摘要:
A semiconductor device (100) with a metal bump (203) on each interior contact pad (202) has a metallic leadframe with lead segments (220) with the first surface (220a) in one plane. The second surface (220b) is castellated across the segment width in two planes so that regions of a first segment thickness (240a) alternate with regions of a reduced (about 50%) second segment thickness (240b); the first thickness regions are in the locations corresponding to the chip interior contact pads (half-etched leadframe). The second segment surface faces the chip so that each first thickness region aligns with the corresponding chip bump. The chip bumps are attached to the corresponding second segment surface using reflow metal. Dependent on the orientation of the attached half-etched segment, thermomechanical stress concentrations away shift from the solder joints into the leadframe metal, or shear stress may reduced.
摘要:
A method for fabricating a low resistance, low inductance device for high current semiconductor flip-chip products. A structure is produced, which comprises a semiconductor chip with metallization traces, copper lines in contact with the traces, and copper bumps located in an orderly and repetitive arrangement on each line so that the bumps of one line are positioned about midway between the corresponding bumps of the neighboring lines. A substrate is provided which has elongated copper leads with first and second surfaces, the leads oriented at right angles to the lines. The first surface of each lead is connected to the corresponding bumps of alternating lines using solder elements. Finally, the assembly is encapsulated in molding compound so that the second lead surfaces remain un-encapsulated.
摘要:
Packaged microelectronic semiconductor devices and methods for their assembly are described. According to preferred embodiments of the invention, chip-on-lead techniques are adapted to provide chip-on-lead packages using cantilevered leads. Exemplary embodiments of the invention include methods using a temporary brace to support the cantilevered leads during chip mounting. Versatile chip package embodiments are disclosed including those in which the chip mounting pad is smaller than the chip(s) mounted thereupon, and further examples wherein the chip mounting pad is dispensed with and a chip is mounted on the cantilevered leads alone.
摘要:
Disclosed herein is a method of manufacturing a semiconductor package with a solder standoff on lead pads that reach to the edge of the package (non-pullback leads). It includes encapsulating a plurality of die on a lead frame strip. The lead frame strip comprises a plurality of package sites, which further comprises a plurality of lead pads and a die pad. The method also includes forming a channel between the lead pads of nearby package sites without singulating the packages. Another step in the method includes disposing solder on the lead pads, the die pad, or the lead pads and the die pads without substantially covering the channel with solder. The manufacturing method further includes singulating the packages.
摘要:
A QFN package and method of making same is provided comprising a substrate having a metal line extending from a connection element on a perimeter region of the substrate to a high current contact pad on interior region of the substrate. A semiconductor chip having an active surface generally faces the interior region of the substrate, wherein a heat-dissipating patterned metal distribution layer is formed over the active surface and electrically connected to an active component thereon. A solder strip electrically and thermally connects the high current contact pad and the metal distribution layer, and a mold compound generally encapsulates the semiconductor chip. The solder strip is generally uniform in depth and surface area, wherein low electrical resistance and inductance is provided between the high current contact pad and the metal distribution layer. An integrated heat sink may be further formed or placed on a passive surface of the chip.
摘要:
An electronic device has a semiconductor chip (101) with a surface and an electric circuit including terminals on the surface. The circuit has a first (103) and a second terminal (104) with a metallurgical composition for wire bonding. The chip has a conductive wire (120) above the chip surface, which has a length and a first and a second end; the first end is attached to the first terminal and the second end to the second terminal. The wire is shaped to form at least one sequence of a concave and a convex portion. The sequence may be configured to form a loop, or multiple wire loops resulting in a spiraling wire coil. The number, shape, and spatial sequence of the loops control the electrical inductance of the wire; the inductance is selected to fine-tune the high frequency characteristics of the circuit.
摘要:
A semiconductor device comprising a metallic leadframe (103) with a first surface (103a) and a second surface (103b). The leadframe includes a chip pad (104) and a plurality of segments (107); the chip pad is held by a plurality of straps (105), wherein each strap has a groove (106). A chip (101) is mounted on the chip pad and electrically connected to the segments. A heat spreader (110) is disposed on the first surface of the leadframe; the heat spreader has its central portion (110a) spaced above the chip connections (108), and also has positioning members (110b) extending outwardly from the edges of the central portion so that they rest in the grooves of the straps. Encapsulation material surrounds the chip, the electrical connections, and the spreader positioning members, and fills the space between the spreader and the chip, while leaving the second leadframe surface and the central spreader portion exposed.
摘要:
A robust, low inductance electronic package for small area semiconductor chips is provided which includes a flexible polymer film having electronic circuitry on one or more major surfaces, a bumped flip chip integrated circuit attached to the first surface, an array of solder balls to the second surface, and the device encapsulated in a plastic molding compound. An assembly and packaging method is disclosed wherein multiple devices are encapsulated simultaneously on a continuous polymer film, thereby providing a method compatible with high volume and low cost manufacturing processes and equipment.
摘要:
A metallurgical interconnection for electronic devices is described, wherein the interconnection has first and second interconnection metals. The first metal is shaped to enlarge the contact area, thus providing maximum mechanical interconnection strength, and to stop nascent cracks, which propagate in the interconnection. Preferred shapes include castellation and corrugation. The castellation may include metal protrusions, which create wall-like obstacles in the interconnection zones of highest thermomechanical stress, whereby propagating cracks are stopped. The surface of the first metal has an affinity to form metallurgical contacts. The second metal is capable of reflowing. The first metal is preferably copper, and the second metal tin or a tin alloy.
摘要:
An integrated circuit (IC) includes a substrate having a semiconducting surface, a first array of devices on and in the semiconducting surface including first and second coacting current conducting nodes, a plurality of layers disposed on the substrate and including at a electrically conductive layers and dielectric layer, and a plurality of bump pads on or in the top surface of the dielectric layers. In the IC, the electrically conductive layers define electrical traces, where a first portion of the electrical traces contact a first portion of the bump pads exclusively to a portion of the first coacting current conducting nodes, where a second portion of the electrical traces contact a second portion of the bump pads exclusively to a portion of the second coacting current conducting nodes, and where the electrical traces are electrically isolated from one another by the dielectric layers.