COVID-19-induced demand for goods in lieu of services combined with supply-chain disruptions has resulted in a chip shortage that is expected to continue well into next year. Predictably, that supply-demand imbalance has led semiconductor manufacturers, including TSMC and Intel, to raise prices. A few companies have even started investing in new plants, and new players have entered the field to take advantage of business opportunities. All of this is good news for high-performance plastics (HPPs), including PI, PEEK/PEKK, PEI, PAI, PPSU, PESU, PPS, LCP, and PFA. These materials have broad applications in the semiconductor industry, especially when high temperatures and chemical cleaning processes are involved. These polymers perform well under extremely harsh conditions, yet they cost relatively less than materials such as ceramics or quartz.
Multiple applications for high-performance polymers
Semiconductor production is a sophisticated and challenging three-stage process — manufacturing, testing, and assembly — in which HPPs play multiple roles. For example, the polymers are used to make parts of wet benches, machines that chemically clean, rinse, and dry wafers at high temperatures. HPPs are the preferred materials for many components, such as CMP rings, wafer carriers, wafer guides/combs, burn-in test sockets, probe cards, and fasteners. Moreover, because of process changes, high-temperature HPPs are gaining popularity for the production of IC handling trays, spin chucks, and other products. HPPs satisfy almost all the required criteria, which include the following:
- Resistance against harsh conditions (chemical, abrasion, thermal, and so forth);
- low thermal and electric conductivity;
- no outgassing;
- ability to withstand high temperatures;
- material purity — low particle generation and ion migration;
- flame retardancy;
- low moisture absorption;
- dimensional stability.
Recently, British chip designer ARM Ltd. (Nvidia) announced that it has built a processor on a polyimide substrate instead of silicon. If implementation and commercialization are successful, this could be another promising HPP application because of its low cost and potential for mass production. A flexible or plastic CPU could have potential applications in smart devices, real-time health monitoring equipment, among many other products. It would also be highly preferred in low-power autonomous and connecting devices. One possible challenge would be its usable shelf life, which has yet to be demonstrated under real-world conditions.
Challenges . . .
The major challenges related to some HPP components include grade selection and price differences among various polymers. PPS, PESU, PSU, and PEI are less expensive than PEAK/PEKK; however, the latter offer some desirable properties.
Volume requirements are inconsistent and limited; consequently, injection molding may not be a suitable manufacturing process in many cases.
Also, the introduction of new materials is complex, as it involves multiple stakeholders.
Wafer size — <150, 200, 300, and 450 mm — is also a complicating factor. The 450-mm wafer has been discontinued because of its large dimensions and weight. The 300-mm wafer seems to have the major market share, and this is expected to continue.
The size of the manufacturing facility is an important aspect, as this affects maintenance and production cycles, and might influence material selection. In addition, innovations in chip design — substrate changes (Si to SiC or GaN) and a reduction in pitch distances to achieve a higher density of pins — may drive a preference for materials over incumbents. It can also increase the temperature rating in a few cases from 150 - 200°C to 200 - 250°C.
Relatively less expensive fluoropolymers (PTFE, PVDF, and ECTFE) are gaining popularity in applications where chemical resistance is crucial, although the materials have processability issues. PEEK seems to dominate the market where high heat resistance is the primary criteria for material selection, but the material is quite expensive.
. . . and the way forward
Along with a sudden jump in consumption, geopolitical activity is responsible for chip shortages. New investments in developing nations such as India, Indonesia, the Philippines, and Vietnam will ease the shortage of chips. Initially these nations will be active in testing and assembly rather than chip production, as that requires significant technological know-how and extensive investment. In the long run, however, these emerging economies will evolve into chip producers.
The United States, Western Europe, Japan, and South Korea are ramping up regional production of chips to cope with shortages, and this will certainly push demand for HPPs. This may be more pronounced at the testing and assembly sites than in manufacturing, where companies may choose to stick with incumbent materials to avoid uncertainties related to quality. The high-temperature baking process in chip handling and sustainability will push the usage of recycled HPPs, as virgin resin would be expensive to use. Also, the emergence of additive manufacturing and new grade developments are anticipated to produce components with a better cost of ownership profile at a similar performance level.
About the author
Vikash Kumar is Program Lead, Polymers & Materials, at ChemBizR, a boutique business research and consulting partner of global chemicals companies. ChemBizR helps customers address critical business challenges and strategic growth initiatives and transform their enterprise for sustainable growth in a highly competitive and rapidly evolving environment. Contact the author and the company at [email protected].