JPH06105652B2 - Air core coil - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-core coil, and more particularly to an air-core coil provided with a suction / transport member for facilitating suction / transport during assembly.

Conventional technology A small air-core coil mounted on a printed circuit board is often used to give inductance to the circuit, but it is small and difficult to handle, so when assembled and mounted, it is usually used by a suction transfer machine called a chip mounter. A method of adsorbing and carrying to a predetermined position of soldering on a printed circuit board is adopted.

FIG. 3 shows a configuration diagram of an example of the related art, where FIG. 3 (A) is a front view and FIG. 3 (B) is a side view. In the figure, reference numeral 1 denotes a coil body, and soldering portions 1a and 1b are provided at both ends thereof. Reference numeral 2 is a member for adsorbing and conveying the polymer resin, which is the coil body 1.
The whole is molded. As shown in the figure, the suction and conveyance member 2 has a substantially box shape, and since the upper surface 2a thereof is flat, it can be easily conveyed to a predetermined position on the printed circuit board by sucking it by a chip mounter. Moreover, since the lower surface 2b is also flat, it can be stably placed at a predetermined position on the printed circuit board. The air core coil is small, and if it is left as it is, it will roll and be difficult to handle.
By providing such a suction conveyance member 2, its handling is facilitated.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention By the way, depending on the circuit to be used, there is also a circuit in which the inductance must be set with high accuracy.In such a case, after mounting the air-core coil on the printed circuit board, Finely adjust the inductance by adjusting the distance between adjacent conductors with tweezers. However,
The conventional example shown in FIG. 3 has a structure in which a polymer resin adsorption / transport member 2 is molded over the entire coil body 1 (note that since the adsorption / transport member 2 is a polymer resin, it is used when soldering). It does not melt even if it is passed through a reflow oven or a curing oven.) Therefore, it is not possible to adjust the coil wire spacing after mounting the coil on the printed circuit board, and therefore it cannot be applied to circuits that require highly accurate inductance. However, there was a problem that was not practical.

It is an object of the present invention to provide an air-core coil in which the suction and transfer work can be easily carried out by a chip mounter, and moreover, the distance between adjacent conductors can be adjusted after being mounted on a printed circuit board.

Means for Solving the Problems According to the present invention, a coil body is provided with a member having a flat portion for placing on a printed circuit board and a suction portion having a flat surface for suction conveyance on a surface different from the base portion. Is provided on the outer peripheral surface of
The suction and conveyance member is formed of a low melting point material that is melted by heat when soldering the coil body to the printed board.

Function During assembly and mounting, the chip mounter sucks the suction part and positions it at a predetermined position on the printed circuit board. In this case, since the suction portion has a flat surface, it is easily sucked, while the base portion has a flat surface, so that it can be stably placed on the printed circuit board.
Further, since the member is made of a low melting point material, it is melted at the time of soldering, and its shape is not retained on the coil body after the mounting is completed. Therefore, after the mounting is completed, the spacing between the adjacent conductors of the coil body can be adjusted with tweezers or the like to easily finely adjust the inductance.

First Embodiment FIG. 1 is a configuration diagram of a first embodiment of the present invention, in which FIG. 1 (A) is a plan view, FIG. 1 (B) is a front view, and FIG. 1 (C) is a side view. In the figure, 10 is a coil body, and soldering parts 10a and 10b are provided at both ends thereof. Reference numeral 11 denotes a suction conveyance member, which is generally integrally formed of a suction portion 11a, a protective band portion 11b, and a base portion 11c, and is fitted and fixed to the outer circumference of the coil body 10. The adsorption conveyance member 11 is formed of, for example, an inorganic low melting point material such as paraffin and its composite, or an organic low melting point material such as low molecular weight resin beer acetate, and the outer peripheral surface of the coil body 10. It is provided in. The size of the coil body 10 does not extend over the entire length of the coil body 10 but is a size that closes a part of the coil body 10 in the longitudinal direction, and is extremely small. As shown in the figure, the suction portion 11a is formed, for example, in a rectangular shape (or a circular shape) on the upper surface side of the coil body 10, and has a flat surface so that the chip mounter can easily suck the suction portion 11a. The protective band portion 10b has a shape along the outer peripheral surface of the coil body 10, and has a width, for example, narrower than that of the suction portion 11a in the front view (FIG. 6B). Stand 11c
Has a flat bottom surface and is formed on a surface of the coil body 10 that is in contact with the surface of the coil body 10 that faces the printed circuit board. In a side view (FIG. 7C), the width is formed to be longer than the diameter of the coil body 10. Has been done.

At the time of assembling and mounting, the suction portion 11a is sucked by the chip mounter, conveyed to a predetermined soldering position on the printed circuit board (preliminarily printed with solder cream), and placed on the printed circuit board. In this case, since the upper surface of the suction portion 11a is a flat surface, it is easy to be sucked by the chip mounter, while the base portion 11c has a flat bottom surface and its width is larger than the diameter of the coil body 10. Since it is formed in a large size, it can be stably placed on a printed circuit board (an adhesive is previously applied to the surface facing the suction and conveyance member 11). The printed circuit board on which the coil body 10 is mounted by the chip mounter is carried into the reflow oven, whereby the solder cream (melting point: about 183 ° C) applied on the printed circuit board is melted and soldered. The part 10a is soldered and mounted on a printed circuit board.

At this time, the suction conveyance member formed of the low melting point material
11 is also melted, and due to this melting, the suction and conveyance member 11 does not retain its shape in the coil body 10 and flows down onto the printed circuit board. In this case, since the sucking and conveying member 11 is extremely small as described above, the amount of the sucking and conveying member 11 flowing down onto the printed circuit board due to melting is very small, which poses no practical problem. In this way, the suction conveyance member 11 used during conveyance has its shape reduced after the mounting is completed.
The inductance can be easily fine-tuned by adjusting the spacing between 10 adjacent conductors with tweezers or the like.

FIG. 2 shows a configuration diagram of a second embodiment of the present invention, in which FIG. 2 (A) is a front view and FIG. 2 (B) is a side view. In the figure,
Reference numeral 11 'denotes a suction conveyance member, which is generally a suction portion 11a' and a base portion 11
Each of the c's is configured separately, and is fitted and fixed to the outer circumference of the coil body 10. Similar to the first embodiment, the suction conveyance member 11 'is also made of a low melting point material which is melted by heat when the coil body 10 is soldered to the printed circuit board, like the first embodiment. ′ Is a flat surface of the upper surface, and is formed on the upper surface side of the coil body 10. Further, the bottom of the base 11c 'is a flat surface,
It is formed on the surface of the coil body 10 that is in contact with the surface facing the printed circuit board. Since the operation and effect are similar to those of the first embodiment, the description thereof will be omitted.

EFFECTS OF THE INVENTION As described above, according to the present invention, suction and conveyance are easy, and it is possible to stably mount on a printed circuit board.
In addition, since the member is made of a low melting point material, the suction and conveyance member is melted by soldering and does not retain its shape in the coil body, which allows the conductor interval of the coil body to be adjusted to reduce its inductance. Can be easily fine-tuned.

[Brief description of drawings]

FIG. 1 is a block diagram of the first embodiment of the present invention, FIG. 2 is a block diagram of the second embodiment of the present invention, and FIG. 3 is a block diagram of a conventional example. 10 ... Coil body, 10a, 10b ... Soldering part, 11, 11 '... Adsorption transport member, 11a, 11a' ... Adsorption part, 11b ... Protective band part, 11
c, 11c '... Stand.

Claims (1)

[Claims] 1. An outer surface of a coil body is provided with a member having a flat portion for mounting on a printed circuit board and a suction portion having a flat surface for sucking and conveying on a surface different from the flat portion. An air-core coil, wherein the member is formed of a low melting point material that is melted by heat when the coil body is soldered to the printed board.