JPH05335709A - Printed wiring substrate - Google Patents

Abstract

PURPOSE:To eliminate the need for an operation to attach a terminal by using a metal plate whose both ends are bent to an L-shape. CONSTITUTION:An insulation layer 2 and a conductor layer 3 thereon are formed on a metal plate 1 whose both ends are bent at approximately right angles to a plate surface and are further bent to an L-shape toward an outside. The L-shaped part functions as a terminal which make continuity to other wiring substrate, for instance. Since a printed wiring substrate which is previously bent to an L shape is used, an operation to attach a terminal is not required. When the printed wiring substrate is mounted on other wiring substrate, etc., solder is applied to the conductor layer 3 of an L-shaped bottom part; however, if the metal plate 1 is exposed to an edge face of the printed wiring substrate, shortcircuiting can be caused. Therefore, the edge face of the L-shaped metal plate 1 is completely coated with the insulation layer 2. Thereby, an operation to attach a terminal becomes unnecessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board, and more particularly to a printed wiring board using a metal plate which requires high heat dissipation.

[0002]

2. Description of the Related Art A typical example of the structure of a conventional printed wiring board using a metal plate is, as shown in FIG. 3, an insulating layer 2 on a flat metal plate 21 and a conductor layer 3 on the insulating layer 2. Had formed.
Then, for example, when this printed wiring board is used in a hybrid integrated circuit device, pellets such as power transistors and various parts are mounted on the conductor layer 3. Further, in order to electrically connect the hybrid integrated circuit device to another wiring board or the like, a conductor layer 3 having a structure with a flat tip such as a lead terminal 5 is used by a method such as thermocompression bonding using solder 4. Was attached to.

[0003]

When the above-mentioned conventional printed wiring board using a metal plate is used in a hybrid integrated circuit device or the like, lead terminals are attached so as to be electrically connected to another wiring board or the like. Since the tip of this lead terminal is flat, a method such as thermocompression bonding is used in the mounting process, which causes a problem that the number of working steps is very large.

Further, the lead terminal having a flat tip has a problem that the bonding strength is weak against vibration.

It is an object of the present invention to provide a printed wiring board which does not require attachment of lead terminals and has excellent adhesive strength with other wiring boards.

[0006]

In the printed wiring board of the present invention, both ends are bent substantially at right angles in the same direction with respect to the plate surface, and are further bent in an L shape in either one of the outside direction and the inside direction. A metal plate, an insulating layer formed on the surface of the metal plate, and a conductor layer arranged on the insulating layer,
The L-shaped tip portions of both ends of the metal plate are covered with the insulating layer.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

FIGS. 1A and 1B are a sectional view and a perspective view of a first embodiment of the present invention.

In the first embodiment, as shown in FIGS. 1 (a) and 1 (b), both ends of the metal plate are bent substantially at right angles to the plate surface and further bent outward in an L-shape. An insulating layer 2 and a conductor layer 3 are formed on the insulating layer 2.

The L-shaped bent portion functions as a terminal for establishing electrical connection with another wiring board or the like.
Therefore, since the printed wiring board bent in an L-shape is used from the beginning, the number of man-hours for mounting the terminal becomes unnecessary. Further, since the printed wiring board and the terminal are not bonded to each other, there is an effect that the terminal bonding strength is very excellent as compared with the conventional lead terminal mounted by soldering.

Here, when this printed wiring board is mounted on another wiring board or the like, solder is applied to the conductor layer 3 at the bottom that is bent in an L shape, but at this time, metal is applied to the end surface of the printed wiring board. If the plate 1 is exposed, it may cause a short circuit. Therefore, the end face of the metal plate 1 bent in the L shape is formed so as to be completely covered with the insulating layer 2.

FIG. 2 is a sectional view of the second embodiment of the present invention.

The second embodiment is different from the first embodiment shown in FIG. 1 by using a metal plate 11 whose both ends are bent inward in an L shape as shown in FIG. When mounted on another wiring board or the like, the mounting area can be reduced.

[0014]

As described above, according to the present invention, since the metal plate whose both ends are bent in the L shape is used, the part bent in the L shape serves as a terminal. Therefore, it is not necessary to attach the lead terminal by a method such as thermocompression bonding as in the conventional case, and there is an effect that the number of man-hours for attaching the terminal becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a sectional view and a perspective view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of an example of a conventional printed wiring board.

[Explanation of symbols]

 1,11,21 Metal plate 2 Insulation layer 3 Conductor layer 4 Solder 5 Lead terminal

Claims (1)

[Claims] 1. A metal plate having both ends bent substantially at right angles to the plate surface in the same direction and further bent in an L-shape in either the outer or inner direction, and formed on the surface of the metal plate. Printed wiring board having an insulating layer formed on the insulating layer and a conductor layer disposed on the insulating layer, and L-shaped tip portions of both ends of the metal plate are covered with the insulating layer. .