Wear detection device

Abstract

The present disclosure relates to a wear detection device that can efficiently monitor the wear rate of a wear surface not only on the macro-scale but also on the micro- and nano-scale. To this end, the device includes a multi-layer substrate formed by an array of plate-like conductors and an array of dielectric layers arranged in an alternating manner. Each of the plate-like conductors is coupled to a control unit. When wear occurs on the wear surface of the multi-layer substrate, the control unit determines the wear rate by monitoring and analyzing the capacitance and / or resistance between every two adjacent plate-like conductors. The control unit then outputs the wear rate to a user. In some embodiments, the control unit can use the monitored capacitance and / or monitored resistance to determine whether at least two plate-like conductors of the array of plate-like conductors have come into direct electrical contact upon wear and output a corresponding signal to a user.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to Finnish Patent Application No. 20225188 (titled "Wear Detection Device"), filed with the Finnish Patent and Registration Office on March 2, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] 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]

[0003] 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.

[0004] 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.

[0005] 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).

[0006] 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]

[0007] 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.

[0008] It is an object of the present disclosure to provide a wear detection device that can efficiently monitor (in real time) the wear rate of a wear surface not only on the macro-scale but also on the micro- and nano-scale.

[0009] 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]

[0010] According to a first aspect, a wear detection device is provided. The device includes a multilayer substrate having a wear surface. The multilayer substrate includes an array of plate conductors and an array of dielectric layers. The array of plate conductors and the array of dielectric layers are arranged alternately with each other. The wear surface is formed by edges of the plate conductors of the array of plate conductors and edges of the dielectric layers of the array of dielectric layers. The device further includes a control unit coupled to each plate conductor of the array of plate conductors. The control unit is configured to monitor a capacitance and / or a resistance between each two adjacent plate conductors of the array of plate conductors when wear occurs on the wear surface of the multilayer substrate, and to determine a wear rate of the multilayer substrate using the monitored capacitance and / or monitored resistance. 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 when wear occurs on the wear surface of the multilayer substrate. Moreover, an apparatus constructed in this manner can be used to determine the relative change in moisture content on the wear surface, particularly during the abrading process.

[0011] In one exemplary embodiment, the control unit is further configured to use the monitored capacitance and / or the monitored resistance to determine whether at least two plate conductors of the array of plate conductors are in direct electrical contact during wear. If at least two plate conductors of the array of plate conductors are in direct electrical contact during wear, 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 wear 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).

[0012] In one exemplary embodiment, each plate conductor in the array of plate conductors extends perpendicular to the wear surface. It is easy to arrange the plate conductors (and thus the dielectric layer) vertically in this manner.

[0013] In one exemplary embodiment, the array of plate-like conductors has equal inter-conductor spacing. In other words, each dielectric layer of the array of dielectric layers has equal width. This equal inter-conductor spacing allows the user to monitor the smearing effect in percentage value and detect the occurrence of large scratches when wear occurs on the wear surface of the multilayer structure. For example, if there are 100 plate-like conductors extending perpendicular to the wear surface of the multilayer board, and capacitance and / or resistance measurements indicate that 32 of these 100 plate-like conductors (e.g., randomly spaced) made direct electrical contact when worn, the amount of smearing effect can be set to 32%. Furthermore, if these 32 (shorted) plate-like conductors are closely located in a portion of the multilayer board (e.g., adjacent to each other at the left edge of the multilayer board), this may also indicate that large scratches have occurred in that portion of the multilayer board.

[0014] In one exemplary embodiment, the array of conductors has a varying inter-conductor spacing. In other words, each dielectric layer in the array of dielectric layers has a different (e.g., gradually increasing or decreasing) width. This varying inter-conductor spacing allows a user to monitor the smear effect in units of length (e.g., microns) and detect the occurrence of large scratches when wear occurs on the wear surface of the multi-layer structure. More specifically, the amount of smear effect can be considered as the widest shorted inter-conductor spacing. For example, if conductor spacings of 1 μm, 5 μm, and 10 μm are all shorted, but conductor spacings of 20 μm and 30 μm are not shorted, the amount of smear effect is 10 μm. Furthermore, if the conductor spacing of 30 μm is shorted, this may also indicate that large scratches have occurred on that portion of the multi-layer board.

[0015] In one exemplary embodiment, the inter-conductor spacing is in the range of about 5 nm to about 10 mm (or may vary 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 effects of smearing and / or the occurrence of scratches with an acceptable level of accuracy.

[0016] In one exemplary embodiment, the array of plate conductors includes a first subarray of plate conductors and a second subarray of plate conductors. The first subarray of plate conductors and the second subarray of plate conductors are non-overlapping. In this embodiment, the first subarray of plate conductors has equal inter-conductor spacing and the second subarray of plate conductors has varying inter-conductor spacing. Using such inter-conductor spacing for the first and second subarrays of plate conductors can provide different levels of precision (resolution) in monitoring the effect of smear on wear.

[0017] In one exemplary embodiment, the inter-conductor spacing of each of the first subarray of planar conductors and the second subarray of planar 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 effects of smearing and / or the occurrence of scratches with an acceptable level of accuracy.

[0018] In one exemplary embodiment, the array of conductors includes a first subarray of plate conductors and a second subarray of plate conductors. The first subarray of plate conductors and the second subarray of plate conductors are non-overlapping. In this embodiment, the first subarray of plate conductors has a first equal inter-conductor spacing and the second subarray of plate conductors has a second equal inter-conductor spacing. The second equal inter-conductor spacing is different from the first equal inter-conductor spacing. By using such inter-conductor spacing for the first and second subarrays of plate conductors, it is possible to provide different levels of precision (resolution) in the monitored effect of smear during wear.

[0019] 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 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 effects of smearing and / or the occurrence of scratches with an acceptable level of accuracy.

[0020] In one exemplary embodiment, each plate conductor of the array of plate 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 semiconductor 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 plate conductors with different widths and / or shapes on a multi-layer substrate, as needed.

[0021] In one exemplary embodiment, each dielectric layer of the array of dielectric layers is made of glass, silicon, SiO2, epoxy, polymer, semiconductor, ceramic, SiC, non-conductive polymer, non-conductive copolymer, or any combination thereof, which have suitable dielectric properties and thus do not allow direct electrical contact between plate-like conductors.

[0022] In one exemplary embodiment, each plate conductor in the array of plate conductors has a width in the range of about 5 nm to about 10 mm. It is noted that the width of each plate conductor can vary within any subrange of this 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, about 50 nm to about 5 mm, etc. Using these conductive dimensions, it is possible to effectively monitor the wear rate (and the effect of smearing, if any).

[0023] In one exemplary embodiment, the apparatus further includes at least one of an accelerometer and a gyroscope on at least one surface of the multi-layer substrate other than the worn surface. By using these sensing devices, a user can obtain different measurement data related to the wear (and smear effect, if any) of the multi-layer substrate and appropriately control the entire process based on the measurement data.

[0024] Other features and advantages of the present disclosure will become apparent upon reading the following detailed description and review of the accompanying drawings.

[0025] The present disclosure is described below with reference to the accompanying drawings. [Brief description of the drawings]

[0026] [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. [Figure 6A] FIG. 6 shows, in the apparatus of FIG. 5, a schematic of how resistance measurements can be used to monitor the effect of smearing, which appears as a metal bridge across a dielectric layer. [Figure 6B] FIG. 6 shows, in the apparatus of FIG. 5, a schematic of how resistance measurements can be used to monitor the effect of smearing, which appears as a metal bridge across a dielectric layer. [Figure 6C] FIG. 6 shows, in the apparatus of FIG. 5, a schematic of how resistance measurements can be used to monitor the effect of smearing, which appears as a metal bridge across a dielectric layer. [Figure 7] 6 shows how the device of FIG. 5 can be implemented in the form of a button-like structure. [Figure 8] 8 illustrates how the button-like structure of FIG. 7 can be used in a polishing process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 extending 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 and / or resistance 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 and / or monitored resistance 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.

[0035] 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. As used herein, the term "adjacent" 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 (e.g., poly(3,4-ethylenedioxythiophene) (PEDOT), poly(azobenzene) (PAz), PEDOT:poly(styrenesulfonate) (PEDOT:PSS), etc.), non-conductive copolymer, indium tin oxide (ITO), fluorine doped tin oxide (FTO), carbon nanotubes (CNT), graphene, nanowire mesh, silver nanowire, generally any transparent conductive film (TCF) or transparent conductive oxide (TCO), or any combination thereof. The device 100 further includes an array 108 of conductors that run parallel to one another on the patterned surface 106 of the dielectric substrate 102. More specifically, each conductor of the array 108 of conductors has a planar linear shape and runs perpendicular to the wear surface 104. The patterned surface 106 is so named because of the very conductor pattern formed thereon. Each conductor of the array 108 of conductors can preferably 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 (e.g., PEDOT, PAz, PEDOT:PSS, etc.), conductive copolymer, ITO, 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 between them can be considered a capacitor.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. Additionally, 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 the spacing between the conductors) that both fall within the same range, which is from 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, extreme ultraviolet (EUV) lithography, electron lithography, sputtering, electrolytic deposition (e.g., electroplating), etc. The upper end of this range is determined primarily by what spacing is practical for a particular sensor application.

[0036] 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.

[0037] 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.

[0038] 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 bond wire to be attached thereto). In another alternative embodiment, when the wear sensor (sensing device) 100 is fabricated using advanced lithography, a UHV chamber, or 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).

[0039] 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.

[0040] 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.

[0041] 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), resistive RAM (ReRAM), spin torque transfer magnetoresistance (STT-MRAM), phase change memory (PCM), etc.

[0042] 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++, Python, 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.

[0043] The display may be implemented as a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED) display, a micro LED display, a plasma display, a backlit screen, a frontlit screen, a smart window, smart glasses, and the like.

[0044] 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 results (i.e., wear rates) 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), Zigbee, LoRaWAN, WiFi, 4G / 5G / 6G, etc.).

[0045] The principle of operation of the wear detection device 100 is as follows.

[0046] 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.

[0047] 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.

[0048] 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).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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).

[0058] 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.

[0059] 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.

[0060] 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).

[0061] 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.

[0062] FIG. 5 shows a schematic block diagram of a wear detection 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 arranged alternately 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 (and thus the dielectric layers 506) are arranged parallel to each other and perpendicular to the wear surface. In other words, the wear surface is formed by the edges of the alternating plate-like conductors 504 and dielectric layers 506. In other embodiments, the wear surface is either the top, front, or back surface of the multi-layer structure 502, each of which is formed by the edges of the alternating plate-like conductors 504 and dielectric layers 506 (as is the bottom surface), as can be seen in FIG. 5. Furthermore, the vertical arrangement of the plate-shaped conductor 504 (and thus the dielectric layer 506) with respect to the wear surface should not be construed as limiting the present disclosure, and can be replaced with an arrangement in which the plate-shaped conductor 504 (and thus the dielectric layer 506) is inclined with respect to the wear surface (e.g., the inclination angle can vary between 1 degree and 90 degrees). Thus, the multilayer substrate 502 can have different shapes, such as a cube (see FIG. 5) or a parallelepiped (when the plate-shaped conductor 502 and the dielectric layer 506 are inclined with respect to the wear surface).

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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) in the multilayer 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.

[0067] 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.

[0068] 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).

[0069] 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).

[0070] 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., on the patterned surface 106 adjacent the array of conductors 108 in the case of device 100, or on any surface other than the wear surface of the multi-layer substrate 502 in the case of device 500), respectively. For example, the combination of accelerometer and gyroscope may be implemented using Microelectromechanical Systems (MEMS) technology. 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).

[0071] In some additional embodiments, the control unit included in each of the devices 100-500 can be configured to determine the wear rate (and detect the effect of smear, if any) by performing resistance measurements in addition to or instead of the capacitance measurements described above. That is, the control unit of each of the devices 100-500 can monitor the resistance between two adjacent conductors, determine the wear rate of the corresponding substrate based on the monitored resistance and / or capacitance measurements, and output the wear rate to a user. For example, referring to FIG. 5, this means that the control unit 508 can be configured to monitor the resistance between two adjacent plate-like conductors 504, determine the wear rate of the multi-layer substrate 502 based on the monitored resistance and / or capacitance, and output the wear rate to a user.

[0072] The effect of smear can be detected using resistance measurements, for example, as described below. Consider device 500 as an example, but the following discussion also applies to devices 100-400. A resistance close to zero means that there is direct contact between adjacent plate-like conductors 504, which is likely caused by the effect of smear (e.g., a metal bridge across the dielectric layer 506 due to the effect of smear). A high resistance means that there is no direct contact between adjacent plate-like conductors 504, and thus suggests that there is no effect of smear across the dielectric layer 506. The capacitance measurements and the resistance measurements allow the on / off state of the effect of smear (i.e., whether a metal bridge across the dielectric layer 506 is formed or not). Furthermore, the capacitance measurements and the resistance measurements also provide several intermediate values ​​(i.e., a continuous measurement signal) that can be used to determine how "strong" the contact caused by the smear is, in other words, how large and continuous the metal bridge is. Generally, the resistance measurements are sufficient for everything, i.e. the wear rate and the effect of smearing can be determined based on the resistance measurements alone (this is because measuring with resistance is much easier than measuring with capacitance), however, the accuracy of detecting the amount of smearing effect can be improved by using the resistance measurements in combination with the capacitance measurements.

[0073] 6A-6C show, in a schematic manner, how resistance measurements can be used to monitor the effect of smearing, which appears as a metal bridge across the dielectric layer 506 of the device 500. The following discussion also applies to the devices 100-400. In the device 500, the inter-conductor spacing is assumed to vary (i.e., increase) from left to right, and the effect of smearing is assumed to appear "evenly" across the (bottom) wear surface. This means that the plate-like conductors 504 in the device 500 are gradually shorted from left to right as the effect of smearing increases (i.e., the plate-like conductors 504 with smaller "gaps" between them are shorted first). The effect of smearing can result, for example, from rough wear being applied to the (bottom) wear surface of the device 500 (such as during machining, chemical mechanical planarization, cutting, grinding, lapping, polishing, or preparation of materialographic samples). The result of the coarse wear is two metal bridges, one connecting the first and second plate conductors 504 and the other connecting the second and third plate conductors 504 (see FIG. 6A). In other words, the first and second plate conductors 504 are shorted and the second and third plate conductors 504 are also shorted, which can be detected by making resistance measurements as described above (i.e. when a resistance close to zero is measured between two adjacent plate conductors 504). The dashed horizontal lines in FIGS. 6A-6C show the assumed depth of the plastic deformation due to wear, in other words the effect of smearing along the wear surface. In FIG. 6B, it is suggested that a fine wear (or polishing) applied to the (bottom) wear surface of the device 500 eliminates the metal bridge between the second and third plate conductors 504. Continued fine wear also eliminates the metal bridge between the first and second plate conductors 504, which is shown in FIG. 6C. Thus, by subjecting the device 500 to fine abrasion after coarse abrasion, the device 500 can be "reset" in the sense that it is ready to be used again in a new abrasion process. Furthermore, the use of varying inter-conductor spacing and different conductor materials allows one to understand how to adjust the parameters (e.g., speed, force, duration, abrasive particle size, etc.) of the material removal process (e.g., grinding or polishing) as needed.

[0074] FIG. 7 illustrates how the device 500 can be implemented in the form of a button-like structure 700. The structure 700 is configured to contain the device 500 within a housing 702 such that the wear surface of the device 500 is aligned with one surface of the housing 702 (e.g., the bottom surface of the housing 702 as shown in FIG. 7). It is assumed that the surface of the housing 702 and the wear surface of the device 500 are subjected to the same wear process (e.g., during machining, chemical mechanical planarization, cutting, grinding, lapping, polishing, or preparation of a materialological specimen). The housing 702 can be fabricated, for example, as a block of epoxy (or other resin) with the device 500 embedded therein, leaving the wear surface of the device 500 exposed on one surface of the epoxy block. In other words, the device 500 can be cast in epoxy (or other resin) to form the structure 700. However, the present disclosure is not limited to this manufacturing technique for the structure 700. In some embodiments, the housing 702 can be implemented as a hollow body with one side having an opening for the wear surface of the device 500, and the device 500 can be mounted inside the hollow body such that its wear surface is located at the opening of the hollow body.

[0075] FIG. 8 shows how the button-like structure 700 can be used in abrasion processes. It is assumed that the plate-like conductor 504 is made of the same material as the specimen 800, or that the plate-like conductor 504 is made of another wear process compatible material, or that the plate-like conductor 504 is made of at least two different wear process compatible materials. The specimen 800 is mounted in the housing 802 in the same or similar manner as the device 500 in the housing 702, and the housings 702 and 802 can have the same or similar dimensions. For example, each of the housings 702 and 802 can be implemented as a block of epoxy (or other resin). In other words, each of the device 500 and the specimen 800 can be cast identically in epoxy (or other resin) to form two similar button-like structures. These structures are then mounted in a specimen holder 804 such that the wear surfaces of the device 500 and the specimen 800 are subjected to the same wear process by using an abrasive disk 806 (or other abrasive or abrasive means such as an abrasive cloth). For example, these structures can be mechanically attached to the sample holder 804 with the possibility of its free rotation (for example provided by a sample moving plate in the preparation of materialological samples) or mechanically fixed without the possibility of free movement (for example provided by a sample holder plate in the preparation of materialological samples). These structures can also be attached to the sample holder 804 using a vacuum or an adhesive (for example used in chemical mechanical planarization). During the polishing process, the user can monitor the degree of smearing effect or the formation of undesired scratches by appropriately performing resistance and / or capacitance measurements with the help of the control unit 508 integrated in the housing 702 and adjust the polishing process appropriately if necessary (for example changing a coarse polishing disc to a fine polishing disc if the former produces a noticeable smearing effect or undesired scratches). For example, the control unit 508 can be equipped with a wireless transceiver unit configured to provide a corresponding signal to the user (for example a mobile phone).

[0076] It should also be noted that the resistance measurement and the capacitance measurement can be used individually or in combination to determine the relative change in moisture content on the wear surface during the wear process. This is relevant for polishing operations where the moisture content on the polishing cloth / surface is measured by utilizing the electrical properties (e.g. dielectric and / or conductive properties) of the polishing suspension. In this case, the resistance measurement can be performed in the same way as described above for the effect of smearing: the polishing suspension reduces the resistance between adjacent conductors (e.g. adjacent plate conductors 504) that contact the wear surface being monitored. By analyzing how the resistance changes during the polishing operation, it is possible to monitor the relative change in moisture content.

[0077] 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 resistance and / or capacitance measured between each two adjacent conductors to the ML algorithm, which can be further configured to predict whether to change the parameters of the abrasion process (e.g., whether to change the type of grinding or polishing from "coarse" to "fine" to speed up the process of materialographic specimen preparation or chemical mechanical planarization, minimize the occurrence of undesirable smearing effects, etc.). For this prediction, the ML model can be pre-trained by using historical data, such as resistance and / or capacitance measurements made in the past for a particular conductor material and a particular inter-conductor spacing.

[0078] 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, comprising: a multi-layer substrate having a wear surface, the multi-layer substrate including an array of plate-shaped conductors and an array of dielectric layers arranged alternately with each other, the wear surface being formed by edges of the plate-shaped conductors of the array of plate-shaped conductors and edges of the dielectric layers of the array of dielectric layers; a control unit coupled to each plate conductor of the array of plate conductors, the control unit being adapted to control the wear surface when wear occurs; monitoring the capacitance and / or resistance between each two adjacent plate conductors of the array of plate conductors; determining a wear rate of the multi-layer substrate based on the monitored capacitance and / or the monitored resistance; outputting the wear rate to a user; A control unit configured as above. A wear detection device comprising:

2. The control unit further comprises: determining whether at least two plate conductors of the array of plate conductors are in direct electrical contact upon wear based on the monitored capacitance and / or the monitored resistance; outputting a signal to the user when the at least two plate conductors of the array of plate conductors come into direct electrical contact upon the wear; The wear detection device according to claim 1 , wherein the wear detection device is configured as follows:

3. 3. A wear detection device according to claim 1 or claim 2, wherein each plate conductor in the array of plate conductors extends perpendicular to the wear surface.

4. A wear detection device according to any one of claims 1 to 3, wherein the array of plate-like conductors has equal inter-conductor spacing.

5. A wear detection device according to any preceding claim, wherein the array of plate-like conductors has a varying inter-conductor spacing.

6. 6. The wear detection device of claim 4 or claim 5, 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.

7. The wear detection device according to any one of claims 1 to 3, wherein the array of plate-shaped conductors includes a first subarray of plate-shaped conductors and a second subarray of plate-shaped conductors, the first subarray of plate-shaped conductors and the second subarray of plate-shaped conductors being non-overlapping, the first subarray of plate-shaped conductors having equal inter-conductor spacing, and the second subarray of plate-shaped conductors having varying inter-conductor spacing.

8. The wear detection device of claim 7, wherein the inter-conductor spacing of each of the first subarray of plate-shaped conductors and the second subarray of plate-shaped 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.

9. The wear detection device according to any one of claims 1 to 3, wherein the array of plate-shaped conductors includes a first subarray of plate-shaped conductors and a second subarray of plate-shaped conductors, the first subarray of plate-shaped conductors and the second subarray of plate-shaped conductors are non-overlapping, the first subarray of plate-shaped conductors has a first equal inter-conductor spacing, and the second subarray of plate-shaped conductors has a second equal inter-conductor spacing, the second equal inter-conductor spacing being different from the first equal inter-conductor spacing.

10. 10. The wear sensing device of claim 9, 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.

11. A wear detection device according to any preceding claim, wherein each plate conductor in the array of plate conductors is made from a ductile material.

12. Each dielectric layer of the array of dielectric layers may be made of glass, silicon, SiO ２ 12. The wear sensing device of any one of claims 1 to 11, 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.

13. The wear detection device according to any one of claims 1 to 12, wherein each plate-shaped conductor in the array of plate-shaped conductors has a width 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.

14. The wear detection device according to any one of claims 1 to 13, further comprising at least one of an accelerometer and a gyroscope on at least one surface of the multi-layer substrate other than the wear surface.

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