TW201337985A - Power inductor structure without lead frame and its manufacturing method - Google Patents

Abstract

A power inductor structure and its manufacturing method are disclosed. The power inductor structure comprises a lower substrate, a coil disposed on the lower substrate, and a middle layer covering the coil. The lower substrate can be a soft magnetic object with the magnetism or a carrier with the magnetism. The coil is a wire with an insulated layer on the surface. The middle layer comprises the colloid containing magnetic powder. The manufacturing method comprises: fixing on the upper surface of the lower substrate a wire packet of an enamelled wire with an insulated layer on the surface of a copper wire or other conductors; coating the wire packet with the colloid containing magnetic powder; cutting the wire packet into dices; sequentially shaping the dices. The wire packet is fixed in the following way: first forming on the substrate a layer of patterned second conductor which can be bonded with the conductor metal of the coil of the wire packet, such that the second conductor can electrically lead the coil out of the terminal electrode, and the use of a lead frame can therefore be eliminated.

Description

Power inductor structure without lead frame and manufacturing method thereof

The invention relates to a power inductor structure without a lead frame and a manufacturing method thereof, in particular to a single piece production method capable of replacing a single production mode, which can increase the production rate of the power inductor, reduce the cost, and produce the power inductor and the external electrode. There is a higher electrical connection reliability when connecting.

For example, as disclosed in U.S. Patent No. 6,204,744 B1, the coil 10 is attached to a circuit board 12 including a housing 14 as shown in Figs. 1A, 1B, 1C, and 1D. The first wire 16 and the second wire 18 are extended from the housing 14 and soldered to the solder joints 20, 22 on the circuit board, respectively. The coil 10 is formed by a vertical flat wire having a right-angled cross section, and the coil is spiraled, has a plurality of turns 30, and includes an inner end 26 and an outer end 28, and a lead frame 32 The two ends 34, 38 are integrally welded to the inner end 26 and the outer end 28 of the bobbin 24, respectively. Then, the winding body 24 to which the wires 16 and 18 have been soldered is placed in a mold, and a magnetic powder material which is preferably colloidal is injected into the mold, and the magnetic powder material is dried to form a block, and after demolding, The portion of the leadframe 32 is severed to obtain the inductive component of the U.S. patent.

However, the US Patent No. 6,204,744B1 has the following shortcomings:

1. In the manufacture, if the coil component is wound by a flat wire, the winding of the flat wire is complicated if the two free ends of the coil are located outside the coil.

2. As shown in Fig. 1D, if the coil component 10 is wound by a circular wire, the multilayer structure of the circular wire is difficult to meet the requirements of light, thin, short, and small electronic components, and the cost thereof is relatively increased.

3. When manufacturing the inductor, the coil component is first soldered to the wire, and then placed in the mold, and then the magnetic powder material is placed in the mold, so that the coil component and the coated magnetic material are less likely to be completely tightly bonded. problem.

4. Because the number of overlapping turns of the coil wire is high, the electromagnetic interference between the multilayer wires will cause the loss of the inductance value to be large.

5. In addition, since the current production of the above-mentioned power inductor products still needs to be produced in units of one unit, it takes a considerable manpower and a relatively long time to reduce the production efficiency. Moreover, the two ends of the coil are respectively welded to the two legs of a lead frame, and then the outer frame of the lead frame is cut off to obtain the coil contact, which also causes material loss, which is maintained for it. At a high cost reason.

6. See the power inductor, the way the coil is connected to the external electrode is a point-to-point connection. Thus, when the device of the power inductor application has a drastic change in temperature or a long-time application of current, the coil and the external electrode are easily separated, causing the circuit to open. In severe cases, the product will be completely burned.

In view of the above-mentioned lack of power inductors, the present inventors have made improvements to the research of these defects, and the invention has been produced by long-term research.

Accordingly, the present invention is directed to a power inductor and a method of fabricating the same that utilizes a conductor layer on a lower substrate, a wire package between the conductors, and a colloid containing a magnetic powder inside the wire package. Then cut into granules, and then form the mold.

According to the power inductor and the manufacturing method thereof of the invention, the power inductor can be mass-produced at one time, and the production efficiency of the product is greatly improved, which is the second object of the invention.

According to the secondary power inductor of the present invention and the manufacturing method thereof, the coil lead wire end portion of the inductor unit does not need to be welded to the leg of a lead frame to form the electrode terminal of the power inductor unit, so that the lead frame can be eliminated and soldered. The process of winding the end of the coil, the cost of the power inductor is greatly reduced, which is another object of the present invention.

According to the power inductor of the present invention and the manufacturing method thereof, since the lead frame is not required in the manufacturing process, the cost of preparing the lead frame is not obtained, and the coil is not welded to the leg of the lead frame, and the lead frame needs to be The process cost of the outer frame cutting and the cost of the outer frame material are another object of the present invention.

According to the power inductor of the present invention and the method of manufacturing the same, the power inductor produced by the manufacturing method can meet the requirements of light, thin, short and small electronic components, and the coil and the external electrode are closely combined to form an inductor. In the unit body of the component, there is no known situation in which the coil of the inductive component is separated from the pin, which causes damage to the electronic device, which is a further object of the present invention.

As for the detailed construction, application principle, function and effect of the present invention, please refer to the following description according to the drawings to obtain a complete understanding.

The power inductor of the present invention has a body as shown in FIG. 2, and includes a lower substrate 100, a conductive layer 300 disposed on the lower substrate, a coil 200 disposed on the lower substrate, and a cladding The coating layer 400 of the coil 200; wherein the lower substrate 100 may be a magnetic soft magnetic magnet or a magnetic carrier, the coil 200 is a wire having an insulating layer on the surface, and the conductive layer 300 may be silver (Ag). A layer of tin (Sn), copper (Cu), aluminum (Al), nickel (Ni) or other electrically conductive material, the conductive layer 300 is electrically coupled to the coil 200, and the coating layer 400 is a colloid containing a magnetic powder.

Further, as shown in Fig. 3, the end electrodes 500 and 600 covering the upper and lower end faces of the body can be formed on both end faces of the inductor body 300 to form the conductive layer 300, so as to be suitable for surface adhesion.

The power inductor of the present invention has a plurality of manufacturing methods as described below:

[Example 1]

1. Preparing a lower substrate 201, which may be a magnetic soft magnetic carrier or a magnetic carrier, such as an iron oxide substrate or an alumina substrate or PET (as shown in Figure 4-1);

2. Forming a plurality of spaced apart conductive metal layers 202a, 202b, 202c... on the lower substrate 201, the conductive metal layers 202a, 202b, 202c... may be copper, silver, aluminum, tin, nickel or other conductive materials, or The alloys of each other overlap each other (as shown in Figure 4-2).

3. A first-line package 203 is provided on the upper surface of the lower substrate 201, and the wire package 203 is a plurality of coil units 203a, 203b, ... arranged in a matrix, and between the adjacent coil units 203a, 203b, ... is a coil unit 203a. The lead lines 203a1, 203a2, 203b1, 203b2, ... of 203b are formed, and the adjacent lead lines 203a2, 203b1 of the adjacent two coil units may be the same. The material of the wire package 203 can be a copper wire or other conductor, and the copper wire can be an enamel wire with an insulating layer on the surface (as shown in Figure 4-3);

4. The lead wires 203a1, 203a2, 203b1, 203b2, ... of the coil units 203a, 203b, ... of the wire package 203 are electrically connected to the conductive metal layers 202a, 202b, ... by a soldering process or a hot stamping process; 203a, 203b... are located between two separate conductive metal layers 202a, 202b... as shown in Figures 4-4.

5. Using a colloid 204 containing a magnetic powder inside, coated on a wire package 203, the magnetic body contained in the colloid 204 may be a ferrite magnet or iron and an alloy powder thereof (as shown in Figures 4-5). Because the magnetic powder colloid is coated rather than molded, the stress can be greatly reduced, and it is not easily cracked, and it can be suitably used for making a thinned product.

6. The upper surface of the colloid 204 is covered with an upper substrate 205 as a fixed layer (as shown in FIGS. 4-6). The upper substrate 205 and the lower substrate 201 may be the same material and then baked at about 200 ° C. The above-mentioned colloid 204 can be cured and bonded to the upper substrate 205; (here, it should be noted that the upper substrate 205 may not be provided).

7. Using a dicing process to divide the baked substrate into granular elements 2000 (as shown in Figures 4-7 and 4-8);

8. The finished granular element is then subjected to a printing process, an electroless plating process or a sputtering process, and the opposite side conductor exposed layer of the component is covered with an electrical conductor layer 206, which may be silver, copper or indium. a conductive material such as aluminum or nickel (as shown in Figures 4-9), the conductor layer 206 may have a thickness of 0.1 to 100 μm;

9. Electroless plating is used to plate another conductive metal layer 207 (as shown in Figures 4-10). The conductive metal layer 207 may be silver/nickel/tin (/Ag/Ni/Sn), copper/ Nickel/tin (Cu/Ni/Sn) or copper/tin (Cu/Sn) makes the component a surface-adhesive component.

[Embodiment 2]

1. Preparing a lower substrate 301, which may be a magnetic soft magnetic magnet or a non-magnetic carrier, such as an iron oxide substrate or an alumina substrate or PET (as shown in Figure 5A);

2. Forming a plurality of separated conductive metal layers 302 on the lower substrate 301. The conductive metal layers 302 may be copper, silver, aluminum, tin, nickel or other conductive materials, or an alloy thereof. Figure 5B);

3. The first wire package 303 is disposed on the upper surface of the lower substrate 301, and the wire package 303 is a plurality of coil units arranged in a matrix, and the adjacent coil units are formed by the lead wires of the coil unit, and adjacent The adjacent lead wires of the two coil units may be the same. The material of the wire package 303 may be a copper wire or other conductor, and the copper wire may be an enameled wire having an insulating layer on the surface, and the wire package is fixed on both sides of the substrate by using a jig (as shown in FIG. 5C); a soldering process or a hot stamping process, electrically connecting the lead wires of the coil unit of the wire package 303 to the conductive metal layer; thus, the coil unit is located between the two separated conductive metal layers;

4. Each of the coils of the wire package 303 is filled with a column 3A which is a rod-shaped body which may be a magnetic material or a non-magnetic material such as Fe and a related alloy or oxide; the column 3A may be used for adjustment Electrical characteristics of the power inductor (as shown in Figure 5D);

5. Using a colloid 304 containing a magnetic powder, coated on the wire package 303, the magnetic body contained in the colloid 304 may be ferrite magnet or iron and alloy powder thereof (as shown in Figure 5E); Since the magnetic powder colloid is coated rather than molded, the stress can be greatly agitated and not easily cracked, and it can be suitably used for making a thinned product.

6. The upper surface of the colloid 304 is covered with an upper substrate 305 as a fixed layer (as shown in FIG. 5F). The upper substrate 305 and the lower substrate 301 may be made of the same material and then baked at about 200 ° C. The above-mentioned colloid 304 can be cured and bonded to the upper substrate 305; (the upper substrate 305 can also be omitted)

7. using a cutting process to divide the baked substrate into granular elements 3000 (as shown in Figures 5G and 5H);

8. The finished granular element is then subjected to a printing process, an electroless plating process or a sputtering process, and the component facing lateral side wire exposed layer is plated with an electrical conductor layer 306, which may be silver, copper or indium. a conductive material such as aluminum or nickel (as shown in FIG. 5I), the conductor layer 306 may have a thickness of 0.1 to 100 μm;

9. Electroless plating is used to plate another conductive metal layer 307 (as shown in FIG. 5J). The conductive metal layer 307 may be silver/nickel/tin (/Ag/Ni/Sn), copper/nickel/ Tin (Cu/Ni/Sn) or copper/tin (Cu/Sn) makes the component a surface-adhesive component.

In the second step of the second embodiment, the conductive metal layer 302 may also be copper, silver, aluminum, tin, nickel or other conductive materials having a melting point of 200 to 600 ° C, or an alloy thereof. Thus, it can be blown in an overheated state, so that the power inductor of the present invention has a protective function similar to that of a fuse.

In step 6 of the above second embodiment, baking at 200 ° C is merely an example and is not intended to limit the baking temperature thereof.

It can be seen from the above that the power inductor structure without the lead frame of the present invention and the manufacturing method thereof, the power inductor produced by the manufacturing method have the advantages of simpler structure, easier manufacture, and safer operation. These effects can improve the disadvantages of the power inductors, but they are not publicly available. In accordance with the provisions of the Patent Law, it is a matter of granting patents.

The above is a preferred embodiment of the present invention. If the changes made by the concept of the present invention are not exceeded by the spirit of the specification and the drawings, the present invention should be Within the scope of the agreement, Chen Ming.

10. . . Coil

12. . . Circuit board

14. . . Ontology

16. . . First wire

18. . . Second wire

20, 22. . . Solder joint

twenty four. . . Winding body

26. . . Medial end

28. . . Outer end

30. . . Majority circle

32. . . Lead frame

34, 38. . . End

100. . . Lower substrate

200. . . Coil

300. . . Conductive layer

400. . . middle layer

500, 600. . . Terminal electrode

101. . . Lower substrate

102. . . Wire package

103. . . colloid

104. . . Upper substrate

105. . . Copper layer

106. . . Protective colloid

107. . . Insulating material layer

108. . . Conductive metal layer

3A. . . Column

201, 301. . . Lower substrate

202a, 202b, 202c, 302. . . Conductive metal layer

203a, 203b. . . Coil unit

203a1, 203a2, 203b1, 203b2. . . Lead line

203, 303. . . Wire package

204, 304. . . colloid

205, 305. . . Upper substrate

206, 306. . . Conductor layer

207, 307. . . Conductive metal layer

1000, 2000, 3000. . . Granular component

1A to 1D are diagrams showing an embodiment of the case of U.S. Patent No. 6,204,744 B1.

2 is a perspective view of the power inductor body of the present invention.

FIG. 3 is a schematic perspective view showing the formation of terminal electrodes on both sides of the power inductor body according to the present invention.

Figures 4-1 to 4-10 are plan views showing the manufacturing flow of the first embodiment of the present invention.

5A to 5J are plan views showing the manufacturing flow of the second embodiment of the present invention.

100. . . Lower substrate

200. . . Coil

300. . . Conductive layer

400. . . middle layer

500, 600. . . Terminal electrode

Claims (21)

A manufacturing method of a power inductor without a lead frame, the method comprising: preparing a lower substrate; forming a plurality of separated conductive layers on the lower substrate; and arranging a plurality of coil units arranged in a matrix and providing an insulating layer on the surface of the coil unit a wire package is disposed on the upper surface of the lower substrate, such that each coil unit is located between the two conductive layers, and the lead wire between the coil unit and the coil unit is connected and fixed to the conductive layer; and a gel containing the magnetic powder is coated The substrate is arranged on the above-mentioned wire package; the substrate is divided into a plurality of granular elements by a cutting process, and each of the divided granular elements has a conductive layer on both sides of the upper surface, and coil units are arranged between the two conductive metal layers. The coil unit is electrically connected to lead the lead wire, and the conductive layer, the coil unit and the lead wire are covered by the colloid; finally, a conductive metal layer is formed on both sides of the element to form a surface-adhesive element. A manufacturing method of a power inductor without a lead frame, the method comprising: preparing a lower substrate; forming a plurality of separated conductive metal layers on the lower substrate; and arranging a plurality of coil units arranged in a matrix and providing an insulating layer on the surface of the coil unit The wire package is placed on the upper surface of the lower substrate such that each coil unit is located between the two conductive metal layers, and the lead wire between the coil unit and the coil unit is connected and fixed to the conductive metal layer; each of the online packages The coil is filled with a column for adjusting the electrical characteristics of the power inductor; a colloid containing the magnetic powder is coated on the above-mentioned wire package; the substrate is divided into a plurality of granular elements by a cutting process, and each of the divided pieces is divided. The granular element has a conductive metal layer on both sides of the upper surface thereof, and a coil unit is arranged between the two conductive metal layers, the coil unit and the conductive metal layer are connected by a lead wire, and the conductive metal layer, the coil unit and the lead wire are both colloidal Covering; Finally, a conductive metal layer is formed on both sides of the element to make it a surface-adhesive element. The manufacturing method of claim 1 or 2, wherein the upper surface of the colloid may be covered with an upper substrate as a fixed layer. The manufacturing method of claim 3, wherein the material of the lower substrate or the upper substrate is a magnetic soft magnetic magnet or a magnetic carrier. The manufacturing method of claim 1 or 2, wherein the thickness of the electrically conductive layer is 0.1 to 100 μm. For example, in the manufacturing method of claim 1 or 2, wherein the wire package is selected for the copper wire or other enamelled wire with an insulating layer on the surface of the conductor, and the opposite end of the wire package is fixed to the electricity by welding or heating. Sexual conductor layer. The manufacturing method of claim 1 or 2, wherein the magnetic powder contained in the colloid is a ferrite magnet or iron and an alloy powder thereof. The manufacturing method of claim 1 or 2, wherein the conductive metal layer is silver/nickel/tin (Ag/Ni/Sn), copper/nickel/tin (Cu/Ni/Sn) or copper/tin. (Cu/Sn). The manufacturing method of claim 2, wherein the column to be filled is made of a material having soft magnetic properties. The manufacturing method of claim 9, wherein the filled column is coupled to the lower substrate. The manufacturing method of claim 9, wherein the column to be filled is connected to the lower portion and the upper substrate. A power inductor includes: a lower substrate; two conductive metal layers respectively formed on both sides of the upper surface of the lower substrate; a coil, a coil and a conductive metal layer disposed between the two conductive metal strips are connected and fixed by a lead wire; A colloid containing a magnetic powder covering the conductive metal layer, the coil, and the lead wire. The power inductor of claim 12, wherein the coil and the conductive metal layer are welded or crimped. The power inductor of claim 12, wherein the coil is coated with an insulating layer on a surface of the copper wire. The power inductor of claim 12, wherein the magnetic powder of the colloid is a ferrite magnet or iron and an alloy powder thereof. For example, in the power inductor of claim 12, an upper substrate is further disposed, and the upper substrate is bonded to the colloid. The power inductor of claim 12, wherein the coil is internally provided with a post, and the position of the post in the coil can be used to adjust the electrical characteristics of the power inductor. The power inductor of claim 12, wherein the upper substrate or the lower substrate is a magnetic soft magnetic magnet or a magnetic carrier. For example, the power inductor of claim 12, wherein the surface of the inductor body component has a surface of an electrically conductive layer, and the other surfaces are covered with a layer of insulating material. For example, the power inductor of claim 12, wherein the conductive metal layer on both sides of the upper surface of the lower substrate is made of a metal having a melting point of 200 to 600 degrees or an alloy thereof. For example, the power inductor of claim 20, wherein the conductor metal layer shrinks and separates when the temperature is higher than its melting point.