JP4983400B2 - Feed-through three-terminal capacitor - Google Patents

Description

The present invention relates to a feedthrough three-terminal capacitor configured by laminating an insulating layer and internal electrodes.

As a conventional feedthrough three-terminal capacitor , a feedthrough three-terminal electronic component described in Patent Document 1 has been proposed. FIG. 9 is an exploded view of the through-type three-terminal electronic component. In the through-type three-terminal electronic component, a dielectric layer 202 having an internal electrode 201 as shown in FIG. 9A and a dielectric layer 204 having an internal electrode 203 as shown in FIG. 9B. Are alternately stacked to form a capacitor.

  In the through-type three-terminal electronic component, dummy internal electrodes 205 that do not contribute to the formation of capacitance are formed on the dielectric layers 202 and 204. Thereby, in each part of the penetration type three-terminal electronic component, the number of electrodes laminated in the lamination direction becomes equal. As a result, the degree of sintering in each part of the through-type three-terminal electronic component is equalized, oversintering and insufficient sintering of the internal electrodes 201 and 203 are prevented, and the direct current resistance of the through-type three-terminal electronic component is reduced.

  However, in the through-type three-terminal electronic component, peeling is likely to occur between the dielectric layers 202 and 204. Specifically, when the internal electrodes 201 and 203 are enlarged in order to increase the capacitance of the capacitor, the portion between the edges of the internal electrodes 201 and 203 and the edges of the dielectric layers 202 and 204 in FIG. The width of the gap is narrowed. As a result, in the vicinity of the end face 206, the contact area between the dielectric layers 202 and 204 is reduced, the adhesion between the dielectric layers 202 and 204 is deteriorated, and peeling between the dielectric layers 202 and 204 is likely to occur. turn into.

There is also a problem that a short circuit occurs between the internal electrodes 201 and 203. Specifically, the dielectric layers 202 and 204 are made thinner as the number of stacked layers increases. Therefore, a short circuit is likely to occur between the internal electrodes 201 and 203.
JP 2003-22932 A

Accordingly, an object of the present invention is to provide a feedthrough three-terminal capacitor that can prevent separation between insulating layers and can prevent a short circuit between internal electrodes.

The present invention includes a laminate configured by laminating a plurality of insulating layers, a plurality of internal electrodes laminated together with the plurality of insulating layers, and a plurality of external electrodes formed on a side surface of the laminate. The plurality of internal electrodes include a main body having a shape in which four corners of a quadrangle are cut off in a straight line, and a lead part connecting the main body part and the external electrode, The width is shorter than the length of the side of the main body portion to which the drawer portion is connected, and the linear portions formed at the four corners of the main body portion are seen from the linear portions of the adjacent main body portions and from the stacking direction. The plurality of internal electrodes include a first internal electrode and a second internal electrode, and constitute a capacitor, and the first internal electrodes are opposed to each other. Formed on the first side surface and the second side surface of the laminate The external electrode includes two lead portions connected to the external electrode, and the second internal electrode is formed on a third side surface and a fourth side surface of the stacked body facing each other. Two linear portions of the first internal electrode do not overlap with the second internal electrode when viewed in plan from the stacking direction, and the first internal electrode A signal potential is connected to the external electrode formed on the side surface and the second side surface, and a ground potential is connected to the external electrode formed on the third side surface and the fourth side surface, It is characterized by.

  According to the present invention, the width of the drawer portion is shorter than the length of the side of the main body portion to which the drawer portion is connected. For this reason, the contact area between adjacent insulating layers is larger than when the width of the lead portion is equal to the length of the side of the main body portion to which the lead portion is connected. As a result, the degree of adhesion between adjacent insulating layers is improved, and peeling between insulating layers is prevented.

  In the present invention, the main body portion may not be formed in the region where the drawer portion is formed when viewed from the stacking direction.

  According to the present invention, the main body portion is not formed in the region where the drawer portion is formed when viewed from the stacking direction. Therefore, there is no possibility that the drawer part is pressed by the main body part during crimping and the drawer part is crushed. As a result, the lead portion and the external electrode are more reliably connected.

  According to the present invention, since the width of the lead portion is shorter than the length of the side of the main body portion to which the lead portion is connected, the degree of adhesion between adjacent insulating layers is improved and peeling between the insulating layers is prevented. .

(About the configuration of feedthrough type three-terminal capacitor )
Hereinafter, a feedthrough three-terminal capacitor according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is an external perspective view of the through-type three-terminal capacitor 1. 2 (a) is a cross-sectional view in the xz plane of the through-type three-terminal capacitor 1, FIG. 2 (b) is a sectional view in the yz plane of the through-type three-terminal capacitor 1. Note that the x-axis, y-axis, and z-axis are orthogonal to each other.

As shown in FIG. 1, the feedthrough three-terminal capacitor 1 includes a multilayer body 10 and external electrodes 12a, 12b, 12c, and 12d. The laminate 10 is configured by laminating a plurality of rectangular insulating layers, and has a rectangular parallelepiped outer shape.

The external electrode 12 a is formed on the side surface of the multilayer body 10 and is electrically connected to a capacitor formed inside the multilayer body 10. The external electrode 12 b is formed on a side surface opposite to the side surface on which the external electrode 12 a is formed, and is electrically connected to a capacitor formed in the multilayer body 10. If the through-type three-terminal capacitor 1 is mounted on a circuit board, the external electrodes 12a, the 12b, a signal voltage having a predetermined voltage value is applied.

The external electrode 12 c is formed on a side surface different from the side surface on which the external electrodes 12 a and 12 b are formed, and is electrically connected to a capacitor formed in the multilayer body 10. The external electrode 12d is formed on a side surface opposite to the side surface on which the external electrode 12c is formed, and is electrically connected to a capacitor formed in the multilayer body 10. If the through-type three-terminal capacitor 1 is mounted on a circuit board, the external electrodes 12c, the 12d, the ground potential is applied.

As shown in FIG. 2, the capacitor built in the multilayer body 10 has internal electrodes 14 (Thru internal electrodes) and internal electrodes 16 (GND internal electrodes) alternately stacked together with an insulating layer in the z-axis direction. Consists of. Below, the internal electrode 14 and the internal electrode 16 are demonstrated, referring FIG.2 and FIG.3. FIG. 3 is a cross-sectional structure diagram of the feedthrough three-terminal capacitor 1 in the xy plane. More specifically, FIG. 3A is a diagram showing a configuration of the insulating layer 13 in which the internal electrode 14 is formed. In FIG. 3A, the internal electrode 16 is indicated by a dotted line. FIG. 3B is a diagram showing a configuration of the insulating layer 15 in which the internal electrode 16 is formed. In FIG. 3B, the internal electrode 14 is indicated by a dotted line.

  As shown in FIG. 3A, the internal electrode 14 extends so as to penetrate the laminate 10 in the x-axis direction on the main surface of the insulating layer 13 so as to connect the external electrode 12a and the external electrode 12b. Exists. As shown in FIG. 3A, the internal electrode 14 includes a main body portion 20 and lead portions 22a and 22b. The main body 20 constitutes a capacitor electrode and has a shape in which four corners of a rectangle are cut off in a straight line. Thus, linear portions L1 are formed at the four corners of the main body portion 20, respectively. In addition, in order to prevent the drawing from becoming complicated, only the straight upper part L1 at the upper left corner is given a reference symbol.

  The lead portions 22a and 22b connect the external electrodes 12a and 12b and the main body portion 20, respectively. Specifically, the lead portion 22a extends in the x-axis direction from the side of the main body 20 that faces the external electrode 12a. Further, the lead-out portion 22b extends in the x-axis direction from the side facing the external electrode 12b among the sides of the main body portion 20. Furthermore, the width in the y-axis direction of the lead portions 22a and 22b is shorter than the length of the side of the main body portion 20 to which the lead portions 22a and 22b are connected.

  As shown in FIG. 3B, the internal electrode 16 extends so as to penetrate the laminate 10 in the y-axis direction on the main surface of the insulating layer 15 so as to connect the external electrode 12c and the external electrode 12d. Exists. As shown in FIG. 3B, the internal electrode 16 includes a main body 30 and lead portions 32a and 32b. The main body 30 constitutes a capacitor electrode and has a shape in which four corners of a rectangle are cut off in a straight line. Thereby, linear portions L <b> 2 are formed at the four corners of the main body 30. In addition, in order to prevent the drawing from becoming complicated, only the straight line upper portion L2 at the upper left corner is given a reference symbol.

  The lead portions 32a and 32b connect the external electrodes 12c and 12d and the main body portion 30, respectively. Specifically, the lead portion 32a extends in the y-axis direction from the side of the main body 30 that faces the external electrode 12c. In addition, the lead portion 32b extends in the y-axis direction from the side facing the external electrode 12d among the sides of the main body 30. Furthermore, the width of the lead portions 32a and 32b in the x-axis direction is shorter than the length of the side of the main body portion 30 to which the lead portions 32a and 32b are connected.

  Here, the positional relationship between the main body 20 of the internal electrode 14 and the main body 30 of the internal electrode 16 will be described with reference to FIG. The main body 20 and the main body 30 are disposed so as to overlap each other when viewed from the z-axis direction (stacking direction). Thereby, a capacity is formed between the main body 20 and the main body 30.

  Further, as shown in FIGS. 3A and 3B, the linear portions L1 formed at the four corners of the main body portion 20 are aligned with the linear portions L2 of the adjacent main body portions 30 in the z-axis direction (lamination). Do not overlap when viewed from (direction). More specifically, when viewed from the z-axis direction (stacking direction), the linear portion L1 is located farther from the center (intersection of diagonal lines) of the insulating layer 13 than the linear portion L2.

  As described above, the insulating layer 13 in which the internal electrode 14 is formed and the insulating layer 15 in which the internal electrode 16 is formed are alternately stacked, and no internal electrode is formed on each of the upper and lower layers. An outer insulating layer is laminated. Thereby, the laminated body 10 as shown in FIG. 2 is obtained.

(About manufacturing method)
Next, a method for manufacturing the feedthrough three-terminal capacitor 1 will be described. First, a dielectric raw material powder mainly composed of barium titanate or the like is dispersed in a solvent to prepare a ceramic slurry, and the ceramic slurry is formed into a sheet by a doctor blade method. Thereby, the ceramic green sheet used as the raw material of the insulating layers 13 and 15 is obtained.

  Next, a conductive paste made of Ag, Pd, Cu, Au or an alloy thereof is applied onto the ceramic green sheet by screen printing, and the internal electrodes 14 and 16 shown in FIGS. 3 (a) and 3 (b) are applied. Form. Below, the formation process of the internal electrodes 14 and 16 is demonstrated in detail.

  The screen printing method is performed by placing a sheet having openings in the shape of the internal electrodes 14 and 16 on a ceramic green sheet, and transferring the conductive paste to the ceramic green sheet with a squeegee rubber or the like. During this transfer, a saddle phenomenon occurs in which more paste is scraped off by the squeegee rubber than at the edge of the opening at the center of the opening. When this saddle phenomenon occurs, the film thickness of the conductive paste becomes thicker at the edge of the opening than at the center of the opening. As described above, when a portion where the film thickness of the conductive paste is increased occurs, a portion where the film thickness is increased also occurs in the internal electrodes 14 and 16, and there is a possibility that a short circuit occurs in the portion.

Therefore, in the feedthrough three-terminal capacitor 1, the main body portions 20 and 30 of the internal electrodes 14 and 16 have a shape in which the four corners of the rectangle are cut off in a straight line, as shown in FIGS. 3 (a) and 3 (b). Formed to have. That is, screen printing is performed using a sheet having an opening having the same shape as the internal electrodes 14 and 16. When screen printing is performed using a sheet having a rectangular opening, the conductive paste tends to accumulate at the four corners of the rectangle. Therefore, the film thickness of the internal electrodes 14 and 16 is made uniform by performing screen printing using a sheet having an opening in which the four corners of the rectangle are cut off. That is, the conductive paste is prevented from becoming thick in the linear portions L1 and L2, and the occurrence of a short circuit between the internal electrodes 14 and 16 is prevented. In addition, it is more preferable that the corners of the main body portions 20 and 30 are cut off in a straight line rather than being rounded off. This is because if the image is cut off with roundness, bleeding occurs during screen printing.

  By the way, when the width of the opening is relatively wide with respect to the traveling direction of the squeegee rubber, the conductive paste is applied thinly, and when the width of the opening is relatively narrow, the conductive paste is applied thickly. Therefore, when the squeegee rubber is moved in the x-axis direction in FIG. 3A and in the y-axis direction in FIG. 3B, the pressure during squeegee rubber squeezing is constant during screen printing. It is preferable to do. Thereby, the main-body parts 20 and 30 are formed relatively thin, and the lead-out parts 22a, 22b, 32a, and 32b are formed relatively thick. As a result, the lead portions 22a, 22b, 32a, 32b and the external electrodes 12a, 12b, 12c, 12d can be more reliably connected.

  Next, a plurality of outer-layer ceramic green sheets on which the internal electrodes 14 and 16 are not formed are stacked and pressure-bonded. Further, the ceramic green sheet on which the internal electrode 14 is formed and the ceramic green sheet on which the internal electrode 16 is formed are alternately laminated on the ceramic green sheet for outer layer, and these are pressure-bonded. Further, a plurality of ceramic green sheets for outer layers are laminated on the ceramic green sheet on which the internal electrodes 14 and 16 are formed, and pressure-bonded. Thereby, an unfired laminated body block is obtained.

  Next, the unfired laminate block is cut into a predetermined size to obtain an unfired laminate. Thereafter, the unfired laminate is fired to obtain the laminate 10.

Next, a Cu paste is applied to the region where the external electrodes 12a, 12b, 12c, and 12d of the multilayer body 10 are to be formed and baked. Furthermore, by plating Ni and Sn in this order on the fired Cu paste, the external electrodes 12a, 12b, 12c and 12d are obtained. The thickness of the Ni plating layer and the thickness of the Sn plating layer are 0.7 to 8.0 μm and 1.5 to 8.0 μm, respectively. Through the above steps, the feedthrough three-terminal capacitor 1 as shown in FIG. 1 is completed.

(effect)
As described above, according to the feedthrough three-terminal capacitor 1, the widths of the lead portions 22a, 22b, 32a, and 32b are equal to the sides of the main body portions 20 and 30 to which the lead portions 22a, 22b, 32a, and 32b are connected. Shorter than length. Therefore, compared with the case where the width of the lead portions 22a, 22b, 32a, 32b is equal to the length of the sides of the main body portions 20, 30 to which the lead portions 22a, 22b, 32a, 32b are connected, the insulating layer 13 , 15 increases the contact area. As a result, the adhesion between the insulating layers 13 and 15 is improved, and peeling between the insulating layers 13 and 15 is prevented. Hereinafter, experiments conducted by the present inventors will be described with reference to the drawings. FIG. 5 is a graph showing the rate of occurrence of peeling of the insulating layer in the feedthrough three-terminal capacitor 1 and the conventional feedthrough three terminal capacitor .

The inventor of the present application, as the feedthrough three-terminal capacitor 1, has a width of the internal electrode 14 at point D in FIG. 3A of 1.05 mm, and the width of the internal electrode 14 at point A is 0.93 mm and 0.85 mm. A through-type three-terminal capacitor 1 was prepared. The inventor of the present application prepared a feedthrough three-terminal capacitor in which the widths of the internal electrodes at point A and point D were both 1.05 mm as a conventional feedthrough three terminal capacitor . Then, with respect to these three types of feedthrough three-terminal capacitors , the occurrence rate of insulation layer peeling was examined.

  According to the graph of FIG. 5, when the width of the internal electrode 14 at the point A (that is, the width of the lead portion 22a) is narrower than the width of the main body portion 20 (the width of the internal electrode 14 at the point A is 0.93 mm). And 0.85 mm), the occurrence rate of peeling was 0%. On the other hand, when the width of the internal electrode at point A (that is, the width of the lead portion 22a) and the width of the main body portion were made equal, the occurrence rate of peeling was 0.08 to 0.16%. As described above, by making the width of the lead portions 22a, 22b, 32a, 32b shorter than the length of the sides of the main body portions 20, 30 to which the lead portions 22a, 22b, 32a, 32b are connected, It can be understood that the peeling between 15 can be prevented.

  Further, since the widths of the lead portions 22a, 22b, 32a, 32b are shorter than the lengths of the sides of the main body portions 20, 30 to which the lead portions 22a, 22b, 32a, 32b are connected, the lead portions 22a, 22b, 32a. , 32b and the external electrodes 12a, 12b, 12c, 12d can be more reliably connected. This will be described below with reference to FIG. FIG. 4 is a graph showing the relationship between the width in the y-axis direction of the internal electrode 14 and the thickness of the internal electrode 14 at four locations A, B, C, and D in FIG. The vertical axis indicates the thickness of the internal electrode 14, and the horizontal axis indicates the width of the internal electrode 14.

  As described above, when screen printing is performed with the pressure of the squeegee rubber being constant, the coating thickness of the conductive paste is relatively thin and the opening width is relatively narrow where the opening width is relatively wide. By the way, the coating thickness of the conductive paste becomes relatively thick. For example, as shown in FIG. 4, the thickness of the internal electrode 14 is distributed in the range of 1.0 to 3.0 μm at the point C and the point D where the width in the y-axis direction of the internal electrode 14 is 600 μm. On the other hand, at the point B where the width of the internal electrode 14 in the y-axis direction is 500 μm and the point A where the width is 200 μm, the thickness of the internal electrode 14 is 1.3 to 3.4 μm and 1.5 to 3.5 μm, respectively. It has become. That is, it can be understood that the lead portions 22a and 22b (points A and B) of the internal electrode 14 are formed thicker than the main body portion 20 (points C and D) of the internal electrode 14. As described above, since the lead portions 22a and 22b of the internal electrode 14 are formed thick, the internal electrode 14 and the external electrodes 12a and 12b are more reliably connected.

Further, in the feedthrough three-terminal capacitor 1, the four corners of the main body portions 20, 30 are cut off in a straight line. Is almost equal. That is, the feedthrough three-terminal capacitor 1 has a structure in which a short circuit is unlikely to occur between the internal electrodes 14 and 16. Further, in the feedthrough three-terminal capacitor 1, the internal electrode 14 and the internal electrode 16 are disposed so that the linear portion L1 and the linear portion L2 do not overlap. That is, in the feedthrough three-terminal capacitor 1, a portion where a short circuit is likely to occur between the internal electrodes 14 and 16 is kept away. As a result, the occurrence of a short circuit between the adjacent internal electrodes 14 and 16 is more reliably prevented. According to the experiments by the inventors of the present application, in the conventional feedthrough three-terminal capacitor , the occurrence rate of the short circuit between the internal electrodes was 2.5%, whereas in the feedthrough three-terminal capacitor 1 The occurrence rate of short circuit between the internal electrodes 14 and 16 was 0.6%. As conventional through-type three-terminal capacitor, using the through-type three-terminal capacitor four corners of the main body portion 20 and 30 is not cut off in a straight line.

Furthermore, in the feedthrough three-terminal capacitor 1, the lead portions 22a and 22b have a certain width as shown in FIG. Therefore, even if a deviation occurs in the x-axis direction when the feedthrough three-terminal capacitor 1 is cut, the widths of the lead portions 22a and 22b do not change. Therefore, the resistance value (RDC (DC resistance between signals)) of the internal electrode 14 is not easily changed.

  Further, as shown in FIG. 3, the main body 30 is not formed in the region where the lead portions 22a and 22b are formed when viewed from the stacking direction. Further, the main body 20 is not formed in the region where the lead portions 32a and 32b are formed when viewed from the stacking direction. Therefore, even if the drawer portions 22a, 22b, 32a, and 32b are formed thick, there is no possibility that the drawer portions 22a, 22b, 32a, and 32b are pressed and crushed by the main body portions 20 and 30 during crimping. . As a result, the lead portions 22a, 22b, 32a, 32b and the external electrodes 12a, 12b, 12c, 12d are connected.

(Modification)
Hereinafter, modified examples of the feedthrough three-terminal capacitor 1 according to the present embodiment will be described with reference to FIGS. FIG. 6 is a diagram illustrating a state in which the internal electrodes 14 and 16 of the feedthrough three-terminal capacitor 1 according to the first modification are overlapped. FIG. 7 is a diagram illustrating a state in which the internal electrodes 14 and 16 of the feedthrough three-terminal capacitor 1 according to the second modification are overlapped. FIG. 8 is a diagram showing an overlapping state of the internal electrodes 14 and 16 of the feedthrough three-terminal capacitor 1 according to the third modification. 6 to 8, the internal electrode 16 is indicated by a dotted line.

  As shown in FIG. 6, when viewed from the z-axis direction (stacking direction), the linear portion L2 is located farther from the center (intersection of diagonal lines) of the insulating layer 13 than the linear portion L1. Also good. In the case where such a structure is realized without changing the shape of the internal electrode 16, the width in the y-axis direction of the lead portions 22a and 22b is made larger than the width in the y-axis direction of the lead portions 22a and 22b in FIG. Narrow it.

  As shown in FIG. 7, the side extending in the x-axis direction of the internal electrode 14 is located closer to the center (intersection of diagonal lines) of the insulating layer 13 than the side extending in the x-axis direction of the internal electrode 16. The side extending in the y-axis direction may be located closer to the center of the insulating layer 15 than the side extending in the y-axis direction of the internal electrode 14. Further, as shown in FIG. 8, the side extending in the x-axis direction of the internal electrode 14 is located farther from the center (intersection of diagonal lines) of the insulating layer 13 than the side extending in the x-axis direction of the internal electrode 16. The side extending in the y-axis direction of the electrode 16 may be located farther from the center of the insulating layer 15 than the side extending in the y-axis direction of the internal electrode 14.

1 is an external perspective view of a feedthrough three-terminal capacitor according to an embodiment of the present invention. 2A is a cross-sectional structure diagram of the feedthrough three-terminal capacitor in the xz plane, and FIG. 2B is a cross-sectional structure diagram of the feedthrough three-terminal capacitor in the yz plane. FIG. 3A is a diagram showing a configuration of an insulating layer on which internal electrodes are formed. FIG. 3B is a diagram showing the configuration of the insulating layer on which the internal electrode is formed. 4 is a graph showing the relationship between the width in the y-axis direction of the internal electrode at four locations A, B, C, and D in FIG. 3A and the thickness of the internal electrode. It is the graph which showed the incidence rate of exfoliation of an insulating layer in a penetration type three terminal capacitor . It is the figure which showed the mode of the overlap of the internal electrode of the penetration type | mold three terminal capacitor which concerns on a 1st modification. It is the figure which showed the mode of the overlap of the internal electrode of the penetration type | mold three terminal capacitor which concerns on a 2nd modification. It is the figure which showed the mode of the overlap of the internal electrode of the penetration type | mold three terminal capacitor which concerns on a 3rd modification. It is an exploded view of the conventional penetration type 3 terminal electronic parts.

1 through-type three-terminal capacitor 10 laminated body 12a, 12b, 12c, 12d external electrode 13, 15 insulating layer 14, 16 internal electrode 20, 30 body 22a, 22b, 32a, 32b lead-out part L1, L2 linear part

Claims (2)

A laminated body constituted by laminating a plurality of insulating layers;
A plurality of internal electrodes laminated together with the plurality of insulating layers;
A plurality of external electrodes formed on a side surface of the laminate;
With
The plurality of internal electrodes are:
A main body having a shape in which four corners of a quadrangle are cut off in a straight line;
A lead portion connecting the main body portion and the external electrode;
Including
The width of the drawer part is shorter than the length of the side of the main body part to which the drawer part is connected,
The linear portions formed at the four corners of the main body portion do not overlap with the linear portions of the adjacent main body portions when viewed from the stacking direction,
The plurality of internal electrodes include a first internal electrode and a second internal electrode, and constitute a capacitor,
The first internal electrode includes two lead portions connected to the external electrode formed on the first side surface and the second side surface of the stacked body facing each other,
The second internal electrode includes two lead portions connected to the external electrode formed on a third side surface and a fourth side surface of the stacked body facing each other,
All of the linear portions of the first internal electrode do not overlap the second internal electrode when viewed in plan from the stacking direction,
A signal potential is connected to the external electrodes formed on the first side surface and the second side surface,
A ground potential is connected to the external electrodes formed on the third side surface and the fourth side surface;
Feedthrough type three-terminal capacitor . In the region where the lead portion is formed, the main body portion is not formed when viewed from the stacking direction,
The feedthrough three-terminal capacitor according to claim 1.

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