JP2008235762A - Inductance component and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inductance component whose moisture resistance is improved and which has a high space factor, and to provide a method of manufacturing the same. <P>SOLUTION: An inductance component includes an insulating resin 1, a coil pattern 2 which is formed in the internal layer portion of the insulating resin 1, and an external electrode 4 which is connected with the coil pattern 2 and part of which is exposed out of the insulating resin 1, and it is constructed in a manner such that a protection film 5 having a water repellency is located on the surface layer portion of the insulating resin 1, whereby, the inductance component excellent in a water repellency can be provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inductance component used in an electronic device such as a mobile phone and a method for manufacturing the same.

  Conventionally, as shown in FIG. 12, this type of inductance component is connected to a spiral coil 102 a, a via 103 connected to the coil 102 a, and the via 103 inside a resin body 101. The coil 102b is formed, and the terminals 104 are electrically connected to the coils 102a and 102b. The material constituting the element body 101 is made of a photosensitive epoxy resin or the like. It was.

As prior art document information relating to this application, for example, Patent Document 1 is known.
JP 2003-203813 A

  However, since such a conventional inductance component uses a photosensitive resin material, an inductance component having further excellent moisture resistance has been demanded.

  That is, in the above conventional configuration, in order to form a coil pattern having a high space factor on the plane on which the spiral coil is wound, the photosensitive resin forming the element body has a resolution, that is, a photolithographic process. The resin material is excellent in fine pattern formation performance that can realize a high aspect ratio with high accuracy by fine etching in the process.

  However, if priority is given to the high resolution over the selection of the resin, there is a problem that the selection of the resin in consideration of the moisture resistance becomes insufficient and the moisture resistance becomes low.

  Therefore, an object of the present invention is to provide an inductance component having a high space factor with improved moisture resistance and a method for manufacturing the same.

  In order to solve the conventional problems, the present invention provides an insulating resin, a coil pattern formed on an inner layer of the insulating resin, and an external electrode connected to the coil pattern and partially exposed from the insulating resin. And a protective film having water repellency is provided on the surface layer portion of the insulating resin.

  The inductance component of the present invention and the manufacturing method thereof have excellent moisture resistance while ensuring a high space factor of the coil pattern by providing a protective film having water repellency on the surface layer portion of the insulating resin. An inductance component and a manufacturing method thereof can be realized.

(Embodiment 1)
Hereinafter, an inductance component and a manufacturing method thereof according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an inductance component according to Embodiment 1 of the present invention.

  In FIG. 1, an element body 1 made of an insulating resin is formed as a laminated structure in order to form a coil pattern 2. In the coil pattern 2, a spiral planar coil 2 a formed in a predetermined layer and a spiral planar coil 2 b formed in another layer are connected via a via electrode 3. And by connecting the terminal electrode 4 to the planar coil 2a and the planar coil 2b, an inductance component having a chip shape is configured.

  More specifically, the planar coil 2b provided inside a predetermined layer of the element body 1 is spirally wound from one terminal electrode 4 in the inner circumferential direction, and is separated from the innermost circumferential portion of the planar coil 2b. Are connected to the innermost peripheral portion of the planar coil 2a provided by the via electrode 3, and the planar coil 2a is spirally wound in the direction toward the other terminal electrode 4 (peripheral direction) to form an inductance component. Yes. In FIG. 1, the two-layer planar coils 2a and 2b are described as an example, but in order to realize a desired inductance value, a predetermined number of layers can be produced by designing in advance by simulation. .

  Further, in order to obtain a small inductance component such as 1005 size or 0603 size, it is necessary to increase the number of spirals per layer. On the other hand, if the pattern width of the planar coils 2a and 2b is reduced, the direct current resistance increases and the electrical characteristics of the inductance component are deteriorated. In consideration of these, it is important to form the planar coils 2a and 2b having a high aspect ratio by reducing the pattern width and increasing the pattern thickness. In order to realize this, for example, it is preferable to form the planar coils 2a and 2b having an inter-pattern distance of 20 μm or less, an aspect ratio of 1.5 or more, and a pattern width of 10 to 30 μm.

  The insulating resin used for the element body 1 is preferably an epoxy resin having a photosensitivity or a polyimide resin. In particular, an epoxy resin is preferable when the coil pattern 2 having a high resolution is formed.

  As another specific configuration, it is also possible to employ a configuration in which a different material such as a filler is mixed in the epoxy resin while the main component of the element body 1 is an epoxy resin.

  Next, by forming a resin having water repellency as the protective film 5 on the surface of the insulating resin constituting the element body 1, an inductance component having excellent moisture resistance can be obtained. As the water-repellent resin, it is preferable to form the protective film 5 using one of silicon resin and fluororesin as a main component.

  As the silicon resin used for this, it is preferable to use a polymer organic compound material having a siloxane bond as a skeleton.

  Fluorine resins include polytetrafluoroethylene resin (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), and tetrafluoroethylene / ethylene. A copolymer, polyvinylidene fluoride (PVDF) and the like are preferable.

  In particular, when the fluororesin is used for the protective film 5, it is possible to suppress the sticking between components by utilizing the small friction coefficient and the excellent slidability that are the characteristics of the fluororesin, and at the time of mounting. It can be easily transported using a parts feeder or the like.

  As an inductance component having such a configuration, a coil pattern 2 having a chip size of 0603 and an L value at that time of 1.8 nH is manufactured, and a chip coil having a protective film 5 coated with silicon resin having different thicknesses is prepared. Prototype.

  The moisture resistance reliability of this chip coil was evaluated. The test contents include a high temperature and high humidity load test (temperature: 60 ° C., humidity: 95%, load condition: 0.5 A as a rated current, continuous application, test time: 1000 hours), and high temperature and high humidity test (temperature). 60 ° C., humidity: 95%, no load, test time: 1000 hours), and the results are shown in Table 1. The determination conditions are indicated by ◯ when the change rate of L is within ± 5% and the change rate of Q is within ± 20%.

  From the results of (Table 1), the thickness of the protective film 5 is preferably in the range of 0.5 to 5.0 μm. If the thickness of the protective film 5 is less than 0.5 μm, the moisture resistance becomes practically insufficient, and if it exceeds 5.0 μm, it is not preferable from the viewpoint of the external dimensions and shape as an inductance component.

  The thickness variation of the protective film 5 is preferably ± 5% or less from the viewpoint of reliability.

  By using the inductance component having such a configuration, it is possible to ensure high space factor of the coil patterns of the planar coils 2a and 2b and at the same time improve the moisture resistance of the entire inductance component.

  Moreover, even if a minute gap is generated between the element body 1 and the terminal electrode 4 during the manufacturing process by providing the protective film 5 having water repellency so as to straddle the end portions of the element body 1 and the terminal electrode 4. Finally, the protective film 5 is filled in the gap in the subsequent process to ensure insulation, and at the same time, the mechanical strength can be increased, realizing a high-quality inductance component with excellent reliability. can do.

  Further, it is preferable to use a resin having a volume resistance of 10 GΩcm or more of the insulating resin constituting the element body 1. By using an insulating resin having a volume resistance of 10 GΩcm or more, an inductance component with little characteristic deterioration can be obtained even at high frequencies.

  In addition, by using a water-repellent protective film as a resin having a coloring property or a light shielding property, it is excellent in electronic recognition of the chip shape (for example, automatic recognition by a CCD camera) and weather resistance (for example, by ultraviolet rays). It can be an inductance component excellent in deterioration.

  The cross-section of the planar coils 2a and 2b is not limited to a square shape, but may be an annular shape or the like. However, the square shape can increase the cross-sectional area of the coil, resulting in a reduction in copper loss. can do.

  It is more desirable that the planar coils 2a and 2b have a thickness of 10 μm or more because a large current can be handled.

  Next, a method for manufacturing the inductance component will be described.

  Next, an inductance component manufacturing process will be described with reference to FIGS.

  This inductance component manufacturing method is a manufacturing method in which a plurality of inductance components are formed at a time in a state of being connected to each other on a single wafer substrate, and finally a plurality of inductance components are separated and separated into individual pieces. .

  First, as shown in FIG. 2, for example, an aluminum thin film having a thickness of 80 to 100 nm is formed on a substrate 8 made of a silicon wafer having a thickness of 0.2 to 1.0 mm by a plating method, a sputtering method, a vapor deposition method, or the like. 9 is formed. At this time, it is preferable to use either silicon, glass or quartz as the substrate 8. These materials are preferable from the viewpoints of flatness, surface roughness and material availability. In particular, silicon wafers are the optimal material for this purpose.

  The sacrificial layer 9 is preferably a metal material having excellent etching properties, and aluminum is particularly preferable. This is particularly preferable from the viewpoints of adhesion to the substrate 8 and etching properties.

  Next, a photosensitive epoxy resin or the like is formed on the sacrificial layer 9 by using a coating machine such as a spin coater, and then a frame-shaped gap portion 11 is formed by a photolithography method.

  Next, as shown in FIG. 3, the metal layer 12 is formed using a plating method or the like. The metal layer 12 is formed to be thicker than a predetermined thickness, and then flattened by controlling to a predetermined thickness using CMP polishing or the like to at least the upper surface of the insulating resin layer 10 as shown in FIG. A frame-like post portion 13 made of a thin metal material having excellent dimensional accuracy can be formed. After forming the metal layer 12 to be thicker than a predetermined thickness, a method for producing an inductance component having excellent lamination accuracy and dimensional accuracy is obtained by laminating a method of polishing to at least the upper surface of the insulating resin layer 10 by polishing. Can be realized (see FIG. 5). In addition, the metal layer 12 is formed by an electrolytic plating method, and by using such a method, inductance components having a fine coil pattern 2 can be manufactured in a lump.

  Then, after forming the insulating resin layer 10 having the gap portion 11 by using a photolithography method on the insulating resin layer 10 having a predetermined pattern as shown in FIG. 5, the inside of the gap portion 11 is plated. Using a method and CMP polishing, a metal material having excellent conductivity, such as copper, is laminated while forming a predetermined pattern of predetermined spiral planar coils 2a and 2b and a frame-like post portion 13 with high accuracy. By repeating the above, a laminated body in which the coil pattern 2 including the planar coils 2a and 2b is formed inside the frame-shaped post portion 13 can be manufactured. The coil pattern 2 has a two-layer laminated structure composed of a planar coil 2a and a planar coil 2b. The coil pattern 2 is determined by an inductance value. The value can be designed.

  Further, the gap portion 11 includes a plurality of frame-like gap portions 11a for forming the frame-like post portion 13, a spiral void portion 11b disposed inside the frame-like gap portion 11a, and a via electrode. The frame-shaped space 11a functions as a frame-shaped post 13 for separating into individual chip-shaped components in the latter half of the manufacturing process. Thus, they are laminated.

  In addition, the coil pattern 2 composed of the planar coils 2a and 2b is formed in the spiral space 11b, the via electrode 15 made of metal is formed in the space 11c for the through hole, and the coil pattern 2 and the frame shape are formed. Insulation with the post portion 13 is intended.

  When the two-layer planar coils 2 a and 2 b are formed, the two-layer planar coils 2 a and 2 b are made conductive by the via electrode 15.

  The width of the post portion 13 is preferably 100 μm or less (not including 0).

  Next, an etching process for dividing the element body 1 that has completed the stacking process for forming the chip coil is entered. Therefore, as shown in FIG. 6, a resist pattern 16 for protecting from the etching process is formed by photolithography.

  Thereafter, as shown in FIG. 7, the frame-shaped post portion 13 is removed by melting with an etching agent, and the sacrificial layer 9 formed on the substrate 8 so as to enter from the gap portion 11a formed by etching is removed. It can be separated into individual pieces by removing.

  Next, as shown in FIG. 8, after removing the resist pattern 16, a nickel plated electrode and a Sn plated electrode are laminated and coated on the surfaces of both end faces of the element body 1 so as to be electrically connected to the exposed electrode 15. Thus, the terminal electrode 4 having excellent mountability as shown in FIG. 9 is formed. The terminal electrode 4 has a five-sided electrode structure, but the configuration of the terminal electrode 4 can be changed as necessary.

Thereafter, as shown in FIG. 10, a silicon resin solution diluted so that the silicon resin has a concentration of 5 wt% is prepared, and part of the terminal electrodes 4 at both ends of the chip-like inductance component is chucked. Or after apply | coating a silicon resin solution to the surface of the element | base_body 1 by the transfer method etc., it is made to dry for 30 minutes at temperature: 80 degreeC. Thereafter, the silicone resin is thermally cured from the dried pieces at a temperature of 190 ° C. for 20 minutes. Thereby, the protective film 5 made of a silicon resin having water repellency can be formed. And when forming this thin protective film 5, it is preferable to apply | coat by lowering | hanging the viscosity of a silicone resin, and as a viscosity, below 20cSt (mm < ² > / S) is preferable from a viewpoint of thickness control and workability | operativity. Furthermore, it is also possible to form a protective film 5 having a high thickness accuracy by preparing a solution having a low viscosity, repeating the coating and drying in a plurality of times, and then thermally curing the solution.

  The chip coil produced by this manufacturing method had a length; 1.00 × width; 0.50 × thickness; 0.30 (1005 size) and a chip coil having an inductance value of 8.4 nH.

  As described above, the element body 1 and the coil pattern 2 formed of at least photosensitive insulating resin are laminated a plurality of times by the photolithography method, and the coil pattern 2 is formed on the inner layer portion of the element body 1 that is insulating resin. Manufacturing a high space factor inductance component having excellent moisture resistance by including at least a step of dividing into individual pieces by etching and a step of forming a protective film 5 by applying and forming a water-repellent resin. A method can be provided.

  Next, the configuration of another example of the inductance component in the first embodiment will be described. The main configuration of another example of the inductance component shown in FIG. 11 is substantially the same as the configuration of the inductance component shown in FIG. 1, and the major difference is that the outer shape of the terminal electrode 4 forms the protective film 5. The point is that it is larger than the outer shape.

  With such an external shape, after the protective film 5 is applied and formed on the entire surface of the inductance component including the terminal electrode 4, only the terminal electrode 4 can be exposed by barrel polishing or the like. This is because the protective film 5 formed on the surface of the terminal electrode 4 can be peeled off when a medium such as a ceramic ball used for barrel polishing collides with the surface of the terminal electrode 4 well. As a result, it is possible to realize an inductance component excellent in mountability and to provide an inductance component excellent in productivity.

  At this time, it is possible to sufficiently infiltrate silicon resin into gaps such as minute pinholes and cracks by vacuum impregnation when immersed in a dilute solution such as silicon resin. can do.

  As described above, at least photosensitive insulating resin and the coil pattern 2 are laminated a plurality of times by the photolithography method, the coil pattern 2 is formed on the inner layer portion of the insulating resin, the step of dividing the coil pattern 2 into individual pieces, the water repellency An inductance component having a high space factor that is efficiently small and excellent in moisture resistance by including at least a step of applying and forming a protective film 5 by immersing a resin having a surface and a step of exposing an external electrode by barrel polishing. Can be produced.

  Since the inductance component and the manufacturing method thereof according to the present invention have high moisture resistance, they are useful in various electric devices such as mobile phones.

Sectional drawing of the inductance component in Embodiment 1 of this invention Cross-sectional process drawing showing the manufacturing process of the same inductance component Cross-sectional process drawing Cross-sectional process drawing Cross-sectional process drawing Cross-sectional process drawing Cross-sectional process drawing Cross-sectional process drawing Cross-sectional process drawing Cross-sectional process drawing Cross section of another example inductance component Sectional view of a conventional inductance component

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Element body 2 Coil pattern 2a, 2b Planar coil 3 Via electrode 4 Terminal electrode 5 Protective film 8 Substrate 9 Sacrificial layer 10 Insulating resin layer 11, 11a, 11b, 11c Air gap part 12 Metal layer 13 Post part 15 Via electrode 16 Resist pattern

Claims (8)

An insulating resin, a coil pattern formed on an inner layer portion of the insulating resin, and an external electrode connected to the coil pattern and partially exposed from the insulating resin, and having a water repellency on a surface layer portion of the insulating resin Inductance component with a protective film. The inductance component according to claim 1, wherein a protective film having water repellency is provided so as to cover a junction between the exposed insulating resin and the external electrode. The inductance component according to claim 1, wherein the insulating resin is a resin having a volume resistance of 10 GΩcm or more. The inductance component according to claim 1, wherein the protective film having water repellency is a resin mainly composed of one of silicon resin and fluororesin. The inductance component according to claim 1, wherein the protective film having water repellency has a thickness of 0.5 to 5.0 μm. The inductance component according to claim 1, wherein the protective film having water repellency is a resin having a coloring property or a light shielding property. An insulating resin, a coil pattern formed on an inner layer portion of the insulating resin, and an external electrode connected to the coil pattern and partially exposed from the insulating resin, and having a water repellency on a surface layer portion of the insulating resin A method of manufacturing an inductance component provided with a protective film, wherein a photosensitive insulating resin and a coil pattern are laminated a plurality of times by a photolithographic method, and a coil pattern is formed on an inner layer portion of the insulating resin, A method of manufacturing an inductance component, comprising at least a step of dividing and a step of applying and forming an insulating resin having water repellency on the surface of the insulating resin to form a protective film. An insulating resin, a coil pattern formed on an inner layer portion of the insulating resin, and an external electrode connected to the coil pattern and partially exposed from the insulating resin, and having a water repellency on a surface layer portion of the insulating resin A method of manufacturing an inductance component provided with a protective film, wherein a photosensitive insulating resin and a coil pattern are laminated a plurality of times by a photolithographic method, and a coil pattern is formed on an inner layer portion of the insulating resin, A method for manufacturing an inductance component, comprising at least a step of dividing, a step of immersing and applying an insulating resin having water repellency, and a step of exposing an external electrode by barrel polishing.

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