Tungsten wire detection method

Abstract

The application discloses a tungsten wire detection method, and belongs to the technical field of tungsten wire detection. The method comprises the following steps: bonding multiple tungsten wires into a wire bundle sample; embedding the wire bundle sample in a mold hole of a mold, with the wire bundle sample being perpendicular to the surface of the mold; adding a cold-embedding solution into the mold and closing the mold; opening the mold after waiting for 1-3 hours and taking out the wire bundle sample; polishing the wire bundle sample, with the polishing mesh number being from 400 mesh to 5000 mesh; performing electron microscope scanning and energy spectrum analysis on the cross section of the wire bundle sample; and determining that the shear resistance and the split resistance of the tungsten wire are good when the proportion of the tungsten wires that are split and broken is within 10%; and determining that the fracture resistance of the tungsten wire is good when the proportions of C elements and O elements are within 8%. The application can directly observe the defects of the cross section of the tungsten wire through a scanning electron microscope, can determine the shear resistance by observing whether the cross section of the tungsten wire is broken through polishing, can analyze the composition elements of the raw material bus through energy spectrum, and can determine the advantages and disadvantages of the tungsten wire drawing process through the proportions of the elements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tungsten wire detection, in particular to a tungsten wire detection method. BACKGROUND

[0002] In the application field of diamond wire, the tungsten wire diamond wire penetration rate gradually increases, about 30% in 2024, and the demand will maintain high growth in the next two to three years. According to the tungsten production release situation and the application of tungsten wire diamond wire in N-type silicon wafer, it is predicted that the tungsten wire penetration rate will be about 50% in 2025; the market space growth rate will be nearly 90% in 2025 / 2026; tungsten wire busbar instead of carbon steel wire busbar will become the mainstream of subsequent diamond wire.

[0003] The current tungsten wire busbar detection mainly includes diameter, breaking force, circle diameter and appearance detection, and the internal shear resistance and internal defects of the tungsten wire cannot be directly indicated, and the missed detection of unqualified tungsten wire busbar will lead to wire breakage in the diamond wire production process, resulting in cost loss. Therefore, strengthening the detection of tungsten wire busbar in the detection process can effectively reduce the cost and resource waste.

[0004] Therefore, a new technical solution is needed to solve the above technical problems. SUMMARY

[0005] The purpose of the present application is to provide a tungsten wire detection method to solve the problem that the performance of the tungsten wire in the prior art cannot be directly detected.

[0006] To achieve the above purpose, the following technical means are adopted in the present application:

[0007] A tungsten wire detection method, comprising the following steps:

[0008] Step 1: stick multiple tungsten wires into a wire bundle sample;

[0009] Step 2: embed the wire bundle sample of step 1 in the mold hole of a mold, the wire bundle sample is perpendicular to the surface of the mold, add cold-embedding solution in the mold and close the mold, wait for 1-3 hours and then open the mold to take out the wire bundle sample;

[0010] Step 3: polish the wire bundle sample, the polishing grit is from 400 grit to 5000 grit;

[0011] Step 4: perform electron microscope scanning and energy spectrum analysis on the cross section of the wire bundle sample polished in step 3, if the proportion of the surface split and broken tungsten wires in the wire bundle sample is within 10%, it is determined that the internal shear resistance and split resistance of the tungsten wire are good, and if the proportion of C element and O element is within 8%, it is determined that the breaking resistance of the tungsten wire is good.

[0012] The metallographic detection method of the application directly observes the defects of the tungsten wire cross section through a scanning electron microscope, judges the shear resistance by observing whether the tungsten wire cross section is broken through polishing, analyzes the composition elements of the raw bus through energy spectrum, and judges the advantages and disadvantages of the tungsten wire drawing process through the proportion of each element.

[0013] As a further improvement, in step 1, the tungsten wire is cut into segments, each segment is equal in length, and each segment is bonded into a bundle with glue.

[0014] As a further improvement, the number of tungsten wires in the wire bundle sample is not less than 8.

[0015] As a further improvement, the hole diameter of the mold hole is slightly larger than the diameter of the wire bundle sample.

[0016] As a further improvement, the cold inlay solution is composed of acrylic powder and metallographic glue, and the volume ratio of the acrylic powder and the metallographic glue is 1:2-5:1.

[0017] As a further improvement, the volume ratio of the acrylic powder and the metallographic glue is 2:3.

[0018] As a further improvement, the preparation of the cold inlay solution includes the following steps:

[0019] First, add 20ml of acrylic powder to a 50ml beaker;

[0020] Then add 20ml of metallographic glue and stir evenly;

[0021] Then add 10ml of metallographic glue, and the prepared solution is a gel-like liquid.

[0022] As a further improvement, in step 3, the polishing time of different grits of sandpaper is not less than 5 minutes, and the polishing direction is changed after replacing the sandpaper, so that the surface grinding marks of the wire bundle sample are shallower.

[0023] As a further improvement, in step 3, 1.5um diamond polishing paste is used for polishing during the polishing process, and the polishing time is not less than 30 minutes.

[0024] As a further improvement, it further includes step 5: distinguish the tungsten wire bus and the plating layer by electron microscope scanning, draw two straight lines at the bus circle arc, draw the perpendicular bisector respectively to determine the bus circle center, and then mark the bus radius and the finished product line radius through the circle center respectively, and the plating layer thickness can be obtained by subtraction.

[0025] Compared with the prior art, the tungsten wire detection method has the following technical effects: the tungsten wire detection method directly observes the defects of the tungsten wire cross section through a scanning electron microscope, judges the shear resistance by observing whether the tungsten wire cross section is broken through polishing, analyzes the composition elements of the incoming bus through energy spectrum, and judges the advantages and disadvantages of the tungsten wire drawing process through the proportion of each element; and the method is also suitable for detecting the plating layer thickness of the electroplated diamond wire product. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0027] Figure 1 A flowchart of the tungsten wire detection method is shown;

[0028] Figure 2 A flowchart of the tungsten wire detection method is shown;

[0029] Figure 3 An electron microscope pre-treatment conductive adhesive diagram of the tungsten wire detection method is shown;

[0030] Figure 4 A different sample electron microscope result diagram of the tungsten wire detection method is shown;

[0031] Figure 5 A tungsten wire line metallographic thickness measurement diagram of the tungsten wire detection method is shown.

[0032] Main element symbol explanation:

[0033] 1-wire harness sample; 2-conductive adhesive. DETAILED DESCRIPTION

[0034] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation on the present application.

[0035] A tungsten wire detection method, comprising the following steps:

[0036] Step 1, a plurality of tungsten wire lines are adhered into a wire harness sample;

[0037] Step 2, the wire harness sample of step 1 is embedded in the mold hole of the mold, the wire harness sample is perpendicular to the surface of the mold, a cold embedding solution is added in the mold and the mold is closed, and the wire harness sample is taken out after the mold is opened after waiting for 1-3 hours;

[0038] Step 3, the wire harness sample is polished, and the polishing mesh number is from 400 mesh to 5000 mesh;

[0039] Step 4, the cross section of the wire harness sample polished in step 3 is scanned by an electron microscope and analyzed by energy spectrum, if the proportion of the surface fork and the broken tungsten wire in the wire harness sample is within 10%, it is determined that the internal shear resistance and the split resistance of the tungsten wire are good, and if the proportion of C element and O element is within 8%, it is determined that the fracture resistance of the tungsten wire is good.

[0040] The metallographic detection method of the application directly observes the defects of the tungsten wire cross section by a scanning electron microscope, judges the shear resistance by observing whether the tungsten wire cross section is broken in a polishing manner, analyzes the composition elements of the incoming bus by an energy spectrum, and judges the advantages and disadvantages of the tungsten wire drawing process by the proportion of each element.

[0041] Embodiment

[0042] The application provides a tungsten wire detection method for performance detection of tungsten wire and element composition detection of tungsten wire.

[0043] More specifically, referring to Figure 1 , the tungsten wire detection method comprises the following steps:

[0044] Step S101, a plurality of tungsten wires are adhered into a wire harness sample;

[0045] Step S102, the wire harness sample of step 1 is embedded in the mold hole of the mold, the wire harness sample is perpendicular to the surface of the mold, a cold embedding solution is added in the mold and the mold is closed, and the wire harness sample is taken out after the mold is opened after waiting for 1-3 hours;

[0046] Step S103, the wire harness sample is polished, and the polishing mesh number is from 400 mesh to 5000 mesh;

[0047] Step S104, the cross section of the wire harness sample polished in step 3 is scanned by an electron microscope and analyzed by energy spectrum, if the proportion of the surface fork and the broken tungsten wire in the wire harness sample is within 10%, it is determined that the internal shear resistance and the split resistance of the tungsten wire are good, and if the proportion of C element and O element is within 8%, it is determined that the fracture resistance of the tungsten wire is good.

[0048] More specifically, referring to Figure 2The segmenting of the tungsten wire in step 1 is to cut the tungsten wire into segments of the same length, and it is necessary to ensure that the length of each segment of the tungsten wire is consistent and presents a straight line; preferably, the number of segments is preferably 8-40 to meet the requirement of electrical conductivity, more preferably, the number of segments is preferably 10-20, and 10 segments are used for illustration in the embodiment.

[0049] More specifically, refer to Figure 2 In step 1, the plurality of segmented tungsten wires are bonded into a bundle, which aims to bond the small segmented tungsten wires into a bundle by glue, which is beneficial to subsequent scanning electron microscope observation and improves the electrical conductivity, wherein the glue can be selected from 502 glue or other glue, and 502 glue is preferred. Preferably, during the bonding process, it is necessary to ensure that each tungsten wire is only bonded and the gap between the wires is minimized, and the bonded tungsten wire bundle sample presents a straight line shape.

[0050] More specifically, refer to Figure 2 In step 2, the metallographic cold inlay mainly inlays the bundle-shaped tungsten wire bundle sample in the resin through an inlay machine. In the cold inlay process, an inlay machine, an inlay mold, resin powder and metallographic glue are mainly used, and the volume ratio of the resin powder and the metallographic glue is 1:2-5:1. The resin powder is preferably acrylic powder, and the volume ratio of the acrylic powder and the metallographic glue is 2:3. If it is necessary to accelerate the solidification speed, it is necessary to increase the volume ratio of the acrylic powder and the metallographic glue. However, too high volume ratio of the acrylic powder and the metallographic glue will have adverse effects on subsequent electron microscope scanning. After numerous repeated experiments, the best volume ratio of the acrylic powder and the metallographic glue is 2:3, which can solidify in a proper time and does not have adverse effects on the test results.

[0051] The inlay process mainly includes mold fixing, wire bundle sample fixing, inlay solution preparation, inlay machine mold closing and mold opening and taking out.

[0052] First, the inlay mold is fixed on the inlay machine, a small hole is drilled in the center of the inlay mold, the hole diameter is slightly larger than the diameter of the tungsten wire bundle sample; then the tungsten wire bundle sample is inserted through the inlay mold, the tungsten wire of the wire bundle sample is perpendicular to the surface of the inlay mold, and it is ensured that the wire bundle sample is inlaid in the middle position of the inlay mold; the gap at the bottom of the inlay mold is filled with 502 glue to avoid material leakage during mold closing; 20ml of acrylic powder is first added to a 50ml beaker, then 20ml of metallographic glue is added, and after stirring evenly, 10ml of metallographic glue is added, and the stirred solution is a gel-like liquid metallographic solution; pour the prepared metallographic solution into the inlay mold, and take out after the inlay machine is closed for 1 hour. The time waiting for opening the mold is inversely proportional to the volume ratio of high acrylic powder and metallographic glue, that is, the larger the volume ratio of high acrylic powder and metallographic glue, the shorter the time waiting for opening the mold. The specification of the inlay mold is designed according to the size of the scanning electron microscope, and the radius and height can be freely selected, wherein the inlay mold is preferably a cylindrical mold with a radius of 30mm and a height of 30mm.

[0053] At present, the metallographic glue adopts epoxy glue, and the curing time of the current epoxy glue is still relatively long. In order to improve the time efficiency of detection, preferably, the metallographic glue adopts a high-efficiency metallographic inlay solidification glue, which is composed of the following components: bisphenol A epoxy resin 30 parts, ethyl acetate 60 parts, polymerization inhibitor 0.2 parts, and single-multiple functional active diluent 9.8 parts. The steps for making are as follows: mix the above-mentioned bisphenol A epoxy resin 30 parts, ethyl acetate 60 parts, polymerization inhibitor 0.2 parts and single-multiple functional active diluent 9.8 parts, seal and shake evenly at room temperature. The solidification time of the metallographic inlay solidification glue will be shortened to within 40 minutes, and the light transmittance after solidification can be as high as more than 99%.

[0054] More specifically, the polishing of the wire bundle sample is based on the material science metallographic polishing, the polishing mesh number is from 400 mesh to 5000 mesh, and the polishing is mainly carried out on the polishing machine. Each type of sandpaper needs to be polished for at least 5 minutes, and the polishing direction needs to be changed after replacing the sandpaper, so that the surface grinding mark of the metallographic sample is shallow.

[0055] First, polish for 10 minutes with 400 mesh sandpaper, polish the surface of the wire bundle sample flat, without any small pits or protrusions; second, polish for 5 minutes on 800 mesh sandpaper, ensure that the polished surface of the wire bundle sample is flat and smooth during polishing; subsequently polish for 5 minutes on 1500 mesh sandpaper to improve polishing accuracy; continue to polish for 5 minutes with 3000 mesh sandpaper to further improve the smoothness of the wire bundle sample surface; finally, polish for 5 minutes with 5000 mesh sandpaper to complete the polishing process.

[0056] After polishing, polish with 1.5um polishing paste on polishing cloth, and the polishing time is 30 minutes; the surface of the bundle sample after polishing is smooth and has high smoothness; after polishing, observe the grinding marks on the surface of the tungsten wire in the metallographic bundle sample by optical microscope, and re-polish if the grinding marks are too deep.

[0057] More specifically, refer to Figure 3 , the scanning electron microscope scanning and energy spectrum analysis in step 4 mainly include electron microscope sample preparation, electron microscope observation and result review; the process of electron microscope sample preparation mainly includes pasting conductive glue 2 on the bundle sample 1 after polishing, and the conductive glue 2 is pasted on the measurement surface of the bundle sample 1 and distributed around the cross section of the tungsten wire of the bundle sample 1, which cannot block the cross section of the tungsten wire of the bundle sample 1, wherein the conductive glue 2 is around the tungsten wire of the bundle sample 1, which aims to increase the conductivity of the bundle sample 1 and accurately locate the position of the tungsten wire. In the process of electron microscope observation, the brightness and contrast of the electron microscope need to be adjusted to ensure that the cross section of the tungsten wire can be clearly observed, and the tungsten wire cross section picture is taken and energy spectrum is analyzed; in the result review process, the shear resistance and split resistance of the tungsten wire are mainly judged by observing the proportion of the tungsten wire with surface split and fracture, and if the proportion reaches 10%, it is considered that the shear resistance and split resistance of the tungsten wire are unqualified, and the batch of tungsten wire is unqualified. In the process of scanning electron microscope measurement, the energy spectrum analysis adopts the mode of surface scanning, and the electron microscope mode adopts the mode of backscattering.

[0058] In the energy spectrum analysis, the proportions of W, C and O elements are mainly analyzed to judge the advantages and disadvantages of the tungsten wire. Among them, the existence of C and O elements greatly increases the concentration of W vacancy defects, and the oxides, tungsten carbide and nitrides in the tungsten wire precipitate in the grain boundary, weaken the grain boundary effect, cause various obstacles to dislocation movement, and promote crack formation; C and O elements are enriched at the fracture of the tungsten wire, which are the main grain boundary impurities of tungsten and the basic reason for the brittle fracture of tungsten.

[0059] Therefore, the fracture resistance is mainly reflected in the element proportion of C and O elements in the energy spectrum interval. Taking the content of C and O elements in Xiamen Tungsten as the standard, if the total content of C and O elements is less than or equal to 5%, it is considered excellent; if it is 5%-8%, it is considered good; if it is higher than 8%, it is considered unqualified.

[0060] Please refer to Figure 4 , the following two examples are used for comparison and illustration:

[0061] In Example 1, tungsten busbars from two different manufacturers were analyzed. The results showed that sample 1 had 5 torn tungsten wires and a total of 15 embedded wires, accounting for 33.3% of the torn wires, and was considered an unqualified product; sample 2 had 0 torn tungsten wires and was considered excellent; the energy spectrum results of the samples before and after are shown in the table. The carbon and oxygen elements accounted for 5.04% of sample 1, which was judged to be good; the carbon and oxygen elements accounted for 4.27% of sample 2, which was judged to be excellent.

[0062]

[0063] Based on Example 1, the incoming tungsten wires were screened. As shown in the table below, batch 1 did not include the quality inspection method of the present invention, and the wire breakage rate was 10.3%; batch 2 included the quality inspection method of the present invention, and the wire breakage rate was 3.1%; with the addition of the quality inspection method of the present invention, the wire breakage rate of the electroplated diamond wire was significantly reduced.

[0064]

[0065] More specifically, the detection method of the present invention can be applied to the coating detection of finished electroplated diamond wires, such as Figure 5 As shown in the figure, under the conditions of scanning electron microscopy, the tungsten wire busbar and the coating can be clearly distinguished. The midpoints of any two straight lines in the busbar arc are respectively drawn as perpendicular lines to determine the center of the busbar circle. The busbar radius and the finished wire radius are respectively marked through the center of the circle. The coating thickness can be obtained by subtracting them.

[0066] Compared with traditional methods of measuring breaking force and torque, the detection method of the present invention is more accurate. It can not only evaluate the shear resistance of tungsten wire based on tearing, but also evaluate its fracture resistance based on the content of C and O elements in the tungsten wire, and can also detect the thickness of the finished diamond wire coating.

[0067] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0068] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A tungsten wire detection method, characterized by: The following steps are involved: Step 1: Bond multiple tungsten wires into a wire harness sample; Step 2: Mount the wire harness sample from step 1 in the mold hole of the mold, with the wire harness sample perpendicular to the mold surface. Add cold mounting solution into the mold and close the mold. After waiting for 1-3 hours, open the mold and take out the wire harness sample. Step 3: Grind and polish the wire harness sample, with the grinding mesh ranging from 400 to 5000 mesh; Step 4: Perform electron microscope scanning and energy spectrum analysis on the cross section of the wire harness sample polished in step 3. If the proportion of surface split and broken tungsten wires in the wire harness sample is within 10%, it is determined that the shear resistance and splitting resistance of the tungsten wire are good. If the proportion of C and O elements is within 8%, it is determined that the tungsten wire has good anti-fracture performance.

2. The tungsten filament detection method according to claim 1, wherein: In step 1, the tungsten wire is cut into segments, each segment of the tungsten wire is equal in length, and each segment of the tungsten wire is glued together into a bundle with glue.

3. The tungsten filament detection method according to claim 1, wherein: The number of tungsten wires in the wire harness specimen shall not be less than 8.

4. The tungsten filament detection method according to claim 1, wherein: The aperture of the die hole is slightly larger than the diameter of the wire harness sample.

5. The tungsten filament detection method according to claim 1, wherein: The cold mounting solution consists of acrylic powder and metallographic glue, and the volume ratio of the acrylic powder to the metallographic glue is 1:2-5:

1.

6. The tungsten filament detection method according to claim 5, characterized in that: The volume ratio of the acrylic powder to the metallographic glue is 2:

3.

7. The tungsten filament detection method according to claim 6, wherein: The preparation of the cold mounting solution comprises the following steps: First add 20ml of acrylic powder into a 50ml beaker; Then add 20ml of metallographic glue and stir evenly; Then add 10ml of metallographic glue and stir the solution until it becomes a colloidal liquid.

8. The tungsten filament detection method according to claim 1, wherein: In step 3, the grinding time of sandpaper with different mesh sizes is not less than 5 minutes, and the grinding direction should be changed after the sandpaper is changed to make the wear marks on the surface of the wire harness sample shallower.

9. The tungsten filament detection method according to claim 1, wherein: In the step 3, 1.5 μm diamond polishing paste is used for polishing, and the polishing time is not less than 30 minutes.

10. The tungsten filament detection method according to claim 1, wherein: It also includes step 5: using electron microscope scanning to distinguish the tungsten wire busbar and the coating, taking any two straight lines on the busbar arc, making perpendicular midlines to determine the center of the busbar, and then marking the busbar radius and the finished wire radius through the center of the circle, and subtracting them to get the coating thickness.

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