JP2009264933A - Acceleration sensor device and method of manufacturing acceleration sensor device - Google Patents

Abstract

An acceleration sensor device capable of maintaining high detection sensitivity after mounting even when the height is reduced.
A weight part 11, a frame-like fixing part 13 surrounding the weight part 11, a beam part 12 having one end connected to the fixing part 13 and the other end connected to the weight part 11, and a beam The sensor element 20 having the resistance element 15 provided in the part 12, the substrate 1 on which the sensor element 20 is placed, and a state where the sensor element 20 is divided into a plurality of locations between the lower surface of the fixing unit 13 and the upper surface of the substrate 1. And an adhesive 8 that joins the sensor element 20 and the substrate 1 at a plurality of locations. A groove portion 7 is provided on the lower surface of the fixing portion 13 so as to surround a region to which the adhesive 8 adheres. Selection diagram] Fig. 5

Description

  The present invention relates to an acceleration sensor device that detects acceleration and a method of manufacturing the acceleration sensor device.

  Acceleration sensors are used for fall protection of devices equipped with hard disk drives such as portable music players and notebook computers, and acceleration detection in automobile navigation systems.

  FIG. 11 shows a cross-sectional view of a conventional acceleration sensor. The acceleration sensor device shown in the figure has a configuration including a sensor element 100 manufactured by processing a silicon substrate and a substrate 200 on which the sensor element 100 is placed.

  The sensor element 100 includes a weight part 101, a frame-shaped fixing part 102 surrounding the weight part 101, a beam part 103 connected to the weight part 101 and the fixing part 102, and a piezoresistor formed on the beam part 103. And an element (not shown).

  When an external force proportional to the acceleration is applied to the acceleration sensor device having such a sensor element 100, the weight part 101 moves, and the beam part 103 is deformed accordingly, and the piezoresistive element is also deformed. The acceleration is detected based on the change in resistance value due to the deformation of the piezoresistive element.

By the way, the sensor element 100 is fixed to the substrate 200 by an adhesive 300 interposed between the lower surface of the fixing portion 102 and the main surface of the substrate 200. Usually, the substrate 200, the adhesive 300, and the sensor element 100 have greatly different linear expansion coefficients, so when the adhesive 300 is applied over the entire lower surface of the fixed portion 102 and the adhesive is cured, Residual stress due to the difference in linear expansion coefficient is likely to occur, and the beam portion 103 is deformed due to the influence of this residual stress, resulting in problems such as reduced acceleration detection sensitivity, increased offset voltage, and worsened temperature drift. Happens. Therefore, the adhesive 300 is applied not to the entire lower surface of the fixing portion 102 but to a plurality of locations, for example, four locations corresponding to the four corners of the lower surface of the fixing portion 102 so as to reduce the bonding area (for example, Patent Documents). 1).
JP 2004-212246 A

  However, in the conventional acceleration sensor device as shown in FIG. 11, the adhesive area of each adhesive 300 varies as the adhesive 300 applied in multiple places spreads along the lower surface of the fixing portion 102. It was easy. Furthermore, as the sensor element 100 becomes smaller and smaller, it is necessary to further reduce the adhesion area, but there is a limit to uniformly controlling the amount of adhesion applied to a plurality of locations using a conventional dispenser. . For example, when the adhesive 300 is applied in four locations corresponding to the four lower corners of the fixed portion 102, the bonding area at one corner may be small and the bonding area at another corner may be large. When the adhesive area of the adhesive 300 varies in this manner, the beam 103 is deformed due to, for example, non-uniform residual stress occurring in the sensor element 100, resulting in a decrease in acceleration detection sensitivity, an increase in offset voltage, and a temperature. Deterioration of drift occurs and the electrical characteristics are deteriorated. In particular, as the acceleration sensor device becomes smaller and smaller, these problems become more prominent.

  The present invention has been devised in view of the various circumstances as described above, and an object thereof is to provide an acceleration sensor device and a method for manufacturing the acceleration sensor device that can be reduced in size while suppressing deterioration of electrical characteristics. And

  The acceleration sensor device of the present invention includes a weight portion, a frame-shaped fixing portion surrounding the weight portion, a beam portion having one end connected to the fixing portion and the other end connected to the weight portion, A sensor element having a resistance element provided in the beam portion; a substrate on which the sensor element is placed; and a lower surface of the fixed portion and an upper surface of the substrate that are interposed in a plurality of locations. And an adhesive that joins the sensor element and the substrate at a plurality of locations, and a groove portion is provided on the lower surface of the fixing portion so as to surround a region to which the adhesive adheres.

  In the acceleration sensor device, the adhesive is preferably provided at positions corresponding to the four corners of the fixing portion.

  In the acceleration sensor device, it is preferable that a planar shape of the weight portion is rectangular, and the beam portion is connected to a center portion of four upper sides of the weight portion.

  Moreover, it is preferable that the said acceleration sensor apparatus is provided with the 2nd groove part on the outer side of the said groove part.

  The acceleration sensor device further includes an IC chip that performs signal processing on an output signal of the sensor element.

  The acceleration sensor device manufacturing method of the present invention includes a weight part, a frame-like fixing part surrounding the weight part, one end connected to the fixing part, and the other end connected to the weight part. A sensor element having a beam portion, a resistance element provided on the beam portion, and a groove portion formed so as to surround an adhesion region on the lower surface of the fixed portion, and a substrate on which the sensor element is placed are prepared. The process A includes a process B and a process B in which the sensor element and the substrate are joined by an adhesive interposed between the adhesive region on the lower surface of the fixed portion and the upper surface of the substrate.

  According to the present invention, since the groove portion is provided on the lower surface of the fixing portion so as to surround the region where the adhesive adheres, excess adhesive enters the groove portion even if the amount of adhesive applied is large. , It is possible to prevent the adhesive from spreading along the longitudinal direction of the lower surface of the fixing portion. As a result, it is possible to reduce the variation in the bonding area of the adhesive, and to suppress the occurrence of non-uniform residual stress in the sensor element, thereby providing an acceleration sensor device with excellent electrical characteristics.

Exemplary embodiments of an acceleration sensor device and a method for manufacturing the acceleration sensor device according to the present invention will be described below in detail with reference to the drawings. Note that the drawings used in the following embodiments are schematic, and the dimensional ratios in the drawings do not necessarily match the actual ones. Further, the present invention is not limited to the following embodiments, and various changes and improvements can be made without departing from the gist of the present invention. In this embodiment, a three-dimensional acceleration sensor device using the piezoresistance effect will be described as an example.
<Acceleration sensor device>
1 is a perspective view of the acceleration sensor device according to the present embodiment, FIG. 2 is a plan view of the acceleration sensor device of FIG. 1 with the lid 10 removed, and FIG. 3 is a cross-sectional view of the acceleration sensor device shown in FIG. 3A corresponds to a cross section taken along the line AA ′ in FIG. 2, and FIG. 3B corresponds to a cross section taken along the line BB ′ in FIG. As shown in these drawings, the acceleration sensor device according to the present embodiment is mainly composed of a substrate 1 and a sensor element 20.

  First, the sensor element 20 will be described. FIG. 4 is a perspective view of the sensor element 20. As shown in FIG. 4, the sensor element 20 includes a weight portion 11, a frame-shaped fixing portion 13 surrounding the weight portion 11, one end connected to the fixing portion 13, and the other end connected to the weight portion 11. It has a beam portion 12, an element-side electrode pad 14 formed on the fixed portion 13, and a resistance element 15 formed on the beam portion 12.

  When acceleration is applied to the sensor element 20, a force corresponding to the acceleration acts on the weight part 11, and the beam part 12 is bent as the weight part 11 moves. The weight part 11 in the present embodiment is provided with four attached weight parts 11 ′ connected to the four corners thereof. The attached weight portion 11 ′ is formed integrally with the weight portion 11. By providing the attached weight portion 11 ′, the deflection of the beam portion 12 with respect to acceleration increases, and the detection sensitivity of acceleration can be improved.

  The weight portion 11 has a substantially square planar shape, and the length of one side thereof is set to, for example, 0.25 mm to 0.5 mm. Moreover, the thickness of the weight part 11 is set to 0.2 mm-0.625 mm, for example. The attached weight portion 11 ′ has a substantially square shape in the same manner as the weight portion 11, and the length of one side thereof is set to 0.1 mm to 0.4 mm, for example. Moreover, the thickness of the attached weight part 11a is set to 0.2 mm-0.625 mm so that it may have the same thickness as the weight part 11, for example. In addition, the planar shape of the weight part 11 and the attached weight part 11a is not restricted to a square, Arbitrary shapes, such as a circle and a rectangle, are possible. The weight part 11 and the attached weight part 11 'are integrally formed by processing, for example, an SOI (Silicon on Insulator) substrate.

  A frame-shaped fixing portion 13 is formed so as to surround the weight portion 11 and the attached weight portion 11 ′. The fixing portion 13 has a substantially square opening, and has a substantially square opening slightly larger than the weight portion 11 and the attached weight portion 11 ′ at the center. One side of the fixed portion 13 is set to 1.4 mm to 3.0 mm, for example, and the width of the arm constituting the fixed portion 13 (width in the direction orthogonal to the longitudinal direction of the arm) is, for example, 0.3 mm to 1.8 mm. Set to Moreover, the thickness of the fixing | fixed part 13 is set to 0.2 mm-0.625 mm, for example. The sensor element 20 is fixed to the substrate 1 by bonding the lower surface of the fixing portion 13 to the main surface 1A of the substrate 1 with the adhesive 8.

  FIG. 5 is a perspective view when the sensor element 20 is viewed from the lower surface side. As shown in FIG. 5, the fixing portion 13 is provided with a groove portion 7 on the lower surface thereof. The groove portion 7 is provided so as to surround the adhesion region of the adhesive 8. In the present embodiment, the four corners of the fixing portion 13 are the adhesion areas of the adhesive 8, and the groove portions 7 are provided so that the lower four corners of the fixing portion 13 are separated from other portions. The groove portion 7 is used to accommodate excess adhesive 8 or to release the adhesive 8 to the outside of the fixing portion 13 when the sensor element 20 is bonded to the substrate 1 with the adhesive 8. As a result, the adhesive 8 can be prevented from spreading along the lower surface of the fixing portion 13, and the adhesive area of the adhesive 8 does not vary greatly. As a result, it is possible to suppress the occurrence of non-uniform residual stress in the sensor element 20 and to provide an acceleration sensor device having excellent electrical characteristics. Since the sensor element 20 is reduced in weight by providing the groove portion 7, the adhesive 8 and the sensor element 20 are difficult to peel off, and there is an advantage that the impact resistance is improved.

  FIG. 6 is a diagram illustrating an example of a planar pattern of the groove portion 7. FIG. 6 shows one corner of the four corners when the adhesive 8 is applied to the four corners of the lower surface of the fixing portion 13. As shown in the figure, the groove portion 7 can have various shapes. Since the spread of the adhesive 8 is suppressed by the groove 7, the approximate planar shape of the adhesive 8 is a shape along the groove 7. That is, the groove 7 can control the area and shape of the adhesive 8. As shown in FIG. 6 (f), if the groove portion 7 that leads to the outside of the fixing portion 13 is provided in the region surrounded by the groove portion 7, the spread of the adhesive 8 can be suppressed more reliably.

FIG. 7 is a diagram showing an example of a cross-sectional pattern of the groove portion 7. FIG. 7 corresponds to a cross section taken along the line CC ′ of FIG. As shown in the figure, the cross-sectional shape of the groove portion 7 can be various shapes such as a rectangular shape, a trapezoidal shape, a triangular shape, and an arc shape. The dimensions of the groove 7 are set, for example, in a range from 10 μm to 200 μm in width W (width in the opening) and 5 μm in depth d to near the SiO ₂ layer.

  Between the fixed portion 13 and the weight portion 11, a beam portion 12 is provided as shown in FIG. The beam portion 12 has one end connected to the center portion on the upper surface side of each side of the weight portion 11, and the other end connected to the center portion on the upper surface side of each side in the inner periphery of the fixed portion 12, in this embodiment. In the sensor element 20, four beam portions 12 are provided.

  The beam portion 12 has flexibility. When acceleration is applied to the sensor element 20, the weight portion 11 moves, and the beam portion 12 bends as the weight portion 11 moves. For example, the beam portion 12 has a length in the longitudinal direction set to 0.3 mm to 0.8 mm, a width (a length in a direction perpendicular to the longitudinal direction) set to 0.04 mm to 0.2 mm, and a thickness of 5 μm. It is set to ˜20 μm. Thus, flexibility is expressed by forming the beam portion 12 to be elongated and thin.

  A plurality of resistance elements 15 are formed on the upper surface of the beam portion 12. More specifically, the resistive element 15 is a piezoresistive element formed by implanting boron into an SOI substrate. In the present embodiment, these resistances are placed at predetermined positions on the beam portion 12 so that the acceleration in the three-axis directions (X-axis direction, Y-axis direction, and Z-axis direction in the three-dimensional orthogonal coordinate system shown in FIG. 4) can be detected. An element 15 is formed. For example, two resistance elements 15 for detecting acceleration in the X-axis direction are provided on the two beam parts 12 extending in the X-axis direction, and two resistance elements 15 are arranged on each beam part 12. . Among these four resistance elements 15, the resistance elements arranged on the fixed portion 13 side are connected in series, the resistance elements arranged on the weight portion 11 side are connected in series, and these are connected in parallel. This constitutes a bridge circuit. The two beam portions 12 extending in the Y-axis direction are provided with four resistance elements 15 for detecting acceleration in the Y-axis direction. These resistance elements 15 are used for detecting acceleration in the X-axis direction. The resistor circuit 15 is arranged in the same manner, and a bridge circuit is configured by connecting the resistor elements. Although not shown, the four resistance elements 15 for detecting acceleration in the Z-axis direction are provided with four beam elements 12 for detecting acceleration in the X-axis direction on the two beam portions 12 extending in the X-axis direction. It is formed so as to be aligned with each of the resistance elements 15. The resistance element 15 for acceleration detection in the Z-axis direction is different from the resistance element 15 for acceleration detection in the X-axis direction in the way of connecting the resistance elements, and in this embodiment, extends in the X-axis direction. A resistance element 15 on the fixed part 13 side provided in one of the two beam parts 12 and a resistance element 15 on the weight part 11 side provided in the other beam part 12 are connected in series. A bridge circuit is configured. When acceleration is applied to the sensor element 20 in which such a bridge circuit is assembled, the beam portion 12 is bent as described above, and the resistance element 15 is deformed along with this bending, so that the output voltage detected by the bridge circuit changes. To do. The direction and magnitude of the applied acceleration can be detected by taking out the change in the output voltage based on the change in the resistance value as an electrical signal and processing it with an external IC. The resistance element 15 for detecting the acceleration in the Z-axis direction may be provided on the two beam portions 12 extending in the Y-axis direction in the same manner as that provided in the beam portion 12 extending in the X-axis direction.

  An element-side electrode pad 14 that is electrically connected to the resistance element 15 is provided on the upper surface of the fixing portion 13. The signal is taken out.

  The sensor element 20 is mounted on the substrate 1 as shown in FIG. The substrate 1 has a function of protecting the sensor element 20, and a cavity 5 that houses the sensor element 20 is provided inside. The substrate 1 is formed by laminating a plurality of insulating layers made of a ceramic material or the like, and is configured by three insulating layers 1a to 1c in the present embodiment. The insulating layer 1a is made of a flat member, and the sensor element 20 is placed on the main surface 1A. The insulating layer 1b is a frame-like member having an opening that is slightly larger than the sensor element 20, and is joined to the insulating layer 1a. The insulating layer 1c is a frame-like member having an opening wider than the opening of the insulating layer 1b, and is joined to the insulating layer 1b so that a part of the main surface of the insulating layer 1b is exposed. A plurality of substrate-side electrode pads 4 are formed on the main surface of the insulating layer 1b exposed from the opening of the insulating layer 1c. The substrate-side electrode pad 4 is electrically connected to the element-side electrode pad 14 provided on the upper surface of the fixed portion of the sensor element 20 by the fine metal wire 6. A plurality of external terminals 2 are provided on the lower surface of the substrate 1, and the external terminals 2 are connected to the substrate-side electrode pads 4 via via-hole conductors 3 provided inside the substrate 1. That is, the electrical signal of the sensor element 20 is extracted to the outside through the element side electrode pad 15, the fine metal wire 6, the substrate side electrode pad 4, the via hole conductor 3, the external terminal 2, and the like.

  The sensor element 20 placed on the main surface 1 </ b> A of the substrate 1 is bonded to the substrate 1 with an adhesive 8. As described above, the groove portion 7 is provided in the fixing portion 13 of the sensor element 20 so as to surround the adhesion region of the adhesive 8. In FIG. 2, the adhesion region 8a of the adhesive 8 and the groove 7 are shown by dotted lines. Thus, since the groove portion 7 is provided so as to surround the adhesion region of the adhesive 8, the excess adhesive 8 is accommodated in the groove portion 7 or flows outside the fixing portion 13 through the groove portion 7. It is like that. Therefore, it is possible to suppress the adhesive 8 from spreading more than necessary along the lower surface of the fixing portion 13. As a result, the variation in the bonding area of the adhesive 8 can be reduced, and non-uniform residual stress can be prevented from occurring in the sensor element 20 to provide an acceleration sensor device with excellent electrical characteristics.

  Moreover, the adhesion area of the adhesive 8 can also be controlled by providing the groove portion 7. For example, when the adhesion area of the adhesive 8 is desired to be 10% or less of the entire area of the lower surface of the fixed portion, the total area of the region partitioned by the groove portion 7 may be 10% of the entire area of the lower surface of the fixed portion. The adhesion area of the adhesive 8 is preferably 5% or more of the entire area of the lower surface of the fixed portion. By setting the adhesion area of the adhesive 8 to 5% or more of the entire area of the lower surface of the fixed portion, the sensor element 20 and the substrate 1 can be firmly bonded. For example, even in an environment where a large acceleration of about 1000 G is applied. It will be tolerable.

  As the adhesive 8, for example, a silicone resin or an epoxy resin can be used. In particular, it is preferable to use a silicone resin from the viewpoint of relaxing the residual stress during bonding.

  The adhesive 8 is mixed with a spherical spacer member 17 having a predetermined diameter so that a gap of a predetermined size is formed between the lower surface of the weight portion 11 and the main surface 1A of the substrate 1. (See FIG. 3). That is, the size of the gap between the lower surface of the weight portion 11 and the main surface 1 </ b> A of the substrate 1 can be controlled by the spacer member 17. The spacer member 17 is a spherical member having a predetermined hardness such as silica, silicon, divinylbenzene, and the diameter thereof is, for example, 2 to 30 μm.

  When the beam portion 12 is connected to the center of the four upper sides of the weight portion 11 as in the present embodiment, the sensor element 20 and the substrate 1 are preferably joined at the four corners of the fixing portion 13. As a result, the distance between the joint portion of the sensor element 20 to the substrate 1 and the beam portion 12 is increased, so that the influence exerted on the beam portion 12 by the residual stress that may be generated due to the bonding by the adhesive 8 is reduced. It is possible to suppress deterioration of the electrical characteristics of the acceleration sensor device.

  The lid 10 is fixed to the upper surface of the substrate 1 so as to close the opening of the cavity of the substrate 1 to which the sensor element 20 is bonded. As a result, the sensor element 20 is hermetically sealed in the cavity 5. The lid 10 is made of, for example, a metal plate such as 42 alloy or stainless steel, and is bonded to the substrate 1 by a thermosetting resin 9 such as an epoxy resin.

  As described above, according to the acceleration sensor device of the present invention, the variation in the bonding area of the adhesive 8 can be reduced, and the generation of non-uniform residual stress in the sensor element 20 can be suppressed, and the electrical characteristics are excellent. And an acceleration sensor device.

(Modification)
FIG. 8 is a cross-sectional view showing a modification of the acceleration sensor device according to the above-described embodiment. In the acceleration sensor device according to this modification, the second groove portion 16 is provided outside the groove portion 7. If the second groove portion 16 is further provided outside the groove portion 7 in this manner, even if the adhesive 8 cannot be accommodated in the inner groove portion 7, the adhesive 8 that could not be accommodated can be accommodated in the second groove portion 16. Therefore, it is possible to prevent the adhesive 8 from spreading more reliably. The structure shown in FIG. 8 is particularly effective when the depth of the groove portion 7 is desired to be reduced.

  FIG. 9 is a sectional view showing another modification of the acceleration sensor device according to the above-described embodiment. Note that the cross-sectional view of FIG. 9 corresponds to a cross section taken along line A-A ′ of FIG. 2. The acceleration sensor device according to this modification further includes an IC chip 30 that performs arithmetic processing on the output signal of the sensor element 20. In the acceleration sensor device shown in FIG. 9, an IC chip 30 is accommodated in a cavity provided on the lower surface side of the substrate 1, and the sensor element 20 and the external terminal 2 are connected via the via-hole conductor 3 and the wiring conductor provided on the substrate 1. And are electrically connected. The IC chip 30 is, for example, an integrated circuit including an amplifier circuit that amplifies the output signal of the sensor element 20, a temperature compensation circuit that corrects temperature characteristics of the sensor element 20, and a noise removal circuit that removes noise. By providing such an IC chip 30, acceleration can be detected with high accuracy.

<Method for manufacturing acceleration sensor device>
Next, a manufacturing process of the acceleration sensor device according to the present embodiment will be described.

(Process A)
First, a weight portion 11, a frame-shaped fixing portion 13 surrounding the weight portion 11, a beam portion 12 having one end connected to the fixing portion 13 and the other end connected to the weight portion 11, and a beam portion 12 A sensor element 20 having a resistance element 15 to be provided and a groove portion 7 formed so as to surround an adhesion region on the lower surface of the fixing portion 13 and a substrate 1 on which the sensor element 20 is placed are prepared.

The sensor element 20 is manufactured using, for example, an SOI substrate. First, a resistance element 15 made of a piezoresistor is formed by implanting boron into a silicon layer on the surface of the SOI substrate by an ion implantation method. After the resistor element 15 is formed, a wiring connected to the piezoresistive element is produced using a metal sputtering and dry etching apparatus. Next, the beam portion 12 and the weight portion 11 are formed by performing processing from the front surface side and the back surface side of the SOI substrate by a conventionally well-known semiconductor fine processing technique such as photolithography or deep dry etching. At this time, the groove portion 7 is also formed at the same time. Or if not dig a trench to a depth of the SiO ₂ layer, forming a forming a groove 7 of the weight portion 11 and the beam portion 12 is carried out in a separate step. In this way, the sensor element 20 as shown in FIG. 4 is manufactured.

  On the other hand, the substrate 1 is formed by laminating a plurality of insulating layers made of a ceramic material such as alumina. Specifically, the substrate 1 having the cavity 5 by sequentially laminating a flat insulating layer 1a, an insulating layer 1b having a rectangular opening, and an insulating layer 1c having an opening larger than the opening of the insulating layer 1b. Is produced.

(Process B)
Next, as shown in FIG. 10, the bonding member 8 ′ is applied to the main surface 1 </ b> A of the substrate 1 and at a position corresponding to the region delimited by the groove 7 when the sensor element 20 is placed. The bonding member 8 ′ is a silicone resin or an epoxy resin before being cured, and is applied to the main surface 1A of the substrate 1 using a dispenser or the like. The dimensions such as the depth of the groove 7 and the formation position are adjusted in relation to the application amount of the bonding member 8 ′. For example, in the case of providing the groove portion 7 as shown in FIG. 6A, when the distance from the center O of the applied bonding member 8 ′ to the groove portion 7 is y and the diameter of the bonding member 8 ′ is x. What is necessary is just to adjust the position and application quantity of the groove part 7 so that the relationship of (x / 2) <= y may be satisfy | filled. Thereby, the adhesive 8 can be more reliably stopped in the region inside the groove portion 7. A spherical spacer member having a diameter of about 2 μm to 30 μm made of silica, silicon, divinylbenzene, or the like is mixed in the bonding member 8 ′, and this spacer member serves as the lower surface of the fixing portion 13 and the main surface 1 A of the substrate 1. Can be formed between the main surface 1A of the substrate 1 and the lower surface of the weight portion 11.

  Next, the sensor element 20 is placed on the main surface 1 </ b> A of the substrate 1, and the bonding member 8 ′ is cured to bond the sensor element 20 and the substrate 1. At this time, since the excess adhesive 8 is accommodated in the groove portion 7, it is possible to suppress the adhesive 8 from spreading along the lower surface of the fixing portion 13. As a result, the variation in the bonding area of the adhesive 8 can be reduced, and non-uniform residual stress can be prevented from occurring in the sensor element 20 to provide an acceleration sensor device with excellent electrical characteristics.

  After the sensor element 20 is bonded to the substrate 1, the element-side electrode pad 15 provided on the sensor element 20 and the substrate-side electrode pad 4 provided on the substrate 1 are connected by a thin metal wire 6 made of gold, copper, aluminum or the like. Finally, a metal lid 10 made of 42 alloy or the like is joined to the upper surface of the substrate 1 (the upper surface of the insulating layer 1d) by a thermosetting resin 9 such as an epoxy resin, thereby completing an acceleration sensor device as a product.

1 is a perspective view of an acceleration sensor device according to an embodiment of the present invention. It is a top view of the state which removed the cover of the acceleration sensor apparatus shown in FIG. FIG. 3 is a cross-sectional view of the acceleration sensor device shown in FIG. 1, where (a) is a cross-sectional view taken along line AA ′ in FIG. 2, and (b) is a cross-sectional view taken along line BB ′ in FIG. Each corresponds to a cross section. It is a perspective view of the sensor element mounted in the acceleration sensor apparatus shown in FIG. It is a perspective view when the sensor element shown in FIG. 4 is seen from the lower surface side. FIG. 4 is a partial plan view showing an example of a planar pattern of a groove portion 7. FIG. 6 is a cross-sectional view showing an example of a cross-sectional pattern of the groove portion 7 and corresponds to a cross section when cut along a C-C ′ line in FIG. 5. It is sectional drawing which shows the modification of the acceleration sensor apparatus which concerns on embodiment of this invention. It is sectional drawing which shows another modification of the acceleration sensor apparatus which concerns on embodiment of this invention. It is a perspective view which shows 1 process of the manufacturing method of the acceleration sensor apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the conventional acceleration sensor apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2 ... External terminal 3 ... Via-hole conductor 4 ... Board | substrate side electrode pad 5 ... Cavity 6 ... Metal fine wire 7 ... Groove part 8 ... Adhesive 11 ... -Weight part 12 ... Beam part 13 ... Fixed part 14 ... Element side electrode pad 15 ... Resistance element 20 ... Sensor element

Claims (6)

A weight portion, a frame-shaped fixing portion surrounding the weight portion, a beam portion having one end connected to the fixing portion and the other end connected to the weight portion, and a resistance element provided in the beam portion And a sensor element having
A substrate on which the sensor element is placed;
An adhesive that is interposed in a plurality of locations between the lower surface of the fixed portion and the upper surface of the substrate, and joins the sensor element and the substrate at a plurality of locations;
An acceleration sensor device, wherein a groove portion is provided on a lower surface of the fixing portion so as to surround a region to which the adhesive adheres. The acceleration sensor device according to claim 1, wherein the adhesive is provided at positions corresponding to the four corners of the fixing portion. The acceleration sensor device according to claim 2, wherein the weight portion has a rectangular planar shape, and the beam portion is coupled to a central portion of four upper sides of the weight portion. The acceleration sensor device according to claim 1, wherein a second groove is provided outside the groove. The acceleration sensor device according to claim 1, further comprising an IC chip that performs signal processing on an output signal of the sensor element. A weight portion, a frame-shaped fixing portion surrounding the weight portion, a beam portion having one end connected to the fixing portion and the other end connected to the weight portion, and a resistance element provided in the beam portion And a step A of preparing a sensor element having a groove formed so as to surround an adhesive region on the lower surface of the fixed part, and a substrate on which the sensor element is placed,
A method of manufacturing an acceleration sensor device, comprising: a step B of bonding the sensor element and the substrate with an adhesive interposed between an adhesive region on the lower surface of the fixed portion and an upper surface of the substrate.

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