JP6167003B2 - Flow sensor element and flow sensor module - Google Patents

Description

  The present invention relates to a flow sensor element and a flow sensor module.

A sensor using a cantilever has been proposed (for example, Patent Document 1).
Patent Document 1 discloses a configuration in which a differential pressure type flow velocity sensor is constructed and a flow velocity is measured by installing a cantilever in a bypass path.

JP 2012-145356 A

  By configuring a circuit (for example, a bridge circuit) using a plurality of cantilevers as described above, the performance (for example, sensitivity) of the flow sensor can be improved. However, in such a case, depending on the arrangement of a plurality of cantilevers, it may be difficult to construct a flow sensor due to the complexity of wiring for configuring a circuit using the plurality of cantilevers. .

  The present invention has been made in view of the above problems, and includes a flow sensor element that includes a plurality of cantilevers and can easily handle wiring, and a flow sensor module using such a flow sensor element. One of the purposes is to provide.

One aspect of the flow sensor element of the present invention includes a substrate, a plurality of cantilevers provided on the substrate and elastically deformable in a predetermined direction and having substantially the same resistance characteristics, and a plurality of cantilevers provided on the substrate. A plurality of cantilevers, a first cantilever provided on one side with respect to a predetermined virtual line on the surface of the substrate, and a first cantilever provided on the other side with respect to the virtual line. The first cantilever and the second cantilever have substantially the same shape in plan view, and the first cantilever is connected to the substrate at one end thereof, and the second cantilever The cantilever has an end on the other side connected to the substrate, and the substrate is a support substrate, an insulating layer formed on the support substrate and having electrical insulation, and a semiconductor formed on the insulating layer. And a resistance layer having electrical resistance formed on the semiconductor layer, and a conductive layer having conductivity formed on the resistance layer, wherein the insulating layer is exposed on the substrate. Each of the plurality of cantilevers includes the semiconductor layer, the resistance layer, and the conductive layer, wherein at least a part of the resistance layer in the plurality of cantilevers is exposed, The resistance element includes a resistance layer having substantially the same shape in plan view as the exposed resistance layer of the plurality of cantilevers, and the plurality of cantilevers and the plurality of resistance elements are electrically connected to each other to form a bridge circuit. It is characterized by forming.
The substrate is provided with a plurality of wiring regions in which the conductive layer is exposed, and the plurality of cantilevers and the plurality of resistance elements are electrically connected to each other by the plurality of wiring regions to form a bridge circuit. It is good also as composition which is doing.
In the bridge circuit, the first cantilever and the second cantilever may be arranged diagonally in terms of electrical wiring.
The plurality of resistance elements include a first resistance element and a second resistance element, and the bridge circuit includes the first cantilever, the second cantilever, the first resistance element, and the second resistance. Elements are electrically connected to each other, and the first cantilever and the second cantilever are arranged point-symmetrically with respect to a predetermined point on the surface of the substrate, The second resistive element may be arranged symmetrically with respect to the predetermined point.
The flow sensor element of the present invention includes a substrate and a plurality of cantilevers provided on the substrate and elastically deformable in a predetermined direction and having substantially the same resistance characteristics, and the plurality of cantilevers are arranged on the substrate. A first cantilever provided on one side with respect to a predetermined virtual line on the surface; and a second cantilever provided on the other side with respect to the virtual line, the first cantilever and the second cantilever Is substantially the same shape in plan view, and the first cantilever has the one end connected to the substrate, and the second cantilever has the other end connected to the substrate. It is characterized by being.

  According to the flow sensor element of the present invention, the first cantilever and the second cantilever are respectively arranged on one side and the other side across a predetermined virtual line, and the first cantilever is connected to the substrate at one end. The second cantilever has the other end connected to the substrate. In other words, the first cantilever and the second cantilever are arranged such that the connecting portion with the substrate faces the outside of the substrate. In the cantilever, the connection portion with the substrate functions as a resistance whose resistance value changes. And a flow sensor module is constructed | assembled by connecting wiring etc. to this connection part and comprising a circuit. According to the flow sensor element of the present invention, since the connecting portions of a plurality of cantilevers face the outside of the substrate, when a flow sensor module is constructed using the flow sensor element, wiring or the like is connected to the flow sensor element. Easy to handle.

  Further, since the first cantilever and the second cantilever have substantially the same shape in plan view, it is easy to make the resistance characteristics of the first cantilever and the second cantilever substantially the same.

The first cantilever and the second cantilever may be arranged symmetrically with respect to the virtual line.
The first cantilever and the second cantilever may be arranged symmetrically with respect to a predetermined point on the surface of the substrate.
According to these configurations, the first cantilever and the second cantilever are arranged symmetrically. Therefore, for example, when the fluid flows perpendicularly to the surface of the substrate, the fluid flow through the first cantilever and the second cantilever tends to be substantially uniform. Therefore, according to these structures, the measurement accuracy of the flow sensor module can be improved.

The first cantilever is provided facing a first opening formed to open on one side of the substrate, and the second cantilever is formed to open on one side of the substrate. It is good also as a structure provided facing the 2nd opening part spaced apart from a part.
In the case where a plurality of cantilevers are provided in one opening, the flow of fluid may be disturbed in the opening due to the installation position of the plurality of cantilevers being shifted from an appropriate position. In such a case, it may be difficult to appropriately measure the flow rate with the cantilever.

  On the other hand, according to this configuration, the first cantilever and the second cantilever are provided so as to face the first opening and the second opening that are provided apart from each other. Therefore, the fluid flow is suppressed from being disturbed in the opening provided with the cantilever. Therefore, according to this structure, the measurement accuracy of the flow rate by the cantilever can be improved.

The substrate may include a support substrate, an insulating layer having electrical insulation formed on the support substrate, and a semiconductor layer formed on the insulating layer.
According to this configuration, since the region on the substrate can be electrically divided by removing the semiconductor layer of the substrate and exposing the insulating layer, the circuit used for the flow sensor module using the flow sensor element Is easy to construct.

A resistance layer having electrical resistance is formed on the semiconductor layer, a conductive layer having conductivity is formed on the resistance layer, and an insulating portion in which the insulating layer is exposed is provided on the substrate. It is good also as a structure currently provided.
According to this configuration, the conductive layer is partitioned by the insulating portion, and at least a part of the circuit using the conductive layer as a wiring is formed on the substrate. Therefore, according to this configuration, it is easy to configure a circuit used in the flow sensor module using the flow sensor element.

Each of the plurality of cantilevers includes the semiconductor layer, the resistance layer, and the conductive layer, and at least a part of the resistance layer in the plurality of cantilevers is exposed, and the exposed in the plurality of cantilevers is It is good also as a structure provided with a resistive element provided with a resistive layer of the same shape as a resistive layer in planar view.
According to this configuration, the portion where the resistance layer is exposed functions as a resistor in the circuit formed on the substrate. And since the resistance layer in the resistance element has the same shape in plan view as the part where the resistance layer of the cantilever is exposed, that is, the part that functions as resistance in the cantilever, the resistance value of the resistance element is not deformed by the cantilever It becomes substantially the same as the resistance value at the time. Therefore, according to this configuration, when a cantilever and a resistance element are used, for example, when a bridge circuit is configured, the offset of each resistor can be reduced, and the measurement accuracy of the flow sensor module can be improved. .

  Further, according to this configuration, since the cantilever has a laminated structure similar to a part of the laminated structure of the substrate, a manufacturing method in which the cantilever is formed by removing a part of the substrate can be employed. Thereby, according to this structure, it becomes easy to make the thickness of several cantilevers uniform, and can suppress the dispersion | variation in the characteristic of a flow sensor element.

The flow sensor module of the present invention includes the above-described flow sensor element.
According to the flow sensor module of the present invention, since the flow sensor element described above is provided, wiring of a circuit using a plurality of cantilevers becomes simple, and the flow sensor module can be easily downsized. .

The bridge circuit may be configured using the plurality of cantilevers.
According to this configuration, the bridge circuit is configured using a plurality of cantilevers having substantially the same resistance characteristics. Thereby, the signal-to-noise ratio of the flow sensor module can be increased, and the sensitivity of the flow sensor module can be improved. Therefore, according to this configuration, it is possible to obtain a flow rate sensor module that can measure the flow rate even in a range where the value of the pressure difference is small, which is difficult to measure with a single cantilever.

  Further, according to this configuration, since the bridge circuit is configured, it is possible to obtain a flow rate sensor module that is hardly affected by the internal resistance and has a small measurement error.

  According to the present invention, a flow sensor element including a plurality of cantilevers and easily handling a wiring and a flow sensor module using such a flow sensor element are provided.

It is a figure which shows the flow sensor element of 1st Embodiment, Comprising: (A) is a top view, (B) is AA sectional drawing in (A). It is a figure which shows the state by which the pressure was applied to the flow sensor element of 1st Embodiment, Comprising: (A) is sectional drawing, (B) is a partial expansion perspective view. It is sectional drawing which showed the procedure of the manufacturing method of the flow sensor element of 1st Embodiment. (A) is a figure which shows the structure of the bridge circuit comprised using the flow sensor element of 1st Embodiment. (B) is a diagram showing a configuration of a bridge circuit equivalent to the bridge circuit of (A). It is sectional drawing which showed an example of the flow sensor module using the flow sensor element of 1st Embodiment. It is the elements on larger scale which showed an example of the flow sensor module using the flow sensor element of a 1st embodiment. It is a top view which shows the flow sensor element of 2nd Embodiment. It is a top view which shows the flow sensor element of 3rd Embodiment. It is a top view which shows the flow sensor element of 4th Embodiment. It is a top view which shows the flow sensor element of 5th Embodiment. It is a top view which shows the flow sensor element of 6th Embodiment. It is a top view which shows the flow sensor element of 7th Embodiment. It is a top view which shows the flow sensor element of 8th Embodiment.

Hereinafter, a flow sensor element and a flow sensor module according to an embodiment of the present invention will be described with reference to the drawings.
The scope of the present invention is not limited to the following embodiment, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, the actual structure may be different from the scale, number, or the like in each structure.

First, the first embodiment will be described.
1A and 1B are views showing a flow sensor element 1 of the present embodiment. FIG. 1A is a plan view. FIG. 1B is a cross-sectional view taken along the line AA in FIG.
2A and 2B are views showing a state in which pressure is applied to the flow sensor element 1. FIG. 2A is a cross-sectional view. FIG. 2B is an enlarged perspective view of the first cantilever 10a.

  In the following description, an XYZ coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ coordinate system. At this time, the stacking direction of the substrate 2 (see FIG. 1A) is orthogonal to the Z-axis direction and the Z-axis direction, and the directions parallel to one side of the outer periphery in plan view of the substrate 2 are the X-axis direction, the Z-axis direction, and The direction orthogonal to both the X-axis directions is taken as the Y-axis direction.

The flow sensor element 1 of the present embodiment includes a substrate 2 and a plurality of cantilevers 10 as shown in FIGS. The plurality of cantilevers 10 include a first cantilever 10a and a second cantilever 10b.
As shown in FIG. 1A, the substrate 2 is a laminated plate having a rectangular shape in plan view. As shown in FIG. 1B, the substrate 2 includes a conductive layer 20, a resistance layer 30, a semiconductor layer 40, an insulating layer 50, and a support substrate 60. On the support substrate 60 of the substrate 2, the insulating layer 50, the semiconductor layer 40, the resistance layer 30, and the conductive layer 20 are laminated in this order.

The support substrate 60 is, for example, a silicon substrate.
The insulating layer 50 is a layer having electrical insulation. As a material of the insulating layer 50, for example, SiO ₂ is used.
The semiconductor layer 40 is made of, for example, single crystal silicon.
The resistance layer 30 is a layer having electrical resistance characteristics. As a material of the resistance layer 30, for example, impurities are diffused in single crystal silicon. As the impurity, for example, B (boron), P (phosphorus), or the like is used.

  The conductive layer 20 is a metal layer made of metal, for example. Examples of the material of the conductive layer 20 when the conductive layer 20 is a metal layer include Au (gold), Al (aluminum), Cr (chromium), Ni (nickel), and Pd (palladium). The conductive layer 20 may have a structure in which a plurality of metal layers are stacked. Alternatively, the conductive layer 20 may be formed by diffusing impurities at a high concentration in single crystal silicon as in the resistance layer 30 described above.

  At the center of the substrate 2 in plan view (see FIG. 1A), as shown in FIG. 1B, an opening 14 is formed that opens to the support substrate 60 side (one side of the substrate, −Z side). ing. The opening 14 includes a first opening 14a and a second opening 14b. The 1st opening part 14a and the 2nd opening part 14b are mutually spaced apart and formed independently. As shown in FIG. 1A, the first opening 14a and the second opening 14b are formed symmetrically with respect to an imaginary line P on the surface of the substrate 2 passing through the center point C in plan view. . The shape of the opening 14 in plan view (XY plane view) is not particularly limited as long as the cantilever 10 functions properly. The planar view shape of the opening 14 is, for example, a rectangular shape in the present embodiment.

As shown in FIG. 1B, a first cantilever 10a is provided on the conductive layer 20 side (+ Z side) of the substrate 2 so as to face the first opening 14a. Similarly, a second cantilever 10b is provided on the conductive layer 20 side of the substrate 2 so as to face the second opening 14b.
On the conductive layer 20 side (+ Z side) of the substrate 2, the first cantilever 10 a is surrounded by a direction perpendicular to the surface (Z-axis) except for the first connection portion 11 a and the second connection portion 12 a described later. A first penetrating portion 15a (penetrating portion 15) penetrating in the direction) is formed.

  The first through portion 15a includes a through hole 15aa formed on a second connection portion 12a side (−Y side) of a first connection portion 11a described later, and a first connection portion 11a side (+ Y side) of the second connection portion 12a. ), The through-hole 15ac connecting the −X side end of the through-hole 15aa and the −X-side end of the through-hole 15ab, and the through-hole 15aa across the first connection portion 11a A through hole 15ad formed on the opposite side (+ Y side), a through hole 15ae formed on the opposite side (-Y side) across the second connection portion 12a, and the -X side of the through hole 15ad And a through hole 15af that connects the end and the −X side end of the through hole 15ae. The first through portion 15a and the first opening portion 14a communicate with each other.

Similarly, on the conductive layer 20 side (+ Z side) of the substrate 2, the second cantilever 10 b is surrounded by the surface except for the first connection portion 11 b and the second connection portion 12 b described later, and perpendicular to the surface. A second penetrating portion 15b (penetrating portion 15) penetrating in any direction (Z-axis direction) is formed. Similarly to the first through portion 15a, the second through portion 15b includes a through hole 15ba, a through hole 15bb, a through hole 15bc, a through hole 15bd, a through hole 15be, and a through hole 15bf. The second penetrating portion 15 b is provided symmetrically with respect to the first penetrating portion 15 a and the virtual line P. The through holes 15ba to 15bf correspond to the through holes 15aa to 15af of the first through part 15a, respectively. The 2nd penetration part 15b and the 2nd opening part 14b are connected.
In addition, the penetration part is formed in the same manner as the first penetration part 15a and the second penetration part 15b in other embodiments described below.

  An insulating portion 51 (insulating portions 51a, 51b, 51c, 51d, 51e, 51f) is formed on the conductive layer 20 side (+ Z side) of the substrate 2. The insulating part 51 is a part where the conductive layer 20, the resistance layer 30 and the semiconductor layer 40 are partially removed and the insulating layer 50 is exposed. That is, as shown in FIG. 2B, the insulating portion 51 is formed in a groove shape on the conductive layer 20 side (+ Z side) of the substrate 2.

  As shown in FIG. 1A, the insulating portion 51a is formed so as to connect from the connecting portion between the through hole 15ad and the through hole 15af to the edge on the + Y side of the substrate 2. The insulating part 51b is formed so as to connect from the + X side end of the through hole 15ab to the + X side edge of the substrate 2. The insulating part 51c is formed so as to connect from the connection point between the through hole 15ae and the through hole 15af to the connection point between the through hole 15bd and the through hole 15bf. The insulating part 51d is formed so as to connect from the connection portion between the through hole 15bd and the through hole 15bf to the edge on the −Y side of the substrate 2. The insulating portion 51e is formed so as to connect from the −X side end of the through hole 15bb to the −X side end edge of the substrate 2. The insulating part 51f is formed so as to connect from the connection point between the through hole 15be and the through hole 15bf to the connection point between the through hole 15ad and the through hole 15af.

  The insulating part 51 is formed point-symmetrically with respect to the center point C in plan view. In addition, also in other embodiments described below, the insulating portion is similarly formed point-symmetrically with respect to the center point in plan view.

  The semiconductor layer 40, the resistance layer 30, and the conductive layer 20 stacked on the insulating layer 50 are divided by the insulating portion 51 and the penetrating portion 15, and wiring regions 21 a and 21 b are formed on the conductive layer 20 side (+ Z side) of the substrate 2. , 21c, 21d are formed. Thereby, a part of the bridge circuit 70 described later is formed on the substrate 2.

  The cantilever 10 is a flat member connected to the substrate 2. The cantilever 10 is configured by stacking a semiconductor layer 40 and a resistance layer 30 as shown in FIG. As described above, the cantilever 10 includes the first cantilever 10a and the second cantilever 10b. In other words, two cantilevers (first cantilever 10a and second cantilever 10b) are provided on one substrate 2, that is, on one chip. The first cantilever 10a is provided facing the first opening 14a. The second cantilever 10b is provided facing the second opening 14b.

  As shown in FIG. 1A, the first cantilever 10a and the second cantilever 10b are provided so as to be line-symmetric with respect to the virtual line P. The first cantilever 10a is provided on one side (+ X side) with respect to the virtual line P. The second cantilever 10 b is provided on the other side (−X side) with respect to the virtual line P. Further, the first cantilever 10a and the second cantilever 10b are provided point-symmetrically with respect to the center point C in plan view.

The first cantilever 10a includes a first connection portion 11a connected to the substrate 2, a second connection portion 12a, and a flat plate portion 13a that connects the first connection portion 11a and the second connection portion 12a.
The first connection portion 11a and the second connection portion 12a are provided on the + X side with respect to the flat plate portion 13a. In other words, the first cantilever 10 a has one side (+ X side) end connected to the substrate 2. The first connection part 11 a includes a resistance part 31 a composed of the resistance layer 30. The second connection part 12 a includes a resistance part 32 a configured by the resistance layer 30.

  The flat plate portion 13a of the first cantilever 10a includes a first connecting portion 11a and a conductive portion 22a that connects the second connecting portion 12a. The conductive portion 22a is provided at the connection portion side (+ X side) end portion of the flat plate portion 13a. The conductive portion 22a electrically connects the resistance portion 31a of the first connection portion 11a and the resistance portion 32a of the second connection portion 12a. The material of the electroconductive part 22a is not specifically limited in the range which has electroconductivity. For example, in the present embodiment, the conductive portion 22a is made of the same material as that of the conductive layer 20.

The second cantilever 10b includes a first connection portion 11b connected to the substrate 2, a second connection portion 12b, and a flat plate portion 13b connecting the first connection portion 11b and the second connection portion 12b.
The 1st connection part 11b and the 2nd connection part 12b are provided in the -X side with respect to the flat plate part 13b. In other words, the second cantilever 10 b has the other side (−X side) end connected to the substrate 2. The first connection part 11 b includes a resistance part 31 b composed of the resistance layer 30. The second connection part 12 b includes a resistance part 32 b constituted by the resistance layer 30.

  The flat plate portion 13b of the second cantilever 10b includes a first connecting portion 11b and a conductive portion 22b that connects the second connecting portion 12b. The conductive portion 22b is provided at the connecting portion side (−X side) end portion of the flat plate portion 13b. The conductive portion 22b electrically connects the resistance portion 31b of the first connection portion 11b and the resistance portion 32b of the second connection portion 12b. The material of the conductive portion 22b is the same as that of the conductive portion 22a of the first cantilever 10a.

  The first cantilever 10a and the second cantilever 10b extend in parallel with the surface of the substrate 2 (a surface parallel to the XY plane). As shown in FIG. 2 (A), the first cantilever 10a and the second cantilever 10b receive pressure and use the first connecting portions 11a, 11b and the second connecting portions 12a, 12b as fulcrums, with the deformation tip sides facing each other. In this state, it can be elastically deformed in the direction intersecting the surface of the substrate 2 (Z-axis direction). In other words, the first cantilever 10a is elastically deformed around the line connecting the first connection portion 11a and the second connection portion 12a, and the second cantilever 10b is formed by the first connection portion 11b and the second connection portion 12b. It is elastically deformed around the line connecting The line connecting the first connection part 11a and the second connection part 12a and the line connecting the first connection part 11b and the second connection part 12b are parallel to the Y-axis direction.

  When the first cantilever 10a and the second cantilever 10b are elastically deformed, the resistance values of the resistance portions 31a and 31b of the first connection portions 11a and 11b and the resistance portions 32a and 32b of the second connection portions 12a and 12b are piezoresistive. Increase or decrease depending on the effect.

  The piezoresistive effect is a phenomenon in which electric resistance changes when stress is applied to an object. The piezoresistive effect is significant in semiconductors such as germanium and silicon. In the piezoresistive effect of a semiconductor, the electric resistance characteristic varies depending on the crystal direction of the semiconductor crystal. That is, the difference in crystal direction determines the rate of change in resistance and whether the resistance value increases or decreases when stress is applied to the semiconductor. For example, in the structure in which the semiconductor layer 40 and the resistance layer 30 are stacked as in this embodiment, when the semiconductor layer 40 is N-type and the resistance layer 30 is P-type, the crystal orientation < The resistance change rate in the 100> direction is maximized.

Next, the manufacturing method of the flow sensor element 1 of this embodiment is demonstrated.
3A to 3E are cross-sectional views illustrating the procedure of the method for manufacturing the flow sensor element 1 of the present embodiment.
The manufacturing method of the flow sensor element 1 of this embodiment includes an SOI substrate forming step, a resistance layer forming step, a conductive layer forming step, a first patterning step, a second patterning step, a recess forming step, and an insulating layer. A removal step.

  First, the SOI substrate forming step is a step in which an insulating layer 50 and a semiconductor layer 40 are stacked in this order on a support substrate 60 as shown in FIG. A substrate having such a configuration, that is, a configuration in which the insulating layer 50 is sandwiched between the support substrate 60 (for example, a silicon substrate) and the semiconductor layer 40 is generally referred to as an SOI substrate. By this step, an SOI substrate that is a base of the flow sensor element 1 is formed.

  Next, the resistance layer forming step is a step of forming the resistance layer 30 over the semiconductor layer 40 as shown in FIG. The resistance layer 30 is formed by adding impurities to the semiconductor layer 40. As the impurity, for example, B (boron) can be used when the semiconductor layer 40 is P-type. Further, when the semiconductor layer 40 is N-type, for example, P (phosphorus) can be used as an impurity.

  As a method for adding impurities to the semiconductor layer 40, for example, a thin film containing impurities is applied to the surface of the semiconductor layer 40, and the impurity is diffused into the semiconductor layer 40 by heating, or impurity ions are added to the semiconductor. An ion implantation method that directly strikes the layer 40 and implants into the semiconductor layer 40 can be selected. By this step, the impurity diffuses in part of the semiconductor layer 40 on the side opposite to the insulating layer 50 (+ Z side), and the resistance layer 30 is formed.

  Next, the conductive layer forming step is a step of forming the conductive layer 20 on the resistance layer 30. Through this step, the substrate 2 in which the insulating layer 50, the semiconductor layer 40, the resistance layer 30, and the conductive layer 20 are stacked is formed on the support substrate 60.

  Next, the first patterning step is a step of patterning the conductive layer 20 as shown in FIG. In this step, for example, the conductive layer 20 is partially removed by photolithography or the like, and the conductive layer 20 is patterned. The portions removed in the conductive layer 20 are the portions where the resistance layer 30 is exposed in the first cantilever 10a and the second cantilever 10b, and the portions where the insulating portion 51 is formed. Through this step, conductive portions 22a and 22b and wiring regions 21a to 21d (not shown in FIG. 3C) are formed.

  Next, the second patterning step is a step of patterning the resistance layer 30 and the semiconductor layer 40 as shown in FIG. In this step, the resistance layer 30 and the semiconductor layer 40 are partially removed by etching and patterned. The locations removed in the resistance layer 30 and the semiconductor layer 40 are locations where the first through portion 15a and the second through portion 15b are formed, and locations where the insulating portion 51 is formed. The etching method is not particularly limited, and for example, a dry etching method can be used. By this step, the first groove portion 19a and the second groove portion 19b are formed. Although not shown in FIG. 3C, the insulating portion 51 is formed by this process.

  As the alignment in the first patterning step and the second patterning step described above, for example, an alignment mark is formed on the surface side (the surface on the + Z side) on the substrate 2 and a method based on the alignment mark can be selected.

  Next, the recess forming step is a step of forming the recess 16 as shown in FIG. The back surface (surface on the −Z side) side of the support substrate 60 is partially removed by etching to form the recess 16. As an etching method, for example, a DRIE (Deep Reactive Ion Etching) method or the like can be used. By this step, the recesses 16 (the first recess 16a and the second recess 16b) that open to the back surface side of the support substrate 60 are located at the positions on the back surface of the support substrate 60 corresponding to the positions of the first groove portion 19a and the second groove portion 19b. It is formed.

  In the recess forming step, the side opposite to the first patterning step and the second patterning step (back side) is partially removed. Therefore, as the alignment in the recess forming step, for example, a method of performing double-sided alignment using the alignment marks formed on the surface side used in the first patterning step and the second patterning step can be selected.

  Next, the insulating layer removing step is a step of partially removing the insulating layer 50 as shown in FIG. In this step, the insulating layer 50 that forms the bottoms of the first recess 16a and the second recess 16b is removed by etching. As an etching method, for example, a dry etching method or a wet etching method can be selected. By this step, the first through portion 15a and the second through portion 15b that penetrate the substrate 2 in the direction perpendicular to the surface (Z-axis direction), and the first opening that communicates with the first through portion 15a and the second through portion 15b. A portion 14a and a second opening 14b are formed. Further, by this step, the first cantilever 10a and the second cantilever 10b are formed facing the first opening 14a and the second opening 14b, respectively.

  With the above process, the manufacturing process is completed, and the flow sensor element 1 of the present embodiment is manufactured.

  In the first patterning step, only the portion of the conductive layer 20 where the insulating portion 51 is formed may be removed, and the patterned conductive layer 20 may be used as a mask in the second patterning step. In this case, after the second patterning step, a step of patterning by removing a part of the conductive layer 20 is further provided.

Next, the bridge circuit 70 using the flow sensor element 1 will be described.
In the following description, unless otherwise specified, the resistance value means a resistance value when an external force, such as a pressure by a fluid, is not applied to the flow sensor element 1.
FIG. 4A is a circuit diagram showing a configuration of the bridge circuit 70 using the flow sensor element 1. FIG. 4B is a circuit diagram showing a bridge circuit 70 </ b> A equivalent to the bridge circuit 70.

As shown in FIG. 4A, the bridge circuit 70 includes a flow sensor element 1 and resistors R1 and R2. The resistance value of the resistor R1 and the resistance value of the resistor R2 are the same. A power source E and a galvanometer G are connected to the bridge circuit 70.
A wiring 71 (wirings 71a, 71b, 71c, 71d) is connected to the flow sensor element 1. The wiring 71a is connected to the wiring region 21a, and connects the wiring region 21a to the + side of the power source E and the resistor R1. The wiring 71b is connected to the wiring area 21b, and connects the wiring area 21b to the galvanometer G and the resistor R2. The wiring 71c is connected to the wiring region 21c, and connects the wiring region 21c to the negative side of the power source E and the resistor R2. The wiring 71d is connected to the wiring region 21d, and the wiring region 21d is connected to the galvanometer G and the resistor R1.

  The wiring 71a and the wiring 71c are connected via a power supply E. The wiring 71a and the wiring 71d are connected via a resistor R1. The wiring 71b and the wiring 71d are connected via a resistor R2. The wiring 71b and the wiring 71d are connected via a galvanometer G.

  The wiring 71 a and the wiring 71 b are connected via the flow sensor element 1. More specifically, the wiring 71a and the wiring 71b include the wiring region 21a, the resistance portion 31a of the first connection portion 11a of the first cantilever 10a, the conductive portion 22a of the first cantilever 10a, and the first portion of the first cantilever 10a. The two connection portions 12a are connected to each other via the resistance portion 32a and the wiring region 21b. The resistance portion 31a and the resistance portion 32a are connected in series by the wiring regions 21a and 21b and the conductive portion 22a. Such a connection state is equivalent to connecting a resistance having a resistance value obtained by adding the resistance value of the resistance portion 31a and the resistance value of the resistance portion 32a between the wiring 71a and the wiring 71b. . The resistance value obtained by adding the resistance value of the resistance portion 31a and the resistance value of the resistance portion 32a (hereinafter referred to as the resistance value of the first cantilever 10a) is the same as the resistance values of the resistors R1 and R2. Is set.

  The wiring 71c and the wiring 71d are connected via the flow sensor element 1. More specifically, the wiring 71c and the wiring 71d include the wiring region 21c, the resistance portion 31b of the first connection portion 11b of the second cantilever 10b, the conductive portion 22b of the second cantilever 10b, and the second portions of the second cantilever 10b. The two connection portions 12b are connected to each other through the resistance portion 32b and the wiring region 21d. The resistance part 31b and the resistance part 32b are connected in series by the wiring regions 21c and 21d and the conductive part 22b. Such a connection state is equivalent to connecting a resistance having a resistance value obtained by adding the resistance value of the resistance portion 31b and the resistance value of the resistance portion 32b between the wiring 71c and the wiring 71d. . The resistance value obtained by adding the resistance value of the resistance portion 31b and the resistance value of the resistance portion 32b is set to be the same as the resistance values of the resistors R1 and R2. That is, the resistance value obtained by adding the resistance value of the resistance part 31b and the resistance value of the resistance part 32b (hereinafter referred to as the resistance value of the second cantilever 10b) is the same as the resistance value of the first cantilever 10a.

  The bridge circuit 70 connected as described above is equivalent to the bridge circuit 70A shown in FIG. The resistance R3 of the bridge circuit 70A corresponds to the resistance part 31b of the first connection part 11b and the resistance part 32b of the second connection part 12b of the second cantilever 10b. The resistance R4 of the bridge circuit 70A corresponds to the resistance part 31a of the first connection part 11a and the resistance part 32a of the second connection part 12a of the first cantilever 10a. That is, the resistors R1, R2, R3, and R4 are resistors having the same resistance value.

  In the bridge circuit 70, the resistance values of the first cantilever 10a and the second cantilever 10b arranged diagonally in terms of electrical wiring vary due to the piezoresistance effect. That is, the bridge circuit 70 is a half bridge circuit.

Next, a measurement method using the bridge circuit 70 will be described.
In the bridge circuits 70 and 70A as described above, no current flows through the galvanometer G if the resistance values of the four wired resistors are the same. More specifically, the product of the resistance values of two diagonally arranged resistors (for example, resistors R1 and R2) and the resistance of the other two diagonally arranged resistors (for example, resistors R3 and R4) If the product of the values is the same, no current flows through the galvanometer G. In the bridge circuit 70, if the product of the resistance value of the resistor R1 and the resistance value of the resistor R2 is the same as the product of the resistance value of the first cantilever 10a and the resistance value of the second cantilever 10b, No current flows through the total G.

  When the pressure by the fluid to be measured is not applied to the flow sensor element 1, as described above, the resistance value of the first cantilever 10a, the resistance value of the second cantilever 10b, the resistance value of the resistor R1, Since the resistance value of the resistor R2 is the same, no current flows through the galvanometer G.

  On the other hand, when a pressure is applied to the flow sensor element 1 by the fluid to be measured, the first cantilever 10a and the second cantilever 10b are elastically deformed according to the applied pressure, and the first cantilever 10a and the second cantilever 10 The resistance value of 10b varies due to the piezoresistance effect. As a result, the resistance balance described above is lost, and a current flows through the galvanometer G. Since the current flowing through the galvanometer G changes according to the fluctuation value of the resistance, the pressure of the fluid applied to the first cantilever 10a and the second cantilever 10b can be measured by measuring this current. . Thereby, it is possible to measure the flow rate of the fluid to be measured by constructing a flow sensor module in which the differential pressure between two points in the flow of the fluid to be measured is applied to the flow sensor element 1. Become.

  The voltage of the power supply E used in this embodiment is, for example, about 1.5V to 5V. The combined resistance of the bridge circuit 70 is, for example, about 1 kΩ to 5 kΩ. Therefore, the current flowing through the bridge circuit 70 is, for example, about 1 mA.

  As an example of the bridge circuit 70 of the present embodiment, a bridge circuit using the flow sensor element 1 of the present embodiment having a power supply voltage of 3.3 V and a combined resistance of 3.3 kΩ was manufactured. As the flow sensor element 1, a flow sensor element having a square shape with a side of 1.5 mm in plan view was used.

Next, an example of a flow sensor module using the flow sensor element 1 of the present embodiment will be described.
FIG. 5 is a cross-sectional view showing a flow sensor module 100 which is an example of a flow sensor module using the flow sensor element 1.
As shown in FIG. 5, the flow sensor module 100 is provided so as to form a bypass path 130 in the pipe 200. The flow sensor module 100 includes a housing 110, a flow sensor element 1, a fixed substrate 17, and a temperature sensor 120. In the pipe line 210 of the pipe 200, the fluid flows in the direction FD (−X direction) indicated by the arrow. The fluid may be, for example, a gas or a liquid.

The housing 110 includes a first member 111 and a second member 114.
The first member 111 is a member connected to the pipe 200. The first member 111 is provided with an upstream connection portion 112 and a downstream connection portion 113. The upstream side connection portion 112 and the downstream side connection portion 113 are provided so as to protrude from the surface of the first member 111 on the pipe 200 side toward the pipe 200, and connect the first member 111 and the pipe 200.

  The upstream connection portion 112 is provided on the upstream side (+ X side) of the first member 111. The upstream connection portion 112 is formed with a through-hole 115 that passes through the upstream connection portion 112 and the first member 111 in a direction perpendicular to the fluid flow (Z-axis direction). The upstream side connection part 112 is connected to the pipe 200 so that the through hole 115 communicates with the pipe line 210 through the hole K1 formed in the pipe 200.

  The downstream connection portion 113 is provided on the downstream side (−X side) of the first member 111. The downstream connection portion 113 is formed with a through-hole 116 that penetrates the downstream connection portion 113 and the first member 111 in a direction perpendicular to the fluid flow (Z-axis direction). The downstream side connection portion 113 is connected to the pipe 200 so that the through hole 116 communicates with the pipe line 210 through a hole K2 formed in the pipe 200.

  A concave portion 118 that opens to the second member 114 side is formed on the surface of the first member 111 on the second member 114 side (+ Z side). The planar view (XY plane view) shape of the recess 118 is set according to the planar view shape of the fixed substrate 17.

  The 2nd member 114 is a member in which the recessed part 117 opened to the 1st member 111 side (-Z side) was formed. The concave portion 117 is formed so as to include the position where the upstream connection portion 112 and the downstream connection portion 113 are formed in a plan view (XY view). The second member 114 is bonded to the first member 111 and the fixed substrate 17 by the sealing material 140.

  The fixed substrate 17 is a member that fixes the flow sensor element 1. The fixed substrate 17 is fitted in the concave portion 118 of the first member 111 and is bonded to the first member 111 by the sealing material 140. The fixed substrate 17 is formed with a through hole 17a and a through hole 17b penetrating in the thickness direction (Z-axis direction). The through hole 17 a communicates with the through hole 115 and the recess 117 formed in the upstream connection portion 112. The through hole 17 b communicates with the through hole 116 and the recess 117 formed in the downstream connection portion 113.

The flow sensor element 1 is provided at a position where the through hole 17a is formed on the surface of the fixed substrate 17 on the second member 114 side (+ Z side). The flow sensor element 1 is fixed by bonding the support substrate 60 and the fixed substrate 17 with the adhesive 18 in the direction in which the support substrate 60 side is the pipe 200 side. The flow sensor element 1 is provided such that the first opening 14a and the second opening 14b overlap the through hole 17a of the fixed substrate 17 and the through hole 115 of the first member 111 in a plan view (XY plane view). It has been.
Although not shown, the flow sensor element 1 is provided by forming a bridge circuit 70 as shown in FIG.

  As shown in FIG. 5, the through hole 115 of the upstream connection portion 112, the through hole 17 a of the fixed substrate 17, the first opening portion 14 a and the second opening portion 14 b of the flow sensor element 1, and the flow sensor element 1 The first through part 15a and the second through part 15b, the concave part 117 of the second member 114, the through hole 17b of the fixed substrate 17, and the through hole 116 of the downstream connection part 113 communicate with each other to form a bypass passage 130. doing. The fluid flowing through the pipe line 210 flows into the bypass path 130 from the through hole 115 of the upstream connection section 112 through the hole K1, passes through the bypass path 130 along the flow direction FD1 indicated by the arrow, and flows downstream. It flows out from the through-hole 116 of the connection part 113 to the pipe line 210 through the hole K2.

  A temperature sensor 120 is provided at a position between the through hole 17 a and the through hole 17 b on the surface of the fixed substrate 17 on the second member 114 side (+ Z side). Although not shown, the temperature sensor 120 is connected to a bridge circuit 70 that includes the flow sensor element 1. The temperature sensor 120 measures the temperature of the fluid flowing in the bypass passage 130 and compensates for a change in the characteristics of the flow sensor element 1 due to a temperature change.

FIG. 6 is a partial enlarged cross-sectional view of a portion of the flow sensor module 100 where the flow sensor element 1 is provided.
As shown in FIG. 6, when the fluid flows in the bypass passage 130 in the direction FD1, the first cantilever 10a and the second cantilever 10b pass through the pipe 210 at the location where the upstream connection portion 112 is connected. The difference between the pressure of the flowing fluid and the pressure of the fluid flowing in the pipe 210 at the location where the downstream connection portion 113 is connected (hereinafter, the differential pressure between the upstream connection portion 112 and the downstream connection portion 113). The second member 114 side (+ Z side).

  When the first cantilever 10a and the second cantilever 10b are elastically deformed, the resistance value of the first cantilever 10a and the resistance value of the second cantilever 10b change according to the degree of elastic deformation of the first cantilever 10a and the second cantilever 10b. To do. Therefore, by measuring the amount of change in the resistance value of the first cantilever 10a and the resistance value of the second cantilever 10b by the bridge circuit 70 from the current value flowing through the galvanometer G, the upstream side connection portion 112 and the downstream side The differential pressure between the connection part 113 can be measured. By calculating the flow rate from this differential pressure, the flow sensor module 100 can measure the flow rate of the fluid flowing in the pipe line 210.

  According to the flow sensor element 1 of the present embodiment, the first cantilever 10a is provided on the + X side across the virtual line P on the surface of the substrate 2, and the first cantilever 10a is the first connection portion. 11a and the 2nd connection part 12a are arrange | positioned so that it may become the + X side. Further, the second cantilever 10b is provided on the −X side across the virtual line P on the surface of the substrate 2, and the second cantilever 10b includes the first connecting portion 11b and the second connecting portion 12b − It arrange | positions so that it may become X side. Therefore, both the first cantilever 10a and the second cantilever 10b are the resistance portions 31a and 31b of the first connection portions 11a and 11b and the resistance portions 32a and 32b of the second connection portions 12a and 12b, which are part of the resistance in the bridge circuit 70. Is arranged to face the outside of the substrate 2. Therefore, in the present embodiment, for example, when the bridge circuit 70 is configured, it is easy to connect the wiring 71 to the flow sensor element 1, and it is easy to route each wiring 71.

Further, when a plurality of cantilevers are provided on one substrate, in other words, when a plurality of cantilevers are provided on one chip, the substrate area of the flow sensor element is increased and the size is increased.
On the other hand, according to this embodiment, by arranging the first cantilever 10a and the second cantilever 10b as described above, the wiring 71 can be efficiently connected, and the area of the substrate 2 in the flow sensor element 1 ( An increase in chip area) can be minimized.

  Further, according to the present embodiment, by arranging the first cantilever 10a and the second cantilever 10b as described above, the first cantilever 10a and the second cantilever 10b can be easily arranged in the center of the substrate 2. Thereby, in this embodiment, when fixing the flow sensor element 1 to the fixed board | substrate 17, the part which can be adhere | attached using the adhesive agent 18, ie, the outer side of the area | region surrounding the 1st cantilever 10a and the 2nd cantilever 10b. Can be enlarged. Therefore, in this embodiment, the adhesive strength of the flow sensor element 1 with respect to the fixed substrate 17 can be improved.

  Moreover, according to this embodiment, the 1st opening part 14a and the 2nd opening part 14b are spaced apart and formed independently. The first cantilever 10a is provided facing the first opening 14a, and the second cantilever 10b is provided facing the second opening 14b. That is, one cantilever 10 is provided for one opening 14.

  For example, in the case where two or more cantilevers are provided for one opening, the installation positions of the plurality of provided cantilevers are shifted from an appropriate position, etc., so that the flows through the openings and the cantilevers. Fluid flow may be disturbed. In such a case, the cantilever may not be elastically deformed properly.

  On the other hand, according to this embodiment, since one cantilever is provided for each opening, the first opening 14a (second opening 14b) and the first penetration 15a (second penetration). When the fluid passes through the flow sensor element 1 through the part 15b), the fluid flow is prevented from being disturbed, and the first cantilever 10a (second cantilever 10b) is prevented from being elastically deformed properly.

  Further, according to the present embodiment, the first cantilever 10a and the second cantilever 10b are provided point-symmetrically with respect to the center point C in plan view and provided symmetrically with respect to the virtual line P. Therefore, as shown in FIG. 6, when the fluid passes through the flow sensor element 1 in a direction substantially perpendicular to the surface of the substrate 2, it flows through the first cantilever 10a and the second cantilever 10b, respectively. The fluid flow can be made substantially uniform. Therefore, in this embodiment, the flow sensor element which can improve the measurement accuracy of a flow sensor module is obtained.

  Further, by forming the first cantilever 10a and the second cantilever 10b symmetrically, it is easy to make the resistance characteristics of the first cantilever 10a and the second cantilever 10b due to the piezoresistance effect the same. As a result, in this embodiment, the offset of the resistance value of each resistor when the bridge circuit 70 is configured can be reduced.

  Further, according to the present embodiment, a part of the substrate 2 is constituted by an SOI substrate. Thereby, in the second patterning step, the insulating layer 50 of the substrate 2 is exposed and the insulating portion 51 is formed by removing the resistance layer 30 and the semiconductor layer 40 of the substrate 2. That is, by removing a part of the substrate 2, the region on the substrate 2 can be easily divided electrically. Therefore, according to this embodiment, it is easy to form a circuit used in the flow sensor module 100 using the flow sensor element 1.

  In addition, according to the present embodiment, the first cantilever 10a and the second cantilever 10b have the same configuration as a part of the layer constituting the substrate 2, and therefore the first cantilever 10a and the second cantilever 10b are removed by removing a part of the substrate 2. A manufacturing method for forming the cantilever 10a and the second cantilever 10b can be employed. Thereby, according to this embodiment, it is easy to form the thickness of the 1st cantilever 10a and the 2nd cantilever 10b mutually uniformly, and the dispersion | variation in the characteristic of the flow sensor element 1 can be suppressed.

  Further, according to the flow sensor module 100 of the present embodiment, two bridges in the flow sensor element 1, that is, a bridge in which the first cantilever 10a and the second cantilever 10b are arranged diagonally in terms of electrical wiring. A circuit 70 (half-bridge circuit) is configured. Thereby, the output value of a sensor can be improved, and the flow rate sensor module which can improve the ratio of the sensor output to noise, that is, the signal-to-noise ratio can be obtained. Therefore, according to the flow sensor module 100 of the present embodiment, a sufficient signal-to-noise ratio cannot be obtained with the conventional flow sensor module, and the flow rate is reduced even in a range where the value of the pressure difference is small, which is difficult to measure. It can be measured. That is, according to the flow sensor module 100 of the present embodiment, it is possible to obtain a flow sensor module that can reduce the influence of noise, have a small measurement error, and improve sensitivity.

  In addition, according to the present embodiment, since the sensor output value can be improved, when the output result from the sensor is digitally processed, the margin for the resolution of the analog-digital converter can be increased.

  Moreover, according to this embodiment, since a sensor output can be improved, even if the cantilever 10 is made small, a larger sensor output can be obtained as compared with a conventional flow sensor module. Thereby, the cantilever 10 can be made small and the diameter of the bypass path 130 connected to the piping 200 can also be made small. In this case, since the holes K1 and K2 formed in the pipe 200 can be made small, it is easy to attach the pipe 200 when the flow sensor module 100 is attached to the pipe 200.

  In the present embodiment, the following configuration may be employed.

  In the present embodiment, the first cantilever 10a and the second cantilever 10b are each formed integrally with the substrate 2, but the present invention is not limited thereto. For example, the first cantilever 10a and the second cantilever 10b may be provided on the substrate 2 as separate members.

  In the present embodiment, the opening 14 includes two openings, a first opening 14a and a second opening 14b, which are formed separately and separately from each other, but is not limited thereto. For example, the opening 14 may be configured to have one opening.

  In the present embodiment, the insulating portion 51 is provided point-symmetrically, but the present invention is not limited to this. For example, the insulating part 51 may be provided line-symmetrically or asymmetrically.

  In the flow sensor module 100 shown in the present embodiment, the flow sensor element 1 is arranged so that the fluid passing through the flow sensor element 1 flows from the support substrate 60 side to the conductive layer 20 side (+ Z direction). However, it is not limited to this. For example, the flow sensor element 1 may be arranged so that the fluid passing through the flow sensor element 1 flows from the conductive layer 20 side to the support substrate 60 side (the direction of −Z).

Next, a second embodiment will be described.
The second embodiment differs from the first embodiment in the arrangement angle of the first cantilever and the second cantilever with respect to the substrate.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 7 is a plan view showing a flow sensor element 1A of the second embodiment.
As shown in FIG. 7, the flow sensor element 1A of this embodiment includes a substrate 2A, a first cantilever 10Aa, and a second cantilever 10Ab.
The first cantilever 10Aa and the second cantilever 10Ab are provided symmetrically with respect to a virtual line Pa on the surface of the substrate 2A passing through the center point Ca in plan view. Further, the first cantilever 10Aa and the second cantilever 10Ab are provided symmetrically with respect to the center point Ca in plan view.

  The virtual line Pa is set obliquely with respect to the outer peripheral side in the plan view of the flow sensor element 1A. That is, the first cantilever 10Aa and the second cantilever 10Ab are disposed obliquely with respect to the outer peripheral side of the flow sensor element 1A. The arrangement angle of the first cantilever 10Aa and the second cantilever 10Ab around the center point Ca in plan view is determined according to the crystal direction of the semiconductor layer of the substrate 2A. That is, the arrangement angle of the first cantilever 10Aa and the second cantilever 10Ab is determined according to the desired resistance characteristics of the first cantilever 10Aa and the second cantilever 10Ab.

  According to this embodiment, similarly to the first embodiment, it is possible to obtain a flow rate sensor element that can be easily connected and wired.

Next, a third embodiment will be described.
The third embodiment differs from the first embodiment in that four cantilevers are provided.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 8 is a plan view showing the flow sensor element 1B of the present embodiment.
As shown in FIG. 8, the flow sensor element 1B of the present embodiment includes a substrate 2B, a first cantilever 10Ba, a second cantilever 10Bb, a third cantilever 10Bc, and a fourth cantilever 10Bd.

  The first cantilever 10Ba and the third cantilever 10Bc are provided on one side (+ X side) with respect to the virtual line Pb on the surface of the substrate 2B passing through the center point Cb in plan view. Each of the first cantilever 10Ba and the third cantilever 10Bc has a + X side end connected to the substrate 2B.

The first cantilever 10Ba has a first through portion 15Ba formed around it. The first cantilever 10Ba is provided facing the first opening 14Ba. The first through portion 15Ba and the first opening portion 14Ba communicate with each other.
The third cantilever 10Bc has a third through portion 15Bc formed around it. The third cantilever 10Bc is provided facing the third opening 14Bc. The third through portion 15Bc and the third opening portion 14Bc communicate with each other.

  On one side (+ X side) of the virtual line Pb on the substrate 2B, wiring areas 21Ba, 21Bb, and 21Bc are formed. The wiring region 21Ba and the wiring region 21Bb are electrically connected via the first cantilever 10Ba. The wiring region 21Bb and the wiring region 21Bc are electrically connected via the third cantilever 10Bc. That is, the first cantilever 10Ba and the third cantilever 10Bc are connected in series between the wiring region 21Ba and the wiring region 21Bc.

  The second cantilever 10Bb and the fourth cantilever 10Bd are provided on the other side (−X side) with respect to the virtual line Pb. The second cantilever 10Bb and the fourth cantilever 10Bd are each connected to the substrate 2B at the −X side end.

The second cantilever 10Bb has a second through portion 15Bb formed around it. The second cantilever 10Bb is provided facing the second opening 14Bb. The second through portion 15Bb and the second opening portion 14Bb communicate with each other.
The fourth cantilever 10Bd has a fourth through portion 15Bd formed around it. The fourth cantilever 10Bd is provided facing the fourth opening 14Bd. The fourth through portion 15Bd and the fourth opening portion 14Bd communicate with each other.

  On the other side (−X side) of the virtual line Pb on the substrate 2B, wiring regions 21Bd, 21Be, and 21Bf are formed. The wiring region 21Bd and the wiring region 21Be are electrically connected via the fourth cantilever 10Bd. The wiring region 21Be and the wiring region 21Bf are electrically connected via the second cantilever 10Bb. That is, the second cantilever 10Bb and the fourth cantilever 10Bd are connected in series between the wiring region 21Bd and the wiring region 21Bf.

The first cantilever 10Ba and the second cantilever 10Bb are provided symmetrically with respect to the virtual line Pb.
The third cantilever 10Bc and the fourth cantilever 10Bd are provided symmetrically with respect to the virtual line Pb.
The first cantilever 10Ba and the fourth cantilever 10Bd are provided symmetrically with respect to the center point Cb in plan view.
The second cantilever 10Bb and the third cantilever 10Bc are provided point-symmetrically with respect to the center point Cb in plan view.

  According to the present embodiment, the resistors corresponding to the resistors R3 and R4 in the bridge circuit 70A shown in FIG. 4B are obtained by connecting two cantilevers in series. Therefore, in this embodiment, when the bridge circuit is configured, the resistance value of each resistor can be made larger than those in the first embodiment and the second embodiment. Therefore, in the present embodiment, the current consumption when the flow rate sensor element 1B is driven at a constant voltage can be reduced.

  In the present embodiment, two cantilevers are connected in series, but the present invention is not limited to this. For example, the flow sensor element may have a configuration in which three or more cantilevers are connected in series.

Next, a fourth embodiment will be described.
The fourth embodiment is different from the first embodiment in that a resistance element is provided.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 9 is a plan view showing the flow sensor element 1C of the present embodiment.
As shown in FIG. 9, the flow sensor element 1C according to the present embodiment includes a substrate 2C, a first cantilever 10Ca, a second cantilever 10Cb, a first resistance element (resistance element) 80Ca, and a second resistance element (resistance). Element) 80Cb.

  The first cantilever 10Ca and the second cantilever 10Cb are arranged in the same manner as the first cantilever 10a and the second cantilever 10b in the first embodiment, respectively. That is, the first cantilever 10Ca and the second cantilever 10Cb are provided symmetrically with respect to an imaginary line Pc on the surface of the substrate 2C passing through the center point Cc in plan view. The first cantilever 10Ca and the second cantilever 10Cb are provided symmetrically with respect to the center point Cc in plan view.

  The first resistance element 80Ca is provided on the + Y side of the first cantilever 10Ca. The first resistance element 80Ca includes a first connection portion 81Ca, a second connection portion 82Ca, and a flat plate portion 83Ca. The first connection portion 81Ca and the second connection portion 82Ca have the resistance layer exposed throughout. The first connection portion 81Ca and the second connection portion 82Ca include a resistance portion 33Ca and a resistance portion 34Ca that are configured by resistance layers. The flat plate portion 83Ca includes a conductive portion 22Cc. The conductive portion 22Cc electrically connects the resistance portion 33Ca and the resistance portion 34Ca. The resistance layer is exposed at portions other than the conductive portion 22Cc of the flat plate portion 83Ca.

The portion of the first resistance element 80Ca where the resistance layer is exposed has the same shape in plan view as the portion of the first cantilever 10Ca where the resistance layer is exposed. In other words, the first resistance element 80Ca includes a resistance layer having the same shape as the exposed resistance layer in the first cantilever 10Ca in plan view.
An insulating portion 52Ca is formed around the first resistance element 80Ca. The insulating part 52Ca has the same shape in plan view as the first through part 15Ca formed around the first cantilever 10Ca.

  The second resistance element 80Cb is provided on the −Y side of the second cantilever 10Cb. The second resistance element 80Cb includes a first connection portion 81Cb, a second connection portion 82Cb, and a flat plate portion 83Cb. The first connecting portion 81Cb and the second connecting portion 82Cb have the resistance layer exposed throughout. The first connection portion 81Cb and the second connection portion 82Cb include a resistance portion 33Cb and a resistance portion 34Cb each formed of a resistance layer. The flat plate portion 83Cb includes a conductive portion 22Cd. The conductive portion 22Cd electrically connects the resistor portion 33Cb and the resistor portion 34Cb. The resistance layer is exposed at portions other than the conductive portion 22Cd of the flat plate portion 83Cb.

The portion of the second resistance element 80Cb where the resistance layer is exposed has the same shape as the portion of the second cantilever 10Cb where the resistance layer is exposed in plan view. In other words, the second resistance element 80Cb includes a resistance layer having the same shape as the exposed resistance layer in the second cantilever 10Cb in plan view.
An insulating portion 52Cb is formed around the second resistance element 80Cb. The insulating part 52Cb has the same shape in plan view as the second through part 15Cb formed around the second cantilever 10Cb.

  The first resistance element 80Ca and the second resistance element 80Cb are provided point-symmetrically with respect to the center point Cc in plan view. The first resistance element 80Ca and the second resistance element 80Cb have the same shape as the plan view of the first cantilever 10Ca and the second cantilever 10Cb. In the present embodiment, the first resistance element 80Ca and the second resistance element 80Cb are, for example, an SOI substrate forming step, a resistance layer forming step, and a conductive layer in the method of manufacturing the flow sensor element shown in the first embodiment. It is formed by a forming process, a first patterning process, and a second patterning process (see FIGS. 3A to 3C).

  An insulating part 51C (insulating parts 51Ca, 51Cb, 51Cc, 51Cd, 51Ce, 51Cf, 51Cg, 51Ch) is formed on the substrate 2C. The insulating portion 51C, the insulating portion 52Ca of the first resistance element 80Ca, the insulating portion 52Cb of the second resistance element 80Cb, the first through portion 15Ca of the first cantilever 10Ca, and the second through portion of the second cantilever 10Cb The wiring regions 21Ca, 21Cb, 21Cc, 21Cd are formed by 15Cb. The wiring regions 21Ca to 21Cd are regions where the conductive layer is exposed.

  The wiring area 21Ca is electrically connected to the wiring area 21Cb via the first cantilever 10Ca. In the first cantilever 10Ca, a resistance portion 31Ca connected to the wiring region 21Ca and a resistance portion 32Ca connected to the wiring region 21Cb are connected by a conductive portion 22Ca. This is equivalent to connecting a resistor having a resistance value obtained by adding the resistance value of the resistance portion 31Ca and the resistance value of the resistance portion 32Ca between the wiring region 21Ca and the wiring region 21Cb.

  The wiring region 21Cb is electrically connected to the wiring region 21Cc via the second resistance element 80Cb. Similarly to the first cantilever 10Ca, the second resistance element 80Cb also has the resistance portion 33Cb and the resistance portion 34Cb electrically connected by the conductive portion 22Cd. This is because a resistor having a resistance value obtained by adding the resistance value of the resistance portion 33Cb of the second resistance element 80Cb and the resistance value of the resistance portion 34Cb is connected between the wiring region 21Cb and the wiring region 21Cc. Is equivalent to

  The wiring region 21Cc is electrically connected to the wiring region 21Cd via the second cantilever 10Cb. In the same manner as described above, this has a resistance value obtained by adding the resistance value of the resistance part 31Cb of the second cantilever 10Cb and the resistance value of the resistance part 32Cb between the wiring area 21Cc and the wiring area 21Cd. This is equivalent to connecting a resistor.

  The wiring region 21Cd is electrically connected to the wiring region 21Ca via the first resistance element 80Ca. In the same manner as described above, a resistance value obtained by adding the resistance value of the resistance portion 33Ca of the first resistance element 80Ca and the resistance value of the resistance portion 34Ca is added between the wiring region 21Cd and the wiring region 21Ca. This is equivalent to connecting a resistor having the same.

  As described above, the first cantilever 10Ca, the second cantilever 10Cb, the first resistance element 80Ca, and the second resistance element 80Cb are electrically connected by the wiring regions 21Ca to 21Cd, respectively. Thereby, a bridge circuit is formed on the flow sensor element 1C. In the bridge circuit, since the first cantilever 10Ca and the second cantilever 10Cb are diagonally arranged in terms of electrical wiring, the first cantilever 10Ca and the second cantilever 10Cb are detected by detecting a change in the resistance value of the first cantilever 10Ca and the second cantilever 10Cb. The pressure applied to the cantilever 10Ca and the second cantilever 10Cb can be measured. Therefore, in this embodiment, the flow rate of the fluid can be measured by configuring a flow rate sensor module as shown in FIG. 5 using the flow rate sensor element 1C, for example.

  According to this embodiment, since the bridge circuit is formed on the flow sensor element 1C, the bridge is connected without connecting other resistors (for example, resistors R1 and R2 shown in FIG. 4) to the flow sensor element 1C. A circuit can be formed. Therefore, in this embodiment, when constructing a flow sensor module, wiring is easy.

  Further, according to the present embodiment, the first resistance element 80Ca is obtained by performing the steps up to the second etching step in the procedure for forming the first cantilever 10Ca and the second cantilever 10Cb, that is, the procedure for manufacturing the flow sensor element. In addition, the second resistance element 80Cb can be formed. Therefore, in the present embodiment, it is easy to form the first resistance element 80Ca and the second resistance element 80Cb.

  In addition, when connecting an external resistor to the flow sensor element when configuring the bridge circuit, it is necessary to connect a resistor having the same resistance value as the resistance value of the cantilever. It takes time to adjust. On the other hand, according to the present embodiment, the first resistance element 80Ca and the second resistance element 80Cb have resistance layers having substantially the same shape in plan view as the exposed resistance layers in the first cantilever 10Ca and the second cantilever 10Cb. Therefore, the resistance values of the first resistance element 80Ca and the second resistance element 80Cb and the resistance values of the first cantilever 10Ca and the second cantilever 10Cb can be accurately matched.

Here, the first cantilever 10Ca is provided with a conductive portion 22Ca that connects the resistance portion 31Ca and the resistance portion 32Ca. Thus, since the current flowing through the first cantilever 10Ca flows through the conductive portion 22Ca, the resistance value of the first cantilever 10Ca is the sum of the resistance value of the resistance portion 31Ca and the resistance value of the resistance portion 32Ca. It becomes almost the same.
Similarly, the second cantilever 10Cb is provided with a conductive portion 22Cb that connects the resistance portion 31Cb and the resistance portion 32Cb. Therefore, the resistance value of the second cantilever 10Cb is substantially the same as the sum of the resistance value of the resistance part 31Cb and the resistance value of the resistance part 32Cb.

However, in reality, the flat plate portions of the first cantilever 10Ca and the second cantilever 10Cb in which the resistance layer is exposed also have a slight resistance value of the first cantilever 10Ca and the second cantilever 10Cb connected in parallel. Influence.
According to the present embodiment, the exposed resistance layers of the first resistance element 80Ca and the second resistance element 80Cb include the first cantilever 10Ca and the second area where the resistance layer is exposed, including the connection portion and the flat plate portion. It has the same shape as cantilever 10Cb in plan view. Therefore, in this embodiment, the resistance value of the cantilever and the resistance value of the resistance element can be matched with higher accuracy.

  In the present embodiment, the first resistance element 80Ca and the second resistance element 80Cb are integrally manufactured with the substrate 2C. However, the present invention is not limited to this. For example, a separately provided resistance element may be provided on the substrate 2C.

Next, a fifth embodiment will be described.
5th Embodiment differs in arrangement | positioning of a cantilever and a resistive element with respect to 4th Embodiment.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 10 is a plan view showing the flow sensor element 1D of the present embodiment.
As shown in FIG. 10, the flow sensor element 1D of this embodiment includes a substrate 2D, a first cantilever 10Da, a second cantilever 10Db, a first resistance element (resistance element) 80Da, and a second resistance element (resistance) Element) 80Db.

  The first cantilever 10Da and the second cantilever 10Db are provided point-symmetrically with respect to the center point Cd in plan view. The first resistance element 80Da is provided on the + Y side of the first cantilever 10Da. The second resistance element 80Db is provided on the −Y side of the second cantilever 10Db. The first resistance element 80Da and the second resistance element 80Db are provided point-symmetrically with respect to the center point Cd in plan view. The Y-axis direction positions of the second cantilever 10Db and the first resistance element 80Da are the same. The Y-axis direction positions of the first cantilever 10Da and the second resistance element 80Db are the same.

  Wiring regions 21Da, 21Db, 21Dc, and 21Dd are formed on the substrate 2D. The wiring region 21Da is electrically connected to the wiring region 21Db via the first cantilever 10Da. The wiring region 21Db is electrically connected to the wiring region 21Dc via the second resistance element 80Db. The wiring region 21Dc is electrically connected to the wiring region 21Dd via the second cantilever 10Db. The wiring region 21Dd is electrically connected to the wiring region 21Da via the first resistance element 80Da. Thereby, a bridge circuit is formed on the flow sensor element 1D.

  According to the present embodiment, the Y-axis direction positions of the second cantilever 10Db and the first resistance element 80Da are the same, and the Y-axis direction positions of the first cantilever 10Da and the second resistance element 80Db are the same. Therefore, in the present embodiment, the first cantilever 10Da, the second cantilever 10Db, the first resistance element 80Da, and the second resistance element 80Db can be easily disposed on the substrate 2D without waste, and the entire flow sensor element is reduced in size. be able to. That is, in the present embodiment, the area (chip area) of the substrate 2D can be reduced.

Next, a sixth embodiment will be described.
The sixth embodiment differs from the fifth embodiment in the arrangement angle of the cantilever and the resistance element.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 11 is a plan view showing the flow sensor element 1E of the present embodiment.
As shown in FIG. 11, the flow sensor element 1E of this embodiment includes a substrate 2E, a first cantilever 10Ea, a second cantilever 10Eb, a first resistance element (resistance element) 80Ea, and a second resistance element (resistance). Element) 80Eb.

  The first cantilever 10Ea and the second cantilever 10Eb are provided point-symmetrically with respect to the center point Ce in plan view. The first resistance element 80Ea and the second resistance element 80Eb are provided point-symmetrically with respect to the center point Ce in plan view. The relative arrangement relationships of the first cantilever 10Ea, the second cantilever 10Eb, the first resistance element 80Da, and the second resistance element 80Db are the same as those in the fifth embodiment.

  The first cantilever 10Ea, the second cantilever 10Eb, the first resistance element 80Da, and the second resistance element 80Db are arranged obliquely with respect to the outer peripheral side in plan view of the flow rate sensor element 1E. The arrangement angle of each element around the center point Ce in plan view is determined according to the crystal direction of the semiconductor layer of the substrate 2E. That is, the arrangement angle of the first cantilever 10Ea and the second cantilever 10Eb can be set according to the desired resistance characteristics of the first cantilever 10Ea and the second cantilever 10Eb.

  According to this embodiment, similarly to the above-described embodiment, a flow rate sensor element that is easy to connect and handle is obtained.

Next, a seventh embodiment will be described.
The seventh embodiment differs from the fourth embodiment in the arrangement of resistance elements.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 12 is a plan view showing the flow sensor element 1F of the present embodiment.
As shown in FIG. 12, the flow sensor element 1F of this embodiment includes a substrate 2F, a first cantilever 10Fa, a second cantilever 10Fb, a first resistance element (resistance element) 80Fa, and a second resistance element (resistance) Element) 80Fb.

  The first cantilever 10Fa and the second cantilever 10Fb are provided symmetrically with respect to a virtual line Pf on the surface of the substrate 2F passing through the center point Cf in plan view. Further, the first cantilever 10Fa and the second cantilever 10Fb are provided symmetrically with respect to the center point Cf in plan view.

  The first resistance element 80Fa and the second resistance element 80Fb are provided point-symmetrically with respect to the center point Cf in plan view. The first resistance element 80Fa and the second resistance element 80Fb are provided symmetrically with respect to a line that passes through the center point Cf in plan view and is perpendicular to the virtual line Pf on the surface of the substrate 2F.

  Wiring areas 21Fa, 21Fb, 21Fc, and 21Fd are formed on the substrate 2F. The wiring region 21Fa electrically connects the first resistance element 80Fa and the first cantilever 10Fa. The wiring region 21Fb electrically connects the first cantilever 10Fa and the second resistance element 80Fb. The wiring region 21Fc electrically connects the second resistance element 80Fb and the second cantilever 10Fb. The wiring region 21Fd electrically connects the second cantilever 10Fb and the first resistance element 80Fa. The wiring areas 21Fa to 21Fd have the same surface area.

  According to the present embodiment, since the surface areas of the wiring regions 21Fa to 21Fd are approximately the same, when the flow sensor module is constructed using the flow sensor element 1F, wiring to the flow sensor element 1F is performed. Connection and wiring are easy.

Next, an eighth embodiment will be described.
The eighth embodiment differs from the seventh embodiment in the shape of the resistance element.
In the following description, the same components as those in the above embodiment may be denoted by the same reference numerals as appropriate, and the description may be omitted.

FIG. 13 is a plan view showing the flow sensor element 1G of the present embodiment.
As shown in FIG. 13, the flow sensor element 1G of the present embodiment includes a substrate 2G, a first cantilever 10Ga, a second cantilever 10Gb, a first resistance element 80Ga, and a second resistance element 80Gb. .

  The first cantilever 10Ga and the second cantilever 10Gb are provided symmetrically with respect to the virtual line Pg on the surface of the substrate 2G passing through the center point Cg in plan view. The first cantilever 10Ga and the second cantilever 10Gb are provided point-symmetrically with respect to the center point Cg in plan view.

  The first resistance element 80Ga includes a first connection portion 81Ga and a second connection portion 82Ga. The first connection portion 81Ga and the second connection portion 82Ga are electrically connected by the conductive portion 22Gc. The second resistance element 80Gb includes a first connection portion 81Gb and a second connection portion 82Gb. The first connection portion 81Gb and the second connection portion 82Gb are electrically connected by the conductive portion 22Gd.

  In the first resistance element 80Ga and the second resistance element 80Gb of the present embodiment, the exposed portion of the resistance layer in the flat plate portion is not provided with respect to the resistance elements shown in the fourth to seventh embodiments. It is different in point. Thereby, the planar view shapes of the first resistance element 80Ga and the second resistance element 80Gb are different from the planar view shapes of the first cantilever 10Ga and the second cantilever 10Gb. More specifically, the size of the first resistance element 80Ga and the second resistance element 80Gb in plan view is smaller than the size of the first cantilever 10Ga and second cantilever 10Gb in plan view.

  According to the present embodiment, the first resistance element 80Ga and the second resistance element 80Gb are not provided with a portion where the resistance layer is exposed in the flat plate portion, and therefore, from the first cantilever 10Ga and the second cantilever 10Gb in plan view. Is also formed small. Therefore, according to this embodiment, a flow sensor element can be reduced in size. That is, in the present embodiment, the area (chip area) of the substrate 2G can be reduced.

  In the present embodiment, the arrangement relationship between the first cantilever 10Ga and the second cantilever 10Gb and the first resistance element 80Ga and the second resistance element 80Gb is the same as the arrangement relationship between the cantilever and the resistance element in the seventh embodiment. However, the present invention is not limited to this. That is, a configuration in which any one of the resistance elements in the fourth to sixth embodiments is replaced with the first resistance element 80Ga and the second resistance element 80Gb in the present embodiment may be adopted.

  1, 1A, 1B, 1C, 1D, 1E, 1F, 1G ... Flow rate sensor element, 2, 2A, 2B, 2C, 2D, 2E, 2F, 2G ... Substrate, 10 ... Cantilever, 10a, 10Aa, 10Ba, 10Ca, 10Da, 10Ea, 10Fa, 10Ga ... 1st cantilever, 10b, 10Ab, 10Bb, 10Cb, 10Db, 10Eb, 10Fb, 10Gb ... 2nd cantilever, 14 ... opening, 14a, 14Ba ... 1st opening, 14b, 14Bb ... Second opening, 20 ... conductive layer, 30 ... resistive layer, 40 ... semiconductor layer, 50 ... insulating layer, 51, 51a, 51b, 51c, 51d, 51e, 51f, 51C, 51Ca, 51Cb, 51Cc, 51Cd, 51Ce , 51Cf, 51Cg, 51Ch, 52Ca, 52Cb ... insulating portion, 60 ... support substrate, 70 ... bridge circuit, 1 0 ... Flow sensor module, 80Ca, 80Da, 80Ea, 80Fa ... First resistance element (resistance element), 80Cb, 80Db, 80Eb, 80Fb ... Second resistance element (resistance element), C, Ca, Cb, Cc, Cd, Ce, Cf, Cg: Plane center point (predetermined point), P, Pa, Pb, Pc, Pf, Pg ... Virtual line

Claims (8)

A substrate,
A plurality of cantilevers provided on the substrate and elastically deformable in a predetermined direction and having substantially the same resistance characteristics;
A plurality of resistance elements provided on the substrate;
With
The plurality of cantilevers include a first cantilever provided on one side with respect to a predetermined virtual line on the surface of the substrate, and a second cantilever provided on the other side with respect to the virtual line,
The first cantilever and the second cantilever have substantially the same shape in plan view,
The first cantilever has an end on the one side connected to the substrate,
The second cantilever is connected to the substrate at the other end.
The substrate is
A support substrate;
An insulating layer having electrical insulation formed on the support substrate;
A semiconductor layer formed on the insulating layer;
A resistance layer having electrical resistance formed on the semiconductor layer;
A conductive layer having conductivity formed on the resistance layer;
With
On the substrate, an insulating portion where the insulating layer is exposed is provided,
Each of the plurality of cantilevers includes the semiconductor layer, the resistance layer, and the conductive layer.
At least a portion of the resistive layer in the plurality of cantilevers is exposed;
The plurality of resistance elements include a resistance layer having substantially the same shape in plan view as the exposed resistance layer in the plurality of cantilevers.
The plurality of cantilevers and the plurality of resistance elements are electrically connected to form a bridge circuit, respectively .   The flow sensor element according to claim 1, wherein the first cantilever and the second cantilever are arranged symmetrically with respect to the virtual line.   The flow sensor element according to claim 1, wherein the first cantilever and the second cantilever are arranged point-symmetrically with respect to a predetermined point on the surface of the substrate. The first cantilever is provided facing a first opening formed on one side of the substrate,
4. The flow rate according to claim 1, wherein the second cantilever is formed so as to open to one side of the substrate and face a second opening spaced apart from the first opening. 5. Sensor element. The substrate is provided with a plurality of wiring regions where the conductive layer is exposed,
The flow sensor according to any one of claims 1 to 4, wherein the plurality of cantilevers and the plurality of resistance elements are electrically connected to each other by the plurality of wiring regions to form a bridge circuit. element. 6. The flow sensor element according to claim 1, wherein in the bridge circuit, the first cantilever and the second cantilever are diagonally arranged in terms of electrical wiring. The plurality of resistance elements include a first resistance element and a second resistance element,
The bridge circuit is formed by electrically connecting the first cantilever, the second cantilever, the first resistance element, and the second resistance element, respectively.
The first cantilever and the second cantilever are arranged point-symmetrically with respect to a predetermined point on the surface of the substrate,
The flow sensor element according to any one of claims 1 to 6, wherein the first resistance element and the second resistance element are arranged symmetrically with respect to the predetermined point.   A flow sensor module comprising the flow sensor element according to claim 1.

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