High frequency latching relay with bending switch bar
First Claim
1. An electrical relay comprises:
- a cap layer;
a circuit substrate;
a switching layer positioned between the circuit substrate and the cap layer and having a switching cavity formed therein;
first and second electrical traces formed on the circuit substrate and terminating at first and second fixed contact pads, respectively, in the switching cavity;
a switch bar having a fixed end coupled to the relay housing and a free end;
first and second switching contacts attached to the free end of the switch bar and positioned between the first and second fixed contact pads;
a third electrical trace formed on the circuit substrate and electrically coupled to at least one of the first and second switching contacts;
a first plurality of ground traces formed on the circuit substrate to provide electrical shielding to the first, second and third electrical traces;
a piezoelectric actuator coupled to the switching layer and to the switch bar between its free end and its fixed end, the piezoelectric actuator being deformable in an extensional mode to displace the switch bar and move the switching contacts between the fixed contact pads;
a first conducting liquid volume in wetted contact with the first switching contact and the first fixed contact pad; and
a second conducting liquid volume in wetted contact with the second switching contact and the second fixed contact pad;
wherein;
motion of the switching contacts in a first direction causes the first conducting liquid volume to form a connection between the first switching contact and the first fixed contact pad and causes the second conducting liquid volume to separate into two droplets, thereby breaking a connection between the second switching contact and the second fixed contact pad; and
motion of the switching contacts in a second direction causes the first conducting liquid volume to separate into two droplets, thereby breaking the connection between the first switching contact and the first fixed contact pad and causes the second conducting liquid volume to form a connection between the second switching contact and the second fixed contact pad.
1 Assignment
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Accused Products
Abstract
An electrical relay that uses a conducting liquid in the switching mechanism. In the relay, a pair of moveable switching contacts is attached to the free end of a switch bar and positioned between a pair of fixed electrical contact pads. The connections to the switching contacts and the fixed contact pads are shielded by ground traces. A surface of each contact supports a droplet of a conducting liquid, such as a liquid metal. A piezoelectric actuator is energized to push or pull the switch bar and move the pair of switching contacts, closing the gap between one of the fixed contact pads and one of the switching contacts, thereby causing conducting liquid droplets to coalesce and form an electrical circuit. At the same time, the gap between the other fixed contact pad and the other switching contact is increased, causing conducting liquid droplets to separate and break an electrical circuit. The piezoelectric actuator is then de-energized and the switching contacts return to their starting positions. The volume of liquid metal is chosen so that liquid metal droplets remain coalesced or separated because of surface tension in the liquid. The relay is amenable to manufacture by micro-machining techniques.
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Citations
15 Claims
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1. An electrical relay comprises:
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a cap layer;
a circuit substrate;
a switching layer positioned between the circuit substrate and the cap layer and having a switching cavity formed therein;
first and second electrical traces formed on the circuit substrate and terminating at first and second fixed contact pads, respectively, in the switching cavity;
a switch bar having a fixed end coupled to the relay housing and a free end;
first and second switching contacts attached to the free end of the switch bar and positioned between the first and second fixed contact pads;
a third electrical trace formed on the circuit substrate and electrically coupled to at least one of the first and second switching contacts;
a first plurality of ground traces formed on the circuit substrate to provide electrical shielding to the first, second and third electrical traces;
a piezoelectric actuator coupled to the switching layer and to the switch bar between its free end and its fixed end, the piezoelectric actuator being deformable in an extensional mode to displace the switch bar and move the switching contacts between the fixed contact pads;
a first conducting liquid volume in wetted contact with the first switching contact and the first fixed contact pad; and
a second conducting liquid volume in wetted contact with the second switching contact and the second fixed contact pad;
wherein;
motion of the switching contacts in a first direction causes the first conducting liquid volume to form a connection between the first switching contact and the first fixed contact pad and causes the second conducting liquid volume to separate into two droplets, thereby breaking a connection between the second switching contact and the second fixed contact pad; and
motion of the switching contacts in a second direction causes the first conducting liquid volume to separate into two droplets, thereby breaking the connection between the first switching contact and the first fixed contact pad and causes the second conducting liquid volume to form a connection between the second switching contact and the second fixed contact pad. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification