Sensor

Abstract

The invention provides a sensor capable of appropriately ensuring insulation between a conductive film pattern and the surface of a metal base material when the metal base material having the surface on which a mark is formed is used. The sensor includes: a metal substrate having a surface on which a trace pattern is formed along a first direction in plan view; and a conductive film pattern formed on the surface via an insulating film, in which a first region, which is present in the first direction in plan view from a conductive film pattern formation region in which the conductive film pattern is formed, on the surface is covered by the insulating film, and a second region, which is present in the second direction, in plan view from the conductive film pattern formation region. The surface has an exposed region exposed from the insulating film at a position different from the first region in plan view.

Description

Technical Field

[0001] The present disclosure relates to a sensor in which a conductive film pattern is formed on a metal substrate via an insulating film. Background Art

[0002] As sensors such as pressure sensors, there are known sensors in which a circuit based on a conductive film pattern is formed on the surface of a metal substrate. For example, there is a circuit that uses the piezoresistive effect (also known as the pressure difference resistance effect) to detect the strain of a substrate (also known as a diaphragm or diaphragm) based on a change in resistance. In addition, in existing sensors using a metal substrate, in order to ensure a contact position between the resistance-welded electrode and the surface of the metal substrate, an exposed portion is sometimes formed on the surface of the metal substrate, which is exposed from the insulating film (see Patent Document 1, etc.).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-43016 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] Conventional pressure sensors and strain sensors use mirror-polished metal substrates. However, the inventors, aiming to reduce costs and improve production efficiency, have developed a technology that uses a metal substrate with a textured surface as the metal substrate for pressure sensors and strain sensors. The inventors discovered that, while providing an exposed portion from an insulating film on the metal substrate surface as in conventional methods, using a textured metal substrate can lead to a problem in which insulation between the conductive film pattern and the metal substrate surface cannot be ensured.

[0008] The technology disclosed herein provides a sensor capable of appropriately ensuring insulation between a conductive film pattern and the surface of the metal substrate when using a metal substrate having a surface with scratches formed thereon.

[0009] Technical solutions to solve problems

[0010] In order to achieve the above objectives, the present disclosure provides a sensor, which has:

[0011] a metal substrate having a surface having scratches formed along a first direction when viewed from above; and

[0012] a conductive film pattern formed on the surface via an insulating film,

[0013] On the surface, a first region existing in the first direction when viewed from a conductive film pattern forming region where the conductive film pattern is formed is covered by the insulating film.

[0014] The surface has an exposed region exposed from the insulating film at a position different from the first region in a plan view.

[0015] The sensor disclosed herein utilizes a metal substrate with a textured surface, enabling cost reduction and improved production efficiency due to, for example, the omission of mirror polishing steps. Furthermore, since the first region is covered with an insulating film, even if etching residue of the conductive film occurs along the texture of the metal substrate, adequate insulation between the conductive film pattern and the metal substrate surface can be maintained. Furthermore, by having an exposed area on the surface at a position different from the first region, short circuits between the conductive film pattern and the metal substrate surface caused by etching residue of the conductive film can be avoided, while allowing resistance welding electrodes to contact the surface.

[0016] In addition, for example, the surface may have at least two exposed regions sandwiching the conductive film pattern in a plan view.

[0017] This type of sensor can be effectively fixed to other components by, for example, contacting the two exposed areas with resistance-welded electrodes.

[0018] In addition, for example, the conductive film pattern may have a rectangular wave shape or a meander shape pattern portion when viewed from above.

[0019] Two of the at least two exposed regions may sandwich the conductive film pattern in an amplitude direction of the rectangular wave shape or the meandering shape in a plan view.

[0020] Conductive film patterns with rectangular or serpentine-shaped pattern portions when viewed from above can measure strain in the amplitude direction of the rectangular or serpentine wave. By configuring the conductive film pattern so that two exposed areas sandwich the pattern in the amplitude direction when viewed from above, and by contacting resistance-welded electrodes with the two exposed areas, the direction in which the metal substrate is fixed relative to other components can be aligned with the direction of the detected strain. This effectively transfers strain generated in other components to the metal substrate, increasing strain detection sensitivity.

[0021] Furthermore, for example, the surface roughness Ra of the surface in a second direction perpendicular to the first direction in a plan view may be 0.05 μm or more and 1 μm or less.

[0022] When the surface roughness Ra is above a specified value, etching residue of the conductive film is likely to form along the first direction. Therefore, the configuration of the first region and the exposed region as described above is particularly effective. In addition, by setting the surface roughness Ra below a specified value, a thin conductive film pattern can be formed with high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a plan view of the sensor according to the first embodiment of the present disclosure, and is a diagram showing the sensor as viewed from above.

[0024] Figure 2 It means Figure 1 This is a conceptual diagram showing the state of scratches formed on the surface of a substrate used in the sensor.

[0025] Figure 3 It means Figure 2 The conceptual diagram of the state of the scratches formed on the surface of the substrate shown is a schematic cross-sectional view of the vicinity of the substrate surface along the second direction.

[0026] Figure 4 It means in use Figure 1 This is a conceptual diagram of the process of fixing the sensor to other components when the sensor shown is used as a pressure sensor.

[0027] Figure 5 It is a plan view of the sensor according to the second embodiment, and is a diagram showing the sensor as seen from above.

[0028] Figure 6 It is a plan view of the sensor according to the third embodiment, and is a diagram showing the sensor as seen from above.

[0029] Figure 7 It is a plan view of the sensor according to the fourth embodiment, and is a diagram showing the sensor as seen from above.

[0030] Figure 8 It means in Figure 1 This figure shows a conceptual diagram of various regions formed on the surface of a metal substrate used in a sensor.

[0031] Figure 9 3 is a top view of a sensor according to a reference example, showing the sensor as viewed from above.

[0032] Figure 10A and Figure 10B This is a conceptual diagram showing an example of the occurrence of a short circuit between the conductive film pattern and the surface of the metal substrate that may occur in the sensor of the reference example.

[0033] Figures 11A to 11C This is a conceptual diagram showing another example of the occurrence of a short circuit between the conductive film pattern and the surface of the metal substrate that may occur in the sensor of the reference example.

[0034] Reference numerals

[0035] 10, 110, 210, 310, 810... sensors

[0036] 20…Metal substrate

[0037] 22…Back surface

[0038] 24…Surface

[0039] 25…Stretch marks

[0040] 26…First Area

[0041] 27a, 27b, 227a, 227b, 327a, 327b, 327c, 327d...exposed areas

[0042] 27b…exposed area

[0043] 28…Area under the conductive film pattern

[0044] 29, 229…non-exposed area

[0045] 30, 230, 330, 830...Insulation film

[0046] 40, 140…conductive film pattern

[0047] 42, 142…resistance film

[0048] 44, 45, 144, 145…Electrode pads

[0049] 46, 146 ...conductive film pattern forming area

[0050] 70…Other parts

[0051] 71…Electrode

[0052] D1…First direction

[0053] D2…Second direction

[0054] 826…First direction exposed area

[0055] 51, 52…etching residue DETAILED DESCRIPTION

[0056] First embodiment

[0057] Hereinafter, the present disclosure will be described based on the embodiments shown in the drawings.

[0058] Figure 1 FIG. 1 is a top view of the sensor 10 according to the first embodiment of the present disclosure. Figure 4 As shown, it is mounted on another component 70 and used as a strain sensor. Figure 4 An example in which the sensor 10 is used as a strain sensor for measuring the strain of another member 70 is shown in a cross-sectional view.

[0059] like Figure 1 and Figure 4 As shown, the sensor 10 includes a metal substrate 20, an insulating film 30, and a conductive film pattern 40. The insulating film 30 and the conductive film pattern 40 are stacked on the surface 24 of the metal substrate 20 in this order.

[0060] Examples of the material for the metal substrate 20 include stainless steel, but any metal material is not particularly limited. Furthermore, when the sensor 10 is subjected to high-temperature measurement conditions, the metal substrate 20 is preferably made of austenitic SUS304 or 316 or precipitation-hardened SUS630 or 631, as these materials have excellent high-temperature characteristics.

[0061] Figure 2 It means Figure 1 A conceptual diagram of the state of the scratches 25 formed on the surface 24 of the metal substrate 20 used in the sensor 10 shown. Figure 2 As shown, the metal substrate 20 has a surface 24 with scratches formed along the first direction D1 when viewed from above. Figure 2 As shown, when the surface 24 of the metal substrate 20 is magnified, scratches 25 consisting of a plurality of fine lines are formed on the entire surface 24 .

[0062] Figure 3 It means Figure 2 The conceptual diagram of the state of the scratches 25 formed on the surface 24 of the metal substrate 20 shown is a schematic cross-sectional view along the second direction D2 near the surface 24 of the metal substrate 20. Figure 3As shown, the marks 25 are observed as undulations formed on the surface 24 in an enlarged cross-section, or as multiple linear flaws that are approximately parallel to the first direction D1 when viewed from above. Examples of the undulations that constitute these marks 25 include grinding marks formed along the grinding direction during the manufacture of the metal substrate 20, or rolling flaws formed along the rolling direction during rolling. These undulations may be formed intermittently or continuously across the entire surface 24. Furthermore, if multiple marks are formed intermittently or continuously across the entire surface 24 (the surface of the substrate) in different directions when viewed from above, the direction of the deeper mark is considered to be the first direction D1. For example, if the surface 24 includes both grinding marks with a depth of 0.1 to 1.0 μm and polishing marks with a depth of 0.01 to 0.1 μm, the direction of the grinding marks with a depth of 0.1 to 1.0 μm is considered to be the first direction D1.

[0063] In the sensor 10, the surface roughness Ra of the surface 24 in the second direction D2 perpendicular to the first direction D1 when viewed from above the surface 24 is preferably not less than 0.05 μm and not more than 1 μm. When the surface roughness Ra of the surface 24 is not less than a predetermined value, etching residue 51 of the conductive film is likely to be generated along the first direction D1 (see Figure 9 ), thus, the effect of preventing the occurrence of a short circuit (a short circuit defect) between the conductive film pattern 40 and the surface 24 of the metal substrate 20 caused by the etching residue 51 is particularly significant. In addition, by setting the surface roughness Ra to be below a predetermined value, a thin conductive film pattern 40 can be formed with high precision.

[0064] Furthermore, the scratches 25 formed on the surface 24 are formed by forming an insulating film 30 or a conductive film pattern 40 on the surface 24 (see Figure 4 ) before the surface 24 is mirror-polished to eliminate the scratches 25, but mirror-polishing the surface 24 to eliminate the scratches 25 requires processing time and cost, thus resulting in a decrease in productivity. Figure 2 As shown in the metal substrate 20, by forming an insulating film 30 or a conductive film pattern 40 on the surface 24 in a state where the scratches 25 are formed (see Figure 1 and Figure 4 ), which can improve the productivity of the sensor 10.

[0065] In addition, in the direction of the sensor 10 and the metal substrate 20, the normal direction of the surface 24 perpendicular to the first direction D1 and the second direction D2 is described as the up-down direction. Figure 4As shown, in the up and down directions, the direction from the surface 24 where the insulating film 30 and the conductive film pattern 40 are formed toward the opposite side of the surface 24, that is, the back surface 22 of the metal substrate 20 is set as the down direction, and the direction from the back surface 22 toward the surface 24 is set as the up direction.

[0066] Figure 1 The conductive film pattern 40 shown is formed on the surface 24 of the metal substrate 20 via the insulating film 30. In the sensor 10, the insulating film 30 is formed to cover the surface 24 of the metal substrate 20 except for the exposed areas 27a and 27b formed at the two ends in the second direction D2. The conductive film pattern 40 includes electrode pads 44 and 45 and a resistive film 42 connecting the electrode pads 44 and 45.

[0067] The thickness of the insulating film 30 is not particularly limited. Figure 3 The surface roughness Ra of the surface 24 shown can be set to 1 to 10 times. By making the thickness of the insulating film 30 greater than or equal to the surface roughness Ra of the surface 24, the insulation between the surface 24 of the metal substrate 20 and the conductive film pattern 40 can be properly ensured. In addition, when the thickness of the insulating film 30 is less than or equal to the surface roughness Ra of the surface 24, it is easy to form undulations of the scratches 25 that track the surface 24 on the conductive film pattern 40 side of the insulating film 30, and it is easy to generate etching residues 51 of the conductive film along the first direction D1 (see FIG. Figure 9 ). Therefore, avoid Figure 9 The first direction exposed area 826 of the sensor 810 of the reference example shown in FIG. 8 is exposed and formed on the surface 24. Figure 1 The necessity and effect of preventing the occurrence of short circuit failure caused by etching residue 51 are particularly great. Figure 9 The details of the etching residue 51 will be described with reference to the sensor 810 of the reference example shown.

[0068] As Figure 1 and Figure 4 The material of the insulating film 30 shown in the figure includes silicon oxide, silicon nitride, aluminum oxide, and the like, but any insulating material is not particularly limited. The method for forming the insulating film 30 is not particularly limited, and examples thereof include sputtering, vacuum evaporation, CVD, and sol-gel methods. Alternatively, the insulating film 30 can be formed using a method with good coverage, such as TEOS-CVD. In this case, the sensor 10 of the present disclosure can effectively prevent short circuits.

[0069] Figure 2The conductive film pattern 40 shown includes electrode pads 44 and 45 and a resistive film 42. The resistive film 42 of the conductive film pattern 40 connects the center position of the electrode pad 44, i.e., the first position, and the center position of the electrode pad 45, i.e., the second position, via a conductive path having a shape longer than the length of a straight line connecting the first and second positions. By configuring the conductive film pattern 40 in this shape, a long conductive path can be formed within a narrow area, thereby improving the detection sensitivity of the conductive film pattern 40.

[0070] The resistive film 42 of the conductive film pattern 40 preferably has a meandering shape in which the conductive path has a folded (or bent) shape. This allows for a narrow and long conductive path to be formed within a narrow area. However, the planar shape of the resistive film 42 is not limited to a meandering shape and may also have other shapes that bypass the first position and the second position and connect them in a straight line. The same applies to other embodiments.

[0071] like Figure 2 As shown, the conductive film pattern 40 includes two electrode pads 44 and 45, and a resistive film 42 electrically connecting the two electrode pads 44 and 45. External wiring (not shown) is connected to the two electrode pads 44 and 45 by wire bonding or the like. The resistive film 42 forms a rectangular wave shape or a meandering shape with the first direction D1 being the amplitude direction, forming a conductive path narrower than the electrode pads 44 and 45, thereby electrically connecting the two electrode pads 44 and 45.

[0072] The conductive film pattern 40 is a pattern made of a conductive film, and only needs to form a conductive path connecting the first position and the second position. Examples include a pattern made of a single film or a pattern made of multiple films. Figure 1 The electrode pads 44 and 45 and the resistive film 42 of the conductive film pattern 40 shown may be made of the same material or different materials. Examples of materials for the resistive film 42 of the conductive film pattern 40 in this embodiment include strain gauge resistor materials containing metals such as Cr, Ni, Al, and Cu; or containing Cr and at least one of Ni, Al, and Cu; and at least one of N and O. Examples of materials for the electrode pads 44 and 45 of the conductive film pattern 40 include good conductor metals such as Al and Au.

[0073] exist Figure 1 In the illustrated sensor 10, on the surface 24 of the metal substrate 20, a first region 26 located in the first direction D1 when viewed from above from the conductive film pattern forming region 46 where the conductive film pattern 40 is formed is covered with the insulating film 30. Figure 1 In FIG. 4 , the conductive film pattern forming region 46 corresponds to a region where the electrode pads 44 and 45 and the resistive film 42 constituting the conductive film pattern 40 are formed.

[0074] In addition, Figure 1 In the illustrated sensor 10, the surface 24 of the metal substrate 20 has exposed regions 27a and 27b exposed from the insulating film 30 at positions different from the first region 26 in a plan view. Figure 1 In the illustrated sensor 10 , the surface 24 of the metal substrate 20 has at least two (two in the embodiment) exposed regions 27 a and 27 b sandwiching the conductive film pattern 40 in a plan view.

[0075] Figure 8 is Figure 1 In the sensor 10 shown, the halo is used to distinguish Figure 2 The surface 24 of the metal substrate 20 shown in FIG. Figure 8 As shown, the surface 24 of the metal substrate 20 has a conductive film pattern lower region 28 , a first region 26 , exposed regions 27 a and 27 b , a non-exposed region 29 , and the like.

[0076] The conductive film pattern lower region 28 is a region directly below the conductive film pattern 40 and is Figure 1 The conductive film pattern forming area 46 shown is consistent. The first area 26 is formed from Figure 1 The conductive film pattern forming region 46 shown is located in the first direction D1 in a plan view. The conductive film pattern lower region 28 and the first region 26 are all covered by the insulating film 30.

[0077] Exposed regions 27a and 27b are formed at both ends in the second direction D2 on surface 24 and are arranged at positions in the second direction D2 that do not overlap with conductive film pattern 40. Insulating film 30 is not formed on exposed regions 27a and 27b, and exposed regions 27a and 27b are exposed from insulating film 30.

[0078] The non-exposed area 29 is formed between the first area 26 and the exposed areas 27a and 27b. Similar to the exposed areas 27a and 27b, the non-exposed area 29 is arranged at a position in the second direction D2 that does not overlap with the conductive film pattern 40. In addition, the position of the non-exposed area 29 in the second direction D2 does not overlap with the exposed areas 27a and 27b. The non-exposed area 29 is covered by the insulating film 30. The width of the non-exposed area 29 along the second direction D2 can be narrower than the width of the first area 26 along the second direction D2 and wider than the width of the resistive film 42 (the width in the direction perpendicular to the conductive path). Forming such a non-exposed area 29 between the first area 26 and the exposed areas 27a and 27b is also preferable in terms of reliably ensuring the insulation between the surface 24 of the metal substrate 20 and the conductive film pattern 40.

[0079] Here, use Figure 9The sensor 810 of the reference example shown will be described to explain the problems encountered when using the metal substrate 20 having the surface 24 on which the scratches 25 are formed. Figure 9 8 is a top view of a sensor 810 of a reference example. The sensor 810 is different from the reference example except that the top view shape of the insulating film 830 and the position of the area where the surface 24 of the metal substrate 20 is exposed from the insulating film 830 are different. Figure 1 The sensors 10 shown are identical.

[0080] like Figure 9 As shown, in sensor 810, insulating film 830 is formed to cover the portion of surface 24 of metal substrate 20 excluding the two end portions in first direction D1. Thus, in sensor 810, surface 24 having scratches 25 formed thereon has first-direction exposed region 826 that exists in first direction D1 but is exposed from insulating film 830 when viewed from above from conductive film pattern forming region 46 having conductive film pattern 40 formed thereon.

[0081] exist Figure 9 In the sensor 810 having the first-direction exposed area 826 as shown, there is the following problem: a short circuit occurs between the conductive film pattern 40 and the surface 24 (first-direction exposed area 826) of the metal substrate 20 due to the etching residue 51 extending along the first direction D1 when viewed from above. This is because grooves or bumps that track the scratches 25 are easily formed on the insulating film 830 formed on the surface 24 where the scratches 25 are formed. Due to this influence, the thickness of the conductive film formed on the insulating film 830 is also uneven. Therefore, when using the metal substrate 20 having the surface 24 where the scratches 25 are formed, when the conductive film formed on the insulating film 830 is etched to form the conductive film pattern 40, as shown in FIG. Figure 9 As shown, etching residues 51 extending in the first direction D1 similar to the scratches 25 tend to be easily generated on the insulating film 830 .

[0082] Figure 10A and Figure 10B 810 is a conceptual diagram illustrating a manufacturing process in which etching residue 51 forms a short-circuit path in sensor 810, and is a schematic cross-sectional view of sensor 810 during manufacturing. Figure 10A As shown, when an insulating film 830a is formed on the surface 24 of the metal substrate 20 and a conductive film pattern 40 is further formed on the insulating film 830a, an etching residue 51 extending in the same first direction D1 as the scratch 25 is generated. Figure 10A The insulating film 830 a shown is formed on the entire surface 24 of the metal substrate 20 .

[0083] form Figure 10A After the conductive film pattern 40 is formed, the Figure 10AA portion of the insulating film 830a shown forms a first direction exposed region 826 ( Figure 10B ). So, if Figure 10B As shown, etching residue 51 generated when forming the conductive film pattern 40 connects the surface 24 of the metal substrate 20 and the conductive film pattern 40 to form a short circuit path.

[0084] Figures 11A to 11C 810 is a conceptual diagram illustrating another manufacturing process in which etching residue 52 forms a short circuit path in sensor 810, and is a schematic cross-sectional view of sensor 810 in the middle of manufacturing. Figure 11A As shown, even in the case where the first direction exposed region 826 is formed before the conductive film pattern 40 is formed, Figure 11B and Figure 11C As shown, etching residue 52 (etching residue when etching the film 40a serving as the base of the conductive film pattern 40) extending in the same first direction D1 as the scratch 25 also connects the surface 24 of the metal substrate 20 and the conductive film pattern 40, forming a short circuit path.

[0085] Therefore, if Figure 9 As shown, in the sensor 810 in which the first direction exposed region 826 that exists in the first direction D1 but is exposed from the insulating film 830 when viewed from above from the conductive film pattern forming region 46 is formed on the surface 24 , a short circuit caused by the etching residue 51 is likely to occur.

[0086] On the other hand, Figure 1 In the sensor 10 shown, on the surface 24, the first region 26 existing in the first direction D1 when viewed from the conductive film pattern forming region 46 is covered with the insulating film 30. Therefore, even if Figure 9 In the case where the etching residue 51 extending in the same first direction D1 as the scratch 25 is generated, the etching residue 51 is not connected to the surface 24 of the metal substrate 20. Figure 9 The situation shown is different and no short circuit path is formed.

[0087] In addition, by forming a Figure 1 The exposed areas 27a, 27b shown are as follows Figure 4 As shown, the resistance-welded electrodes 71 can be brought into contact with the exposed areas 27a and 27b during the process of attaching the sensor 10 to another component 70, making it easier to weld and attach the sensor 10 to the other component. The sensor 10 detects strain in a component in contact with the metal substrate 20 based on, for example, changes in the resistance of the resistive film 42 of the conductive film pattern 40.

[0088] Figures 1 to 4The sensor 10 shown is manufactured, for example, by the following manufacturing process. First, in manufacturing the sensor 10, a Figure 2 The metal substrate 20 is made by, for example, stamping, cutting, grinding, or other mechanical processing of a predetermined metal material. Figure 2 and Figure 3 As shown, the surface 24 is not mirror-polished, and the scratches 25 are left, thereby simplifying the manufacturing process.

[0089] Next, after forming a plurality of layers of films that form the basis of the insulating film 30 and the conductive film pattern 40 on the surface 24 of the metal substrate 20, the formed films are micro-processed by semiconductor processing technology including etching, thereby forming the insulating film 30 and the conductive film pattern 40. Through these steps, Figure 2 The sensor 10 including the metal substrate 20 is shown in FIG. Figure 4 As shown, the sensor 10 including the metal substrate 20 is fixed to another component 70 or the like by resistance welding or the like, and the electrode pads 44 and 45 of the conductive film pattern 40 are connected to an external substrate (not shown) or the like by wire bonding or the like. Furthermore, an insulating protective layer may be formed on the conductive film pattern 40 to protect the conductive film pattern 40. Furthermore, the insulating film 30 may be formed on the metal substrate 20 so that the insulating film 30 has a wraparound portion that wraps around at least a portion of the side surface connected to the surface 24 of the metal substrate 20.

[0090] This sensor 10 utilizes a metal substrate 20 having a surface 24 formed with scratches 25, thereby achieving cost reduction and improved production efficiency due to, for example, omitting a mirror polishing step. Furthermore, since the first region 26 is covered with the insulating film 30, even if etching residue 51 is generated along the scratches 25 of the conductive film forming the conductive film pattern 40 during the manufacturing process, adequate insulation between the conductive film pattern 40 and the surface 24 of the metal substrate 20 can be ensured. Furthermore, by having exposed regions 27a and 27b on the surface 24 at locations different from the first region D1, a short circuit between the conductive film pattern 40 and the surface 24 of the metal substrate 20 caused by etching residue 51 of the conductive film can be avoided, while ensuring an area for contacting the surface 24 with electrodes for resistance welding.

[0091] Second embodiment

[0092] Figure 5 FIG. 1 is a top view of the sensor 110 according to the second embodiment. In the sensor 110, the posture of the conductive film pattern 140 with respect to the first direction D1 is different, but other points are the same as those in FIG. Figure 1The sensor 110 is the same as the sensor 10 shown. The description of the sensor 110 will focus on the differences from the sensor 10, and the same reference numerals are used for the same points as the sensor 10, and the description thereof will be omitted.

[0093] like Figure 5 As shown, Figure 1 The conductive film pattern 40 of the sensor 10 shown is the same as that of the sensor 110. The conductive film pattern 140 of the sensor 110 has two electrode pads 144 and 145, and a resistive film 142 electrically connecting the two electrode pads 144 and 145. The resistive film 142 of the conductive film pattern 140 forms a rectangular wave shape or a meander shape with the second direction D2 being the amplitude direction. Figure 1 The resistor film 42 shown is different. In addition, the two electrode pads 144 and 145 are arranged along the first direction D1, which is different from the sensor 10 in which the two electrode pads 44 and 45 are arranged along the second direction D2 (see FIG. Figure 1 In the sensor 110, two of the at least two exposed regions 27a and 27b (two in the embodiment) sandwich the conductive film pattern 140 in the amplitude direction of the rectangular wave shape or the meandering shape of the resistive film 142 in a plan view.

[0094] As according to Figure 1 The sensor 10 shown and Figure 5 As can be understood from the comparison of the sensor 110 shown, the shape and posture of the conductive film patterns 40 and 140 formed on the surface 24 of the metal substrate 20 via the insulating film 30 are not particularly limited, and can be set to any shape that can detect deformation of the metal substrate 20 based on the change in its resistance. Figure 5 As shown, by setting the structure in which the two exposed areas 27a and 27b sandwich the conductive film pattern 140 in the amplitude direction of the meandering shape of the resistor film 142 in a plan view, the metal substrate 20 can be connected to the other component 70 (see FIG. 1 ) by making the electrodes for resistance welding contact the two exposed areas 27a and 27b. Figure 4 ) is fixed in the same direction as the direction of the strain to be detected. Thus, the strain generated in the other components 70 can be effectively transferred to the metal substrate 20, thereby increasing the detection sensitivity of the strain. Figure 5 In the illustrated sensor 110, the first region 26 located in the first direction D1 is covered with the insulating film 30 when viewed from above from the conductive film pattern forming region 146 where the conductive film pattern 140 is formed. This ensures adequate insulation between the conductive film pattern 40 and the surface 24 of the metal substrate 20. With respect to other similarities with the sensor 10, the sensor 110 achieves the same effects as the sensor 10.

[0095] Third embodiment

[0096] Figure 6 FIG3 is a top view of a sensor 210 according to a third embodiment. The shape and arrangement of the exposed areas 227a and 227b and the non-exposed area 229 are different in the sensor 210, but the other points are the same. Figure 1 The sensor 210 is the same as the sensor 10 shown. The description of the sensor 210 will focus on the differences from the sensor 10, and the common points with the sensor 10 are denoted by the same reference numerals and the description thereof will be omitted.

[0097] like Figure 6 As shown, in the sensor 210, two exposed areas 227a and 227b are arranged on the surface 24 of the metal substrate 20 so as to sandwich the conductive film pattern 40 from both sides in the second direction D2 when viewed from above. However, the exposed areas 227a and 227b of the sensor 210 are not located at the ends of the metal substrate 20 in the second direction D2. Figure 6 As shown, on the surface 24 of the metal substrate 20, the exposed areas 227a and 227b are surrounded by a non-exposed area 229, and the non-exposed area 229 is covered by the insulating film 230. In other words, the exposed areas 227a and 227b of the sensor 210 are exposed from the insulating film 230 through the through-holes formed in the insulating film 230.

[0098] like Figure 6 As shown, the shape and area of ​​the exposed areas 227a and 227b are not particularly limited and can be any shape and area according to the application.

[0099] Fourth embodiment

[0100] Figure 7 310 is a top view showing a sensor 310 according to a fourth embodiment. The sensor 310 is different in that it has four exposed areas 327a, 327b, 327c, and 327d, but is otherwise the same as the sensor 310. Figure 1 The sensor 310 is the same as the sensor 10 shown. The description of the sensor 310 will focus on the differences from the sensor 10, and the common points with the sensor 10 are denoted by the same reference numerals and the description thereof will be omitted.

[0101] like Figure 7 As shown, on the surface 24 of the metal substrate 20 in the sensor 310, exposed areas 327a, 327b, 327c, and 327d are formed at the four corners of the rectangular surface 24, exposed from the insulating film 330. Each exposed area 327a, 327b, 327c, and 327d is substantially square in shape.

[0102] like Figure 7As shown, the number or arrangement of exposed areas 327a, 327b, 327c, and 327d is not particularly limited, and surface 24 may have three or more exposed areas 327a, 327b, 327c, and 327d. Other than these, sensor 310 achieves the same effects as sensor 10 in terms of similarities with sensor 10.

[0103] While the sensor disclosed herein has been described above using multiple embodiments, the technical scope of the sensor disclosed herein is not limited to the aforementioned embodiments and naturally encompasses numerous other embodiments and variations. For example, the number of conductive film patterns 40, 140 formed on the surface 24 of the metal substrate 20 is not limited to one; two or more conductive film patterns 40, 140 may be formed on the surface 24 of the metal substrate 20 via an insulating film. Furthermore, when multiple conductive film patterns 40, 140 are formed, the conductive film patterns 40, 140 may be electrically independent or electrically connected to form a bridge circuit, for example.

Claims

1. A sensor, wherein: have: A metal substrate having a surface having scratches formed along a first direction when viewed from above; and a conductive film pattern formed on the surface via an insulating film, On the surface, a first region existing in the first direction when viewed from a conductive film pattern forming region where the conductive film pattern is formed is covered by the insulating film. The surface has an exposed region exposed from the insulating film at a position different from the first region in a plan view.

2. The sensor according to claim 1, wherein The surface has at least two exposed regions sandwiching the conductive film pattern in a plan view.

3. The sensor according to claim 2, wherein The conductive film pattern has a rectangular wave shape or a meandering shape when viewed from above. At least two of the exposed regions sandwich the conductive film pattern in an amplitude direction of the rectangular wave shape or the meandering shape in a plan view.

4. The sensor according to any one of claims 1 to 3, wherein The surface roughness Ra of the surface in a second direction perpendicular to the first direction in a plan view is not less than 0.05 μm and not more than 1 μm.

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