Grinding method

Abstract

To provide a polishing method by which damage to a ceramic element can be suppressed.SOLUTION: A polishing method includes steps of filling a barrel tank with a plurality of chip components 1 and a plurality of media 2, and performing wet type barrel polishing. Each chip component 1 includes an element assembly 10. A diameter of a virtual ball S1, which passes two apexes of a plurality of apexes of the element assembly 10 that define a longest diagonal line in an element assembly 2, is "D". A maximum width of the media 2 is "d". A length in a third direction of the element assembly 10 is "T". A density of the media 2 is "p". In this case, the relationships of 2.37≤D / d≤8.65, d / T≤1.7, and 2.2 g / cm3≤ρ≤3.0 g / cm3 are satisfied.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a polishing method. [Background technology]

[0002] A polishing method for polishing chip component bodies by barrel polishing is known (for example, see Patent Document 1). In wet barrel polishing, a plurality of chip components and a plurality of media are filled into a barrel tank and agitated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-150256 Summary of the Invention [Problem to be solved by the invention]

[0004] In wet barrel polishing, media contacts the element body and promotes polishing of the element body. Furthermore, it is thought that the media suppresses contact between the element bodies and suppresses damage to the element body. The inventors of the present application have noticed that damage to the element body changes depending on the relationship between various parameters of the media and the element body.

[0005] An object of one aspect of the present invention is to provide a polishing method that can suppress damage to an element body. [Means for solving the problem]

[0006] In one aspect of the present invention, a polishing method includes filling a barrel tank with a plurality of chip components and a plurality of media, and performing wet barrel polishing. Each chip component includes a base body. Each base body has a rectangular parallelepiped shape including a pair of end faces facing each other in a first direction, a pair of side faces facing each other in a second direction intersecting the first direction, and a pair of main faces facing each other in a third direction intersecting the first direction and the second direction. In the base body, the length in the third direction is shorter than the length in the first direction and the length in the second direction. Among the plurality of vertices of the base body, the diameter of the virtual sphere passing through two vertices that define the longest diagonal line in the base body is "D". The maximum width of the media is "d". The length in the third direction of the base body is "T". The density of the media is "ρ". In this case, 2.37≦D / d≦8.65, d / T≦1.7, and 2.2g / cm 3 ≦ρ≦3.0g / cm 3 The following relationship is satisfied.

[0007] The inventor of the present application has found that chipping occurs in the base body according to the relationship between various parameters of the media and the base body. For example, the smaller the width of the media, the more difficult it is to ensure the distance between the base bodies. The larger the width of the media, the larger the exposed area of the surface of the base body when one media is separated from the surface of the base body. In the above polishing method, an appropriate relationship is ensured in the parameters of the media and the base body, and the occurrence of chipping in the base body can be suppressed.

[0008] In the above one aspect, when the length in the first direction is "L" and the length in the second direction is "W", the relationships of 5.2mm≦L≦6.0mm, 4.6mm≦W≦5.4mm, and 1.5mm≦T≦3.1mm may be further satisfied. In this case, the suppression of chipping in the base body can be significantly manifested.

[0009] In the above one aspect, the relationship of 1.0mm<d<3.0mm may be further satisfied. In this case, the suppression of chipping in the base body can be further suppressed.

[0010] In the above one embodiment, the relationship 1.5 mm≦d≦3.0 mm may further be satisfied, in which case chipping in the element body can be further suppressed.

[0011] In the above one embodiment, the relationship 0.4≦d / T may further be satisfied. In this case as well, chipping in the element body can be further suppressed.

[0012] In the above one embodiment, the relationship 0.6≦d / T may further be satisfied. In this case, chipping in the element body can also be further suppressed.

[0013] In the above one embodiment, the relationship D / d≦5.3 may further be satisfied, which also makes it possible to further suppress chipping in the element body.

[0014] In the above-mentioned one embodiment, the hardness of the media may be equal to or less than 100 in the Rockwell hardness test. In this case, chipping in the element body can be further suppressed. [Effects of the Invention]

[0015] An object of one aspect of the present invention is to provide a polishing method that can suppress damage to an element body. [Brief explanation of the drawings]

[0016] [Figure 1] 1 shows an element body in this embodiment and a virtual sphere that shows the general shape of the element body. [Figure 2] 10(a) to 10(e) are diagrams showing the contact state between the element body and the media. [Figure 3] 10(a) to 10(e) are diagrams showing the contact state between the element body and the media. [Figure 4] FIG. 10 is a diagram showing a state in which different element bodies are in contact with each other. [Figure 5] FIG. 10 is a diagram showing a state in which different element bodies are in contact with each other. [Figure 6] 10 is a graph showing the relationship between chipping defects and media width. [Figure 7] 10(a) and 10(b) are diagrams showing the state of chipping. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0018] In the polishing method of this embodiment, a plurality of chip components 1 are polished using a plurality of media 2. The polishing method is wet barrel polishing. The chip components 1 include an element body 10 and internal electrodes provided inside the element body 10. The chip components 1 constitute, for example, a multilayer electronic component. The multilayer electronic component is, for example, a multilayer capacitor or a multilayer inductor.

[0019] The element body 10 is made of, for example, a sintered body. The element body 10 is, for example, a ceramic element body made of ceramic. In this case, even if the ends of the internal electrodes are exposed from the element body 10 before firing, the ends of the internal electrodes are buried inside the element body 10 during firing due to the difference in shrinkage rate between the element body 10 and the internal electrodes. Therefore, by wet barrel polishing the element body 10 after firing, the ends of the internal electrodes can be reliably exposed from the element body 10. As a result, for example, the internal electrodes can be reliably connected to terminal electrodes provided on the outside of the element body 10.

[0020] In wet barrel polishing, a plurality of chip components 1 and a plurality of media 2 are loaded into a barrel tank. The barrel tank is also called a pot. Water, compound, etc. are loaded into the barrel tank. The loading rate of the plurality of chip components 1 and the plurality of media 2 in the barrel tank is, for example, 30% to 50% by volume. For example, if the volume of the plurality of chip components 1 loaded into the barrel tank is "v1" and the volume of the plurality of media 2 loaded into the barrel tank is "v2," then "v1" is 25% or less by volume of "(v1+v2)."

[0021] The barrel tank is driven with a plurality of chip components 1, a plurality of media 2, water, etc. placed inside, and the contents of the barrel tank are agitated. The barrel tank is driven, for example, by rotating the barrel tank, vibrating the barrel tank, or both. In this manner, wet polishing is performed.

[0022] The chip component 1 of this embodiment will be described in further detail with reference to Fig. 1. Fig. 1 shows an element body 10 and a virtual sphere S1 that indicates the general shape of the element body 10.

[0023] The element body 10 shown in FIG. 1 includes a pair of end faces 11, a pair of side faces 12, and a pair of main faces 13. The pair of side faces 12 and the pair of main faces 13 are located between the pair of end faces 11. The pair of end faces 11 face each other in the X-axis direction. The pair of side faces 12 face each other in the Y-axis direction. The pair of main faces 13 face each other in the Z-axis direction. For example, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. For example, the X-axis direction corresponds to a first direction, the Y-axis direction corresponds to a second direction, and the Z-axis direction corresponds to a third direction.

[0024] The plurality of element bodies 10 have a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. Each element body 10 includes eight vertices 15.

[0025] In element body 10, the length in the Z-axis direction is shorter than the lengths in the X-axis direction and the Y-axis direction. For example, in element body 10, the length in the X-axis direction is 5.6 mm, the length in the Y-axis direction is 5.0 mm, and the length in the Z-axis direction is 2.3 mm. In element body 10, the lengths in the X-axis direction, the Y-axis direction, and the Z-axis direction are changed within the tolerance range. For example, in element body 10, if the length in the X-axis direction is "L", the length in the Y-axis direction is "W", and the length in the Z-axis direction is "T", then, taking the tolerance range into consideration, the following relationships are satisfied: 5.2 mm≦L≦6.0 mm, 4.6 mm≦W≦5.4 mm, and 1.5 mm≦T≦3.1 mm.

[0026] The virtual sphere S1 is a circumscribed sphere that passes through two vertices that define the longest diagonal line in the prime field 10 among the multiple vertices 15 of the prime field 10. For example, the virtual sphere S1 passes through at least three of the multiple vertices 15 of the prime field 10. In the example shown in FIG. 1, the virtual sphere S1 passes through eight vertices 15 of the prime field 10. The diameter of the virtual sphere S1 is, for example, 7.85 mm.

[0027] The media 2 are arranged around the element 10 in, for example, a barrel tank. The media 2 contact the pair of end faces 11, the pair of side faces 12, and the pair of main faces 13. When the barrel tank is driven, the media 2 slide along the pair of end faces 11, the pair of side faces 12, and the pair of main faces 13, polishing the element 10. The media 2 cover each element 10 of the chip components 1, preventing contact between the different chip components 1. The media 2 cover the pair of end faces 11, the pair of side faces 12, and the pair of main faces 13 of each element 10. The media 2 have, for example, a spherical shape. In this specification, the term "spherical shape" includes not only a perfect spherical shape but also an approximately spherical shape having an elliptical cross section and an approximately spherical shape with at least a chipped portion. The following description will be given assuming that the media 2 are spherical. As a variation of this embodiment, the media 2 may have a shape other than spherical.

[0028] The medium 2 includes, for example, alumina and silica as materials. When the density of the medium 2 is "ρ", for example, 2.2 g / cm 3 ≦ρ≦3.0g / cm 3 The hardness of the medium 2 corresponds to, for example, 100 or less in HR15T of the Rockwell hardness test. The Rockwell hardness test in this specification is standardized in JIS Z 2245:2016.

[0029] When the maximum diameter of media 2 is "d", for example, the relationship 1.0 mm≦d≦3.0 mm is satisfied. More preferably, the relationship 1.5 mm≦d≦3.0 mm is satisfied. "Maximum diameter of media 2" refers to the largest diameter among the diameters of multiple media 2 placed in a barrel tank. "Diameter of media 2" corresponds to the maximum width of each media 2. In this specification, "maximum width" corresponds to the longest width value of each media 2. "Maximum diameter of media 2" corresponds to the largest maximum width among the maximum widths of multiple media 2 placed in a barrel tank.

[0030] When the diameter of the virtual sphere S1 is "D" and the maximum diameter of the media 2 is "d", for example, the relationship 2.37≦D / d≦8.65 is satisfied. More preferably, the relationship 2.62≦D / d≦7.85 is satisfied. Even more preferably, the relationship D / d≦5.3 is satisfied. In particular, when the length of the element body 10 in the X-axis direction is 5.60 mm, the length in the Y-axis direction is 5.00 mm, and the length in the Z-axis direction is 2.30 mm, the relationship 2.62≦D / d≦7.85 may be satisfied.

[0031] When the maximum diameter of the media 2 is "d" and the length of the element body 10 in the Z-axis direction is "T", for example, the relationship d / T≦1.7 is satisfied. More preferably, the relationship d / T≦1.1 is satisfied. Even more preferably, the relationship 0.4≦d / T is satisfied. Even more preferably, the relationship 0.6≦d / T is further satisfied. In particular, when the length of the element body 10 in the X-axis direction is 5.60 mm, the length in the Y-axis direction is 5.00 mm, and the length in the Z-axis direction is 2.30 mm, the relationship d / T≦1.1 may be satisfied.

[0032] FIGS. 2(a) to 2(e) show contact between the element body 10 and multiple media 2. Multiple media 2 cover the element body 10. FIGS. 3(a) to 3(e) show a state in which one media 2 is separated from the surface of the element body 10. FIGS. 2(a) to 2(e) and 3(a) to 3(e) show states in which media 2 of different sizes are used. In FIGS. 2(a) and 3(a), the maximum diameter of the media 2 is 1 mm. In FIGS. 2(b) and 3(b), the maximum diameter of the media 2 is 2 mm. In FIGS. 2(c) and 3(c), the maximum diameter of the media 2 is 3 mm. In FIGS. 2(d) and 3(d), the maximum diameter of the media 2 is 4 mm. In FIGS. 2(e) and 3(e), the maximum diameter of the media 2 is 5 mm.

[0033] Figure 4 shows the state in which different element bodies 10 are in contact with each other in the state of Figure 3(a). Figure 5 shows the state in which different element bodies 10 are in contact with each other in the state of Figure 3(c). In Figure 4, the ratio of the diameter of the virtual sphere S1 to the maximum diameter of the medium 2 is 7.85. In Figure 5, the ratio of the diameter of the virtual sphere S1 to the maximum diameter of the medium 2 is 2.61.

[0034] The smaller the width of the medium 2, the smaller the distance between different element bodies 10 and the easier it is for different element bodies 10 to come into contact with each other. The larger the width of the medium 2, the larger the exposed area of ​​the surface of the element body 10 when one medium 2 is separated from the surface of the element body 10, and the easier it is for different element bodies 10 to come into contact with each other.

[0035] Next, the effects of the polishing method according to this embodiment and the modified example will be described.

[0036] It is believed that the smaller the width of the media 2, the more difficult it is to ensure the distance between the element bodies 10. The larger the width of the media 2, the larger the exposed area of ​​the surface of the element body 10 when one media 2 is separated from the surface of the element body 10. In the polishing methods of this embodiment and its modified examples, 2.37≦D / d≦8.65, d / T≦1.7, and 2.2 g / cm3 ≦ρ≦3.0g / cm 3 In this case, an appropriate relationship is ensured between the parameters of the medium 2 and the element body 10, and chipping in the element body 10 can be suppressed. For example, if the relationships 5.2 mm≦L≦6.0 mm, 4.6 mm≦W≦5.4 mm, and 1.5 mm≦T≦3.1 mm are further satisfied, chipping in the element body 10 can be significantly suppressed.

[0037] Table 1 below shows data from experimental examples. [Table 1]

[0038] FIG. 6 is a graph showing the relationship between chip defects and the width of the media 2 in the experimental results including Experimental Examples 1 to 5. FIG. 7(a) shows a state in which a relatively small chip D1 has occurred in the element body 10. FIG. 7(b) shows a state in which a relatively large chip D2 has occurred in the element body 10. The dimensions of the chip components 1 are the same in the experimental results shown in FIG. 6. Plot P1 is data related to a relatively large chip. Plot P2 is data related to a relatively small chip. Plot P3 is data related to all chips. The horizontal axis shows the diameter of the multiple media 2 filled in the barrel tank in mm. The vertical axis shows the number of chip-related defects as an index. In Experimental Example 1, the number of chip components that had chip-related defects was set to 100 as a reference.

[0039] When various parameters indicating the relationship between the medium 2 and the element 10 are appropriately set, the occurrence of chipping in the element 10 can be suppressed. In particular, when 2.62≦D / d≦7.85, d / T≦1.1, and 2.2 g / cm 3 ≦ρ≦3.0g / cm 3 If the following relationship is satisfied, the occurrence of chips in the element body 10 can be suppressed. In this case, the occurrence of relatively large chips can be particularly suppressed.

[0040] For example, the relationship of 1.0 mm < d < 3.0 mm is further satisfied. In this case, chipping in the base body 10 can be further suppressed. In particular, the occurrence of relatively large chipping can be suppressed, and the occurrence of all chipping can also be suppressed more than in Experimental Example 1.

[0041] For example, the relationship of 1.5 mm < d < 3.0 mm is further satisfied. In this case, the suppression of chipping in the base body 10 can be further suppressed.

[0042] For example, the relationship of 0.4 ≦ d / T is further satisfied. Also in this case, chipping in the base body 10 can be further suppressed.

[0043] For example, the relationship of 0.6 ≦ d / T is further satisfied. Also in this case, chipping in the base body 10 can be further suppressed.

[0044] For example, the relationship of D / d ≦ 5.3 is further satisfied. Also in this case, chipping in the base body 10 can be further suppressed.

[0045] For example, the hardness of the medium 2 may be 100 or less in the Rockwell hardness test. Also in this case, chipping in the base body 10 can be further suppressed.

[0046] As described above, the embodiments and modifications of the present invention have been described. However, the present invention is not necessarily limited to the above-described embodiments and modifications, and various changes can be made without departing from the gist thereof.

[0047] For example, the shape of the chip component 1 is not limited to the above-described shape. It can also be applied to various chip components 1.

[0048] As understood from the description of the above-described embodiments, this specification includes the disclosure of the following aspects. (Appendix 1) Filling a barrel tank with a plurality of chip components including a base body and a plurality of media, and performing wet barrel polishing, each of the element bodies has a rectangular parallelepiped shape including a pair of end faces opposing each other in a first direction, a pair of side faces opposing each other in a second direction intersecting the first direction, and a pair of main faces opposing each other in a third direction intersecting the first direction and the second direction, In the element body, the length in the third direction is shorter than the length in the first direction and the length in the second direction, When the diameter of a virtual sphere passing through two vertices defining the longest diagonal line of the element body among the multiple vertices of the element body is D, the maximum width of the medium is d, the length of the element body in the third direction is T, and the density of the medium is ρ, 2.37≦D / d≦8.65 d / T≦1.7 2.2g / cm 3 ≦ρ≦3.0g / cm 3 The polishing method satisfies the relationship. (Appendix 2) When the length in the length direction is L and the length in the width direction is W, 5.2mm≦L≦6.0mm 4.6mm≦W≦5.4mm 1.5mm≦T≦3.1mm 2. The polishing method according to claim 1, further satisfying the following relationship: (Appendix 3) 1.0mm <d<3.0mm 3. The polishing method according to claim 2, further satisfying the following relationship: (Appendix 4) 1.5mm≦d≦3.0mm 3. The polishing method according to claim 2, further satisfying the following relationship: (Appendix 5) 0.4≦d / T 5. The polishing method according to any one of claims 1 to 4, wherein the following relationship is further satisfied: (Appendix 6) 0.6≦d / T 5. The polishing method according to any one of claims 1 to 4, wherein the following relationship is further satisfied: (Appendix 7) D / d≦5.3 7. The polishing method according to any one of claims 1 to 6, wherein the following relationship is further satisfied: (Appendix 8) 8. The polishing method according to any one of claims 1 to 7, wherein the hardness of the media corresponds to 100 or less in the Rockwell hardness test HR15T. [Explanation of symbols]

[0049] 1...chip component, 2...media, 10...element body, 11...end face, 12...side face, 13...main surface, 15...vertex, S1...virtual sphere.

Claims

1. The method includes filling a barrel tank with a plurality of chip components each including an element body and a plurality of media, and performing wet barrel polishing, each of the element bodies has a rectangular parallelepiped shape including a pair of end faces opposing each other in a first direction, a pair of side faces opposing each other in a second direction intersecting the first direction, and a pair of main faces opposing each other in a third direction intersecting the first direction and the second direction, In the element body, the length in the third direction is shorter than the length in the first direction and the length in the second direction, When the diameter of a virtual sphere passing through two vertices defining the longest diagonal line of the element body among the multiple vertices of the element body is "D", the maximum width of the medium is "d", the length of the element body in the third direction is "T", and the density of the medium is "ρ", 2.37≦D / d≦8.65 d / T≦1.7 2.2g / cm ３ ≦ρ≦3.0g / cm ３ The polishing method satisfies the relationship.

2. If the length in the first direction is "L" and the length in the second direction is "W", 5.2mm≦L≦6.0mm 4.6mm≦W≦5.4mm 1.5mm≦T≦3.1mm 2. The polishing method according to claim 1, further satisfying the following relationship:

3. 1.0mm<d<3.0mm 3. The polishing method according to claim 2, wherein the following relationship is further satisfied:

4. 1.5mm≦d≦3.0mm 3. The polishing method according to claim 2, wherein the following relationship is further satisfied:

5. 0.4≦d / T 2. The polishing method according to claim 1, further satisfying the following relationship:

6. 0.6≦d / T 2. The polishing method according to claim 1, further satisfying the following relationship:

7. D / d≦5.3 2. The polishing method according to claim 1, further satisfying the following relationship:

8. 8. The polishing method according to claim 1, wherein the media has a hardness equivalent to 100 or less in HR15T of the Rockwell hardness test.

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