JPH02202090A - Large current board device - Google Patents

Abstract

PURPOSE:To improve a board device of this design in reliability of electric connection, mechanical strength, and productivity, and to enable a large current to flow at a low impedance by a method wherein a circuit element is fixed by sandwiching a bus bar and a board between large type lead terminals and nuts. CONSTITUTION:A bar linking section 21 of a bus bar 1 is inserted into a inserting through-hole of a board 6 and fixed, and a small type lead terminal 42 of a circuit element 3 is inserted from the upside of the bus bar 1. At this point, a large type lead terminal 41 bears against the bus bar 1 to function as a stopper which limits the length of the inserted portion of the terminal 42, and the threaded portion of the small type lead terminal 42 of a small diameter protrudes from the rear of the board 6. A nut 11 is screwed into the protruding threaded portion of the small type lead terminal 42 to fix the circuit element fastening tight the bus bar 1 and the board 6. Therefore, the large type lead terminal 41 of the circuit element 3 is brought into area contact with the bus bar 1 and a copper foil pattern used for fixing the bus bar 1 to the board 6 can be dispersed with. By this setup, a board device of this design can be improved in reliability of electric connection, mechanical strength, and productivity, and enable a large current to flow at a low impedance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a large current board device, and particularly to a method for fixing circuit elements and bus bars.

[Prior Art] FIG. 2 is a cross-sectional view showing the configuration of the main parts of a conventional large current board device disclosed in, for example, Japanese Utility Model Application Publication No. 55-77882. ) is the busbar (
1) is the burring part, (3) is the circuit element, (4) is the lead terminal, (5) is the through hole of the burring part (2), (6) is the board, and (7) is the insertion hole of the board (6). hole, (8) is the substrate (
6) and the copper foil pattern interposed between the bus bar (1) and the bus bar (1).
) is solder.

The burring portion (2) of the bus bar (1) is inserted into the insertion hole (7) of the substrate (6). The through hole (5) of this burring part (2) has a lead terminal (
4) is inserted and soldered with molten solder to establish an electrical connection between the bus bar (1) and the lead terminal (4).

As is clear from Figure 2, the lead terminal (4) of the circuit element (3) is directly connected to the bus bar +1 at the barring part (2), so the electrical impedance of the conduction path can be reduced. .

[Problems to be Solved by the Invention] Since the conventional high-current board device is configured as described above, the barring portion (2) of the bus bar (11) can be soldered to each lead terminal (4) with good soldering properties. It has a tapered shape and is soldered near the tip of the taper.For this reason, the reliability of the electrical connection between the bus bar (1) and the solder (9) is poor, and there is a limit to the reduction of impedance. Furthermore, the shape and fixing method of the bus bar (1) is mechanically weak and unsuitable for passing large currents.

Furthermore, the busbar +1) is attached to the copper foil pattern (
The soldering is fixed via the bus bar (1).
) There are problems in that forming the copper foil pattern (8) only for the purpose of fixing the copper foil pattern (8) is cumbersome and prolongs the process, and goes against the reduction in manufacturing costs.

This invention was made in order to solve the above problems, and it is possible to improve the reliability and mechanical strength of electrical connections, to enable the conduction of large currents and low impedance, and to improve productivity. The purpose is to obtain a current substrate device.

[Means for Solving the Problems] A large current board device according to the present invention includes a board having an insertion hole, a burring portion whose burring length does not exceed the depth of the insertion hole, and the burring portion has a A circuit in which a bus bar is inserted and fitted into the insertion hole, a small diameter lead terminal on the distal end with a thread formed at the tip is inserted through the bar ring part, and a large diameter lead terminal on the base side comes into contact with the bus bar. The circuit element is provided with a nut that is screwed into the screw thread of the small-diameter lead terminal to fix the circuit element.

[Function] In this invention, the circuit element is fixed between the bus bar and the board by the large diameter lead terminal and the nut, and the contact between the large diameter lead terminal of the circuit element and the bus bar is surface contact, so that the mechanical strength is improved. The reliability of electrical connections is greatly improved, electrical impedance is reduced, and large currents can flow.

Furthermore, since a copper foil pattern for fixing the bus bar to the board is not required, the work is simplified, productivity is significantly improved, and applications can be expanded.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
In the figure, (21) is the burring part of the bus bar (1), and the burring length is the insertion hole (21) of the board (6).
7), and when the burring portion (21) is inserted into the insertion hole (7) of the substrate (6), a gap (10) is created in this example. (41) is a large diameter lead terminal on the root side, which is fixed to the circuit element (3). (42) is a small-diameter lead terminal on the tip side with a thread formed at the tip, and (+11 is a nut).

The burring portion (21) of the bus bar (1) is inserted and fitted into the insertion hole (7) of the substrate (6). Further, a small diameter lead terminal (42) of the circuit element (3) is inserted through the top of the bus bar +11. At this time, use the large diameter lead terminal (
41) comes into contact with the bus bar (1) and serves as a stopper to limit the insertion dimension, and the screw portion of the small diameter lead terminal (42) is configured to protrude from the board (6), and the small diameter lead terminal (42) that protrudes from the board (6) Attach a nut (
The circuit element (3) is firmly fixed by screwing in the bus bar (1) and the board (6).

[Effects of the Invention] As described above, according to the present invention, there is provided a substrate having an insertion hole, a burring portion whose burring length does not exceed the depth of the insertion hole, and this burring portion is connected to the insertion hole. a bus bar that is inserted and fitted into the hole, a circuit element in which a small diameter lead terminal on the distal end having a thread formed at the distal end is inserted through the bar ring part and a large diameter lead terminal on the root side abuts on the bus bar; Since it is equipped with a nut that screws into the thread of the small diameter lead terminal to fix the circuit element,
The reliability and mechanical strength of electrical connections are improved, and a large current board device that can conduct large current with low impedance and has improved productivity can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the main part of a large current board device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the structure of the main part of a conventional large current board device. In the figure, (1) is a bus bar (2), (211 is a barring part, (3) is a circuit element, (4) is a lead terminal,
(41) is a large diameter lead terminal, (42) is a small diameter lead terminal, (6) is a substrate, (7) is an insertion hole, and (II) is a nut. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A substrate having an insertion hole, a burring portion whose burring length does not exceed the depth of the insertion hole, and a bus bar to which the burring portion is inserted and fitted into the insertion hole, and a tip portion thereof. A small-diameter lead terminal on the tip side with a thread formed thereon is inserted through the bar ring part, and a large-diameter lead terminal on the base side is screwed into the circuit element that comes into contact with the bus bar, and with the thread of the small-diameter lead terminal. A high-current board device equipped with nuts that secure circuit elements.