JPH08107001A - Connection structure of surface mounting electronic part and circuit substrate of surface mounting electronic part - Google Patents

Abstract

PURPOSE: To provide a surface mounting electronic part which has good soldering wettability to a circuit substrate and enables high density mounting of a circuit substrate without misregistration to a land and its connection structure. CONSTITUTION: An electronic part 11 is provided with a terminal 13 extended downwards from a side surface of a main body 2 along the side surface. The terminal 13 is formed by performing surface treatment such as plating desirably, for plate-like or rod-like metal. It is led out to an outside of a side surface from an inside of the main body 2, bent downwards along the side surface and extended so that an end edge 14 of the terminal 13 is almost flush with a lower surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between a surface mounting electronic component capable of increasing the mounting density of a circuit board and a circuit substrate of the surface mounting electronic component.

[0002]

2. Description of the Related Art Conventional surface mount electronic components of this type are
For example, its side surface is configured as shown in FIG. 6 or 7. In FIG. 6, a surface mount electronic component (hereinafter referred to as an electronic component) 1 is an electronic component main body (hereinafter referred to as a main body) 2
And a plurality of metal terminals 3 (two shown in the figure). The metal terminal 3 extends from the side surface of the main body 2 in the lower surface direction, and further has a flat surface portion 4 which is bent along the lower surface toward the inner surface of the lower surface.

In FIG. 7, the electronic component 6 comprises a main body 2 and a plurality of metal terminals 8 (two shown in the figure). The metal terminal 8 extends from the side surface of the main body 2 in the lower surface direction, and further has a flat surface portion 9 which is flush with the lower surface and is bent outward of the lower surface.

When the electronic components 1 and 6 are soldered to a circuit board (not shown), the flat portions 4 and 9 are soldered to the lands provided on the circuit board.

[0005]

However, the surface-mounting electronic components 1 and 6 having such a structure have the following problems. 1. It is necessary to process the bent portion R on the terminals 3 and 8 in order to form the flat portions 4 and 9, and cracks or the like occur in the metal terminal of the bent portion R or the surface-treated plating. Solder wettability deteriorates.

2. Since the electronic parts 1 and 6 have large flat areas 4 and 9, the electronic parts 1 and 6 may be moved by the influence of buoyancy caused by the molten solder, and the positions of the electronic parts 1 and 6 may be displaced with respect to the land of the circuit board. is there. 3. Due to the area occupied by the flat portions 4 and 9 of the electronic components 1 and 6, the circuit provided on the circuit board on the lower surface side of the main body 2 is restricted. Further, in the case of the electronic component 6, the area occupied by the circuit board becomes large, and there is a limit to high-density mounting in the wiring of the circuit board. An object of the present invention is to solve the above-mentioned problems. It has good solder wettability with respect to a circuit board and can be mounted on a circuit board at a high density without misalignment with a land. It is to provide a component and its connection structure.

[0007]

In order to achieve the above object, in an electronic component according to the present invention, a terminal led out from a side surface of an electronic component main body is provided along the side face in a lower surface direction of the electronic component main body. It is extended, and the end edge of the terminal is on the same plane as the lower surface or further downward from the lower surface by up to 2 m.
It is characterized in that it extends in a substantially straight line.

In addition, the terminal led out from the lower surface of the electronic component body has an edge of the terminal that is 2 m at the maximum downward from the lower surface.
It is characterized in that it extends in a substantially straight line.

Further, the edge of the terminal is a cut surface cut along a surface substantially perpendicular to the length direction of the terminal.

In the connection structure of the electronic component to the circuit board according to the present invention, the edge of the terminal on the lower surface side of the electronic component body is soldered by abutting against the land of the circuit board. Characterize.

[0011]

According to the present invention, with the above-described structure, it is possible to solder the terminal of the electronic component having good solder wettability to the land having a small area on the circuit board.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described in detail with reference to FIGS. However, the same parts as those of the above-described conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

The electronic component 11 is composed of a main body 2 and a plurality of terminals 13 (two shown in the figure) extending from the side surface to the lower surface along the side surface. Although not shown, the main body 2 has a variable resistor in which a slider slides on a resistance film formed on an insulating substrate, and an overlapping area of a fixed electrode formed on a stator and a movable electrode formed on a rotor. It is an electric element such as a passive component or an active component which is a variable capacitor to be changed.

The terminals 13 can be soldered to a plate-shaped or rod-shaped metal by surface treatment such as plating, and are led out from the inside of the main body 2 to the outside of the side surface.
Along the side surface, the end surface 14 of the terminal 13 is formed in the direction of the lower surface of the main body 2 and extends substantially flush with the lower surface.

In the electronic component 11 having such a structure, the end edge 14 of the terminal 13 to be soldered serves as a ground plane, and the end edge 14 is a cut surface cut along a plane substantially perpendicular to the length direction of the terminal 13. To solder the electronic component 11 to the circuit board 15, first, cream solder is applied to the lands 16 provided on the circuit board 15. Next, the electronic component 11 is mounted on the cream solder and heated in a reflow oven or the like, so that the electronic component 11 is soldered to the circuit board 15. At this time, the solder fillet 17 is formed on the vertical surface side of the terminal 13, as shown in FIG.

Next, a second embodiment according to the present invention will be described.
This will be described in detail with reference to FIGS. However, the same parts as those of the above-described conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

The electronic component 21 includes a main body 2 and a plurality of terminals 23 extending downward from the lower surface along the side surface.
(Two are shown in the figure).

The terminal 23 is made of a plate-like or rod-like metal which is preferably subjected to surface treatment such as plating.
It is led out from the inside of the main body 2 to the outside of the side surface, is bent toward the lower surface of the main body 2 along the side surface, and the end edge 24 of the terminal 23 extends downward from the lower surface in a substantially linear shape up to a maximum of 2 mm.

In the electronic component 21 having such a configuration, the end edge 24 of the terminal 23 to be soldered serves as a ground plane, and the end edge 24 is a cut surface cut along a plane substantially perpendicular to the length direction of the terminal 23. To solder the electronic component 21 to the circuit board 15, first, cream solder is applied to the lands 16 provided on the circuit board 15. Next, the electronic component 21 is mounted on the cream solder and heated in a reflow oven or the like, so that the lower surface of the main body 2 of the electronic component 21 is soldered to the circuit board 15 in a raised state. At this time, the solder fillet 17 is formed on the vertical surface of the terminal 23, as shown in FIG.

Therefore, since a gap is formed between the main body 2 of the electronic component 21 and the circuit board 15, flux does not accumulate on the lower surface of the main body 2 and the electronic component 21 is prevented from deterioration of insulation resistance and corrosion. Is effective for.

Further, a third embodiment according to the present invention will be described in detail with reference to FIG. However, this embodiment shows an example in which the main body 32 is applied to a variable resistor. The electronic component 31 includes a main body 32 and three terminals 33, 35, 35 extending downward from the lower surface of the main body 32.

In the main body 32, a rotor 32b having a slider (not shown) housed therein is rotatably attached to an insulating substrate 32a having a resistance film (not shown) formed thereon.

The terminals 33, 35, 35 are made of a plate-like or rod-like metal, preferably surface-treated by plating or the like. One end of the terminal 33 is electrically connected to the slider, one ends of the terminals 35 and 35 are electrically connected to the resistance film and soldered to the insulating substrate 32a with solder 32c.
The other ends of the terminals 33, 35, 35 extend downward from the lower surface of the main body 32 in a substantially linear manner at a maximum of 2 mm.

In the electronic component 31 having such a configuration, the edge 34 of the terminal 33 to be soldered serves as a ground plane, and the edge 34 is a cut plane cut along a plane substantially perpendicular to the longitudinal direction of the terminal 33. The electronic component 31 will be described with reference to FIG.
By applying cream solder to the lands 16 provided on the circuit board 15 and then mounting the electronic component 31 on the cream solder and heating it in a reflow oven or the like, the circuit board 1
5 is soldered with the lower surface of the main body 32 of the electronic component 31 being lifted. At this time, the solder fillet 17 is formed on the vertical surface of the terminal 33, as in FIG.

Therefore, since a gap is formed between the main body 32 of the electronic component 31 and the circuit board 15, flux does not accumulate on the lower surface of the main body 2 and the electronic component 31 is prevented from deterioration of insulation resistance and corrosion. Is effective for.

Further, when the present embodiment is applied to an existing lead type electronic component, for example, a variable resistor, the main body 32
The surface-mounting electronic component can be easily obtained by cutting the terminal (shown by the alternate long and short dash line in FIG. 5) 43 to have a length from the lower surface of the main body 32 to the edge 34 of 2 mm or less.

The terminals 13 shown in the first and second embodiments,
23 does not require a processing step for molding the flat surface portions 4 and 9 unlike the terminals 3 and 8 of the conventional example, so that the terminal 1 can be easily formed.
3,23 can be molded.

Further, the terminals 23 shown in the second and third embodiments,
Maximum length from each main body 2, 32 of 33 is 2 mm
The reason for this is that the flux is not accumulated between the main bodies 2 and 32 and the circuit board 15, which is a sufficient distance.
In addition, the instability of the electronic components 21 and 31 at the time of soldering due to the excessively wide interval is eliminated, and the circuit board 15 is eliminated.
This is to prevent the height from the upper surface of the electronic components 21 and 31 to be too high.

[0029]

As described above, in the electronic component for surface mounting according to the present invention, there is no bent portion in the terminal to be soldered to form the solder fillet, so that the solder wettability is good. Further, since the ground surface of the terminal is a cut surface and is small, the electronic component does not float and move due to surface tension due to the melted solder, and the positional accuracy with respect to the land provided on the circuit board is improved. Further, since the ground plane of the terminal is small, the area of the land may be small, and the effective area where wiring is possible for the circuit board can be widened, which enables high-density mounting.

[Brief description of drawings]

FIG. 1 is a side view of a first embodiment of an electronic component according to the present invention.

FIG. 2 is a partial cross-sectional view showing a state where the electronic component of FIG. 1 is soldered to a circuit board.

FIG. 3 is a side view of a second embodiment of the electronic component according to the present invention.

FIG. 4 is a partial cross-sectional view showing a state in which the electronic component of FIG. 3 is soldered to a circuit board.

FIG. 5 is a side view of a third embodiment of the electronic component according to the present invention.

FIG. 6 is a side view of a conventional electronic component.

FIG. 7 is a side view of another conventional electronic component.

[Explanation of symbols]

 2,32 Electronic component main body 11,21,31 Surface mounting electronic component 13,23,33,35 Terminal 14,24,34 Edge 15 Circuit board 16 Land

Claims (4)

[Claims] 1. A terminal led out from a side surface of an electronic component main body is extended along the side surface toward a lower surface of the electronic component main body, and an edge of the terminal is flush with the lower surface or from the lower surface. A surface-mounting electronic component having a substantially straight line extending up to 2 mm further downward. 2. An electronic component for surface mounting, characterized in that a terminal led out from the lower surface of the electronic component main body has an end edge of the terminal extending downward from the lower surface in a substantially linear shape at a maximum of 2 mm. 3. The surface mount electronic component according to claim 1, wherein the edge of the terminal is a cut surface cut along a surface substantially perpendicular to the length direction of the terminal. . 4. An electronic component circuit board for surface mounting, wherein an edge of the terminal on the lower surface side of the electronic component body is soldered by abutting against a land of the circuit substrate. Connection structure.