TOFA 2012

TOFA 2012 :
Pula, Croatia 23-28, September, 2012

MAIN TOPICS
1. Experimental and theoretical thermodynamics
2. Phase diagrams
3. Computational thermodynamics
4. Thermodynamics of nanoparticles
5. Structure of Alloys
6. Metallic clusters
7. Surface and interfacial phenomena
8. Thermodynamic aspects of the reactivity
9.Thermochemistry of metallurgical processes

EU consultation on RoHS2 impact

Consultation website

Various aspects including:
- measuring concentraion limits
- spare parts and supply chain for the new Category 11 equipment ("anything not in other categories")

UK consultation on RoHS2 implementation

Consultation document

Closing date 6th July

LinkedIn announcement

POP, LGA, QFN Designing & Assembly Workshop

SMART Group:

Stoke Mandeville Stadium – Aylesbury

To book your place or table top exhibition space contact Tony Gordon
Package on Package (PoP) and LGA QFN applications are growing in popularity for mobile and handheld professional electronics applications and with it placing further demands on assembly engineers. In simple terms POP represents the stacking of components one on top of another either during the original component manufacture or during printed board assembly. As real estate is at a premium for logic and memory, PCB designers say the only way to go is up and up. POP packaging systems may include direct soldering, wire bonding or conductive adhesives for device to device interconnection.

Lead-Free Experience Workshop – 6 Years On!!

event website

Thursday 10th May – Enterprise Ireland, East Point Dublin

iMAPS New England 39th Symposium & Expo

Tuesday May 8th, 2012
Holiday Inn Boxborough Woods Conference Center


Event programme


"Void Free Soldering in Vapor Phase Reflow"
J. Bashe, Rehm Thermal Systems LLC


"RoHS Recast"
K. Stanvick, Design Chair Associates



“Microstructure and Failure Modes of Pb-Free TSOP, QFN and LGA Solder Joints”
M. Anselm, Universal Instruments


"Lead-free Nanosolders and their Application for Nanowire Assembly and Joining"
F. Gao, & Z. Gu, University of Massachusetts Lowell

"Developing Lead-free Nanosolders for Nanoelectronics Assembly and Packaging"
F. Gao, & Z. Gu, University of Massachusetts Lowell (poster)

"Developing Lead-free Nanosolders for Nanoelectronics Assembly and Packaging"
F. Gao, & Z. Gu, University of Massachusetts Lowell

New book on Lead-free Solders

Wiley:

Providing a viable alternative to lead-based solders is a major research thrust for the electrical and electronics industries - whilst mechanically compliant lead-based solders have been widely used in the electronic interconnects, the risks to human health and to the environment are too great to allow continued widescale usage. Lead-free Solders: Materials Reliability for Electronics chronicles the search for reliable drop-in lead-free alternatives and covers:

Phase diagrams and alloy development
Effect of minor alloying additions
Composite approaches including nanoscale reinforcements
Mechanical issues affecting reliability
Reliability under impact loading
Thermomechanical fatigue
Chemical issues affecting reliability
Whisker growth
Electromigration
Thermomigration

Presenting a comprehensive understanding of the current state of lead-free electronic interconnects research, this book approaches the ongoing research from fundamental, applied and manufacturing perspectives to provide a balanced view of the progress made and the requirements which still have to be met.

Polymer-Core solder balls anyone?

Polymer-Core solder balls anyone? | LinkedIn: Dag Andersson • Just started a Eurostars project on PCSB. Will inform the group when first results are published.

Could be a news item - if Dag is prepared to talk about it.

Dag.Andersson@swerea.se
00 46 31 706 6141
00 46 707 80 6141

Bob Willis new book on "Pin in Hole Intrusive Reflow Book" now available

LinkedIn: Bob Willis new book on "Pin in Hole Intrusive Reflow Book" now available for free download at www.pihrtechnology.com
This what other people say:

Sue Knight, Dennis Price and Peter Starkey give their views ---------

"Once again Bob has managed to write a users guide which gives a good basic overview of the subject, whilst still providing the depth of information to allow those of us who’ve been using PiHR successfully for years to nod sagely in agreement at the nuances and still learn a few new tricks to try in the process. The breakdown of areas prompts a logical progression for designing your first successful PiHR product and associated processes, and provides that most invaluable of resources: pictures, illustrations and notes throughout of what it should look like both when it goes right and when there are problems that need the process engineer’s input.

An excellent book for those embarking on PiHR as a new process and also as a reference manual for more established users."

Sue Knight, Project Engineer
Surface Technology International Ltd.
Chairman of the SMART Group Technical Committee
www.sti-limited.com

Any break through in high temp resistant Pb free solder for power electronics ???? | LinkedIn

LinkedIn: Any break through in high temp resistant Pb free solder for power electronics ????
March 27, 2011


Manoj Raghav likes this
4 comments

Follow Shahid
Shahid Mehmood • Use of nano silver paste through sintering process might be a better alternative if high temperature is the requirement
5 months ago• Like1

Follow Craig
Craig Hillman • Jaspreet,

At what temperature? The current approach seems to be developing different solutions for different temperature ranges.
5 months ago• Like

Follow Shahid
Shahid Mehmood • Well, theoritically the bond formed as a result of sintering of nano silver paste would be stable below 961oC. But as a rule of thumb for solders joint can work below the homologous temperature which is 0.8Tm of the solder. In the case of nano silver paste it is 768oC.

Below is the link to the paper where you can find more information:
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5730660

Hope it works
5 months ago• Like

Follow karthik
karthik vijayamadhavan • what about the pressure required and subsequent wire-bond reliability with nano-Ag sintering?

Expert committee seeks evidence on nanosilver

Call for information | Scientific Committees: The Scientific Committee on Emerging and newly Identified Health Risks (SCENIHR) has received a request for a scientific opinion on Nanosilver: safety, health and environmental effects and role in antimicrobial resistance(17 KB).

Scope of the call for information:
Interested parties are invited to submit any relevant information that could assist the scientific committee with the assessment of the safety, health and environmental effects of nanosilver. In particular, the Scientific Committee is interested in receiving any scientific information related to the "nano" forms of silver.

-----------------------------------------


One of the European Commission's scientific committees is seeking information on the health and environmental effects of nanosilver particles used in medical and consumer products. The consultation will run until 4 June.

Information received by the committee on emerging and newly identified health risks (SCENIHR) will feed into a commission review due to be completed by early 2013.

Nanosilver is one of the most common nanomaterials in consumer goods because of its antimicrobial properties. But there are concerns about its effects on bacteria in sewage works and rivers, as well as its potential to increase antibiotic resistance.

MEPs wanted nanosilver banned from electrical and electronic products under the RoHS directive, while some NGOs have called for restrictions on its use in consumer goods until there has been a more thorough risk assessment.

The commission issued a separate request to SCENIHR for advice on the health effects of nanomaterials used in medical devices at the end of March.

Effect of reflow and flux on tin whiskers

IPC Outlook Sn whisker growth behavior of Sn-Ag-Cu solder fillets, on lead-frames of quad flat packages (QFPs), on OSP printed circuits boards during 85°C/85% relative humidity (RH) exposure was evaluated. Three different concentrations of halogen activated flux (Sn-3.0wt%Ag-0.5wt%Cu) were soldered in an air and an inert N2 reflow atmospheres. The lead frames of QFPs were metalized with Sn plated Cu and Fe-42wt%Ni (alloy 42). Sn whiskers were observed on the surface of solder fillets of the QFPs joints reflowed with halogen flux in air atmosphere. Substantial amount of Sn oxides were formed for those solder fillets with whisker growth and the amount of Sn oxides increased with the halogen content. Sn oxide formation apparently enhanced whisker formation. The combination of air reflow atmosphere and high halogen flux was the worst for oxidation of solder fillet resulting in Sn whisker formation, regardless of electrode lead frame for Cu and alloy 42. In contrast, an inert N2 reflow atmosphere prevented the Sn whisker formation of Sn-Ag-Cu solder fillets, for all conditions of current work.


Alongheng Baated, Keun-Soo Kim, and Katsuaki Suganuma
Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan


Sharon Huang, Benjamin Jurcik, and Shigeyoshi Nozawa
Air Liquide Laboratories, Tsukuba, Ibaraki, Japan


Bryan Stone
Air Liquide Industrial U.S. LP, Santa Fe Springs, CA, USA


Minoru Ueshima
Senju Metal Industry Co., Tokyo, Japan
This program first published June 2010

Effect of Cooling Rate on the Intermetallic Layer in Solder Joints

IPC Outlook While it has long been known that the Cu6Sn5 intermetallic that plays a critical role in the reliability of solder joints made with tin-containing alloys on copper substrates exists in two different crystal forms over the temperature range to which electronics circuitry is exposed during assembly and service, it has only recently been recognized that the change from one form to the other has implications for solder joint reliability. Under equilibrium conditions the change from the hexagonal to monoclinic form occurs in the cooling solder joint at 186°C. However, cooling rates after common commercial soldering processes are typically faster than the rate that would permit complete transformation under such equilibrium conditions. In this paper the authors report a study of the effect of cooling rates on Cu6Sn5 crystals. Cooling rates from 200°C ranged from 10°C/minute to 100°C/minute and the effect of isothermal ageing at intermediate temperatures was also studied. The extent of the phase transformation after each regime was determined using synchrotron X-ray diffraction. The findings have important implications for the manufacture of solder joints and their in-service performance.

Presented at APEX 2012, Feb 29th 2012



Authored By:
Keith Sweatman, Tetsuro Nishimura
Nihon Superior Co. Ltd.
Osaka, Japan


Stuart D. McDonald, Kazuhiro Nogita
University of Queensland
Brisbane, Australia
This program first published April 2012

Does anyone have experience using dross eliminators?

 LinkedIn: Does anyone have experience using dross eliminators in solder wave processes? Do they really help or is it a waste of money?
I am trying to figure out a way to reduce the amount of solder we are using in our wave process(Lead Free and Leaded).

Andy - this is a popular topic because of the high price of tin.

Possible headline: New interest in solder dross recovery technologies

Background... high price of tin etc..
Brief description of different technologies

LinkedIn Group is:

Surface Mount Technology group

ICEP-IAAC 2012

ICEP-IAAC 2012 The JIEP was requested to hold the IMAPS All Asia Conference (IAAC) by the IMAPS.
In response, the JIEP made a proposal to hold it as the joint conference with ICEP based on the discussions in the international affairs committee of the JIEP.
Since it was well accepted by Asian Members such as China, Hong Kong, Korea, Taiwan, as well as US and Europe, the JIEP decided to hold ICEP 2012 as a joint conference with the 1st IAAC.

We think it is very important and meaningful that we will have the conference on electronics packaging under cooperation of various Asian members.
Currently, after the 1st joint conference, Taiwan, Korea and Japan will hold the IAAC in that order.

Development of High Producing Micro Solder Flip Chip Bonding Process 
Daisuke Sakurai¹, Takatoshi Osumi¹, Kazuya Ushirokawa¹, Takashi Nakamura² and Takatoshi Ishikawa² (¹Panasonic Corporation and ²Panasonic Factory Solutions Co., Ltd., Japan)

Disapperance of Sn Layer and Microstructure Evolution of Intermetallic Compounds in Nano-scale Solder Thickness Cu-Sn-Cu Sandwich Structure
Qingqian Li, Pei QIN, Sha Xu and Y. C. Chan (City University of Hong Kong, Hong Kong)


Comparative Study of Dendrite Formation on Solder Pads with ImAg and OSP Surface Finishes using Water Drop Test Method
Kun Tang, F. B. Song, S. W. Ricky Lee (Hong Kong University of Science and Technology, Hong Kong)


Simulation Assisted Physics of Failure based Reliability AssessmentMei-Ling Wu ¹, Elviz George² and Michael Pech^2,3 (¹National Sun Yat-Sen University, Taiwan, ²University of Maryland, USA and City University of Hong Kong, Hong Kong)


iNEMI Experimental Investigation of Creep Corrosion
Haley Fu and Masahiro Tsuriya (iNEMI, USA)


Reliability of Pb-free Solder fatigue under Thermalmechanical Conditions 
Yung-Wen Wang and and Mei-Ling Wu (National Sun Yat-Sen University, Taiwan)


Quick Assessment Approach of Lead-free Solder Joint Fatigue under Mechanical BendingJia-Shen Lan and Mei-Ling Wu (National Sun Yat-Sen University, Taiwan)


A Unique Low-Ag Alloy Solder Paste for High-Reliability SMT Applications
Masato Shimamura (Senju Metal Industry Co., Ltd., Japan)


Copper Wire Bonding Is a Viable Interconnection Method
Bernd Karl Appelt¹, Andy Tseng¹, Louie Huang², Scott Chen² (¹ASE Group, USA and ²ASE Group, Taiwan)

Formation and growth of tin whiskers on aluminum tin alloys

Scopus : In order to clarify the mechanism of formation of nodules and whiskers on the conducting wires used in aluminum electrolytic capacitors, aluminumtin binary alloys were subjected to an investigation as the model alloys for the joints in the conducting wires. The concentration of tin in the binary alloys was 1, 5 or 10 at%. The 10 at% tin alloy showed the highest number of nodules or whiskers on its polished surface after storing under ambient conditions for 7.8 Ms. Many whiskers whose length were greater than several tens of micrometers were observed for 5 at% tin alloy. The 1 at% tin alloy showed few nodules or whiskers. Growth of the nodules and whiskers is caused by diffusion of the tin atoms from the strained or high-energy areas into the low-energy ones or the root grains. The extrusion toward the surface at the root grains then develops nodules and whiskers. As a preventive measure of whisker formation, selective etching of the aluminum phase using a solution of sodium hydroxide was confirmed to be successful. Thus the aluminum phase was thought to form a non-uniform distribution of strain in the tin phase. This acts as the driving force for diffusion of the tin atoms

Cookson mulls spin off of unit that makes iPad parts

Telegraph: Analysts believe that splitting its electronics and ceramics businesses will unlock shareholder value as the shares are currently trading at a 20pc discount to the wider industrials sector.
The ceramics business makes consumable that are used in the production of steel and the electronics business manufactures the high- performance materials used in circuit boards. Cookson also owns a small precious metals processing business.
Talk of a potential spin off gathered pace after activist investor Cevian, the hedge fund chaired by former City minister Lord Myners, recently become the largest shareholder in Cookson, with an 18pc stake earlier this year.
However, Nick Salmon, Cookson's chief executive, is also understood to believe the electronics division, which accounts for about a third of the group's 2.8bn of annual sales, would thrive as a separate business.

Annual IeMRC Conference, UK

IeMRC - Welcome: The vision of the IeMRC is to be the UK's internationally recognised provider of world-class electronics manufacturing research. It will focus on sustaining and growing high value manufacturing in the UK by delivering innovative and exploitable new technologies through its highly skilled people and by providing strategic value to the electronics industry