136 results about "Contact angle" patented technology

The invention discloses a capillary pressure and contact angle synchronous characterization method and device of a microfluidic fluid interface, and relates to the field of interface analysis and multiphase seepage in pore media, and the method comprises the following steps: based on a pre-configured pore, particle and fluid binary image, distinguishing and extracting a fluid-particle contact interface contour and an attack / defense fluid interface contour; fitting and determining the curvature radius of each fluid interface contour through a watershed region division algorithm and reordering smoothing of Fourier descriptors; generating a multi-level size pore space based on the pore binary image, and obtaining a pore overlook radius; calculating a necking angle in combination with the curvature radius and the multi-stage size pore space to obtain an apparent contact angle and an intrinsic contact angle; and calculating the capillary pressure of the attack / defense fluid interface by combining the curvature radius, the pore overlook radius, the chip depth and the interfacial tension. According to the invention, high-precision technical support is provided for micro-fluidic multiphase seepage research.

The invention relates to the technical field of high polymer material processing and coating, in particular to an acrylic plate antifouling and antibacterial enhancing method based on a nano-composite coating, which comprises the following steps: S1, pretreating the surface of an acrylic plate; s2, preparing a nano composite coating; s3, coating: coating the surface of the acrylic plate with the activated surface with the nano-composite coating liquid, adopting a spin-coating method for coating, determining the spin-coating speed through an early test so as to control the thickness of the coating, checking the uniformity of the coating through vision after coating, and re-coating if non-uniform parts exist, in the coating process, the environment humidity is monitored through a humidity sensor and controlled at a low level so as to prevent coating defects, and the acrylic plate coated with the nano composite coating is obtained; and S4, coating curing. The antifouling and antibacterial effects of the coating are comprehensively evaluated by means of contact angle measurement, dirt adhesion experiments and the like, and the concentration or spin-coating speed of the nano material is adjusted according to a test result, so that the performance of the coating is further optimized.

The invention discloses a method and a device for measuring a dynamic contact angle of liquid on a solid surface. The method comprises the following steps: constructing a to-be-measured system containing a first liquid phase, a fluid phase and a solid phase; immersing the to-be-detected surface of the solid phase in the environment phase upwards or downwards; an end surface object is arranged opposite to the to-be-detected surface, and the two are immersed in the same environment phase; the relative distance and position of the two are adjusted, and a longitudinal fluid bridge is formed through the liquid adding device; the camera device obtains a fluid bridge interface contour image from the side surface; horizontally moving the surface of the end surface object or the solid phase, and applying transverse lateral dragging acting force to the fluid bridge to promote the fluid bridge to deform and contact the peripheral line to move or be about to move; and recording the time sequence change of the image, analyzing and calculating to obtain the time change relationship between the contact angle value and the three-phase contact point position value, and further determining the static, forward and backward contact angles and the contact angle hysteresis value. The method is simple and accurate, has wide applicability, and can cover reliable dynamic contact angle data measurement from hydrophilic to super-hydrophobic surfaces.

The invention belongs to the technical field of oil and gas reservoir engineering and multiphase seepage dynamic monitoring, relates to a characterization method of seepage behaviors of multiphase fluid in a porous medium, and particularly provides a dynamic construction method of a multiphase displacement capillary pressure-saturation relationship based on nuclear magnetic resonance. Comprising the following steps: S1, acquiring a low-field nuclear magnetic resonance relaxation spectrum of a porous medium in a gas-water two-phase displacement process; s2, determining two-phase fluid interfacial tension, a wetting contact angle and a rock surface relaxation rate; s3, determining the dynamic cut-off relaxation time of the displacement stage; s4, calculating equivalent capillary pressure; the residual water saturation is calculated, and the equivalent capillary pressure is the capillary pressure corresponding to the current displacement stage and is used for constructing a capillary pressure-saturation curve. According to the method, the capillary pressure change in the porous medium can be obtained only through spectral analysis without a centrifugal or mercury injection experiment.

This invention relates to the technical field of surface lubrication and friction measurement of machinery, and provides an apparatus and method for measuring the energy barrier at the surface solid-liquid interface of a microstructure. [Solution] The apparatus includes a micro-pump, a fixed elbow, a capillary tube, an upper contact surface, a lower contact surface, a droplet, a micro-movement stage, and a high-speed microscope camera. In this method, the micro-pump transports liquid to form a droplet between the upper and lower contact surfaces, the micro-movement stage is used to drag the lower contact surface at a constant speed to slide the droplet, and the high-speed camera monitors the deflection deformation caused by the droplet drag force of the capillary tube, calculates the dynamic drag force, and integrates the drag force-displacement curve to obtain the energy consumed by the droplet to overcome the microstructure. Finally, the solid-liquid interface energy barrier per unit area is obtained, overcoming the limitations of the conventional contact angle method, which cannot measure the dynamic interface energy barrier, and enabling direct and quantitative measurement of the surface solid-liquid interface energy of the microstructure.

The invention discloses an antistatic ABS material antistatic performance detection and analysis system, and relates to the ABS material antistatic performance detection technology field, and the method comprises the following steps: generating a steady state relative humidity set point sequence at a set temperature, using 60 DEG C gloss and white light interference to quantify surface roughness, and calculating an effective contact area amplification amount; calculating the adsorption wet film coverage based on the contact angle spectrum constant; carrying out four-probe measurement under different electrode relative orientation angles in double processes of humidifying and dehumidifying, and extracting a humidifying threshold value, a dehumidifying threshold value and a lag ratio; and calculating a collaborative percolation threshold index according to the effective contact area amplification amount, the adsorption wet film coverage degree, the direction factor of threshold inversion and the critical connection degree, and giving a passing conclusion of a target humidity interval. According to the method, stable positioning and reliable release judgment of the threshold value of the antistatic ABS material can be realized.

The invention provides an in-situ emulsion surfactant optimization method, and belongs to the technical field of oil and gas field development engineering, and the method comprises the following steps: S1, constructing an emulsion in-situ generated droplet property characterization device; s2, injecting the simulated oil and the surfactant solution into an emulsion in-situ generated droplet property characterization device at a constant speed, preparing an emulsion, and injecting the simulated oil and the surfactant solution at a preset flow ratio and a preset speed; s3, observing the type of the emulsion, and measuring the particle size and the contact angle of the emulsion; and S4, repeating the steps S2 to S3, comparing the emulsifying properties of the surfactants according to types and concentrations, and preferably selecting the type and concentration of the oil displacement surfactant suitable for reservoir in-situ oil. According to the method, the process that in-situ emulsion generates liquid drops under the reservoir condition is simulated, the properties of the liquid drops of the in-situ emulsion are quantitatively represented, and the surfactant suitable for the reservoir is preferably selected.

The invention belongs to the technical field of surface modification, and particularly relates to a super-hydrophobic insulating coating with a surface microstructure and a preparation method and application of the super-hydrophobic insulating coating. The defects of poor environmental stability, low regulation and control precision, insulation performance attenuation and the like in the prior art are overcome, the static contact angle of the disclosed super-hydrophobic insulation coating is larger than or equal to 150 degrees, the rolling angle is smaller than or equal to 5 degrees, meanwhile, the insulation strength is larger than or equal to 90% of that of an original substrate (the breakdown field strength is larger than or equal to 20 kV / mm), and collaborative optimization of the super-hydrophobic performance and the insulation performance is achieved; moreover, after the coating is naturally aged outdoors for 3 years, the contact angle change rate is smaller than or equal to 10%, the insulation strength attenuation rate is smaller than or equal to 8%, and the long-term environmental stability of the super-hydrophobic insulating coating is effectively improved. A precise regulation and control mechanism is also established based on a molecular dynamics simulation-based low-droplet adhesion microstructure insulation surface design method, so that the droplet contact time is reduced by more than 60% compared with a flat surface, the instantaneous leakage current is reduced by 40%-60%, and the method not only adapts to a polluted environment with the temperature range of-40 DEG C to 180 DEG C and the salt mist concentration of less than or equal to 0.5 mg / m, but also meets the preparation requirements of power equipment with complex shapes.

The invention discloses an optimal selection method of a surfactant for an oil reservoir, and belongs to the technical field of oil development. The optimal selection method comprises the following steps: preparing N pretreated parallel plunger samples, displacing a simulated oil layer with crude oil, aging the plunger samples under a formation condition until the plunger samples reach the wettability of an oil reservoir, and sampling and measuring an initial contact angle; performing oil displacement on the N aged plunger samples by using N surfactants to obtain corresponding oil displacement efficiency, and sampling and measuring a contact angle; comprehensive indexes are calculated based on the oil displacement efficiency, the contact angle and the initial contact angle, and the surfactants are sorted according to the comprehensive indexes. According to the method, a parallel plunger sample is selected to carry out an oil displacement efficiency experiment by adopting different surfactants in a simulated oil layer state, the performance of the surfactant is evaluated based on the oil displacement efficiency experiment and indexes such as wettability and oil displacement efficiency obtained before and after oil displacement implementation, finally a comprehensive index is selected, and the surfactant is preferably selected based on the comprehensive index.

The invention discloses a transient contact angle calculation method for an angular contact ball bearing. The method comprises the following steps: constructing an angular contact ball bearing model; performing simulation by using the angular contact ball bearing model to obtain a contact stress distribution diagram; identifying a typical elliptical contact area in the contact stress distribution diagram, and calibrating a contact center of the typical elliptical contact area; extracting a sphere center coordinate and a bearing geometric center coordinate of the angular contact ball bearing model, and jointly constructing a first vector from the sphere center to the contact center and a second vector from the bearing geometric center to the sphere center with the coordinate of the contact center; and according to a space vector included angle formula, calculating an included angle between the first vector and the second vector as a transient contact angle and outputting the transient contact angle. The invention further provides a transient contact angle calculation device. The method provided by the invention can solve the problems of difficult measurement, insufficient calculation precision, poor adaptability and the like in the existing contact angle evaluation means.

The application is suitable for the technical field of machine tool combination assembly, and provides a micro contact joint surface static friction coefficient calculation method, which comprises the following steps: obtaining joint surface characteristic parameters; based on fractal theory and elastic theory, constructing base additional deformation and micro convex body normal deformation equation, through micro stress analysis, establishing single micro convex body deformation geometric parameters; considering three deformation stages of micro convex body, obtaining joint surface contact area and contact load; using modified island distribution function to integrate joint surface real contact area and contact load in different deformation stages, obtaining joint surface real contact area and contact load; considering the influence of static friction coefficient on contact surface characteristics, establishing joint surface static friction coefficient model. The application establishes surface static friction coefficient model from the micro contact angle, and simultaneously considers the interaction of micro convex body and base and three stages of material elastic, elastic-plastic and complete plastic deformation.

The invention provides a method for analyzing the wetting behavior of a liquid drop on a rough solid surface under the action of an electric field, and the method comprises the following steps: S1, building an initial simulation system and a simulation model based on a research and information collection result; s2, configuring operation parameters of the simulation model, and executing simulation calculation; s3, in the molecular dynamics simulation process, applying electric fields with different intensities, and monitoring the state change of the simulation system until the simulation system reaches dynamic balance; and S4, exporting the calculation data in the dynamic balance state, and carrying out visualization processing and data analysis on the calculation data to summarize the internal law of the calculation data. Influences of electric field intensity and roughness factors on complex electrowetting are described through a contact angle and some interface characteristics, and an electrowetting expansion mechanism of micro-nano liquid drops on a rough wall surface is explained from a microscopic perspective.

The invention relates to the technical field of crystal structure prediction, and discloses a quantum algorithm-based energetic CxNyOz crystal structure prediction method, which comprises the following steps of: calculating an evaporation and diffusion dimensionless number and capillary pressure by obtaining surface tension, a contact angle, a geometric feature scale, temperature, partial pressure, a diffusion coefficient and an evaporation rate; establishing a residual solvent mole fraction and solvent chemical potential sequence; constructing a binary layer occupancy model Hamiltonian containing layer occupancy energy, adjacent layer action energy, a capillary pressure volume term and a molecular polarity action term, and obtaining a hierarchical occupancy number by using a quantum approximation optimization algorithm; calculating interlayer respiration and shear frequency and mode volume sensitivity based on a quantum variation algorithm; and finally, the lattice spacing and the prediction result are obtained through cost functional minimization, and accurate prediction and quantitative analysis of the structure of the energetic crystal under the unbalanced desolvation condition are realized.

This invention discloses a method for predicting the volume of fracturing fluid in shale oil, comprising the following steps: Step 1, processing downhole rock samples or outcrops from the same stratum of the shale oil reservoir into standard cores, testing the microstructure of the standard rock samples, obtaining the pore parameters of the standard cores, and conducting wetting contact angle tests; Step 2, conducting spontaneous absorption experiments on the standard cores and calculating the field-scale absorption area; Step 3, establishing a multi-scale pore absorption model based on the rock microstructure and the characteristic parameters obtained from the spontaneous absorption experiments, and calculating the absorption volume using the multi-scale pore absorption model. This invention can achieve quantitative calculation of the volumetric fracturing absorption volume in shale oil horizontal wells.

Provided is a base material film for forming an inorganic thin film layer, wherein: a surface treatment is performed on at least one surface of a base material film that contains a polypropylene-based resin as a main component; with respect to contact angle with water of the base material film, the ratio (C1 / C2) of the contact angle (C1) with water of an untreated surface to the contact angle (C2) with water of a treated surface is 1.4 or more; and the ten-point average roughness (Rzjis) of the surface of the base material film is 15 nm or less.

The invention discloses a water contact angle prediction method, a control system, a storage medium and electronic equipment, and belongs to the field of material surface property prediction.The water contact angle prediction method comprises the steps that image data are acquired, water contact angle data are recognized according to the image data, and a prediction model is established according to the water contact angle data; setting a target range of the water contact angle data, and calculating a water contact angle predicted value and an experimental parameter predicted value according to the prediction model; performing an experiment according to the experiment parameter predicted value, calculating a difference value between the water contact angle data of the experiment and the water contact angle predicted value, judging whether the difference value exceeds a preset angle error or not, and if yes, re-establishing a prediction model; by analyzing the relationship between experimental parameters and water contact angle data and establishing a prediction model, the change of the water contact angle under different experimental conditions can be rapidly predicted, a researcher or a producer is helped to optimize experimental design, accurate control over the water contact angle is achieved, and the material performance and the production efficiency are effectively improved.

The invention relates to the technical field of superconducting magnet manufacturing and process simulation, and discloses a prediction method, a recommendation method, a device, equipment and a medium for a resin filling process, the method comprises the following steps: obtaining first fluid parameters and first structure parameters, the first fluid parameters comprise resin density, viscosity, surface tension and contact angle, and the first structure parameters comprise the resin density, the viscosity, the surface tension and the contact angle; the first structure parameters comprise the porosity and the permeability of the resin filling area; converting the first fluid parameter and the first structure parameter into a first static feature vector; inputting the first static feature vector into a target neural network model, and determining a power function parameter according to the output of the target neural network model; according to the power function parameters, a resin filling curve is determined, and the resin filling curve is a curve with the filling proportion changing along with time and is used for predicting the resin filling process in the vacuum pressure impregnation technological process. The complete filling curve can be directly output through neural network prediction, and the prediction accuracy and the prediction efficiency are improved.

The invention discloses a water lubricated bearing rubber interface contact angle numerical simulation system based on a bionic microstructure, and relates to the technical field of mechanical engineering and fluid mechanics, and the system comprises a bionic microstructure parameter module which obtains geometric parameters such as the shape and depth of the microstructure; the multi-physics field coupling calculation module is used for constructing a fluid-solid-heat-electricity four-field bidirectional coupling model, and synchronously calculating a lubricating water flow field, a rubber solid field, a friction heat field, an interface electric field, correction water viscosity, a rubber elastic modulus and interface surface energy in combination with a Navier-Stokes equation, a rubber superelasticity constitutive model and the like; the contact angle solving module is used for solving a dynamic contact angle and a lag amount based on the multi-field parameters, a VOF model and a dynamic contact angle constitutive equation; and the result output module is used for outputting the parameters, the multi-field cloud picture and the contact angle change curve. The simulation precision is improved, data support is provided for water lubricated bearing bionic structure optimization, and the environment-friendly lubrication requirement is met.

The invention relates to the technical field of measurement, and provides a textile dynamic composite environment waterproof performance test method and system, and the method comprises the following steps: constructing a dynamic test environment, and setting corresponding test parameters; fixing the textile sample on a test platform, and applying a plurality of different acting forces; monitoring the water contact angle, the water permeation amount and the water repellent duration in real time; and acquiring a comprehensive evaluation index according to the monitored water contact angle, the water permeation amount and the water repellent duration, and evaluating the waterproof performance of the textile according to the comprehensive evaluation index. The comprehensive evaluation index is obtained according to the monitored water contact angle, the water permeation amount and the water repellency duration, the waterproof performance of the textile is evaluated according to the comprehensive evaluation index, the waterproof performance of the textile can be comprehensively measured, quantifiable comprehensive evaluation of the waterproof performance of the textile in a dynamic composite environment is achieved, and the waterproof performance of the textile is evaluated. And the limitation that the test dimension is relatively single in the traditional static test of the waterproof performance of the textile is overcome.

An object of this disclosure is a film-coated glass in which a contact angle with an aqueous content is large, transparency is high, lubricating properties (gliding properties) are excellent, peeling (delamination) of a silica component in the glass is less likely to occur, elution of a glass-derived component (silicon, boron, sodium, potassium, and aluminum) with respect to the contents is less likely to occur, aggregation (adsorption) of a protein that is an active component of a medicinal product is less likely to occur when the film-coated glass fits a medical glass container, heat resistance is exhibited, and peeling of a film-coated glass is suppressed, a method of production therefor, and a modified glass substrate.The coated film-adhered glass (1) according to this disclosure includes a glass substrate (2) and a coating film (3) provided over at least a portion of a surface (2a) of the glass substrate (2), wherein a region of the surface (2a) of the glass substrate (2) on the side of the coating film (3) to a predetermined depth (d1) is a modified layer (4), and the modified layer (4) has a microcrystalline structure at least in part.

The invention relates to the technical field of alcohol detection, in particular to a preparation method of a metal-based energy-consumption-free alcohol detection material and an application method of the metal-based energy-consumption-free alcohol detection material in alcohol concentration detection and alcohol molecule recognition. A continuous groove micro-nano structure is machined on the surface of a substrate material, chemical composition is changed, and the continuous groove micro-nano structure comprises a plurality of grooves with preset widths, perpendicular to the length direction, in a laser processing area with the preset length; the depth of the groove is 8-12 microns, and the width of the groove is 30-40 microns; the alcohol concentration can be identified according to the diffusion length of alcohol on the surface, and meanwhile whether gas contains alcohol or not can be detected by changing the surface contact angle and the rolling angle. The substrate material is convenient and rapid to prepare and low in cost, and the method for detecting the alcohol concentration and identifying the alcohol molecules is simple to operate, saves a detection solvent and is short in time consumption.

This invention relates to the field of unconventional oil and gas field development technology, specifically to a method for determining dynamic capillary force in coal and rock. The method includes: selecting target core samples to prepare coal samples and obtaining the full-scale pore size distribution of the coal samples; constructing a three-dimensional random pore network model based on the full-scale pore size distribution; obtaining a topology-corrected static pore network model; establishing a dynamic model of contact angle variation with pore pressure; establishing dynamic deformation equations for pore and throat radii variation with effective stress; and simulating the gas-driven water process under different pore pressures based on an intrusion permeation algorithm, outputting capillary force-saturation curves under different pore pressure conditions, and forming a dynamic capillary force surface plot. This application has significant application value and promising prospects in the field of unconventional oil and gas field development, significantly improving the scientific nature of reservoir seepage behavior characterization and the rationality of development engineering decisions.

The application belongs to the field of rock physics and geophysical exploration, and relates to a simulation method for wettability affecting dispersion and attenuation of partially saturated sandstone, which comprises the following steps: S1. establishing a relationship between capillary pressure and water saturation for wettability correction; S2. calculating equivalent pore throat radius and effective permeability according to the relationship between capillary pressure and water saturation; S3. calculating characteristic frequency and complex bulk modulus under different wettability conditions based on a partially saturated patchy medium model; S4. simulating and comparing the characteristics of longitudinal wave velocity and attenuation under different wettability and water saturation conditions, analyzing the modulation law of frequency-dependent acoustic response caused by wettability change, and realizing quantitative characterization of the wettability effect. The step-by-step modeling method proposed in the application, combined with the wettability correction parameter represented by the contact angle, can systematically calculate the continuous coupling process from capillary pressure to equivalent pore throat structure and equivalent permeability to acoustic response, and realize quantitative analysis of the wettability change on the dispersion and attenuation law.

The method for measuring the distribution and evolution characteristics of gas-water-oil three-phase contact angle in oil reservoir porous media belongs to the technical field of oil and gas exploitation and wettability measurement. The method is based on micro-nano CT imaging technology, through three-phase fluid seepage experiment, micro-nano CT scanning, CT image processing and analysis, and finally the statistical distribution characteristics of gas-water-oil three-phase contact angle in oil reservoir porous media under different flow states are obtained. By real-time acquisition of the interface state in the seepage process, in-situ, real and efficient measurement of three-phase contact angle is realized, which can reveal the seepage-induced wettability transition and local wettability reversal phenomenon. The fine division of water-wet, oil-wet and gas-wet pore space in oil reservoir porous media can be realized; the measurement results can provide reliable wettability data for pore-scale multiphase seepage simulation. Since the measurement results are the statistical characteristics of a large number of local contact angles, the authenticity and statistical accuracy of the contact angle measurement are significantly improved.

The invention discloses a PVA optical film casting solution with excellent stripping performance and an evaluation method thereof, and belongs to the technical field of polaroids. The invention relates to a PVA optical film casting solution with excellent stripping performance. The PVA optical film casting solution comprises polyvinyl alcohol, a solvent, a plasticizer and a surfactant, the evaluation method comprises the five steps of test preparation, coating, observation and recording calculation and characterization. A series of membrane casting liquid formulas and performance basic indexes are provided, the membrane casting liquid of different formulas can be rapidly screened, and the membrane casting liquid obtained based on the indexes has good stripping performance; the stripping performance evaluation method based on the combination of laboratory film coating machine film stripping time measurement and contact angle test is provided. The method simulates the production line working condition of stripping of the film and the roller, is simple and convenient to operate, has high efficiency and accuracy, and provides a reliable basis for optimization of a casting solution formula.

Provided is a resin composition capable of suppressing bleeding on a ceramic substrate during thermal curing.　This resin composition comprises: (A) an epoxy resin; (B) a curing agent; and (C) a rheology controlling agent, the component (C) satisfying the feature (1). Feature (1): When 1 μL of a composition containing 99 g of a bisphenol F epoxy resin and 1 g of the component (C) is formed at the tip of a Cathelin needle at room temperature, and the contact angle θ1 measured 6 seconds after droplet deposition on a ceramic substrate is taken as 100%, the contact angle θ3 measured 5 minutes after the droplet deposition is 88%-100%.

This invention discloses a method for rapidly measuring the surface wettability of mineral particles based on low-field nuclear magnetic resonance (NMR), belonging to the field of wettability measurement technology. This invention uses the seated drop method to test the contact angles of some energy, metallic, and non-metallic mineral particles, then obtains the T2 relaxation spectrum through low-field NMR testing, and finally obtains the T2 weighted average value T for different wetting times. 2g The value was calculated, and T was calculated for different wetting times. 2g The slope value k of the linear function was obtained by performing a linear quantitative fitting between the value and the wetting time. T2g Then k T2g k is obtained by performing a first-order linear fit with the corresponding mineral particle contact angle θ. T2g The relationship between the contact angle θ and the wettability of the mineral particles being tested is expressed as k. T2g The wettability of mineral particles is obtained from the relationship between the contact angle θ and the T2 weighted average value. The linear model established in this invention, which relates the slope of the wetting time fitting function to the contact angle, is accurate and reliable. It can complete the evaluation of the wettability of mineral particle surfaces in just 3 minutes, and has the advantages of being fast and efficient.

The invention discloses a liquid drop dynamic three-dimensional shape measuring method and system, relates to the technical field of interface science and engineering, and aims to improve the accuracy of liquid drop measurement, and the liquid drop dynamic three-dimensional shape measuring method comprises the following steps: obtaining a top view image and a side view image of a liquid drop; based on the side view image, a base line of the liquid drop and a side contour line of the liquid drop are determined, and the base line is a line where the liquid drop makes contact with a substrate bearing the liquid drop; based on the color value of each pixel point in the top view image, obtaining a top view contour line of the liquid drop, and determining the length and the width of the liquid drop according to the top view contour line; based on the length and width of the liquid drop and the side contour line, performing three-dimensional reconstruction on the liquid drop to obtain a three-dimensional model of the liquid drop; and based on the three-dimensional model and a substrate plane corresponding to the base line, obtaining a contact angle of a contact point where the liquid drop is in contact with the substrate plane.

The purpose of the present invention is to provide a tape for protecting the front surface of a wafer, which can sufficiently fill irregularities on the front surface of the wafer and can be removed without damaging the wafer after grinding of the back surface of the wafer. The purpose is achieved by: a tape that is for protecting, during grinding of the back surface of a wafer having irregularities on the front surface, the front surface of the wafer and that comprises a base material layer and a thermoplastic resin layer, which is in contact with the wafer on the surface opposite to the side on which the base material layer is positioned, the O / C on said surface, obtained by ESCA, being 18x10-3-54x10-3; and a tape that is for protecting, during grinding of the back surface of a wafer having irregularities on the front surface, the front surface of the wafer and that comprises a base material layer and a thermoplastic resin layer, which is in contact with the wafer on the surface opposite to the side on which the base material layer is positioned, the water contact angle on said surface being 90-103°.

The invention relates to the technical field of semiconductor processing, and provides a silicon wafer edge surface pollution type detection method comprising the following steps: obtaining a silicon wafer slice comprising a to-be-detected area; measuring the contact angle between the to-be-measured area and the aqueous liquid through a seat drop method to obtain an actual test value of the contact angle of the to-be-measured area, and recording the actual test value as theta a; taking a standard clean silicon wafer and repeating the steps to obtain a contact angle theta0 of the standard clean silicon wafer; calculating to obtain a calibration value theta b of the contact angle of the to-be-measured area; comparing thetab with theta0; and judging the pollution type. According to the detection method, the influence of measurement environment difference on the contact angle can be eliminated, the problem of measurement deviation caused by measurement temperature and roughness difference on the edge of the silicon wafer is solved, and rapid and accurate judgment of metal / organic matter pollution types is realized.