CN110600235A - Surface mount inductor and preparation method thereof - Google Patents

Abstract

The embodiment of the present invention provides a chip inductor and its preparation method. The chip inductor includes a magnetic core, a coil winding, and several terminal electrodes electrically connected to each end of the coil winding. The magnetic core includes a base body and a Two sets of bearing blocks are used to carry the base body. The two bearing blocks are symmetrically arranged at both ends of the base body, and a number of terminal electrodes are respectively set on the corresponding bearing blocks. The coil winding and a number of end electrodes are etched by the conductive layer formed on the magnetic core. to make. A conductive layer is formed on the surface of the magnetic core, and the conductive layer is etched to form a coil winding and a terminal electrode, so that there is no solder joint at the connection between the terminal electrode and the coil winding, which effectively improves the chip inductance The performance consistency and reliability of the device, and reduce the process of winding the coil winding and the assembly of the coil winding and the terminal electrode, and improve the production efficiency; in addition, the coil winding is carved from a conductive layer, so there is no need to add an insulating layer between the windings , to facilitate the miniaturization of the chip inductor set.

Description

SMD inductor and manufacturing method thereof

technical field

The invention relates to the technical field of inductors, and in particular provides a chip inductor and a preparation method thereof.

Background technique

With the continuous advancement of science and technology and the rapid development of the information industry, large-scale and ultra-large-scale integrated circuits have become the mainstream and trend of development. SMD inductors have the characteristics of small size and high space utilization, and are suitable for surface assembly and high density. Mounting can well meet the requirements of integrated circuits and has high practical value. At present, chip inductors are mainly prepared based on the stacking process and winding process. The inductors prepared based on the stacking process have certain advantages in small size and size standardization, but they cannot meet the requirements of high inductance. Inductors prepared based on the winding process have the characteristics of wide coverage of inductance and large working current, but the consistency of product performance, production efficiency and small size cannot meet the requirements of use. Requirements hinder the wide application and promotion of chip inductors.

Contents of the invention

The purpose of the present invention is to provide a chip inductor, aiming to solve the technical problems of the chip inductor in the prior art, such as large volume, low production efficiency and poor performance consistency.

In order to achieve the above object, the technical solution adopted by the present invention is: a chip inductor is provided, including a magnetic core, a coil winding wrapped on the outer surface of the magnetic core, and each end of the coil winding is electrically connected. connected to several terminal electrodes, the magnetic core includes a matrix for supporting the coil winding and two sets of bearing blocks for supporting the matrix, the two bearing blocks are symmetrically arranged at both ends of the matrix, and several The terminal electrodes are respectively arranged on the corresponding bearing blocks, and the coil winding and several terminal electrodes are carved from the conductive layer formed on the magnetic core.

Optionally, the two ends of each of the bearing blocks are respectively provided with the terminal electrodes, and each of the bearing blocks is also provided with a connection line for connecting the two terminal electrodes on the bearing block.

Optionally, each of the terminal electrodes includes a connection part that is closely attached to the end surface of the corresponding bearing block and an extension part extending along the peripheral side of the connection part toward the centerline of the bearing block, close to the coil The extension part on one side of the winding is electrically connected to the lead-out end of the coil winding, and the extension part on the side facing away from the coil winding among the two terminal electrodes on the same bearing block passes through the connection line connected.

Optionally, the connection line is formed by etching the conductive layer.

Optionally, the chip inductor further includes a protective layer covering the circumference of the coil winding, and four corners of the protective layer are respectively provided with chamfers.

Optionally, the chip inductor further includes a casing for protecting the magnetic core, and the magnetic core is accommodated in an accommodating cavity of the casing.

Optionally, the housing is molded by curing magnetic glue or plastic sealant.

Optionally, the chip inductor further includes an identification plate, and the identification plate is arranged on the outer surface of the magnetic core.

An object of the present invention is to provide a method for preparing a chip inductor, comprising the following steps:

S1: providing a magnetic core, and covering the outer surface of the magnetic core with a conductive layer;

S2: removing excess metal on the conductive layer, and leaving conductive patterns forming coil windings, terminal electrodes and connecting wires on the magnetic core;

S3: Cover or package the main body of the chip inductor with curing glue.

Optionally, after forming the conductive pattern, S21 is also included:

Thicken the conductive pattern.

Beneficial effects of the present invention: Compared with the prior art, the chip inductor of the present invention forms a conductive layer on the surface of the magnetic core and etches the conductive layer to form a coil winding and several terminals. Electrode, so that the terminal electrode and the coil winding are integrally formed, there is no connection solder joint or heterogeneous connection point at the connection between the terminal electrode and the coil winding, which effectively improves the performance consistency and reliability of the chip inductor, and reduces the winding coil Winding and the process of assembling the coil winding and the terminal electrode improve production efficiency; in addition, the coil winding is carved from a conductive layer, so there is no need to add an insulating layer between the windings, which effectively simplifies the production process and saves materials, thereby ensuring The chip inductor has a small volume, which facilitates the miniaturization of the chip inductor.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the descriptions of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only of the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without paying creative efforts.

FIG. 1 is a schematic structural diagram of a chip inductor provided by an embodiment of the present invention;

Fig. 2 is a structural schematic diagram 2 of a chip inductor provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of the packaged structure of the chip inductor provided by the embodiment of the present invention;

FIG. 4 is a schematic diagram of a post-package structure of a chip inductor provided by another embodiment of the present invention;

FIG. 5 is a second schematic diagram of the packaged structure of the chip inductor provided by another embodiment of the present invention;

FIG. 6 is a schematic flowchart of a method for manufacturing a chip inductor provided by an embodiment of the present invention.

Among them, the main marks of each accompanying drawing in the figure are:

1-magnetic core; 11-substrate; 12-carrying block;

2 - coil winding;

3-terminal electrode; 31-connection part; 32-extension part;

4- connecting line;

5-protective layer; 51-chamfering;

6 - shell;

7- Identification plate.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

It should be noted that when an element is referred to as being “fixed” or “disposed on” another element, it may be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it may be mechanical connection or electrical connection; it may be direct connection or indirect connection through an intermediary, and it may be the internal communication of two elements or the interaction relationship between two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

Please refer to FIG. 1 to FIG. 3 together, and now the chip inductor provided by the embodiment of the present invention will be described. The adjustable chip inductor includes a magnetic core 1, a coil winding 2 and several terminal electrodes 3, wherein the coil winding 2 is wrapped on the magnetic core 1, and the terminal electrodes 3 are electrically connected to each end of the coil winding 2 , so that the external current passes through the coil winding 2. Specifically, the magnetic core 1 can be made of a soft magnetic core or a non-magnetic core, a soft magnetic core, such as a ferrite core, an iron powder core, a soft magnetic powder doped polymer material core, etc. Magnetic cores, such as alumina ceramic cores, dielectric ceramic cores, and non-magnetic polymer materials. Specifically, the magnetic core 1 includes a base body 11 and two sets of bearing blocks 12, the two sets of bearing blocks 12 are symmetrically arranged at both ends of the base body 11, wherein the coil winding 2 is wound on the outer surface of the base body 11, so that the base body 11 supports The coil winding 2, the bearing block 12 and the base body 11 are all cuboid structures, and the height of the base body 11 is smaller than the height of the bearing block 12, so that the two bearing blocks 12 bear the weight of the base body 11, so that the base body 11 is suspended in the air, so that The coil winding 2 wrapped on the base body 11 is suspended, so that when the inductor is installed on the printed circuit board, the coil winding 2 is separated from the circuit board. The coil winding 2 and several terminal electrodes 3 are formed by carving a conductive layer (not shown) formed on the magnetic core 1. It can be understood that the conductive paste is coated on the surface of the magnetic core 1 to form a layer with a certain thickness. the conductive layer. With such a structure, a conductive layer is formed on the surface of the magnetic core 1, and the conductive layer is etched to form a coil winding 2 and a number of terminal electrodes 3, so that the terminal electrode 3 and the coil winding 2 are integrally formed, and the terminal electrodes There is no connection solder joint or heterogeneous connection point at the connection between 3 and coil winding 2, which effectively improves the performance consistency and reliability of the chip inductor, and reduces the need for winding coil winding 2 and assembling coil winding 2 and terminal electrode 3 technology, improve production efficiency. In addition, the coil winding 2 is formed by etching the conductive layer, so there is no need to add an insulating layer between the windings, which effectively simplifies the production process and saves materials, thereby ensuring that the chip inductor is small in size and convenient for the chip inductor. Inductor miniaturization setting.

Compared with the prior art, the chip inductor provided by the embodiment of the present invention has such a structure that the outer surface of the magnetic core 1 is treated with a conductive layer, and then the substrate 11 is etched in a spiral or coil pattern. The conductive layer leaves a number of guide strips or windings in the spiral channel as required, and several guide strips and windings form the coil winding 2, and then etches the conductive layer on the bearing block 12 to form the terminal electrode 3, which can be understood as, After the coil winding 2 is manufactured, the terminal electrodes 3 are etched outward along the ends of the coil winding 2, so that the coil winding 2 and the terminal electrodes 3 are integrally processed and formed by the same conductive layer, and the coil winding 2 and the terminal electrodes 3 are integrally formed. There are no connection solder joints or heterogeneous connection points at the connection, which effectively improves the performance consistency and reliability of the chip inductor, and reduces the process of winding the coil winding 2 and assembling the coil winding 2 and the terminal electrode 3, improving production efficiency In addition, the coil winding 2 is formed by etching the conductive layer, so there is no need to add an insulating layer between the windings, which effectively simplifies the production process and saves materials, and can adjust the connection between the two windings according to the number of turns of the coil winding 2 The gap between them ensures that the volume of the chip inductor is small, which facilitates the miniaturization of the chip inductor.

Optionally, please refer to FIG. 1 to FIG. 3 together. As a specific implementation of chip inductors provided by the embodiment of the present invention, terminal electrodes 3 are respectively provided at both ends of each bearing block 12 , and each bearing block 12 There is also a connection line 4 on the top, which can be a metal wire or a sheet-shaped conductor etched from the above-mentioned conductive layer, and the connection line 4 is arranged between the corresponding two terminal electrodes 3 to connect the two terminals. The terminal electrodes 3 are connected together. In this way, by providing terminal electrodes 3 on both ends of the bearing block 12 , the efficiency of identifying the terminal electrodes 3 in the automatic production process of products is effectively improved, thereby improving production efficiency. In addition, terminal electrodes 3 are respectively provided on both ends of the bearing block 12, that is, the two ends of the coil winding 2 have two output terminals respectively, so as to facilitate connection and use. At the same time, two different terminal electrodes 3 can also be connected as required. In order to obtain different inductances in the inductor, the applicability and flexibility of the chip inductor are effectively improved.

Optionally, please refer to FIG. 1 to FIG. 2 together. As a specific implementation of a chip inductor in an embodiment of the present invention, each terminal electrode 3 includes a connection part 31 and an extension part 32, wherein the connection part 31 Closely attached to the end surface of the corresponding bearing block 12, it can be welded to the external integrated circuit board, and the extension part 32 extends along the peripheral side of the connecting part 31 toward the centerline of the bearing block 12, near the side of the coil winding 2 The extension portion 32 of the coil winding 2 is electrically connected to the lead-out end of the coil winding 2, and the extension portion 32 on the side away from the coil winding 2 of the two terminal electrodes 3 on the same bearing block 12 connects the two corresponding extension portions 32 through the connecting wire 4 together. The extension part 32 is provided on the terminal electrode 3 to facilitate the electrical connection between the two terminal electrodes 3 and the ends of the coil winding 2 and the terminal electrode 3, and the extension part 32 close to the side of the coil winding 2 extends directly to the coil The lead-out end of the winding 2, thus eliminating the length of the wiring part of the coil winding 2 and the terminal electrode 3, thus eliminating the parasitic loss that causes the Q value to decrease and the inductance value to decrease, so that the inductor and the coil winding 2 have a basic equal inductance and Q.

Optionally, please refer to Fig. 1 to Fig. 3 together. As a specific implementation mode of the chip inductor provided by the embodiment of the present invention, the connecting wire 4 is formed by etching the conductive layer, so as to ensure that the two terminal electrodes There are no connection solder joints or heterogeneous connection points at the connection between 3, which effectively improves the performance consistency and reliability of the chip inductor. Specifically, the conductive layer can be made of conductive paste, such as silver paste, copper paste, gold paste, carbon-based composite paste, graphene-doped composite paste, carbon nanotube-doped composite paste, which can be passed through the printing screen Printing, directional coating, trench filling or coating technology or chemical deposition technology or physical vapor deposition technology or surface spraying technology or the combination of mask and surface spraying technology or physical vapor deposition technology or the use of conductive paste Coating technology or chemical deposition technology or physical vapor deposition technology or surface spraying technology covers the surface of the magnetic core 1 with the conductive paste, so that a conductive layer is formed on the outer surface of the magnetic core 1 . Of course, the conductive layer can also be made of metal powder. Specifically, firstly a certain thickness of conductor powder is applied on the surface of the magnetic core 1 , and then part of the conductor powder is melted and coated on the surface of the magnetic core 1 by surface cladding technology to form a certain thickness of conductor layer. Preferably, the conductive layer is a metal layer, such as copper or aluminum.

Optionally, please refer to FIG. 1 to FIG. 3 together. As another specific implementation mode of the chip inductor provided by the embodiment of the present invention, the chip inductor also includes a protective layer 5 covering the wire The circle side of the coil winding 2 effectively reduces the influence of the diffusion magnetic flux and protects the coil winding 2, and the protective layer 5 can be made of magnetic glue or plastic sealant, so that the protective layer 5 has little stress and has good The buffering effect, thus improving the anti-vibration and anti-shock ability of the inductor. Preferably, chamfers 51 are provided at the four corners of the protective layer 5 , so as to reduce the stress concentration at the transition of the protective layer 5 and prolong the service life of the protective layer 5 .

Optionally, please refer to FIG. 4 to FIG. 5 together. As another specific implementation mode of the chip inductor provided by the embodiment of the present invention, the chip inductor also includes a shell 6, which is used to protect The magnetic core 1, the magnetic core 1 is accommodated in the housing cavity 6, wherein the depth of the housing cavity is less than the height of the magnetic core 1, specifically, the depth of the housing cavity is half the height of the magnetic core 1, so When the shell 6 is placed on the magnetic core 1 , a part of the magnetic core 1 is exposed to the external environment, which not only protects the inductor, but also facilitates the bonding of the inductor into the printed circuit board. Preferably, the housing 6 can be cured and molded by magnetic glue or plastic sealant, wherein the use of plastic sealant can protect and reinforce the main body of the inductor, thereby effectively improving the reliability of the inductor; the use of magnetic glue can not only improve the inductance The performance index and the role of magnetic shielding can also protect and reinforce the main body of the inductor, thereby effectively improving the electrical performance index, environmental adaptability and reliability of the inductor.

Optionally, please refer to Fig. 1 and Fig. 5 together. As a specific implementation mode of the chip inductor provided by the embodiment of the present invention, the chip inductor also includes an identification plate 7, and the identification plate 7 is arranged on the magnetic core 1, specifically, the identification plate 7 is set on the casing 6 or the protective layer 5, and the inductor mark can be formed on the surface of the coating or the package by printing ink, spraying paint, laser engraving, mechanical engraving, etc. For example, "100" is engraved on the identification plate 7, wherein 100 represents the nominal inductance in one turn, which is convenient for distinguishing and identifying inductors with different electrical performance indexes.

In the present invention, a method for preparing a chip inductor is also provided, as shown in Figure 1 and Figure 6, specifically, the preparation method includes the following steps:

S1: providing a magnetic core 1, and covering the outer surface of the magnetic core 1 with a conductive layer;

Specifically, the magnetic core 1 can be made of soft magnetic cores or non-magnetic magnetic cores, wherein soft magnetic cores such as ferrite cores, iron powder cores, soft magnetic powder doped polymer material cores, etc., Non-magnetic cores such as alumina ceramic cores, dielectric ceramic cores, and non-magnetic polymer material cores are not limited here. The conductive layer covering the magnetic core 1 can be made of conductive paste, such as silver paste, copper paste, gold paste, carbon-based composite paste, graphene-doped composite paste, carbon nanotube-doped composite paste, etc. , specifically by means of screen printing, directional coating, trench filling or coating technology or chemical deposition technology or physical vapor deposition technology or surface spraying technology or a combination of mask and surface spraying technology or physical vapor deposition technology The conductive paste is covered on the surface of the magnetic core 1 by means of conductive paste coating technology or chemical deposition technology or physical vapor deposition technology or surface spraying technology, so that the outer surface of the magnetic core 1 forms a conductive layer with a certain thickness. Floor. Of course, the conductive layer can also be made of metal powder. Specifically, first apply a certain thickness of conductive powder on the surface of the magnetic core 1, and then use surface cladding technology to melt and coat part of the conductive powder on the magnetic core 1. A conductive layer with a certain thickness is formed on the surface.

S2: remove the excess metal on the conductive layer, and leave the conductive pattern forming the coil winding 2, a number of terminal electrodes 3 and the connecting wire 4 on the magnetic core 1;

Specifically, the excess metal on the surface of the magnetic core can be removed by using high-energy beam modification etching technology or yellow photolithography technology, which can be understood as etching the conductive layer on the base body 11 of the magnetic core 1 in a spiral or coil pattern , leaving a number of guide strips or windings in the spiral channel as required, and a number of guide strips and windings form the coil winding 2, and then etch the conductive layer on the bearing block 12 on the magnetic core 1 to form terminal electrodes 3 and connecting wires 4 , that is, after the coil winding 2 is produced, it is respectively etched outward along the ends of the coil winding 2 to form sheet-shaped terminal electrodes 3 and connecting wires 4 at both ends of each bearing block 12, and the connecting wires 4 are connected to The above two terminal electrodes 3, so that the coil winding 2 and the terminal electrode 3 are integrally processed and formed by the same conductive layer, then there is no connecting solder joint or heterogeneous connection point at the connection between the coil winding 2 and the terminal electrode 3, which effectively improves the patch The performance consistency and reliability of the type inductor, and reduce the process of winding the coil winding 2 and assembling the coil winding 2 and the terminal electrode 3, and improve the production efficiency; in addition, the coil winding 2 is formed by etching the conductive layer, and the winding and There is no need to add an insulating layer between the windings, which effectively simplifies the production process and saves materials, and the gap between the two connected windings can be adjusted according to the number of turns of the coil winding 2, thereby ensuring that the chip inductor is small in size. This facilitates miniaturization of the chip inductor.

S3: Cover or package the main body of the chip inductor with curing glue.

Specifically, in this embodiment, curable glue such as plastic sealant or magnetic glue can cover or package the main body of the inductor, that is, a protective layer 5 or a shell 6 is formed on the outer surface of the coil winding 2 to protect the inductor. , and improve the inductor's ability to withstand pressure and impact. The use of plastic sealant can protect and reinforce the inductor, thereby effectively improving the reliability of the inductor; the use of magnetic glue can not only improve the inductance performance index and play the role of magnetic shielding, but also play a role in the inductor The role of protection and reinforcement, thereby effectively improving the electrical performance index, environmental adaptability and reliability of the inductor. The completion of coating or packaging also includes printing ink, spraying paint, laser engraving, mechanical engraving, etc. to form an identification plate 7 on the surface of the coating layer or packaging layer, and the identification plate 7 records the nominal inductance of the inductor. It is convenient to distinguish and identify inductors with different electrical performance indicators.

Further, a method for preparing a chip inductor further includes S21 after forming the conductive pattern:

Thicken the conductive pattern.

Specifically, electrodeposition technology can be used to thicken the conductive layer, that is, to increase the diameter of each winding in the coil winding 2 and the diameter of the terminal electrode 3, so as to reduce the resistance of the coil winding 2 and improve the electrical index.

In the present invention, the conductive layer is processed on the outer surface of the magnetic core 1, and then the conductive layer is etched on the substrate 11 according to a spiral pattern or a coil pattern, leaving a number of guide strips or windings in the spiral channel as required, and A number of guide strips and windings form the coil winding 2, and then the conductive layer on each bearing block 12 is etched to form terminal electrodes 3 and connecting wires 4. The end of each bearing block 12 is etched outward to form the terminal electrode 3 and the connecting wire 4, so that the coil winding 2 and the terminal electrode 3 are integrally processed and formed by the same conductive layer, and the coil winding 2 and the terminal electrode There is no connection solder joint or heterogeneous connection point at the connection of 3, which effectively improves the performance consistency and reliability of the chip inductor, and reduces the process of winding the coil winding 2 and assembling the coil winding 2 and the terminal electrode 3, improving production efficiency; in addition, the coil winding 2 is carved from a conductive layer, so there is no need to add an insulating layer between the windings, which effectively simplifies the production process and saves materials, and can be adjusted according to the number of turns of the coil winding 2. The gap between the windings ensures that the volume of the chip inductor is small, which facilitates the miniaturization of the chip inductor.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. The utility model provides a SMD inductor, include the magnetic core, wrap up in the coil winding of magnetic core surface and with each tip electric connection's of coil winding a plurality of end electrodes, its characterized in that, the magnetic core is including being used for supporting coil winding's base member with be used for bearing two sets of carrier blocks of base member, two the carrier block symmetry is located the both ends of base member, it is a plurality of the end electrode is located respectively and is corresponded on the carrier block, coil winding and a plurality of the end electrode by form in conducting layer on the magnetic core sculpture loses and forms.

2. The chip inductor according to claim 1, wherein the two ends of each of the carrier blocks are respectively provided with the terminal electrodes, and each of the carrier blocks is further provided with a connecting wire for connecting the two terminal electrodes of the carrier block.

3. The chip inductor according to claim 2, wherein each of the terminal electrodes includes a connecting portion closely attached to the end surface of the corresponding carrier block and an extending portion extending along a peripheral side of the connecting portion toward a center line of the carrier block, the extending portion near one side of the coil winding is electrically connected to the leading end of the coil winding, and the extending portion on a side facing away from the coil winding of two terminal electrodes on the same carrier block is connected to the connecting wire.

4. The chip inductor according to claim 3, wherein the connection line is etched from the conductive layer.

5. The chip inductor according to claim 1, wherein the chip inductor further comprises a protective layer covering the periphery of the coil winding, and chamfers are respectively disposed at four corners of the protective layer.

6. The chip inductor according to claim 1, wherein the chip inductor further comprises a housing for protecting the core, the core being received in a receiving cavity of the housing.

7. The chip inductor according to claim 6, wherein the housing is formed by curing magnetic glue or plastic glue.

8. The chip inductor according to any one of claims 1-7, further comprising a logo plate disposed on an outer surface of the core.

9. A preparation method of a patch type inductor is characterized by comprising the following steps:

s1: providing a magnetic core, and covering a conductive layer on the outer surface of the magnetic core;

s2: removing redundant metal on the conducting layer, and leaving a conducting pattern for forming a coil winding, a plurality of end electrodes and a connecting wire on the magnetic core;

s3: and coating or packaging the surface mount inductor main body by using curing glue.

10. The method for manufacturing a chip inductor according to claim 9, further comprising, after forming the conductive pattern, S21:

and thickening the conductive pattern.