摘要:
A high frequency power supply module (800) of a synchronous Buck converter having the control die (810) directly soldered drain-down to the pad (801) of a leadframe; pad (801) is connected to VIN and the VIN connection to control die (810) exhibits vanishing impedance and inductance, thus reducing the amplitude and duration of switch node voltage ringing by more than 90%. Consequently, the input current enters the control die terminal vertically from the pad. The switch node clip (840), topping the control die (810), is designed with an area large enough to place the sync die (820) drain-down on top of the control die; the current continues to flow vertically through the converter stack. The active area of the sync die is equal to or greater than the active area of the control die; the physical area of the sync die is equal to or greater than the physical area of the control die. The source terminal of sync die (820) is connected to ground by clip (860) designed to act as a heat spreader.
摘要:
A power supply converter (100) comprising a first FET (210) connected to ground (230), the first FET coupled to a second FET (220) tied to an input terminal (240), both FETs conductively attached side-by-side to a first surface of a metal carrier (120) and operating as a converter generating heat; and a packaged load inductor (110) tied to the carrier and an output terminal (241), the inductor package wrapped by a metal sleeve (113) in touch with the opposite surface of the metal carrier, the sleeve operable to spread and radiate the heat generated by the converter.
摘要:
A field-effect transistor package includes a leadframe with a first linear thickness (150a) and a leadframe pad (151) of a reduced thickness; a first terminal of a field-effect transistor chip (140) attached to the pad and a second and a third terminal remote from the pad; a metal sheet (110) of a second linear thickness (110a) connecting the second transistor terminal to a package terminal; a metal sheet (112) of a third linear thickness (112a) connecting the third transistor terminal to a package terminal; the sum of the first linear thickness (about 0.125 mm) and the second linear thickness (about 0.125 mm) plus attach material (about 0.05 mm) comprising the package thickness (about 0.3 mm).
摘要:
A high frequency power supply module (200) of a synchronous Buck converter stacking the control FET (210) and sync FET (220) and having the driver IC (230) integrated in the final package solution. A QFN leadframe has a rectangular flat pad (201) destined to become the heat spreader of the package; the leads (202) are positioned in line with two opposite sides of the pad, the other pad sides being free of leads. The sync FET die (220) is soldered to the pad; a first clip (240), soldered on the sync die, has the control die (210) attached by solder. A second clip (260) is soldered on top of the control die. Also soldered on the same pad, yet not stacked with the other dies, is IC driver chip (230). The IC driver is wire bonded (233) to the pins of the package and to the stacked dies. All die attach and clip attach use the same solder material in order to be reflowed in the same reflow step.
摘要:
A packaged power transistor device (100) having a leadframe including a flat plate (110) and a coplanar flat strip (120) spaced from the plate, the plate having a first thickness (110a) and the strip having a second thickness (120a) smaller than the first thickness, the plate and the strip having terminals (212; 121a). A field-effect power transistor chip (210) having a third thickness (210a), a first and a second contact pad on one chip side, and a third contact pad (211) on the opposite chip side, the first pad being attached to the plate, the second pad being attached to the strip, and the third pad being coplanar with the terminals. Encapsulation compound (130) filling the thickness difference between plate and strip, and spaces between chip and terminals, wherein the compound has a surface (101) coplanar with the plate surface (111) and the opposite surface (102) coplanar with the third pad (211) and the terminals (212; 212a), the distance (104) between the surfaces being equal to the sum of the first (110a) and third (210a) thicknesses.
摘要:
A power supply module (400) comprising a metal leadframe with a pad (401) and a first metal clip (440) including a plate (440a), an extension (440b) and a ridge (440c); the plate and extension are spaced from the leadframe pad, and the ridge connected to an input supply. A synchronous Buck converter is in the space between the clip plate and the leadframe pad, the converter including a control FET die (410) soldered onto a sync FET die (420), the clip plate soldered to the control die having an input inductance (462), and the sync die soldered to the leadframe pad having an output capacitance. A capacitor (480a, 480b) integrated into the space between the clip extension and the leadframe pad, the clip extension soldered to the capacitor having a desired integrated inductance (463) operable to channel electrical energy from the switch node to ground.
摘要:
A packaged power supply module (100) comprising a chip (110) with a first power field effect transistor (FET) and a second chip (120) with a second FET conductively attached side-by-side onto a conductive carrier (130), the transistors having bond pads of a first area (210) and the carrier having bond pads of a second area (230) smaller than the first area. Conductive bumps (114, 115, 124, 125) attached to the transistor bond pads and conductive bumps (126) attached to the carrier bond pads have equal volume and are coplanar (150), the bumps on the transistor pads having a first height and the bumps on the carrier pads having a second height greater than the first height.