technique used for manufacturing a silicon semiconductor device when the gap member 90 is formed. As a result, the gap member 90 can be formed with a fine and high accuracy.

  (6) Since the lid 50 is formed including silicon, it is possible to apply a processing technique used for manufacturing a silicon semiconductor device when the lid 50 is formed. As a result, the lid 50 can be formed with a fine and high accuracy.

  (7) Since the base body 10 is formed to include glass, it is not necessary to interpose an insulating film on the base body 10 to maintain insulation between the base body 10 and the functional element 80, and insulation separation can be easily performed. can do.

  (8) Since the base 10 and the lid 50 are joined with the low melting point glass, they can be joined at a low temperature. As a result, it is possible to reduce the exposure of the base body 10 and the lid body 50 to a high temperature and to suppress breakage.

(Modification 1)
FIG. 11 is a front sectional view schematically showing the acceleration sensor according to the first modification, in which the gap member and the protrusion are enlarged. In the above embodiment, as shown in FIG. 2, the acceleration sensor 100 includes a gap member 90 that is in contact with the surface of the base body 10 on the lid body 50 side and the surface of the lid body 50 on the base body 10 side. Although described as being, it is not limited to this configuration.
Hereinafter, the acceleration sensor 200 according to Modification 1 will be described. In addition, about the component same as embodiment, the same number is attached | subjected and the overlapping description is abbreviate | omitted.

  The gap member 290 is formed integrally with the lid 250, and the material is, for example, glass (borosilicate glass) or silicon.

  In the method of manufacturing the acceleration sensor 200 according to this modification, the gap member 90 is not formed in the etching step (step S105) described in the embodiment, and the gap member 290 is formed in the lid preparation step (step S103). . For the formation, a photolithography technique and an etching technique can be applied.

  As described above, according to the acceleration sensor 200 according to the present modification, in addition to the effects in the embodiment, the following effects can be obtained.

  Since the gap member 290 is integrated with the lid body 250, the gap member 290 and the lid body 250 can be easily formed collectively from the same substrate, and the cost can be reduced.

  In the above embodiment, the gap member 90 is not limited to being arranged on two sides so as to face each other with the functional element 80 interposed therebetween. FIGS. 12-16 is a schematic plan view which shows arrangement | positioning of the gap | interval member 90 which concerns on a modification.

(Modification 2)
As shown in FIG. 12, in the acceleration sensor described above, the gap member 90 may be provided along at least one corner of the functional element 80. In FIG. 12, the gap member 90 is disposed at each of the four corners of the functional element 80.

(Modification 3)
As shown in FIG. 13, in the acceleration sensor described above, the gap member 90 may be provided at a position facing the diagonal of the functional element 80. In FIG. 13, an example in which the gap member 90 is provided at the corner of the functional element 80 in the + X-axis direction and the + Y-axis direction and the corner of the functional element in the −X-axis direction and the −Y-axis direction. Show.

(Modification 4)
As shown in FIG. 14, in the acceleration sensor described above, the gap member 90 may be provided along the periphery of the functional element 80.

(Modification 5)
As shown in FIG. 15, in the acceleration sensor described above, the gap member 90 may be provided outside the functional element 80 along the X-axis direction and the Y-axis direction.

(Modification 6)
As shown in FIG. 16, in the acceleration sensor described above, the gap member 90 may be provided at a position where the functional element 80 is sandwiched along the X-axis direction.

[Electronics]
Next, an electronic apparatus including the above electronic device will be described. FIG. 17 is a perspective view schematically illustrating a configuration of a mobile (or notebook) personal computer as an electronic apparatus including an electronic device.

  As shown in FIG. 17, the personal computer 1100 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1101. The display unit 1106 is connected to the main body portion 1104 via a hinge structure portion. And is rotatably supported. Such a personal computer 1100 incorporates the electronic device (for example, the acceleration sensor 100) described above.

  FIG. 18 is a perspective view schematically showing a configuration of a mobile phone (including PHS) as an electronic apparatus including the electronic device. As shown in FIG. 18, the cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1201 is disposed between the operation buttons 1202 and the earpiece 1204. . Such a cellular phone 1200 incorporates an electronic device (for example, the acceleration sensor 100).

  FIG. 19 is a perspective view schematically illustrating a configuration of a digital still camera as an electronic apparatus including the electronic device (for example, the acceleration sensor 100). Note that FIG. 19 also shows a simple connection with an external device.

  Here, an ordinary camera sensitizes a silver salt photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image pickup device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

  A display unit 1310 is provided on the back surface (front side in the figure) of the case (body) 1302 in the digital still camera 1300, and the display unit 1310 is configured to perform display based on an imaging signal from the CCD. Functions as a viewfinder that displays images as electronic images.

  A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the figure) of the case 1302. When the photographer confirms the subject image displayed on the display unit 1310 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308.

  In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. A television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication, if necessary.

  Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 incorporates an electronic device.

  Since such an electronic apparatus includes the above-described electronic device, the effects described in the above embodiments are reflected, the size is reduced, and the reliability is excellent.

  In addition to the above, the electronic apparatus provided with the above-described electronic device includes, for example, an ink jet ejection device (for example, an ink jet printer), a laptop personal computer, a television, a video camera, a video tape recorder, and various navigation devices. , Pager, electronic organizer (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV monitor, electronic binoculars, POS terminal, medical device (eg, electronic thermometer, blood pressure) Meter, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder, various measuring instruments, instruments, flight simulator, and the like.

  In any case, since these electronic devices include the above-described electronic device, the effects described in the above embodiments are reflected, and the electronic devices are excellent in reliability.

[Moving object]
Next, a moving body provided with the above electronic device will be described. FIG. 20 is a perspective view schematically showing an automobile as an example of a moving body. The above-described electronic device is mounted on the automobile 1500.

  For example, as shown in FIG. 20, an automobile 1500 as a moving body has an electronic device (for example, the acceleration sensor 100) built therein, and an electronic control unit 1502 that controls a tire 1503 and the like is mounted on the vehicle body 1501. . According to this, since the automobile 1500 includes the above-described electronic device, the effect described in the above-described embodiment is reflected and the reliability is excellent.

  In addition, the above electronic devices include keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake system (ABS), air bag, tire pressure monitoring system (TPMS: Tire Pressure Monitoring System), The present invention can be widely applied to electronic control units (ECUs) such as engine controls, battery monitors of hybrid vehicles and electric vehicles, and vehicle body attitude control systems.

  The electronic device is not limited to the automobile 1500, and can be suitably used as a posture detection sensor of a moving body including a self-propelled robot, a self-propelled transport device, a train, a ship, an airplane, an artificial satellite, In any case, the effect described in the above embodiment is reflected, and a mobile object having excellent reliability can be provided.

The electronic device described above is not limited to the acceleration sensor 100, but the functional element is an angular velocity sensor having an angular velocity detection function, the functional element is a pressure sensor having a pressure detection function, and the functional element is weight detection. It may be a weight sensor having a function or a composite sensor in which these sensors (including an acceleration sensor) are combined.
In addition, the electronic device may be a vibrator whose function element is a vibrating piece, an oscillator, a frequency filter, or the like.

  DESCRIPTION OF SYMBOLS 8 ... Silicon substrate, 10 ... Base | substrate, 11 ... 1st surface, 12 ... 2nd surface, 14 ... Recessed part, 15, 16, 17 ... Groove part, 20, 22, 24 ... Wiring, 30, 32, 34 ... External connection terminal , 40, 42, 44 ... contact part, 50 ... lid, 51 ... third surface, 52 ... fourth surface, 53 ... projection, 54 ... fifth surface, 55 ... terminal hole, 56 ... internal space, 57 ... Recessed portion, 58 ... through hole, 60 ... joining material, 61 ... joined portion, 70 ... sealing member, 80 ... functional element, 81 ... fixed portion, 82 ... fixed portion, 84 ... connecting portion, 84a ... beam, 85 ... coupled , 85a ... beam, 86 ... movable part, 87 ... movable electrode part, 88 ... fixed electrode part, 89 ... fixed electrode part, 90 ... gap member, 100 ... acceleration sensor as electronic device, 200 ... acceleration sensor, 250 ... Lid, 290 ... Gap member, 1100 ... Personal as electronic equipment Computer 1101 Display unit 1102 Keyboard 1104 Main unit 1106 Display unit 1200 Mobile phone as an electronic device 1201 Display unit 1202 Operation button 1204 Earpiece 1206 Sending Mouth, 1300 ... Digital still camera as electronic device, 1302 ... Case, 1304 ... Light receiving unit, 1306 ... Shutter button, 1308 ... Memory, 1310 ... Display unit, 1312 ... Video signal output terminal, 1314 ... Input / output terminal, 1430 ... TV monitor, 1440 ... personal computer, 1500 ... automobile as a moving body, 1501 ... car body, 1502 ... electronic control unit, 1503 ... tire.

Claims (12)

A substrate;
A functional element bonded on the substrate;
A lid that is bonded to a bonding portion on the base via a bonding material, covers the functional element, and forms an internal space with the base;
A gap member in contact with the surface on the lid side of the base and the surface on the base side of the lid;
The electronic device according to claim 1, wherein a height of the gap member is larger than a thickness of the bonding material.   The electronic device according to claim 1, wherein a height of the gap member is substantially the same as a thickness of the functional element.   The electronic device according to claim 1, wherein the gap member is made of the same material as the functional element.   The electronic device according to any one of claims 1 to 3, wherein the gap member is disposed so as to surround the functional element.   5. The electronic device according to claim 1, wherein the gap member includes silicon. 6.   The electronic device according to any one of claims 1 to 5, wherein the lid includes silicon.   The electronic device according to any one of claims 1 to 6, wherein the gap member is integrated with the lid.   The electronic device according to any one of claims 1 to 7, wherein the base includes glass.   The electronic device according to any one of claims 1 to 8, wherein the bonding material includes a low-melting glass. A first bonding step of bonding a functional element on a substrate;
An etching step for forming a gap member;
A second bonding step of bonding a lid to the bonding portion of the base body so as to cover the functional element and form an internal space with the base body via a flexible bonding material. ,
The second joining step includes a step of bringing the gap member into contact with the lid-side surface of the base and the base-side surface of the lid,
The method of manufacturing an electronic device, wherein a height of the gap member is larger than a thickness of the bonding material.   An electronic apparatus comprising the electronic device according to any one of claims 1 to 9.   A moving body comprising the electronic device according to any one of claims 1 to 9.

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