TWI470655B - Inductor and its manufacturing method - Google Patents

Description

Inductor and method of manufacturing same

The present invention relates to a first magnetic core that separates a magnetic core member into a housing portion having a coil and a second magnetic core as a cover body, and after the coil is housed in the first magnetic core, the second magnetic core and the second magnetic core An inductor formed by bonding a magnetic core and a method of manufacturing the same.

The coil-sealed core (inductor) 1 shown in FIG. 7 is compression-molded in a state in which the coil 3 is sealed inside the powder magnetic core 2. The powder magnetic core 2 is preferably a Fe-based amorphous alloy powder excellent in soft magnetic properties. However, since the Fe-based amorphous alloy powder has a large magnetostriction, in order to obtain the original performance of the amorphous powder, it is necessary to increase the molding pressure to increase the molding density, and it is necessary to perform annealing treatment at a high temperature to promote stress relaxation. . However, there is a problem in that the coil wire covering material is broken or thermally decomposed. Therefore, the molding pressure and the annealing temperature are restricted by the coil wire covering material.

On the other hand, as shown in the patent document, if a plurality of core members are formed and the coils are housed, the coil is sealed with a magnetic core as shown in FIG. According to the restriction, the core member can be molded at a high pressure and an optimum annealing temperature, and the original performance of the Fe-based amorphous alloy powder can be obtained.

However, even if a gap formed between the core member and the coil is filled with a resin, the gap is caused to deteriorate the characteristics. Therefore, a structure in which the magnetic powder is mixed and filled in the resin is disclosed in the following patent document.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 60-214510

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2000-182845

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-235773

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2005-175158

[Patent Document 5] Japanese Laid-Open Patent Publication No. 2008-218724

However, it is understood that when a Fe-based amorphous alloy powder having a large magnetostriction is used for the core member, the inductance L is lowered by the Young's modulus of the resin. In each of the patent documents, the Young's modulus of the resin is not particularly mentioned.

Therefore, the present invention has been made to solve the above-described problems, and an object of the invention is to provide an inductor which can obtain a high inductance L in particular, and a method in which a Young's modulus and a magnetic powder are appropriately filled together, and a method for manufacturing the same.

The inductor of the present invention is characterized by comprising: a coil; a core member comprising: a first magnetic core formed with a bottomed receiving portion for the coil; and a second magnetic core covering an opening side of the receiving portion; And a filling material, wherein a space between the accommodating portion and the second magnetic core located on an open end side of the accommodating portion is filled with a gap between the coil; and the magnetic core member is made of Fe-based Amorphous alloy powder and adhesive material are formed by compression molding, The filler is composed of a resin and a magnetic powder, and the Young's modulus of the resin is 0.1 GPa or more and 3.2 GPa or less, and the magnetic powder is contained in the filler in a range of 30% by volume or more and 60% by volume or less.

Further, a method of manufacturing an inductor according to the present invention is characterized in that the inductor includes: a coil; and a core member including a first core on which the bottom portion of the coil is formed and an opening side covering the housing portion And a filler material filling a gap between the accommodating portion and the second magnetic core located at an open end side of the accommodating portion in a substantially enclosed space; The Fe-based amorphous alloy powder and the bonding material are compression-molded to form the magnetic core member, and the resin having a Young's modulus of 0.1 GPa or more and 3.2 GPa or less is in a range of 30% by volume or more and 60% by volume or less. The magnetic material is mixed to form the filling material, the coil is housed in the housing portion of the first magnetic core, the filling material is filled in the opening side of the housing portion, and the second magnetic core is placed on the first magnetic core. The opening side of the core is joined between the first magnetic core and the second magnetic core.

As described above, the present invention is filled with a filling material in a space between the coil and the space surrounded by the housing portion formed in the first magnetic core and the second magnetic core. In this configuration, in order to obtain high In the present invention, the inductance L is defined as described above, and the content of the magnetic powder contained in the filler and the Young's modulus of the resin are specified. Thereby, the filling material can be appropriately maintained The fluidity is such that the filler material can appropriately flow between the core member and the coil, and a considerable amount of magnetic powder can be interposed in the gap between the core member and the coil. Further, even when a Fe-based amorphous alloy powder having a large magnetostriction is used for the magnetic core member, the internal stress of the filler itself can be reduced, and the stress acting on the core member can be reduced. According to the above, in the present invention, the improvement of the inductance L can be achieved. In particular, in the present invention, it is possible to obtain an inductance L that is higher than a coil-sealed core in which a magnetic core is compression-molded in a state in which a coil is sealed.

In the present invention, it is preferable that the magnetic powder is contained in the filler in a range of 40% by volume or more and 60% by volume or less. Thereby, a high inductance L can be obtained more efficiently.

Further, in the invention, it is preferable that the resin has a Young's modulus of 0.9 GPa or more and 3.2 GPa or less. Further, in the invention, it is preferable that the resin has a Young's modulus of 0.9 GPa or more and 1.5 GPa or less. Thereby, a high inductance L can be obtained more efficiently.

Preferably, the magnetic powder contained in the filler is Fe-based amorphous alloy powder. Thereby, high soft magnetic characteristics can be ensured, and a high inductance L can be obtained more efficiently.

Further, in the invention, it is preferable that the composition formula of the Fe-based amorphous alloy powder is represented by Fe _100-abcxyzt Ni _a Sn _b Cr _c P _x C _y B _z Si _t , and 0 at% a 10 at%, 0 at% b 3 at%, 0 at% c 6 at%, 6.8 at% x 10.8 at%, 2.0 at% y 9.8 at%, 0 at% z 8.0 at%, 0 at% t 5.0 at% Fe-based soft magnetic alloy powder.

In addition, the inductor of the present invention is characterized by comprising: a coil; a magnetic core structure And a first magnetic core formed with a bottomed storage portion for the coil and a second magnetic core covering an opening side of the storage portion; and a filling material in the storage portion and the storage portion a gap between the coil and the coil is filled in a substantially enclosed space between the second cores on the open end side, and the core member is formed by compression molding of a Fe-based amorphous alloy powder and a bonding material. The filler has a resin and a magnetic powder, and the Young's modulus of the resin is 3.2 GPa or more and 5.2 GPa or less, and the magnetic powder is contained in the filler in a range of 40% by volume or more and 55% by volume or less.

In the present invention, it is possible to obtain an inductance L that is higher than a coil-sealed core in which a magnetic core is compression-molded in a state in which a coil is sealed.

According to the inductor of the present invention and the method of manufacturing the same, a high inductance L can be obtained.

Fig. 1 is an exploded perspective view of the inductor of the embodiment.

As shown in FIG. 1, the inductor 10 includes a first magnetic core (forming body) 11, a coil 12, and a second magnetic core (cover) 13. The core member 14 is constituted by the first core 11 and the second core 13.

The core member 14 is a member obtained by compression-molding a Fe-based amorphous alloy (Fe-based metallic glass alloy) powder and a bonding material. In the present embodiment, the Fe-based amorphous alloy can be produced into a powder by, for example, a spray method, or It is produced in the form of a ribbon by a liquid quenching method.

The Fe-based amorphous alloy powder includes a substantially spherical shape or an ellipsoid shape. The Fe-based amorphous alloy powder is present in a plurality of magnetic cores, and is in a state of insulating each Fe-based amorphous alloy powder by a bonding material (adhesive resin).

Examples of the adhesive material include liquid or powdery resins or rubbers such as an epoxy resin, a polyoxyxylene resin, a polyoxyxylene rubber, a phenol resin, a urea resin, a melamine resin, a PVA (polyvinyl alcohol), and an acrylic resin. Or water glass (Na ₂ O-SiO ₂ ), oxide glass powder (Na ₂ OB ₂ O ₃ -SiO ₂ , PbO-B ₂ O ₃ -SiO ₂ , PbO-BaO-SiO ₂ , Na ₂ OB ₂ O ₃ -ZnO, CaO-BaO-SiO ₂ , Al ₂ O ₃ -B ₂ O ₃ -SiO ₂ , B ₂ O ₃ -SiO ₂ ), a glassy substance formed by a sol-gel method (with SiO ₂ , Al _{2 )} O ₃ , ZrO ₂ , TiO ₂ and the like are main components).

Further, as the lubricant, zinc stearate, aluminum stearate or the like may be added. The mixing ratio of the bonding material is 5% by mass or less, and the amount of the lubricant added is about 0.1% by mass to 1% by mass.

In the present embodiment, the first core 11 and the second core 13 can be individually compression-molded. Therefore, unlike the structure in which the coil is sealed in the magnetic core in the state shown in FIG. 7, the molding pressure and the annealing treatment are not restricted by the material of the coil wire coating, and high pressure can be formed. It is suitable for the annealing treatment at the temperature of the core material, so that the original performance of the Fe-based amorphous alloy can be appropriately achieved.

As shown in FIG. 1, a bottomed storage portion 11a for accommodating the coil 12 is formed on the first core 11. Here, the planar shape of the accommodating portion 11a is larger than the coil 12 Slightly larger, the height h1 of the side wall 11b of the accommodating portion 11a is slightly larger than the height h2 of the coil 12. Further, as shown in FIGS. 4 and 5, a notch portion 11c for accommodating the terminal portion 12b of the coil 12 is formed on the back surface of the first core 11.

The second magnetic core 13 is a cover body formed with a specific thickness, for example, the upper surface 13a and the lower surface 13b are formed by a flat surface.

The coil 12 is formed by winding a wire wound through an insulating film into a spiral shape. The coil 12 has a winding portion 12a and terminal portions 12b and 12b that are pulled out from the winding portion 12a. The number of windings of the coil 12 can be appropriately set according to the required inductance L. The coil 12 is an edgewise coil, and the cross-sectional area of each conductor can be increased as compared with the round wire coil, and the desired high inductance L can be obtained with a small number of turns. In addition, in the case where a higher inductance L is required, it is necessary to realize a larger number of turns of the twisted line through a narrow space, and therefore, in this case, a round line having a small cross-sectional area and effective application of a space can be used. Coil.

FIG. 2 shows a state in which the coil 12 shown in FIG. 1 is placed in the housing portion 11a of the first core 11. 4 is a longitudinal cross-sectional view showing the middle of the inductor cut in the height direction along the line A-A of FIG. 2 and viewed from the direction of the arrow, and particularly showing the state in which the filler 16 is filled.

The filler 16 shown in FIG. 4 is composed of a resin 17 and a magnetic powder 18 . Further, in FIGS. 4 and 5, the magnetic powder 18 in the filler 16 is schematically indicated by black dots.

In the first embodiment, the resin 17 having a Young's modulus of 0.1 GPa or more and 3.2 GPa or less is used. Further, the filling amount of the magnetic powder 18 contained in the filler 16 is set to 30% by volume or more and 60% by volume or less.

As shown in FIG. 4, the filler material 16 flows into the gap a between the coil 12 and the side wall 11b of the accommodating portion 11a constituting the first core 11. Further, as shown in FIG. 4, the inside of the accommodating portion 11a is filled with the filling material 16, the upper surface and the lower surface of the coil 12 are covered with the filling material 16, and the filling material 16 is also applied to the upper surface 11d of the first magnetic core 11. In this way, by covering the periphery of the coil 12 with the filler material 16, the sound and vibration of the inductor can be prevented.

The resin 17 can be preferably applied to an epoxy resin having a Young's modulus of 0.1 GPa or more and 3.2 GPa or less and a polyoxyxylene resin. Further, the magnetic powder 18 may have a crystallinity such as ferrite, but the magnetic powder 18 is preferably represented by, for example, a composition formula of Fe _100-abcxyzt Ni _a Sn _b Cr _c P _x C _y B _z Si _t , and 0 at% a 10 at%, 0 at% b 3 at%, 0 at% c 6 at%, 6.8 at% x 10.8 at%, 2.0 at% y 9.8 at%, 0 at% z 8.0 at%, 0 at% t 5.0 at% Fe-based amorphous alloy powder.

The Fe-based amorphous alloy powder as described above is a metallic glass obtained by adding Fe and Ni, Sn, Cr, P, C, B, and Si as main components to the above composition ratio. The Fe-based amorphous alloy powder is amorphous and has a glass transition point (Tg), and has excellent soft magnetic properties.

The magnetic powder 18 contained in the filler 16 is preferably of the same type as the Fe-based amorphous alloy constituting the core member 14. Here, the same type refers to the same powder (a powder produced by the same manufacturing process or a composition which is substantially the same even if the process is different), or a different powder (different composition) but a saturation magnetic flux density Bs or The basic characteristics required for the core of an inductor such as a magnetic permeability are substantially equal. However, the magnetic powder 18 contained in the filler 16 may be a material having a small magnetostriction such as an Fe-Ni alloy or an Fe-Al-Si alloy. in In this case, it is possible to suppress a change in magnetic characteristics caused by environmental changes such as temperature and humidity, and it is possible to have a preferable structure depending on the application to be used.

As shown in FIG. 4, after the filling material 16 is filled into the first magnetic core 11, as shown in FIGS. 3 and 5, the second magnetic core 13 is superposed on the first magnetic core 11 via the filling material 16. In addition, FIG. 5 is a longitudinal cross-sectional view taken along the line B-B shown in FIG. 4 in the height direction and viewed from the direction of the arrow, and shows a state in which the terminal portion 12b shown in FIG. 3 is bent.

As shown in FIG. 5, the filling material 16 fills the gap a with the coil 12 in the substantially enclosed space 15 between the bottomed housing portion 11a and the second core 13 on the open end 11a1 side of the housing portion 11a. . Here, as shown in FIG. 5, a filler 16 and a resin 17 are provided between the upper surface 11d of the first core 11 and the second core 13, so that there is a slight gap, and the second portion of the terminal portion 12b There is also a slight gap in the lead portion of a magnetic core 11. Therefore, the "space surrounded by the space" does not mean a space completely surrounded between the accommodating portion 11a and the second core 13, and may have a gap as described above (the upper surface 11d and the second surface of the first core 11) Between the magnetic cores 13).

In the present embodiment, after the second core 13 is superposed on the first core 11 via the filler 16, heat treatment is performed to thermally cure the resin 17 constituting the filler 16. Thereby, the first magnetic core 11 and the second magnetic core 13 can be joined. Further, the temperature of the heat treatment mentioned here is lower than the temperature of the annealing treatment for relaxing the stress when the core member 14 is molded, and is a temperature which does not adversely affect the coil wire coating material. In addition, since the temperature of the heat treatment applied to the coil wire covering material is lower than before, Therefore, the material used as the coil wire covering material can be replaced with an inexpensive material having low heat resistance, and the production cost can be reduced.

Moreover, the terminal portion 12b shown in FIG. 3 is bent downward, and as shown in FIG. 5, the terminal portion 12b is accommodated in the notch portion 11c formed on the back surface of the first core 11.

As described above, in the first embodiment, the filling amount of the magnetic powder 18 contained in the filler 16 is set to 30% by volume or more and 60% by volume or less in the filler 16, and 0.1 GPa or more and 3.2 GPa or less are used. The Young's modulus of the resin 17. Thereby, the filling material 16 can be appropriately caused to flow into the narrow space between the first core 11 and the coil 12 while ensuring the fluidity of the filler material 16, and the gap between the core member 14 and the coil 12 can be obtained. A considerable amount of magnetic powder 18 is interposed. As shown in FIG. 5, the filling material 16 fills the gap a with the coil 12 in the substantially enclosed space 15 between the bottomed housing portion 11a and the second core 13 on the open end 11a1 side of the housing portion 11a. . Since the filler 16 is filled in the space 15 thus surrounded, the filler 16 can be held in the space 15 even in a state where the Young's modulus is relatively low, so that it can be applied with a lower limit of 0.1 GPa. Young's modulus of resin 17.

Further, when the filling amount of the magnetic powder 18 is increased, the fluidity of the filler 16 is lowered and the gap a cannot be appropriately filled, so the upper limit is made 60% by volume.

In the present embodiment, when the Fe-based amorphous alloy powder having a large magnetostriction is used for the core member and the Fe-based amorphous alloy powder is also used as the filler 16, the filler 16 itself can be reduced. Internal stress, from The stress acting on the core member 14 can be reduced.

According to the above, in the present embodiment, the improvement of the inductance L can be achieved. In particular, in the present embodiment, the filling amount of the magnetic powder 18 contained in the filler 16 is set to 30% by volume or more and 60% by volume or less in the filler 16, and further, 0.1 GPa or more and 3.2 GPa or less are used. As shown in the test results described later, the resin 17 of the Young's modulus can obtain an inductance L higher than that of the coil-sealed core in which the magnetic core is compression-molded in a state in which the coil is sealed.

The filling rate of the magnetic powder 18 contained in the filler 16 is preferably 40% by volume or more and 60% by volume or less, more preferably 45% by volume or more and 60% by volume or less, or 40% by volume or more and 55% by volume or less. More preferably, it is 45 volume% or more and 55 volume% or less. Thereby, the improvement of the inductance L can be realized more effectively.

Moreover, it is preferable to set the Young's modulus of the resin 17 to 0.9 GPa or more and 3.2 GPa or less. Furthermore, it is more preferable to set the Young's modulus of the resin 17 to 0.9 GPa or more and 1.5 GPa or less. In addition, it is thereby possible to more effectively achieve an improvement in the inductance L.

In addition, in the second embodiment, the amount of the magnetic powder 18 contained in the filler 16 is 40% by volume or more and 55% by volume or less of the filler 16, and Young's having 3.2 GPa or more and 5.2 GPa or less is used. Modulus resin 17. When the Young's modulus of the resin 17 and the filling rate of the magnetic powder 18 become high, the filler 16 cannot properly flow into the gap a between the coil 12 and the inductance L is lowered. In the test described later, by adjusting to the Young's modulus and the filling amount described above, it is possible to obtain a pressure in a state in which a coil is enclosed. The coil formed by shrinking the core is sealed with a higher inductance L of the core.

[Examples]

Hereinafter, an inductor which is a structure of FIG. 5 (completed sectional view) of the embodiment is manufactured.

The same powder is used for the core member 14 of the inductor and the Fe-based amorphous alloy powder contained in the filler 16. The Fe-based amorphous alloy powder used in the test was produced by a water spray method and had a composition of Fe _71.4 Ni ₆ Cr ₂ P _10.8 C _7.8 B ₂ . The Fe-based amorphous alloy powder was mixed with 3% by mass of the acrylic resin and 0.3% by mass of the lubricant (zinc stearate), and the pressing force was set to 1471 MPa, and the annealing temperature was set to about 350 ° C. The holding time was set to 1 hour, and the first magnetic core 11 including the housing portion 11a and the second magnetic core 13 as a cover were formed. The obtained first core 11 has a lateral dimension, a longitudinal dimension, and a height dimension of 10 mm, 10 mm, and 3.19 mm, respectively. In addition, the lateral size, the longitudinal dimension, and the height dimension of the second core 13 are 10 mm, 10 mm, and 0.61 mm, respectively. As shown in FIG. 4, the housing portion 11a constituting the first core 11 is formed such that the side wall 11b is slightly higher than the coil 12 when the coil 12 is housed. The gap a between the coil 12 and the side wall 11b shown in Fig. 4 is about 0.03 to 0.07 mm.

Further, the resin constituting the filler 16 is an epoxy resin having a Young's modulus E of 0.9 GPa (sample 1 in Table 1 below) and an epoxy resin having a Young's modulus E of 1 GPa (hereinafter, Table 1) 1 is a sample 2), an epoxy resin having a Young's modulus E of 1.4 GPa (sample 3 in Table 1 below), and an epoxy resin having a Young's modulus E of 1.5 GPa (in Table 1 below) It is a sample 4), an epoxy resin having a Young's modulus E of 3.2 GPa (sample 5 in Table 1 below), and a Young's modulus E of 4.9. GPa epoxy resin (sample 6 in Table 1 below), epoxy resin having Young's modulus E of 5.15 GPa (sample 7 in Table 1 below), and Young's modulus E of 5.6 GPa Epoxy resin (sample 8 in Table 1 below). Further, the Young's modulus of the resin can be appropriately adjusted by using a polyoxyl resin other than the above epoxy resin, or adding various additives to the resin, or adding a fine filler as needed.

In the test, in the state of Fig. 5, the sample 1 was subjected to a heat treatment at 100 ° C for 3 hours, and the sample 3 was hardened at 70 ° C for 1 hour and hardened at 150 ° C for 5 hours, and the sample 6 was sampled. The heat treatment was carried out at 120 ° C for 20 minutes to thermally cure the resin 17 of the filler material 16. The other sample is thermally hardened at 50 ° C to 150 ° C for 20 minutes to 3 hours, and further cured at 70 ° C to 150 ° C for 2 hours to 5 hours as needed.

The reference value of the inductance L is the inductance L enclosed in the core using the coil shown in FIG. The Fe-based amorphous alloy powder used for encapsulating the coil in the core was made of the same composition as Fe _71.4 Ni ₆ Cr ₂ P _10.8 C _7.8 B _{2 described} above. In the Fe-based amorphous alloy powder, 2% by mass of the acrylic resin and 0.3% by mass of the lubricant (zinc stearate) were mixed, and the pressing force was set to 590 MPa, and the annealing temperature was set to about 350 ° C. The holding time was set to 1 hour, and a coil was formed to enclose the core. The obtained coils are enclosed in a core having a lateral dimension, a longitudinal dimension and a height dimension of 10 mm, 10 mm, and 3.8 mm, respectively.

Further, the coils used in the test were all flat coils having the same number of turns and sizes in the embodiment of Fig. 5 and the comparative example of Fig. 7.

The inductance L was measured using a HEWLETT PACKARD 4285A at a frequency of 100 kHz and a measurement signal voltage of 10 mA.

In the test using the inductor of the embodiment shown in FIG. 5, the above plurality of resins were used, and the filling ratio r of the magnetic powder contained in the filler was changed to 0% by volume, 20% by volume, 30% by volume, 40. The inductance L was measured by volume%, 45 volume%, 50 volume%, 55 volume%, and 60 volume%.

The measurement results are shown in Table 1 and Figure 6 below.

In Fig. 6, the horizontal axis represents the Young's modulus of the resin, and the vertical axis represents the inductance L. Further, Fig. 6 is divided into Fig. 6 (a) and Fig. 6 (b). 6(a) and 6(b) are graphs showing the results of the test, but the range of application of the Young's modulus is set to a different range. In addition, the test results are described below using FIG. 6(a).

As shown in Fig. 6 (a) and Table 1, when the Young's modulus E of the resin is 1 GPa and 1.4 GPa, the filling ratio of the magnetic powder is 30% by volume or more, and a specific reference value can be obtained. (Ref) Large inductance L. In the test, the maximum value of the filling rate of the magnetic powder was 60% by volume, but if the filling ratio was larger than this, the fluidity of the filler was lowered.

When the Young's modulus E of the resin is 4.9 GPa, if the filling ratio of the magnetic powder is 60% by volume, the inductance L is drastically lowered. When the filling ratio is 60% by volume and the Young's modulus E of the resin is 0.9 GPa to 3.2 GPa, the increasing tendency of the inductance L is found by increasing the filling rate of the magnetic powder, but the Young's modulus E of the resin is set. In the test of 4.9 GPa, this trend may not be seen. Further, when the Young's modulus E of the resin is increased to 4.9 GPa, when the filling ratio of the magnetic powder is 0% by volume, 20% by volume, 30% by volume, and 60% by volume, the inductance L is larger than the reference value ( Ref) is low.

The magnetostriction of the Fe-based amorphous alloy powder contained in the magnetic core and the filler is large. Specifically, it has a magnetostriction λs of about 10 × 10 ^-6 to 27 × 10 ^-6 . Therefore, when a resin having a high Young's modulus is used, the internal stress in the filler increases, and the stress acting on the core member increases. As shown in FIG. 5, since the space 15 is filled in the space 15 surrounded by the filler 16, it is important to ensure the fluidity of the filler 16 and to reduce the internal stress in order to obtain a high inductance L.

Furthermore, as shown in Fig. 6 (a), when the filling ratio of the magnetic powder is 30% by volume or more and 60% by volume or less, the inductance L exceeds the reference value by setting the Young's modulus of the resin to 3.2 GPa or less. (Ref).

Further, the lower limit of the Young's modulus of the resin was set to 0.1 GPa. Even if the lower limit of the Young's modulus is reduced to about 0.1 GPa, as shown in Fig. 5, the coil 12 can be held in the substantially enclosed space 15, and the terminal portion 12b shown in Fig. 3 can be As shown in Fig. 5, it is appropriately bent to the notch portion 11c on the back surface. Therefore, the lower limit of the Young's modulus of the resin is set to 0.1 GPa or more.

In the present embodiment, the filling rate of the magnetic powder contained in the filler is 30% by volume or more and 60% by volume or less, and the Young's modulus of the resin is set to 0.1 GPa or more and 3.2 GPa or less. It can be seen that an inductance L larger than the reference value (Ref) can be obtained.

In addition, it is understood that the inductance L larger than the reference value can be obtained more reliably by setting the filling ratio of the magnetic powder to 40% by volume or more. In addition, it is estimated that the inductance L larger than the reference value can be obtained more effectively by setting the filling ratio of the magnetic powder to 55 vol% or less or 45 vol% or more.

In view of the above, it is preferable to set the filling ratio of the magnetic powder to 40% by volume or more and 60% by volume or less, more preferably 45% by volume or more and 60% by volume or less, or 40% by volume or more and 55% by volume or less. More preferably, it is 45 volume% or more and 55 volume% or less.

Further, it is preferable to set the Young's modulus of the resin to 0.9 GPa or more and 3.2 GPa or less. Further, it is more preferable to set the Young's modulus of the resin to 0.9 GPa or more and 1.5 GPa or less. It can be seen that the inductance L larger than the reference value (Ref) can be obtained more effectively.

As shown in Fig. 6 (a), when the Young's modulus E of the resin is 0.9 GPa or more and 1.5 GPa or less, and the filling ratio of the magnetic powder is 40% by volume or more and 60% by volume or less, about 0.47 is obtained. The inductance L of μH or more can obtain an inductance L that is 0.1 μH or more higher than the reference value (E=0.366 μH).

Next, as shown in FIG. 6(b), the range of the Young's modulus different from that of FIG. 6(a) is defined.

In Fig. 6(b), the Young's modulus of the resin is set to be 3.2 GPa or more and 5.2 GPa or less. Further, the filling rate of the magnetic powder is set to 40% by volume or more and 55 A range of volume % or less. It can be seen that an inductance L higher than the reference value (E=0.366 μH) can be obtained.

10‧‧‧Inductors

11‧‧‧First core

11a‧‧‧Storage Department

12‧‧‧ coil

12a‧‧‧Winding Department

12b‧‧‧Terminal Department

13‧‧‧Second magnetic core

14‧‧‧ magnetic core components

16‧‧‧Filling materials

17‧‧‧Resin

18‧‧‧Magnetic powder

Fig. 1 is an exploded perspective view of the inductor of the embodiment.

Fig. 2 is a perspective view showing a state in which a coil is housed in the first magnetic core shown in Fig. 1;

3 is a perspective view of the inductor in a state in which the filling material is filled in the state of FIG. 2 and the second core is placed on the first core.

Fig. 4 is a longitudinal cross-sectional view showing the inductor in a state in which the filling material is filled from the state of Fig. 2.

Fig. 5 is a longitudinal cross-sectional view showing the inductor in a state in which the second magnetic core is joined to the upper surface of the first magnetic core via the filling material from the state of Fig. 4.

Fig. 6(a) is a graph showing the relationship between the Young's modulus of the resin constituting the filler and the inductance L, and shows a first embodiment in which the range of Young's modulus is 0.1 GPa to 3.2 GPa.

Fig. 6(b) is a graph showing the relationship between the Young's modulus of the resin constituting the filler and the inductance L, and shows a second embodiment in which the range of the Young's modulus is set to 3.2 GPa to 5.2 GPa.

Fig. 7 is a plan view showing a core in which a magnetic core is compression-molded in a state in which a coil is sealed.

Claims (9)

An inductor comprising: a coil; a core member comprising: a first core formed with a bottomed receiving portion for the coil; and a second core covering an opening side of the receiving portion; and a filling material filling a gap between the accommodating portion and the second magnetic core located at an open end side of the accommodating portion in a substantially enclosed space; the magnetic core member is made of Fe-based When the amorphous alloy powder and the adhesive material are compression-molded, the filler has a resin and a magnetic powder, and the resin has a Young's modulus of 1 GPa or more and 3.2 GPa or less, and 30% by volume of the filler. The above magnetic powder is contained in the range of 60% by volume or less. An inductor comprising: a coil; a core member comprising: a first core formed with a bottomed receiving portion for the coil; and a second core covering an opening side of the receiving portion; and a filling material filling a gap between the accommodating portion and the second magnetic core located at an open end side of the accommodating portion in a substantially enclosed space; the magnetic core member is made of Fe-based Amorphous alloy powder and bonding material pressure In the shrinkage molding, the filler is composed of a resin and a magnetic powder, and the Young's modulus of the resin is 0.9 GPa or more and 3.2 GPa or less, and the filler is contained in a range of 45 vol% or more and 60 vol% or less. The above magnetic powder. The inductor according to claim 1, wherein the magnetic powder is contained in a range of 40% by volume or more and 60% by volume or less in the above filler. The inductor according to claim 1 or 2, wherein the resin has a Young's modulus of 1 GPa or more and 1.5 GPa or less. An inductor comprising: a coil; a core member comprising: a first magnetic core formed with a bottomed receiving portion for the coil; and a second magnetic core covering an opening side of the receiving portion; and a filling material which fills a gap between the accommodating portion and the second magnetic core located on the open end side of the accommodating portion and is surrounded by the coil; the magnetic core member is made of Fe-based When the amorphous alloy powder and the adhesive material are compression-molded, the filler is composed of a resin and a magnetic powder, and the Young's modulus of the resin is 3.2 GPa or more and 5.2 GPa or less, and 40% by volume of the filler. The above magnetic powder is contained in the range of % or more and 55 vol% or less. The inductor according to any one of the items 2, wherein the magnetic powder contained in the filler is Fe-based amorphous alloy powder. The inductor of claim 6, wherein the composition of the Fe-based amorphous alloy powder is represented by Fe _100-abcxyzt Ni _a Sn _b Cr _c P _x C _y B _z Si _t , and 0 at% a 10at%, 0at% b 3at%, 0at% c 6at%, 6.8at% x 10.8at%, 2.0at% y 9.8at%, 0at% z 8.0at%, 0at% t 5.0 at% Fe-based soft magnetic alloy powder. A method of manufacturing an inductor, characterized in that the inductor includes: a coil; and a core member including a first core formed with a bottomed storage portion of the coil and an opening side covering the storage portion And a filler material, wherein a gap between the accommodating portion and the second magnetic core located at an open end side of the accommodating portion is filled in a space substantially surrounded by the coil; The Fe-based amorphous alloy powder and the adhesive material are compression-molded to form the magnetic core member, and the magnetic powder is mixed in a range of 30% by volume or more and 60% by volume or less to a resin having a Young's modulus of 1 GPa or more and 3.2 GPa or less. And forming the filler, the coil is housed in the housing portion of the first core, and the filler is filled in the opening side of the housing portion, and the second core is placed on the first core. The opening side is joined between the first magnetic core and the second magnetic core. A method of manufacturing an inductor, characterized in that the inductor includes: a coil; and a core member including a first core formed with a bottomed storage portion of the coil and an opening side covering the storage portion And a filler material, wherein a gap between the accommodating portion and the second magnetic core located at an open end side of the accommodating portion is filled in a space substantially surrounded by the coil; The Fe-based amorphous alloy powder and the bonding material are compression-molded to form the magnetic core member, and the magnetic material is mixed in a range of 40% by volume or more and 55 % by volume or less in a resin having a Young's modulus of 3.2 GPa or more and 5.2 GPa or less. The filler is formed by the powder, the coil is housed in the housing portion of the first core, and the filler is filled in the opening side of the housing portion, and the second core is placed on the first core. The opening side is joined to the first magnetic core and the second magnetic core.