JP2528106Y2 - Surface mount type coil parts - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type coil component such as a transformer and an inductor, and more particularly to a structure of a lead portion of a coil terminal between a case for protecting a coil mounted on the base and the base.

[0002]

[Problems to be solved by the prior art and the invention] FIG.
(A) is a side view showing a surface mount type pulse transformer which is an example of a conventional coil component. A coil 3 wound around a toroidal core is fixed on a plastic base 1A via a double-sided adhesive tape 2 or the like. The terminal 3a of the coil 3 is soldered to the terminal 4 fixed to the end face of the base 1A. However, according to the conventional structure, it is impossible to automatically mount the coil 3 on a printed circuit board, and since the coil 3 is exposed, the coil 3 cannot be protected.

FIG. 5 (B) shows another conventional example of a coil component. A coil 3 is mounted on a base 1B and transfer-molded integrally with a terminal 6 formed of a lead frame by a resin 5, and the terminal 6 is formed of a resin 5. The surface is mounted along the outer wall of the device. Although this structure is highly reliable, it is expensive, and since the resin 5 is molded in the flow process of the lead frame and further includes a bending process, the number of series of processes is large, and the production time is long. There was a problem that sex was bad.

In order to solve such a problem, it is conceivable to cover the base with a case. If the case is fixed to the base to cover the coil, a gap must be formed between the base and the case to pull out the coil terminal to the terminal side. If the case is insufficiently protected, and if the gap is too small, there is a problem that the coil terminal may come into contact with the base or the corner of the case and the thin wire coil may be broken.

The present invention has been made in view of the above problems, and when realizing a structure in which a case is connected to a base in a surface mount type coil component, protection of the helical portion of the coil terminal can be sufficiently performed and the base and the case can be protected. An object of the present invention is to provide a structure in which disconnection due to contact of a coil terminal with a corner portion of the cable does not easily occur.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a surface mount type coil component having a structure in which a coil is fixed to a surface of a base, a terminal for fixing a coil terminal is fixed to an outer periphery of the base, and a case is covered on the base. A gap for drawing out the terminal of the coil is formed between the base and the lower side of the case, and an upper corner portion of the base and the inner side of the lower side of the case facing each other through the gap are chamfered.

[0007]

In the present invention, the upper corner of the base and the inner side of the lower side of the case which are opposed to each other with a gap therebetween are chamfered, so that the gap for pulling out the coil end is sufficiently secured and this gap is also secured. Therefore, a structure in which the lower side of the case is close to the coil terminal can be realized.

[0008]

1 and 2 are longitudinal sectional views showing one embodiment of a coil component according to the present invention, respectively, for coil extraction portions on both sides of a base, and FIGS. 3 (A), 3 (B) and 3 (C) respectively show the same. FIG. 4 is an exploded perspective view of the embodiment, and FIG. 4 is a front view, a side view, and a plan view of the embodiment. 1 is almost 4 made of plastic
The rectangular base 3 is a coil fixed on the surface thereof, and is wound around a toroidal core to constitute a pulse transformer. Reference numeral 4 denotes a terminal molded integrally with the base 1 so as to protrude from two opposite sides of the base 1 of the embodiment, and 8 denotes a plastic case. The base 1 of the present embodiment is a wholly aromatic polyester-based thermoplastic liquid crystal polymer (Cider (registered trademark) manufactured by Nippon Petrochemical Co., Ltd.)
Consisting of rod-shaped rigid molecules, and has heat resistance (melting point of about 420 ° C.), strength, weather resistance,
It has excellent dimensional stability. As an example, the base 1 has a width of about 4 mm × about 5 mm. The base 1
The upper corner 1a of the two sides on which the terminal 4 is fixed is R
It is chamfered so as to form a surface or an inclined surface as shown. On the other hand, the inner side 1e of the lower side 1d of the surface of the case 8 on the coil terminal lead-out side is chamfered so as to form an R surface or an inclined surface as shown.

The connection structure of the case 8 to the base 1 is as follows. Projections 1b are formed on the surface of the base 1, that is, at four corners of the mounting surface of the coil 3. On the other hand, the case 8 is a plastic case having a substantially quadrangular shape with a lower opening.
The case 8 of the present embodiment is made of a thermoplastic and heat-resistant liquid crystal polymer similarly to the base 1, and has stoppers 8a formed at four corners inside thereof, and extends downward on two opposite sides of the lower surface opening. An extension piece 8b is formed, and a locking piece 8c is formed on the inner surface of the extension piece 8b. On the other hand, a concave locking portion 1c for locking the locking piece 8c is formed on two sides of the base 1 where the terminal 4 is not fixed.

When assembling the coil component, the coil 3 is placed on the base 1 so that the coil 3 is located in a region surrounded by the protrusion 1b of the base 1. As a result, the horizontal movement of the coil 3 on the base 1 is prevented by the protrusion 1b, and the coil 3 is positioned. In this manner, the coil terminal 3a is wrapped around the terminal 4 in a state where the coil 3 is prevented from freely moving, and soldered 9 (see FIG. 1). Then, the adhesive is dropped from the upper portion of the coil 3 to the base 1 and cured, thereby fixing the coil 3 to the base 1. Next, the case 8 is put on the base 1, the locking claw 8 c is pressed against the side surface of the base 1, and the extension piece 8 b is pushed in while being opened, and the locking claw 8 c is inserted into the concave locking portion 1 c on the side surface of the base 1. At the same time that the base 1 is prevented from falling out by being locked, the protrusion 1b of the base 1 comes into contact with the stopper 8a, so that the base 1 is prevented from further entering the case 8. Thus, in the state where the case 8 is fixed to the base 1, as shown in FIG. 1, a gap G for drawing out the coil end 3 a is formed between the base 1 and the lower side 8 d of the case 8. This gap G
Can be made large by providing the chamfered portions 1a and 8e of the base 1 and the case 8, so that as shown in FIG. A structure in which the cover portion 10 is sufficiently covered can be realized. As shown in FIG. 1, when the coil end 3a is pulled out from the lower side of the core, the coil end 3a may come into contact with the chamfered portion 1a on the base 1, but this contact portion is chamfered. Therefore, the occurrence rate of disconnection is reduced. Also, as shown in FIG. 2, when the coil terminal 3a is pulled out from the upper side of the core, the coil terminal 3a may come into contact with the chamfered portion 1e on the lower side of the case 8. Is less.

In the present embodiment, the outer surface 8f of the lower side 8d of the case 8 is connected to the coil end portion 1 of the terminal 4 in order to further enhance the protective effect of the case 8 on the coil end 3a.
This prevents the coil 3 from breaking due to an object colliding with the coil terminal bar 10 or its vicinity during an assembling operation or the like.

In the above-described embodiment, an example has been described in which the base 1 forms a quadrangle, but the base 1 may be formed in another polygon or a circle. The case 8 may be fixed to the base 1 by other means such as bonding.

[0013]

According to the present invention, by providing the coil component with the case, the coil component can be provided which can protect the coil and can be automatically mounted, and can be manufactured more easily than the integrally molded type. It goes without saying that a gap for drawing out the terminal of the coil is formed between the base and the lower side of the case, and the upper corner of the base and the inner side of the lower side of the case facing each other through the gap are chamfered. Therefore, a gap for pulling out the coil end can be sufficiently ensured, and a structure in which the coil end portion is sufficiently covered can be realized. Further, since the contact portion of the coil terminal is chamfered, the rate of occurrence of disconnection due to the coil terminal contact is reduced, and the yield is improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a coil component according to the present invention.

FIG. 2 is a side sectional view showing the opposite side of the coil component of FIG. 1;

FIGS. 3A, 3B, and 3C are a front view, a side view, and a plan view of the embodiment, respectively.

FIG. 4 is an exploded perspective view of the embodiment.

FIG. 5A is a side view illustrating an example of a conventional coil component, and FIG. 5B is a cross-sectional view illustrating another example of a conventional coil component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1A, 1B Base 1a Chamfered part 1b Projection 1c Locking part 2 Double-sided tape 3 Coil 4, 6 Terminal 5 Resin 8 Case 8a Stopper 8b Extension piece 8c Locking claw 8d Lower side 8e Chamfered part G Gap

Claims (1)

(57) [Scope of request for utility model registration] 1. A surface mounting coil component having a structure in which a coil is fixed to a surface of a base, a terminal for winding a coil terminal is fixed to an outer periphery of the base, and a case is covered on the base, a gap for drawing out the terminal of the coil. Is formed between the base and the lower side of the case, and the upper corner of the base and the inner side of the lower side of the case facing each other through the gap are chamfered.