JP4493276B2 - Manufacturing method of chip-shaped ceramic parts - Google Patents

Description

【００３８】
表２は、本発明実施例のチッピング発生数を示す。サンプルやロットが異なっても、チッピング発生率は８５ｐｐｍ以下と極めて低いことが判る。なお、チッピングの有無は、双眼顕微鏡を用いて倍率２０倍で０．０３×０．０３ｍｍ以上のチッピング発生率を調査した。
【００３９】
【表２】

【００４０】
さらに、表面粗さを測定した結果を表３に示すように、磁器（セラミック）素材の表面粗さ（Ｒａ）は0.2〜0.5μｍ、Cuメッキ品の表面粗さ（Ｒａ）は0.03〜0.06μｍと低く、かつそのバラツキも少ないことがわかる。
【００４１】
【表３】

【００４３】
また、本発明の製造方法によれば、チップコイル、チップインダクタのセラミック部品製造工程において、バレル研磨の最適条件により磁器の欠け、チッピングや割れの不良発生を低減させることができる。しかも、コーナーＲ及び表面粗度を管理することにより、巻き線タイプでは、稜部及びコーナー部の曲率半径を最適条件で管理することにより、コイルの断線を改善でき、非巻き線タイプ（メッキ処理レーザー加工タイプ）では、稜部及びコーナー部の曲率半径を最適条件で管理することにより、断線を改善でき、かつ、表面粗さを最適条件で均一な仕上がりに管理することにより、メッキ強度が向上すると共にメッキ層が均一になり品質特性が安定する。
【図面の簡単な説明】
【図１】 本発明のチップ状セラミック部品を示す斜視図である。
【図２】 本発明のチップ状セラミック部品の製造方法を説明するための図である。
【図３】 本発明のセラミック部品を用いた巻き線型チップコイルの説明図である。
【図４】 本発明のセラミック部品を用いた非巻き線型チップコイルの説明図である。
【図５】 本発明実施例におけるコーナー部の測定個所を示す説明図である。
【符号の説明】
１： セラミック部品
１ａ：稜部
１ｂ：コーナー部
１ｃ；表面
２；回転ポット本体
２ ａ；水
２ ｂ；セラミック部品
２ ｃ；セラミックボール
２ ｄ；セラミック粉末
３ ａ；セラミック部品
３ ｂ：電極（メタライズ）
３ ｃ；コイル
３ ｄ；樹脂キャップ
４ ａ；銅メッキ
４ ｂ；セラミック部品
４ ｃ；電極（メタライズ）
５ ａ；Ｒ測定個所
５ ｂ；Ｒ測定個所
５ ｃ；Ｒ測定個所
５ｄ； Ｒ測定個所
５ ｅ；セラミック部品
５ ｆ；セラミック部品コア部断面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ceramic component for a chip-shaped ceramic electronic component and a manufacturing method thereof.
[0002]
[Prior art]
Ceramic electronic components such as a chip coil and a chip inductor include a winding type shown in FIG. 3 and a non-winding type shown in FIG. Both use chip-shaped ceramic parts with flanges at both ends as the core, and there is a need for ceramic parts that reduce the occurrence of chipping, chipping and cracking defects by making the ridges and corners curved. .
[0003]
Therefore, conventionally, a method has been employed in which a large number of ceramic sintered bodies are introduced into a rotating pot, and the rotating pot is rotated to polish and round the corner portion of the sintered body.
Specifically, a plurality of ceramic sintered bodies having a ratio of about 20 to 40% by volume of the total internal volume in the rotating pot and water as a buffering agent at a ratio of about 90 to 95% by volume of the total internal volume. After that, the pot is sealed and rotated at a predetermined rotation speed for several hours. Due to this rotation, the ceramic sintered bodies collided with each other, and the corner portions of the ceramic sintered bodies were rounded.
[0004]
In Patent Document 1, when a ceramic sintered body is prepared, an inorganic powder having an average particle diameter of 100 μm or less and an inner volume of 25 to 50% by volume as a buffering agent is placed in the rotating pot. Although the manufacturing method of the ceramic component and a step of rotating by introducing a plurality of the ceramic sintered body is shown, chipping, even defectives chip ping or cracking occurs to generate in the portion not desired.
[0005]
In Patent Document 2, a process of preparing a ceramic sintered body, a plurality of ceramic sintered bodies, an abrasive having a hardness lower than that of the ceramic sintered body, and a buffer solution are put into a polishing container and polished. A method of manufacturing a ceramic component comprising the steps is shown.
[0006]
Patent Document 3 discloses a ceramic substrate for chip-shaped electronic components having curved surfaces with a curvature radius of 0.02 to 0.2 mm at all ridges and corners. This is characterized in that after the ceramic green sheet is cut into a single size of a chip-shaped electronic component, barrel polishing is performed in the state of the formed body, after calcination, or at any stage. As a specific example, the barrel polishing conditions are as follows: a sintered body and an alumina ball having a diameter of 5 mm in a cylindrical pot having an inner dimension of 25 cm × 30 cm in a volume ratio of 1:10:10, respectively. The pot was made to have a space ratio in the pot of 50%, and the pot was rotated at a speed of 15 revolutions per minute for 120 hours, barrel polished, washed in running water, and dried.
[0007]
[Patent Document 1]
JP 7-22271 A [Patent Document 2]
JP-A-7-37751 [Patent Document 3]
Japanese Patent Application No. 7-14813 [0008]
[Problems to be solved by the invention]
In the conventional polishing method for rounding the ridges and corners of the ceramic sintered body, the number of rotations of the pot barrel is increased or the polishing time is extended in order to increase the polishing amount. When a material having a higher hardness than the ceramic sintered body is used as the abrasive, chipping occurs in the ceramic sintered body due to collision between the sintered body and the abrasive. When a polishing material having a hardness lower than that of the ceramic sintered body is used, there is a problem that burrs at the ridges and corners cannot be completely removed.
[0009]
For a method of Patent Document 3, in particular by suppressing the occurrence of chipping in the ceramic component having flanges at both ends, it is difficult to form a curved surface on ridge and corner of the entire hand.
[0010]
In addition, in the non-wound type chip ceramic component as shown in FIG. 4, uniform surface roughness is required, and management is necessary so that the surface roughness becomes uniform at the same time that the ridges and corners are rounded. . Since burrs of ceramic sintered bodies do not exist uniformly at all the ridges and corners, the conventional polishing method has partial burrs or rounds more than necessary. It was difficult to obtain a uniform finish, and there was a problem with stable quality.
[0012]
Further, the present invention provides a method for manufacturing a chip-shaped ceramic part having flange portions at both ends, and after dry pressing the raw material powder, the molded body is allowed to stand at 30 ° C. to 60 ° C. for 8 hours or more and dried, followed by barrel polishing. Te deburring, was to produce a chip-shaped ceramic components by performing Device barrels polishing after firing.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0014]
As shown in FIG. 1, the chip-shaped ceramic component 1 having flange portions at both ends has a size of, for example, 1.0 × 0.5 × 0.5 mm, and has a curvature at all the ridge portions 1a and corner portions 1b. While having a curved surface with a radius of 0.01 to 0.2 mm, the arithmetic average roughness (Ra) of the surface 1c is 1 μm or less.
[0015]
Here, the curvature radius of 0.01 to 0.2 mm is less than 0.01 mm, and there is a risk that breakage may occur in both the winding type and the copper plating type, and the effect of preventing cracks is poor. On the other hand, if it exceeds 0.2 mm, the width of the flange portion as a chip coil becomes narrow, so that the mounting strength becomes weak at the stage of mounting.
[0016]
The reason why the arithmetic average roughness (Ra) of the surface 1a is 1 μm or less is that when it exceeds 1 μm, in the Cu plating type, the plating layer becomes non-uniform and the quality characteristics become unstable.
[0017]
The material of the ceramic component of the present invention is not particularly limited, and is widely used according to the purpose of use, such as alumina, steatite, forsterite, and ferrite.
[0018]
About the manufacturing method of the chip-shaped ceramic component which has this flange part at both ends, after carrying out dry press molding of the raw material powder, the molded body is allowed to stand at 30 ° C. to 60 ° C. for 8 hours or more and dried, and then barrel-polished to remove burrs. removed, and performs Device barrels polishing after firing.
[0019]
Hereinafter, the manufacturing method of the chip-shaped ceramic component 1 will be described in detail.
[0020]
When ceramic powder (alumina) is dry-pressure molded, barrel molding of the molded body using mesh is performed before sintering the burrs of the molded body generated on the upper and lower surfaces of the mold. What was removed without generation of cracks or the like is fired, and the obtained sintered body is subjected to barrel polishing.
[0021]
At this time, the deburring operation is not performed immediately after the molding, and it is allowed to stand at 30 ° C. to 60 ° C. for 8 H or more and dried. The purpose is to facilitate deburring during deburring. Moreover, it is for preventing the removed burr | flash adhering to a molded object. If the deburring operation is performed in a dry state, the bonding of the particles in the burr portion is stronger than that in the dried state, and it is difficult to remove the burrs.
[0022]
Regarding the barrel treatment process, in the conventional method, a plastic net was used, but in the present invention, the inner wall of a stainless steel net with a handle has a smaller size than a plastic (polyethylene, nylon, for example) molded body. [For example, a 40 mesh (wire diameter: 244 μm, opening: 503 to 550 μm)] is applied and deburring is performed.
[0023]
Bury is removed by putting hundreds of thousands of ceramic molded bodies for chip coils into this fixed net with a handle, swinging up and down so as not to spill, and causing the molded bodies to collide with each other. The stainless steel mesh uses a mesh larger than the plastic mesh. This is because the shape of the net is not deformed even if hundreds of thousands of molded bodies are put and shaken.
[0024]
In addition, the use of a plastic net for the inner wall may be due to wear of the plastic when the molded product is put in and shaken to deburr, but this wear disappears during firing and does not affect the product. If a metal net is used for the inner wall, the worn material will adhere to the molded body and cause discoloration and foreign matter defects after firing.
[0025]
For post-processing after the molded body barrel treatment, after removing burrs from the molded body in the fixed net colander, the raw material powder adhering to the molded colander or the molded body (powdered powder) is locally exhausted. On the dust collection duct connected to the device (dust collector), it is blown off with an air gun to remove burrs in the net.
[0026]
The molded body thus obtained is placed on a firing jig and fired in an oxidizing atmosphere at about 1400 ° C. using a continuous tunnel furnace.
[0027]
Next, barrel polishing shown in FIG. 2 is performed on the obtained sintered body, and curved surface processing is performed on each ridge and corner .
[0028]
In the present invention, in a cylindrical rotary pot 2 having an inner dimension of 220 mm × 240 mm, a plurality of sintered bodies 2b, ceramic balls 2c having an average particle diameter of 3 to 50% of an inner volume of 50 to 90% by volume, ceramic powder (grains) An abrasive and a buffer containing 2d and water 2a (diameter of 100 μm or less) are charged. By this combination, the required characteristics of the surface roughness and corner R can be obtained at the same time, and the occurrence rate of chipping (chip) defects of the ceramic sintered body can be minimized. The pot is rotated for 6 hours at a speed of 45 revolutions per minute, barrel polished, washed in running water and dried.
[0029]
As a result, has a curved surface of radius of curvature 0.01~0.1mm to all of the ridges 1a and corner portions 1b as shown in FIG. 1, the arithmetic mean roughness of the surface 1a (Ra) is 1μm Chip-shaped ceramic parts having flange portions at both ends as described below can be obtained.
[0030]
As the rotary pot to be used, one having an appropriate structure conventionally used in a method of manufacturing a ceramic electronic component or the like can be adopted. Further, the rotation speed and the rotation time of the pot can be appropriately determined according to the shape and size of the ceramic sintered body to be charged.
[0031]
In addition, according to the manufacturing method of the present invention, particularly in a ceramic for chip inductor which is a small molded product, the production can be greatly increased from several million to several hundred million, and a large amount of product (molded product) can be efficiently produced. Deburring is performed, and there is no cracking, chipping or chipping in the barrel polishing step after sintering, and a uniform curvature radius of each ridge and corner and surface roughness of the sintered body are obtained simultaneously. It becomes possible . In addition, the quality problem due to burrs is eliminated, and due to the improvement of work efficiency, the conventional method performs deburring work in units of 10,000 to 20,000 pieces at a time. Deburring can be done in units of ~ 300,000).
[0032]
Processing time is the same as before. The treatment time depends on the wear of the mold, 5 minutes for the new mold and 15 to 20 minutes for the worn one.
[0033]
Then, if this ceramic part is used as a core part and an electrode 3b, a coil 3c, and a resin cap 3d are formed as shown in FIG. 3, a wound chip coil is obtained. Further, as shown in FIG. 4, when a copper plating 4a is formed, and the plating is peeled off in a coil shape by a laser to form an electrode 4c, a non-winding chip coil is obtained.
[0034]
【Example】
As an embodiment of the present invention, the above-described molded body barrel-polished and deburred is placed in a cylindrical rotating pot 2 having an inner dimension of 250 × 300 mm when post-processing the ceramic sintered body with the rotating pot. An abrasive and a buffer containing ceramic balls 2c having an average particle size of 3 to 50% by volume of the internal volume, ceramic balls 2c, ceramic powder (particle size of 100 μm or less) 2d, and water 2a were added. A plurality of ceramic sintered bodies were put into the rotating pot and rotated. The 3φ ceramic balls have a slightly lower hardness than the ceramic sintered body (aluminum oxide + silicon dioxide is the main component), and the ridges and corners of the ceramic sintered body are stressed by the weight (specific gravity 1.6 to 2.4) The surface is ground and curved surface processing (R attachment) is performed. Since it is a sphere, the occurrence of chipping of the ceramic sintered body can be suppressed, and uniform processing can be obtained with less variation in curved surface processing.
[0035]
Ceramic powder (100 μm or less) has higher hardness than ceramic sintered body (aluminum oxide 99% or more), and is interposed between ceramic sintered body and ceramic sintered body or ceramic ball, and receives stress, and ceramic sintered body Grind the surface. Since the particle size configuration is fine and the grinding force is excellent, the surface of the ceramic sintered body can be uniformly treated without unevenness. Water acts as a buffer and works to obtain a uniform finish. This combination is the point, and the above composition ratio is an indispensable element for everything to function.
[0036]
Table 1 shows the relationship between the barrel polishing time of the chip coil and the radius of curvature of the corner portion. Note that the measurement points of the radius of curvature are as shown in FIG. From this result, the radius of curvature R of the corner can be adjusted according to the barrel processing time, and the optimum barrel processing is 6 hours. However, if it is desired to increase the radius of curvature, the time may be lengthened.
[0037]
[Table 1]

[0038]
Table 2 shows the number of chipping occurrences in the embodiment of the present invention. It can be seen that even if the samples and lots are different, the chipping occurrence rate is as low as 85 ppm or less. In addition, the presence or absence of chipping was investigated using a binocular microscope for a chipping occurrence rate of 0.03 × 0.03 mm or more at a magnification of 20 times.
[0039]
[Table 2]

[0040]
Furthermore, as shown in Table 3, the results of measuring the surface roughness are as follows. The surface roughness (Ra) of the porcelain (ceramic) material is 0.2 to 0.5 μm, and the surface roughness (Ra) of the Cu plated product is 0.03 to 0.06 μm. It is low and there is little variation.
[0041]
[Table 3]

[0043]
Further, according to the manufacturing method of the present invention, in the ceramic component manufacturing process of the chip coil and the chip inductor, the occurrence of chipping, chipping and cracking defects can be reduced under the optimum conditions for barrel polishing. Moreover, by managing the corner R and surface roughness, the winding type, by managing the curvature radius of the ridge portion and the corner portion under optimum conditions, can improve breakage of the coil, the non-winding type (plating in laser processing type), by managing the curvature radius of the ridge portion and the corner portion under optimum conditions, can be improved disconnection, and by managing the surface roughness uniform finish optimum, improved plating strength In addition, the plating layer becomes uniform and the quality characteristics are stabilized.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a chip-shaped ceramic component of the present invention.
FIG. 2 is a diagram for explaining a method of manufacturing a chip-shaped ceramic component according to the present invention.
FIG. 3 is an explanatory diagram of a wound chip coil using the ceramic component of the present invention.
FIG. 4 is an explanatory diagram of a non-winding chip coil using the ceramic component of the present invention.
FIG. 5 is an explanatory diagram showing measurement points of a corner portion in an embodiment of the present invention.
[Explanation of symbols]
1: Ceramic part 1a: Ridge part 1b: Corner part 1c; Surface 2; Rotary pot body 2a; Water 2b; Ceramic part 2c; Ceramic ball 2d; Ceramic powder 3a; Ceramic part 3b: Electrode (metallized) )
3 c; coil 3 d; resin cap 4 a; copper plating 4 b; ceramic component 4 c; electrode (metallized)
5 a; R measurement location 5 b; R measurement location 5 c; R measurement location 5 d; R measurement location 5 e; Ceramic component 5 f;

Claims (2)

  In the manufacturing method of chip-shaped ceramic parts having flange portions at both ends, after the raw material powder is dry-pressure-molded, the molded body is left to dry at 30 ° C to 60 ° C for 8H or more and then barrel-polished to remove burrs. A method for producing a chip-shaped ceramic component, comprising performing barrel polishing after firing. Barrel polishing after the firing, and an average particle size of 3mm ceramic balls as an abrasive, using a following ceramic powder having an average particle diameter of 100 [mu] m, using water as a buffer, the internal volume of these in the rotational pot The method for producing a chip-shaped ceramic component according to claim 1, wherein the method is performed in a range of 50 to 90% by volume.

Images