A container "Package substrate" carrying semiconductors, essential components for electronic devices, is more and more downsized and microminiaturized as technology advances. The key technology to make this trend successful is the ultra-fine patterning technology enabling to draw super fine signal lines. In the advanced PCs and network instruments, less than 20µm width lines (Japanese women's hair width is about 80µm) are used reliably, making them perform to the maximum degree.

These lines are generated by a technology called "Litho Photography" ("litho: slate print" by "photography"). The UV sensitive resin film, like a photographic film, pasted on a substrate is exposed with a pre-designed pattern. By doing so, light exposed portions are solidified and when immersed in a development solution, un-solidified portions are dissolved away – this is equivalent to the processes for photographing and development. The part where resin is removed forms the original structure of ultra-fine patterning.

Future signal processing technology will further improve. We are responding to challenges in developing circuit forming technologies for even finer lines and higher reliability.

Appearance of package C4 solder bump

While miniaturization, faster speed, and enhanced functionalities are progressing in recent years, the C4 Flip Chip interconnect technology is becoming increasingly favored for the electrical and mechanical interconnects between semiconductor chips and packaging substrates.

Until recently, C4 Flip Chip interconnect uses mostly tin/lead eutectic solder bump formed on the package substrate surface, but in the future lead-free solder should be used pursuant to Restriction of Hazardous Substances Directive (RoHS).

We are working on how to improve surface mount ability and reliability of lead-free solder even for 100-200µm pitch fine solder bumps.

Porous structure of DPF

IBIDEN's DPF is prepared by consolidating SiC powders at high temperatures of more than 2000°C. The micro scale pores thus formed during sintering process serve as filtering medium for the soot exhausted from diesel engine cars.

Since the pore size and distribution of these micro scale pores significantly affect the DPF performance, we are developing better high temperature sintering technologies for better control.

Our company manufactures ceramic filters for cleaning SPM (Suspended Particulate Materials) emitted from diesel engine cars. This is formed by mixing raw materials of powder, water and binders as glues, which are then kneaded with dispersants to finally be extruded through a die. For ceramics products, mixing/kneading are critical process influencing the final product quality. Only with homogeneous mixtures, materials may be extruded at a uniform rate, enabling to conduct stable extrusion forming devoid of deformation and variations. Furthermore, the extrusion rate directly relates to productivity, so we are working on development to increase extrusion rate taking advantage of our new ideas.

In the future, as the product performance is enhanced along which more complex forming technology be expected, we are developing technologies to improve material dispersion by analyzing its flow using simulation technique.