ABF Semiconductor Insulation: How This Innovation Changed The Game

ABF Semiconductor Insulation: How This Innovation Changed The Game

Have you heard the story of the ABF semiconductor insulation which is essential for the production of central processing units (CPUs) found in modern personal computers and many of our consumer electronic devices? Find out here the story of how ABF substrates were first developed, how they were adopted into PCs, the many benefits they provide in terms of insulation for high-performance computing, and how their manufacture is connected to the present semiconductor supply chain issues like chip shortages.    

What Is The Ajinomoto Build-Up Film (ABF) Substrate

What Is The Ajinomoto Build-Up Film (ABF) Substrate | INQUIVIX TECHNOLOGIES
A diagram showing the ABF substrate inside the device package 

The Ajinomoto Build-Up Film or ABF substrate as it is known in the semiconductor industry is a thin film of electrical insulation. This is used in the manufacture of the circuit substrate in high-performance chips like those used in personal computers and smartphones, as well as the more advanced ones used for artificial intelligence, cloud computing, and smart driving technologies.  The ABF film is made up of a series of film dielectrics and the ABF process that makes the whole thing possible was developed by the Ajinomoto Group. 

How ABF Substrates Were Developed 

The Ajinomoto company is mostly known as a biotechnology and food company that makes seasoning products. However, their scientists were aware that some of the material properties of the epoxy resins and amino acids they used in their regular products could prove useful in the semiconductor manufacturing process as coating agents. As the central processing unit got smaller and more sophisticated with the explosion in the popularity of PCs, there grew a need for the complex circuits that powered them to be better insulated.

The Strong Demand For Better Insulation In Highly Integrated Circuits

The Strong Demand For Better Insulation In Highly Integrated Circuits | INQUIVIX TECHNOLOGIES
A 1990s desktop PC

In the 1990s when most PCs were making the transition from MS-DOS to Windows operating systems, a chip manufacturing company approached Ajinomoto to develop a new type of film-based insulation. This became essential since the conventional ink-based liquid insulators needed to be dried after applying them, which slowed down production. This was an issue since production was too slow to keep up with the rapidly increasing demand.   

Furthermore, the insulation needed to meet the recent advancements made in circuit integration. Conventional insulators were incapable of accommodating the complex wiring, increase in terminals and multiple layers of circuit substrates that processing technologies were heading towards. They also suffered from impurities that affected the yield, and their manufacture resulted in environmentally harmful byproducts. Modern semiconductor-based processing units, especially the ones used for consumer PCB applications needed a better alternative. 

The Challenges Of Developing A New Insulation Technique 

The Challenges Of Developing A New Insulation Technique | INQUIVIX TECHNOLOGIES
President of Ajinomoto Fine-Techno Shigeo Nakamura (second from the right), and his team. 

The first hurdle was to find an insulator with the perfect resin composition that functioned as intended. The second was to find a process where the insulating resins could be laminated onto the substrate with sufficient yield control to make it viable in production. The man tasked with overcoming these major challenges was Shigeo Nakamura, a materials science expert who specialized in insulation material used in printed circuit boards.  

The Development Of The ABF Substrate

The Development Of The ABF Substrate | INQUIVIX TECHNOLOGIES
The Ajinomoto Build-up Film

Nakamura’s team found a combination of organic epoxy resin, inorganic multiparticle filler, and a hardener that required deep refrigeration and a machine that was capable of applying it to the substrate. They were able to test the new process repeatedly by working closely with the machine manufacturer. After months of research and development, Nakamura’s team made a thermosetting film with beneficial characteristics like low thermal expansion, and high durability among others. 

The final result is the ABF substrate that would soon be adopted by a major manufacturer of advanced semiconductors in 1999. This ABF technology would soon become widely adopted by the semiconductor industry, going on to revolutionize high-performance CPUs for decades to come. The Ajinomoto Group remains the ABF market leader to this day. 

Why The ABF Substrate Is So Important 

Why The ABF Substrate Is So Important  | INQUIVIX TECHNOLOGIES
Diagram showing how the ABF substrate facilitates the production of advanced microchips and printed circuit boards. 

Graphic processing units (GPUs), server hardware, 5G base stations, and even the smarter cell phones that are upgraded yearly, all depend on high-end chips and printed circuit boards. The nanoscale-CPU found in such a device needs to be connected with the rest of the electronic components which are in the millimeter scale. The precision nanometer processes required for interconnecting electronics in such devices are facilitated by the ABF substrate. This is possible because its surface allows direct copper plating and laser processing. 

The ABF Substrate Shortage And The Semiconductor Supply Chain Issues

The current supply chain problems experienced by the semiconductor industry is due to many issues. One is the state of the China-US chip trade and the export restrictions that were imposed by the United States. There may also be another issue if semiconductor shortages in the trailing edge semiconductor manufacturing side don’t ramp up as required. 

The supply chain problem is also related to the limited capacity in the current production of ABF substrates. Until recently, repairing RDL defects in ABF substrate circuit boards was possible. However, the complexity and smaller size of the latest chips make it too difficult to repair RDL defects, making it harder for manufacturers to increase yield as they did before. Due to this, the short supply of advanced chips and related devices has caused companies like Intel and Nvidia to be affected.

The Future Of The ABF Substrate

In the face of these challenges, the Ajinomoto company is continuing to improve its ABF substrate technology to accommodate the further downsizing and sophistication of the next generation of microprocessors. They are also focused on improving the yield, allowing the semiconductor manufacturing companies to meet the growing demand for faster, smaller, and more reliable chips in the future. 

To learn more about semiconductors, manufacturing, and the industry itself, visit Inquivix Technologies today!


What Is The Ajinomoto Build-up Film?

The Ajinomoto Build-up Film (AFB) is an insulation material that is used in the manufacture of circuit substrates of high-performance microprocessor units.  

What is The ABF Substrate Made From?

The ABF substrate is made from a combination of organic epoxy resin, inorganic multiparticle filler, and a hardener.

Who Produces ABF Substrate?

The Ajinomoto Group is a Japanese company that pioneered the technique of making ABF substrates that are used by semiconductor manufacturers today.

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