A sample of Sunfort™ dry film photoresist from Asahi Kasei. (Photo: Business Wire)
Asahi Kasei’s new material series is targeted for back-end processing of advanced semiconductor packaging used in AI servers, as well as automotive and IoT applications.
TOKYO & NOVI, Mich., & DÜSSELDORF, Germany—A new series of dry film photoresist material for back-end processing is designed to meet growing demand in the field of advanced semiconductor packages used in applications such as artificial intelligence (AI) servers.
Asahi Kasei developed the TA Series of Sunfort™ dry film photoresist as a new product within the company’s Material sector, aiming to strengthen its footprint in the rapidly growing market of next-generation chip packaging. The dry film is reported to deliver an ultra-high resolution with conventional stepper exposure systems and laser direct imaging (LDI) systems, which transfer circuit patterns onto substrates during packaging. This contributes to enhanced performance and precision in back-end processes, according to a release from Asahi Kasei.
“The development of the TA Series comes after years of close collaboration with our customers and a deep understanding of their most pressing pain points,” said Yu Hasegawa, managing executive and senior general manager of the Electronics Interconnecting Materials Division at Asahi Kasei, in the release. “Through this development, we address the evolving requirements of semiconductor packaging in AI, automotive, and IoT applications.”
The Sunfort™ dry film photoresist is described as “a mainstay” of Asahi Kasei’s Electronics business, which comprises electronic materials and components. The entity is positioned as a “first priority” business to drive growth under the company’s medium-term management plan, “Trailblaze Together.” As demand for electronic components continues to expand, the business is projecting “an estimated 25 percent increase in operating profit between fiscal 2024 and 2027,” the release stated.
Interposers serve as a bridge between chips and substrates and are used along with package substrates in advanced semiconductor packages. These components require a large area, high-multilayer structures, and increasingly sophisticated technologies for forming high-density micro wiring, the company said in the release.
In photolithography, liquid resist has long been the mainstream photoresist material for the redistribution layer (RDL) due to its superior resolution. In contrast, dry film photoresist offers advantages for panel-level processing (which involves a larger surface area than conventional wafer-level processing), such as ease of handling and ease of processing on both the top and bottom sides of the substrate. Still, it has not been adopted for RDL formation due to limited resolution performance, according to the release.
“Developed based on Asahi Kasei’s long experience with photosensitive material and new material design, the TA Series enables fine wiring formation in panel-level packages and similar applications,” the release stated. “The TA Series also allows patterning with a resist width of 1.0 µm using LDI exposure in the 4 µm pitch design required for RDL formation. The resulting fine resist pattern can be plated by a semi-additive process (SAP, a method for forming fine conductive patterns using partial electroplating), followed by resist stripping to form a 3 µm wide plating pattern in a 4 µm pitch design.”
The company expects Sunfort™ dry film photoresist to continue to play a key role in developing panel-level packaging technology as panel sizes grow.
“The new TA Series allows manufacturers to achieve finer wiring with greater production efficiency, helping to reduce cost and increase yield in advanced semiconductor packaging,” the release stated.
Asahi Kasei’s TA Series comes at a pivotal time as demand in AI, automotive, and IoT markets grows.
“With growing demand, particularly in Asia and North America, we at Asahi Kasei are enhancing our global support framework to deliver timely solutions and technical services tailored to regional needs,” Hasegawa said.