Method of making an inductor chip

Assignee: San Fernando Electric Manufacturing Co

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Filing: 1972-09-20

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Granted: 1973-10-16

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Expires: 1992-09-20

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Abstract

Abstract A monolithic inductor chip for use in electronic circuits, especially integrated and/or hybrid micro-electronic circuits, is formed by providing a plurality of ferrite wafers each having a conductive element of generally U shape silk screened on its top surface. An end portion of each element passes through a hole in the wafer to a point on the bottom of the wafer. The various wafers are stacked in such a manner that the end portion on the bottom of one wafer electrically connects to the initial point of the U shape element on the top of the next successive wafer so that the stacked wafers define an inductive coil. The resulting stack is sintered to provide the monolithic chip.

Inventors

👤 M Zyetz

Bibliographic Details

Application Number —

Jurisdiction US

Data Source google_patents

Last Synchronized 2026-10-25 15:02

CPC Classifications

H; H01; H01F; H01F17/00; H01F17/0006; H01F17/0013; H01F41/00; H01F41/02; H01F41/04; H01F41/041; H01F41/046; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902

Claims Analysis

Total Claims: 6

Claim 1

Independent Claim 190 words

A method of providing a monolithic inductor chip including the steps of: a. providing a plurality of ferrite wafers dimensioned to be stacked, one on top of the other, with their peripheries approximately in registering relationship; b. drilling a small hole through each wafer adjacent to a peripheral edge portion; c. imprinting a conductive element of general U shape having initial and end points on a top surface of each wafer, the end point of the U terminating at said hole; d. filling the hole in each wafer with conductive material; e. orienting the wafers in a stack such that the open portion of the U shape on each successive wafer is oriented at 90* to the U shape on its preceeding wafer whereby the hole at the end point is in vertical alignment with the initial point of the succeeding U shape on the succeeding wafer so that a conductive connection between the one element and other is effected through the hole thereby electrically connecting the U shaped elements on successive wafers to define a coil; and, f. sintering the resulting stack to thereby provide said monolithic inductor chip.

Claim 2

Independent Claim 190 words

Claim 3

Dependent Claim 64 words

The method of claim 1, including the steps of providing blank ferrite wafers of greater thickness than the wafers making up said plurality, on the top and bottom of the stack prior to sintering and providing electrical leads extending from the stack connecting to opposite ends of the defined coil thereby providing an inductor chip for ready connection in integrated or hybrid micro-electronic circuits.

Claim 4

Dependent Claim 100 words

The method of claim 1, including the steps of drilling an additional hole in each wafer; providing an additional U shaped element imprinted on each wafer in side by side relationship with the first mentioned U shaped element, the terminal end point of the additional elements terminating at the additional hole and filling the additional hole with conductive material; orienting and connecting the additional elements such as to provide a continuation of the coil defined by the first mentioned elements to thereby provide multiple coiled inductor chip configuration of increased inductance relative to that of the first mentioned defined coil.

Claim 5

Dependent Claim 96 words

The method of claim 1, including the steps of drilling an additional hole in each wafer; providing an additional U shaped element imprinted on each wafer in side by side relationship with the first mentioned U shaped element, the terminal end point of the addtional element terminating at the additional hole and filling the additional hole with conductive material; orienting and connecting the additional elements to define an additional coil; and providing electrical leads extending from the stack connected to opposite ends of the first mentioned defined coil and additional coil to thereby provide a transformer.

Claim 6

Dependent Claim 92 words

The method of claim 2, including the steps of providing blank ferrite wafers with sufficient thicknesses and the margins of each of the plurality of wafers from the U shaped element to the edges of sufficient width to provide a magnetic path which closes the magnetic circuit of cross-sectional area equal to or greater than the area within the U shaped elements thereby providing a non-restrictive closed magnetic path to maximize magnetic coupling between turns of the coil and therebY provide the effect of maximizing the inductance obtainable in a solid chip.

References Cited (Backward Citations)

GB772528A Cited

US3492665A Cited

US3423517A Cited

US3683494A Cited

US3534471A Cited

US3518756A Cited

US3561110A Cited

US3629939A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-10-15	1977-04-16	1977-10-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-10-15	1981-04-16	1981-10-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-10-15	1985-04-16	1985-10-16	$7700.00	Window Closed / Lapsed

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