Patent Application
20120161909
The subject disclosure relates to switching devices and more particularly to miniature switching device structures.
Electromechanical and solid state switches and relays have long been known in the art. More recently, the art has focused on micro electromechanical systems (MEMS) technology.
In an illustrative embodiment, a switching device structure comprises a top layer and a bottom layer, each comprising a permalloy plug or other magnetizable material disposed within a coil; and an armature suspended in a cavity between the top and bottom layers, the armature having ferromagnetic material disposed on each of a top and bottom surface thereof. Each permalloy plug may be pulsed by its respective coil to switch it from a magnetic state to a non-magnetic state and thereafter may be subsequently pulsed by its respective coil to switch it from a non-magnetic state to a magnetic state. Such switching of states is used to move the armature from a “contacts open” to “contacts closed” state and vice versa and to assist in holding the armature in a selected state.
An end sectional view of a miniature relay structure 11 is shown in
The top permalloy plug layer 17 includes vertically disposed cylindrical permalloy plugs 25, 27, each of which is centrally disposed within a respective conductive coil 29, 31. Similarly, the bottom permalloy plug layer 19 includes vertically disposed permalloy plugs 33, 35. Each permalloy plug is centrally disposed within a respective conductive coil 37, 39. The bottom permalloy plug layer 19 also has conductive pads or relay contacts 38, 40 formed thereon. It will be appreciated that the permalloy plugs 25, 27 each comprise a body of material which may be magnetized and demagnetized and that, while permalloy is disclosed for use in an illustrative embodiment, other readily magnetizable materials could be used.
Each armature, e.g. 21, 23 may comprise a generally rectangular piece of flexible material, such as, for example, fr 4 PCB (printed circuit board) material, which also may be used to form the top and bottom layers 17, 19 and an edge layer structure 45, 47. The respective outer ends, e.g. 41, 43 of the flexible armatures are sandwiched between laminated layers of the edge layer structure 45, 47 to thereby hinge the respective armatures to the side walls of the device. Respective relay contacts 46, 48 are formed on the underside of the respective inner ends 47, 49 of each of the armatures 21, 23.
As may be better seen in
Each armature 21, 23 further has respective ferromagnetic material layers, e.g., 55, 57 formed on its top and bottom sides. These layers 55, 57 are centrally disposed between respective top and bottom permalloy plugs 25, 33. The ferromagnetic layers 55, 57 render the armatures 21, 23 responsive to magnetic forces. In various embodiments, the ferromagnetic layers 55,57 could comprise an iron powder composition such as an iron epoxy or iron polyimide composition, a solid piece of magnetic material, or other mixture of ferromagnetic powders with a binding agent.
The vertically running vias 53 supply coil-in and coil-out current paths for each coil, e.g. 29, 37, 31, 39 and tip and ring current paths for each armature contact pair and for each base layer contact pair. Conductor paths to the vias 53 are suitably formed in the laminated layers of the structure.
In operation, each permalloy plug 25,33 acts like a magnetic switch. When the permalloy is pulsed with a coil, e.g., 29, 37, it switches from magnetic to non-magnetic. When pulsed again it switches back to magnetic. Pulsing the coils 29,37 implements two functions. First, the magnetic force generated by pulsing attracts the ferro magnetic coating 55,57 on the armature 21 to the plug 25, 33, whose coil was pulsed. Second, the magnetic force switches the permalloy “on” thereby adding to the magnetic power of the top or bottom magnet, thereby forcing the armature 21 to move to the now magnetized permalloy plug. Once the armature 21 is moved to either an up or down position through activation of the coils 29, 37, the top and bottom permanent magnets 13, 15 hold the armature 21 in that respective position until the coils are oppositely pulsed to move the armature 21 to the other respective position.
Thus, in one embodiment, to close the relay contacts 48 and 40, the top coil 29 is pulsed or driven so as to neutralize the force exerted by the top magnet 13 on the armature 21. At the same time, the bottom coil 37 is pulsed or driven so as to exert a force which pulls the armature 21 downwardly until the contacts 48 and 40 are in a closed position or state. Driving the bottom coil 37 in this manner also magnetizes the bottom permalloy plug 33 so that it exerts a holding force in a direction tending to hold the armature 21 in the closed contact position. This holding force adds to the force of the bottom magnet 15, thus securely holding the contact 40, 48 in the closed state.
To open the relay contacts 48, 40, the bottom coil 37 is pulsed so as to exert a force opposite to that of the holding force, thus neutralizing the force of the bottom magnet 15 and urging the armature 21 upward. This pulsing also demagnetizes the bottom permalloy plug 33. At the same time, the top coil 29 is pulsed in a manner which attracts the armature 21 upwardly, with the net result that the relay contacts 48 and 40 are opened to an “open” non-conducting state. The top permalloy plug 25 is also magnetized by this operation such that it thereafter assists the top magnet 13 in holding the contacts 40, 48 in the “open” state. That “open” state is maintained until the top and bottom coils 29, 37 are appropriately pulsed so as to again close the contacts 40, 48 in the manner described in the previous paragraph.
The conductive coils, e.g. 29, 31, may be planar coils such as a spiral coil formed in a single layer of a plurality of laminated layers, or may be constructed within a plurality of laminated layers, each of which contains a horizontal slice of a three dimensional coil structure and wherein the plurality of layers, when attached together, form a complete coil, similar to the coil structure taught in U.S. patent application Ser. No. 12/838,160, the subject matter of which is incorporated by this reference in its entirety herein.
The flexible armature material may have a compliance selected to reduce rotational torque requirements and may also employ conductor traces and contact pads scaled down to reduce size.
Illustrative embodiments enable the construction of relatively large arrays of relays such as the “eight groups of eight” arrangement 71 illustrated in
Those skilled in the art will appreciate that various adaptations and modifications of the just described illustrative embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/407,315, filed Oct. 27, 2010, entitled “Multi Integrated Switching Device Structures,” the contents of which are incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61407315 | Oct 2010 | US |
