New DuPont™ Zytel® HTNLX smoothes the path to lead-free circuit assembly

To meet growing demand for electronic components that can withstand the higher temperatures required for board assembly with lead-free solders, DuPont scientists have developed the new LX series of DuPont™ Zytel® HTN high performance polyamide. Following successful application development in the Asia-Pacific region, DuPont Engineering Polymers is introducing the LX series of glass-reinforced, flame-retardant Zytel® HTN globally at K 2004.

“Connectors and other parts molded from Zytel® HTNLX deliver outstanding performance in surface-mount reflow processes using lead-free solder,” said Jeroen Van Campen, European regional business manager for High Temperature Solutions. Operating temperatures with lead-free solder are typically in the 250 to 260ºC range, about 20 to 30 degrees higher than those employed with conventional lead-containing solder.

“During assembly at these higher temperatures and during molding, Zytel® HTNLX delivers valuable advantages over several alternative polymers,” Mr. Van Campen added.

Among them:

• Faster line speeds. Zytel® HTNLX withstands higher peak reflow temperatures than PA46 and other similar PA6T polymer grades. Higher temperatures result in faster solder melting, thus enabling increased line speed.
• Less part breakage. Test data using actual connectors show more toughness for Zytel® HTNLX than PA9T and PPS polymer grades and greater weld line strength than PA9T, PPS and another PA6T. Increased toughness pays off with reduced damage of parts and assembled circuits during shipping, handling and service.
• Water-controlled molds. Molders can avoid the drawbacks of oil temperature control with Zytel® HTNLX. Unlike PA9T and another PA6T, it can produce fully crystallized parts when molded in water-controlled tooling.
• Faster molding, more design freedom. During molding, Zytel® HTNLX flows more easily than PA9T and other PA6T grades. Better flow can allow faster molding cycles, lower injection pressure, and successful molding of parts with thinner walls and/or longer flow paths.

Several electronic manufacturers in Asia are already profiting from the use of Zytel® HTNLX. In a connector for SIM (subscriber identity module) cards in mobile phones, for example, Wooyoung Company Ltd. of Korea is benefiting from its resistance to higher reflow temperatures and its excellent dimensional stability, toughness and strength. Commercial applications at other manufacturers include surface-mount switches and I/O (input/output) connectors.

New LX series resins are glass-reinforced flame-retardant materials with a V 0 classification under the UL94 standard. Grades with glass-fiber content of 20, 30 and 45 percent are available.
Zytel® HTN is one of ten families of high-performance engineering polymers supplied by DuPont.