Wear detection device

Abstract

The present disclosure relates to a wear sensing device (100; 200; 300; 400) capable of efficiently monitoring the wear rate of one or more wear surfaces (104; 204; 304; 306; 308; 404) on the macro-scale as well as the micro- and nano-scale. To this end, the device (100; 200; 300; 400) includes an array of elongated planar conductors (108; 208; 312; 408) extending parallel to one another on a patterned surface (106; 206; 310; 406) of a dielectric substrate (102; 202; 302; 402) underlying a dielectric layer. Each of the conductors is coupled to a control unit (110; 210; 314; 410). When wear occurs on at least one wear surface (104; 204; 304; 306; 308; 404) of the dielectric substrate (102; 202; 302; 402) adjacent to the patterned surface (106; 206; 310; 406), the control unit (110; 210; 314; 410) determines the wear rate by monitoring and analyzing the capacitance between each two adjacent conductors. The control unit (110; 210; 314; 410) then outputs the wear rate to a user. In certain embodiments, the control unit (110; 210; 314; 410) can use the monitored capacitance to determine whether at least two conductors of the array of conductors (108; 208; 312; 408) have come into direct electrical contact upon wear and output a corresponding signal to a user.

Description

[Technical field]

[0001] The present disclosure relates generally to techniques for monitoring the properties of machine and tool parts and other materials that are subject to mechanical wear, and more particularly, to devices for detecting mechanical wear of such parts and materials on a macro-scale as well as a micro-scale and nano-scale. [Background technology]

[0002] Mechanical wear is a typical physical phenomenon found in various mechanical systems, e.g. industrial, agricultural and other machines or tools, tribological testing equipment, surface finishing equipment, etc. Mechanical wear consists of the damage and gradual removal of material due to contact with the solid surfaces of the machine or tool parts. In particular, the relative movement of two contacting solid surfaces can cause damage to one or both of them. This damage is manifested as a gradual loss of material, i.e. as material particles detached from the contacting solid surfaces. The detached material particles are also called wear debris.

[0003] With this in mind, it is usually necessary to monitor the degree of wear (also called wear rate or wear depth) associated with a particular mechanical system. This monitoring can be done by manual inspection or by using wear sensors. In some situations where manual inspection is physically impossible or would require significant downtime of the machine or equipment, using wear sensors is the only viable option.

[0004] Existing wear sensors are typically based on using an electrical circuit of resistive or capacitive elements connected in parallel above or below the wear surface. When such a wear sensor experiences wear, the resistive or capacitive elements (typically surface mounted resistors or capacitors) are electrically disconnected from the circuit one by one, thereby changing the total measurable electrical property of the circuit (e.g., the total measurable resistance or capacitance).

[0005] Existing wear sensors are good at monitoring the degree of wear on a macroscale, but may not be as effective on the microscale and nanoscale due to the aforementioned sensor designs. Summary of the Invention [Problem to be solved by the invention]

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features of the disclosure, nor is it intended to be used to limit the scope of the disclosure.

[0007] It is an object of the present disclosure to provide a wear sensing device that can efficiently monitor (in real time) the wear rate of one or more wear surfaces on the macro-scale as well as the micro- and nano-scale.

[0008] The above object is achieved by means of the features of the attached independent claims. Further embodiments and examples are evident from the dependent claims, the description and the accompanying drawings. [Means for solving the problem]

[0009] According to a first aspect, a wear detection device is provided. The device includes a dielectric substrate having at least one wear surface and a patterned surface adjacent to the at least one wear surface. The device further includes an array of conductors extending parallel to one another on the patterned surface of the dielectric substrate. Each conductor of the array of conductors has an elongated planar shape. The device further includes a dielectric material covering the patterned surface of the dielectric substrate with the array of conductors, and a control unit coupled to each conductor of the array of conductors. The control unit is configured to monitor a capacitance between each two adjacent conductors of the array of conductors as wear occurs on the at least one wear surface of the dielectric substrate, and to determine a wear rate of the dielectric substrate using the monitored capacitance. The control unit is further configured to output the wear rate to a user. The device thus configured can be efficiently used to monitor the wear rate not only on a macro-scale but also on a micro-scale and nano-scale, without the need to inspect the wear surface with an additional device such as a microscope. Furthermore, the device thus configured can observe or detect scratches, cracks and undulations as wear occurs on the at least one wear surface of the dielectric substrate.

[0010] In one exemplary embodiment, the control unit is further configured to use the monitored capacitance to determine whether at least two conductors of the array of conductors have come into direct electrical contact during abrasion. If at least two conductors of the array of conductors have come into direct electrical contact during abrasion, the control unit is further configured to output a signal (e.g., visual, acoustic, vibration, or any combination thereof) to a user. In response to such a signal, the user can terminate or appropriately adjust the abrasion process. Furthermore, this functionality of the control unit allows the device to be used not only to monitor wear, but also to detect the occurrence of smear (surface deformation or plastic deformation). The possibility of detecting the occurrence of smear is particularly important when processing materials (e.g., during cutting, grinding and polishing processes).

[0011] In one exemplary embodiment, the at least one wear surface includes a single wear surface, and each conductor in the array of conductors is linear and extends perpendicular to the wear surface. This conductor configuration can be used efficiently when the wear rate of a single wear surface needs to be monitored.

[0012] In one exemplary embodiment, each conductor in the array of conductors has a curved shape, which can provide a variety of conductor configurations, each of which can be useful in a particular device application.

[0013] In one exemplary embodiment, the at least one wear surface includes a single wear surface, and each conductor in the array of conductors includes a first portion perpendicular to the wear surface and a second portion parallel to the wear surface. This conductor configuration can be used efficiently when the wear rate of a single wear surface needs to be monitored.

[0014] In one exemplary embodiment, the at least one wear surface includes two or three wear surfaces, and each conductor in the array of conductors has a circular shape. This circular conductor configuration can be used efficiently when the wear rate of more than one wear surface needs to be monitored.

[0015] In one exemplary embodiment, the at least one wear surface comprises a single wear surface, and each conductor in the array of conductors comprises a first portion and a second portion, the first portion and the second portion originating from a single point and diverging away from the wear surface. This conductor configuration can be used efficiently when the wear rate of a single wear surface needs to be monitored.

[0016] In one exemplary embodiment, each conductor in the array of conductors has a triangular shape. These parallel triangular conductor shapes can be used efficiently when the wear rate of a single wear surface needs to be monitored.

[0017] In one exemplary embodiment, the array of conductors has equal inter-conductor spacing. This equal inter-conductor spacing allows the user to monitor the wear rate (and smearing effect, if any) as a percentage value. For example, if there are 100 conductors running parallel to each other on a dielectric substrate, and capacitance measurements indicate that only the first 32 conductors (e.g., counting from the wear surface in the case of any of the curved conductor configurations discussed above) have been worn, the wear rate can be set to 32%.

[0018] In one exemplary embodiment, the array of conductors has a varying inter-conductor spacing, which allows the user to monitor the wear rate (and the effects of smearing, if any) in units of length (e.g., microns). For example, if each subsequent inter-conductor spacing is 1 μm larger than the previous spacing, and capacitance measurements indicate that only the first three conductors (e.g., counting from the wear surface, for any of the curved conductor configurations described above) have been worn, the wear rate can be set to approximately 3×(x+1) μm (where x is the width of the first inter-conductor spacing) (without taking into account the width of the conductors).

[0019] In one exemplary embodiment, the array of conductors has varying inter-conductor spacing that increases and decreases in a direction away from each of the at least one wear surface of the dielectric substrate. Such increasing and decreasing inter-conductor spacing can be used to provide different levels of precision (resolution) in monitoring the wear rate in a direction away from the wear surface (i.e., in the wear path). In other words, the inter-conductor spacing can be selected based on how closely the user wants to monitor the removal of material from the wear surface in the wear path. For example, a higher level of precision may be required when the wear rate reaches a critical level. Thus, the conductors can be placed closer to each other at a particular location in the wear path compared to the conductors at another location.

[0020] In one exemplary embodiment, the inter-conductor spacing is in the range of about 5 nm to about 10 mm (or varies within any subrange of this spacing range, e.g., about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, or about 50 nm to about 5 mm). Using this spacing range, it is possible to monitor the wear rate (and the effects of smear, if any) with an acceptable level of accuracy.

[0021] In one exemplary embodiment, the array of conductors includes a first subarray of conductors and a second subarray of conductors. The first subarray of conductors and the second subarray of conductors are non-overlapping. In this embodiment, the first subarray of conductors has equal inter-conductor spacing and the second subarray of conductors has varying inter-conductor spacing. Using such inter-conductor spacing for the first and second subarrays of conductors can provide different levels of precision (resolution) in monitoring wear rates within the wear path.

[0022] In one exemplary embodiment, the inter-conductor spacing of each of the first subarray of conductors and the second subarray of conductors ranges from about 5 nm to about 10 mm (or varies within any subrange of this spacing range, e.g., from about 10 nm to about 9 mm, from about 20 nm to about 8 mm, from about 30 nm to about 7 mm, from about 40 nm to about 6 mm, or from about 50 nm to about 5 mm). Using this spacing range, it is possible to monitor the wear rate (and the effects of smearing, if any) with an acceptable level of accuracy.

[0023] In one exemplary embodiment, the array of conductors includes a first subarray of conductors and a second subarray of conductors. The first subarray of conductors and the second subarray of conductors are non-overlapping. In this embodiment, the first subarray of conductors has a first equal inter-conductor spacing and the second subarray of conductors has a second equal inter-conductor spacing. The second equal inter-conductor spacing is different from the first equal inter-conductor spacing. Using such inter-conductor spacing for the first and second subarrays of conductors can provide different levels of precision (resolution) in monitoring wear rates within the wear path.

[0024] In one exemplary embodiment, each of the first equal inter-conductor spacing and the second equal inter-conductor spacing is in the range of about 5 nm to about 10 mm (or ranges within any subrange of this spacing range, e.g., about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, or about 50 nm to about 5 mm). Using this spacing range, it is possible to monitor the wear rate (and the effects of smear, if any) with an acceptable level of accuracy.

[0025] In one exemplary embodiment, each conductor of the array of conductors is made of a ductile material (e.g., gold, silver, aluminum, copper, titanium, nickel, any alloy thereof, as well as any conductive polymer, conductive copolymer, or any semiconducting material belonging to groups III-V of Mendeleev's periodic table, etc.). Ductile materials can be particularly advantageous when the device is also used to detect and monitor smearing effects. Furthermore, ductile materials can simplify the fabrication of different curved conductors on a dielectric substrate, if desired.

[0026] In one exemplary embodiment, the dielectric substrate is made of glass, silicon, SiO2, epoxy, polymer, semiconductor, ceramic, SiC, non-conductive polymer, non-conductive copolymer, or any combination thereof. These materials have suitable dielectric properties and therefore do not allow direct electrical contact between conductors through the substrate.

[0027] In one exemplary embodiment, each conductor in the array of conductors has a width in the range of about 5 nm to about 10 mm and a thickness in the range of about 5 nm to about 10 mm. It is noted that the width and thickness of each conductor can vary within any subrange of this range, such as, for example, about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, about 50 nm to about 5 mm, etc. Using these conductor dimensions, it is possible to monitor the wear rate (and the effects of smearing, if any) with an acceptable level of accuracy.

[0028] Other features and advantages of the present disclosure will become apparent upon reading the following detailed description and review of the accompanying drawings.

[0029] The present disclosure is described below with reference to the accompanying drawings. [Brief description of the drawings]

[0030] [Figure 1] 1 shows a schematic block diagram of a wear sensing device according to a first exemplary embodiment; [Diagram 2] FIG. 4 shows a schematic block diagram of a wear sensing device according to a second exemplary embodiment. [Diagram 3] FIG. 13 shows a schematic block diagram of a wear sensing device according to a third exemplary embodiment. [Figure 4] FIG. 13 shows a schematic block diagram of a wear sensing device according to a fourth exemplary embodiment. [Diagram 5] FIG. 13 shows a schematic block diagram of a wear sensing device according to a fifth exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Various embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. However, the present disclosure may be embodied in many other forms and should not be construed as being limited to any specific structure or function discussed in the following description. On the contrary, these embodiments are provided so that the description of the present disclosure will be thorough and complete.

[0032] According to the detailed description, it will be clear to those skilled in the art that the scope of the present disclosure encompasses any embodiment disclosed herein, regardless of whether the embodiment is implemented independently or in cooperation with any other embodiment of the present disclosure. For example, the device disclosed herein can be actually implemented using any number of the embodiments provided herein. Furthermore, it should be understood that any embodiment of the present disclosure can be implemented using one or more of the elements presented in the appended claims.

[0033] The term "exemplary" is used herein to mean "used as an example." Unless specifically stated otherwise, any embodiment described herein as "exemplary" is not to be construed as preferred or advantageous over other embodiments.

[0034] Any orientation terms, such as "left", "right", "top", "bottom", "upper", "lower", "upper" and "lower", may be used herein for convenience to describe the relationship of one element or feature to one or more other elements or features according to the drawings. It is clear that the orientation terms are intended to encompass different orientations of the devices disclosed herein in addition to the orientation shown in the figures. By way of example, if the device in the figures were to be imaginatively rotated 90 degrees clockwise, elements or features described as "left" and "right" relative to other elements or features would be oriented "above" and "below" the other elements or features, respectively. Thus, the orientation terms used herein should not be construed as limiting the present disclosure.

[0035] Although numerical terms such as "first" and "second" may be used herein to describe various embodiments, elements, or features, these embodiments, elements, or features should not be limited by these numerical terms. These numerical terms are used herein only to distinguish one embodiment, element, or feature from another embodiment, element, or feature. Thus, the first embodiment described below can be called the second embodiment, and vice versa, without departing from the teachings of the present disclosure.

[0036] Mechanical wear (hereafter referred to as wear for short) as used in the embodiments disclosed herein may refer to the continuous loss of material from the surface of a solid object due to mechanical action, such as the contact and relative movement of solid or fluid counterbodies. In general, the term "wear" can be used for both the wear or abrasion process and its results. The surface subjected to wear is referred to herein as the wear surface, and the direction in which wear occurs (i.e., away from the wear surface) is referred to herein as the wear path. Wear thus defined can be observed in different mechanical systems related to tribology, tool wear monitoring, surface finishing, machine wear monitoring, etc. It is noted that wear may also involve scratches, cracks and undulations, as well as the so-called smearing effect, which can be of major concern in the preparation of metallographic specimens from ductile materials.

[0037] Smear, as used in the embodiments disclosed herein, can refer to the mechanism of deformation / damage / wear of the surface of a material, particularly a ductile material. It occurs by plastic deformation, where the material is pushed across the wear surface, but at the same time, the pushed material remains attached to the wear surface. Correspondingly, smear can be considered as a thin layer of deformation / damage / wear of such surface on the surface of a fabricated sample. It generally occurs during the mid-to-late fabrication stages (e.g., diamond polishing and oxide polishing). For example, the key factors for the formation of smear in the polishing process are the applied load, the amount of lubrication, the rotation speed and direction of the polishing plate and the sample plate, the properties of the polishing pad, the amount and properties of the polishing liquid, etc.

[0038] Exemplary embodiments disclosed herein provide technical solutions that allow to mitigate or even eliminate the drawbacks of the prior art mentioned in the description section of the "Background Art". In particular, the technical solutions disclosed herein relate to a wear detection device that can efficiently monitor the wear rate of one or more wear surfaces, not only on the macro-scale but also on the micro- and nano-scale. To this end, the device includes an array of elongated planar conductors that extend parallel to each other on a patterned surface of a dielectric substrate. Each of the conductors is coupled to a control unit. When wear occurs on at least one wear surface of the dielectric substrate adjacent to the patterned surface, the control unit determines the wear rate by monitoring and analyzing the capacitance between each two adjacent conductors. The control unit then outputs the wear rate to a user. In a particular embodiment, the control unit can use the monitored capacitance to determine whether at least two conductors of the array of conductors have come into direct electrical contact upon wear and output a corresponding signal to a user.

[0039] FIG. 1 shows a schematic block diagram of a wear sensing device 100 according to a first exemplary embodiment. The device 100 includes a dielectric substrate 102 having a (bottom) wear surface 104 and a (front) patterned surface 106 adjacent to the wear surface 104. The term "adjacent" as used herein means that the wear surface and the patterned surface have a common boundary or edge. The dielectric substrate 102 can be made of glass, silicon, SiO2, epoxy, polymer, semiconductor, ceramic, SiC, non-conductive polymer, non-conductive copolymer, or any combination thereof. The device 100 further includes an array of conductors 108 extending parallel to each other on the patterned surface 106 of the dielectric substrate 102. More specifically, each conductor of the array of conductors 108 has a planar linear shape and extends perpendicular to the wear surface 104. The name of the patterned surface 106 is due to the very fact that such a conductor pattern is formed thereon. Preferably, each conductor of the array of conductors 108 can be made of a ductile material. Examples of ductile materials include, but are not limited to, gold, silver, aluminum, copper, titanium, hafnium, nickel, zirconium, or any alloy or combination thereof, any conductive polymer, conductive copolymer, or any semiconductor material belonging to groups III-V of the Mendeleev periodic table (e.g., Ge, Si). A layer of dielectric material (not shown in FIG. 1) is provided on the patterned surface 106 of the dielectric substrate 102 so as to cover each conductor of the array 108 of conductors as well as each space between the conductors. With this in mind, the structure formed by each of two adjacent conductors and the dielectric material therebetween can be considered a capacitor. The space between the conductors may range from about 5 nm to about 10 mm, or may vary within any subrange of this space range, such as, for example, from about 10 nm to about 9 mm, from about 20 nm to about 8 mm, from about 30 nm to about 7 mm, from about 40 nm to about 6 mm, from about 50 nm to about 5 mm, etc. Further, each conductor in the array of conductors 108 can have a width and thickness (e.g., similar to those set forth above with respect to inter-conductor spacing) that are both in the same range, which is about 5 nm to about 10 mm, or any subrange of this range.Generally, the lower end of this range is determined by the capabilities of existing manufacturing techniques such as lithography (e.g., photolithography), 3D printing, atomic layer deposition (ALD), chemical vapor deposition (CVD), ultra-high vacuum CVD (UHV-CVD), chemical beam epitaxy (CBE), laser ablation, electron lithography, sputtering, electrochemical deposition (e.g., electroplating), etc. The upper end of this range is determined primarily by what spacing is practical for a particular sensor application.

[0040] Here, an example of a method for forming an array 108 of aluminum conductors (and aluminum contact pads for the conductors, if necessary) on the patterned surface 106 of the dielectric substrate 102 represented by a SiO2 substrate is shown. The aluminum conductors can be formed by sputtering a 100 nm thick layer of aluminum onto the SiO2 substrate. After sputtering, the aluminum-coated SiO2 substrate is covered with a positive photoresist (e.g., Positive-20). Using a suitably patterned photomask, the photoresist is then exposed to ultraviolet (UV) light for 5 minutes. After this exposure, the photoresist is developed using 1% NaOH, and then the aluminum layer is etched using a phosphoric acid-based aluminum etchant. Finally, the entire sample is washed with acetone to remove the remaining photoresist. A layer of dielectric material (e.g., epoxy or any other dielectric material, or any combination of dielectric materials) can then be formed on the SiO2 substrate, such that the aluminum conductors and the spaces between them are covered with the layer of dielectric material.

[0041] Those skilled in the art will recognize that the above sample preparation examples do not limit the present disclosure in any way. In some other embodiments, any other lithography technique (e.g., based on the use of X-rays, gamma rays, or electron beams instead of UV or extreme UV (EUV) light) can be used to create the same conductor pattern on the patterned surface 106 of the dielectric substrate 102. As another non-limiting example, the same conductor pattern may be formed using either direct laser writing, multiphoton lithography, soft lithography, or nanoimprint lithography. Each of these techniques can result in relatively thick conductors and also allows for precise patterning of the conductors.

[0042] As also shown in FIG. 1, the device 100 further includes a control unit 110 coupled to each conductor of the array of conductors 108 via a contact connector 112. Any existing contact connector can be used, which allows many conductors or wires to be individually coupled to a specific measurement device (such as the control unit 110). In one other embodiment, instead of forming actual contact connectors directly on the dielectric substrate 102, wire bonding or a similar technique can be used to connect the array of conductors 108 to the control unit 110, in which case each conductor of the array of conductors 108 can have a contact pad at one end (a contact pad is a larger area of ​​a conductor that allows a bonding wire to be attached thereto). In another alternative embodiment, when the wear sensor (sensing device) 100 is fabricated using advanced lithography, an ultra-high vacuum (UHV) chamber, or molecular beam epitaxy (MBE), at least a part of the control unit 110 (e.g., a measurement means) can be provided directly on the dielectric substrate 102 (e.g., on the patterned surface 106 of the dielectric substrate 102).

[0043] With respect to the control unit 110, the control unit 110 may include a display, a processor, and a memory coupled to the processor. The memory may store processor-executable instructions that, when executed by the processor, cause the processor to determine a wear rate in a wear path (see solid arrows in FIG. 1 ), as described in more detail below.

[0044] A processor may be implemented as a CPU, a general purpose processor, a memristor, a neuromorphic computing chip, an artificial intelligence (AI) chip (also referred to as AI hardware), a single purpose processor, a microcontroller, a microprocessor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a complex programmable logic device. It should also be noted that a processor may be implemented as any combination of one or more of the foregoing. By way of example, a processor may be a combination of two or more microprocessors.

[0045] The memory can be implemented as classical non-volatile or volatile memory used in modern electronic computers. By way of example, non-volatile memory can include read only memory (ROM), ferroelectric random access memory (RAM), programmable ROM (PROM), electrically erasable PROM (EEPROM), solid state drive (SSD), flash memory, magnetic disk storage (such as hard drives and magnetic tapes), memristors, optical disk storage (such as CDs, DVDs and Blu-ray disks), etc. With respect to volatile memory, examples include dynamic RAM, synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), static RAM, non-volatile resistive RAM (RRAM), spin torque transfer magnetoresistance (STT-MRAM), phase change memory (PCM), etc.

[0046] The processor-executable instructions stored in the memory can be configured as computer-executable program code that causes the processor to perform aspects of the present disclosure. The computer-executable program code that performs the operations or steps of aspects of the present disclosure can be written in any combination of one or more programming languages, such as Java, C++, etc. In some examples, the computer-executable program code can be in a high-level language form or in a compiled form and can be generated on-the-fly by an interpreter (also pre-stored in the memory). In other examples, when the processor is implemented as an AI chip or a neuromorphic computing chip, the computer-executable program code can be generated on-the-fly by the AI ​​chip or the neuromorphic computing chip.

[0047] The display may be implemented as a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED) display, a plasma display, or the like.

[0048] It should be noted that the display may be omitted from the control unit 110. Instead, the control unit 110 may further include a transceiver, with the help of which the control unit 110 may be configured to provide the work result (i.e., wear rate) to a user's mobile device (e.g., via a mobile application installed on the user's mobile phone) by using any available wireless communication standard (e.g., Bluetooth, Near Field Communication (NFC), Radio Frequency Identification (RFID), etc.).

[0049] The principle of operation of the wear detection device 100 is as follows.

[0050] First, the dielectric substrate 102 can be attached or otherwise placed near an object susceptible to wear (e.g., a machine or tool part, a sample of a material to be subjected to surface finishing such as polishing, etc.) so that the dielectric substrate 102 is subjected to the same wear process as the object (i.e., the dielectric substrate 102 is machined / grinded / polished together with (or against) the object). This attachment or placement can be performed by various methods. For example, a cavity can be formed on the wear surface of the object and the dielectric substrate 102 can be placed in this cavity such that the wear surface 104 faces the wear direction. As another example, the dielectric substrate 102 can be glued near the wear surface of the object such that the wear surface 104 faces the wear direction.

[0051] When wear occurs on the wear surface 104 of the dielectric substrate 102, the wear surface 104 gradually wears away, which in turn gradually wears away the conductors on the patterned surface 106. This wear can cause changes in the length of the conductors and the area between some adjacent conductors, which can cause a corresponding change in the selected capacitance. For example, it is well known that the capacitance of a plate capacitor is directly proportional to the surface area of ​​its plates, and therefore the rate of change in capacitance is directly proportional to the rate of reduction in surface area. In this case, the plates are replaced by adjacent conductors, and the rate of reduction in their lengths depends on the rate of wear of the wear surface 104.

[0052] During wear at the wear surface 104, the control unit 110 is configured to monitor the capacitance of each capacitor (i.e., each structure formed by two adjacent conductors with dielectric material therebetween) formed on the patterned surface 106 of the dielectric substrate 102. The control unit 110 is then configured to use the monitored capacitance to determine the wear rate (i.e., wear depth) of the dielectric substrate 102 within the wear path (see solid arrows in FIG. 1). The control unit 110 is further configured to output the wear rate to a user (e.g., via a display).

[0053] As mentioned above, wear may be accompanied by a smearing effect. In Fig. 1, the smearing effect is assumed to result in the occurrence of a thin layer 114 of plastic surface deformation. This may result in a situation where at least some of the conductors of the array of conductors 108 may be in direct electrical contact near the wear surface 104. In one embodiment, the control unit 110 may be further configured to detect the occurrence of such a short circuit between the conductors upon wear using the monitored capacitance. The control unit may also be further configured to output a signal (e.g., visual, audio, vibration, or any combination thereof) to a user indicative of the occurrence of a short circuit between the conductors.

[0054] It should be noted that short circuits between conductors can occur not only due to the effect of smear, but also when the object (on which the dielectric substrate 102 is attached or placed nearby, so that the dielectric substrate 102 is exposed to the same wear process as the object) is made of a conductive material. In this case, to distinguish between the effect of smear and a short circuit (or direct electrical contact) caused by the contact of a conductor and a conductive material, the conductive object can be moved along the wear surface 104 or moved away from the wear surface 104 in another way. The direct electrical contact induced by the smear remains constant even after the contact with the conductive object is removed. For example, when a machining tool (usually made of metal) is used to machine the surface of the specimen, the wear sensor 100 can be placed on or near the specimen such that the wear surface 104 of the dielectric substrate 102 is also machined by the tool. In this example, the direct electrical contact between the tool and the wear sensor 100 can cause a short circuit between the conductors of the wear sensor 100. When the tool is removed, the direct electrical contact induced by the smear remains constant, but the direct electrical contact by the tool is gone. Furthermore, for example, when monitoring the effects of smear in a polishing process, the polishing pad is not as conductive as smear-induced contact between conductors.

[0055] In one embodiment, the array of conductors 108 can have equal inter-conductor spacing. Equal inter-conductor spacing allows a user to monitor the wear rate (and the effects of smear, if any) in percentage values. In another embodiment, the array of conductors 108 can have varying inter-conductor spacing. This varying inter-conductor spacing allows a user to monitor the wear rate (and the effects of smear, if any) in units of length (e.g., microns). It is noted that varying inter-conductor spacing can be particularly useful for monitoring the effects of smear.

[0056] 2 shows a schematic block diagram of a wear sensing device 200 according to a second exemplary embodiment. The device 200 includes a dielectric substrate 202 having a (bottom) wear surface 204 and a (front) patterned surface 206 adjacent to the wear surface 204. The dielectric substrate 202 can be made of the same material as the dielectric substrate 102. The device 200 further includes an array of conductors 208 that extend parallel to one another on the patterned surface 206 of the dielectric substrate 202. More specifically, each conductor of the array of conductors 208 includes a first planar linear portion that extends perpendicular to the wear surface 204 and a second planar linear portion that extends parallel to the wear surface 204. Similar to the conductors of the device 100, the conductors of the device 200 can be made of a ductile material by using any existing lithography technique (e.g., following the sample preparation example above). Similarly, a layer of dielectric material (not shown in FIG. 2) is provided on patterned surface 206 of dielectric substrate 202 so as to cover each conductor in array 208 of conductors as well as each space between the conductors. Again, the spacing between the conductors may range from about 5 nm to about 10 mm, or may vary within any subrange of this spacing range, such as, for example, from about 10 nm to about 9 mm, from about 20 nm to about 8 mm, from about 30 nm to about 7 mm, from about 40 nm to about 6 mm, from about 50 nm to about 5 mm, etc. Again, each conductor in array 208 of conductors may have a width and thickness (e.g., similar to those set forth above with respect to spacing between conductors) that both fall within the same range, or any subrange of this range, of from about 5 nm to about 10 mm.

[0057] As also shown in FIG. 2, the device 200 further includes a control unit 210 coupled to each conductor of the array of conductors 208 via a contact connector 212. Any existing contact connector can be used, which allows many conductors or wires to be individually coupled to a specific measurement device (such as the control unit 210). In one other embodiment, instead of forming an actual contact connector directly on the dielectric substrate 202, wire bonding or a similar technique can be used to connect the array of conductors 208 to the control unit 210, in which case each conductor of the array of conductors 208 can have a contact pad at one end to which a bonding wire is attached. In another alternative embodiment, when the wear sensor 200 is fabricated using advanced lithography, a UHV chamber, or MBE, at least a part of the control unit 210 (e.g., a measurement means) can be provided directly on the dielectric substrate 202 (e.g., on the patterned surface 206 of the dielectric substrate 102).

[0058] As for the control unit 210, it may be implemented in the same way as the control unit 110 and may be configured to operate in the same way as the control unit 110. More specifically, the control unit 210 may be configured to monitor the capacitance of each capacitor (i.e., each structure formed by two adjacent conductors and the dielectric material between them) formed on the patterned surface 206 of the dielectric substrate 202, determine the wear rate of the dielectric substrate 202 in the wear path (see the solid arrows in FIG. 2) based on the monitored capacitance, and output this wear rate to a user. The control unit 210 may also be configured to detect and monitor the effects of smearing, similar to the control unit 110. For example, the effects of smearing may result in a situation where the second (parallel) portion of the conductor closest to the wear surface 204 is in direct electrical contact with the second (parallel) portion of the next conductor.

[0059] It should be noted that the configuration of the conductor array 208 allows the general wear depth to be simultaneously monitored by detecting how many conductors have "lost" their second portion (parallel to the wear surface 204) as the wear surface 104 wears. When one conductor "loses" its second portion, this leads to a large loss of mutual capacitance between this conductor and the next conductor. The configuration of the conductor array 108 also allows the wear rate to be determined by monitoring the decrease in mutual capacitance between each two adjacent conductors, although this will likely not provide accurate results.

[0060] FIG. 3 shows a schematic block diagram of a wear sensing device 300 according to a third exemplary embodiment. The device 300 includes a dielectric substrate 302 having more than one wear surface, namely a left wear surface 304, a bottom wear surface 306, and a right wear surface 308. Thus, the dielectric substrate 302 is intended to be polished on two or three sides, unlike the dielectric substrates 102 and 202. The dielectric substrate 302 also has a (front) patterned surface 310 adjacent to each of the wear surfaces 304, 306, and 308. The dielectric substrate 302 can be made of the same material as the dielectric substrate 102. The device 300 further includes an array of conductors 312 that extend parallel to one another on the patterned surface 310 of the dielectric substrate 302. More specifically, each conductor of the array of conductors 312 has a planar circular shape. As with the conductors of device 100, the conductors of device 300 can be fabricated of a ductile material using any existing lithography technique (e.g., following the sample preparation example above). Similarly, a layer of dielectric material (not shown in FIG. 3) is provided on patterned surface 310 of dielectric substrate 302 so as to cover each conductor in array 312 of conductors as well as each space between the conductors. Again, the spacing between the conductors can range from about 5 nm to about 10 mm, or can vary within any subrange of this spacing range, e.g., from about 10 nm to about 9 mm, from about 20 nm to about 8 mm, from about 30 nm to about 7 mm, from about 40 nm to about 6 mm, from about 50 nm to about 5 mm, etc. Again, each conductor in array 312 of conductors can have a width and thickness (e.g., similar to those set forth above with respect to spacing between conductors) that both fall within the same range, or any subrange of this range, which is from about 5 nm to about 10 mm. It is the combination of the circular conductor configuration and the layers of dielectric material that allows for capacitance measurements on two or more sides of the dielectric substrate 302.

[0061] As also shown in FIG. 3, the device 300 further includes a control unit 314 coupled to each conductor of the array of conductors 312 via a contact connector 316. Any existing contact connector can be used, which allows many conductors or wires to be individually coupled to a specific measurement device (such as the control unit 314). In one other embodiment, instead of forming an actual contact connector directly on the dielectric substrate 302, wire bonding or a similar technique can be used to connect the array of conductors 312 to the control unit 314, in which case each conductor of the array of conductors 312 can have a contact pad at one end to which a bonding wire is attached. In another alternative embodiment, when the wear sensor 300 is fabricated using advanced lithography, a UHV chamber, or MBE, at least a part of the control unit 314 (e.g., a measurement means) can be provided directly on the dielectric substrate 302 (e.g., on the patterned surface 310 of the dielectric substrate 302).

[0062] As for the control unit 314, it may be implemented in the same way as the control unit 110 and may be configured to operate in the same way as the control unit 110. More specifically, the control unit 314 may be configured to monitor the capacitance of each capacitor (i.e., each structure formed by two adjacent conductors and the dielectric material between them) formed on the patterned surface 310 of the dielectric substrate 302, determine the wear rate of the dielectric substrate 302 in the wear path (see the solid arrows in FIG. 3) based on the monitored capacitance, and output this wear rate to a user. The control unit 314 may also be configured to detect and monitor the effects of smearing, similar to the control unit 110. For example, the effects of smearing may result in a situation where the outermost circular conductor (closest to each of the wear surfaces 304, 306, and 308) is in direct electrical contact with the next circular conductor at one or more points.

[0063] FIG. 4 shows a schematic block diagram of a wear sensing device 400 according to a fourth exemplary embodiment. The device 400 includes a dielectric substrate 402 having a (bottom) wear surface 404 and a (front) patterned surface 406 adjacent to the wear surface 404. The dielectric substrate 402 can be made of the same material as the dielectric substrate 102. The device 400 further includes an array of conductors 408 extending parallel to one another on the patterned surface 406 of the dielectric substrate 402. More specifically, each conductor of the array of conductors 408 has a planar triangular shape. Similar to the conductors of the device 100, the conductors of the device 400 can be made of a ductile material by using any existing lithography technique (e.g., following the sample preparation example above). Similarly, a layer of dielectric material (not shown in FIG. 4) is provided on the patterned surface 406 of the dielectric substrate 402 so as to cover each conductor of the array of conductors 408 as well as each space between the conductors. Again, the spacing between the conductors may range from about 5 nm to about 10 mm, or may vary within any subrange of this spacing range, e.g., from about 10 nm to about 9 mm, from about 20 nm to about 8 mm, from about 30 nm to about 7 mm, from about 40 nm to about 6 mm, from about 50 nm to about 5 mm, etc. Further, again, each conductor in the array of conductors 408 may have a width and thickness (e.g., similar to those set forth above with respect to inter-conductor spacing) that both fall within the same range, which is from about 5 nm to about 10 mm, or any subrange of this range.

[0064] As also shown in FIG. 4, the device 400 further includes a control unit 410 coupled to each conductor of the array of conductors 408 via a contact connector 412. Any existing contact connector can be used, which allows many conductors or wires to be individually coupled to a specific measurement device (such as the control unit 410). In one other embodiment, instead of forming actual contact connectors directly on the dielectric substrate 402, wire bonding or similar techniques can be used to connect the array of conductors 408 to the control unit 410, in which case each conductor of the array of conductors 408 can have a contact pad at one end to which a bonding wire is attached. In another alternative embodiment, when the wear sensor 400 is fabricated using advanced lithography, a UHV chamber, or MBE, at least a part of the control unit 410 (e.g., a measurement means) can be provided directly on the dielectric substrate 402 (e.g., on the patterned surface 406 of the dielectric substrate 402).

[0065] As for the control unit 410, it may be implemented in the same way as the control unit 110 and may be configured to operate in the same way as the control unit 110. More specifically, the control unit 410 may be configured to monitor the capacitance of each capacitor (i.e., each structure formed by two adjacent conductors and the dielectric material between them) formed on the patterned surface 406 of the dielectric substrate 402, determine the wear rate of the dielectric substrate 402 in the wear path (see the solid arrow in FIG. 4) based on the monitored capacitance, and output this wear rate to a user. The control unit 410 may also be configured to detect and monitor the effects of smearing, similar to the control unit 110. For example, the effects of smearing may result in a situation where the first two adjacent triangular conductors (counting from the wear surface 404) are in direct electrical contact near the triangle apex.

[0066] 5 shows a schematic block diagram of a wear sensing device 500 according to a fifth exemplary embodiment. The device 500 includes a substrate 502 configured as a multi-layer structure formed by plate-like conductors 504 alternating with dielectric layers 506. In this multi-layer structure, it is assumed that the wear surface (not shown in FIG. 5) is the bottom surface, and the plate-like conductors 504 are arranged parallel to each other and perpendicular to the wear surface.

[0067] Any film and / or coating formation technique can be used to make the dielectric layers 506 out of the same material as the dielectric substrate 102. For example, each of the dielectric layers 506 can be formed by spin-coating a thin (e.g., 20 μm) layer of non-conductive adhesive onto one plate-like conductor 504, and then attaching the plate-like conductor 504 to another plate-like conductor 504 so that the spin-coated layer of non-conductive adhesive is sandwiched therebetween.

[0068] Similar to the conductors of device 100, the conductors 504 of device 500 can be made of a ductile material. Again, the spacing between the conductors (i.e., the width of each dielectric layer 506) can range from about 5 nm to about 10 mm, or can vary within any subrange of this spacing range, such as, for example, about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, about 50 nm to about 5 mm, etc. Additionally, each plate-like conductor 504 can have a width that falls within the same range, which is about 5 nm to about 10 mm, or any subrange of this range (e.g., similar to those set forth above for the spacing between the conductors). In general, the substrate 502 can be made by using any deposition technique that allows for alternating deposition of conductor and dielectric layers.

[0069] 5, the apparatus 500 further includes a control unit 508 coupled to each flat conductor 504 via a corresponding bonding wire 510. In one other embodiment, any existing contact connector can be used in place of the bonding wires 510, allowing many flat conductors to be individually coupled to a particular measurement device (such as the control unit 508).

[0070] As for the control unit 508, it may be implemented in the same way as the control unit 110 and may be configured to operate in the same way as the control unit 110. More specifically, the control unit 508 may be configured to monitor the capacitance of each capacitor (i.e., each structure formed by two adjacent plate-shaped conductors 504 and the dielectric layer 506 between them) on the substrate 502, determine the wear rate of the substrate 502 in the wear path (see the solid arrow in FIG. 5) based on the monitored capacitance, and output this wear rate to a user. The control unit 508 may also be configured to detect and monitor the effect of smearing, similar to the control unit 110. For example, the effect of smearing may result in a situation where some or each two adjacent plate-shaped conductors 504 are in direct electrical contact near the bottom wear surface.

[0071] Apparatus 500 is particularly advantageous in terms of detecting and monitoring the effects of smearing. In each of apparatuses 100-400, only a thin layer of conductive material (i.e., planar conductors) is formed on the patterned surface, so that smearing has difficulty "moving" the conductive material so that at least two conductors are in direct electrical contact. This is because there is less conductive material on which smearing can occur in the first place. Conversely, the multi-layer structure used in apparatus 500 provides a larger abraded surface of conductive material on which smearing can occur, making the effects of smearing more pronounced.

[0072] It should be noted that the present invention is not limited to the conductor configurations shown in Figures 1-5. In some other embodiments, any other conductor configurations are possible. For example, each conductor can have any other curved shape, such as a trapezoid, a square, etc., which allows the conductor to be formed on the patterned surface of the dielectric substrate without an initial direct contact between the conductor and the patterned surface of the dielectric substrate. As another example, each conductor can include a first portion and a second portion that originate from a single point and diverge in a direction away from the wear surface (the triangular conductor shape shown in Figure 4 is one particular example of such a configuration).

[0073] Additionally, in some embodiments, the inter-conductor spacing may be increased or decreased within the wear path. For example, an array of conductors (any of those shown in Figures 1-5) may include two (first and second) sub-arrays of non-overlapping conductors, each of which may have a different inter-conductor spacing. For example, the first sub-array of conductors may have a first equal inter-conductor spacing and the second sub-array of conductors may have a second equal inter-conductor spacing that is different from the first equal inter-conductor spacing. Alternatively, the first sub-array of conductors may have equal inter-conductor spacing while the second sub-array of conductors may have a varying inter-conductor spacing. Additionally, for the array of conductors shown in Figures 2-4, the first and second sub-arrays of conductors may be positioned differently relative to the wear surface (e.g., the first sub-array of conductors may be disposed closer to the respective wear surface than the second sub-array of conductors, or vice versa).

[0074] In some additional embodiments, the devices 100-500 may further include an accelerometer and / or gyroscope mounted on the dielectric substrate 102-502 (e.g., in the case of the device 100, on the patterned surface 106 adjacent the array of conductors 108), respectively. The accelerometer and / or gyroscope may have a built-in transmitter (e.g., a Bluetooth transmitter) so that the measurement data can be transmitted to a mobile user device (e.g., via a mobile application installed on a mobile phone).

[0075] Additionally, machine learning (ML) algorithms (e.g., neural networks, decision trees, regression models, etc.) can be incorporated into each of the devices 100-500. For example, during the abrasion process, a control unit included in each of the devices 100-500 can provide the capacitance measured between each two adjacent conductors to an ML algorithm, which can be further configured to predict whether to change parameters of the abrasion process (e.g., whether to change the type of grinding or polishing from "coarse" to "fine" to speed up the materialographic sample preparation or chemical mechanical planarization process, minimize the occurrence of undesirable smearing effects, etc.). For this prediction, the ML model can be pre-trained by using historical data, such as capacitance measurements made in the past for a particular conductor material and a particular inter-conductor spacing.

[0076] Although exemplary embodiments of the present disclosure have been described herein, it should be noted that various changes and modifications can be made in these embodiments without departing from the scope of legal protection defined by the appended claims. In the appended claims, the term "comprising" does not exclude other elements or operations, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A wear detection device (100; 200; 300; 400), comprising: a dielectric substrate (102; 202; 302; 402) having at least one wear surface (104; 204; 304; 306; 308; 404) and a patterned surface (106; 206; 310; 406) adjacent said at least one wear surface (104; 204; 304; 306; 308; 404); an array of conductors (108; 208; 312; 408) extending parallel to one another on the patterned surface (106; 206; 310; 406) of the dielectric substrate (102; 202; 302; 402), each conductor having an elongated planar shape; a dielectric material covering said patterned surface (106; 206; 310; 406) of said dielectric substrate (102; 202; 302; 402) together with said array of conductors (108; 208; 312; 408); a control unit (110; 210; 314; 410) coupled to each conductor of the array of conductors (108; 208; 312; 408), the control unit (110; 210; 314; 410) configured to, upon wear occurring on at least one wear surface (104; 204; 304; 306; 308; 404) of the dielectric substrate (102; 202; 302; 402), monitoring the capacitance between every two adjacent conductors of said array of conductors (108; 208; 312; 408); determining a wear rate of the dielectric substrate (102; 202; 302; 402) based on the monitored capacitance; outputting the wear rate to a user; A control unit (110; 210; 314; 410) configured as follows: A wear detection device (100; 200; 300; 400) comprising:

2. The control unit (110; 210; 314; 410) further comprises: determining whether at least two conductors of the array of conductors (108; 208; 312; 408) are in direct electrical contact upon wear based on the monitored capacitance; outputting a signal to the user when the at least two conductors of the array of conductors (108; 208; 312; 408) are in direct electrical contact upon the abrasion; The wear detection device (100; 200; 300; 400) according to claim 1, configured as follows:

3. 3. The wear detection device (100) of claim 1 or claim 2, wherein the at least one wear surface comprises a single wear surface (104), and each conductor in the array of conductors (108) is linear and extends perpendicular to the wear surface (104).

4. The wear sensing device (200; 300; 400) of claim 1 or 2, wherein each conductor of the array of conductors (208; 312; 408) has a curved shape.

5. 5. The wear sensing device (200) of claim 4, wherein the at least one wear surface comprises a single wear surface (204), and each conductor of the array of conductors (208) comprises a first portion perpendicular to the wear surface (204) and a second portion parallel to the wear surface (204).

6. The wear sensing device (300) of claim 4, wherein the at least one wear surface includes two or three wear surfaces (304; 306; 308), and each conductor in the array of conductors (312) has a circular shape.

7. 5. The wear detection device (400) of claim 4, wherein the at least one wear surface comprises a single wear surface (404), and each conductor in the array of conductors (408) includes a first portion and a second portion originating from a single point and diverging in a direction away from the wear surface (404).

8. The wear sensing device (400) of claim 7, wherein each conductor in the array of conductors (408) has a triangular shape.

9. The wear sensing device (100; 200; 300; 400) of any one of claims 1 to 8, wherein the array of conductors (108; 208; 312; 408) has equal inter-conductor spacing.

10. The wear sensing device (100; 200; 300; 400) of any one of claims 1 to 8, wherein the array of conductors (108; 208; 312; 408) has a varying inter-conductor spacing.

11. The wear detection device (100; 200; 300; 400) of any one of claims 4 to 8, wherein the array of conductors (108; 208; 312; 408) has a varying inter-conductor spacing that increases or decreases in a direction away from each of the at least one wear surface (104; 204; 304; 306; 308; 404) of the dielectric substrate (102; 202; 302; 402).

12. The wear detection device (100; 200; 300; 400) according to any one of claims 9 to 11, wherein the inter-conductor spacing is in the range of about 5 nm to about 10 mm, more preferably about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, or about 50 nm to about 5 mm.

13. The wear detection device (100; 200; 300; 400) of any one of claims 1 to 8, wherein the array of conductors (108; 208; 312; 408) comprises a first subarray of conductors and a second subarray of conductors, the first subarray of conductors and the second subarray of conductors being non-overlapping, the first subarray of conductors having equal inter-conductor spacing, and the second subarray of conductors having varying inter-conductor spacing.

14. 14. The wear sensing device (100; 200; 300; 400) of claim 13, wherein the inter-conductor spacing of each of the first subarray of conductors and the second subarray of conductors is in the range of about 5 nm to about 10 mm, more preferably about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, or about 50 nm to about 5 mm.

15. 9. The wear detection device (100; 200; 300; 400) of any one of claims 1 to 8, wherein the array of conductors (108; 208; 312; 408) comprises a first subarray of conductors and a second subarray of conductors, the first subarray of conductors and the second subarray of conductors being non-overlapping, the first subarray of conductors having a first equal inter-conductor spacing, and the second subarray of conductors having a second equal inter-conductor spacing, the second equal inter-conductor spacing being different from the first equal inter-conductor spacing.

16. 16. The wear sensing device (100; 200; 300; 400) of claim 15, wherein each of the first equal inter-conductor spacing and the second equal inter-conductor spacing is in the range of about 5 nm to about 10 mm, more preferably about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, or about 50 nm to about 5 mm.

17. Wear sensing device (100; 200; 300; 400) according to any one of the preceding claims, wherein each conductor of the array of conductors (108; 208; 312; 408) is made of a ductile material.

18. The dielectric substrate (102; 202; 302; 402) is made of glass, silicon, SiO ２ 18. The wear sensing device (100; 200; 300; 400) of any one of claims 1 to 17, made of a material selected from the group consisting of epoxy, polymer, semiconductor, ceramic, SiC, non-conductive polymer, non-conductive copolymer, and any combination thereof.

19. 19. The wear sensing device (100; 200; 300; 400) of any one of the preceding claims, wherein each conductor of the array of conductors (108; 208; 312; 408) has a width in the range of about 5 nm to about 10 mm and a thickness in the range of about 5 nm to about 10 mm, more preferably about 10 nm to about 9 mm, about 20 nm to about 8 mm, about 30 nm to about 7 mm, about 40 nm to about 6 mm, or about 50 nm to about 5 mm.

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