JPH0793483B2 - Power composite parts - Google Patents

Description

The present invention relates to a structure of a power composite component in which a circuit part for supplying power to a small electric device such as a small video movie or a portable personal computer is unitized. Is.

[Conventional technology and its problems]

2. Description of the Related Art In recent years, with the miniaturization of electric devices, circuit devices around power sources are required to be even lighter and thinner.

As a conventional composite component of this type, there are one having a circuit element mounted on the upper and lower surfaces of a double-sided printed circuit board and one having a structure having a circuit element mounted on a single-sided printed circuit board. Due to the large currents flowing through the power circuit, a large amount of heat is generated in these composite components during operation. However, since the surface of the printed circuit board is covered with a large number of circuit elements and circuit patterns in a power circuit that makes heavy use of choke coils and capacitors,
It was difficult to have a structure that effectively dissipates the heat.

[Object of the Invention]

The present invention has been made to solve the above problems, and an object of the present invention is to provide a composite component for electric power, which has an excellent heat dissipation effect and can be thinned.

[Means for Solving the Problems]

According to the present invention, the circuit pattern and the print coil electrically connected through the through holes are formed on the upper surface and the lower surface of the first magnetic body substrate, respectively, and the flat plate-shaped second coil is formed on the lower surface of the first magnetic body substrate. It is characterized in that magnetic substrates are laminated and fixed, and circuit elements are mounted on a circuit pattern.

〔Example〕

1 and 2 show an embodiment in which the present invention is applied to a DC-DC converter.

In these figures, 10 and 20 are magnetic substrates made of nickel zinc ferrite or the like. As shown in an enlarged view in FIG. 3, an insulating layer 21 such as a glass film is provided on the upper surface of one magnetic substrate 10, and a circuit pattern 22 made of copper or the like is printed and printed on the insulating layer 21. It is formed by the means. Another circuit pattern 24 is formed on the circuit pattern 22 via an insulating layer 23. These two layers of circuit patterns 22 and 24 are electrically connected through through holes 25. A plurality of printed coils 30 as shown in FIG. 4 connected to the circuit pattern 22 through the through holes 15 are formed on the lower surface of the magnetic substrate 10. Another magnetic substrate 20 is bonded and fixed to the lower surface of the magnetic substrate 10 so as to cover the print coil 30. Reference numeral 28 is a concave portion of the magnetic substrate 20 provided at a position facing the printed coil 30. By thus sandwiching the print coil 30 between the two magnetic substrates 10 and 20, it is possible to obtain a sufficiently large inductance as a choke coil for a power supply circuit, despite the thinness.

On the circuit pattern 24, electrodes 52 and 53 are embedded inside a dielectric plate 51 formed by stacking as shown in FIG. 5 together with a surface-mounted circuit element 40 such as a transistor and a diode. Circuit board pattern 24
It has an electrical connection with. In this embodiment, two such capacitors 50 are provided. Two layers of circuit patterns 62, 64 are formed on the upper surface of the dielectric plate 51 of the capacitor 50 with an insulating layer 63 interposed therebetween, and the surface-mounted circuit element 40 is also mounted on the circuit pattern 64. . A part of the circuit pattern 62 extends to the side surface of the dielectric plate 51, and this part is connected to the circuit pattern 24 by soldering.

As shown in FIG. 6, a through hole 12 is provided in a part of the magnetic substrate 10, and a transformer 70 is mounted in the hole 12. The transformer 70 includes a core 72 having an E-shaped cross section and a magnetic substrate.
The end of the core 72 is attached to the upper surface of the magnetic substrate 20 so as to form a closed magnetic path together with 20. In the core 72, a frame body 76 made of a synthetic resin in which the leads 74 are planted on the side surface is formed.
Is fitted. Then, as shown in FIG. 7, the lead 74
Are soldered to the wiring pattern 23.

Magnetic substrates 10, 20 and capacitors laminated in this way
50, transformer 70 and other circuit elements incorporated therein
40 is housed in a shield metal case 80 including a bottom plate 81 and a lid 82. The lower surface of the magnetic substrate 20 is adhered and fixed to the bottom plate 81 of the case 80. Reference numeral 90 in FIG. 2 denotes a terminal plate in which terminals 91 for external connection are implanted.

The capacitor 50 does not necessarily have to be flat. Since the circuit patterns 62 and 64 on the upper surface of the capacitor 50 are eliminated, a slightly larger magnetic substrate 10 is required, but a surface-mounted capacitor may be mounted on the circuit pattern 24.

Further, the magnetic substrate 10 and the circuit pattern on the dielectric plate 51, and the printed coil 30 are not limited to the embodiments, but may be formed in multiple layers with an insulating layer interposed. The lower surface of the magnetic substrate 20 may be adhered to a single metal plate such as the bottom plate 81, or may be left flat without adhering to the metal plate and its housing is incorporated into an electric device. It may be fixed to the body or the like so that it can be fixed.

〔The invention's effect〕

According to the present invention, since the magnetic substrate having good thermal conductivity is used and the lower surface of the magnetic substrate can be adhered and fixed to the metal plate or the case of electric equipment, it is possible to obtain a composite component having an extremely high heat dissipation effect. In addition, since the coil and the capacitor are built in the laminated thin printed circuit board, the height dimension can be reduced to 6 mm or less from the conventional 12 mm.
There is an effect that a remarkable thinning can be achieved.

[Brief description of drawings]

FIG. 1 is a partially sectional front view showing an embodiment of the composite component of the present invention, FIG. 2 is a plan view in which a part of the case of the composite component is cut away, and FIG. 3 is an enlarged view thereof. 4 is an enlarged front sectional view of the capacitor, FIG. 6 is an enlarged front sectional view of the transformer portion, and FIG. 7 is an enlarged front sectional view of the transformer portion. It is a side sectional view. 10 ・ 20 …… magnetic substrate, 30 …… print coil 22 ・ 24 …… circuit pattern, 40 …… circuit element 62 ・ 64 …… circuit pattern, 50 …… capacitor 80 …… metal case

Claims (2)

[Claims] 1. A circuit pattern and a print coil electrically connected through a through hole are formed on an upper surface and a lower surface of a first magnetic substrate, respectively, and a flat second plate is formed on a lower surface of the first magnetic substrate. The magnetic composite substrate is laminated and fixed, and a circuit element is mounted on the circuit pattern. 2. A flat plate-shaped capacitor having electrodes embedded in a dielectric is fixed on the circuit pattern, and
The composite component for electric power according to claim 1, wherein a second circuit pattern electrically connected to the circuit pattern is provided on the upper surface of the capacitor, and a circuit element is mounted on the second circuit pattern.