Heraeus Electronics introduces cost efficient, highly reliable Ag-free AMB solution for high powered electronics

Sponsored by Heraeus Electronics

In recent years, the demand for high powered electronics has grown exponentially. With rapid growth in electric/hybrid vehicles, we are seeing that more electronics and power modules are needed to keep up with demand. However, EV/Hybrid vehicles are not the only applications driving this increased demand. Other major applications, such as rail traction, wind turbines, photovoltaic inverters and motor drives are also driving the increased demand. These applications are extremely demanding and are operating at high voltage and high current densities that must cope with high temperatures and harsh conditions. One of the key components for a highly reliable power module is an extremely reliable metal ceramic substrate. Substrate materials for these applications must have outstanding characteristics in terms of electrical, thermal, insulation, and mechanical performance during operation. To have a reliable system in place you need to have a compatible interconnection and assembly materials like solder paste, sinter paste, and wire bonding, to name a few.

Due to cost efficiency, Al₂O₃ based metal ceramic substrates, like direct copper bonded substrates are often used for power module manufacturing. Although, it is a cheaper solution, it is not always the best for certain applications, especially for high power modules. Al₂O₃ based ceramic substrates struggle to harness the full power of wide band gap semiconductors. In this instance, a superior substrate is needed. Silicon nitride (Si₃N₄) based metal ceramic substrates have been used in recent years for power module assembly. Its superior mechanical properties, such as bending strength, fracture toughness and thermal conductivity makes Si₃N₄ an attractive solution for a highly reliable, high power density module base. Today Si₃N₄substrates are manufactured using active metal brazing (AMB) technology, which uses Ag-filled and titanium containing brazing pastes. Precious metal and complex processing steps drive the prices up for AMB substrates making it a more expensive option.

Heraeus Electronics has developed a solution that solves the cost and performance roadblocks previously described. It is a cost efficient, highly reliable Ag-free AMB copper bonding technology for joining nitride-based ceramics with copper foils. The material was developed using a technique where there is no requirement for using expensive vacuum-based brazing and longer process time. The product is named: Condura®.ultra, a Si₃N₄ Ag free AMB substrate.

Key Features

Outstanding reliability and processing (eg. Sintering, bonding, soldering…)
Cost efficient Si₃N₄ metal ceramic substrate
Enables thick Cu layers
Thinner ceramics vs. AIN possible for equal thermal

resistance

Thermal conductivity of Si₃N₄ ceramic:
- > 80 W/m∙K
- > 60 W/m∙K

Condura®.ultra is a cost-efficient Ag free AMB bonding technology for metal ceramic substrates that are suitable for high end applications. The cost reduction of Condura®.ultra is achieved by using a silver-free brazing technology combined with an efficient brazing process.

Below in Figure 1, it gives a look at the thermal shock performance of Condura®.ultra.

SAM pictures of 20 individual Condura®.ultra test layouts before and after thermal shock tests (liquid to liquid -65 ° C to + 150 ° C). No major degradation is visible after 8000 cycles. The red color indicates the etched isolation groove which is part of the test layout. In the event of delamination between copper and brazed metal due to thermal shock, the red color groove would broaden. This shows that Condura®.ultra qualifies to fully leverage the mechanical robustness of the Si₃N₄ ceramics in a similar manner as the Ag containing AMB technology.

Heraeus Electronics exhibits at PCIM Europe 10-12^th May

Condura®.ultra will launch globally this year at PCIM Europe. PCIM Europe is the leading conference and exhibition for power electronics, renewable energy, and energy management, taking place in Nuremberg from May 10-12, 2022. While at the show visit Heraeus Electronics in Hall 6, Booth 322 to speak with our team about Condura®.ultra or some of our other new solutions for interconnects and die attach.

Join Heraeus Electronics Live at the e-mobility forum

On Tuesday May 10^th at 11:20am CEST Heraeus Electronics will offer a sneak peak at our mAgic® Copper Sinter Paste with a presentation titled “ How near is copper sintering”. For more information, please visit us at the show or reach out to your local account manager.

On Wednesday May 11^th at 12:50pm CEST Heraeus Electronics present on the Condura® product family and how Heraeus Electronics will meet rising customer expectations on the reliability, thermal performance, lifetime and price of metal ceramic substrates. Also in this presentation a new addition to the Condura® product line will be unveiled.

More information on Heraeus Electronics

PCIM Europe E-Mobility Forum

Sponsored by Heraeus Electronics