Multilayer electronic component

Abstract

The laminated electronic component of the present application has a body having a first main surface constituting a mounting surface, a second main surface opposite to the first main surface, and a side surface adjacent to the first main surface and the second main surface, and has a plurality of particles, the proportion of gaps between the plurality of particles occupying the first main surface or the side surface being smaller than the proportion of gaps occupying the second main surface.

Description

Technical Field

[0001] This disclosure relates to a stacked electronic component. Background Technology

[0002] A type of stacked electronic component having a substrate is known (for example, see Japanese Patent Application Publication No. 2023-028451). Japanese Patent Application Publication No. 2023-028451 describes a method in which recesses are provided on the main surface and side surface of the substrate, thereby increasing the surface area of ​​the substrate and improving the heat dissipation of the inductor component. Summary of the Invention

[0003] When the aforementioned inductor components are reflow soldered onto electronic devices, flux flows into a recess located on the main surface of the mounting surface and the side adjacent to the mounting surface. As a result, the flux dosage is relatively reduced, thus decreasing the wettability of the solder.

[0004] The purpose of this disclosure is to provide a laminated electronic component capable of suppressing flux inflow.

[0005] (1) A stacked electronic component according to one aspect of the present disclosure has a base body having a first main surface constituting a mounting surface, a second main surface opposite to the first main surface, and a side surface adjacent to the first main surface and the second main surface, and having a plurality of particles, wherein the gap between the plurality of particles is in a proportion of the first main surface or the side surface less than the proportion of the gap in the second main surface.

[0006] In the above-mentioned stacked electronic components, the gaps between the first main surface, which serves as the mounting surface, and the side adjacent to the first main surface are small, thus suppressing the inflow of flux.

[0007] (2) In the stacked electronic component described in (1) above, the proportion of the gap to the first main surface may be smaller than the proportion of the gap to the second main surface. In this case, flux inflow can be suppressed more effectively.

[0008] (3) In the stacked electronic component described in (2) above, the proportion of the gap to the side surface may be smaller than the proportion of the gap to the second main surface. In this case, flux inflow can be reliably and effectively suppressed.

[0009] (4) In any of the stacked electronic components described in (1) to (3) above, the surface roughness of the first main surface or the side surface may be less than the surface roughness of the second main surface. In this case, flux inflow can be suppressed.

[0010] (5) In any of the above (1) to (4) stacked electronic components, the plurality of particles may also be made of a material containing a soft magnetic metal. In this case, gaps between the plurality of particles are easily generated, and the structure that suppresses flux inflow is effective. Attached Figure Description

[0011] Figure 1 This is a perspective view showing one embodiment of a stacked electronic component.

[0012] Figure 2 It means Figure 1 The diagram shows the cross-sectional structure of the stacked electronic component.

[0013] Figure 3 It is a three-dimensional diagram showing the structure of the coil.

[0014] Figure 4 It is a magnified top view showing a portion of the mounting surface.

[0015] Figure 5 It is a magnified top view showing a portion of the side.

[0016] Figure 6 It is a magnified top view showing a portion of the upper surface. Detailed Implementation

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in the description of the drawings, the same or equivalent elements are labeled with the same reference numerals, and repeated descriptions are omitted.

[0018] Reference Figures 1-5 The structure of the stacked electronic component 1 according to this embodiment will be described. Figure 1 As shown, the stacked electronic component 1 includes a cuboid-shaped body 2 and a pair of external electrodes 4, 4. The pair of external electrodes 4, 4 are respectively disposed at both ends of the body 2 and are separated from each other. The cuboid shape includes a cuboid shape with chamfered corners and edges, and a cuboid shape with rounded corners and edges. The stacked electronic component 1 is, for example, a coil component. The stacked coil component 1 can be applied, for example, to a bead inductor or a power inductor.

[0019] The cuboid-shaped body 2 has: a pair of opposing side faces 2a, 2a; a pair of opposing main faces 2b, 2c; and a pair of opposing side faces 2d, 2d. Side faces 2a, 2a are positioned adjacent to the pair of main faces 2b, 2c. Side faces 2d, 2d are positioned adjacent to the pair of main faces 2b, 2c.

[0020] Main face 2b ( Figure 1 The bottom surface of the main surface (2c) constitutes the mounting surface. When, for example, a laminated electronic component 1 is mounted to other electronic devices (circuit board, electronic components, etc.), the mounting surface is the surface opposite to that other electronic device. Figure 1 The upper surface of the body 2 is provided with a mark indicating the orientation of the body 2. Alternatively, the mark may be provided on the side surfaces 2a and 2d.

[0021] In this embodiment, the relative direction (first direction D1) of a pair of side surfaces 2a, 2a is set as the length direction of the body 2. The relative direction (second direction D2) of a pair of main surfaces 2b, 2c is set as the height direction of the body 2. The relative direction (third direction D3) of a pair of side surfaces 2d, 2d is set as the width direction of the body 2. The first direction D1, the second direction D2, and the third direction D3 are orthogonal to each other.

[0022] The length of the base body 2 in the first direction D1 is greater than the length of the base body 2 in the second direction D2 and the third direction D3. The length of the base body 2 in the second direction D2 is equal to the length of the base body 2 in the third direction D3. That is, in this embodiment, the pair of side surfaces 2a, 2a are square, and the pair of main surfaces 2b, 2c and the pair of side surfaces 2d, 2d are rectangular.

[0023] The length of body 2 in the first direction D1 can also be equal to the length of body 2 in the second direction D2 and the third direction D3. The length of body 2 in the second direction D2 can also be different from the length of body 2 in the third direction D3. "Equal" means, in addition to being identical, that it includes slight differences or manufacturing errors within a predetermined range. For example, if multiple values ​​are within ±5% of the average of those values, then those values ​​can also be considered equal.

[0024] A pair of side faces 2a and 2b extend in the second direction D2, connecting to a pair of main faces 2b and 2c. A pair of side faces 2a and 2a also extend in the third direction D3, connecting to side faces 2d and 2d. A pair of main faces 2b and 2c extend in the first direction D1, connecting to a pair of side faces 2a and 2a. A pair of main faces 2b and 2c also extend in the third direction D3, connecting to a pair of side faces 2d and 2d. A pair of side faces 2d and 2d extend in the first direction D1, connecting to a pair of end faces 2a and 2a. A pair of side faces 2d and 2d also extend in the second direction D2, connecting to a pair of main faces 2b and 2c.

[0025] Body 2 consists of multiple layers of magnetic bodies 11 (see reference). Figure 3It is composed of magnetic material layers 11 stacked in the opposite direction of the main surfaces 2b and 2c. That is, the stacking direction of each magnetic material layer 11 is consistent with the opposite direction of the main surfaces 2b and 2c (hereinafter, the opposite direction of the main surfaces 2b and 2c is referred to as the "stacking direction"). Each magnetic material layer 11 is roughly rectangular in shape. In the actual body 2, each magnetic material layer 11 is integrated to the point that the boundaries between its layers cannot be distinguished.

[0026] Within base body 2, such as Figures 2-3 As shown, a coil 15 is provided. The coil 15 includes a plurality of coil conductors 16 (16a to 16f). The plurality of coil conductors 16a to 16f contain a conductive material (e.g., Ag or Pd). The plurality of coil conductors 16a to 16f are configured as a sintered body of a conductive paste containing a conductive material (e.g., Ag powder or Pd powder).

[0027] The coil conductor 16a includes a connecting conductor 17. The connecting conductor 17 is disposed on one side 2a of the body 2 and has an end exposed on one side 2a. The end of the connecting conductor 17, exposed on one side 2a near the main surface 2c, is connected to an external electrode 4. That is, the coil 15 is electrically connected to an external electrode 4 via the connecting conductor 17. In this embodiment, the conductor pattern of the coil conductor 16a and the conductor pattern of the connecting conductor 17 are integrally and continuously formed.

[0028] Multiple coil conductors 16a to 16f are formed in the stacking direction of the magnetic layer 11 within the body 2. The multiple coil conductors 16a to 16f are arranged in the order of coil conductor 16a, coil conductor 16b, coil conductor 16c, coil conductor 16d, coil conductor 16e, and coil conductor 16f. In this embodiment, the coil 15 is composed of the portion of coil conductor 16a excluding the connecting conductor 17, the multiple coil conductors 16b to 16e, and the portion of coil conductor 16f excluding the connecting conductor 18.

[0029] The ends of coil conductors 16a to 16f are connected to each other via through-hole conductors 19a to 19e. The coil conductors 16a to 16f are electrically connected to each other via through-hole conductors 19a to 19e. The coil 15 is constructed by electrically connecting multiple coil conductors 16a to 16f. Each through-hole conductor 19a to 19e contains a conductive material (e.g., Ag or Pd). Similarly, each through-hole conductor 19a to 19e, like the multiple coil conductors 16a to 16f, is constructed as a sintered body of a conductive paste containing a conductive material (e.g., Ag powder or Pd powder).

[0030] The external electrode 4 is arranged to cover the end of the body 2 on side 2a. For example... Figure 1As shown, the external electrode 4 has: an electrode portion 4a covering the side surface 2a, electrode portions 4b and 4c extending to a pair of main surfaces 2b and 2c, and electrode portions 4d and 4d extending to a pair of side surfaces 2d and 2d. That is, the external electrode 4 is formed by five surfaces of electrode portions 4a, 4b, 4c, 4d and 4d.

[0031] The electrode portion 4a is configured to cover the ends of the connecting conductors 17 and 18 exposed on the side 2a, and the connecting conductors 17 and 18 are directly connected to the external electrode 4. That is, the connecting conductors 17 and 18 are connected to the ends of the coil 15 and the electrode portion 4a. Thus, the coil 15 is electrically connected to the external electrode 4.

[0032] Adjacent electrode portions 4a, 4b, 4c, 4d, and 4d are continuous and electrically connected at the edge portion of the body 2. Electrode portions 4a and 4b are connected at the edge portion between side surface 2a and main surface 2b. Electrode portions 4a and 4c are connected at the edge portion between side surface 2a and main surface 2c. Electrode portions 4a and 4d are connected at the edge portion between side surface 2a and side surface 2d.

[0033] The external electrode 4 is configured to contain a conductive material, such as Ag or Pd. The external electrode 4 is a sintered electrode, configured as a sintered body of a conductive paste. The conductive paste contains conductive metal powder and glass powder, such as Ag powder or Pd powder. A plating layer is formed on the surface of the external electrode 4. The plating layer is formed, for example, by electroplating, such as Ni plating or Sn plating.

[0034] Secondly, the structure of the aforementioned base body 2 will be explained in more detail.

[0035] Figure 4 This is a magnified top view of a portion of the mounting surface, viewed from a direction perpendicular to the mounting surface (main surface 2b). Figure 5 It is a rough top view, magnified to show a portion of the side, viewed from a direction perpendicular to the side (side 2d). Figure 6 This is a magnified top view, taken from a direction perpendicular to the top surface (main surface 2c), showing a portion of the top surface. For example... Figures 4-6As shown, the base body 2 comprises multiple particles P. These particles P are, for example, composed of a magnetic material containing a soft magnetic metal. Examples of such magnetic materials include soft magnetic alloys such as Fe-Si alloys. Fe-Si alloys may also contain P. The soft magnetic alloy may also be, for example, an Fe-Ni-Si-M alloy. "M" contains one or more elements selected from Co, Cr, Mn, P, Ti, Zr, Hf, Nb, Ta, Mo, Mg, Ca, Sr, Ba, Zn, B, Al, and rare earth elements. The multiple particles P can be composed of a magnetic material containing ferrite or a dielectric material.

[0036] In the substrate 2, particles P, P' are bonded to each other. This bonding of particles P, P' is achieved, for example, through the bonding of oxide films formed on the surface of particles P. Substrate 2 includes resin-filled portions. The resin is present in at least a portion between the plurality of particles P, P'. The resin is an electrically insulating resin. Examples of resins that can be used include silicone resin, phenolic resin, acrylic resin, epoxy resin, etc. There may also be voids between the plurality of particles P, P' that are not filled with resin.

[0037] On the surface of substrate 2, multiple particles P are exposed. Gap G exists between the exposed particles P. The proportion of gap G to the main surface 2b is less than the proportion of gap G to the main surface 2c. The proportion of gap G to a pair of side surfaces 2d, 2d is less than the proportion of gap G to the main surface 2c. The top view of the pair of side surfaces 2a, 2a is omitted, but the proportion of gap G to the pair of side surfaces 2a, 2a is equal to the proportion of gap G to the pair of side surfaces 2d, 2d. That is, the proportion of gap G to the pair of side surfaces 2a, 2a is less than the proportion of gap G to the main surface 2c. The proportion of gap G to the pair of side surfaces 2a, 2a may also be different from the proportion of gap G to the pair of side surfaces 2d, 2d.

[0038] The proportion of gap G in the pair of side surfaces 2a, 2a and the pair of side surfaces 2d, 2d is smaller than the proportion of gap G in the main surface 2b. The pair of side surfaces 2a, 2a and the pair of side surfaces 2d, 2d are surfaces formed by cutting with a dicing blade. Compared to the particles P in the main surface 2b, each particle P in the pair of side surfaces 2a, 2a and the pair of side surfaces 2d, 2d has a larger area due to being stretched in the cutting direction. The cutting direction is the tangential direction of the dicing blade. The cutting direction of side surface 2d is the first direction D1, and the cutting direction of side surface 2a is the third direction D3.

[0039] The proportion of gaps G to each surface of substrate 2 is determined as follows. First, each surface of substrate 2 is observed using a scanning electron microscope (SEM) from a direction perpendicular to the surface to obtain SEM images. Next, the obtained SEM images are analyzed to determine particles P and gaps G. Based on the difference in contrast in the image, particles P and gaps G can be determined. Finally, the area proportion of gaps G is calculated, and this value is set as the proportion of gaps G to the surface.

[0040] The surface roughness of principal surface 2b is less than that of principal surface 2c. The surface roughness of a pair of side surfaces 2a, 2a and a pair of side surfaces 2d, 2d is less than that of principal surface 2c. The surface roughness of a pair of side surfaces 2a, 2a and a pair of side surfaces 2d, 2d are equal to each other, but may also be different. The surface roughness of a pair of side surfaces 2a, 2a and a pair of side surfaces 2d, 2d is less than that of principal surface 2b. The surface roughness is, for example, the arithmetic mean roughness (Ra).

[0041] The manufacturing method of base body 2 will be explained.

[0042] First, a laminated green substrate is prepared, comprising multiple magnetic green sheets stacked together and a conductive paste film serving as an internal conductor. The magnetic green sheets are formed, for example, by coating a magnetic slurry containing multiple particles P, insulating resin, and solvent onto a substrate (e.g., a PET film) using methods such as screen printing or blade coating. The bottom layer of the laminated green substrate (i.e., the layer having the main surface 2b) is subjected to a calendering process, using the gaps G between the particles P to crush the magnetic green sheets. The conductive paste film is formed on the corresponding magnetic green sheets, for example, by a plating method or screen printing.

[0043] Next, a cutting machine equipped with a rotating blade cuts the stacked green substrate into chips of a specified size, forming multiple monolithic stacks. The cut surfaces formed by the rotating blade become a pair of side surfaces 2a, 2a and a pair of side surfaces 2d, 2d. By adjusting the cutting conditions, the state of the particles P and the gaps G in the cut surfaces can be adjusted. For example, the faster the rotating blade rotates, the more deformed the particles P become, and the more the gaps G are crushed.

[0044] Next, the monolithized laminate is fired. Then, a conductive paste is applied to the outer surface of the fired laminate, and the conductive paste is sintered into the laminate by heat treatment to form the external electrode 4. Next, the fired laminate is immersed in a resin solution, and after the resin is impregnated in the laminate, the resin on the surface of the laminate is rinsed with toluene. This rinsing creates gaps on the surface of the laminate. Next, the resin impregnated in the laminate is cured by heat to form the substrate 2. Then, plating can also be performed on the external electrode 4. The above steps yield a laminated electronic component 1.

[0045] As explained above, in the stacked electronic component 1, the gaps between the main surface 2b and the side surfaces 2a and 2d are small. Since the main surface 2b is a mounting surface, the small gaps through the main surface 2b can suppress the flow of flux from the solder applied to the mounting surface into the gaps. Since each side surface 2a and 2d is adjacent to the mounting surface, solder sometimes wraps around the mounting surface in the region on the mounting surface side of each side surface 2a and 2d. In this case, the small gaps through each side surface 2a and 2d can also suppress the flow of flux into the gaps. As a result, the flux dosage is relatively reduced, which can suppress the decrease in solder wettability. In particular, since external electrodes 4 are formed on the side surfaces 2a and 2d, the structure for suppressing flux inflow is effective.

[0046] The multiple particles P are composed of a material containing a soft magnetic metal, therefore, gaps are more easily generated between the multiple particles P compared to the case where the multiple particles P are composed of a ferrite material. Thus, the structure is particularly effective in suppressing flux inflow.

[0047] The embodiments have been described above, but the present invention is not necessarily limited to the embodiments described above, and various modifications can be made without departing from its spirit. The embodiments and variations described above can also be appropriately combined.

Claims

1. A stacked electronic component, wherein, It comprises: a base body having a first main surface constituting a mounting surface, a second main surface opposite to the first main surface, and side surfaces adjacent to the first main surface and the second main surface, and having multiple particles. The proportion of the gap between the plurality of particles to the first main surface or the side surface is less than the proportion of the gap to the second main surface.

2. The stacked electronic component according to claim 1, wherein, The proportion of the gap to the first main surface is less than the proportion of the gap to the second main surface.

3. The stacked electronic component according to claim 2, wherein, The proportion of the gap to the side surface is less than the proportion of the gap to the second main surface.

4. The stacked electronic component according to any one of claims 1 to 3, wherein, The surface roughness of the first main surface or the side surface is less than that of the second main surface.

5. The stacked electronic component according to any one of claims 1 to 3, wherein, The plurality of particles are composed of a material containing a soft magnetic metal.

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