US-20260128213-A1 - METHOD TO FORM MULTIPLE ELECTRICAL COMPONENTS AND A SINGLE ELECTRICAL COMPONENT MADE BY THE METHOD

US20260128213A1US 20260128213 A1US20260128213 A1US 20260128213A1US-20260128213-A1

Abstract

A method to form a plurality of inductors in a single process by stacking multiple magnetic sheets, wherein each sheet is made to form a particular part in quantities, which can be a base part, a pillar part, a hollow part, or a cover part, for forming a magnetic body of an inductor.

Inventors

Chih Hung We
Min Lian Kuo

Assignees

CYNTEC CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20260101

Claims (6)

1 . A method to form an electrical component, comprising: forming a first magnetic sheet, wherein a plurality of bases are formed in the first magnetic sheet; forming a second magnetic sheet, wherein a plurality of pillars are formed in the second magnetic sheet; forming a third magnetic sheet, wherein a plurality of through openings are formed in the third magnetic sheet; and forming a fourth magnetic sheet, wherein a plurality of covers are formed in the fourth magnetic sheet; stacking the first magnetic sheet, the second magnetic sheet, the third magnetic sheet and the fourth magnetic sheet for forming a magnetic body with a plurality of coils disposed in the magnetic body, wherein a bottom surface of a pillar is disposed over a top surface of a corresponding base with at least one portion of the pillar being placed in a hollow space of a corresponding coil, wherein the coil and at least one portion of the pillar being placed in a corresponding through opening that is located above the top surface of the corresponding base, and a corresponding cover is disposed over the pillar and the coil; and cutting the magnetic body into a plurality of pieces with each piece comprising a corresponding coil encapsulated by a corresponding portion of the magnetic body.
2 . The method according to claim 1 , wherein said stacking step comprising: disposing a plurality of coils on the first magnetic sheet, wherein each coil is disposed on a corresponding base of the first magnetic sheet; stacking the second magnetic sheet over the first magnetic sheet, wherein each pillar of the second magnetic sheet is placed in a hollow space of a corresponding coil; stacking the third magnetic sheet over the first magnetic sheet, wherein each through opening of the third magnetic sheet is placed over a corresponding base of the first magnetic sheet and surrounds a corresponding coil and a corresponding pillar of the second magnetic sheet; and stacking the fourth magnetic sheet over the second magnetic sheet and the third magnetic sheet, wherein each cover of the fourth magnetic sheet is disposed over a corresponding pillar and a corresponding coil.
3 . The method according to claim 1 , wherein said stacking step comprising: stacking the third magnetic sheet over the fourth magnetic sheet; disposing a plurality of coils on the fourth magnetic sheet, wherein each coil is placed in a corresponding through opening of the third magnetic sheet; stacking the second magnetic sheet over the fourth magnetic sheet, wherein each pillar of the second magnetic sheet is placed in a hollow space of a corresponding coil; and stacking the first magnetic sheet over the second magnetic sheet and the third magnetic sheet.
4 . The method according to claim 1 , wherein the base is made of a first magnetic material and the pillar is made of a second magnetic material, wherein the first magnetic material and the second magnetic material are different magnetic materials.
5 . The method according to claim 4 , wherein the second magnetic material comprises at least one magnetic powder and a polymer material, wherein the at least one magnetic powder weights 3˜8 wt % of a total weight of the at least one first magnetic powder and the polymer material.
6 . The electrical component according to claim 1 , wherein the first magnetic sheet is made of a first magnetic material, the second magnetic sheet is made of a second magnetic material, the third magnetic sheet is made of a third magnetic material and the fourth magnetic sheet is made of a fourth magnetic material with the first magnetic material, the second magnetic material, the third magnetic material and the fourth magnetic material being different from each other with a permeability of the second magnetic material being greater than a permeability of the first magnetic material.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation of U.S. application Ser. No. 17/165,936 filed on Feb. 3, 2021, which claims the benefit of U.S. Provisional Application Ser. No. 63/065,496 filed on Aug. 14, 2020, which is hereby incorporated by reference herein and made a part of the specification. BACKGROUND OF THE INVENTION I. Field of the Invention The invention relates to a method for forming an inductor, in particular for forming multiple inductors in a single process. II. Description of the Related Art Conventional power inductor is made by filling a magnetic powder into a single-piece mold with a coil placed therein, and then formed by high-tonnage pressing or heating. Due to the space limitation of the single-piece mold, the particle size of the magnetic powder must be kept below an appropriate particle size to avoid the bridging effect hindering the accumulation of the powder as well as to increase the fluidity and filling density of the magnetic powder. Furthermore, due to the limitation of the pressing process, glue material to bind the powder needs to be held below an appropriate ratio to avoid the glue material from sticking to the mold and causing damage to the mold. Furthermore, the conventional power inductor is made by pressing filled magnetic powder with a coil wound around a bump or pillar, after which a lead frame is used for forming electrodes of the power inductor. However, the use of lead frames requires a large amount of space, which is not suitable as electrodes for smaller electrical components, such as the power inductor. In addition, due to the difference of the pressure between the bump and the filled magnetic powder, the coil is easily deformed after being heated and pressed, thereby causing particles of the magnetic powder to penetrate into the insulating layer of the coil, which can cause short circuits and increase resistance of the coil. Accordingly, there is demand for a better solution to solve these problems. SUMMARY OF THE INVENTION One objective is to provide a method for forming a plurality of inductors in a single process to save cost and time for mass production. One objective is to provide a method for forming an inductor in a single process by assembly different parts that are separately formed, for adjusting the inductance of an inductor through choosing appropriate materials for each part, respectively. One objective is to provide a method for forming a plurality of inductors in a single process without using a single-piece mold, thereby avoiding the afore-mentioned problems in the prior art. In one embodiment, an electrical component is disclosed, wherein the electrical component comprises: a magnetic body and a coil disposed in the magnetic body, wherein the magnetic body is formed by a plurality of parts, each part being pre-formed separately from each other, wherein the plurality of parts comprises a first part comprising a base, a second part comprising a pillar, a third part comprising a through opening, and a fourth part comprising a cover, wherein a bottom surface of the pillar is disposed over a top surface of the base with at least one portion of the pillar being placed in a hollow space of the coil, wherein the third part is disposed over the top surface the base with the pillar and the coil being placed in said through openings, wherein the cover is disposed over the pillar and the coil with the base and the cover being located on two opposite sides of the bottom surface of the pillar. In one embodiment, the electrical component is an inductor. In one embodiment, the base is made of a first magnetic material and the pillar is made of a second magnetic material, wherein the first magnetic material and the second magnetic material are different magnetic materials, wherein a permeability of the second magnetic material is different from a permeability of the first magnetic material. In one embodiment, a permeability of the second magnetic material is greater than a permeability of the first magnetic material. In one embodiment, the third part is made of a third magnetic material, wherein the first magnetic material, the second magnetic material and the third magnetic material are different from each other. In one embodiment, the cover is made of a fourth magnetic material, wherein the first magnetic material, the second magnetic material, the third magnetic material and the fourth magnetic material are different from each other. In one embodiment, the first magnetic material comprises a first magnetic powder, and the D50 of the first magnetic powder is in a range of 0.5 um to 50 um. In one embodiment, the second magnetic material comprises a second magnetic powder, and the D50 of the second magnetic powder is in a range of 0.5 um to 50 um. In one embodiment, the first magnetic material comprises a first magnetic powder and a second magnetic powder, wherein a ratio of the D50 of the first magnetic powder to the D50 of the