Electronic component and electronic apparatus

Abstract

Provided is an electronic component with improved mechanical strength.　The electronic component comprises a body, a first external electrode, and a second external electrode. The body has a laminate including at least one first internal electrode layer, at least one second internal electrode layer, and a plurality of dielectric layers containing crystal particles. The first internal electrode layer includes a first electrode body and a first lead-out part that leads the first electrode body to the first external electrode. The second internal electrode layer includes a second electrode body and a second lead-out part that leads the second electrode body to the second external electrode. When viewed in the lamination direction, the body has a gap region including a dielectric layer between a first lead-out region, which includes the first lead-out part, and a second lead-out region which includes the second lead-out part. In the gap region, there is a difference in the average particle size of the crystal particles between the central region and the other region.

Description

Electronic components and electronic equipment

[0001] This disclosure relates to electronic components and electronic equipment.

[0002] Electronic components comprising a conductive layer and a dielectric layer containing crystalline particles are known. For example, Patent Documents 1 and 2 disclose multilayer capacitors in which ceramic crystalline particles are contained in the dielectric layer.

[0003] Japanese Patent Publication No. 2023-35851 Japanese Patent Publication No. 2024-78408

[0004] One aspect of the present disclosure is an electronic component comprising: (1) a main body, a first external electrode, and a second external electrode, wherein the main body has a laminate comprising at least one first internal electrode layer, at least one second internal electrode layer, and a plurality of dielectric layers containing crystalline particles, the first internal electrode layer has a first electrode body and a first pull-out portion for pulling the first electrode body to the first external electrode, the second internal electrode layer has a second electrode body and a second pull-out portion for pulling the second electrode body to the second external electrode, and when viewed from the stacking direction, the main body has a gap region containing the dielectric layer between a first pull-out region including the first pull-out portion and a second pull-out region including the second pull-out portion, and the gap region has a difference in the average particle size of the crystalline particles between the central region and other regions.

[0005] (2) The electronic component according to (1), wherein the average particle size of the crystal grains is larger in the central region than in the other regions.

[0006] (3) The electronic component according to (1) or (2), wherein the other region comprises a peripheral region and an intermediate region located between the central region and the peripheral region, and the average grain size of the crystal grains gradually decreases in the order of the central region, the intermediate region, and the peripheral region.

[0007] (4) The electronic component according to (1) to (3), wherein the other region has a peripheral region, and the difference in the average particle size of the crystal grains between the central region and the peripheral region is in the range of 100 to 300 nm.

[0008] (5) The electronic component according to (1) to (4), wherein the other region has a peripheral region, and the average particle size of the crystal grains in the peripheral region is in the range of 100 to 350 nm.

[0009] (6) The electronic component according to (1) to (5), wherein the average particle size of the crystal grains in the central region is in the range of 300 to 450 nm.

[0010] (7) Electronic equipment including a circuit board on which the electronic components described in (1) to (6) are mounted.

[0011] According to this disclosure, it is possible to provide electronic components and electronic devices with improved mechanical strength.

[0012] This is a perspective view of the capacitor of this embodiment. This is a cross-sectional view taken along line II-II in Figure 1. This is a cross-sectional view taken along line III-III in Figure 1. This is a view of the layer (pattern A) included in the effective portion as seen from the Z-axis direction. This is a view of the layer (pattern B) included in the effective portion as seen from the Z-axis direction. This is a transparent view of the effective portion as seen from the Z-axis direction. This is a perspective view of the effective portion. This is a transparent view of the effective portion as seen from the Z-axis direction in another embodiment. This is a transparent view of the effective portion as seen from the Z-axis direction in another embodiment. This is an explanatory diagram of the central and peripheral regions within the gap region. This is a schematic diagram of crystal grains in the gap region of this embodiment. This is a diagram explaining the method for measuring the average grain size for each sub-region. This is a diagram explaining the measurement position of the average grain size. This is a diagram explaining the method for measuring the flexural strength. This is a diagram explaining an electronic device on which the capacitor is mounted.

[0013] The electronic components of the embodiments of this disclosure will be described below with reference to the drawings. Note that the figures used in the following description are schematic diagrams, and the dimensional ratios, etc., shown in the drawings do not necessarily correspond to actual values. The dimensional ratios, etc., between the drawings also do not necessarily correspond to actual values. Furthermore, in this specification, numerical ranges expressed using "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits.

[0014] [Electronic Device] Figure 14 is a diagram illustrating an electronic device 100 on which a capacitor 1 is mounted as an example of this embodiment. The capacitor 1 is, for example, a surface-mounted chip-type component, and is electrically connected to the circuit board 40 by its first external electrode 5A and second external electrode 5B. However, the electronic component in this embodiment is not limited to a surface-mounted chip type, and may be a through-hole mounted type. The capacitor 1 is positioned, for example, with its upper or lower surface facing the circuit board 40. The two pads of the circuit board 40 and the first external electrode 5A and second external electrode 5B of the capacitor 1 are joined by a conductive bonding material (not shown), such as solder. In this way, the capacitor 1 is mounted on the circuit board 40.

[0015] Electronic devices may include, for example, personal computers, digital still cameras, smartphones, tablet devices, watches including smartwatches, printers, wearable devices such as HMDs (head-mounted displays), televisions, video cameras, video tape recorders, car navigation systems, pagers, electronic organizers, electronic dictionaries, calculators, electronic game devices, word processors, workstations, video phones, security television monitors, electronic binoculars, POS terminals, medical equipment, fish finders, various measuring instruments, vehicles, aircraft, ships, base stations for mobile devices, flight simulators, etc.

[0016] [Overview of Capacitor] Capacitor 1 is an example of an electronic component in this embodiment, and is a multilayer ceramic capacitor.

[0017] Figure 1 is a perspective view of the capacitor 1 of this embodiment. The capacitor 1 has, for example, a roughly rectangular parallelepiped body 3 and a first external electrode 5A and a second external electrode 5B located at both ends of the body 3 when viewed from the X-axis direction. If it is not necessary to distinguish between the first external electrode 5A and the second external electrode 5B, the distinction between A and B is omitted and they are referred to as external electrode 5. The capacitor 1 may further have an outer resin (not shown) that covers the entire structure shown in Figure 1, and lead wires (not shown) that are connected to the external electrodes 5 and extend from the outer resin.

[0018] Figure 2 is a cross-sectional view taken along line II-II in Figure 1. Figure 3 is a cross-sectional view taken along line III-III in Figure 1. The cross-section is a plane parallel to the YZ plane. The main body 3 has an effective part 11 that directly performs the function of a capacitor. The effective part 11 has a plurality of alternatingly overlapping dielectric layers 7 and a plurality of internal electrode layers 9. The plurality of internal electrode layers 9 include at least one first internal electrode layer 9A and at least one second internal electrode layer 9B. The first lead-out portion 92A and the first dummy portion 93A shown in Figure 3 are part of the first internal electrode layer 9A, and will be described in detail later. The second lead-out portion 92B and the second dummy portion 93B are part of the second internal electrode layer 9B, and will be described in detail later. Also, the number of layers of dielectric layers 7 and internal electrode layers 9 does not necessarily match the number shown in Figures 2 and 3. In Figures 2 and 3, the thickness of the external electrode 5, i.e., the length in the Y-axis direction, is made relatively long from the viewpoint of making the cross-sectional structure easier to understand.

[0019] In capacitor 1, the two surfaces with the largest area, i.e., the two surfaces parallel to the YZ plane, are designated as the upper surface 41 and the lower surface 42, respectively. In capacitor 1, the two surfaces parallel to the XZ plane that are covered by the two external electrodes 5 are designated as the first end surface 43 and the second end surface 44, respectively. In capacitor 1, the two surfaces parallel to the XY plane are designated as the first side surface 45 and the second side surface 46, respectively. Note that if there is no need to distinguish between the first and second surfaces, the distinction between the first and second surfaces is omitted.

[0020] The dimensions of capacitor 1 are not particularly limited. If capacitor 1 is relatively small, the length in the X-axis, Y-axis, and Z-axis directions may be within the range of 0.03 to 0.20 mm.

[0021] [Details of the Capacitor] The following describes in more detail each component of capacitor 1.

[0022] (1) Main body The main body 3 has an effective portion 11, and may also have two cover portions 13 that overlap the upper and lower surfaces of the effective portion 11, respectively.

[0023] The shape of the main body portion 3 is not particularly limited, and may be a thin rectangular parallelepiped. The rectangular parallelepiped may be square or rectangular in any plan view in the X-axis direction, Y-axis direction, and Z-axis direction.

[0024] (1.1) Active Portion As shown in FIG. 2 and FIG. 3, the active portion 11 is a laminate in which dielectric layers 7 and internal electrode layers 9 are laminated in the Z-axis direction.

[0025] The thickness of the dielectric layer 7 is not particularly limited, and is appropriately selected according to the characteristics required for the capacitor 1 and the like. The thickness between adjacent internal electrode layers 9 may be within the range of 0.1 to 3.0 µm, within the range of 0.5 to 2.0 µm, or within the range of 0.5 to 1.0 µm. The thickness between adjacent internal electrode layers 9 herein refers to the thickness between a first internal electrode layer 9A and a second internal electrode layer 9B.

[0026] The shape of the dielectric layer 7 is not particularly limited in plan view in the Z-axis direction, and may be square or rectangular. In plan view in the Z-axis direction, the shape and dimensions of the dielectric layer 7 are basically the same as the shape and dimensions of the active portion 11.

[0027] The material of the dielectric layer 7 is, for example, ceramics. The type of ceramic is not particularly limited and may be any. The ceramic is, for example, a general formula ABO containing Ba, Ca, Zr or Ti ３ it may be a compound having a perovskite structure represented by . Further, the ceramic may be (Ca １－ｘ－ｙ , Sr ｘ , Ba ｙ ) ｍ (Zr １－ｚ－ａ , Ti ｚ , Hf ａ )O ３ it may be a compound represented by . Provided that in this case, x is 0 or more and 1 or less, y is 0 or more and 0.4 or less, m is 1.0 or more and 1.1 or less, z is 0 or more and 0.2 or less, and a is 0 or more and 0.3 or less. Specifically, the ceramic is CaZrO ３ , BaTiO ３ , BaZrO ３ , CaTiO ３The materials for the dielectric layer 7 may include ceramics, or other materials depending on the purpose. The additives may be oxides of Mn, Mg, Dy, Cr, or V, or oxides of rare earth elements such as Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb, and Y. The additives may also be oxides of Co, Ni, Li, B, Na, K, or Si, or glass, etc.

[0028] The thickness of the internal electrode layer 9 is not particularly limited. The thickness of the internal electrode layer 9 may be in the range of 0.3 to 3.0 μm, in the range of 0.5 to 2.0 μm, or in the range of 0.5 to 1.0 μm.

[0029] The material of the internal electrode layer 9 is, for example, a metal. The type of metal is not particularly limited. The metal used as the material for the internal electrode layer 9 may be entirely or primarily composed of a base metal. Base metals include Ni, Cu, etc., and these may be used in combination. The term "primary component" refers to a component that accounts for 60% or more of the total mass.

[0030] Figures 4A and 4B show the layers included in the effective portion 11 as viewed from the Z-axis direction. The effective portion 11 is, for example, a laminate of layers of pattern A and layers of pattern B. Patterns A and B each include a first internal electrode layer 9A and a second internal electrode layer 9B on the dielectric layer 7. As a result, the first internal electrode layer 9A and the second internal electrode layer 9B face each other with the dielectric layer 7 in between. Patterns A and B may be laminated alternately one layer at a time, or multiple layers at a time. The number of layers of patterns A and B is not particularly limited and may be in the range of 200 to 400 layers in total. Hereafter, if there is something common to both patterns A and B and there is no need to distinguish between them, the distinction between A and B will be omitted.

[0031] The internal electrode layer 9 includes an electrode main body 91, a lead-out portion 92, and a dummy portion 93. In the first internal electrode layer 9A, the first lead-out portion 92A is led out from the first electrode main body 91A to the outer edge of the dielectric layer 7, and is further connected to the first external electrode 5A. In the second internal electrode layer 9B, the second lead-out portion 92B is led out from the second electrode main body 91B to the outer edge of the dielectric layer 7, and is further connected to the other second external electrode 5B. In the present embodiment, one first lead-out portion 92A and one second lead-out portion 92B constitute a pair of lead-out portions. The plurality of first dummy portions 93A and the plurality of second dummy portions 93B each function as a dummy electrode as a whole. The provision of the dummy electrode can improve the connection strength between the main body portion 3 and the external electrode 5. Further, when the external electrode 5 is formed by a plating method, the dummy electrode functions as a base layer.

[0032] The shape and dimensions of the internal electrode layer 9 are not particularly limited. As shown in Fig. 4, the electrode main body 91, the lead-out portion 92, and the dummy portion 93 may all be rectangular. The internal electrode layer 9 may be line-symmetric with respect to a straight line parallel to the Y-axis direction. The first internal electrode layer 9A may have a shape obtained by inverting the second internal electrode layer 9B with respect to the X-axis direction.

[0033] Fig. 5 is a transparent view when the effective portion 11 is viewed from the Z-axis direction. That is, Fig. 5 is a diagram in which the layer of pattern A and the layer of pattern B shown in Fig. 4 are stacked and the dielectric layers are made transparent. In the present embodiment, the "internal electrode region" refers to a region where the internal electrode layer 9 exists when the effective portion 11 is viewed from the Z-axis direction, and the "first lead-out region" refers to a region where the first lead-out portion 92A exists when the effective portion 11 is viewed from the Z-axis direction. The "second lead-out region" refers to a region where the second lead-out portion 92B exists when the effective portion 11 is viewed from the Z-axis direction. The "electrode main body region" refers to a region where the electrode main body 91 exists when the effective portion 11 is viewed from the Z-axis direction.

[0034] The internal electrode region 21 includes a first lead-out region 22 including the first lead-out portion 92A connected to the first external electrode 5A, a second lead-out region 23 including the second lead-out portion 92B connected to the second external electrode 5B, and an electrode main body region 25 including the electrode main body 91.

[0035] FIG. 6 is a perspective view of the active portion 11. In the portion indicated by the internal electrode region 21 in FIG. 6, internal electrode layers and dielectric layers are actually alternately stacked in the Z-axis direction. On the other hand, in the portion indicated by the gap region 24 in FIG. 6, only dielectric layers are stacked in the Z-axis direction.

[0036] In the present embodiment, the "gap region" refers to a region located between the first lead-out region 22 and the second lead-out region 23 when the active portion 11 is viewed from the Z-axis direction as shown in FIGS. 5 and 6, and is constituted only by stacked dielectric layers.

[0037] FIGS. 7 and 8 are transmission views of the active portion 11 in another embodiment when viewed from the Z-axis direction. As shown in FIG. 7, the internal electrode region 21 does not necessarily need to extend to the end portion of the active portion 11 in the Y-axis direction. Note that the first dielectric region 26 in FIG. 7 is not located between the first lead-out region 22 and the second lead-out region 23, and therefore does not correspond to the gap region in the present embodiment. Further, the internal electrode region 21 may have a shape as shown in FIG. 8. The second dielectric region 27 in FIG. 8 is also not located between the first lead-out region 22 and the second lead-out region 23, and therefore does not correspond to the gap region in the present embodiment.

[0038] FIG. 9 is an explanatory diagram of a central region in the gap region and other regions. Note that FIG. 9 shows the gap region 24 when viewed from the Z-axis direction, and the position in the Z-axis direction is not limited. Let the length of the gap region 24 in the Y-axis direction be a, and the position within the gap region 24 is represented by y=0 to a. Let the length of the gap region 24 in the X-axis direction be b, and the position within the gap region 24 is represented by x=0 to b. The plurality of dotted lines are lines parallel to the X-axis direction that divide the length a in the Y-axis direction into five equal parts, and lines parallel to the Y-axis direction that divide the length b in the X-axis direction into five equal parts, respectively. By these lines, the gap region 24 is divided into a total of 25 partial regions, which are regions P1 to P25. Further, the straight line of x=b represents a side (surface) that is not surrounded by the internal electrode region 21.

[0039] In this embodiment, the central region of the gap region 24 is defined as the central region AR1, and the peripheral region in contact with the internal electrode region 21 is defined as the peripheral region AR2. Specifically, as shown in Figure 9, the regions that satisfy the following conditions are defined as the central region AR1 and the peripheral region AR2, respectively. (I) Central region AR1: 2b / 5 ≤ x ≤ b, and 2a / 5 ≤ y ≤ 3a / 5 (II) Peripheral region AR2: When 0 ≤ x ≤ b / 5, 0 ≤ y ≤ a, and when b / 5 < x ≤ b, 0 ≤ y ≤ a / 5, 4a / 5 ≤ y ≤ a

[0040] The central region AR1 is the combined region of partial regions P3, P8, and P13. The peripheral region AR2 is the combined region of partial regions P1, P5, P6, P10, P11, P15, P16, and P20-P25. The intermediate region AR3 is located between the central region AR1 and the peripheral region AR2, and the intermediate region AR3 is the combined region of partial regions P2, P4, P7, P9, P12, P14, and P17-P19. In this embodiment, "other regions" refers to regions other than the central region AR1, and is composed of the peripheral region AR2 and the intermediate region AR3.

[0041] As shown in Figures 5, 7, and 8, when the effective portion 11 has two gap regions 24, a central region AR1 and a peripheral region exist for each. Note that only the central region AR1 is shown in Figures 5, 7, and 8.

[0042] Figure 10 is a schematic diagram of crystal grains in the gap region 24 of this embodiment. In Figure 10, the crystal grains are shown as larger than those in the gap region 24 in order to make the shape of the crystal grains easier to understand. The gap region 24 is particularly susceptible to external influences in the central region AR1, which is not surrounded by the internal electrode region 21. In this embodiment, as shown in the example in Figure 10, there is a difference in the average grain size of the crystal grains between the central region AR1 and the peripheral region AR2. In this embodiment, "a difference in average grain size" means that the difference in average grain size is 100 nm or more. As a result, the boundaries between crystal grains (grain boundaries) have a complex tertiary structure. Therefore, even if external pressure is applied to the effective portion 11, cracks are less likely to occur along the grain boundaries in the gap region 24, and the mechanical strength can be improved.

[0043] Furthermore, because the grain boundaries have a complex tertiary structure, even if moisture penetrates the gap region 24, the pathway for the moisture to penetrate along the grain boundaries tends to be long and complex. As a result, it is difficult for moisture to reach the deeper parts of the gap region 24 and the internal electrode region 21, thereby reducing the effects of moisture and improving moisture resistance.

[0044] Furthermore, as shown in Figure 10, the average particle size of the crystal grains may be larger in the central region AR1 than in the peripheral region AR2. When external pressure is applied to the effective portion 11, the impact is transmitted in the order of central region AR1, peripheral region AR2, and internal electrode region 21. Because the average particle size of the crystal grains in the peripheral region AR2 is relatively small, the crystal grains can absorb and disperse the impact, thereby reducing the impact transmitted to the internal electrode region 21. As a result, the mechanical strength can be improved.

[0045] In addition, because the average grain size of the crystal grains in the central region AR1 is relatively large, when external pressure is applied to the effective portion 11, relatively large stress is generated from the central region AR1 to the peripheral region AR2, and further to the internal electrode region 21. In other words, stress is generated in a way that expands the gap region 24. As a result, the bonding between the peripheral region AR2 and the internal electrode region 21 can be improved. Furthermore, because the average grain size of the crystal grains in the peripheral region AR2 is relatively small, the surface area of ​​the crystal grains in contact with the internal electrode region 21 is increased, further improving the bonding between the peripheral region AR2 and the internal electrode region 21.

[0046] The method for measuring the average grain size of crystal grains in the interstitial region 24 will be explained. For the subregions P1, P3, P5, P11, P13, P15, P21, P23, and P25 included in the central region AR1 or peripheral region AR2, as shown in Figure 9, the average grain size will be measured for each subregion.

[0047] Figure 11 illustrates the method for measuring the average particle size for each sub-region. First, the area near the center point of each sub-region is imaged at 20,000x magnification using a scanning electron microscope (SEM). Next, the particle located at the center point of each sub-region in the image is designated as the reference particle. Using the reference particle as the center point of each sub-region, 20 adjacent particles are measured, starting from the particle closest to the reference particle. In Figure 11, the particle indicated as No. 1 is the reference particle, and the 20 particles No. 1 to No. 20 are all adjacent. Next, the contour of each particle is traced and its area is calculated. The calculated area is considered the area of ​​a perfect circle and converted to the diameter of a perfect circle. The arithmetic mean of the diameters of the 20 converted particles is calculated and used as the average particle size for each sub-region.

[0048] Furthermore, the arithmetic mean of the average particle sizes of subregions P3 and P13 is calculated from the calculated average particle sizes of each subregion and is used as the average particle size of the central region AR1. The arithmetic mean of the average particle sizes of subregions P1, P5, P11, P15, P21, P23, and P25 is calculated and used as the average particle size of the peripheral region AR2.

[0049] The average grain size of the crystal grains may gradually decrease in the order of central region AR1, intermediate region AR3, and peripheral region AR2. This can further improve the aforementioned moisture resistance and mechanical strength.

[0050] The average grain size of crystal grains in the intermediate region AR3 can be measured using the same method as in the central region AR1 and the peripheral region AR2. Furthermore, it can be confirmed that the average grain size of crystal grains gradually decreases in the order of central region AR1, intermediate region AR3, and peripheral region AR2 using the following method.

[0051] As shown in Figure 9, for subregions P1-P5 and P11-P15 contained within the central region AR1, intermediate region AR3, or peripheral region AR2, the average particle size is measured at two locations for each subregion. The detailed method for calculating the average particle size is as described above. The arithmetic mean of the average particle sizes measured at two locations for each subregion is calculated and used as the average particle size for each subregion. If the average particle size gradually decreases in the order of subregions P3, P2, P1, or P3, P4, P5, it can be confirmed that it gradually decreases in the order of central region AR1, intermediate region AR3, and peripheral region AR2.

[0052] Figure 12 illustrates the measurement locations for the average particle size. Although Figure 12 only shows the subregions P1 to P5, the same applies to P11 to P15. Two measurement locations are selected for each subregion, for a total of 10 locations, Q1 to Q10. At measurement locations Q1 to Q10, the position in the X-axis direction is the same. In Figure 12, x is given as an example of x = 9b / 10, but it is sufficient for the position in the X-axis direction to be the same at measurement locations Q1 to Q10. Furthermore, at measurement locations Q1 to Q10, there are two points in the Y-axis direction for each subregion, and they are equally spaced.

[0053] The difference in average particle size between the central region AR1 and the peripheral region AR2 should be 100 nm or more, preferably in the range of 100 to 300 nm, with a more effective range of 150 to 200 nm. The average particle size of the crystal grains in the peripheral region AR2 is preferably in the range of 100 to 350 nm, with a more effective range of 140 to 310 nm. The average particle size of the crystal grains in the central region AR1 is preferably in the range of 300 to 450 nm, with a more effective range of 330 to 420 nm.

[0054] The thickness of the effective portion 11, i.e., its length in the Z-axis direction, is not particularly limited. The thickness of the effective portion 11 may be in the range of 30 to 90%, 40 to 80%, or 50 to 70% of the thickness of the main body portion 3. Here, the thickness of the effective portion 11 is, for example, the thickness from the top surface of the uppermost internal electrode layer 9 to the bottom surface of the lowest internal electrode layer 9. The thickness of the main body portion 3 is, for example, the thickness from the top surface of the cover portion 13 on the upper surface 41 side to the bottom surface of the cover portion 13 on the lower surface 42 side.

[0055] The shape of the effective portion 11 is not particularly limited in a plan view in the Z-axis direction, i.e., the stacking direction, and may be square or rectangular. Basically, the shape of the effective portion 11 is the same as that of the main body portion 3 in a plan view in the Z-axis direction.

[0056] (1.2) Cover portion The cover portion 13 protects the effective portion 11 and improves the strength of the main body portion 3.

[0057] The shape of the cover portion 13 is not particularly limited in a plan view in the Z-axis direction. The shape of the cover portion 13 is basically the same as the shape of the effective portion 11 in a plan view in the Z-axis direction.

[0058] The material of the cover portion 13 is not particularly limited. The material of the cover portion 13 may be the same as or different from the material of the dielectric layer 7. The material of the cover portion 13 may be, for example, ceramics or a material other than ceramics.

[0059] The shape and dimensions of the cover portion 13 are not particularly limited, and it may be layered having a shape and dimensions that overlap the effective portion 11 without excess or deficiency. When the cover portions 13 are located on both sides in the Z-axis direction as shown in Figures 2 and 3, the thickness of one cover portion 13 may be in the range of 5 to 30%, 10 to 25%, or 15 to 25% of the thickness of the main body portion 3. Specifically, the thickness of one cover portion 13 may be in the range of 50 to 150 μm. The cover portion 13 may have multiple layers made of multiple materials. In this case, it may have a dielectric layer, and the thickness of the dielectric layer in the cover portion 13 may be in the range of 2 to 10 μm. Note that the thickness of the cover portion 13 here refers to the thickness from the top surface to the bottom surface of the cover portion 13.

[0060] (2) External Electrodes The shape of the external electrodes 5 is not particularly limited and may be layered with a certain thickness. For example, as shown in Figure 1, they may cover the two end faces 43 and 44 of the main body 3 and also cover a part of the upper surface 41 and the lower surface 42. This allows the external electrodes 5 to be connected to the lead-out portion 92 in the internal electrode layer 9 at the end faces 43 and 44 of the main body 3, and the capacitor 1 can be surface mounted on the circuit board on either the upper surface 41 or the lower surface 42. The shape of the portion of the external electrodes 5 located on the upper surface 41 or the lower surface 42 of the main body 3 may be rectangular with a length of α in the Z-axis direction in a plan view in the X-axis direction. Also, the shape of the portion of the external electrodes 5 located on the end faces 43 and 44 of the main body 3 may be rectangular with a length of α in the Z-axis direction in a plan view in the Y-axis direction. The value of length α here is not particularly limited.

[0061] The material of the external electrode 5 is, for example, a metal. The type of metal is not particularly limited. The metal used as the material of the external electrode 5 may be entirely or primarily composed of a base metal. Base metals include Ni, Cu, Sn, etc., and these may be used in combination. Furthermore, the external electrode 5 may be made up of layers of different materials as needed. For example, the external electrode 5 may be made up of layers of Cu, Ni, and Sn. The material of the external electrode 5 may be the same as or different from the material of the other electrodes.

[0062] The thickness of the external electrode 5 is not particularly limited and may be thicker than the other electrodes. The thickness of the external electrode 5 may be in the range of 3 to 300 μm or in the range of 10 to 100 μm.

[0063] [Manufacturing Method for Capacitors] The manufacturing method for capacitor 1 is not particularly limited, and various methods can be used. Below, a basic method for manufacturing capacitors will be described, followed by a description of a manufacturing method applicable to this embodiment.

[0064] (Green sheet fabrication process) First, a ceramic green sheet corresponding to the dielectric layer 7 is fabricated. The ceramic green sheet here is the size of a base substrate from which multiple capacitors 1 can be cut.

[0065] (Coating process) Next, a conductive paste prepared using Ni powder and Ba is applied to the fabricated ceramic green sheet by printing or other means to form an internal electrode layer 9. Here too, the conductive paste is applied so that multiple capacitors 1 can be made in large quantities.

[0066] (Lamination Process) Next, the ceramic green sheets coated with conductive paste are laminated so that, for example, patterns A and B shown in Figure 4 are alternated, to create a laminate. Here, a laminate corresponding only to the effective portion 11 may be created, or a laminate corresponding to the effective portion 11 and the cover portion 13, i.e., the main body portion 3, may be created. If a laminate corresponding only to the effective portion 11 is created, a layer corresponding to the cover portion may be laminated separately afterward.

[0067] (Individualization process) The laminate, formed by stacking ceramic green sheets, is cut or otherwise divided into individual pieces corresponding to the size of the capacitor 1.

[0068] (Firing Process) The individualized laminates are subjected to a debinder treatment, for example, in a nitrogen atmosphere, and then fired. Here, the binder refers to organic substances, etc., that are added for purposes such as facilitating handling. The firing may be carried out in a reducing atmosphere. The firing conditions may be, for example, 1220°C or lower, for 10 minutes to 2 hours.

[0069] Furthermore, degreasing may be performed before firing. Re-oxidation heat treatment may be performed after firing. The laminate may be polished (barrel polishing, etc.) before and after firing. During polishing, the edges of the laminate may be chamfered, and the end faces and sides may be polished. If the fired laminate corresponds only to the effective portion 11, a layer corresponding to the cover portion 13 is laminated onto the fired laminate to form the main body portion 3.

[0070] (External electrode formation process) A metal film is formed on the obtained main body 3 to form the external electrode 5. Various methods may be used to form the external electrode 5. For example, metal may be deposited on the surface of a dummy electrode by electroless plating or electrolytic plating. For example, metal may be deposited on the edge of the internal electrode layer 9 that is exposed to the outside by electroless plating or electrolytic plating. Alternatively, the metal film may be formed using thin film formation methods such as the dip method, printing method, CVD (Chemical Vapor Deposition), or PVD (Physical Vapor Deposition). The dummy electrode may or may not contribute to the deposition of the metal. A capacitor 1 is thus obtained.

[0071] In this embodiment, as described above, the particle size of the ceramic crystal grains is changed in the gap region 24. Three methods can be used to change the particle size. In the following three methods, as an example, as shown in Figure 10, the particle size is controlled to be relatively large in the central region AR1 and relatively small in the peripheral region AR2.

[0072] The ceramic crystal particles contained in the dielectric layer 7 undergo sintering during the firing process, resulting in an increase in particle size. Therefore, the particle size can be controlled by controlling the degree of sintering. The dielectric layer 7 may also contain barium (Ba), and the degree of sintering can be controlled by controlling the Ba content.

[0073] (Manufacturing Method I) In the first method, first, in the green sheet manufacturing process, the Ba / Ti ratio is controlled so that sintering proceeds relatively well. Next, in the coating process, a sintering-inhibiting additive such as Ba is applied around the formed internal electrode layer 9. The subsequent steps from the lamination process to the external electrode formation process are as described above.

[0074] (Manufacturing Method II) In the second method, instead of producing a ceramic green sheet with a uniform composition in the green sheet manufacturing process, ceramic green sheets with partially different compositions are produced. Ceramic green sheets with different compositions can be produced, for example, by coating them with different compositions using printing or other methods. First, the Ba content is increased and the Ba / Ti ratio is controlled to be high in the area where the internal electrode layer 9 is to be applied and its surroundings, so that sintering does not proceed as easily. Next, the Ba content is decreased and the Ba / Ti ratio is controlled to be low in the remaining area, so that sintering proceeds as easily. The procedure from the subsequent coating process to the external electrode formation process is as described above.

[0075] (Manufacturing Method III) In the third method, first, in the green sheet manufacturing process, the Ba / Ti ratio is controlled to allow sintering to proceed relatively well. Next, in the coating process, more Ba is added to the conductive paste that forms the drawout portion 92. As a result, the formed drawout portion contains more Ba, and some of that Ba leaks out into the peripheral region AR2, making it relatively difficult for sintering to proceed in the peripheral region AR2. The subsequent steps from the lamination process to the external electrode formation process are as described above.

[0076] In this embodiment, a multilayer ceramic capacitor was used as an example of an electronic component, but the applicable electronic components are not limited to multilayer ceramic capacitors. Furthermore, the electronic component may be a multilayer electronic component such as a multilayer composite component, or an electronic component other than a multilayer electronic component. The electronic components as a whole may constitute an electronic circuit such as a resonant circuit.

[0077] As described above, the electronic component (capacitor 1) of this embodiment comprises a main body 3, a first external electrode 5A, and a second external electrode 5B. The main body 3 has a laminate including at least one first internal electrode layer 9A, at least one second internal electrode layer 9B, and a plurality of dielectric layers 7 containing crystalline particles. The first internal electrode layer 9A has a first electrode body 91A and a first lead-out portion 92A that leads the first electrode body 91A to the first external electrode 5A. The second internal electrode layer 9B has a second electrode body 91B and a second lead-out portion 92B that leads the second electrode body 91B to the second external electrode 5B. When viewed from the stacking direction, the main body 3 has a gap region 24 including the dielectric layer 7 between a first lead-out region 22 including the first lead-out portion 92A and a second lead-out region 23 including the second lead-out portion 92B. The gap region 24 has a difference in the average grain size of crystal grains between the central region AR1 and the other regions (peripheral region AR2 and intermediate region AR3). This improves the mechanical strength of the electronic component.

[0078] Furthermore, the average grain size of the crystal grains may be larger in the central region AR1 than in other regions. This can improve the mechanical strength of the electronic component.

[0079] Furthermore, the other regions may include a peripheral region AR2 and an intermediate region AR3 located between the central region AR1 and the peripheral region AR2. The average grain size of the crystal grains may gradually decrease in the order of central region AR1, intermediate region AR3, and peripheral region AR2. This can improve the mechanical strength of the electronic component.

[0080] Furthermore, other regions may have peripheral regions AR2. The difference in average grain size of crystal grains between the central region AR1 and the peripheral region AR2 may be within the range of 100 to 300 nm. This can improve the mechanical strength of electronic components.

[0081] Furthermore, other regions may have peripheral regions AR2. The average grain size of the crystal grains in peripheral regions AR2 may be in the range of 100 to 350 nm. This can improve the mechanical strength of the electronic component.

[0082] Furthermore, the average particle size of the crystal grains in the central region AR1 may be within the range of 300 to 450 nm. This can improve the mechanical strength of the electronic component.

[0083] Furthermore, the specific configurations, structures, positional relationships, materials, etc., shown in the above embodiments can be modified as appropriate without departing from the spirit of this disclosure. The scope of the present invention includes the scope of the invention as described in the claims and its equivalents.

[0084] The present disclosure will be specifically described below with reference to examples, but this disclosure is not limited to these examples. In the following examples, the operations were carried out at room temperature (25°C) unless otherwise specified.

[0085] The capacitor sample smp1 was prepared using the following procedure.

[0086] First, BaTiO ３ A ceramic slurry was prepared by mixing an organic vehicle with a raw material powder mainly composed of BaTiO. ３ Mg per 100 moles of powder ２ CO ３ The powder is equivalent to 0.8 moles of MgO, Dy ２ O ３ 0.8 moles of powder, MnCO ３ Add 0.3 moles of powder in terms of MnO, and further add glass powder to BaTiO ３ The composition was determined by adding 1 part by mass to 100 parts by mass of powder.

[0087] A butyral-based resin was used as the resin to be incorporated into the organic vehicle. The amount of butyral-based resin added was 10 parts by mass per 100 parts by mass of raw material powder. A solvent of ethyl alcohol and toluene mixed in a 1:1 ratio was used. Subsequently, ceramic green sheets with an average thickness in the range of 0.5 to 10 μm were formed using the doctor blade method with the prepared ceramic slurry.

[0088] Next, a first conductive paste was prepared using Ni powder and Ba. An organic vehicle was mixed with the prepared raw material powder to prepare a ceramic slurry. The organic vehicle was, for example, a resin such as ethyl cellulose dissolved in a solvent which was a mixture of a dihydroterpineol-based solvent and butyl cellosolve. Separately, a second conductive paste with a higher Ba concentration than the first conductive paste was prepared. The second conductive paste was prepared using the same procedure as the first conductive paste, except that Ba was added to a concentration of 5.0% by mass relative to the Ni powder.

[0089] Using the prepared first conductive paste and second conductive paste, the pattern of the internal electrode layer 9 shown in Figure 4 was printed on the main surface of the ceramic green sheet to form a pattern sheet for the effective portion. Only the lead-out portion 92 was printed using the second conductive paste, while the other electrode body 91 and dummy portion 93 were printed using the first conductive paste.

[0090] Next, a base laminate was prepared using green sheets and pattern sheets. For the effective portion, 350 pattern sheets for the effective portion were laminated so that pattern A and pattern B, as shown in Figure 4, alternated. For the cover portion, green sheets were laminated on the upper and lower sides of the effective portion, as shown in Figure 2. Subsequently, the base laminate was cut using a press-cutting machine to produce multiple main body parts.

[0091] Next, the main body was degreased. The degreased main body was H ２ -N ２ The material was fired in a mixed gas atmosphere using reduction. The firing temperature was 1100°C, and the heating rate was 10000°C / hr. Subsequently, the main body after firing was treated with O ２ The re-oxidation heat treatment was performed in an atmospheric environment. The temperature for the re-oxidation heat treatment was 1000°C. ２ The equilibrium partial pressure was set to 1 to 1.1 MPa. After barrel polishing the main body that had undergone re-oxidation heat treatment, an external electrode was formed on the main body to obtain sample smp1.

[0092] Samples smp2 to 5 of the main body were manufactured under the same conditions as sample smp1. Sample smp6 was manufactured under the same conditions as sample smp1, except that the drawer section 92 was also formed using the first conductive paste and the firing temperature was higher than 1100°C. Sample smp7 was manufactured under the same conditions as sample smp1, except that the drawer section 92 was also formed using the first conductive paste and the firing temperature was lower than 1100°C. In other words, the Ba concentration and firing temperature in the drawer section 92 were changed by comparing samples smp1 to 5 with samples smp6 to 7.

[0093] For samples smp1 to 7, the average grain size of crystal grains in the interstitial region was measured using the following procedure. First, each sample was polished for 200 μm in the Z-axis direction from the second side surface 46 shown in Figure 1. This removed the cover portion and exposed the interior of the effective portion. This exposed surface was photographed at 20,000x magnification using a scanning electron microscope (SEM). From the captured images, the average grain size at the center points of partial regions P1, P3, P5, P11, P13, P15, P21, P23, and P25 was measured using the method described above. From the measurement results, the average grain size of the central region AR1 (ar1) and the average grain size of the peripheral region AR2 (ar2) were calculated, and the difference between them (ar1) - (ar2) was calculated.

[0094] The flexural strength of samples smp1 to 7 was measured using the following procedure. A bond tester "MFM1200L" (manufactured by Chiyoda Trading Co., Ltd.) was used for the measurement.

[0095] Figure 13 illustrates the method for measuring flexural strength. The ends of the sample 30, which are equipped with external electrodes, were placed across a pair of bridges 31. The upper or lower surface of the sample 30 was supported by the pair of bridges 31. A load was applied to the center of the upper or lower surface of the sample 30 using a blade 32. The descent speed of the blade 32 was set to 100 μm / sec. The load at which the sample 30 broke was recorded and defined as the flexural strength [N].

[0096] Table I below shows the average grain size and flexural strength of the crystal grains in the interstitial regions of samples smp1 to 7.

[0097]

[0098] In samples smp1 to 5, the difference (ar1) - (ar2) was 100 nm or more, indicating a difference in average particle size. On the other hand, in samples smp6 to 7, the difference (ar1) - (ar2) was less than 100 nm, indicating no difference in average particle size. Samples smp1 to 5 showed higher flexural strength than samples smp6 to 7, indicating that the mechanical strength was improved in the embodiments of this model where there was a difference in average particle size.

[0099] Next, each sample was polished for 400 μm in the Z-axis direction from the second side 46 side shown in Figure 1. Similarly, in the exposed surfaces, samples smp1 to 5 showed a difference of 100 nm or more between (ar1) and (ar2), indicating a difference in average grain size. On the other hand, samples smp6 to 7 showed a difference of less than 100 nm between (ar1) and (ar2), indicating no difference in average grain size. Furthermore, samples smp1 to 5 exhibited higher flexural strength than samples smp6 to 7. This indicates that, regardless of the position in the Z-axis direction of the capacitor, the difference in average grain size between the central region AR1 and the peripheral region AR2 improves mechanical strength.

[0100] Next, the average grain size of crystal grains in the interstitial region was measured for samples smp1 and 3 using the following procedure. First, each sample was polished for 200 μm in the Z-axis direction from the second side 46 side shown in Figure 1. This removed the cover portion and exposed the interior of the effective portion. This exposed surface was photographed at 20,000x magnification using a scanning electron microscope (SEM). From the captured images, the average grain size at two locations (measurement positions 1 to 10) in each of the partial regions P1 to P5 was measured using the method described above, and the average grain size for each partial region (region average) was calculated from the arithmetic mean. The average grain size for partial regions P11 to P15 was measured using the same method.

[0101] Tables II and III below show the average particle size of the crystal grains of samples smp1 and 3.

[0102]

[0103]

[0104] In both samples smp1 and smp3, the region-average values ​​decreased in the order of P3, P2, P1, and then in the order of P3, P4, P5. Furthermore, the region-average values ​​decreased in the order of P13, P12, P11, and then in the order of P13, P14, P15. In other words, it can be seen that the values ​​gradually decreased in the order of central region AR1, intermediate region AR3, and peripheral region AR2.

[0105] This disclosure can improve the mechanical strength of electronic components and electronic devices.

[0106] 1 Capacitor 3 Main body 5 External electrode 5A First external electrode 5B Second external electrode 7 Dielectric layer 9 Internal electrode layer 9A First internal electrode layer 9B Second internal electrode layer 11 Effective portion 21 Internal electrode region 22 First lead region 23 Second lead region 24 Gap region 40 Circuit board 91 Electrode body 92 Lead portion 93 Dummy portion 100 Electronic device AR1 Central region AR2 Peripheral region AR3 Intermediate region

Claims

1. An electronic component comprising a main body, a first external electrode, and a second external electrode, wherein the main body has a laminate comprising at least one first internal electrode layer, at least one second internal electrode layer, and a plurality of dielectric layers containing crystal particles, the first internal electrode layer has a first electrode body and a first pull-out portion for pulling the first electrode body to the first external electrode, the second internal electrode layer has a second electrode body and a second pull-out portion for pulling the second electrode body to the second external electrode, and when viewed from the stacking direction, the main body has a gap region containing the dielectric layer between a first pull-out region including the first pull-out portion and a second pull-out region including the second pull-out portion, and the gap region has a difference in the average particle size of the crystal particles between the central region and other regions.

2. The electronic component according to claim 1, wherein the average particle size of the crystal grains is larger in the central region than in the other regions.

3. The electronic component according to claim 1 or 2, wherein the other region comprises a peripheral region and an intermediate region located between the central region and the peripheral region, and the average grain size of the crystal particles gradually decreases in the order of the central region, the intermediate region, and the peripheral region.

4. The electronic component according to any one of claims 1 to 3, wherein the other region has a peripheral region, and the difference in the average particle size of the crystal grains between the central region and the peripheral region is in the range of 100 to 300 nm.

5. The electronic component according to any one of claims 1 to 4, wherein the other region has a peripheral region, and the average particle size of the crystal grains in the peripheral region is in the range of 100 to 350 nm.

6. The electronic component according to any one of claims 1 to 5, wherein the average particle size of the crystal grains in the central region is in the range of 300 to 450 nm.

7. An electronic device including a circuit board on which the electronic components described in any one of claims 1 to 6 are mounted.

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