Master Advanced Packaging Inspection

Ms. Solin Ahmad, Business Operations Manager, Koh Young Europe

With increasing customer expectations and demands on electronics equipment, manufacturers are raising their equipment performance requirements. Powerful wearables, Internet of Things (IoT) sensors, mobile communication devices, and new data storage systems push the semiconductor industry and its electronics designers to new heights, which is leading production specialists to find the limits of existing inspection machines. Devices are shrinking and becoming lighter, while designers continually enhance performance, so this trend will continue.

Semiconductor manufacturers are increasingly adopting different advanced packaging technologies and heterogeneous integration is a hot topic, especially for designing multiple systems in a single package. Advanced packaging is among the fastest evolving areas of the semiconductor industry, featuring even smaller component sizes, lower power consumption, and remarkably increased I/O connectivity for added functionality. Several advanced packaging options, such as System-in-Package (SiP), Fan-out wafer-level packaging (FOWLP), 2.5D, 3D chip build-up, and others have added design flexibility and system performance to many applications. As customers demand more sophisticated functionality in smaller devices, using advanced packages and components is a necessity. However, we must remember that all those advancements bring increased package complexity with more layers, finer features, and more I/O channels.

These challenging requests stemming from design improvements means the conventional approach to inspection and quality control is going to become even more critical. The new packaging technologies and solutions are more demanding than the semiconductor packages just a few years ago. Manufacturers must replace inefficient or inadequate manual or semi-automated inspection methods with effective systems designed to meet or surpass the requirements of current electronic designs with an eye to the future. Manufacturers should remember that automated optical inspection (AOI) systems for printed circuit boards may not provide the accuracy and repeatability to manage exceedingly small, printed solder pads associated with advanced packages. So, a generation of new inspection technologies are necessary to deliver solutions for the continually increasing complexity in the industry. Koh Young, the leading provider of True 3D measurement-based inspection solutions, has launched the Meister S, Meister D, and Meister D+ inspection machines. This lineup delivers unsurpassed levels of repeatability and accuracy for inspection of advanced packaging devices from solder to wafer to package.

Integrated Evolution

Semiconductor packaging technology has been rapidly and constantly evolving to support increased package density, advanced functionality, and higher I/O connections. Moore’s Law observes and projects that the number of transistors in a dense IC will double every two years. This is a longstanding and time-tested theory, which is still delivering exponential improvements, albeit at a slower pace. For example, the number of transistors in the benchmark microprocessor design has been reducing across many applications. After, 30 years of continued progress, the rate of acceleration is slowing, but industry experts have not reached a consensus on exactly when Moore’s law will end.

The industry focused previous semiconductor designs on miniaturization and complexity. The trend is now towards versatility with sophisticated functions in a lot of different applications. And at the same designers consider development time, cost-effectiveness, increased performance, and higher integration. These facets combine to deliver the industry with novel devices with more functionality to meet the needs of customers.

To meet these demands, manufactures are adopting SiP package configurations. The alternative System on Chip (SoC) approach differs significantly from SiP packages. SoC design includes a single complex die with all necessary functions integrated into the design. For comparison, instead of designing a single semiconductor die with multiple functions, the SiP design separates functionality into unique die that are combined on a single substrate with other components to form a single package. This technique enables a higher level of integration; in turn, leading to package size reductions for embedded systems. Refer to Figure 1 to highlight the SiP design elements.

Fig 1: System-in-Package (SiP) Source: https://ase.aseglobal.com/en/technology/sip_module

Growing Inspection Challenges

As the devices evolve with more layers, higher density, and more I/O connections in a smaller package, the potential for defects increases and the ability to detect the defects becomes harder for the current inspection systems available. Additionally, as electronic devices continue to shrink, the greatest wafer yield becomes paramount to reduce waste and increase available known good die. As these die geometries continue to shrink, the number of individual die on the wafer increases. Yet, this higher density causes a particularly demanding situation. The die not only become smaller, but the higher density creates challenging shadow effects, which severely challenges the capabilities of traditional inspection machines.

For years, the industry had relied upon optical 2D solder paste inspection (SPI) and automated optical inspection (AOI) systems to identify defects. However, certain aspects of the semiconductor applications seen today significantly challenges conventional inspection systems. For example, highly reflective or shiny die surfaces diffuse inter- reflections, which may create an unacceptable level of uncertainty between the height of the die and the tilt of the surface. The inability to detect defects with high accuracy has a direct impact on the yields. The costs of an undetected production failure can increase in the field dramatically, especially when health and safety concerns are involved. This is especially true in applications like automotive advanced driver-assistance systems (AADAS) applications.

Manufacturers face considerable difficulties when inspecting shiny die in 3D and 2D techniques. Koh Young developed the Meister D and Meister D+ to master the inspection of advanced packages designers are developing. These systems combine True3D with 2D inspection to help manufacturers overcome critical manufacturing tasks and easily address failures like fine cracks and foreign material.

Master Advanced Package Inspection

The Meister S, Meister D, and Meister D+ all combine the proven Moiré technology from Koh Young with modern optical configurations to reliably inspect highly reflective and shiny components. With the newly developed vision and illumination technology, the machine set is an ideal fit for the unique inspection challenges of advanced packages.

The Meister S solder paste inspection machine combines innovative vision algorithms and high-resolution optical technology, to deliver the ultimate True 3D SPI for advanced packaging. Its 0.1um high-resolution optics with a high- speed camera system afford inspection of solder deposits down to 10-microns. The Meister S also provides an active substrate warpage compensation system using both 3D Z-tracking and 2D Pad-referencing. What is more, the system is capable of transparent flux inspection using our proprietary optical system.

With these systems, users can overcome critical manufacturing challenges.

The latest Meister D series of automated optical inspection systems ensures the fastest, most reliable measurement tailored for SiP modules combining multiple die and microchips. With an 8-projector inspection probe, the Meister solves the shadowing problems caused by small or narrow gaps. The decreased angle of the projection units enables the measurement of low heights and the compensation of interfering reflections. With the ongoing package miniaturization trend, the requirements for a higher resolution of inspection systems. As such, the Meister D series uses a 25-megapixel camera with 3.5m-micron resolution to deliver remarkably precise inspection results.

The system allows full and uncompromised 3D inspection of die, as well as of cracks in 0201M (008004 in.) microchips. The new evolution is based on Koh Young’s proven inspection technology, which is now employed in a novel way and available for other critical tasks. By adding the new solution to our proven platform, Koh Young ensured manufacturers will have extremely reliable results with the highest possible confidence. The Meister series guarantees measurements.

The benefits of the Meister series should be quite clear: with their high accuracy, they drastically minimize the number of unidentified defects, in turn, increasing production yield with higher quality. Trustworthy inspection and higher yield in an early stage of production is key for increasing value and reducing costs.

Forming a Partnership

Advanced packaging is becoming prevalent in the market, thanks in part to its advantages over traditional device packaging methods. However, board complexity and shiny die surface make the inspection process more challenging. The industry requires a high-precision inspection solution to overcome these challenges. When looking for the proper inspection system, first clearly understand the complexity of the advanced package. Once defined, set the inspection criteria, and then manufacturers can define the ideal equipment set.

Talking with a competent supplier versed in advanced package inspection, will help simplify the process and define the ideal solution. Therefore, it is of utmost importance for manufacturers to trust and rely upon a solid partner with market experience, proven technologies, and process understanding. Koh Young, the leading 3D measurement-based inspection solutions provider, with the Meister S, Meister D, and Meister D+ is providing the next generation of inspection systems for extended repeatability and accuracy to help manufacturers master the most sophisticated advanced packaging devices.

About Koh Young Technologies

Established in 2002, Koh Young revolutionized inspection by launching the industry’s first 3D SPI & AOI and became the leader in measurement-based inspection solutions with over 3,500 users and over 20,000 installations. Using our True3D and Artificial Intelligence (AI) technology, we extended our applications beyond solder paste and components. Koh Young offers award-winning solutions for inspection challenges with

machined parts, press-fit and through-hole pins, conformal coatings, dispensed materials, and advanced semiconductor packages. Our R&D program helps us develop innovative solutions to solve real-world challenges supported by an award-winning service team focused on delivering excellence. Based near Seoul in South Korea, Koh Young has a network of regional sales and support headquarters across Europe, Asia, and the Americas. These branch offices ensure it stays close to the market, and more importantly, its growing customer group. Learn more about our trusted solutions at www.kohyoung.com or join our social media community for the latest information to help you solve inspection challenges.