Method of making an inductive circuit incorporated in a planar circuit support member

• US 4,253,231 A
• Filed: 01/11/1978
• Issued: 03/03/1981
• Est. Priority Date: 01/13/1977
• Status: Expired due to Term

• Current Assignee: Compagnie industrielle des télécommunications CIT-ALCATEL
• Original Assignee: Compagnie Industrielle des Telecommunications Cit-Alcatel SA
• Inventors: Nouet, Christian
• Primary Examiner(s): Hall, Carl E.
• Application Number:
  US05/868,581
• Time in Patent Office: 1,147 Days
• Field of Search: 29/602 R, 29/605, 29/625, 29/626, 29/622, 29/832, 29/841, 335/187, 335/203, 335/279, 335/199, 336/200, 361/400-402, 427/96-99, 427/116, 427/127
• US Class Current: 29/602.1
• CPC Class Codes: G02B 6/353 the optical element being a shutter, baffle, beam dump or opaque element absorbers on light guide termination G02B6/243
• CPC Class Codes: G02B 6/3552 1x1 switch, e.g. on/off switch
• CPC Class Codes: G02B 6/3572 Magnetic force magnetic forces controlling reflecting elements in general G02B26/085; magneto-optic devices G02F1/09
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 41/02 for manufacturing cores, coils, or magnets H01F41/14 takes precedence; for dynamo-electric machines H02K15/00
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01F 41/14 for applying magnetic films to substrates
• CPC Class Codes: H05K 1/056 the metal substrate being covered by an organic insulating layer
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/09063 Holes or slots in insulating substrate not used for electrical connections
• CPC Class Codes: H05K 2201/09081 Tongue or tail integrated in planar structure, e.g. obtained by cutting from the planar structure
• CPC Class Codes: H05K 2201/097 Alternating conductors, e.g. alternating different shaped pads, twisted pairs; Alternating components
• CPC Class Codes: H05K 2201/10053 Switch
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.

Abstract

A planar support member for an electric circuit, e.g. a printed circuit board, wherein at least a region of the support member includes magnetic material through at least a part of its thickness. A magnetic circuit is made in this material by forming at least one opening through it. The support member is then coated with insulative material and conductor paths are made on both faces of the support member by conventional techniques for such members. These paths include a winding disposed around a core part of the magnetic circuit with alternate half turns being formed on opposite faces and interconnected by through plating. The inductive circuit thus formed may constitute an inductor, a transformer or a relay.

Claims

1. A method of manufacturing an inductive circuit which is incorporated in a planar support member for supporting an electric circuit, said method comprising the steps of:

providing a planar metallic support member which includes at least a portion having magnetic material extending through at least a part of its thickness, said magnetic material and said support member having a configuration which forms a magnetic circuit including a magnetic core region with at least one opening adjacent to the magnetic core region;

coating at least the core region with a layer of insulative material;

forming conductor paths on both faces of said support member for interconnecting different components of an electric circuit to be supported by said support member, said conductor paths including a winding extending around said magnetic core region, said winding being electrically insulated from the magnetic material by the layer of insulative material, and interconnecting the portions of the winding which are located on opposite faces of the magnetic core via said opening;

forming said magnetic core region in the form of a strip lying between two slots and interconnecting the two slots by a third slot so that the magnetic core region takes the form of a tongue surrounded on three sides by a single opening; and

plastically deforming the tongue to adopt a position lying outside the plane of the magnetic circuit when unstressed to form the armature of a relay such that the tongue returns to said plane when magnetic flux flows through the magnetic circuit.

2. A method according to claim 1, including further steps of applying a second insulative coating to the tongue-shaped magnetic core followed by forming a conductor strip on said insulated core with said conductor strip bridging the opening around the tongue when the tongue is in the plane of the magnetic circuit to contact a conductor on the other side of the opening such that said contact is interrupted when the tongue adopts its position lying outside the said plane whereby the inductive circuit constitutes a switching relay incorporated in the support member.