A process for the production of inductors

Abstract

The application discloses an inductor production process, and belongs to the technical field of inductors.The application solves the problem that the inductor heat pressure powder filling process in the prior art is limited by powder flowability and powder filling plate aperture, and the non-lead surface powder filling amount of the inductor is insufficient, thereby becoming a bottleneck of inductor inductance, and the scheme is as follows: S1, a first semi-finished product is prepared; S2, an enameled wire is wound on a column body of the first semi-finished product; S3, the first semi-finished product is buckled in a second semi-finished product; S4, the buckled first semi-finished product and the second semi-finished product are placed in a heat pressure station for pressure bonding; and S5, the product after the heat pressure station pressure bonding is spaced and placed on a flat plate for cooling.The application has the effects that the inductor has higher inductance and lower resistance, and the inductor inductance and / or resistance required by the application is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of inductors, and particularly relates to an inductor production process. BACKGROUND

[0002] The existing inductor hot-pressing powder filling process is limited by the flowability of the powder material and / or the aperture of the powder filling plate, resulting in insufficient powder filling amount on the non-lead surface of the inductor, thereby becoming a bottleneck of the inductance value of the inductor. Therefore, the existing process cannot meet the requirements of some customers for high inductance value models, or the yield is low. SUMMARY

[0003] The application provides an inductor production process, which solves the problem in the prior art that the inductor hot-pressing powder filling process is limited by the flowability of the powder material and the aperture of the powder filling plate, resulting in insufficient powder filling amount on the non-lead surface of the inductor, thereby becoming a bottleneck of the inductance value of the inductor.

[0004] In view of the above problems, the application provides an inductor production process, which comprises

[0005] S1. Preparing a first semi-finished product, the first semi-finished product comprising a flat plate and a column, the flat plate being connected to the column downward, the flat plate being a rectangular surface, and each side of the rectangular surface extending outward along a side edge line to form a side edge protrusion, the side edges of two adjacent side edge protrusions being perpendicular to each other to form a vertical port, and the flat plate forming four vertical ports in total.

[0006] S2. Wrapping an enameled wire around the column of the first semi-finished product.

[0007] S3. Clamping the first semi-finished product in a second semi-finished product, the second semi-finished product being a columnar groove capable of accommodating the column of the first semi-finished product, the flat plate and the side edge protrusions of the first semi-finished product covering the top opening of the second semi-finished product, and leaving a gap in communication with the groove of the second semi-finished product at the vertical port of the flat plate, so that the two lead wires of the enameled wire are led out from two of the gaps, and at least one of the other two gaps can be used as a powder filling gap.

[0008] S4. Placing the clamped first semi-finished product and second semi-finished product together in a hot-pressing station for pressing.

[0009] S5. Spacing the finished product after hot-pressing station pressing on the flat plate for cooling.

[0010] Further, step S3 comprises

[0011] Step 3.1. The first semi-finished product and the second semi-finished product form a closed body, and the enameled wire is wrapped around the column of the first semi-finished product and is wrapped in the second semi-finished product.

[0012] Step 3.2. Detecting the interval of the fitting gap between the first semi-finished product and the second semi-finished product, if the interval of the fitting gap is less than a set value, the closure is qualified, if the interval of the fitting gap is greater than or equal to the set value, the closure is unqualified, the closure is re-separated and implanted again. After buckling, whether it is qualified is detected by using a CCD.

[0013] Step 3.3. The closure implanted again is repeated step 3.1.

[0014] Further, the set value is 2mm.

[0015] Further, step S4 further comprises that after each piece of the pressed product is placed for a preset number of times, whether the production error is within a normal range is detected, if not, the equipment data is adjusted, and after the production error of the pressed product produced by the adjusted equipment is within the normal range, batch production is carried out.

[0016] Further, the finished product is placed at an interval of 5cm and is placed until the product is cooled to room temperature.

[0017] Further, the first semi-finished product is made by a cold pressing forming process.

[0018] Further, a spacer plate is further arranged between the finished product and the flat plate.

[0019] Further, the flat plate is a square surface.

[0020] Beneficial effects: Compared with the prior art, the technical problems of low inductance and high resistance can be overcome, the inductance has higher inductance and lower resistance, the effect of realizing the inductance inductance and / or resistance required by customers is achieved, and the effect of mass production is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a process flow diagram of an inductance production process in the embodiment of the application.

[0022] Figure 2 It is a top view of the first semi-finished product in the embodiment of the application. DETAILED DESCRIPTION

[0023] The embodiment of the application provides an inductance production process, which is used for solving the problem that in the prior art, the inductance hot-pressing powder filling process is limited by powder flowability and filling plate aperture, so that the filling amount of the inductance non-lead surface is insufficient, thereby becoming a bottleneck of inductance inductance.

[0024] The technical scheme provided by the present application is a preparation method of an inductor, comprising: preparing a first semi-finished product, wherein the first semi-finished product is made by a cold pressing forming process; winding an enameled wire on the first semi-finished product; according to the non-lead thickness design requirement of the inductor, a corresponding second semi-finished product is made; the first semi-finished product is pressed together with the enameled wire in the second semi-finished product, and the first semi-finished product and the second semi-finished product that are buckled together are put into a hot pressing station for pressing, and powder is injected into the second semi-finished product during the pressing process; the processed finished product is placed on the ground for cooling and stacking in intervals.

[0025] In the above scheme, the first semi-finished product comprises a flat plate and a column, the flat plate is connected to the column downward, the flat plate is a rectangular face, and each side of the rectangular face extends outward along a side edge line to form a side edge protrusion, the side edges of two adjacent side edge protrusions are perpendicular to each other to form a vertical port, and the flat plate forms four vertical ports in total. The second semi-finished product is a columnar groove and can accommodate the column of the first semi-finished product, the flat plate and the side edge protrusion of the first semi-finished product cover the top opening of the second semi-finished product, and a gap is reserved at the vertical port of the flat plate to communicate with the groove of the second semi-finished product, so that the two end leads of the enameled wire are led out from two of the gaps, and at least one of the other two gaps can serve as a powder filling gap.

[0026] Compared with the prior art, the present application wraps the column with the wrapped wire by making the second semi-finished product instead of directly filling the powder, so that the present application can realize mass production, reduces the possibility of the coil being pierced by the powder, and ensures the uniformity of the hot pressing and powder filling through the setting of the vertical port, so that the positive and negative electrode joints do not need to be led out by folding the line, and the technical problems of low inductance and high resistance can be overcome, so that the inductor has higher inductance and lower resistance, and the effect of realizing the inductance inductance and / or resistance required by the customer is achieved.

[0027] The technical scheme of the present application will be described in detail below by means of the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical scheme of the present application, and are not limitations of the technical scheme of the present application. In the case of no conflict, the technical features in the embodiments and the embodiments can be combined with each other.

[0028] In this paper, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects.

[0029] Embodiment one

[0030] Figure 1 Figure 1 is a schematic diagram of a process flow of an inductor production process according to an embodiment of the present application. Figure 1 As shown in Figure 1, the inductor production process according to an embodiment of the present application comprises the following steps:

[0031] Preparation of the plate material, polishing and arranging the plate material, stacking the polished plate material, and placing the plate material into a cold-press forming device;

[0032] Step s101, preparation of a first semi-finished product, wherein the first semi-finished product is made by a cold-press forming process;

[0033] Step s102, winding an enameled wire on the first semi-finished product;

[0034] Step s103, making a corresponding second semi-finished product according to the non-lead thickness design requirements of the inductor;

[0035] Step s104, pressing the first semi-finished product together with the enameled wire into the second semi-finished product;

[0036] Step s105, placing the first semi-finished product and the second semi-finished product that are buckled together into a hot-press station for pressing;

[0037] Cooling and stacking, and placing the processed finished product at intervals on the ground, wherein a spacer plate is further arranged between the finished product and the ground.

[0038] By improving the traditional direct column hot-press powder filling mode to press the second semi-finished product with a U-shaped longitudinal section in advance, and after hot-press forming, the product has the technical problems of low inductance and high resistance can be overcome, so that the inductor has higher inductance and lower resistance, and the effect of realizing the inductance and / or resistance required by the customer is achieved.

[0039] In one technical solution, the pressing of the first semi-finished product together with the enameled wire into the second semi-finished product comprises the following steps: step 1011, the first semi-finished product and the second semi-finished product form a closed body, and the enameled wire is wrapped in the first semi-finished product and the second semi-finished product;

[0040] Step 1012, detecting the spacing of the fitting gap between the first semi-finished product and the second semi-finished product, if the spacing of the fitting gap is less than 2mm, the closed body is qualified, if the spacing of the fitting gap is greater than or equal to 2mm, the closed body is unqualified, the closed body is re-separated and re-implanted;

[0041] Step 1013, repeating step 1012 for the re-implanted closed body.

[0042] Optionally, the distance between the first half-product and the second half-product can be measured manually using a vernier caliper or measured using an electronic measuring device, and the measurement error is within 10 um.

[0043] In one technical solution, the first half-product has a T-shaped longitudinal section.

[0044] In one technical solution, the first half-product includes a flat plate and a column, the flat plate is connected to the column downward, the flat plate has a rectangular surface, and each side of the rectangular surface extends outward along a side edge to form a side edge protrusion, the side edges of two adjacent side edge protrusions are perpendicular to each other to form a vertical port, and the flat plate forms four vertical ports. Compared with the scheme of directly using a flat plate with a rectangular surface, the scheme provides four symmetrical vertical ports for wrapping the wire joint and as a powder filling port in the pressing station. The effects achieved mainly include the following points:

[0045] For the joint of the wrapped wire, the existing scheme of directly using a flat plate with a rectangular surface has a lead-out point on the long side and in an opposite position, the lead-out point position is relatively fixed, and the lead-out point position needs to be considered when wrapping the wire, and the lead line needs to be folded to the lead-out point. The four symmetrical vertical ports formed by the present application can all be used as lead-out positions, and the lead line can be led out nearby without folding when wrapping the wire.

[0046] For the pressing step of the pressing station, the existing scheme of directly using a flat plate with a rectangular surface has a feeding point on the long side and in an opposite position, and it is difficult to make the feeding uniform and dispersed between the second half-product and the first half-product after feeding, and a special vibrating disc needs to be used. The four symmetrical vertical ports of the present application can all be used as feeding ports, and the symmetrical ports are symmetrically arranged, the feeding is uniform and dispersed uniformly, and a general vibrating disc can be used.

[0047] In one technical solution, the flat plate has a square surface, which can ensure better symmetry.

[0048] In one technical solution, the step of winding the enameled wire on the first half-product includes winding the enameled wire on the lower part of the half-product with a T-shaped longitudinal section.

[0049] In one technical solution, the second half-product has a U-shaped longitudinal section.

[0050] In one technical solution, the first half-product and the second half-product form a closed body, which includes pressing the part of the half-product with a T-shaped longitudinal section and the enameled wire on the opening of the half-product with a U-shaped longitudinal section, and the two ends of the top of the half-product with a T-shaped longitudinal section close the top of the half-product with a U-shaped longitudinal section.

[0051] In one technical solution, after the first and second half products buckled together are put into a hot pressing station for the pressing step, the production process further comprises: checking whether the production error of each piece of the pressed product is within a normal range after the pressed product is spaced for a preset number of times, if not, adjusting the equipment data, and when the pressed product produced by the adjusted equipment has an error within the normal range, batch production is performed.

[0052] In one technical solution, the interval of the placed processed products is 5 cm, and the products need to be placed for three hours to cool to room temperature.

[0053] The present application can solve the problem of low yield, make the inductance have higher inductance and lower resistance, achieve the effect of inductance and / or resistance required by customers, and realize mass production.

[0054] In one preferred embodiment, the magnetic core preparation method of the inductance is as follows:

[0055] (1) A required amount of carbonyl iron powder is added into an acetone solution for ultrasonic cleaning;

[0056] (2) The acetone solution is removed and the carbonyl iron powder is dried;

[0057] (3) The carbonyl iron powder obtained in step (2) is added into a phosphoric acid alcohol solution for ultrasonic cleaning, so that a phosphate layer is formed on the surface of the carbonyl iron powder;

[0058] (4) The carbonyl iron powder obtained in step (3) is dried and ground;

[0059] (5) A blended resin is prepared;

[0060] (6) The blended resin is used to coat the carbonyl iron powder obtained in step (4);

[0061] (7) The carbonyl iron powder obtained in step (6) is demolded;

[0062] (8) The carbonyl iron powder obtained in step (7) is pressed into shape.

[0063] Further, step (5) comprises: mixing high-temperature epoxy resin and silicone resin according to a mass ratio of 1:5, then adding acetone, and adding a curing agent, the mass of the curing agent being 10-20% of the total mass of the high-temperature epoxy resin and the silicone resin, and stirring in an ultrasonic cleaner to obtain the blended resin.

[0064] Further, the step (6) is to weigh the blending resin, the mass of the blending resin is 2-3% of the used carbonyl iron powder, add acetone to dilute the blending resin, the added amount of acetone is 10-20% of the mass of the carbonyl iron powder, then add the carbonyl iron powder into the blending resin acetone solution, continuously stir until the acetone solution is completely volatilized, dry the slurry-like magnetic powder in the air, sieve to granulate, and finally dry the granulated powder to obtain the blending resin coated carbonyl iron powder.

[0065] Further, the step (7) is to add barium stearate as a release agent into the blending resin coated carbonyl iron powder and mix well, the mass of the barium stearate is 0.1-0.3% of the mass of the carbonyl iron powder.

[0066] Further, the step (8) is to hot-press 1.8g of the magnetic powder under the condition of 6T / cm2 and 180℃ for 30s to obtain a ring-shaped magnetic powder core with an outer diameter of 13.5-14.5mm, an inner diameter of 7.5-8.5mm, and a height of 2.5-3.5mm.

[0067] Further, the step (8) is to cold-press under the condition of 800MPa to obtain a ring-shaped or columnar magnetic powder core block.

[0068] Further, the ultrasonic cleaning time of the step (1) is 10min.

[0069] Further, the ultrasonic cleaning time of the step (3) is 15min.

[0070] Further, the grinding of the step (4) is ball milling, the phosphoric acid coated carbonyl iron powder is placed in a vacuum drying box at 65℃ for 1h, then a planetary ball mill is used to ball mill at a speed of 250r / min for 1h to obtain the ultrasonic assisted phosphoric acid coated carbonyl iron powder.

[0071] Further, the step (6) is to dry the slurry-like magnetic powder in the air for 25min, sieve with a 80-mesh sieve, and finally dry the granulated powder at 80℃ for 30min to obtain the blending resin coated carbonyl iron powder.

[0072] Embodiment scheme 1: a preparation method, comprising the following steps:

[0073] (1) washing the powder: add the carbonyl iron powder into an acetone solution, then put it into an ultrasonic cleaning machine to wash for 10min to remove the oil on the surface of the carbonyl iron powder, finally pour out the acetone solution and dry in a vacuum drying box.

[0074] (2) Phosphoric acid coating: After drying, the carbonyl iron powder is added to a phosphoric acid alcohol solution for reaction, and an ultrasonic cleaner is turned on at a power of 300 W for 15 min. The purpose is to generate a phosphate layer on the surface of the carbonyl iron powder through passivation under the action of ultrasonic waves.

[0075] (3) Drying and ball milling: The carbonyl iron powder coated with phosphoric acid is dried in a vacuum drying oven at 65°C for 1 hour, and then ball milled at a speed of 250 r / min for 1 hour using a planetary ball mill to obtain the ultrasonic-assisted phosphoric acid-coated carbonyl iron powder.

[0076] (4) Preparation of blended resin: High-temperature epoxy resin and silicone resin are mixed at a mass ratio of 1:5, then a small amount of acetone is added, and KH550 curing agent is added at a mass of 20% of the total mass of the high-temperature epoxy resin and silicone resin, and stirred in an ultrasonic cleaner for 15 min to obtain the blended resin.

[0077] (5) Organic coating: The blended resin is weighed, and the mass of the blended resin is 3% of the mass of the carbonyl iron powder. Acetone is added to dilute the blended resin, and the amount of acetone added is 12% of the mass of the carbonyl iron powder. Then, the carbonyl iron powder is added to the blended resin-acetone solution, and stirring is continued until the acetone solution is completely volatilized. The slurry-like magnetic powder (i.e., the mixed powder of the blended resin and the carbonyl iron powder) is air-dried for about 25 min, sieved with an 80-mesh sieve, and finally the sieved powder is dried at 80°C for 30 min to obtain the blended resin-coated carbonyl iron powder.

[0078] (6) Pressing of magnetic powder core: Barium stearate is added as a release agent to the blended resin-coated carbonyl iron powder and mixed thoroughly, and the mass of the barium stearate is 0.2% of the mass of the carbonyl iron powder. 1.8 g of the magnetic powder is hot-pressed at 6 T / cm2 and 180°C for 30 s to obtain a ring-shaped magnetic powder core with an outer diameter of 13.5-14.5 mm, an inner diameter of 7.5-8.5 mm, and a height of 2.5-3.5 mm.

[0079] The inductance L and quality factor Q of the magnetic ring are tested at 1 MHz and 1 V using a WK3260B magnetic element analyzer, with a copper wire diameter of 0.65 mm and 13.5 uniform tight windings. The WK3260B magnetic element analyzer and WK3265B DC bias source are used to test the inductance of the magnetic ring at 1 MHz and 1 V, and the superimposed inductance with a 25 A DC current, and the superimposed percentage at 25 A DC is calculated. The test results are shown in Table 1.

[0080] Example Scheme 2: The difference from the above-mentioned example scheme is that in step (4), the mass of the KH550 curing agent is 10-20% of the total mass of the high-temperature epoxy resin and silicone resin, and the blended resin is prepared by stirring in an ultrasonic cleaner for 10-20 min.

[0081] Example 3: The difference between this example and the above examples is that the mass of the blended resin in step (5) is 2-3% of the mass of the magnetic powder used.

[0082] Example 4: The difference between this example and the above examples is that the amount of acetone added in step (5) is 10-20% of the mass of the magnetic powder.

[0083] Example 5: The difference between this example and the above examples is that the slurry of the magnetic powder is air-dried for 20-40 minutes in step (5).

[0084] Example 6: The difference between this example and the above examples is that the granulated powder is dried in an oven at 80°C for 30-60 minutes in step (5) to obtain the magnetic powder coated with the blended resin.

[0085] Example 7: The difference between this example and the above examples is that the mass of the barium stearate in step (6) is 0.1-0.3% of the mass of the magnetic powder.

[0086] Example 8: The difference between this example and the above examples is that the cold pressing in step (6) is used to obtain a ring-shaped or columnar magnetic powder core body under a pressure of 800 MPa, i.e., the pressing in step (8) can be hot pressing or cold pressing.

[0087] Example 9: In one embodiment, the method for preparing the magnetic powder core of the inductor of the present application includes alloy smelting, mechanical crushing, annealing treatment, insulation coating (inorganic-organic), mold pressing, heat treatment curing, and surface paint spraying, and in the method, the coating step is the method described in the above examples.

[0088] Comparative Example 1:

[0089] The method for preparing the magnetic powder is the same as that in Example 1, except that the blended resin of the high-temperature epoxy resin and the silicone resin in the formula is replaced by the high-temperature epoxy resin alone, and other processes and test conditions remain unchanged. The specific results are shown in Table 1.

[0090] Comparative Example 2:

[0091] The method for preparing the magnetic powder is the same as that in Example 1, except that the blended resin of the high-temperature epoxy resin and the silicone resin in the formula is replaced by the silicone resin alone, and other processes and test conditions remain unchanged. The specific results are shown in Table 1.

[0092] Table 1: Performance test results of examples

[0093] Number Inductance L (uH) Permeability Q value L drop at 25A (%) Example 1 2.13 40.12 150 24.6 Comparative Example 1 2.43 48.11 128 29.1 Comparative Example 2 2.16 40.51 131 24.8

[0094] In an alternative embodiment, the surface of the carbonyl iron powder is modified first, and then a phosphate layer is generated on the surface. The modification method is as follows: by weight, carbonyl iron powder: nano-silicon dioxide: silane coupling agent: magnesium oxide: = 20:8:1:2, as in a preferred embodiment, 20g of carbonyl iron powder, 8g of nano-silicon dioxide, 1g of silane coupling agent, and 2g of magnesium oxide. A tube furnace is used, and the mixture of carbonyl iron powder, silicon dioxide, and magnesium oxide is placed inside. Nitrogen gas is dried and preheated and introduced into the tee joint, first by one way to preheat the mixture of carbonyl iron powder and silicon dioxide, and after preheating, the other way is opened to press the coupling agent and high-temperature nitrogen gas mixture into vaporization, which enters the bottom of the reactor together, so that the mixture of carbonyl iron powder, silicon dioxide, and magnesium oxide is in contact with the coupling agent for reaction, and the reaction temperature is controlled for heating. After the reaction is complete, the coupling agent is closed, and after purging with hot nitrogen gas, the container is closed, and the modified carbonyl iron powder coating is removed. Then the dried carbonyl iron powder coating is added to the phosphoric acid alcohol solution for reaction, and at the same time, the ultrasonic cleaner is turned on, with a power of 300W and a processing time of 15min. The purpose is to generate a phosphate layer on the surface of the carbonyl iron powder through passivation under the action of ultrasonic waves.

[0095] Since the carbonyl iron powder is easily reacted with water and oxygen, has poor oxidation resistance, and is easily agglomerated, the impedance matching performance is poor. Through modification experiments, the oxide coating can improve the oxidation resistance, disperse uniformly, and improve the impedance matching performance. And it can reduce the agglomeration for subsequent phosphate layer coating. And through modification, the interface bonding performance can be enhanced, and the stability can be improved.

[0096] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include these modifications and variations.

Claims

1. An inductor production process, characterized by, comprising S1. preparing a first semi-product, the first semi-product comprises a flat plate and a column, the flat plate is connected to the column downward, the flat plate is a rectangular face and each side of the rectangular face extends outward along a side edge line to form a side edge protrusion, the side edges of two adjacent side edge protrusions are perpendicular to each other to form a vertical port, and the flat plate forms four vertical ports in total; S2. winding an enameled wire on the column of the first semi-product; S3. buckling the first semi-product in a second semi-product, the second semi-product is a columnar groove and can accommodate the column of the first semi-product, the flat plate and the side edge protrusions of the first semi-product cover the top opening of the second semi-product, and gaps are reserved at the vertical ports of the flat plate to communicate with the groove of the second semi-product, so that the lead wires at both ends of the enameled wire are led out from the two gaps nearby, the four vertical ports are used as charging ports, and the vertical ports are symmetrically arranged; S4. placing the buckled first semi-product and second semi-product together in a hot pressing station for pressing, and injecting powder into the second semi-product during the pressing process; S5. placing the products after hot pressing in the station at intervals on the flat plate for cooling.

2. The production process according to claim 1, characterized in that, Step S3 comprises Step 3.

1. The first semi-product and the second semi-product form a closed body, the enameled wire is wound on the column of the first semi-product and is wrapped in the second semi-product; Step 3.

2. Detecting the interval of the fitting gap between the first semi-product and the second semi-product, if the interval of the fitting gap is less than a set value, the closed body is qualified, if the interval of the fitting gap is greater than or equal to the set value, the closed body is unqualified, the closed body is re-separated and re-implanted; Step 3.

3. Repeating step 3.1 for the closed body after re-implantation.

3. The production process according to claim 2, wherein The set value is 2mm.

4. The production process according to claim 1, wherein Step S4 further comprises checking whether the production error of each piece of product after pressing is within a normal range after a preset number of intervals, if not, adjusting the equipment data, and then producing the pressing products with the adjusted equipment in a batch production mode when the production error of the pressing products is within the normal range.

5. The production process according to claim 1, wherein The product placement interval is 5cm, and the product is left to cool to room temperature.

6. The inductor production process of claim 1, wherein, The first semi-product is made by cold pressing forming process.

7. The inductor production process of claim 1, wherein, A backing plate is further arranged between the product and the flat plate.

8. The inductor production process of claim 1, wherein, The flat plate is a square face.

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