Multilayer electronic components

Abstract

To provide a multilayer electronic component in which generation of a void is suppressed.SOLUTION: In a photosensitive conductor paste containing a photosensitive organic component, a conductive powder, and a quartz powder, melting of the quartz powder is not generated or is hardly generated in a heat treatment step S11. Since it is sufficiently functioned so that both contraction ratio and a contraction action are brought close when both of a conductive layer and an element body layer in the heat treatment step S11 are contracted, generation of a void can be suppressed when it is used for manufacturing a lamination coil component.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a laminated electronic component. [Background technology]

[0002] Conventionally, a technique for forming a conductor pattern of a laminated electronic component by photolithography using a photosensitive conductor paste has been known. Patent Document 1 below discloses a photosensitive conductor paste to which glass powder is added as an inorganic additive component. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-264965 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have conducted extensive research into inorganic additives to be added to photosensitive conductor pastes and have found that adding inorganic additives can adjust the difference in shrinkage rate and shrinkage behavior between the base body and the conductor pattern of a laminated electronic component. However, in photosensitive conductor pastes that contain glass powder as an inorganic additive, the glass softens during heat treatment in the manufacturing process, which can result in voids between the base body and the conductor pattern.

[0005] An object of the present invention is to provide a laminated electronic component in which the generation of voids is suppressed. [Means for solving the problem]

[0006] A photosensitive conductor paste according to one aspect of the present invention contains a photosensitive organic component, a conductor powder, and a quartz powder.

[0007] Since the melting point of quartz is higher than the heat treatment temperature when manufacturing laminated electronic components, the quartz powder is less likely to melt in the photosensitive conductive paste, and the occurrence of voids can be suppressed when used to manufacture laminated electronic components.

[0008] In the photosensitive conductive paste according to another embodiment, the median diameter of the quartz powder is 0.4 to 5.0 μm.

[0009] In a photosensitive conductor paste according to another embodiment, the median diameter of the conductor powder is equal to or larger than the median diameter of the quartz powder.

[0010] In another embodiment of the photosensitive conductive paste, the conductive powder is silver powder.

[0011] A laminated electronic component according to one aspect of the present invention has a laminated structure including a plurality of element layers each having a rectangular cross-sectional missing portion and a plurality of conductor layers filled in the missing portion of each of the plurality of element layers, and the conductor layers are composed of a conductor containing quartz powder.

[0012] In the above laminated electronic component, the conductor layer contains quartz powder, which prevents melting during heat treatment during manufacturing, thereby preventing voids from occurring between the element layer and the conductor layer.

[0013] In a laminated electronic component according to another embodiment, a plurality of conductor layers form a coil.

[0014] In a laminated electronic component according to another embodiment, the element layer is made of a material containing a glass component.

[0015] A method for manufacturing a laminated electronic component according to one aspect of the present invention includes the steps of forming a laminate including a plurality of stacked element patterns, each having a rectangular cross-sectional missing portion, and a plurality of conductor patterns filled in the missing portions of each of the plurality of element patterns, and heat-treating the laminate to convert the element patterns into element layers and the conductor patterns into conductor layers, wherein the conductor patterns are formed by photolithography using a photosensitive conductor paste containing a photosensitive organic component, conductor powder, and quartz powder.

[0016] In the method for manufacturing a laminated electronic component described above, the quartz powder added to the photosensitive conductor paste is difficult to melt in the heat treatment step, so that the generation of voids between the element layer and the conductor layer is suppressed. [Effects of the Invention]

[0017] According to the present invention, a laminated electronic component in which the generation of voids is suppressed is provided. [Brief explanation of the drawings]

[0018] [Figure 1] 3 is an electron microscope photograph of the photosensitive conductive paste according to the first embodiment after heat treatment. [Figure 2] FIG. 1 is a perspective view of a laminated coil component manufactured by a method for manufacturing a laminated coil component according to a first embodiment. [Figure 3] FIG. 2 is an exploded perspective view of the laminated coil component shown in FIG. [Figure 4] 3 is a flowchart showing a method for manufacturing the laminated coil component according to the first embodiment. [Figure 5] 1A to 1C are cross-sectional views conceptually showing a method for manufacturing the laminated coil component according to the first embodiment. [Figure 6] 1A to 1C are cross-sectional views conceptually showing a method for manufacturing the laminated coil component according to the first embodiment. [Figure 7] 1 is an electron microscope photograph of a photosensitive conductive paste containing glass powder after heat treatment. [Figure 8] 10 is a flowchart showing a method for manufacturing a laminated coil component according to a second embodiment. [Figure 9] 5A to 5C are cross-sectional views conceptually showing a method for manufacturing a laminated coil component according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same functions will be denoted by the same reference numerals, and redundant description will be omitted.

[0020] [First embodiment] (Photosensitive conductive paste) The photosensitive conductor paste according to the first embodiment contains a conductor powder as a conductive component and a quartz powder as an inorganic additive component in a photosensitive organic component. More specifically, the photosensitive conductor paste has the conductor powder and the quartz powder dispersed in the photosensitive organic component. The photosensitive conductor paste does not contain glass as an inorganic additive component.

[0021] The photosensitive organic component of the photosensitive conductive paste includes an organic binder and an organic solvent, and may further include, for example, a photopolymerizable monomer or a photopolymerization initiator, etc. The photosensitive organic component may be either negative or positive.

[0022] The conductive powder is, for example, a metal powder such as silver powder or an alloy powder. In this embodiment, the conductive powder is silver powder. In this embodiment, the silver powder has a median diameter (d50 particle size) of 0.5 to 5.0 μm (for example, 2.5 μm).

[0023] The quartz powder is a fine powder (silica sand) made of quartz and is obtained, for example, by pulverization. In this embodiment, the quartz powder has a median diameter (d50 particle size) of 0.4 to 5.0 μm. In this embodiment, the median diameter of the silver powder is equal to or greater than the median diameter of the quartz powder. The quartz powder may have a d95 particle size of 1.0 to 7.0 μm. The quartz powder may have a maximum particle size of 2.0 to 10 μm. For example, the quartz powder has a median diameter of 1.0 μm, a d95 particle size of 2.0 μm, and a maximum particle size of 5.0 μm. If the quartz powder is too fine, the thickness (reaction film thickness) at which light reaches and photopolymerization occurs when the photosensitive conductive paste is dried and formed into a film will be reduced, so the quartz powder must have a relatively large particle size. The quartz powder is added to the silver powder at a ratio of approximately 0.5 to 2.5 wt%. By adjusting the proportion of quartz powder added, the shrinkage rate when the photosensitive conductor paste is heat-treated can be adjusted. For example, by increasing the proportion of quartz powder added, the shrinkage rate (final shrinkage rate) decreases, making it possible to reduce the difference in shrinkage rate between the conductor layer and the element layer in the laminated electronic component described below. Furthermore, by adjusting the proportion of quartz powder added, the behavior of the element layer from the start to the end of shrinkage (shrinkage behavior) can be made to be closer to the shrinkage behavior of the conductor layer. By making the shrinkage rates and shrinkage behaviors between the conductor layer and the element layer closer, it is possible to suppress voids that occur near the interface between the conductor layer and the element layer due to differences in shrinkage rate and shrinkage behavior.

[0024] As shown in Figure 1, the quartz powder has a shape with multiple corners (or sharp points), for example, a polygonal cross section. The quartz powder does not melt and maintains its shape when heat treated at a temperature lower than the melting point of quartz (approximately 1600 to 1700°C). If the quartz powder does not melt, the quartz powder particles do not aggregate and remain dispersed even after heat treatment.

[0025] Furthermore, since the quartz powder has sufficient light transmittance (UV transmittance), the quartz powder does not interfere with the exposure of the photosensitive conductive paste during photolithography.

[0026] (Laminated coil components) The laminated coil component according to the first embodiment will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a perspective view of the laminated coil component manufactured by the manufacturing method of the laminated coil component according to the first embodiment. Fig. 3 is an exploded perspective view of the laminated coil component shown in Fig. 2.

[0027] As shown in FIGS. 2 and 3, the laminated coil component 1 according to the first embodiment includes an element body 2, mounting conductors 3 and 4, a plurality of coil conductors 5c, 5d, 5e, and 5f, and connecting conductors 6 and 7.

[0028] The element body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The element body 2 has end faces 2a and 2b and side faces 2c, 2d, 2e, and 2f. The end faces 2a and 2b face each other. The side faces 2c and 2d face each other. The side faces 2e and 2f face each other. Hereinafter, the facing direction of the end faces 2a and 2b is referred to as direction D1, the facing direction of the side faces 2c and 2d as direction D2, and the facing direction of the side faces 2e and 2f as direction D3. Directions D1, D2, and D3 are approximately perpendicular to each other.

[0029] End faces 2a and 2b extend in direction D2 to connect side faces 2c and 2d. End faces 2a and 2b also extend in direction D3 to connect side faces 2e and 2f. Side faces 2c and 2d extend in direction D1 to connect end faces 2a and 2b. Side faces 2c and 2d also extend in direction D3 to connect side faces 2e and 2f. Side faces 2e and 2f extend in direction D2 to connect side faces 2c and 2d. Side faces 2e and 2f also extend in direction D1 to connect end faces 2a and 2b.

[0030] The side surface 2c is a mounting surface that faces another electronic device (e.g., a circuit board or an electronic component) not shown when the laminated coil component 1 is mounted on the other electronic device. The end surfaces 2a and 2b are surfaces that are continuous with the mounting surface (i.e., the side surface 2c).

[0031] The length of the element body 2 in direction D1 is longer than the length of the element body 2 in direction D2 and the length of the element body 2 in direction D3. The length of the element body 2 in direction D2 and the length of the element body 2 in direction D3 are equal to each other. That is, in this embodiment, the end faces 2a and 2b are square-shaped, and the side faces 2c, 2d, 2e, and 2f are rectangular-shaped. The length of the element body 2 in direction D1 may be equal to or shorter than the length of the element body 2 in direction D2 and the length of the element body 2 in direction D3. The length of the element body 2 in direction D2 and the length of the element body 2 in direction D3 may be different from each other.

[0032] In this embodiment, "equivalent" does not only mean equal, but also may mean values ​​that include slight differences or manufacturing errors within a preset range. For example, if multiple values ​​are within a range of ±5% of the average value of the multiple values, the multiple values ​​are defined as equivalent.

[0033] The element body 2 is provided with recesses 21, 22, 23, and 24. The recesses 21 and 22 are integrally formed and correspond to the mounting conductor 3. The recesses 23 and 24 are integrally formed and correspond to the mounting conductor 4.

[0034] The recess 21 is provided on the end face 2a side of the side face 2c and is recessed toward the side face 2d. The recess 22 is provided on the end face 2a side of the end face 2a and is recessed toward the end face 2b. The recess 23 is provided on the end face 2b side of the side face 2c and is recessed toward the side face 2d. The recess 24 is provided on the side face 2c side of the end face 2b and is recessed toward the end face 2a. The recesses 21, 22, 23, and 24 have, for example, the same shape. The recesses 21, 22, 23, and 24 are provided spaced apart from the side faces 2d, 2e, and 2f. The recess 21 and the recess 23 are provided spaced apart from each other in the direction D1.

[0035] The element body 2 is formed by stacking a plurality of element layers 12a-12f in direction D3. A specific stacking configuration will be described later. In the actual element body 2, the plurality of element layers 12a-12f are integrated to the extent that the boundaries between the layers are not visible. The element layers 12a-12f are formed, for example, from a magnetic material (such as a Ni-Cu-Zn ferrite material, a Ni-Cu-Zn-Mn ferrite material, or a Ni-Cu ferrite material). The magnetic material forming the element layers 12a-12f may include an Fe alloy or the like. The element layers 12a-12f may include a glass material, or may be formed from a non-magnetic material (such as a glass ceramic material or a dielectric material).

[0036] The mounting conductors 3 are disposed in the recesses 21 and 22. The mounting conductors 4 are disposed in the recesses 23 and 24. The mounting conductors 3 and 4 are spaced apart from each other in the direction D1. The mounting conductors 3 and 4 have, for example, the same shape. The mounting conductors 3 and 4 have, for example, an L-shaped cross section. It can also be said that the mounting conductors 3 and 4 have an L-shape when viewed from the direction D3, for example. The mounting conductors 3 and 4 may be subjected to electrolytic plating or electroless plating to form a plating layer on their outer surfaces. The plating layer contains, for example, Cu, Ni, Sn, Au, etc.

[0037] The mounting conductor 3 is configured by stacking a plurality of mounting conductor layers 13, each of which has an L-shape when viewed from the direction D3, in the direction D3. In an actual mounting conductor 3, the plurality of mounting conductor layers 13 are integrated to the extent that the boundaries between the layers are not visible. The mounting conductor 3 has conductor portions 31 and 32 that are integrally formed. The conductor portions 31 and 32 are shaped like a substantially rectangular plate. The conductor portions 31 and 32 have, for example, the same shape. The conductor portion 31 is disposed in the recess 21. The conductor portion 32 is disposed in the recess 22.

[0038] The mounting conductor 4 is configured by stacking a plurality of mounting conductor layers 14, each of which has an L-shape when viewed from the direction D3, in the direction D3. In an actual mounting conductor 4, the plurality of mounting conductor layers 14 are integrated to the extent that the boundaries between the layers are not visible. The mounting conductor 4 has conductor portions 41 and 42 that are integrally formed. The conductor portions 41 and 42 are shaped like a substantially rectangular plate. The conductor portions 41 and 42 have, for example, the same shape. The conductor portion 41 is disposed in the recess 23. The conductor portion 42 is disposed in the recess 24.

[0039] The multiple coil conductors 5c, 5d, 5e, and 5f are connected to each other to form a coil 10 within the element body 2. The coil conductors 5c, 5d, 5e, and 5f are arranged so that they at least partially overlap each other when viewed from direction D3. The coil conductors 5c, 5d, 5e, and 5f are arranged spaced apart from the end faces 2a and 2b and the side faces 2c, 2d, 2e, and 2f.

[0040] The coil conductor 5c constitutes one end of the coil 10. One end of the coil conductor 5c and the connecting conductor 6 are adjacent to each other in the direction D1 and are connected to each other. The other end of the coil conductor 5c and one end of the coil conductor 5d are adjacent to each other in the direction D3 and are connected to each other. The other end of the coil conductor 5d and one end of the coil conductor 5e are adjacent to each other in the direction D3 and are connected to each other. The other end of the coil conductor 5e and one end of the coil conductor 5f are adjacent to each other in the direction D3 and are connected to each other. The other end of the coil conductor 5f and the connecting conductor 7 are adjacent to each other in the direction D1 and are connected to each other.

[0041] The coil conductors 5c, 5d, 5e, and 5f are formed by stacking multiple coil conductor layers 15c, 15d, 15e, and 15f in the direction D3. That is, the multiple coil conductor layers 15c, 15d, 15e, and 15f are arranged so that they all overlap each other when viewed from the direction D3. The coil conductors 5c, 5d, 5e, and 5f may be formed by a single coil conductor layer 15c, 15d, 15e, and 15f. Note that FIG. 3 shows only one coil conductor layer 15c, 15d, 15e, and 15f. In the actual coil conductors 5c, 5d, 5e, and 5f, the multiple coil conductor layers 15c, 15d, 15e, and 15f are integrated to the extent that the boundaries between the layers are not visible.

[0042] The connecting conductor 6 extends in direction D1 and is connected to the coil conductor 5c of the coil 10 and the conductor portion 42. The connecting conductor 7 extends in direction D1 and is connected to the coil conductor 5f and the conductor portion 32. The connecting conductors 6 and 7 are formed by stacking a plurality of connecting conductor layers 16 and 17 in direction D3. Note that only one connecting conductor layer 16 and 17 is shown in FIG. 3. In the actual connecting conductors 6 and 7, the multiple connecting conductor layers 16 and 17 are integrated to the extent that the boundaries between the layers are not visible.

[0043] The mounting conductor layers 13 and 14, the coil conductor layers 15c, 15d, 15e, and 15f, and the connection conductor layers 16 and 17 are made of conductors containing silver and quartz powder. These layers may be made of the same material or different materials. Each of these layers has a rectangular cross section. In this embodiment, a "rectangular cross section" refers to a rectangular cross section of a portion extending in a predetermined direction when cut along a plane perpendicular to that direction. In addition, the "rectangle" in this embodiment is not limited to a shape surrounded by four straight lines with all four corners at right angles (rectangle or square). As long as the shape has an approximately rectangular outline, the opposing straight lines may not be parallel, some or all of the straight lines may be curved, and the corners may not be right angles or may be rounded.

[0044] The laminated coil component 1 includes a plurality of layers La, Lb, Lc, Ld, Le, and Lf. The laminated coil component 1 is configured by stacking, for example, two layers La, one layer Lb, three layers Lc, three layers Ld, three layers Le, three layers Lf, one layer Lb, and two layers La in this order from the side surface 2f side. Note that in FIG. 3 , one of the three layers Lc, one of the three layers Ld, one of the three layers Le, and one of the three layers Lf is illustrated, and the other two are not illustrated.

[0045] The layer La is composed of an element layer 12a.

[0046] Layer Lb is formed by combining element layer 12b and mounting conductor layers 13, 14. Element layer 12b has a shape corresponding to the shape of mounting conductor layers 13, 14, and is provided with a recess Rb into which mounting conductor layers 13, 14 are filled. Element layer 12b and the entire mounting conductor layers 13, 14 have a complementary relationship with each other.

[0047] The layer Lc is formed by combining the base layer 12c with the mounting conductor layers 13 and 14 and the coil conductor layer 15c. The base layer 12c has a shape corresponding to the shapes of the mounting conductor layers 13 and 14 and the coil conductor layer 15c, and is provided with a recess Rc that is filled with the mounting conductor layers 13 and 14, the coil conductor layer 15c, and the connecting conductor layer 16. The base layer 12c and the entirety of the mounting conductor layers 13 and 14, the coil conductor layer 15c, and the connecting conductor layer 16 have a complementary relationship with each other.

[0048] The layer Ld is formed by combining the base layer 12d with the mounting conductor layers 13, 14 and the coil conductor layer 15d. The base layer 12d has a shape corresponding to the shapes of the mounting conductor layers 13, 14 and the coil conductor layer 15d, and is provided with a recess Rd into which the mounting conductor layers 13, 14 and the coil conductor layer 15d are filled. The base layer 12d and the entire mounting conductor layers 13, 14 and the coil conductor layer 15d have a complementary relationship.

[0049] The layer Le is formed by combining the base layer 12e with the mounting conductor layers 13, 14 and the coil conductor layer 15e. The base layer 12e has a shape corresponding to the shapes of the mounting conductor layers 13, 14 and the coil conductor layer 15e, and is provided with a recess Re into which the mounting conductor layers 13, 14 and the coil conductor layer 15e are filled. The base layer 12e and the entire mounting conductor layers 13, 14 and the coil conductor layer 15e have a complementary relationship with each other.

[0050] The layer Lf is formed by combining the base layer 12f with the mounting conductor layers 13 and 14, the coil conductor layer 15f, and the connecting conductor layer 17. The base layer 12f has a shape corresponding to the shapes of the mounting conductor layers 13 and 14, the coil conductor layer 15f, and the connecting conductor layer 17, and has a recess Rf that is filled with the mounting conductor layers 13 and 14, the coil conductor layer 15f, and the connecting conductor layer 17. The base layer 12f and the entirety of the mounting conductor layers 13 and 14, the coil conductor layer 15f, and the connecting conductor layer 17 have a complementary relationship with each other.

[0051] The recesses Rb, Rc, Rd, Re, and Rf are integrated to form the recesses 21, 22, 23, and 24. The widths of the recesses Rb, Rc, Rd, Re, and Rf (hereinafter, the widths of the recesses) are generally set to be wider than the widths of the mounting conductor layers 13 and 14, the coil conductor layers 15c, 15d, 15e, and 15f, and the connecting conductor layers 16 and 17 (hereinafter, the widths of the conductor portions). To improve adhesion between the element layers 12b, 12c, 12d, 12e, and 12f and the mounting conductor layers 13 and 14, the coil conductor layers 15c, 15d, 15e, and 15f, and the connecting conductor layers 16 and 17, the widths of the recesses may be intentionally set to be narrower than the widths of the conductor portions. The value obtained by subtracting the width of the conductor portion from the width of the recesses is, for example, preferably −3 μm or more and 10 μm or less, and more preferably 0 μm or more and 10 μm or less.

[0052] (Manufacturing method of laminated coil components) A method for manufacturing the laminated coil component 1 according to the embodiment will be described with reference to Figs. 4 to 6. Fig. 4 is a flowchart showing a method for manufacturing the laminated coil component according to the first embodiment. Figs. 5 and 6 are cross-sectional views conceptually showing the method for manufacturing the laminated coil component according to the first embodiment. The cross-sectional views of Figs. 5 and 6 are shown conceptually and do not necessarily coincide with the cross-sectional views of the actual laminated coil component 1.

[0053] First, as shown in FIG. 5(a), an element formation layer 21 is formed on a substrate 20 (step S1). The substrate 20 is, for example, a PET film. The element formation layer 21 is formed, for example, by applying an element paste containing a photosensitive organic component to which the constituent materials of the above-mentioned element layers 12a to 12f have been added onto the substrate 20. The photosensitive organic component contained in the element paste may be either a negative or positive type, and a known one may be used.

[0054] 5(b), the element formation layer 21 is exposed and developed by photolithography using, for example, a Cr mask, to form an element pattern 22 on the substrate 20, from which a shape corresponding to the shape of the conductor pattern 32 described below has been removed (step S2). The element pattern 22 is a layer that will become the element layers 12b to 12f after heat treatment. That is, in step S2, an element pattern 22 is formed that has defects 23 that will become the defects Rc, Rd, Re, and Rf. Note that the "photolithography" of this embodiment is not limited to any particular type of mask, as long as it is a method of exposing and developing a layer to be processed that contains a photosensitive organic component to light to form a desired pattern.

[0055] Meanwhile, as shown in FIG. 5(c), a conductor-forming layer 31 is formed on the substrate 30 (step S3). The substrate 30 is, for example, a PET film. The conductor-forming layer 31 is formed by applying the above-mentioned photosensitive conductor paste onto the substrate 30. Subsequently, as shown in FIG. 5(d), the conductor-forming layer 31 is exposed and developed by, for example, a photolithography method using a Cr mask, to form a conductor pattern 32 on the substrate 30 (step S4). The conductor pattern 32 is a layer that will become the mounting conductor layers 13 and 14, the coil conductor layers 15c, 15d, 15e, and 15f, and the connection conductor layers 16 and 17 after heat treatment.

[0056] 5(e), the element body formation layer 21 formed in step S1 above is transferred from the substrate 20 onto the support 40 (step S5). By repeating step S5 multiple times, multiple element body formation layers 21 may be stacked on the support 40. In this embodiment, by repeating step S5 twice, two element body formation layers 21 are stacked on the support 40. These element body formation layers 21 are layers that will become layer La after heat treatment.

[0057] Next, the conductor patterns 32 and the element body patterns 22 are repeatedly transferred onto the support 40, thereby stacking the conductor patterns 32 and the element body patterns 22 in direction D3. Specifically, first, as shown in Fig. 5(f), the conductor pattern 32 formed in the above step S4 is transferred from the substrate 30 onto the element body formation layer 21 transferred in the above step S5 (step S6). Next, as shown in Fig. 5(g), the element body pattern 22 formed in the above step S2 is transferred from the substrate 20 onto the element body formation layer 21 transferred in the above step S5 (step S7). The conductor patterns 32 transferred onto the element body formation layer 21 in the above step S6 are filled into the missing portions 23 of the element body pattern 22, so that the element body pattern 22 and the conductor patterns 32 are on the same layer.

[0058] 6(a), the above steps S6 and S7 are repeatedly performed to laminate the element body pattern 22 and the conductor pattern 32 in a combined state (step S8). This results in the lamination of layers that will become layers Lb, Lc, Ld, Le, and Lf after heat treatment. In step S8, steps S6 and S7 do not necessarily have to be repeated one-to-one; for example, step S6 may be repeated more times than step S7. This allows, for example, the conductor pattern 32 corresponding only to the mounting conductor layers 13 and 14 to be transferred onto the element body pattern 22 in excess. Subsequently, as shown in FIG. 6(b), the element body formation layer 21 formed in step S1 is transferred from the substrate 20 onto the layer laminated in step S8 (step S9). By repeating step S9 multiple times, multiple element body formation layers 21 may be laminated on the layer. In this embodiment, by repeating this process twice, two element body forming layers 21 are laminated on the layer from the base material 20. These element body forming layers 21 are layers that will become layers La after heat treatment.

[0059] As described above, the laminate 50 that constitutes the laminated coil component 1 after the heat treatment is formed on the support 40. Note that the laminate 50 may be formed by further laminating, as necessary, a layer provided with a cutting mark or a mark indicating the orientation of the chip (laminated coil component 1), or a colored layer.

[0060] Next, the obtained laminate 50 is cut to a predetermined size (step S10).

[0061] The cut laminate 50 is then subjected to a binder removal process and then a heat treatment (step S11). The heat treatment temperature is, for example, about 850 to 900°C. This results in the production of the laminated coil component 1. If necessary, the mounting conductors 3 and 4 may be subjected to electrolytic plating or electroless plating.

[0062] The heat treatment step S11 transforms the photosensitive conductor paste into a conductor pattern composed of silver containing quartz powder. It is not necessary for all of the quartz powder to be present inside the conductor pattern; some of the quartz powder may be partially exposed from the surface of the conductor pattern. As shown in the electron microscope photograph in Figure 1, the heat treatment temperature in the heat treatment step S11 is lower than the melting point of quartz, so the quartz powder in the photosensitive conductor paste does not melt and maintains its shape. Furthermore, the quartz powder particles do not fuse together, and the dispersed state of the quartz powder in the photosensitive conductor paste is maintained even after the heat treatment step S11.

[0063] On the other hand, when the photosensitive conductive paste contains glass powder as an inorganic additive, the softening point of glass (for example, about 800°C) is lower than the melting point of quartz, and the heat treatment temperature in the heat treatment step S11 may be higher than the softening point of the glass. In this case, the glass powder in the photosensitive conductive paste softens as shown in Figure 7. In Figure 7, the black area around the glass is a phase (heterogeneous phase) in which the glass component is solid-dissolved in the conductive component. The glass powder does not maintain its shape after the heat treatment step and becomes spherical. Furthermore, as a result of the softening of the glass powder, aggregation occurs among the glass powder particles, and the dispersion state of the glass powder in the photosensitive conductive paste is not maintained. Note that when the photosensitive conductive paste contains quartz powder as an inorganic additive, the thickness of the heterogeneous phase at the interface with the conductive component is narrow, 10 μm or less, preferably 6 μm or less.

[0064] Subsequently, as required, the mounting conductors 3 and 4 are subjected to electrolytic plating or electroless plating to form plating layers on the outer surfaces of the mounting conductors 3 and 4. In this way, the multilayer coil component 1 is obtained.

[0065] As described above, in the photosensitive conductor paste according to this embodiment, melting of the quartz powder does not occur or occurs very little in the heat treatment step S11, and the paste functions sufficiently to make the shrinkage rates and shrinkage behaviors of the conductor layer and the base layer similar when they shrink in the heat treatment step S11, and therefore, when the paste is used in manufacturing the laminated coil component 1, the generation of voids can be suppressed.

[0066] In this embodiment, the element patterns 62a, 62b and the conductor pattern 72 are all formed by photolithography, which allows the element patterns 62a, 62b and the conductor pattern 72 to be formed with greater precision than when using a printing method, for example.

[0067] [Second embodiment] A method for manufacturing the laminated coil component 1 according to the second embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing a method for manufacturing the laminated coil component according to the second embodiment. FIG. 9 is a cross-sectional view conceptually illustrating the method for manufacturing the laminated coil component according to the second embodiment. The cross-sectional view in FIG. 9 is shown conceptually and does not necessarily coincide with the cross-sectional view of the actual laminated coil component 1. Note that the laminated coil component 1 manufactured by the manufacturing method according to the second embodiment and the laminated coil component 1 manufactured by the manufacturing method according to the first embodiment have the same configuration.

[0068] In the manufacturing method according to the second embodiment, first, as shown in FIG. 9(a), an element body formation layer 21 is formed on a support 40 (step S21). The element body formation layer 21 is formed, for example, by applying an element body paste to the surface of the support 40. In this embodiment, step S21 is performed twice to stack two element body formation layers 21. These element body formation layers 21 are layers that will become layers La after heat treatment.

[0069] 9(b), a conductor formation layer 31 is formed on the element body formation layer 21 (step S22). The conductor formation layer 31 is formed by applying the above-mentioned photosensitive conductor paste onto the element body formation layer 21. Then, as shown in FIG. 9(c), the conductor formation layer 31 is exposed and developed by photolithography using a Cr mask, for example, to form a conductor pattern 32 on the element body formation layer 21 (step S23). The conductor pattern 32 is a layer that will become the mounting conductor layers 13 and 14, the coil conductor layers 15c, 15d, 15e, and 15f, and the connection conductor layers 16 and 17 after heat treatment.

[0070] 9(d), a new element body formation layer 21 is formed on the element body formation layer 21 so as to cover the conductive pattern 32 provided on the element body formation layer 21 (step S24). The newly formed element body formation layer 21 is formed so as to fill in the periphery of the conductive pattern 32.

[0071] 9(e), the newly formed element body formation layer 21 is patterned by photolithography using, for example, a Cr mask (step S25). The conductive pattern 32 formed in step S23 is filled into the missing portion 23 of the element body pattern 22, so that the element body pattern 22 and the conductive pattern 32 are on the same layer.

[0072] Next, the above steps S22, S23, and steps S24, S25 are repeated to laminate the element body pattern 22 and the conductor pattern 32 in a combined state, as shown in FIG. 6(a). (Step S26) In step S26, steps S22, S23 and steps S24, S25 do not necessarily have to be repeated one-to-one. For example, steps S22, S23 may be repeated more times than steps S24, S25. This allows, for example, the conductor pattern 32 corresponding only to the mounting conductor layers 13, 14 to be transferred onto the element body pattern 22 in excess. Next, to achieve the configuration shown in FIG. 6(b), a new element body formation layer 21 is formed on the layer laminated in step S26. (Step S27) By repeating step S27 multiple times, multiple element body formation layers 21 may be laminated on the layer in question. In this embodiment, by repeating this process twice, two element body forming layers 21 are laminated on the layer from the base material 20. These element body forming layers 21 are layers that will become layers La after heat treatment.

[0073] As described above, the laminate 50 that will constitute the laminated coil component 1 after the heat treatment is formed on the support 40. Next, as in the first embodiment, the obtained laminate 50 is cut to a predetermined size (step S28), and the cut laminate 50 is subjected to a binder removal process and then a heat treatment (step S29). In this way, the laminated coil component 1 is obtained.

[0074] As described above, in the second embodiment, as in the first embodiment, a photosensitive conductor paste is used, and therefore, melting of the quartz powder does not occur or occurs very little in the heat treatment step S29. This sufficiently functions to make the shrinkage rates and shrinkage behaviors of the conductor layer and the base layer similar when they shrink in the heat treatment step S29, and therefore, when used in the manufacture of the laminated coil component 1, the generation of voids can be suppressed.

[0075] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0076] The element patterns 62a, 62b and the conductor pattern 72 may be formed by, for example, a printing method rather than by photolithography. The element patterns 62a, 62b and the conductor pattern 72 do not necessarily have to be formed on different base materials 60, 70, and may be formed on a common base material as long as the element patterns 62a, 62b and the conductor pattern 72 are spaced apart from each other.

[0077] In the above-described first and second embodiments, the laminated coil component 1 has been described as an example of a laminated electronic component, but the present invention is not limited to this and can also be applied to manufacturing methods for other electronic components such as a laminated ceramic capacitor, a laminated varistor, a laminated piezoelectric actuator, a laminated thermistor, or a laminated composite component. [Explanation of symbols]

[0078] 1... multilayer coil component, 2... element body, 3, 4... mounting conductors, 5c, 5d, 5e, 5f... coil conductors, 6, 7... connecting conductors, 12a to 12f... element body layers, 15c, 15d, 15e, 15f... coil conductor layers, 21... element body forming layer, 22... element body pattern, 31... conductor forming layer, 32... conductor pattern, 40... support, 50... laminate.

Claims

1. a laminated structure including a plurality of element layers each having a rectangular cross-section cutout, and a plurality of conductor layers each filling the cutout of each of the plurality of element layers, The conductor layer is composed of a conductor containing quartz powder having a d95 particle size of 1.0 to 7.0 μm.

2. The laminated electronic component according to claim 1 , wherein the plurality of conductor layers form a coil.

3. 3. The laminated electronic component according to claim 1, wherein the element layer is made of a material containing a glass component.

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