The Thick Film Materials Business Unit of Heraeus has developed two new products to improve the efficiency of mounting silicon IC's to aluminum substrates. Working in tandem, this new thick film dielectric and conductor system provides very low thermal resistance between the chip and the heat sink in high power applications, such as HB LEDs. 

In applications that require significant heat dissipation to prevent damage to the circuit, alumina becomes an inadequate substrate material due to its low thermal conductivity. Aluminum is a much more attractive alternative due to its high thermal conductivity and low cost. However, the main disadvantage of aluminum is its high coefficient of thermal expansion (CTE) compared to glass insulating layers. This mismatch with the insulating materials can cause significant bowing of the substrate.

The unique glass system of the new lead- and cadmium-free dielectric paste (IP6075) from Heraeus was developed to offer excellent thermal conductivity on both 3003- and 6061-grade alloy aluminum substrates. The dielectric paste significantly reduces bowing by closely matching the CTE of aluminum, while providing excellent breakdown strength. To complete the package of materials for this application, Heraeus has developed a new lead-free silver conductor paste (C8829A). The conductor paste, fired together at 550°C with the dielectric paste, provides excellent solderability and adhesion.

This new technology is ideal for applications such as direct-mounted light emitting diode (LED) arrays that require significant heat dissipation to increase the lighting efficiencies.

About Heraeus Thick Films Materials Business Unit

The Heraeus Thick Film Materials Business Unit is part of Heraeus, the precious metals and technology group with headquarters in Hanau, a globally active, family-owned company with business areas that include precious metals, sensors, dental and medical products, quartz glass and specialty lighting sources. With a business volume of over €12 billion and more than 12,000 employees in over 110 subsidiaries worldwide, Heraeus has been an internationally recognized specialist in materials and precious metals for more than 150 years.

The Thick Film Materials Business Unit is a market leader in electronic materials like thick film pastes and materials for passive components and hybrid circuits, as well as advanced materials like LTCC materials and photoetchable pastes. Heraeus Thick Film Materials has extensive expertise in the development, application and processing of thick film materials and provides global product manufacturing and regional support through applied technology labs. A diverse product offering has evolved over years of experience to now include metallization materials for silicon solar cells.

All Heraeus products are supported by in-depth process knowledge, personalized service, and custom solutions for emerging applications. 

With multiple R&D sites and a global network of production and support facilities, Heraeus continually introduces new products that meet both local and global requirements.  The company's goal is to achieve a level of quality and performance unsurpassed in the industry. For more information, visit www.