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Advanced Semiconductor Packaging & Circuit Materials

Science of Semiconductor Packaging & Circuit Materials

Ceramic Circuit Technology

What is Thick Film?

Thick film refers to mixtures of precious metals, glass, and/or ceramic powders dispersed in an organic medium and applied to a non-conductive substrate. Specialized compositions create conductors, resistors, and dielectrics for a variety of applications and operating environments.

Complex multi-layer circuits can be created with relatively simple, flexible, and cost-effective manufacturing processes. Thick film compositions can be applied using a variety of techniques, from photo-imaging to dipping or spraying to rotogravure, flexographic, and screen printing techniques. Thick film is less capital intensive than competing technologies, such as thin film or sputtering.

The characteristics of ceramics include low dielectric loss, high thermal conductivity, integral component packaging, fine line patterning, environmental stability and design flexibility with miniaturization potential. The low TCE (thermal coefficient of expansion) of ceramic materials guarantees mechanical stability and is closely matched to that of ICs for bare chip assembly.

Thick film metallized circuits offer:

Low thermal coefficient of expansion for direct solder attach and flip chip mounting High thermal conductivity to handle a wide range of heat dissipation requirements Proven capability for blind and buried vias for increased circuit density Embedded and surface passive elements for increased reliability and lower costs Low loss substrates and dielectric materials for high frequency applications High performance material systems for harsh environments Active and passive trimming for active filter Hermetic packaging and high reliability

What is Low Temperature Co-fired Ceramic?

DuPont™ Green Tape™ Low Temperature Co-fired Ceramic (LTCC) technology is an extension of thick film multi-layer technology. The properties of printed thick film conductors combine with ceramic tape dielectric to enable fabrication of multi-layer circuits at high volumes. DuPont™ Green Tape™ material systems are the industry standard, with a complete system of materials developed to match the tape dielectric, manufacturing processes, and end use applications. DuPont™ 951 Green Tape™ systems can deliver line spacing and resolution as fine as 100 µm, via diameters as small as 100 µm, and can be fabricated with more than 100 layers. The DuPont™ 943 Low Loss Green Tape™ system delivers excellent high frequency performance with minimal dielectric loss. Firing temperatures for Green Tape™ range between 850C to 950C.

DuPont™ Green Tape™ delivers high density, high reliability, excellent performance, and low cost interconnect packages and substrates for extreme heat and other harsh environments which can punish ordinary electronic devices.

LTCC technology is typically chosen for a number of reasons:

Proven reliability in high performance and environmentally stringent applications Excellent high frequency performance Embedded & surface passive components Excellent thermal performanceMixed analog, digital, RF packaging; high circuit densities