sponsoredCONNECTORS, PRESS-FIT ZONE, PCB HYBRO+ metal composite stops rising bronze prices

Sponsored by

voestalpine Precision Strip GmbH

Metal specialist voestalpine Precision Strip is replacing solid bronze strip with a laser-welded metal composite strip made of bronze and copper-coated iron. While maintaining the same processability and similar electrical conductivity, this enables material cost savings of up to 25%.

Bronze strips have long been considered the state-of-the-art material for manufacturing press-fit zones in electronic connectors. Their combination of reliable electrical conductivity and high spring hardness ensures the secure force-fit and form-fit connection required when press-fit contacts are inserted into printed circuit boards (PCBs).

Today, however, increasing cost pressure and the need for more efficient material utilization are driving the search for innovative alternatives. As a specialist in metal composites and advanced laser welding technologies, voestalpine Precision Strip has developed a novel bronze-iron composite material that significantly reduces material costs without compromising functionality or reliability.

Significant cost savings through intelligent material design

The key innovation lies in using bronze only where it is functionally required. In the composite design, the press-fit zone itself remains bronze to preserve the mechanical and electrical properties essential for connector performance. The larger, non-critical areas of the component are replaced by an iron strip that is longitudinally laser-welded (1) to the bronze material. After pre-punching (2) , the welded and punched strip is electro plated with copper (3).

By intelligently combining these two materials, manufacturers can achieve material cost reductions of up to 25% compared with conventional solid bronze strips. A good starting point for cost savings is using at least 80% iron in the strip. The more iron, the better.

Advanced manufacturing process

The production concept combines proven metallurgical expertise with highly precise laser welding technology:

• 1. Bronze material for the press-fit zone is longitudinally laser-welded to an iron strip.

• 2. Press-fit zones and connector geometries are pre-stamped.

• 3. The material is electroplated with copper extending beyond the weld seam, ensuring excellent conductivity and comprehensive corrosion protection of all stamped areas.

• 4. The finished material is supplied in coil form for efficient downstream stamping and processing operations.

This innovative manufacturing approach combines cost efficiency with high-volume production capability, making it particularly attractive for the electronics and connector industry.

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Extensive testing confirms performance and reliability

A major focus during the development phase was ensuring that the composite material performs at a level comparable to traditional solid bronze strips. To verify this, a comprehensive testing program was carried out by independent companies and recognized testing institutions.

The results consistently confirmed the suitability of the bronze-iron composite design for demanding connector applications. The selected plating configuration demonstrated excellent functionality across multiple joining technologies, including:

• Brazing

• Ultrasonic welding

• Laser welding

Independent validation across multiple test methods

Numerous mechanical, electrical, and corrosion-related evaluations were conducted to validate the material concept. These included:

• Solderability testing in accordance with DIN EN 60068-2-20

• Tensile testing of laser-welded components

• Tensile testing of ultrasonic-welded components

• Tensile testing of resistance-welded components

• Water vapor corrosion testing with various surface finishes

• Current-carrying capacity measurements performed independently by FEF GmbH, part of the Institute for Welding and Joining Technology (ISF) at RWTH Aachen University

The results showed that the composite material achieves mechanical strength, joining performance, corrosion resistance, and electrical conductivity levels that are highly comparable to those of conventional CuSn6 bronze strip solutions. Furthermore, the tests verified reliable electrical conductivity across both the laser weld seam and the plated surfaces.

Proven technology for greater competitiveness

The combination of up to 25% material cost savings and comprehensive independent performance validation makes the bronze-iron composite material a highly attractive alternative to solid bronze strips. By using premium bronze only where it is truly needed and replacing the remaining material with a cost-efficient iron substrate, manufacturers can significantly optimize costs while maintaining the quality, reliability, and performance demanded by modern electronic connector applications.

This innovative solution demonstrates how advanced material engineering can deliver both economic and technical benefits, enabling customers to improve competitiveness without compromise.

Innovative consulting expertise, tailored to project needs

As a specialist in laser-welded metal composites, voestalpine Precision Strip develops customized material solutions for innovative stamped and formed components. Backed by the expertise of many application engineers and R&D scientists the company support customers from concept to series production. Combining decades of metal strip experience with advanced laser welding technology, we enable unconventional designs, optimized material usage, and cost-efficient implementation. The result: high-performance components, reduced costs, and a sustainable competitive advantage.

Contact

voestalpine Precision Strip GmbH
Waidhofner Strasse 3, AT- 3333 Boehlerwerk
www.voestalpine.com/precision-strip

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