JP2589781Y2 - Surface mount type electronic components - 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 electronic component such as a surface mount type potentiometer.

[0002]

2. Description of the Related Art FIGS. 6 to 12 show the structure of a conventional surface mount type electronic component. The example of the figure shows the case of a surface mount potentiometer. FIG. 6 shows the manufacturing process. Lead frames LF ₁ , LF ₂ and LF ₃ are continuously formed by punching from a strip-shaped conductive plate. The lead frame LF ₃ is cut at the central portion, the electronic components 100 are electrically, mechanically mounted on the cut end, ie In the other lead frame LF _1, LF ₂ central portion .

[0003] In this example, the electronic component 100 is a resistor substrate for forming a potentiometer. In other words, as shown in FIG. 7, the resistor substrate for the potentiometer has the current collector 5 adhered to one surface of the insulating plate 4.
A resistance film 6 is formed in a semicircular shape surrounding the current collector 5.
And electrodes 7, electrically connected to both ends of the resistance film 6,
8 and 9 are formed.

The end ₃ of the lead frame LF ₃ is soldered to the electrode 7, and the lead frames LF ₁ , LF
₂ is soldered to the center, and the electronic component 100 is attached to the lead frames LF ₁ , LF ₂ , LF ₃ by this soldering. After the electronic component 100 is attached, the part including the electronic component 100 is inserted into the mold of the resin molding machine, and FIG.
A case 11 surrounding the electronic component 100 is formed as shown in FIG. The case 11 has a circular hole 12 formed on the upper surface side, and a rotating shaft 13 shown in FIG.
A slider 14 is supported on the rotating shaft 13.
Slides over the current collector 5 and the resistive film 6 shown in FIG. 7 to form a potentiometer. The rotating shaft 13 is held down by a metal cover 16 via an O-ring 15 and is rotatably supported in the case 11.

In the state where the case 11 is formed, the lead frames LF ₁ , LF ₂ , LF ₃ are linearly led out from the side surface of the case 11 as shown in FIG. 11 is bent toward the bottom side along the side surface to form a vertical surface portion V, and is again bent outward to form external lead terminals 1, 2, 3 parallel to the bottom surface. FIGS. 9 and 10 show a case where a so-called outer-type surface mount component is formed in which the external lead-out terminals 1, 2, and 3 protrude outside the case 11. As shown in FIGS. The terminals 1, 2, and 3 may be bent toward the bottom of the case 11 to form a so-called inner mounting component. In any case, the rear surfaces of the external lead terminals 1, 2, 3 protrude from the bottom surface of the case 11 by, for example, about 1 to 2 mm and are supported.

FIGS. 13 and 14 show the mounting state of the outer and inner mounting parts. As shown in the figure, the bottom surfaces of the external lead terminals 1, 2 and 3 are
Is soldered by solder 19. Solder 19 with this
Is raised in contact with the vertical surface portion V and is firmly fixed.
That is, the vertical surface portion V functions as a portion which is always necessary to obtain the mechanical strength of soldering.

[0007]

Conventionally, in order to form a vertical surface V on the lead frames LF ₁ , LF ₂ , LF ₃ , a bending process is performed after the case 11 is formed.
During this bending process, the lead frames LF ₁ , LF ₂ , LF
_A stress may be applied to a connection portion between the electronic component 100 and the electronic component 100, and the connection portion may be separated and a connection failure accident may occur.

An object of the present invention is to provide a surface-mount type electronic component in which a connection failure does not occur between the lead frame and the electronic component.

[0009]

The electronic component is made of a resin material.
The electronic components are housed in a case
Is electrically connected to the other end and bent twice outside the case
And a vertical surface portion and a horizontal surface portion are formed.
The inner surface is along the outer surface of the case, and
Each vertical surface is soldered to the wiring conductor of the printed circuit board
Mounted electronic components having a structure with a lead frame
In the above lead frame, the stepped part has the upper part
Inside the case and the lower part outside the case
It is formed, and the electronic component is mounted on the upper part,
Exposing the bottom of the lower part to the bottom of the case,
The exposed part is an external lead-out terminal that constitutes the horizontal part
A part to be soldered to the wiring conductor of the printed circuit board
And a tongue piece having a width smaller than the width from the external lead-out terminal.
To the outside of the side of the case.
Fold along the side of the base to make the vertical surface
The part where the outer surface of the piece is soldered to the wiring conductor of the printed circuit board
It is said.

Further, in this invention, only the tongue protrudes from the side of the case to the outside from the external lead-out terminal exposed on the bottom surface of the case, and the tongue is bent along the side of the case to form a vertical portion. To form an inner terminal type surface mount electronic component. According to the configuration of the present invention, the portion constituting the vertical surface portion is a tongue piece smaller than the cross-sectional area of the external lead-out terminal in both the terminal type of the outer terminal type and the inner terminal type. Therefore, the force required for bending is small. As a result, the stress applied to the connection portion with the electronic component in the case is reduced, and there is no possibility that the connection with the electronic component is separated due to the bending process.

[0011]

1 to 5 show an embodiment of the present invention.
In this invention, as shown in FIG. 2, the electronic components 10 are connected to the lead frames LF ₁ , LF ₂ , LF ₃ in the state of the hoop material.
A step ST is formed in advance between the connection portion to the terminal 0 and the portions to be the external lead-out terminals 1, 2, and 3, and the electronic component 100 is mounted on the upper surface of the upper side of the step ST. For this reason, in this embodiment, the back surface of the insulating plate 4 constituting the electronic component 100 is provided on the back surface of FIG.
The electrodes 7, 8, 9 are formed as shown in FIG. This electrode 7,
Numerals 8 and 9 are electrically connected to the current collector 5 formed on the front side and both ends of the resistive film 6 through the through holes or the side surfaces of the insulating plate 4. The connection between the lead frames LF ₁ , LF ₂ , LF ₃ and the electronic component 100 is made by, for example, melting solder plating applied to the electrodes 7, 8, 9. This soldering causes the electronic component 100 to be connected to the lead frame LF ₁ , ₁ . LF ₂ , LF ₃
The upper part is electrically connected and held mechanically.

On the lower side of the step ST formed on the lead frames LF ₁ , LF ₂ , LF ₃ , tongue pieces 21, 22, 23 which are cut and raised after forming the case to form a vertical surface portion V
Is provided. In order to form the tongues 21, 22, 23, slits SL are formed in advance, and after the case 11 is formed, the tongues 21, 22, 23 are bent along the side surface of the case 11 to form the vertical surface portion V. Form.

The case 11 is formed by inserting a mounting portion of the electronic component 100 into a mold of a resin molding machine while keeping the hoop shape shown in FIG. 2 and molding the electronic component 100 to form the case 11 shown in FIG. As shown in FIG. 4, a circular hole 12 is formed on the upper surface of the case 11, and the rotating shaft 13 is inserted into the circular hole 12. As shown in FIG.
5 and held in the case 11 by being held down by the metal cover 16.

In this embodiment, the slider 14 rotated by the rotating shaft 13 is formed of a metal plate having a spring property, and the contactor 14A which contacts the current collector 5 by the metal plate.
And a slider 14B slidingly contacting the resistive film 6 is formed as one body. Further, a contact grease 10 is applied to a sliding contact portion between the slider 14A and the current collector 5. Case 11
Is formed, a step S of the lead frames LF _{1 to} LF ₃ is formed.
The lower back surface of T is exposed on the bottom surface of the case 11, and the exposed portions constitute the external lead terminals 1, 2, and 3. The amount of protrusion of the external lead terminals 1, 2, 3 from the bottom surface of the case 11 is about 1 to 2 mm from the bottom surface of the case 11.

After the case 11 is formed, the tongue pieces 21, 22, and 23 are bent by a press machine as shown in FIG. In this bending process, the part to be bent is tongue piece 2.
1, 22, 23, and since the cross-sectional area of the portion to be bent is small, bending can be performed with a small force.
At this point, no stress is transmitted to the electronic component 100 in the case 11. In addition, since the steps ST are formed in the lead frames LF _{1 to} LF ₃ in the case 11 in particular, even if stress is applied from the outside, the stress is reduced to the steps S.
The light is absorbed by the bent part constituting T and is not transmitted to the connection part with the electronic component 100.

By bending the tongue pieces 21, 22, 23, a vertical surface portion V is formed corresponding to the external lead-out terminals 1, 2, 3. A vertical surface portion V is formed, and the slider 14 and the rotating shaft 1 are formed.
3, O-ring 15, when mounting the metal cover 16 for cutting the lead frame LF ₁ ~LF _3. Figure 4 shows the cutting position
By cutting along the cutting line LI ₁ shown in FIG.
The outer terminal type surface mount type electronic component shown in FIG. 1 in which H, 2H, and 3H are left is obtained. Also, tongue pieces 21, 22, 2
By cutting along the cutting line LI ₂ that leaves the respective thicknesses of No. 3, the inner terminal type surface mount electronic component shown in FIG. 5 can be obtained.

[0017]

As described above, according to the present invention, the members for forming the vertical surface portion V are provided with the tongue pieces 21, 22, 2
3, and the tongue piece 21,
The force for bending the 22, 22 can be small. Therefore, the stress applied to the electronic component 100 through the lead frames LF _{1 to} LF ₃ is small, and there is no occurrence of an accident that the connection portion with the electronic component 100 is peeled off.

Further, in the present invention, the bent portion for forming the step ST is buried inside the resin material forming the case 11, so that the stress generated when the tongue pieces 21, 22, 23 are bent is It is absorbed by the bent portion and is not transmitted inside. Therefore, also in this respect, the lead frames LF _{1 to} LF
₍₃₎ It is possible to provide a highly reliable surface-mounted electronic component in which the separation of the electronic component is less likely to occur.

In the above embodiment, the case where the electronic component is a potentiometer has been described. However, it can be easily understood that the present invention can be applied to other electronic components such as a chip type rotary switch, a digital setting switch, and a trimmer type capacitor. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective view for explaining a manufacturing process of the surface-mounted electronic component according to the present invention.

FIG. 3 is a bottom view for explaining the structure of the back surface of the electronic component used in the embodiment shown in FIG. 1;

FIG. 4 is a perspective view for explaining a state in which the case of the embodiment shown in FIG. 1 is formed.

FIG. 5 is a sectional view showing a modified embodiment of the present invention.

FIG. 6 is a perspective view for explaining a conventional technique.

FIG. 7 is a plan view illustrating the structure of a conventional electronic component.

FIG. 8 is a perspective view for explaining a manufacturing process of a conventional technique.

FIG. 9 is a cross-sectional view illustrating a structure of a conventional outer terminal type surface mount electronic component.

FIG. 10 is a sectional view taken along line AA of FIG. 8;

FIG. 11 is a cross-sectional view for explaining the structure of a conventional inner terminal type surface mount electronic component.

FIG. 12 is a sectional view taken along line BB of FIG. 11;

FIG. 13 is a cross-sectional view for explaining a mounting state of a conventional outer terminal type surface mount electronic component.

FIG. 14 is a cross-sectional view for explaining a mounting state of a conventional inner terminal type surface mount electronic component.

[Explanation of symbols]

1,2,3 External lead terminals 1H, 2H, 3H Horizontal protrusion 4 Insulating plate 5 Current collector 6 Resistive film 7,8,9 Electrode 100 Electronic component 10 Contact grease 11 Case 12 Circular hole 13 Rotating shaft 14A, 14B Sliding child 15 O-ring 16 the metal cover 17 printed circuit board 18 wiring conductor 19 solder V vertical surface portion 21, 22, 23 tongues LF _1, LF _2, LF ₃ leadframe ST step

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-112204 (JP, A) JP-A 63-121408 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01C 1 / 14,10 / 00,10 / 32-10/36

Claims (3)

(57) [Scope of request for utility model registration] An electronic component is housed in a case made of a resin material, and one end of the electronic component is electrically connected in the case.
The other end is bent twice outside the above case and
Part and a horizontal part are formed, and the inner surface of the vertical part is
Along the outer surface of the ground, the horizontal surface and the vertical surface
Lead soldered to the wiring conductors of the printed circuit board
In the surface-mount type electronic component having a structure having a frame, the lead frame has an upper portion with an upper portion of the case.
Formed inside and the lower part as outside of the case
The electronic component is mounted on the upper part, and the lower part is mounted.
And expose the bottom of the case to the bottom of the case.
As an external lead-out terminal that constitutes the horizontal surface,
And solder it to the wiring conductors on the board.
From the external lead-out terminal, insert a tongue piece with a width
The tongue is formed so as to protrude from the outside of the side, and this tongue is
Fold along the to make the above-mentioned vertical surface, and the outer surface of this tongue piece
Surface mounting electronic component characterized in that it is a part component be soldered to the printed circuit board wiring conductor. 2. A said external lead terminal according to claim 1, the horizontal projection projecting from a side surface of the case provided with the tongue, a surface mount electronic device that the outer terminal structure by projecting the horizontal projection. In the external lead terminals of 3. The method of claim 1, wherein, in the bent portion of the tongue by cutting the lead frame, a surface mount electronic device that the inner terminal structure.