Advanced Interconnections intros solder preform terminals

Connector Specifier: "The solder preform now available from Advanced provides a predictable percent of fill and eliminates extra processing steps. The company notes that using a solder preform can often reduce total system processing costs by eliminating the need for wave soldering, solder fountains, or additional solder stencil steps associated with intrusive reflow or pin-in-paste processes."

Co addition to SAC - Malaysia

Factiva: "Effects of Co nanoparticle additions to Sn-3.8Ag-0.7Cu on the structure of solder/copper interface have been studied after reflow and high temperature aging (150 degrees C, up to 1008 h),' investigators in Kuala Lumpur, Malaysia report.

'the Co nanoparticles substantially suppress the growth of Cu3Sn but enhance Cu6Sn5 growth. Cobalt nanoparticles reduce interdiffusion coefficient in Cu3Sn,' wrote A.S.M.A. Haseeb and colleagues.

The researchers concluded: 'It is suggested that the Co nanoparticles undergo surface dissolution during reflow and exert their influence, at least partially, through alloying effect.'

Haseeb and colleagues published their study in Intermetallics (Effects of Co nanoparticle addition to Sn-3.8Ag-0.7Cu solder on interfacial structure after reflow and ageing. Intermetallics, 2011;19(5):707-712).

For additional information, contact A.S.M.A. Haseeb, University of Malaya, Dept. of Mech Engineering, Kuala Lumpur 50603, MALAYSIA."

NPL to Present Technical Webinars

EMS007 : "NPL's Electronic Interconnection Group will be presenting eight technical Webinars over the coming months. The Group will also host a European Technical Seminar at its facility at Teddington, UK, October 29, 2011"

This Group is internationally recognised for its practical and innovative work on lead-free reliability, PCB interconnection failures, tin whisker mitigation and conformal coating research.

These free online Webinars provide you or a team of your company engineers with an opportunity to draw on years of practical experience without leaving your desk. The Webinars focus on test methods used in industry to monitor or help evaluate possible failure modes in electronic assemblies. Alternatively, you can attend the annual seminar and tabletop exhibition in October.

Each Webinar will last approximately 60 minutes and can be booked online by selecting the topic of choice at http://www.npl.co.uk/ei.

NPL Technology Webinar series:

Tin Whiskers Evaluation Techniques and Benefits of Conformal Coating - Wednesday, June 22, 2011

X-Ray Fluorescence Testing results with Laboratory and Handheld Systems - Thursday, September 8, 2011

Solderability Assessment – Testing, Ageing and Practical Impact on Assembly Yield - Tuesday, October 11, 2011

How to Test and Qualify Packages with Scanning Acoustic Microscopy (SAM) - Thursday, October 27, 2011

Using Surface Insulation Resistance (SIR) to Qualify Production Processes and Materials - Tuesday, November 8, 2011

Cleanliness Assessment Using Solvent Extract and Ionic Extraction to Improve Reliability - Thursday, November 24, 2011

Characterisation of Solder Joints, Test Methods and Typical Failure Modes - Tuesday, January 24, 2012

Using Mechanical Testing to Diagnose Design, Product and Process Failures - Tuesday, February 21, 2012.

The webinars have been created to support the successful launch of the NPL Process Defect Database, a free online solutions to PCB assembly problems and the monthly IPC Defect of the Month Video. Analysis has shown that engineers require a better understanding of the laboratory investigation techniques used in industry to solve process issues.

Example

New Book on Lead-Free Released

EMS007: "Carol Handwerker of Purdue University and Greg Henshall of HP offer a overview of their new book, Lead-Free Solder Process Development, which they co-authored and co-edited with Jasbir Bath, explaining the relevance and importance of their new work."

Press-fit pins for solder-less assembly of power modules

Presswire: "Solder pins have been the interface of choice for power modules for many years. In this day and age, when cost saving very often leads to compromises in quality, Vincotech's new Press-fit technology goes against the trend. The new Press-fit pin takes the assembly properties of Vincotech power modules a step further: the solder-less assembly of the modules, equally easy on both sides of the PCB, leads to higher reliability and design flexibility, and drastically reduces production costs."

Reliability of printed circuit boards containing lead-free solder in aggressive environments

Scopus: "Lead-free solders were never an industry choice until government legislation, their wide spread use is still in its infancy due to long term reliability issues. A specific SAC (Tin-Silver-Copper) family of solder alloys has emerged as the favourite to offer technical advantages as well as meeting those legislative requirements.

This paper investigates accelerated life behaviour of lead-free solder joints and printed circuit boards using thermal and electrical stress cycling. The aim is to understand the degradation of these materials in a practical operating environment. Whilst corrosion and debris deposits have been found, no significant evidence has been obtained for tin whiskering. EDX analysis has shown the presence of high concentrations of elements considered to arise from the packaging material.

Thermal cycling tests have presented an aggressive environment to the samples and the effect on them has been supported by microscopic and macroscopic observations of debris and corrosion. The electrical behaviour, i.e., the joint resistance, has not however, significantly degraded"

Indium Technology Expert to Present at SMTA Penang

EMS007: "Indium Corporation's Area Technical Manager, Sehar Samiappan will present two technical papers at SMTA's South East Asia Technical Conference on Electronics Assembly Technologies, Penang, Malaysia, on May 19-20, 2011.

Selection of Dip Transfer Fluxes and Solder Pastes for PoP Assembly offers an easy way to select a flux or solder paste that could be used for dip transfer of PoP assembly applications.

Room Temperature LED and D-Pak Type Component Attach and Reliability Testing will discuss technology improvements for improved assembly materials and process enhancements to increase throughput, reduce cost, and improve product efficiency and reliability."

SAC105 Mn | Indium Corporation

SAC105 Mn | Indium Corporation: "SAC105 Mn (SACM)

First RELIABLE low-Ag solder alloy
Thermal Cycling: Comparable to SAC305
Drop Testing: Significantly better than SAC305
Available for licensing in China
SuperFlex is the 1st licensee
Lead-free with low environmental impact
Reduces the silver content and price volatility
Drop shock reliability better than SAC105 for hand held device market
Thermal reliability characteristics comparable to, and in some cases better than, standard high cost, high silver solder alloys
Manufacturing yield comparable to SAC305
Only very small adjustments needed for soldering process
Compatible with high-silver, low-silver, or no-silver alloys used in wave soldering and hand soldering
Selling in high volume to Chinese licensees"

NEPCON Malaysia

NEPCON Malaysia: "NEPCON Malaysia is the single largest sourcing ground for PCB/SMT, components, testing & measurement,semiconductor, LED and support services sectors in Malaysia. It is well recognized by the electronics industry as the most effective platform for international suppliers to launch their new products and services to local and regional buyers, gain new contacts and grow new businesses."

Nihon Superior to address key industry trends, concerns at the SMTA Ohio Valley Chapter Meeting

Global SMT and Packaging : "Since the move to lead-free solders that typically have a tin content of more than 95 percent, there has been concern about the possibility of circuit malfunctions due to growth of tin whiskers. There is a widely accepted view that whisker growth is a response to compressive stress within the tin crystal so that an effective mitigation strategy should be the identification and elimination or at least minimization of the processes that can generate such stress. Corrosion has been identified as one source of that stress. The likelihood of whisker growth occurring on lead-free assemblies soldered using no-clean technologies can be significantly reduced by using a halogen-free flux that does not promote the sort of corrosion that appears to be a driver for whisker growth.

Keith Howell has 25 years"

Heraeus Materials Technology - Innolot

Heraeus Materials Technology - Innolot: "By developing Innolot, the alloy with top-level reliability, Heraeus has successfully mastered the challenge. Application of the top quality product InnoRel makes it possible to deploy modules at operating temperatures of up to 150C trouble-free.
InnoRel Paste
InnoRel Rework Flux
InnoRel Ltdraht
InnoRel Dispens Ltpaste

innolot@heraeus.com
Heraeus Innolot - the preferred choice thanks to:
Highest possible reliability at operating temperatures of 125 C
Suitable for operating temperatures of up to 150C
No further changes to the reflow process window under N2
Large process window for printing and assembling
Incorporates a flux system widely in use throughout the automotive industry"

New packaging technology replaces wire bonding to double the current density in power semiconductors

EETimes: "In addition to removing the need for wire bonding, the new packaging solution is free of solder thermal paste. Instead, a sinter layer replaces the thermal paste layer and the soldered base plate. Thermal paste is responsible for around 30% of the total thermal resistance in a system. By replacing this, the thermal conductivity between chip and heat sink is improved, resulting in a 30% increase in usable electric current."

P. KAY Metal's MS2 Usage Reaches All-Time High in May

EMS007: "P. KAY Metal announces sales of its MS2 dross elimination molten solder surfactant product have increased exponentially in the past year with usage in May of 2011 reaching a new all-time high. MS2 has been available for three years; however the first year was dedicated to proving that the process works as described. In the past year a number of patents have been issued with a very broad U.S. patent being granted in early 2011. Since then interest and market share has skyrocketed"

RoHS to adopt REACH approach?

Directive Decoder: "The other main difference is that RoHS bans substances present in electrical and electronic equipment that fall within the scope of the 8 product categories (currently) of the directive. REACH affects all chemicals including those used to make the equipment (alloys, solvents, paints, etc.) and chemicals present in finished products of all types. There are very few exclusions and exemptions.

In Europe industry is starting to prefer the REACH approach and there increasingly appears to be a consensus by both industry, the EC and many politicians that this approach should be used for future RoHS restrictions once the recast enters force some 18 months after publication in the Official Journal."

TiO2 nanocomposite + study of IMC changes

Factiva: "'A Sn3.5Ag0.5Cu-0.5nano-TiO2 composite lead-free solder was prepared by adding 20 nm TiO2 to Sn3.5Ag0.5Cu" (wt.%) solder. This study investigates the morphology of the intermetallic compounds (IMCs) formed during the soldering reactions between Sn3.5Ag0.5Cu-0.5nano-TiO2 solder and Cu substrates at various temperatures ranging from 250 to 325 degrees C. The Cu6Sn5 grains formed in all soldering below 300 degrees C were scallop-type, while those formed at both 300 degrees C and 325 degrees C were prism-type in the early stage of soldering (less than 30 min)."

"Also, Cu6Sn5 grains that formed at both 300 degrees C and 325 degrees C changed from prism-type to scallop-type with increasing soldering time. It is quite interesting that the morphology of Cu6Sn5 grains affects absorption by nano-Ag3Sn particles. Especially, the scallop-type Cu6Sn5 grains formed by the ripening process are likely to be ''captured'' by the large amount of nano-Ag3Sn particles. These nanoparticles apparently decrease the surface energy and hinder the growth of the Cu6Sn5 IMC layer. In addition, the grain size of the nano-Ag3Sn compounds increased with increasing soldering temperature and time

Tsao and colleagues published their study in the Journal of Alloys and Compounds (Evolution of nano-Ag3Sn particle formation on Cu-Sn intermetallic compounds of Sn3.5Ag0.5Cu composite solder/Cu during soldering. Journal of Alloys and Compounds, 2011;509(5):2326-2333).

For additional information, contact L.C. Tsao, National Pingtung University Science &Technol, Dept. of Materials Engineering, 1 Hseuhfu Rd., Neipu 91201, Pingtung, TAIWAN

Method for Removing Solder Oxides Floating on Molten Solder

Factiva: "'There are disclosed a soldering apparatus comprising a solder wave shape forming means for melting solder and forming solder wave shape, and a separating agent dusting means for dusting solder oxides with a separating agent which separates solder and solder oxides, wherein said separating agent is any one selected from the group consisting of offal, cereal grain or flour, bean flour, seed grain or flour, soybean-cake flour, and peanut hull flour, or a combination thereof, as well as an agent and a method for separating solder and solder oxides.'"

Method for Removing Solder Oxides Floating on Molten Solder

Factiva: "'There are disclosed a soldering apparatus comprising a solder wave shape forming means for melting solder and forming solder wave shape, and a separating agent dusting means for dusting solder oxides with a separating agent which separates solder and solder oxides, wherein said separating agent is any one selected from the group consisting of offal, cereal grain or flour, bean flour, seed grain or flour, soybean-cake flour, and peanut hull flour, or a combination thereof, as well as an agent and a method for separating solder and solder oxides.'"

Micro-via approaches for reducing solder voiding

Circuit World: "The purpose of this paper is to evaluate the influence of microvia design on solder joint reliability and to present a printed circuit board (PCB) microvia design approach capable of reducing or eliminating voiding in solder joints.

Design/methodology/approach – Five different types of via-in-pad designs were incorporated into a test vehicle and their performance evaluated using a variety of standard reliability tests."

Ping Liu, (Zhejiang Province Key Laboratory of Soldering & Brazing Materials and Technology, Zhejiang Metallurgical Research Institute, Hangzhou, People's Republic of China

Ink with tin nanoparticles could print future circuit boards

Physorg.com: "Almost all electronic devices contain printed circuit boards, which are patterned with an intricate copper design that guides electricity to make the devices functional. In a new study, researchers have taken steps toward fabricating circuit boards with an inkjet printer. They have synthesized tin (Sn) nanoparticles and then added them to the ink to increase its conductivity, leading to an improved way to print circuit boards."