US 12,273,026 B2
Step-down converter including a step-down transformer and a resin molded body
Hirofumi Inoue, Tokyo (JP); and Kosuke Inoue, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
Filed on Dec. 20, 2021, as Appl. No. 17/556,394.
Claims priority of application No. 2021-053467 (JP), filed on Mar. 26, 2021.
Prior Publication US 2022/0311332 A1, Sep. 29, 2022
Int. Cl. H02M 3/00 (2006.01); H02M 3/335 (2006.01); H05K 7/14 (2006.01); H05K 7/20 (2006.01)
CPC H02M 3/003 (2021.05) [H02M 3/33569 (2013.01); H02M 3/33573 (2021.05); H05K 7/14329 (2022.08); H05K 7/209 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A step-down converter, comprising:
a step-down transformer including a primary-side coil and a secondary-side coil;
a resin molded body integrally molded through use of a non-conductive resin together with the primary-side coil and the secondary-side coil; and
a rectifier element configured to rectify an induced voltage of the secondary-side coil,
wherein the rectifier element is a rectifier element of a surface mount type,
wherein the resin molded body has a mounting surface on which the rectifier element is to be mounted,
wherein the secondary-side coil includes a first plate-shaped terminal,
wherein the first plate-shaped terminal is exposed from the resin molded body in the mounting surface,
wherein, on the mounting surface, a second plate-shaped terminal is provided in parallel to the first plate-shaped terminal, a gap being formed between the first plate-shaped terminal and the second plate-shaped terminal above the mounting surface,
wherein the rectifier element is bonded to both of the first plate-shaped terminal and the second plate-shaped terminal by soldering using solder,
wherein the non-conductive resin has a melting point higher than a melting point of the solder,
wherein, in the mounting surface positioned between the first plate-shaped terminal and the second plate-shaped terminal, a cavity portion is formed to penetrate through the resin molded body under the gap, a width of the cavity portion being equal to a width of the gap,
wherein the second plate-shaped terminal includes a protruding portion bonded to the rectifier element, and
wherein the second plate-shaped terminal has a groove portion formed in a bonding surface and surrounding the protruding portion.