JP2014099586A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component which prevents a mounting defect or a relaying defect and improves reliability by canceling variation in height of an end face of a terminal fitting caused by variation in thickness of an adhesive.SOLUTION: The coil component comprises: a coil 7 which is formed by winding a wire; a drum core supporting the coil 7; terminal fittings 6a-6f to which a terminal of the coil 7 is connected; and an adhesive 11B for adhering the terminal fittings to flange parts 4A, 4B of the drum core. The drum core includes a bottom face Sof a flange part to be a mounting surface, and each of the terminal fittings includes a bottom face Tpositioned on the bottom face of the flange part of the drum core. In the bottom face Sof each of the flange parts, a step is provided which is formed from an upper step face Sand a lower step face S. The bottom face Tof the terminal fitting is brought into direct contact with the upper step face S, and a gap dbetween the bottom face Sof the terminal fitting and the lower step face Sis filled with a first adhesive 11B. A part of the adhesive 11B also fills the inside of a groove Sformed on the lower step face Sright under the step.

Description

  The present invention relates to a coil component, and more particularly to a terminal electrode structure of a surface mount type coil component.

  With recent miniaturization of electronic devices, high-density mounting is also required for coil components. For example, Patent Document 1 discloses a surface mount type coil component capable of high density mounting.

  The coil component includes a core having a winding core portion and a flange portion, an insulating case in which a housing space for the core is formed, and a terminal that is mechanically fixed to the case with at least a portion exposed to the outside. A metal fitting and a winding (wire) that is connected to the terminal metal fitting and wound around the core portion through the case are provided. The core accommodating space is defined to include a bottom surface substantially parallel to the mounting surface, and the core portion and the flange portion each have a lower surface of the core portion facing the bottom surface and a lower surface of the flange portion. The lower surface of the part is flush with the lower surface of the collar part. A leg portion that projects toward the mounting surface is defined at a position facing the collar portion of the case, and the mounting portion of the terminal fitting is disposed on the leg portion. Since the terminal fitting has a blade-like fixing part embedded in the case, even if the terminal fitting is affected by heat during mounting or connection, the terminal fitting will fall off the insulating container. Can be suppressed.

JP 2009-117627 A

  In the above-described coil component, a method of embedding the fixing portion of the terminal fitting in the case is used to attach the terminal fitting, but generally an adhesive is often used. However, when an adhesive is used, there is a problem that the height of the terminal surface between the plurality of terminal fittings varies due to variations in the position and amount of the adhesive between the terminal fitting and the mounting surface. This variation in the height of the terminal surface becomes a variation in pressure when the terminal portion of the coil is connected to the terminal surface by thermocompression bonding, which causes a connection failure. There is also a problem of poor mounting of coil parts.

  Further, in the coil component described above, the connection between the wire and the terminal fitting is realized by thermocompression bonding the tip end portion of the wire on the terminal fitting. When the wire is thermocompression bonded to the terminal fitting, the wire material (Cu) of the wire and the plating film (Ni and Sn) on the surface of the terminal fitting react to form an alloy layer. Here, since the alloy layer has a high melting point, when this portion becomes a solder joint surface when the coil component is mounted on the circuit board, it becomes a factor of reducing the wettability of the solder. In particular, as shown in FIG. 16A, when the position of the distal end portion 20e of the wire 20 to be thermocompression bonded is aligned with the end portion of the terminal surface of the terminal fitting 21, from the end of the terminal surface in the wire extending direction. An alloy layer is formed up to the end, that is, in a wide range of the terminal surface, and the alloy layer may hinder the formation of the solder fillet and cause mounting failure.

  In order to solve this problem, as shown in FIG. 16 (b), the tip 20e of the wire 20 may be set not on the end of the terminal surface of the terminal fitting but on the inner side (near the center). . In this case, the wire 20 drawn from the core portion of the core passes through the terminal surface of the terminal fitting 21 and is drawn forward, and then the wire portion behind the position to be the tip of the wire. The (practical part) is thermocompression bonded to the terminal surface, and the front wire part (see the broken line) needs to be cut and removed. However, if the front wire portion is in contact with the terminal surface of the terminal fitting 21, the wire adheres to the surface of the terminal fitting when the plating film on the surface of the terminal fitting is melted by heat during thermocompression bonding. There is a problem that can not be cut and removed well.

  In order to solve the above problems, a coil component according to the present invention includes a coil formed by winding a wire, a base body that supports the coil, at least one terminal fitting to which a terminal portion of the coil is connected, and the terminal fitting. And a first adhesive that adheres to the base, the base has a first surface that is a mounting surface, and the terminal fitting is a first located on the first surface of the base. The first surface is provided with a step formed by an upper step surface and a lower step surface, and the first terminal portion of the terminal fitting is in direct contact with the upper step surface. The first adhesive is filled in a gap between the first terminal portion of the terminal fitting and the lower step surface.

  ADVANTAGE OF THE INVENTION According to this invention, the dispersion | variation in the height of the terminal surface by the thickness of the adhesive agent between a terminal metal fitting and a collar part can be suppressed, and the flatness between several terminal metal fittings can be improved. Accordingly, it is possible to eliminate problems such as mounting defects due to variations in the mounting state on the printed circuit board, and connection failures due to variations in pressure when connecting the terminal portions of the coils by thermocompression bonding. Furthermore, according to the present invention, the terminal fitting can be made elastic by the gap, and when the terminal portion of the coil is cut, a cushion at the time of cutting can be given by the elasticity of the terminal fitting. A terminal part can be cut | disconnected reliably.

  The coil component according to the present invention preferably further includes a groove formed in the lower step surface immediately below the step, and a part of the first adhesive is filled in the groove. According to this configuration, it is possible to reliably prevent variations in the height of the terminal fitting due to variations in the amount of adhesive applied.

  In the present invention, it is preferable that the terminal portion of the coil is connected to the first terminal surface of the terminal fitting that is positioned above the upper surface and overlaps the upper surface in plan view. According to this configuration, the terminal portion can be reliably thermocompression bonded to the terminal surface of the terminal fitting, and the wire can be reliably cut after thermocompression bonding. Further, the gap as the first adhesive reservoir space can be used as a cushion when cutting the terminal portion of the coil, and the adhesive reservoir space can be effectively utilized.

  The base body has a second surface orthogonal to the first surface, the terminal fitting is L-shaped, and further includes a second terminal portion located on the second surface, It is preferable that the second terminal portion is bonded and fixed to the second surface with a second adhesive. According to this configuration, the terminal fitting can be reliably fixed by the first adhesive and the second adhesive, and the connection by the thermocompression of the terminal portion of the wire and the subsequent cutting can be reliably performed. it can.

  The coil component according to the present invention preferably includes a plurality of the terminal fittings. The greater the number of terminal fittings, the greater the variation in height. However, according to this configuration, the height variation between multiple terminal fittings can be suppressed, and mounting defects and poor connection can be prevented. it can.

  In the present invention, the base is a drum core having a core part around which the coil is wound and a pair of flanges provided at both ends of the core part, and the first surface of the base is It is preferable that it is a bottom face of the collar part, and the second surface of the base body is an outer side surface of the collar part. According to this configuration, in the surface mount type coil component using the drum core, the solder wettability of the terminal surface to which the wire is connected can be improved, and the reliability of the electrical and mechanical connection can be improved. Can do.

  In this invention, it is preferable that the said 1st terminal part of the said terminal metal fitting has a level | step difference shape match | combined with the said level | step difference of the said base | substrate. In this case, the first terminal portion of the terminal fitting is located on an extension line of the terminal portion of the coil, and is a second terminal located at a position lower than the first terminal surface when viewed from the base. It is preferable to have a surface. According to this configuration, since the end portion of the wire is not pressed against the surface of the terminal fitting during thermocompression bonding, it is possible to avoid the crimping of the end portion of the wire, and the wire is reliably and easily removed after thermocompression bonding. be able to. Further, the terminal fitting can be provided along the stepped surface of the base body, and the gap between the terminal fitting and the lower stepped surface can be set to an appropriate height. Further, since the area of the terminal surface to be solder-mounted can be ensured widely, it is not necessary to accurately position the terminal portion of the coil at the time of crimping, and the terminal portion of the wire can be easily crimped.

  The coil component according to the present invention further includes a recess formed on the lower surface, and the recess is preferably provided in a region of the lower surface that does not overlap the terminal fitting. According to this configuration, when the terminal fitting integrated with the lead frame is bonded and fixed, the adhesive can be prevented from flowing through the lead frame to an unintended region, and the lead frame is bonded. Can be prevented.

  In the present invention, the terminal fitting includes at least first to third terminal fittings that are arranged in order in a predetermined direction, and is between the first terminal fitting and the second terminal fitting in the predetermined direction. Is wider than the insulation interval between the second terminal fitting and the third terminal fitting in the predetermined direction, and the recessed portion is formed on the lower surface of the second terminal fitting and the third terminal fitting. It is preferable to be provided in a region sandwiched between the terminal fittings. When the terminal fitting is provided on the flange portion of the drum core, the predetermined direction is the width direction of the flange portion. According to this configuration, it is possible to prevent a situation in which the adhesive flows out to a wide area between the second terminal fitting and the third terminal fitting and the lead frame is bonded.

  According to the present invention, it is possible to eliminate the variation in the height of the terminal surface caused by the variation in the thickness of the adhesive interposed between the terminal fitting and its mounting surface. Therefore, it is possible to provide a highly reliable coil component that is free from mounting failure and connection failure. Moreover, according to this invention, the unnecessary part of the wire after thermocompression bonding can be cut | disconnected reliably, and can be removed easily. Accordingly, a coil component having a terminal surface with good solder wettability can be realized.

FIG. 1 is a schematic perspective view showing an external configuration of a coil component according to the first embodiment of the present invention. FIG. 2 is an exploded perspective view of the coil component of FIG. FIG. 3 is a schematic perspective view showing a state where the coil component of FIG. 1 is turned upside down. FIG. 4 is an equivalent circuit diagram of the coil component 1. FIG. 5 is a schematic perspective view showing the configuration of the drum core 2, and shows a state in which the terminal fittings 6a to 6f are attached. FIG. 6 shows the drum core 2 without the terminal fittings 6a to 6f in the inverted state with the bottom face facing upward. 7A and 7B show a configuration of the flange portion to which the terminal fitting is attached, wherein FIG. 7A is a schematic plan view of the flange portion viewed from the bottom surface side, and FIG. 7B shows the flange portion viewed from the outer side surface side. FIG. 8A and 8B are schematic side sectional views showing the shapes of the terminal fittings attached to the flange portions 4A and 4B, respectively. FIGS. 9A to 9C are schematic views for explaining a wire thermocompression bonding process using a heater chip. FIG. 10 is a schematic perspective view showing the structure of the coil component 30 according to the second embodiment of the present invention. FIG. 11 is a schematic perspective view showing the shape of the drum core of the coil component 30. FIG. 12 is an equivalent circuit diagram of the coil component 30. FIG. 13 is a diagram showing the structure of the coil component 40 according to the third embodiment of the present invention, and particularly shows the shape of the drum core 2. FIG. 14 is a schematic perspective view showing a state before the terminal fitting attached to the drum core is separated from the lead frame. FIGS. 15A and 15B are schematic side views showing a state in which the terminal fittings 6a to 6c are bonded, in which FIG. 15A shows a conventional configuration without a recess, and FIG. 15B shows a configuration of the present embodiment with a recess. . FIGS. 16A and 16B are schematic views for explaining a conventional coil component.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing an external configuration of a surface mount type coil component according to a first embodiment of the present invention. 2 is an exploded perspective view of the coil component shown in FIG. 1, and FIG. 3 is a schematic perspective view showing a state where the coil component shown in FIG. 1 is turned upside down.

  As shown in FIGS. 1 to 3, the coil component 1 includes a drum core 2, a plate-like core 5, six terminal fittings 6 a to 6 f, and a coil 7 made of a wire wound around the drum core 2. ing. Although not particularly limited, the coil component 1 is a surface mount type pulse transformer, and the size thereof is about 4.5 mm × 3.2 mm × 2.6 to 2.8 mm, or about 3.2 mm × 3.2 mm × 2. .8 to 2.9 mm.

  The drum core 2 is made of, for example, a magnetic material such as Ni—Zn-based ferrite, and includes a core portion 3 around which the coil 7 is wound, and a pair of flange portions 4A and 4B disposed at both ends of the core portion 3. Yes. The plate-like core 5 is also made of a magnetic material such as Ni—Zn ferrite, and is placed on the upper surfaces of the pair of flange portions 4A and 4B and fixed with an adhesive or the like.

  Since the upper surface of the plate-like core 5 is a flat smooth surface, this upper surface can be mounted as a suction surface when the coil component 1 is suction mounted. Furthermore, it is preferable that the surface of the plate-like core 5 bonded to the upper surfaces of the flange portions 4A and 4B is also a smooth surface. When the smooth surface of the plate-like core 5 is in contact with the flange portions 4A and 4B, both can be securely brought into contact with each other, and a closed magnetic path free from magnetic flux leakage can be formed.

  The terminal fittings 6a to 6f are L-shaped metal pieces extending from the bottom surfaces of the flange portions 4A and 4B to the outer side surfaces. Here, the outer side surface of the collar portion is a surface located on the side opposite to the attachment surface of the core portion 3. These terminal fittings 6a to 6f are preferably portions cut out from a lead frame obtained by processing a single metal plate. The terminal fittings 6a to 6f are bonded and fixed to the drum core 2 in the state of the lead frame, and become independent terminals by being separated from the frame portion. When the terminal fittings 6a to 6f are used, the formation thereof is easier than the plating electrode, which is advantageous in terms of cost in mass production. Furthermore, the positional accuracy when the terminal fittings 6a to 6f are attached can be increased.

  Of the terminal fittings 6a to 6f, three terminal fittings 6a, 6b, 6c are provided on the flange 4A side, and the other three terminal fittings 6d, 6e, 6f are provided on the flange 4B side. Further, of the three terminal fittings 6a, 6b, 6c, the two terminal fittings 6a, 6b are provided on the right side of the flange portion 4A, and the terminal fitting 6c is provided on the left side of the flange portion 4A. A constant insulation interval is provided between them. Similarly, of the three terminal fittings 6d, 6e, 6f, the two terminal fittings 6d, 6e are provided on the right side of the flange portion 4B, and the terminal fitting 6f is provided on the left side of the flange portion 4B. A constant insulation interval is provided between the two.

As shown in FIG. 2, each of the L-shaped terminal fittings 6a to 6f includes a bottom surface portion T _B (first terminal portion) in contact with the bottom surface (first surface) of the flange portions 4A and 4B, and the flange portion. 4A, 4B has a side surface portion T _S (second terminal portion) in contact with the outer side surface (second surface). Then, as shown in FIG. 3, the terminal portion of the coil 7 is thermocompression bonding surface of the bottom portion T _B of the terminal fitting 6 a to 6 f.

  The coil 7 is composed of four wires S1 to S4. The wires S <b> 1 to S <b> 4 are coated conductors and are wound around the winding core portion 3 with a two-layer structure. More specifically, the wires S1 and S4 constitute a first layer by bifilar winding (two wires are wound in parallel in a single layer), and the wires S2 and S3 constitute a second layer by bifilar winding. The number of turns of the wires S1 to S4 is the same.

  Further, the winding direction of the wires S1 to S4 is different between the first layer and the second layer. That is, for example, when the winding direction from the flange 4A toward the flange 4B is viewed from the flange 4A, the winding direction of the wires S1 and S4 is clockwise, whereas the winding direction of the wires S2 and S3 is It is counterclockwise and opposite to each other. This is because it is not necessary to stretch each wire from one end side to the other end side of the core portion 3 at the start and end of winding.

  Connection of the wires S1 to S4 and the terminal fittings 6a to 6f will be described. One end S1a and the other end S1b of the wire S1 are connected to the terminal fittings 6a and 6f, respectively, and one end S2a and the other end S2b of the wire S2 are connected to the terminal fittings 6f and 6b, respectively. Also, one end S3a and the other end S3b of the wire S3 are connected to the terminal fittings 6e and 6c, respectively, and one end S4a and the other end S4b of the wire S4 are connected to the terminal fittings 6c and 6d, respectively.

  As is apparent from FIG. 3, the terminal fitting 6c is provided slightly apart from the terminal fittings 6a and 6b. Similarly, the terminal fitting 6f is provided slightly apart from the terminal fittings 6d and 6e. This is to secure a withstand voltage between the primary winding constituted by the wires S1 and S2 and the secondary winding constituted by the wires S3 and S4.

  FIG. 4 is an equivalent circuit diagram of the coil component 1.

  As shown in FIG. 4, the terminal fittings 6a and 6b serve as a pair of balanced input terminals, that is, a positive terminal power IN + and a negative terminal electrode IN−. The terminal fittings 6e and 6d serve as a pair of balanced output terminals, that is, a positive terminal electrode OUT + and a negative terminal electrode OUT−. The terminal fittings 6c and 6f serve as center taps CT on the output side and input side, respectively. The wires S1 and S2 constitute the primary winding of the pulse transformer, and the wires S3 and S4 constitute the secondary winding of the pulse transformer.

  FIG. 5 is a schematic perspective view showing the configuration of the drum core 2, and shows a state in which the terminal fittings 6a to 6f are attached. FIG. 6 shows the drum core 2 without the terminal fittings 6a to 6f in a reversed state in which the bottom surface faces upward. Further, FIG. 7A is a schematic plan view of the flange portion 4A as viewed from the bottom surface side, and FIG. 7B is a schematic plan view of the flange portion 4A as viewed from the outer side surface side.

  As shown in FIGS. 5 and 6, the drum core 2 includes a core portion 3 and a pair of flange portions 4 </ b> A and 4 </ b> B disposed at both ends of the core portion 3. The drum core 2 has a rotationally symmetric shape in plan view, and the flange portions 4A and 4B have the same shape. Therefore, FIG. 7 shows only the collar part 4A, and the illustration of the collar part 4B is omitted.

As shown in FIG. 5, the flange portion 4A, the upper surface S _T of 4B is a smooth flat surface, thereby the adhesion between the plate core 5 is enhanced. As described above, the flange portion 4A, the plate-like core 5 is spanned Between the upper surface S _T of 4B, thereby substantially closed magnetic path is formed.

As shown in FIGS. 5, 6 and FIG. 7 (b), the flange portion 4A, the outer side surface S _S of 4B, low installation area of the terminal fitting 6 a to 6 f, the other regions become the high step surface Yes. Terminal fitting 6a~6f is provided on the lower surface _{S S1} of the outer side _{S S,} the height of the upper surface _{S S2} of the outer side _{S S} is to be substantially flush with the upper surface of the terminal fitting 6a~6f Is formed. In FIG. 7B, the hatched region is the upper step surface S _S2 , and the region without hatching is the lower step surface S _S1 .

6 and FIG. 7 (a), the flange portion 4A, 4B bottom S _B of the installation area of the base end of the terminal fitting 6a~6f is high, it is the other region with a lower step surface ing. That is, an upper step surface S _B2 and a lower step surface S _B1 are provided in the installation area of the terminal fittings 6a to 6f, and most of the non-installation region of the terminal fittings 6a to 6f is the lower step surface S _B1 . The proximal end of the bottom portion _{T B} of the terminal fitting 6a~6f is provided on the upper surface _{S B2} of the bottom surface _{S B} of the flange 4A, 4B, the corners of the bottom portion _{T B} of the terminal fitting 6a~6f parts side is provided on the lower surface _{S B1} of the bottom surface _{S B} of the flange 4A, 4B. In FIG. 7A, the hatched region is the upper step surface S _B2 , and the region without hatching is the lower step surface S _B1 .

In the present embodiment, the groove S _B3 is provided in the lower step surface S _B1 directly below the step. Here, “directly below the level difference” means that the side wall surface connecting the upper step surface S _B2 and the lower step surface S _B1 extends downward as it is, and is continuously formed as the inner wall surface of the groove S _B3 , It means that there is no lower step surface S _{B1 in the} middle. The groove S _B1 extends in parallel with the step, and its length is equal to the length of the step. The width of the groove S _B3 is not particularly limited, but can be about 0.1 to 0.2 mm. The cross-sectional shape of the groove S _B3 may be rectangular, U-shaped, or V-shaped. Although details will be described later, by forming such a groove S _B3 , the space between the terminal fitting and the bottom surface of the flange can be appropriately expanded, and the space between the bottom surface of the flange and the terminal fitting is Variations in the amount of adhesive applied can be absorbed.

  8A and 8B are schematic side sectional views showing the shapes of the terminal fittings 6a to 6f attached to the flange portions 4A and 4B, respectively, and (a) is a schematic side view including the entire drum core, (B) is the elements on larger scale of the terminal metal fitting by the side of the collar part 4A. In addition, the structure by the side of the collar part 4B is the same as the side of the collar part 4A.

Figure 8 (a) and (b), the bottom portion _{T B} and the side surface portion _{T S} of the L-shaped terminal fitting 6a~6f is a flange 4A, 4B bottom _{S B} (first surface) of And the outer side surface S _S (second surface). Here, the side surface portion T _S is bonded and fixed by an adhesive 11A on the outer side surface S _S of the flange portion, a bottom portion T _B are bonded and fixed by an adhesive 11B to the bottom surface S _B of the flange. It is also possible to bond only fixed side portion T _S, according to this configuration, it is possible to eliminate the height variation of the bottom T _B of the terminal fitting 6a~6f due to variations in coat-weight of the adhesive. However, in the present embodiment, since the groove S _B3 is provided, the variation in the amount of adhesive applied can be absorbed to some extent. Accordingly, while preventing the height variation of the bottom T _B of the terminal fitting 6a~6f by adhesive, it is possible to further increase the mounting strength.

Force for pressing the bottom portion T _B of the terminal fitting 6a~6f is to act as a shearing force against the adhesive 11A, bonding and fixing is easily peeled off. In contrast, the direction of the force pressing the bottom portion T _B of the terminal fitting, since the direction substantially perpendicular to the adhesive surface of the adhesive 11B, that the adhesive 11B receives such a force is peeled off Absent. Therefore, it is possible to prevent a situation where the terminal fitting is removed from the flange due to the pressure applied at the time of connection by thermocompression bonding or cutting of the wire, and the adhesive strength of the terminal fitting can be increased.

Bottom portion T _B of the terminal fitting 6a~6f the terminal portion of the coil 7 is joined has a stepped shape. The flange portion 4A, the stepped surface of the bottom _{S B} of 4B has a combined shape stepped shape of the terminal fitting 6 a to 6 f.

Bottom portion _{T B} of the terminal fitting 6a~6f is a flange 4A, an upper portion _{T B1} provided inside the side surface side of the 4B (core portion 3 closer), the flange portion 4A, the outer side _{S S} side of the 4B made from the lower portion _{T B2} provided. Here, the upper step portion T _B1 is a portion (contact portion) that provides a terminal surface (upper step surface S _U ) that contacts the terminal portion of the coil 7, and the lower step portion T _B2 does not contact the terminal portion of the coil 7. It is a site | part (non-contact part) which provides a terminal surface (lower stage surface _SL ). That is, the lower portion T _B2 does not have a terminal surface on the upper surface S _U and the same plane.

Upper surface S _U of the bottom T _B of the terminal fitting 6a~6f receives a pressing force to the terminal portion of the coil 7 at the time of thermocompression bonding to provide a "contact face". Further, the lower surface S _L of the bottom portion T _B of the terminal fitting 6a~6f may escape the pressure contact force to the terminal portion of the coil 7 provides a "non-contact face." By having a stepped surface which is the bottom portion _{T B} of the terminal fitting 6a~6f consisting upper surface _{S U} and the lower surface _{S L,} the terminal portion of the coil 7, extends in the coils in the bottom portion of the terminal fitting 6a~6f It is possible to avoid thermocompression bonding over the entire width of the direction. Therefore, it is possible to secure a wide area where the alloy layer is not formed by the reaction between the wire and the plating film, and the wire can be cut and removed reliably and easily.

Rear face flange portion 4A of the lower portion _{T B2} of the bottom portion _{T B} of the terminal fitting 6 a to 6 f, between the lower surface _{S B1-side} surface of 4B, it is preferable that a clearance _{d 1} is provided. If such a gap d ₁ is provided with a can, when cutting the terminal portion of the coil 7 after thermocompression bonding to the cutter, it is possible to provide a cushion by the elastic force of the terminal fitting 6 a to 6 f. Therefore, the terminal portion of the coil 7 can be reliably cut.

The adhesive 11B filled in the gap d ₁ is firmly cushion of the terminal fitting during wire cutting, but not the cushion is eliminated. Rather, a more appropriate cushion can be provided than without the adhesive 11B. And the presence of such a gap d _1, it is possible to absorb variations in coat-weight of adhesive used in bonding the terminal fitting, thereby increasing the flatness of the terminal surface between a plurality of terminal fittings Can do.

In FIG. 8 (b), the although the two at the lower portion _{T B2} of the side surface portion _{T S} and the bottom portion _{T B} (part of the gap _{d 1)} is bonded and fixed, the upper portion _{T B1} is not bonded. Therefore, it is possible to reliably ensure contact between the upper step surface S _B2 and the upper step portion T _B1 of the bottom surface of the flange while increasing the adhesive strength. Therefore, the joint line position of the terminal portion of the coil, it is possible to prevent the height variation of the bottom T _B of the terminal fitting 6 a to 6 f.

  FIGS. 9A to 9C are schematic views for explaining the thermocompression bonding process of the terminal portion of the coil 7.

  As shown to Fig.9 (a), in the thermocompression bonding process, the terminal part of the coil 7 wound by the core part 3 of the drum core 2 is wired on corresponding terminal metal fittings 6a-6f. The terminal portion of the coil 7 passes through the terminal fittings 6a to 6f and is drawn to the outside of the flange portions 4A and 4B, and extends substantially parallel to the bottom surfaces of the flange portions 4A and 4B.

Next, as shown in FIG.9 (b), the terminal part of the coil 7 is thermocompression-bonded to the surface of the terminal metal fittings 6a-6f using the heater chip 12. FIG. Wire portion located above the upper surface S _U of the bottom T _B of the terminal fitting 6a~6f is sandwiched between the heater chip 12 and the upper surface S _U, the terminal surface in pressure contact force of the high temperature heater chip 12 The wire wire (Cu) and the plating film (Ni and Sn) on the terminal surface are alloyed to obtain a sufficient bonding force.

On the other hand, the wire portion located above the lower surface _{S L} of the bottom portion _{T B} of the terminal fitting 6a~6f is escaped into the gap _{d 2} between the heater chip 12 and the lower surface _{S L,} as the upper surface _{S U} A sufficient pressure contact force is not applied. Therefore, thermocompression bonding to the terminal surface of the wire portion can be avoided.

As shown in FIG.9 (c), the terminal part of the coil 7 heat-pressed on the terminal metal fittings 6a-6f in this way is cut | disconnected by the cutter 13, and the length is adjusted. At this time, the cutting position of the coil 7 is in the vicinity of the steps of the terminal fittings 6a to 6f. Even when the end portion of the coil 7 is cut, the extra wire portion 7r of the wire that has not been thermocompression bonded is not fixed to the terminal surface, or even if it is fixed to the terminal surface by a plating film melted during thermocompression bonding. Since the fixing force is weak, it peels off with a little force. As a result, only the wire surface of which the upper surface S _U of the bottom T _B of the terminal fitting is thermocompression bonding, a state the wire is not in the lower surface S _L.

In the upper surface S _U, around the wire becomes a solder having poor wettability region by alloying, more about the present or areas not alloyed, this region contributes to the solder connection. On the other hand, the lower surface S _L is absent wire, the solder wettability of the good region. The lower surface S _L is a portion in contact with the side surface portion T _S of the terminal fitting, at the time of surface mounting, a portion contributing to the formation of the solder fillet with the side surface portion T _S. Therefore, when such a coil component 1 the surface mounting, can increase the solder wettability of the terminal fitting 6 a to 6 f, the solder fillet reliably from the lower portion T _B2 of the terminal toward the side surface portion T _S Can be formed. Therefore, the reliability of the electrical and mechanical connection of the coil component 1 can be improved.

As described above, the coil component 1 according to this embodiment, the flange portion 4A of the drum core 2 to the terminal fitting 6a~6f is attached, the stepped surface is provided on the bottom surface S _B of 4B, the terminal fitting upper surface S _B2 in direct contact with, and between the terminal fitting and the lower surface S _B1 a gap d ₁ is provided, the adhesive 11B is filled into the gap d _1, the plurality of terminal fittings 6a The variation in the height of the terminal surfaces between ˜6f can be suppressed, and the flatness of the terminal surfaces of the terminal fittings 6a-6f can be ensured.

In the present embodiment, the groove S _B3 formed in the lower step surface S _B2 immediately below the step is further provided, and a part of the adhesive 11B is filled in the groove S _B3 . Variations in the height of the terminal surfaces between 6a to 6f can be reliably suppressed.

  Moreover, since the coil component 1 according to the present embodiment is provided with a stepped surface that avoids contact with the tip of the coil 7 on the terminal surfaces of the terminal fittings 6a to 6f to which the terminal portion of the coil 7 is joined, It is possible to avoid the tip portion of the wire from being thermocompression bonded to the terminal surface. Therefore, the wire can be cut and removed reliably after thermocompression bonding.

  Furthermore, in this embodiment, since the non-contact part with the terminal part of a wire is an electrode surface lower than a contact part, the electrode surface of a terminal metal fitting can be ensured widely. Therefore, high accuracy is not required for positioning of the terminal portion of the coil, and the terminal portion of the wire can be easily thermocompression bonded.

  FIG. 10 is a schematic perspective view showing the structure of the coil component 30 according to the second embodiment of the present invention, and shows a state in which it is turned upside down. FIG. 11 is a schematic perspective view showing the shape of the drum core of the coil component 30.

  As shown in FIGS. 10 and 11, the coil component 30 according to the present embodiment divides the terminal fitting 6c into two center tap terminal fittings 6c1 and 6c2, and the terminal fitting 6f into two center tap terminal fittings 6f1, It is divided into 6f2 and is characterized in that four terminal fittings are attached to each of the pair of flange portions 4A and 4B. Terminal fittings 6a, 6b, 6c1, 6c2 are provided on the flange 4A, and terminal fittings 6d, 6e, 6f1, 6f2 are provided on the flange 4B.

  In the present embodiment, the other end S3b of the wire S3 is connected to the terminal fitting 6c2, and one end S4a of the wire S4 is connected to the terminal fitting 6c1. One end S2a of the wire S2 is connected to the terminal fitting 6f2, and the other end S1b of the wire S1 is connected to the terminal fitting 6f1. When the terminal fittings 6f1 and 6f2 are short-circuited and the terminal fittings 6c1 and 6c2 are short-circuited through the wiring pattern (land) on the printed circuit board, the coil component 1 substantially shown in FIGS. The same function can be realized.

The center tap terminal fittings 6c1, 6c2, 6f1, 6f2 are configured in the same manner as the terminal fittings 6a, 6b, 6d, 6e. That is, the center tap terminal fitting 6c1,6c2,6f1,6f2 is in direct contact with the upper surface _{S B2} of the bottom surface _{S B} of the corresponding flange portion, and between the terminal fittings 6c1,6c2 and the lower surface _{S B1} Is provided with a gap d ₁ (see FIG. 8), and the gap d ₁ is filled with an adhesive. Therefore, the variation in the height of the terminal surface between the plurality of terminal fittings can be suppressed, and the flatness of the terminal surface of each terminal fitting can be ensured. Further, since the groove S _B3 is formed in the lower step surface S _B2 immediately below the step, and a part of the adhesive is filled in the groove S _B3 , the height of the terminal surface between the plurality of terminal fittings varies. Can be reliably suppressed.

  FIG. 12 is an equivalent circuit diagram of the coil component 30.

  As shown in FIG. 12, the terminal fittings 6a and 6b are used as a pair of balanced input terminals, that is, a primary side positive terminal electrode IN + and a negative side terminal electrode IN−. The terminal fittings 6e and 6d are used as a pair of balanced output terminals, that is, a secondary side positive terminal electrode OUT + and a negative side terminal electrode OUT−. Terminal fittings 6c1 and 6c2 are used as center taps CT2 and CT2 on the output side, and are short-circuited to each other via land LD1 when mounted. The terminal fittings 6f1 and 6f2 are used as the center tap CT1 on the input side and are short-circuited to each other via the land LD2 when mounted. The wires S1 and S2 constitute the primary winding of the transformer, and the wires S3 and S4 constitute the secondary winding of the transformer.

  As described above, the coil component 30 according to the present embodiment connects the terminal fittings 6c1 and 6c2 via the land LD1 on the mounting substrate, and connects the terminal fittings 6f1 and 6f2 via the land LD2. The configuration can be the same as that of the coil component 1 according to the first embodiment.

  FIG. 13 is a diagram showing the structure of the coil component 40 according to the third embodiment of the present invention, and in particular, a schematic perspective view showing the shape of the drum core 2.

As shown in FIG. 13, the features of the coil component 40 according to this embodiment is that the collar portion 4A, a concave portion 41 on the lower surface _{S B1} of the bottom surface _{S B} of 4B are formed. Recess 41 plays a role of adhesive when bonded to the bottom surface S _B of the flange portion to the corresponding terminal fittings 6a~6f prevents its flow out to remain in place.

Recess 41 of the flange portion 4A side is a region between the terminal fitting 6a, 6b installation area and installation area of the terminal fitting 6c of, provided in a region which does not overlap with the terminal fitting 6a~6c of the lower surface S _B1 It has been. The recess 41 on the flange 4B side is an area between the installation area of the terminal fittings 6d and 6e and the installation area of the terminal fitting 6f, and is an area that does not overlap with the terminal fittings 6d to 6f in the lower step surface S _B1. Is provided. The width of the recess 41 is slightly narrower than the width of the upper surface S _S2 of the outer side surface S _S of the flanges 4A and 4B, and both ends in the width direction of the recess 41 are close to the installation area of the terminal fittings 6a to 6f. ing. Recess 41, the flange portion 4A, it is provided through to the outer side surface S _S of 4B, it does not reach the inner side. The recess 41 is provided in order to minimize the bonding area of the lead frame described later, and the depth, width (planar shape), position, etc. of the recess 41 are particularly limited as long as the purpose can be achieved. Not.

  Further, a deep groove 42 that is narrower and deeper than the recess 41 is formed at the center in the width direction of the flanges 4A and 4B. Although not particularly limited, the deep groove 42 is used for fixing the drum core 2 when the coil component is manufactured. The deep groove 42 extends in the thickness direction of the collar portion so as to penetrate from the outer side surface to the inner side surface of the collar portions 4A and 4B, and crosses the formation region of the recess 41. In the present invention, it is not essential to provide the deep groove 42, and the deep groove 42 may be omitted.

  FIG. 14 is a schematic perspective view showing a state in which the terminal fittings 6a to 6f are attached to the drum core 2 together with the lead frames.

  As shown in FIG. 14, the terminal fittings 6a to 6f are integrated with the lead frame 43. In particular, the terminal fitting 6a is supported by a connecting piece 43a of the lead frame 43, and the terminal fittings 6b and 6c are lead frames. 43 connecting pieces 43b. Similarly, the terminal fitting 6 d is supported by the connecting piece 43 a of the lead frame 43, and the terminal fittings 6 e and 6 f are supported by the connecting piece 43 b of the lead frame 43. As illustrated, the terminal fittings 6 a to 6 f are bonded and fixed to the drum core 2 while being integrated with the lead frame 43, and then separated from the lead frame 43. The terminal fittings 6a to 6c are arranged in order along the width direction of the flange portion 4A, and between the terminal fitting 6a (first terminal fitting) and the terminal fitting 6b (second terminal fitting) in the width direction. The insulation interval is wider than the insulation interval between the terminal fitting 6b (second terminal fitting) and the terminal fitting 6c (third terminal fitting). The configuration of the terminal fittings 6d to 6f is the same.

Here, the terminal fitting 6b and the terminal fitting 6c are connected to each other via a connecting piece 43b, the connecting piece 43b is above the lower surface S _B1 of the bottom surface S _B of the flange 4A is located. In such a structure, if an adhesive is applied to the back surfaces of the terminal fittings 6a to 6f (or a predetermined position on the bottom surface of the collar portion) and the adhesive is fixed to the bottom surfaces Sb of the collar portions 4A and 4B, a fluid adhesive is obtained. The agent tries to spread uniformly on the lower surface of the connecting piece 43b through a slight gap between the connecting piece 43b and the bottom surface Sb. However, as will be described later, when the recess 41 is provided, it is possible to prevent such spreading of the adhesive.

  15A and 15B are schematic side views showing a state in which the terminal fittings 6b and 6c are bonded to the flange portion 4A. FIG. 15A is a configuration without the recess 41 (first embodiment), and FIG. Each of the configurations of this embodiment is shown. The case where the terminal fittings 6e and 6f are bonded to the flange portion 4B is the same as this, and the description thereof is omitted.

As shown in FIG. 15 (a), in the configuration without recesses 41, an adhesive which is between the lower surface S _B1 of the back surface and the flange portion 4A of the terminal fitting 6b flows out in the direction indicated by the arrow F1, also the terminal fitting The adhesive 11C located between the back surface of 6c and the lower step surface S _B1 of the flange 4A flows out in the direction indicated by the arrow F2. As described above, if the rear surface of the lower portion _{T B2} of the bottom portion _{T B} of the terminal fitting 6a~6f and the flange 4A, a gap _{d 1} between the lower surface _{S B1} and 4B are intentionally provided (FIG. 8 (See (b)), the adhesive easily moves, and the adhesive easily diffuses by capillary action. If the adhesive 11C adheres widely to the back surface of the connecting piece 43b, the connecting piece 43b is adhered, and even if the terminal fitting is cut off, it is very difficult to remove the lead frame 43.

On the other hand, as shown in FIG. 15B, in the configuration of the present embodiment having the concave portion 41, the adhesive 11C between the back surface of the terminal fitting 6b and the lower step surface S _B1 of the flange portion 4A is indicated by the arrow F1. It flows in the direction indicated by the adhesive present between the lower surface S _B1 of the back surface of the terminal fitting 6c and the flange 4A is flowing in the direction indicated by the arrow F1. However, when the concave portion 41 is provided, the capillary phenomenon is weakened by widening the gap at that position, and the flow of the adhesive 11C stops at the position of the concave portion 41. Therefore, the adhesive 11C adhering to the back surface of the connecting piece 43b is a little. It is. That is, the adhesive 11C does not flow into the range W2, but remains in the range W1. Therefore, it is possible to easily remove the lead frame 43 (the connecting piece 43b) after the terminal fitting is cut off.

As described above, the coil component 40 according to this embodiment, the flange portion 4A, since the recess 41 in a region which does not overlap with the terminal fitting 6a~6f of the lower surface S _B1 of the bottom surface SB of 4B are formed, the In addition to the effect of the invention according to the first embodiment, it is possible to prevent the adhesive from flowing out when the terminal fittings 6a to 6f are bonded and to prevent the lead frame 43 from being bonded to the flange portions 4A and 4B. Can do. In addition, although this embodiment is a modification of the coil component 1 which has six terminal metal fittings 6a-6f, it is also possible to apply to the coil component 30 which has eight terminal metal fittings demonstrated in 2nd Embodiment. is there.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention, and it goes without saying that these are also included in the present invention. .

  For example, in the above-described embodiment, a horizontal drum core having a winding core portion around which the coil is wound and a pair of flange portions provided at both ends thereof is used as a base around which the coil is wound. A vertical drum core may be used, and other shapes of cores may be used. The number of terminal fittings is not particularly limited.

DESCRIPTION OF SYMBOLS 1,30,40 Coil component 2 Drum core 3 Core part 4A, 4B Eaves part 5 Plate-shaped core 6a-6f Terminal metal fitting 6c1, 6c2, 6f1, 6f2 Terminal metal fitting 7 Coil 7r Remaining wire part 11A, 11B, 11C Adhesive 12 Heater chip 13 Cutter 20 Wire 20e Tip 21 Terminal fitting 33 Lead frame 40 Coil component 41 Recess 42 Deep groove 43 Lead frame 43a, 43b Lead frame connecting piece d ₁ gap d ₂ gap S _B bottom face S _B1 flange the bottom surface of the lower surface S _B2 lower surface of the outer side of the outer side surface S _S1 flange portion of the lower surface S _S flange portion of the bottom portion of the groove S _L terminal fitting of the bottom surface of the upper surface S _B3 flange portion of the bottom surface of the flange portion S _S2 upper portion T _B2 terminal fitting of the bottom portion of the bottom portion T _B1 terminal fitting of the upper surface T _B terminal fitting of the bottom portion of the upper surface S _U terminal fittings of the upper surface S _T flange portion of the outer side surface of the flange Side portions of the lower portion T _S terminal fitting of the bottom part

Claims (10)

A coil formed by winding a wire;
A base that supports the coil;
At least one terminal fitting to which a terminal portion of the coil is connected;
A first adhesive that bonds the terminal fitting to the base;
The base has a first surface to be a mounting surface,
The terminal fitting has a first terminal portion located on the first surface of the base body,
The first surface is provided with a step consisting of an upper step surface and a lower step surface,
The first terminal portion of the terminal fitting is in direct contact with the upper surface;
The coil component, wherein a gap between the first terminal portion of the terminal fitting and the lower step surface is filled with the first adhesive. Further comprising a groove formed in the lower step surface immediately below the step,
The coil component according to claim 1, wherein a part of the first adhesive is filled in the groove.   The said terminal part of the said coil is located above the said upper stage surface, and is connected to the 1st terminal surface of the said terminal metal fitting which overlaps with the said upper stage surface in planar view, The Claim 1 or 2 Coil parts. The base has a second surface orthogonal to the first surface;
The terminal fitting is L-shaped and further includes a second terminal portion located on the second surface,
The coil component according to any one of claims 1 to 3, wherein the second terminal portion is bonded and fixed to the second surface with a second adhesive. The base is a drum core having a core portion around which the coil is wound and a pair of flange portions provided at both ends of the core portion,
The first surface of the base is a bottom surface of the flange;
The coil component according to claim 4, wherein the second surface of the base body is an outer side surface of the flange portion.   The coil component according to any one of claims 1 to 5, comprising a plurality of the terminal fittings.   The coil component according to any one of claims 1 to 6, wherein the first terminal portion of the terminal fitting has a step shape matching the step of the base.   The first terminal portion of the terminal fitting has a second terminal surface located on an extension line of the terminal portion of the coil and lower than the first terminal surface when viewed from the base body. The coil component according to claim 7. Further comprising a recess formed in the lower surface,
The coil component according to any one of claims 1 to 8, wherein the concave portion is provided in a region of the lower step surface that does not overlap the terminal fitting. The terminal fitting includes at least first to third terminal fittings arranged in order in a predetermined direction,
The insulation interval between the first terminal fitting and the second terminal fitting in the predetermined direction is larger than the insulation interval between the second terminal fitting and the third terminal fitting in the predetermined direction. Wide,
10. The coil component according to claim 9, wherein the recess is provided in a region sandwiched between the second terminal fitting and the third terminal fitting on the lower stage surface.

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