Abstract: A piezoelectric transformer includes a single crystal relaxor ferroelectric element poled along a [0 11] direction and selected from the group consisting of PZN-PT, PMN-PZT, PZN-PT and PMN-PT. The element has two opposed surfaces substantially perpendicular to the [0 11] direction with an input electrode and an output electrode positioned on one surface. The output electrode is isolated from electrical communication with the input electrode. A ground electrode is positioned on the second, opposed surface. Input electrical energy results in piezoelectric change in the element that is mechanically coupled through the element to generate piezoelectric output energy.

Abstract: A lead-free solder joint is formed between a tin-silver-copper solder alloy (SAC), SACX, or other commonly used Pb-free solder alloys, and a metallization layer of a substrate. Interaction of the SAC with the metallization layer forms an intermetallic compound (IMC) that binds the solder mass to the metallization layer. The IMC region is substantially free of any phosphorous-containing layers or regions.

Abstract: A lead-free solder joint is formed between a tin-silver-copper solder alloy (SAC), SACX, or other commonly used Pb-free solder alloys, and a metallization layer of a substrate. Interaction of the SAC with the metallization layer forms an intermetallic compound (IMC) that binds the solder mass to the metallization layer. The IMC region is substantially free of any phosphorous-containing layers or regions.

Abstract: An assembly comprises a stiffener, a circuit substrate and an IC chip. The stiffener has a surface with a first region and a second region. The circuit substrate covers at least a portion of the first region of the stiffener, while the IC chip overlies at least a portion of each of the first and second regions of the stiffener. The assembly further comprises a signal solder bump and a thermally conductive feature. The signal solder bump contacts the IC chip and the circuit substrate. The thermally conductive feature is disposed between, and is metallurgically bonded to, the integrated circuit chip and the second region of the stiffener. The thermally conductive feature provides an efficient thermal conductivity pathway between the IC chip and the stiffener.

Abstract: A device fabrication method, according to which a tin-copper-alloy layer is formed adjacent to a copper-plated pad or pin that is used to electrically connect the device to external wiring. Advantageously, the tin-copper-alloy layer inhibits copper dissolution during a solder reflow process because that layer is substantially insoluble in liquid Sn—Ag—Cu (tin-silver-copper) solder alloys under typical solder reflow conditions and therefore shields the copper plating from direct physical contact with the liquefied solder.

Abstract: A lead-free solder joint is formed between a tin-silver-copper solder alloy (SAC), SACX, or other commonly used Pb-free solder alloys, and a metallization layer of a substrate. Interaction of the SAC with the metallization layer forms an intermetallic compound (IMC) that binds the solder mass to the metallization layer. The IMC region is substantially free of any phosphorous-containing layers or regions.

Abstract: An assembly comprises a stiffener, a circuit substrate and an IC chip. The stiffener has a surface with a first region and a second region. The circuit substrate covers at least a portion of the first region of the stiffener, while the IC chip overlies at least a portion of each of the first and second regions of the stiffener. The assembly further comprises a signal solder bump and a thermally conductive feature. The signal solder bump contacts the IC chip and the circuit substrate. The thermally conductive feature is disposed between, and is metallurgically bonded to, the integrated circuit chip and the second region of the stiffener. The thermally conductive feature provides an efficient thermal conductivity pathway between the IC chip and the stiffener.