JP2010183007A - Multilayer electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer electronic component with a low DC resistance in total of coils and lead out parts, and superior reliability. <P>SOLUTION: In the multilayer electronic component, each of first internal conductor layers C2 to C9 includes two sides mutually crossing. Each of second internal conductor layers C1 and C10 consists of one side. Adjacent layers of the first internal conductor layers C2 to C9 in a stack direction are connected by overlapping their one sides when viewed from the stack direction, and the second internal conductor layers C1 and C10 are connected overlappingly when viewed from the stack direction in one side constituting the lead-out part at the first internal conductor layer C2 and C9 located at both ends in the stack direction. Here, the multilayer electronic component is designed so that the total cross section area of two overlapping sides in positions where the first internal conductor layers C2 to C9 are connected is equal to that of two overlapping sides in positions where the first internal conductor layers C2 and C9 and the second internal conductor layers C1 and C10 are connected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multilayer electronic component.

  2. Description of the Related Art A multilayer electronic component that includes a plurality of internal conductor layers and includes a coil portion and lead portions positioned at both ends of the coil portion is known (for example, a patent) Reference 1). The multilayer electronic component described in Patent Document 1 includes a plurality of internal conductor (coil conductor) layers that have two side portions intersecting each other and are stacked, and the internal conductor layers adjacent to each other in the stacking direction are stacked. When viewed from the direction, one side portion of each inner conductor layer is connected by overlapping to constitute a coil portion. One side portion of the inner conductor layer located at both ends in the stacking direction constitutes a lead portion that electrically connects the coil portion to the outside.

JP 2001-244117 A

  In recent years, there has been a demand for multilayer electronic components corresponding to a large current, such as a rated current of 1.0 A or more, as multilayer electronic components used in various electronic devices. In order to make a multilayer electronic component compatible with a large current, first, it is necessary to reduce the direct current resistance of the conductor to suppress the heat generation of the conductor.

  In the multilayer electronic component described in Patent Document 1, since the side portions of the internal conductor layer constituting the coil portion overlap, the DC resistance of the coil portion is relatively low. On the other hand, in the side portion constituting the lead portion, the side portions of the other internal conductor layers do not overlap, and the conductor cross-sectional area in the lead portion becomes smaller than the conductor cross-sectional area in the coil portion. For this reason, the direct current resistance of the lead portion becomes higher than the direct current resistance of the coil portion, and the side portion constituting the lead portion is likely to generate heat. When the side portion constituting the lead portion generates heat, disconnection of the side portion, deterioration of the substrate, etc. are caused, and the reliability of the multilayer electronic component is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer electronic component that has low DC resistance in the entire coil portion and lead portion and is excellent in reliability.

  The multilayer electronic component according to the present invention includes a plurality of internal conductor layers, and a multilayer electronic in which a coil portion and lead portions positioned at both ends of the coil portion are configured by the multiple internal conductor layers. A plurality of first inner conductor layers having two side portions intersecting each other and laminated as a plurality of inner conductor layers, and a pair of second inner conductors comprising one side portion. And the first inner conductor layers adjacent to each other in the stacking direction are connected by overlapping one side portion of each first inner conductor layer when viewed from the stacking direction. The second inner conductor layer is connected to one side portion constituting the lead portion in the first inner conductor layer located at both ends in an overlapping manner when viewed from the stacking direction, and the first inner conductor layers are connected to each other. The sum of two side parts that overlap at the place where is connected Characterized in that the area, the total cross-sectional area of the two side portions of the first inner conductor layer and the second internal conductor layer overlap at a place that is connected is set to be equal to.

  In the multilayer electronic component according to the present invention, the second inner conductor layer overlaps with one side portion constituting the lead portion in the first inner conductor layer located at both ends in the stacking direction when viewed from the stacking direction. And the total cross-sectional area of the two side portions that overlap at the place where the first inner conductor layers are connected to each other, and the first inner conductor layer and the second inner conductor layer are connected. Since the total cross-sectional areas of the two side portions that overlap in the place are set to be equal, not only the DC resistance of the coil portion but also the DC resistance of the lead portion is lowered. As a result, it is possible to realize a multilayer electronic component that suppresses heat generation in the drawer portion and has excellent reliability.

  Preferably, the second inner conductor layer extends to an intersection of two side portions of the first inner conductor layer to which the second inner conductor layer is connected. In this case, it is difficult to generate a portion where the conductor cross-sectional area rapidly decreases between the coil portion and the lead portion. For this reason, the direct current resistance in the whole coil part and the lead-out part can be further reliably reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the direct current resistance in the whole coil part and the drawer | drawing-out part is low, and the multilayer electronic component excellent in reliability can be provided.

1 is a perspective view of a multilayer inductor according to an embodiment. FIG. 2 is an exploded perspective view of a multilayer body of the multilayer inductor in FIG. 1. It is a partially broken perspective view which shows an example of the lamination sheet of the laminated body of FIG. FIG. 2 is an exploded perspective view of a conductive part of the multilayer inductor of FIG. 1. FIG. 2 is a perspective view of a conductive part of the multilayer inductor of FIG. 1. It is a disassembled perspective view of the multilayer inductor type multilayer body concerning one modification of this embodiment. It is a disassembled perspective view of the electroconductive part of the laminated body of the multilayer inductor of FIG. It is a perspective view of the electroconductive part of the laminated body of the multilayer inductor of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted. In addition, the wording including the concepts of “upper” and “lower” in the text is used based on the top and bottom of the states shown in FIGS.

  A multilayer inductor 1 shown in FIGS. 1 to 5 includes a rectangular parallelepiped multilayer body 3 and a pair of terminal electrodes 5 formed on both end surfaces 3a (both side surfaces in the longitudinal direction) of the multilayer body 3, respectively. ing. The multilayer body 3 includes an element body 7 and a conductive portion 9 disposed inside the element body 7. The element body 7 is formed of a magnetic material such as ferrite. The conductive portion 9 is made of a conductive material mainly composed of Ag or the like. In the rectangular parallelepiped laminated body 3, the side surface orthogonal to the upper and lower surfaces and orthogonal to the end surface 3a as shown in FIG. 1 may be referred to as “side surface 3b” in the following description.

  The conductive portion 9 shown in FIGS. 4 and 5 includes a coil portion 13 wound in a coil shape and a lead portion 15 drawn from the coil portion 13. The coil portion 13 has a coil shape having an axis in the vertical direction at the central portion of the conductive portion 9. One end of the lead portion 15 is exposed to the end surface 3 a of the multilayer body 3 and connected to the terminal electrode 5. That is, the lead portion 15 is located at both ends of the coil portion 13 and connects the coil portion 13 and the terminal electrode 5. The coil portion 13 is electrically connected to the outside via the terminal electrode 5 and the lead portion 15. A plane indicated by reference sign “q” in FIG. 4 shows a horizontal cross section of the virtual rectangular parallelepiped Q including the coil portion 13.

  As shown in FIG. 2, the laminate 3 is formed by laminating 12 rectangular plate-like sheets vertically. Among these, the uppermost layer and the lowermost sheet are the surface sheets P0 made of a magnetic material. And the 10-layer laminated sheets P1 to P10 sandwiched between the top sheets P0 are respectively the first inner conductor layers C2 to C9 or the second inner conductor layers C1 and C10 formed in a predetermined pattern with a conductor. The magnetic layers F1 to F10 fill the margins of the inner conductor layers C1 to C10.

  Each of the inner conductor layers C1 to C10 is exposed on the upper and lower surfaces of the laminated sheets P1 to P10, and extends in a rectangular cross section while drawing a predetermined pattern when viewed from the lamination direction.

  In the laminated sheet P1, as shown in FIG. 3 and FIG. 4 (a), the second sheet is formed of one side portion extending along one long side of the rectangle as viewed from above and has an I-shape. The inner conductor layer C1 is present. The second inner conductor layer C1 is present in a uniform plan view over the entire thickness of the laminated sheet P1, and the upper end surface and the lower end surface of the second inner conductor layer C1 are respectively laminated sheets. It is exposed on the upper and lower surfaces of P1. Similarly to the laminated sheet P1, the laminated sheet P10 has one side portion extending along one long side of the rectangle as viewed from above, and the second inner conductor layer C10 having an I-shape. Is present. Here, the “planar shape” means a shape viewed from the stacking direction (a shape viewed from above).

  In the laminated sheet P2, as shown in FIG. 3 and FIG. 4 (b), it has two side portions extending along one long side and one short side of a rectangle when viewed from above, and is L-shaped. There is a first inner conductor layer C2 exhibiting The first inner conductor layer C2 is present in a uniform plan view over the entire thickness of the laminated sheet P2, and the upper end surface and the lower end surface of the first inner conductor layer C2 are respectively laminated sheets. It is exposed on the upper and lower surfaces of P2. Similarly to the laminated sheet P2, the laminated sheets P3 to P9 have two side portions extending along one long side and one short side of a rectangle when viewed from above, and have an L shape. There are first inner conductor layers C3 to C9.

  Thus, in each lamination sheet P1-P10, since the 1st or 2nd internal conductor layers C1-C10 are exposed in the up-and-down surface, each internal conductor layer C1-C10 adjacent vertically is laminated. The sheets P1 to P10 are joined and electrically connected at the boundary surface. That is, the first inner conductor layers C2 to C9 adjacent to each other in the stacking direction are connected by overlapping one side portion of each first inner conductor layer C2 to C9 when viewed from the stacking direction. The second inner conductor layers C1 and C10 are overlapped and connected to one side portion of the first inner conductor layers C2 and C9 located at both ends in the stacking direction as viewed from the stacking direction.

  At the intersection of the two side portions of the first inner conductor layers C3 to C8, three portions of the first inner conductor layers C2 to C9 that are continuous in the vertical direction overlap three when viewed from above. The place exists. At the intersection of the two side portions of the first inner conductor layers C2 and C9, a part of the two first inner conductor layers C2, C3, C8 and C9 that are continuous in the vertical direction is seen from above. There are two overlapping parts.

  Thus, since the inner conductor layers C1 to C10 adjacent in the vertical direction are formed in a planar view shape so that at least a part thereof overlaps when viewed from above, eventually, as shown in FIGS. All the first and second inner conductor layers C <b> 1 to C <b> 10 are sequentially joined and integrated to form the conductive portion 9. That is, the conductive portion 9 including a three-dimensional coil shape is formed by stacking the two-dimensional first and second inner conductor layers C1 to C10. The first and second inner conductor layers C1 to C10 are directly joined at the boundary surfaces between the laminated sheets P1 to P10, and there is no magnetic layer between the laminated sheets P1 to P10, and a through-hole electrode is provided. There is no need. Therefore, the dimension in the stacking direction of the multilayer inductor 1 can be reduced, and the height can be reduced.

  As shown in FIG. 2, one end surface of one side portion of the second inner conductor layer C <b> 10 and the first inner conductor layer C <b> 9 overlapping the second inner conductor layer C <b> 10 is an end surface 3 a of the multilayer body 3. And is connected to the terminal electrode 5 (see FIG. 1). Therefore, one side portion of the second inner conductor layer C10 and the first inner conductor layer C9 overlapping the second inner conductor layer C10 constitutes the lead portion 15 described above. Similarly, one side portion of the second inner conductor layer C1 and the first inner conductor layer C2 that overlaps the second inner conductor layer C1 also constitutes the lead portion 15 connected to the other terminal electrode 5. To do.

  Next, a method for manufacturing the multilayer inductor 1 will be described.

  First, a magnetic paste and a conductor paste are made. The magnetic paste is obtained by blending and kneading magnetic powders such as Ni—Cu—Zn ferrite powder, Ni—Cu—Zn—Mg ferrite powder, and Ni—Cu ferrite powder together with a binder and a solvent. The conductor paste is obtained, for example, by blending Ag powder together with a binder and a solvent and kneading. For kneading, a three-roll, a homogenizer, a sand mill or the like is used.

  Subsequently, the magnetic paste is printed on the support film by, for example, a printing method to form a green sheet. The thickness of this green sheet is, for example, 20 μm. And it is set as the state (hardness) which is easy to process by heating and drying this green sheet. Then, the green sheet is punched out by a die press machine to form a hollow portion having a predetermined shape corresponding to each of the internal conductor layers C1 to C10. A green sheet before firing in which an internal electrode pattern is formed is obtained by filling the cut-through portion with a conductive paste mainly composed of Ag or the like.

  The green sheet can be produced by repeatedly applying the magnetic paste to a desired thickness, then drying the green sheet and punching with a mold, or until a plurality of green sheets have the desired thickness. After the lamination, these green sheets may be punched together with a mold, or after green sheets are punched one by one with a mold, a plurality of green sheets may be stacked to obtain a desired thickness. .

  In addition to punching with the above-mentioned mold, the punched-out part is formed by printing a pattern by placing a printing plate for laser drilling, sandblasting, etching, photolithography, or hole formation on a support film. It may be dried.

  Subsequently, a green laminate is produced by laminating the green sheet before firing on which the internal electrode pattern is formed and the green sheet for the surface layer, and the green laminate is cut into a predetermined size. Then, after removing the binder from the green laminate, the green laminate is integrally fired. In addition, the baking temperature at this time is about 850-900 degreeC, for example. Thereby, a green laminated body is baked and said laminated body 3 is obtained.

  Next, a conductive paste mainly composed of Ag, for example, is applied to both end surfaces 3a of the laminate 3 (see FIG. 1) and baked at, for example, about 600 ° C., and then electroplated, whereby the terminal electrode 5 is formed. Form. As described above, the multilayer inductor 1 described above is completed.

  In this multilayer inductor 1, the total cross-sectional area of two overlapping side portions where the first inner conductor layers C2 to C9 are connected, the first inner conductor layers C2 and C9, and the second inner conductor layers C2 to C9 are connected to each other. The total cross-sectional areas of the two overlapping side portions at the locations where the conductor layers C1 and C10 are connected are set to be equal. For this reason, the direct current resistance of the lead portion 15 is reduced to be equal to the direct current resistance of the coil portion 13.

  As described above, in the present embodiment, not only the direct current resistance of the coil portion 13 but also the direct current resistance of the lead portion 15 is reduced, so that heat generation in the lead portion 15 is suppressed and the multilayer inductor 1 having excellent reliability is obtained. Can be realized.

  The preferred embodiments of the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  In the above embodiment, the length of the second inner conductor layers C1 and C10 is such that the second inner conductor layers C1 and C10 do not overlap at the intersection of the two side portions in the first inner conductor layers C2 and C9. However, as shown in FIGS. 6 to 8, the second inner conductor layers C1 and C10 overlap each other at the intersection of the two side portions in the first inner conductor layers C2 and C9. It may be set. That is, the second inner conductor layers C1 and C10 may extend to the intersection of the two side portions of the first inner conductor layers C2 and C9. In this case, the three first inner conductor layers C2, C3, C8, C9 and the second inner conductor layer that are continuous in the vertical direction also at the intersection of the two side portions of the first inner conductor layers C2, C9. There are three overlapping portions of C1 and C10 when viewed from above, and it is difficult to generate a portion where the conductor cross-sectional area suddenly decreases between the coil portion 13 and the lead portion 15. . For this reason, the direct current resistance in the whole coil part 13 and the drawer | drawing-out part 15 can be made much more reliable.

  The present invention is not limited to a multilayer inductor as a multilayer electronic component, and the same effect can be obtained even when applied to an LC component or a chip bead having both an inductor and a capacitor.

  DESCRIPTION OF SYMBOLS 1 ... Multilayer inductor, 3 ... Multilayer body, 5 ... Terminal electrode, 7 ... Element body, 13 ... Coil part, 15 ... Lead-out part, C1, C10 ... 2nd internal conductor layer, C2-C9 ... 1st inside Conductor layer, F1 to F10 ... magnetic layer, P1 to P10 ... laminated sheet.

Claims (2)

A multilayer electronic component comprising a plurality of inner conductor layers, wherein the plurality of inner conductor layers comprise a coil portion and lead portions positioned at both ends of the coil portion,
As the plurality of inner conductor layers, a plurality of first inner conductor layers having two side portions intersecting each other and laminated, and a pair of second inner conductor layers each having one side portion, Have
The first inner conductor layers adjacent to each other in the stacking direction are connected by overlapping one side portion of each of the first inner conductor layers as viewed from the stacking direction,
The second internal conductor layer is overlapped and connected to one side portion constituting the lead portion in the first internal conductor layer located at both ends in the stacking direction as viewed from the stacking direction. ,
At the location where the total cross-sectional area of two side portions overlapping at the location where the first inner conductor layers are connected to each other, and the location where the first inner conductor layer and the second inner conductor layer are connected A multilayer electronic component, wherein a total cross-sectional area of two overlapping side portions is set to be equal.   The said 2nd internal conductor layer is extended to the cross | intersection part of the said 2 side part of the said 1st internal conductor layer to which this 2nd internal conductor layer is connected. Multilayer electronic components.