CN111210986A - Manufacturing method of integrally formed inductor and integrally formed inductor - Google Patents
Manufacturing method of integrally formed inductor and integrally formed inductor Download PDFInfo
- Publication number
- CN111210986A CN111210986A CN202010071257.1A CN202010071257A CN111210986A CN 111210986 A CN111210986 A CN 111210986A CN 202010071257 A CN202010071257 A CN 202010071257A CN 111210986 A CN111210986 A CN 111210986A
- Authority
- CN
- China
- Prior art keywords
- equal
- integrally formed
- powder
- manufacturing
- metal powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0206—Manufacturing of magnetic cores by mechanical means
- H01F41/0246—Manufacturing of magnetic circuits by moulding or by pressing powder
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
- H01F27/255—Magnetic cores made from particles
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
- H01F27/32—Insulating of coils, windings, or parts thereof
- H01F27/324—Insulation between coil and core, between different winding sections, around the coil; Other insulation structures
- H01F27/325—Coil bobbins
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/33—Arrangements for noise damping
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Soft Magnetic Materials (AREA)
Abstract
The invention discloses a manufacturing method of an integrally formed inductor and the integrally formed inductor, comprising the following steps: manufacturing a coil blank according to a set requirement; manufacturing fine spherical metal powder; the preparation method of the fine spherical metal powder comprises the following steps of mixing hydroxyl powder, epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 5-20:2-15: 3-10, then preserving heat for 1-2 hours at the temperature of 80-90 ℃, then grinding, and detecting whether the prepared powder meets the conditions that the sphericity is more than or equal to 90% and the particle size meets the following conditions: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m; if so, finishing the preparation of the fine spherical metal powder; if not, preparing by adopting the method until the requirements are met; putting the coil blank into a die of a film pressing machine, and injecting the micro spherical metal powder into a grinding tool to wrap and punch the coil blank; and carrying out post-forming treatment. The preparation method has simple process. The magnetic shielding device has a fully-closed structure, has a good magnetic shielding effect, and is suitable for automatic mass production.
Description
Technical Field
The invention relates to the technical field of manufacturing methods of integrally formed inductors, in particular to a manufacturing method of an integrally formed inductor and the integrally formed inductor.
Background
The integrated inductor is an important component in new electronic information materials and is a fundamental stone for the development of information technology industry, and the traditional inductor is formed by winding a wire on a ferrite magnetic core element so as to form an inductor element. The traditional inductance element is formed by combining an upper magnetic core and a lower magnetic core and a coil, wherein the lower magnetic core is provided with a groove for accommodating the coil, the upper magnetic core is covered with the upper magnetic core correspondingly, and the two magnetic cores are combined into a coating body through processes of glue dispensing, bonding, baking and the like. The inductance element has the defects of large volume, difficult automation realization and electromagnetic leakage, thereby generating vibration and noise, increasing magnetic loss and influencing the quality factor of the inductance. On the other hand, the traditional inductor needs manual operation, has the disadvantages of environmental pollution and high processing cost, and cannot realize mass production. In order to solve the above problems, the market mostly adopts a method of adding an outer cover outside the magnetic core, commonly called as a combined magnetic core element, but the design still has the problem of component gap, and the gap will cause magnetic loss.
Disclosure of Invention
The invention aims to solve the problems and provides a manufacturing method of an integrally formed inductor and the integrally formed inductor, the process flow is simple, the manufactured inductor has a fully-closed structure, the magnetic shielding effect is good, the noise is low, the electromagnetic interference is effectively reduced, and the integrally formed inductor is suitable for automatic mass production.
In order to achieve the purpose, the invention adopts the following technical scheme:
a manufacturing method of an integrally formed inductor comprises the following steps:
step one, manufacturing a coil blank according to a set requirement;
step two, manufacturing fine spherical metal powder;
the preparation method of the fine spherical metal powder comprises the following steps of mixing hydroxyl powder, epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 5-20:2-15: 3-10, then preserving heat for 1-2 hours at the temperature of 80-90 ℃, then grinding, and detecting whether the prepared powder meets the conditions that the sphericity is more than or equal to 90% and the particle size meets the following conditions: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m;
if so, finishing the preparation of the fine spherical metal powder;
if not, mixing the prepared powder with epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 5-20:2-15: 3-10, and then preserving heat for 1-2 hours at the temperature of 80-90 ℃; then crushing and grinding are carried out until the sphericity is more than or equal to 90 percent and the particle size of the powder is as follows: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m;
putting the coil blank into a mold of a film pressing machine, and injecting the micro spherical metal powder into a grinding tool to wrap and punch the coil blank;
and step four, performing post-forming treatment.
The oxygen content of the fine spherical metal powder in the second step is less than or equal to 1000 ppm.
The hydroxyl powder is hydroxyl iron powder, and the epoxy resin is a polycondensation product of epichlorohydrin and bisphenol A.
The pressing pressure in the third step is 20T-40T.
The post-treatment of the step four comprises the following steps:
step 4.1, performing sand blasting and polishing on the molded product obtained in the step three by using a sand blasting machine;
step 4.2, spraying paint on the product treated in the step 4.1;
4.3, spraying and printing a label according to a set requirement;
step 4.4, cutting off redundant material sheets, and bending the terminals to be flatly attached to the surface of the product;
and 4.5, detecting the electrical performance.
The content of the electrical property detection in the step 4.5 includes an inductance value, a loss value, a direct current bias, a saturation current and a temperature rise current.
The post-processing also comprises checking whether the appearance meets the set requirement; placing the qualified product into a woven carrier tape; and putting the woven carrier tape disc into a packaging box.
The coil blank comprises frame sides located on two sides and a plurality of equidistant intermediate connecting sides for connecting the two frame sides, two symmetrical terminal sides are arranged between every two intermediate connecting sides, and a coil is connected between the two terminal sides.
An integrally formed inductor is manufactured by any one of the manufacturing methods of the integrally formed inductor.
Direct current bias characteristics: DC-Bias100oe is more than or equal to 85 percent; loss: pc is less than or equal to 800mW/cm 3; the direct current resistance Rdc is less than or equal to 53m omega; the saturation current Isat is more than or equal to 4.0A; the temperature rise current Idc is more than or equal to 3.5A.
The invention has the beneficial effects that:
the preparation method has simple process. This integrated into one piece inductance belongs to SMD surface patch element, has totally closed structure, and the magnetism shielding effect is good, and the low noise effectively reduces electromagnetic interference, is fit for automatic mass production, can be used for electronic product such as 5G, cell-phone, notebook in a large number.
The fine spherical metal powder prepared by the method has good thin-wall insulation effect, excellent magnetic property and good fluidity and pressing property.
The method not only ensures the surface insulation effect of the fine spherical metal powder, but also effectively avoids the reduction of magnetic performance, improves the comprehensive performance of the integrally formed inductor,
the multi-stage crushing method is adopted, and the defects that the powder is irregular in shape, ellipsoidal particles are easy to form, the content of fine powder is low, and the price is high are overcome.
Drawings
FIG. 1 is a schematic structural view of a coil blank;
the structure comprises a frame edge 1, a middle connecting edge 2, a terminal edge 3 and a coil 4.
Detailed Description
The invention is further described with reference to the following figures and examples.
Example one
A manufacturing method of an integrally formed inductor comprises the following steps:
step one, manufacturing a coil blank according to a set requirement;
step two, manufacturing fine spherical metal powder;
the preparation method of the fine spherical metal powder comprises the following steps of mixing hydroxyl powder, epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 5: 2: 3, uniformly mixing, then preserving heat for 1 hour at the temperature of 80 ℃, then grinding, and detecting whether the prepared powder meets the conditions that the sphericity is more than or equal to 90% and the particle size of the powder meets the following conditions: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m; epoxy resin is used as a binder, and zinc stearate is added as a lubricant; the hydroxyl powder is hydroxyl iron powder, and the epoxy resin is a polycondensation product of epichlorohydrin and bisphenol A.
If so, finishing the preparation of the fine spherical metal powder;
if not, mixing the prepared powder with epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 5: 2: 3, uniformly mixing, and then preserving heat for 1 hour at the temperature of 80 ℃; then crushing and grinding are carried out until the sphericity is more than or equal to 90 percent and the particle size of the powder is as follows: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m;
putting the coil blank into a mold of a film pressing machine, and injecting the micro spherical metal powder into a grinding tool to wrap and punch the coil blank; the pressing pressure is 20T-40T.
And step four, performing post-forming treatment.
The method not only ensures the surface insulation effect of the fine spherical metal powder, but also effectively avoids the reduction of magnetic performance, improves the comprehensive performance of the integrally formed inductor, the key material of the integrally formed inductor is insulated soft magnetic metal powder, and the insulation coating of the powder is a key technology for realizing low loss and low direct current offset. If the cladding is incomplete, the loss will rise rapidly and the magnetic resistance will increase, but if the cladding is too thick, the saturation flux density will decrease, and if the cladding is too thin, the loss will increase. In order to develop a high-frequency integrally-formed inductance soft magnetic material, a thin-wall high-resistance insulating layer needs to be prepared. The method is suitable for the uniformly-coated thin-wall high-resistance insulating layer with high magnetic permeability manufactured by the high-frequency integrally-formed inductor. The high-frequency low-loss high-saturation magnetic flux density soft magnetic material is realized by combining the functions of high insulativity and magnetic permeability of the magnetic oxide.
The multi-stage crushing method is adopted, and the defects that the powder is irregular in shape, ellipsoidal particles are easy to form, the content of fine powder is low, and the price is high are overcome.
Example two
A manufacturing method of an integrally formed inductor comprises the following steps:
step one, manufacturing a coil blank according to a set requirement;
step two, manufacturing fine spherical metal powder;
the preparation method of the fine spherical metal powder comprises the following steps of mixing hydroxyl powder, epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 20: 15: 10, uniformly mixing, then preserving heat for 2 hours at the temperature of 90 ℃, then grinding, and detecting whether the prepared powder meets the conditions that the sphericity is more than or equal to 90% and the particle size of the powder meets the following conditions: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m; epoxy resin is used as a binder, and zinc stearate is added as a lubricant; the hydroxyl powder is hydroxyl iron powder, and the epoxy resin is a polycondensation product of epichlorohydrin and bisphenol A.
If so, finishing the preparation of the fine spherical metal powder;
if not, mixing the prepared powder with epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 20: 15: 10, uniformly mixing, and then preserving heat for 2 hours at the temperature of 90 ℃; then crushing and grinding are carried out until the sphericity is more than or equal to 90 percent and the particle size of the powder is as follows: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m;
putting the coil blank into a mold of a film pressing machine, and injecting the micro spherical metal powder into a grinding tool to wrap and punch the coil blank; the pressing pressure is 20T-40T.
And step four, performing post-forming treatment.
EXAMPLE III
A manufacturing method of an integrally formed inductor comprises the following steps:
step one, manufacturing a coil blank according to a set requirement;
step two, manufacturing fine spherical metal powder;
the preparation method of the fine spherical metal powder comprises the following steps of mixing hydroxyl powder, epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 15.26: 8.65: 5.26, uniformly mixing, then preserving heat for 1.6 hours at the temperature of 86.6 ℃, then grinding, and detecting whether the prepared powder meets the conditions that the sphericity is more than or equal to 90 percent and the particle size of the powder meets the following conditions: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m; epoxy resin is used as a binder, and zinc stearate is added as a lubricant; the hydroxyl powder is hydroxyl iron powder, and the epoxy resin is a polycondensation product of epichlorohydrin and bisphenol A.
If so, finishing the preparation of the fine spherical metal powder;
if not, mixing the prepared powder with epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 15.26: 8.65: 5.26, mixing evenly, and then preserving heat for 1.6 hours at the temperature of 86.6 ℃; then crushing and grinding are carried out until the sphericity is more than or equal to 90 percent and the particle size of the powder is as follows: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m;
putting the coil blank into a mold of a film pressing machine, and injecting the micro spherical metal powder into a grinding tool to wrap and punch the coil blank; the pressing pressure is 20T-40T.
And step four, performing post-forming treatment.
The following are the methods commonly employed in the examples.
The oxygen content of the fine spherical metal powder in the second step is less than or equal to 1000 ppm.
The post-treatment of the step four comprises the following steps:
step 4.1, performing sand blasting and polishing on the molded product obtained in the step three by using a sand blasting machine; the sand blasting machine is used for blasting and punching the surface of a molded product by using glass sand;
step 4.2, spraying paint on the product treated in the step 4.1; spraying corresponding paint on the surface of the molded product according to the requirements of customers;
4.3, spraying and printing a label according to a set requirement; spraying and printing a product label on a product according to the requirement of a client;
4.4, cutting off redundant material pieces of the formed product by using automatic equipment, and bending the terminals to be flatly attached to the surface of the product;
and 4.5, detecting the electrical performance.
The content of the electrical property detection in the step 4.5 includes an inductance value, a loss value, a direct current bias, a saturation current and a temperature rise current.
The post-processing also comprises checking whether the appearance meets the set requirement; placing the qualified product into a woven carrier tape, so that the product is convenient for a terminal customer to use; the woven carrier tape disc is placed in a packaging box, so that the transportation requirement is met, and the product is prevented from being damaged.
The coil blank comprises frame sides located on two sides and a plurality of equidistant intermediate connecting sides for connecting the two frame sides, two symmetrical terminal sides are arranged between every two intermediate connecting sides, and a coil is connected between the two terminal sides.
An integrally formed inductor is manufactured by any one of the manufacturing methods of the integrally formed inductor.
Direct current bias characteristics: DC-Bias100oe is more than or equal to 85 percent; loss: pc is less than or equal to 800mW/cm 3; the direct current resistance Rdc is less than or equal to 53m omega; the saturation current Isat is more than or equal to 4.0A; the temperature rise current Idc is more than or equal to 3.5A; loss: pc is less than or equal to 800mW/cm 3.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.
Claims (10)
1. A manufacturing method of an integrally formed inductor is characterized by comprising the following steps:
step one, manufacturing a coil blank according to a set requirement;
step two, manufacturing fine spherical metal powder;
the preparation method of the fine spherical metal powder comprises the following steps of mixing hydroxyl powder, epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 5-20:2-15: 3-10, then preserving heat for 1-2 hours at the temperature of 80-90 ℃, then grinding, and detecting whether the prepared powder meets the conditions that the sphericity is more than or equal to 90% and the particle size meets the following conditions: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m;
if so, finishing the preparation of the fine spherical metal powder;
if not, mixing the prepared powder with epoxy resin, zinc stearate and acetone according to the weight ratio of 100: 5-20:2-15: 3-10, and then preserving heat for 1-2 hours at the temperature of 80-90 ℃; then crushing and grinding are carried out until the sphericity is more than or equal to 90 percent and the particle size of the powder is as follows: d50 is less than or equal to 15 mu m, and D90 is less than or equal to 30 mu m;
putting the coil blank into a mold of a film pressing machine, and injecting the micro spherical metal powder into a grinding tool to wrap and punch the coil blank;
and step four, performing post-forming treatment.
2. The method for manufacturing an integrally formed inductor as claimed in claim 1, wherein the oxygen content of the fine spherical metal powder in the second step is not more than 1000 ppm.
3. The method of claim 1, wherein the hydroxyl powder is iron hydroxyl powder, and the epoxy resin is a polycondensation product of epichlorohydrin and bisphenol a.
4. The method for manufacturing an integrally formed inductor as claimed in claim 1, wherein the pressing force in the third step is 20T-40T.
5. The method for manufacturing an integrally formed inductor according to claim 1, wherein the post-processing of the fourth step comprises:
step 4.1, performing sand blasting and polishing on the molded product obtained in the step three by using a sand blasting machine;
step 4.2, spraying paint on the product treated in the step 4.1;
4.3, spraying and printing a label according to a set requirement;
step 4.4, cutting off redundant material sheets, and bending the terminals to be flatly attached to the surface of the product;
and 4.5, detecting the electrical performance.
6. The method according to claim 5, wherein the electrical property test in step 4.5 includes inductance, loss, DC bias, saturation current and temperature rise.
7. The method as claimed in claim 5, wherein the post-processing further comprises checking whether the appearance meets a predetermined requirement; placing the qualified product into a woven carrier tape; and putting the woven carrier tape disc into a packaging box.
8. The method as claimed in any one of claims 1 to 7, wherein the coil blank comprises frame sides at both sides and a plurality of intermediate connecting sides arranged at equal intervals connecting the two frame sides, two symmetrical terminal sides are arranged between each two intermediate connecting sides, and the coil is connected between the two terminal sides.
9. An integrally formed inductor, characterized in that the inductor is manufactured by the method for manufacturing an integrally formed inductor according to any one of claims 1 to 7.
10. An integrally formed inductor according to claim 9 wherein the dc bias characteristics are: DC-Bias100oe is more than or equal to 85 percent; loss: pc is less than or equal to 800mW/cm 3; the direct current resistance Rdc is less than or equal to 53m omega; the saturation current Isat is more than or equal to 4.0A; the temperature rise current Idc is more than or equal to 3.5A.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010071257.1A CN111210986A (en) | 2020-01-21 | 2020-01-21 | Manufacturing method of integrally formed inductor and integrally formed inductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010071257.1A CN111210986A (en) | 2020-01-21 | 2020-01-21 | Manufacturing method of integrally formed inductor and integrally formed inductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111210986A true CN111210986A (en) | 2020-05-29 |
Family
ID=70786745
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010071257.1A Withdrawn CN111210986A (en) | 2020-01-21 | 2020-01-21 | Manufacturing method of integrally formed inductor and integrally formed inductor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111210986A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114334428A (en) * | 2020-10-30 | 2022-04-12 | 宁波磁性材料应用技术创新中心有限公司 | Manufacturing method of integrally-formed molded inductor |
| CN114400139A (en) * | 2022-01-19 | 2022-04-26 | 山东恒瑞磁电科技有限公司 | Integrally-formed inductor bending method |
-
2020
- 2020-01-21 CN CN202010071257.1A patent/CN111210986A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114334428A (en) * | 2020-10-30 | 2022-04-12 | 宁波磁性材料应用技术创新中心有限公司 | Manufacturing method of integrally-formed molded inductor |
| CN114400139A (en) * | 2022-01-19 | 2022-04-26 | 山东恒瑞磁电科技有限公司 | Integrally-formed inductor bending method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7089576B2 (en) | Manufacturing method of integrated chip inductor consisting of metal magnetic powder core | |
| CN103151134B (en) | Soft-magnetic powder core of silicone resin _ ferrite compound coating and preparation method thereof | |
| CN102637518B (en) | Method for preparing iron-based composite magnetic powder core | |
| CN111210986A (en) | Manufacturing method of integrally formed inductor and integrally formed inductor | |
| CN102971100B (en) | Composite magnetic body and manufacture method thereof | |
| CN106469603A (en) | Coil electronic building brick | |
| CN104766684A (en) | Magnetically soft alloy powder composition | |
| CN103310937B (en) | A kind of high saturated magnetic induction iron cobalt-based nano-crystal soft-magnetic powder core and preparation method thereof | |
| CN105702410A (en) | Method for preparing soft magnetic powder core | |
| CN114373626A (en) | Preparation method of high-frequency and high-efficiency integrated inductor | |
| EP3306629B1 (en) | Method for manufacturing high-density integrally-molded inductor | |
| CN202307439U (en) | Anti-magnetic interference magnetic core | |
| CN113223845B (en) | Insulating coating method of soft magnetic alloy powder | |
| JP7251468B2 (en) | Composite magnetic materials, magnetic cores and electronic components | |
| CN214476869U (en) | Novel coupling inductor | |
| CN113999627A (en) | Magnetic glue, inductor and preparation method | |
| CN201063289Y (en) | Enclosed inductor structure | |
| CN102306530B (en) | Fe-Ni alloy soft magnetic material with magnetic permeability mu of 60 and manufacturing method for Fe-Ni alloy soft magnetic material | |
| CN110853861A (en) | Magnetic separation sheet for wireless charging receiving end and preparation method thereof | |
| KR20210044121A (en) | A Surface Mounted Metal Composite Power Inductor And A Method Of Manufacturing The Same | |
| CN111599567B (en) | Composite magnetic material, magnetic core, and electronic component | |
| CN111383810A (en) | Preparation method of amorphous alloy magnetic powder core | |
| CN109148070A (en) | A kind of NEW TYPE OF COMPOSITE powder core and its manufacturing method | |
| CN103426607A (en) | Iron core of amorphous alloy transformer and manufacture method thereof | |
| CN102214510A (en) | Ferronickel soft magnetic material and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20200529 |