JP2011171544A - Method of manufacturing winding coil component and method of manufacturing electronic component module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a winding coil component by which a substance of a flush cleaning liquid etc., hardly remain at a part made of a resin material such as a suction surface constituting resin part, and a pinhole is hardly formed in a molding resin when used as a module component of a resin molding mold. <P>SOLUTION: The winding coil component A is manufactured which includes: a magnetic core 3 provided with a core part 1 between collar parts 2a and 2b; a winding 4 wound around the core part; and the suction surface constituting resin part 5 arranged to cover at least a part of the wiring and constituting a suction surface 15 for vacuum suction, and the suction surface constituting resin part is formed using a resin composition including as a base resin a curing type epoxy acrylate resin or epoxy resin of ≤700 in molecular weight. As the resin composition, a resin composition which includes an epoxy acrylate resin of ≤700 in molecular weight and a photoinitiator or a resin composition which includes a bisphenol A type epoxy resin of ≤700 in molecular weight and a curing agent is used. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a wound coil component and a method for manufacturing an electronic component module. More specifically, the present invention relates to a wound coil component having a suction surface constituting resin portion that serves as a suction surface for holding by a vacuum suction method during mounting. The present invention relates to a manufacturing method and an electronic component module manufacturing method.

  One of the winding coil components is, for example, a common mode choke coil as shown in FIG. 6 (see Patent Document 1).

The common mode choke coil is a chip-type winding coil component, and includes a core 53 having a core 51 and a pair of flanges 52a and 52b disposed on both ends thereof, and a core of the core 53. Covering the portion of the winding 54 wound around the part 51 with a pair of insulating coatings and the part of the winding 54 wound around the core part 51 located on the upper surface of the core part 51 A protective layer (resin portion) 55 formed using a polymer resin material (in this example, epoxy acrylate) disposed between the pair of flange portions 52a and 52b is electrically connected to both ends of the winding. The external electrode 56 is provided.
In this common mode choke coil, the characteristic impedance can be adjusted with high accuracy, the production efficiency is not lowered, and the common mode can be quickly mounted without considering the signal input / output direction. It is said that a choke coil can be provided.

  However, when this coiled coil component (common mode choke coil) is mounted on a circuit board and then used in an electronic component module manufactured by molding with a molding resin (sealing resin), when molding, Pin holes may occur in the molding resin (sealing resin).

  That is, when an electronic component module is manufactured using the above-described conventional winding coil component (common mode choke coil), the winding coil component is first mounted on a circuit board by a method such as reflow soldering, and then a cleaning liquid. At this time, a part of the cleaning liquid is adsorbed and remains on the protective layer (resin part) of the coiled coil component, so that the protective layer is sealed when sealing with the molding resin. The cleaning liquid adsorbed on the substrate evaporates, and a pinhole is formed after the evaporated vapor passes through the molding resin, thereby impairing the reliability of the product (electronic component module).

  In the case of the wound coil component disclosed in Patent Document 1, the protective layer is formed of a resin material, and the cleaning liquid is adsorbed on the portion formed of the resin material, resulting in the formation of pinholes in the molding resin. However, not only the protective layer, but also when the coiled coil component has a portion made of a resin material, a pinhole may be formed in the molding resin as in the case described above. There is sex.

JP 2006-147728 A

  The present invention solves the above problem, and when the wound coil component has a portion made of a resin material such as an adsorption surface constituting resin portion, a substance such as a flux cleaning liquid remains in the resin portion. An object of the present invention is to provide a method of manufacturing a wound coil component that is difficult to prevent pinholes from being formed in a molding resin even when used as a resin-molded module component.

In order to solve the above problems, a method for manufacturing a wound coil component according to the present invention includes:
A magnetic core having a winding core and a pair of flanges disposed on both ends thereof;
A winding wound around the core portion of the magnetic core;
An external electrode to which both ends of the winding are electrically connected;
A winding provided with an adsorption surface constituting resin portion that is disposed so as to cover at least a part of the winding wound around the winding core portion and constitutes an adsorption surface when sucked and held by a vacuum suction method. A method of manufacturing a coil component,
A curable epoxy acrylate resin having a molecular weight of 700 or less or a resin composition based on an epoxy resin is applied and cured so as to cover at least a part of the winding wound around the winding core. Thus, the adsorption surface constituting resin portion is formed.

  In the wound coil component manufactured by the method of the present invention, it is desirable that the adsorption surface constituting resin part covers at least a part of the collar part.

Moreover, it is desirable to be used as a module component of a resin mold type that is mounted on a circuit board, cleaned, and then sealed with a molding resin.

  The present invention also includes a step of mounting the above-described winding coil component on a circuit board, a step of cleaning the circuit board, and a step of sealing the surface of the circuit board on which the winding coil component is mounted with a molding resin. Is also directed to a method for manufacturing an electronic component module.

  In the method for manufacturing a wound coil component according to the present invention, a magnetic core, a winding wound around the winding core, an external electrode to which both ends of the winding are electrically connected, and a winding core In manufacturing a wound coil component that is disposed so as to cover at least a part of the wound winding and includes a suction surface constituting resin portion that forms a suction surface when sucked and held by a vacuum suction method. Applying and curing a curable epoxy acrylate resin having a molecular weight of 700 or less or a resin composition based on an epoxy resin so as to cover at least a part of the winding wound around the core. Therefore, the flux cleaning solution or the like is not easily left on the adsorption surface constituting resin portion, and even when used as a resin mold type module component, the pin is not fixed to the mold resin. hole Be formed can provide winding coil component capable of preventing.

That is, by using an epoxy acrylate resin or an epoxy resin having a specific molecular weight (molecular weight of 700 or less) as the resin composition used for forming the adsorption surface constituting resin portion, the crosslink density is increased, for example, solder mounting is performed. It is possible to suppress or prevent the cleaning liquid used in the subsequent flux cleaning process from remaining on the adsorption surface constituting resin portion.
Moreover, since heat resistance improves and it can also endure the heat processing which becomes comparatively high temperature, decomposition | disassembly of resin can be prevented and generation | occurrence | production of the pinhole in an adsorption surface structure resin part can be suppressed.

  In the wound coil part manufactured by the method for manufacturing a wound coil part according to the present invention, when the adsorption surface constituting resin part covers at least a part of the collar part, the part covering the collar part is a part where pinholes are particularly likely to occur. Therefore, it is particularly meaningful.

  When used as a resin mold-type module part that is cleaned after mounting and sealed with a mold resin, for molds due to residual flux cleaning liquid on the adsorption surface constituting resin part in the flux cleaning process after mounting This is particularly meaningful because it is possible to obtain a highly reliable module product by suppressing and preventing the occurrence of pinholes in the resin.

  An electronic device comprising: a step of mounting the winding coil component on a circuit board; a step of cleaning the circuit board; and a step of sealing the surface of the circuit board on which the winding coil component is mounted with a molding resin. According to the method for manufacturing a component module, it is possible to obtain a highly reliable electronic component module by suppressing or preventing the occurrence of pinholes in the molding resin.

It is a front view which shows the winding coil component element of the stage before arrange | positioning exterior resin prepared in the Example of this invention. (a) is front sectional drawing which shows the state which apply | coated the resin composition to the winding coil component element at 1 process of the manufacturing method of the winding coil component concerning the Example of this invention, (b) is a top view. (a) Front sectional drawing which shows the winding coil components manufactured by the manufacturing method of the winding coil components concerning the Example of this invention, (b) is a top view. It is a figure which shows the state which mounted the coiled coil components on the circuit board at the process of manufacturing the resin mold component mounting substrate using the coiled coil components of FIG. It is a figure which shows the principal part structure of the resin mold component mounting board produced using the coiled coil components of FIG. It is a figure which shows the conventional winding coil components (common mode choke coil).

  Embodiments of the present invention will be described below to describe the features of the present invention in more detail.

<Example 1>
[1] Preparation of resin composition
(a) 473 g of bisphenol A type epoxy acrylate resin (molecular weight 514) as the main agent,
(b) 32 g of 2,2-dimethoxy-1,2-diphenylethane-1-one as a photoinitiator,
(c) 237 g of dicyclopentenyloxyethyl methacrylate as an acrylic monomer for viscosity adjustment,
(d) 250g of talc as filler
Were weighed and mixed to prepare a resin composition for forming the adsorption surface constituting resin portion.

[2] Production of Winding Coil Part Having Adsorption Surface Containing Resin Part In Example 1, as shown in FIG. 1, a core part 1 as a wound coil part element to which a resin composition is applied. And a magnetic core 3 having a pair of flange portions 2a and 2b disposed on both ends thereof, and a winding 4 wound around the core portion 1 of the magnetic core 3 and having an insulating coating on the surface. A winding coil component element (winding coil component before arranging the adsorption surface constituting resin portion) A1 provided with external electrodes 6a and 6b to which both ends of the winding 4 are electrically connected was prepared.
The magnetic core 3 constituting the coiled coil component element A1 has dimensions of length L = 2.0 mm, width W = 1.2 mm, and height T = 0.9 mm.

  Then, as shown in FIGS. 2A and 2B, the winding coil component element A1 is wound in a region extending from the upper surface of one flange portion 2a of the magnetic core 3 to the upper surface of the other flange portion 2b. The resin composition 5a was applied by a dipping coating method so as to cover the upper surface side of the winding 4 wound around the core portion 1. The resin composition 5a is applied so that the upper surface is flat, and the application thickness T of the resin composition 5a (distance from the outer peripheral surface of the core 1 to the surface of the resin composition 5a) is 150 μm. The coating conditions were adjusted so that

Then, the resin composition 5a applied to the coiled coil component element A1 is irradiated with UV under the condition that the integrated light amount is 5400 mJ / cm ^2, and as shown in FIGS. 3 (a) and 3 (b) Was obtained, and the coiled coil part A provided with the suction surface constituting resin portion 5 which becomes the suction surface 7 when sucked and held by the vacuum suction method was obtained.

[3] Preparation of cured resin film for characteristic evaluation Further, in order to evaluate the characteristics of the cured resin that becomes the adsorption surface constituting resin part obtained by curing the resin composition, a resin composition applied to the magnetic core and The same resin composition was applied and cured under the same conditions as described in [2] above, thereby producing a cured resin film having a thickness of 150 μm.

[4] Measurement and Evaluation of Characteristics The following characteristics were examined for the wound coil parts and the cured resin film produced as described above.

(1) Absorption rate of cleaning liquid The cured resin film having a thickness of 150 μm prepared in the above [3] was immersed in a flux cleaning liquid at 70 ° C. for 20 minutes.
Then, after rinsing with running water for 20 minutes and wiping off the water on the surface, the weight was measured. And the washing | cleaning-solution absorption factor was computed from the weight change from the resin cured film before being immersed in a flux washing | cleaning liquid.
Cleaning liquid absorption rate (% by weight) =
{(Weight after immersion−weight before immersion) / weight before immersion} × 100
In addition, it is desirable that the value of the cleaning liquid absorption rate is usually 3.0% by weight or less.

(2) Weight change rate after drying The cured resin film obtained after wiping off the surface water obtained in (1) above was dried at 80 ° C. for 10 minutes, and the weight was measured. And the weight change rate after drying was computed from the weight change from the resin cured film before immersion in a flux washing | cleaning liquid.
Weight change after drying (% by weight) =
{(Weight before drying-weight after drying) / weight before drying} × 100
The value of the rate of change in weight after drying is usually desirably 2.0% by weight or less.

  In order to examine the above (1) cleaning liquid absorption rate and (2) weight change rate after drying, as shown in Table 1, Pine Alpha (manufactured by Arakawa Chemical Co., Ltd.), Microclean WS-1014 was used as the cleaning liquid. Three types of flux cleaning liquids (manufactured by Kaken Tech) and microclean WS-1942 (manufactured by Kaken Tech) were used.

(3) Evaluation of heat resistance The dried resin cured film obtained in (2) above was heat-treated at 150 ° C. for 10 hours, and the weight was measured. And heat resistance was evaluated from the weight reduction rate of the film before and after heat treatment.
Weight reduction rate in heat treatment process (wt%) =
{(Weight before immersion-weight after heat treatment) / weight before immersion} × 100
In addition, it is desirable that the value of the weight reduction rate in this heat treatment step is usually 0.5% by weight or less.

  In order to examine the weight reduction rate in the heat treatment step for this heat resistance evaluation, as shown in Table 1, as a cleaning solution, Microclean WS-1014 (manufactured by Kaken Tech) and Microclean WS-1942 Two types of flux cleaning solutions (manufactured by Kaken Tech) were used.

(4) Existence of occurrence of pinhole In FIG. 4, the wound coil component A produced through the step of forming the adsorption surface constituting resin portion by applying and curing the resin composition in FIG. As shown, it was mounted on the lands 12 of the circuit board 11 by a reflow soldering method, and the flux was cleaned using a flux cleaning solution. The washing was performed under the conditions of 70 ° C. and 20 minutes.
Here, as a flux cleaning liquid, Microclean WS-1942 (manufactured by Kaken Tech) was used.
Then, after rinsing with running water for 20 minutes, it was dried at 80 ° C. for 10 minutes.

  Next, a thermosetting sealing resin (in this example, an epoxy resin) is applied under vacuum and heated at 100 ° C. for 70 minutes to cure the sealing resin, as shown in FIG. A resin mold component mounting substrate B having a structure in which the wire coil component A was sealed in the sealing resin 13 was obtained.

And the presence or absence of the generation | occurrence | production of a pinhole was confirmed by observing the external appearance and cross section of this resin mold component mounting board | substrate B. FIG.
The results are shown in Table 1.

<Example 2>
A sample (winding coil component) under the same conditions as in Example 1 except that 447 g of bisphenol A type epoxy acrylate resin having a molecular weight of 614 and 263 g of dicyclopentenyloxyethyl methacrylate as an acrylic monomer for viscosity adjustment were used. Resin cured film and resin mold component mounting substrate) were prepared, and the characteristics were evaluated in the same manner as in Example 1 above.
The results are also shown in Table 1.

<Example 3>
[1] Preparation of resin composition
(a) As a main agent, bisphenol A type epoxy resin (molecular weight 380): 350 g
(b) 360 g of acid anhydride as a curing agent
(c) 30 g of imidazole as a curing accelerator
(d) 250g of talc as filler
Were weighed and mixed to prepare a resin composition for forming the adsorption surface constituting resin portion.

[2] Production of Winding Coil Component Having Adsorption Surface Constituent Resin Portion In this Example 3, as in the case of Example 1, as the winding coil component element to which the resin composition is applied, FIG. The coil composition element A1 shown in FIG. 2 was prepared, and the resin composition prepared in [1] was applied in the same manner as in Example 1. Then, after passing through the first stage heat treatment step (drying step) at 90 ° C. for 30 minutes and the second stage heat treatment step (curing step) at 150 ° C. for 60 minutes, the resin composition is cured to obtain the adsorption surface constituting resin portion. Obtained winding coil parts.

[3] Preparation of cured resin film for characteristic evaluation In addition, in order to evaluate the characteristics of the cured resin to be the adsorption surface constituting resin part obtained by curing the resin composition, the resin prepared in the above [1] The composition was applied and cured under the same conditions as described in [2] above, to produce a cured resin film having a thickness of 150 μm.
Further, in the same manner as in the case of Example 1, a resin molded component mounting board for examining whether or not a pinhole was generated was produced.

[4] Measurement and Evaluation of Characteristics Each characteristic was examined by the same method as in Example 1 above. Evaluation was performed in the same manner as in Example 1.
The results are also shown in Table 1.

<Example 4>
Sample (winding coil component) under the same conditions as in Example 1 except that the bisphenol A type epoxy acrylate resin having a molecular weight of 514 in Example 1 was replaced with a bisphenol F type epoxy acrylate resin having a molecular weight of 480. Resin cured film and resin mold component mounting substrate) were prepared, and the characteristics were evaluated in the same manner as in Example 1 above.
The results are also shown in Table 1.

<Comparative Example 1>
As the main component of the resin composition, a bisphenol A type epoxy resin having a molecular weight of 1094 is used, the blending amount is 320 g, dicyclopentenyloxyethyl methacrylate is used as the acrylic monomer for viscosity adjustment, and the blending amount is 387 g. A resin composition was produced under the same conditions as in Example 1 except that the above was performed, and a sample (winding coil component, resin cured film, and resin mold component mounting substrate) was produced using this resin composition. The characteristics were evaluated in the same manner as in.
The results are also shown in Table 1.

<Comparative example 2>
The main component of the resin composition is a bisphenol A type epoxy resin having a molecular weight of 720, the blending amount is 405 g, dicyclopentenyloxyethyl methacrylate is used as an acrylic monomer for viscosity adjustment, and the blending amount is 305 g. A resin composition was produced under the same conditions as in Example 1 except that the above was performed, and a sample (winding coil component, resin cured film, and resin mold component mounting substrate) was produced using this resin composition. The characteristics were evaluated in the same manner as in.
The results are also shown in Table 1.

  As shown in Table 1, in the case of Examples 1 to 4 having the requirements of the present invention, the cleaning liquid absorption rate, the weight change rate after drying, the heat resistance evaluation, and the presence or absence of occurrence of pinholes are good. It was confirmed that a result was obtained.

  As for the cleaning solution absorption rate and the weight change rate after drying, as shown in Table 1, Pine Alpha (made by Arakawa Chemical Co., Ltd.), Micro Clean WS-1014 (made by Kaken Tech) and Micro Clean are used as flux cleaning solutions. It was confirmed that good results were obtained when any of the three types of flux cleaning solutions of WS-1942 (manufactured by Kaken Tech) was used.

  For heat resistance evaluation, either of two types of flux cleaning liquids, Microclean WS-1014 (manufactured by Kaken Tech) and Microclean WS-1942 (manufactured by Kaken Tech), are used as the flux cleaning liquid. It was confirmed that good results were obtained.

  As for the presence or absence of pinholes, it was confirmed that good results were obtained when Microclean WS-1942 (manufactured by Kaken Tech) was used as the flux cleaning solution.

On the other hand, in Comparative Examples 1 and 2, it was confirmed that both the cleaning liquid absorption rate and the weight change rate after drying were large and the heat resistance was also poor.
Further, in the case of Comparative Examples 1 and 2, when the occurrence of pinholes on the resin mold component mounting substrate was examined, the occurrence of pinholes was observed, and it was confirmed that an undesirable result was obtained.

  As described above, in Comparative Examples 1 and 2, the unfavorable result is that the cross-linking point of the three-dimensional network cross-linking becomes rough because the main component constituting the resin composition uses a high molecular weight. This is because the flux cleaning liquid easily enters the space and remains.

  In addition, when a resin having a large molecular weight is used as the main component constituting the resin composition, since the glass transition point (Tg) is lowered, the resin is easily decomposed by heating, and the heating and drying conditions after flux cleaning are restricted. There is a problem.

  On the other hand, as in the present invention, when the main component constituting the resin composition is one having a low molecular weight (one having a molecular weight of 700 or less), the cross-linking points become dense, the residual cleaning liquid is small, and the cleaning resistance is high. Since the heat resistance and the thermal decomposition resistance during heat drying are improved, the occurrence of pinholes can be effectively prevented.

In the above embodiment, the case where the adsorption surface constituting resin portion 5 is formed in a region extending from the upper surface of one flange portion 2a to the upper surface of the other flange portion 2b has been described as an example. May be formed only in a region between the pair of flange portions 2a and 2b excluding the upper surface of the flange portion.
However, there is no particular restriction on the arrangement mode of the adsorption surface constituting resin portion 5, and the adsorption surface constituting resin portion 5 may be arranged so as to cover the entire winding 4 wound around the core portion 1. Is possible.

  In addition, this invention is not limited to the said Example, The kind and molecular weight of resin used as the main ingredient of a resin composition, the specific composition of a resin composition, the arrangement | positioning aspect of an adsorption surface structure resin part, magnetic Various applications and modifications can be made within the scope of the invention with respect to the shape of the core and the number of windings.

DESCRIPTION OF SYMBOLS 1 Core part 2a, 2b Eaves part 3 Magnetic core 4 Winding 5 Adsorption surface constituent resin part 5a Resin composition 6a, 6b External electrode 7 Adsorption surface 11 Circuit board 12 Land 13 Sealing resin A1 Winding coil component element A Winding Wire coil component B Resin mold component mounting board

Claims (4)

A magnetic core having a winding core and a pair of flanges disposed on both ends thereof;
A winding wound around the core portion of the magnetic core;
An external electrode to which both ends of the winding are electrically connected;
A winding provided with an adsorption surface constituting resin portion that is disposed so as to cover at least a part of the winding wound around the winding core portion and constitutes an adsorption surface when sucked and held by a vacuum suction method. A method of manufacturing a coil component,
A curable epoxy acrylate resin having a molecular weight of 700 or less or a resin composition based on an epoxy resin is applied and cured so as to cover at least a part of the winding wound around the winding core. Thus, the method for manufacturing a wound coil component is characterized in that the adsorption surface constituting resin portion is formed.   The method of manufacturing a wound coil component according to claim 1, wherein the adsorption surface constituting resin portion covers at least a part of the flange portion.   2. The method of manufacturing a wound coil component according to claim 1, wherein the method is used as a resin mold type module component which is mounted on a circuit board, cleaned and then sealed with a molding resin. Mounting the wound coil component according to any one of claims 1 to 3 on a circuit board;
Cleaning the circuit board;
Sealing the surface of the circuit board on which the winding coil component is mounted with a molding resin.

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