Completed projects

Project type: Halogen-Free
Halogen-Free Materials Database
Evaluation of Environmentally-Sensitive Material Content in IT Products (DfE 1)

Over the past several years, increased attention has been placed upon the potential environmental impacts of IT products.  Largely due to the tremendous growth of electronics used in our every-day lives, environmental concerns have been raised regarding materials contained in electronic devices (e.g. lead solder), the power that electronic devices consume, and the growing number of electronic devices that end up in our waste streams.  Both voluntary and regulatory measures have been taken to address some of these concerns.

BFR/PVC Cables & Wires

Download the HDPUG-iNEMI Whitepaper on both consortia's Halogen Free Cables Projects.

A coordinated activity within the Materials/cable manufacturers/OEMs supply chain to quickly and thoroughly evaluate PVC/phthalate-free cable/wire options.  An effort like this is needed to quickly determine the best alternatives, and significantly reduce the cost and effort by the suppliers, by focusing on the specific needs of the OEMs and ODMs.  When we are finished, the users will be ready to implement the alternatives, because they have been part of the development.


BFR/PVC Free Cables 2

This project is a follow on project to the PVC Free 1 project completed in 2011.

In project 1 we used the current industry specifications, they are for materials that do contain PVC. For this project we are considering modifying the current specifications or developing new specifications for non-PVC containing materials.

Halogen-Free Assembly Reliability Phase 2

Several governments in Europe and the Far East are considering regulation to prohibit or restrict the use of certain types of substances in electronic (and other) products.  Within the marketplace, the OEM's have initiated environmentally-preferable purchasing standards that also include restrictions on the use of these substances in certain products.

In order for the electronics industry to continue its commitment to product stewardship, companies throughout the supply chain will need to understand which alternatives are available, as well as the electrical, mechanical and environmental, health and safety properties of these alternatives.

Halogen-free Guideline

Flame-retarded plastics are commonly needed to meet strict fire safety codes for electronic equipment.  Certain halogenated compounds are used as flame retardants in a variety of applications including thermoplastics, insulation materials, component mold compounds, solder masks and printed circuit board laminates.  In addition, polyvinyl chloride or PVC (a resin that contains chlorine, a halogen) is a commonly used base resin for certain cable jacketing.  However, concerns have arisen that these materials may pose certain risks to health or the environment particularly at end-of-life.

The project team will prepare a comprehensive Halogen-free Guideline.

Environmental Assessment of Halogen-free Printed Circuit Boards (DFE 2)

The HDP User Group Design for Environment (DfE) group was formed in 2002 and was represented by companies such as Dell, Ericsson, HP, IBM, Intel and Nokia. The HDP User Group released two publicly-available reports regarding key environmental attributes of electronic products. Both reports were also presented at the 2003 and 2004 IEEE International Symposium on Electronics & the Environment.

Transition to Halogen-free Electronics

At the 2nd International Workshop on Lead & Halogen-free Electronics produced by SEMI and HDP User Group in Tokyo and Makuhari in December, 2000, some issues of halogen-free printed circuit board material were pointed out from NEC. The issues indicated from NEC obtained approval from many electronics manufacturers including the electronics manufactures that have already adopted it as a product, and it has been recognized that it is a common subject. Then, the activity as a project of HDP User Group was proposed, and activity was started in November, 2001.

High Frequency Laminate Measurements

There is no standard platform to evaluate high frequency PWB materials, and there are several methods for measuring properties such as dielectric loss.  Furthermore, there is no definition of moisture for any of these tests and moisture can significantly change a test result.  Suppliers and OEM’s need to work together to evaluate test methods and characterize materials.

Project type: Lead-Free
SAC Microvoids

 This project:

Measure the effects of bath parameters and other treatments upon the intermetallic compound layer and the root cause of brittle fractures in SAC Alloys-Microvoids
Support Electronic Industry efforts to improve the Reliability of SAC Alloys
Obtain quantitative results that will provide corrective action guidance to industry to mitigate the occurrence of brittle failures in drop or shock; for example cell phones
Develop fracture mechanics models that account for the effect of microvoids and intermetallic compounds material properties in simulated loads
GPLF Guideline II

This is a continuation of the activiy in the GPLF Guideline I project, and resulted in a major revision to the Guideline produced in the GPLF I project.  Visit the GPLF I Project page for the pilosophy and description of the GPLF projects.

General Purpose Lead Free (GPLF) I

This implementation guideline has considered industry-wide Pb-free development efforts and focused on presenting a common, compatible lead-free solder system that would facilitate the introduction of Pb-free products by system integrators and EMS providers.

Multiple Alloy Screening
  • BGA suppliers have introduced a significant number of new Pb-free BGA solder ball alloys.
  • Most have been introduced to address drop/shock performance issues.
  • Very little/almost zero data is available on the thermal cycle performance of these alloys - which is key to many of the high reliability community not building hand-held consumer products.
    • The limited data available suggests that thermal cycle performance may be significantly different between the various alloys.
    • Many of these same components end up in high-reliability products.
Evaluation of the Solderability of an Alternate Alloy

This project is a part of General Purpose Lead Free assembly system, which has been planned to define a guideline compatible with tin-lead based soldering. Although tin-silver-copper solder pastes are in mainstream of lead-free, the composition of the pastes differs in areas. Europeans and North Americans would like to use Sn- (3.8-4.0) Ag- (0.6-0.7) Cu, whereas Japanese would like to use Sn-3.0Ag-0.5Cu. As HDP User Group had not had any experimental data about the Sn-3.0Ag-0.5Cu paste, the Japanese team decided to evaluate the solderability of this composition as an Alternate Solder Alloy. We hope that HDP User Group will be able to gather tremendous data and findings by sharing this activity with European / American activities on the Sn- (3.84.0) Ag- (0.6-0.7) Cu.

Lead Free Board Materials Reliability 3

This project is the third phase of an initiative originally started in 2006 to assess the performance of latest generation (at the time) PWB laminate systems after being exposed to simulated Pb-Free surface mount soldering conditions.  The third phase looked at recently released materials and focused on laminates designed for high speed applications. The project submited selected laminate systems to an extensive mechanical and electrical integrity testing program to verify whether the materials are prone to deterioration during higher temperature soldering conditions. 

Lead Free Board Materials Reliability Phase 2

This is a follow up to the Lead Free Board Materials Reliability Project. New materials and formulations are tested to see how much improvement has been accomplished since the first project.

SAC Aging Factors - A

Endeavor to answer the following questions: What is the effect of aging time (post assembly) on SAC solder joint reliability? What is the effect of aging temperature?  How does SAC305 compare to SAC387?  How does strain level interact with aging?

SAC Aging 2

There is evidence that the ATC performance of SAC solders is affected by thermal preconditioning or aging.  This project will use an existing test board design and component(s) to facilitate the further understanding of this phenomenon, and attempt to relate ATC performance to microstructural changes that occur during aging.  Baseline microstructural characterization will be performed on ambient (no age) and aged samples. Failure mode analysis and characterization will be performed on ATC samples to determine extent of microstructural evolution and impact on final failure.

Predict Lead Free Solder Joint Life from Microstructure Evolution

The aim of this project was to predict the remaining life of LF solder joints by analyzing the joint's microstructure after the board has been in service for several years where some fatigue damage has occured but the joint has not yet cracked.Test vehicles, as well as field returns, were micro sectioned and analyzed for structural change.  Observed structural changes were correlated to failure and field life. 

Lead Free Process Guideline version 3.0

The General Purpose Lead Free (GPLF) assembly system guideline was originally developed in 2004 with a minor revision added in 2005. The aim of the document was to produce a handbook that would assist system integrators/ electronics producers and their supply chain in developing Pb-Free manufacturing solutions that meet required levels of reliability while complying with forthcoming environmental legislation.  This is the next revision in that series.

GPLF Optimization Study

The introduction of RoHS and similar environmental legislation has driven the need to transition PCB products to be manufactured with Pb Free solder. While simpler designs can be produced with alternative Tin Solder Copper solder with little difficult, manufacturing larger and more complicated products, with high reliability demands, presents significant challenges, specifically in minimizing thermal stresses on certain components through the SMT solder reflow process. In order to overcomethese issues, process optimization is essential.

Mild Acceleration Factors - A
  • Current testing (industry and consortium) of Pb-free assemblies in accelerated conditions (0-100C, -40 to +125C, etc.) shows significant reductions in solder joint reliability (SAC reliability <<SnPb) for certain component types (high strain components).  These components are used on the majority of high reliability products.  There are no accepted acceleration factors or models for SAC reliability that relate accelerated conditions to field conditions.
  • The data available also indicates that SAC reliability SnPb for low strain components.
  • Aging factors affecting microstructure, creep and fatigue on SAC alloys have only recently been identified.
Lead-Free Board Material Reliability

There are numerous laminates available to the PCB designer today. Some of these laminates have been around for a number of years and the designers and OEM's understand their capabilities and limitations. However with the advent of lead free solders and their higher processing temperatures new laminates that are designated "Lead Free Capable" are appearing. These products while tested for consumer products have not necessarily been qualified for more complex PWB designs where peak SMT reflow temperatures on the PWB surface tend to be significantly higher with the potential reulst of internal delamination. This project conducts extensive testing of a selection of latest generation laminates and pre-pregs to measure their reliability in these higher SMT reflow environments. 


This project explores whether PWB laser drilled micro-vias positioned in surface mount lands used for attachment of ball grid array components, have a negative impact on long term product reliability. Both plastic and ceramic ball grid arrays are included in the study.

Definition of Lead/Halide-free Products

This project was organized to develop a draft definition/specification of Lead-Free and Halogen-Free materials as it applies to electronic components and Printer Wiring Boards and get it accepted on a global scale. The specification can allow manufacturable alternative materials to be developed and an “affordable” cost, while meeting the intent of legislative directives aimed at minimizing environmental concerns.

SAC Microvoids II

Phase I of this study was a screening experiment to determine which plating and treatment parameters contribute to microvoid formation.  Phase I indicated correlations with current density, solder alloy, bath age, wetting agent, brightener content, and copper layer thickness.  There were also strong interactions of the above, all involving the wetting agent.

Lead Free PWB Materials Reliability Phase 4
Phase 4 of the Lead-Free PWB materials reliability program evaluates selected latest generation high speed PWB laminates. As with previous phases the focus will be on how the chosen materials  will perform mechanically and electrically when exposed to higher end Pb-Free surface mount reflow temperatures, typical of the conditions needed to assemble large, thick and high complexity printed circuit board designs. The testing program will monitor for any delamination issues, CAF concerns, and thermal cycling performance. Furthermore, electrical properties will be evaluated both before and after reflow. 
Lead Free Acceleration Factors

Numerous papers (Sahasrabudhe, Clech, Lau, others) indicate that ATC test conditions have a different effect on the results of SAC solder fatigue life than they do on SnPb solder fatigue life.

Alternative Alloy Study for Hole Fill and Copper Dissolution

Investigate the damage to PWB wiring patterns caused by copper erosion in lead-free assembly. Copper erosion can occur during dipping, wave soldering and rework processes.

Project type: Opto-Electronics

Address performance limitations encountered in high-speed electrical backplanes (15-20+ Gbps) by use of optical signal transmission.  Demonstrate, by building a test vehicle design, that optical waveguides within a backplane can benefit the system’s interconnect topology by providing: Higher data rates, Additional I/O, and better interconnect architectures

Materials and Reliability of Optical Packages

The purpose of the project was to develop a knowledge and database system enabling materials selection for assembly of dimensionally stable optical and optoelectronic modules and to propose suitable approaches for modeling non-elastic deformation of polymers in optical modules.

Optical FPC Assembly

This project evaluates the various manufacturing options for attaching very fine pitch flexible printed circuits typically used to connect optical transceiver modules to PWBs. The project will explore several different attachment techniques assessing their suitability for high volume high yielding assembly applications.

Project type: Power Supply
Board Mounted Power Supply evaluation

Power bricks are one of few “hold-out” components still demanding wave solder. The conversion to SMT bricks would allow the elimination of wave processing for many printed circuit assemblies. Currently 1/16th and 1/8th brick types have wide adoption in SMT with a variety pin/leg styles, this is not the case for the 1/4 brick and above sizes.

 This project focuses on the impact of DC/DC module (bricks) features on soldered PTH hole-fill and the module-PWB attachment reliability of SMT bricks. The project will measure the impact of various brick pin and footprint feature variants such as, gas vents, hole size, and thermal plane connections on the hole-fill of a pin through hole soldered joint. Besides the PTH configuration, SMT attach variants to be studied are “Pure Post”, “PIP/SMT hybrid”, and “Pedestal and ball”. Figure 18 shows a Pedestal and Ball configuration. Different brick styles will be studied in a 1/4 brick package to assess comparative thermal cycling and vibration reliability with the bricks carrying full current.

Board Mounted Power Supplies (BMPS) Guideline I
The cooperation shall consist of the following items:

PSMA and EPSMA would support the “General Purpose Lead-free Assembly System” concept. It is understood that several details of the assembly system remains to be defined

Board Mount Power Supply (BMPS) Guideline II

System integrators want to have well defined lead-free requirements on Board Mount Power Supplies (BMPS), Pin compatibility between functionally compliant BMPS, and industry standards for function compatibility of BMPS.  They also want to eliminate the need for modules to be attached using "press fit technology" or manual soldering.  Update and extend the information available in the BMPS Guideline.  Issue an updated version of the Guideline.

Project type: Printed Wiring Board Technology
Counterfeit PCB Materials

The Counterfeit PCB Materials Project identifies and investigates two issues in the electronics industry: Safety as a function of counterfeit materials, and Trust   involving anti-counterfeit, anti-tamper, chain of custody and access control.

PWB Environmental Life Cycle Analysis

An environmental life cycle analysis study measures the CO2 emissions and energy consumption associated with the full life of a product including the impact from raw material extraction, manufacturing processes, transportation/packaging, operational life and end of life disposal. The technique is becoming increasingly recognized as an important measure for determining the impact of electrical products. This project focused on the environmental consequences of producing and using printed wiring boards and  involved representatives from the complete PWB supply chain.


Digital Speckle Correlation (DSC)

The Digital Image Speckle Correlation Project (DISC) is an experimental physics-based study, which will assess whether a unique but mature Digital Image/Speckle Correlation test method for the measurement of the thermal stress in microvias and surrounding areas can be used to predict the relative reliability differences in PWB stackup structures. The unique quantitative measurement of the strain and other deformation kinematic parameters makes it possible for a relatively short term mechanistic-based failure analysis instead of having to perform long term traditional reliability studies.

Electro-Chemical Migration

Much of the Assembly industry has experienced the effects of Electro-Chemical Migration.  It has been shown that contaminants on the surface of PCBs can migrate and cause creep corrosion and/or shorts.  This occurs primarily on the newer Pb free surfaces/finishes.  It is thought to be driven by changing geometry, surface finishes and board cleanliness.

PWB Back Drilling Failure Analysis

Back drilling or controlled depth drilling of plated through holes (PTH) is increasingly being used in High Speed Designs. While back drilling of PWB's helps to remove signal distortion by removing via related stubs, reliability issues attributed to this practice appear to be on the rise. The drivers for this project include the lack of Design Guidelines, PWB Fabrication Tolerances, Material and Lead Free Assembly. This project also evaluated new electrical methodologies for measuring copper stub length and depth of the backdrill along with determining exactly where the layer of interest (no cut) lies in the PCB board stack up.

Focus/Area of Concern: This project explored the reason for back drilling related PWB failures and to identified potential solutions and design/process guidelines to prevent future problems associated with this process.

·         The project assessed the backdrill capability of the Industry through a survey. The Survey targeted both OEM and PCB fabricators. The results were coded to keep all data anonymous.

·         Evaluated the reliability of backdrilled via compared to standard plated through hole. Designed a set of IST coupon that were tested as received, pre-conditioned (6X @ 260 C) and after simulated reflow.

·         Developed and analyzed a series of electrically testable backdrill coupons for stub length and inner layer laminate thickness measurement

Thin Cu Stress Test

The reliability of plated through hole copper (Cu) in Printed Wiring Boards (PWB) is typically evaluated using air-to-air thermal cycling.  This takes a long time, and does not provide material data that can be used for finite element modeling of the structure.  This project will evaluate the use of rapid cycle stress testing to evaluate thin Cu and provide good material properties.

Project type: Emerging Technology
TSV Board Level Reliability

Through silicon vias (TSV) offer a potential solution to addressing some of the interconnect issues that impact the CPU-Memory latency bottle neck. This project focuses on how TSVs can be adopted for this purpose and evaluates the challenges to applying this technology in future packaging solutions.  Possible exploration areas might include reliability of TSV interconnect, road mapping, fabrication of high density TSV, and/or design tools.

Anti Counterfeit of Electronics Phase 3

The High Density Packaging User Group announces Phase 3 of the Anti-counterfeit of Electronics Project. Building on Phase 1 of this project in which the team defined the protocol for information required to pass down (and up) the Supply Chain for traceability. In Phase 2, the team identified current and emerging technologies capable of transmitting the required information along the Supply Chain and mapped the technologies against the segments of the Supply that they may be best suited for. Phase 3 allows the team to test selected technologies to confirm applicability and effectiveness of those protocols and technologies.

TSV Signal Integrity

TSV (Through-Silicon Vias) Signal Integrity Project:  (Lead: NIST)
This project was initiated as an evaluation of the status of TSV, and during that evaluation, identified some potential avenues of exploration for HDP User Group. The Signal Integrity project was first proposed in February 2014, entered the Definition Phase in June 2014, and was concluded in April 2016.  The approach here was to generate an experimental project to compare the signal quality of TSV packaging to traditional packaging. 
This empirical approach required the procurement of hardware which to-date has not been made available for non-proprietary experimentation. 
Benefits of the Project:
To conclude this project, Yaw Obeng and Dave Love wrote up a short review, summarizing of the current status of the public knowledge of TSV signal integrity. This summary can be found on the website in the Projects section. In that document, there are 14 references to published work on the topic.
Anti Counterfeit Phase 2

Phase 2: List, evaluate and compare the existing and emerging technologies for product authentication throughout the electronics supply chain that support the protocol, their applicability and effectiveness at all stages.

Project type: Lead Finish
Component Terminal Finishes Phase 2

Various techniques have been proposed to reduce the Sn-whisker risk with matte Sn finishes. Nevertheless, most end users of electronic still have concerns about long term Sn-whisker growth risk with Sn based terminal finishes. NiPd-based Pre-Plated lead Leadframe (PPF) finishes have been introduced as one Pb-free alternative with no Sn-whisker risk. An improved technology that overcomes the technical limitations of the existing NiPd-based finishes has been developed and applied extensively, but degradation in the Moisture Sensitivity Level (MSL) of a package component due to the limited adhesion quality between compound and noble metal surface and the increase in Pb-free SMT temperature (260℃) has occurred more frequently with NiPd-based finish packages.

Nickel-Palladium Based Component Terminal Finishes I

Erroneous perceptions such as high cost driven by Pd content and price, quality problems at board mounting, and package reliability limits MSL(Moisture Sensitivity Level) have led some IC component suppliers to reject adopting or even evaluating NiPd based PPFs.

Component Terminal Finishes Phase 3

This project measures MSL results by surface treatment type and development results of new NiPd-based finishes for enhanced MSL, based on the results presented in Phases I and II.  Data includes the use of surface treatments and finishes such as Cu surface Zn-Cr coating (A2 coating), Micro Etching, Brown Oxidation Treatment and Surface Adhesion Promoter Coating.

Lead Free Assembly Guideline - Version 3.0

The General Purpose Lead Free (GPLF) assembly system guideline was originally developed in 2004 with a minor revision added in 2005. The aim of the document was to produce a handbook that would assist system integrators/ electronics producers and their supply chain in developing Pb-Free manufacturing solutions that meet required levels of reliability while complying with forthcoming environmental legislation.

The guideline has not been revised since 2005 and is in urgent need of updating. The proposed Guideline – 3rd Edition Project is therefore aimed at making the document more relevant to the current challenges and issues faced by the industry.

Project type: Printed Wiring Board Assembly
Mechanical Fatigue Phase II - A

This is a follow on to the Phase I Project which showed some promise for using rapid mechanical stressing to predict quality and life of Lead Free solders, but much quicker than conventional thermal cycle.  This project will study the difference of fatigue life in solder joints of leadless packages (QFN packages) between conventional temperature cycle test and mechanical fatigue test.  It will also study the similarities and differences at the same maximum strain in solder joints between mechanical fatigue and bending test.

Low/No Silver Alloy Solder Paste Phase 1 Process Characterization


The price of metals and particularly silver (Ag) has been increasing in recent years. This has created an increased interest in the use of low/no silver alloy in the manufacturing process. Low silver alloy BGA solder balls (such as SAC105) are being used in products, but there is very little information about the alternative (low/no) silver alloy solder pastes, it’s process feasibility and reliability. Within the past couple of years, many alternative low/no silver alloy solder pastes have been developed and are available in the market.

 This is a multi-phased project, the first phase was designed to characterize the candidate solderpaste to verify that they could be used to assemble the Phase 2 reliability components. Phase 2 will evaluate the reliability of some of the candidate solderpaste.

 The Phase 1 project studied and documented the process feasibility/characterization of low/no silver alloy solder pastes compared to the standard SAC 305 paste for integration into a development assembly line.

 Phase 1 studied the process feasibility and reliability of low/no silver alloy solder pastes including

 ·         Low/no silver high temperature alloy solder pastes (liquidus temperature >217°C)

 ·         Low/no silver low temperature alloy solder pastes. (liquidus temperature <217°C)


Mechanical Fatigue Test for Solder Joint Reliability - A
Shortening of the product development cycle requires a new method that can evaluate the reliability of solder joint in the short time instead of the conventional thermal cycle test.
There are several proposals on the solder joint reliability test using the mechanical fatigue test from universities and an institute. Mechanical shear fatigue test have been proposed to IEC standards.
Project type: Component Packaging
TE-Migration II
Process Sensitive Components

This project is intended to compile and publish an industry guideline document on recommended practices for the treatment of temperature sensitive components (TSC). This guideline will include inputs from IC component, non-IC component, and connector suppliers as well as OEM users and Contract Manufacturers. This document will also identify Best Practices for assembling process sensitive components, along with other component process sensitities.

Wafer Level Packaging Materials

A coordinated activity within the Materials/Wafer Fabricators/OEMs supply chain to quickly and thoroughly evaluate new material options.  Increasing pace of new materials introduction by multiple suppliers can overwhelm design, packaging, and testing resources –if everything is evaluated.  By the time a material (i.e., mold compound, repassivation, coating, doped solder, etc.) is qualified, newer “improved’ materials are offered.  An effort like this is needed to quickly determine the best alternatives, and significantly reduce the cost and effort by the suppliers, by focusing on the specific needs of the OEMs and ODMs.  When we are finished, the users will be ready to implement the alternatives, because they have been part of the development.

FCBGA Package Warpage
Most of the assembly industry is experiencing problems with the ever decreasing IC package thickness.  With denser packages (QFN's, Area Array's and Stacked Packages), the flatness of the packages and boards becomes more and more critical.
Warpage as a result of the thickness of the IC's used, can be a manufacturing night mare.  Defects such as open joints or very weak joints can be caused by short leads on the IC's combined with very flexible carriers.  This combination will most likely cause interconnections that will be poorly made or never made, resulting in a defect.
With the IC's becoming increasingly thinner, the silicon has less impact on resisting deformation of the package. The net result is that warpage will become an increasing problem in the future.

Advanced QFN Evaluation

This project explored component footprint design and associated circuit board assembly processes for the latest generation of fine pitch QFN devices. The project conducted both post assembly yield assessments and longer term reliability testing (using accelerated thermal cycling techniques) to evaluate the impact of using different design and process parameters.

Anti-Counterfeit Electronics

The project will define the optimum Protocols for forward and backward traceability that provide built-in integrity to transactions throughout the electronics supply chain, evaluate the technologies that support those protocols and conduct a multi-link test to confirm applicability and effectiveness of the selected protocols and technologies.

Polymer Ball Interconnect - A

The use of plated polymer cored balls to replace solder balls in BGAs and CSPs has been developed and trailled  over several years but has yet to see signifcant take up in the industry.  However with larger ceramic components presenting increasingly challenging long term reliability concerns the flexible nature of polymer ball technology is becoming increasingly attractive.This project looked into latest products from  two polymer ball manufacturers, including multiple polymer compositions, coatings and soldering methods. Bend testing and thermal cycling were conducted on different size ceramic BGAs.  The project team was made up of member companies from across the supply the supply chain.

Thermo-Electromigration in WL-CSP Pb-Free Solder Joints
Project type: High Frequency
High Frequency Measurements Phase 2

Phase II of this project proposes to evaluate the effect of moisture on each of the high frequency Dk and Df test methods, except Equivalent Band Width (EBW). The lower loss laminate material selected for a pilot run will be known to absorb significant amounts of moisture, but without having any fillers capable of releasing water or moisture into the material during thermal excursions or at higher temperatures.

 HDP’s High Frequency Measurements Phase 1 project completed in 2015. That project was the industry’s first characterization of all of the different high frequency test methods available for measuring Dk and Df. The final report of that project was selected as the best paper of IPC Apex-Expo 2015.

 During the testing and analysis of the Phase 1 project, it was determined that there were strong Dk and Df data correlations between high frequency test methods that were of the same type. However, differences in moisture content were found to contribute up to a 20 percent difference in the measured Df values of some laminate materials tested.