Power inductor and production process thereof

Abstract

The invention relates to the technical field of inductors, in particular to a power inductor, comprising: a lower module comprising a bottom plate and a center pillar arranged on the bottom plate, the two sides of the upper end face of the bottom plate being provided with mounting blocks; a coil winding is in a hollow cylinder shape, two ends of the coil extend out of lead portions, two leads are bent downwards in the axial direction from two sides of the coil to the lower end face of the coil and bent upwards again along the direction of the bottom face, terminals of the lead portions are bent again towards the direction of the coil, and the lead portions form rectangular grooves below the coil. The two sides of the bottom plate are arranged in the grooves; and the upper module wraps the coil and is exposed out of the lead part of the lower end face of the bottom plate, and the upper module and the lower module are integrally pressed and formed. The electrode length is increased, the yield is improved, the defect rate increased due to inaccurate subsequent electrotinning position caused by too short electrodes is avoided, and the influence on the inductor use effect in the use process due to too short electrodes is also avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of inductors, and in particular relates to a power inductor and a production process thereof. Background Art

[0002] Inductors are an electronic component widely used in various electronic circuits. Together with resistors and capacitors, they are known as the three major passive components. They have the properties of passing DC and blocking AC, and can isolate AC signals, oscillate, choke, tune, and select frequencies.

[0003] Power inductors are generally used in DC-DC circuits to stabilize current and store energy. When a power inductor is required to pass a larger current while having a smaller size, a smaller size requires higher precision. In the existing technology, the pins of small-volume inductors are easily broken when connected to the lead frame, resulting in defective products. Therefore, a power inductor and its production process are needed to solve the above problem. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a power inductor and a production process thereof to solve the problems in the existing market raised in the above background technology.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A power inductor, comprising:

[0007] The lower mold assembly comprises a bottom plate and a center column arranged on the bottom plate, and mounting blocks are arranged on both sides of the upper surface of the bottom plate;

[0008] The coil is an enameled wire, the coil winding is a hollow cylindrical shape, the two ends of the coil extend out lead wire parts, the two lead wires are axially bent downward from the two sides of the coil to the lower end surface of the coil, and are bent upward again along the bottom surface direction, and the terminal of the lead wire part is bent again toward the coil direction, the lead wire part forms a rectangular groove under the coil, and the two sides of the bottom plate are arranged in the groove;

[0009] The upper mold group covers the coil and exposes the lead wire portion at the lower end surface of the bottom plate, and the upper mold group and the lower mold group are integrally pressed and formed.

[0010] Through the above technical scheme, the bottom plate and the middle column are molded separately, which is convenient for improving the inductance value of the middle column and thus improving the overall performance of the inductor. The coil is made of metal, and the lead part arranged below the coil forms a rectangular groove. The two sides of the bottom plate are convenient for installation and snap-fit ​​into the rectangular groove, which improves the installation efficiency and prevents the bottom plate from falling off. After the bottom plate is installed, the lead part arranged on the lower end surface of the bottom plate is the electrode. The electrode part is consistent with the width of the bottom plate, which increases the length of the electrode, improves the yield rate, avoids the electrode being too short, resulting in inaccurate subsequent electroplating tinning position increasing the defective rate, and avoids the electrode being too short to affect the use effect of the inductor during use.

[0011] As a preferred embodiment of the present invention, the portion of the lead wire bent downward along the axial direction of the coil winding is lead wire 1, and the lead wire 1 extends to 0.01-1 cm below the coil.

[0012] Through the above technical solution, the lead wire 1 is bent from top to bottom in the axial direction of the coil to the bottom of the coil.

[0013] As a preferred solution of the present invention, the portion of the lead wire extending along the lower end surface of the coil is lead wire 2, and the length of lead wire 2 is 0.01-1 cm greater than the length of the coil winding.

[0014] Through the above technical solution, the lead wire 2 extends along the longitudinal direction of the coil to the other side of the coil and exceeds the longitudinal direction of the coil by 0.01-1 cm. The lead wire 2 is the electrode part, so that the electrode fits the bottom plate, increasing the service life of the inductor and the yield rate.

[0015] As a preferred solution of the present invention, the portion of the lead wire that is bent upward along the axial direction of the coil is lead wire three, and the height of the lead wire three is equal to the height of the mounting block plus the height of the bottom plate.

[0016] As a preferred solution of the present invention, the mounting block is 0.01-1 cm higher than the bottom plate, and the distance between the two mounting plates is 0.01-1 cm greater than the diameter of the coil winding.

[0017] As a preferred solution of the present invention, the outer peripheral surface of the inductor is sprayed with glue.

[0018] As a preferred solution of the present invention, the surface of the second lead wire is stripped of paint, and the second lead wire is tin-plated.

[0019] A power inductor production process includes the following steps:

[0020] S1, preparing a middle column, weighing 60% of alloy powder and 40% of carbonyl powder in proportion, adding epoxy resin and mixing at 220° C. to obtain a first soft magnetic powder, and pressing the first soft magnetic powder into a middle column through a mold;

[0021] S2, preparing a base plate, weighing 70% of amorphous powder and 30% of carbonyl powder in proportion, adding epoxy resin and mixing at 270° C. to obtain a second soft magnetic powder, and pressing the second soft magnetic powder into the base plate through a mold;

[0022] S3, winding the coil, winding the metal wire into a central cylindrical shape, bending the two lead wires extending from the coil axially downward from both sides of the coil to the lower end surface of the coil, and bending upward again along the bottom surface direction, and bending the terminal end of the lead wire part again toward the coil direction, so that the lead wire part forms a rectangular groove below the coil;

[0023] S4, assembling the lower module, inserting the bottom plate into the rectangular groove formed by the lead part, and placing the middle column in the hollow part of the coil;

[0024] S5, molding the upper mold group, placing the lower mold group on the mold, and molding the second soft magnetic powder and the lower mold group into one body to form an inductor semi-finished product;

[0025] S6, spraying paint stripping, spraying glue material on the surface of the semi-finished inductor in step s5, and stripping the paint on the outer surface of the second lead wire by laser, so that the metal conductor of the second lead wire is exposed;

[0026] S7, electroplating, electroplating tin on the second part of the lead wire in step s6 to form an inductor.

[0027] As a preferred solution of the present invention, the magnetic induction of the middle column is greater than the magnetic induction of the bottom plate.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The bottom plate and the middle column are molded separately, which is convenient for improving the inductance value of the middle column and thus improving the overall performance of the inductor;

[0030] The lead wire part under the coil forms a rectangular groove, and the two sides of the bottom plate are easy to install and snap into the rectangular groove, which improves the installation efficiency and prevents the bottom plate from falling off;

[0031] After installing the base plate, the lead part located at the lower end surface of the base plate is the electrode. The electrode part is consistent with the width of the base plate, which increases the electrode length and improves the yield rate. It avoids the electrode being too short, which leads to inaccurate subsequent electroplating tin position and increases the defective rate. It also avoids the electrode being too short and affecting the use effect of the inductor during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 It is a schematic diagram of the structure of the power inductor of the present invention;

[0034] Figure 2 For the present invention Figure 1 Schematic diagram of the structure of the middle coil;

[0035] Figure 3 For the present invention Figure 1 Structural diagram of the middle and lower modules;

[0036] Figure 4 For the present invention Figure 1 Schematic diagram of the structure of the middle base. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The present invention provides the following embodiments:

[0039] A power inductor, comprising:

[0040] The lower mold assembly 1 includes a bottom plate 11 and a center column 12 arranged on the bottom plate 11, and mounting blocks 111 are arranged on both sides of the upper end surface of the bottom plate 11;

[0041] The coil 3 is an enameled wire, and the outer surface of the coil 3 is covered with an insulating layer, which is made of epoxy resin. The coil 3 is wound into a hollow cylindrical shape, and lead wire parts 31 extend from both ends of the coil 3. The two lead wires are axially bent downward from both sides of the coil 3 to the lower end surface of the coil 3, and are bent upward again along the bottom surface direction. The terminal of the lead wire part 31 is bent again toward the direction of the coil 3. The lead wire part 31 forms a rectangular groove 32 under the coil 3, and both sides of the bottom plate 11 are arranged in the groove 32;

[0042] The upper mold assembly 2 covers the coil 3 and exposes the lead wire portion 31 at the lower end surface of the bottom plate 11 . The upper mold assembly 2 and the lower mold assembly 1 are integrally pressed and formed.

[0043] As a further improvement of the present invention, the part of the lead wire bent downward along the axial direction of the winding of the coil 3 is a lead wire 311, the lead wire 311 extends to 0.01-1 cm below the coil 3, and the lead wire 311 is bent from top to bottom in the axial direction of the coil 3 to the bottom of the coil 3;

[0044] The lead wire extending along the lower end surface direction of the coil 3 is the second lead wire 312, the length of the second lead wire 312 is greater than the winding length of the coil 3 by 0.01-1 cm, the second lead wire 312 extends along the longitudinal direction of the coil 3 to the other side of the coil 3, and exceeds the longitudinal direction of the coil 3 by 0.01-1 cm, the second lead wire 312 is the electrode part, so that the electrode is attached to the bottom plate 11, increasing the service life of the inductor and the yield rate;

[0045] The portion of the lead wire that is bent upward along the axial direction of the coil 3 is the lead wire three 313 , and the height of the lead wire three 313 is equal to the height of the mounting block 111 plus the height of the bottom plate 11 , and the lead wire three 313 is L-shaped.

[0046] As a further improvement of the present invention, the mounting block 111 is higher than the bottom plate 11 by 0.01-1 cm, and the distance between the two mounting plates is greater than the winding diameter of the coil 3 by 0.01-1 cm.

[0047] As a further improvement of the present invention, the outer peripheral surface of the inductor is sprayed with glue.

[0048] As a further improvement of the present invention, the surface of the second lead wire 312 is stripped of paint, and the surface of the second lead wire 312 is tin-plated.

[0049] A power inductor production process comprises the following steps:

[0050] S1, preparing the middle column 12, weighing 60% of alloy powder and 40% of carbonyl powder in proportion, adding epoxy resin and mixing at 220° C. to obtain a first soft magnetic powder, and pressing the first soft magnetic powder into the middle column 12 through a mold;

[0051] S2, preparing the bottom plate 11, weighing 70% of amorphous powder and 30% of carbonyl powder in proportion, adding epoxy resin and mixing at 270° C. to obtain a second soft magnetic powder, and pressing the second soft magnetic powder into the bottom plate 11 through a mold;

[0052] S3, winding the coil 3, winding the metal wire into a cylindrical shape of the middle column 12, bending the two lead wires extending from the coil 3 from both sides of the coil 3 axially downward to the lower end surface of the coil 3, and bending upward again along the bottom surface direction, and bending the terminal of the lead wire part 31 again toward the direction of the coil 3, so that the lead wire part 31 forms a rectangular groove 32 below the coil 3;

[0053] S4, assemble the lower module 1, insert the bottom plate 11 into the rectangular groove 32 formed by the lead part 31, and place the middle column 12 in the hollow part of the coil 3;

[0054] S5, molding the upper mold group 2, placing the lower mold group 1 on the mold, and molding the second soft magnetic powder and the lower mold group 1 into one body to form an inductor semi-finished product;

[0055] S6, spraying paint stripping, spraying glue material on the surface of the semi-finished inductor in step s5, and stripping the paint on the outer surface of the second lead wire 312 by laser, so that the second lead wire 312 leaks out the metal conductor;

[0056] S7, electroplating, electroplating tin is performed on the lead wire 2 312 portion in step S6 to form an inductor.

[0057] As a further improvement of the present invention, the magnetic induction of the middle column 12 is greater than that of the bottom plate 11 , the bottom plate 11 and the upper mold assembly 2 can be made of the same material, and the magnetic induction of the bottom plate 11 and the upper mold assembly 2 can be the same or different.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] The bottom plate 11 and the middle column 12 are molded separately, which is convenient for improving the inductance of the middle column 12 and thus improving the overall performance of the inductor; the lead portion 31 arranged below the coil 3 forms a rectangular groove 32, and the two sides of the bottom plate 11 are convenient for installation and snap-fitting into the rectangular groove 32, thereby improving installation efficiency and preventing the bottom plate 11 from falling off; after the bottom plate 11 is installed, the lead portion 31 arranged on the lower end surface of the bottom plate 11 is an electrode, and the electrode portion is consistent with the width of the bottom plate 11, thereby increasing the electrode length and improving the yield rate, thereby avoiding the electrode being too short, resulting in inaccurate subsequent electroplating tinning position and increasing the defective rate, and also avoiding the electrode being too short, affecting the use effect of the inductor during use, thereby reducing complex production processes and techniques, and being able to better serve and expand the market.

[0060] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power inductor, characterized in that ,include: The lower mold assembly (1) comprises a bottom plate (11) and a center column (12) arranged on the bottom plate (11), and mounting blocks (111) are arranged on both sides of the upper end surface of the bottom plate (11); A coil (3), wherein the coil (3) is an enameled wire, the coil (3) is wound into a hollow cylindrical shape, lead wire portions (31) extend from both ends of the coil (3), the two lead wires are axially bent downward from both sides of the coil (3) to the lower end surface of the coil (3), and are bent upward again along the bottom surface direction, the terminal end of the lead wire portion (31) is bent again toward the direction of the coil (3), the lead wire portion (31) forms a rectangular groove (32) under the coil (3), and the two sides of the bottom plate (11) are arranged in the groove (32); An upper mold assembly (2), the upper mold assembly (2) covers the coil (3) and exposes the lead wire portion (31) on the lower end surface of the bottom plate (11), and the upper mold assembly (2) and the lower mold assembly (1) are integrally pressed and formed.

2. The power inductor according to claim 1, characterized in that: The portion of the lead wire that is bent downward along the axial direction of the winding of the coil (3) is lead wire one (311), and the lead wire one (311) extends to 0.01-1 cm below the coil (3).

3. The power inductor according to claim 1, characterized in that: The portion of the lead wire extending along the lower end surface of the coil (3) is lead wire 2 (312), and the length of the lead wire 2 (312) is greater than the winding length of the coil (3) by 0.01-1 cm.

4. The power inductor according to claim 1, characterized in that: The portion of the lead wire that is bent upward along the axial direction of the coil (3) is a lead wire three (313), and the height of the lead wire three (313) is equal to the height of the mounting block (111) plus the height of the bottom plate (11).

5. The power inductor according to claim 1, characterized in that: The mounting block (111) is 0.01-1 cm higher than the bottom plate (11), and the distance between the two mounting plates is 0.01-1 cm greater than the winding diameter of the coil (3).

6. The power inductor according to claim 1, characterized in that: The outer peripheral surface of the inductor is sprayed with glue material.

7. The power inductor according to claim 3, characterized in that: The surface of the second lead wire (312) is stripped of paint, and the second lead wire (312) is tin-plated.

8. A power inductor production process, the inductor production process as claimed in claims 1-7, characterized in that: The following steps are involved: S1, preparing a middle column (12), weighing 60% of alloy powder and 40% of carbonyl powder in proportion, adding epoxy resin and mixing at 220° C. to obtain a first soft magnetic powder, and pressing the first soft magnetic powder into a middle column (12) through a mold; S2, preparing a base plate (11), weighing 70% of amorphous powder and 30% of carbonyl powder in proportion, adding epoxy resin and mixing at 270° C. to obtain a second soft magnetic powder, and pressing the second soft magnetic powder into the base plate (11) through a mold; S3, winding the coil (3), winding the metal wire into a cylindrical shape of a center column (12), axially bending the two lead wires extending from the coil (3) downward from both sides of the coil (3) to the lower end surface of the coil (3), and bending upward again along the bottom surface direction, and bending the terminal of the lead wire part (31) again toward the direction of the coil (3), so that the lead wire part (31) forms a rectangular groove (32) below the coil (3); S4, assembling the lower module (1), inserting the bottom plate (11) into the rectangular groove (32) formed by the lead portion (31), and placing the middle column (12) in the hollow portion of the coil (3); S5, molding the upper mold assembly (2), placing the lower mold assembly (1) on the mold, and molding the second soft magnetic powder and the lower mold assembly (1) into one body to form a semi-finished inductor; S6, spraying paint stripping, spraying glue material on the surface of the semi-finished inductor in step s5, and stripping the paint on the outer surface of the lead wire 2 (312) by laser, so that the lead wire 2 (312) leaks out the metal conductor; S7, electroplating, electroplating tin on the lead wire 2 (312) in step s6 to form an inductor.

9. A power inductor production process according to claim 8, characterized in that: The magnetic induction of the middle column (12) is greater than the magnetic induction of the bottom plate (11).

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