Integrally-formed small-size inductor and preparation method thereof

Abstract

The invention discloses an integrally formed small-size inductor and a preparation method thereof. The integrally formed small-size inductor comprises an I-shaped CORE, a flat copper wire is wound on the I-shaped CORE, a square CORE is arranged outside the I-shaped CORE, and the I-shaped CORE and the square CORE are integrally formed through hot pressing; the preparation method comprises the following steps: S1, preparing I-shaped CORE and square CORE; s2, winding wires on the I-shaped CORE, and bending the wound wires to form an electrode surface; s3, aligning and combining the I-shaped CORE and the square CORE; s4, carrying out hot pressing on the I-shaped CORE and the square CORE which are combined; and S5, curing and glue spraying are performed, and the electrode surface is subjected to paint stripping electroplating to form an electrode. The method has the advantages that the I-shaped CORE and the square CORE are subjected to thermocompression bonding to form the inductor, and the inductor has higher inductance value and more stable ISAT.

Description

Technical Field

[0001] The present invention relates to the technical field of inductor preparation, and in particular to an integrally formed small-size inductor and a preparation method thereof. Background Art

[0002] Inductance is a property of a closed loop. When current passes through a coil, a magnetic field is induced in the coil, and the induced magnetic field generates an induced current to resist the current passing through the coil. Inductance is a circuit parameter that describes the induced electromotive force effect caused in the coil or in another coil due to the change in coil current. Inductance is a general term for self-inductance and mutual inductance. The device that provides inductance is called an inductor. With the continuous development of mobile devices, the inductors used need to have the characteristics of miniaturization and low DC impedance, and require low loss and high reliability.

[0003] In the prior art, T-Core+ hot pressing technology is usually used to make one-piece molded inductors. The density and strength required for the product can be achieved with relatively low pressure, and the relatively low pressure greatly reduces the deformation of the coil during the molding process. However, the inductance is relatively low, and the inductor saturation current (ISAT) decreases significantly. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present application proposes an integrated small-size inductor and a preparation method thereof, which forms an inductor by hot pressing an I-shaped CORE and a square CORE, and has a higher inductance and a more stable ISAT.

[0005] The present invention provides the following technical solution: an integrally formed small-size inductor, comprising: an I-shaped CORE, a flat copper wire is wound on the I-shaped CORE, a square CORE is arranged outside the I-shaped CORE, and the I-shaped CORE and the square CORE are integrally formed by hot pressing.

[0006] In this solution, the I-shaped CORE and the square CORE are designed into an I-shaped shape by a mold, and after being filled with composite powder, pressure is applied to press them into shape. A flat copper wire is vertically wound on the I-shaped CORE, and the wound I-shaped CORE is set in the square CORE. The I-shaped CORE and the square CORE are hot-pressed into one piece through hot pressing technology to prepare an integrated inductor.

[0007] Preferably, the I-shaped CORE is provided with a first connecting portion, the first connecting portion is connected to the center column, and the center column is connected to the winding portion;

[0008] The first connecting part is used for hot pressing connection with the second connecting part, and the middle column and the winding part are used for vertically winding the flat copper wire.

[0009] Preferably, the square CORE is provided with a receiving groove, a second connecting portion is provided at the top of the receiving groove, and an opening is provided at the bottom of the receiving groove;

[0010] The second connection part is used for hot pressing connection with the first connection part, the receiving groove is used for receiving the I-shaped CORE, and the opening is used for allowing the electrode surface on the winding part of the I-shaped CORE to extend out of the square CORE.

[0011] Preferably, the first connection portion and the second connection portion coincide with each other, the area of ​​the first connection portion is larger than the circumscribed rectangular area of ​​the winding portion, and the bottom surface area of ​​the accommodating groove of the square CORE is larger than the circumscribed rectangular area of ​​the winding portion of the I-shaped CORE.

[0012] Preferably, the opening of the square CORE is located on the same side as the convex portion of the winding portion of the I-shaped CORE, and the convex portion of the winding portion of the I-shaped CORE is located between the two openings of the square CORE.

[0013] Preferably, the center column is arranged on the center line of the winding portion.

[0014] A method for preparing an integrally formed small-size inductor comprises the following steps:

[0015] S1. Prepare I-shaped CORE and square CORE;

[0016] S2, winding the wire on the I-shaped CORE, and bending the wire to form an electrode surface;

[0017] S3, align and combine the I-shaped CORE and the square CORE;

[0018] S4, hot pressing the assembled I-shaped CORE and square CORE;

[0019] S5, curing and spraying, stripping the paint on the electrode surface and electroplating to form an electrode.

[0020] Preferably, in S1, composite powder is added to the I-shaped CORE and the square CORE, and the composite powder is an iron-based alloy powder, and the composition and proportion of the iron-based alloy powder are as follows:

[0021] Iron powder: 80-90%;

[0022] Nickel powder: 5-10%;

[0023] Silica powder: 0.5-2%.

[0024] Preferably, in S1, the I-shaped CORE and the square CORE are filled with composite powder and then pressed into shape under pressure;

[0025] Among them, the pressing pressure of I-shaped CORE molding is 4-5T / cm 2 , pressing time 2 seconds;

[0026] The pressing pressure of square CORE molding is 3.5-4T / cm 2 , pressing time 2 seconds.

[0027] Preferably, in S2, winding is performed on the center column and winding portion of the I-shaped CORE, the winding method is vertical winding, and the winding is in two layers, upper and lower.

[0028] Beneficial effects of the present invention: The present invention can form an inductor by hot pressing an I-shaped CORE and a square CORE, and has a higher inductance and a more stable ISAT. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the integrated small-size inductor of the present invention;

[0030] Figure 2 It is a schematic diagram of an I-shaped CORE of an integrated small-size inductor of the present invention;

[0031] Figure 3 It is a schematic diagram of the I-shaped CORE of the one-piece small-size inductor of the present invention after winding;

[0032] Figure 4 It is a schematic diagram of the CORE of the integrated small-size inductor of the present invention;

[0033] Figure 5 It is a schematic diagram of the inductor after pressing of the one-piece small-size inductor of the present invention;

[0034] Figure 6 This is a flow chart of a method for preparing an integrated small-size inductor according to the present invention;

[0035] In the figure: 1. I-shaped CORE; 2. flat copper wire; 3. square CORE; 11. first connecting part; 12. middle column; 13. winding part; 21. electrode surface; 31. receiving groove; 32. second connecting part; 33. opening. DETAILED DESCRIPTION

[0036] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0037] Embodiment 1:

[0038] like Figures 1 to 5As shown, an integrated small-size inductor includes: an I-shaped CORE 1, a flat copper wire 2 is wound around the I-shaped CORE 1, a square CORE 3 is arranged outside the I-shaped CORE 1, and the I-shaped CORE 1 and the square CORE 3 are integrated by hot pressing.

[0039] The I-shaped CORE1 is provided with a first connection part 11, the first connection part 11 is connected to the middle column 12, and the middle column 12 is connected to the winding part 13, wherein the first connection part 11 is used for hot pressing connection with the second connection part 32, and the middle column 12 and the winding part 13 are used for vertical winding of the flat copper wire 2. The first connection part 11 is square, and the middle part of the first connection part 11 is connected to one end of the middle column 12, the middle column 12 is cylindrical, and the other end of the middle column 12 is connected to the winding part 13, the winding part 13 is convex, and winding is performed on both sides of the convexity of the winding part 13. The I-shaped CORE1 is designed into an I-shaped mold, and after filling with composite powder, pressure is applied to press it into shape, and the pressure is 4-5T / cm 2 , pressing time 2 seconds.

[0040] The flat copper wire 2 is wound on the center column 12 and the winding part 13 in a vertical winding manner with two layers, with different numbers of turns according to different inductance products. The flat copper wire 2 is bent at the winding part 13 to form an electrode surface 21 .

[0041] The square CORE3 is provided with a receiving groove 31, a second connecting portion 32 is provided at the top of the receiving groove 31, and an opening 33 is provided at the bottom of the receiving groove 31, wherein the second connecting portion 32 is used to be hot-pressed with the first connecting portion 11, the receiving groove 31 is used to receive the I-shaped CORE1, and the opening 33 is used to allow the flat copper wire 2 on the winding portion 13 of the I-shaped CORE1 to extend out of the square CORE3 for easy use. The square CORE3 is formed by mold design, and after filling with composite powder, pressure is applied to press it into shape, and the pressure is 3.5-4T / cm 2 , pressing time 2 seconds.

[0042] In this embodiment, the first connection part 11 and the second connection part 32 match each other, so that after the I-shaped CORE 1 is placed in the square CORE 3 , the first connection part 11 of the I-shaped CORE 1 and the second connection part 32 of the square CORE 3 are aligned and combined together for hot pressing.

[0043] In this embodiment, the area of ​​the first connection portion 11 is larger than the circumscribed rectangular area of ​​the winding portion 13 , so that the I-shaped CORE 1 can be easily placed in the square CORE 3 and the first connection portion 11 and the second connection portion 32 of the I-shaped CORE 1 can be matched.

[0044] In this embodiment, the bottom area of ​​the receiving groove 31 of the square CORE 3 is larger than the circumscribed rectangular area of ​​the winding portion 13 of the I-shaped CORE 1 .

[0045] In this embodiment, the opening 33 of the square CORE3 is located on the same side as the convex portion of the winding portion 13 of the I-shaped CORE1, and the convex portion of the winding portion 13 of the I-shaped CORE1 is located between the two openings 33 of the square CORE3, so that after the I-shaped CORE1 is placed in the square CORE3, the winding portion 13 of the I-shaped CORE1 is in contact with the square CORE3, and the flat copper wire 2 wound on the winding portion 13 of the I-shaped CORE1 extends out of the square CORE3 through the opening 33 of the square CORE3.

[0046] In this embodiment, the center column 12 is disposed on the center line of the winding portion 13 .

[0047] Implementation plan: Use a mold to make an I-shaped CORE 1 and a square CORE 3, and wind a flat copper wire 2 vertically on the I-shaped CORE 1. The flat copper wire 2 is divided into two layers, upper and lower. After the winding of the I-shaped CORE 1 is completed, the end lead of the flat copper wire 2 on the winding part 13 forms a raised electrode surface 21. Align the electrode surface 21 with the opening 33 of the square CORE 3, and put the I-shaped CORE 1 into the square CORE 3. At this time, the electrode surface 21 extends out of the square CORE 3, and the first connecting part 11 of the I-shaped CORE 1 and the second connecting part 32 of the square CORE 3 are aligned and combined together. Temperature and pressure are applied by a servo hot press machine and a mold to make the I-shaped CORE 1 and the square CORE 3 hot-pressed. After hot pressing, the product is placed in an oven for baking for further curing, and then a layer of anti-rust glue is sprayed, and the electrode surface 21 is stripped of paint and electroplated to form an electrode.

[0048] Embodiment 2:

[0049] like Figure 6 As shown, a method for preparing an integrally formed small-size inductor comprises the following steps:

[0050] S1, prepare I-shaped CORE1 and square CORE3;

[0051] S2, winding a wire on the I-shaped CORE1, and bending the wire to form an electrode surface 21;

[0052] S3, align and combine I-shaped CORE1 and square CORE3;

[0053] S4, hot pressing the combined I-shaped CORE1 and square CORE3;

[0054] S5, curing and spraying, the electrode surface 21 is stripped of paint and electroplated to form an electrode.

[0055] In step S1, an I-shaped CORE1 and a square CORE3 are prepared. Specifically, the I-shaped CORE1 and the square CORE3 are prepared by a mold, and the first connecting part 11 and the second connecting part 32 are matched, the area of ​​the first connecting part 11 is larger than the circumscribed rectangular area of ​​the winding part 13, and the bottom area of ​​the receiving groove 31 of the square CORE3 is larger than the circumscribed rectangular area of ​​the winding part 13 of the I-shaped CORE1. Add composite powder to the mold, and the composite powder can be an iron-based alloy powder, wherein the components and proportions are iron powder: 80-90%; nickel powder: 5-10%; silicon powder: 0.5-2%. In a possible embodiment, in addition to iron powder, nickel powder and silicon powder, the components also include copper powder, and the proportion of copper powder is 1-5%. Add composite powder to the I-shaped CORE1, and apply pressure to press into shape after filling the composite powder, wherein the pressure is 4-5T / cm 2 The composite powder is added to the CORE3, and after filling the composite powder, pressure is applied to press the mold, wherein the pressure is 3.5-4T / cm 2 , pressing time 2 seconds.

[0056] In step S2, winding is performed on the I-shaped CORE 1, and the winding is bent to form an electrode surface 21. Specifically, winding is performed on the center column 12 and the winding portion 13 of the I-shaped CORE 1, and the winding method is vertical winding, and the winding is two layers, and different numbers of turns are wound according to different inductance products. The flat copper wire 2 is bent at the winding portion 13 to form the electrode surface 21, and the electrode surface 21 is located on the outer surface of the winding portion 13 of the I-shaped CORE 1.

[0057] In step S3, the I-shaped CORE 1 and the square CORE 3 are aligned and combined. Specifically, the end lead of the flat copper wire 2 on the winding part 13 forms a raised electrode surface 21, and the electrode surface 21 is aligned with the opening 33 of the square CORE 3, and the I-shaped CORE 1 is placed in the square CORE 3. At this time, the electrode surface 21 extends out of the square CORE 3, and the first connecting portion 11 of the I-shaped CORE 1 and the second connecting portion 32 of the square CORE 3 are aligned and combined together.

[0058] In step S4, the combined I-shaped CORE1 and square CORE3 are hot pressed. Specifically, the temperature and pressure are applied by the servo hot press machine and the mold to form the I-shaped CORE1 and square CORE3 by hot pressing. The servo hot press machine is started to heat it. When the temperature reaches the preset hot pressing temperature, the servo hot press machine starts to apply pressure. The size and application method of the pressure are determined according to the design requirements and material properties of the inductor.

[0059] In step S5, curing and spraying are performed, and the electrode surface 21 is stripped of paint and electroplated to form an electrode. Specifically, after hot pressing, the inductor is placed in an oven for further curing, and then the inductor is taken out, and a layer of anti-rust glue is sprayed on the inductor by rolling spraying. Finally, the electrode surface 21 is stripped of paint and electroplated to form an electrode, and the preparation of the inductor is completed.

[0060] In the prior art, an inductor is prepared by T-CORE and powder filling. When preparing inductors with the same specification size and direct current resistance (DCR), the inductor performance of the prior art and Example 1 is tested. The test parameters include inductance L and saturation current (ISAT). The test results are shown in Table 1.

[0061] Table 1. Test parameter value table.

[0062]

[0063] It can be seen from Table 1 that when preparing inductors with the same specifications, dimensions and DCR, compared with the prior art, Example 1 has a higher inductance, and Example 1 has a smaller decrease in ISAT and has a more stable ISAT.

[0064] The present invention can form an inductor by hot pressing the I-shaped CORE 1 and the square CORE 3, and has a higher inductance and a more stable ISAT.

[0065] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An integrated small-size inductor, characterized in that: include: I-shaped CORE, flat copper wire is wound on the I-shaped CORE, square CORE is arranged outside the I-shaped CORE, and the I-shaped CORE and the square CORE are integrally formed by hot pressing.

2. The one-piece small-size inductor according to claim 1, characterized in that: The I-shaped CORE is provided with a first connection portion, the first connection portion is connected to the center column, and the center column is connected to the winding portion; The first connecting part is used for hot pressing connection with the second connecting part, and the middle column and the winding part are used for vertically winding the flat copper wire.

3. The one-piece small-size inductor according to claim 2, characterized in that: The square CORE is provided with a receiving groove, a second connecting part is provided at the top of the receiving groove, and an opening is provided at the bottom of the receiving groove; wherein the second connecting part is used for hot pressing connection with the first connecting part, the receiving groove is used for accommodating the I-shaped CORE, and the opening is used for allowing the electrode surface on the winding part of the I-shaped CORE to extend out of the square CORE.

4. The one-piece small-size inductor according to claim 3, characterized in that: The first connection part and the second connection part are consistent with each other, the area of ​​the first connection part is larger than the circumscribed rectangular area of ​​the winding part, and the bottom surface area of ​​the receiving groove of the square CORE is larger than the circumscribed rectangular area of ​​the winding part of the I-shaped CORE.

5. The one-piece small-size inductor according to claim 3, characterized in that: The opening of the square core is located on the same side as the convex portion of the winding portion of the I-core, and the convex portion of the winding portion of the I-core is located between the two openings of the square core.

6. The one-piece small-size inductor according to claim 3, characterized in that: The center column is arranged on the center line of the winding part.

7. A method for preparing an integrally formed small-size inductor, applicable to an integrally formed small-size inductor as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Prepare I-shaped CORE and square CORE; S2, winding the wire on the I-shaped CORE, and bending the wire to form an electrode surface; S3, align and combine the I-shaped CORE and the square CORE; S4, hot pressing the assembled I-shaped CORE and square CORE; S5, curing and spraying, stripping the paint on the electrode surface and electroplating to form an electrode.

8. The method for preparing an integrally formed small-size inductor according to claim 7, characterized in that: In S1, composite powder is added to the I-shaped CORE and the square CORE. The composite powder is an iron-based alloy powder. The composition and proportion of the iron-based alloy powder are as follows: Iron powder: 80-90%; Nickel powder: 5-10%; Silica powder: 0.5-2%.

9. The method for preparing an integrally formed small-size inductor according to claim 7, characterized in that: In S1, the I-shaped CORE and the square CORE are filled with composite powder and then pressed and molded; Among them, the pressing pressure of I-shaped CORE molding is 4-5T / cm 2 , pressing time 2 seconds; The pressing pressure of square CORE molding is 3.5-4T / cm 2 , pressing time 2 seconds.

10. The method for preparing an integrally formed small-size inductor according to claim 7, characterized in that: In S2, winding is performed on the center column and winding part of the I-shaped CORE. The winding method is vertical winding, and the winding is in two layers, upper and lower.

Images