# US 12,015,336 B2 · Power converter for high power density applications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,336 B2 - Document ID: US12015336B2 - Status: Granted - Kind: B2 - Application number: 18/241,836 - Filed: 2023-09-01 - Published: 2023-12-21 - Granted: 2024-06-18 - Earliest claimed: 2021-10-28 - Assignees: Alpha and Omega Semiconductor International LP - Applicants: Alpha and Omega Semiconductor International LP - Inventors: Ziwei Yu; Lin Chen; Zhiqiang Niu - Web page: https://patentgrep.com/patent/US12015336B2 ## CPC - H02M 1/44: Circuits or arrangements for compensating for electromagnetic interference in converters or inverters - H10W 70/481: {for devices being provided for in groups H10D8/00 - H10D48/00} - H02M 3/003: {Constructional details, e.g. physical layout, assembly, wiring or busbar connections} - H02M 3/158: including plural semiconductor devices as final control devices for a single load - H05K 1/111: {Pads for surface mounting, e.g. lay-out} - H05K 1/181: associated with surface mounted components - H05K 7/209: {Heat transfer by conduction from internal heat source to heat radiating structure (H05K7/20909 takes precedence)} - H10W 40/10: Arrangements for heating - H10W 90/811: {Multiple chips on leadframes} - H05K 2201/10166: Transistor - H10W 40/70: Fillings or auxiliary members in containers or in encapsulations for thermal protection or control - H10W 70/427: {Bent parts} - H10W 74/111: {the semiconductor body being completely enclosed} - H10W 90/00: Package configurations - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract A power semiconductor package comprises a lead frame, a semiconductor chip, and a molding encapsulation. The lead frame comprises an elevated section comprising a source section; a drain section; and a plurality of leads. The semiconductor chip includes a metal-oxide-semiconductor field-effect transistor (MOSFET) disposed over the lead frame. The semiconductor chip comprises a source electrode, a drain electrode, and a gate electrode. The source electrode of the semiconductor chip is electrically and mechanically connected to the source section of the elevated section of the lead frame. The semiconductor chip is served as a low side field-effect transistor as a flipped-chip connected to a heat sink by a first thermal interface material. A high side field-effect transistor is connected to the heat sink by a second thermal interface material. The low side field-effect transistor and the high side field-effect transistor are mounted on a printed circuit board. ## Claims ### Claim 1 A high power density power converter comprising: a printed circuit board comprising a plurality of contact pads isolated from one another, the plurality of the contact pads comprising a high side drain pad and a low side source pad; a high side field-effect transistor mounted on the printed circuit board, the high side field-effect transistor comprising a high side drain lead electrically connected to the high side drain pad of the printed circuit board; and a top drain electrode electrically connected to the high side drain lead; a low side field-effect transistor mounted on the printed circuit board, the low side field-effect transistor comprising a low side source lead electrically connected to the low side source pad of the printed circuit board; and a top source electrode electrically connected to the low side source lead; a heat sink disposed on top of the high side field-effect transistor and the low side field-effect transistor, wherein the plurality of the contact pads of the printed circuit board further comprises a switch node pad; wherein the high side field-effect transistor further comprises a high side source lead connected to the switch node pad of the printed circuit board; and wherein the low side field-effect transistor further comprises a low side drain lead connected to the switch node pad. ### Claim 2 (depends on 1) The high power density power converter of claim 1, wherein the plurality of the contact pads of the printed circuit board further comprises a high side gate pad and a low side gate pad; wherein the high side field-effect transistor further comprises a high side gate lead connected to the high side gate pad of the printed circuit board; and wherein the low side field-effect transistor further comprises a low side gate lead connected to the low side gate pad of the printed circuit board. ### Claim 3 (depends on 1) The high power density power converter of claim 1, wherein the high side field-effect transistor and the low side field-effect transistor are mounted on a top surface of the printed circuit board; wherein the high side field-effect transistor is sandwiched between the printed circuit board and the heat sink; and wherein the low side field-effect transistor is sandwiched between the printed circuit board and the heat sink. ### Claim 4 (depends on 3) The high power density power converter of claim 3, wherein the heat sink comprises a bottom surface facing the top surface of the printed circuit board; and wherein the bottom surface of the heat sink is parallel to the top surface of the printed circuit board. ### Claim 5 (depends on 3) The high power density power converter of claim 3, wherein the high side field-effect transistor further comprises a first molding encapsulation having a first thickness; and wherein the low side field-effect transistor further comprises a second molding encapsulation having a second thickness. ### Claim 6 (depends on 5) The high power density power converter of claim 5, wherein the first thickness is the same as the second thickness. ### Claim 7 (depends on 5) The high power density power converter of claim 5, wherein the top source electrode of the low side field-effect transistor has an L shape exposing from a top surface of the second molding encapsulation. ### Claim 8 (depends on 5) The high power density power converter of claim 5, wherein an area of the top source electrode of the low side field-effect transistor exposing from the top surface of the second molding encapsulation is in a range from fifty percent to ninety percent of a top surface area of a package of the low side field-effect transistor. ### Claim 9 (depends on 5) The high power density power converter of claim 5, wherein an area of the top source electrode of the low side field-effect transistor exposing from the top surface of the first molding encapsulation is in a range from sixty percent to seventy percent of a top surface area of a package of the low side field-effect transistor. ### Claim 10 (depends on 1) The high power density power converter of claim 1, wherein the top drain electrode of the high side field-effect transistor is connected to a fixed bus voltage; and wherein the top source electrode of the low side field-effect transistor is connected to a ground.