In a typical electronic assembly, many of the solder joints undergo multiple reflow cycles during the course of a complete manufacturing process from wafer bumping to the board level assembly. Effect of these reflows on the solder joint formation and its evolution during these cycles was investigated. In the first part of the study, small size BGA’s were assembled with 12mil spheres of a number...

The aim of this paper is twofold: 1) to examine the nature, scope and function o f the paralinguistic features on the basis o f a survey of the previous studies, and 2) to make an attempt to search and exempli fy paralinguistic features operating at vari ous linguistic and non-linguistic units in s everal languages. A special emphasis will be placed on the paralinguistic functions o f phonetic ...

In new high definition lighting modules, assembling more than thousand elements (pixels) with a single mm-sized motherboard is achieved by reflow soldering. Lead-free solders may constitute weak part of electronic components and LED assemblies. During reflow, the distance between pixels controls solder heights (10 μm). After assembly, all are in plane. To ensure constant heights, this plane has...

Solder reflow connection of semiconductor devices to substrates has been shown to be a reliable, effective, and readily automated technique. Rigid copper spheres, which remain rigid during solder reflow, have been used successfully for some time as a major element of the contact joint. However, to expand the capability of such joints to larger devices such as multiple-transistor chips in hybrid...

ne of the corporate goals at AT&T is to eliminate chloroflurocarbons (CFCs) from its manufacturing operations by the end of 1994. Many alternatives have been implemented to meet this objective, including noclean wave soldering using low-solids flux, aqueous cleaning of water-soluble flux, aqueous cleaning with saponifiers and semiaqueous (terpene) cleaning. Part 1 of this article describes the ...

BACKGROUND No previous study has assessed the possible role of dipyridamole for treatment of no-reflow during acute myocardial infarction (AMI). METHODS AND RESULTS Forty-six consecutive patients (age 64 ± 13 years, 37 men) with no reflow during primary percutaneous coronary intervention were randomized to initial treatment with either dipyridamole (0.56 mg/kg i.c.) or verapamil (1 mg i.c.). ...

The goal of the study is to compare quality of vapour phase reflowed solder joints soldered on different printed circuit board (PCB) surface finishes. Vapour phase reflow soldering guarantees the highest reliability, quality of processing and process safety. The big advantage of heat transfer in vapour phase soldering (VPS) is the extremely efficient transfer of latent heat through the condensi...

Miniaturization of electronic devices has led to the development of 3D IC packages which require ultra-small-scale interconnections. Such small interconnects can be completely converted into Cu-Sn based intermetallic compounds (IMCs) after reflow. In an effort to improve IMC based interconnects, an attempt is made to add Ni to Cu-Sn-based IMCs. Multilayer interconnects consisting of stacks of C...

OBJECTIVE To investigate the effects of tirofiban on the no-reflow phenomenon of acute myocardial infarction (AMI) rats received reperfusion, as well as the underlying mechanisms. METHODS Fifty-six male Sprague-Dawley rats were randomly divided into four groups: Sham operation group (Sham), AMI/reperfusion group (AMI/R), Tirofiban group (Tiro) and Tiro+N-nitro-L-arginine group (L-NNA; an endo...

Twenty-nine intact, working pig hearts were extracorporeally perfused and divided into two study groups (16 Aerobic and 13 Ischemic/Reflow hearts). Step function, equilibrium labeling with [14C]palmitate was used to develop uptake and washout curves of radioactive fatty acid products contained in coronary effluent during either aerobic perfusion or reperfusion after ischemia (60% reduction in l...