FIELD OF THE DISCLOSURE

The present disclosure relates generally to the field of voltage suppression devices and relates more particularly to a surface mount metal oxide varistor device that is temperature resistant, space saving, and amenable to high speed manufacturing and installation processes.

FIELD OF THE DISCLOSURE

Metal oxide varistors (MOVs) are voltage dependent, nonlinear devices that are commonly employed in electronic circuits for providing transient voltage suppression. A conventional MOV device includes a metal oxide ceramic chip (the MOV) having electrodes disposed on opposite sides thereof. Conducive wire leads may be connected (e.g., soldered) to the metal electrodes to facilitate electrical connection of the MOV device within a circuit. The MOV, the metal electrodes, and portions of the leads that are connected to the electrodes are typically coated with epoxy to protect these components from environmental contaminants and to prevent interference with surrounding electrical devices.

Conventional MOV devices of the type described above are associated with several shortcomings. For example, during installation, the wire leads of a conventional MOV device are inserted into through holes in a printed circuit board (PCB). The wire leads must then be soldered to both the frontside and the backside of the PCB, making the installation procedure incompatible with pick and place processes necessary for achieving high speed, automated assembly. Furthermore, conventional MOV devices stand quite tall on a PCB, which may necessitate an undesirably large form factor in a completed electronic device. Still further, the protective epoxy coating of a conventional MOV device cannot withstand the high operating temperatures (e.g., up to 125 degrees Celsius) necessary for meeting the AEC-Q200 stress resistance standard.

In view of the above, it is desirable to provide a MOV device amenable to installation using high speed, pick and place processes. It is further desirable to provide such an MOV device having a compact form factor compared to conventional MOV devices. It is further desirable to provide such an MOV device capable of withstanding high operating temperatures (e.g., up to 125 degrees Celsius) necessary for meeting the AEC-Q200 stress resistance standard. It is with respect to these and other considerations that the present improvements may be useful.

SUMMARY

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

An exemplary embodiment of a metal oxide varistor (MOV) device in accordance with the present disclosure may include a MOV chip having first and second electrodes disposed on opposing side thereof, a first lead frame portion including a first contact tab electrically connected to the first electrode and a first lead contiguous with the first contact tab and extending away from the MOV chip for connecting the MOV device within a circuit, a second lead frame portion including a second contact tab electrically connected to the second electrode and a second lead contiguous with the second contact tab and extending away from the MOV chip for connecting the MOV device within a circuit, and a device body encasing the MOV chip, the first contact tab, the second contact tab, and portions of the first and second leads, wherein the first and second leads extend out of the device body and are bent into flat abutment with a bottom surface of the device body.

Another exemplary embodiment of a MOV device in accordance with the present disclosure may include a MOV chip having first and second electrodes disposed on opposing side thereof, a first lead frame portion including a first contact tab electrically connected to the first electrode and a first lead contiguous with the first contact tab and extending away from the MOV chip for connecting the MOV device within a circuit, a second lead frame portion including a second contact tab electrically connected to the second electrode and a second lead contiguous with the second contact tab and extending away from the MOV chip for connecting the MOV device within a circuit and a plastic device body encasing the MOV chip, the first contact tab, the second contact tab, and portions of the first and second leads, wherein the first and second leads extend out of the device body and are bent into flat abutment with a bottom surface of the device body, with portions of the first and second leads disposed within complementary recesses formed in the bottom surface.

An exemplary embodiment of a method of manufacturing a metal oxide varistor (MOV) device in accordance with the present disclosure may include stamping first and second lead frame portions out of a sheet of metal, the first and second lead frame portions being “L” shaped and extending from respective first and second frame members, separating the first lead frame portion from the second lead frame portion, bending the first and second leads frame portions to define respective first and second contact tabs, arranging the first and second leads frame portions in a mirror image relationship with the first contact tab of the first lead frame portion disposed in a confronting, parallel relationship with the second contact tab of the second lead frame portion, placing a MOV chip between the first and second contact tabs and electrically connecting the first and second contact tabs to respective first and second electrodes of the MOV chip, overmolding a device body onto the MOV chip, the first and second contact tabs, and portions of first and second leads of the first and second lead frame portions, cutting the first and second leads away from the first and second frame members, and bending the first and second leads into flat abutment with a bottom surface of the device body.

