US5466892A — Circuit boards including capacitive coupling for …

Claim 1

Independent Claim 186 words

A circuit board for mounting electrical components and having conductive layers spaced apart and electrically insulated from each other, and at least one circuit for transmitting AC signals from one layer to another, the AC signal transmitting circuit comprising a conductive signal pad formed by a first conductive layer in the circuit board and adapted for coupling with means for generating an AC signal, a conductive receptor pad formed by a second conductive layer in the circuit board and adapted for coupling with means for responding to the AC signal, and a dielectric layer arranged between the signal and receptor pads, the thickness and dielectric constant of the dielectric layer and the respective areas of the signal and receptor pads being selected for developing effective capacitive coupling between the signal and receptor pads in order to electrostatically transmit the AC signal from the signal pad to the receptor pad, the signal and receptor pads and the dielectric layer having electrical characteristics approaching a resonant frequency condition in the AC signal transmitting circuit whereby capacitive reactance and inductive reactance approach equality in order to optimize capacitive coupling.

Claim 2

Dependent Claim 186 words

A circuit board for mounting electrical components and having conductive layers spaced apart and electrically insulated from each other, and at least one circuit for transmitting AC signals from one layer to another, the AC signal transmitting circuit comprising a conductive signal pad formed by a first conductive layer in the circuit board and adapted for coupling with means for generating an AC signal, a conductive receptor pad formed by a second conductive layer in the circuit board and adapted for coupling with means for responding to the AC signal, and a dielectric layer arranged between the signal and receptor pads, the thickness and dielectric constant of the dielectric layer and the respective areas of the signal and receptor pads being selected for developing effective capacitive coupling between the signal and receptor pads in order to electrostatically transmit the AC signal from the signal pad to the receptor pad, the signal and receptor pads and the dielectric layer having electrical characteristics approaching a resonant frequency condition in the AC signal transmitting circuit whereby capacitive reactance and inductive reactance approach equality in order to optimize capacitive coupling.

Claim 3

Dependent Claim 67 words

The circuit board of claim 1 further comprising additional conductive circuit means formed on the first and second conductive layers, the thickness and dielectric constant of the dielectric layer, the respective areas of the signal and receptor pads also being selected in combination with spacing of the additional conductive circuit means front the signal and receptor pads for minimizing capacitive coupling with the additional conductive circuit means.

Claim 4

Dependent Claim 59 words

The circuit board of claim 2 wherein the additional conductive circuit means on the first and second conductive layers form additional signal and receptor pads separated by additional dielectric layers for developing effective capacitive coupling between sets of the additional signal and receptor pads on the first and second conductive layers also for electrostatic transmission of AC signals therebetween.

Claim 5

Dependent Claim 81 words

The circuit board of claim 1 wherein the circuit board is of a multi-layer type having at least a third conductive layer and further wherein the additional conductive circuit means on the adjacent pairs of the first, second and third conductive layers form additional signal and receptor pads separated by additional dielectric layers for developing effective capacitive coupling between sets of the additional signal and receptor pads on the first and second conductive layers for electrostatic transmission of AC signals therebetween.

Claim 6

Dependent Claim 163 words

The circuit board of claim 1 wherein: capacitive reactance is defined by the equation (I) ##EQU6## where F is frequency and C is capacitance; inductive reactance is defined by the equation (II) X.sub.L =2πFL where F is frequency and L is inductance; capacitance is defined by the equation (III) ##EQU7## where A is the effective mutual area of the transmitting and receptor pads, D is Faraday's constant, E is the dielectric constant, and τ is the thickness of the dielectric layer; and inductance is defined by the equation (IV) L=0.005 ln (4h/d)μH/in. where ln indicates the natural logarithm for the value 4h/d, where h is the distance above a ground plane, and d is the equivalent diameter of a conductor; wherein capacitance and inductance are established in equations I and II with X C and X L being equal or approaching equality and the values of A, D, τ, I N , h (etc.) are preselected or calculated from equations III and IV.

Claim 7

Dependent Claim 33 words

The circuit board of claim 5 wherein capacitance is initially selected followed by calculation of capacitive reactance from equation I with inductive reactance being assumed equal to or approaching equality with capacitive reactance.

Claim 8

Independent Claim 194 words

A method of forming a circuit board for mounting electrical components and having conductive layers spaced apart and electrically insulated from each other, and at least one circuit for transmitting AC signals from one layer to another, comprising the steps of forming a conductive signal pad and conductive receptor pad on surfaces of the circuit board spaced apart in a Z direction with a dielectric layer therebetween, the conductive signal pad being adapted for coupling with means for generating an AC signal, coupling the conductive signal pad with means for generating an AC signal, coupling the conductive receptor pad with means for responding to the AC signal, selecting the thickness and dielectric constant of the dielectric layer and the respective areas of the signal and receptor pads for developing effective capacitive coupling between the signal and receptor pads in order to electrostatically transmit the AC signal from the signal pad to the receptor pad, and selecting electrical characteristics of the signal and receptor pads and the dielectric layer to approach a resonant frequency condition in the AC signal transmitting circuit whereby capacitive reactance and inductive reactance approach equality in order to optimize capacitive coupling.

Claim 9

Independent Claim 194 words

A method of forming a circuit board for mounting electrical components and having conductive layers spaced apart and electrically insulated from each other, and at least one circuit for transmitting AC signals from one layer to another, comprising the steps of forming a conductive signal pad and conductive receptor pad on surfaces of the circuit board spaced apart in a Z direction with a dielectric layer therebetween, the conductive signal pad being adapted for coupling with means for generating an AC signal, coupling the conductive signal pad with means for generating an AC signal, coupling the conductive receptor pad with means for responding to the AC signal, selecting the thickness and dielectric constant of the dielectric layer and the respective areas of the signal and receptor pads for developing effective capacitive coupling between the signal and receptor pads in order to electrostatically transmit the AC signal from the signal pad to the receptor pad, and selecting electrical characteristics of the signal and receptor pads and the dielectric layer to approach a resonant frequency condition in the AC signal transmitting circuit whereby capacitive reactance and inductive reactance approach equality in order to optimize capacitive coupling.

Claim 10

Dependent Claim 69 words

The method of claim 7 further comprising the step of forming additional conductive circuit means on the first and second conductive layers, the thickness and dielectric constant of the dielectric layer, the respective areas of the signal and receptor pads also being selected in combination with spacing of the additional conductive circuit means from the signal and receptor pads for minimizing capacitive coupling with the additional conductive circuit means.

Claim 11

Dependent Claim 58 words

The method of claim 8 wherein the additional conductive circuit means on the first and second conductive layers form additional signal and receptor pads separated by additional dielectric layers for developing effective capacitive coupling between sets of the additional signal and receptor pads on the first and second conductive layers also for electrostatic transmission of AC signals therebetween.

Claim 12

Dependent Claim 80 words

The method of claim 7 wherein the circuit board is of a multi-layer type having at least a third conductive layer and further wherein the additional conductive circuit means on the adjacent pairs of the first, second and third conductive layers form additional signal and receptor pads separated by additional dielectric layers for developing effective capacitive coupling between sets of the additional signal and receptor pads on the first and second conductive layers for electrostatic transmission of AC signals therebetween.

Claim 13

Dependent Claim 162 words

The method of claim 7 wherein: capacitive reactance is defined by the equation (I) ##EQU8## where F is frequency and C is capacitance; inductive reactance is defined by the equation (II) X.sub.L =2πFL where F is frequency and L is inductance; capacitance is defined by the equation (III) ##EQU9## where A is the effective mutual area of the transmitting and receptor pads, D is Faraday's constant, E is the dielectric constant, and τ is the thickness of the dielectric layer; and inductance is defined by the equation (IV) L=0.005 ln (4h/d)μH/in. where ln indicates the natural logarithm for the value 4h/d, where h is the distance above a ground plane, and d is the equivalent diameter of a conductor; wherein capacitance and inductance are established in equations I and II with X C and X L being equal or approaching equality and the values of A, D, τ, I N , h (etc.) are preselected or calculated from equations III and IV.

Claim 14

Dependent Claim 40 words

The method of claim 11 further comprising the step of initially selecting capacitance for the AC signal transmitting circuit and then calculating capacitive reactance from equation I with inductive reactance being assumed equal to or approaching equality with capacitive reactance.

Claim 15

Dependent Claim 195 words

A circuit board for mounting electrical components and having conductive layers spaced apart and electrically insulated from each other, and at least one circuit for transmitting AC signals from one layer to another, the AC signal transmitting circuit comprising a conductive signal means formed by a first conductive layer in the circuit board and adapted for coupling with means for generating an AC signal, a conductive receptor means formed by a second conductive layer spaced apart in a Z direction from the first conductive layer in the circuit board and adapted for coupling with means for responding to the AC signal, a dielectric layer arranged between the signal and receptor means, characteristics for the conductive signal means, the conductive receptor means and the dielectric layer arranged therebetween being selected for developing effective signal transmission coupling between the signal and receptor means in order to electrostatically transmit the AC signal from the signal means to the receptor means, and the signal and receptor means and the dielectric layer having electrical characteristics approaching a resonant frequency condition in the AC signal transmitting circuit whereby capacitive reactance and inductive reactance approach equality in order to optimize capacitive coupling.

Claim 16

Dependent Claim 195 words

A circuit board for mounting electrical components and having conductive layers spaced apart and electrically insulated from each other, and at least one circuit for transmitting AC signals from one layer to another, the AC signal transmitting circuit comprising a conductive signal means formed by a first conductive layer in the circuit board and adapted for coupling with means for generating an AC signal, a conductive receptor means formed by a second conductive layer spaced apart in a Z direction from the first conductive layer in the circuit board and adapted for coupling with means for responding to the AC signal, a dielectric layer arranged between the signal and receptor means, characteristics for the conductive signal means, the conductive receptor means and the dielectric layer arranged therebetween being selected for developing effective signal transmission coupling between the signal and receptor means in order to electrostatically transmit the AC signal from the signal means to the receptor means, and the signal and receptor means and the dielectric layer having electrical characteristics approaching a resonant frequency condition in the AC signal transmitting circuit whereby capacitive reactance and inductive reactance approach equality in order to optimize capacitive coupling.

Claim 17

Dependent Claim 82 words

The circuit board of claim 13 wherein the circuit board is of a multi-layer type having at least a third conductive layer and further wherein the additional conductive circuit means on the adjacent pairs of the first, second and third conductive layers form additional signal and receptor means separated by additional dielectric layers for developing effective signal transmitting coupling between sets of the additional signal and receptor means on the first and second conductive layers for electrostatic transmission of AC signals therebetween.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-11-13	1999-05-15	1999-11-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-11-13	2003-05-15	2003-11-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-11-13	2007-05-15	2007-11-14	$7700.00	Window Closed / Lapsed

Circuit boards including capacitive coupling for signal transmission and methods of use and manufacture

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