Keyboard with edge vent

DETAILED DESCRIPTION What is claimed is: 1.
An electrical switch assembly comprising: first circuitry layer means, said first circuitry layer means including a flexible non-conductive substrate having first and second oppositely disposed surfaces, said first circuitry layer means having an electrically conductive pattern disposed upon its second surface; second circuitry layer means, said second circuitry layer means including a non-conductive substrate having first and second oppositely disposed surfaces, said second circuitry layer means having an electrically conductive pattern disposed upon its first surface, said first surface of said second circuitry layer means being positioned to face said second surface of said first circuitry layer means; spacer means, said spacer means being a layer of electrical insulating material positioned between said first and said second circuitry layer means, said spacer means cooperating with said first and said second circuitry layer means to define at least a first peripheral edge of the switch assembly, said spacer means being provided with at least one aperture which forms a cavity between said first and second circuitry layer means whereby said conductive patterns on said circuitry layer means may be moved into electrical contact with one another; and vent passage means for venting said cavity, said vent passage means extending from said switch assembly first peripheral edge to said cavity whereby gas may flow freely between said edge and said cavity, said vent passage means comprising interconnected passage segments in said spacer means and in at least one of said first and second circuitry layer means.
2.
The electrical switch assembly of claim 1 wherein said vent passage means comprises a cooperating arrangment of passage segments in said spacer means and said first and said second circuitry layer means, said cooperating passage segments defining a passage which is at least partly undulating between said spacer means and at least one of said first and second circuitry layers