Electronic transformer/inductor devices and methods for making same

Abstract

The present invention relates to the methods of construction for inductive components of, preferably, ferromagnetic materials such as inductors, chokes, and transformers when used as an integral part of the fabrication of PCB's or FLEX's. In one preferred embodiment, holes are formed through a ferromagnetic substrate and plated with conductive material. The arrangement of these holes, and the subsequent design that ensues, will form the inductive components within the plane of the media in which the device is formed; using the substrate for a magnetic core. By using this approach, the inductive components can be miniaturized to physical sizes compatible with the requirements of modem surface mount technology (SMT) for integrated circuitry (IC). This process also allows these components to be fabricated using mass production techniques, thereby avoiding the need to handle discrete devices during the manufacturing process. In another preferred embodiment, a series of thin, concentric high permeability rings are etched on a substrate to provide high permeability transformers and inductors having minimal eddy current effects.

Description

PRIORITY CLAIM [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 234,636 filed Sept. 22, 2000 entitled “Electronic Transformer / Inductor Devices And Methods For Making Same” and U.S. Provisional Application No. 60 / 237,356 filed Sept. 27, 2000 entitled “Electronic Transformer / Inductor Devices And Methods For Making Same.”FIELD OF THE INVENTION [0002] The present invention relates to inductive components and methods for manufacturing these components. BACKGROUND OF THE INVENTION [0003] Inductive components are commonly fabricated using ferromagnetic cores and windings of insulated electrical wire. The ferromagnetic cores are typically toroidal cores, rod cores, or assemblies made of a lower E shaped ferromagnetic part and a ferromagnetic cap connecting the three legs of the E such as shown in FIG. 1. [0004] The toroid and rod cores are manually or automatically wound with the insulated copper wire to form a number of multiple turn windings for a transfor...

AI Technical Summary

Benefits of technology

[0007] The preferred embodiments of the present invention provide inductors and transformers and methods of manufacturing these devices which offer very significant advantages over the state-of-the-art. These inductors and transformers connected in accordance with this invention have a number of applications in the electronics, telecommunication and computer fields. In one preferred embodiment described below, a rectangular slab of ferromagnetic material is encapsulated between printed circuitry. A plurality of through holes (vias) are drilled through or formed during manufacture of the slab from the top face of the slab to the bottom face of the slab, the number of holes corresponding to the number of desired turns of the windings. This embodiment utilizes Ampere's Law in a very novel manner to form a transformer, inductor, or the like within the circuit board rather than the use or assembly of discrete inductive devices to the circuit board. Thus, the windings are not insulated electric wires. Rather, the holes through the slab are made electrically conductive by through hole plating or the like and electrically connect with the printed circuits encapsulating the slab. This pattern of plated through holes and the printed circuitry form the inductor and transformer windings with the core of the inductors and transformers being the drilled or formed slab of ferromagnetic material. This embodiment provides substantial improvements, particularly in fabricating high frequency inductors and transformers.

[0009] In addition to the advantages described above, the preferred embodiments have a number of additional significant advantages. These include: superior heat removal, outside connections that are more accessible to simplify electrical connection, shorter flux paths to increase magnetic performance, simpler fabrication, interconnections that are more integrated, smaller inductive devices, superior performance, and excellent manufacturing repeatability.

Problems solved by technology

Thus, the windings are not insulated electric wires.

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