Electronic Components

Abstract

To provide an electronic component having low relative permittivity ε and high strength.SOLUTION: An electronic component includes a glass ceramic layer and a conductor layer. The glass ceramic layer includes feldspar crystal phases, non-crystalline glass phases, and Al2O3 phases. An area ratio of the feldspar crystal phases in the vicinity of the conductor layer is larger than an area ratio of the feldspar crystal phases away from the conductor layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to electronic components. [Background technology]

[0002] Patent Document 1 describes an invention relating to a method for manufacturing a glass ceramic substrate. The glass ceramic contains a filler, some or all of which are flat particles.

[0003] Patent Document 2 describes an invention of a laminated inductor. A coil conductor is embedded in the laminated structure, and it is suitable for use in the high frequency range. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 09-71472 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-73536 Summary of the Invention [Problem to be solved by the invention]

[0005] An ideal inductor's impedance increases as the frequency increases. However, the impedance of an actual inductor decreases in the high frequency range in inverse proportion to the magnitude of its stray capacitance. The stray capacitance of an inductor is proportional to the dielectric constant of the inductor's material. Therefore, ceramics used in RF inductors, particularly those used in high frequency ranges, must have a low dielectric constant. High strength is also important for RF inductors, and this is particularly required for RF inductors used in automobiles.

[0006] An object of the present invention is to provide an electronic component having a low relative dielectric constant ε and high strength. [Means for solving the problem]

[0007] The electronic component according to the present invention is an electronic component including a glass ceramic layer and a conductor layer, the glass-ceramic layer includes a feldspar crystalline phase, an amorphous glass phase, and an Al2O3 phase; The area ratio of the feldspar crystalline phase in the vicinity of the conductor layer is greater than the area ratio of the feldspar crystalline phase in the portion other than the vicinity of the conductor layer.

[0008] The conductor layer may mainly contain Ag. 。

[0009] The average aspect ratio of each Al2O3 filler constituting the Al2O3 phase may be 15 or more and 75 or less.

[0010] The feldspar crystalline phase may contain primarily Sr.

[0011] The feldspar crystalline phase may contain Ag. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view of a laminated coil component. [Figure 2] FIG. 2 is an exploded perspective view of the laminated coil component of FIG. 1. [Figure 3] 10 is an image illustrating an example of a portion other than the vicinity of the conductor layer. [Figure 4] 10 is an image illustrating the vicinity of a conductor layer. [Figure 5] This is a STEM image of a cross section of glass ceramic. [Figure 6] 1 is a phase separation analysis image of a cross section of a glass ceramic. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] (Structure of multilayer coil components) Fig. 1 is a perspective view of a laminated coil component 1, which is a type of electronic component. Fig. 2 is an exploded perspective view of the laminated coil component 1 of Fig. 1. As shown in Figs. 1 and 2, the laminated coil component 1 includes a glass ceramic body 2, a coil 10 formed of a pair of mounting conductors 3 and a coil conductor 5, and connecting conductors 6 and 7.

[0015] The glass ceramic body 2 has a rectangular parallelepiped shape. Rectangular parallelepiped shapes include those with chamfered corners and ridges, and those with rounded corners and ridges. The glass ceramic body 2 has, as its outer surfaces, end faces 2a and 2b and side faces 2c, 2d, 2e, and 2f. Hereinafter, the opposing direction of the end faces 2a and 2b is referred to as the X direction, the opposing direction of the side faces 2c and 2d as the Y direction, and the opposing direction of the side faces 2e and 2f as the Z direction. The X direction, Y direction, and Z direction are perpendicular to one another.

[0016] End faces 2a and 2b extend in the Y direction to connect side faces 2c and 2d. Furthermore, end faces 2a and 2b also extend in the Z direction to connect side faces 2e and 2f. Side faces 2c and 2d extend in the X direction to connect end faces 2a and 2b. Furthermore, side faces 2c and 2d also extend in the Z direction to connect side faces 2e and 2f. Side faces 2e and 2f extend in the Y direction to connect side faces 2c and 2d. Furthermore, side faces 2e and 2f also extend in the X direction to connect end faces 2a and 2b.

[0017] For example, when the laminated coil component 1 is mounted on another electronic component (e.g., a circuit board, a laminated coil component, etc.), the side surface 2c is parts The side surface 2c is adjacent to the end surfaces 2a and 2b and the side surfaces 2e and 2f.

[0018] There are no particular limitations on the length of the glass ceramic body 2 in any direction.

[0019] The outer surface of the glass ceramic body 2 is provided with a pair of recesses 21 and a pair of recesses 22. Specifically, one recess 21 is provided on the end face 2a side of the side face 2c and is recessed toward the side face 2d. The other recess 21 is provided on the end face 2b side of the side face 2c and is recessed toward the side face 2d. One recess 22 is provided on the end face 2a side of the side face 2c and is recessed toward the end face 2b. The other recess 22 is provided on the end face 2b side of the side face 2c and is recessed toward the end face 2a.

[0020] One recess 21 and one recess 22 are provided continuously and correspond to one mounting conductor 3. The other recess 21 and the other recess 22 are provided continuously and correspond to the other mounting conductor 3. The recess 21 and the recess 22 have, for example, the same shape. The pair of recesses 21 are provided spaced apart from each other in the X direction.

[0021] The glass ceramic body 2 is formed by stacking a plurality of glass ceramic body layers 12a to 12h shown in FIG. 2 in the Z direction. That is, the stacking direction of the glass ceramic body layers 12a to 12h is the Z direction. The specific stacking configuration will be described later. In an actual glass ceramic body 2, the glass ceramic body layers 12a to 12h are integrated, making it difficult to visually recognize the boundaries between the layers. The glass ceramic body layers 12a to 12h are made of glass ceramic, which will be described later.

[0022] A pair of mounting conductors 3 are disposed in the glass ceramic element body 2. Specifically, one mounting conductor 3 is disposed in one recess 21 and one recess 22, and the other mounting conductor 3 is disposed in the other recess 21 and other recess 22. The pair of mounting conductors 3 are spaced apart from each other in the X direction. The mounting conductor 3 is formed by stacking multiple mounting conductor layers 13 in the Z direction. That is, the stacking direction of the mounting conductor layers 13 is the Z direction. In an actual mounting conductor 3, the multiple mounting conductor layers 13 are integrated, and it is difficult to visually recognize the boundaries between the layers.

[0023] The mounting conductor 3 has an L-shape when viewed from the Z direction. The mounting conductor 3 has conductor portion 31 and conductor portion 32 that are integrally formed with each other. When viewed from the Z direction, conductor portion 31 extends in the X direction, and conductor portion 32 extends in the Y direction. The conductor portion 31 is disposed in a recess 21 provided in the side surface 2c, spaced apart from the side surfaces 2e and 2f. The conductor portion 32 is disposed in a recess 22 provided in the end faces 2a and 2b, spaced apart from the side surfaces 2d, 2e, and 2f.

[0024] The conductor portions 31 and 32 are substantially rectangular plate-like. The pair of mounting conductors 3 have the same shape. The L-shape may be any shape that is generally L-shaped overall. For example, even if the surface of the mounting conductor 3 is uneven, it is sufficient that the overall shape is generally L-shaped.

[0025] Conductor portion 31 includes two ends facing each other in the X direction. Conductor portion 32 includes two ends facing each other in the Y direction. One end of conductor portion 31 and one end of conductor portion 32 are connected to each other and provided integrally. Corners at the other ends of conductor portion 31 and 32, which are located inside glass ceramic body 2, may have a rounded shape.

[0026] The mounting conductor 3 may be provided with a plating layer containing, for example, Ni, Sn, Au, etc. The plating layer may be provided by electrolytic plating or electroless plating.

[0027] The coil 10 is formed by connecting a plurality of coil conductors 5 to each other within the glass ceramic body 2. The coil conductors 5 are arranged spaced apart from the end faces 2a and 2b and the side faces 2c, 2d, 2e, and 2f.

[0028] Coil conductors 5 adjacent to each other in the Z direction may be arranged so that at least a portion of each of them overlaps with each other when viewed from the Z direction.

[0029] The coil conductor 5 is configured by stacking coil conductor layers 15c, 15d, 15e, and 15f in the Z direction.

[0030] The connecting conductor 6 extends in the X direction and is connected to the coil conductor 5 and one conductor portion 32. The connecting conductor 7 extends in the X direction and is connected to the coil conductor 5 and the other conductor portion 32.

[0031] The connecting conductor 6 is composed of a connecting conductor layer 16 shown in FIG. 2. The connecting conductor 6 may be composed of one connecting conductor layer 16. The connecting conductor 6 may be composed of a plurality of connecting conductor layers 16 stacked in the Z direction. The connecting conductor 7 is composed of a connecting conductor layer 17 shown in FIG. 2. The connecting conductor 7 may be composed of one connecting conductor layer 17. The connecting conductor 7 may be composed of a plurality of connecting conductor layers 17 stacked in the Z direction.

[0032] Each of the conductor layers is made of a conductive material. There are no particular limitations on the type of conductive material. Each conductor layer may contain mainly Ag. Furthermore, each conductor layer may be made of a conductive material having the same composition, or each conductor layer may be made of a conductive material having a different composition.

[0033] The laminated coil component 1 may be configured by laminating a layer La, a layer Lb, a layer Lc, a layer Ld, a layer Le, a layer Lf, a layer Lg, and a layer Lh in this order from the side surface 2f toward the side surface 2e.

[0034] There are no particular limitations on the types of the layers La and Lh, and they may be composed of glass ceramic body layers 12a and 12h.

[0035] The layers Lb and Lg are formed by combining glass ceramic body layers 12b and 12g with a pair of mounting conductor layers 13. 、12gThe glass ceramic body layer 12b has recesses Rb and Rg having shapes corresponding to the shapes of the pair of mounting conductor layers 13, into which the pair of mounting conductor layers 13 are fitted. 、12g have a complementary relationship with each other.

[0036] The layer Lc is formed by combining a glass ceramic body layer 12c, a pair of mounting conductor layers 13, a coil conductor layer 15c, and a connection conductor layer 16. The glass ceramic body layer 12c has a recess Rc. The recess Rc has a shape corresponding to the shapes of the pair of mounting conductor layers 13, the coil conductor layer 15c, and the connection conductor layer 16. The pair of mounting conductor layers 13, the coil conductor layer 15c, and the connection conductor layer 16 are fitted into the recess Rc. The pair of mounting conductor layers 13, the coil conductor layer 15c, and the connection conductor layer 16 as a whole have a mutually complementary relationship with the glass ceramic body layer 12c.

[0037] The layer Ld is formed by combining a glass ceramic body layer 12d, a pair of mounting conductor layers 13, and a coil conductor layer 15d. The glass ceramic body layer 12d has a recess Rd. The recess Rd has a shape corresponding to the shape of the pair of mounting conductor layers 13 and the coil conductor layer 15d. The pair of mounting conductor layers 13 and the coil conductor layer 15d are fitted into the recess Rd. The pair of mounting conductor layers 13 and the coil conductor layer 15d as a whole and the glass ceramic body layer 12d have a complementary relationship.

[0038] The layer Le is formed by combining a glass ceramic body layer 12e, a pair of mounting conductor layers 13, and a coil conductor layer 15e. The glass ceramic body layer 12e has a recess Re. The recess Re has a shape corresponding to the shape of the pair of mounting conductor layers 13 and the coil conductor layer 15e. The pair of mounting conductor layers 13 and the coil conductor layer 15e are fitted into the recess Re. The pair of mounting conductor layers 13 and the coil conductor layer 15e as a whole and the glass ceramic body layer 12e have a complementary relationship.

[0039] The layer Lf is formed by combining a glass ceramic body layer 12f, a pair of mounting conductor layers 13, a coil conductor layer 15f, and a connection conductor layer 17. The glass ceramic body layer 12f has a recess Rf. The recess Rf has a shape corresponding to the shapes of the pair of mounting conductor layers 13, the coil conductor layer 15f, and the connection conductor layer 17. The pair of mounting conductor layers 13, the coil conductor layer 15f, and the connection conductor layer 17 are fitted into the recess Rf. The pair of mounting conductor layers 13, the coil conductor layer 15f, and the connection conductor layer 17 as a whole and the glass ceramic body layer 12f have a complementary relationship.

[0040] Basically, the widths of the recesses Rb to Rg (hereinafter sometimes simply referred to as recesses) are set to be wider than the widths of the mounting conductor layer 13, the coil conductor layers 15c to 15f, and the connection conductor layers 16 and 17 (hereinafter sometimes simply referred to as conductor layers). However, to improve the adhesion between the glass ceramic body layers 12b to 12g and each conductor layer, the widths of the recesses may be set to be narrower than the widths of the conductor layers. The value obtained by subtracting the width of the conductor layer from the width of the recesses may be, for example, −3 μm to 10 μm, or 0 μm to 10 μm.

[0041] A plurality of layers La, Lb, Lg and / or Lh may be laminated. Rule 1 When increasing the number of turns of layer L0, a layer having an appropriate shape may be added between layer Lc and layer Lf as needed.

[0042] (near the conductor layer) 3 and 4 are images showing a cross section perpendicular to the Z direction of the laminated coil component 1 shown in Fig. 1. These images were obtained by observation using an optical microscope, and the magnification was 500 times.

[0043] Fig. 3 illustrates a portion 51 other than the vicinity of the conductor layer. Fig. 4 illustrates a portion 53 near the conductor layer. The vicinity 53 of the conductor layer is a portion that is 10 μm or less away from the nearest conductor layer, and the portion 51 other than the vicinity of the conductor layer is a portion that is more than 10 μm away from the nearest conductor layer.

[0044] (Material of the glass ceramic body 2 (glass ceramic body layer 12)) 5 and 6, the glass ceramic body 2 of this embodiment includes at least a feldspar crystalline phase 113, an amorphous glass phase 112, and an Al2O3 phase 114. An SiO2 phase 111 may also be included.

[0045] The feldspar crystal phase 113 is a phase that mainly contains feldspar crystals. Feldspar crystals are crystals that contain a Group 2 metal element, alumina, and silica, and are represented by the general formula M(Si,Al)4O8. M is a Group 2 metal element (excluding Be). M may mainly be Sr. When M is mainly Sr, it means that the content ratio of Sr is the highest on a mass basis among the elements contained as M in the feldspar crystals. Note that when it is simply stated that "the feldspar crystal phase 113 mainly contains Sr," it means that the content ratio of Sr is the highest on a mass basis among the elements contained as M in the feldspar crystals contained in the feldspar crystal phase 113.

[0046] The feldspar crystalline phase 113 may contain a metal oxide in addition to feldspar crystals. Examples of metal oxides include Na2O, K2O, ZrO2, and Ag2O. That is, the feldspar crystalline phase 113 may contain Ag. 113 There is no particular limitation on the proportion of feldspar crystals in the crystalline phase, and it may be, for example, 80 mass % or more.

[0047] The area ratio of the feldspar crystalline phase 113 in the vicinity of the conductor layers is larger than the area ratio of the feldspar crystalline phase 113 in the portions other than the vicinity of the conductor layers. Specifically, the value obtained by dividing the area ratio of the feldspar crystalline phase 113 in the vicinity of the conductor layers by the area ratio of the feldspar crystalline phase 113 in the portions other than the vicinity of the conductor layers is larger than 1.0. It may be 1.1 or larger, or may be 1.3 or larger. There is no particular upper limit to the value obtained by dividing the area ratio of the feldspar crystalline phase 113 in the vicinity of the conductor layers by the area ratio of the feldspar crystalline phase 113 in the portions other than the vicinity of the conductor layers. For example, it may be 3.0 or smaller. Since the area ratio of the feldspar crystalline phase 113 in the vicinity of the conductor layers is larger than the area ratio of the feldspar crystalline phase 113 in the portions other than the vicinity of the conductor layers, the flexural strength of the laminated coil component 1 is increased.

[0048] The feldspar crystalline phase 113 contained in the vicinity of the conductor layer may have an Ag content of 4 mass % or more.

[0049] The amorphous glass phase 112 is a phase made of glass that does not contain crystals. There are no particular limitations on the composition of the glass contained in the amorphous glass phase 112. For example, the amorphous glass phase 112 may contain 70 mass % or more of M oxide, Si oxide, Al oxide, and B oxide in total.

[0050] The Al2O3 phase 114 is a phase that mainly contains Al2O3 (alumina) crystals. There is no particular limit to the proportion of Al2O3 in the Al2O3 phase 114. For example, it may be 97 mass% or more. The SiO2 phase 111 is a phase that mainly contains SiO2 (silicon dioxide). There is no particular limit to the proportion of SiO2 in the SiO2 phase 111. For example, it may be 97 mass% or more.

[0051] At least one set of Al2O3 phases 114 may be bonded via the feldspar crystalline phase 113. When the Al2O3 phases 114 are bonded via the feldspar crystalline phase 113, the strength tends to be high.

[0052] The glass ceramic body 2 having the above structure tends to have a low relative dielectric constant ε and high strength.

[0053] The microstructure of the glass ceramic body 2 can be confirmed by observing a cross section of the glass ceramic body 2 using STEM-EDS or the like, followed by phase separation analysis. Fig. 5 shows an image obtained by observing a cross section of the glass ceramic of this embodiment using STEM (hereinafter, sometimes simply referred to as a STEM image). Fig. 6 shows an image obtained by performing RGB image phase analysis as a phase separation analysis on the same observation area as Fig. 5 (hereinafter, sometimes simply referred to as a phase separation analysis image). There are no particular limitations on the size of the observation area or the magnification of the image, as long as it is large enough to observe the microstructure of the glass ceramic. For example, the size of the observation area is 200 μm 2 The magnification of the image should be 5000 times or more. Multiple observation ranges may be set. The total size of the multiple observation ranges must be 200 μm. 2 Anything above that is fine.

[0054] As shown in Figures 5 and 6, the glass ceramic body 2 includes a feldspar crystalline phase 113, an amorphous glass phase 112, an Al2O3 phase 114, and an SiO2 phase 111. The boundary between the feldspar crystalline phase 113 and the Al2O3 phase 114 is not clear in the STEM image of Figure 5. However, by using the STEM image of Figure 5 in combination with the phase separation analysis image of Figure 6, the boundary between the feldspar crystalline phase 113 and the Al2O3 phase 114 becomes clear. The feldspar crystalline phase 113 and / or the amorphous glass phase 112 are present around the Al2O3 phase 114. At least one pair of the Al2O3 phases 114 may be bonded via the feldspar crystalline phase 113.

[0055] Furthermore, to identify each phase, an electron beam may be irradiated onto each phase to measure the electron beam diffraction pattern. When measuring the electron beam diffraction pattern of the amorphous glass phase 112, only a halo pattern derived from the amorphous material is obtained, and no spots derived from the crystals are observed. In contrast, when measuring the electron beam diffraction pattern of the feldspar crystal phase 113 and the Al2O3 phase 114, many spots derived from the crystals are observed. When measuring the electron beam diffraction pattern of the SiO2 phase 111, a halo pattern derived from the amorphous material and / or spots derived from the crystals are observed.

[0056] In the glass ceramic body 2, phases other than the four phases of the feldspar crystalline phase 113, the amorphous glass phase 112, the Al2O3 phase 114, and the SiO2 phase 111 may be negligibly small. For example, the area ratio of the phases other than the above may be 5% or less (including 0).

[0057] The glass ceramic body 2 may contain pores. However, the glass ceramic body 2 is denser with fewer pores, and fewer pores is preferable, particularly from the perspective of improving strength. For example, the area ratio of pores may be 5% or less (including 0).

[0058] The average aspect ratio of each Al2O3 filler constituting the Al2O3 phase 114 may be 15 or more and 75 or less. When the average aspect ratio of the Al2O3 filler is within the above range, the strength of the glass ceramic body 2 is likely to be improved compared to when the average aspect ratio of the Al2O3 filler is small. However, when the average aspect ratio of the Al2O3 filler exceeds 75, the sinterability is likely to decrease, voids are likely to increase, and the strength is likely to decrease.

[0059] The average aspect ratio of the Al2O3 filler can be calculated by measuring the aspect ratio of each Al2O3 phase 114 in a phase separation analysis image and averaging the measured aspect ratios.

[0060] The average particle size of each SiO filler constituting the SiO phase 111 may be 0.10 μm or more and 3.0 μm or less. The smaller the average particle size of the SiO filler, the more likely it is that the sinterability will be reduced. Furthermore, it becomes more difficult for the AlO phase 114 to be bonded via the feldspar crystal phase 113. The larger the average particle size of the SiO filler, the more likely it is that the surface roughness of the glass ceramic body layer 12 will increase, particularly when fabricating the glass ceramic body layer 12.

[0061] The average particle size of the SiO2 filler can be calculated by measuring and averaging the equivalent circle diameter of each SiO2 phase 111 in a phase separation analysis image. The equivalent circle diameter of the SiO2 phase 111 means the diameter of a circle having the same area as the projected area of ​​the SiO2 phase 111.

[0062] The amorphous glass phase 112 and the feldspar crystalline phase 113 are phases mainly composed of glass components. In the glass ceramic body 2 of this embodiment, SiO2 filler and Al2O3 filler are dispersed in the glass component.

[0063] The value obtained by dividing the area ratio of the feldspar crystalline phase 113 by the area ratio of the amorphous glass phase 112 may be 0.10 or more and less than 1.00. The smaller the value obtained by dividing the area ratio of the feldspar crystalline phase 113 by the area ratio of the amorphous glass phase 112, the more difficult it becomes for the Al2O3 phase 114 to be bonded via the feldspar crystalline phase 113. The larger the value obtained by dividing the area ratio of the feldspar crystalline phase 113 by the area ratio of the amorphous glass phase 112, the more likely it is that the strength will be improved, but the relative dielectric constant ε will also be higher.

[0064] The area ratio of the feldspar crystalline phase 113 is not particularly limited, but the area ratio of the feldspar crystalline phase 113 in the portion other than the vicinity of the conductor layer may be 6.5% to 20.5%, or 16.0% to 20.5%. The area ratio of the feldspar crystalline phase 113 in the vicinity of the conductor layer may be 16.3% to 30.5%, or 20.5% to 30.5%.

[0065] The area ratio of the Al2O3 phase 114 may be 7.0% or more and 20.0% or less. The smaller the area ratio of the Al2O3 phase 114, the more difficult it is for the Al2O3 phase 114 to bond via the feldspar crystalline phase 113.

[0066] The area ratio of the SiO2 phase 111 may be 10.0% or more and 30.0% or less. The smaller the area ratio of the SiO2 phase 111, the higher the relative dielectric constant. The larger the area ratio of the SiO2 phase 111, the lower the sinterability. Furthermore, the Al2O3 phase 114 becomes less likely to bond via the feldspar crystalline phase 113.

[0067] The area ratio of each phase can be calculated by image analysis of the phase separation analysis image.

[0068] (Manufacturing Method of the Laminated Coil Component 1) First, a glass raw material, an SiO2 filler raw material, and an Al2O3 filler raw material are mixed to form the glass ceramic body layer 12. Although the SiO2 filler raw material is not essential, it is included in the following description.

[0069] As glass raw materials, crystallized glass and amorphous glass are prepared and mixed.

[0070] As the crystallized glass, a glass containing a component that will become a feldspar crystal during the heat treatment described below is prepared. Examples of the component that will become a feldspar crystal during the heat treatment described below include oxides of M, oxides of Si, and oxides of Al. The crystallized glass may also contain other components. For example, it may contain various oxides such as oxides of B as appropriate.

[0071] There are no particular limitations on the amorphous glass. For example, the amorphous glass may be glass that contains an oxide appropriately selected from various oxides such as an oxide of Si, an oxide of B, an oxide of K, and the like, but does not contain crystals. Most of the glass components contained in the crystallized glass may ultimately be contained in the feldspar crystalline phase 113, or most of the amorphous glass may ultimately be contained in the amorphous glass phase 112.

[0072] The amorphous glass may be mixed with the crystallized glass during the heat treatment described below. The amorphous glass phase 112 may contain oxides that are not contained in the amorphous glass.

[0073] When only amorphous glass is used as a glass raw material, it is difficult to generate a feldspar crystalline phase 113. When only crystallized glass is used as a glass raw material, the content ratio of the amorphous glass phase 112 tends to be small. By controlling the ratio of each raw material, it is possible to control the area ratio of each phase. In particular, by controlling the ratio of crystallized glass to amorphous glass, it is possible to control the value obtained by dividing the area ratio of the feldspar crystalline phase 113 by the area ratio of the amorphous glass phase 112.

[0074] There are no particular restrictions on the particle size of the glass raw materials. For example, D90 may be 1 to 5 μm as measured by a laser diffraction particle size distribution analyzer. In addition, it is preferable that the content of alkali metals in the glass raw materials is low. Specifically, the content of alkali metals is preferably less than 1 mass % when the total of the glass raw materials, SiO2 filler raw material, and Al2O3 filler raw material is 100 mass %. If the content of alkali metals is high, it becomes difficult for feldspar crystals to form near the conductor layer.

[0075] The Al2O3 filler raw material is preferably α-alumina, which has a relatively high melting point. This is to ensure that the glass ceramic after heat treatment contains the Al2O3 phase 114. The shape of the Al2O3 filler raw material may be particulate or plate-like. The average aspect ratio of the Al2O3 phase 114 can be controlled by controlling the shape of the Al2O3 filler raw material. For example, a particulate Al2O3 filler raw material results in a low aspect ratio, while a plate-like Al2O3 filler raw material results in a high aspect ratio. While some of the Al2O3 contained in the Al2O3 filler raw material may react with M and Si and be incorporated into the feldspar crystalline phase 113, most of the Al2O3 contained in the Al2O3 filler raw material forms the Al2O3 phase 114. Furthermore, the higher the aspect ratio of the Al2O3 filler, the larger the surface area of ​​the Al2O3 phase 114 (the longer the perimeter in the STEM image), and the larger the area ratio of the feldspar crystal phase 113 in contact with the Al2O3 phase 114 tends to be.

[0076] Quartz glass (amorphous silica) can be used as the SiO2 filler raw material. The average particle size of the SiO2 phase 111 can be controlled by controlling the particle size of the SiO2 filler raw material. Although some of the SiO2 contained in the SiO2 filler raw material may be incorporated into the amorphous glass phase 112 or the feldspar crystalline phase 113 by heat treatment, most of the SiO2 contained in the SiO2 filler raw material is contained in the SiO2 phase 111.

[0077] Next, the mixed raw materials are wet-mixed with a solvent commonly used in this technical field for 24 hours to obtain a raw material slurry. The solvent may be an alcohol commonly used in this technical field. There are no particular limitations on the equipment used for wet-mixing. For example, a ball mill may be used.

[0078] The raw material slurry is then dried until the solvent is removed to obtain a glass-ceramic material. There are no particular limitations on the drying device used. For example, a spray dryer may be used.

[0079] Next, the obtained glass ceramic material may be subjected to a silane coupling treatment if necessary. Specifically, a silane coupling agent is added to the glass ceramic material and mixed in a mixer. There are no particular restrictions on the type of silane coupling agent. The silane coupling treatment improves the coupling between the glass ceramic material and the binder described below.

[0080] Next, a binder and a photosensitive material are added to the glass ceramic material to form a paint. There are no particular restrictions on the type of binder. For example, an acrylic resin binder can be used. The photosensitive material may be either negative or positive, and any known material can be used. There are also no particular restrictions on the equipment used to form the paint. For example, a ball mill can be used.

[0081] Next, the resulting coating material is applied to a PET film to form an element formation layer. There are no particular limitations on the equipment used to apply the coating material to the PET film. For example, a coater may be used. Next, the element formation layer is exposed and developed by photolithography using, for example, a Cr mask to form an element pattern having defects corresponding to the shape of the conductor formation layer described below. The element pattern becomes glass ceramic element layers 12b-12g after heat treatment. In other words, an element pattern having defects that will become defects Rb-Rg is formed on the PET film. Note that the "photolithography method" is not limited to any particular method as long as it is a method of exposing and developing a layer containing a photosensitive material to be processed into a desired pattern. For example, it is not limited to the type of mask.

[0082] A conductor paste containing the above-mentioned conductor layer constituent materials and a photosensitive material is separately prepared and applied to a PET film to form a conductor-forming layer. There are no particular restrictions on the device used to apply the conductor paste to the PET film. For example, a coater can be used. The photosensitive material contained in the conductor paste may be either negative or positive, and any known material can be used. Next, the conductor-forming layer is exposed and developed by photolithography using, for example, a Cr mask, to form a conductor pattern on the PET film. The conductor pattern becomes a conductor layer after heat treatment.

[0083] Next, the element forming layer without any defects is transferred from the PET film onto the support, thereby forming a layer that will become layer La after heat treatment.

[0084] Next, the conductor pattern and element pattern are repeatedly transferred onto the support, thereby stacking the conductor pattern and element pattern in the Z direction. Specifically, first, the conductor pattern is transferred from the PET film onto the element formation layer. Next, the element pattern is transferred from the PET film onto the element formation layer. The conductor pattern is combined with the missing part of the element pattern, and the element pattern and conductor pattern become the same layer on the element formation layer. Furthermore, the above-mentioned transfer process of the conductor pattern and element pattern is repeated. This stacks layers that will become layers Lb to Lg after heat treatment.

[0085] Next, the element forming layer without any defects is transferred from the PET film onto the support, thereby forming a layer that will become layer Lh after heat treatment, and thus producing the glass ceramic element 2.

[0086] Next, the glass ceramic body 2 is densified by pressing. There are no particular limitations on the apparatus used for pressing. For example, a hot isostatic press (WIP) can be used.

[0087] When multiple glass ceramic bodies 2 are to be produced simultaneously, they are then singulated. There are no particular limitations on the apparatus used for singulation. For example, a dicer may be used.

[0088] Next, the obtained glass ceramic body 2 is subjected to heat treatment and fired. When the conductor layer mainly contains Ag, it is preferable to perform heat treatment at a lower temperature (hereinafter also referred to as low-temperature heat treatment) before performing heat treatment at a temperature at which the glass ceramic body layer 12 crystallizes (hereinafter also referred to as high-temperature heat treatment). There are no particular restrictions on the heat treatment conditions for the low-temperature heat treatment and the high-temperature heat treatment. For example, the heat treatment temperature for the low-temperature heat treatment may be 750 to 850°C, and the heat treatment time for the low-temperature heat treatment may be 10 to 120 minutes. The heat treatment temperature for the high-temperature heat treatment may be 850 to 950°C, and the heat treatment time for the high-temperature heat treatment may be 10 to 120 minutes.

[0089] The low-temperature heat treatment is performed at a heat treatment temperature at which the glass contained in the glass ceramic element layer 12 softens but does not crystallize. Softening the glass allows the substances contained in the glass ceramic element layer 12 to migrate. By performing the low-temperature heat treatment, Ag diffuses from the conductor layer into the glass ceramic element layer 12 (particularly near the conductor layer) before the glass ceramic element layer 12 crystallizes, and the glass ceramic element layer 12 becomes dense. As a result, the Ag content near the conductor layer increases, and the area proportion of the feldspar crystal phase 113 near the conductor layer and the Ag content of the feldspar crystal phase 113 increase. As a result, the flexural strength is likely to improve.

[0090] Even when only high-temperature heat treatment is performed, the Ag content in the vicinity of the conductor layer increases, and the area proportion of the feldspar crystalline phase 113 in the vicinity of the conductor layer and the Ag content in the feldspar crystalline phase 113 increase. High-temperature heat treatment also increases the area proportion of the feldspar crystalline phase 113 more easily than low-temperature heat treatment. This is because high-temperature heat treatment facilitates the crystallization of feldspar. However, high-temperature heat treatment crystallizes the glass ceramic body layer 12, inhibiting the increase in the Ag content in the vicinity of the conductor layer. As a result, compared to low-temperature heat treatment, the Ag content in the vicinity of the conductor layer increases less, and the area proportion of the feldspar crystalline phase 113 in the vicinity of the conductor layer and the Ag content in the feldspar crystalline phase 113 increase less. As a result, the flexural strength is less likely to improve.

[0091] Next, terminal electrodes may be formed as needed. There are no particular limitations on the material or method of forming the terminal electrodes; terminal electrodes may be formed using a material commonly used in this technical field and by a commonly used method. For example, terminal electrodes made of Ag or other material may be baked in a baking furnace at 600 to 700°C.

[0092] Next, if necessary, the terminal electrodes or the mounting conductors 3 may be subjected to electrolytic plating or electroless plating to provide a plating layer.

[0093] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, multiple coil conductor layers may be connected to each other by through-hole conductors. Conductor Pattern The electronic component may be formed by screen printing instead of photolithography. The electronic component does not have to be a laminated electronic component. That is, the number of glass ceramic layers and / or conductor layers may be one.

[0094] The electronic component according to this embodiment may be used for any purpose, including, for example, RF inductors, which are particularly suited to in-vehicle RF inductors that require high strength. [Example]

[0095] The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

[0096] (Experimental Example 1) Glass raw materials, SiO2 filler raw materials, and Al2O3 filler raw materials were prepared. Crystallized glass and amorphous glass were prepared as glass raw materials. These raw materials were then mixed in the following ratios: 45.5 parts by mass of crystallized glass, 30.0 parts by mass of amorphous glass, 24.5 parts by mass of Al2O3 filler raw material, and 10.0 parts by mass of SiO2 filler raw material.

[0097] The glass-ceramics prepared had a Si-Sr-Al composition (SiO2 content of 37-45 mass%, SrO content of 35-40 mass%, Al2O3 content of 5-15 mass%, and B2O3 content of 1-5 mass%).

[0098] The amorphous glass has a Si-BK composition (SiO2 content of 75-85 mass%, B2O3 content of 15-20 mass%, K2O content of 1-5 mass%). ) An amorphous glass having the following structure was prepared.

[0099] In Comparative Examples 2 and 3, Na2O and K2O were further added to the glass raw materials so that the alkali metal content was 1% by mass or more, with the total of the glass raw materials, SiO2 filler raw material, and Al2O3 filler raw material being 100% by mass.

[0100] The average particle size of the SiO2 filler material was adjusted so that the average particle size of the SiO2 filler observed in the final analysis was 0.5 μm. The average particle size of the Al2O3 filler material was adjusted to 1-3 μm. Filler raw materials The aspect ratio of the Al2O3 filler was adjusted so that the average aspect ratio of the Al2O3 filler finally observed would be the value shown in Table 1.

[0101] Next, the mixed raw materials were wet-mixed with a solvent (99% methanol-denatured ethanol) in a ball mill (zirconia ball media) for 24 hours to obtain a raw material slurry, which was then dried in a dryer until the solvent was completely removed, yielding a glass-ceramic material.

[0102] The resulting glass ceramic material was then subjected to a silane coupling treatment. Specifically, 1 part by mass of KBM-103 as a silane coupling agent was added to 100 parts by mass of the glass ceramic material, and the mixture was mixed in a mixer.

[0103] Next, a binder and a photosensitive material were added to the obtained glass ceramic material to prepare a coating material. Specifically, the binder and photosensitive material were added to 100 parts by mass of the obtained glass ceramic material. acrylic 40 parts by mass of resin was added to obtain a coating material.

[0104] A conductor paste containing the constituent materials of the conductor layer and a photosensitive material was prepared by mixing 100 parts by mass of Ag powder, 2 parts by mass of varnish, 10 parts by mass of dipropylene glycol monomethyl ether as an organic solvent, and 10 parts by mass of acrylic resin as a photosensitive material.

[0105] Next, an element pattern was fabricated using the above-mentioned paint. Also, a conductor pattern was fabricated using the conductor paste. The shapes of the element pattern and the conductor pattern were determined so that the shapes of the many multilayer coil components finally obtained would be as shown in Figure 1.

[0106] The above coating material was applied to a PET film to form a body formation layer. A coater was used to apply the coating material to the PET film. The body formation layer was then exposed and developed using a photolithography method with a Cr mask to form a body pattern.

[0107] On the other hand, the above-mentioned conductive paste was applied to a PET film to form a conductive layer. A coater was used as the device for applying the conductive paste to the PET film. Then, a photolithography method using a Cr mask was used to form a conductive layer. Guidance The conductive layer was exposed and developed to form a conductor pattern.

[0108] Subsequently, the element forming layer, the element pattern, and the conductor pattern were laminated so that the shape of the final laminated coil component obtained would be the above-mentioned shape.

[0109] Next, the glass ceramic body 2 was densified by pressing using a WIP.

[0110] Next, a dicer was used to separate the glass ceramic body 2 into a plurality of pieces.

[0111] Next, the obtained glass ceramic body 2 was subjected to heat treatment and fired. In experimental examples in which both low-temperature and high-temperature heat treatments were performed, heat treatment was performed at 800°C for the time shown in Table 1, and then heat treatment was performed at 900°C for the time shown in Table 1. In experimental examples in which only high-temperature heat treatment was performed, heat treatment was performed at 900°C for the time shown in Table 1.

[0112] Next, the mounting conductor 3 was subjected to electrolytic plating to provide a plating layer made of Ni and Sn.

[0113] Next, the microstructure and various properties of the obtained glass-ceramic sintered body were evaluated under the conditions shown below. The results are shown in Table 1.

[0114] [Fine structure] STEM images were observed using a STEM (JEM-2200FS) for the cross section of the glass-ceramic sintered compact, at the center of the coil (the area other than the area near the conductor layer) and the area near the conductor layer. Furthermore, phase separation analysis was performed using RGB image phase analysis. The observation area was 7.5 μm × 7.5 μm and the magnification was 7500x. Five different observation areas were set, and STEM images were taken and phase separation analysis was performed for each observation area. The average aspect ratio of the Al2O3 filler and the area fraction of the feldspar crystalline phase were calculated from the five STEM images and five phase separation analysis images obtained. The area fraction of the feldspar crystalline phase near the conductor layer was then divided by the area fraction of the feldspar crystalline phase in the area other than the area near the conductor layer. Furthermore, the mass fraction of Ag contained in the feldspar crystalline phase near the conductor layer was calculated. The results are shown in Table 1.

[0115] In this example, the amorphous glass did not contain oxides of Sr or Al, but it was confirmed that the amorphous glass phase contained in the final glass-ceramic sintered body contained SrO and Al2O3.

[0116] [Relative permittivity ε] The dielectric constant ε (unitless) was measured by a resonance method (JIS R 1627) using a network analyzer (8510C manufactured by Hewlett-Packard Co.) In this example, a dielectric constant ε of 6.00 or less was considered good, and a dielectric constant of 5.80 or less was considered even better.

[0117] [Deflection strength test] For the deflection strength test, a sample was soldered to the center of a substrate (glass epoxy substrate, size 100 mm × 40 mm, thickness 1.6 mm) using the multilayer coil components of each Example and Comparative Example, and then a load was applied to the surface (back of the substrate) other than the surface to which the sample was soldered for 5 seconds at a specified deflection amount, and the appearance of the sample after the load application and the presence or absence of internal cracks were evaluated.

[0118] For each example and comparative example, a deflection strength test was first performed using 10 samples for each example with a deflection of 1.2 mm. Next, a deflection strength test was performed using 10 samples for each example with a deflection of 1.6 mm. Finally, a deflection strength test was performed using 10 samples for each example with a deflection of 2.0 mm. In other words, a total of 30 samples were used for each example and comparative example to perform the deflection strength test.

[0119] In this example, when no cracks occurred at a deflection of 1.2 mm, that is, when no cracks occurred among 10 samples, the sample was judged to be good.

[0120] At a deflection of 1.6 mm, a crack occurrence rate of 10% or less, i.e., one crack or less out of 10 pieces, was rated as good. If no cracks occurred, i.e., zero cracks out of 10 pieces, it was rated as even better.

[0121] At a deflection of 2.0 mm, a crack occurrence rate of 50% or less, i.e., 5 or fewer cracks out of 10 pieces, was rated as good. A crack occurrence rate of 20% or less, i.e., 2 or fewer cracks out of 10 pieces, was rated as even better. No cracks, i.e., 0 cracks out of 10 pieces, was rated as best.

[0122] (Experimental Example 2) Experimental Example 1 was carried out under the same conditions as in Example 1, except that the metal element mainly contained in the glass raw material of Example 1 was changed from Sr to Mg, Ca or Ba. The results are shown in Table 1.

[0123] [Table 1]

[0124] As can be seen from Table 1, in each Example in which the value obtained by dividing the area ratio of the feldspar crystal phase near the conductor layer by the area ratio of the feldspar crystal phase in the portion other than the conductor layer was greater than 1.0, the relative dielectric constant ε was low and the flexure strength was high. In contrast, in each Comparative Example in which the value obtained by dividing the area ratio of the feldspar crystal phase near the conductor layer by the area ratio of the feldspar crystal phase in the portion other than the conductor layer was 1.0 or less, the flexure strength was reduced.

[0125] In Examples 6 to 8, in which the metal element mainly contained in the glass raw material of Example 1 was changed from Sr to Mg, Ca, or Ba, the metal element mainly contained in the feldspar crystal phase changed from Sr to Mg, Ca, or Ba.

[0126] Examples 6 to 8, in which Mg, Ca, or Ba was used, had good properties. Example 6, in which Mg was used, and Example 7, in which Ca was used, had decreased strength compared to Example 1. Example 8, in which Ba was used, had an increased relative dielectric constant ε compared to Example 1.

[0127] Examples 4 and 5, in which the average aspect ratio of the Al2O3 filler was 15 or more and 75 or less, had better flexural strength than Example 1, which had the same conditions except that the average aspect ratio of the Al2O3 filler was less than 15. [Explanation of symbols]

[0128] 1...Laminated coil component 2...Glass ceramic element 2a, 2b...end face 2c~2f…side 3... Mounting conductor 5...Coil conductor 6, 7...Connecting conductor 10...Coil 21, 22...recesses 31, 32...conductor parts 12a~12h...Glass ceramic body layer 13...Conductor layer for mounting 15c~15f...Coil conductor layers 16, 17...Connecting conductor layers La~Lh...layers Rb~Rg...Defective area 51...Area other than the vicinity of the conductor layer 53...Via the conductor layer 111...SiO2 phase 112...Non-crystalline glass phase 113...feldspar crystalline phase 114…Al2O3 phase

Claims

1. 1. An electronic component comprising a glass ceramic layer and a conductor layer, The glass ceramic layer comprises a feldspar crystalline phase, an amorphous glass phase, and Al 2 O 3 phase, the feldspar crystalline phase mainly contains Sr; An electronic component in which the area ratio of the feldspar crystalline phase in the vicinity of the conductor layer divided by the area ratio of the feldspar crystalline phase in the portion other than the vicinity of the conductor layer is 1.5 or more and 3.0 or less.

2. 2. The electronic component according to claim 1, wherein the conductor layer mainly contains Ag.

3. The Al 2 O 3 Each Al constituting the phase 2 O 3 3. The electronic component according to claim 1, wherein the filler has an average aspect ratio of 15 or more and 75 or less.

4. 4. The electronic component according to claim 1, wherein the feldspar crystal phase contains Ag.

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