摘要:
A method and apparatus to minimize thermal impedance using copper on the die or chip backside. Some embodiments use deposited copper having a thickness chosen to complement a given chip thickness, in order to reduce or minimize wafer warpage. In some embodiments, the wafer, having a plurality of chips (e.g., silicon), is thinned (e.g., by chemical-mechanical polishing) before deposition of the copper layer, to reduce the thermal resistance of the chip. Some embodiments further deposit copper in a pattern of bumps, raised areas, or pads, e.g., in a checkerboard pattern, to thicken and add copper while reducing or minimizing wafer warpage and chip stress.
摘要:
A ball-limiting metallurgy (BLM) stack is provided for an electrical device. The BLM stack resists tin migration toward the metallization of the device. A solder system is also provided that includes a eutectic-Pb solder on a substrate that is mated to a high-Pb solder, and that withstands higher temperature reflows and other higher temperature processes.
摘要:
Lead-free solders comprising 85-96% tin (Sn) and 4-15% Indium (In) by weight percentage (wt. %) and exemplary uses of the same are disclosed. The Sn—In solder undergoes a martensitic phase change when it is cooled from a reflow temperature to room temperature. As a result, residual stresses that would normally occur due to solder strain caused by relative movement between joined components are substantially reduced. Typically, the relative movement results from a coefficient of thermal expansion (CTE) mismatch between the joined components. The disclosed exemplary uses include flip-chip assembly and IC package to circuit board mounting, such as ball grid array packages.
摘要:
A composite of two or more thermal interface materials (“TIMs”) is placed between a die and a heat spreader to improve cooling of the die in an integrated circuit package. The two or more TIMs vary in heat-dissipation capability depending upon the locations of die hot spots. In an embodiment, a more thermally conductive material may be positioned over one or more die hot spots, and a less thermally conductive material may be positioned abutting and/or surrounding the more thermally conductive material. The two or more TIMs may comprise a solder and a polymer. The composite TIM may be preformed as one unit or as a plurality of units. Methods of fabrication, as well as application of the package to an electronic assembly and to an electronic system, are also described.
摘要:
Methods of forming a microelectronic structure are described. Those methods include applying a solder paste to a portion of a board, wherein the solder paste is not applied to a ball grid array region, and placing a BGA package comprising at least one low temperature solder ball on the ball grid array region, wherein the at least one low temperature solder ball comprises a eutectic tin bismuth based solder doped with at least one of copper and nickel.
摘要:
Reactive solder material. The reactive solder material may be soldered to semiconductor surfaces such as the backside of a die or wafer. The reactive solder material includes a base solder material alloyed with an active element material. The reactive solder material may also be applied to a portion of a thermal management device. The reactive solder material may be useful as a thermally conductive interface between a semiconductor surface and a thermal management device.
摘要:
A structure including a substrate, a copper bump formed over the substrate, and a barrier layer comprising an alloy of at least one of iron and nickel, formed over the copper bump, and methods to make such a structure.
摘要:
A ball-limiting metallurgy (BLM) stack is provided for an electrical device. The BLM stack resists tin migration toward the metallization of the device. A solder system is also provided that includes a eutectic-Pb solder on a substrate that is mated to a high-Pb solder, and that withstands higher temperature reflows and other higher temperature processes.
摘要:
A ball-limiting metallurgy (BLM) stack is provided for an electrical device. The BLM stack resists tin migration toward the metallization of the device. A solder system is also provided that includes a eutectic-Pb solder on a substrate that is mated to a high-Pb solder, and that withstands higher temperature reflows and other higher temperature processes.
摘要:
A ball-limiting metallurgy (BLM) stack is provided for an electrical device. The BLM stack resists tin migration toward the metallization of the device. A solder system is also provided that includes a eutectic-Pb solder on a substrate that is mated to a high-Pb solder, and that withstands higher temperature reflows and other higher temperature processes.