JP4135265B2 - Manufacturing method of chip-type electronic component - Google Patents

Description

【００２６】
表１から明らかなように、チップ型電子部品１の平均抵抗値は、抵抗値のバラツキが大きかった抵抗ランクｂ１ないしｂ７のすべてについて、目標とするバラツキが小さい抵抗値範囲９．９ＫΩないし１０．１ＫΩ内に入った。また、本発明の製造方法によることで、抵抗ランクｂ１ないしｂ３のセラミック素体１ａについては、抵抗値を増大させて目標とする抵抗値範囲に、抵抗ランクｂ５ないしｂ７のセラミック素体１ａについては、抵抗値を減少させて目標とする抵抗値範囲に入れることができた。
【００２７】
なお、上記実施例において焼結体２は負特性サーミスタを用いて説明したが、ＢａＴｉＯ₃系半導体セラミック等を主原料とする正特性サーミスタ、あるいはセラミックコンデンサ、バリスタにも適用することができる。
【００２８】
なお、本実施例のチップ型電子部品は、焼結体２の内部に外部電極５，５とそれぞれ電気的に接続された内部電極３，３を備えるが、内部電極３，３は焼結体２の内部にとどまり、何れの外部電極とも電気的に接続されなくてもよい。また、必ずしも内部電極３，３を備えていなくてもよい。
【００２９】
また、本実施例のチップ型電子部品は、仮外部電極４，４ならびに外部電極５，５の導電成分としてＡｇ−Ｐｄを用いたが、本発明は特にこれに限定されることなく、Ｎｉ、Ｃｕ、Ｃｒ、Ｚｎ、Ａｕ等の金属あるいは合金を適宜選択して用いることができる。
【００３０】
【発明の効果】
以上述べたように、本発明によるチップ型電子部品の製造方法によれば、焼結体の持つ電気特性に基づいて外部電極を形成するため、焼結体の材料に起因する電気特性のバラツキを減少させたチップ型電子部品を、比較的簡易な製造工程で製造することができる。
【００３１】
また、本発明によるチップ型電子部品の製造方法によれば、抵抗値の減少と増大の双方について同一方法によって抵抗値を修正することができ、より自由度の高い目標抵抗値の設定を実現できる。
【図面の簡単な説明】
【図１】本発明に係わる一つの実施形態のチップ型電子部品の製造工程を示した説明図である。
【図２】本発明に係る一つの実施形態のチップ型電子部品の断面図である。
【図３】図２のチップ型電子部品の製造工程におけるセラミック素体の断面図である。
【図４】図２に示したチップ型電子部品の抵抗値分布を示す説明図である。
【図５】従来のチップ型電子部品の断面図である。
【図６】従来の他のチップ型電子部品の断面図である。
【符号の説明】
１ チップ型電子部品
１ａ セラミック素体
２ 焼結体
３ 内部電極
４ 仮外部電極
５ 外部電極[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a chip-type electronic component in which an external electrode is formed on a ceramic sintered body, and more particularly to a method for manufacturing a chip-type electronic component having high electrical property accuracy.
[0002]
[Prior art]
FIG. 5 shows a cross-sectional view of a conventionally known chip electronic component such as a chip thermistor. The chip-type electronic component 11 includes a sintered body 12 made of a ceramic having a negative resistance temperature coefficient composed of a transition metal oxide as a main raw material, and external electrodes 13 and 13 provided at both ends of the sintered body 12. It consists of.
[0003]
The sintered body 12 is formed by laminating a plurality of ceramic green sheets so as to have a predetermined thickness, pressing them, cutting them into predetermined dimensions, and then firing them. The external electrodes 13 and 13 are formed as thick film electrodes by applying and baking an electrode paste on both ends of the sintered body 12. Although not shown, the chip-type electronic component 11 has a structure in which, for example, an internal electrode is formed inside the sintered body 12 and one end of the internal electrode is electrically connected to one of the external electrodes 13 and 13. There is also.
[0004]
By the way, the electrical characteristics of the chip-type electronic component 11, for example, the resistance value, is the variation in specific resistance of the material of the sintered body 12, the dimensional variation of the sintered body 2, and the positions of the edges 13 a and 13 b of the external electrodes 13 and 13. It varies depending on factors such as variation. Therefore, in the case of a chip-type thermistor, variation in resistance value occurs between ± 6% and ± 8%, even though specific resistance variation is reduced and cut dimensional accuracy is improved.
[0005]
Therefore, as a method for solving such a problem, a chip-type electronic component having an external electrode formed into a thin film by a sputtering method is disclosed in Japanese Patent Laid-Open No. 10-226704, which is shown in a sectional view in FIG. explain. The sintered body 22 was the same as the sintered body 12 used in the chip-type electronic component 11 described above.
[0006]
The chip-type electronic component 21 includes, for example, first layer external electrodes 24 and 24 made of Ni, second layer external electrodes 25 and 25 made of Ni, and a third layer made of Ni—Cu alloy at both ends of the sintered body 22. The external layer electrodes 26 and 26 and the fourth external layer electrodes 27 and 27 made of an Ag alloy are provided.
[0007]
First, the first layer external electrodes 24 and 24 are formed on both ends of the sintered body 22. Next, the resistance value between the first layer external electrodes 24, 24 is measured, and the sintered bodies 22 are layered based on the measurement results. Next, second layer external electrodes 25 and 25 are formed at both ends of the layered sintered body 22 so as to completely cover the first layer external electrodes 24 and 24. At this time, the distance between the electrodes of the second layer external electrodes 25, 25 is formed to be a predetermined distance L4 based on each layer. Next, the opposing edges 25a and 25b of the second layer external electrodes 25 and 25 are exposed, and third layer external electrodes 26 and 26 and fourth layer external electrodes 27 and 27 are formed in this order. In such a chip-type electronic component 21, regarding the variation in specific resistance of the material of the sintered body 22, the sintered body 22 is divided into layers, and between the second layer external electrodes 25, 25 based on the layered result. By solving the problem by determining the distance L4, the position variations of the end edges 13a, 13b of the external electrodes 13, 13 are formed by a thin film in which the dimensions of the second layer external electrodes 25, 25 can be set with high accuracy. Since the problem was solved, the resistance value variation was significantly reduced as compared with the chip-type electronic component 11.
[0008]
[Problems to be solved by the invention]
However, since the thin film external electrode is thin and easily oxidized, a plurality of thin films are overlapped to form the external electrodes 24, 24 to 26, 26 as described above, and the uppermost layer is formed to prevent migration. In addition, it is necessary to form the fourth layer external electrodes 27, 27 made of Sn-Pb, and there is a problem that the manufacturing process becomes complicated as compared with the chip-type electronic component 31 in which the external electrodes are formed with a thick film.
[0009]
Further, according to the conventional invention, since the second layer external electrode is formed so as to cover the first layer external electrode, the resistance value variation is corrected in the direction of reducing the interval between the external electrodes, that is, in the direction of decreasing the resistance value. However, in order to perform correction to increase the resistance value, it is necessary to apply a different technique such as etching.
[0010]
An object of the present invention is to solve the above-mentioned problems, and a chip in which an external electrode is formed by only one layer of a thick film material and variation in electrical characteristics caused by a sintered body material is reduced. An object of the present invention is to provide a method for manufacturing a mold electronic component by a relatively simple manufacturing process.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing a chip-type electronic component according to the present invention includes a step of obtaining a ceramic body by forming a pair of temporary external electrodes on a sintered body, and electrical characteristics between the temporary external electrodes. Measuring and layering the ceramic body based on the measurement results; removing a pair of temporary external electrodes formed at both ends of the ceramic body; and And a step of forming a pair of external electrodes on the sintered body from which the electrodes have been removed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A chip-type electronic component according to one embodiment of the present invention will be described in detail with reference to FIG.
[0013]
The chip-type electronic component 1 includes a sintered body 2, internal electrodes 3 and 3, and external electrodes 5 and 5. The sintered body 2 is made of a ceramic having a negative resistance temperature coefficient using an oxide of Mn, Ni, and Co as a main raw material. The internal electrodes 3 and 3 are mainly made of a conductive component such as Ag, Ag / Pd, etc., and are formed inside the sintered body 2 so that one ends thereof are opposed to each other with a predetermined interval, and the other end is formed of the sintered body 2. The both ends are electrically connected to the external electrodes 5 and 5, respectively. The external electrodes 5 and 5 are mainly composed of conductive components such as Ag and Ag / Pd, and are formed at both ends of the sintered body 2. Next, a manufacturing method of the chip-type electronic component 1 will be described with reference to FIGS. This will be described in detail based on the above.
[0014]
First, a predetermined amount of a plurality of transition metal oxides such as Mn, Ni and Co, an organic binder, a dispersing agent, a surfactant, an antifoaming agent and a solvent are added to form a ceramic green sheet (not shown) having a thickness of 50 μm. This is manufactured and cut into a predetermined size to obtain a cell (not shown). Next, electrode paste is printed on a predetermined number of cells to form a pair of internal electrodes 3, 3, and dummy cells that do not print internal electrodes are stacked above and below the cells on which the internal electrodes 3, 3 are printed. The sintered body 2 is obtained by calcining and integrating them, cutting them to a predetermined size, and firing them.
[0015]
Next, as shown in FIG. 3, an electrode paste made of, for example, an Ag—Pd alloy is applied and baked on both ends of the thermistor body so that the distance between the electrodes is L1, and temporary external electrodes 4 and 4 are formed. As a result, the ceramic body 1a is obtained. In addition, although the film | membrane structure and film thickness of the temporary external electrodes 4 and 4 are not specifically limited, It is preferable that it can remove easily after measuring the resistance value between electrodes.
[0016]
Next, the electrical characteristics of the ceramic body 1a, that is, the resistance value between the temporary external electrodes 4 and 4 are measured. The measured resistance distribution of the ceramic body 1a is a curve a shown in FIG. The horizontal axis of the graph shown in FIG. 4 indicates the resistance value (KΩ), and the vertical axis indicates the quantity (n) of the ceramic body 1a having the resistance value.
[0017]
Next, the ceramic body 1a is layered based on the graph of FIG. That is, when stratifying the ceramic body 1a, the resistance value range having the lowest resistance value is set as rank b1, and thereafter, the resistance rank is determined up to rank b7 as rank b2 and rank b3 for each predetermined resistance value range, The ceramic body 1a is layered.
[0018]
Next, the temporary external electrodes 4 and 4 of the ceramic body 1a layered in the resistance ranks b1 to b7 are removed, and the layered sintered body 2 is obtained. The removal method of the temporary external electrodes 4 and 4 includes chemical removal by nitric acid cleaning or the like, but is not particularly limited.
[0019]
Next, the external electrodes 5 and 5 are formed on both ends of the sintered body 2 from which the temporary external electrodes 4 and 4 have been removed based on the layered result, and the chip electronic component 1 shown in FIG. 2 is obtained. The external electrodes 5 and 5 extend to the main surface and side surfaces of the sintered body 2 so that the end edges 5a and 5a reach predetermined positions, for example, the sintered body 2 is made of an Ag—Pd alloy. It is formed by dipping in an electrode paste and baking.
[0020]
An interval L2 between the edges 5a and 5a of the external electrodes 5 and 5 formed on the ceramic body 1a is determined for each resistance rank b1 to b7. That is, the resistance value of the chip-type electronic component 1 is determined by the interval L2 between the external electrodes 5 and 5, and if the interval L1 <the interval L2, the resistance value of the chip-type electronic component 1 is greater than the resistance value of the ceramic body 1a. If the distance L1 is greater than the distance L2, the resistance value of the chip-type electronic component 1 is smaller than the resistance value of the ceramic body 1a. Therefore, in the present invention, for example, when the target resistance value range is the resistance rank b4, the chip-type electronic component 1 having the resistance ranks b1 to b3 is larger than the resistance value of the ceramic body 1a. External electrodes 5 and 5 are formed so as to have a distance L2. On the other hand, in order to lower the resistance value of the chip-type electronic component 1 having the resistance ranks b5 to b7 to be lower than the resistance value of the ceramic body 1a, the external electrodes 5 and 5 are formed so that the interval L1> the interval L2. The ceramic element body 1a having the resistance rank b4 is already within the target resistance value range. However, if the temporary external electrodes 4 and 4 are formed as a thin film by sputtering or the like, it is necessary to form a thick film again. Therefore, the external electrodes 5 and 5 are formed so that the distance L2 = the distance L1.
[0021]
The resistance value distribution of the chip-type electronic component 1 obtained in this way is as shown by a curve c shown in FIG. The range in which the resistance value varies around the target resistance value of 10 KΩ is reduced, and by performing the process of forming the external electrodes 5 and 5 for each of the resistance ranks b1 to b7, variation in the resistance value of the chip-type electronic component is greatly increased. It turns out that it can narrow.
[0022]
In addition, by further subdividing the resistance ranks b1 to b7 and finely setting the distance L2 between the external electrodes 5 and 5 for each of the subdivided resistance ranks, it is possible to further reduce the resistance value variation. Further, in the chip-type electronic component of the present embodiment, the target resistance value range is the resistance rank b4, but can be an arbitrary range.
[0023]
【Example】
Experiments based on the present invention were conducted using the chip-type electronic components shown in FIGS.
[0024]
Temporary external electrodes 4 and 4 are placed on both ends of sintered body 2 having a length of 1.80 mm and a height of 1.00 mm so that the distance L1 between the electrodes of temporary external electrodes 4 and 4 is 1.0 mm. After forming, the resistance value was measured. Next, based on the measured resistance value, as shown in FIG. 4, the resistance value range was set to 9.3 KΩ to 10.7 KΩ, and each rank width was divided into resistance ranks b1 to b7 having 0.2 KΩ. Next, the temporary external electrodes 4 and 4 were removed, and external electrodes 5 and 5 were formed for each of the resistance ranks b1 to b7. The dimensions of the chip-type electronic component 1 were 2.00 mm in length including the external electrodes 5 and 5 and 1.25 mm in height. Therefore, the distance L2 between the external electrodes 5 and 5 and the average resistance value of the chip-type electronic component 1 are summarized in Table 1 for each resistance rank.
[0025]
[Table 1]

[0026]
As is clear from Table 1, the average resistance value of the chip-type electronic component 1 is a resistance value range of 9.9 KΩ to 10.10 with a small target variation for all of the resistance ranks b1 to b7 where the variation of the resistance value was large. It was within 1KΩ. Further, according to the manufacturing method of the present invention, the ceramic element body 1a having the resistance ranks b1 to b3 is increased in resistance value to a target resistance value range, and the ceramic element body 1a having the resistance ranks b5 to b7 is used. Then, the resistance value was decreased to be within the target resistance value range.
[0027]
In the above embodiment, the sintered body 2 has been described using a negative characteristic thermistor, but it can also be applied to a positive characteristic thermistor mainly made of BaTiO ₃ based semiconductor ceramic or the like, a ceramic capacitor, or a varistor.
[0028]
Note that the chip-type electronic component of this example includes internal electrodes 3 and 3 that are electrically connected to the external electrodes 5 and 5, respectively, inside the sintered body 2. 2 does not need to be electrically connected to any external electrode. Further, the internal electrodes 3 and 3 are not necessarily provided.
[0029]
Moreover, although the chip-type electronic component of this example used Ag-Pd as the conductive component of the temporary external electrodes 4 and 4 and the external electrodes 5 and 5, the present invention is not particularly limited to this, A metal or alloy such as Cu, Cr, Zn, or Au can be appropriately selected and used.
[0030]
【The invention's effect】
As described above, according to the chip-type electronic component manufacturing method of the present invention, the external electrode is formed based on the electrical characteristics of the sintered body. The reduced chip type electronic component can be manufactured by a relatively simple manufacturing process.
[0031]
Further, according to the chip type electronic component manufacturing method of the present invention, the resistance value can be corrected by the same method for both the decrease and increase of the resistance value, and the setting of the target resistance value with a higher degree of freedom can be realized. .
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a manufacturing process of a chip-type electronic component according to one embodiment of the present invention.
FIG. 2 is a cross-sectional view of a chip-type electronic component according to one embodiment of the present invention.
3 is a cross-sectional view of the ceramic body in the manufacturing process of the chip-type electronic component of FIG. 2;
4 is an explanatory diagram showing a resistance value distribution of the chip-type electronic component shown in FIG. 2; FIG.
FIG. 5 is a cross-sectional view of a conventional chip type electronic component.
FIG. 6 is a cross-sectional view of another conventional chip-type electronic component.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Chip-type electronic component 1a Ceramic body 2 Sintered body 3 Internal electrode 4 Temporary external electrode 5 External electrode

Claims (1)

Forming a pair of temporary external electrodes on the sintered body to obtain a ceramic body; and
Measuring electrical characteristics between the temporary external electrodes, and stratifying the ceramic body based on the measurement results;
Removing a pair of temporary external electrodes formed at both ends of the ceramic body;
Forming a pair of external electrodes on the sintered body from which the temporary external electrodes have been removed based on the layers;
A method for manufacturing a chip-type electronic component, comprising:

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