US 11,756,718 B2
Galvanic isolation of integrated closed magnetic path transformer with BT laminate
Zhemin Zhang, Allen, TX (US); Roberto Giampiero Massolini, Pavia (IT); and Joyce Marie Mullenix, San Jose, CA (US)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed on Dec. 30, 2018, as Appl. No. 16/236,571.
Prior Publication US 2020/0211754 A1, Jul. 2, 2020
Int. Cl. H01F 17/00 (2006.01); H01F 19/08 (2006.01); H01L 25/16 (2023.01)
CPC H01F 19/08 (2013.01) [H01F 17/0013 (2013.01); H01F 2017/0066 (2013.01); H01F 2017/0086 (2013.01); H01F 2019/085 (2013.01); H01L 25/16 (2013.01)] 26 Claims
OG exemplary drawing
 
1. An integrated circuit comprising:
a first isolation barrier including first and second isolation layers without a metal layer between the first and second isolation layers, in which the first and second isolation layers each includes a respective pre-preg layer and form a first laminate having a first through-hole, the second isolation layer has opposite first and second sides, and the first side opposes the first isolation layer;
a first metal layer embedded in the second side of the second isolation layer, the first metal layer including a primary coil of a transformer;
a second isolation barrier including third and fourth isolation layers without a metal layer between the third and fourth isolation layers, in which the third and fourth isolation layers each includes a respective pre-preg layer and form a second laminate having a second through-hole, the fourth isolation layer has opposite third and fourth sides, and the third side opposes the third isolation layer;
a second metal layer embedded in the fourth side of the fourth isolation layer, the second metal layer including a secondary coil of the transformer;
magnetic material having a first magnetic portion over at least a portion of the first isolation barrier, a second magnetic portion over all of the second metal layer, and a third magnetic portion between the first and second magnetic portions and extending through the first and second through-holes; and
a lead frame on which the second magnetic portion is mounted, in which the second magnetic portion is between the second metal layer and the lead frame.