JP5500186B2 - Coil component and manufacturing method thereof - Google Patents

Description

  The present invention relates to a coil component and a manufacturing method thereof, and more particularly, to a structure of a thin film common mode filter incorporating a coil conductor and a manufacturing method thereof.

  In recent years, the USB 2.0 standard and the IEEE 1394 standard have become widespread as high-speed signal transmission interfaces, and are used in many digital devices such as personal computers and digital cameras. These interfaces employ a differential transmission method in which a differential signal (differential signal) is transmitted using a pair of signal lines, and signal transmission at a higher speed than the conventional single-ended transmission method is realized.

  A common mode filter is widely used as a filter for removing noise on the high-speed differential transmission line. The common mode filter has a characteristic that impedance for a differential component of a signal transmitted through a pair of signal lines is low and impedance for a common-mode component (common mode noise) is high. Therefore, by inserting a common mode filter on a pair of signal lines, common mode noise can be blocked without substantially attenuating the differential mode signal.

  FIG. 8 is a schematic exploded perspective view showing the structure of a conventional surface mount type common mode filter.

  As shown in FIG. 8, a conventional common mode filter 1 includes a thin film coil layer 2 including a pair of coil conductors 5 and 6 magnetically coupled to each other, and a magnetic substrate made of ferrite provided above and below the thin film coil layer 2. 3 and 4 are provided. End portions of the coil conductors 5 and 6 are connected to the external terminal electrodes 7a to 7d, respectively, and the external terminal electrodes 7a to 7d are formed on the side surfaces and the upper and lower surfaces of the magnetic substrates 3 and 4, respectively. Usually, the external terminal electrodes 7a to 7d are formed by sputtering or plating on the surface of the magnetic substrate.

  Patent Document 1 discloses a terminal electrode structure of a common mode filter. The terminal electrode of this common mode filter is formed by applying a conductive paste containing Ag on the surface of a component, or forming an Ag film by sputtering or vapor deposition, and performing wet electrolytic plating on the Ag film. The metal film is further formed.

  Further, in Patent Document 2, an insulating layer, a coil layer including a coil conductor, and an external electrode electrically connected to the coil conductor are sequentially formed on a silicon substrate by a thin film forming technique, and have a rectangular parallelepiped outer shape as a whole. A common mode choke coil is disclosed. In this common mode choke coil, the external electrode is formed so as to spread over the upper surface (mounting surface) of the insulating layer. The internal electrode terminal is configured as an electrode having a multilayer structure in which a plurality of conductive layers are stacked.

Special table WO2006 / 073029 JP 2007-53254 A

  Since the conventional common mode filter 1 shown in FIG. 8 has a structure in which a thin film coil layer is sandwiched between two magnetic substrates, the magnetic characteristics of the common mode filter are high and not only excellent in high frequency characteristics, but also in mechanical strength. It has the feature of being high. However, the structure of the conventional common mode filter uses a magnetic substrate made of ferrite at the top and bottom, and if the ferrite substrate is too thin, it is difficult to reduce the thickness because it is prone to cracking. It was difficult to provide a chip component with a reduced thickness due to the increased thickness. In addition, since a large amount of expensive magnetic material is used, the manufacturing cost is high, and there is a problem that the filter performance is excessively speci? C depending on the intended use.

  In addition, since the conventional common mode filter forms minute terminal electrodes on the surface of each chip component by sputtering or the like, there is a problem that it is very difficult to form the terminal electrodes with high accuracy. Furthermore, in the common mode choke coil described in Patent Document 2, since the internal electrode terminals are formed by the conductor layers stacked in layers, the probability that a defective electrode is formed is high, and the man-hours for forming the electrodes are high. There is a problem in that the manufacturing cost increases due to the increase in the number of.

  Accordingly, an object of the present invention is to provide a coil component that can be manufactured at a low cost while being reduced in size and height while ensuring desired filter performance. Moreover, the objective of this invention is providing the manufacturing method which can manufacture such a coil component easily and at low cost.

  In order to solve the above problems, a coil component according to the present invention includes a magnetic substrate made of a magnetic ceramic material, a thin film coil layer including a coil conductor formed on one main surface of the magnetic substrate, and a main component of the thin film coil layer. A bump electrode formed on the surface, and an insulating resin layer formed on the main surface of the thin film coil layer excluding the formation position of the bump electrode, the bump electrode overlapping the coil conductor in plan view It is characterized by having a part.

  According to the present invention, a thin coil component in which one of the magnetic substrates is omitted can be provided at a low cost. In addition, since the bump electrode is used as the external terminal electrode, the electrode can be formed with higher accuracy than in the past. Moreover, since the insulating resin layer is provided around the bump electrode, the bump electrode can be reinforced and peeling of the bump electrode can be prevented. Further, since a part of the bump electrode overlaps with the coil conductor in a plan view, the coil component can be downsized.

  In the present invention, it is preferable that a side surface of the bump electrode in contact with the insulating resin layer has a curved shape without an edge. The insulating resin layer is formed by pouring a softened resin after the bump electrode is formed, but if there is a corner with an edge on the side surface of the bump electrode, a fluid insulating resin is successfully formed around the bump electrode. It does not enter and it is easy to hold bubbles. However, when the side surface of the bump electrode is a curved surface, the viscous resin spreads to every corner, so that a high-quality resin layer containing no bubbles can be formed. In addition, since the adhesion between the insulating resin layer and the bump electrode is increased, the reinforcing force for the bump electrode can be increased.

  In the present invention, the insulating resin layer is made of a resin material containing magnetic powder, and the coil conductor includes first and second spiral patterns that are magnetically coupled to each other, and the first and second spiral patterns are common mode filters. It is preferable to constitute. According to this, since the insulating resin layer includes the magnetic material, the magnetic coupling of the common mode filter sandwiched between the magnetic substrate and the insulating resin layer can be enhanced.

  In order to solve the above problems, a method for manufacturing a coil component according to the present invention includes a step of forming a thin film coil layer including a coil conductor on one main surface of a magnetic substrate made of a magnetic ceramic material, and a main component of the thin film coil layer. Forming a bump electrode on the terminal electrode of the coil conductor exposed on the surface by plating; filling the main surface of the thin film coil layer on which the bump electrode is formed with an insulating resin paste; and curing the paste In this case, the method includes a step of forming an insulating resin layer around the bump electrode, and a step of polishing or grinding the upper surface of the insulating resin layer to expose the upper surface of the bump electrode.

  According to the present invention, one of the upper and lower magnetic substrates used conventionally is omitted, and the insulating resin layer is formed instead. Therefore, the coil component can be manufactured easily and at low cost. Moreover, since the bump electrode is used as the terminal electrode and the bump electrode is formed by plating, the processing accuracy of the external electrode can be increased. Further, since the periphery of the bump electrode is surrounded by the insulating resin layer, the bump electrode can be reinforced.

  In the present invention, it is preferable to include a step of forming a plurality of the coil components on a wafer made of the magnetic ceramic material, and a step of dividing the plurality of coil components into individual pieces. In this case, after a plurality of coil parts formed on the wafer are separated into pieces, a step of barrel-polishing the outer surface of each coil part to remove edges, and bumps exposed on the surface of each coil part It is preferable to further comprise a step of plating the surface of the electrode. According to the present invention, it is possible to easily form an external terminal electrode and to manufacture a coil component that is less susceptible to damage such as chip chipping.

  In the present invention, it is preferable that the step of dividing the plurality of coil components on the wafer includes a step of dicing at a position passing over the bump electrode. In such a case, since the bump electrode is exposed on the side surface of the coil component, a solder fillet at the time of mounting can be formed, and the fixing strength of the solder can be increased.

  In the present invention, it is preferable that the step of dividing the plurality of coil components on the wafer includes a step of dicing at a position passing through the outside of the bump electrode. According to the present invention, since the bump electrode is not exposed on the side surface of the coil component, it is possible to provide a coil component in which no solder fillet is formed during mounting. Therefore, space-saving mounting is possible, and high-density mounting can be realized.

  According to the present invention, it is possible to provide a coil component that can be manufactured at a low cost while being reduced in size and height while ensuring desired filter performance. Moreover, according to this invention, the manufacturing method which can manufacture such a coil component easily and at low cost can be provided.

It is a schematic perspective view which shows the general | schematic structure of the coil component 100 by the 1st Embodiment of this invention, and the mounting surface has shown the state facing upward. 3 is a schematic exploded perspective view showing a layer structure of a coil component 100 in detail. FIG. 3 is a plan view showing a planar positional relationship of a conductor pattern of a coil component 100. FIG. 3 is a flowchart illustrating an example of a method for manufacturing a coil component 100. It is a schematic plan view showing a configuration of a magnetic wafer before dicing on which a large number of coil components 100 are formed. It is a schematic perspective view which shows the general-view structure of the coil component 200 by the 2nd Embodiment of this invention, and has shown the state in which the mounting surface is facing upward. It is a schematic plan view showing a configuration of a magnetic wafer before dicing on which a large number of coil components 200 are formed. It is a substantially exploded perspective view which shows the structure of the conventional common mode filter.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing an overview structure of the coil component 100 according to the first embodiment of the present invention, and shows a state in which the mounting surface faces upward.

  As shown in FIG. 1, the coil component 100 according to the present embodiment is a common mode filter, and includes a magnetic substrate 11 and a thin film coil including a common mode filter element provided on one main surface (upper surface) of the magnetic substrate 11. The main surface of the thin film coil layer 12 excluding the formation position of the layer 12, the first to fourth bump electrodes 13a to 13d provided on the main surface (upper surface) of the thin film coil layer 12, and the bump electrodes 13a to 13d. And a magnetic resin layer 14 provided. As shown in the drawing, the coil component 100 is a substantially rectangular parallelepiped surface-mounted chip component, and the first to fourth bump electrodes 13 a to 13 d are laminated layers including a magnetic substrate 11, a thin film coil layer 12, and a magnetic resin layer 14. It is formed so as to be exposed on the outer peripheral surface of the body. Among these, the 1st and 2nd bump electrodes 13a and 13b are exposed from the 1st side surface 10a orthogonal to the longitudinal direction of a laminated body, and the 3rd and 4th bump electrodes 13c and 13d are 1st side surfaces. It is exposed from the second side face 10b opposite to 10a. Needless to say, it is turned upside down at the time of mounting, and the bump electrodes 13a to 13d are used facing downward. In this specification, for convenience of explanation, the vertical direction is defined with reference to the state in which the mounting surface shown in FIG. 1 faces upward, and the exposed surface of the magnetic resin layer 14 is defined as the upper surface of the coil component 100.

  The magnetic substrate 11 secures the mechanical strength of the coil component 100 and serves as a closed magnetic circuit for the common mode filter. As the material of the magnetic substrate 11, for example, a magnetic ceramic material such as sintered ferrite can be used. Although not particularly limited, when the chip size is 1.0 × 1.25 × 0.56 (mm), the thickness of the magnetic substrate 11 can be about 0.55 to 0.6 mm. .

  The thin film coil layer 12 is a layer including a common mode filter element provided between the magnetic substrate 11 and the magnetic resin layer 14. As will be described in detail later, the thin film coil layer 12 has a multilayer structure formed by alternately laminating insulating layers and conductor patterns. As described above, the coil component 100 according to the present embodiment is a so-called thin film type, and is distinguished from a winding type having a structure in which a conducting wire is wound around a magnetic core.

  The magnetic resin layer 14 is a layer constituting the mounting surface (bottom surface) of the coil component 100, and protects the thin film coil layer 12 together with the magnetic substrate 11 and plays a role as a closed magnetic circuit of the coil component 100. However, since the mechanical strength of the magnetic resin layer 14 is smaller than that of the magnetic substrate 11, it has an auxiliary role in terms of strength. As the magnetic resin layer 14, an epoxy resin (composite ferrite) containing ferrite powder can be used. Although not particularly limited, when the chip size is 1.0 × 1.25 × 0.6 (mm), the thickness of the magnetic resin layer 14 may be about 0.08 to 0.1 mm. it can.

  FIG. 2 is a schematic exploded perspective view showing the layer structure of the coil component 100 in detail.

  As shown in FIG. 2, the thin film coil layer 12 includes first to fourth insulating layers 15a to 15d, which are stacked in order from the magnetic substrate 11 side to the magnetic resin layer 14 side, and the second insulating layer 15b. The first spiral conductor 16 and terminal electrodes 24a to 24d formed on the first insulating layer 15a, the second spiral conductor 17 and terminal electrodes 24a to 24d formed on the first insulating layer 15a, and the third insulating layer 15c. The first and second lead conductors 20 and 21 and the terminal electrodes 24a to 24d formed on the first insulating layer 15 and the terminal electrodes 24a to 24d formed on the fourth insulating layer 15d are provided.

  The first to fourth insulating layers 15a to 15d serve to insulate between conductor patterns provided in different layers and to ensure flatness of a plane on which the conductor patterns are formed. In particular, the first insulating layer 15a plays a role of absorbing irregularities on the surface of the magnetic substrate 11 and increasing the processing accuracy of the conductor pattern. As a material for the insulating layers 15a to 15d, it is preferable to use a resin that is excellent in electrical and magnetic insulation and easy to process, and is not particularly limited, but a polyimide resin or an epoxy resin is used. it can.

  The inner peripheral end of the first spiral conductor 16 is connected to the first terminal electrode 24a through the first contact hole conductor 18 and the first lead conductor 20 that penetrate the insulating layer 15c. The outer peripheral end of the first spiral conductor 16 is connected to the third terminal electrode 24 c through the third lead conductor 22.

  The inner peripheral end of the second spiral conductor 17 is connected to the second terminal electrode 24b through a second contact hole conductor 19 and a second lead conductor 21 that penetrate the insulating layers 15c and 15b. The outer peripheral end of the second spiral conductor 17 is connected to the fourth terminal electrode 24 d through the fourth lead conductor 23.

  Both the first and second spiral conductors 16 and 17 have the same planar shape, and are provided at the same position in plan view. Since the first and second spiral conductors 16 and 17 are completely overlapped, a strong magnetic coupling is generated between them. With the above configuration, the conductor pattern in the thin film coil layer 12 forms a common mode filter.

  The outer shapes of the first and second spiral conductors 16 and 17 are both circular spirals. Since the circular spiral conductor has little attenuation at high frequency, it can be preferably used as an inductance for high frequency. In the present embodiment, the second lead conductor 21 is provided on the insulating layer 15 c shared with the first lead conductor 20, but is provided on an insulating layer different from the first lead conductor 20. May be. In the present invention, the vertical relationship between the first and second spiral conductors 16 and 17 and the first and second lead conductors 18 and 19 is not particularly limited, and any positional relationship may be used. .

  An opening 25 penetrating the first to fourth insulating layers 15a to 15d is formed in the central region of the first to fourth insulating layers 15a to 15d and inside the first and second spiral conductors 16 and 17. A magnetic core 26 for forming a magnetic path is formed inside the opening 25. As the material of the magnetic core 26, it is preferable to use a magnetic powder-containing resin (composite ferrite) which is the same material as the magnetic resin layer 14.

  First to fourth bump electrodes 13a to 13d are provided on the insulating layer 15d, respectively. The first bump electrode 13a is connected to the terminal electrode 24a, the second bump electrode 13b is connected to the terminal electrode 24b, the third bump electrode 13c is connected to the terminal electrode 24c, and the fourth bump electrode 13d is a terminal It is connected to the electrode 24d. In the present specification, the “bump electrode” is a thick film plating electrode formed by a plating process, different from the one formed by thermocompression bonding of metal balls such as Cu and Au using a flip chip bonder. Means. The thickness of the bump electrode is equal to or greater than the thickness of the magnetic resin layer 14 and can be about 0.08 to 0.1 mm. That is, the thickness of the bump electrodes 13 a to 13 d is thicker than the conductor pattern in the thin film coil layer 12, and particularly has a thickness five times or more that of the conductor pattern in the thin film coil layer 12.

  A magnetic resin layer 14 is formed on the fourth insulating layer 15d on which the first to fourth bump electrodes 13a to 13d are formed. The magnetic resin layer 14 is provided so as to fill the periphery of the bump electrodes 13a to 13d.

  FIG. 3 is a schematic plan view showing the positional relationship between the conductor pattern in the thin film coil layer 12 and the bump electrodes 13a to 13d.

  As shown in FIG. 3, since the first and second spiral conductors 16 and 17 are completely overlapped in a plan view, strong magnetic coupling occurs between them. In the present embodiment, part of the first to fourth bump electrodes 13 a to 13 d overlaps with the spiral conductors 16 and 17. In order to ensure solder mounting on the printed circuit board, it is necessary to secure a certain area on the mounting surface side of the bump electrodes 13a to 13d, but the bump electrodes 13a to 13d are arranged so as to overlap the spiral conductors 16 and 17. In this case, the electrode area can be secured without increasing the chip area. Of course, it is possible to configure the bump electrodes 13a to 13d so as not to overlap the spiral conductors 16 and 17, but in this case, the chip component becomes large.

  Further, as shown in the drawing, the side surfaces 13e of the bump electrodes 13a to 13d that are in contact with the magnetic resin layer 14 are preferably curved surfaces having no edges. As will be described in detail later, the magnetic resin layer 14 is formed by pouring a composite ferrite paste after forming the bump electrode 13. At this time, a corner portion having an edge on the side surface 13 e of the bump electrodes 13 a to 13 d is formed. If there is, the paste is not completely filled around the bump electrodes, and bubbles are likely to be included. However, when the side surfaces of the bump electrodes 13a to 13d are curved surfaces, the fluid resin spreads to every corner, so that a dense insulating resin layer that does not contain bubbles can be formed. In addition, since the adhesion between the magnetic resin layer 14 and the bump electrodes 13a to 13d is increased, the reinforcement to the bump electrodes 13a to 13d can be enhanced.

  As described above, in the coil component 100 according to the present embodiment, the magnetic substrate 11 is provided only on one side of the thin film coil layer 12, the insulating substrate on the opposite side is omitted, and the magnetic resin layer 14 is provided instead. Therefore, a thin chip part can be provided at low cost. Further, by providing the bump electrodes 13a to 13d having the same thickness as the magnetic resin layer 14, the step of forming the external electrode surface on the side surface and the upper and lower surfaces of the chip component can be omitted, and the external electrode can be easily formed. In addition, it can be formed with high accuracy. Furthermore, according to this embodiment, since a part of bump electrode 13a-13d is provided so that it may overlap with a coil conductor pattern by planar view, size reduction of a chip component can be achieved.

  Next, the manufacturing method of the coil component 100 will be described in detail.

  FIG. 4 is a flowchart showing a method for manufacturing the coil component 100. FIG. 5 is a schematic plan view showing the configuration of a magnetic wafer on which a large number of coil components 100 are formed.

  As shown in FIGS. 4 and 5, in the manufacture of the coil component 100, after forming a large number of common mode filter elements (coil conductor patterns) on a single large magnetic substrate (magnetic wafer), each element is individually manufactured. A mass production process for producing a large number of chip parts by cutting is performed. Therefore, a magnetic wafer is first prepared (step S11), and a thin film coil layer 12 in which a number of common mode filter elements are laid out is formed on the surface of the magnetic wafer (step S12).

  The thin film coil layer 12 is formed by a so-called thin film construction method. Here, the thin film method is a method in which a photosensitive resin is applied, exposed and developed to form an insulating layer, and then a process of forming a conductive pattern on the surface of the insulating layer is repeated, whereby the insulating layer and the conductive layer are formed. Is a method of forming a multilayer film in which are alternately formed. Hereafter, the formation process of the thin film coil layer 12 is demonstrated in detail.

  In the formation of the thin film coil layer 12, the insulating layer 15a is first formed, and then the second spiral conductor 17 and the terminal electrodes 24a to 24d are formed on the insulating layer 15a. Next, after forming the insulating layer 15b on the insulating layer 15a, the first spiral conductor 16 and the terminal electrodes 24a to 24d are formed on the insulating layer 15b, and the contact hole conductor 19 penetrating the insulating layer 15b is formed. To do. Next, after forming an insulating layer 15c on the insulating layer 15b, lead conductors 20 and 21 and terminal electrodes 24a to 24d are formed on the insulating layer 15c, and contact hole conductors 18 and 19 penetrating the insulating layer 15c are formed. Form each one. Finally, after the insulating layer 15d is formed, the terminal electrodes 24a to 24d are formed.

  Here, each of the insulating layers 15a to 15d can be formed by spin-coating a photosensitive resin on the base surface, and exposing and developing it. In particular, the insulating layers 16 b to 16 d are formed as insulating layers having openings 25, and the insulating layers 15 b and 15 c are formed as insulating layers having contact hole conductors 18 and 19. Moreover, Cu etc. can be used as a material of a conductor pattern, and after forming a conductor layer by a vapor deposition method or sputtering, it can form by patterning this.

  Next, bump electrodes 13 (13a to 13d) are formed on the insulating layer 15d (step S13). The bump electrode 13 is formed by first forming a Cu film on the entire surface of the insulating layer 15d where the terminal electrodes 24a to 24d are exposed by electroless plating. Thereafter, a sheet resist is pasted, exposed and developed to selectively remove the sheet resist at the position where the bump electrode is to be formed, exposing the electrode forming region including the terminal electrodes 24a to 24d on the insulating substrate 15d. Let Thick bump electrodes 13a to 13d are formed in this exposed region by electroplating. Thereafter, the sheet resist is removed, the entire surface is etched, the unnecessary Cu film is removed, and the bump electrode 13 is left only above the terminal electrodes 24a to 24d, whereby the substantially columnar bump electrode 13 is completed. At this time, as shown in FIG. 5, the substantially columnar bump electrode 13 is formed as an electrode common to two chip components adjacent in the longitudinal direction of the chip component. The bump electrode 13 is divided into two parts by dicing described later, whereby individual bump electrodes 13a to 13d corresponding to each element are formed.

  Next, the magnetic wafer on which the bump electrodes 13 are formed is filled with a composite ferrite paste and cured to form the magnetic resin layer 14 (step S14). At this time, in order to reliably form the magnetic resin layer 14, a large amount of paste is filled, whereby the bump electrode 13 is buried in the resin. Therefore, the magnetic resin layer 14 is polished to a predetermined thickness until the upper surface of the bump electrode 13 is exposed, and the surface is smoothed (step S15). Further, the magnetic wafer is also polished so as to have a predetermined thickness (step S16). Thereafter, each common mode filter element is separated (chiped) by dicing the magnetic wafer to produce the chip component shown in FIG. 1 (step S17). At this time, as shown in FIG. 5, the cutting line C1 extending in the direction (X direction) orthogonal to the longitudinal direction (Y direction) of the chip component passes through the center of the bump electrode 13, and the obtained bump electrodes 13a to 13d are obtained. The cut surface is exposed on the side surface of the coil component 100. Since the side surfaces of the bump electrodes 13a to 13d become solder fillet forming surfaces during mounting, the fixing strength during solder mounting can be increased.

  Next, after barrel-polishing the chip component 100 to remove the edges (step S18), electroplating is performed (step S19), and the terminal electrodes 24a to 24d and the bump electrodes 13a to 13 exposed on the side surfaces of the thin film coil layer 12 are performed. A smooth electrode surface that is completely integrated with 13d is formed, whereby bump electrodes 13a to 13d shown in FIG. 1 are completed. As described above, by barrel polishing the outer surface of the chip component, it is possible to manufacture a coil component that is unlikely to be damaged such as chip chipping. Moreover, since the surface of bump electrode 3a-13d exposed to the outer peripheral surface of a chip component is plated, the surface of bump electrode 13a-13d can be made into a smooth surface.

  As described above, the manufacturing method of the coil component 100 according to the present embodiment omits one of the upper and lower magnetic substrates used in the past, and forms an insulating resin layer instead, thereby simplifying the coil component. And it can manufacture at low cost. Further, since the resin is filled around the bump electrode, the bump electrode can be reinforced and peeling of the bump electrode can be prevented. Moreover, since the bump electrode is formed by plating in the method for manufacturing the common mode filter according to the present embodiment, it is possible to provide a stable external terminal electrode with higher processing accuracy than when formed by sputtering, for example.

  FIG. 6 is a schematic perspective view showing the structure of the coil component 200 according to the second embodiment of the present invention. FIG. 7 is a schematic plan view showing the configuration of a magnetic wafer on which a large number of coil components 200 are formed.

  As shown in FIGS. 6 and 7, the coil component 200 is characterized in that the side surface of the bump electrode 27 is not exposed from the outer peripheral surface of the chip component, and only the upper surface of the bump electrode 27 is exposed. Therefore, in the manufacture of the coil component 200, the bump electrode 27 is formed inside the mounting area of each element. When a large number of common mode filter elements formed on the magnetic wafer are separated by dicing, the cutting line C1 passes outside the bump electrodes 27a to 27d. According to this embodiment, since the side surfaces of the bump electrodes 27a to 27d are not exposed to the side surfaces of the coil component 200, it is possible to provide an external terminal electrode in which no solder fillet is formed during mounting. Therefore, space-saving mounting is possible and high-density mounting can be realized. In addition, the bump electrode 27 is not a cutting target when dicing the magnetic wafer, and only the magnetic wafer and the resin layer are cutting targets, so that dicing is also facilitated.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the present invention.

  For example, in the above embodiment, a thin film coil layer and a magnetic resin layer are formed on a magnetic wafer, separated by dicing, and further electroplated after barrel polishing, but the present invention is not limited to this method, Dicing may be performed after the electroless plating treatment is performed on the wafer before dicing.

  Moreover, in the said embodiment, although the magnetic resin layer 14 which consists of composite ferrite is formed in the main surface of the thin film coil layer 12, you may form the simple insulating resin layer which does not have magnetism. Moreover, although the thin film common mode filter has been exemplified as the coil component, the present invention is applicable to various types of coil components in which the upper and lower sides of the coil conductor layer are sandwiched between magnetic substrates.

  Moreover, in the said embodiment, although the magnetic core 26 is provided, the magnetic core 26 is not essential in this invention. However, since the magnetic core 26 can be formed of the same material as that of the magnetic resin layer 14, the magnetic core 26 and the magnetic resin layer 14 can be simultaneously formed without going through a special process as long as the opening 25 is formed. Can be formed.

10a, 10b Side surface of laminated body (coil component) 11 Magnetic substrate 12 Thin film coil layers 13, 13a-13d Bump electrode 14 Magnetic resin layers 15, 15a-15d Insulating layer 16 First spiral conductor 17 Second spiral conductor 18 First One contact hole conductor 19 Second contact hole conductors 20 to 23 Lead conductors 24, 24a-24d Terminal electrode 25 Opening 26 Magnetic core 27 Bump electrode 100 Coil component 200 Coil component

Claims (17)

A magnetic substrate made of magnetic ceramic material;
A thin film coil layer including a coil conductor formed on one main surface of the magnetic substrate;
Bump electrodes formed on the main surface of the thin film coil layer;
An insulating resin layer formed on the main surface of the thin film coil layer excluding the formation position of the bump electrode;
The bump electrode is a thick film electrode formed by plating ,
The coil component, wherein the bump electrode is thicker than the conductor pattern in the thin film coil layer . The coil component according to claim 1, wherein a part of a side surface of the bump electrode is exposed and a remaining part of the side surface is covered with the insulating resin layer.   3. The coil component according to claim 1, wherein the bump electrode has a thickness of five times or more of the conductor pattern in the thin film coil layer.   4. The coil component according to claim 1, wherein a thickness of the bump electrode is not less than 0.08 mm and not more than 0.1 mm. 5.   5. The coil component according to claim 1, wherein the bump electrode has a thickness equal to or greater than that of the insulating resin layer.   6. The coil component according to claim 1, wherein a side surface of the bump electrode in contact with the insulating resin layer has a curved surface shape without an edge. The insulating resin layer is made of a magnetic powder-containing resin material,
The coil conductor includes first and second spiral conductors that are magnetically coupled to each other, and the first and second spiral conductors constitute a common mode filter. The coil component according to claim 1. A magnetic core provided inside the first and second spiral conductors;
The coil component according to claim 7, wherein the magnetic core is formed of the same material as that of the insulating resin layer at the same time. Forming a thin film coil layer including a coil conductor on one main surface of a magnetic substrate made of a magnetic ceramic material; and on the terminal electrode of the coil conductor exposed on the main surface of the thin film coil layer, Forming a bump electrode thicker than the conductor pattern by plating;
Filling the main surface of the thin film coil layer on which the bump electrode is formed with an insulating resin paste, and curing the paste to form an insulating resin layer around the bump electrode;
Polishing or grinding the upper surface of the insulating resin layer to expose the upper surface of the bump electrode ;
And a step of exposing a part of the side surface of the bump electrode .   10. The method of manufacturing a coil component according to claim 9, wherein the bump electrode has a thickness of five times or more the conductor pattern in the thin film coil layer.   The thickness of the said bump electrode is 0.08 mm or more and 0.1 mm or less, The manufacturing method of the coil components of Claim 9 or 10 characterized by the above-mentioned.   The method for manufacturing a coil component according to claim 9, wherein the bump electrode has a thickness equal to or greater than that of the insulating resin layer. The step of forming the thin film coil layer includes a step of forming first and second spiral conductors that are magnetically coupled to each other, and a step of forming a magnetic core provided inside the first and second spiral conductors. Including
The method of manufacturing a coil component according to claim 9, wherein the magnetic core is formed of the same material as the insulating resin layer at the same time.   14. The method according to claim 9, comprising a step of forming a plurality of the coil components on a wafer made of the magnetic ceramic material, and a step of dividing the plurality of coil components into individual pieces. Manufacturing method of coil parts. After separating the plurality of coil parts formed on the wafer into pieces, removing the edges by barrel polishing the outer surface of each coil part;
The method of manufacturing a coil component according to claim 14, further comprising a step of plating the surface of the bump electrode exposed on the surface of each coil component. The step of dividing the plurality of coil components on the wafer includes a step of dicing at a position passing over the bump electrode, and a part of the side surface of the bump electrode is exposed by the dicing. The method for manufacturing a coil component according to claim 15.   The method for manufacturing a coil component according to claim 15, wherein the step of dividing the plurality of coil components on the wafer includes a step of dicing at a position passing outside the bump electrode.

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