Generally, while organic materials are outstanding in terms of their processability, they are poor conductors of heat and electricity and have a large linear expansion coefficient. In order to overcome such drawbacks they are normally mixed with inorganic material to form composite materials.
Recently, however, there have been calls for properties such as higher levels of thermal conductivity and, in optical applications, calls for higher refraction ratios and lower linear expansion coefficients, properties that are just not possible to achieve using simple organic/inorganic composite materials. One way of solving this problem that has become quite popular in research and development is to use organic/inorganic hybrid technology to design more advanced materials.
The use of this organic/inorganic hybrid technology in its transparent optical semiconductor encapsulating resin has helped Nitto Denko to lower the linear expansion coefficient and increase reliability.
Transparent Optical Semiconductor Encapsulating Resin
As the purpose of this resin is to protect optical semiconductors, transparency is essential. This has ruled out the use of conventional inorganic fillers, meaning that we were left with the problem of how to reduce the high linear expansion coefficient.
We were able to overcome this problem by using a composite metal oxide with a refractive index and wavelength dispersion characteristics that were the same as those of the resin to develop a product that was both transparent and had a low linear expansion coefficient.