JPH0418447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a signal line filter with lead terminals used for a circuit board of a digital device.

(Prior art) As the signals handled by electronic devices become more digital and faster, it has become important to take measures against signal interference and malfunction due to unnecessary radiation noise generated or received between signal lines and power lines. ing. As one means for these countermeasures, a signal line filter circuit is used in which a ferrite core is combined on a signal line circuit board or in a signal cable for connecting equipment.

Conventionally, this type of signal line filter often uses a small ferrite bead core, and when it is mounted directly onto a device circuit board, the mounting work is not easy because of the large number of signal lines. For this reason, a ferrite bead core was housed in a container having an external terminal and used as a line filter.

(Problems to be Solved by the Invention) In the method described above, the container with the external terminal is manufactured by molding an electrically insulating resin, and the external terminal made of highly conductive metal is buried so as to protrude into the inside of the container. . After wrapping and soldering the end of the signal line passed through the through-hole of the ferrite core around the tip of the external terminal protruding into the container, the ferrite core is fixed to the container with adhesive, and the outer cover is placed on top to form an exterior. ing. Therefore, the work of winding the signal line terminals in particular is complicated and takes a long time, and it is difficult to automate the work, resulting in an expensive filter circuit.

(Means for Solving the Problems) The present invention inserts a circuit board having a plurality of circuit patterns having the same terminal arrangement as a signal circuit board of an electronic device into a flat cylindrical ferrite core, and A clamping piece provided at the tip of a lead terminal piece of a chain lead terminal made of a thin strip-shaped metal plate is set on the terminal seats provided at both ends of the pattern and connected by soldering. Thereafter, the above-mentioned problem is solved by molding the ferrite core and the circuit board together with the solder connection portion using an electrically insulating resin, a resin liquid, or the like.

(Example) An example of the present invention will be described with reference to FIGS. 1 to 5.

As shown in Fig. 2, a flat cylindrical ferrite core 1
has a through hole 11, and the thin circuit board 2 shown in FIG. Accordingly, a plurality of circuit patterns 21 are formed in parallel to each other. At both ends of the circuit pattern 21, terminal seats 22 and 23, which are wider than the width of the circuit pattern 21, are provided for connecting external terminals. The back surface of the circuit board 2 corresponding to the terminal seats 22 and 23 is tapered (not shown) for convenience when setting external lead terminals, which will be described later.

Further, a stopper 25 for positioning insertion into the flat cylindrical ferrite core 1 is provided on the side edge of the circuit board 2 parallel to the circuit pattern 21. circuit board 2
is made so that the terminal seats 22 and 23 are outside the flat cylindrical ferrite core 1 when inserted into the flat cylindrical ferrite core 1.

FIG. 4 shows a chain lead terminal 3 in which a large number of lead terminal pieces 31 are molded at regular intervals to sandwich a circuit board 2 and lead out as external terminals. This is made of brass, beryllium copper, stainless steel, iron, or an alloy thereof, and is manufactured by precision punching or etching a highly elastic and highly conductive band-shaped metal plate. Chain lead terminal 3 is
Lead terminal pieces 31 are formed at regular intervals in a perpendicular direction on a frame part 37 having a positioning hole 35 during automatic feeding, and a protrusion 32 for determining the standoff height is provided at the tip. Two cuts are made in the length direction at the tip of the protrusion 32, and clamping pieces 33 and 34 are used to clamp the terminal seats 22 and 23 of the circuit board 2.
is provided. Further, depending on the direction in which the terminal is led out, the tip portion including the clamping pieces 33 and 34 is bent at right angles and so as to form a step between the clamping pieces 33 and 34.

In FIG. 5, the circuit board 2 is inserted into the through hole 11 of the flat cylindrical ferrite core 1 until the stopper 25 of the circuit board 2 abuts against it. Chain lead terminal 3
In this case, the holding pieces 33 and 34 of the lead terminal piece 31 of the chain lead terminal 3 are positioned on the terminal seats 22 and 23 at both ends of the circuit board 2, and the circuit board 2 is held by pressing them to their bases. Next, the terminal seats 22, 2
3, the clamping pieces 33 and 34 are soldered and connected using high temperature melting point solder.

At this time, the gap after assembly can be minimized by selecting the dimensions of the flat cylindrical ferrite core 1 and the circuit board 2. Therefore, the leading positions of the flat cylindrical ferrite core 1 and the lead terminal pieces 31 are accurately positioned.

Next, the flat cylindrical ferrite core 1 and the circuit board 2
In order to protect and fix the soldered connection part 4 of the lead terminal piece 31, the exterior is applied with electrically insulating resin, resin liquid, etc., and finally the lead terminal piece 31 is separated from the frame part 37 leaving the required length. It will be done.

The signal line filter formed in this manner is assembled to an electronic device circuit board and connected to a signal line using the lead terminal piece 31.
The lead terminal piece 31 and the circuit pattern 21 become part of the signal line, forming a filter circuit equivalent to a signal line penetrated into a ferrite core.

Furthermore, the arrangement of the lead terminal pieces of chain lead terminals used as external terminals can be easily matched to the integrated circuit mold package, and can be automatically mounted using an automatic integrated circuit component insertion machine when mounted on the circuit board of electronic equipment. becomes.

(Effects of the Invention) As explained above, according to the present invention, the signal line penetrating the flat cylindrical ferrite core is formed as a pattern on the thin circuit board, and the connection with the external terminal is made by fitting the signal line into the circuit board. It is only necessary to set a chain lead terminal having a clamping piece, and there is no need for complicated work such as winding the end of a signal line around an external terminal as in the past. Therefore, it is easy to automate the assembly work, and a signal line filter having a terminal arrangement with high positional accuracy can be provided at a low cost.

Further, automatic mounting of the signal line filter according to the present invention onto an electronic device circuit board can be easily carried out using an automatic mounting machine by matching the terminal arrangement to a general integrated circuit component.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a signal line filter according to the present invention, FIG. 2 is a perspective view of a flat cylindrical ferrite core used in the present invention, FIG. 3 is a perspective view of a circuit board used in the present invention, and FIG. 4 is a perspective view of a circuit board used in the present invention. The chain lead terminal used in the present invention is shown. FIG. 5 is a sectional view after the signal line filter according to the present invention is assembled. 1: Oblate cylindrical ferrite core, 2: Circuit board,
3: Chain lead terminal, 21: Circuit pattern,
31: Lead terminal piece, 33, 34: Clamping piece.

Claims (1)

[Claims] 1. A plurality of circuit patterns are formed in parallel to each other using a good conductor metal on a flat cylindrical ferrite core and a thin plate-like base material having electrical insulation properties, and lead terminals are provided at both ends of each circuit pattern. A circuit board provided with a terminal seat for connecting the circuit board, and a lead terminal piece having a clamping piece for clamping the terminal seat of the circuit board are molded at the same intervals as the circuit pattern in the length direction. The circuit board is inserted into the flat cylindrical ferrite core, and the lead terminal pieces of the chain lead terminal are held in the terminal seats on both sides of the circuit board. A method for manufacturing a signal line filter, characterized in that after setting the strips and soldering the terminal seat and the holding strip, the connecting portion, the core and the circuit board are covered with an electrically insulating resin. . 2. A method of manufacturing a signal line filter according to claim 1, characterized in that the arrangement and external dimensions of the lead terminal pieces are made to match an integrated circuit molded package.