JPH054801B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is directed to the use of a metal material for providing a metal member in a mold die when molding a main body such as a synthetic resin, such as a chip-type variable resistor. This invention relates to an electronic component in which a reinforcing metal piece is embedded during molding of the piece or main body.

<Conventional technology> Conventional electronic components with metal pieces embedded inside the main body are
For example, as shown in Fig. 5, the main body 1 is made of synthetic resin, etc.
A metal piece 2 is embedded therein, and its end protrudes from the surface of the main body 1.

This metal piece 2 is set in the mold for supplying a metal member or for reinforcement when molding the main body using a mold, and is embedded in the main body 1 after molding. Furthermore, the portion protruding from the main body 1 is cut away.

<Problems to be Solved by the Present Invention> In the electronic component as described above, the end of the metal piece 2 protruding from the main body 1 is cut off, and as shown in FIG. However, due to the structure of the cutting machine, the ends of the metal pieces 2 often protrude slightly as shown in FIG. 6.

If the end of the metal piece 2 protrudes from the surface of the main body 1 even slightly in this way, when it is mounted at high density on the printed circuit board 3 as shown in FIG.
contact with the metal piece 2 protruding from the solder 4
This caused a problem in that the metal piece 2 came into electrical contact with another electronic component 5, resulting in a shorted state.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and a metal piece made up of a part of the metal frame material is incorporated into the main body by insert molding. In the electronic component, the weak point for cutting provided at a required part of the metal piece located slightly inside the surface of the main body is the cutting part of the metal piece, and the cutting part of the metal piece remaining inside the main body is It is positioned slightly inside the main body surface.

<Embodiment> FIGS. 1 and 2 show a chip type variable resistor as an embodiment of the present invention. Reference numeral 11 denotes a box-shaped main body made of synthetic resin, and the bottom part 12 of this main body 11
An insulating substrate 13 is provided on top, and a slider 16 integrated with a driver plate 15 is rotatably fixed to the upper part of the inner terminal 14 rising from the center of the bottom 12. The contact 17 is brought into contact with the arc-shaped resistive film 18 on the insulating substrate 13.

19, 20, and 21 are external terminals, all of which are embedded in the bottom 12 of the main body 11. The external terminal 19 is formed integrally with the middle terminal 14. The external terminals 20 and 21 have exposed portions 20a and 21a on the inner bottom surface of the main body 11.
0a is electrically connected to one end of the resistive film 18, and the exposed portion 21a is electrically connected to the other end of the resistive film 18 by solder 22, respectively.

By the way, when molding the main body 11, the external terminal 20 is integrally connected to the metal piece 23 via the cutting weak point 23a, which is a part where the mechanical strength is reduced by a groove-shaped notch provided in the metal piece. The external terminal 21 is integrated with the reinforcing metal piece 24 via a groove-shaped cutting weak point 24a. Note that the weak points 23a and 24a for cutting are both attached to the main body 1.
It is provided slightly inside the surface of 1.

After molding the main body 11, the metal pieces 23 and 24 are cut at the weak point 23 for cutting.
It has been excised from a, 24a. Since the weak points 23a and 24a for cutting are provided slightly inside the surface of the main body 11, the metal pieces 23 and 24
After cutting, the cut surfaces of the weak point parts 23a and 24a are not exposed on the surface of the main body 11.

3a, b, and c show the order in which the ends of the metal pieces 26 protruding from both ends of the synthetic resin main body 25 are cut off.

The metal pieces 26 to be incorporated into the main body 25 include those that constitute metal terminals within electronic components;
Some are used for reinforcement.

That is, these metal pieces 26 are connected by a metal frame material obtained by press-forming metal plates, etc., but during processing after forming the insert, due to the weight of the main body. Since positioning becomes difficult, providing the metal piece 26 connected to the metal frame material stabilizes the main body and facilitates processing.

The portions of these metal pieces 26 that protrude from the main body 25 are finally cut off. First, FIG. 3a shows a state in which a metal piece 26 having a weak point 27 for cutting is buried, and FIG. It is in a state of being pressed down by the press die 29, and this press die 2
By pressing down the main body 25 of 9, the end of the metal piece 26 is moved to the cutting weak point 27 as shown in FIG. 3c.
The end of the remaining metal piece 26 is removed from the main body 25.
It becomes retracted inside.

FIGS. 4a, b, and c show examples of weak points 27 for cutting the metal piece 26, and in a, the weak points 27 for cutting are provided as notches on both sides.

b is a groove provided on the upper and lower surfaces.

C are provided at different levels, and in each case, a large number of metal pieces 26 are provided at regular intervals on one side of the band-shaped metal plate 30.

<Effects> As described above, the present invention provides an electronic component in which a metal piece that is a part of a metal frame material is incorporated into a main body by insert molding, and the metal piece is located slightly inside the surface of the main body. The weak point for cutting provided at the required part is the cutting part of the metal piece, and the cut surface of the metal piece remaining inside the main body is
Since it is positioned slightly inside the main body surface, when a large number of the electronic components of the present invention are mounted on a printed circuit board, there is no possibility that adjacent electronic components will be shorted by the ends of the metal pieces. This has the effect that there is no risk of shortening due to soldering when other adjacent electronic components are soldered to a printed circuit board.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the present invention, Fig. 2 is a vertical sectional view taken along line A-A of the same, Fig. 3 a,
b, c are longitudinal sectional views showing the state in which a metal piece is cut from the main body, Fig. 4 a, b, c are perspective views showing each row of cutting weak points, and Figs. 5 and 6 are the conventional main body. A longitudinal sectional view showing the relationship between the metal piece and the metal piece, No. 7
This figure is a perspective view of the same as above, and FIG. 8 is a perspective view of the same as shown in the mounted state. 11, 15... Main body, 23, 24, 26... Metal piece, 23a, 24a, 27... Weak point for cutting.

Claims (1)

[Claims] 1. In an electronic component in which a metal piece made up of a part of a metal frame material is incorporated into a main body by insert molding, a cutting week is provided at a required part of the metal piece located slightly inside the surface of the main body. An electronic component characterized in that the point is a cut part of a metal piece, and the cut part of the metal piece remaining inside the main body is located slightly inside the main body surface.