Introduction

Over the past several decades, engineers have been at the forefront of innovation, working to bring forth cutting-edge technologies such as AI, autonomous vehicles, and smartphones. These advanced products are heavily reliant on semiconductors, which play a critical role in powering complex computations and improving overall performance by speeding the movement of data. Without high-quality chips, these systems would not function optimally. In other words, the semiconductor industry is the fundamental industry that can help engineers accomplish their goals. However, the front-end process of semiconductor manufacturing is expected to reach its limits. The industry analyzed that the micro-process competition has reached its limit due to technical problems such as quantum tunneling. To improve the quality of the semiconductor, the development of the back-end process becomes essential and packaging is the key to this back-end process. Before the introduction to packaging, an understanding of the overall manufacturing process is needed. Samsung and ASML, semiconductor manufacturing companies, introduced the eight main steps of making semiconductors from sand.

<Fig 1. Semiconductor Manufacturing Process>

The first step is the extraction of the ingot, a large circular pillar made of silicon which is the main ingredient of semiconductors due to its electrical properties. The ingot is then sliced into wafers, which will be given a protective layer of SiO2. Next, tiny circuits are drawn on the wafers at a scale of nanometers and the material is ionized to enhance its electrical properties. These wafers are then cut into even smaller chips, and these steps are considered as front-end processes. The final step in the process is packaging, which serves to protect the chip from external damage, check its electrical performance, and meet dimensional requirements (Timings, 2021).

Why packaging has become so important nowadays?

Packaging has become increasingly important recently due to advancements in technology. With the development of complex computations and larger batteries, there is a growing need for more components in products. For example, companies have started to explore innovative methods of chip stacking and arrangement, in order to save space and reduce energy waste. In the 1970s, the traditional single-die packaging method, which consisted of a single die in a package, was widely used. However, as society demanded more functionality in smaller spaces, engineers developed the System on Chip (SoC) technology. This innovative solution embeds the entire system on a single chip and has become a widely adopted method in the industry, such as Qualcomm Snapdragon. SoC not only reduces the space required for the system but also reduces energy waste and costs. The reduction of energy was possible because engineers could downsize the multi-chip designs to a single chip. This downsize had another positive effect of securing space in the device and making the size of the device itself smaller. Nevertheless, the increasing complexity of these technologies underscores the challenge of rising manufacturing costs, emphasizing the need for cost-effective solutions in the industry. As we navigate these complexities, packaging remains a crucial component in the quest for high-performing, efficient, and affordable semiconductor devices.

<Fig 2. Image of System on Chip from Physical Design for 3D System on Package>

What is the current technology?

With numerous companies competing to develop cutting-edge packaging technologies, there are now various types of packaging available. One that has made remarkable advancements in this field is Taiwan Semiconductor Manufacturing Company (TSMC). TSMC has achieved great success by incorporating Fan-out Wafer Level Packaging (FOWLP) technologies into its products. To understand the significance of this technology, it's important to know about Wafer-Level Packaging. Unlike the traditional method, where the packaging was done after cutting the wafer into chips, Wafer-Level Packaging involves applying the packaging on the entire wafer before cutting it into individual chips. This approach has two key advantages - improved signal integrity and the ability to carry out reliability and testing processes at the wafer level.

<Fig 3. Comparison of traditional packaging and Wafer-Level Packaging>

Fan-Out Wafer Level Packaging (FOWLP) is one of the Wafer-Level Packaging types. This FOWLP becomes more attractive since it has the key advantages of Wafer-Level Packaging and flexible integration on diverse devices is possible after the thermal process. The experiment which was progressed at Nanyang Technological University showed the thermal test effect on FOWLP. The study showed that the flexure strength of FOWLP increased significantly after the thermal process.

<Fig 4. Flexure Strength before and after the thermal process>

Packaging and Emerging Technologies:

Packaging plays a crucial role in enabling emerging technologies such as the Internet of Things (IoT) and autonomous vehicles. The IoT, which refers to the interconnectivity of physical devices, has the potential to revolutionize industries ranging from healthcare to manufacturing. However, the success of the IoT depends on the ability to collect, transmit, and analyze data from a vast network of devices. Packaging plays a critical role in this process by providing the necessary connectivity and protection for sensors and other devices.

Similarly, packaging is essential for the development of autonomous vehicles. Autonomous vehicles rely on a complex network of sensors and other devices to navigate, communicate with other vehicles, and avoid obstacles. This network requires robust and reliable packaging solutions that can protect the sensors from damage and interference while ensuring reliable connectivity.

As these emerging technologies continue to evolve, packaging will play an increasingly critical role in enabling their success. For example, as the demand for IoT devices continues to grow, new packaging solutions will need to be developed that can support larger and more complex networks of devices. And as autonomous vehicles become more prevalent, the packaging industry will need to develop new solutions that can meet the unique challenges posed by this technology, such as the need for real-time communication and extreme reliability.

In addition to enabling emerging technologies, packaging can also play a crucial role in addressing the ethical and social implications of these technologies. For example, packaging can be used to ensure the security and privacy of data transmitted by IoT devices or to protect the safety of passengers in autonomous vehicles. By developing packaging solutions that address these ethical and social considerations, the semiconductor industry can help ensure that these emerging technologies are developed and deployed responsibly and ethically.

Challenges

While the semiconductor industry has been at the forefront of technological advancements, it faces several challenges that threaten to limit its growth and impact. One significant challenge is the continuous demand for smaller and more powerful chips, which drives the necessity for more advanced packaging solutions like SoC technology and FOWLP. As the demand for smaller and more powerful devices increases, the size of the chips used in these devices must shrink to keep up. However, shrinking the size of chips has its limitations. As the size of the chip decreases, the amount of heat generated by the chip increases, leading to performance issues and even damage to the chip. This challenge directly relates to the need for innovation in packaging solutions capable of effectively managing heat, ensuring chip performance and longevity.

Another challenge faced by the semiconductor industry is the rising cost of manufacturing. As the complexity of chips increases, so does the cost of producing them. This has led to a concentration of the semiconductor industry in a few large players, which can afford the high capital costs associated with chip manufacturing. This concentration of the semiconductor industry in a few large players, as illustrated in Fig.5, might limit innovation. Additionally, smaller players are finding it increasingly difficult to compete, which threatens to stifle innovation and limit the options available to consumers. However, by exploring and reducing the cost of packaging, smaller players may be able to compete, fostering greater innovation and diverse options for consumers.

The third significant challenge is the escalating demand for energy efficiency. The drive towards more powerful devices also means that the energy consumption by the semiconductor industry is rapidly growing. Packaging plays a direct role in addressing this challenge. By developing energy-efficient packaging solutions, such as those we can anticipate with the future evolution of technologies like FOWLP, the industry can reduce its environmental impact and meet the growing demand for sustainable electronics.

In the face of these challenges, packaging plays a critical role in addressing many of these issues. By developing new packaging solutions that can dissipate heat more effectively, for example, the industry can continue to shrink the size of chips without sacrificing performance or durability. By reducing the cost of packaging, smaller players can more easily compete, leading to greater innovation and more options for consumers. And by developing energy-efficient packaging solutions, the industry can reduce its environmental impact and meet the growing demand for sustainable electronics.

Conclusion

The semiconductor industry has played a significant role in driving innovation and technological advancements over the past several decades. As it faces a new set of challenges, particularly as the front-end process of semiconductor manufacturing approaches its limits, the focus on the back-end process, especially packaging, has heightened. Packaging methods like System on Chip (SoC) technology and Fan-Out Wafer Level Packaging (FOWLP) have revolutionized the industry. Despite the challenges of shrinking chip sizes, increasing manufacturing costs, and growing demand for energy efficiency, advancements in packaging technology are poised to help the industry navigate these hurdles. In this sense, packaging will remain a critical component in the production of high-quality chips and will likely play a crucial role in enabling the development of smaller, more powerful, and more energy-efficient devices. As such, it is a key area of focus for the industry's future.

Works Cited

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Samsung Electronics (2022, Nov 15) Semiconductor Packaging Explained | All about Semiconductors. Retrieved 9 Feb. 2023 from https://www.youtube.com/watch?v=7gg2eVVayA4

Timings, Jessica (2000, Oct 6) 6 crucial steps in semiconductor manufacturing. Retrieved 9 Feb. 2023 from https://www.asml.com/en/news/stories/2021/semiconductor-manufacturing-process-steps

Xu, Cheng; Zhoung, Zhao Wei; Choi, W.K (2017 May 8). Effect of high temperature storage on fan-out wafer level package strength. IEEE. Retrieved Mar 24 from https://ieeexplore.ieee.org/abstract/document/7919844?casa_token=LSM_ciYcPEQAAAAA:Mn2HPdc1WxK362W1BcBulLaz7IwDP7JFFplsd-6jz7cJ2JvO25oqnNJj6EIAuxfV0DeSg2I6z7g