Nonuniform spacing layer for magnetic bubble circuits

Claim 2

A bubble chip, comprising a sheet of magnetic bubble material, a nonferromagnetic spacing layer of varying thickness disposed on said sheet, and an overlay pattern of ferromagnetic circuit elements forming a bubble interaction logic circuit disposed on said spacing layer for guiding bubbles in said sheet, said spacing layer having a raised area at a selected location determined by said overlay pattern, said selected location coinciding with the section of said logic circuit where a bubble interaction is designed to take place so as to weaken the magnetic coupling of bubbles in said sheet to said overlay pattern at said selected location.

Claim 3

The chip of claim 1, wherein said spacing layer is a stratified spacing layer composed of a first sublayer of one material of uniform predetermined thickness, said raised area being provided by a second sublayer of another material of uniform predetermined thickness disposed on top of said first sublayer at said selected location, said one element being at least partially disposed on top of said second sublayer.

Claim 4

The bubble chip of claim 1, wherein said raised area of said spacing layer is formed integrally with the rest of said spacing layer.

Claim 5

The bubble chip of claim 1, wherein said raised area of said spacing layer and said spacing layer are made of the same material.

Claim 6

A bubble chip, comprising a sheet of magnetic bubble material, a nonferromagnetic spacing layer of varying thickness disposed on said sheet, said spacing layer having a raised area at a selected location, and an overlay pattern of ferromagnetic circuit elements disposed on said spacing layer for guiding bubbles in said sheet, one of said elements being at least partially disposed on said raised area so as to weaken the magnetic coupling of bubbles in said sheet to said one element, said overlay pattern including elements forming a logic circuit, said one element being an element of said logic circuit from which bubbles are deflectible by bubble-to-bubble repulsion.

Claim 7

A bubble chip, comprising a sheet of magnetic bubble material, a nonferromagnetic spacing layer of varying thickness disposed on said sheet, said spacing layer having a raised area at a selected location, and an overlay pattern of ferromagnetic circuit elements disposed on said spacing layer for guiding bubbles in said sheet, one of said elements being at least partially disposed on said raised area so as to weaken the magnetic coupling of bubbles in said sheet to said one element, said overlay pattern including elements forming a logic circuit, said one element being an element of said logic circuit from which bubbles are deflectible by bubble-to-bubble repulsion.

Claim 8

A bubble chip, comprising a sheet of magnetic bubble material, a nonferromagnetic spacing layer of varying thickness disposed on said sheet, said spacing layer having a raised area at a selected location, and an overlay pattern of ferromagnetic circuit elements disposed on said spacing layer for guiding bubbles in said sheet, one of said elements being at least partially disposed on said raised area so as to weaken the magnetic coupling of bubbles in said sheet to said one element, said spacing layer being a stratified spacing layer composed of a first sublayer of one material of uniform predetermined thickness, said raised area being provided by a second sublayer of another material of uniform predetermined thickness disposed on top of said first sublayer at said selected location, said one element being at least partially disposed on top of said second sublayer, said overlay pattern including elements forming a logic circuit, said one element being an element of said logic circuit from which bubbles are deflectible by bubble-to-bubble repulsion.

Claim 9

A bubble chip, comprising a sheet of magnetic bubble material, a nonferromagnetic spacing layer of varying thickness disposed on said sheet, said spacing layer having a raised area at a selected location, and an overlay pattern of ferromagnetic circuit elements disposed on said spacing layer for guiding bubbles in said sheet, one of said elements being at least partially disposed on said raised area so as to weaken the magnetic coupling of bubbles in said sheet to said one element, said spacing layer being a stratified spacing layer composed of a first sublayer of one material of uniform predetermined thickness, said raised area being provided by a second sublayer of another material of uniform predetermined thickness disposed on top of said first sublayer at said selected location, said one element being at least partially disposed on top of said second sublayer, said overlay pattern including elements forming a logic circuit, said one element being an element of said logic circuit from which bubbles are deflectible by bubble-to-bubble repulsion.

Claim 10

The chip of claim 6, wherein the prEdetermined thickness of said first sublayer is optimum for orderly bubble propagation and the predetermined thickness of said second sublayer is chosen such that the combined thickness of said sublayers is optimum for conditional deflection of bubbles from said one element of said logic circuit.

Claim 11

A bubble chip comprising a sheet of magnetic bubble material, a nonferromagnetic spacing layer of varying thickness disposed on said sheet, said spacing layer having a raised area at a selected location, and an overlay pattern of ferromagnetic circuit elements disposed on said spacing layer for guiding bubbles in said sheet, one of said elements being at least partially disposed on said raised area so as to weaken the magnetic coupling of bubbles in said sheet to said one element, said spacing layer being a stratified spacing layer composed of a first sublayer of one material of uniform predetermined thickness, said raised area being provided by a second sublayer of another material of uniform predetermined thickness disposed on top of said first sublayer at said selected location, said one element being at least partially disposed on top of said second sublayer, said second sublayer being composed of an electrically conductive, and nonferromagnetic material.

Claim 12

A bubble chip comprising a sheet of magnetic bubble material, a nonferromagnetic spacing layer of varying thickness disposed on said sheet, said spacing layer having a raised area at a selected location, and an overlay pattern of ferromagnetic circuit elements disposed on said spacing layer for guiding bubbles in said sheet, one of said elements being at least partially disposed on said raised area so as to weaken the magnetic coupling of bubbles in said sheet to said one element, said spacing layer being a stratified spacing layer composed of a first sublayer of one material of uniform predetermined thickness, said raised area being provided by a second sublayer of another material of uniform predetermined thickness disposed on top of said first sublayer at said selected location, said one element being at least partially disposed on top of said second sublayer, said second sublayer being composed of an electrically conductive, and nonferromagnetic material.

Claim 13

The chip of claim 8, further comprising a pattern of electrical control leads disposed on said first sublayer, said control leads being composed of the same material as said second sublayer.

Claim 14

The bubble chip of claim 8, wherein in additon to said raised area and separate therefrom said second sublayer defines a pattern of electrical control leads.

Claim 15

A bubble chip, comprising a sheet of magnetic bubble material, nonferromagnetic spacing layer of varying thickness having raised areas at selected locations, a ferromagnetic overlay circuit pattern operatively disposed on said spacing layer defining a field-accessed bubble logic circuit having a plurality of channels, one of said channels having a controllable junction to which bubbles on said one channel normally pass in one direction in the absence of a corresponding bubble on another channel and take a different direction from said junction in the presence of a corresponding bubble on said other channel, a portion of said circuit overlay defining said controllable junction on said one channel being located on one of the raised areas of said spacing layer whereby magnetic coupling of the ferromagnetic circuit pattern at said controllable junction is weaker than the magnetic coupling of corresponding portions of the overlay pattern in said other channel such that bubble deflection is facilitated without weakening the coupling of bubbles on said other channel to the overlay pattern.

Claim 16

A bubble chip, comprising a sheet of magnetic bubble material, nonferromagnetic spacing layer of varying thickness having raised areas at selected locations, a ferromagnetic overlay circuit pattern operatively disposed on said spacing layer defining a field-accessed bubble logic circuit having a plurality of channels, one of said channels having a controllable junction to which bubbles on said one channel normally pass in one direction in the absence of a corresponding bubble on another channel and take a different direction from said junction in the presence of a corresponding bubble on said other channel, a portion of said circuit overlay defining said controllable junction on said one channel being located on one of the raised areas of said spacing layer whereby magnetic coupling of the ferromagnetic circuit pattern at said controllable junction is weaker than the magnetic coupling of corresponding portions of the overlay pattern in said other channel such that bubble deflection is facilitated without weakening the coupling of bubbles on said other channel to the overlay pattern.