Laminated electronic component and method of manufacturing the same

Abstract

A laminated electronic component includes a multilayer body including multiple insulator layers that are laminated and including a bottom surface, a top surface, and multiple side surfaces. The laminated electronic component includes a shield film provided on at least one side surface of the multilayer body. In the laminated electronic component, at least one step difference is provided along a ridge at which the bottom surface and a corresponding one of the side surfaces of the multilayer body are connected to each other, and the shield film includes an edge portion disposed within the at least one step difference.

Claims

1. A laminated electronic component comprising: a multilayer body including a plurality of insulator layers that are laminated, the multilayer body including a bottom surface, a top surface, and four side surfaces connecting the bottom surface and the top surface to each other; and a shield film provided on at least the four side surfaces of the multilayer body; wherein at least one step difference is provided along four ridges at which the bottom surface and the four side surfaces of the multilayer body are respectively connected to each other; the at least one step difference has a rectangular or substantially rectangular and annular shape along the four ridges at which the four side surfaces and the bottom surface are respectively connected to each other; and the shield film includes an edge portion disposed within the at least one step difference.

2. The laminated electronic component according to claim 1, wherein the multilayer body includes an internal shield film disposed between adjacent ones of the plurality of insulator layers at or adjacent to the top surface.

3. The laminated electronic component according to claim 1, wherein the shield film is provided over an entirety or substantially an entirety of the four side surfaces.

4. The laminated electronic component according to claim 1, wherein each of the at least one step differences includes one surface parallel or substantially parallel to a corresponding one of the four side surfaces and another surface parallel or substantially parallel to the bottom surface.

5. The laminated electronic component according to claim 1, wherein each of the at least one step difference has a stepwise shape.

6. The laminated electronic component according to claim 1, wherein the shield film is also provided on the top surface.

7. A laminated electronic component, comprising: a multilayer body including a plurality of insulator layers that are laminated, the multilayer body including a bottom surface, a top surface, and a plurality of side surfaces connecting the bottom surface and the top surface to each other; and a shield film provided on at least one of the side surfaces of the multilayer body; wherein the multilayer body includes rounded edges that connect adjacent ones of the top surface, the plurality of side surfaces and the bottom surface; at least one step difference is provided along a ridge at which the bottom surface and the at least one of the side surfaces of the multilayer body are connected to each other; and the shield film includes an edge portion disposed within the at least one step difference.

8. The laminated electronic component according to claim 7, wherein each of the at least one step differences includes one surface parallel or substantially parallel to a corresponding one of the side surfaces and another surface parallel or substantially parallel to the bottom surface.

9. The laminated electronic component according to claim 7, wherein each of the at least one step difference has a stepwise shape.

10. The laminated electronic component according to claim 7, wherein the multilayer body includes an internal shield film disposed between adjacent ones of the plurality of insulator layers at or adjacent to the top surface.

11. A method of manufacturing a laminated electronic component, the method sequentially comprising: a step of providing an unsintered multilayer body including a bottom surface, a top surface, and a plurality of side surfaces that connect the bottom surface and the top surface to each other and in which a plurality of ceramic green sheets are laminated and resin paste is applied on the bottom surface along peripheral edges thereof; a step of pushing the resin paste into the bottom surface; a step of firing the unsintered multilayer body to form a multilayer body in which at least one step difference is formed along a ridge at which the bottom surface and a corresponding one of the side surfaces are connected to each other; and a step of forming a shield film on the corresponding one of the side surfaces of the multilayer body, the shield film including an edge disposed within the at least one step difference.

12. The method of manufacturing the laminated electronic component according to claim 11, further comprising: a step of rounding portions of the unsintered multilayer body, using barrel polishing, at which adjacent ones of the top surface, the plurality of side surfaces, and the bottom surface of the unsintered multilayer body are connected to each other, the step of rounding being performed between the step of pushing the resin paste into the bottom surface and the step of firing the unsintered multilayer body to form the multilayer body.

13. The method of manufacturing the laminated electronic component according to claim 11, wherein the resin paste applied on the bottom surface of the unsintered multilayer body along the peripheral edges thereof is applied in advance on a bottom main surface of one of the plurality of ceramic green sheets that is laminated as a bottommost layer of the unsintered multilayer body along peripheral edges of the bottom main surface.

14. The method of manufacturing the laminated electronic component according to claim 11, wherein the shield film is formed using sputtering.

15. The method of manufacturing the laminated electronic component according to claim 11, wherein the unsintered multilayer body includes four side surfaces; the resin paste is applied on the bottom surface of the unsintered multilayer body rectangularly or substantially rectangularly and annularly along peripheral edges thereof; and the at least one step difference is formed into a rectangular or substantially rectangular and annular shape along four ridges of the multilayer body at which the four side surfaces and the bottom surface are respectively connected to each other.

16. A laminated electronic component, comprising: a multilayer body including a plurality of insulator layers that are laminated, the multilayer body including a bottom surface, a top surface, and a plurality of side surfaces connecting the bottom surface and the top surface to each other; and a shield film provided on at least one of the side surfaces of the multilayer body; wherein at least one step difference is provided along a ridge at which the bottom surface and the at least one of the side surfaces of the multilayer body are connected to each other; and the shield film includes an edge portion disposed within the at least one step difference; and the shield film is provided over an entirety or substantially an entirety of the top surface.

17. The laminated electronic component according to claim 16, wherein each of the at least one step differences includes one surface parallel or substantially parallel to a corresponding one of the side surfaces and another surface parallel or substantially parallel to the bottom surface.

18. The laminated electronic component according to claim 16, wherein each of the at least one step difference has a stepwise shape.

19. The laminated electronic component according to claim 16, wherein the multilayer body includes an internal shield film disposed between adjacent ones of the plurality of insulator layers at or adjacent to the top surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a front view illustrating a laminated electronic component 100 according to a first preferred embodiment of the present invention. FIG. 1B is a side view of the laminated electronic component 100. FIG. 1C is a bottom view of the laminated electronic component 100.

(2) FIG. 2A is a cross section of the laminated electronic component 100 as viewed from the front side thereof. FIG. 2B is a cross section of the laminated electronic component 100 as viewed laterally.

(3) FIGS. 3A and 3B are cross-sectional views depicting steps performed in a non-limiting example of a method of manufacturing the laminated electronic component 100.

(4) FIGS. 4C to 4E are cross-sectional views depicting steps performed successively after the step in FIG. 3B in the non-limiting example of a method of manufacturing the laminated electronic component 100.

(5) FIGS. 5F to 5H are cross-sectional views depicting steps performed successively after the step in FIG. 4E in the non-limiting example of a method of manufacturing the laminated electronic component 100.

(6) FIG. 6 is a bottom view (a view illustrating the bottom main surface) of a mother green sheet 11a illustrated in FIG. 3A.

(7) FIG. 7A is a cross section of a laminated electronic component 200 according to a second preferred embodiment of the present invention as viewed from the front side thereof. FIG. 7B is a cross section of the laminated electronic component 200 as viewed laterally.

(8) FIG. 8A is a cross section of a laminated electronic component 300 according to a third preferred embodiment of the present invention as viewed from the front side thereof. FIG. 8B is a cross section of the laminated electronic component 300 as viewed laterally.

(9) FIG. 9 is a perspective view illustrating a laminated electronic component 1100 disclosed in Japanese Unexamined Patent Application Publication No. 9-121093.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(10) Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(11) The preferred embodiments described herein are examples, and the present invention is not limited thereto. In addition, configurations described in different preferred embodiments may be combined to each other, and resulting configurations are also within the scope of the present invention. The drawings are provided for the purpose of better understanding of the specification. Figures may be drawn schematically, and elements drawn therein and scaling of the elements may not reflect what are described in the specification. In addition, elements described in the specification may be omitted in the drawings, and the number of individual elements may be different from what is described in the specification.

First Preferred Embodiment

(12) FIGS. 1A to 1C and FIGS. 2A and 2B are views illustrating a laminated electronic component 100 according to the first preferred embodiment of the present invention. FIG. 1A is a front view of the laminated electronic component 100, FIG. 1B is a side view thereof, and FIG. 1C is a bottom view thereof. In addition, FIG. 2A is a cross section of the laminated electronic component 100 as viewed from the front side thereof, and FIG. 2B is another cross section as viewed laterally.

(13) The laminated electronic component 100 is preferably, for example, a multilayer LC filter in which capacitors and inductors are provided so as to define a predetermined filter circuit. However, the laminated electronic component 100 may be any other type of device and is not limited to the multilayer LC filter.

(14) The laminated electronic component 100 includes a multilayer body 1 that is made of insulators, such as ceramic insulators, for example.

(15) The multilayer body 1 has a cuboid including a top surface T, a bottom surface B, and four side surfaces S. The multilayer body 1 includes rounded edges at which adjacent surfaces are connected to each other.

(16) The multilayer body 1 includes multiple insulator layers made of ceramics, of which illustration is omitted. Via conductors are provided at predetermined positions so as to penetrate a predetermined insulator layer between two main surfaces thereof. In addition, conductor patterns, each having a predetermined shape, are formed at predetermined positions between predetermined insulator layers. The conductor patterns may be grouped into capacitor conductor patterns, inductor conductor patterns, ground conductor patterns, and the like. For example, capacitors are provided to have capacitance generated between pairs of capacitor conductor patterns. For example, inductors are provided by connecting multiple inductor conductor patterns to each other by the via conductors.

(17) The laminated electronic component 100 defines a predetermined filter circuit by connecting capacitors and inductors provided inside the multilayer body 1.

(18) The via conductors and the conductor patterns are made of a metal having a main ingredient, such as silver and copper, for example.

(19) Multiple terminal electrodes 2 are provided at the bottom surface B of the multilayer body 1. The terminal electrodes 2 are connected to predetermined portions of the filter circuit provided inside the multilayer body 1. However, the terminal electrodes 2 may include “dummy” electrodes that are not connected to the filter circuit.

(20) The terminal electrodes 2 are also made of a metal having a main ingredient, such as silver and copper, for example. A plating layer (not illustrated) is provided on the surfaces of the terminal electrode 2. For example, the plating layer preferably includes a first layer made of nickel and a second layer made of a metal selected from the group consisting of gold, copper, and tin. However, the plating layer may have a single layer structure instead of the multilayer structure. In addition, the material of the plating layer is not specifically limited and may be any other suitable metal.

(21) Step differences 3 are provided in a rectangular or substantially rectangular and annular shape along the ridges of the multilayer body 1 at which respective side surfaces S are connected to the bottom surface B. Each step difference 3 is structured so as to include two surfaces such that one surface is parallel or substantially parallel to the bottom surface B and the other surface is parallel or substantially parallel to a corresponding side surface S.

(22) A shield film 4 is provided on the top surface T and four side surfaces S of the multilayer body 1. The shield film 4 reduces or prevents outside noise from entering the inside of the laminated electronic component 100 and also reduces or prevents noise from leaking out of the laminated electronic component 100. The structure and material of the shield film 4 is not specifically limited although in the present preferred embodiment, the shield film 4 preferably has a multilayer structure formed by repeating sputtering multiple times. For example, the shield film 4 may have a two-layer structure including a first layer made of copper and a second layer made of a stainless steel (SUS). Alternatively, the shield film 4 may have a two-layer structure including a first layer made of copper and a second layer made of nickel. Alternatively, the shield film 4 may have a three-layer structure including a first layer made of a stainless steel, a second layer made of copper, and a third layer made of a stainless steel. Alternatively, the shield film 4 may have a three-layer structure including a first layer made of copper, a second layer made of nickel, and a third layer made of a stainless steel. Alternatively, the shield film 4 may have a three-layer structure including a first layer made of nickel, a second layer made of copper, and a third layer made of a stainless steel. Alternatively, the shield film 4 may have a three-layer structure including a first layer made of a stainless steel, a second layer made of copper, and a third layer made of nickel. In addition, a plating layer (not illustrated) is preferably provided on the surface of the shield film 4. For example, the plating layer may preferably include a first layer made of nickel and a second layer made of a metal selected from the group consisting of gold, copper, and tin. The plating layer, however, may have a single layer structure instead of the multilayer structure. The material of the plating layer is not specifically limited and may be made of other metals.

(23) Note that the shield film 4 is preferably connected to ground via at least one terminal electrode 2.

(24) Edges 4a of the shield film 4 are disposed inside respective step differences 3.

(25) In the laminated electronic component 100, the edges 4a of the shield film 4 are disposed inside the step difference 3 and, accordingly, the shield film 4 does not peel off easily from the multilayer body 1. In other words, in the laminated electronic component 100, the edges 4a of the shield film 4 from which detachment tends to start are disposed inside the step differences 3 and are thus protected. Accordingly, other objects (for example, other laminated electronic components 100) do not hit the edges 4a easily, which makes it difficult for the shield film 4 to peel off from the multilayer body 1.

(26) In addition, in the laminated electronic component 100, the multilayer body 1 includes rounded edges at which adjacent surfaces are connected. Accordingly, in the laminated electronic component 100, when an object (such as another laminated electronic component 100) hits a ridge portion of the multilayer body 1, the ridge portion of the multilayer body 1 does not produce cracks or chipping easily. In addition, in the laminated electronic component 100, when the ridge portion of the multilayer body 1 hits an object (such as another laminated electronic component 100), an impact on the object is small.

(27) The laminated electronic component 100 may be manufactured, for example, by a method described as follows. The method will be described with reference to FIGS. 3A to 5H and FIG. 6.

(28) First, as illustrated in FIG. 3A, multiple mother green sheets 11a to 11k are prepared for manufacturing of the multilayer body 1. The mother green sheets 11a to 11k are prepared so as to manufacture a number of laminated electronic components 100 together. The mother green sheets 11a to 11k include the same number of individual green sheets that are arranged in a matrix on each of the mother green sheets 11a to 11k.

(29) As illustrated in FIGS. 3A and 6 (which is the bottom view of the mother green sheet 11a), conductive paste 12 for forming terminal electrodes 2 is applied in a predetermined shape in advance at predetermined positions on the bottom main surface of each individual green sheet of the mother green sheet 11a that is laminated as the bottommost layer.

(30) Resin paste 13 for forming the step differences 3 is applied in advance rectangularly or substantially rectangularly and annularly on the bottom main surface of each individual green sheet of the mother green sheet 11a that is laminated as the bottommost layer, such that the resin paste 13 surrounds all of the bumps of the conductive paste 12 already applied on the green sheet. As a result, the resin paste 13 is applied along the peripheral edges of each green sheet so as to partition adjacent green sheets that are arranged side by side in the lengthwise and widthwise directions on the bottom main surface of the mother green sheet 11a. Note that in this stage, the resin paste 13 applied on each individual green sheet extends to the resin paste 13 applied on adjacent green sheets.

(31) In each individual green sheet of the mother green sheets 11a to 11j, holes (not illustrated) for forming the via conductors are pierced in advance at predetermined positions as necessary between both main surfaces of the individual green sheet, and the holes are filled with conductive paste. In each individual green sheet of the mother green sheets 11a to 11j, conductive paste for forming conductor patterns (not illustrated) is applied in a predetermined shape in advance as necessary on the main surface at predetermined positions.

(32) Each individual green sheet of the mother green sheet 11k to be laminated as the topmost layer becomes a protection layer. Accordingly, no holes are formed and no conductive paste is applied.

(33) Next, as illustrated in FIG. 3B, the mother green sheets 11a to 11k are stacked on each other.

(34) Subsequently, as illustrated in FIG. 4C, an unsintered mother multilayer body 11 is produced by pressing the mother green sheets 11a to 11k in the vertical direction into one body. As a result, both of the conductive paste 12 and the resin paste 13 applied on the bottom main surface of the mother green sheet 11a are pushed into the bottom surface of the unsintered mother multilayer body 11.

(35) Next, as illustrated in FIG. 4D, the unsintered mother multilayer body 11 is separated into individual unsintered multilayer bodies 1′. The separation is performed, for example, by using a dicer.

(36) Next, as illustrated in FIG. 4E, the unsintered multilayer body 1′ is polished by barrel polishing. As a result, the multilayer body 1 is rounded so as to include rounded edges at which that adjacent surfaces are connected. Note that the edges where the resin paste 13 has been pushed into the bottom surface of each unsintered multilayer body 1′ are also rounded. Note that the scale used in FIG. 4E is different from that used in FIGS. 3A to 4D.

(37) Next, as illustrated in FIG. 5F, the multilayer body 1 is produced by firing the unsintered multilayer body 1′ in accordance with a predetermined firing profile. As a result, the conductive paste (not illustrated) that has been filled in the holes pierced between both main surfaces of each of the mother green sheets 11a to 11j is fired simultaneously, and the conductive paste (not illustrated) that has been applied as conductor patterns onto the main surface of each of the mother green sheet 11a to 11j is also fired simultaneously. Thus, the via conductors and the conductor patterns are formed inside the multilayer body 1. In addition, the conductive paste 12 that has been pushed into the bottom surface of the unsintered multilayer body 1′ is also fired simultaneously. Thus, the terminal electrodes 2 are formed on the bottom surface B of the multilayer body 1. Moreover, the resin paste 13 that has been pushed into the bottom surface of the unsintered multilayer body 1′ is burnt off. Thus, the step differences 3 are formed along the ridges at which respective side surfaces S and the bottom surface B of the multilayer body 1 are connected. As described above, the step differences 3 are formed into a rectangular or substantially rectangular and annular shape.

(38) Next, as illustrated in FIG. 5G, the bottom surface B of the multilayer body 1 is fixed to a fixing jig 50 including a cohesive surface, and sputtering is performed on the surfaces of the multilayer body 1. Thus, the shield film 4 is formed on the top surface T and the four side surfaces S of the multilayer body 1. Here, providing a gap between the surface of the fixing jig 50 and each step difference 3 allows each edge 4a of the shield film 4 to be formed inside the step difference 3.

(39) Finally, after the multilayer body 1 is removed from the fixing jig 50, as illustrated in FIG. 5H, a plating layer is formed on the surface of each terminal electrode 2 and on the surface of the shield film 4, for example, by electrolytic plating. Thus, the laminated electronic component 100 is manufactured.

(40) In the above manufacturing method, a plating layer is formed on the surface of each terminal electrode 2 and on the surface of the shield film 4, for example, by electrolytic plating after the shield film 4 is formed on the multilayer body 1 by sputtering as illustrated in FIG. 5G. However, these two steps may be switched. In other words, the plating layer may be formed first on the surfaces of the terminal electrodes 2, for example, by electrolytic plating, and subsequently, the shield film 4 may be formed on the surfaces of the multilayer body 1 by sputtering. In this case, the plating layer is not formed over the surface of the shield film 4. However, a plating layer may be formed on the surface of the shield film 4, if necessary, by adding such a step.

Second Preferred Embodiment

(41) FIGS. 7A and 7B illustrate a laminated electronic component 200 according to the second preferred embodiment of the present invention. FIG. 7A is a cross section of the laminated electronic component 200 as viewed from the front side thereof, and FIG. 7B is another cross section as viewed laterally.

(42) The laminated electronic component 200 has a configuration partially different from that of the laminated electronic component 100 according to the first preferred embodiment. More specifically, the laminated electronic component 200 has step differences 23 that are provided stepwise, unlike the laminated electronic component 100 in which the step differences 3 are each provided so as to include two surfaces with one surface being parallel or substantially parallel to the bottom surface B and the other surface being parallel or substantially parallel to a corresponding side surface S. In other words, each step difference 23 includes a surface parallel or substantially parallel to the bottom surface B and a surface parallel or substantially parallel to a corresponding side surface S and also includes another surface parallel or substantially parallel to the bottom surface B and another surface parallel or substantially parallel to the side surface S, of which the surfaces are connected to each other in this order. Note that the step differences 23 have a rectangular or substantially rectangular and annular shape along the ridges at which respective side surfaces S and the bottom surface B of the multilayer body 1 are connected, which is the same or substantially the same as the laminated electronic component 100.

(43) As described in the method of manufacturing the laminated electronic component 100, the resin paste 13 is applied rectangularly or substantially rectangularly and annularly on each of the green sheets of the mother green sheet 11a laminated as the bottommost layer. In the laminated electronic component 200, the resin paste 13 preferably has a stepwise shape, for example, by applying the resin paste 13 twice, which enables the step differences 23 have the stepwise shape.

(44) In the case of the laminated electronic component 200, objects (for example, other laminated electronic components 200) do not easily hit the edges 4a of the shield film 4 from which detachment tends to start, which makes it difficult for the shield film 4 to peel off from the multilayer body 1.

Third Preferred Embodiment

(45) FIGS. 8A and 8B illustrate a laminated electronic component 300 according to a third preferred embodiment of the present invention. FIG. 8A is a cross section of the laminated electronic component 300 as viewed from the front side thereof, and FIG. 8B is another cross section as viewed laterally.

(46) The laminated electronic component 300 also has a configuration partially different from that of the laminated electronic component 100 according to the first preferred embodiment. More specifically, the laminated electronic component 100 includes the shield film 4 provided on the top surface T of the multilayer body 1 and also on the four side surfaces S thereof. However, in the laminated electronic component 300, a shield film 34 is provided only on the four side surfaces S of the multilayer body 1 and not on the top surface T thereof. In addition, in the laminated electronic component 300, an internal shield film 35 is provided between insulator layers of the multilayer body 1 located near the top surface T thereof. The internal shield film 35 is connected to the shield film 34.

(47) The internal shield film 35 may be formed by applying a conductive paste for forming the internal shield film onto the main surface of a green sheet (mother green sheet) laminated near the top surface T when the unsintered mother multilayer body 11 is produced. To avoid formation of the shield film 34 on the top surface T, a mask may be formed on the top surface T before the shield film 34 is formed by sputtering.

(48) The internal shield film 35 may preferably be utilized for circuit formation (filter circuit formation) in the laminated electronic component 300. For example, a capacitor conductor pattern may be provided between insulator layers located adjacent to the insulator layers between which the internal shield film 35 is provided. The capacitor conductor pattern and the internal shield film 35 generate capacitance, thus defining a capacitor (a shunt capacitor connected to ground, for example).

(49) Note that the laminated electronic component 300 does not include the shield film 34 on the top surface T of the multilayer body 1. However, the shield film may be provided on the top surface T of the multilayer body 1 so that both the shield film 34 and the internal shield film 35 are provided.

(50) The laminated electronic components 100, 200, and 300 according to the first, second, and third preferred embodiments have been described. However, the present invention is not limited to these preferred embodiments, and may be subjected to various modifications within the scope of the present invention.

(51) For example, in each of the laminated electronic components 100, 200, and 300, the shield film 4 or 34 is provided on the entirety or substantially the entirety of the four side surfaces S of the multilayer body 1. However, the shield film 4 or 34 may be partially provided on each side surface S. Moreover, the shield film 4 or 34 need not be provided on all of the four surfaces S, and may be provided on at least one side surface S.

(52) Furthermore, in each of the laminated electronic component 100, 200, and 300, the step differences 3 or 23 have an annular shape along the ridges at which respective side surfaces S and the bottom surface B of the multilayer body 1 are connected. However, the step differences 3 or 23 need not be continuously provided into an annular shape, and may be discontinuously provided.

(53) Furthermore, the laminated electronic components 100, 200, and 300 are described as multilayer LC filters. However, the laminated electronic components are not limited to the multilayer LC filters, and may define various other types of laminated electronic components.

(54) While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.