As the demand for high-tech materials is localized due to Japan's export control of materials, Ntrium, the material startup is attracting attention. The company, which was selected as a "Technological Innovation Company" by SK Hynix as an EMI shielding material for semiconductors, recently succeeded in developing and commercializing a material that Japanese companies dominate.

Samsung's Galaxy A50 has a glasstic film attached to its back plate./Samsung electronics
Samsung's Galaxy A50 has a glasstic film attached to its back plate./Samsung electronics

Entryum (CEO Se-young Jung) recently announced that it has commercialized a back cover film for 5G mobile communication smartphones. Following the conductive bonding film (CBF), the company again challenged the market that was dominated by Japanese companies. Entryum is a material startup founded in 2013.

The smartphone back cover film is a plastic material with high hardness and has a glassy gloss and feel. Like tempered glass, it is not easily broken by external shocks and the production cost can be reduced. Currently, Japan's MSK dominates the market.

Samsung calls it 'The glasstic', which is applied to Samsung's Galaxy A50 series, which was released this year.

Entryum commercialized the back cover film for 5G smartphones using a plastic material composed of polycarbonate (PC) and polyethylene terephthalate (PET).

It is more moldable than other glass material 'PC + PMMA (Polymethyl methacrylate)', and can be applied to flexible displays. 

The dielectric constant is also low. Since 5G mobile communication uses high frequency with low diffraction, signals with high dielectric constant can bounce off the signal and the smartphone antenna cannot catch the signal well. In addition, electromagnetic wave shielding and heat conduction layer can be selectively installed, so that it can be used for high heat generation 5G smartphone.

Earlier, the company developed and delivered CBF to China, where TTSUTA and TOYO took up over 80% of the market. CBF is a material that is electrically shielded by attaching a flexible printed circuit board (FPCB) and a reinforcement plate such as stainless steel (SUS) and at the same time serves as an EMI shielding function. It enters camera module, connector, etc.

Jung Se-young, CEO of Entryum, said, “We were able to develop a low-k material-based back cover film by collaborating with domestic large companies and film companies.

Upgrade also EMI shields High frequency + low frequency simultaneously

At the same time, Ntrium has developed an EMI hybrid shield that blocks both high and low frequencies at the request of large smartphone makers. It is also targeting the automotive, aerospace and aerospace markets where safety and stability are paramount. Commercialization is next year.

EMI shielding differs depending on the low frequency (100 kHz to 30 MHz) and the high frequency (30 MHz to 100 GHz). High frequencies are like shielding, and low frequencies are absorption.

The shielding material is different as the two methods are different. Metal-based materials are used to bounce high frequencies and carbon-based composites are used to absorb low frequencies. The company has coated silver(Ag) with materials suitable for each characteristic, to prevent both low and high frequencies.

Earlier, the company developed a spray-type high frequency EMI shield. The spray method has a short process time and is 60% cheaper than conventional sputters. The high aspect ratio (A / R) allows the material to be applied evenly from surface to side. It will be applied to the NAND flash package in 2H.

Competitors announced successive developments of spray-based EMI shields, but only have been approved for mass production.

CEO Jung said, “The technical difficulty is high because we need to concentrate everything from basic materials such as conductive particles, binders, solvents, and additives to technologies that handle materials such as dispersion and blending.” ”He said.

In cooperation with global semiconductor companies, EMI low frequency absorber has also been developed. It is used as a sheet in addition to a power amplifier (PA) or a wireless charging antenna.

"I can be confident that EMI shielding materials for semiconductors are far ahead of Japanese companies," he said.

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