JP4453808B2 - Inductance component manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, production of the inductance section product having a winding terminal has a structure that joint line by welding to the metal terminal frame, and was mechanically determinable by a suitable bonding state and connecting wire state imaging structure Regarding the method.
[0002]
[Prior art]
Conventionally, one or a plurality of windings have been applied to a magnetic core, and the ends of the windings have been entangled with a metal terminal frame and then connected with high-temperature solder. As described above, the solder of the connecting portion is made of high-temperature solder as a countermeasure against fusing at the time of board mounting. Further, the appearance of the joint was affected by the amount of solder supplied and the way of temporary fixing to the metal terminal frame.
[0003]
[Problems to be solved by the invention]
As in the above prior art, when the connection process is performed with a high-temperature solder, if lead-free solder is used for board mounting, the connection part melts, and thus there is a possibility of disconnection after board mounting. In addition, performing the connecting process with lead-free solder causes deterioration of the connecting workability. Further, in the soldering process using solder, the appearance of the joint becomes uneven for each product, and it is difficult to determine whether or not the product is complete, and the quality of the solder joint has been manually inspected.
[0004]
In view of the above points, the present invention is capable of solderless connection corresponding to lead-free in board mounting, can improve characteristics, improve structure, improve workability, the bonding quality determination as easy structure, and an object thereof is to provide a method for producing a mechanically feasible and the inductance section product quality determination.
[0005]
Other objects and novel features of the present invention will be clarified in embodiments described later.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing an inductance component according to the present invention includes:
A connecting wire step of welding the winding terminals are tied to the upper end portion of the metallic terminal frame and said upper portion of said metal terminal frame, so as to form a spherical connecting wire portions to the upper end of the metal terminal frame ,
An imaging step of imaging the welded portion from above in a state where an illumination beam is applied from above to the welded portion in the connecting step ;
A discriminating step for discriminating the quality of welding in the connecting step based on the image taken in the imaging step,
At least a part of the upper end surface of the metal terminal frame is a flat surface,
In the state before the winding terminal is entangled and the connecting step, the upper end surface of the metal terminal frame is exposed,
In the image captured in the imaging step, the area of the upper end surface where the upper end surface of the metal terminal frame is exposed has a luminance of a certain level or more, the spherical joint portion is formed, The brightness of the spherical connecting portion when the upper end surface of the metal terminal frame is not exposed is larger than the area of the region that is equal to or higher than the certain level,
Prior Symbol Determination process, characterized in that the bright areas of the luminance is more than the predetermined level in the image captured by the imaging step is good welding in the case of less than the predetermined area, it determines that the defective welding exceeds the predetermined area It is said.
In the above method, when the area of the flat portion of the upper end surface of the metal terminal frame is larger than the area of the cross section of the portion of the metal terminal frame where the winding terminal is entangled. Good.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the manufacturing method of the inductance section article according to the present invention with reference to the accompanying drawings.
[0009]
FIG. 1 shows an embodiment of the present invention, showing a manufacturing process of an inductance component and a completed state of the inductance component, and FIG. 2 is an explanatory diagram of a method for determining the quality of a connected portion in a connected portion image determining step.
[0010]
First, the manufacturing process of the inductance component will be described with reference to FIG. As shown in FIG. 1A, an interior resin 10 (elastic resin such as silicon resin) is applied around a coil body 3 in which a winding 2 is applied to a ring-shaped magnetic core 1 such as ferrite, and is provided by resin casting or the like. . In the illustrated example, a common mode choke coil in which a pair of windings 2 are wound around a ring-shaped magnetic core 1 is configured.
[0011]
On the other hand, the metal terminal frame 20 is formed to be bent in a substantially L shape, the tip portion 21 of the horizontal portion becomes a surface mounting terminal portion, and the upper end portion of the vertical portion rising vertically with respect to the horizontal portion is connected to the binding portion 22. It has become. Further, the upper end surface 23 of the vertical portion is a flat surface. This is so that the upper end surface 23 constitutes a flat light reflection surface so that pass / fail determination is easy in a connecting portion image determination step to be described later. The metal terminal frame 20 is a lead frame in the inductance component manufacturing process, as shown by the alternate long and short dash line, and the horizontal portions are integrally connected to each other. It is cut into a predetermined length and shape after molding.
[0012]
Therefore, in the state of FIG. 1A, the two left and right metal terminal frames 20 have a fixed positional relationship as a lead frame, and the coil body 3 provided with the interior resin 10 is incorporated therein, and the interior resin. The winding terminal 2a drawn out from 10 is entangled with the binding part 22, and an unnecessary winding terminal part is cut off. Thereby, the coil body 3 provided with the interior resin 10 is temporarily fixed to the metal terminal frame 20.
[0013]
Thereafter, as shown in FIG. 1B, the binding portion 22 of the metal terminal frame 20 and the winding terminal 2a are connected by welding (using a laser welding, arc welding (arc discharge) device or the like). At this time, the upper part of the metal terminal frame 20 and the winding terminal 2a are given energy to melt in a spherical shape by the welding device, and the spherical connecting part 25 is formed at the upper end of the metal terminal frame. The number of winding turns of the winding terminal 2a to the metal terminal frame 20 and the joining conditions by the welding device are set so that a spiral winding terminal conductor that does not melt remains in the lower part. Incidentally, the metal terminal frame 20 is a copper alloy such as phosphor bronze, and the winding 2 is an insulation coated copper wire such as a urethane wire.
[0014]
After the connecting process by welding in FIG. 1B is finished, the quality of the connecting part is determined in the connecting part image determining step. In this method, the direction of the field of view of the imaging means (camera) and the direction of the light beam of illumination are set in the direction of arrow P in the figure, and each spherical connecting portion 25 at the upper end of the metal terminal frame is placed at the upper end of the metal terminal frame 20. Images are taken from the facing direction (the direction facing the upper end surface of the metal terminal frame before welding).
[0015]
FIG. 2 (A) is a photograph taken under the above conditions (view from the upper surface of the product). The upper pair of metal terminal frames is a state before welding by only the winding terminal binding process, and the lower one. The pair of metal terminal frames shows a state in which the welding process after the winding ends are successfully performed and the spherical connecting portion is formed. When the lower spherical joint portion 25 is formed (when welding is good), only the light at the spherical apex reflects, so the light reflection area is small, and before the upper joint portion is welded, a spiral shape is formed. Since light is reflected by the upper end surface 23 which is a flat surface of the winding terminal and the metal terminal frame 20, the reflection area is large. That is, in the connection structure of the present embodiment, consideration is given so as to maximize the difference in the amount of light before and after welding.
[0016]
FIG. 2 (B) is an image obtained by imaging the upper pair and the lower pair of connecting portions and binarized with a constant luminance as a threshold value. Is shown in white, and dark areas with brightness below a certain level are shown in black. Before welding the upper connecting portion, the spiral winding terminal and the upper end surface 23 of the metal terminal frame 20 become a white region, and the lower spherical connecting portion 25 is formed although the area of the white region is large. Things have little reflection and the white area is very small.
[0017]
Therefore, as shown in FIG. 1 (B), if the connecting process by welding at four points is performed satisfactorily, the spherical connecting part 25 is formed, and the connecting part in the image of FIG. 2 (B) is formed. The white area corresponding to is extremely small, and the area of the white area increases when the shape of the flat upper end surface 23 of the metal terminal frame 20 remains due to unwelded or poorly welded connection portions. As a result, when the captured image of the imaging unit is binarized into black and white, image processing is performed, and the area of the white portion corresponding to the connecting portion is calculated and digitized, and when it is less than a predetermined value (that is, a bright area is less than a predetermined area) When the predetermined value is exceeded (that is, when the bright area exceeds the predetermined area), it is possible to mechanically automatically determine that the welding is defective.
[0018]
Exterior resin molding is performed as shown in FIG. 1 (C) for those in which the welding of all four connecting portions is determined to be good in the connecting portion image discrimination step. That is, in a lead frame state including two pairs of metal terminal frames 20, an exterior body 30 that further covers the periphery of the interior resin 10 that covers the coil body by exterior resin molding is molded (for example, injection molding), and from the lead frame The two pairs of metal terminal frames 20 are separated so as to have a predetermined shape.
[0019]
Thus, the coil body 3 provided with the winding 2 on the core 1 is covered and protected by the elastic interior resin 10 (which becomes a protective layer), and the interior resin 10 and the metal terminal frame 20 are further packaged by exterior resin molding. An inductance component having a structure covered with 30 is completed.
[0020]
According to this embodiment, the following effects can be obtained.
[0021]
(1) Due to the structure in which the winding terminal 2a is spirally wound around the vertical portion of the metal terminal frame 20 positioned in the vertical direction and the tie end of the metal terminal frame 20 is melted, Since it cools and solidifies while diffusing in the direction of the terminal frame itself, it becomes a linear weld instead of spot welding, and the volume of the joint is large and the reliability is high.
[0022]
(2) In the structure in which the winding terminal 2a is spirally wound around the vertical portion of the metal terminal frame 20 positioned in the vertical direction and the tip of the terminal is melted, the frame itself in which the molten portion that has become spherical diffuses is in the direction of gravity. Therefore, the spherical shape of the tip can be maintained, and the spherical connecting portion 25 is formed after cooling and solidification, and the apex of the spherical portion necessary for machine discrimination by image recognition (automatic discrimination without manual operation) can be maintained. .
[0023]
(3) By adopting a connection structure in which the conductor of the spiral winding terminal 2a remains in the lower part of the spherical connection portion 25 even after welding, it has both mechanical strength and electrical connection.
[0024]
(4) In the connecting part image discriminating process in the manufacturing process of the inductance component, when the welding is defective, the upper end surface 25 of the metal terminal frame 20 and the entangled part of the winding terminal 2a are reflected and lightened, and the welding is good. Focusing on the formation of a spherical connecting portion 25 with less reflection at the time of the above, in the image obtained by imaging the connecting portion, when a bright region having a certain level or more of brightness is less than a predetermined area, welding is good, When the predetermined area is exceeded, it is possible to determine that the welding is defective. In this way, the discrimination criteria can be digitized and the discrimination criteria can be clearly set. Therefore, machine discrimination by the image processing apparatus is possible, and the process can be automated.
[0025]
In the above embodiment, a common mode choke coil in which a pair of windings are wound around a ring-shaped magnetic core is illustrated, but the present invention has a connection structure in which a winding terminal is entangled with a metal terminal frame. It is clear that the present invention can be applied to an inductance component having the same.
[0026]
Although the embodiments of the present invention have been described above, it will be obvious to those skilled in the art that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.
[0027]
【The invention's effect】
As described above, according to the present invention, since the connecting portion between the winding terminal and the metal terminal frame is welded, the connecting portion does not melt in the board mounting temperature region using lead-free solder. Therefore, it is highly reliable. In addition, since the connecting part is formed in a spherical shape by welding, it is easy to find a welding defect and it is easy to visually distinguish the appearance, and automatic determination of the quality of the connecting part is also possible by image processing. Since this becomes possible, the cost can be reduced. Furthermore, since lead-free solder is not used for the connecting portion, the member cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an inductance component according to an embodiment of the present invention and a method for manufacturing the same, and showing an inductance component in a manufacturing process and a completed state.
FIG. 2 is a photographic diagram showing an image for explaining a connecting portion image discriminating step after the connecting processing by welding is completed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ring-shaped magnetic body core 2 Winding | winding 2a Winding terminal 3 Coil main body 10 Interior resin 20 Metal terminal frame 22 Binding part 23 Upper end surface 25 Spherical connection part 30 Exterior body

Claims (2)

A connecting wire step of welding the winding terminals are tied to the upper end portion of the metallic terminal frame and said upper portion of said metal terminal frame, so as to form a spherical connecting wire portions to the upper end of the metal terminal frame ,
An imaging step of imaging the welded portion from above in a state where an illumination beam is applied from above to the welded portion in the connecting step ;
A discriminating step for discriminating the quality of welding in the connecting step based on the image taken in the imaging step,
At least a part of the upper end surface of the metal terminal frame is a flat surface,
In the state before the winding terminal is entangled and the connecting step, the upper end surface of the metal terminal frame is exposed,
In the image captured in the imaging step, the area of the upper end surface where the upper end surface of the metal terminal frame is exposed has a luminance of a certain level or more, the spherical joint portion is formed, The brightness of the spherical connecting portion when the upper end surface of the metal terminal frame is not exposed is larger than the area of the region that is equal to or higher than the certain level,
Prior Symbol Determination process, characterized in that the bright areas of the luminance is more than the predetermined level in the image captured by the imaging step is good welding in the case of less than the predetermined area, it determines that the defective welding exceeds the predetermined area A method for manufacturing an inductance component. 2. The method according to claim 1, wherein an area of a flat surface portion of the upper end surface of the metal terminal frame is a cross section of a portion of the metal terminal frame where the winding terminal is entangled. A method of manufacturing an inductance component that is larger than the area.

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