Porous member provided with ceramic particles and method for producing same

Abstract

Provided are: a porous member provided with ceramic particles, the porous member having good air permeability and low pressure loss while suppressing the generation of particles; and a method for producing the porous member. A porous member having ceramic particles according to the present invention comprises: a cylindrical case (2) having openings at both ends; a plurality of ceramic particles (3) filled in the housing; and a pair of porous lids (4) that close both ends of the cylindrical case and enclose the ceramic particles inside the case.

Description

Technical Field

[0001] The present invention relates to a porous component including ceramic particles and a method for manufacturing the same, and particularly to a porous component including ceramic particles in which a housing is filled with ceramic particles and both ends of the housing are sealed with a porous lid body, and a method for manufacturing the same. Background Art

[0002] In semiconductor manufacturing apparatuses that require extremely high cleanliness, various types of filters are used to remove particles and the like. Among them, ceramic filters are particularly widely used because of their excellent heat resistance, durability, corrosion resistance, etc.

[0003] A ceramic filter is composed of a ceramic porous body. For example, a ceramic porous body that can be used as a semiconductor processing component is disclosed in Patent Document 1. The semiconductor processing component disclosed in Patent Document 1 is formed of a ceramic porous sintered body. In this ceramic porous sintered body, the porosity of the skeleton portion formed by stirring and foaming is 5% or less, and the overall porosity is 50% or more.

[0004] However, since a ceramic filter is a porous body, it is particularly fragile and may be damaged during its handling. Therefore, in order to facilitate its handling before being assembled into a semiconductor manufacturing apparatus, an operation of installing a housing is performed.

[0005] That is, a ceramic porous body main body having connected bubbles is housed in a housing (such as a hollow cylindrical outer tube) for assembly into a semiconductor manufacturing apparatus.

[0006] Patent Document 2 discloses a method for manufacturing a composite component composed of a ceramic porous body and a ceramic dense body surrounding the ceramic porous body.

[0007] Specifically, when integrating a ceramic porous body and a ceramic peripheral component surrounding the ceramic porous body, a sintered body is used as the ceramic porous body, and a pre-fired formed body is used as the ceramic peripheral component, and the porous body and the peripheral component are assembled.

[0008] Then, by performing formal firing on it, the ceramic porous body and the ceramic dense body surrounding the ceramic porous body are integrated by using the mechanical bonding force generated by the sintering shrinkage of the peripheral component formed body and the sintering of the porous body and the peripheral component, thereby manufacturing a composite component.

[0009] Prior Art Documents

[0010] Patent Documents

[0011] Patent Document 1: Japanese Patent No. 3894365 Gazette

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2003-238267 Summary of the Invention

[0013] Technical Problem to be Solved by the Invention

[0014] However, as disclosed in Patent Document 2, in a method for manufacturing a composite member composed of a ceramic porous body and a ceramic dense body surrounding the ceramic porous body, the ceramic porous body of the main body is a ceramic porous sintered body formed by stirring and foaming in the same manner as the ceramic porous body disclosed in Patent Document 1.

[0015] However, in the case of producing a porous body with a porosity of 50% or more by stirring and foaming, the framework portion of the pores where the bubble-like pores communicate with each other has to be formed extremely thin, and there is a problem that particles are likely to be generated due to grain detachment.

[0016] On the other hand, if it is manufactured in such a way that there is no thin wall in order to suppress the generation of particles, the porosity becomes small and the air permeability deteriorates. Even if it is installed in the exhaust part of a device or the like, a new problem such as time-consuming exhaust will occur.

[0017] In addition, in the case of housing the ceramic porous body main body in a housing, in the method disclosed in Patent Document 2, in the portion where the ceramic cylinder contacts the ceramic porous body, the ceramic porous body may be damaged during firing.

[0018] The present invention has been completed in view of the above circumstances. Instead of using a ceramic porous sintered body formed by stirring and foaming, a new porous member and its manufacturing method are studied, and the present invention is conceived and completed.

[0019] An object of the present invention is to provide a porous member including ceramic particles and a manufacturing method thereof, which are a new porous member and a manufacturing method using ceramic particles, and can suppress the generation of particles, or have good air permeability and can reduce pressure loss.

[0020] Technical Means for Solving the Problem

[0021] In order to solve the above problems, the porous member including ceramic particles according to the present invention is characterized by including: a cylindrical housing having openings at both ends; a plurality of ceramic particles filled in the housing; and a pair of porous lids that seal both ends of the cylindrical housing and enclose the ceramic particles inside the housing.

[0022] The porous component with the above-described ceramic particles having such a structure is not a porous body made by stirring and foaming, but a porous component composed of a plurality of ceramic particles filled in a housing. Therefore, there is no thin-walled portion generated when forming the main body of the conventional porous body by stirring and foaming, and it is possible to suppress the occurrence of defects such as particle generation due to the peeling of the thin-walled portion.

[0023] Alternatively, the porous component with ceramic particles according to the present invention can obtain good air permeability and reduce pressure loss by setting the average pore diameter of the porous cover and the particle diameter of the above-described ceramic particles within a specific range.

[0024] Here, it is preferable that the particle diameter of the above-described ceramic particles is 100 μm or more and 800 μm or less. In addition, it is preferable that the filling area ratio of the ceramic particles is 34% or more and 95% or less with respect to the length connecting both ends of the housing. Further, it is preferable that the average pore diameter of the porous cover is 22 μm or more and 200 μm or less, and the porosity is 20% or more and 40% or less.

[0025] In this way, by setting the particle diameter of the ceramic particles to 100 μm or more and 800 μm or less, more preferably 600 μm or more and 800 μm or less, setting the filling area ratio of the ceramic particles with respect to the housing to 34% or more and 95% or less with respect to the length connecting both ends of the housing, and setting the average pore diameter of the porous cover to 22 μm or more and 200 μm or less, it is possible to achieve good air permeability and reduce pressure loss.

[0026] In addition, in order to solve the above problems, the manufacturing method of the porous component with the above-described ceramic particles according to the present invention is characterized by including: a step of filling a plurality of ceramic particles into a cylindrical housing having openings at both ends; and a step of closing both ends of the cylindrical housing with a pair of porous covers and enclosing the ceramic particles inside the housing.

[0027] According to such a method, the porous component with ceramic particles of the present invention can be manufactured.

[0028] Advantages of the Invention

[0029] According to the present invention, it is possible to obtain a porous component with ceramic particles capable of suppressing particle generation, or having good air permeability and capable of reducing pressure loss, and a manufacturing method thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a cross-sectional view schematically showing the structure of the porous component according to the present invention.

[0031] Figure 2 (a) to (d) are for explainingFigure 1 Cross-sectional view of a method for manufacturing a porous component

[0032] Figure 3 It is a diagram showing a schematic structure of an evaluation apparatus for evaluation examples and comparative examples

[0033] Explanation of reference numerals

[0034] 1 Porous component containing ceramic particles

[0035] 2 Outer cylinder component (housing)

[0036] 3 Ceramic particles

[0037] 4 Porous cover Detailed implementation manners

[0038] Hereinafter, a porous component containing ceramic particles and a method for manufacturing the same according to the present invention will be described with reference to the drawings

[0039] Figure 1 It is a cross-sectional view schematically showing the structure of a porous component containing ceramic particles according to the present invention Figure 1 The shown porous component 1 containing ceramic particles can be used, for example, as: a ceramic filter utilizing continuous pores, a heat insulating material utilizing a structure containing pores, a light diffusing plate for uniformly diffusing and transmitting light, or a component for a semiconductor manufacturing apparatus used in a plasma processing step or the like

[0040] Figure 1 The porous component 1 containing ceramic particles includes: a cylindrical outer cylinder component 2 having openings at both ends; ceramic particles 3 filled in the outer cylinder component 2; and a pair of porous covers 4 for closing the openings at both ends of the outer cylinder component 2. That is, it is a structure in which ceramic particles 3 are housed and filled in the outer cylinder component 2 as a housing

[0041] The outer cylinder component 2 is preferably formed of a resin with high heat resistance, a resin with a low dielectric constant (e.g., Teflon (registered trademark)) or quartz. For example, the diameter (outer diameter) d1 is formed to be 50 mm, the length L is formed to be 80 mm, and the thickness t1 is formed to be 5 mm

[0042] The outer cylinder component 2 is not limited to a cylindrical shape, and may also be a square cylinder shape with a polygonal cross-section

[0043] The ceramic particles 3 filled in the outer cylinder component 2 are only in a state of being housed and filled in the outer cylinder component 2. The ceramic particles 3 are preferably formed of silica, and their shape is preferably crushed powder or spherical

[0044] The ratio of the filling area of ​​the ceramic particles 3 in the outer tube member 2 is 34% or more and 95% or less relative to the length L connecting both ends of the outer tube member 2 .

[0045] It should be noted that the filling area ratio refers to the ratio of the length between the pair of porous covers inside the outer tube member, that is, the length of the ceramic particles filled, to the length L connecting the two ends of the outer tube member 2. Here, when the length L connecting the two ends of the outer tube member 2 is set to a specific length, if the filling area ratio becomes smaller, the ratio (length) of the porous cover 4 becomes larger. On the other hand, if the filling area ratio becomes larger, the ratio (length) of the porous cover 4 becomes smaller.

[0046] When the filling area ratio of the ceramic particles 3 in the outer tube member 2 is less than 34%, the ratio of the porous cover 4 to the length L connecting both ends of the outer tube member 2 increases, and the pressure loss may increase.

[0047] When the filling area ratio of the ceramic particles 3 in the outer tube member 2 exceeds 95%, the ratio of the porous cover 4 to the length L connecting the two ends of the outer tube member 2 becomes small, and the porous cover 4 may be damaged.

[0048] The maximum particle size of the ceramic particles 3 is preferably 800 μm or less.

[0049] If the maximum particle size exceeds 800 μm, the gaps between particles become larger, the gripping force between particles becomes weak, and the particles are easy to move in the outer cylinder component, which may damage (break) the porous cover. In addition, when used as a light diffuser or heat insulating material, the heat insulating effect and light diffusion effect may be weakened.

[0050] In order to suppress pressure loss, the minimum particle size of the ceramic particles 3 is preferably 100 μm or more, and more preferably 600 μm or more.

[0051] Therefore, the particle size of each ceramic particle 3 preferably ranges from 100 μm to 800 μm, and more preferably ranges from 600 μm to 800 μm.

[0052] It should be noted that the ceramic particles 3 can be classified using a sieve. For example, ceramic particles of 600 μm or more and 800 μm or less can be classified using sieves with mesh sizes of 600 μm and 800 μm. That is, ceramic particles of 600 μm or more and 800 μm or less can be obtained in the form of ceramic particles that pass through a sieve with a mesh size of 800 μm but not through a sieve with a mesh size of 600 μm.

[0053] In addition, a pair of porous caps 4 for closing the two open ends of the outer cylinder member 2 and enclosing the ceramic particles 3 inside the outer cylinder member 2 are formed of a porous resin or silica. The outer peripheral portion of the porous cap 4 is joined to the inner peripheral surface of the outer cylinder member 2.

[0054] Specifically, a countersunk portion 2a is formed on the inner peripheral surface of both end portions of the outer cylinder member 2, and an adhesive 5 is filled in the side surface of the countersunk portion 2a. That is, the porous cap 4 is joined to the inner peripheral surface of the outer cylinder member 2 via the adhesive 5.

[0055] Here, the case where the countersunk portion 2a is formed on the inner peripheral surface of both end portions of the outer cylinder member 2 is shown, but it is not particularly limited to the countersunk portion 2a. A stepped portion for filling the adhesive 5 may be formed on the porous cap 4 side, or the stepped portions may not be formed on both the outer cylinder member 2 and the porous cap 4 for joining.

[0056] It should be noted that the adhesive 5 is not particularly limited as long as it has heat resistance. For example, epoxy-based or silica-based adhesives can be used.

[0057] In addition, when the porous cap 4 is formed of resin, for example, the porous cap 4 can be formed of PTFE. In addition, when the porous cap 4 is formed of silica, for example, the porous cap 4 can be formed by the sol-gel method.

[0058] The average pore diameter of the porous cap 4 is preferably 22 μm or more and 200 μm or less, and the porosity is 20% or more and 40% or less. When the average pore diameter is less than 22 μm or the porosity is less than 20%, good air permeability cannot be obtained, and the pressure loss may become high.

[0059] On the other hand, when the average pore diameter exceeds 200 μm or the porosity exceeds 40%, the possibility of generating particles becomes high.

[0060] It should be noted that the average pore diameter and porosity of the porous cap can be obtained by measurement using a mercury porosimeter in the same manner as the average pore diameter and porosity of the porous body.

[0061] In addition, it is preferable that the ratio of the average pore diameter of the porous cap to the particle diameter of the ceramic particles is 1:1.1 to 1:80.

[0062] By making the ratio of the average pore diameter of the porous cap to the particle diameter of the ceramic particles 1:1.1 to 1:80, good air permeability can be obtained and the pressure loss can be reduced.

[0063] In addition, the thickness t2 of the porous lid 4 is preferably formed to be 2 mm or more and 20 mm or less for each piece. When the thickness t2 of the porous lid 4 is less than 2 mm, the strength becomes weak, so there is a possibility of breakage. On the other hand, when the thickness t2 of the porous lid 4 exceeds 20 mm, the pressure loss may become high.

[0064] In addition, the planar shape of the porous lid 4 is formed to match the cross-sectional shape of the outer cylinder member 2.

[0065] The porous member 1 configured in this way does not have a porous body made by stirring and foaming, but is formed by a plurality of ceramic particles 3 filled in the outer cylinder member 2.

[0066] In addition, since the porosity of the porous lid 4 that closes both ends of the outer cylinder member 2 is 20% or more and 40% or less, there is no thin-walled part generated when forming the conventional porous body main body by stirring and foaming, and it is possible to suppress defects such as generation of particles due to its degranulation.

[0067] In particular, by preferably setting the particle diameter of the ceramic particles 3 to be 100 μm or more and 800 μm or less, more preferably 600 μm or more and 800 μm or less, setting the filling area ratio of the ceramic particles 3 with respect to the outer cylinder member 2 to be 34% or more and 95% or less with respect to the length L connecting both ends of the outer cylinder member 2, and preferably setting the average pore diameter of the porous lid 4 to be 22 μm or more and 200 μm or less, more preferably 22 μm or more and 150 μm or less, the air permeability can be made good and the pressure loss can be reduced.

[0068] In addition, since the ceramic particles 3 filled in the outer cylinder member 2 are only in a state of being housed and filled in the outer cylinder member 2, a large gap is not generated between the outer cylinder member 2 and the ceramic particles 3. In addition, since the ceramic particles 3 are not fired after being housed and filled in the outer cylinder member 2, breakage of the ceramic particles 3 in close contact with the outer cylinder member 2 can be prevented.

[0069] In addition, the ceramic particles 3 filled in the outer cylinder member 2 can also be fixed. As a fixing method, a method of filling in a state where a photocurable adhesive or the like is previously coated on the ceramic particles 3 can be used. By fixing the ceramic particles 3, deviation will not occur even when vibration is applied after filling.

[0070] Next, use Figure 2 The manufacturing method of the porous member including ceramic particles according to the present invention will be described.

[0071] First, a countersunk portion 2a is formed on the inner peripheral surfaces at both ends of an outer cylinder member 2 formed of a resin with high heat resistance (e.g., Teflon) or quartz. The outer cylinder member 2 is formed, for example, with an outer diameter d1 of 50 mm, an inner diameter d3 of 40 mm, a length L of 80 mm, a thickness t1 of 5 mm, a diameter d2 of the countersunk portion 2a of 42 mm, and a depth t2 of 5 mm.

[0072] Then, as shown in (a) of Figure 2 , an epoxy-based adhesive 5 is applied to the side surface of the countersunk portion 2a of the porous member 1. As shown in (b) of Figure 2 , the porous lid 4 is attached to the porous member 1 and dried at 80°C for 3 hours.

[0073] In addition, the porous lid 4 is pre-formed such that the top view outer shape of the porous lid 4 matches the shape of the countersunk portion 2a of the outer cylinder member 2, and the outer diameter of the porous lid 4 is substantially the same as the inner diameter of the countersunk portion 2a of the outer cylinder member 2, enabling the porous lid 4 to be fitted into the end portion of the outer cylinder member 2.

[0074] Next, as shown in (c) of Figure 2 , the above-mentioned outer cylinder member 2 is placed on a vibrator 10 (e.g., product name VIBRATORY PACKER) in an upside-down state.

[0075] As a result, a state is formed in which the previously joined porous lid 4 (4A) is disposed at the bottom of the outer cylinder member 2.

[0076] Then, ceramic particles 3 are put into the outer cylinder member 2 until they reach the same position as the bottom surface of the countersunk portion 2a.

[0077] Next, the vibrator 10 is operated to vibrate at a frequency of 60 Hz for about 1 minute. After the upper surface of the put-in ceramic particles has dropped, ceramic particles are added and replenished, and the vibrator 10 is again operated at a frequency of 60 Hz for about 1 minute. Moreover, the addition and replenishment of the ceramic particles and the vibration of the vibrator 10 are repeated until the upper surface of the put-in ceramic particles after vibration is at the same position as the bottom surface of the countersunk portion 2a.

[0078] As a result, the larger gaps between the ceramic particles 3 filled in the outer cylinder member 2 are eliminated, and the gaps between the ceramic particles 3 are made uniform.

[0079] Then, as shown in (d) of Figure 2 , an epoxy-based adhesive 5 is applied to the side surface of the countersunk portion 2a of the porous member 1, the porous lid 4 (4B) is attached to the porous member 1, and dried at 80°C for 3 hours.

[0080] By performing the above processes, Figure 1The porous component 1 with ceramic particles shown.

[0081] Thus, in the manufactured porous component, ceramic particles 3 with a particle size of 100 μm or more and 800 μm or less, more preferably 600 μm or more and 800 μm or less, are introduced. Finally, the filling area ratio of the ceramic particles 3 in the outer cylinder component 2 is 34% or more and 95% or less with respect to the length L connecting the two ends of the outer cylinder component 2.

[0082] [Examples]

[0083] Hereinafter, the porous component with ceramic particles and its manufacturing method according to the present invention will be further described based on examples.

[0084] (Example 1)

[0085] In Example 1, the porous component 1 with ceramic particles having the Figure 1 shown structure was used. As specific conditions, the particle size of the ceramic particles 3 was 600 - 800 μm (average particle size 700 μm). For the outer cylinder component 2, a component with a diameter (outer diameter) d1 of 50 mm, an inner diameter d3 of 40 mm, a length L of 80 mm, a thickness t1 of 5 mm, a countersunk hole part 2a with a diameter d2 of 42 mm, and a depth t2 of 5 mm was used.

[0086] The filling area ratio of the ceramic particles in the outer cylinder component 2 was set to 88% with respect to the length L connecting the two ends of the outer cylinder component 2.

[0087] In addition, the porous lid 4 was formed of silica by the sol - gel method, with an average pore diameter of 38 μm and a porosity of 40%. The porous lid 4 was pre - formed such that the top - view outer shape of the porous lid 4 was the same as the shape of the countersunk hole part 2a of the outer cylinder component 2, and the outer diameter of the porous lid 4 was substantially the same as the inner diameter of the countersunk hole part 2a of the outer cylinder component 2, and the porous lid 4 could be fitted into the end of the outer cylinder component 2.

[0088] N2 gas was introduced into the porous component 1 from the porous lid 4A at one end of the porous component 1 at a flow rate of 50 ml (milliliters) / min (minute), and discharged from the porous lid 4B at the other end of the porous component 1, and thus the pressure loss (Pa) was measured.

[0089] The measurement was carried out using the Figure 3 shown system. While observing the flow meter, nitrogen was circulated at a specified flow rate, and the differential pressure at this time was read with a differential pressure gauge, thereby evaluating the pressure loss. In addition, a particle counter in the air was used to count the number of particles detected within 1 minute, thereby evaluating the particles. The results of Example 1 are shown in Table 1.

[0090] (Comparative Example 1)

[0091] As Comparative Example 1, a cylindrical porous body having an average pore diameter of 150 μm and a diameter of 40 mm × a length of 80 mm was formed by a sol-gel method using silica powder (average particle size: 600 μm), and the porous body was inserted into an outer cylinder member of the same shape as that of Example 1 (diameter d1 of 50 mm, inner diameter d3 of 40 mm, and length L of 80 mm), and the pressure loss and the number of particles were measured under the same conditions as those of Example 1. The results of Comparative Example 1 are shown in Table 1.

[0092] (Example 2 to Example 9)

[0093] The particle evaluation was performed by counting the number of particles in the same manner as in Example 1 except that the average pore diameter of the porous cover and the particle diameter of the ceramic particles were changed as shown in Table 1. In addition, N2 gas was flowed into the porous component 1 from the porous cover 4A at one end of the porous component 1 at a flow rate of 50 ml (milliliter) / min (minute) and discharged from the porous cover 4B at the other end of the porous component 1, thereby measuring the pressure loss (Pa).

[0094] [Table 1]

[0095]

[0096] In all of Examples 1 to 9, no large gap was generated between the shell and the ceramic particles, and no damage to the shell and the ceramic particles was confirmed.

[0097] In addition, in Examples 1 to 9 except for Examples 4 and 9, as shown in Table 1, the pressure loss of the N 2 gas flow rate was lower than that of Comparative Example 1 (conventional porous body).

[0098] In addition, in Examples 1 to 9, the number of particles generated was equal to or less than that in Comparative Example 1.

[0099] In particular, in Examples 1 to 9 other than Examples 4 and 9, it was confirmed that both the number of generated particles was reduced and the differential pressure was reduced compared with Comparative Example 1.

[0100] (Example 10 to Example 13)

[0101] The average pore size of the porous cover and the filling area ratio of the ceramic particles were changed as shown in Table 2.

[0102] The number of particles was counted in the same manner as in Example 1, thereby evaluating the particles. In addition, N2 gas was flowed into the porous component 1 from the porous cover 4A at one end of the porous component 1 at a flow rate of 50 L / min, and discharged from the porous cover 4B at the other end of the porous component 1, thereby measuring the pressure loss (Pa).

[0103] The results are shown in Table 2.

[0104] [Table 2]

[0105]

[0106] In Examples 10 to 13, no large gap was generated between the housing and the ceramic particles, and no damage to the housing and the ceramic particles was confirmed.

[0107] As shown in Table 2, when the filling area ratio of the ceramic particles was 34% to 95% (Examples 11 to 13), a decrease in differential pressure was confirmed compared with Comparative Example 1.

[0108] (Examples 14 to 20)

[0109] The average pore diameter of the porous lid and the porosity of the porous lid were changed as shown in Table 3. Except for this, the number of particles was counted in the same manner as in Example 1, and thus the particles were evaluated. In addition, N2 gas was introduced into the porous member 1 from the porous lid 4A at one end of the porous member 1 at a flow rate of 50 ml (milliliters) / min (minute), and discharged from the porous lid 4B at the other end of the porous member 1, and thus the pressure loss (Pa) was measured.

[0110] The results are shown in Table 3.

[0111] [Table 3]

[0112]

[0113] In Examples 14 to 20, no large gap was generated between the housing and the ceramic particles, and no damage to the housing and the ceramic particles was confirmed.

[0114] In addition, as shown in Table 3, when either the average pore diameter of the porous lid satisfied 22 μm to 200 μm or the porosity of the porous lid satisfied 20% to 40%, a decrease in the number of generated particles or a decrease in differential pressure was confirmed compared with Comparative Example 1.

Claims

1. A porous component having ceramic particles, characterized in that: have: A cylindrical shell with openings at both ends; a plurality of the ceramic particles, wherein the ceramic particles are filled in the shell; and A pair of porous covers closes both ends of the cylindrical shell and seals the ceramic particles inside the shell.

2. The porous component having ceramic particles according to claim 1, wherein: The particle size of the ceramic particles is 100 μm or more and 800 μm or less.

3. The porous component having ceramic particles according to claim 1 or 2, characterized in that: The ratio of the filling area of ​​the ceramic particles is 34% or more and 95% or less relative to the length connecting both ends of the shell.

4. The porous member having ceramic particles according to claim 1, wherein: The porous cover has an average pore diameter of 22 μm to 200 μm, and a porosity of 20% to 40%.

5. A method for producing a porous component having ceramic particles, characterized in that: A method for producing a porous member having ceramic particles according to any one of claims 1 to 4, wherein the method comprises: A step of filling a plurality of ceramic particles into a cylindrical shell having openings at both ends; and A step of sealing both ends of the cylindrical shell with a pair of porous lids and sealing the ceramic particles inside the shell.

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