INDUCTOR CHOKE COIL WIRE INTERFERENCE PREVENTION STRUCTURE

Abstract

An inductor choke coil wire interference prevention structure includes a choke coil having a flat body portion wound into a continuous electrical coil portion, two end portions respectively downwardly extending from two opposite ends of the flat body portion and respectively bent into a respective soldering electrode. An extension tip is located on a distal end of each end portion remote from the flat body portion, and a layer of insulating film covers a contact surface of the end portion or an adjacent contact surface of the electrical coil portion to allow direct contact between the electrical coil portion and the contact surface of the end portion without causing electrical conduction or shorting.

Claims

1. An inductor choke coil wire structure, comprising a choke coil comprising a flat body portion wound into a continuous electrical coil portion, two end portions respectively downwardly extending from two opposite ends of said flat body portion and respectively bent into respective soldering electrodes, an extension tip located on a distal end of each said end portion remote from said flat body portion, and an insulating film selectively covering a contact surface of said end portion or an adjacent contact surface of said electrical coil portion.

2. The inductor choke coil wire structure as claimed in claim 1, wherein said insulating film is plated onto said adjacent contact surface of said electrical coil portion in contact with one said end portion by anodization of the wire metal.

3. The inductor choke coil wire structure as claimed in claim 1, wherein said insulating film is plated onto said contact surface of said end portion by anodization of the wire metal.

4. The inductor choke coil wire structure as claimed in claim 2, wherein said insulating film is an oxide, nitride, or carbide material.

5. The inductor choke coil wire structure as claimed in claim 1, wherein said insulating film is coated onto said adjacent contact surface of said electrical coil portion using a coating process.

6. The inductor choke coil wire structure as claimed in claim 1, wherein said insulating film is coated onto said contact surface of one said end portion using a coating process.

7. The inductor choke coil wire structure as claimed in claim 5, wherein said insulating film is a dry film material.

8. The inductor choke coil wire structure as claimed in claim 1, wherein said insulating film is coated onto said adjacent contact surface of said electrical coil portion using a solder mask (S/M) process.

9. The inductor choke coil wire structure as claimed in claim 1, wherein said insulating film is coated onto said contact surface of one said end portion using a solder mask (S/M) process.

10. The inductor choke coil wire structure as claimed in claim 1, wherein said insulating film is a resin material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a schematic drawing illustrating a high current, low profile inductor according to U.S. Pat. No. 6,204,744B1.

[0007] FIG. 2 is a schematic drawing illustrating an unwound choke coil according to CN1285086C.

[0008] FIG. 3 is a schematic drawing illustrating the choke coil material of CN1285086C wound into a choke coil.

[0009] FIG. 4 is a schematic sectional view illustrating the magnetic molding material molded in the wire coil according to U.S. Pat. No. 6,204,744B1.

[0010] FIG. 5 is a schematic sectional view illustrating the magnetic molding material molded in the choke coil according to CN1285086C.

[0011] FIG. 6 is a schematic elevational view of an inductor using an inductor choke coil wire interference prevention structure in accordance with an embodiment of the present invention.

[0012] FIG. 7 is a schematic drawing illustrating a layer of insulating film covering a contact surface of one end portion of an unwound choke oil in accordance with an embodiment of the present invention.

[0013] FIG. 8 is a schematic drawing illustrating a layer of insulating film covering an adjacent contact surface of a flat body portion of an unwound choke coil in accordance with an embodiment of the present invention.

[0014] FIG. 9 illustrates a flat body portion of the choke coil wound into an electrical portion according to an embodiment of the present invention.

[0015] FIG. 10 is a schematic sectional view illustrating magnetic molding material molded onto a choke coil according to an embodiment of the present invention.

[0016] FIG. 11 corresponds to FIG. 10, illustrating extension tips bent into shape.

[0017] FIG. 12 is an enlarged view of a portion of FIG. 10, illustrating positioning of the layer of insulating film.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] Referring to FIGS. 6-12, an inductor choke coil wire interference prevention structure in accordance with an embodiment of the present invention is shown. The inductor choke coil wire interference prevention structure provides a choke coil 5 with a conductive wire interference structure. As illustrated in FIG. 7, the choke coil 5 comprises a flat body portion 51, two opposing end portions 52, 53 respectively downwardly extending from two opposite ends of the flat body portion 51, and two extension tips 54, 55 respectively located on respective distal ends of the end portions 51, 53 remote from the flat body portion 51. The flat body portion 51 is wound into a continuous electrical coil portion 56. The two end portions 52, 53 are respectively bent into a respective welding electrode. A contact surface 521 of one end portion 52 of the choke coil 5 electrical coil portion 56 is coated with a layer of insulating film 57 so that the contact surface 521 of the end portion 52 does not provide a gap (corresponding to the isolation height G of the choke coil of the inductor according to the prior art), i.e., the insulating film 57 is kept in direct contact with the contact surface 521 of the end portion 52 so that the contact surface 521 of the end portion 52 can be directly kept in direct contact with other objects without causing electrical conduction or shorts. As illustrated in FIGS. 6 and 9, the end portions 52, 53 are bent into respective soldering electrodes and kept flush with the outer surface 58 of the inductor (see also FIG. 5). Thus, a magnetic molding material 6 is filled into the electrical coil portion 56 of the choke coil 5 (see the imaginary line in FIG. 9 and FIGS. 10 and 11), and then molded into the desired inductor. According to this method, the overall height H of the choke coil 5 is effectively reduced. Further, the end portions 52, 53 are exposed external to the outer surface 58 of the inductor. Therefore, the inductor has a large bonding area. Further, as shown in FIG. 10, the layer of insulating film 57 is isolated between the extension tip 54 and electrical coil portion 56 of the choke coil 5. Because the insulating film 57 is not a magnetic material, the extension portion 54 and the electrical coil portion 56 do not cause electromagnetic interference during the energization operation due to electromagnetic effects. Therefore, the choke coil is suitable for making a high-performance, high-current, low-profile inductor for use in a high-tech computer product.

[0019] In this embodiment, the insulating film 57 is plated onto the contact surface 521 of the end portion 52 by anodization, as illustrated in FIG. 7. Alternatively, as shown in FIG. 8, the insulating film 57 can be plated onto the contact surface 561 of the electrical coil portion 56 by anodization. The insulating film 57 can be an oxide, nitride or carbide material for anodization. In this embodiment, a copper material is used and subjected to an anodizing treatment, with the electroplating treatment chemical formula of the anode treatment being Cu+2 NaOH to form a Na2CuO2+H2O, and then the Na2CuO2+H2O is dehydrated to form a CuO+2 NaOH, that is, an insulating composition of copper oxide for insulating film 57.

[0020] Alternatively, the insulating film 57 can be coated onto the contact surface 521 of the end portion 52 or the adjacent contact surface in contact with the contact surface 521 of the end portion 52 using a coating process. In the example shown in FIG. 7, the insulating film 57 is coated onto the contact surface 521 of the end portion 52 using a coating process. In the example shown in FIG. 8, the insulating film 57 is contacted with the contact surface 561 of the electrical coil portion 56 using a coating process. Further, the insulating film 57 can be a dry film material.

[0021] In still another embodiment, the insulating film 57 described above may also be coated onto the contact surface 521 of the end portion 52 or the adjacent contact surface in contact with the contact surface 521 of the end portion 52 using a solder mask (S/M) process. On the contact surface, for example, as shown in FIG. 7, the insulating film 57 can be coated on the contact surface 521 of the end portion 52 using a solder mask (S/M) process or coated on the contact surface 561 of the electrical coil portion 56 using a solder mask (S/M) process, as shown in FIG. 8. The insulating film 57 can be a resin material.

[0022] In conclusion, embodiments of the invention provide an inductor choke coil wire interference prevention structure, which comprises a choke coil comprising an electrical coil portion, two end portions respectively extending from two opposite ends of the electrical coil portion and respectively bent into a respective soldering electrode and an extension tip located on a distal end of each end portion remote from the electrical coil portion, and a layer of insulating film coated onto a contact surface of one end portion of the choke coil. The inductive choke coil wire interference prevention structure has the advantages of easy stamping, long tool life, space savings, ease of winding, easy control of the outer diameter, and no internal solder joints. The end portions are kept flush with the outer surface of the inductor. After the magnetic molding material is filled into the choke coil and molded into shape, the end portions are exposed external to the outer surface of the inductor for bonding. Thus, the inductor made according to embodiments of the present invention has a large bonding area, and its choke coil is provided with a wire interference preventive structure, avoiding magnetic interference between the extension tips and the electrical coil portion. Thus, the inductor choke coil wire interference prevention structure of the present invention is well-suited for making a high-performance, high-current, low-profile inductor.