CN110718359A

CN110718359A - Manufacturing structure and method of surface-mounted integrally-formed inductor

Info

Publication number: CN110718359A
Application number: CN201911090216.0A
Authority: CN
Inventors: 庄仲郑; 王丹娜
Original assignee: Shantou Xinji Electronic Technology Co Ltd
Current assignee: Shantou Xinji Electronic Technology Co Ltd
Priority date: 2019-11-08
Filing date: 2019-11-08
Publication date: 2020-01-21

Abstract

The invention relates to a manufacturing structure and a method of a surface-mounted integrally-formed inductor. In a forming die, two groups of pressing plate main bodies are respectively placed right above and right below a built-in coil, the pressing surface of each pressing plate main body needs to face the built-in coil, two poles of the built-in coil need to respectively exceed the range of two end parts of each pressing plate main body, and the two groups of pressing plate main bodies and the built-in coil are integrally formed into a blank body by adopting pressurization or heating. Two poles of the built-in coil are exposed outside the blank after molding, and external electrodes are formed at two ends of the blank. The inductor manufactured by the invention has good blank coverage, almost has no leakage magnetic flux, can increase the size of the coil to the maximum extent, improve Isat and reduce Rdc, and can reduce the damage to the pressing plate main body and reduce the size of the inductor by combining the shape of the pressing plate main body.

Description

Manufacturing structure and method of surface-mounted integrally-formed inductor

Technical Field

The invention belongs to the technical field of manufacturing surface-mounted inductors, and particularly relates to a manufacturing structure and a manufacturing method of a surface-mounted integrally-formed inductor.

Background

At present, a coil surface-mount inductor formed of a sealing material made of magnetic powder and resin has been widely used in the industry, and this field emphasizes the Isat value of direct current superimposed current and the Rdc value of DC resistance, and requires that the higher Isat value and the lower Rdc value are required as the Isat value becomes higher and the smaller size becomes, and therefore, it is required to increase the size of a built-in coil while reducing leakage flux and to secure the coil in the middle of the whole body with a small outer size.

As in the patent literature: japanese patent No. 4714779 discloses a manufacturing method using an E-type tablet in which a coil formed by winding a copper wire is placed on an E-type flat plate, and both end portions of the coil are placed outside the outer wall of the flat plate, and then the coil and the flat plate are placed in a molding die so as to be sandwiched between the inner walls of the molding die, and a green body is formed by resin molding or powder molding. Although this method can ensure the coil to be centered, as shown in fig. 4, the thickness of the outer wall of the E-shaped plate needs to be at least 0.1 to 0.15mm or more because the formed E-shaped plate needs to maintain its wrapping property and durability, and if the size of the surface mount inductor is smaller, it is not negligible that the outer wall of the E-shaped plate cannot be reduced, so that the built-in coil can only be reduced, and the Rdc value cannot be reduced;

as another example, patent document: japanese patent No. 6060116 discloses a manufacturing method using a flat sheet shape, which employs a flat sheet type instead of an E-shaped flat sheet to increase the size of a built-in coil, as shown in fig. 5, but this method cannot fix the coil position when molding in a mold, and the resulting blank is not balanced in left and right directions, and the coil is exposed and generates more leakage flux, and the final product cannot achieve the best uniformity.

Disclosure of Invention

The invention aims to provide a manufacturing structure of a surface-mounted integrally-formed inductor and a method thereof aiming at the prior technical situation, wherein the upper and lower pressing plate main bodies are utilized to complete positioning and cover the whole coil, the formed blank has almost no leakage magnetic flux, the coil can be enlarged to the maximum extent, and high Isat and low Rdc are obtained.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a surface mounting integrated into one piece inductor's manufacture structure, built-in coil has, two sets of clamp plate main parts are located built-in coil upper and lower side respectively, the clamp plate main part has the pressfitting face, both sides have the arch, form the form that both sides are high, the centre is low, the both ends of built-in coil have and expose the copper line as the electrode, and the electrode part surpasss clamp plate main part both ends, the both sides of built-in coil then correspond the bellying of pressfitting face, through the mould pressfitting, upper and lower two sets of clamp plate main parts accomplish parcel and the packing to built-in coil.

As a structural form, the two sides of the pressing surface are horn-shaped bulges, and the middle of the pressing surface is flat.

As a structural form, both sides and the middle of the pressing surface form an inwards concave cambered surface.

As a structural form, the angular bulges at the two sides of the pressing surface extend to the middle part to be combined to form an inward concave included angle.

Further, as a small-sized inductor, the distance between the side surface of the outer diameter of the built-in coil and the outer surface of the side of the green body may be less than 0.15 mm.

The invention relates to a method for manufacturing a surface-mounted integrally-formed inductor, which specifically comprises the following steps:

(1) pre-rolling a hollow built-in coil;

(2) preforming a mixture of magnetic powder and thermosetting resin into two groups of completely same pressing plate main bodies, wherein the pressing plate main bodies are provided with pressing surfaces, and the pressing surfaces are high at two sides and low in the middle;

(3) in a forming die, two groups of pressing plate main bodies are respectively placed right above and right below a built-in coil, the pressing surface of each pressing plate main body faces the built-in coil, two poles of the built-in coil need to respectively exceed the range of two end parts of each pressing plate main body, and then the two groups of pressing plate main bodies and the built-in coil are integrally formed into a blank body by adopting pressurization or heating;

(4) after the two poles of the built-in coil are exposed outside the blank body after molding, and after insulators of the two poles are removed, external electrodes are formed at two ends of the blank body.

The invention has the beneficial effects that: adopt the coil that the coiling copper line formed and the sealing material that contains magnetic material and resin, integrated into one piece has the sealed blank of coil in the middle of, in the forming process, because the coil obtains the location parcel of clamp plate main part, not only make magnetic powder flow under the drive of thermosetting resin, realize filling and the parcel to the coil, simultaneously under the restriction of mould, can make the side of coil external diameter and the formation blank side outer wall thickness minimization, magnetic leakage flux has been reduced, the area proportion of built-in coil has been increased, be fit for the production of small-size inductor, its manufacturing cost is lower.

Description of the drawings:

FIG. 1 is a view showing a molding structure of a first embodiment of the present invention;

FIG. 2 is a view showing a molding structure of a second embodiment of the present invention;

FIG. 3 is a view showing a molding structure of a third embodiment of the present invention;

FIG. 4 is a cross-sectional view of the resin flow within the forming die during the practice of the present invention;

FIG. 5 is a process diagram of the surface mount inductor molding of Japanese patent No. 4714779;

fig. 6 is a process diagram of the surface mount inductor molding in japanese patent No. 6060116.

The specific implementation mode is as follows:

please refer to fig. 1 to 4, which are schematic structural diagrams illustrating a preferred embodiment of the present invention, the present invention is a manufacturing structure of a surface mount integrated inductor and a method thereof, the structure includes a built-in coil 1 and two sets of pressing plate main bodies 2, the two sets of pressing plate main bodies 2 are respectively located above and below the built-in coil 1, the pressing plate main bodies 2 have a pressing surface, both sides of the pressing plate main bodies have protrusions to form a shape with a high side and a low middle, both ends of the built-in coil 1 have exposed copper wires as electrodes, and the electrodes partially exceed both ends of the pressing plate main bodies 2, so that the electrodes of the built-in coil 1 can be exposed after pressing, both sides of the built-in coil 1 correspond to the protrusions of the pressing surface, so that during pressing, the upper and lower pressing plate main bodies 2 can complete wrapping and filling of the built.

(1) pre-coiling a hollow built-in coil 1;

(2) preforming a mixture of magnetic powder and thermosetting resin into two groups of completely identical pressing plate main bodies 2, wherein the pressing plate main bodies 2 are provided with pressing surfaces 21, and the pressing surfaces 21 are embodied as high at two sides and low in the middle;

(3) in a forming die, two groups of pressing plate main bodies 2 are respectively placed right above and right below an internal coil 1, a pressing surface 21 of each pressing plate main body 2 needs to face the internal coil 1, two poles of the internal coil 1 need to respectively exceed the range of two end parts of each pressing plate main body 2, and then the two groups of pressing plate main bodies 2 and the internal coil 1 are integrally formed into a blank body by adopting pressurization or heating;

(4) two poles of the built-in coil 1 are exposed outside the blank after molding, and external electrodes are formed at two ends of the blank after insulators of the two poles are removed.

In specific implementation, the upper and lower pressing plate main bodies 2 must be opposite to each other in terms of the pressing surfaces 21, the built-in coil 1 is arranged between the two pressing plate main bodies 2, two side surfaces of the built-in coil 1, which do not include electrodes, need to correspond to two protruding sides of the pressing plate main bodies 2, and the two pole end parts of the built-in coil 1 should exceed two end parts of the pressing plate main bodies 2, so that the two poles of the coil can be positioned outside a blank body after the two pole end parts.

The upper and lower pressing plate main bodies 2 have the functions of positioning, wrapping and filling, so the shapes of the upper and lower pressing plate main bodies 2 are necessarily the same and are opposite, and the pressing surface 21 of the pressing plate main body 2 can have several forms:

in the first embodiment, as shown in fig. 1, the pressing surface 21 of the pressing plate body 2 has two sides formed with angular protrusions and a flat middle.

In the second embodiment, as shown in fig. 2, two sides and the middle of the pressing surface 21 form an inward-concave arc surface.

In the third embodiment, as shown in fig. 3, the corner-like protrusions on both sides of the pressing surface 21 extend to the middle part to form an inward concave included angle.

Isat and Rdc are preferable if the built-in coil 1 is as large as possible, so that the outer diameter of the coil can be kept small from the inner dimension of the mold, and as a small-sized inductor, the length of the side of the outer diameter of the built-in coil from the outer surface of the side of the billet can be less than 0.15 mm.

The thermosetting resin may be a hot air epoxy resin having a temperature resistance level of 220 c, and by molding with the resin, the protrusions corresponding to the press-fit surfaces on the side surfaces of the coil flow between the side surfaces of the coil and the inner wall of the mold, and even if the coil is enlarged, a molded body in which the entire coil is covered with the resin can be formed.

It should be understood that the above-mentioned drawings are merely illustrative of the preferred embodiments of the present invention, and that the scope of the invention is not limited thereto.

Claims

1. The utility model provides a surface mounting integrated into one piece inductor's manufacture structure which characterized in that: the coil pressing device is provided with a built-in coil and two groups of pressing plate main bodies, wherein the two groups of pressing plate main bodies are respectively positioned above and below the built-in coil, the pressing plate main bodies are provided with pressing surfaces, two sides of each pressing plate main body are provided with bulges to form a shape with a high two sides and a low middle part, two ends of the built-in coil are provided with exposed copper wires serving as electrodes, the electrode parts exceed two ends of the pressing plate main bodies, two sides of the built-in coil correspond to the bulges of the pressing surfaces, and the upper and lower groups of pressing plate main bodies wrap and fill the built-in.

2. The structure of claim 1, wherein: the two sides of the pressing surface are horn-shaped bulges, and the middle of the pressing surface is flat.

3. The structure of claim 1, wherein: the two sides and the middle of the pressing surface form an inwards concave cambered surface.

4. The structure of claim 1, wherein: the hornlike bulges at the two sides of the pressing surface extend to the middle part to be combined to form an inward concave included angle.

5. The structure for manufacturing a surface-mount integrated inductor according to any one of claims 1 to 4, wherein: and the distance between the side surface of the external diameter of the built-in coil and the external surface of the side of the blank body is less than 0.15 mm.

6. A manufacturing method of a surface-mounted integrally-formed inductor is characterized in that: the method specifically comprises the following steps:

(1) pre-rolling a hollow built-in coil;