JP2008235390A - Smd coil and manufacturing method of smd coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin, compact and low-cost SMD coil having high productivity and reliability. <P>SOLUTION: The SMD coil comprises a lead frame 11 which is made of a metal material formed with a plurality of terminal electrodes 14a-14d, and a bobbin 2, and the lead frame 11 is formed with a through hole 13 wherein the bobbin 2 is mounted. A coil winding 3 is wound around the bobbin 2, and the winding ends 3a and 3b of the coil winding 3 are electrically connected to the electrodes 14a and 14b. Due to this structure, the lead frame 11 and the bobbin will not overlap in the thickness direction, and a thin, compact and low-cost SDM coil, having high productivity and reliability, can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thin and small SMD type coil used in an electronic circuit and a method for manufacturing the SMD type coil.

  Conventionally, SMD type coils using a magnetic material such as a ferrite material as a core have been widely used in power supply devices and various drive circuits such as small electronic devices typified by mobile phones and notebook personal computers. For example, see Patent Document 1).

  Hereinafter, the outline of the SMD type coil disclosed in Patent Document 1 will be described with reference to FIG. In FIG. 13, 50 is a sectional view of a conventional SMD type coil. Reference numeral 51 denotes a circuit board made of a double-sided printed wiring board, and the wiring pattern 53 on the front surface and the wiring pattern 54 on the back surface are electrically connected to each other by a through hole 52 formed at each corner of the circuit board 51. Reference numeral 55 denotes a bobbin made of a magnetic material mounted on the circuit board 51, and has flange portions 55b having large diameters at both ends of a cylindrical core 55a.

  Reference numeral 56 denotes a coil winding wound around the winding core 55a. Winding terminals 56a and 56b at the beginning and end of winding of the coil winding 56 are respectively thermocompression-bonded or soldered to the wiring pattern 53 of the circuit board 51. It is attached. This conventional SMD type coil 50 is shown to be excellent in productivity by using a collective circuit board that can take a large number of circuit boards 51.

JP 2006-13054 A (page 4, FIG. 2)

  However, since the bobbin 55 is mounted on the circuit board 51 in the conventional SMD type coil 50 and the circuit board 51 and the bobbin 55 overlap in the thickness direction, the thickness of the SMD type coil 50 is the thickness of the circuit board 51 + the bobbin 55. Therefore, it is difficult to reduce the thickness of the SMD type coil 50. Further, if the circuit board 51 is provided with a recess and the bobbin 55 is mounted in the recess, or if the circuit board 51 is made extremely thin, the thickness can be reduced to some extent, but the processing man-hour of the circuit board 51 increases and the strength is insufficient. There is a problem such as the occurrence of this is not possible. Furthermore, although the wiring pattern 54 of the circuit board 51 is used as an electrode for connecting to the outside, the wiring pattern of the circuit board tends to cause pattern peeling, and it is difficult to realize a highly reliable SMD type coil.

  An object of the present invention is to solve the above-mentioned problems and to provide a thin and small SMD type coil which is excellent in productivity and reliability and is low in cost, and a method for manufacturing the SMD type coil.

  In order to solve the above-mentioned object, the SMD type coil and the SMD type manufacturing method of the present invention employ the following configuration and manufacturing method.

  The SMD type coil of the present invention includes a lead frame made of a metal material on which a plurality of terminal electrodes are formed, and a bobbin. The lead frame has a bobbin mounting portion for mounting the bobbin, and the bobbin is wound by coil winding. The winding terminal of the coil winding is electrically coupled to the terminal electrode.

  Since the SMD type coil of the present invention uses a lead frame that can collectively form terminal electrodes by processing such as punching, the productivity is improved, and it is possible to flexibly respond from a variety of small-quantity production to mass production, and Cost reduction can be realized. In addition, since the lead frame is a metal material, the strength does not decrease even when the thickness is reduced, and a highly reliable and thin SMD type coil can be provided.

  Further, the bobbin mounting portion of the lead frame has a through hole into which the bobbin is fitted, and the bobbin is press-fitted or loosely fitted into the through hole.

  Thereby, since the bobbin is fitted in the through hole of the lead frame, the bobbin and the lead frame do not overlap in the thickness direction, and an extremely thin SMD type coil can be realized.

  The bobbin mounting portion of the lead frame has a bobbin fixing surface to which the bobbin is fixed and a separation hole for electrically separating the terminal electrode into at least two.

  As a result, the bobbin is fixed to the lead frame, and the terminal electrode electrically separated by the separation hole is formed, so that an SMD type coil with a simple structure and low cost can be realized.

  In addition, the terminal electrode has a bent portion that is partially bent in one direction, and a winding terminal is coupled to the bent portion.

  As a result, the winding end of the coil winding can be easily entangled with the bent portion of the terminal electrode, so that the work of winding the coil winding around the bobbin is facilitated, and the winding end of the coil winding is facilitated. It becomes easy to perform welding work or soldering work for joining the coil to the terminal electrode, and the reliability of electrical coupling between the coil winding and the terminal electrode can be improved.

  The bobbin is made of a ferrite material.

  As a result, a ferrite material having a high magnetic permeability and a high electric resistance is used as a bobbin material. Therefore, a high-performance SMD coil having a high saturation magnetic flux density and excellent high-frequency characteristics can be obtained even with a small coil. It can be realized.

  The bobbin around which the lead frame and the coil winding are wound is sealed by a sealing member, and the bent portion of the terminal electrode is embedded in the sealing member.

  Thereby, since it is sealed with the sealing member, an SMD type coil which is mechanically strong and excellent in weather resistance can be realized. Further, since the bent portion of the terminal electrode is embedded in the sealing member, it is possible to realize a highly reliable SMD type coil in which the terminal electrode is hardly peeled off.

  A method for manufacturing an SMD type coil according to the present invention is a method for manufacturing an SMD type coil having a lead frame made of a metal material on which a plurality of terminal electrodes are formed, and a bobbin mounted on the lead frame. Adhesive material is fixed to the collective lead frame that can take a large number of pieces, bobbin mounting process that installs multiple bobbins on the collective lead frame at once, and coil winding is continuously applied to the bobbin mounted on the collective lead frame A coil winding step for winding the coil winding, a terminal processing step for coupling the winding end of the coil winding to the terminal electrode, and a bobbin around which the assembly lead frame and the coil winding are wound is sealed by a sealing member. It includes a sealing step of forming a coil and a cutting step of cutting the collective coil into a single SMD type coil.

  The SMD type coil manufacturing method of the present invention enables collective manufacturing using a collective lead frame, enabling mass production, reducing the size and characteristic variation of the product, and reducing the cost and excellent reliability. A mold coil can be provided.

  As described above, according to the present invention, since the lead frame that can collectively form the terminal electrodes by processing such as punching is used, the productivity is improved, and it is possible to flexibly respond from a variety of small-quantity production to mass production. In addition, cost reduction can be realized. Further, since the lead frame is made of a metal material, the strength does not decrease even when the thickness is reduced, and a highly reliable and thin SMD coil can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of an SMD type coil according to the first embodiment of the present invention. FIG. 2 is a side view of the SMD type coil according to the first embodiment of the present invention. FIG. 3 is a perspective view of an assembly lead frame for taking a large number of SMD type coils according to the first embodiment of the present invention. FIG. 4 is a perspective view of an SMD type coil according to the second embodiment of the present invention. FIG. 5 is a side view of the SMD type coil according to the second embodiment of the present invention. FIG. 6 is a perspective view of an assembly lead frame for taking a large number of SMD type coils according to the second embodiment of the present invention.

  FIG. 7 is a flowchart of a manufacturing process for explaining a method of manufacturing an SMD type coil as Embodiment 3 of the present invention. FIG. 8 is a perspective view for explaining a process of bonding an adhesive material to the assembly lead frame of the manufacturing method of the present invention. FIG. 9 is a perspective view for explaining a bobbin mounting step for mounting a plurality of bobbins on the collective lead frame of the manufacturing method of the present invention at once. FIG. 10 is a perspective view illustrating a coil winding process and a terminal processing process of the manufacturing method of the present invention. FIG. 11 is a perspective view for explaining a sealing process in which the assembly lead frame and bobbin of the manufacturing method of the present invention are sealed with a sealing member to form an assembly coil. FIG. 12A is a perspective view for explaining a cutting step of cutting the collective coil of the manufacturing method of the present invention into a single SMD type coil. FIG. 12B is a perspective view for explaining that a plurality of SMD type coils are completed by the cutting step of the manufacturing method of the present invention.

  Based on FIG. 1, the structure of the SMD type coil of Example 1 of this invention is demonstrated. The feature of Example 1 is that a very thin SMD type coil can be realized. In FIG. 1, reference numeral 1 denotes an SMD type coil according to the first embodiment of the present invention. Reference numeral 2 denotes a substantially cylindrical bobbin made of a magnetic material such as a ferrite material, around which a coil winding 3 is wound. Reference numeral 11 denotes a lead frame made of a metal material, which has a bobbin mounting portion 12 on which the bobbin 2 is mounted. In this embodiment, the bobbin mounting portion 12 is formed with a circular through hole 13 into which the bobbin 2 is press-fitted or loosely fitted. Is done.

  Reference numerals 14a to 14d denote four terminal electrodes formed at the four corners of the SMD type coil 1 by the lead frame 11 (the terminal electrodes 14d are hidden behind the bobbin 2 in the drawing). Part of each of the terminal electrodes 14a to 14d has bent portions 15a to 15d that are bent in one direction on the coil winding 3 side. As a result, bent portions 15 a to 15 d are formed at the four corners of the SMD type coil 1. The winding terminals 3a and 3b of the coil winding 3 are entangled with the bent portions 15a and 15b of the two terminal electrodes 14a and 14b among the terminal electrodes 14a to 14d, and thereafter, by welding, soldering, or the like. Electrically coupled.

  The other two terminal electrodes 14c and 14d are normally not connected and are used as dummy terminals. The connection of the winding terminals 3a and 3b to the terminal electrodes 14a to 14d is not limited and may be arbitrary. When the SMD type coil 1 is used as a transformer, for example, the coil winding 3 is preferably wound twice, and the four winding terminals of the coil winding 3 are coupled to the terminal electrodes 14a to 14d.

  Reference numeral 4 denotes a sealing member made of epoxy resin or the like, which seals the bobbin 2 around which the terminal electrodes 14a to 14d and the coil winding 3 are wound by the lead frame 11. Thereby, the SMD type coil 1 which is mechanically strong and excellent in weather resistance can be completed. Further, since the bent portions 15 a to 15 d of the terminal electrodes 14 a to 14 d are embedded in the sealing member 4, the terminal electrodes 14 a to 14 d are securely fixed to the sealing member 4. For convenience of explanation, the sealing member 4 is shown as a transparent member in FIG.

  Next, a configuration and a mounting example of the SMD type coil according to the first embodiment of the present invention viewed from the side will be described with reference to FIG. FIG. 2 is a side view of the SMD type coil 1 of FIG. In FIG. 2, the bobbin 2 of the SMD type coil 1 has a cylindrical core 2a and large flange portions 2b at both ends thereof. The coil winding 3 is wound around the core 2a of the bobbin 2, and the winding terminals 3a and 3b are entangled and electrically coupled to the bent portions 15a and 15b as described above.

  Further, since the bobbin 2 is press-fitted or loosely fitted into the through hole 13 of the lead frame 11, the bobbin 2 and the lead frame 11 do not overlap in the thickness direction, and the thickness T 1 of the SMD type coil 1 is equal to the bobbin 2. Is approximately equal to the thickness of As a result, an extremely thin SMD type coil can be realized.

  Further, the back surfaces of the terminal electrodes 14a to 14d of the SMD type coil 1 are exposed from the sealing member 4, and the SMD type coil 1 is mounted on an external circuit board or the like via the back surfaces of the terminal electrodes 14a to 14d. I can do it. Here, FIG. 2 shows an example of mounting the SMD type coil 1 on the circuit board 20. Reference numerals 21 a and 21 b are pattern electrodes made of copper foil or the like, and are formed on the surface of the circuit board 20 so as to be aligned with the terminal electrodes 14 a to 14 d of the SMD type coil 1.

  Then, the SMD type coil 1 is disposed on the pattern electrodes 21 a and 21 b of the circuit board 20, and the terminal electrodes 14 a to 14 d and the pattern electrodes 21 a and 21 b are electrically and mechanically coupled by the solder 22. Thereby, the SMD type coil 1 can be mounted on the circuit board 20 and operate as a coil. Although not shown, the terminal electrodes 14c and 14d, which are dummy terminals, are also coupled to the pattern electrodes 21a and 21b by the solder 22, whereby the mounting strength of the SMD type coil 1 can be increased.

  Further, as described above, since the bent portions 15a to 15d formed in a part of the terminal electrodes 14a to 14d are embedded in the sealing member 4, the SMD type coil 1 is mounted on the circuit board 20. The terminal electrodes 14a to 14d are unlikely to be peeled off from the sealing member 4, and a highly reliable SMD type coil can be realized even when heated by soldering. As an example, the size of the SMD type coil 1 can be realized as a thin and small 2 mm × 2 mm square with a thickness of 0.6 mm, but the size can be arbitrarily determined based on required specifications.

  Next, an example of a collective lead frame for taking a large number of SMD type coils 1 of this embodiment will be described with reference to FIG. In FIG. 3, reference numeral 10 denotes a thin plate-like collective lead frame, in which a large number of lead frames 11 shown in FIGS. 1 and 2 are arranged, and a large number of SMD type coils 1 are formed from the collective lead frame 10. Can be taken.

  Here, X and Y are cutting lines indicating cutting positions for separating the single lead frame 11 from the collective lead frame 10. The cutting lines X and Y are positioned at equal intervals perpendicular to each other, and a plurality of SMD type coils 1 are cut by cutting the assembly lead frame 10 along the cutting lines X and Y in a cutting process described later. Can be completed. In the present embodiment, the assembly lead frame 10 has an arrangement of 3 × 3 lead frames 11 for convenience of explanation, but is not limited to this arrangement, and the assembly lead frame 10 is long in the X direction, for example. It may be in the form of a reel, or may be a collective lead frame obtained by cutting a long collective lead frame into a certain length.

  The assembly lead frame 10 is formed with a large number of circular through-holes 13 along the arrangement of the lead frames 11 and bent portions 15a to 15d that are bent upward in a part of the terminal electrodes 14a to 14d. The SMD type coil of the present invention is manufactured in a lump based on the assembly lead frame 10, and details of each manufacturing process will be described later. The through holes 13 formed in the collective lead frame 10 are not limited to a circular shape because they are formed by pressing or the like. For example, according to the shape of the bobbin 2 fitted into the through holes 13, for example, an elliptical shape or a It can be processed into an arbitrary shape such as a square.

  Next, based on FIG. 4, the structure of the SMD type coil of Example 2 of this invention is demonstrated. A feature of the second embodiment is that an SMD type coil that has a simple structure and is easy to manufacture can be realized. In FIG. 4, 30 is an SMD type coil of Example 2 of the present invention. 31 is a substantially cylindrical bobbin made of a magnetic material such as a ferrite material, around which a coil winding 32 is wound. Reference numeral 41 denotes a lead frame made of a metal material, which has a bobbin mounting portion 42 on which the bobbin 31 is mounted. In this embodiment, the bobbin mounting portion 42 has a bobbin fixing surface 43 to which the bobbin 31 is fixed. And a separation hole 44.

  Reference numerals 45 and 46 denote terminal electrodes formed by the lead frame 41. A part of each corner of each of the terminal electrodes 45 and 46 has bent portions 47a, 47b, 48a and 48b bent in one direction on the coil winding 32 side (the bent portion 47b is the bobbin 31 in the drawing). Hiding on the back). That is, the terminal electrode 45 is formed with two bent portions 47a and 47b, and the terminal electrode 46 is formed with two bent portions 48a and 48b.

  As a result, the bent portions 47a, 47b, 48a, and 48b are formed at the four corners of the SMD type coil 30 as in the first embodiment. The winding terminals 32a and 32b of the coil winding 32 are entangled with the bent portion 47a of the terminal electrode 45 and the bent portion 48a of the terminal electrode 46, and are electrically coupled by welding, soldering, or the like.

  The other two bent portions 47b and 48b are not connected to the coil winding 32, but the bent portion 47b is integrated with the bent portion 47a, and the bent portion 48b is integrated with the bent portion 48a. It is also electrically coupled.

  Reference numeral 33 denotes a sealing member made of epoxy resin or the like, which seals the bobbin 31 around which the terminal electrodes 45 and 46 by the lead frame 41 and the coil winding 32 are wound. Thereby, the SMD type coil 30 which is mechanically strong and excellent in weather resistance can be completed. Further, since the bent portions 47 a, 47 b, 48 a, 48 b of the terminal electrodes 45, 46 are embedded in the sealing member 33, the terminal electrodes 45, 46 are securely fixed to the sealing member 33. The sealing member 33 is shown as a transparent member for convenience of explanation as in the first embodiment.

Next, a configuration and a mounting example of the SMD type coil according to the second embodiment of the present invention viewed from the side will be described with reference to FIG. FIG. 5 is a side view of the SMD type coil 30 shown in FIG. In FIG. 5, the bobbin 31 of the SMD type coil 30 has a cylindrical core 31a and large flange portions 31b at both ends thereof. The coil winding 32 is wound around the core 31a of the bobbin 31, and the winding terminals 32a and 32b are entangled and electrically coupled to the bent portions 47a and 48a as described above.

  The bobbin 31 is fixedly mounted on the bobbin mounting part 42 on the upper surface of the lead frame 41 with an adhesive (not shown). As a result, the thickness T2 of the SMD type coil 30 becomes the thickness of the bobbin 31 + the thickness of the lead frame 41, which is slightly thicker than the thickness of the SMD type coil 1 of the first embodiment.

  However, since the lead frame 41 is made of a metal material and can sufficiently maintain mechanical strength even if its thickness is small, a thin SMD type coil can be realized. In addition, since it has a simple structure in which the bobbin 31 is fixed to the upper surface of the lead frame 41, an SMD type coil that is easy to manufacture and inexpensive can be realized.

  Similarly to the first embodiment, the back surfaces of the terminal electrodes 45 and 46 of the SMD type coil 30 are exposed from the sealing member 33, and the SMD type coil 30 is connected to the outside via the back surfaces of the terminal electrodes 45 and 46. It can be mounted on a circuit board. Here, FIG. 5 shows an example of mounting the SMD type coil 30 on the circuit board 20. Reference numerals 21 a and 21 b are pattern electrodes made of copper foil or the like, and are formed on the surface of the circuit board 20 so as to be aligned with the terminal electrodes 45 and 46 of the SMD type coil 30.

  Then, the SMD type coil 30 is disposed on the pattern electrodes 21a and 21b of the circuit board 20, and the terminal electrodes 45 and 46 and the pattern electrodes 21a and 21b are electrically and mechanically coupled by the solder 22. Thereby, the SMD type coil 30 can be mounted on the circuit board 20 and operate as a coil. Further, similarly to the first embodiment, the bent portions 47a, 47b, 48a, 48b formed in a part of the terminal electrodes 45, 46 are embedded in the sealing member 33, so that the SMD type coil 30 is formed. When mounted on the circuit board 20, the terminal electrodes 45 and 46 are difficult to peel off from the sealing member 33, and a highly reliable SMD type coil can be realized.

  Next, based on FIG. 6, the structure of the collective lead frame which takes many SMD type coils 30 of this embodiment will be described. In FIG. 6, reference numeral 40 denotes a thin plate-like collective lead frame, in which a large number of lead frames 41 shown in FIG. 4 and FIG. 5 are arranged, and many SMD type coils 30 are formed from the collective lead frame 40. Can be taken. Here, X and Y are cutting lines indicating the cutting positions for separating the single lead frame 41 from the collective lead frame 40, as in the first embodiment.

  The collective lead frame 40 has a large number of bobbin mounting portions 42 indicated by broken-line circles along the arrangement of the lead frames 41, and terminal electrodes 45 and 46 are formed around the bobbin mounting portions 42. Each bobbin mounting portion 42 has an opposing bobbin fixing surface 43 and separation holes 44 for separating the terminal electrodes 45 and 46 from each other. In the separation hole 44, grooves 44b and 44c are added to a polygonal center hole 44a to separate the terminal electrodes 45 and 46 from each other. The separation hole 44 is not limited to this shape. For example, the center hole 44a may be circular. Further, bent portions 47a, 47b, 48a, and 48b that are bent upward are formed in part of the terminal electrodes 45 and 46, respectively.

  Next, as a third embodiment, a method for producing an SMD type coil of the present invention will be described with reference to the drawings. As shown in the flowchart of FIG. 7, the manufacturing method of the SMD type coil of the present invention includes an assembly lead frame manufacturing process S1, an adhesive material bonding process S2, a bobbin mounting process S3, a coil winding process S4, a terminal processing process S5, a sealing process. Manufactured according to the order of each of the stopping step S6 and the cutting step S7. Hereafter, each manufacturing process is demonstrated based on drawing.

  First, the collective lead frame manufacturing step S1 will be described by taking the collective lead frame 10 shown in FIG. In FIG. 3, by pressing the thin metal material, a large number of through holes 13 and bent portions 15a to 15d of the terminal electrodes 14a to 14d are formed in a lump, and a large number of lead frames 11 can be obtained. The assembly lead frame 10 is completed. As described above, the arrangement of the assembly lead frame 10 is not limited, and may be a long reel, or an assembly lead frame obtained by cutting a long reel-shaped assembly lead frame into a certain length.

  Next, adhesive material bonding process S2 is demonstrated based on FIG. In FIG. 8, a sheet-like adhesive tape 16 as an adhesive material is bonded to the entire back surface of the assembly lead frame 10 by applying pressure in the direction of arrow C. Through this step, the adhesive surface 16 a of the adhesive tape 16 is exposed from the plurality of through holes 13 formed in the assembly lead frame 10.

  Next, the bobbin mounting step S3 will be described with reference to FIG. In FIG. 9, a plurality of bobbins 2 are aligned with the position of the through hole 13 of the assembly lead frame 10 by a tray (not shown), and the tray is moved in the direction of arrow D to move the bobbin 2 in the through hole 13. Mounted on. That is, as described above, the adhesive surface 16a of the adhesive tape 16 is exposed on the bottom surface of the through hole 13, so that each bobbin is pressed by pressing the bobbins 2 aligned by the tray in the direction of arrow D. 2 is fitted into the through-hole 13, is in close contact with the adhesive surface 16 a, and is fixed in the through-hole 13.

  Here, if the diameter of the through hole 13 is slightly smaller than the diameter of the bobbin 2 and the bobbin 2 is press-fitted into the through hole 13, the bobbin 2 is firmly bonded to the assembly lead frame 10, and the adhesive force of the adhesive tape 16 is increased. Even if it is somewhat weak, the bobbin 2 does not come off from the through hole 13. Further, the press-fitting of the bobbin 2 improves the positional accuracy of the bobbin 2 with respect to the collective lead frame 10, and the coil winding step S4, which is a subsequent step, can be performed smoothly.

  Further, if the diameter of the through hole 13 is slightly larger than the diameter of the bobbin 2 to provide a clearance, and the bobbin 2 is gently fitted into the through hole 13, the bobbin 2 can be assembled only by the adhesive force of the adhesive tape 16. The bobbin 2 can be fitted into the through hole 13 even if the alignment of the bobbin 2 with respect to the through hole 13 is not precise. Thereby, the tray for aligning the bobbins 2 can be designed roughly to some extent, and the bobbin mounting step S3 can be simplified. Accordingly, whether the bobbin 2 and the through hole 13 of the assembly lead frame 10 are to be press-fitted or loose-fitted may be selected according to product specifications and manufacturing process capability.

  Next, the coil winding step S4 and the terminal processing step S5 will be described with reference to FIG. In FIG. 10, reference numeral 25 denotes a nozzle of a winding machine (not shown). This nozzle 25 has a rotating shaft and can feed the coil winding 3 while rotating in the direction of arrow E. As a result, the bobbin 2 mounted on the assembly lead frame 10 is wound by the coil winding 3 fed from the nozzle 25 to manufacture a coil. That is, the nozzle 25 is moved according to a program by a winding machine that moves in the XY directions, and the coil winding 3 is wound around the bent portion 15b and then rotated in the direction of arrow E to be wound around the core 2a of the bobbin 2. After winding a predetermined number of times, it is entangled with the bent portion 15a.

  Next, the nozzle 25 moves to the adjacent bobbin 2 and entangles it with the corresponding bent part 15b, and then winds it around the core 2a of the bobbin 2, winds a predetermined number of times, and then entangles with the bent part 15a. Geru. Thus, the coil 25 can be wound around the bobbins 2 arranged in the collective lead frame 10 in a short time by continuously performing the winding work so that the nozzle 25 performs one stroke according to the program. I can do it. The order of the winding operation by the nozzle 25 is not limited and can be arbitrarily determined.

  And after coil winding process S4 is complete | finished, terminal process is performed by arc welding, soldering, etc. as the terminal process process S5 to bending part 15a, 15b in which the coil winding 3 was entangled, and coil winding 3 The winding terminals 3a and 3b are securely coupled to the bent portions 15a and 15b. As described above, by providing the bent portions 15a to 15d in the collective lead frame 10, the operations of the coil winding step S4 and the terminal processing step S5 are facilitated, and the electrical connection between the coil winding 3 and the bent portions 15a and 15b is facilitated. Reliable coupling is ensured, and a highly reliable SMD type coil can be manufactured.

  Next, sealing process S6 is demonstrated based on FIG. In FIG. 11, after the coil winding 3 is wound around all the bobbins 2 mounted on the collective lead frame 10, the collective lead frame 10 and the sealing member 4 made of a liquid resin such as an epoxy material or a molded resin are used. The bobbin 2 around which the coil winding 3 is wound is resin-sealed. Thereby, the collective coil 17 in which a large number of SMD type coils are assembled is completed.

  Thus, since the collective coil 17 is resin-sealed by the sealing member 4, an SMD type coil that is mechanically strong and excellent in weather resistance can be realized. Further, since the bent portions 15a to 15d formed in the collective lead frame 10 are bent in the direction of being embedded in the sealing member 4, the terminal electrodes 14a to 14d formed by the collective lead frame 10 are sealed. The SMD type coil can be realized with high reliability by being firmly fixed to the member 4 and hardly peeled off. The sealing member 4 does not seal the back surface of the assembly lead frame 10 and is preferably sealed to the same height as the bobbin 2 or slightly lower than the bobbin 2.

  Next, a cutting step S7 for cutting the collective coil into a single SMD type coil will be described with reference to FIGS. 12 (a) and 12 (b). In FIG. 12A, the completed collective coil 17 is cut along a cutting line X, Y by a processing method such as dicing or press punching. In the case of cutting the collective coil 17 by punching, although not shown, the arrangement interval of the collective lead frames 10 is widened, and sealing is performed by the sealing member 4 in the vicinity of the cutting lines X and Y (that is, the press punching region). It is preferable to form the collective coil 17 without performing the above.

  In addition, when the nozzle 25 that winds the coil winding 3 is large, it is necessary to widen the arrangement interval of the assembly lead frame 10 to some extent so that the nozzle 25 enters between the bobbins 2. In this case, when dancing along the cutting lines X and Y, there is a problem that the outer shape of a single SMD type coil becomes large. In order to prevent this, it is possible to manufacture an SMD type coil having a small outer shape even if the arrangement interval is wide, by cutting with two lines having a fixed interval around the cutting lines X and Y.

  Next, FIG. 12B shows a state in which the collective coil 17 is cut by the cutting step S7 and a large number of single SMD type coils 1 are completed. As described above, according to the SMD type coil manufacturing method of the present invention, a large number of SMD type coils can be manufactured simultaneously by the collective lead frame. It is possible to provide a low-cost SMD type coil with little variation in characteristics.

  Moreover, although the manufacturing method of the SMD type coil of the present invention has been described by taking the SMD type coil 1 of the first embodiment as an example, the present invention is not limited thereto, and is similarly applicable to the manufacturing method of the SMD type coil 30 of the second embodiment. I can do it. Here, the difference in the process of manufacturing the SMD type coil 30 of Example 2 is that the adhesive material is bonded or applied to at least the bobbin fixing surface 43 on the surface of the assembly lead frame 40 in the adhesive material bonding step S2. That is. As a result, the bobbin 31 can be fixed to the bobbin mounting portion 42 of the assembly lead frame 40. Further, the SMD type coil manufacturing method of the present invention is not limited to the SMD type coil of Example 1 and Example 2, and can be applied to SMD type coil manufacturing methods using various types of lead frames.

  In addition, although the Example of this invention demonstrated as the SMD type | mold coil which mounts the single bobbin, it is not limited to this form, The bobbin was mounted in multiple by changing the shape of a lead frame arbitrarily. It can also be applied to multiple coils. Further, the present invention is not limited to a coil, and can be applied to a composite type SMD component in which another electronic component such as an IC chip is mounted on a lead frame together with a bobbin.

It is a perspective view of the SMD type coil of Example 1 of this invention. It is a side view of the SMD type coil of Example 1 of this invention. It is a perspective view of the assembly lead frame which takes many SMD type coils of Example 1 of the present invention. It is a perspective view of the SMD type coil of Example 2 of this invention. It is a side view of the SMD type coil of Example 2 of the present invention. It is a perspective view of the assembly lead frame which takes many SMD type coils of Example 2 of the present invention. It is a flowchart of the manufacturing process explaining the manufacturing method of the SMD type coil as Example 3 of this invention. It is a perspective view explaining the process of bonding an adhesive material to the assembly lead frame of the manufacturing method of the SMD type coil of the present invention. It is a perspective view explaining the bobbin mounting process which mounts a several bobbin collectively in the collective lead frame of the manufacturing method of the SMD type coil of this invention. It is a perspective view explaining the coil winding process and terminal processing process of the manufacturing method of the SMD type coil of this invention. It is a perspective view explaining the sealing process of sealing the collective lead frame and bobbin of the manufacturing method of the SMD type coil of the present invention with the sealing member, and forming the collective coil. It is a perspective view explaining the cutting process of cutting the collective coil of the manufacturing method of the SMD type coil of the present invention into a single SMD type coil. It is a perspective view explaining that a plurality of SMD type coils are completed by the cutting process of the manufacturing method of the SMD type coil of the present invention. It is sectional drawing of the conventional SMD type coil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 30 SMD type coil 2, 31 Bobbin 2a, 31a Winding core 2b, 31b Flange part 3, 32 Coil winding 3a, 3b, 32a, 32b Winding terminal 4, 33 Sealing member 10, 40 Collecting lead frame 11, 41 Lead frame 12, 42 Bobbin mounting part 13 Through hole 14a-14d, 45, 46 Terminal electrode 15a-15d, 47a, 47b, 48a, 48b Bending part 16 Adhesive tape 16a Adhesive surface 17 Collective coil 20 Circuit board 21a, 21b Pattern Electrode 25 Nozzle 43 Bobbin fixing surface 44 Separation hole 44a Center hole 44b, 44c Groove

Claims (7)

  A lead frame made of a metal material on which a plurality of terminal electrodes are formed and a bobbin are provided, the lead frame has a bobbin mounting portion on which the bobbin is mounted, and the bobbin is wound by a coil winding. An SMD type coil, wherein a wire winding end is electrically coupled to the terminal electrode.   The SMD type coil according to claim 1, wherein the bobbin mounting portion of the lead frame has a through hole into which the bobbin is fitted, and the bobbin is press-fitted or loosely fitted into the through hole.   2. The SMD type according to claim 1, wherein the bobbin mounting portion of the lead frame has a bobbin fixing surface to which the bobbin is fixed and a separation hole for electrically separating the terminal electrode into at least two. coil.   4. The SMD according to claim 1, wherein the terminal electrode has a bent portion that is partially bent in one direction, and the winding terminal is coupled to the bent portion. 5. Type coil.   The SMD type coil according to any one of claims 1 to 3, wherein the bobbin is made of a ferrite material.   The bobbin around which the lead frame and the coil winding are wound is sealed by a sealing member, and the bent portion of the terminal electrode is embedded in the sealing member. The SMD type coil according to any one of 5. A method of manufacturing an SMD type coil having a lead frame made of a metal material on which a plurality of terminal electrodes are formed, and a bobbin mounted on the lead frame,
A step of fixing an adhesive material to a collective lead frame that can take a large number of the lead frames;
A bobbin mounting step of mounting a plurality of bobbins on the collective lead frame at a time;
A coil winding step of continuously winding a coil winding around the bobbin mounted on the collective lead frame;
A terminal processing step of coupling a winding terminal of the coil winding to the terminal electrode;
Sealing the bobbin around which the collective lead frame and the coil winding are wound with a sealing member, and forming a collective coil;
A cutting step of cutting the collective coil into a single SMD type coil;
The manufacturing method of the SMD type coil characterized by including these.

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