Allegro Microsystems, LLC

Marie-Adelaide Lo

Andreas P Friedrich

William P Taylor

Michael C Doogue

Paul A David

Ravi Vig

Eric G Shoemaker

Eric Burdette

Andrea Foletto

P Karl Scheller

Nicolas Yoakim

A magnetic field sensor includes a lead frame, a passive component, semiconductor die supporting a magnetic field sensing element and attached to the lead frame, a non-conductive mold material enclosing the die and at least a portion of the lead frame, and a ferromagnetic mold material secured to a portion of the non-conductive mold material. The lead frame has a recessed region and the passive component is positioned in the recessed region. The ferromagnetic mold material may comprise a soft ferromagnetic material to form a concentrator or a hard ferromagnetic material to form a bias magnet.

Magnetic field sensor integrated circuit with integral ferromagnetic material

A magnetic field sensor includes one or more magnetic field sensing elements and a back-biased magnet arranged to avoid saturation of the one or more magnetic field sensing elements, particularly when the one or more magnetic field sensing elements comprise one or more magnetoresistance elements. The one or more magnetoresistance elements can be arranged in a resistor bridge.

Back-biased magnetic field sensor having one or more magnetoresistance elements

A magnetic field sensor includes a lead frame, a semiconductor die supporting a magnetic field sensing element, a non-conductive mold material enclosing the die and a portion of the lead frame, a ferromagnetic mold material secured to the non-conductive mold material and a securing mechanism to securely engage the mold materials. The ferromagnetic mold material may comprise a soft ferromagnetic material to form a concentrator or a hard ferromagnetic material to form a bias magnet. The ferromagnetic mold material may be tapered and includes a non-contiguous central region, as may be an aperture or may contain the non-conductive mold material or an overmold material. Further embodiments include die up, lead on chip, and flip-chip arrangements, wafer level techniques to form the concentrator or bias magnet, integrated components, such as capacitors, on the lead frame, and a bias magnet with one or more channels to facilitate overmolding.

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Chene Bougeries, Switzerland

Marie-Adelaide Lo