Track Hyper | Low-temperature PSPI materials are in urgent demand: Do domestic companies have a chance?

Author: Zhou Yuan / Wall Street Insight

As the global semiconductor industry accelerates its transformation towards advanced packaging technology, the stability of the material supply chain is facing new challenges.

In late May, Wall Street Insight learned from authoritative supply chain channels that TSMC's (Taiwan Semiconductor Manufacturing Company) capacity expansion plan in the advanced packaging field has directly triggered a global supply tightness of low-temperature photosensitive polyimide (PSPI) materials.

As one of the main suppliers of this material, Japan's Asahi Kasei has had to implement supply restrictions on Chinese packaging and testing companies in order to fully meet TSMC's demand, a change that unexpectedly accelerates the industrialization speed of domestic low-temperature PI materials.

In recent years, TSMC's layout in the advanced packaging field has been aggressive.

The core technology of TSMC's current packaging—CoWoS (Chip-on-Wafer-on-Substrate): achieves a leap in chip performance through three-dimensional stacking, has become a key packaging solution for AI chips such as NVIDIA's H100/H200.

To meet market demand, TSMC plans to increase CoWoS capacity by up to 100%; in late May, TSMC's expansion demand affected the supply of specialized materials.

This expansion involves not only Taiwan but also the construction of a new packaging base in Kumamoto, Japan, which is expected to introduce CoWoS technology production lines.

Low-temperature PSPI materials play a critical role in advanced packaging.

This material has a low dielectric constant, high thermal resistance, and photolithography compatibility, and is widely used in interlayer insulation of silicon intermediate layers, RDL (redistribution layer) preparation, and TSV (through-silicon via) filling processes.

Asahi Kasei has long been one of the main suppliers of low-temperature PSPI materials for TSMC.

With its technological accumulation in the field of electronic materials, its PSPI products are at the forefront of the industry in terms of thermal resistance (Tg≥320℃) and resolution (0.1μm level).

However, as TSMC's capacity surges, Asahi Kasei's capacity bottleneck has gradually emerged.

To prioritize the needs of core customers, Asahi Kasei will no longer be able to supply Chinese packaging and testing companies starting from the second quarter of 2025. This supply restriction directly impacts the Chinese packaging and testing industry.

Leading companies such as Changdian Technology and Tongfu Microelectronics face the risk of material supply interruptions in their advanced packaging expansion plans. Wall Street Insight has learned that several domestic packaging and testing giants have recently received notices from Asahi Kasei clearly stating the cessation of supply for low-temperature PSPI materials.

"What to do?" Wall Street Insight asked the supply chain. Several individuals stated, "We can only accelerate the verification of domestic products, of course, including those from other companies, taking multiple approaches."

Domestic suppliers are seizing development opportunities in this context.

Mingshi New Materials has achieved phased results in the research and development of low-temperature PSPI, with its self-developed product having a curing temperature of ≤250℃, a resolution of 0.1μm, and a dielectric constant of ≤3.0 (1MHz), with performance indicators close to those of leading international companies' similar products.

This material from the company has passed process verification by leading domestic packaging and testing factories and has entered the supply chain system, adapting to the technical requirements of the advanced packaging field. In the packaging scenario of memory chips, the characteristics of this material can meet the precise requirements for insulation layers in HBM3 memory chip stacking and 3D IC integration However, it is strange that according to the public ruling documents of the Intermediate People's Court of Shenzhen, Guangdong Province, Mingshi New Materials was applied for bankruptcy reorganization by creditors in July 2024 due to insolvency and is currently in the judicial reorganization stage.

Owning materials required for high-end packaging but going bankrupt due to insolvency likely indicates that the company's materials have not been validated by the industry. As of now, Mingshi New Materials has not disclosed the integration of its technical team and production recovery plan after reorganization.

There is another domestic company called Aisen Co., Ltd., which is the first in the country to achieve positive PSPI mass production, with a product resolution of 3μm, suitable for traditional wafer-level packaging (WLP) and some 2.5D packaging bottom structures.

However, the materials provided by Aisen Co., Ltd. are not low-temperature PSPI materials, making them more suitable for mid-to-low-end packaging scenarios and unable to meet the requirements for high-end applications.

The technological breakthroughs of domestic companies stem from long-term R&D accumulation and policy support.

For instance, DING LONG relies on its technological reserves in the PSPI field for OLED displays to develop low-temperature curing formulations suitable for semiconductor packaging, focusing on solving the edge lithography clarity issue; additionally, TRONLY focuses on supporting materials for photoresists, developing low-hygroscopic PSPI precursors suitable for wafer-level packaging (WLP), and has passed testing verification by Tongfu Microelectronics.

Among them, TRONLY has also poached talent from Xuri Cheng to focus on developing low-temperature PSPI materials that benchmark against Xuri Cheng.

These developments indicate that domestic low-temperature PSPI is moving from laboratory to industrial application. The unexpected surge in market demand provides a rare window for domestic materials.

With the popularization of Chiplet technology and the deepening of 3D packaging, the performance requirements for low-temperature PSPI will further increase.

Domestic companies need to continue breakthroughs in the following areas: first, reducing the curing temperature to below 200°C to adapt to more advanced processes; second, improving temperature resistance to above 350°C to meet automotive-grade chip requirements; third, developing fluorine-free formulations to address environmental and cost issues.

In this process, collaboration within the industry chain will be key.

TSMC's expansion actions are reshaping the global semiconductor materials supply chain landscape. The domestic substitution in the low-temperature PSPI field is not only a technological breakthrough but also a crucial step towards self-controllable industry chain. Based on the current stage of technological development, it is expected that domestic companies will achieve large-scale industrial application of low-temperature PSPI within 3-5 years, providing solid support for the advanced packaging industry