Dexerials owns a wide range of technologies used to build production processes for making functional materials. For example, organic material technology to mix/disperse/synthesize materials, inorganic technology for crystal growth, technology to coat thin materials on base film or forming thin layers in vacuum environment, and technology to slit films into required shapes.
Many engineers with expertise in mechanics, electronics and controlling system are searching new production methods for our functional materials to be utilized in customer’s products seeking downsizing and higher performance.
Nanoimprint is another unique process of Dexerials. This ultra-precise process can form minute shapes on film or inorganic base material to realize unprecedented special functions unachievable by material design alone.
Microstructure formation technology
Creating submicron structures on flat or curved substrates
We are able to form submicron structures using technologies widely known in semiconductor manufacturing such as photolithography. One of our strengths is that we are able to form such structures on flat substrates and curved structures. The former technology is applied to inorganic optical devices such as inorganic polarizers launched in 2008. The latter is applied for continuously making submicron to micron order structures on a 4,000-m long roll film, and products using this technology are being shipped to various industries.
Many engineers with expertise in physics, electronics and mechanical systems are involved in development of nanostructures and microstructures by working together with our chemical engineers to realize functions required by our customers.
We will introduce some actual examples to explain what can be done using submicron structures, and also mention on other possible applications.
Diffuse light in a smart manner to use light source effectively
Compared to conventional light sources, lasers have better power efficiency and is friendlier for the environment. Thus, we can see more lasers used as light source for optical devices such as projectors.
However due to the directionality of laser, the beam need to be diffused to function as a light source. Inorganic diffuser, which spreads the laser beam at a required angle in uniform brightness, becomes necessary.
With the use of our unique micro-lens formation technology we have successfully commercialized an extremely reliable diffuser with ideal diffusion characteristics.
This technology, which we have developed over the span of many years, can create very accurate lens shapes on a transparent inorganic material such as glass or quartz.
Examples of products using this technology
Technology to form minute structures on a cylindrical master and transfer such structures continuously on base film
Displays such as liquid crystal panels are being used for showing information to car drivers and passengers. Displays are often placed around the dashboard in front of the vehicle, so, they are susceptible to sunlight and headlamps from oncoming vehicles. It is necessary to ensure high visibility even in such environment.
For many years, we have been developing a process to realize a film showing extremely low reflection over a wide wavelength range, using nanostructures. By combining "ultra-precision cylindrical mastering process" and "nanoimprint technology", we have succeeded in producing this outstanding antireflective film continuously.
Examples of products using this technology
"Ultra-precision cylindrical mastering process" is a technique to engrave minute patterns on cylindrical rolls using precision machining or photolithography. A variety of structures can be produced, ranging from nanosized moth-eye shapes to microsized reflectors, diffusers and micro-lens arrays.
In addition to creating a same structure continuously, it is also possible to draw any pattern on the master.
"Nanoimprint technology" is a technology that reproduce inverted patterns (structures) on roll films or on rigid substrates from a master having minute patterns (structures).
●This figure shows the process of continuous pattern formation onto a roll base film (roll-to-roll process).
Base film moves from left to right. After applying UV curable resin on the surface of the base film, cylindrical master engraved with micro (nano) pattern is pressed against the base film (and UV resin). When UV light is exposed, patterns on master will be transferred to the roll film.
The shape of the pattern transferred to the base film is an inversion of the pattern made on the master.
Every process from master production to nanoimprinting is available in-house, enabling us to respond to detailed requirements for various applications.
For example, the moth-eye shape can be applied to automotive instrument clusters, head-up displays, and optical elements where stray light should be kept to a minimum.
In addition, special patterns can be created to create unique designs onto optical waveguides.