JP2013115220A - Metal core wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal core wiring board capable of improving wiring efficiency of a circuit while suppressing a magnetic field generated by a metal core layer.SOLUTION: There is provided a metal core wiring board 1 having a metal core layer 10 connected to an electric component R as an object of heat radiation to radiate heat of the electric component R, the metal core layer 10 having a large-diameter wiring part 11 having a wiring pattern formed so that wiring where current flows reversely is arranged nearby, and also having a connection part for the electric component R and its peripheral region formed to be thicker than the wiring width of the other part.

Description

  The present invention relates to a metal core wiring board having a metal core layer that dissipates heat of an electrical component when connected to the electrical component to be radiated.

  Conventionally, electrical components such as relays are attached to control boards such as lamps and motors mounted on vehicles. In order to prevent temperature rise due to heat generation of such electrical parts, a so-called metal core wiring board is provided, which is provided with a metal core layer made of a metal plate with high thermal conductivity to dissipate heat and equalize the heat generated by the electrical parts. There has been proposed a semiconductor device having (see, for example, Patent Document 1).

  In the metal core wiring board described in Patent Document 1, two metal core layers are provided with an insulating layer in between, and the current direction of each metal core layer is reversed to cancel the magnetic field generated by the metal core layer. The parasitic inductance is reduced.

JP 2004-266213 A

  By the way, in recent years, a metal core wiring board mounted on an in-vehicle electrical connection box (junction box) is connected to a plurality of loads such as a lamp and a motor, and thus a plurality of circuits connected to a battery are formed. For this reason, it is important to improve the wiring efficiency of the circuit.

  However, the metal core wiring board described in Patent Document 1 has a problem that the wiring efficiency of the circuit is poor because the metal core layer is provided in two layers in order to cancel the magnetic field, so that the metal core layer is multilayered.

  The present invention has been made in view of the above, and an object of the present invention is to provide a metal core wiring board capable of improving the wiring efficiency of a circuit while suppressing a magnetic field generated from the metal core layer.

  In order to solve the above-described problems and achieve the object, the metal core wiring board according to claim 1 of the present invention is provided with a metal core layer that dissipates heat of the electrical component by being connected to the electrical component to be radiated. A metal core wiring board, wherein the metal core layer is formed with a wiring pattern so that wiring in which current flows in a reverse direction is arranged in the vicinity, and a connection portion with the electrical component and its peripheral region And having a thick wiring portion formed thicker than the wiring width of other portions.

  In the metal core wiring board according to claim 2 of the present invention, in the above invention, the metal core wiring board is connected to a plurality of loads to which power is supplied, and a plurality of circuits corresponding to the plurality of loads are provided. The metal core layer is formed by patterning two or more of the plurality of circuits.

  In the metal core wiring board according to claim 1 of the present invention, the metal core layer is formed with a wiring pattern so that wiring in which the current flows in the reverse direction is arranged in the vicinity, and an electrical component to be radiated is connected. Since the heat dissipation region in the metal core layer is efficiently limited by forming the portion and the periphery thereof thicker than the other portions, the magnetic field generated from the metal core layer can be suppressed while suppressing the magnetic field generated from the metal core layer. Wiring efficiency can be improved.

  In the metal core wiring board according to claim 2 of the present invention, since two or more circuits are patterned on the metal core layer, even if the metal core wiring board is connected to the plurality of loads, The wiring efficiency of the circuit can be improved while suppressing the generated magnetic field.

FIG. 1 is a schematic diagram showing a metal core wiring board according to an embodiment of the present invention, and a battery and a motor connected to the metal core wiring board. FIG. 2 is a view showing the metal core layer of the metal core wiring board shown in FIG. FIG. 3 is a cross-sectional view taken along the line AA of the metal core wiring board shown in FIG. FIG. 4 is a diagram showing the direction in which heat is transmitted to the cross-sectional view taken along the line BB of the metal core wiring board shown in FIG. 1 by arrows. FIG. 5 is a diagram showing a manufacturing procedure of the metal core wiring board according to the embodiment of the present invention. FIG. 6 is a view showing the metal core layer of the metal core wiring board according to the first modification of the embodiment of the present invention. FIG. 7 is a cross-sectional view of a main part of a metal core wiring board according to a second modification of the embodiment of the present invention.

  Hereinafter, embodiments of a metal core wiring board according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a metal core wiring board 1 and a battery B and a motor M connected to the metal core wiring board 1 according to an embodiment of the present invention. FIG. 2 is a view showing the metal core layer 10 of the metal core wiring board 1 shown in FIG. FIG. 3 is a cross-sectional view taken along line AA of the metal core wiring board 1 shown in FIG. FIG. 4 is a diagram showing the direction in which heat is transmitted to the cross-sectional view taken along the line BB of the metal core wiring board 1 shown in FIG. 1 by arrows.
Note that the arrows in FIG. 2 indicate the direction of current flow, and the black circles in FIG. 2 indicate conduction holes connected to circuit wiring on the mounting surface 1a.

The metal core wiring board 1 according to the embodiment of the present invention is mounted on an in-vehicle electrical junction box used for supplying electric power to each electronic device mounted on, for example, an automobile. As a load to which electric power is supplied, two motors M such as a radiator fan motor (hereinafter referred to as a first motor M1 and a second motor M2) are connected.
The metal core wiring board 1 functions as a control unit that controls electric power supplied from the battery B to each motor M, and has a metal core layer 10 made of metal for radiating heat of the mounted electrical components. It becomes. The battery B and each motor M are connected to the metal core wiring board 1 by electric wires or the like connected to terminals (not shown) provided on the metal core wiring board 1.
In addition, a CPU (Central Processing Unit) 100 is installed on the mounting surface of the metal core wiring board 1, and arithmetic processing related to power control is performed by the CPU 100.

  Such a metal core wiring board 1 is formed with two circuits corresponding to the two motors M1 and M2. That is, the metal core wiring board 1 includes a first circuit C1 that is a circuit that drives the first motor M1, and a second circuit C2 that is a circuit that drives the second motor M2.

  The first circuit C1 is sequentially connected to the first relay R1, the first surge protection circuit T1, the first motor M1, and the cathode side of the battery B from the anode side of the battery B toward the downstream in the current flow direction. Circuit.

  The second circuit C2 is sequentially connected from the anode side of the battery B toward the downstream of the current flow direction to the second relay R1, the second surge protection circuit T2, the second motor M2, and the cathode side of the battery. Circuit.

  The first relay R <b> 1 and the second relay R <b> 2 prevent a reverse current from flowing to each motor M when the battery B is reversely connected.

  The first surge protection circuit T1 and the second surge protection circuit T2 are realized by a Zener diode or the like, and prevent an excessive voltage from being applied to each motor when a surge occurs.

Here, it demonstrates more concretely, referring the cross-sectional structure about the metal core wiring board 1. FIG.
As shown in FIGS. 3 and 4, the metal core layer 10 is provided between the insulating layers 20, 20a, 20b made of an insulating resin, and a copper foil is formed on the surface of the insulating layer 20a located on the mounting surface 1a side. The surface wiring pattern 2 on the mounting surface 1a is formed by the laminated copper foil.

As shown in FIG. 2, the metal core layer 10 is formed with a wiring pattern such that wirings in which current flows in the reverse direction are arranged in the vicinity.
Further, the metal core layer 10 has a wide wiring portion 11.
The wide wiring portion 11 forms a connection portion with each relay R (R1, R2) to be radiated and its peripheral region, and is formed thicker than the wiring width of other portions.
More specifically, the metal core layer 10 is formed with a wiring pattern in the first circuit C1 so that the wiring in which the current flows in the reverse direction is arranged in the vicinity, and is connected to the first relay R1. In addition, a first wide wiring portion 11a is formed which forms a peripheral region thereof and is thicker than the wiring width of other portions.
In addition, the metal core layer 10 is formed with a wiring pattern in the second circuit C2 so that the wiring in which the current flows in the reverse direction is arranged in the vicinity, and forms a connection portion with the second relay R2 and its peripheral region. In addition, the second wide wiring portion 11b is formed to be thicker than the wiring width of other portions.

As described above, the first circuit C1 and the second circuit C2 are formed so that the wiring in which the current flows in the reverse direction in the metal core layer 10 is arranged in the vicinity, as shown in FIG. In addition, the magnetic field B generated by the current flowing through the metal core layer 10 is offset. Thereby, parasitic inductance is reduced.
Further, as shown in FIG. 4, the first relay R1 and the second relay portion 11b are formed by the first thick wiring portion 11a and the second thick wiring portion 11b which are formed thicker than the wiring width of other portions. The heat of the second relay R2 is dispersed and soaked on the metal core wiring board.
The wiring width and the wiring length of the first wide wiring portion 11a and the second wide wiring portion 11b are appropriately set in consideration of layout restrictions.

Next, the manufacturing method of the metal core wiring board 1 is demonstrated using FIG. FIG. 5 is a diagram showing a manufacturing procedure of the metal core wiring board 1 according to the embodiment of the present invention.
First, a metal core substrate 10a made of a plate-like metal is bonded to the insulating layer 20b (see FIG. 5A). The insulating layer 20b is made of, for example, an adhesive sheet (not shown) made of an insulating resin substrate 21 and an insulating resin, a so-called prepreg, and the insulating resin substrate 21 and the metal core substrate 10a are bonded to each other with the prepreg interposed therebetween. In this bonding, hot vacuum pressing or the like is used.

  Thereafter, a wiring pattern is formed on the metal core substrate 10a (see FIG. 5B). A known photolithography method is used for pattern formation of the metal core substrate 10a. Thereby, the wiring patterns of the first circuit C1 and the second circuit C2 are formed in the metal core layer 10 so that the wiring in which the current flows in the reverse direction is arranged in the vicinity. In addition, the first wide wiring portion 11a and the second wide wiring portion 11b, which are formed thicker than the wiring width of other portions, are patterned.

Then, after laminating copper foil (not shown) with the insulating layer 20a in between, the surface wiring pattern 2 is formed on the mounting surface 1a to complete the metal core wiring board 1 (see FIG. 5C). Here, the insulating layer 20a is made of, for example, the prepreg described above, and when the copper foil is laminated, the resin of the prepreg is embedded between the circuits by hot vacuum pressing.
In addition, in the manufacturing method of the metal core wiring board 1 described above, a hole drilling step for establishing conduction between the terminal insertion holes (not shown) into which the terminals of the relays R and the like are inserted, and layers, Known processes necessary for manufacturing the circuit board, such as a plating process, are performed.

  In the metal core wiring board 1 according to the embodiment of the present invention, the metal core layer 10 is formed with a wiring pattern so that the wiring in which the current flows in the reverse direction is arranged in the vicinity, and the relay R to be radiated is connected. Since the heat dissipation region in the metal core layer 10 is efficiently limited by forming the portion and the periphery thereof thicker than the other portions, the circuit while suppressing the magnetic field generated from the metal core layer 10 The wiring efficiency can be improved.

  In addition, the metal core wiring board 1 according to the embodiment of the present invention is a case where the metal core wiring board 1 is connected to the two motors M1 and M2 because the two circuits C1 and C2 are patterned on the metal core layer 10. However, the wiring efficiency of the circuit can be improved while suppressing the magnetic field emitted from the metal core layer 10.

(Modification 1)
Next, Modification 1 of the metal core wiring board 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 6 is a view showing the metal core layer 12 of the metal core wiring board 2 according to the first modification of the embodiment of the present invention.
The metal core wiring board 2 of the first modification is different from the metal core wiring board 1 of the embodiment in that it has one circuit that is connected to one motor M and drives the motor M.
Other configurations are the same as those in the embodiment, and the same components as those in the embodiment are denoted by the same reference numerals.

  In the metal core wiring board 2 of the first modification, the metal core layer 10 is formed with a wiring pattern so that the wiring in which the current flows in the reverse direction is arranged in the vicinity, and the portion to which the relay R to be radiated is connected And the periphery thereof are formed thicker than the other parts, so that the heat dissipation region in the metal core layer 10 is efficiently limited. Therefore, as with the metal core wiring board 1 of the first embodiment, the metal core The wiring efficiency of the circuit can be improved while suppressing the magnetic field emitted from the layer 10.

(Modification 2)
Next, Modification 2 of the metal core wiring board 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view of the main part of the metal core wiring board 3 according to Modification 2 of the embodiment of the present invention.
The metal core wiring board 3 of the second modification is different from the metal core wiring board 1 of the embodiment in that two metal core layers 10 and 13 are provided.
Other configurations are the same as those in the embodiment, and the same components as those in the embodiment are denoted by the same reference numerals.

  In the metal core wiring board 3, two metal core layers 10 and 13 are formed with an insulating resin layer in between and an insulating layer 20c in between. The metal core wiring board 3 is connected to, for example, three motors M (not shown). In each metal core layer 10, 13, a wiring pattern is formed so that wirings in which current flows in the reverse direction are arranged in the vicinity. Further, the wide wiring portion 11 formed thicker than the wiring width of other portions is patterned.

  The metal core wiring board 3 of this modification 2 can have the same effect as the metal core wiring board 1 of the embodiment.

  In addition, although the metal core wiring boards 1, 2, and 3 which concern on the Example of this invention illustrated what was connected to the motor M, it is not restricted to this. That is, as long as the load is the supply destination of power from the battery B, it may be connected to another load. For example, the metal core wiring boards 1, 2, and 3 may be connected to the lamp instead of the motor M.

  Moreover, although the metal core wiring boards 1, 2, and 3 which concern on the Example of this invention illustrated what the electrical component used as the heat radiation object is the relay R, not only this but another electric component is made into the heat radiation object. The thick wiring portion 11 may be connected.

  The invention made by the present inventor has been specifically described based on the above-described embodiments of the invention. However, the present invention is not limited to the above-described embodiments of the invention and does not depart from the gist thereof. Various changes can be made.

1, 2, 3 Metal core wiring board 1a Mounting surface 2 Surface wiring pattern 10, 12, 13 Metal core layer 10a Metal core substrate 11 Wide wiring part 11a First wide wiring part 11b Second wide wiring part 20, 20a, 20b insulating layer 21 insulating resin substrate C1 first circuit C2 second circuit R relay R1 first relay T surge protection circuit T1 first surge protection circuit R2 second relay T2 second surge protection circuit B battery M Motor M1 First motor M2 Second motor 100 CPU

Claims (2)

A metal core wiring board having a metal core layer that dissipates heat of the electrical component by being connected to the electrical component to be radiated,
The metal core layer is
The wiring pattern is formed so that the wiring in which the current flows in the reverse direction is arranged in the vicinity,
A metal core wiring board, characterized in that a connection portion with the electrical component and a peripheral region thereof are formed and a wide wiring portion is formed thicker than a wiring width of other portions. The metal core wiring board
It is connected to a plurality of loads to which power is supplied, and a plurality of circuits corresponding to the plurality of loads are formed,
The metal core layer is
2. The metal core wiring board according to claim 1, wherein two or more of the plurality of circuits are patterned.

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