JP2605438B2 - High current printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention includes a circuit conductor of a copper foil through which a minute current for signal flows and a circuit conductor of a stamped metal plate through which a large current for power flows. The present invention relates to a high current printed wiring board.

[Conventional technology]

Conventionally, this type of high-current printed wiring board can be formed by attaching a thin copper foil for a normal signal circuit to one side of an insulating substrate and attaching a thick copper foil to the other side, and pattern-etching each. Are known. When a through hole is formed in a power circuit conductor, a conductor layer is formed by electroless plating on the inner surface of the hole formed in the insulating substrate, as in the case of a signal circuit conductor.

[Problems to be solved by the invention]

However, in a configuration in which a copper foil is pasted and pattern-etched as in the above-described conventional large-current printed wiring board, the thickness of the copper foil that can be etched is limited. Must be increased, and it is difficult to make the circuit compact.

Similarly, it is difficult to increase the thickness of the conductor layer formed by electroless plating with respect to the through hole, so that a large current cannot be passed.

Therefore, an object of the present invention is to provide a large-current printed wiring that can use a conductor of an arbitrary thickness for a large current and can make the thickness of the conductor in the through-hole portion sufficiently large, and thus can realize a compact circuit. Is in providing board.

[Means for solving the problem]

The high-current printed wiring board according to the present invention includes a signal circuit conductor formed by pattern-etching a thin-film conductor attached to an insulating substrate and a circuit conductor obtained by punching a conductive metal plate into a required pattern for power. In the high current printed wiring board to be used, a power circuit conductor in which a portion other than the fixed portion to the insulating substrate is bent so as to rise from the insulating substrate and a cylindrical embossed portion is provided in the fixed portion; An insulating substrate having a positioning hole corresponding to the processed part; and a through-hole metal part formed by punching a conductive metal plate into a donut shape and burring a central portion thereof, and forming the power circuit conductor and the insulating member. The present invention is characterized in that the through-hole fitting inserted and fixed in the through-hole portion of the substrate is tightened with a screw and a nut and is brought into pressure contact with the substrate.

In this case, it is preferable that at least two embossed portions are provided for each of the punched power circuit conductors.

In addition, it is preferable that a portion of the through-hole fitting protruded by burring be longer than the thickness of the insulating substrate so as to be electrically connected to a metal terminal of a component below the insulating substrate.

Further, it is preferable that the bending of the power circuit conductor be configured so that at least the plate thickness of the through hole fitting rises from the insulating substrate.

In the large current printed wiring board, the power circuit conductor may be positioned by the cylindrical embossed portion and the positioning hole, and the fixed portion may be fixed to the insulating substrate by soldering or an adhesive. .

(Operation)

According to the high-current printed wiring board according to the present invention, a small current for a signal flows through a circuit conductor formed by etching a copper foil attached to an insulating substrate, and a large current for a power flows through a conductive metal plate. A circuit conductor that has been punched and bent so that the part other than the part fixed to the insulating substrate is raised, and a through-hole that is pressed and connected to this circuit conductor with screws and nuts and inserted and fixed in the through-hole part of the insulating substrate Flow through the hole fittings.

In this case, by providing at least two embossed portions for one punched power circuit conductor, positioning can be easily performed only by inserting the embossed portions into the corresponding holes of the insulating substrate.

Also, by making the protruding part of the through-hole metal fitting burring longer than the thickness of the insulating substrate,
Connection with the metal terminal of the component under the insulating substrate is also facilitated.

Further, since the power circuit conductor is floating from the insulating substrate except for the fixed portion, even when heat is generated by applying a large current, distortion due to thermal expansion can be absorbed and heat dissipation is improved.

Further, the power circuit conductor positioned by the cylindrical embossed portion and the corresponding positioning hole of the insulating substrate can be fixed on the insulating substrate by soldering or an adhesive.

〔Example〕

Next, an embodiment of a high current printed wiring board according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view of a main part of a high-current printed wiring board showing one embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. In FIG. 1, reference numeral 10 denotes an insulating substrate made of a glass epoxy resin or the like, and a circuit conductor 12 for signals is provided on one or both surfaces of the insulating substrate 10. The circuit conductor 12 is formed by etching a copper foil having a thickness of, for example, 35 μm or 70 μm attached to the insulating substrate 10 into a required pattern in the same manner as in the related art.

On the other hand, the power circuit conductor 14 through which a large current flows has, for example, a thickness
A steel plate, a copper plate or a copper alloy plate of about 0.5 to 3 mm is punched into a required pattern, and A, B,
Except for the fixing portion 16 shown as C, bend the insulating substrate 10 so as to float at least by the thickness of the through-hole bracket 18, and furthermore, the fixing portions 16 each have a diameter of, for example, 3 m.
The emboss 20 is formed so as to protrude from the insulating substrate 10 by about 0.5 to 1 mm in height at m. In addition, this emboss 20 is
If necessary, one or several embosses 20 are formed, and in the case of the fixing portions 16 at the positions indicated by A and B in the present embodiment, one embossment 20 is fixed, and the short power circuit conductor 14 as indicated by C is fixed. In the case of the part 16, at least two embosses 20 are formed so that positioning can be performed.

The insulating substrate 10 also includes a fixing portion 16 for the power circuit conductor 14.
The positioning holes 22 are formed in the portions corresponding to the respective embosses 20 formed in the above. Further, the metal plate used as the power circuit conductor 14 is punched into a donut shape in the through-hole portion 24 of the insulating substrate 10 so that the center is 0.
Through-hole metal fittings with burring 2 to 0.3mm long
Insert 18 In order to make the through-hole fitting 18 and the signal circuit conductor 12 conductive, they are attached by soldering, and the power circuit conductor 14 is attached to the insulating substrate 10 by soldering or an adhesive or the like at the fixing portion 16. At this time, the through-hole metal fitting 18 is attached so as to be always below the connecting portion 26 of the power circuit conductor 14. In a state in which the fixing portion 16 is attached to the insulating substrate 10 by soldering or the like, only unstable conduction can be obtained between the through-hole metal fitting 18 and the power circuit conductor 14, but finally, a power transistor, a rectifying diode, or the like is obtained. As shown in FIG. 2, the metal terminal 28 of the component is tightened and fixed with the screw 30 and the nut 32, so that the through-hole fitting 18 and the power circuit conductor 14 are always in press contact, so that a large integrated current can be supplied. It will function as an integrated conductor. At the same time, the center portion, which is slightly longer than the insulating substrate 10 during the burring process of the through-hole metal fitting 18, comes into press contact with the metal terminal 28 by the screw 30 and the nut 32, so that conduction is easily achieved. Note that the power circuit conductor 14 may be formed from a material which has been subjected to solder plating or tin plating as necessary.

Also, if the hole 26 of the portion of the power circuit conductor 14 that is pressed and contacted with the screw is punched slightly larger, the insulating substrate 10
Alignment with the through hole fitting 18 inserted and fixed above is facilitated.

〔The invention's effect〕

As is clear from the above-described embodiment, according to the large current printed wiring board of the present invention, the power circuit conductor for flowing a large current can have a sufficient thickness to be formed by stamping a metal plate. The conductor width can be significantly reduced as compared with copper foil. Moreover, since the through-hole fitting is used, there is no limitation on the thickness of the film as in the case of the conventional electroless plating, and the thickness of the conductor in the through-hole portion can be sufficiently increased. Therefore, the power circuit conductor and the through-hole metal can be easily connected by tightening the screws and nuts, and the current capacity can be larger than that of the conventional structure, so that the board size can be made compact. Since the through-hole portion and the power circuit conductor are connected via separate and separate through-hole metal fittings, it is easy to provide a margin for alignment.

In addition, since the power circuit conductors are all floating above the insulating substrate except for the fixed part, even when heat is generated by energization, the thermal expansion can be absorbed by the distortion of the floating part, and the heat radiation is good.

Further, by forming an embossment on the fixed portion of the power circuit conductor and forming at least two embosses, positioning with the corresponding positioning hole of the insulating substrate can be easily performed.

The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and it is needless to say that various design changes can be made without departing from the spirit of the present invention.

[Brief description of the drawings]

FIG. 1 is a plan view of an essential part showing an embodiment of a large current printed wiring board according to the present invention, and FIG. 2 is a sectional view taken along line II-II of the embodiment of FIG. 10 ... insulating substrate, 12 ... signal circuit conductor 14 ... power circuit conductor, 16 ... fixed part 18 ... through-hole bracket 20 ... embossed, 22 ... positioning hole 24 ... through-hole part, 26 … Connections 28 Metal terminals, 30 Screws 32 Nuts

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-239894 (JP, A) JP-A-63-271996 (JP, A) Jiko 58-1928 (JP, Y2)

Claims (5)

(57) [Claims] 1. A high-current printed wiring using a signal circuit conductor formed by pattern-etching a thin film conductor attached to an insulating substrate and a circuit conductor obtained by stamping a conductive metal plate into a required pattern for power. In the board, a power circuit conductor having a cylindrical embossed portion provided on the fixed portion and having a portion other than the portion fixed to the insulating substrate bent and raised from the insulating substrate, and a positioning corresponding to the embossed portion An insulating substrate having holes, and a through-hole fitting formed by punching a conductive metal plate into a donut shape and burring the center portion thereof, forming the power circuit conductor and the through-hole portion of the insulating substrate. A large-current printed wiring board, wherein the inserted and fixed through-hole metal fitting is tightened with a screw and a nut to make pressure contact. 2. The high-current printed wiring board according to claim 1, wherein at least two embossed portions are provided for each of the punched power circuit conductors. 3. A burring projecting portion of the through hole fitting is longer than a thickness of the insulating substrate so as to be capable of conducting with a metal terminal of a component below the insulating substrate. Item 3. A large current printed wiring board according to item 1 or 2. 4. The power circuit conductor according to claim 1, wherein the power circuit conductor is bent so that at least a portion of the through-hole metal plate is raised from the insulating substrate. The large current printed wiring board as described. 5. The power circuit conductor, wherein the power circuit conductor is positioned by the cylindrical embossed portion and the positioning hole, and a fixed portion is fixed to the insulating substrate by soldering or an adhesive. Item 6. A large current printed wiring board according to any one of Items 1 to 4.