A previously developed ball grid array (BGA) solder joint vibration fatigue life prediction model,which was experimentally
validated by Test Vehicle One (TV1) test data for the BGAs with and without under-filled materials,has been used to
determine the solder joint integrity of BGAs. However,the newly obtained TV2 test results show that this previously
developed life prediction model has a tendency to under estimate the fatigue life of BGA solder joints. Therefore,there is a
need to re-validate the previously developed life prediction model and it then becomes the objective of the present study.
A TV2,on which various sizes of BGA daisy-chained packages with/without under-filled materials (including nonreworkable
and reworkable) are soldered,is designed,fabricated and subjected to random vibration tests with continuously
monitoring the solder joint integrity. Based on the measurement results,a destructive physical analysis is conducted to further
verify the failure locations and crack paths of the solder joints. The previous developed life prediction model combined with
a finite element analysis is re-calibrated by the TV2 test results. This updated model is then recommended to serve as an
effective tool to determine the solder joint integrity of the BGAs (with/without under-filled materials) during vibration. The
determination of the relationship between the BGA solder joint fatigue life and the elastic modulus of under-filled material is
illustrated. The analysis results show that BGA fatigue life exponentially increases as the elastic modulus of under-filled
material increases to a certain threshold value and this relationship can be used to select the under-filled material for
improving BGA solder joint vibration fatigue life.

In this report,the group activity of developing and proposing standard EMC models for numerical EMC simulation is presented. Our group has developed some basic and standard EMC models which contain the essential characteristics of EMC and has discussed about the calculated behaviors. These models can be used for studying EMC and EMC simulation
and for comparing different simulators. The developed models are briefly presented. A model of differential transmission lines,for example recently took up,is explained as an example. The differential transmission line which has a difference in height on the middle of the line was developed to investigate the emission depending on the parameters of line height,line separation,phase of the driver and so on. For example,the contribution of the common and differential mode radiation was
studied by changing phases of the differential drivers. From the calculated results,it is suggested that the emission from the
line was dominated common mode radiation because the emission was almost proportional to common mode voltage of the differential drivers.

The paper will address issues that will impact defect levels and defect spectrum during the transition to lead-free
manufacturing. Since there are exemptions of which product types are mandated to go lead-free,and not all components will
be available in lead-free versions,there is not a clean path to lead-free manufacturing. Both manufacturers that are forced to
go lead-free as well as companies that are exempted will be impacted. This and other issues will have a big impact on the
optimal test strategy. Data of defect levels and defect spectrum from lead-free production will be presented below. The paper
will also address different test and inspection systems’ readiness to test lead-free printed circuit board assemblies (PCBA).

Metal-base printed circuit boards (PCBs),multilayer PCBs and embedded PCBs are constructed with a thin insulation layer.
In these PCBs,particularly those used for Power Electronics,the insulation layer is stressed under a high-strength electric
field. Metal-base PCBs are applied to 100-400 V power circuits for power transistor modules,general purpose inverters and
so on. Since the insulation layer is stressed under a high-strength electric field of approximately 1-3 kV/mm,the reliability of
the insulation layer is important. In order to investigate the migration process,we have studied the behaviour of ionic
impurities in the insulation layer of various PCBs by measuring space charge profiles using the pulsed electroacoustic (PEA)
method. Since space charge behaviour affects the internal field profile,the experimental results should contribute to the
insulation design of PCBs. Consequently,hetero charge accumulated in the vicinity of the electrode in the insulation layer of
two types of metal-base PCBs and two types of Aramid/Epoxy PCBs,and the electric field strength near each electrode are
enhanced two-three times more than the average field strength of 5 kV/mm and 10kV/mm. Two types of PCBs (Glass/Epoxy,
PTFE/Epoxy) do not exhibit significant electric field distortion under 5 kV/mm and 10 kV/mm. After thermal humidity bias
(THB) testing for 20 and 59 hours (DC 1250 V at 85°C and 70% RH),the space charge measurement detected a conductive
region that was formed in the insulation layer near the anode of the metal-base PCB A. Element distribution analysis verifies
that the conductive region is formed due to copper ionic migration. These results reveal that space charge measurement can
carry out a non-destructive observation of the growth of copper migration.

The 2002 International Electronics Manufacturing Initiative (iNEMI) Optoelectronics roadmap anticipated a cross-over in
cost-performance whereby a system using optical transmission of high speed signals would have lower overall “cost” than a
pure electrical system of equivalent function. In 2003,iNEMI formed a task group to investigate this cross-over point via cost
modeling analysis. The activities to date have been to adapt and verify an existing cost model for copper-based PCBs and
develop an electrical backplane technology roadmap to 40 GHz,with logical combinations of bus type,connectors and signal
conditioning chip sets. We are currently reviewing the relevant optical technologies,including optical fiber,fiber flex or
embedded polymer waveguide,optical connectors and transceivers to develop the equivalent optical roadmap. This
presentation will be a work-in-progress report on the iNEMI project activities with the goal of developing cost and
performance models to compare different designs of electrical and optical backplanes.

This paper summarizes research performed by the NEMI (National Electronics Manufacturing Initiative) Fiber Optic Signal
Performance Project team. The project focused on the development of a cleanliness specification for single mode connectors.
The influence of two grades of Arizona road dust on optical performance of single mode fibers is investigated.
The researchers record insertion loss,return loss,and fiber optic microscope images for each connector pair before and after
contamination. Interferometry data including radius of curvature,apex offset and fiber undercut are also recorded for each
test and reference connector. The changes of insertion loss and return loss as a function of distance of the closest particle
from the core are investigated. Results of mathematical modeling of contaminated fibers are correlated with experimental
data. The results show that contamination particles can prevent direct physical contact creating an air gap between two endfaces.
The area encompassed by a 25 µm diameter from the core is identified as critical. Particles located in this area,even if not
directly on the core,result in an increase in insertion loss (a delta of 0.5 to 1.8 dB) and an increase in reflectance (a delta of
10 to 44 dB). Dust particles of 1-25 µm result in an air gap of up to 200 nm.
The NEMI team is collaborating with the International Electrotechnical Committee (IEC),Telecommunications Industry
Association (TIA) and IPC (Optoelectronic Assembly and Packaging Technology). Specifications will be jointly submitted to
IEC SC86B Working Group 6 (interconnecting devices) for incorporation with IEC 61300-3-35,and to IPC as a draft of the
IPC-8497-01 standard. In addition,the project will collaborate with TIA and IPC on the development of cleaning methods
and contamination assessment for multi-level optical assemblies.

The concept revealed is a simple architecture for an optical printed circuit board,which permits manufacturing with the
materials normally used in printed circuit board fabrication. This concept is that the very short distances of Z travel within a
printed circuit board can be best traveled electrically,allowing the surface devices and general layout to be nearly standard
and with inexpensive devices. The internal transmission of optical signals is done only within a plane,making the
manufacturing much easier and the reliability as good as other embedded device PCBs. This should enable a much less
expensive optical PCB.

In order to cope with a rapid increase in information processing speed,additional technical developments of an
optical-electrical composite board are required. Generally speaking,it is more difficult to interconnect between optical
devises and optical lines than between electrical devises and electrical lines,and this fact is one of the reasons why it is big
challenges to put these boards to practical use. In this paper,we have investigated on this problem using an Optical Wiring
Board (OWB) prototype with embedded micro-mirrors. The OWB prototype is consisted of polymeric multimode optical
waveguides layer in conventional PWB and micro-mirrors that is embedded at the both ends of the optical waveguides. The
height of the mirrors is the same as that of optical waveguides,and optical signal pass between optical waveguides and the
board surface vertically through an upper cladding layer. We first calculated coupling efficiency of mirror by ray tracing
method,and we found that mounting tolerance on optical misalignment for 1dB loss is plus or minus 10 microns. The
calculated results were also supported by measurement using OWB prototype. We concluded that the OWB with the
embedded micro-mirrors as the optical coupler is promising for a future practical application.

The number of PCB manufacturers in Europe declined from 700 in the nineties to 400 early this decade and is forecasted to shrink to the range of 100 by 2010. A share of these companies will not survive the coming years; while the majority are
financially under heavy pressure do to global pricing and off shoring activities of their customers. A number of companies,large ones,medium size and small ones have found their way to be very successful in this environment. What are business models and secrets of these successors?

The dramatic economic downturn of the PWB industry starting in the forth quarter of 2000,which resulted in a reduction of 1/3 of the demand and corresponding supply chain within one year,has changed our industry fundamentally. There is now a
slow recovery,however,it does not take place worldwide but is concentrated in low cost regions. Many of the established PWB companies in the Western World are confronted with the question: "Is there a business model enabling a Western
company to survive and be successful again?"
AT&S,almost bankrupt at the beginning of the nineties,was given a new direction by the new owners and management with the MBO in 1994. This direction consisted mainly of changing from a low price supplier dependent on one big customer to a
competent partner for locally and globally acting companies. We followed a total cost approach according to the principal "Who can afford to buy cheap?" or "Paying a higher price for a product is often the less expensive solution,no matter
whether it is a component or a finished product".
Essential for this business model is to find the right balance between the factors: quality,technology,supply chain,optimization of customer solution,responsiveness and proximity to customers. The intent is not to focus on one of them following just a temporary trend. These items are decisive for building up customer confidence and trust to become a partner of competence. Their right balance leads to a total cost approach with the aim to offer the customers the best solution for their
final products in order to enable them to meet competitive price levels for their own products.