Transformer guard trace

A method for fabricating an electronic device, the method comprising:

• attaching a magnetic assembly to a support structure with a first side of a multilevel lamination structure facing first conductive leads, a second side of the multilevel lamination structure facing second conductive leads, and a conductive guard trace of the multilevel lamination structure spaced apart from and between a first winding of the multilevel lamination structure and the second conductive leads;
• attaching a first semiconductor die to a first die attach pad;
• attaching a second semiconductor die to a second die attach pad;
• performing an electrical connection process that couples the first semiconductor die, the first winding of the magnetic assembly, and at least one of the first conductive leads in a first circuit, and couples the second semiconductor die, a second winding of the magnetic assembly, the conductive guard trace, and at least one of the second conductive leads in a second circuit isolated from the first circuit;
• and
• performing a molding process that encloses the magnetic assembly, the die attach pads, the semiconductor dies, portions of the first and second conductive leads in a package structure.

A method for fabricating an electronic device, the method comprising:

• attaching a multilevel lamination structure to a support structure with a first side of the multilevel lamination structure facing first conductive leads, a second side of the multilevel lamination structure facing second conductive leads, and a conductive guard trace of the multilevel lamination structure spaced apart from and between a first winding of the multilevel lamination structure and the second conductive leads;
• attaching a first semiconductor die to a first die attach pad;
• attaching a second semiconductor die to a second die attach pad;
• performing an electrical connection process that couples the first semiconductor die, the first winding of the multilevel lamination structure, and at least one of the first conductive leads in a first circuit, and couples the second semiconductor die, a second winding of the multilevel lamination structure, the conductive guard trace, and at least one of the second conductive leads in a second circuit isolated from the first circuit;
• and
• performing a molding process that encloses the multilevel lamination structure, the die attach pads, the semiconductor dies, portions of the first and second conductive leads in a package structure.

A method for fabricating a packaged electronic device, comprising:

• providing first conductive leads along a first side of a lead frame;
• providing second conductive leads along a second side of the lead frame;
• attaching a first semiconductor die attached to a first die attach pad of the lead frame;
• attaching a second semiconductor die attached to a second die attach pad of the lead frame;
• attaching a magnetic assembly to a support structure in the package structure, the magnetic assembly including:
• a multilevel lamination structure, including:
• a first patterned conductive feature having multiple turns in a first level to form a first winding, a second patterned conductive feature having multiple turns in a different level to form a second winding, and a conductive guard trace spaced apart from and between the first patterned conductive feature and the second side of the package structure;
• a first core structure attached to a first side of the lamination structure;
• and
• a second core structure attached to a second side of the lamination structure;
• coupling the first semiconductor die, the first patterned conductive feature, and at least one of the first conductive leads in a first circuit with a first set of electrical connections;
• and
• coupling the second semiconductor die, the second patterned conductive feature, the conductive guard trace, and at least one of the second conductive leads in a second circuit isolated from the first circuit with a second set of electrical connections.

A method for fabricating a magnetic assembly, comprising:

• providing a multilevel lamination structure, including:
• forming a first side;
• forming a second side spaced apart from the first side along a first direction;
• forming a third side;
• forming a fourth side spaced apart from the third side along a second direction, the second direction being perpendicular to the first direction;
• forming a first patterned conductive feature having multiple turns in a first level to form a first winding;
• forming a second patterned conductive feature having multiple turns in a different level to form a second winding;
• and
• forming a conductive guard trace spaced apart from and between the first patterned conductive feature and the second side of the multilevel lamination structure;
• attaching a first core structure to a first side of the lamination structure;
• and
• attaching a second core structure to a second side of the lamination structure.