New ROHS standards are forcing the electronics industry to find a replacement for leaded surface finishes. Even more
rapidly than the legislative decision to move away from lead,electronics were moving to much smaller,faster and higher
function applications. Not only does the new surface finish have to be lead free but it will have to perform with circuit
designs that are increasingly challenging. A flat,planar surface is an obvious and minimum requirement. Beyond this,a
preferred finish should be simple to apply,consistent in performance,and durable/resistant to aggressive and corrosive
environments.
A final finish that has been able to deliver a planar surface for the solderability of fine components as well as maintain ease of
use for fabricators is immersion silver. In recent years,immersion silver has grown as the final finish of choice for a large
variety of end use applications. Immersion silver has a wide variety of fabrication/manufacturing and functional advantages
over other lead free surface finishes. One shortcoming of immersion silver is its potential to tarnish in sulfur and sulfide
environments. A post treatment has been developed which delivers significant tarnish inhibition to thin silver coatings,
translating to a more robust and corrosion resistant finish. This work investigates and verifies the effectiveness of a tarnish
inhibited coating,with focus on confirming the coating’s compatibility in modern,fine-pitch assembly applications.
Controlled assembly studies focus on wetting characteristics,solder paste compatibility,and bridging risks are discussed.

In order to meet the growing requirement of eliminating lead from electronics,the printed wiring board (PWB) industry is migrating from hot-air-leveled solder (Sn/Pb) to lead free compatible alternative final finishes. Among the available alternatives which include organic solderability preservative (OSP) immersion silver,immersion tin and electroless nickel/immersion gold,the OSP type coating is considered to be one of the leading candidates because of its excellent solderability,ease of processing and low cost.
This paper uses Gas Chromatography-Mass Spectroscopy (GC/MS),Thermogravimetric Analysis (TGA),and X-ray Photoelectron Spectroscopy (XPS) to characterize the relative thermal properties of a novel high temperature (HT) resistant OSP coating. The GC work performed in this study clearly shows the key organic components in the HT OSP coating that affects solderability. The GC work also shows the alkyl benzimidazole-HT used in HT OSP is of the lowest volatility. The accompanying TGA data also illustrates that the HT OSP coatings have a higher decomposition temperature compared to existing industry standard OSP coatings. The XPS shows that HT OSP has only about 1% increase of oxygen content after five lead-free reflow cycles. In combination,these improvements are assessed relative to the industry needs to meet the performance challenges of lead free soldering.

Since the issue of the European Union directive [1] on the restriction of the use of certain hazardous substances in electrical
and electronic equipment (RoHS) and its predecessor WEEE directive [2],the global electronics industry has been actively
interpreting the resulting EU member state regulations,defining responsive business strategies,and implementing the
technical and business processes necessary to meet all facets of these directives. Many companies have allocated significant
resources to ensure that their products can be marketed within the European Union and are now generally in the final
implementation stages of their RoHS compliance strategies.
China is motivated to reap similar environmental benefits for its citizenry and the China Ministry of Information Industry
(MII) is actively drafting its own environmental regulations for Electronic Information Products (EIP). Key elements of
these China environmental regulations may deviate substantially from the EU RoHS directive. Such deviations could pose
severe logistical challenges to the electronics industry.
Known differences to date include the use of government issued labeling requirements for all EIP products and the
mandatory use of government certified product compliance testing prior to market introduction. As well,uncertainty exists
around the use of an EIP catalogue that will define applicability of the China regulations (potentially incorporating products
that are now exempt from EU RoHS). At this time the catalogue does not exist,but efforts are underway to select the
products that will be incorporated. All regulations that require business procedures or unique product attributes over and
above EU RoHS will drive up production costs and increase product introduction cycle times.
This paper describes the requirements of the China MII environmental regulations as currently proposed,comparing and
contrasting the key differences with the EU RoHS directive and highlighting the resulting electronics industry challenges. It
discusses the business consequences of complying with multiple directives and emphasizes the need for convergence of all
global environmental stewardship programs.

The Restriction of Hazardous Substances (RoHS) directive is requires companies to change the way they design,
manufacture,track,and bring new products into the market. In order to provide the necessary controlled processes for RoHS
compliant electronic design and manufacturing,original equipment manufacturers (OEMs) and Electronic Manufacturing and
design Service providers (EMS) must partner to develop product-based strategies. Tactics utilized are customized depending
on the exact end market requirements.

Companies are refining their processes to better ensure their compliance with environmental regulations evolving around the world. These processes reflect internal use models and collaborative processes for obtaining compliance information. Companies are moving from sourcing simple part and material compliance to developing sustainable environmental compliance use models that incorporate due diligence and methods to obtain and analyze critical information. Company approaches to gathering information are evolving to include:
• Direct sourcing of more detailed compliance information (RoHS/WEEE) from suppliers
• Physical lab-based verification to ensure sourced information is consistent and to fill gaps when manufacturers don’t provide the needed information
• Use of in-field X-Ray Fluorescence (XRF) testing to screen parts and materials as they are received to ensure expected material composition
• Methods to monitor worldwide regulations and translate them to business rules used in compliance processes
In the past couple of years,industry organizations and companies have strategized to address compliance regulations such as the development of standards for sourcing material composition content (IPC-1752),standards for certifying products and processes compliance (IECQ),development of tools to manage content and roll-up material content to report at the finished product level,refinement of XRF (X-Ray Fluorescence) to provide in-field testing for hazardous substances.
This presentation helps companies to identify and detail the internal and collaborative environmental compliance use models needed to confidently support regulations with appropriate due diligence. The presentation details types of data and best practical techniques to obtain the crucial information required to drive the use models. It includes a review of material declaration standards,certification standards,testing and their roles in confident due diligence. This session also discusses companies and products considered exempt or out-of-scope from the compliance regulations,such as aerospace and defense companies,and the business and technical impact.
The information presented is based on IHS’ experience with sourcing environmental compliance information and work with industry providers of lab-based and in-field testing solutions. The practical information presented here will have a strong appeal to OEMs and EMS-providers who need to ensure environmental compliance and manage supply chains.

The IPC's Lead Free program addresses one of the 6 Hazardous Substances regulated by the RoHs directive. Certification to the QC 080000,the IECQ HSPM Specification, addresses the other 5 Hazardous Substances called out by RoHS.

The process challenges of lead free wave soldering often require the use of new flux chemistries when compared with the
relatively tolerant tin-lead wave soldering process. In some cases,the fluxes used in tin-lead soldering work well in lead free
assembly. In other cases,however,the complexity of the assemblies dictate more active,heat-sustainable products
formulated specifically for lead free applications.
This paper reviews the J-STD-004 and how it is used in flux categorization and selection. It also discusses the major types of
flux formulations available,and the design,process and reliability implications of using each type. The purpose of the paper
is to help the reader make an informed choice when selecting wave solder fluxes for lead free processing.

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We have developed a new thermosetting polyimide build-up material for high performance build-up PWBs,which can mount
high speed CPUs with high I/O numbers. These PWBs meet the following requirements; good processability for the
fine-pitched circuits,the low dielectric characteristics,and the excellent mechanical properties.
Our proposed polyimide build-up material shows a dielectric constant (Dk) of 3.1 and a dielectric loss (Df) of 0.01 (at 1GHz).
Moreover the material shows following mechanical properties; a low coefficient of thermal expansion (CTE) of 45ppm and a
tensile strength of 100MPa. Even though the material has a low surface roughness Ra of less than 200n meters,we have
successfully deposited an electro-less plated copper layer with very high peel strength. This means that the material is
suitable for fabricating fine-pitched circuits,even when using a conventional semi-additive process. Actually,we could make
a fine-pitched circuit of less than 10micron L/S (Line and Space).

As a promising candidate for future substrate with high pin-count and low transmission loss at high frequency,we have
developed an all polyimide multi-layered board laminated by single batch process. Compared with circuit boards of glassepoxy
and ceramics,this circuit board made from polyimide films is thin and decreases transmission loss. It makes wiringdensity
higher and manufacturing cost lower,because of having all-layer IVH,Inner Via Hole,structure fabricated by single
batch process. It is a significant feature that the process applies new interconnection technology to formation of conductive
paste via in polyimide films,by laser-drilling and screen printing. By the most suitable condition of paste volume,
temperature and pressure in laminating process,we have achieved 1.0 milli-ohms in resistance for each via.