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Cleaning

"Cleaning Qualification Methodology for Inline Aqueous Assembly Process"

Author: Steven Perng; sperng@cisco.com.

Abstract; This assessment of the cleanliness of the area beneath a component uses an 8" * 9" * 0.093" test vehicle with FR-4 laminate, OSP (Online Service Provider) See online service.

OSP - Optical Signal Processor
 surface finish, and 21 package types. The TVs underwent assembly and inline aqueous cleaning. The two test methodologies used were ion chromatography Ion-exchange chromatography (or ion chromatography) is a process that allows the separation of ions and polar molecules based on the charge properties of the molecules.  and electromigration. Based on the test results, most of components pass the criteria, except three high-pin-count LBGAs, which showed high levels of bromide bromide, any of a group of compounds that contain bromine and a more electropositive element or radical. Bromides are formed by the reaction of bromine or a bromide with another substance; they are widely distributed in nature.  using a certain paste. No significant differences were found between the low standoff components group and other groups. Among the four low standoff components, LGA LGA
abbr.
large for gestational age


LGA Large for gestational age, see there
133, which has the lowest standoff, shows a higher total anion anion (ăn`ī'ən), atom or group of atoms carrying a negative charge. The charge results because there are more electrons than protons in the anion.  level. Test results also verified that, within the similar package types, the ionic level is likely proportional to the stencil stencil, cutout device of oiled or shellacked tough and resistant paper, thin metal, or other material used in applying paint, dye, or ink to reproduce its design or lettering upon a surface.  paste volume. There were no statistical differences among the three time-to-wash cases: If the board is washed within 72 hrs., there is no significant difference on ionic level. (IPC (1) (InterProcess Communication) The exchange of data between one program and another either within the same computer or over a network. It implies a protocol that guarantees a response to a request.  Midwest, September 2008)

Environmental Compliance

"REACH for Electronics Manufactures"

Author: John Fox; jfox@synapsistech.com.

Abstract: REACH presents a new set of direct and indirect risks for article manufactures. Direct risks arise from obligations explicitly outlined in the REACH regulation itself: article 7 and 13. Indirect risks arise from upstream and downstream supply chain ripple effects caused by REACH. These ripple effects will impact article manufacturers, including those who do not import directly into the EU. Article manufacturers--particularly those with complex products and supply chains--are adopting data-driven risk management approaches to help ensure the future viability and profitability of their products. This presentation presents a framework to identify and mitigate REACH risks, both direct and indirect. It outlines a fact-based and systematic approach, describing what product and supply chain data are needed and how to make decisions based on these data. This paper is based in part on the REACH initiatives underway at several large MNCs. (IPC Mid-west. September 2008)

Nanotechnology

"Large Scale 3-D Vertical Assembly of Single-Wall Carbon Nanotubes at Ambient Temperatures"

Authors: Evin Gultepe, Dattatri Nagesha, Bernard Didier Frederic Casse, Selvapraba Selvarasah, Ahmed Busnaina and Srinivas Sridhar; s.sridhar@neu.edu.

Abstract: The authors demonstrate 3-D directed assembly of single-wall carbon nanotubes (SWNT SWNT Single-Walled Nanotube ) into porous alumina nanotemplates on silicon substrates by means of electrophoresis and dielectrophoresis Dielectrophoresis (or DEP) is a phenomenon in which a force is exerted on a dielectric particle when it is subjected to a non-uniform electric field. This force does not require the particle to be charged.  at ambient temperatures. Assembled SWNT provided and interconnection between the surface and base of the nanotemplate. I-V I-V Current/Voltage  measurements clearly show that the connection between silicon and SWNT is established inside the templates. This technique is particularly useful for large-scale areas under mild conditions for nanoscale electronic applications. (Nanotechnology, Oct. 8, 2008)

Solder Joint Reliability

"1st Order Failure Model for Area CSP (1) (Certified Systems Professional) An earlier award for successful completion of an ICCP examination in systems development. See ICCP.

(2) (Commerce Service P
 Devices with Pb-Free Solder"

Authors: Nathan Blattau, Joelle Arnold, Gerd Fischer, Craig Hillman Hillman was a famous British automobile marque, manufactured by the Rootes Group. It was based in Ryton-on-Dunsmore, near Coventry, England, from 1907 to 1976. Before 1907 the company had built bicycles. ; nblattau@dfrsolutions.com

Abstracts: The thermomechanical reliability of solders with little or no silver is not well known because the main focus has been on improving the solder interconnects' mechanical shock/drop performance. This study presents preliminary thermal cycling data for a SnNiCu-soldered area array CSP. These data are then used to develop a first-order analytical model to make thermal mechanical fatigue life predictions. The model uses basic distance to neutral point and continuous attach type equations to predict the strain energy dissipated by the solder joint. The energy dissipation is used to make fatigue predictions. (IPC Midwest, September 2008)

Wave Soldering Applying liquid solder to the underside of printed circuit boards in order to bond the chips and discrete components that are placed on top of the board and whose metal leads (pins) extend through the board.  

"Design for Manufacturing in Lead-Free Wave Solder Process"

Author: Ramon Mendez; rmendez@celestica.com.

Abstract: The effect of pin-to-hole ratio, quantity of large copper planes connected to a pin through-hole barrel, connection types for PTH PTH
abbr.
parathyroid hormone


Parathyroid hormone (PTH)
A chemical substance produced by the parathyroid glands. This hormone is a major element in regulating calcium in the body.
 and land patterns for glue and wave chip components are some of the main features that require further investigation for design optimization. It is also important to determine if a set of DfM guidelines result in similar results among the various Pb-free alloys. This paper discusses the outcome of a study of several DfM features incorporated on an internally designed test vehicle created to evaluate alternative Pb-free alloys. DfM features included land pattern design and varying component spacing for chip components, pin-to-hole ratio and its interaction with the quantity of large copper planes connected to a PTH, quantity of large copper planes connected to a PTH and its interaction with the type of connection either solid or four spokes. The TV was assembled with four Pb-free alloys (SnCuNi, SnAgCuBi, SnCuX and SAC 405) and Sn Pb37 alloy as a baseline. (IPC Midwesst, September 2008)

CIRCUITS ASSEMBLY provides abstracts of papers from recent industry conferences and company white papers. With the amount of information increasing our goal is to provide an added opportunity for readers to keep abreast of technology and business trends.
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Title Annotation:Technical Abstracts
Publication:Circuits Assembly
Date:Dec 1, 2008
Words:779
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