Industry associations,such as IPC,were quick to develop standards to help the electronics industry deal with emerging environmental regulations; however,for regulatory compliance,smooth international trade and international supply chains,we rely heavily on International Standards Organizations such as ISO and IEC. In 2004,the International Electrotechnical Commission (IEC) launched TC111 on Environmental Standardization.
IEC/TC111 has a comprehensive work program developing international standards and guidelines for Environmentally Conscious Design,analytical test methods,materials declaration,and guidance for evaluating products with respect to restricted substances,and recycling and reuse.
IEC recently published IEC 62321 on Analytical test methods; IEC/PAS 62596 with guidelines for sampling procedures; and IEC 62430 on Environmentally Conscious Design. The IEC62321 standard was considered crucial for International trade to ensure that manufacturers and authorities are using the same test methods for assessing conformity to RoHS. Obtaining accurate substance concentration levels near the legal thresholds is difficult and requires the use of the right extraction and test methods.
The ECD standard (IEC62430) specifies requirements and procedures to integrate environmental aspects into design and development processes. It provides a framework of ECD requirements and provides a level of alignment with emerging international regulations that will require an ECD process.

Restrictions on the use of chemicals in began 30 years ago in the US with the passage of the Toxic Substances Control Act. Over the last five years we have seen a logarithmic increase in product and
substance legislation globally with China,the EU,Korea,Argentina,Australia,Canada,and Mexico to name a few. These regulations ban the use of chemicals in everything from baby bottles and batteries to electronics,children’s toys and medical devices.
During the next 2 to 5 years,the chemical industry,consumer product companies and manufacturers will face increasing regulatory pressures and burdens globally,as more substances will be restricted,banned or otherwise regulated. Increased substance regulation is coming; the only real question remaining is how fast. Green products will not offer a marketing advantage as much as being table stakes to remaining the game.
The successful organization will see this as a strategic opportunity by investing the time in developing the expertise,people and systems that result in a full suite of compliant products that anticipate the next change.
Successful individuals will see this as an opportunity to get involved in the standards setting process and regulatory process adding another skill in their portfolio to bring added value to the organization and the customer.

The formation during the soldering process of the layer of intermetallic compound Cu6Sn5 at the solder substrate interface
provides the essential evidence that a metallurgical bond that is the basis of a solder joint has been established. Although the
importance of this interfacial intermetallic was long recognized in tin-lead solders the implications of the change to lead-free solders on this layer and its impact on solder joint reliability are yet to be fully understood. An obvious and important difference is that the copper required to form that intermetallic that for tin-lead solder joints could come only from the substrate is now a constituent of all of the commonly used lead-free solders. It has recently been found that the allotropic transformation of the Cu6Sn5 from the hexagonal close packed form to the monoclinic form as the temperature falls below 186°C appears to have implications in lead-free solders that it did not have in tin-lead solders. This paper reports the discovery that the inclusion of a specific level of nickel in the formulation of a tin-copper solder has the effect of stabilizing
the hexagonal close packed form of the intermetallic at normal operating temperatures. The consequences of this stabilization
on the mechanical integrity and three-dimensional structure of the intermetallic layer will be described and the implications for solder joint reliability reviewed.

With increasing use of portable appliances such as PDA and cellular phone,changing environment of application requires higher solder joint reliability. The Cu-OSP process has been widely used for portable devices due to its benefits including good surface planarity,cheapest finish and higher drop reliability than others.
This study is about reliability according to solder materials on package with OSP finished,and is evaluated the various Ag,Cu contents and adding few special dopants.
The Inter-Metallic Compound between pad and solder material after reflow has the scallop type and is composed Cu6Sn5 by using EDS.
Investigated the 3 types fracture mode after drop strength: The first is the crack propagating along IMC layer which composed of Cu6Sn5 (interfacial fracture mode),the second is the crack propagating along solder side (bulk fracture mode); the final is the crack propagating along the above IMC layer between IMC and solder.
The unstable interface exists through IMC,pad material and solder bulk by the lattice mismatch,so that the thermal and physical stress due to the continuous exterior impact is transferred to the IMC interface.
Therefore,it is strongly requested to control solder morphology,IMC shape and thickness to improve the solder reliability. In case of increasing the Cu contents,IMC shape changed scallop type to spike type,and IMC had larger toughness by using nano-indenter.
Accelerated stress propagated along the weaken surface between solder and IMC,this phenomenon is caused to increasing drop performance.
Moreover,as the special dopants were added,the relatively weak thermal shock strength could be improved.

Electroless nickel immersion gold (ENIG) has captured the major share of the lead free final finish market globally even though it’s not the least expensive. ENIG not only provides a robust metallic
coating required for assembly with lead free alloys,but also,an effective barrier to virtually stop copper migration into the attachment surface of the PCB. This provides a true surface with long term,low contact resistance with long shelf life and good solderability. So why make any changes to ENIG?
Three reasons;
• Improved window on lead free soldering
• Improved robustness for touch contacts.
• Wire bonding of fine features
Lead Free Soldering: After years of testing,discussions,failures and success,lead free soldering has completed the transition from the lab to production. Lead while bad for the environment,was great for soldering and had a tremendous operating window. When compared to eutectic tin lead,liquidous time and spreadability of lead free alloys is less making the final finish on the PCB more critical. As far as ENIG,imperfections in the ENIG deposit,which were not critical with eutectic tin lead,can become an issue because the operating window on Pb-free soldering processes are tighter.
Soldering actually occurs on the electroless nickel as the immersion gold is dissolved into the solder joint. Oxides or intermetallics on the electroless nickel decrease the solderability of the electroless
nickel surface causing poor solder wetting or weak solder joints. The oxides and intermetallics are actually corrosion products from the deposition of immersion gold on the electroless nickel. With
eutectic tin lead this was called black pad and as suppliers we have learned to reduce the aggressiveness of the immersion gold by shorter times or chemical changes and to increase the chemical resistance of the electroless nickel by increasing the phosphorus content and selection of stabilizers. Classic black pad was a major issue with eutectic solder,but minor amounts of corrosion products typically soldered fine. Now with reduced wetting from lead free soldering,the amount of corrosion products that can be
tolerated is reduced.
These corrosion products can be observed under the immersion gold by stripping the gold and evaluating the surface below. A few things become evident in the location and formation of the
corrosion products. They almost always initiate around the electroless nickel grain boundaries and or in areas where the electroless nickel coverage is not complete,like around micro-pits or edges of traces or around pads. When cross-sectioned,if due to imperfections in the electroless nickel deposit,large corrosion spikes can be seen at relatively low power. These areas while extremely small would still solder completely with eutectic tin lead and with most lead free soldering processes. The exception is a
lead free process with extremely short liquidious time. This provides less wetting time to penetrate the corrosion products.

Excessive moisture entrapped/absorbed within printed board laminates can expand during soldering operations,causing delamination or other damage. While moisture absorption data is available for some materials used in PB construction,little information has been made available for finished PBs,where not
only the laminate material is important in moisture gain or loss,but also the board thickness,copper content,details of the construction,and assembly process conditions. This study measures moisture absorption and desorption rates within various representative rigid multilayer PB structures,under varying conditions of temperature and humidity,including shop ambient environments and baking operations. Weight gain or loss attributable to moisture was measured using an analytical balance. The effectiveness and response times of humidity indicator cards used in PB packaging was also assessed. This information may be used to develop process controls for PB fabrication or PB assembly operations,dry storage practices,or baking procedures.

This presentation will review the findings of a HDPUG consortia effort to evaluate 29 different bare board material and stack-up combinations and their associated performance after 6X Pb-free reflows at 260C. Data presented will focus on the air-air thermal cycling results. IST testing and material survivability after Pb-free assembly reflow portions of this testing are also presented. Test board design aspects,manufacturing processes,Weibull analysis and failure analysis data will be presented. The impact of “plated through hole pitch” on laminate integrity and how material properties relate to the results will be discussed.
This presentation was originally presented by Joe Smetana (ALU) at the APEX 2009 conference,and it be presented here again at the request of the mid-west IPC committee.

Recent increases in assembly temperatures in response to removing lead from solder used in printed circuit boards (PCBs)
assembly has increase the strain and stress on interconnect structures. The elevated assembly temperature has reduced the
reliability of interconnect structures including microvias. This paper addresses how microvias may fail in response to the thermal excursion associated with assembly and the end use environment. The logic of different elevated temperature testing on FR4 (G10) and polyimide materials is reviewed. The paper compares and contrasts the implications of testing the microvia passively and under an electrical load. Also addressed are microsectioning techniques to improve the acuity of microscopic analysis. The failure modes addressed include separation between the base of the microvia and capture pad,microvia barrel cracks,and corner cracks,circumferential cracks around the base of the microvia in the capture pad and microvia misregistration to the base of the capture pad. This paper addresses the reliability implications of microvia constructions including stand alone,staggered,stacked microvias,copper and epoxy filled microvias and the failure modes
unique to these structures.

As more electronic assembly moves from OEM to EMS providers,a number of key issues arise in the overall value stream of production. This presentation will provide a comprehensive look at quality and reliability issues in circuit assembly processes from one of the world’s leading EMS providers. OEMs,material and component suppliers,and
EMS companies will gain valuable insight on how to avoid these pitfalls and directly impact their bottom line.

This presentation attempts to convince the reader that while all the logistical,equipment,financial and process aspects of any business are important,the high performance work team is the critical factor for success and defining difference,especially in the EMS (Electronic Manufacturing Services) industry.
It’s a relatively simple matter to replicate equipment and logistical strategies with enough money and time. Also,most of the day to day manufacturing processes are not terribly difficult and most are not proprietary. What is very difficult to achieve is a highly functioning team hitting on all cylinders with a minimum of wasted energy on organizational politics. Some “Lean Enterprise” concepts will be discussed as they apply to work teams.
The presentation will address tactics and strategies for developing,maintaining and continually improving the effectiveness of the EMS team.