Preparation method of metal magnetic powder core high-temperature co-fired chip inductor

Abstract

The invention provides a preparation method of a metal magnetic powder core high-temperature co-fired chip inductor. The preparation method comprises the following steps of magnetic cup forming, copper sheet implanting, magnetic core forming, curing, chamfering, detecting and packaging. According to the scheme, the copper sheet is adopted to replace a coil, the preparation process is simpler, winding is not needed, the copper sheet can be directly pressed (bent) and formed, an electrode metallization process is not needed any more, and the process difficulty is greatly reduced; the contact surface of the copper sheet is larger, so that the use effect is better; after the scheme is adopted, welding is not needed, reliability is high, and the overall size is small.

Description

Technical Field

[0001] The invention relates to the technical field of inductor preparation, and in particular to a method for preparing a metal magnetic powder core high-temperature co-fired chip inductor. Background Art

[0002] In order to meet the needs of modern communications, computers, audio-visual equipment, electronic office equipment, automotive electronic systems, military electronic devices and electromagnetic compatibility, co-fired chip inductor technology has achieved remarkable results, thereby greatly promoting the development of miniaturized inductors; most inductors on the market need to be wound with special equipment, and then filled and pressed into shape. The production cost is high, the technology is difficult, the production cycle is long, and the process is complex. The cross-section of the middle column of this type of inductor is small, the current it carries is small, the inductance value is low, and the current stability is poor. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing a metal magnetic powder core high temperature co-fired chip inductor with reasonable structure and good reliability.

[0004] To achieve the above object, the technical solution provided by the present invention is: a method for preparing a metal magnetic powder core high temperature co-fired chip inductor, which includes the following steps: magnetic cup forming, copper sheet implantation, magnetic core forming, curing, chamfering, testing, and packaging, wherein: Magnetic cup molding: metal powder is injected into the mold cavity and molded into a magnetic cup; Copper sheet implantation: implant the copper sheet into the magnetic cup and flatten it, with the electrode feet of the copper sheet embedded at both ends of the magnetic cup; Magnetic core molding: metal powder is injected into the mold cavity and molded into a magnetic core.

[0005] The raw materials used in the magnetic cup molding are as follows: 0.01-95 parts of alloy powder, 5-95 parts of carbonyl iron powder, 2-6 parts of epoxy resin, 0.1-0.5 parts of curing agent, and 10-20 parts of acetone.

[0006] The magnetic core molding is to inject the magnetic core powder into the magnetic cup, fill the inner cavity of the magnetic cup and then solidify it.

[0007] The copper sheet is implanted by first bending the copper sheet into a U shape, and then bending the tops of the side walls on both sides of the U shape outward horizontally to form electrode feet, and the surface of the electrode feet is flush with the surface of the magnetic cup.

[0008] Curing is done by hot pressing at a temperature of 80-200°C and a pressure of 20-45kg / cm 2 , or directly put the mold together with the blank into a hot press for hot pressing and curing, or take out the molded blank and put it into a baking oven for heating and curing, with the temperature controlled within 200°C for 3-8 hours.

[0009] The technical advantages of the present invention are: 1. The copper sheet is used instead of the coil, and its preparation process is simpler. No winding is required. The copper sheet can be directly pressed (bent) into shape, and no electrode metallization process is required, which greatly reduces the process difficulty. In addition, the contact surface of the copper sheet is larger, and the use effect is better. 2. It adopts implantable inlay instead of laser welding process, which reduces equipment investment; 3. No need to use processes such as electrode metallization, electrode surface grinding and multiple coating, which reduces the process and reduces the manufacturing cost; 4. The electrode pins are formed in one step, without the need for terminal bending and shaping, which simplifies the process and reduces the preparation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0011] Figure 2 It is a cross-sectional view of the magnetic core of the present invention. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with all the accompanying drawings. The preferred embodiments of the present invention are as follows: Figure 1 and attached Figure 2 The method for preparing a metal magnetic powder core high temperature co-fired chip inductor described in this embodiment includes the following steps: magnetic cup forming, copper sheet implantation, magnetic core forming, curing, chamfering, testing, and packaging.

[0013] Magnetic cup molding: metal powder is made into a magnetic cup: a shell cavity is set in the mold, a corresponding shell upper mold is made, metal powder is injected into the shell cavity, and then pressed through the shell upper mold to form a shell; The shell 1 is provided with a concave magnetic core chamber at the top, a concave lower copper sheet groove at the bottom, side copper sheet grooves connected to the lower copper sheet groove are provided on the side walls of the shell 1, and electrode grooves connected to the side copper sheet grooves are provided at both ends of the top of the shell 1; The copper sheet 2 is implanted by first bending the copper sheet into a U shape, and then horizontally bending the top of the side walls of the U shape outward to form electrode feet, and then implanting the copper sheet 2 into the magnetic cup and flattening it; the electrode feet of the copper sheet are embedded at both ends of the magnetic cup; After flattening, the bottom of the copper sheet is located in the lower copper sheet groove, the side walls of the copper sheet 2 are located in the side copper sheet grooves, and the surface of the electrode foot is flush with the surface of the magnetic cup; Magnetic core molding: After the copper sheet is pressed in, the magnetic core powder is injected into the magnetic cup (magnetic core chamber). After the magnetic core chamber is filled, it is molded into the blank. This method has a higher integrity of the magnetic core.

[0014] Finally, it is cured by hot pressing at a temperature of 80-200°C and a pressure of 20-45kg / cm 2, or directly put the mold together with the blank into a hot press for hot pressing and curing, or take out the molded blank and put it into a baking oven for heating and curing, with the temperature controlled within 200°C for 3-8 hours.

[0015] Then, conventional testing methods are used as needed to complete the entire process. This solution uses copper sheets instead of coils, and its preparation process is simpler. No winding is required. The copper sheets can be directly pressed (bent) into shape, and no electrode metallization process is required, which greatly reduces the process difficulty. In addition, the contact surface of the copper sheet is larger, and the use effect is better. After adopting this solution, no welding is required, the reliability is high, and the overall volume is small.

[0016] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a metal magnetic powder core high temperature co-fired chip inductor, characterized in that: The method includes the following steps: magnetic cup forming, copper sheet implantation, magnetic core forming, curing, chamfering, testing, and packaging, among which, Magnetic cup molding: metal powder is injected into the mold cavity and molded into a magnetic cup; Copper sheet implantation: implant the copper sheet into the magnetic cup and flatten it, with the electrode feet of the copper sheet embedded at both ends of the magnetic cup; Magnetic core molding: metal powder is injected into the mold cavity and molded into a magnetic core.

2. The method for preparing a metal magnetic powder core high temperature co-fired chip inductor according to claim 1, characterized in that: The raw materials used in the magnetic cup molding are as follows: 0.01-95 parts of alloy powder, 5-95 parts of carbonyl iron powder, 2-6 parts of epoxy resin, 0.1-0.5 parts of curing agent, and 10-20 parts of acetone.

3. The method for preparing a metal magnetic powder core high temperature co-fired chip inductor according to claim 1, characterized in that: The magnetic core molding is to inject the magnetic core powder into the magnetic cup, fill the inner cavity of the magnetic cup and then solidify it.

4. The method for preparing a metal magnetic powder core high temperature co-fired chip inductor according to claim 1, characterized in that: The copper sheet is implanted by first bending the copper sheet into a U shape, and then bending the tops of the side walls on both sides of the U shape outward horizontally to form electrode feet, and the surface of the electrode feet is flush with the surface of the magnetic cup.

5. The method for preparing a metal magnetic powder core high temperature co-fired chip inductor according to claim 1, characterized in that: Curing is done by hot pressing at a temperature of 80-200°C and a pressure of 20-45kg / cm 2 , or directly put the mold together with the blank into a hot press for hot pressing and curing, or take out the molded blank and put it into a baking oven for heating and curing, with the temperature controlled within 200°C for 3-8 hours.

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