IPC Conference Paper Archive

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 .. read more

Hot gas rework of BGAs with a mirrored BGA design configuration using SnAgCu based lead-free alloys is more challenging as compared to conventional SnPb techniques. Rework of BGAs using a conve .. read more

During lead-free wave soldering or rework operation for through hole components,high rate copper dissolution may occur to printed wiring boards. It is widely believed that Sn-Ag-Cu (SAC) lead-f .. read more

Implementation of lead-free assembly processes results in higher copper dissolution rate than traditional SnPb alloys. The rate at which copper is dissolved could be dependent on many factors,s .. read more

Lead-free selective soldering can result in extended times at high temperatures,which in turn can result in excessive dissolution of exposed copper,such as plated through holes. This phenomenon .. read more

The high temperature exposures associated with lead-free soldering of printed circuit boards (PCBs) can alter the laminate material properties thereby creating a shift in the performance and re .. read more

For decades the manufacturers of electronic components have furnished products that were most compatible with soldering processes that employed a eutectic alloy composition that contained tin a .. read more

Though the electronics industry is nearing the 3-year anniversary marking the ban of lead from electronics products,several challenges still remain with existing lead-free materials for certain .. read more

The plated thru hole has changed considerably in 50 years of electronic packaging,but in its many forms remains the most common interconnection in 1st and 2nd level electronic packaging,and is .. read more

The conversion to lead free Ball Grid Array (BGA) packages has raised several new assembly and reliability issues. One reliability concern becoming more prevalent is the increased propensity fo .. read more

Although the advantages of Hot Air Solder Leveling (HASL) in providing the most robust solderable finish for printed circuit boards are well recognized,in the years leading up to the implementa .. read more

Although the EU RoHS legislation restricts the use of lead in electronics equipment,many high-end multi layer server printed circuit board assemblies (PCBAs) continue to be built with lead unde .. read more

As the electronic industry moves to lead-free assembly and finer-pitch circuits,widely used printed wiring board (PWB) finish,SnPb HASL,has been replaced with lead-free and coplanar PWB finishe .. read more

The New England Lead Free Consortium,composed of many companies in the electronic supply chain in the regional area and chaired by the author; has embarked on an extensive long term reliability .. read more

Since July 1st 2006,the 2002/95/EC RoHS European directive has forced the electronic industry to switch from Tin-Lead to lead-free soldering alloys for components assembly. Exemption domains ha .. read more

Although the official implementation of the EU Restriction of Hazardous Substances (RoHS) directive officially started on July 1,2006,a significant portion of the avionics electronics supply ch .. read more

The SMT industry is going through a challenging phase of assembling miniature components,such as micro BGA,0.3mm CSP and 01005 passives onto Printed Circuit Boards (PCB). This effort is primari .. read more

Tombstoning,the phenomena where a chip component stands up on one end during the reflow cycle,is well-documented and understood in tin-lead systems. It is reported to occur more frequently in l .. read more

The change to lead-free solders has forced the electronics industry to consider more than it ever has before what properties are important in a solder. When the tin-lead eutectic was the only s .. read more

In general,new lead-free solder alloys with the following characteristics are desired in order to enable the continuation of miniaturization trend: (1) alloy with a reduced melting temperature, .. read more

Advancements and evolutions in printed circuit board manufacturing,design,and electronics assembly have driven new research on high temperature organic solderability preservative (HT OSP) surfa .. read more

SN100C (Sn99Cu0.7 with Ni- and Ge-micro-additions) is a lead-free solder alloy that is finding increased acceptance globally and holds promise as a mainstream solution in terms of long-term sol .. read more

As the use of area array connectors has become more widespread in electronic assemblies,the need to evaluate their reliability has increased. There is,however,limited information on how best to .. read more

Recent industry trends have focused around alternatives for the commonly used SAC305 or SAC405 alloys for wave soldering and solder fountain rework processes. Industry consortia are currently f .. read more

The increasing use of lead-free solder has introduced a new set of process parameters when setting up wave solder equipment for effective soldering. Determining the proper flow characteristics .. read more

During the development of a new medical imaging system,via quality was identified as a potentially source of infantile failures. Premature via failures were precipitated in a critical 14 layer .. read more

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 Hazardo .. read more

Planar microvoids have been observed on second level interconnections between solder metallizations and copper lands on PCB boards with immersion silver surface finish. These planar microvoids .. read more

For some years now,an area ratio of 0.66 or greater has been the criterion for stencil apertures to achieve acceptable volume control in the printed solder paste “brick,” for small apertures Me .. read more

boards in the in-line aqueous cleaning process. As lead-free circuit boards become more complex and component spacing decreases,the effectiveness of direct blow-off drying is greatly diminished .. read more

As the electronic industry is moving to lead-free PWB final finishes and high density circuit boards,the widely used PWB finish,SnPb HASL,has to be replaced with a lead-free and coplanar PWB fi .. read more

This paper will present seven different materials used for the production of both wave solder and reflow solder pallets. The goal of this study will be for the purpose of depicting machining ca .. read more

A perplexing challenge for RoHS compliance is adapting large,complex and thick,high-layer count multilayers to lead-free assembly. These are typically dense,complex assemblies with large BGAs a .. read more

With the introduction of lead free electronics assembly worldwide,greater concerns are raised over factory control of materials and processes. Due to the mix of both leaded and lead free produc .. read more

Corrosion of solder pots and solder pot components in wave soldering equipment has been reduced with the introduction of corrosion resistant coatings and improved lead free solder alloys. The l .. read more

This paper analyzes the differences in plated through hole fill performance between the regular OSP and Pb-free OSP PCB surface finish chemistries in a Pb-free wave solder process. The variable .. read more

The pressure on manufacturers of electronic devices to continually reduce the cost of products has continued,despite the challenges of higher cost lead-free production. In many cases assemblers .. read more

This paper provides a high-level overview of many of the key lessons learned thus far in working with PCB fabricators in qualifying laminate/fabrication processes that will yield fundamental pr .. read more

Organic Solderability Preservatives (OSP) continue to attract significant attention as circuit board final finishes. They have evolved from simple and thin benzotriazole coatings to thicker and .. read more

The pressure on manufacturers of electronic devices to continually reduce the cost of products has continued,despite the challenges of higher cost lead-free production. In many cases assemblers .. read more

Soldering with lead-free solders has become an international standard. A study conducted by the Dresden Technical University and rehm Anlagenbau examines which influences various parameters hav .. read more

In this paper,factors that influence the ability for a flex circuit,especially a multilayer flex circuit,to survive the lead-free soldering and other thermal processes during the circuit fabric .. read more

The reliability of aged and repaired lead-free and mixed lead-free/lead-based solder interconnects is an important issue for electronic equipment manufacturers. As a result of the global transi .. read more

The migration to lead free reflow is bringing many challenges for the PCB industry. High Tg laminates,stability of materials thru 2X reflows,rework,moisture sensitivity etc. This requires caref .. read more

The whisker concern has been greatly affecting lead free RoHS conversion confidence in the lead frame packages,particularly for high end product conversion. Although plenty of related study in .. read more

The reliability of aged and repaired lead-free and mixed lead-free/lead-based solder interconnects is an important issue for electronic equipment manufacturers. As a result of the global transi .. read more

This paper presents the results of our study on the development and optimization of lead-free wave soldering process for large and thick printed circuit boards (PCB),through multiple designs of .. read more

The debate on the effect of voiding on BGA reliability has continued for years. Many PWB assemblers strive to minimize voiding,particularly with the advent of lead-free processing and in fine f .. read more

This paper describes a new lead-free SMT rework process which avoids component overheating,reduces board warpage and cratering,and prevents adjacent components from thermal damage. In the repla .. read more

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 fl .. read more