JPH0220759Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to the shape of a connecting terminal for connecting a power supply pattern and a ground pattern of a printed wiring board to an external circuit.

(b) Background of the technology In printed wiring boards for electronic devices, connections between power supply patterns and ground patterns and external circuits are made using different patterns in order to make it possible to remove the printed wiring board with a simple operation during inspection or repair. Power supply terminals and ground terminals connected to external circuits are often screwed to connection terminals on printed wiring boards connected to external circuits. For example, in the case of an MCC (multi-chip carrier) unit, which is a type of printed wiring board for computers, there are 42 units on a 190 mm square printed wiring board.
The LSI is installed, and the power terminal and ground terminal are screwed to the connection terminals provided at the four corners and in the middle.

On the other hand, in equipment where many printed wiring boards are mounted at high density, the height of the parts mounted on the printed wiring board is important, and the height of the power terminal and ground terminal after they are screwed to the connection terminal is also important. , it is required that the performance is equal to or lower than that of other components mounted on the printed wiring board. Therefore, a washer-shaped connection terminal is often soldered to a printed wiring board, and a power terminal or a ground terminal is screwed to the connection terminal.

The present invention relates to an improvement in the shape of such a connecting terminal.

(c) Prior art and problems Figure 1 is a cross-sectional view of a connection terminal attached to a printed wiring board 1, and shows two washer-like connection terminals attached to the same through-hole, that is, the first connection. It is composed of a terminal 3 and a second connection terminal 4. The connection terminals 3 and 4 each include a flange portion 31 and a mounting portion 32, and the connection terminals 3 and 4 have the mounting portion 32 fitted into the opening of the same through hole.
It is soldered to wiring patterns 2 provided on the front and back sides of a printed wiring board 1.

Further, the external terminal 5 such as a power supply terminal or a ground terminal is provided with a screw 51 at its tip, and is adapted to be screwed to the second connection terminal 4 having a threaded portion 34. For reference, to describe the size of the embodiment shown in FIG. M3.5 threaded part is formed.

The connecting terminals 3 and 4 are soldered to the wiring pattern 2 using a soldering iron, and the upper surface of the flange portion 31 of the connecting terminal 3 is used as a flat surface 33 for making surface contact with the external terminal 5, as shown in FIG. As shown, the amount of solder 6 is too large and the ridge line 3
If it exceeds 5, solder will be present between the flat surface 33 of the connecting terminal 3 and the external terminal 5 when the external terminal 5 is screwed, resulting in insufficient surface contact, resulting in poor contact. Particularly when the external terminal 5 is a power supply terminal, this effect causes a large problem.

A dedicated soldering iron is used to solder the connection terminals, but the amount of flux, amount of solder, contact time of the iron, etc. vary, and solder bulges are likely to occur, especially when repair work involves reheating a portion. . Conventionally, therefore, connection terminals were soldered or repaired with great care, and then thoroughly inspected to prevent failures due to poor contact.

(d) Purpose of the invention The purpose of the invention is to provide a shape of a connecting terminal that will not cause trouble due to the solder that bulges up during normal soldering.

(e) Structure of the device The above object is a connecting terminal for screwing an external terminal to a printed wiring board, which consists of a pair of washer-like connecting terminals that are soldered to both sides of the printed wiring board, and each The washer-like connection terminal consists of a flange part and a mounting part protruding from the bottom surface of the flange part, and the top surface of the flange part, which is a flat surface for external terminal connection, is surrounded by an annular notch, and the mounting part has a diameter smaller than that of the flange part. This is achieved by using a printed wiring board connecting terminal configured to be inserted into a through hole.

(f) Embodiment of the invention FIG. 3 shows the shape of a connection terminal for a printed wiring board according to the invention, which is composed of a first connection terminal 7 and a second connection terminal 8. The connection terminals 7 and 8 each include a flange portion 31 and a mounting portion 32, and the connection terminals 7 and 8, each having the mounting portion 32 fitted into the opening of the same through-hole, are connected to the printed wiring board 1.
It is soldered to the wiring pattern 2 provided on the front and back sides of the board.

Further, the upper surface of the flange portion 31 is used as a flat surface 91 with which the external terminal is brought into surface contact.
is surrounded by an annular notch 9. By screwing the external terminal 5 to the screw portion 34 provided on the second connection terminal 8, the external terminal 5 forms the first connection terminal 7 at the flange portion 3.
The external terminal is connected to the wiring pattern 2 on the printed wiring board.

By providing the connecting terminals 7 and 8 with the annular notch 9 surrounding the flat surface 91, even if the solder 6 exceeds the ridgeline 35 of the first connecting terminal 7,
Even if the solder solidifies at a position beyond the ridge line 35 and bulges there, the solder does not adhere to the flat surface 91 over the notch 9.
Since it is located higher than that, failures due to solder swelling do not occur.

The height of the annular notch surrounding the plane is 1 mm.
Even within the soldering area, the plane on which the external terminal makes surface contact is isolated from the soldered part of the flange part, so that no failure will occur due to the solder that bulges up during normal soldering. The purpose of the present invention of providing a terminal shape can be achieved.

(g) Effects of the invention As mentioned above, by surrounding the plane to which the external terminals are connected with the annular notch, adhesion of solder to the plane to which the external terminals are connected is prevented, making it easier to use during soldering and subsequent inspection. Since there is no need to take special precautions, work efficiency when attaching connection terminals can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a connecting terminal attached to a printed wiring board, FIG. 2 is an explanatory diagram of contact failure due to solder swelling, and FIG. 3 is a sectional view of a connecting terminal according to the present invention. In the figure, 1 is a printed wiring board, 2 is a wiring pattern, 5 is an external terminal, 6 is solder, 7 and 8 are washer-shaped connection terminals, 9 is an annular notch, 31 is a flange part, 32 is a mounting part, 34 35 represents a ridgeline, and 91 represents a plane for external terminal connection.

Claims (1)

[Scope of utility model registration request] A connecting terminal for screwing an external terminal to a printed wiring board, which is composed of a pair of washer-like connecting terminals soldered to both sides of the printed wiring board, and each washer-like connecting terminal is connected to a flange part. The flange part has a mounting part that protrudes from the bottom surface of the flange part, and the top surface of the flange part, which is a flat surface for external terminal connection, is surrounded by an annular cutout, and the mounting part, which has a smaller diameter than the flange part, is connected to the through-hole hole. A connection terminal for a printed wiring board, characterized in that it is configured to be inserted into the terminal.