JP2013167525A - Resin embedding mold for electron microscope observation sample and method for preparing electron microscope observation sample - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin embedding mold for an electron microscope observation sample, which can efficiently prepare a sample on which cross section polishing (CP) or ion milling (IM) is performed with the density of powder increased and bubbles reduced.SOLUTION: In a mold 50 for preparing a resin sample including powder, through-holes 3 having a rectangular cross section are provided at a mold block having an upper surface and an under surface. The through-holes 3 are tapered off in a manner to become larger from the under surface toward the upper surface.

Description

  The present invention relates to a mold for preparing a resin-embedded sample in the stage before cross-sectional polishing, and a method for preparing a sample for electron microscope observation, for producing a sample for electron microscope observation, and particularly suitable for observing a powder sample with an electron microscope. The present invention relates to a resin-embedded mold for an electron microscope observation sample and a method for producing an electron microscope observation sample.

  Powder is a fine material mixed with oxides, nitrides, fluorides, etc., but is used to form key materials in fields such as electrochemistry, communication optics, magnetism, and friction mechanical engineering. . For this reason, research has been made to the level of a minute structure by a scanning electron microscope (SEM), a transmission electron microscope (TEM), or the like. In order to perform electron microscope observation, the powder must be used as a sample for electron microscope observation. A conventional method for observing the powder is shown in FIG. First, as shown in FIG. 5 (a), a cylindrical container 150a is arranged on a receiving tray 150b, and for example, a defoamed fluid resin 107 is poured, and then a powder 105 as a test specimen is introduced. In a state where the powder 105 is charged, defoaming is performed by evacuation. At this time, there is a problem that the powder 105 is stirred in the resin 107. After that, let it solidify over a dozen hours. After the resin hardens, as shown in FIG. 5B, the resin 107 containing the powder 105 is taken out, and the curved upper surface is parallel-polished to the parallel surface 112. As a result, the resin 107 containing the powder 105 becomes a substantially complete cylinder. Next, as shown in FIG. 5C, a plate-shaped rectangular parallelepiped 110 is finished through four cuttings <1> to <4> by a band saw by a cutting procedure in which the number of cuttings is minimized. By processing into the shape of this plate-shaped rectangular parallelepiped 110, it can be mounted on a polishing apparatus such as cross section polishing (CP) or ion milling (IM) for the first time.

The above process has the following problems.
(1) Although the observation target powder is small, it is widely dispersed and it is difficult to efficiently observe the powder (test body).
(2) It is difficult for bubbles to escape and scratches are caused by CP or the like to deteriorate the observed image. There is also a problem that the powder is stirred when defoaming (evacuation) is performed.
(3) There are many man-hours to cut out from a cylindrical resin into a flat rectangular parallelepiped.
(4) The amount of unnecessary resin is large.
Among the above problems, in order to increase the density of the observation object (to solve the above (1)), a method of making a mixture of powder and fluidized resin and applying pressure to the mixture was proposed ( Patent Document 1). According to this method, the volume ratio of the powder to the resin can be increased to 2 or more.
In addition, in order to improve efficiency until a flat rectangular parallelepiped is produced, a method of performing ion milling by filling a hole of a sheet mesh with a mixture of a powder and a fluid resin, solidifying, cutting in half so as to give a cross section Has been proposed. According to this method, many powder samples can be processed in a short time at a time.

JP 2003-294594 A JP 2007-47053 A

  However, with the above-described method of applying pressure, in the case of powders such as brittle ceramics, they are broken and cannot be observed in normal form. Further, when a sheet mesh or the like is used, bubbles remain at a high density, and it is difficult to finish a good sample. As in the prior art, it is preferable to follow the procedure in which the powder is put into the mold together with the resin and fixed in the resin because the influence of pressure, bubbles, etc. on the powder is small.

  The present invention is a resin-embedded mold for an electron microscope observation sample that can increase the density of the powder in the sample without reducing pressure, reduce the bubbles, and efficiently prepare the sample to be subjected to CP or IM, And it aims at providing the preparation method of the sample for electron microscope observation.

  The resin-embedded mold for an electron microscope observation sample of the present invention (hereinafter referred to as a resin-embedded mold or a mold) is a resin sample containing an observation object such as powder, which is subjected to a precision polishing apparatus for electron microscope observation. It is a mold for manufacturing. This mold is characterized in that a mold block having an upper surface and a lower surface is provided with a through hole having a rectangular cross section, and the through hole is tapered so as to expand from the lower surface to the upper surface.

As a result, the rectangular cross section on the lower surface can be reduced, and the powder or the like to be observed is likely to sink toward the lower surface during resin casting and is accumulated in a reduced rectangular portion. As a result, the powder is not dispersed in a wide range, but is disposed in the resin at a high density near the lower surface.
If the resin is cast including the powder and then moved to the space where the entire mold block is evacuated and evacuated, the through-hole has a wide taper, so that bubbles can be easily extracted.
Furthermore, since the cross section is rectangular, it is easy to produce a flat, rectangular parallelepiped precision polishing sample to be subjected to CP or IM.

A taper in which at least a short side of the rectangular cross section increases from the lower surface to the upper surface can be provided.
Accordingly, the short side of the rectangular cross section on the lower surface can be shortened, and powder or the like can be easily dropped toward the lower surface during resin casting, and can be easily accumulated in the rectangular portion with the shorter side reduced. As a result, the powder is collected in an elongated rectangular portion, and the powder or the like can be easily put into the field of view, and observation with an electron microscope is facilitated.

The length of the short side on the lower surface can be 1 mm or more and 4 mm or less.
As a result, the powder sinking in the resin can be accumulated at the bottom with high density. When the length of the short side of the lower surface exceeds 4 mm, the density of the powder becomes small, and when the amount of the powder (test body) is small, it is difficult to efficiently observe with an electron microscope. Moreover, when it is less than 1 mm, it becomes difficult to handle the mounting of the cross section polishing (CP) or ion milling (IM) on the apparatus.

One of the two opposing faces formed by the long side of the rectangular cross section × height of the through-hole can be configured to be orthogonal to the upper surface and the lower surface.
As a result, one surface (first long side × height = upright surface) is left as it is, cut-out is omitted, and the other surface (second long side × height = oblique surface) side is deleted. Thus, it is possible to prepare a sample for precise polishing such as CP which must be a plate-shaped rectangular parallelepiped. As a result, the machining process can be simplified.

It is preferable that at least the wall surface of the through hole be formed of polytetrafluoroethylene or a surface coating material having a friction coefficient equal to or smaller than that of the polytetrafluoroethylene.
This makes it easier to remove bubbles and the like by evacuation. In addition, since a smooth upright surface can be formed, it is possible to omit processing or cut out the upright surface. Furthermore, it becomes easy to take out the cast resin molded body.

  The method for producing an electron microscope observation sample of the present invention is a method for producing an electron microscope observation sample comprising a resin sample containing powder or the like by applying to a precision polishing apparatus such as cross section polishing. In this method, a mold block having an upper surface and a lower surface is provided with a through hole having a rectangular cross section, and a taper mold is prepared so that the through hole extends from the lower surface to the upper surface. A step of preparing a resin sample containing powder and taking it out of the mold, and a step of cutting out the resin sample and preparing a mounting sample to be mounted on the precision polishing apparatus. In the mold preparation step, the long side of the rectangular cross section × In the process of preparing the mounting sample, one of the two surfaces facing each other is perpendicular to the top and bottom surfaces, and in the process of preparing the mounting sample, the long side × height surface perpendicular to the top and bottom surfaces of the resin sample taken out of the mold is It is characterized by leaving it as it is.

  By this method, the processing process of the sample mounted on the CP or the like can be greatly simplified. In addition, it is possible to obtain a sample in which the powder is not dispersed in a wide range, is disposed at a high density near the lower surface in the resin, has few bubbles, and easily captures the powder in the field of view of an electron microscope.

  According to the mold of the present invention, it is possible to increase the density of the powder in the sample, reduce bubbles, and efficiently apply the sample to CP or IM without applying pressure or the like.

The resin embedding mold in embodiment of this invention is shown, (a) is a whole perspective view, (b) is sectional drawing which follows the IB-IB line | wire. It is sectional drawing of the stage which put the fluid resin in the casting_mold | template and put the powder. (A) is a figure which shows the procedure which processes the resin sample taken out from the casting_mold | template, (b) is a figure which shows the resin sample after a process. It is a figure which shows the state which carries out CP grinding | polishing of the processed resin sample. In the conventional resin sample, (a) is a resin embedding, (b) is a part where the resin sample taken out from the mold is subjected to parallel polishing, and (c) is a diagram showing a procedure of cutting with a band saw.

1A and 1B show a resin-embedded mold 50 according to an embodiment of the present invention, in which FIG. 1A is an overall perspective view seen from the upper surface 50t side of the mold 50, and FIG. 1B is a cross-sectional view taken along line IB-IB. It is. The entire block is made of polytetrafluoroethylene (PTFE), and is a rectangular parallelepiped having a size of, for example, height (thickness) 12 mm × width 30 mm × length 110 mm. The PTFE block is provided with a through hole 3 extending from the upper surface 50t to the lower surface 50b. In the through hole 3, the inner wall surface 3 v is orthogonal to the upper and lower surfaces 50 t and 50 b, and the inner wall surface 3 s facing the inner wall surface 3 v is tapered slightly so as to become wider. The length b of the short side of the lower surface 50b is 1 mm or more and 4 mm or less. The length t of the short side of the upper surface 50t of the through hole 3 is preferably about 4 mm to 7 mm, for example. The length of the long side in the cross section of the through hole 3 is constant from the lower surface to the upper surface, and can be, for example, about 8 mm to 11 mm. The length of the solid part 50D between the through holes 3 can be set as appropriate.
The number of through-holes 3 per mold is 5 in FIG. 1, but the number of through-holes 3 is not particularly limited as long as it is 1 or more. In addition, in FIG. 1, a saucer as shown in FIG. 5 is not shown, but a saucer may be used.

FIG. 2 is a view showing a state after pouring the defoamed resin 7 in a fluid state into the through-hole 3 shown in FIG. 1 and then pouring the powder 5 into the resin 7. In the resin sample, an orthogonal surface 3v or an upright surface 3v is formed at a location in contact with the inner wall surface 3v, and an oblique surface 7s is formed at a location in contact with the inner wall surface 3s. The top surface 7t of the resin sample rarely pours resin to the full opening of the mold 50, and is usually at a position closer to the lower surface 50t. The bottom surface 7b coincides with the lower surface 50b of the mold.
Since the through-hole 3 has a taper in which the shorter side becomes smaller as it goes downward, the powder 5 tends to sink downward in the resin 7, while bubbles are easily extracted by evacuation. Further, the powder 5 is accumulated at a high density on the bottom having a small cross-sectional area. Since the powder 5 is entangled with each other and confined in a narrow space, even if the defoaming process is performed by, for example, vacuuming, the powder 5 is hardly stirred or the range of stirring is limited. That is, even if it stirs, the range is limited and there is no possibility of stirring over the entire resin molded body.

FIG. 3A is a diagram showing a procedure for cutting out the resin sample 10 as it is taken out of the mold and the plate-shaped rectangular parallelepiped 10a to be mounted on a precision polishing apparatus such as a CP by a band saw with respect to the resin sample 10. The symbols <1> and <2> indicate the position of the surface that appears by processing.
In FIG. 3A, the process of reference numeral <2> is performed in a process of grinding by polishing. Since the taper angle is not so large, it is difficult to cut with a band saw. Then, the tip of the lower surface 7b where the powder 5 is gathered at a high density is cut along the sign <1> with a band saw. The upright surface 7v of the resin sample that has been in contact with the upright surface 3v of the through hole 3 is bonded and fixed to the CP sample table 15. The upright surface 7v is not processed and remains removed from the mold 50. As shown in FIG. 3B, the resin sample 10a processed into a plate-shaped rectangular parallelepiped has a shape that can be attached to a precision polishing apparatus such as CP.

  As shown in FIG. 4, the plate-shaped rectangular parallelepiped resin sample 10 a is mounted on the CP apparatus together with the CP sample table 15. The ion beam 13 is applied to the portion protruding from the CP sample stage 15 to form the polished surface S. While this polished surface S is scanned with a scanning electron microscope, the location of the powder is observed.

<Points of this embodiment>
The method for producing the template and the sample for electron microscope observation shown in FIGS. 1 to 4 has the following characteristics.
1. The observation target powder sinks in the vicinity of the lower surface 7 b of the resin sample 10. The short side length b of the lower surface 7b is not less than 1 mm and not more than 4 mm. In the present embodiment, the powder 5 is collected in a much narrower area as compared with a diameter of about 30 mm in a conventional cylindrical resin sample. As shown in FIG. 3A, the lower surface 7b of the resin sample 10 is removed by cutting, but the thickness to be removed is very small, and most of the powder 5 remains in the processed resin sample 10a. It is.
As a result, when the polishing surface S is formed as shown in FIG. 4, the powder 5 is arranged on the polishing surface S with a high density. For this reason, when the visual field is moved along the polished surface S, it is very easy to capture the powder 5 in the visual field, and the electron microscope observation can be performed efficiently.
2. As shown in FIGS. 1A and 1B, the through-hole 3 has a taper that is wide from the lower surface to the upper surface. For this reason, air bubbles can be easily extracted by a defoaming process by evacuation.
Further, the powder 5 accumulated in the vicinity of the narrow and slender lower surface sinks to the bottom, and even when the bubbles are removed by the defoaming process, the powder 5 is not greatly shaken and is not stirred throughout.
3. The mold 50 is produced by opening the wide through-hole 3 in a PTFE block. For this reason, the wall surface 3v, 3s of the through-hole 3 has a small friction coefficient. Since the coefficient of friction is small, when the powder 5 is introduced, it can sink smoothly to the lower surface without being attached to or moored to the wall surface. Also, the bubbles in the defoaming process are smoothly discharged to the outside without being attached to or moored on the wall surface of the through hole 3.
The same effect can be obtained even if the wall surface of the through-hole 3 of the mold is provided with a surface coating having a friction coefficient equal to or smaller than that of PTFE.
4). The amount of processing from the resin sample 10 taken out from the mold 50 to the processed and molded resin sample 10a is much smaller than that in the past. The time required for conventional processing was 45 minutes / piece. On the other hand, in this embodiment, the processing time is 10 minutes / piece. Processing time can be greatly shortened. In particular, as in the case of the resin surface 7v in the present embodiment, the CP sample 10a is greatly effective without any processing while being taken out from the mold.
5. Reflecting the reduction in the number of processing steps, the amount of resin during casting can be reduced. In the case of a conventional cylindrical resin sample, the amount of cast resin was 5 g / piece. On the other hand, when obtaining the CP sample 10a having the same shape in the present embodiment, it is 1 g / piece. The amount of resin can be reduced to approximately 1/5.

  Although the embodiments and examples of the present invention have been described above, the embodiments and examples of the present invention disclosed above are merely examples, and the scope of the present invention is the implementation of these inventions. It is not limited to the form. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  According to the resin-embedded mold or the like of the present invention, a sample to be subjected to CP or IM efficiently can be produced without increasing the pressure or the like by increasing the density of the powder in the sample and reducing bubbles. It becomes possible to easily observe raw materials such as various ceramics and fine structures of powders in the adjustment process.

3 through hole, 3v upright wall surface, 3s slant wall surface, 5 powder, 7 resin, 7t resin top surface, 7b resin bottom surface, 7s resin slant surface, 7v resin upright surface, 10 resin sample containing powder, 10a processed resin Sample, 13 ion beam, 15 CP sample stage, 50 mold, 50t upper surface of mold, 50b lower surface of mold, 50D mold solid part, b short side length of bottom surface of through hole, short side length of top surface of t through hole , Polished surface by SCP (electron microscope observation surface).

Claims (6)

A mold for producing a resin sample containing powder or the like, which is applied to a precision polishing apparatus such as cross section polishing for electron microscope observation,
A mold block having an upper surface and a lower surface is provided with a through hole having a rectangular cross section,
A resin-embedded mold for an electron microscope observation sample, wherein the through hole is tapered so that the through hole expands from the lower surface to the upper surface.   2. The resin-embedded mold for an electron microscope observation sample according to claim 1, wherein at least a short side of the rectangular cross section is tapered so as to increase from the lower surface to the upper surface.   The resin-embedded mold for an electron microscope observation sample according to claim 1 or 2, wherein a length of a short side on the lower surface is 1 mm or more and 4 mm or less.   One of the two facing surfaces formed by the long side of the rectangular cross section x the height of the through hole is orthogonal to the upper surface and the lower surface. A resin-embedded mold for an electron microscope observation sample described in 1.   2. The wall surface of at least the through hole is formed of polytetrafluoroethylene (PTFE) or a surface coating material having a friction coefficient equal to or smaller than that of the polytetrafluoroethylene. The resin embedding mold for the electron microscope observation sample of any one of -4. A method for producing an electron microscope observation sample comprising a resin sample containing powder or the like through a precision polishing apparatus such as cross section polishing,
Providing a mold block having a rectangular cross section in a mold block having an upper surface and a lower surface, and preparing a taper mold so that the through hole extends from the lower surface to the upper surface;
Using the mold to prepare a resin sample containing powder and the like, and removing from the mold;
Cutting out the resin sample and preparing a mounting sample to be mounted on the precision polishing apparatus,
In the step of preparing the mold, one of two opposing surfaces of the long side of the rectangular cross section × height is orthogonal to the upper and lower surfaces, and in the step of preparing the mounting sample, the surface is removed from the mold. A method for producing a sample for electron microscope observation, wherein a surface of a resin sample is left as it is with a long side orthogonal to the top and bottom surfaces.

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