Coil chip and preparation method thereof, detection chip and lubricating oil sensor

Abstract

The embodiment of the present application provides a coil chip and a method for preparing the same, a detection chip and a lubricating oil sensor. The coil chip based on the micro-electromechanical system includes a substrate having a first surface and a second surface arranged opposite to each other, and at least two sensing areas are provided on the substrate; the substrate is provided with a first insulating layer and a second insulating layer on the first surface and the second surface in each sensing area, respectively, and the first insulating layer is provided with at least one induction coil layer on the surface away from the second insulating layer, and the inner circle position of the induction coil layer is provided with a detection through hole that runs through the entire coil chip for the passage of lubricating oil, so that an induction coil structure unit is formed in each sensing area. The embodiment of the present application provides a coil chip and a method for preparing the same, a detection chip and a lubricating oil sensor, which can improve the detection sensitivity of the lubricating oil sensor.

Description

Technical Field

[0001] The present application belongs to the technical field of coil chips, and in particular to a coil chip based on a micro-electro-mechanical system (MEMS), a detection chip for detecting lubricating oil metal chips, and a method for preparing a coil chip of a lubricating oil sensor. Background Art

[0002] In the operation of engines, bearings, gears, etc., in order to reduce wear and loss, it is often necessary to configure a lubricating oil system. Experience shows that there is a strong correlation between the degree of damage to the equipment's wear parts (such as engines, rolling bearings, gears, etc.) and the metal chips in the lubricating oil system. Therefore, in order to evaluate the wear of the equipment, a lubricating oil sensor is often installed in the lubricating oil system to monitor the entire wear process of the equipment.

[0003] Traditional inductive oil sensors such as Figure 1 As shown, the excitation coil 101 and the induction coil layer 102 are both arranged on the lubricating oil pipeline 103, and a shielding cover 104 is arranged outside the excitation coil 101 and the induction coil layer 102. The two excitation coils 101 magnetize the metal chips, and when the metal chips flow through the induction coil layer 102, electromagnetic induction generates eddy currents, which eventually changes the magnetic flux, thereby realizing the detection of the metal chips. However, the traditional inductive lubricating oil sensor can only detect metal chips of a size of several hundred microns, and is powerless against metal chips of 100um or less, that is, the detection sensitivity is poor.

[0004] Therefore, how to improve the detection sensitivity of the lubricating oil sensor is a technical problem that technical personnel in this field need to solve urgently. Summary of the invention

[0005] The embodiments of the present application provide a coil chip based on a micro-electromechanical system, a detection chip for detecting lubricating oil metal chips, and a method for preparing a coil chip of a lubricating oil sensor, which can improve the detection sensitivity of the lubricating oil sensor.

[0006] In a first aspect, an embodiment of the present application provides a coil chip based on a micro-electromechanical system, comprising a substrate having a first surface and a second surface arranged opposite to each other, and at least two sensing areas are provided on the substrate; a first insulating layer and a second insulating layer are respectively provided on the first surface and the second surface in each sensing area of ​​the substrate, and the first insulating layer is provided with at least one induction coil layer on the surface away from the second insulating layer, and a detection through hole is provided at the inner circle position of the induction coil layer for lubricating oil to pass through the entire coil chip, so that an induction coil structure unit is formed in each sensing area.

[0007] Optionally, the induction coil layer in each sensing area is provided with at least one third insulating layer on the surface away from the second insulating layer, and the at least one induction coil layer and the at least one third insulating layer are alternately arranged in sequence, and each third insulating layer is arranged around the detection through hole and covers the induction coil layer of the corresponding layer.

[0008] Optionally, the induction coil layer and the third insulating layer are at least two layers respectively, each third insulating layer is provided with a connection hole for exposing the induction coil layer of the corresponding layer, and the tails of adjacent induction coil layers are electrically connected via the connection hole.

[0009] Optionally, the third insulating layer located at the top layer in each sensing area is provided with a lead coil layer and a fourth insulating layer in sequence on the surface away from the second insulating layer, and the fourth insulating layer is provided with a lead hole. The lead coil layer is used to lead out the head of the induction coil layer located at the first layer and the tail of the induction coil layer located at the top layer through the lead hole.

[0010] Optionally, the substrate is an intrinsic silicon member, a quartz member or a glass member; or,

[0011] The first insulating layer and the second insulating layer are respectively a silicon dioxide layer or a silicon nitride layer or other electrically insulating material layers; or,

[0012] The induction coil layer is a titanium induction coil layer, a gold induction coil layer, a platinum induction coil layer, an aluminum induction coil layer or a copper induction coil layer.

[0013] Optionally, the thickness of the first insulating layer and the second insulating layer are 0.1um-10um respectively; or,

[0014] The thickness of the induction coil layer is 0.01nm-10000nm.

[0015] Optionally, at least two detection through-hole arrays are arranged in at least two sensing areas.

[0016] In the second aspect, an embodiment of the present application provides a detection chip for detecting lubricating oil metal chips, including a substrate and at least two coils of conductive material, the substrate is provided with at least two detection through holes for lubricating oil to pass through, the at least two coils are respectively arranged in one-to-one correspondence with the at least two detection through holes, and the coils are arranged around the holes of the detection through holes.

[0017] Optionally, it also includes an insulating connector for fixing the coil on an insulating substrate and / or a protective member provided on the surface of the coil.

[0018] In a third aspect, an embodiment of the present application provides a lubricating oil sensor, comprising a lubricating oil pipe and two excitation coils arranged on the outer wall of the lubricating oil pipe, and also comprising a coil chip based on a micro-electromechanical system as shown in the first aspect, or a detection chip for detecting lubricating oil metal chips as shown in the second aspect, which is arranged inside the lubricating oil pipe and located between the two excitation coils.

[0019] Optionally, the lubricating oil sensor further includes an insulating holder for fixing the coil chip or the detection chip on the lubricating oil channel.

[0020] In a fourth aspect, an embodiment of the present application provides a method for preparing a coil chip based on a micro-electromechanical system, comprising the following steps:

[0021] (1) dividing the substrate into at least two sensing areas, and thermally oxidizing a first surface and a second surface of the substrate that are opposite to each other, respectively, to form a first insulating layer and a second insulating layer in sequence;

[0022] (2) At least one induction coil layer is formed on the first insulating layer in each induction area; and a detection through hole is formed at the inner circle position of the induction coil layer, which penetrates the entire coil chip and allows lubricating oil to pass through.

[0023] Optionally, in step (2), at least one third insulating layer that completely covers the first surface is alternately provided on at least one induction coil layer, and a connection hole that exposes the corresponding induction coil layer is formed on each third insulating layer along the winding direction of the induction coil layer, and then the tails of two adjacent induction coil layers are electrically connected through the connection hole; finally, detection through holes are formed in the overlapping parts of the second insulating layer, the substrate, the first insulating layer and the third insulating layer from bottom to top.

[0024] Optionally, in step (2), a first connection hole exposing the tail of the induction coil layer of the corresponding layer and a second connection hole exposing the head of the induction coil layer of the first layer are respectively formed on the topmost third insulating layer along the winding direction of the induction coil layer, and then a lead coil layer is formed on the topmost third insulating layer, the tail of the lead coil layer is electrically connected to the tail of the induction coil layer of the corresponding layer through the first connection hole, and the head of the lead coil layer is electrically connected to the head of the induction coil layer of the first layer through the second connection hole; then a fourth insulating layer completely covering the first surface is provided on the lead coil layer, and then a lead hole exposing the lead coil layer is formed on the fourth insulating layer along the winding direction of the induction coil layer; finally, detection through holes are formed in the overlapping parts of the second insulating layer, the substrate, the first insulating layer, the third insulating layer and the fourth insulating layer from bottom to top to obtain a coil chip.

[0025] Optionally, a stripping or etching process is used to form the induction coil layer; or,

[0026] Using dry etching, wet etching or laser cutting process to form the detection through hole, connection hole or lead hole; or,

[0027] A deposition process is used to form the first insulating layer, the second insulating layer, the third insulating layer or the fourth insulating layer.

[0028] The micro-electromechanical system-based coil chip, the detection chip for detecting lubricating oil metal shavings, the lubricating oil sensor and the preparation method of the micro-electromechanical system-based coil chip provided in the embodiments of the present application can improve the detection sensitivity of the lubricating oil sensor. The micro-electromechanical system-based coil chip has at least two sensing areas on the substrate, and the first surface and the second surface of each sensing area are respectively provided with a first insulating layer and a second insulating layer. The first insulating layer is provided with at least one layer of induction coil layer on the surface away from the second insulating layer, and the inner circle position of the induction coil layer is provided with a detection through hole that runs through the entire coil chip for the passage of lubricating oil, so that an induction coil structure unit is formed in each sensing area. In other words, the micro-electromechanical system-based coil chip includes at least two induction coil structure units, which can divide the cross section of the oil pipe into multiple detection areas, greatly improve the detection sensitivity, and can detect metal shavings with smaller particle sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] Figure 1 It is a schematic diagram of the structure of a traditional inductive lubricating oil sensor;

[0031] Figure 2 is a schematic structural diagram of a coil chip based on a micro-electromechanical system provided in an embodiment of the present application;

[0032] Figure 3 is a structural schematic diagram of a single induction coil structural unit provided in an embodiment of the present application;

[0033] Figure 4 is a flow chart of a method for preparing a coil chip based on a micro-electromechanical system provided in an embodiment of the present application;

[0034] Figure 5 is a schematic structural diagram of a substrate provided in an embodiment of the present application;

[0035] Figure 6 It is a schematic diagram of peeling off the first layer of the induction coil provided in an embodiment of the present application;

[0036] Figure 7This is a schematic diagram of depositing a silicon dioxide layer and etching a connection hole provided in an embodiment of the present application;

[0037] Figure 8 It is a schematic diagram of peeling off a second layer of induction coil provided in an embodiment of the present application;

[0038] Fig. 9 This is a schematic diagram of depositing a silicon dioxide layer and etching a connection hole provided in an embodiment of the present application;

[0039] Fig.10 This is a schematic diagram of metal stripping of a lead layer provided in an embodiment of the present application;

[0040] Fig.11 This is a schematic diagram of depositing a silicon dioxide layer and etching a connection hole provided in an embodiment of the present application;

[0041] Fig.12 This is a schematic diagram of substrate release provided in an embodiment of the present application;

[0042] Fig.13 is a cross-sectional schematic diagram of a single-layer induction coil provided in an embodiment of the present application;

[0043] Fig.14 is a cross-sectional schematic diagram of a three-layer induction coil provided in an embodiment of the present application;

[0044] Fig.15a It is a schematic diagram of the structure of a detection chip for detecting lubricating oil metal chips provided in an embodiment of the present application;

[0045] Fig.15b is a schematic diagram of the structure of a coil provided in an embodiment of the present application;

[0046] Fig.16 is a structural schematic diagram of a lubricating oil sensor provided in an embodiment of the present application;

[0047] 101-excitation coil; 102-induction coil layer; 103-lubricating oil pipeline; 104-shielding cover;

[0048] 201-substrate; 202-induction coil structure unit; 203-detection through hole;

[0049] 601-first insulating layer; 602-second insulating layer; 701-third insulating layer of the first layer;

[0050] 702-connection hole; 901-third insulation layer of the second layer; 902-lead hole;

[0051] 1001-lead coil layer; 1101-fourth insulating layer; 1401-third insulating layer of the third layer;

[0052] 1501-coil; 1601-holder. DETAILED DESCRIPTION

[0053] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0055] As can be seen from the background technology, the traditional inductive lubricating oil sensor can only detect metal chips with a size of several hundred microns, and is powerless against metal chips with a size of 100 um or less, that is, the detection sensitivity is poor.

[0056] In order to solve the problems of the prior art, the embodiments of the present application provide a coil chip based on a micro-electromechanical system, a detection chip for detecting lubricating oil metal chips, a lubricating oil sensor, and a method for preparing a coil chip based on a micro-electromechanical system. The coil chip based on a micro-electromechanical system provided in the embodiments of the present application is first introduced below.

[0057] Figure 2 and Figure 3 They are respectively a schematic diagram of the structure of a coil chip based on a micro-electromechanical system and a schematic diagram of the structure of a single induction coil structure unit 202 provided in an embodiment of the present application.

[0058] like Figure 2 and Figure 3As shown, the coil chip based on the micro-electromechanical system includes a substrate 201 having a first surface and a second surface arranged opposite to each other, and at least two sensing areas are provided on the substrate 201; the substrate 201 is provided with a first insulating layer 601 and a second insulating layer 602 on the first surface and the second surface in each sensing area respectively, and the first insulating layer 601 is provided with at least one induction coil layer 102 on the surface away from the second insulating layer 602, and the inner circle position of the induction coil layer 102 is provided with a detection through hole 203 that runs through the entire coil chip for the passage of lubricating oil, so that an induction coil structure unit 202 is formed in each sensing area.

[0059] The coil chip based on micro-electromechanical system has at least two sensing areas on the substrate 201, and the first surface and the second surface of each sensing area are respectively provided with a first insulating layer 601 and a second insulating layer 602, and the first insulating layer 601 is provided with at least one layer of induction coil layer 102 on the surface away from the second insulating layer 602, and the inner circle position of the induction coil layer 102 is provided with a detection through hole 203 that runs through the entire coil chip for the passage of lubricating oil, so that an induction coil structure unit 202 is formed in each sensing area. In other words, the coil chip based on micro-electromechanical system includes at least two induction coil structure units 202, and these induction coil structure units 202 can divide the cross section of the oil pipe into multiple detection areas, greatly improving the detection sensitivity, and can detect metal chips with smaller particle size.

[0060] In one embodiment, the induction coil layer 102 in each induction region is provided with at least one third insulating layer on the surface away from the second insulating layer 602, and the at least one induction coil layer 102 and the at least one third insulating layer are alternately arranged in sequence, and each third insulating layer is arranged around the detection through hole 203 and covers the corresponding induction coil layer 102. In one embodiment, an adhesive layer is further arranged between each third insulating layer and the corresponding induction coil layer 102 it covers, and the thickness of the adhesive layer is 0.01nm-10000nm.

[0061] In one embodiment, the induction coil layer 102 and the third insulating layer are at least two layers respectively, and each third insulating layer is provided with a connection hole 702 for exposing the corresponding induction coil layer 102, and the tails of adjacent induction coil layers 102 are electrically connected via the connection holes 702. In one embodiment, the winding directions of at least two induction coil layers 102 are the same.

[0062] In one embodiment, the third insulating layer located at the top layer in each sensing area is provided with a lead coil layer 1001 and a fourth insulating layer 1101 in sequence on a surface away from the second insulating layer 602, and the fourth insulating layer 1101 is provided with a lead hole 902. The lead coil layer 1001 is used to lead out the head of the induction coil layer 102 located at the first layer and the tail of the induction coil layer 102 located at the top layer through the lead hole 902.

[0063] In one embodiment, the substrate 201 is an intrinsic silicon member, a quartz member or a glass member; or, the first insulating layer 601 and the second insulating layer 602 are silicon dioxide layers or silicon nitride layers, respectively; or, the induction coil layer 102 is a titanium induction coil layer, a gold induction coil layer, a platinum induction coil layer, an aluminum induction coil layer or a copper induction coil layer.

[0064] In one embodiment, the thickness of the first insulating layer 601 and the second insulating layer 602 are 0.1 um-10 um respectively; or the thickness of the induction coil layer 102 is 0.01 nm-10000 nm.

[0065] In one embodiment, at least two detection through holes 203 are arranged in an array in at least two sensing regions.

[0066] The embodiment of the present application also provides a detection chip for detecting lubricating oil metal chips, including a substrate 201 and at least two coils 1501 of conductive material, the substrate 201 is provided with at least two detection through holes 203 for lubricating oil to pass through, the at least two coils 1501 are respectively arranged in one-to-one correspondence with the at least two detection through holes 203, and the coils 1501 are arranged at the circumference of the detection through holes 203.

[0067] The detection chip for detecting lubricating oil metal chips has at least two detection through holes 203 for the lubricating oil to pass through on the base 201, at least two coils 1501 are respectively arranged in one-to-one correspondence with the at least two detection through holes 203, and the coils are arranged on the circumference of the detection through holes 203. Therefore, the detection chip for detecting lubricating oil metal chips can divide the oil pipe cross section into multiple detection areas, greatly improving the detection sensitivity, and can detect metal chips with smaller particle sizes.

[0068] In one embodiment, the detection chip for detecting lubricating oil metal chips also includes an insulating connector for fixing the coil 1501 on the insulating substrate 201 and / or a protective member provided on the surface of the coil 1501 .

[0069] An embodiment of the present application also provides a lubricating oil sensor, including a lubricating oil pipe 103 and two excitation coils 101 arranged on the outer wall of the lubricating oil pipe 103, and also includes a coil chip based on a micro-electromechanical system as shown in any of the above embodiments, which is arranged inside the lubricating oil pipe 103 and located between the two excitation coils 101, or a detection chip for detecting lubricating oil metal chips as shown in any of the above embodiments.

[0070] Since the lubricating oil sensor includes the above-mentioned coil chip based on the micro-electromechanical system or the detection chip for detecting lubricating oil metal chips, the lubricating oil sensor can detect metal chips with smaller particle sizes.

[0071] In one embodiment, the lubricating oil sensor further includes an insulating retainer 1601 for fixing the coil chip or the detection chip on the lubricating oil channel.

[0072] like Figure 4 As shown, the embodiment of the present application also provides a method for preparing a coil chip based on a micro-electromechanical system, comprising the following steps:

[0073] S401, dividing the substrate 201 into at least two sensing areas, and thermally oxidizing the first surface and the second surface of the substrate 201 which are opposite to each other, to form a first insulating layer 601 and a second insulating layer 602 in sequence;

[0074] S402 , forming at least one induction coil layer 102 on the first insulating layer 601 in each induction region; forming a detection through hole 203 penetrating the entire coil chip at the inner circle position of the induction coil layer 102 for the passage of lubricating oil.

[0075] In one embodiment, step S402 may include: alternately arranging at least one third insulating layer that completely covers the first surface on at least one induction coil layer 102, forming a connection hole 702 that exposes the corresponding induction coil layer 102 on each third insulating layer along the circumferential direction of the induction coil layer 102, and then electrically connecting the tails of two adjacent induction coil layers 102 through the connection hole 702; and finally forming a detection through hole 203 in sequence from bottom to top at the overlapping parts of the second insulating layer 602, the substrate 201, the first insulating layer 601 and the third insulating layer.

[0076] In one embodiment, step S402 may include: forming a first layer of induction coil layer 102 on the first insulating layer 601 in each induction region, respectively, and then laminating a first layer of third insulating layer 701 completely covering the first surface on the first layer of induction coil layer 102, and then forming a connection hole 702 exposing the first layer of induction coil layer 102 on the first layer of third insulating layer 701 along the winding direction of the induction coil layer 102, and then laminating a second layer of induction coil layer 102 completely covering the first surface on the first layer of third insulating layer 701, and then laminating a second layer of third insulating layer 901 completely covering the first surface on the second layer of induction coil layer 102, and then forming a connection hole exposing the second layer of induction coil layer 102 on the second layer of third insulating layer 901 along the winding direction of the induction coil layer 102, and electrically connecting the tails of the first layer of induction coil layer 102 and the second layer of induction coil layer 102 through the connection hole 702 provided on the first layer of third insulating layer 701, and repeating the above lamination operation to obtain at least one layer of alternately laminated induction coil layer 102 and third insulating layer.

[0077] In one embodiment, step S402 may include: forming a first connection hole 702 for exposing the tail of the induction coil layer 102 of the corresponding layer and a second connection hole 702 for exposing the head of the induction coil layer 102 of the first layer on the third insulating layer at the top layer along the winding direction of the induction coil layer 102, and then forming a lead coil layer 1001 on the third insulating layer at the top layer, electrically connecting the tail of the lead coil layer 1001 to the tail of the induction coil layer 102 of the corresponding layer through the first connection hole 702, and connecting the head of the lead coil layer 1001 to the tail of the induction coil layer 102 of the corresponding layer. The first portion is electrically connected to the head of the induction coil layer 102 of the first layer through the second connecting hole 702; a fourth insulating layer 1101 completely covering the first surface is provided on the lead coil layer 1001, and then a lead hole 902 exposing the lead coil layer 1001 is formed on the fourth insulating layer 1101 along the circumferential direction of the induction coil layer 102; finally, detection through holes 203 are formed in sequence from bottom to top at the overlapping parts of the second insulating layer 602, the substrate 201, the first insulating layer 601, the third insulating layer and the fourth insulating layer 1101 to obtain a coil chip.

[0078] In one embodiment, the induction coil layer 102 is formed by a stripping or etching process; or, the detection through hole 203, the connection hole 702 or the lead hole 902 is formed by a dry etching, wet etching or laser cutting process; or, the first insulating layer 601, the second insulating layer 602, the third insulating layer or the fourth insulating layer 1101 is formed by a deposition process.

[0079] The method for preparing the coil chip based on micro-electromechanical systems utilizes the MEMS preparation process to replace the traditional coil winding method, thereby reducing the weight and volume of the induction coil layer 102, and is particularly suitable for fields such as aerospace that have strict requirements on component weight and volume.

[0080] Since the induction coil layer 102 has at least one layer, the following takes two layers of induction coil layers 102 as an example to describe in detail the processing flow of the coil chip based on the micro-electromechanical system.

[0081] (1) First, intrinsic silicon can be selected as the material for making the substrate 201. The thickness of the substrate 201 can be 0.5 mm. The thickness can be adjusted according to the requirements and is not specifically limited here. The structural diagram of the substrate 201 can be found in Figure 5 .

[0082] (2) Double-sided thermal oxidation of the substrate 201 forms a first insulating layer 601 and a second insulating layer 602 on the upper surface and the lower surface of the substrate 201. The first insulating layer 601 and the second insulating layer 602 can both be silicon dioxide layers with a thickness of 0.1 um to 10 um.

[0083] like Figure 6 As shown, on the first insulating layer 601, a first induction coil layer 102 is processed by a peeling method. In one embodiment, an adhesive layer may be provided between the first insulating layer 601 and the first induction coil layer 102. The material of the induction coil layer 102 may be gold, and the material of the adhesive layer may be titanium. The thickness of the induction coil layer 102 and the adhesive layer may be 0.01nm-10000nm. Optionally, the thickness of the induction coil layer 102 is 400nm, and the thickness of the adhesive layer is 20nm.

[0084] (3) Figure 7 As shown, after the first layer of the induction coil layer 102 is prepared, a first layer of the third insulating layer 701 of a certain thickness is deposited to achieve electrical isolation of the two layers of the induction coil layer 102, and then a connection hole 702 for electrically connecting the first layer of the induction coil layer 102 and the second layer of the induction coil layer 102 (the top layer of the induction coil layer in this embodiment) is etched on the first layer of the third insulating layer 701. The first layer of the third insulating layer 701 can be a silicon dioxide layer, and the thickness can be 0.1um-10um.

[0085] (4) After the connection hole 702 is etched, the second induction coil layer 102 is formed by a lift-off method. Figure 8 .

[0086] (5) Fig. 9As shown, a third insulating layer 901 of a second layer with a certain thickness is deposited on the second induction coil layer 102, and the metal at the head of the first induction coil layer 102 and the metal at the tail of the second induction coil layer 102 are led out by etching a connection hole 702. The third insulating layer 901 of the second layer can be a silicon dioxide layer with a thickness of 0.1um-10um.

[0087] (6) Fig.10 As shown, the leads and electrodes of the top induction coil layer 102 are manufactured again by peeling off to obtain the lead coil layer 1001 .

[0088] (7) To protect the top layer leads, such as Fig.11 As shown, a fourth insulating layer 1101 of a certain thickness needs to be deposited again on the lead coil layer 1001. In order to subsequently connect the lead wire, the fourth insulating layer 1101 on the electrode needs to be etched to form a lead wire hole 902 to expose the electrode. The lead wire can be led to the substrate 201 through the lead wire hole 902. The fourth insulating layer 1101 can be a silicon dioxide layer with a thickness of 0.1um-10um.

[0089] (8) Fig.12 As shown, the substrate 201, the first insulating layer 601, the second insulating layer 602, the first third insulating layer 701, the second third insulating layer 901 and the fourth insulating layer 1101 inside the induction coil layer 102 are removed by dry etching to form a lubricating oil channel.

[0090] The structure of the single-layer induction coil layer 102 is similar to this, except that after the first-layer induction coil layer 102 is completed, the metal at the head of the first-layer induction coil layer 102 and the metal at the tail of the first-layer induction coil layer 102 are directly led out by etching the connection hole 702 on the third insulating layer 701 of the first layer. Then the lead coil layer 1001 is manufactured by peeling. Then a fourth insulating layer 1101 of a certain thickness is deposited again on the lead coil layer 1001. The fourth insulating layer 1101 on the electrode is etched to form a lead hole 902 to expose the electrode. The cross-sectional schematic diagram of the single-layer induction coil layer 102 can be seen in Fig.13

[0091] The three-layer induction coil layer 102 structure is to repeat the induction coil layer 102 three times, and then connect the leads. The cross-sectional schematic diagram of the coil chip with three-layer induction coil layer 102 can be seen in Fig.14 , Fig.14 The top layer is the fourth insulating layer 1101, and the first layer of the induction coil layer 102, the second layer of the induction coil layer 102, the third layer of the induction coil layer 103, the first layer of the third insulating layer 701, the second layer of the third insulating layer 901, and the third layer of the third insulating layer 1401 are respectively Fig.14 The fourth insulating layer 1101 may be a silicon dioxide layer, and the thickness may be 0.1 um-10 um.

[0092] The following is an introduction to the detection chip for detecting lubricating oil metal chips provided in the embodiment of the present application.

[0093] See also Fig.15a -b, Fig.16 as well as Figure 3 The detection chip includes a substrate 201, at least two coils 1501 of conductive material, an insulating connector for fixing the coil 1501 on the insulating substrate 201, and a protective member arranged on the surface of the coil 1501. The substrate 201 is provided with at least two detection through holes 203 for lubricating oil to pass through. The at least two coils 1501 are respectively arranged in one-to-one correspondence with the at least two detection through holes 203, and the coils 1501 are arranged on the circumference of the detection through holes 203.

[0094] The coil 1501 is made of conductive material. In principle, any existing conductive material can be used for the coil 1501 in this case as long as it can generate an induction signal. The connector is generally made of insulating material that will not interfere with the induction signal. The connection method can be bonding, such as insulating glue. The protective member can be made of titanium alloy and other materials to protect the surface structure of the coil 1501 and prevent the lubricating oil from damaging the coil 1501. The specific shape and structure of the connector and protective member are not limited, and can be, for example, a plate-like structure.

[0095] The following is an introduction to the method for preparing the detection chip for detecting lubricating oil metal chips provided in the embodiment of the present application.

[0096] The detection chip can be made by a photolithography machine. First, a plurality of detection through holes 203 are formed on the substrate 201. Specifically, a plurality of detection through holes 203 are formed that are evenly spaced and distributed in an array. The outside of each detection through hole 203 is engraved with many turns of spiral coils 1501 of conductive material, such as conductive wires that meet specification requirements. The two ends of the coil 1501 are led to the edge of the chip, and then the signal line is connected to the circuit board. In this way, each detection through hole 203 is equivalent to a separate induction coil. The chip is then packaged by gluing a protective plate on the front and back. In this way, the chip has a good ability to resist fluid impact and will not easily deform or crack. After being manufactured, it is inserted into the oil pipe, and the inner diameter of the oil pipe is divided into several small detection areas (see Fig.16 ).

[0097] The lubricating oil sensor provided in the embodiment of the present application is introduced below.

[0098] See also Fig.16The lubricating oil sensor, especially the large-caliber lubricating oil sensor, comprises a lubricating oil pipeline 103, two excitation coils 101 disposed on the outer wall of the lubricating oil pipeline 103, the above-mentioned coil chip based on micro-electromechanical system or the above-mentioned detection chip for detecting lubricating oil metal chips disposed inside the lubricating oil pipeline 103 and between the two excitation coils 101, and an insulating holder 1601 for fixing the coil chip or the detection chip on the lubricating oil channel. The holder 1601 can be an existing structure as long as it can stably fix the coil chip or the detection chip on the lubricating oil pipeline 103.

[0099] Specifically, when designing the central oil pipe of the sensor, the lubricating oil pipe 103 is divided into two parts radially from the middle position, and enameled wires of the same specification and the same number of turns are wound on each part, and the excitation signal source is connected to generate an excitation signal. The packaged coil chip or detection chip is fixed between the two sections of the oil pipe, and the two sections of the lubricating oil pipe 103 are fixed and sealed together by welding.

[0100] The two groups of excitation coils 101 on the lubricating oil pipeline 103 generate a magnetic field inside the oil pipeline after the excitation signal is passed. When particulate matter passes through the oil pipeline, it will also pass through at least one detection area (i.e., detection through hole 203) on the coil chip or detection chip. A group of coils 1501 or induction coil structure unit 202 arranged around each detection through hole 203 plays a signal sensing role. By detecting the electrical signals of all detection through holes 203, as long as the electrical signal of one group of coils 1501 or induction coil structure unit 202 changes, it can be determined that particulate matter has passed. Then, through algorithm analysis, the size and number of particles can be obtained.

[0101] In this way, it is equivalent to dividing the large-diameter lubricating oil pipeline 103 into many small-diameter sub-lubricating oil pipelines 103, and then detecting the sensing signal of each sub-lubricating oil pipeline 103 respectively, which can greatly improve the detection sensitivity of the sensor.

[0102] In addition, the coil chip or the detection chip is directly disposed in the lubricating oil pipeline 103. Since there is no metal shielding, the sensitivity of the lubricating oil quality sensor can be greatly improved.

[0103] The above description is only a specific implementation manner of the present application. It should be understood that the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and these modifications or substitutions should be included in the protection scope of the present application.

Claims

1. A lubricating oil sensor, comprising a lubricating oil pipeline and two excitation coils arranged on the outer wall of the lubricating oil pipeline, It is characterized in that It also includes a coil chip based on a micro-electromechanical system or a detection chip for detecting metal chips of lubricating oil, which is arranged inside the lubricating oil pipeline and between two excitation coils; The coil chip based on the micro-electromechanical system comprises a substrate having a first surface and a second surface arranged opposite to each other, and at least two sensing areas are arranged on the substrate; the substrate is provided with a first insulating layer and a second insulating layer respectively on the first surface and the second surface of each sensing area, and the first insulating layer is provided with at least one induction coil layer on the surface away from the second insulating layer, and the inner circle position of the induction coil layer is provided with a detection through hole for the passage of lubricating oil that runs through the entire coil chip, so that an induction coil structure unit is formed in each sensing area; The detection chip for detecting lubricating oil metal chips includes a base and at least two coils of conductive material, the base is provided with at least two detection through holes for lubricating oil to pass through, the at least two coils are respectively arranged in one-to-one correspondence with the at least two detection through holes, and the coils are arranged on the circumference of the detection through holes.

2. The lubricating oil sensor according to claim 1, It is characterized in that The induction coil layer in each induction area of ​​the micro-electromechanical system-based coil chip is provided with at least one third insulating layer on the surface away from the second insulating layer, and the at least one induction coil layer and the at least one third insulating layer are alternately arranged in sequence, and each third insulating layer is arranged around the detection through hole and covers the induction coil layer of the corresponding layer.

3. The lubricating oil sensor according to claim 2, It is characterized in that The induction coil layer and the third insulating layer of the MEMS-based coil chip are at least two layers respectively, each third insulating layer is provided with a connection hole for exposing the corresponding induction coil layer, and the tails of adjacent induction coil layers are electrically connected via the connection holes.

4. The lubricating oil sensor according to claim 2 or 3, It is characterized in that The third insulating layer located at the top layer in each induction area of ​​the coil chip based on the micro-electromechanical system is provided with a lead coil layer and a fourth insulating layer in sequence on a surface away from the second insulating layer, and the fourth insulating layer is provided with a lead hole, and the lead coil layer is used to lead out the head of the induction coil layer located at the first layer and the tail of the induction coil layer located at the top layer through the lead hole.

5. The lubricating oil sensor according to claim 1, It is characterized in that The substrate of the micro-electromechanical system-based coil chip is an intrinsic silicon piece, a quartz piece or a glass piece; or, The first insulating layer and the second insulating layer of the micro-electromechanical system-based coil chip are respectively a silicon dioxide layer or a silicon nitride layer; or, The induction coil layer of the micro-electromechanical system-based coil chip is a titanium induction coil layer, a gold induction coil layer, a platinum induction coil layer, an aluminum induction coil layer or a copper induction coil layer.

6. The lubricating oil sensor according to claim 1, It is characterized in that The thickness of the first insulating layer and the second insulating layer of the MEMS-based coil chip are 0.1um-10um respectively; or, The thickness of the induction coil layer of the micro-electromechanical system-based coil chip is 0.01 nm-10000 nm.

7. The lubricating oil sensor according to any one of claims 1 to 3 and 5 to 6, It is characterized in that At least two detection through-hole arrays are arranged in at least two sensing regions of the micro-electromechanical system-based coil chip.

8. The lubricating oil sensor according to claim 1, It is characterized in that The detection chip for detecting lubricating oil metal chips also includes an insulating connector for fixing the coil on an insulating substrate and / or a protective member arranged on the surface of the coil.

9. The lubricating oil sensor according to claim 1, It is characterized in that It also includes an insulating holder for fixing the coil chip or the detection chip on the lubricating oil channel.

10. The lubricating oil sensor according to claim 1, It is characterized in that The method for preparing a coil chip based on a micro-electromechanical system comprises the following steps: (1) dividing the substrate into at least two sensing areas, and thermally oxidizing a first surface and a second surface of the substrate that are opposite to each other, respectively, to form a first insulating layer and a second insulating layer in sequence; (2) At least one induction coil layer is formed on the first insulating layer in each induction area; and a detection through hole is formed at the inner circle position of the induction coil layer, which penetrates the entire coil chip and allows lubricating oil to pass through.

11. The lubricating oil sensor according to claim 10, It is characterized in that In the step (2), at least one third insulating layer completely covering the first surface is alternately provided on at least one induction coil layer, a connection hole exposing the corresponding induction coil layer is formed on each third insulating layer along the circumferential direction of the induction coil layer, and then the tails of two adjacent induction coil layers are electrically connected through the connection hole; finally, the detection through hole is formed in sequence from bottom to top at the overlapping parts of the second insulating layer, the substrate, the first insulating layer and the third insulating layer.

12. The lubricating oil sensor according to claim 11, It is characterized in that In the step (2), a first connection hole for exposing the tail of the induction coil layer of the corresponding layer and a second connection hole for exposing the head of the induction coil layer of the first layer are respectively formed on the third insulating layer of the top layer along the winding direction of the induction coil layer, and then a lead coil layer is formed on the third insulating layer of the top layer, the tail of the lead coil layer is electrically connected to the tail of the induction coil layer of the corresponding layer through the first connection hole, and the head of the lead coil layer is electrically connected to the head of the induction coil layer of the first layer through the second connection hole; A fourth insulating layer completely covering the first surface is provided on the lead coil layer, and then a lead hole exposing the lead coil layer is formed on the fourth insulating layer along the circumferential direction of the induction coil layer; finally, the detection through hole is formed in sequence from bottom to top at the overlapping parts of the second insulating layer, the substrate, the first insulating layer, the third insulating layer and the fourth insulating layer to obtain the coil chip.

13. The lubricating oil sensor according to claim 12, It is characterized in that The induction coil layer is formed by a stripping or etching process; or, The detection through hole, connection hole or lead hole is formed by dry etching, wet etching or laser cutting process; or, The first insulating layer, the second insulating layer, the third insulating layer or the fourth insulating layer is formed by a deposition process.

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