A manufacturing structure and method of a surface mounted integrated inductor

Abstract

The present invention is a manufacturing structure and method of a surface mounted integrally formed inductor, which has the characteristics of using a mixture of magnetic powder and thermosetting resin to preform two groups of completely identical pressing plate bodies, the pressing plate bodies having a pressing surface, and the pressing surface is specifically high on both sides and low in the middle. In the forming mold, the two groups of pressing plate bodies are placed directly above and directly below the built-in coil, respectively, the pressing surface of the pressing plate body needs to face the built-in coil, and the two poles of the built-in coil need to exceed the two end ranges of the pressing plate body respectively, and the two groups of pressing plate bodies and the built-in coil are formed into a blank by pressurization or heating. After forming, the two poles of the built-in coil are exposed outside the blank, and external electrodes are formed at both ends of the blank. The inductor manufactured by the present invention has good blank coverage and almost no leakage flux, which can maximize the coil size, improve Isat and reduce Rdc. Combined with the shape of the pressing plate body, it can reduce damage to the pressing plate body and reduce the size of the inductor.

Description

Technical Field

[0001] The invention belongs to the technical field of manufacturing surface mounted inductors, and particularly relates to a manufacturing structure and method of a surface mounted integrated inductor. Background Art

[0002] At present, the industry has widely used sealing materials made of magnetic powder and resin to form inductors with coil surface mounts. This field emphasizes the Isat value of the DC superposition current and the Rdc value of the DC resistance, and requires that the Isat value must be higher while the size is getting smaller and smaller. The higher the Isat value, the lower the Rdc value is required. Therefore, it is necessary to reduce the leakage flux while increasing the size of the built-in coil in a small size, and ensure that the coil is in the middle of the whole.

[0003] For example, the patent document: Japanese Patent No. 4714779 discloses a manufacturing method using an E-type tablet, in which a surface mount inductor is formed by placing a coil formed by winding a copper wire on an E-type flat plate, and placing both ends of the coil outside the outer wall of the flat plate, and then placing the coil and the flat plate in a molding die so that they are sandwiched between the inner walls of the molding die, and forming a blank by resin molding or powder molding. Figure 4 As shown, although this method can ensure that the coil is centered, the E-shaped plate needs to maintain its wrapping and durability, so the thickness of its outer wall needs to be at least 0.1 to 0.15 mm or even larger. If the size of the surface mount inductor is smaller, the fact that the outer wall of the E-shaped plate cannot be reduced cannot be ignored, resulting in the built-in coil can only be reduced, and the Rdc value cannot be reduced.

[0004] Another example is the patent document: Japanese Patent No. 6060116, which discloses a manufacturing method using a flat sheet, which uses a flat sheet shape instead of an E-shaped plate to increase the size of the built-in coil, such as Figure 5 As shown, when this method is used in the mold, the position of the coil cannot be fixed, the formed blank is unbalanced from left to right, the coil is exposed and more leakage flux is generated, and the final product cannot achieve the best consistency. Summary of the invention

[0005] The purpose of the present invention is to provide a manufacturing structure and method of a surface mounted integrated inductor in view of the existing technical status, using upper and lower pressure plate bodies to complete positioning and cover the entire coil, the formed blank has almost no leakage flux, the coil can be maximized, and high Isat and low Rdc can be obtained.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] A manufacturing structure of a surface mounted integrated inductor comprises a built-in coil and two sets of pressing plate bodies, wherein the two sets of pressing plate bodies are respectively located above and below the built-in coil, the pressing plate body has a pressing surface, and both sides have protrusions, forming a shape with high sides and low middle. Both ends of the built-in coil have exposed copper wires as electrodes, and the electrode parts exceed the two ends of the pressing plate body, and the two sides of the built-in coil correspond to the protrusions of the pressing surface. After being pressed by a mold, the upper and lower sets of pressing plate bodies complete the wrapping and filling of the built-in coil, and are integrally formed into a blank.

[0008] As a structural form, the pressed surface has angular protrusions on both sides and is flat in the middle.

[0009] As a structural form, the two sides and the middle of the pressed surface form a concave arc surface.

[0010] As a structural form, the two sides of the pressed surface are angularly raised and extend all the way to the middle to intersect, forming an inward concave angle.

[0011] Furthermore, 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 blank side can be less than 0.15 mm.

[0012] A method for manufacturing a surface mounted integrated inductor of the present invention specifically comprises the following steps:

[0013] (1) Pre-rolled hollow core internal coil;

[0014] (2) Preforming a mixture of magnetic powder and thermosetting resin into two sets of identical pressing plate bodies, wherein the pressing plate bodies have pressing surfaces, and the pressing surfaces are specifically high at two sides and low in the middle;

[0015] (3) In the molding die, two sets of pressing plate bodies are placed directly above and directly below the built-in coil, respectively. The pressing surfaces of the pressing plate bodies need to face the built-in coil, and the two poles of the built-in coil need to extend beyond the two end ranges of the pressing plate bodies, respectively. Then, pressurization or heating is applied to form the two sets of pressing plate bodies and the built-in coil into a blank;

[0016] (4) After molding, the two poles of the built-in coil are exposed outside the blank. After removing the insulators of the two poles, external electrodes are formed at both ends of the blank.

[0017] The beneficial effects of the present invention are as follows: a coil formed by winding copper wire and a sealing material containing magnetic material and resin are integrally formed into a sealed blank with a coil in the middle. During the forming process, since the coil is positioned and wrapped by the pressing plate body, not only can the magnetic powder flow under the drive of the thermosetting resin to achieve filling and wrapping of the coil, but also, under the limitation of the mold, the side of the outer diameter of the coil and the thickness of the outer wall of the side of the blank formed can be minimized, thereby reducing leakage magnetic flux and increasing the area ratio of the built-in coil. This is suitable for the production of small-sized inductors and has a lower manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attached Figure 1 This is a molding structure diagram of the first embodiment of the present invention;

[0019] Attached Figure 2 This is a molding structure diagram of the second embodiment of the present invention;

[0020] Attached Figure 3 This is a molding structure diagram of the third embodiment of the present invention;

[0021] Attached Figure 4 A cross-sectional view of the resin flow inside the molding die during the implementation of the present invention;

[0022] Attached Figure 5 This is a process diagram for forming a surface mounted inductor in Japanese Patent No. 4714779;

[0023] Attached Figure 6 This is a diagram of the molding process of a surface-mount inductor in Japanese Patent No. 6060116. DETAILED DESCRIPTION

[0024] See also Figures 1 to 4 The figure is a schematic diagram of the structure of a preferred embodiment of the present invention. The present invention is a manufacturing structure and method of a surface mounted integrated inductor, which has a built-in coil 1 and two sets of pressure plate bodies 2. The two sets of pressure plate bodies 2 are respectively located above and below the built-in coil 1. The pressure plate body 2 has a pressing surface and protrusions on both sides to form a shape with high sides and low middle. The two ends of the built-in coil 1 have exposed copper wires as electrodes, and the electrode parts exceed the two ends of the pressure plate body 2, so that the electrodes of the built-in coil 1 can be exposed after pressing. The two sides of the built-in coil 1 correspond to the protrusions of the pressing surface, so that during the pressing process, the upper and lower pressure plate bodies 2 can complete the complete wrapping and filling of the built-in coil 1 and form it into a blank.

[0025] A method for manufacturing a surface mounted integrated inductor of the present invention specifically comprises the following steps:

[0026] (1) A pre-rolled hollow core internal coil 1;

[0027] (2) Preforming a mixture of magnetic powder and thermosetting resin into two sets of identical pressing plate bodies 2, wherein the pressing plate bodies 2 have a pressing surface 21, and the pressing surface 21 is higher on both sides and lower in the middle;

[0028] (3) In the molding die, two sets of pressing plate bodies 2 are placed directly above and directly below the built-in coil 1, respectively. The pressing surface 21 of the pressing plate body 2 needs to face the built-in coil 1, and the two poles of the built-in coil 1 need to extend beyond the two end ranges of the pressing plate body 2, and then pressurization or heating is applied to form the two sets of pressing plate bodies 2 and the built-in coil 1 into a blank;

[0029] (4) After molding, the two poles of the built-in coil 1 are exposed outside the blank. After removing the insulators of the two poles, external electrodes are formed at both ends of the blank.

[0030] During specific implementation, the pressing surfaces 21 of the upper and lower pressing plate bodies 2 must be opposite, the built-in coil 1 is placed between the two pressing plate bodies 2, and the two side surfaces of the built-in coil 1 that do not contain electrodes must correspond to the two sides of the protrusion of the pressing plate body 2, and the two extreme ends of the built-in coil 1 should exceed the two ends of the pressing plate body 2. After integral molding, the two poles of the coil can be located outside the blank.

[0031] Since the upper and lower pressing plate bodies 2 play the role of positioning, wrapping and filling, the shapes of the upper and lower pressing plate bodies 2 must be exactly the same and face each other. The pressing surface 21 of the pressing plate body 2 can have several forms:

[0032] Implementation method 1: Figure 1 As shown, the pressing surface 21 of the pressing plate body 2 has angular protrusions on both sides and is flat in the middle.

[0033] Implementation method 2: Figure 2 As shown, the two sides and the middle of the pressing surface 21 form an inwardly concave arc surface.

[0034] Implementation method three: Figure 3 As shown, the two sides of the pressed surface 21 are angularly raised and extend to the middle to intersect, forming an inwardly concave angle.

[0035] If the built-in coil 1 is as large as possible, Isat and Rdc will be better, so the outer diameter of the coil can be smaller from the inner size of the mold. As a small-size inductor, the length of the side of the outer diameter of the built-in coil and the outer surface of the blank side can be less than 0.15mm.

[0036] The thermosetting resin can be hot air epoxy resin, which has a temperature resistance grade of 220°C. By molding with resin, the corresponding pressing surface protrusions on the side of the coil flow between the side of the coil and the inner wall of the mold. Even if the coil is enlarged, a molded body in which the entire coil is covered with resin can be formed.

[0037] Of course, the above diagrams are only preferred embodiments of the present invention and are not intended to limit the scope of use of the present invention. Therefore, any equivalent changes made to the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A manufacturing structure of a surface mounted integrated inductor, comprising a built-in coil and two sets of pressing plate bodies, the two sets of pressing plate bodies being respectively located above and below the built-in coil, the pressing plate body having a pressing surface, the two sides of the pressing surface having protrusions, forming a shape of high sides and low middle, the two ends of the built-in coil having exposed copper wires as electrodes, and the electrode portions exceeding the two ends of the pressing plate body, the top side and the bottom side of the built-in coil corresponding to the protrusions of the pressing surface, after being pressed by a mold, the upper and lower sets of pressing plate bodies complete the wrapping and filling of the built-in coil, and are integrally formed into a blank; The distance between the side of the outer diameter of the built-in coil and the outer surface of the blank is less than 0.15 mm; Features: The two sides of the pressed surface are angularly raised and extend to the middle to intersect, forming an inwardly concave angle; The inner side of the upper pressing plate body forms an upward concave angle, and the inner side of the lower pressing plate body forms a downward concave angle; The two ends of the built-in coil are respectively located at the two ends of a direction perpendicular to the plane where the inner concave angle is located.

2. A manufacturing method corresponding to the manufacturing structure of a surface mounted integrated inductor as claimed in claim 1, characterized in that: The specific steps include: (1) Pre-rolled hollow core internal coil; (2) preforming a mixture of magnetic powder and thermosetting resin into two sets of identical pressing plate bodies, wherein the pressing plate bodies have pressing surfaces, and the pressing surfaces are specifically high at two sides and low in the middle; (3) In the molding die, two sets of pressing plate bodies are placed directly above and directly below the built-in coil, respectively, with the pressing surfaces of the pressing plate bodies facing the built-in coil, and the two poles of the built-in coil respectively exceeding the two end ranges of the pressing plate bodies, and then pressurizing and / or heating are applied to form the two sets of pressing plate bodies and the built-in coil into a blank; (4) After molding, the two poles of the built-in coil are exposed outside the blank. After removing the insulators of the two poles, external electrodes are formed at both ends of the blank.

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