KR20210044121A - A Surface Mounted Metal Composite Power Inductor And A Method Of Manufacturing The Same - Google Patents

Abstract

The present invention relates to a surface-mounted metal composite power inductor manufactured by press-molding a metal electrode terminal piece welded to a lead wire of an air-core coil together with magnetic metal powder. Provided are a surface mount metal composite power inductor with a new terminal structure and a manufacturing method thereof, wherein longitudinal sides divided by cutting and removing central portions of both longitudinal sides of the metal electrode terminal piece in an inverted trapezoid are bent at acute angles inward with respect to the plane of the terminal piece, respectively, so that they are bent and embedded in the inductor body in a hook shape during molding.

Description

Surface Mounted Metal Composite Power Inductor and A Method Of Manufacturing The Same with New Terminal Structure

In the present invention, instead of a lead frame constituting a typical surface mount type metal composite inductor, the present invention introduces a bent metal external electrode terminal structure (hereinafter, simply referred to as “metal terminal” or “electrode terminal”). It relates to a type metal composite inductor and a method of manufacturing the same.

In the case of small portable electronic devices or devices, or general inductor products that are comprehensively applied to industrial or electronic applications, an external metal terminal is implemented using a lead frame or an external terminal is implemented by introducing a conductive adhesive. I'm doing it. The three-dimensional standard of these small inductors can be designed in a variety of applications. Currently, the standard of small inductors available on the market is 3.2 ㎜×2.5 ㎜×1.2 ㎜ (weight about 0.06 g). For these small inductors, electrode terminal pieces of arbitrary shape and structure are devised and used. For example, technology.

KR10-0861103 provides a through hole through which the lead wire at both ends of the air core can penetrate in the approximately center of the metal terminal in the form of an “L” (or inverse “L” shape), and the lead wire passing through the through hole is provided. A method of forming an electrode terminal to be welded to a metal terminal is disclosed, wherein a roughness treatment is performed on the surface of the metal terminal in contact with the magnetic body for the purpose of improving the bonding strength with the magnetic metal powder. It is the content.

In this way, it is generally expected that the metal surface is roughened to improve mutual adhesion with the magnetic powder after molding. However, for this, a separate surface treatment process is required, and it is a reality that the effect is encountered in this technical field that it is not always consistent with expectations.

KR10-1981515 uses magnetic metal powder to press-form two rectangular upper and lower tablets, and then applies a flat line (also called a'square line'), which is an enamel coating, to the lower type of tablets prepared in advance. After inserting the alpha-wound air core coil, assemble the upper mold to manufacture a molded body. This patent document is known as a general method of manufacturing a surface-mounted chip product in which a terminal is formed by coating or immersion treatment of a curable conductive resin on both ends of a molded article manufactured in this way.

KR10-1044607 describes a composite inductor in which the entire three-dimensional shape of the electrical terminal is inverted trapezoid and bonded to the end of the coil. Even so, a defect that often falls out against external shocks such as long-term extreme vibration forces has been found. . In addition, KR10-1044608 proposes a method for mass-producing composite inductors as expected in KR10-1981515 at once, but this also points out the weak seismic resistance of the electrode terminal pieces to the inductor body.

KR10-1154248 is described by quoting the reference numerals used here in parentheses, the square upper and lower plates 11 and 11 are formed in an octagonal shape by cutting corners, and the central axis of a predetermined length between the two plates [In this technical field, this is usually referred to as a bobbin.] A core 10 with a coil 20 pre-wound around it is placed and fixed in a predetermined position on the printed circuit board 40 in advance. An inductor configured to match (or assemble) the lower plate 11 on the terminal 30 by placing it in a snap button manner is described. However, the inductor is a structure that cannot be used as it is technically or structurally to the structure of a composite inductor using the bobbinless air core coil. This is because, as can be seen from the drawings shown in this document, the bent terminals do not penetrate into the magnetic body constituting the inductor body, but completely protrude to the outside. Therefore, in this technical field, an inductor having such a structure is called a "open magnetic circuit" and is treated differently. In such a circuit, as is well known to those skilled in the art, there is a drawback in that the influence of the magnetic field generated around the coil on the peripheral circuit must be considered.

Next, in the case of the inductor described in KR10-0835886, the configuration of a typical surface mount type inverter manufactured by bonding the lead frame 2 to both ends 1b and 1b of air core coils via the junctions 4 and 4 is shown. Are giving. The lead frame protrudes outward from both sides of the center of the body of the inductor product after molding, and may be bent upward or downward as necessary. The inductor has a configuration in which a crack state is likely to appear due to an unbalanced molding inside the exposed portion of the lead frame on the side of the inductor product (see FIG. 3 of this patent document). In particular, this product is repetitive according to the vibration pressure gradient mounted on a device or circuit used in a device with severe vibration due to its weight, when assembling the inductor body in a shape suspended by both lead frames in an electrical circuit in which vibration that continues for a long period of time is inevitable. In particular, due to the equilibrium deviation, a gap is easily formed between the main body and the terminal because it is greatly shaken up and down. Accordingly, unexpected defects are likely to occur due to the vulnerability of moisture resistance through the gap or the influence of peripheral devices due to leakage magnetic flux.

However, as the development and commercialization of electric vehicles in particular progress in recent years, the standard of the surface mount metal composite power inductor used in the electric vehicle for the driving device is the above-described standard used in the existing small portable electronic devices or electronic equipment. It increased more markedly. Accordingly, its weight will also increase significantly. For example, when the standard is 10.0 mm×10.0 mm×8.0 mm, the final weight of the molded product is measured in the range of approximately 3.5 to 4.0 g. When such a large-standard composite power inductor is mounted on the circuit surface of an electronic component of an automobile or industrial machine where violent vibration force is continuously applied for a long time during operation/driving, its electrode terminal is caused by the continuous vibration force due to its size and weight. The risk of being easily removed from the inductor body is very high compared to the small metal composite power inductor. In addition, in the case of an inductor having a conventional lead frame structure, there are many cases where it is easy to cause interference and damage to the characteristics of the inductor due to the influence of the magnetic flux leakage phenomenon as the lead frame is located inside the product.

In addition, it is a general reality that most of the existing inductors have to be individually molded because it is difficult to produce a large amount at once. In addition, since the conventional inductor molding method mainly relies on the uniaxial compression molding method as described above, it is difficult to achieve a uniform molding density of the magnetic body due to the non-uniform pressure gradient and the moisture resistance is poor. Accordingly, cracks [cracks] easily occur inside and outside the terminal, and the magnetic field shielding effect is reduced, so that electromagnetic interference is likely to occur.

Therefore, in the field of electrical equipment manufacturing technology for large machines or devices such as electric vehicles and industrial machines, the quality of electrode terminal pieces does not easily come off from the inductor body even under severe conditions accompanied by violent vibrations that occur during long driving/operation. High weight and large size capable of maintaining the uniformity of, such as size 8 mm×8 mm×4 mm (weight 1.64 g); The appearance of a metal composite power inductor of 10 mm×10 mm×5 mm (3.2 g in weight) to 13 mm×13 mm×6 mm (6.5 g in weight) is urgently desired.

The problem to be solved by the present invention is a surface mounting provided with an electrode terminal piece of a new structure that can ensure the prevention of the electrode terminal piece from falling out even in an environment where intense vibration force is applied for a long time, especially when used in an electric vehicle or an industrial machine. Its purpose is to provide a type metal composite inductor and a method for mass-producing the same.

The above-described problem to be solved by the present invention is such that the portion of the metal electrode terminal piece of the metal composite inductor body, which is located inside the bottom of the inductor body, is embedded in the magnetic body inside the body in a hook (or anchor) shape. This can be achieved by providing the constructed terminal piece of a new structure.

The metal electrode terminal is formed by punching into a designed shape and size from a metal sheet having generally excellent electrical conductivity, such as copper, tungsten, beryllium copper, or the like. In the present invention, a phosphor bronze metal sheet material plated with tin is used in consideration of ease of acquisition, electrical conductivity, strength, and economical aspects.

The electrode terminal piece according to the present invention may be bent in a “hook shape” inside the bottom of the magnetic metal body of the main body of the inductor product after the final molding to be firmly fixed and buried. In the present invention, in order to distinguish this from various electric terminal pieces applied to the conventional composite power inductor, it will sometimes be referred to as a "hook type terminal piece" for convenience throughout this specification.

Wires used in the practice of the present invention, that is, insulating coils having a diameter of 0.5 to 1.0 mm may be used, but in the present invention, 1.0 mm was used. The phosphor bronze metal electrode sheet material preferably has a thickness of 0.2 mm (200 µm) that can be easily obtained on the market.

As described above, the thickness of the metal terminal piece material of the present invention was 0.2 mm, and the width (width) of each punched terminal piece was 4 mm, and the length (length) was 8 mm to 10 mm. The fine wires that connect each terminal and the terminal vertically and left and right can be easily removed by laser irradiation or dicing according to a conventional method after completion of the process.

Further, the surface-mounted metal composite power inductor provided with the hook-shaped electrode terminal piece of the present invention is an air core coil/electrode terminal welding assembly in which electrode terminal pieces are respectively welded to both lead wires of a plurality of air core coils that are continuously wound. In a method for manufacturing a surface-mounted metal composite power inductor comprising a step of pressing and molding together with a predetermined amount of magnetic metal powder in a predetermined inductor molding machine, the electrode terminal pieces are continuously connected in one group on the top, bottom, left and right. A step of punching from an electrically conductive metal thin film sheet so that both vertical sides or both horizontal sides of each electrode terminal piece are bent at an acute angle with respect to the plane of the terminal piece, and both vertical sides or both sides of the electrode terminal piece bent. A method of manufacturing a surface-mounted metal composite power inductor having a new electrode terminal structure, characterized in that it further comprises a step of bending and embedding the side of the inductor into a hook shape in the body of the inductor by the molding pressure during press-molding of the inductor. Is achieved by

Further, the magnetic metal powder used in the present invention is mixed with an appropriately selected curable caking agent, and the material and mixing ratio thereof are well known in the art. The term “magnetic metal powder” refers to an iron-based metal powder, for example, carbonyl iron, Fe-Si, Fe-Si-Cr, sendust, permalloy, Metal powders with high magnetic permeability, such as amorphous iron-based powders, are mentioned, and they are readily available on the market. Various magnetic metal powder products with an average particle diameter ranging from 1 µm to 100 µm are commercially available, and are appropriately selected according to conditions such as required characteristics and specifications of the product. In the case of the magnetic powder, the surface coating is performed by a known method to have predetermined insulating properties.

In implementing the method of the present invention, the vertical sides of each electrode terminal piece punched from the metal electrode terminal sheet are set at an acute angle inward with respect to the plane of the terminal piece along a bending line, and the lower portions of the central divisions on both sides thereof are reversed. Use the one removed by cutting it into a trapezoid (wedge shape). In addition, instead of the vertical side, the horizontal side of each electrode terminal piece is bent at an acute angle with respect to the plane of the terminal piece, or after bending at an acute angle, the upper edge thereof is again horizontally bent to a predetermined width to form an approximately “c” shape. It can also be used as an electrode terminal piece.

The above-described acute angle range is to be suitable for guiding the vertical side or the horizontal side bent at an acute angle during molding to be deflected and bent toward the plane of the electrode terminal, and can be selected in the range of approximately 45° to 85°. The range of -80° is preferred.

The range is not limited thereto because it can be arbitrarily changed and modified according to the required standard of the inductor or the material condition of the electrode terminal piece. However, in the case of 85° or more, there is a possibility that the vertical side or the horizontal side of the electrode terminal piece may spread in an unexpected opposite direction when the inductor is pressed and molded. In that case, there is a possibility that a defective product that does not meet the intended purpose of the present invention may occur. The bending angle of 60° is when the electrode terminal piece is reliably deflected and bent in a predetermined direction expected in the present invention. It is an angle that can be guided to contain as much magnetic metal powder as possible inside.

The air core coil can be wound by a known automatic winding machine that can be easily obtained because it is manufactured and marketed in various formats by various domestic manufacturers. Therefore, the description of the configuration of the winding machine and the winding method of the coil will be omitted here.

In the present invention, it is advantageous when the left and right lead wires of the winding coil are pulled out from the coil winding unit in a straight and parallel direction and be refracted outwardly at a right angle at an appropriate point during electrode terminal welding, which will be described later. The length from the winding part to the inflection point is variable according to the standard or shape (cylindrical or rectangular parallelepiped) of the required product, but it is important to adjust the coil winding part to be located at the center of the inductor molded body.

In the molding, first, the assembly of the air core coil and the electrode terminal piece is transferred into an individual inductor molding machine, and a predetermined amount of magnetic metal powder is added thereto, and a predetermined uniaxial pressure is applied to obtain a primary preform. Subsequently, a predetermined amount of magnetic metal powder is added to the first preform, and the same uniaxial pressure is applied to obtain a second preform. Accordingly, since the pressing force of the uniaxial pressure causes the vertical side or the horizontal side of the metal electrode terminal piece to be bent or bent in a predetermined direction, the magnetic metal powder is driven into the bent or bent portion. That is, the terminal pieces are firmly bent and buried by forming a uniform distribution density with the magnetic metal body in the pressed molded body.

As can be seen from the above, the technical essence of the metal composite power inductor of the present invention is to increase the coupling force between the inductor body and the terminal by using an electrode terminal piece designed in a specific structure, that is, a hook type, and the dropout rate of the terminal piece. It can be pointed out that it lies in the fact that it can be lowered to almost “zero”.

According to the present invention, it is possible to manufacture a large number of surface-mounted metal composite power inductors at once that can reliably prevent the phenomenon that the electrode terminal pieces fall out of the inductor body even when used in any electric circuit under intense vibration conditions that last a long time. . In other words, in the present invention, since a large amount of composite power inductor products are manufactured by isotropic pressing molding at one time, the effect of ensuring the uniformity of the distribution density of the magnetic material, and in particular, unlike lead frame type products, electrode terminals on the bottom of the inductor Since it is located on the side, it is possible to minimize interference and deterioration of characteristics during molding, and thus, magnetic flux leakage does not occur. In addition, electrode terminals from the inductor body even when mounted in the electric circuit of a device or device used under intense vibration conditions for a long time. The unique effect of being able to reliably prevent dropout of convenience is exerted.

1(A) to 1(D) are microscopic photographs showing a cracking phenomenon due to an imbalance of a lead frame exposed portion and an internal molded portion on the surface of a conventional general lead frame type composite inductor, and a state of the electrode terminal pieces being removed. In particular, FIG. 1(A) shows a state of lowering the molding density of the lead frame, FIG. 1(B) shows the distortion of the winding shape, and FIG. 1(C) and FIG. 1(D) show two different types, respectively. It shows the lead frame type inductor product divided into two in the horizontal direction, and shows the state of the electrode terminal stripping off in more detail.
2A(A) is a state diagram in which a plurality of electrode terminal pieces punched out from an electrically conductive metal sheet are connected to each other in a horizontal and vertical direction by a connecting fine wire, and an electrode terminal piece sheet is disposed on the surface of a pallet, and FIG. 2A (B) shows a plan view of one of the terminal strips of each set of the terminal strip sheet, and Fig. 2B(A) shows both vertical sides of the electrode terminal strip (throughout this specification, the long side of the terminal strip is referred to as “ It is called "longitudinal side", and the short side is unified as "horizontal side") is cut into an inverted trapezoid (wedge-shaped part divided so that the coil lead wire passes) and bent at a predetermined angle according to the bending line 2B (B) is a perspective view illustrating a state in which the horizontal side is bent twice in an approximately “C” shape instead of the vertical side.
3 is a cross-sectional view showing the drawing method of both (left and right) lead wires of the air core coil of the present invention by sketching.
Fig. 4(a) is a plan view of a state in which an air core coil continuously wound on the (a set of) metal electrode terminal sheet sheets shown in Fig. 2(a) is placed in a correct position and assembled, and Fig. 4(b) is an air core coil It is a perspective view depicting a state in which electrode terminal pieces are welded to each of the left and right lead wires.
Fig. 5(a) is a perspective view of a honeycomb array type jig used in the method of the present invention, and Fig. 5(b) is a uniaxial pressurization of the inductor of the present invention using the array type jig. It is a cross-sectional view illustrating a molding method, FIG. 5(C) is a detailed explanatory view of FIG. 5(B), and FIG. 5(D) is a diagram schematically showing a cross-section of a molded article.
6(A) is a schematic cross-sectional view of the inside of a molded body showing a state in which the electrode terminal pieces of the metal composite power inductor for surface mounting manufactured according to the present invention are firmly embedded and coupled in a hook shape inside the inductor, and FIG. 6( B) is a bottom perspective view of the appearance of the molded body of Fig. 6(A) viewed from the bottom side where the electrode terminals are located.

In the following illustrating the best embodiment of the present invention, the standard (width × height × height) of the surface-mounted metal composite inductor to be manufactured is 10 mm × 10 mm × 6 mm (weight: about 3.2 g). Set and explain. The coil for the air core coil to be used in the present invention is a copper wire with a diameter of 1.0 mm insulated with enamel, and the magnetic metal powder is a raw material obtained by mixing an iron-based magnetic powder and a known binder in an appropriate ratio.

2A (a ) shows a state in which a plurality of sets of metal electrode terminal pieces 2 are punched out on a metal sheet 1 according to the present invention and aligned on the surface of a metal pallet PL. Left and right terminal pieces 2a and 2b are attached to the electrode terminal piece sheet 1 A plurality of sets of electrode terminal pieces 2 as a set are connected to each other in the horizontal and vertical directions and are punched out. Each of the above terminal pieces 2 They are connected to each other in the horizontal and vertical directions through the horizontal connection fine wire 3a and the vertical connection fine wire 3b.

2A(B ) and 2B(A) show the terminal strips 2a and 2b of the first set. Among them, for convenience of explanation, the terminal piece 2a was selected and the plan view and perspective view thereof were enlarged and illustrated, respectively. Each electrode terminal piece 2 (i.e. 2a,2b ) of each vertical side 2′ It is a tin-plated phosphor bronze thin plate with a length ℓ of 8 mm, a width w of 2″ at a width of 2 mm, and a thickness of 0.2 mm. The inverted trapezoidal division 2c of at least about 3 to 4 mm is provided in the center of each of the vertical sides 2' , through which the left and right lead wires 5a and 5b of the air core coil 5 are respectively disposed (to be described later). Longitudinal sides 2 'are then bent into the branch width (height) of 1 ㎜ along the fold lines indicated by dotted lines 4b of the longitudinal sides the divided left and right by two installments 2c 4a, 4a in a second (B), respectively.

The cutting angle θ ₁ formed by each vertical side 4a divided by the divided space part 2c with the terminal piece plane (See Fig. 2a(b) ) is about 45° to 60°, and the cross-sectional shape of the divided space portion 2c is generally inverted trapezoid. The above-described left and right (horizontal and vertical) thin wires 3a and 3b have a width of about 0.5 mm, and the distance between the left and right terminal pieces 2a and 2b is about 4 Mm. The lengths of the horizontal connection fine wire 3a and the vertical connection fine wire 3b are arbitrarily selected in the range of 5 to 10 mm, respectively, according to the design value of the electrode terminal strip standard punched from the metal sheet 1. According to the present invention, although it mainly depends on the product standard, the bending inclination angle θ ₂ formed by the vertical sides 4a and 4a with the plane of the terminal piece 2a is preferably in the range of about 60° to 80°.

2B(b) shows a state in which both horizontal sides 2" are bent in a "c" shape, taking the electrode terminal piece 2a as an example. The bending height of both ends of the terminal piece is 0.5 mm, and the horizontal bending width is also designed to be 0.5 mm. Accordingly, the length of the entire vertical side is 10 mm, but the length ℓ'minus the width of the bent portion (0.5 mm×4=2.0 mm) at both ends of the horizontal side is 8 mm. Therefore, in the example of this embodiment, in any case, the width and length of the electrode terminal pieces exposed to the outside of the inductor were set to be 2 mm and 8 mm, respectively. Here, the horizontal connection fine wire 3a is indicated, but the vertical connection fine wire 3b is omitted for convenience.

3 is an enlarged view illustrating a winding state of an air core coil 5 to be used in the present invention. Here, the coil lead wires 5a and 5b are drawn out substantially vertically in parallel from the winding part A of the air core coil 5 and are bent outwardly at a predetermined height h at a substantially right angle. In general, the inner core diameter d of the air core coil 5 can be selected in consideration of electrical characteristics within 1/2 to 1/4 of the overall standard of the product. The height h of the coil lead wires 5a and 5b varies depending on the total thickness of the inductor molded product. Here, the winding part A is It is desirable to adjust so that it can be located almost close to the center of the molded product. In general, the winding part A is located within the range of 1/5 to 1/2 of the thickness of the molded product. This winding structure of the coil is intended to facilitate welding of each coil lead wire and electrode terminal.

Fig. 4(a) shows a plan view in which lead wires 5a and 5b of each air core coil 5 are bonded to the left and right electrode terminal pieces 2a and 2b through both divided spaces 2c of each electrode terminal piece 2 punched from the metal sheet 1 . The left and right terminal pieces The technique of joining the 2a, 2b and the corresponding coil lead wires 5a and 5b is preferably carried out by electric resistance welding. The resistance welding method may be performed by an electric resistance welding method in which the metal pallet PL in which the metal sheet 1 is aligned is used as an anode, and the air core coil 5 is used as a cathode, but vice versa. Since the electric resistance welding method is remarkable in this technical field, a detailed description of the process will be omitted. In addition, known wet welding methods can also be used, so those skilled in this technical field will be able to appropriately select and use according to the immediate manufacturing environment conditions. When the electric resistance welding process is completed, a welding assembly 6 in which both electrode terminal pieces 2a and 2b are welded to the welded air core coil 5 is completed, as illustrated in FIG . 4( b).

Wherein in Fig. 4 (B) is, for convenience of understanding, the electrode terminals of the metal sheet 1 shown in Figure 4 (a) 2a, 2b Of the welding assembly 6 to which the corresponding lead wires 5a and 5b of the air core coil 5 are welded (hereinafter referred to as this) The state is schematically expressed as a perspective view.

5(A ) is a metal array type jig 7 , in which a number of compartments [cells] 8 having a square cross-section through top and bottom are formed, the number of which is shown in Fig. 4 (B) It is the same as the number of welding assembly 6 in (B). The dimensions of the width, length and depth of each compartment 8 correspond to the specifications of the inductor product to be manufactured, but the height is not. In other words, in the case of manufacturing the product of the present invention of the standard exemplified above, width × length = 10 ㎜ × 10 ㎜, but the height is about 2 to 2.5 times the thickness of the product to be manufactured (in the case of the present invention, 15 to 20 ㎜) It is recommended to set it to. The reason for setting the height larger than the product thickness is to secure a sufficient space for accommodating magnetic powder in consideration of the amount by which the magnetic metal powder to be injected is compressed and reduced by a plurality of uniaxial pressure molding. The width of the partition 8a and the outer circumferential partition 8b between each compartment 8 of the jig 7 may be designed in a range of approximately 5 to 10 mm, respectively. In the case of applying this standard [in the case of the example shown in Fig. 5(A) ], the overall external standard (width×length×height) of the jig 7 is 50~70 ㎜×50~70 ㎜×15~20㎜. In this case, it is, of course, variable depending on the design value of the product standard.

In Fig. 5(A) , it is illustrated that the number of compartments 8 is 9 (3×3) in each of 3 in the horizontal and vertical directions, but for mass production at a time, the number is calculated according to the number of welding assemblies 6 of Fig. 2, For example, it is obvious to those skilled in the art that it can be increased to 10 × 10 = 100. As previously described with respect to Fig. 4(A) , the coil lead wires on the electrode terminal pieces 2a and 2b When the electric resistance welding processes of 5a and 5b are completed, respectively, the welding assembly 6 (the coil lead wires 2a and 2b corresponding to the terminal pieces 5a and 5b are welded) are inserted into the corresponding compartments 8, respectively. Recall the array type jig 7 Place it on the pallet PL and adjust it so that it is in the correct position.

Subsequently, as briefly shown in Fig. 5(b ), the jig 7 including the welding assembly 6 is installed in a predetermined external molding frame M , and a predetermined amount of magnetic metal powder 9 is put thereinto, and then press-molded using a conventional uniaxial molding method. do. The uniaxial compression molding may be performed normally about two times, including the initial preliminary pressure molding followed by a subsequent pressure molding performed by supplementing a predetermined amount of magnetic powder. Depending on the requirements of the product, if necessary, the so-called'isotropic pressure molding method' may be additionally performed.

Here, the unexplained reference numeral " PR " describes a press to which a plurality of pressing pins p are attached to match each compartment 8.

Figure 5(c) shows It is a conceptual diagram of the uniaxial compression molding process. According to this, as described above, the welding assembly 6 in which the coil lead wires 2a and 2b corresponding to the terminal pieces 5a and 5b are welded is placed and aligned in each compartment 8 of the jig 7 and press-molded together with the magnetic metal powder 9 You will be able to understand how. Here, the marking of the mold M is omitted for convenience.

Figure 5 (d) is in the FIG. 5 (B), (C) after the molding process is complete geotinde showing the embellish to demold a series of molded article a cross-sectional view, cut line provided in vertical and horizontal in both directions designed standard (in view Individual inductor product I can be obtained by cutting along only the imaginary cut line AA in the direction is shown). Here, the above-described thin horizontally connected wires 3a and 3b of vertically connected fine wires are all erased by a known dicing method, as described above. As an example of the individual product cutting method, in relation to the processes included in Fig. 6 of the aforementioned patent document KR10-1044608 and Fig. 4 of KR10-1430427, respectively, It will be easier to understand by referring to the description.

Figure 6 (a) and 6 (B) is inside the cured magnetic material of the terminal pieces 2a, 2b of the shaping inductor product I These are drawings that are sketched by exaggerating the state of the bent and buried state and the state of the part exposed to the outside (bottom). In particular, as shown in Fig . 6(A) , the vertical sides (i.e., 2' ) of each electrode terminal piece 2a, 2b inside the inductor product I are inclined toward the center by the uniaxial molding pressure applied from the top to the bottom. do. Accordingly, the vertical sides are bent in a substantially hook shape, and at the same time, even magnetic metal powder 9 is contained in the curved space. As the magnetic metal powder 9 is hardened like rock or metal by the continuous heating/press molding process , the electrode terminal pieces 2a and 2b are each very firmly fixed in the body of the inductor I, compared to previous products. The impact resistance strength to the electrode terminal piece can be remarkably increased.

In the above description, reference numerals 5a , 5b , 2a , and 2b used to indicate both lead wires and both electrode terminal pieces of the air core coil are not determined in the order of indicating a and b , respectively, and for convenience, the left and right lead wires and It should be understood that the corresponding left and right terminal pieces are simply used to distinguish and indicate each, and that the left and right positions can be reversed.

[Test result]

The metal composite power inductor product I (standard: 10 mm×10 mm×6 mm) manufactured by the method of the present invention described above was applied to a single-sided printed circuit board (PCB) made of copper foil coated with tin. A drop test was performed by mounting and mounting, and the quality of the inductor body (a drop rate of a terminal piece from the inductor body) was evaluated according to the result. At the same time, for the purpose of comparison, the above-described well-known lead frame type power inductor product manufactured to the same standard using the same material (the shape and structure will be easily understood, for example, from the patent document KR10-0835886) is compared. It was used as a product and the same test was performed under the same conditions. The number of products of the present invention and control products used in the above test was 60 each.

In order to perform the above test, a tumble tester known as a free fall test equipment for small home appliances operating at a rotation speed of 5 to 15 times/min (KSC, IEC 60068-2-3) ( Commercial product) was used.

For each of the product of the present invention and the control product, a drop test was performed under the most severe conditions of a drop height of 1 m, a rotation speed of 5 times/minute, and a number of drops of 50 times. The test results are shown in Table 1 below.

Test Items Test result Product of the present invention Control
Drop test
Until 50 times, no products were found to be removed from the terminal strip. From the 20th time, the product was found to be removed from the terminal piece, and in 50 times, about 30~40% of the product was found to be removed from the terminal piece.

According to the above test results, it was found that the product of the present invention has almost no dropping phenomenon of the terminal piece due to the drop impact under the dropping condition. Even in the product using the electrode terminal strip [see Fig. 2b(b) ] formed by bending the horizontal side instead of the vertical side, there was no significant difference in its effect.

The composite power inductor of the present invention does not cause the electrode terminal to fall off even if it is mounted and mounted on an electronic product placed under any severe environmental conditions in which violent vibration conditions last for a long time.Therefore, industries that require such products, such as electric vehicles, construction equipment, , It has a high possibility of application in industrial fields such as medical devices.

In the above, the present invention has been described with respect to one best embodiment, but those skilled in the art, with respect to the embodiments of the present invention described and illustrated in this specification, the psychiatric department of the present invention defined in each claim. It will be easy to understand that appropriate modifications and changes can be made without going out of scope.

1 : electrode terminal piece sheet
2 : electrode terminal piece
2´ : vertical side of electrode terminal
2˝ : The side of the electrode terminal section
3a , 3b : Fine wire for connecting electrode terminal
4b : bending guide line
θ ₁ : Cut-off angle at the center of the vertical side of the electrode terminal piece
θ _2:: Bending inclination angle with respect to the plane of the vertical side of the electrode terminal strip
5 : air core coil
6 : welding assembly
7 : Array type jig
I : inductor products

Claims (8)

In a surface mount type metal composite power inductor manufactured by pressing a metal electrode terminal piece welded to a lead wire of an air core coil together with magnetic metal powder in a molding machine,
Characterized in that the vertical sides of the metal electrode terminal piece are cut and removed in an inverted trapezoid and bent at an acute angle inward with respect to the plane of the terminal piece to be bent and buried in a hook shape in the inductor body during molding. Surface Mount Metal Composite Power Inductor. The surface-mounted metal composite power inductor according to any one of claims 1 to 2, wherein the acute angle is in the range of 45° to 85°. The surface-mounted metal composite power inductor of claim 2, wherein the acute angle is 60° to 80°. In a surface mount type metal composite power inductor manufactured by pressing a metal electrode terminal piece welded to a lead wire of an air core coil together with magnetic metal powder in a molding machine,
A surface-mounted metal composite power inductor in which both horizontal sides of the metal electrode terminal piece are erected at an acute angle with respect to the plane of the terminal piece, and then both edges thereof are bent to form an approximately “C” shape. The surface-mounted metal composite power inductor of claim 4, wherein the acute angle is 45°. A surface-mounted type including a process of pressing and molding air core coil/electrode terminal welding assemblies in which electrode terminal pieces are respectively welded to both lead wires of a plurality of air core coils wound continuously together with a predetermined amount of magnetic metal powder in a predetermined inductor molding machine. In the method of manufacturing a metal composite power inductor,
The electrode terminal pieces are punched out of an electrically conductive metal thin-film sheet so that they are continuously connected in a set of top and bottom, left and right, and both vertical sides or both horizontal sides of each electrode terminal piece are bent at an acute angle with respect to the plane of the terminal piece. Process,
It characterized in that it further comprises a step of bending and embedding both vertical sides or both horizontal sides of the electrode terminal piece into a hook shape in the inductor body by the molding pressure during press-molding of the inductor. A method of manufacturing a surface mount metal composite power inductor. The method of claim 5, wherein the acute angle is in the range of 45° to 85°. The method of claim 5, wherein the acute angle is in the range of 60° to 80°.

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