CN115642030A - Preparation method of inductor - Google Patents
Preparation method of inductor Download PDFInfo
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- CN115642030A CN115642030A CN202211272591.9A CN202211272591A CN115642030A CN 115642030 A CN115642030 A CN 115642030A CN 202211272591 A CN202211272591 A CN 202211272591A CN 115642030 A CN115642030 A CN 115642030A
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Abstract
The invention discloses a preparation method of an inductor, which comprises the following steps: pressing the magnetic material coated with the insulating resin into a magnetic core and a base, and winding a coil on the surface of the magnetic core to form a coil and magnetic core combined part; detachably fixing a plurality of coil magnetic core combined parts on a jig, transferring the jig to a base, and enabling the coil magnetic core combined parts to be in contact with the base; giving pressure to the jig towards the base, so that at least half of the coil and magnetic core combined part is embedded into the base to form an assembly body, and simultaneously separating the coil and magnetic core combined part from the jig and removing the jig; filling magnetic powder coated with insulating resin on one side of the base, where the coil and magnetic core combined part is embedded, to fill the side smoothly, and then processing the side to obtain a magnetic sheet; and cutting the magnetic sheet into a plurality of inductor substrates, coating the inductor substrates with an outer coating, removing part of the outer coating on the side surface, and manufacturing electrode terminals on the side surface from which the coating is removed to obtain the finished inductor.
Description
Technical Field
The invention relates to the field of inductor preparation, in particular to a preparation method of an inductor.
Background
Electronic products such as mobile phones, tablet computers, intelligent wearable devices and the like are continuously developed towards miniaturization and lightness, functions are increasingly abundant, and higher requirements are provided for electronic components; the inductor is one of the most important passive devices of an electronic circuit, and needs to have the characteristics of small size, low direct-current resistance, large current and low loss simultaneously in order to meet market demands.
Chinese patent publication No. CN108735429A discloses a coil component (inductor) in which a coil conductor is embedded in a magnetic portion containing metal particles and a resin material, and a groove is provided in the bottom of the magnetic portion and the coil conductor is led out, thereby obtaining a smaller coil component. The magnetic part is formed by pressing, the strength is further improved by heat treatment, the coil conductor is directly wound on the magnetic part, and then the magnetic material powder is added for pressing to obtain the inductor matrix. The main drawbacks of this method are: firstly, because the coil conductor is directly wound on the magnetic part, the magnetic part needs high strength and needs to be subjected to heat treatment, and the magnetic part after the heat treatment is difficult to bond with the magnetic material powder added and pressed for the second time because the resin is solidified, air gaps are easily formed in a layered mode, and the inductance value of a finished product is reduced; second, the magnetic part has a leaf-like pendulum at the clamping position during winding, and when manufacturing 2016, 1608, or other small-sized inductors, the leaf-like pendulum is likely to break even if the magnetic part is subjected to heat treatment.
In order to improve the above problems, chinese patent publication No. CN105355409A discloses a method for manufacturing a surface mount inductor, which includes steps of manufacturing a base with a boss, winding an air-core coil, and then sleeving the base boss, so as to overcome the problems of difficult winding and easy leaf breakage, and further optimizing the method of pressing into a whole piece and then cutting into an inductor base, but the method also has some disadvantages: firstly, in order to enable an air-core coil to be smoothly sleeved on a boss, the inner diameter size of the coil must be larger than that of the boss, moving spaces in all directions exist after the coil is sleeved, and the problem that the coil is cut during cutting exists; secondly, the inductor boss with small size is small, and the pressing difficulty of the base is high; thirdly, in the pressing process, the boss can bear large pressure, when manufacturing 2016, 1608 and other small-sized inductors, the boss is easy to break due to the undersize, and the joint of the boss and the base is a stress concentration position, so that an air gap is formed in the inductor, and inductance can be reduced.
When the inductor is applied to a switching power supply circuit, in order to improve the conversion efficiency of the power supply, how to reduce the hysteresis loss and the eddy current loss in a high-frequency application environment is also an important research subject; iron-based amorphous powder and iron-based nanocrystalline powder are widely applied to inductor manufacturing due to the characteristic of low loss, but the two kinds of powder have high hardness, are not easy to deform when being pressed and have poor pressing performance, so that the magnetic core manufactured by the iron-based amorphous powder and the iron-based nanocrystalline powder has low common strength. Both of the above two technical solutions have high requirements on the strength of the magnetic core, and further increase the process difficulty, so a new technical solution is urgently needed to overcome the difficulties encountered in the prior art.
Disclosure of Invention
In order to solve the problems in the prior art, the invention discloses a preparation method of an inductor.
A method for preparing an inductor comprises the following steps:
step 1, pressing the magnetic material coated with the insulating resin into a magnetic core and a base, wherein the density of the pressed magnetic core is higher than that of the base, winding a coil on the surface of the magnetic core to form a coil and magnetic core combined part with two connecting pins,
step 2, detachably fixing a plurality of coil and magnetic core combination parts on a jig, transferring the jig with the coil and magnetic core combination parts to a base, and enabling the coil and magnetic core combination parts to be in contact with the base;
step 3, giving pressure to the jig towards the base to enable at least half of the coil and magnetic core combined part to be embedded into the base, enabling the coil and magnetic core combined part to be separated from the jig and moving away from the jig, and enabling the coil and magnetic core combined part and the base to form an assembly body;
step 4, filling magnetic powder coated with insulating resin on one side of the base, in which the coil and magnetic core combined part is embedded, to fill the side smoothly, and then carrying out cold pressing, hot pressing and heat treatment on the assembly body filled with the magnetic powder to obtain a magnetic sheet;
step 5, cutting the magnetic sheet into a plurality of inductor bases according to the position of the coil and magnetic core combination part, respectively taking two side surfaces corresponding to two connecting pins on the inductor bases as a first terminal surface and a second terminal surface, and taking the side surface on the inductor bases, which is vertical to the first terminal surface and the second terminal surface, as a third terminal surface;
step 6, coating an outer coating on the outer surface of the inductor substrate, and then removing the outer coatings on the first terminal surface, the second terminal surface and the third terminal surface;
and 7, manufacturing two electrode terminals on the side surface of the inductor substrate with the coating removed, wherein each electrode terminal is electrically communicated with one corresponding connecting pin, and thus obtaining the finished inductor product.
Specifically, if the density of the base is equal to or greater than that of the magnetic core, the coil and magnetic core combination portion is difficult to be embedded into the base, and even if the coil and magnetic core combination portion is embedded into the base, the base and the base are deformed greatly, so that the density of the pressed base is lower than that of the magnetic core;
the coil and magnetic core combined parts are firstly fixed on the jig, and pressure is applied to the jig, so that the coil and magnetic core combined parts fixed on the jig can be simultaneously embedded into the base, the efficiency of embedding the coil and magnetic core combined parts into the base can be obviously improved, and the consistency of embedding the coil and magnetic core combined parts into the base can be improved;
in addition, when the overcoat layers on the first terminal face, the second terminal face, and the third terminal face are removed, laser removal or grinding removal may be employed; the electrode terminal is manufactured by brushing and/or plating the electric paste.
Preferably, the magnetic material is one or a mixture of more of carbonyl iron powder, iron-based amorphous powder, iron-based nanocrystalline powder, iron silicon chromium powder, iron silicon aluminum powder and iron nickel powder. More preferably, the magnetic material is an iron-based amorphous powder, an iron-based nanocrystalline powder, or a mixture of both and other soft magnetic powders.
Preferably, the jig is provided with a plurality of positioning grooves for fixing the coil and magnetic core combination part, and the plurality of positioning grooves are arranged in sequence at certain intervals.
Specifically, fix coil magnetic core composite portion after on the tool and then to the whole pressure that applys of tool make coil magnetic core composite portion imbed the base, because the constant head tank arranges in order on the locating plate, consequently with coil magnetic core composite portion imbed in the base after, coil magnetic core composite portion still is the orderly arrangement on the base.
Preferably, the jig comprises a positioning plate provided with a plurality of positioning grooves and a vacuumizing device connected with each positioning groove;
when the coil and magnetic core combination part is fixed, the coil and magnetic core combination part is firstly placed in the positioning groove, and then the vacuumizing device is started to vacuumize the positioning groove so as to fix the coil and magnetic core combination part on the positioning plate; the coil magnetic core combination part is embedded into the base, and the positioning plate is separated from the coil magnetic core combination part after the vacuumizing device is closed.
Specifically, this kind of fixed mode, not only effectually fix coil magnetic core composite portion, can also effectually prevent that the constant head tank from being worn and torn, the life of effectual extension locating plate.
Preferably, the positioning plate is provided with a resetting device which enables the jig to reset after the coil and magnetic core combined part is embedded into the base.
Specifically, after embedding the coil and magnetic core combination part into the base, the vacuumizing device is closed, the jig is stopped from exerting pressure, the jig moves towards the direction far away from the base under the action of the resetting device, the auxiliary jig is separated from the coil and magnetic core combination part, and then the jig is moved out.
Preferably, the coil is wound on the magnetic core in an external winding mode, and after winding is completed, two connecting pins of the coil are located on two outermost sides opposite to the magnetic core.
Specifically, the angle between the connecting line between the two connecting pins and the central axis of the magnetic core is 30-180 degrees.
Preferably, the coating is applied to the outer surface of the inductor substrate by hot roll coating or dip coating or spray coating.
Preferably, the magnetic sheet is cut into the inductor substrate by physically cutting with a grinding wheel.
Compared with the prior art, the invention has the advantages that:
the base of the finished inductor is simple in shape and low in manufacturing cost, the problems of layering, leaf pendulum fracture and the like in the existing manufacturing method are solved, and the advantages are more obvious when the inductor with the small size is manufactured; the coil and magnetic core combination part is directly pressed into the base with proper density, so that the purpose of accurately positioning the coil is achieved, the risk of breakage of the boss in the subsequent pressing process is avoided, and the finished product performance of the inductor is more stable; the coil is not dependent on boss positioning, and is directly embedded into the base after being transferred, so that positioning inaccuracy caused by fit clearance is avoided, and the qualified rate of cutting can be ensured; in addition, the technical scheme that this application provided can solve iron-based amorphous powder, iron-based nanocrystalline powder preparation magnetic core not enough problem of intensity, realizes being applied to inductance manufacturing with above-mentioned two kinds of powders, can show the reduction loss. .
Drawings
Fig. 1 is a flow chart of a method for manufacturing an inductor according to the present invention;
fig. 2 is a schematic structural diagram of a coil and core assembly provided by the present invention;
FIG. 3 is a schematic view of a positioning plate of the jig according to the present invention;
FIG. 4 is a schematic view of the structure of an assembly provided by the present invention;
FIG. 5 is a schematic structural diagram of a magnetic sheet according to the present invention;
FIG. 6 is a schematic diagram of a magnetic sheet according to the present invention;
FIG. 7 is a schematic structural diagram of an inductor base according to the present invention;
fig. 8 is a schematic structural diagram of a finished inductor product provided by the present invention.
Detailed Description
The invention is further described with reference to the following figures and specific embodiments.
A method for manufacturing an inductor, as shown in fig. 1, includes the following steps:
step 1, pressing a magnetic material coated with insulating resin into a magnetic core 11 and a base 20, wherein the density of the pressed magnetic core 11 is greater than that of the base 20;
if the density of the base 20 is equal to or greater than that of the magnetic core 11, the coil-core combination 13 is difficult to be embedded in the base 20, the base 20 cannot position the coil-core combination 13, and the coil-core combination 13 and the base 20 are greatly deformed even if the base 20 is embedded in the base 20, so that the density of the pressed base 20 should be lower than that of the magnetic core 11;
as shown in fig. 2, a coil 12 is wound on the surface of a magnetic core 11 to form a coil-magnetic core combination part 13 with two connecting pins;
the coil 12 is wound on the magnetic core 11 in an external winding mode, and after the winding is finished, two connecting pins 14 of the coil 12 are positioned at two opposite outermost sides of the magnetic core 11; after the winding is finished, the included angle between the connecting line between the two connecting pins 14 and the central axis of the magnetic core 11 is 30-180 degrees;
the magnetic material is one or a mixture of more of carbonyl iron powder, iron-based amorphous powder, iron-based nanocrystalline powder, iron silicon chromium powder, iron silicon aluminum powder and iron nickel powder. More preferably, the magnetic material is iron-based amorphous powder, iron-based nanocrystalline powder, or a mixture of the iron-based amorphous powder and the iron-based nanocrystalline powder with other soft magnetic powder.
Step 2, detachably fixing a plurality of coil and magnetic core combination parts 13 on a jig 30, transferring the jig 30 with the coil and magnetic core combination parts 13 onto a base 20, and enabling the coil and magnetic core combination parts 13 to be in contact with the base 20;
the jig 30 is provided with a plurality of positioning slots 32 for fixing the coil and magnetic core assembly 13, and the plurality of positioning slots 32 are arranged in order at certain intervals.
The positioning slots 32 are usually arranged in an array, after the coil and core assembly 13 is fixed on the jig 30, pressure is applied to the whole jig 30 to embed the coil and core assembly 13 into the base 20, and since the positioning slots 32 are arranged in an array on the positioning plate 31, the coil and core assembly 13 is still arranged in an array on the base 20 after the coil and core assembly 13 is embedded into the base 20;
as shown in fig. 3, the jig 30 includes a positioning plate 31 having a plurality of positioning slots 32, and a vacuum extractor connected to each positioning slot 32;
when the coil and magnetic core combination part 13 is fixed, the coil and magnetic core combination part 13 is firstly placed in the positioning groove 32, and then the vacuumizing device is started to vacuumize the positioning groove 32 so as to fix the coil and magnetic core combination part 13 on the positioning plate 31; the coil-core assembly 13 is fitted into the base 20, and after the vacuum-pumping device is closed, the positioning plate 31 is separated from the coil-core assembly 13.
This kind of fixed mode, not only effectual coil magnetic core composite portion 13 is fixed, can also effectually prevent that constant head tank 32 from being worn and torn, the effectual life who prolongs positioning plate 31.
The positioning plate 31 is provided with a resetting device for resetting the jig 30 after the coil and magnetic core combination part 13 is embedded into the base 20.
After the coil and magnetic core combination part 13 is embedded into the base 20, the vacuumizing device is closed, the pressure applied to the jig 30 is stopped, the jig 30 moves towards the direction far away from the base 20 under the action of the resetting device, the auxiliary jig 30 is separated from the coil and magnetic core combination part 13, and then the jig 30 is moved out;
step 3, applying a pressure to the jig 30 toward the base 20 to embed at least half of the coil and core combination portion 13 into the base 20, and simultaneously separating the coil and core combination portion 13 from the jig 30 and removing the jig 30, as shown in fig. 4, the coil and core combination portion 13 and the base 20 form an assembly body 41;
fixing a plurality of coil and magnetic core combination parts 13 on a jig 30, and applying pressure to the jig 30, so that the plurality of coil and magnetic core combination parts 13 fixed on the jig 30 can be embedded into the base 20 at the same time, thereby not only remarkably improving the efficiency of embedding the coil and magnetic core combination parts 13 into the base 20, but also improving the consistency of embedding the coil and magnetic core combination parts 13 into the base 20;
in addition, the volume of the coil-core combination part 13 embedded in the base 20 is 50-100% of the volume of the coil-core combination part;
step 4, filling magnetic powder coated with insulating resin on one side of the base 20 where the coil and core combination part 13 is embedded, so as to fill the side surface smoothly, and then performing cold pressing, hot pressing and heat treatment on the assembly 41 filled with the magnetic powder to obtain a magnetic sheet 42 as shown in fig. 5;
step 5, as shown in fig. 6, according to the position of the coil-core assembly 13, cutting the magnetic sheet 42 into a plurality of inductor bases 50 as shown in fig. 7 by using a grinding wheel physical cutting method, wherein two side surfaces corresponding to the two connection pins 14 on the inductor bases 50 are respectively used as a first terminal surface 51 and a second terminal surface 52, and a side surface perpendicular to the first terminal surface 51 and the second terminal surface 52 on the inductor bases 50 is used as a third terminal surface 53;
step 6, coating an outer coating on the outer surface of the inductor substrate 50 by adopting a hot roll coating or dip coating or spray coating method, and then removing the outer coatings on the first terminal surface 51, the second terminal surface 52 and the third terminal surface 53 by adopting a laser removal or grinding removal mode;
In order to further clarify the advantages obtained by successfully applying the iron-based amorphous powder and the iron-based nanocrystalline powder in the technical scheme of the invention, the following processing groups are arranged by taking magnetic materials of different materials as variables, inductor finished products are respectively manufactured for performance detection,
the magnetic material powder composition for each treatment group is shown in table 1:
TABLE 1
Taking 1412065-R47 specifications as an example, the inductance, the direct current resistance, the saturation current and the conversion efficiency of the inductor are tested, the conversion efficiency test method is that each group of inductors are respectively installed on the same voltage reduction module circuit and are tested under the condition of the same frequency and input voltage, and the test results of each processing group are shown in Table 2:
TABLE 2
Therefore, under the condition that other performances are not changed, the conversion efficiency of the processing group 1 is superior to that of the comparison group, the proportion of the iron-based amorphous powder in the raw material is continuously increased, the saturation current is reduced, but the conversion efficiency is continuously improved, and the advantage is obvious in a circuit requiring high conversion efficiency.
The base 20 of the finished inductor 60 manufactured by the method provided by the embodiment has a simple shape and low manufacturing cost, and meanwhile, the problems of layering, blade pendulum fracture and the like of the existing manufacturing method are avoided, and the advantages are more obvious when a micro-size inductor is manufactured; the coil magnetic core combination part 13 is directly pressed into the base 20 with proper density, so that the purpose of accurately positioning the coil 12 is achieved, the risk of breakage of the boss in the subsequent pressing process is avoided, and the performance of the finished inductor product 60 is more stable; the coil 12 is not dependent on boss positioning, and is directly embedded into the base 20 after being transferred, so that positioning inaccuracy caused by fit clearance is avoided, and the qualified rate of cutting can be ensured; the technical scheme provided by the embodiment can solve the problem that the strength of the magnetic core 11 manufactured by the iron-based amorphous powder and the iron-based nanocrystalline powder is not enough, and can remarkably reduce the loss by applying the two powders to inductor manufacturing.
Claims (9)
1. The preparation method of the inductor is characterized by comprising the following steps of:
step 1, pressing the magnetic material coated with the insulating resin into a magnetic core and a base, wherein the density of the pressed magnetic core is higher than that of the base, winding a coil on the surface of the magnetic core to form a coil and magnetic core combined part with two connecting pins,
step 2, detachably fixing a plurality of coil and magnetic core combination parts on a jig, transferring the jig with the coil and magnetic core combination parts to a base, and enabling the coil and magnetic core combination parts to be in contact with the base;
step 3, giving pressure to the jig towards the base to enable at least half of the coil and magnetic core combined part to be embedded into the base, enabling the coil and magnetic core combined part to be separated from the jig and moving away from the jig, and enabling the coil and magnetic core combined part and the base to form an assembly body;
step 4, filling magnetic powder coated with insulating resin on one side of the base, in which the coil and magnetic core combined part is embedded, to fill the side smoothly, and then carrying out cold pressing, hot pressing and heat treatment on the assembly body filled with the magnetic powder to obtain a magnetic sheet;
step 5, cutting the magnetic sheet into a plurality of inductor matrixes according to the position of the coil and magnetic core combination part, respectively taking two side surfaces corresponding to two connecting pins on the inductor matrixes as a first terminal surface and a second terminal surface, and taking the side surfaces, which are perpendicular to the first terminal surface and the second terminal surface, on the inductor matrixes as third terminal surfaces;
step 6, coating an outer coating on the outer surface of the inductor substrate, and then removing the outer coatings on the first terminal surface, the second terminal surface and the third terminal surface;
and 7, manufacturing two electrode terminals on the side surface of the inductor substrate with the coating removed, wherein each electrode terminal is electrically communicated with one corresponding connecting pin, and thus obtaining the finished inductor product.
2. The method of claim 1, wherein the magnetic material is a mixture of one or more of carbonyl iron powder, iron-based amorphous powder, iron-based nanocrystalline powder, iron silicon chromium powder, iron silicon aluminum powder, and iron nickel powder.
3. The method of claim 2, wherein the magnetic material is an iron-based amorphous powder, an iron-based nanocrystalline powder, or a mixture of both with other soft magnetic powders.
4. The method for manufacturing an inductor according to claim 1, wherein the jig is provided with a plurality of positioning slots for fixing the coil and core assembly, and the plurality of positioning slots are arranged in order at a certain interval.
5. The method for manufacturing an inductor according to claim 4, wherein the jig comprises a positioning plate having a plurality of positioning grooves, and a vacuum-pumping device connected to each positioning groove;
when the coil and magnetic core combination part is fixed, the coil and magnetic core combination part is firstly placed in the positioning groove, and then the vacuumizing device is started to vacuumize the positioning groove so as to fix the coil and magnetic core combination part on the positioning plate; the coil magnetic core combination part is embedded into the base, and the positioning plate is separated from the coil magnetic core combination part after the vacuumizing device is closed.
6. The method for manufacturing an inductor according to claim 4, wherein the positioning plate is provided with a resetting device for resetting the jig after the coil and core assembly is embedded in the base.
7. The method as claimed in claim 1, wherein the coil is wound around the core by an external winding method, and the two connecting pins of the coil are located at two outermost sides of the core after the winding is completed.
8. The method for preparing the inductor according to claim 1, wherein the coating is applied on the outer surface of the inductor substrate by hot roll coating, dip coating or spray coating.
9. The method of claim 1, wherein the magnetic sheet is cut into the inductor base by physically cutting the magnetic sheet with a cut-off wheel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211272591.9A CN115642030A (en) | 2022-10-18 | 2022-10-18 | Preparation method of inductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211272591.9A CN115642030A (en) | 2022-10-18 | 2022-10-18 | Preparation method of inductor |
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| Publication Number | Publication Date |
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| CN115642030A true CN115642030A (en) | 2023-01-24 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211272591.9A Pending CN115642030A (en) | 2022-10-18 | 2022-10-18 | Preparation method of inductor |
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| CN (1) | CN115642030A (en) |
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- 2022-10-18 CN CN202211272591.9A patent/CN115642030A/en active Pending
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