GE Helps Winchester Transition its Connectors to High-Temperature Soldering for Lead-Free Applications without Costly Retooling

Lead and other heavy metals have been shown to accumulate in the environment. The European Union’s (EU) Restriction of Hazardous Substances (RoHS) Directive limits the use of these materials in electrical/electronic (E/E) components and products. The RoHS regulations have led to industry adoption of a soldering process that meets lead-free requirements for surface mounting of connectors onto printed circuit boards.

As a result, Winchester Electronics, a manufacturer of high-speed, high-bandwidth interconnect solutions, began developing a complete line of RoHS-compliant products. But the company found the polybutylene terephthalate (PBT) resin, which it was using could not withstand the higher temperatures generated by infrared (IR) reflow ovens used in lead-free soldering. Not only did Winchester need a plastic that could take the heat, but the material had to comply with regulations mandating the elimination of halogens from flame retardants, plus provide an array of key properties. Equally important, to avoid the high cost and long lead times for development and testing of new tooling, Winchester sought a material compatible with its existing molds. To achieve this seemingly impossible goal, the company consulted GE Plastics.

GE Plastics and Winchester Electronics

The Challenge: Moving to Soldering to Meet Lead-Free Requirements for Regulatory Compliance

Winchester Electronics designs and manufactures a wide variety of electronic connectors used by OEMs and contract manufacturers in the computer, military/aerospace, industrial, and medical equipment industries. The company manufactures many of its products in China and Malaysia; these connectors are sold to multinational companies whose products are distributed worldwide and must comply with global standards.

Anticipating implementation of the EU’s RoHS standard in July 2006, Winchester began developing a full line of compliant products. However, to accommodate the higher temperatures of the new soldering process to meet lead-free requirements for surface-mount technology, which has been widely adopted for its improved speed, cost-effectiveness, and RoHS compliance, Winchester was forced to find a replacement for the PBT resin that it had been using for molding connectors.

“We needed a material capable of withstanding temperatures in excess of 260 C while maintaining mechanical integrity during the IR reflow process and in everyday operational use,” explained Steven Fournier, Director of Engineering for Winchester.

Other requirements for the new plastic included: flame retardance without the use of halogenated additives to comply with the RoHS and Waste Electrical and Electronic Equipment (WEEE) directives, and excellent mechanical properties including tensile strength and impact resistance.

Winchester had one other major challenge: avoiding the high cost and extensive time to develop and qualify new tools. Understandably, the company wanted a plastic that could meet all of its environmental and performance requirements while seamlessly replacing PBT in existing molds.

The Solution: GE’s LNP* Starflam* X-Gen Specialty Compound

As the date of implementation for RoHS and WEEE regulations approached, GE Plastics had not been idle. Foreseeing the higher heat requirements of lead-free soldering for surface-mount technologies and their potential impact on E/E manufacturers, the company proactively developed new grades to meet the requirements of the European directives – and the demands of the new high-heat soldering process.

One of these materials is GE’s LNP Starflam UF-1006 HW Z270 specialty compound, a high-temperature nylon with 30 percent glass fiber reinforcement that is part of the LNP Starflam X-Gen product line. The grade features a proprietary flame-retardant technology from GE to provide halogen-free performance with a UL 94 V-0 rating.

LNP Starflam UF-1006 HW Z270 specialty compound has a minimum heat distortion temperature (HDT) of 260 C, making it an excellent candidate for soldering that meets lead-free requirements. Further, it is based on a hot-water-moldable grade of polyphthalamide (PPA), avoiding the energy costs of using hot oil for processing. Its low specific gravity compared to other materials can mean more parts per pound, yielding cost savings for customers.

And it has one more critical attribute. “The beauty of this LNP Starflam grade is that GE engineered it specifically to have the same shrinkage as PBT resins commonly used by electronic component manufacturers like Winchester,” said Jamie Tebay, Product Manager for GE Plastics. “The steel molds that Winchester uses for its connectors are designed for a particular level of shrinkage and would be very expensive to replace. By substituting GE’s LNP Starflam specialty compound for PBT resin, the company did not have to retool.”

The Value-Added Services: Local Support and Global Resources

Because Winchester manufactures many of its connectors in China, GE Plastics’ extensive resources there were greatly appreciated. Fournier noted, “We have worked extremely hard for the last few years developing our global supply chain in Asia of which GE played an important role. We were very pleased that GE’s China office could provide local support to our mold shops, providing guidance in the same language. Also, GE has the expertise and facilities to fully support their products globally, which can be critical during new production runs and product transfers.”

The Benefits: Seamless Material Replacement Saves Time and Money

Substituting GE’s LNP Starflam specialty compound for PBT resin enabled Winchester to save time, money, and business. Fournier said, “Retooling costs would have been as much as $2 million, and would have required up to a year to develop and qualify new molds. Further, we would have been forced to pass on several design programs during the conversion period – with the potential for lost business.”

Not only are the connectors molded from GE’s LNP Starflam specialty compound dimensionally identical to those molded from PBT resin, the replacement material has also boosted performance. “We have gained improved mechanical properties that have increased the robustness of our connector design, allowing greater durability of the parts in demanding environments,” he said.

According to Fournier, GE’s LNP Starflam specialty compound has become the standard for the company’s RoHS molding needs. “We researched other materials but they could not provide the required mechanical properties over the thermal range. LNP Starflam compound delivers great structural performance at the required reflow temperature of 260 C, as well as compliance with standards for non-halogenated flame retardants.”

Tebay added, “GE’s ecomagination* initiative was designed to address challenges like this one by creating innovative materials that meet stringent environmental mandates while helping customers adapt and succeed.”

Details at: www.winchesterelectronics.com.