A powder embedding plate and embedding method

Abstract

The application discloses a powder embedding plate, which comprises a bottom plate and a cover plate, and a plurality of grooves are arranged on the bottom plate at intervals, at least one side wall of the grooves is smooth and flat, a supporting piece is movably arranged at the bottom of the grooves, and the cover plate is used for covering the upper end of the grooves. According to the application, the supporting piece is movably arranged at the bottom of the grooves, so that the powder sample after embedding can be conveniently taken out from the bottom plate; when ion beam cutting is carried out, the supporting piece is attached to a shielding plate, the sample is effectively protected from being damaged by ion beam polishing, and the embedding efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of powder sample cross-section characterization, in particular to a powder embedding plate and an embedding method using the same. BACKGROUND

[0002] When a sample is characterized for internal structure, the sample cross-section needs to be displayed. Different cross-section sample preparation methods have different characteristics. Currently, the following methods are commonly used to prepare cross-sections: ① traditional mechanical grinding method, which may leave grinding scratches and abrasive particles after sample grinding, and is not suitable for processing composite materials; ② microscope chip machine, which requires high technical level and experience, and is suitable for soft materials such as polymers and biology; ③ focused ion beam (FIB) cutting method, which is not suitable for large-area processing, and is usually used to process a width and depth of several um to several tens of um, with a positioning precision of less than 100 nm; and ④ cross-section polisher (CP) ion beam polishing, which can prepare a smooth cross-section without stress damage and surface contamination, and is very suitable for scanning electron microscopy (SEM), element content analysis, and crystal structure analysis, etc. Compared with the mechanical grinding method, the CP ion beam polishing method has small processing deformation, smooth processing of composite materials, and can make larger cross-sections than FIB, usually 1 mm in height and width, and some instruments can polish a 4 mm wide area, with a polishing depth of usually ≤1 mm.

[0003] The argon ion cross-section polisher is a common pre-processing tool for SEM observation and surface analysis (EDX, EBSD, etc.), which can remove the surface layer without stress and process a smooth mirror surface, and is widely used in many fields such as materials and semiconductors, including composite materials, semiconductor ceramics, metals, resins, etc. Before the sample is used for argon ion polishing, the sample needs to be pre-processed to meet the requirements of size, flatness of end face and side face. Different brands of polishing instruments have different requirements for sample size. For example, the Japan Electron IB-19520 CCP polisher requires that the sample thickness is not more than 2 mm, and the cutting depth is generally within 1 mm. However, all polishing instruments require that the upper and lower end faces and the side face of the sample need to be flat to reduce scratches (curtain effect). For argon ion polishing of powder samples, the pre-processing method of epoxy resin embedding is usually used, and the powder materials include, for example, positive ternary powder, negative graphite powder, silicon-carbon material, etc.

[0004] The powder sample for argon ion polishing usually adopts the method of embedding powder with epoxy resin, mainly two kinds, one is the traditional sample preparation method, usually embedding the powder sample in silica gel mold or centrifuge tube with epoxy resin, then grinding the end face and side face of the sample, and then putting it into the ion beam polishing instrument for polishing. The traditional technical method has the following disadvantages: disadvantage one, in the process of ion polishing, the front end of the embedded block is attached to the baffle, because the thickness of the silica gel mold or centrifuge tube is relatively thick, the polishing time is relatively long, these areas are non-observation areas, causing waste of time and polishing instrument resources; disadvantage two, the powder sample is too dispersed in the embedding process, and the utilization rate of the powder sample is not high; disadvantage three, the powder sample pretreatment time is too long, because the embedded silica gel or centrifuge tube material cannot be heated, the epoxy resin is naturally air dried, and it usually takes tens of hours or even dozens of hours to completely solidify; disadvantage four, the solidified sample needs to be ground. After the powder is pretreated and solidified into an epoxy resin embedded block, the upper and lower end faces and the side face need to be ground flat, because the sample is small, it is not easy to operate, and it is time-consuming.

[0005] Another method is to embed the powder in the middle of two cover glass or silicon wafers, which mainly uses two cover glass or silicon wafers to embed the powder and epoxy resin mixture in the middle by two times of heating and solidification. This method has the following disadvantages: disadvantage one, this method uses two times of embedding, the process is complicated, and needs to go through two times of solidification process, and the embedding process needs about two and a half hours; disadvantage two, the side face of the resin embedded block needs to be polished to meet the requirements of the ion polishing instrument, and the embedded block is small and not easy to operate, and the 50um / 100um cover glass or ultra-thin silicon wafer is easy to break in the polishing process; disadvantage three, this method uses 2 pieces of cover glass / silicon wafer to embed the powder, and needs to be solidified twice, which is high in cost; disadvantage four, the thickness of the samples obtained by this method is relatively large, although it does not affect the test quality, but when comparing the samples, it is easy to cause height difference and affect the appearance.

[0006] Therefore, it is necessary to provide a powder embedding plate and embedding method to overcome the above defects. SUMMARY

[0007] The main purpose of the present application is to provide a powder embedding plate and embedding method which is low in cost, simple in structure and high in embedding efficiency.

[0008] To achieve the above purpose, the powder embedding plate provided by the present application is characterized in that the powder embedding plate comprises a bottom plate and a cover plate, a plurality of grooves are arranged on the bottom plate at intervals, at least one side wall of the groove is smooth, and a support piece is movably placed at the bottom of the groove; the cover plate is used to cover the upper port of the groove.

[0009] Optionally, the flatness of the smooth surface of the groove is ≤0.15mm, and the friction coefficient is 0.01-0.16.

[0010] Optionally, the material of the support plate and the cover plate is polytetrafluoroethylene.

[0011] The polytetrafluoroethylene has the advantages of non-stickiness, wear resistance, corrosion resistance, excellent anti-aging property and heat resistance, and can work stably for a long time at a temperature of -180℃ to 250℃.

[0012] Optionally, the cover plate is in a strip structure.

[0013] The strip structure is easy to bend under stress, facilitating the covering and separating of the cover plate and the bottom plate.

[0014] Optionally, the support sheet is any one of a silicon sheet, a copper sheet or a cover glass, and the thickness of the support sheet is not more than 100um.

[0015] Optionally, the powder embedding plate further comprises a pressing block, and when the cover plate closes the upper port of the groove, the pressing block presses the upper part of the cover plate.

[0016] The application further provides an embedding method, comprising the following steps:

[0017] S1: taking epoxy resin and a curing agent, mixing them according to a volume ratio of 10:1, and stirring to obtain a first mixture;

[0018] S2: mixing the first mixture and a powder sample according to a volume ratio of 1:1 to 5:1, and stirring to obtain a second mixture;

[0019] S3: tightly attaching one end of the support sheet to the smooth side wall of the groove, applying the second mixture to the support sheet along the end of the support sheet that is tightly attached to the side wall of the groove, and the thickness of the applied second mixture is higher than the depth of the groove;

[0020] S4: placing the bottom plate with the applied second mixture on a heating device to heat for a period of time, and then placing it in a vacuum device to perform vacuumizing treatment;

[0021] S5: covering the cover plate on the upper port of the groove of the bottom plate that has been vacuumized, placing the bottom plate with the cover plate on the heating device, heating the second mixture in the groove for 25 to 30 minutes, and then removing the cover plate to obtain an embedded sample.

[0022] Optionally, in step S4, the heating temperature of the heating device is 60 to 80℃, the heating time is 5 to 10 minutes, the vacuum degree of the vacuum device is 2 to 10 pa, and the vacuumizing time is 5 to 10 minutes.

[0023] Optionally, in step S5, when the cover plate covers the bottom plate groove, the cover plate at least exceeds one edge of the bottom plate, so as to facilitate subsequent separation of the cover plate from the bottom plate.

[0024] Optionally, in step S5, the heating temperature of the heating device is 100-120°.

[0025] In the technical scheme of the present application, the support piece movably arranged at the bottom of the groove facilitates taking out the embedded powder sample from the bottom plate, and the support piece is attached to the shielding plate during ion beam cutting, effectively protecting the sample from damage caused by ion beam polishing.

[0026] In the powder sample embedding process of the technical scheme of the present application, one end of the support piece is attached to the smooth side wall of the groove, the second mixture is applied on the support piece along the one end of the support piece attached to the side wall of the groove, the thickness of the applied second mixture is higher than the depth of the groove, the lower end surface of the second mixture is attached to the support piece, the upper end surface is attached to the cover plate, and at least one side surface is attached to the smooth side wall of the groove, so that the upper and lower end surfaces and at least one side surface of the prepared solidified sample are smooth and flat, without the need for grinding, and the method only needs to be solidified once, with high embedding efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical schemes in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the structures shown in the drawings.

[0028] Figure 1 FIG. 1 is a structural schematic diagram of a bottom plate 10 of a powder embedding plate according to an embodiment of the present application;

[0029] Figure 2 FIG. 2 is a side view of the powder embedding plate bottom plate 10 shown in FIG. 1; Figure 1

[0030] Figure 3 FIG. 3 is a structural schematic diagram of a cover plate 20 of a powder embedding plate according to an embodiment of the present application;

[0031] Explanation of reference numerals:

[0032] Reference Name Reference Name 10 Base plate 12 Supporting sheet 11 Groove 20 Cover plate

[0033] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION ​

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0035] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0036] Please see Figure 1 , Figure 2 and Figure 3 , Figure 1 This is a schematic diagram of the structure of the powder embedding plate base plate 10 according to an embodiment of this application. Figure 2 for Figure 1 The side view of the powder embedding plate base 10 shown is shown. Figure 3 This is a schematic diagram of the structure of a powder embedding plate cover 20 according to an embodiment of this application.

[0037] This application provides a powder embedding plate, which includes a base plate 10 and a cover plate 20.

[0038] The material of the bottom plate 10 can be any material suitable for contact and easy to separate in the art, for example, but not limited to, polytetrafluoroethylene. It can be understood that polytetrafluoroethylene has the advantages of non-stickiness, wear resistance, corrosion resistance, excellent aging resistance, and heat resistance, and can work stably for a long time at a temperature of -180°C to 250°C. The bottom plate 10 is provided with a plurality of grooves 11 at intervals, and at least one side wall of the groove 11 is smooth. In this embodiment, the bottom plate 10 is provided with one groove 11. In other embodiments of the application, the number of grooves 11 can be determined according to the size of the bottom plate 10 and the actual demand. The number of grooves 11 is not limited herein. In this embodiment, the depth of the groove 11 is 500 um. In other embodiments of the application, the depth of the groove 11 can be determined according to the size of the bottom plate 10 and the actual sample demand. The depth of the groove 11 is not limited herein. The flatness of the smooth surface of the groove 11 is ≤0.15 mm, and the friction coefficient is 0.01-0.16. It can be understood that the flatness and smoothness of the groove 11 directly affect the embedding quality of the sample attached thereto. Therefore, when the flatness exceeds 15 mm and the friction coefficient exceeds 0.16, the flatness and smoothness of the end surface of the sample cannot meet the requirement of no need for grinding. The support sheet 12 is movably placed at the bottom of the groove 11. It can be understood that the support sheet 12 plays a role in supporting and fixing the embedded sample. The support sheet 12 can be any one of a silicon wafer, a copper sheet, or a cover glass. In this embodiment, the thickness of the support sheet 12 is 100 um. It can be understood that in order to protect the embedded powder sample, the support sheet 12 is usually attached to the shielding plate during ion beam cutting. Therefore, the thickness of the support sheet should not be too thick, so as to avoid wasting too many resources and time during cutting. In other embodiments of the application, the thickness of the support sheet 12 is not more than 100 um.

[0039] In this embodiment, the groove 11 is made by sticking two plate materials with the same width as the bottom plate 10 and smooth surfaces on the bottom plate 10 at intervals. The two plate materials and the bottom plate 10 form a groove 11 structure. The material of the plate can be any material suitable for contact and easy to separate in the art, for example, but not limited to, a polytetrafluoroethylene plate, a glass slide, or a plate of other materials with a Teflon adhesive paper attached to the surface. In other embodiments of the application, the groove 11 can also be directly cut on the bottom plate 10 by a cutting machine. The groove prepared by this embodiment has two smooth side surfaces.

[0040] The cover plate 20 is used to cover the upper end of the groove 11. The material of the cover plate 20 can be any material suitable for contact and easy to separate in the art, for example, but not limited to, polytetrafluoroethylene. The shape of the cover plate 20 can be any shape that is easy to bend under force in the art, for example, but not limited to, a long strip structure.

[0041] In the embodiment, the powder embedding plate further comprises a pressing block, when the cover plate 20 closes the upper port of the groove 11, the pressing block presses the upper part of the cover plate 20, and it can be understood that the pressing block plays a role of pressing the embedded sample flat by applying pressure to the cover plate 20, and the pressing block can be a metal block, and in other embodiments of the application, the pressing block can be any material that can apply pressure.

[0042] The technical scheme of the application is provided with the supporting sheet 12 movably arranged at the bottom of the groove 11, which facilitates the taking out of the embedded powder sample from the bottom plate 10, and when the ion beam cutting is performed, the supporting sheet 12 is attached to the shielding plate, thereby effectively protecting the sample from damage caused by ion beam polishing.

[0043] The embodiment of the application further provides an embedding method, comprising the following steps:

[0044] S1: Take the epoxy resin and the curing agent, mix them according to a volume ratio of 10:1, and stir to obtain a first mixture;

[0045] S2: Mix the first mixture with the powder sample according to a volume ratio of 1:1 to 5:1, and stir to obtain a second mixture;

[0046] S3: One end of the supporting sheet 12 is tightly attached to the smooth side wall of the groove 11, the second mixture is applied to the supporting sheet 12 along the one end of the supporting sheet 12 that is tightly attached to the side wall of the groove 11, and the thickness of the applied second mixture is higher than the depth of the groove 11;

[0047] S4: After the bottom plate 10 with the applied second mixture is placed on the heating device and heated for a period of time, it is placed in a vacuum device for vacuum treatment, which aims to remove air contained in the sample, so that the epoxy resin fills the gaps of the powder sample, eliminates the gaps between the powder sample and the epoxy resin, and avoids the generation of air bubbles after the solidification of the second mixture;

[0048] Specifically, the heating temperature of the heating device is 60-80℃, the heating time is 5-10min, the vacuum degree of the vacuum device is 2-10pa, and the vacuum time is 5-10min.

[0049] S5: The cover plate 20 is covered on the upper port of the groove 11 of the bottom plate 10 after the vacuum treatment, the bottom plate 10 with the cover plate 20 is placed on the heating device, the second mixture in the groove 11 is heated and solidified at 100-120℃ for 25-30min by the heating device, and then the cover plate 20 is removed, thereby obtaining the embedded sample.

[0050] Specifically, when the cover plate 20 covers the groove 11 of the base plate 10, the cover plate 20 at least exceeds one edge of the base plate 10, so as to facilitate subsequent separation of the cover plate 20 from the base plate 10.

[0051] In the powder sample embedding process, one end of the support sheet 12 is tightly attached to the smooth side wall of the groove 11, the second mixture is applied on the support sheet 12 along the one end of the support sheet 12 tightly attached to the side wall of the groove 11, the thickness of the second mixture is higher than the depth of the groove 11, so that the lower end surface of the second mixture is attached to the support sheet 12, the upper end surface is attached to the cover plate 20, and at least one side surface is attached to the smooth side wall of the groove 11, the prepared solidified sample is smooth on the upper and lower end surfaces and at least one side surface, without grinding, and the method only needs to be solidified once, with high embedding efficiency.

[0052] The above is only an optional embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation, direct / indirect application in other related technical fields within the concept of the present application, and the contents of the present application specification and drawings are included in the patent protection scope of the present application.

Claims

1. An embedding method, characterized in that, The invention includes a powder embedding plate, which comprises a base plate and a cover plate. The base plate has a plurality of grooves spaced apart, at least one side wall of each groove is flat and smooth, and a support piece is movably placed at the bottom of each groove. The cover plate is used to cover the upper port of the groove. The groove is formed by two pieces of material that are bonded to the base plate at intervals and enclosed by the base plate, or the groove is formed by cutting on the base plate; The width of the support piece between the two side walls is smaller than the distance between the two side walls; Includes the following steps: S1: Take epoxy resin and curing agent, mix them in a volume ratio of 10:1, and stir evenly to obtain the first mixture; S2: Mix the first mixture with the powder sample in a volume ratio of 1:1 to 5:1, and stir until homogeneous to obtain the second mixture; S3: Press one end of the support sheet against the smooth and flat sidewall of the groove, and apply the second mixture along the end of the support sheet that is pressed against the sidewall of the groove onto the support sheet. The thickness of the second mixture applied is greater than the depth of the groove. S4: After heating the base plate coated with the second mixture on a heating device for a period of time, place it in a vacuum device for vacuuming. S5: Cover the upper port of the vacuum-evacuated bottom plate groove with the cover plate, place the bottom plate covered with the cover plate on the heating device, and heat and solidify the second mixture in the groove for 25 min to 30 min. Then remove the cover plate to obtain the embedded sample.

2. The embedding method according to claim 1, characterized in that, The flatness of the groove's smooth surface is ≤0.15mm, and the coefficient of friction is 0.01~0.

16.

3. The embedding method according to claim 1, characterized in that, Both the support plate and the cover plate are made of polytetrafluoroethylene.

4. The embedding method according to claim 1, characterized in that, The cover plate has a long strip-shaped structure.

5. The embedding method according to claim 1, characterized in that, The support sheet is any one of silicon wafer, copper sheet or cover glass, and the thickness of the support sheet does not exceed 100 μm.

6. The embedding method according to claim 1, characterized in that, The powder embedding plate also includes a pressing block, which presses against the upper part of the cover plate when the cover plate closes the upper port of the groove.

7. The embedding method according to claim 1, characterized in that, In step S4, the heating temperature of the heating device is 60-80℃ and the heating time is 5-10 min. The vacuum device evacuates to a vacuum degree of 2-10 Pa and the evacuation time is 5-10 min.

8. The embedding method according to claim 1, characterized in that, In step S4, when the cover plate covers the groove of the base plate, the cover plate extends beyond at least one edge of the base plate.

9. The embedding method according to claim 1, characterized in that, In step S5, the heating temperature of the heating device is 100-120°C.

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