Allegro Microsystems, LLC

Sprague Electric Company

Jay J Gagnon

William P Taylor

Nirmal Sharma

Michael C Doogue

Richard Dickinson

Virgil Ararao

John B Sauber

Raymond W Engel

Elsa Kam-Lum

Paul J Panaccione

Andreas P Friedrich

Kirsten Doogue

Thomas J Martiska

Raymond W Engle

Paul A Guillotte

Leonardo T Magpantay

Methods and apparatus for a magnetic field sensor in a molded IC package having a magnetic field sensing element in a die with a component coupled to a leadframe at a downset area. In embodiments, a thickness of the leadframe in the downset area is less than a thickness of the leadframe in a non-downset area adjacent to the downset area.

Sensor and method of providing a sensor

Magnetic field sensors and associated methods of manufacturing the magnetic field sensors include molded structures to encapsulate a magnetic field sensing element and an associated die attach pad of a lead frame and to also encapsulate or form a magnet or a flux concentrator.

Magnetic field sensors and methods for fabricating the magnetic field sensors

An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and substrate having a first surface in which is disposed one or more magnetic field transducers, with the first surface being proximate the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit relative to a conventional orientation. With this arrangement, a current sensor is provided for which the one or more magnetic field transducers are very close to the current conductor portion, resulting in a current sensor having improved sensitivity.

Current sensor

An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and substrate having a first surface in which is disposed one or more magnetic field transducers, with the first surface being proximate the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit relative to a conventional orientation. A current conductor portion can be deposited proximate to a surface of the substrate and proximate to the one or more magnetic field sensors. With this arrangement, a current sensor is provided for which the one or more magnetic field transducers are very close to the current conductor portion, resulting in a current sensor having improved sensitivity. An insulating layer can be disposed between the current conductor portion and the substrate.

An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and substrate having a first surface in which is disposed one or more magnetic field transducers, with the first surface being proximate the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit relative to a conventional orientation. A current conductor portion can be deposited on a surface of the substrate proximate to the one or more magnetic field sensors. With this arrangement, a current sensor is provided for which the one or more magnetic field transducers are very close to the current conductor portion, resulting in a current sensor having improved sensitivity.

A semiconductor device includes a lead frame assembly having a die attach pad with a die secured by a die bonding material. A portion of the die bonding material may flow out from between the die and the die attach pad to form a squash out layer. A raised bond pad is at least partially in the squash out layer area and extends upward from said die attach pad sufficient to be above the squash out layer. A bond wire has one end secured to a ground terminal on the die and the other end to the raised bond pad. The whole structure is encapsulated in a plastic package.

Semiconductor device leadframe die attach pad having a raised bond pad

The lead-frame in an integrated circuit package, a standard package designated SOT-89, has a plurality of leads of which at least one is an extension of a die-attach pad. At least one ground wing is formed as an extension of a peripheral portion of the die-attach pad and extends upward to approximately the plane of the top of the die. The ground wing has an upstanding portion and a horizontal portion that are at an angle to each other so as to lock the distal end of the wing in the body of encapsulating resin. An integrated circuit die having at least one electrical connection which is grounded electrically via a terminal and wire bonded to the distal part of the ground wing. A contact surface near the distal end of wing is positioned approximately in the plane of the top of the die. This ground circuit can parallel and can be redundant to a ground circuit through the die via the conductive bond that attaches the bottom of the die to the die-attach pad. The ground lead that is an extension of the die-attach pad serves both to remove heat from the die and to provide an electrical ground connection. The contact surface of the wing provides a point of ground-wire attachment that does not move relative to the encapsulating resin as do other peripheral parts of the die attach pad during temperature cycling and mechanical stress. Thus, a common failure mode, which is called heal-cracking, is substantially eliminated.

Integrated-circuit lead-frame package with failure-resistant ground-lead

A uniformly thick dielectric polyimide coating is provided on the back face of an integrated circuit and the die is mounted to a copper lead frame finger by interposing an epoxy resin bonding agent between the uniformly thick polyimide coating and the copper support finger. The die coating is provided before separating die from the precursive water. Liquid polyimide is poured onto the back side of the water which is spun, in a manner similar to that usually used for obtaining uniformly thick photoresist films. After curing the polyimide, the die are cut from the wafer by sawing.

Semiconductor die and mounting assembly

The lead-frame in an integrated circuit package, a dual-inline-package (DIP), has a plurality of leads of which four are extensions of a down-set die-attach pad. A dog-leg finger lines in the plane of the leads and is an extension of a peripheral portion of the die-attach pad. The dog-leg finger has first and second parts that are at right angles to each other so as to lock a distal port of it in the body of encapsulating resin. An integrated circuit die having at least one power transistor is grounded electrically via a terminal and wire bonded to the distal part of the dog-leg finger. This ground circuit parallels and is redundant to a ground circuit through the die via the conductive resin that attaches the bottom of the die to the die-attach pad, the later circuit having a relatively high electrical resistance. The four leads that are extensions of the die-attach pad serve both to remove heat from the die and to provide an electrical ground connection. The extending finger of dog-leg shape provides a point of ground-wire attachment that does not move relative to the encapsulating resin as do other peripheral parts of the die attach pad during temperature cycling.

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Holden, MA, United States of America

Jay J Gagnon