SiP (System-in-Package) enables the assembly of multiple active electronic components with optional passive devices such as MEMS or optical components, which have different functionalities, into a single standard package that can perform a specific function, forming a system or subsystem.
At first glance, SiP and SoC (System-on-Chip) are very similar. What sets them apart? SiP maximizes system performance, avoids redundant packaging, shortens development cycles, lowers costs, and increases integration. Compared to SoC, SiP features high flexibility, high integration, short design cycles, low development costs, and ease of entry. However, despite its development, SoC faces challenges such as high technical bottlenecks, difficulties in integrating different processes such as CMOS, DRAM, GaAs, and SiGe, low production yield, high production costs, and lengthy development time. These factors have created a bottleneck in the development of SoC and have led to widespread discussions and positive outlooks for the development of SiP.
What are the differences between SiP and other packaging forms?
① SiP vs 3D and Chiplet
Chiplets can be manufactured using more reliable and cheaper technologies and do not need to use the same process. Moreover, smaller chips themselves are less likely to produce manufacturing defects. Chiplets with different process technologies can be integrated together through advanced packaging technologies. Chiplets can be seen as a hard-core form of IP, but they are provided in the form of chips.
3D packaging is to change a large chip that needs to have flowed once into several small-area chips, and then assemble these small-area chips into a large chip with advanced packaging technology, which is silicon-level packaging, to achieve the function and performance of the large chip. The small area chips used are Chiplets.
Therefore, Chiplets can be considered as a unit in packaging. Advanced packaging is composed of Chiplets/chips, and 3D is an advanced packaging technology means. SiP refers to the completed packaging as a whole. Through 3D technology, SiP can achieve higher system integration, and encapsulate more chips in a smaller area. However, whether advanced packaging technology is used is not the focus of SiP, and SiP focuses on the implementation of the system within the packaging.
② SiP vs Advanced Packaging
The focus of SiP is on the implementation of the system within the packaging, so the system is its main concern, and the counterpart of SiP system-level packaging is single-chip packaging. The focus of advanced packaging is on the advanced technology and process of packaging, so advanced technology is its main concern, and the counterpart of advanced packaging is traditional packaging.
SiP packaging has no fixed form. As far as the arrangement of chips is concerned, SiP can be a 2D packaging of a multi-chip module (MCM) in a flat form, or it can use the structure of 3D packaging to effectively reduce the packaging area. The internal bonding technology can be simply wire bonding or flip-chip, or a combination of both. In addition to the 2D and 3D packaging structures, another way of integrating components with multi-functional substrates can also be included in the scope of SiP. This technology mainly embeds different components in the multi-functional substrate, which can also be regarded as a concept of SiP to achieve the purpose of functional integration. Different chip arrangement methods, combined with different internal bonding technologies, make SiP packaging form a diversified combination, which can be customized or flexibly produced according to customer or product needs.
③ Application Scenarios of SiP
SiP (System-in-Package) technology is an advanced system integration and packaging technology that has unique technical advantages compared to other packaging technologies. It meets the development needs of today’s electronic products for being lighter, smaller, and thinner, and has a broad application market and development prospects in the field of microelectronics.
SiP was the first and is most widely used in the field of wireless communications. In the wireless communication field, the requirements for functional transmission efficiency, noise, volume, weight, and cost are becoming increasingly high, forcing wireless communication to develop towards low-cost, portable, multifunctional, and high-performance directions. SiP is an ideal solution that combines the advantages of existing core resources and semiconductor production processes, reduces costs, shortens time to market, and overcomes difficulties in SOC such as process compatibility, signal mixing, noise interference, and electromagnetic interference. The RF power amplifier in mobile phones, which integrates functions such as power amplification, power control, and transceiver switching, is completely solved in SiP.
SiP is an important application scenario for automotive electronics. SiP applications in automotive electronics are gradually increasing. Taking the engine control unit (ECU) as an example, the ECU is composed of a microprocessor (CPU), memory (ROM, RAM), input/output interface (I/O), analog-to-digital converter (A/D), and shaping, driving, and other large-scale integrated circuits. The process of each type of chip is different, and SiP is currently used more to integrate chips into a complete control system. In addition, SiP is also increasingly being used in various units such as anti-lock braking systems (ABS), fuel injection control systems, safety airbag electronic systems, steering wheel control systems, and tire low-pressure alarm systems. In addition, SiP technology has been successfully applied in the rapidly growing in-vehicle office and entertainment systems.
Currently, SiP is increasingly used in electronic products, especially in the consumer electronics field with high requirements for miniaturization such as TWS earphones, smart watches, and UWB. However, the largest proportion is still in smartphones, accounting for 70%. Because the different parts of the mobile phone RF system often use different materials and processes, including silicon, silicon germanium, gallium arsenide, and other passive components. The current technology cannot integrate these parts made with different process technologies on a silicon chip. However, SiP technology can integrate silicon and gallium arsenide chips using surface mount technology (SMT), and can also use embedded passive components to economically and effectively produce high-performance RF systems. The miniaturization of special process devices such as optoelectronic devices and MEMS will also be widely applied to SiP technology.
④ Challenges in the Development of SiP
As demand for SiP packaging increases, the pain points of the SiP packaging industry begin to emerge, such as the lack of SiP industry standards, insufficient internal bare die resources, difficulties in SiP R&D and mass production, and challenging SiP module and packaging design.
Because a SiP module integrates many devices, if there is even a slight yield loss in each process, the cumulative effect can result in a significant loss of yield for the entire module, posing very high requirements for packaging technology. Additionally, SiP technology is still in its early stages, and although many products use SiP technology, the packaging technology involved is not highly sophisticated, and the system configuration is similar to system integration on a PCB. The only difference is the use of unpackaged chips combined with passive components through COB technology. Most of the passive components in the system are not integrated into the carrier but are separate SMT components.
Currently, from wafer foundries, and OSAT to EMS, the entire manufacturing industry chain is actively engaged in the research and practice of SiP technology.
SiP manufacturers worldwide are primarily concentrated in mainland China and Taiwan, followed by the United States and Japan. SiP manufacturers in mainland China include Shennan Circuits, Changjiang Electronics Technology, Luxshare Precision, Wingtech Technology, and GoerTek Inc.; SiP manufacturers in Taiwan include ASE Technology, Siliconware Precision Industries, and others; and SiP manufacturers in the United States and Japan include Amkor Technology, Murata Manufacturing, and others.
In Apple’s supply chain, electronic products such as AirPods, Apple Watch, and iPhone have a higher pursuit of chip miniaturization, driving more Apple component suppliers to accelerate their SiP layouts.
For example, the global system-level packaging SiP, and the leading player in the field of wearable electronic products manufacturing, Jiangsu Changjiang Electronics Technology (JCE), has been continuously increasing its R&D efforts as the number of SiP chips in Apple Watch and smartphones continues to grow. JCE’s SiP module products mainly involve WiFi modules, UWB modules, AiP modules, fingerprint recognition modules, smart wearable watches, and earphone modules. The SiP module has contributed 60% of the company’s revenue in 2021. With the increasing use of MEMS and sensors, power, communication chips, lighting components, and processors in automotive electronic devices, the growth in the number of automotive electronic devices will drive the development of the packaging market, which is the key area for JCE’s future layout.
System assemblers such as GoerTek and Luxshare Precision are also providing SiP services for Apple. Both GoerTek and Luxshare Precision, as core suppliers of smart terminals, have seen the role of SiP technology in this field and have vigorously developed SiP. GoerTek and Luxshare Precision are both developing SiP chip packaging technology mainly to compete for Apple AirPods’ contract orders. Developing SiP business can not only enable Goertek to win more AirPods orders but also provide one-stop services from design to testing to finished products. As Apple’s first Chinese mainland contract manufacturer, Luxshare Precision is building a chip system-level packaging (SiP) for Apple’s AirPods earphones and has received high recognition.
Leading packaging manufacturer Changdian Technology in mainland China is also closely following the trend. With the acquisition of Xingke Jinpeng, Changdian has obtained SiP technology and can compete with TSMC. Changdian Technology focuses on the development of several advanced packaging technologies: firstly, SiP, as the deployment of 5G accelerates, the application of this type of packaging technology will become more and more extensive. Secondly, the 2.5D/3D packaging applied to Chiplet SiP, and wafer-level packaging, and the use of wafer-level technology to promote fan-out packaging with RF advantages.
Many semiconductor manufacturers have their own SiP technology, each with a different naming convention. For example, Intel calls it EMIB, and TSMC calls it SoIC. These are all SiP technologies and the difference lies in the process technology.
In the field of smartphones, besides the RF module, the demand for miniaturization of universal unit circuits is driving the adoption rate of SiP technology; in the wearable field, Wentai has already applied SiP technology to TWS earphones and smartwatches. In addition, the company has also started to explore and develop SiP in power and automotive communication.
In addition to the market competition in consumer electronics, automotive Tier 1 manufacturer Desay SV Automotive has also started to deploy automotive-grade SiP business this year.
Words in the end
With the continuous evolution of electronic hardware, the cost of products faces development bottlenecks as performance advantages increase. Advanced semiconductor packaging technology can not only increase functionality and improve product value but also effectively reduce costs. SiP combines the advantages of low cost, low power consumption, high performance, miniaturization, and diversification.
In 2021, the global SiP market size was approximately $15 billion. It is estimated that from 2021 to 2026, the compound annual growth rate of the global SiP market will be around 5.8%, and the market size will reach approximately $19.9 billion by 2026. Benefiting from the rapid development of industries such as artificial intelligence, the Internet of Things, and 5G, wearable smart devices and IoT devices are expected to be important drivers of global SiP market growth in the next five years.
Currently, the output value of packaging in the world accounts for only 10% of the total value of integrated circuits. When SiP technology is mastered by packaging companies, the industrial structure will begin to adjust, and the output value of the packaging industry will experience a leap in improvement. The explosion point of SiP in the application terminal product field (smartwatches, TWS, mobile phones, wearables, 5G modules, AI modules, and smart cars) will also be closer and closer.