Abstract When a conventional printed wiring board is subjected to a harsh environment, leakage can develop between adjacent conductors over a period of time. If high impedance circuits are employed on the board, such leakage can adversely affect circuit performance. The effect of such leakage can be minimized if the circuit layout is so arranged that potentially troublesome leakage occurs only to elements that operate at comparable operating potentials. In one embodiment of the invention, a circuit is shown having a high impedance point on a printed wiring board intended for an automotive application. The high impedance wiring conductor is completely surrounded by a metal conductor that is connected to a potential point in the circuit that approximates the potential at which the high impedance point will operate. When the automotive environment results in surface leakage, there will be very little change in the operational character of the high impedance circuit.
A printed wiring circuit board for mounting a group of electronic components and interconnecting said components to form an electronic circuit, said board comprising: an insulating substrate, an array of conductors disposed on said substrate, said array being contoured to complete the interconnections between said components to achieve said circuit, a first conductor in said array interconnecting elements of said components to form a point operating at an impedance that is high relative to the impedance normally encountered at other points in said circuit, and a second conductor in said array adjacent to and surrounding said first conductor, said second conductor being connected to a source of potential approximating the potential at said point.
Claim 2
Dependent Claim
114 words
A printed wiring circuit board for mounting a group of electronic components and interconnecting said components to form an electronic circuit, said board comprising: an insulating substrate, an array of conductors disposed on said substrate, said array being contoured to complete the interconnections between said components to achieve said circuit, a first conductor in said array interconnecting elements of said components to form a point operating at an impedance that is high relative to the impedance normally encountered at other points in said circuit, and a second conductor in said array adjacent to and surrounding said first conductor, said second conductor being connected to a source of potential approximating the potential at said point.
Claim 3
Dependent Claim
22 words
The device of claim 1 wherein said second conductor is additionally employed as an interconnecting element in the remainder of said array.