JPS61234094A - Mounting of check terminal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for mounting components on a printed circuit board when check terminals are provided on the circuit board to be used when inspecting, adjusting, etc. various circuits formed on the printed circuit board. In this case, if the lead terminal of the component is long or the lead terminal has an extra length,
After inserting the component onto the board, solder dipping is performed, and then the remaining length is cut off and trimmed to a predetermined length. This work was traditionally done manually using nippers.
However, this method requires time and effort, and has the drawback of extremely poor workability, especially in the current situation where components are mounted in high density in recent years.

Conventionally, the parts were fixed by soldering or temporarily fixed, and then the excess length of the lead terminals was cut and removed at once using an automatic cutting machine, etc., and the parts were trimmed to a predetermined length. I was worried. However, according to this method, the lead terminals are forcibly cut and removed, so the stress applied during processing may cause cracks in the soldering, or in extreme cases, heat generation (
(approximately 500 to 800 degrees Celsius), the solder portions melt, resulting in insufficient solder, and it has been pointed out that the solder portions deteriorate and deteriorate over time.

In order to deal with this problem, the parts are soldered and fixed on the board by solder dipping, the excess length of the lead terminals is then cut to a predetermined length using an automatic cutting machine, and then the parts are soldered and dipped again. Double solder dip method′
A method called is used.

The present invention relates to a method for attaching check terminals provided on a printed circuit board when components are mounted on the circuit board by the two-dip soldering method.

This type of printed circuit board is usually provided with at least one check terminal to which an oscilloscope probe or the like is connected in order to inspect, adjust, or repair the circuit. This check terminal is generally provided on the component mounting surface of the board, but it may be desired to provide it on the back side of the board as necessary.

However, when using the double solder dip method 1 as described above, all the lead terminals on the back side of the board are cut uniformly short, so it is impossible to attach check terminals on this back side during the component mounting process. Therefore, in subsequent steps, it is necessary to manually insert the board into the mounting hole of the board and fix it by soldering, which is extremely troublesome, complicated, and inefficient.

Therefore, the present invention provides a method for easily attaching the check terminal when providing the check terminal as described above on the back side of the printed circuit board.
Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIGS. 1 and 2 show an example of a check terminal according to the present invention, and this check terminal 1 includes a cylindrical member 2,
It consists of a shaft-shaped terminal body 3 that is loosely fitted into this member 2 so as to be slidable in the axial direction, and is inserted into a mounting hole of a printed circuit board from the component mounting surface.

The member 2 is open at one end (upper end) and closed at the other end (bottom surface), and the terminal body 3 is integrally inserted and mounted through this opening. The upper end of the member 2 is bent inward, and the collar 3a of the terminal body 3 is abutted against and latched to the upper end 2a to prevent it from being pulled out downward. At a predetermined position on the outer periphery of this member 2, a collar-shaped locking portion 2b is formed to protrude outward, so that the member 2 can be positioned when inserted into a board mounting hole.

The terminal body 3 is provided with a collar 3a on its upper portion to prevent the member 2 from falling out, and a piece 3b to prevent the member 2 from falling off from the upper end opening is formed to protrude at a predetermined position in the longitudinal direction.

On the other hand, FIG. 3 shows a printed circuit board to which the present invention is applied, and various electronic components al, bl, c, . . . are mounted on the component mounting surface 4a of this printed circuit board 4.

These components a, b, C... are inserted into the insertion holes of the board 4 with their lead terminals and temporarily fixed, and then soldered and fixed to the board 4 by soldering dip, and then soldered using an automatic cutting machine or the like. The excess length of the lead terminal protruding from the back surface 4b of the substrate is then trimmed to a predetermined length. However, at this stage, it is common for soldering defects to occur in parts of the lead terminal itself or the solder paste that cannot be visually seen due to stress and heat generated when the extra length is cut.

Therefore, in this case, after the above-mentioned extra length is cut and removed, solder dipping is performed again, and as a result, parts a,
btc.11 is completely fixed to the printed circuit board 4 by soldering.

A mounting position 5 for the check terminal 1 is positioned at a predetermined position on the printed circuit board 4, as shown by the two-dot chain line in the figure, and a mounting hole 6 into which the check terminal 1 is inserted passes through the position 5 vertically. FIGS. 4(a) to 4(e) show the installation process when inserting the check terminal 1 into the printed circuit board 4. First, as shown in FIG. 1 is the component mounting surface 4 in the mounting hole 6 of the printed circuit board 4.
When inserted from a, the locking portion 2b of the member 2 is locked at the periphery of the mounting hole 6 on the component mounting surface 4a, positioning in the insertion direction is performed, and the tip of the member 2 is placed at a predetermined height on the back side 4b of the board. It stands out. At this time, the terminal body 3 is held within the member 2 with its tip in contact with the bottom surface 2e. Next, in this state, the printed circuit board 4 is subjected to a first solder dip process, and the above-mentioned electronic components a, b+c...
At the same time, the member 2 is soldered and fixed to the board 4 (FIG. 4(b)). The terminal body 3 is
At this time, it is in a freely movable state within the member 2. After that, the cutting process of the lead terminals of each of the parts al bl c... is performed, and as described above, the back side 4b of the board
The excess length of the lead terminal protruding from the side is cut off and removed to shorten it to a predetermined length.
The tip of the terminal body 3 is cut to a predetermined length along with the tip of the terminal body 3, and the bottom surface 2e thereof is opened (see FIG. 4(C)). Then,
As shown in FIG. 4(d), the terminal body 3 slides downward in the axial direction within the member 2 due to its own weight, and its tip end 3c moves a predetermined height 2 from the mounting hole 6 toward the back surface 4b of the board. stand out. In this case, the collar 3a abuts and locks on the upper end 2a of the member 2, preventing its downward removal and regulating the protrusion height I toward the back surface 4b of the board.

Thereafter, the printed circuit board 4 is subjected to another soldering dip process, and the lead terminals of the components at bl c . At this time, at the same time, Fig. 4(e)
As shown in the figure, solder is applied to the base end of the protrusion of the terminal body 3 on the back surface 4b of the board, and the solder A is applied to the member 2.
The soldering between the member 2 and the terminal body 3 is performed by entering the tip of the member 2 and the terminal body 3. This allows the check terminal 1 to be at a predetermined height from the back surface 4b of the board! Printed circuit board 4 with only
The soldering is fixed.

Therefore, when inspecting or adjusting the circuit formed on the printed circuit board 4, if you connect an oscilloscope probe or alligator grip to the check terminal 1, you can observe the waveform or measure the voltage on the back side of the printed circuit board. It can be done very easily from the side.

As explained above, according to the present invention, when the type check terminal is provided on the back side of the printed circuit board, it can be installed at the same time as component mounting. It is easy to do and can be done efficiently. In the above embodiment, the check terminal is provided at only one location on the printed circuit board, but the check terminal is not limited to this, and it goes without saying that the number can be increased or decreased as appropriate depending on the type of circuit, etc.

[Brief explanation of drawings]

1 and 2 are perspective views showing an example of a check terminal according to the present invention, FIG. 3 is a perspective view of a printed circuit board to which the present invention is applied, and FIGS. It is a figure explaining the attachment process when providing a check terminal on the back surface of a board|substrate. 2...Materials, 3...Life terminal body, 10O...Check terminal, 4...Printed circuit board, θ...Mounting hole, 2c...Bottom (other end), 3c...φ tip (part) ), 4b...back side of the board, l...projection height (of the terminal body). Patent applicant: NEC Home Electronics Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) In a check terminal consisting of a cylindrical member with one end open and the other end closed, and a shaft-shaped terminal body loosely fitted into this member, the cylindrical member is inserted into a mounting hole of a printed circuit board. After soldering and fixing, when cutting lead terminals of other components to be mounted on the printed circuit board, the other end of the member is cut and opened, and the tip of the terminal body is made to protrude from this opening at a predetermined height to the back side of the board. , a check terminal installation method characterized by solder dipping in this protruding state.