A coil inductor and a method of manufacturing the same

Abstract

The application provides a coil inductor and a manufacturing method thereof. The coil inductor comprises an inductor main body and a magnet wrapped outside the inductor main body. The inductor main body comprises a coil body, a lower lead and a bottom electrode. The coil body comprises a plurality of conductive coils. The coil body has a first end and a second end. The first end and the second end are the inflow end and the outflow end of the current flowing through the coil body. The lower lead is provided with two lower leads corresponding to the first end and the second end. The lower lead is parallel to the axis of the coil body and extends in the same direction. The bottom electrode is provided with two bottom electrodes located at the other end of each lower lead. The end surface of the bottom electrode is flush with the end surface of the magnet. The two ends of the coil body of the coil inductor are connected to the bottom electrode through the lower lead, so that the coil inductor is convenient for the surface mount device (SMD) installation mode, thereby greatly optimizing the installation efficiency of the coil inductor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic components, in particular to a coil inductor and a manufacturing method thereof. BACKGROUND

[0002] An inductor is a component that can convert electrical energy into magnetic energy for storage. A common power inductor is formed by winding a wire with a circular or rectangular cross-section into a spiral shape, with both ends of the wire exposed from the two ends or the side of the two ends. As product requirements diversify and miniaturize, the space utilization of electronic components has become a goal for practitioners to strive for, and therefore, power inductors with bottom electrodes have become the mainstream of current device requirements. SUMMARY

[0003] To solve the above problems, the present application realizes the following technical solutions:

[0004] A coil inductor, comprising an inductor body and a magnet wrapped outside the inductor body, wherein the inductor body comprises:

[0005] a coil body comprising a plurality of conductive coils, the coil body having a first end and a second end, the first end and the second end being the inflow end and the outflow end of the current flowing through the coil body;

[0006] a lower lead, the lower lead being provided with two corresponding to the first end and the second end, the lower lead being parallel to the axis of the coil body and extending in the same direction;

[0007] a bottom electrode, the bottom electrode being provided with two on the other end of each lower lead, the end surface of the bottom electrode being flush with the end surface of the magnet.

[0008] Further, the coil body comprises:

[0009] a plurality of conductive coils;

[0010] a plurality of insulating films, the insulating films being arranged in layers along the first direction and spaced apart from the conductive coils; each insulating film comprises at least one first through hole, and the first through holes on adjacent insulating films are distributed in a staggered manner; and

[0011] a contact, the contact being arranged in each first through hole to electrically contact the conductive coils on both sides of the through hole.

[0012] Further, the lower lead comprises:

[0013] a plurality of lower lead rings;

[0014] a plurality of insulating films are arranged in layers along a first direction and spaced apart from the conductive coil; each of the insulating films includes a second through hole, and the second through holes on adjacent insulating films are aligned; and

[0015] a contact is arranged in each of the second through holes to make electrical contact between the lower lead pieces on both sides of the through hole.

[0016] A manufacturing method of a coil inductor, comprising the steps of:

[0017] The conductive layer and the insulating layer are alternately laid along a first direction, and each layer is formed into a desired shape by photoetching and / or etching; thereby forming a plurality of inductor bodies arranged in an array, the inductor body including two bottom electrodes, a lower lead piece in electrical connection with each of the bottom electrodes, and a coil body in electrical connection with the other end of the lower lead piece.

[0018] The bottom electrodes of the plurality of inductor bodies arranged in an array are placed horizontally in a mold with the bottom facing down, and a magnetic material is introduced into the mold to cover the inductor bodies, thereby forming an inductor group.

[0019] The inductor group is cut to form a plurality of coil inductors, each coil inductor including one of the coil bodies and a magnet covering the inductor body.

[0020] Compared with the prior art, the technical scheme and the beneficial effects of the present application are as follows:

[0021] (1) The two ends of the coil body of the coil inductor of the present application are connected to the bottom electrodes through the lower lead pieces. When the electrodes are soldered to a circuit board, the tin paste only exists directly below the electrodes, occupying a smaller area. The arrangement of chips and components on the circuit board can be more dense. The electrodes are located on the same side, making the coil inductor easy to install in a surface mount device (SMD) manner, thereby greatly optimizing the installation efficiency of the coil inductor.

[0022] (2) In the present application, each layer is photoetched / etched into a desired pattern, and the inductor group with two electrodes on the bottom is formed after lamination. The inductor group is then subjected to magnetic material forming and cutting, thereby realizing batch production of inductors and greatly improving the production efficiency of inductors, especially the inductors with bottom electrodes. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a perspective view of a coil inductor provided by an embodiment of the present application;

[0024] Figure 2 is a front view of an inductor body provided by an embodiment of the present application;

[0025] Figures 3 to 18 is a step of forming an inductor body provided by an embodiment of the present application, wherein (a) is a top view and (b) is a front view.

[0026] Illustration:

[0027] Magnet - 100;

[0028] Inductor body - 200;

[0029] Coil body - 210; First coil - 211; Second coil - 212; Third coil - 213; Fourth coil - 214; Fifth coil - 215; Sixth coil - 216; Seventh coil - 217;

[0030] First via - 218 (contact 218a between first and second conductive coils, contact 218b between second and third conductive coils, contact 218c between third and fourth conductive coils, contact 218d between fourth and fifth conductive coils, contact 218e between fifth and sixth conductive coils, contact 218f between sixth and seventh conductive coils);

[0031] Insulating layer - 219;

[0032] First down body - 220;

[0033] Second via - 221 (contact 221x under first conductive coil, contact 221a flush with contact 218a, contact 221b flush with contact 218b, contact 221c flush with contact 218c, contact 221d flush with contact 218d, contact 221e flush with contact 218e, contact 221f flush with contact 218f);

[0034] Down coil - 222 (down coil 222x under first conductive coil, down coil 222a flush with first conductive coil, down coil 222b flush with second conductive coil, down coil 222c flush with third conductive coil, down coil 222d flush with fourth conductive coil, down coil 222e flush with fifth conductive coil, down coil 222f flush with sixth conductive coil);

[0035] Second down body - 230;

[0036] First electrode end - 240; Second electrode end - 250. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application but not all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0038] Figure 1 Fig. 1 shows a perspective view of an exemplary coil inductor according to some aspects of the present disclosure, Figure 2 Fig. 2 shows a front view of an exemplary inductor body 100 according to some aspects of the present disclosure.

[0039] Referring to Figure 1 An inductor body 200 and a magnet 100 covering the inductor body. The magnet 100 can be formed from a mixture of magnetic alloy powder and adhesive, and the magnetic alloy powder includes but is not limited to various soft magnetic metal alloys such as iron-silicon, iron-silicon-chromium, iron-nickel, iron-silicon-aluminum, etc.

[0040] Referring to Figure 2 The inductor body 200 includes a coil body 210, a lower lead body and a bottom electrode.

[0041] The coil body 210 includes a plurality of conductive coils, and the coil body has a first end 201 and a second end 202. When current flows through the coil body 210, the current flows from the first end 201 into the conductive coils and then flows out from the second end 202, i.e. the first end 201 and the second end 202 are electrode ends of the coil body 210.

[0042] The lower lead body is provided with two, one corresponding to the first end 201 and the second end 202 respectively. In this embodiment, the first lower lead body 220 corresponds to the first end 201, and the second lower lead body 230 corresponds to the second end 202. The first lower lead body 220 and the second lower lead body 230 extend in the same direction and are parallel to the axial direction of the coil body 210, so as to lead the electrode ends of the coil body 210 to the same side.

[0043] The bottom electrode is provided with two, in this embodiment, the first bottom electrode 240 is correspondingly arranged at one end of the first lower body 220 away from the coil body 210, and the second bottom electrode 250 is correspondingly arranged at one end of the second lower body 230 away from the coil body 210. When the coil inductor works, the current flows into the end of the first bottom electrode 240, flows through the first lower body 220 to the first end 201 of the coil body 210, and then flows out of the coil body 210 from the second end 202 and is conducted to the second bottom electrode 250 through the second lower body 230. The end surface of the first bottom electrode 240 and the end surface of the second bottom electrode 250 are located in the same plane as the end surface of the magnet 100, so that the coil inductor is installed in a patch type. It is not difficult to understand that the end surface of the bottom electrode is parallel to the cross section of the coil body 210, so that the formed coil inductor is a regular body, such as a cylinder or a square body.

[0044] Continuing to refer to Figure 2 , the coil body 210 includes a plurality of conductive coils and a plurality of insulating films arranged in a first direction. Each insulating film includes a first through hole 218, and a contact is arranged in the first through hole 218. The conductive coils on both sides of the same first through hole 218 are electrically connected through the contact. The adjacent first through holes 218 are misaligned to avoid short circuiting the conductive coils in the middle position.

[0045] In combination Figures 6 to 18 , this embodiment only uses an inductor with seven layers of conductive coils as an example for description, that is, the first conductive coil 211 and the second conductive coil 212, the third conductive coil 213 and the second conductive coil 212, the third conductive coil 213 and the fourth conductive coil 214, the fifth conductive coil 215 and the fourth conductive coil 214, the fifth conductive coil 215 and the sixth conductive coil 216, and the sixth conductive coil 216 and the seventh conductive coil 217 are all provided with insulating films 219. A contact is arranged in the first through hole 218 of each insulating film 219, and the adjacent contacts are not aligned. It can be understood that according to actual production and application, the structure of the inductor body can be more than or less than five layers of conductive coils.

[0046] The current path of the inductor can enter the first conductive coil 211 from the first end 201, flow through the first conductive coil 211 and the contact 218a to enter the second conductive coil 212. Then, the current path passes through the second conductive coil 212 and the contact 218b to enter the third conductive coil 213, and so on, flows through to the seventh conductive coil 217, and then flows out from the second end 202 at the end of the seventh conductive coil. Conversely, the current path flows into the seventh conductive coil from the end and flows out from the beginning of the first conductive coil.

[0047] The conductive coil can be formed of metal, such as copper foil. The insulating film is formed of non-conductive material, such as polyimide film, and has a thickness of 5 μm to 50 μm. Each conductive coil can be a solenoid coil, a square coil, an oval coil, a T-shaped coil, and other suitable shapes. Each conductive coil mentioned in the present embodiment can include one layer of conductive film or several layers of conductive film stacked in the first direction, and the conductive film can be copper film. The adjacent conductive films can be bonded by an adhesive layer or a copper bonding operation, thereby forming a conductive coil of different thicknesses.

[0048] Continuing to refer to Figure 2 , the downlead includes several downlead coils 222 and several insulating film first direction interval layers, each insulating film includes a second through hole 221, and the second through holes 221 on adjacent insulating films are aligned, and each second through hole 221 is provided with a contact, and the downlead coils 222 on both sides of the same second through hole 221 are electrically connected through the contact. The downlead coil can be formed of metal, such as copper foil, and the downlead body leads current from one end to the other end in a straight line. The first end 201 and the first bottom surface low level 240 are linearly connected through the first downlead body 220, and the second end 202 and the second bottom surface low level 250 are linearly connected through the second downlead body 230.

[0049] The present embodiment also provides a manufacturing process of a coil inductor. The coil inductor is formed by alternately laying conductive layers and insulating layers in the first direction, and each layer is formed into a desired shape by photolithography and / or etching, thereby forming several inductor bodies arranged in an array. A magnet is formed by covering the several inductor bodies arranged in an array with magnetic material, and then cutting uniformly. More specific steps are as follows.

[0050] Figures 3-18 The plan view of different layers of the coil inductor body 100 and the manufacturing process schematic diagram according to some aspects of the present disclosure are shown.

[0051] As shown in Figure 3 , the bottom conductive layer is formed into an arbitrary image by photolithography and / or etching, and the image is the bottom electrode of the inductor body. Each inductor body includes two bottom electrodes, namely the first bottom electrode 240 and the second bottom electrode 250. It can be understood that on the same layer of conductive layer, a plurality of array-arranged bottom electrode pairs can be formed by photolithography, and the subsequent steps in the present embodiment are the same. Each layer is batch-formed into several desired structures. The present embodiment only shows the formation process of one inductor body, and in fact, several inductor bodies arranged in an array are batch-formed.

[0052] As shown in Figure 4As shown, a second through hole 221 is provided in the insulating layer adjacent to the bottom electrode. The second through hole 221 corresponds to the bottom electrode. A contact 221x is provided in the second through hole 221. That is, a contact 221x is provided on the first bottom electrode 240 and a contact 221x is provided on the second bottom electrode 250.

[0053] The conductive layer adjacent to contact 221x is used to form a lower lead ring 222x through photolithography and / or etching. The lower lead ring 222x corresponds to contact 221x. Figure 5 As shown. In this embodiment, the first lower lead 230 is provided with only one layer of contact 221x and one layer of lower lead coil 222x. According to the actual design and production, the first lower lead 230 may also include two or more layers of insulating layer and lower lead coil.

[0054] like Figure 6 As shown, the conductive layer above contact 221x is formed by photolithography and / or etching to create a first conductive coil 211 and a lower lead 222a. The first conductive coil 211 and the lower lead 222a have no electrical contact. The first conductive coil 211 is in contact with one of the lower leads 222, and the lower lead 222a is in contact with the other lead 222.

[0055] An insulating layer above the first conductive coil 211 has a first through hole and a second through hole. A contact 218a is disposed in the first through hole, and a contact 221a is disposed in the second through hole. Contact 218a is offset from the lower lead coil 222x, and contact 221a is located above the other lower lead coil 222x. Figure 7 As shown.

[0056] A conductive layer is further deposited on the insulating layer containing contacts 218a and 221a, and this conductive layer is photolithographically and / or etched to form a second conductive coil 212 and a lower lead 222b. The second conductive coil 212 contacts contact 218a, and the lower lead 222b corresponds to contact 221a. Figure 8 As shown.

[0057] An insulating layer is laid above the second conductive coil 212 and the lower lead coil 222b. This insulating layer has a first through hole and a second through hole. A contact 218b is disposed in the first through hole, and a contact 221b is disposed in the second through hole. Contacts 218a and 218b are offset, and contact 221b is located above the lower lead coil 222b and aligned with 221a. Figure 9 As shown.

[0058] A conductive layer is further deposited on the insulating layer containing contacts 218b and 221b, and this conductive layer is photolithographically and / or etched to form a third conductive coil 213 and a lower lead 222c. The third conductive coil 213 contacts contact 218b, and the lower lead 222c corresponds to contact 221b. Figure 10as shown.

[0059] An insulating layer is laid over the third conductive coil 213 and the lower lead 222c, which is provided with a first through hole and a second through hole, the first through hole of the layer is provided with the contact 218c, and the second through hole is provided with the contact 221c, the contact 218c is staggered with the contact 218b, and the contact 221c is above the lower lead 222c and aligned with 221b, as shown. Figure 11

[0060] A conductive layer is continued to be laid on the insulating layer containing the contact 218c and the contact 221c, and the layer is photoetched and / or etched to form the fourth conductive coil 214 and the lower lead 222d, the fourth conductive coil 214 is in contact with the contact 218c, and the lower lead 222d corresponds to the contact 221c, as shown. Figure 12

[0061] An insulating layer is laid over the fourth conductive coil 214 and the lower lead 222d, which is provided with a first through hole and a second through hole, the first through hole of the layer is provided with the contact 218d, and the second through hole is provided with the contact 221d, the contact 218d is staggered with the contact 218c, and the contact 221d is above the lower lead 222d and aligned with 221c, as shown. Figure 13

[0062] A conductive layer is continued to be laid on the insulating layer containing the contact 218d and the contact 221d, and the layer is photoetched and / or etched to form the fifth conductive coil 215 and the lower lead 222e, the fifth conductive coil 215 is in contact with the contact 218d, and the lower lead 222e corresponds to the contact 221d, as shown. Figure 14

[0063] An insulating layer is laid over the fifth conductive coil 215 and the lower lead 222e, which is provided with a first through hole and a second through hole, the first through hole of the layer is provided with the contact 218e, and the second through hole is provided with the contact 221e, the contact 218e is staggered with the contact 218d, and the contact 221e is above the lower lead 222e and aligned with 221d, as shown. Figure 15

[0064] A conductive layer is continued to be laid on the insulating layer containing the contact 218e and the contact 221e, and the layer is photoetched and / or etched to form the sixth conductive coil 216 and the lower lead 222f, the sixth conductive coil 216 is in contact with the contact 218e, and the lower lead 222f corresponds to the contact 221e, as shown. Figure 16

[0065] ​​​​​​An insulating layer is deposited on top of the sixth conductive coil 216 and the lower lead 222f, and the insulating layer is provided with a first through hole and a second through hole, the first through hole is provided with the contact 218f, and the second through hole is provided with the contact 221f, the contact 218f is staggered with the contact 218e, and the contact 221f is located above the lower lead 222f and is aligned with 221e, as shown in Figure 17 .

[0066] The conductive layer is continuously deposited on the insulating layer containing the contact 218f and the contact 221f, and the conductive layer is photoetched and / or etched to form the seventh conductive coil 217, the seventh conductive coil 217 is in contact with the contact 218f, and the end of the seventh conductive coil 217 extends above the contact 221f to form the second end 202, as shown in Figure 18 .

[0067] In this way, a plurality of inductor bodies arranged in an array are formed.

[0068] The bottom surface electrodes of the array group of inductor bodies are placed horizontally in the mold with the bottom surface electrodes facing down, and the magnetic material is introduced into the mold to cover all the inductor bodies to form an inductor group.

[0069] The electrode end portions are placed horizontally in the mold with the electrode end portions facing down, which means that the electrode end portions are in contact with the bottom of the mold. After the magnetic material is introduced into the mold, the magnetic material wraps the inductor body, and the electrode end portions in contact with the bottom of the mold are not covered by the magnetic material, so that all the electrode end portions of the finally formed inductor group are exposed to the magnet, and the bottom surface electrodes are formed. It can be understood that the magnetic material penetrates between the individual electrode end portions and the bottom of the mold, and the electrode end portions are very close to the surface of the magnet, and the electrode end portions can be exposed by shallow grinding.

[0070] The magnetic material includes a magnetic alloy powder and a binder. In some embodiments, the magnetic alloy powder includes, but is not limited to, various soft magnetic metal alloys such as iron-silicon, iron-silicon-chromium, iron-nickel, iron-silicon-aluminum, etc.

[0071] The magnetic alloy mixture can also be compressed by a soft medium to compress the magnetic alloy mixture into a magnet. The soft medium can include the magnetic alloy mixture, which is compressed into a magnet. Alternatively, the soft medium can be a liquid medium, such as water.

[0072] A planarization operation can also be performed on the surface of the magnet to improve the roughness of the rough magnet surface after compression by the soft medium.

[0073] After the planarization operation, a grinding process can also be included, such as grinding the side of the magnet close to the electrode end to completely expose the end of the electrode to the magnet, i.e., end grinding.

[0074] Thus, an inductor set is obtained in which the end surface of each bottom electrode is flush with the end surface of the magnetic material.

[0075] The inductor set is cut to form a plurality of coil inductors, each coil inductor including one of the coil bodies and the magnet surrounding the coil body. Thus, a plurality of coil inductors is obtained at one time, thereby effectively improving the production efficiency of the bottom electrode inductor.

[0076] The foregoing description shows and describes preferred embodiments of the application, but it is to be understood that the application is not limited to the foregoing description but is capable of numerous modifications and embodiments apparent to those skilled in the art. Accordingly, the application is to be considered as limited only by the scope of the appended claims, wherein changes in the order, or of equivalents, are intended to be within the scope of the application.

Claims

1. A coil inductor comprising an inductor body and a magnet coated on the outside of the inductor body, characterized in that, The inductor body comprises: a coil body comprising a plurality of conductive coils, the coil body having a first end and a second end, the first end and the second end being the inflow end and the outflow end of the current flowing through the coil body; a lower lead provided with two lower leads corresponding to the first end and the second end, the lower leads extending in the same direction and being parallel to the axis of the coil body; the lower lead comprises a plurality of lower lead coils, a plurality of insulating films arranged in layers along a first direction and spaced apart from the conductive coils, each insulating film comprises a second through hole, and the second through holes on adjacent insulating films are aligned, and a contact provided in each second through hole to enable electrical contact between the lower lead coils on both sides of the through hole; a bottom electrode provided with two bottom electrodes respectively located at the other end of each lower lead, the end surface of the bottom electrode being flush with the end surface of the magnet.

2. A coil inductor according to claim 1, characterized in that The coil body comprises: a plurality of conductive coils; a plurality of insulating films arranged in layers along a first direction and spaced apart from the conductive coils, each insulating film comprises at least one first through hole, and the first through holes on adjacent insulating films are distributed in a staggered manner; and a contact provided in each first through hole to enable electrical contact between the conductive coils on both sides of the through hole.

3. A coil inductor according to claim 2, wherein The thickness of the insulating film is 5-50 μm.

4. A coil inductor according to claim 1, characterized in that The conductive coil comprises one or a plurality of conductive films stacked along the first direction.

5. A method of manufacturing a coil inductor, characterized by, The method comprises the steps of: alternately laying conductive layers and insulating layers along a first direction, and forming the required shape by photolithography and / or etching after laying each layer; thereby forming a plurality of inductor bodies arranged in an array, the inductor body comprising two bottom electrodes, a lower lead in electrical communication with the bottom electrode, and a coil body in electrical communication with the other end of the lower lead; The method for forming the lower lead comprises: opening a second through hole in the insulating layer above the bottom electrode, the second through hole corresponding to the electrode end; the conductive layer above the second through hole is formed into a first lower lead coil by photolithography and / or etching, the first lower lead coil corresponding to the second through hole, and the first lower lead coil and the electrode end being in electrical communication through the contact provided in the second through hole; the insulating layer above the first lower lead coil is also provided with a second through hole and a contact, and the conductive layer above the second through hole forms a second lower lead coil; and so on, thereby forming two lower leads of different lengths, the lower lead coil above the same bottom electrode and the insulating layer with the second through hole forming a lower lead, and the second through holes in the same lower lead being aligned; placing the bottom electrodes of the plurality of inductor bodies arranged in an array into a mold with the bottom facing down and horizontally, and introducing a magnetic material into the mold to cover the inductor bodies, thereby forming an inductor group; cutting the inductor group to form a plurality of coil inductors, each coil inductor comprising one of the coil bodies and a magnet covering the inductor body.

6. A method of manufacturing a coil inductor according to claim 5, wherein, The method for forming the electrode end comprises: forming an arbitrary image on the bottom conductive layer by photolithography and / or etching, the image being the bottom electrode of the inductor body.

7. A method of manufacturing a coil inductor according to claim 6, characterized in that, The method for forming the coil body comprises: forming a first conductive coil by photolithography and / or etching; The insulating layer above the first conductive coil comprises a first through hole, and a contact is arranged in the first through hole; The conductive layer above the first through hole forms a second conductive coil; The insulating layer above the second conductive coil also comprises a first through hole, and a contact is arranged in the first through hole; By analogy, the top layer is a conductive coil, thereby forming a coil body in which the conductive coils and the insulating layers are alternately stacked, adjacent conductive coils are electrically connected through the contacts, and adjacent first through holes are distributed in a staggered manner; The first conductive coil is electrically connected to the upper end of the short lower lead, and the top layer conductive coil is electrically connected to the upper end of the long lower lead.

8. A method of manufacturing a coil inductor according to claim 7, characterized in that, The electric coils and the lower lead in the same plane are obtained by photoetching and / or etching of the same conductive layer, and the first through hole and the second through hole in the same plane are formed in the same insulating layer.

9. A method of manufacturing a coil inductor according to claim 7, wherein, Each of the conductive coils can be circular, spiral, rectangular, or spiral rectangular.

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