Milestone-Proposal:Thin Film Hall Elements
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Docket #:2025-19
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To the proposer’s knowledge, is this achievement subject to litigation? No
Is the achievement you are proposing more than 25 years old? Yes
Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes
Did the achievement provide a meaningful benefit for humanity? Yes
Was it of at least regional importance? Yes
Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes
Has the IEEE Section(s) in which the plaque(s) will be located agreed to arrange the dedication ceremony? Yes
Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes
Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes
Year or range of years in which the achievement occurred:
1983
Title of the proposed milestone:
Commercialization of Thin Film Hall Elements, 1983
Plaque citation summarizing the achievement and its significance; if personal name(s) are included, such name(s) must follow the achievement itself in the citation wording: Text absolutely limited by plaque dimensions to 70 words; 60 is preferable for aesthetic reasons.
Thin Film Hall Element revolutionized magnetic sensing for their application when first commercialized by Asahi Kasei in 1983.The thin-film InSb Hall element sandwiched between ferrite substrate and ferrite chip is a semiconductor magnetic sensor and Hall element with the structure largely enhanced sensitivity and stability. Moreover, these sensors are produced very small size. Their compact size and high performance quickly enabled widespread use across DC brushless motors, contactless switches, current sensors, and automotive systems, marking a pivotal milestone in solid-state magnetic sensor technology.
200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.
Thin Film Hall Element technology made its commercial debut in 1983, marking a transformative milestone in magnetic sensing technology. These indium antimonide (InSb) or similar semiconductor thin films are produced by vacuum deposition on mica substrate. Next, these films are peel off from mica and transferred on ferrite substrate. This is the starting of Hall element fabrication prosses. Thin film Hall element on ferrite substrate significantly amplify sensitivity compared to bulk devices. This innovation allowed for compact, high-performance Hall elements capable of precise magnetic field detection in a variety of environments.
Following their introduction, thin-film Hall elements were rapidly integrated into numerous applications. They became fundamental components of DC brushless (Hall) motors with precise angular velocity control and very low noise, enabling smaller and more efficient designs. Their contactless operation, robustness against wear, and immunity to dust and water also made them ideal for switches and current sensors in industrial, domestic, and automotive systems. Between 1980 and the early 21st century, billions of these devices were produced, underlining their commercial success and technological impact.
Technological progress in thin-film deposition techniques—such as vacuum evaporation, molecular-beam epitaxy, and ferrite sandwich structuring—further refined sensitivity, temperature stability, and form factor. These advances not only solidified Hall elements as a mainstay in sensor ecosystems but also opened pathways for future developments like graphene-based devices, quantum effect devices and integrated sensor circuits.
By 2025, thin-film Hall elements remain a cornerstone of precision magnetic sensing, foundational to innovations in motor control, automation, consumer electronics, and automotive safety. Their enduring legacy reflects both the ingenuity of the 1983 commercialization and the adaptability of sensor technology to evolving market and technical demands.
IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.
IEEE Electron Devices Society
In what IEEE section(s) does it reside?
IEEE Fukuoka Section
IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:
IEEE Organizational Unit(s) paying for milestone plaque(s):
Unit: IEEE Fukuoka Section
Senior Officer Name: Tadashi Suetsugu
IEEE Organizational Unit(s) arranging the dedication ceremony:
Unit: IEEE Fukuoka Section
Senior Officer Name: Tadashi Suetsugu
IEEE section(s) monitoring the plaque(s):
IEEE Section: IEEE Fukuoka Section
IEEE Section Chair name: Tadashi Suetsugu
Milestone proposer(s):
Proposer name: Chiaki Ishikawa
Proposer email: Proposer's email masked to public
Proposer name: Ichiro Shibasaki
Proposer email: Proposer's email masked to public
Proposer name: Naofumi Uesugi
Proposer email: Proposer's email masked to public
Proposer name: Tsuyoshi Shiraki
Proposer email: Proposer's email masked to public
Proposer name: Takashi Yoshida
Proposer email: Proposer's email masked to public
Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.
Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):
Asahi Kasei Nobeoka Exhibition Center, 6-4100, Asahi-cho, Nobeoka-Shi, Miyazaki, 882-0847, Japan.
GPS coordinates: 32.5708047,131.6681052,16
Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.
Please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. 旭化成の延岡支社の製品展示室？ 建物は旭化成の所属？
Are the original buildings extant?
No.
Details of the plaque mounting:
屋内なのか屋外なのか。台置きなのか、壁埋め込み等々、展示方法をどうするのか聞いている。
How is the site protected/secured, and in what ways is it accessible to the public?
一般人が入る場合の手続きを聞いている。自由には入れるのか、許可が要るのか等々。盗難対策？
Who is the present owner of the site(s)?
Asahi-kasei corporation
What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include detailed support at the end of this section preceded by "Justification for Inclusion of Name(s)". (see section 6 of Milestone Guidelines)
Historical Significance of Thin-Film InSb Hall Elements
Early History of Asahi Kasei's Hall Device Development and Commercialization
Beginning of Hall Device Research at Asahi Kasei (1974–1980)
In 1974, Asahi Kasei began full-scale research on InSb thin-film Hall devices using the vacuum evaporation method. During this early stage, four key technologies were developed:
1. Thin Film Vapor Deposition (1980): A method to mass-produce 0.8 μm-thick InSb thin films with high electron mobility (20,000–30,000 cm²/Vs) on thin mica substrates, overcoming the vast vapor pressure gap between indium and antimony.
2. Ferrite Sandwich Magnetic Amplification: Theoretical and experimental validation of a structure that increased magnetic sensitivity by placing the InSb thin film between soft magnetic ferrite layers, enhancing signal strength via magnetization.
3. Constant-Voltage Drive Innovation: A new constant-voltage drive system for thin-film Hall elements was established, greatly reducing the temperature dependence of Hall voltage by one order of magnitude.
4. Photolithographic Fabrication Process: The world's first photolithographic Hall element patterning process was created, alongside resin packaging and small-scale mass production capabilities.
These innovations formed the conceptual foundation of the magnetic sensor as a Hall motor component. In July 1980, Asahi Kasei built a factory in Nobeoka City, Miyazaki Prefecture, and began producing thin-film Hall elements for motors used in audiovisual devices like VCRs and audio players.
Challenges in Early Production and Limitations (1981-1982)
The manufacturing process involved peeling off the deposited InSb thin film from a mica substrate, bonding it to a ferrite base using an insulating adhesive, and forming Hall element patterns via semiconductor-based wafer processes.
Despite these advances, the early-stage technology could not meet mass production demands. The initial production volume was low, and the manufacturing process lacked the stability and scalability required for widespread industrial use.
A report in The Yomiuri Shimbun on February 12, 1982, covered the status of the Hall element factory in Nobeoka and its production challenges.
Breakthrough with the HW Series (1983)
To address these production and performance issues, Asahi Kasei launched the HW Series in 1983, marking a major technological breakthrough. The HW-101A and HW-300A models introduced a new era of highly sensitive InSb thin-film Hall elements.
Key Features of the HW Series:
- Extremely high magnetic sensitivity
- Low temperature dependence of Hall voltage (±0.1%/°C)
- High heat resistance (up to 260°C)
- Compact resin packaging suitable for mass production
This series adopted a complete semiconductor device production process for the first time, including:
- Wire bonding of 0.8 µm InSb thin films using Au wires
- Epoxy resin packaging via transfer molding
Mass production began in June 1983 at the Nobeoka plant, with initial application in DC brushless motors used in VCRs.
Rapid Market Expansion and Industrial Impact
The HW Series enabled Asahi Kasei to respond to skyrocketing global demand for VCRs and other consumer electronics. Monthly production of Hall elements grew rapidly:
- June 1983: HW Series launched
- October 1983: Reached 3 million units per month
- November 1983: Planned expansion to 7 million units/month
These magnetic sensors allowed precise, contact-free angular velocity detection in miniaturized motors, playing a crucial role in the success of products like:
- Home-use VCRs
- Personal computers
- Audio devices
Historical Milestones and Production Growth
Key milestones in Asahi Kasei's Hall element development:
- 1973: Start of research
- 1975: Discovered benefits of low-voltage operation; filed three patents
- 1975 (July): Established vapor deposition method
- 1981: Constructed second factory
- 1983 (June): Introduced HW101A (mini-mold chip) and HW300A (DIP type)
- 1983 (July): Released HW300B (SIP type with inline leads)
Figures in Asahi Kasei’s 15-year history illustrate production growth and the diversification of applications for the Hall element.
Long-Term Societal Contribution and Market Leadership
Before the HW Series, Hall elements lacked the performance needed for practical use—low sensitivity and poor temperature stability. The HW Series changed this:
- 20–30 times higher sensitivity
- Reduced temperature dependence by one order of magnitude
These advances led Asahi Kasei to dominate the Hall element market with a 70% global share, and cumulative production exceeding 40 billion units.
Wider Applications:
- DC brushless motors in VCRs and PCs
- Air conditioners and home appliances
- Power tools and various non-contact sensors
- Automotive applications (recent years)
This technology helped realize the industry’s vision of "light, thin, short, and small" electronic systems and contributed significantly to the 20th–21st century’s industrial revolution.
Miyazaki Electronics and Early Manufacturing Success
Asahi Kasei established Miyazaki Electronics as a wholly-owned subsidiary responsible for Hall element manufacturing. The Nobeoka plant was built in July 1980 and scaled production as demand increased.
According to The Yomiuri Shimbun (Feb 12, 1982), the factory was producing 3 million units/month with a staff of 250 and was preparing to scale up to 7 million units/month. These components were crucial to the production of VCRs and audio players.
What Are Thin-Film Hall Elements – A Primer
Fundamental Principle of the Hall Effect
A Hall element is a device based on the Hall effect, discovered by American physicist Edwin H. Hall in 1879. The principle is straightforward yet powerful:
There are two driving methods for Hall elements: constant current drive and constant voltage drive. The temperature characteristics parameters vary depending on which method is used.
- Constant Current Drive:
When a constant current (IC) is applied to terminals 1 and 3, the voltage output at terminals 2 and 4 can be expressed by the following equation:
VH = RH × (1 / d) × IC × B
Here, RH is the Hall coefficient, and d is the thickness of the semiconductor film in the direction perpendicular to the terminal surface. The Hall coefficient RH is defined using the electron charge e and the carrier concentration n as follows:
RH = 1 / (e × n)
The temperature characteristic of the output voltage in constant current drive is determined by the temperature dependence of RH.
- Constant Voltage Drive:
When a constant voltage (VC) is applied to terminals 1 and 3, the voltage output at terminals 2 and 4 can be expressed by the following equation:
VH = μH × (W / L) × VC × B
Here, μH is the electron mobility, and W and L are the lengths in the directions of terminals 2-4 and 1-3, respectively. The temperature characteristic of the output voltage in constant voltage drive is determined by the temperature dependence of μH.
Fig. 1 Hall element principal (n-type semiconductor)
Characteristics of Thin-Film Hall Elements
A thin-film Hall element refers to a Hall device fabricated using thin layers of semiconducting material, typically in the nanometer to micrometer range. Thin-film Hall elements offer several key advantages:
- High Sensitivity and Small temperature dependence of sensor signal
The thin film InSb has high sheet resistance and reduced sensor signal or Hall voltage by constant voltage drive and enhances sensitivity to magnetic fields.
- Miniaturization and Integration
Thin-film fabrication is compatible with modern semiconductor processes, allowing integration into ICs and sensor arrays.
- Tailored Material Properties
Material engineering allows for control over temperature dependence, linearity, and noise characteristics.
Common materials for thin-film Hall elements include GaAs, GaN, and InSb (indium antimonide)—the latter being especially notable due to its very high electron mobility, which contributes to superior sensitivity and performance in Hall devices.
Example Images of Thin-Film Hall Devices
The following are representative images that may be included to aid understanding:
Figure A: Scanning electron microscope (SEM) image of a thin InSb layer patterned on a substrate with electrodes configured for Hall voltage measurement. Figure B: Optical micrograph of a fabricated thin-film Hall element, showing the cross-shaped active region and metal contacts for current injection and voltage sensing.
Figure 2 Schematic Diagram of Thin Firm Hall Element
Photo 2 photo of Thin Firm Hall Element
Importance of Thin-Film InSb Hall Elements
- Advanced Material Performance
InSb thin films combine high carrier mobility with the controllability of thin-film deposition, enabling highly responsive and precise magnetic sensing.
- Enabler of Micro/Nano Magnetic Sensors
Their small size and high sensitivity have paved the way for applications in compact magnetometers, contactless current sensors, and biomedical magnetic sensing.
- Integration with Modern Electronics
Thin-film Hall elements can be co-fabricated with CMOS and other semiconductor technologies, allowing for system-on-chip (SoC) or system-in-package (SiP) implementations.
Historical Context & Emerging Societal Needs
In the late 1970s and early 1980s, consumer electronics underwent a profound transformation. After the oil shocks of the 1970s, Japan’s electronics giants pivoted from traditional home appliances—such as TVs and stereos—toward emerging sectors: personal audio, consumer video (VCR), and personal computing. This transformation was encapsulated by the slogan “keitai-shou-jun‑sho” (“light, thin, short, small”), reflecting desires for ever more compact and portable devices. Semiconductor innovations, not only in computing and communications but also in sensors and drive electronics, were essential to delivering these aspirations.
Figure 1 Market trend
A key technological gap hindered this evolution: precise, miniature motors were critical for new portable systems—like tape recorders, VCR transport systems, hard disk drives, floppy disk drives, CD-ROMs, and early portable electronics. Each device demanded motors capable of stable angular speed and precise positional control. Conventional brushed motors were inadequate—they generated noise, electromagnetic interference, wore brushes, and lacked reliability and miniaturization. What was needed was a brushless, electronically controlled motor—one that required a non-contact, high-resolution method to detect rotor position and rotational speed.
Thus emerged a central technological challenge: to develop a tiny, high-sensitivity, low-offset, non-contact magnetic sensor that could detect rotor position without brushes and enable electronic motor control. Of the principal requirements—strong permanent magnets, integrated control electronics, and a suitable sensor—the latter was the key gating factor. Traditional Hall effect sensors (based on bulk InSb or GaAs) were expensive, bulky, low-sensitivity, and ill-suited to mass production.
The Thin-Film InSb Hall Elements
In this context, Ichirō Shibasaki at Asahi Kasei (not a traditional semiconductor firm) embarked on groundbreaking research. His aim was to integrate high‐mobility InSb thin films with a magnetic flux–amplifier structure to create a small, inexpensive, high‑sensitivity Hall Elements appropriate for mass production. Shibasaki’s breakthrough hinged on three innovations:
(1) Scalable InSb thin-film vacuum‐deposition: Shibasaki developed a two-temperature multi-source vacuum evaporation (the “Gunther–Sakai method”) which allowed the production of uniform 0.8 µm InSb films on 2‑inch wafers, yielding electron mobility of 20,000–30,000 cm²/V s—unmatched at the time.
(2) Magnetic-flux amplification with soft ferrite “sandwich” structures: Embedding the InSb film between soft-ferrite layers increased effective sensitivity by 3–6×, achieving 20–30× higher detection efficiency with low off‑offset.
(3) Integration-friendly packaging and production: Applying resin packaging compatible with automatic PCB assembly and LSI-based control ensured reliable, high-temperature capable, mass-producible diodes, emphasizing low-temperature drift (<±0.2 %/°C) and resistance to 200 °C environments.
The result was the HW series high-sensitivity InSb thin-film Hall Elements, a compact, robust, low-cost magnetic sensor that delivered breakthrough performance in motor control applications. This device uniquely addressed the non-contact detection challenge, enabling wide-scale adoption of electronic motor control.
Pioneering the Era of Electronic Control Motors
By solving the critical sensing problem, Shibasaki’s sensor opened the way for mass deployment of brushless motors in a diverse range of devices—ushering in the era of the “Hall motor.”
- In consumer electronics, brushless motor systems were integrated into VTR capstan motors, rotary-head motors, CD-ROM drives, floppy-disk drives, and hard-disk drives.
- In audio, miniature motors were essential to portable cassette players and early CD walkmans.
- In computing and office automation, stable motor rotation became foundational to disk-drive performance and reliability.
Shibasaki’s sensor, thanks to its compact form, high sensitivity, low-temperature drift, and compatibility with LSI control, became the de facto standard driving electronics motor control. From 1989 through 2003, the HW series held over 70 % global market share in magnetic sensors used in motor control, with annual production peaking at 1.5 billion units (circa 2003). From 1997 to 2011, over one billion sensors were produced annually, cumulatively exceeding 21 billion units––a staggering figure emblematic of pervasive technology penetration.
This ubiquity underscores the scale of the sensor’s impact: enabling brushless, electronically controlled motors across consumer electronics, computing, communications, and household appliances. It disrupted traditional mechanical-driven device design, advancing the digital age.
Photo 3 (a) Capstan motor for VCR, (b) Motor for CD-ROM Drive
Technological Ripple Effects & Cross-Disciplinary Synthesis
Shibasaki’s Hall Elements was more than a single product; it exemplified holistic innovation through cross-disciplinary integration:
- Semiconductor thin-film physics: Mastery of high-mobility InSb film deposition.
- Magnetic materials science: Ferrite-layer-based flux amplification.
- Motor control circuitry: Seamless integration with LSI-driven electronics.
- Mechanical/industrial packaging and manufacturability: Achieving mass production with stability and compatibility.
By fusing these domains, the HW series sensor catalyzed the broader brushless motor ecosystem—and demonstrated that the synthesis of diverse technological disciplines can be transformative.
Enabling Broader Applications and Efficiency Gains
Beyond computing and VCRs, Shibasaki’s sensors propelled the mass adoption of electronically controlled motors in household appliances:
- Washing machines: Brushless motors with Hall Elementss enabled precise speed control, power savings, and reverse direction, fostering drum control and eco‑friendly operation.
- Air conditioners: Brushless compressors achieved ~10 % efficiency improvements through Hall-motorization.
- Inverter-driven appliances: The integration of Hall Elementss into control loops improved energy efficiency, reduced noise, and minimized wear.
- Electric vehicles and hybrid appliances: While brushless power motors often utilize current sensors rather than position sensors, the earlier maturation of Hall Elements tech informed design practices in modern inverter-driven systems.
The energy-saving implications are tremendous. In Japan circa 2000, motors consumed over 50 % of the country's total electricity generation (about 960 TWh/year). Even modest improvements in motor efficiency—e.g., 2 % savings via Hall motor systems—translate to power generation reduction equivalent to a 1 GW power plant. This magnifies the environmental and socio-economic significance of Shibasaki’s invention.
Legacy and Continued Evolution
Since its 1980s commercialization, Shibasaki’s work laid the foundation for a sensor-centric “electronic motor age.” His innovations have yielded enduring benefits:
- Scale of Production: Over 200 billion units manufactured by 2011, with reliable supply chains and automated manufacturing.
- Ecosystem Growth: Forged markets for ferrite magnets, LSI motor controllers, and advanced semiconductor packaging.
- Technological Branching: Led to derivative sensor forms (digital Hall ICs, current sensors, hybrid Hall ICs) used in washing machines, power inverters, and industrial monitoring.
- Scientific Influence: Spurred further research in high-mobility semiconductor sensors (e.g., InAs, InAs quantum wells), driven by the demonstration that high sensitivity and low offset unlock high-reliability device domains.
Ichirō Shibasaki’s innovation illustrates that small sensors can enable big systems—it was both enabler and emblem for the broader shift to electronically driven, sensor-rich devices.
Social & Industrial Impact
- Consumer products: Enabled quieter, more compact, efficient appliances—from tape decks to air conditioners—improving daily life.
- Industrial competitiveness: Gave Japanese electronics manufacturers a technical edge in motor-driven devices.
- Environmental gains: Applied energy efficiency contributed to reduced greenhouse gas emissions across consumer and industrial sectors.
- Technology democratization: The sensor’s price point and mass producibility lowered barriers, influencing applications from hobbyist robotics to automotive electronics.
- Knowledge catalyst: Shibasaki’s work exemplifies how new materials, cross-disciplinary integration, and manufacturing innovation can spark new device paradigms.
Why It Merits IEEE Milestone Recognition
- First-of-its-kind: The first large-scale, high-mobility thin-film Hall Elements with integrated magnetic amplification, scalable via automated packaging.
- Technological Enabler: Central to the commercialization of brushless, electronically controlled motors across major device categories.
- Broad Influence: Its principles underpin digital Hall ICs, current sensors, motor controllers, and efficient inverter drives.
- Quantified Reach: Tens of billions of units in active use across the globe; foundational to modern electronics reliability and energy efficiency.
- Interdisciplinary Impact: A hallmark of modern engineering—the confluence of semiconductors, magnetics, LSI, and packaging.
Conclusion
Shibasaki’s thin-film InSb Hall Elements from Asahi Kasei fundamentally transformed how mechanical motion is sensed and controlled in devices. It triggered the global brushless-motor revolution by delivering a compact, cost-effective, high‐performance, and mass-producible sensor—thus realizing electronic motor control in compact consumer electronics, appliances, and industrial systems. Its design principles and material innovations have permeated modern electronics, improving reliability, energy efficiency, functionality, and convenience for billions. The world today—of silent disk drives, efficient air conditioners, smart power tools, and green motors—owes much to this unassuming but game-changing sensor. IEEE Milestone recognition would honor not just a device but the broader innovation ecosystem it enabled.
What obstacles (technical, political, geographic) needed to be overcome?
Obstacles to overcome
Technical Challenges
First-ever industrial-scale vacuum‑deposition of InSb thin films
- Prior Hall elements used polished thin bulk InSb crystals—fragile, expensive (¥ thousands–tens of thousands each), and unsuitable for compact electronic motors. Moreover, more than millimeter size and could not mass production.
- The Asahi‑Kasei team, with no semiconductor‐device background, had to invent a completely new deposition route: the two‐temperature multi‑boat vacuum evaporation for co‑depositing Indium and Antimony on mica substrates.
- This overcame the huge vapor‑pressure difference (five orders of magnitude between In and Sb) to yield uniform ~0.8 µm‑thick InSb films with In and Sb 1:1 composition and high mobility (20,000–30,000 cm²/Vs), sheet resistance ~130–150 Ω/□, over 36 2‑inch substrates simultaneously.
- These innovations enabled, for the first time, reproducible industrial‐scale deposition of compound‑semiconductor thin films.
Dramatically increased magnetic sensitivity with ferrite magnetic‑amplification
- Even with high‑mobility films, sensitivity was insufficient. So the team sandwiched the InSb between soft‑ferrite chips (“magnetic amplification”).
- This approach magnified the local field inside the Hall film by 3–6×, boosting magnetic sensitivity by ~20–30× over conventional InSb bulk elements.
- It also improved the output signal offset ratio (signal vs. residual voltage) by 1/3–1/6, significantly enhancing reliability.
Resolution of InSb’s notorious temperature drift
- Conventional InSb sensors drove with constant current, suffering large temperature coefficients (~−2%/°C).
- Using thin‑film, high‑resistance InSb and applying constant‑voltage drive, temperature effects shrink to ±0.1–0.2 %/°C—10–20× improvement.
- This improvement was crucial for real-world motor control and laid the basis for reliable mass production.
Packaging, assembly, and high‑temperature reliability
- Transition from bare chips to automatable molded resin packages, compatible with wire‑bonding and PCB mounting, was critical for large‐scale manufacturing.
- The new resin packages endured automated reflow at 260 °C, enabling SMT insertion—yet another first for compound semiconductors.
- The packaged sensor demonstrated high durability, essential for demanding applications in VTRs, disk drives, and motors.
Organizational and Political Challenges
A chemical company diversifying into a foreign domain
- Asahi‑Kasei, primarily a chemical firm, took a bold leap into compound‑semiconductor electronics, entirely outside its established competency.
- Their management strategy, transformed by the 1970s oil shocks, supported risky experimentation beyond traditional petrochemistry—a crucial enabling cultural and financial commitment.
- Internally, teams faced friction between chemists, physicists, and engineers, requiring extensive cross‐disciplinary dialogue and learning cycles.
Overcoming external skepticism and a lack of expert involvement
- In the 1970s, semiconductor firms focused on silicon; magnetic‑sensor development attracted little interest.
- Asahi‑Kasei’s new path was often dismissed as outdated or too academically-oriented, with no prior industrial benchmarks.
- The team overcame this by delivering concrete functional modules (HW series) meeting demanding temperature, assembly, and durability specs—transforming skepticism into industrial trust.
Collaboration with LSI circuits and motor‑controller firms
- High‑sensitivity sensors alone faced limitations; motor drives required matching control circuits.
- Asahi‑Kasei partnered with Si‑LSI vendors to develop dedicated bipolar hybrid ICs for sensor interfacing, and later hybrid Hall ICs combining InSb sensors and Si amplifiers in a 3 mm resin package.
- These synergies were vital in aligning sensor output characteristics with electronic motor systems, enabling practical deployment.
Geographic and Infrastructure Challenges
Industrial scale‑up at newly built Nobeoka, Miyazaki plant
- In 1980 Asahi‑Kasei launched a small‑scale factory in Nobeoka, Miyazaki Prefecture—rural, lacking semiconductor infrastructure.
Ref.＊
Key issues:
- Talent shortages: no local semiconductor expertise meant relocation or heavy training.
- Need for specialized vacuum chambers, cleanrooms, precise temperature systems—all developed on-site.
- Logistics for procurement of chemical precursors and shipping resin‑sealed sensors from rural Japan to global clients.
Sourcing of high‑purity In and Sb materials
- Achieving uniform InSb films demanded ultra‐pure sources—rarely domestically available.
- Asahi‑Kasei's chemical roots aided securing supply chains and developing in-house refining procedures, bridging material‑science constraints.
Establishing market distribution networks
Target industries (VTR, PC drives, appliances) already had established electronic‑parts distributors.
Asahi‑Kasei had to build:
- Sales teams focused on motor OEMs,
- Technical support units for design-in,
- Quality assurance protocols across variable environments and client specs.
How These Obstacles Were Overcome
Challenge: How Overcome
Vapor‑pressure engineering: Invented two‑temperature multi‑boat vacuum deposition
Low sensitivity: Designed ferrite‑sandwich amplification, achieving 20–30× gain
Thermal drift: Switched to constant‑voltage drive, thin films
Packaging: Developed resin packages passively tolerant to 260 °C SMT processes
Cross-disciplinary knowledge: Fostered internal chem‑electronic collaboration, external partnerships with Si‑LSI vendors
Production scale and location: Built Nobeoka factory, acquired staff, trained engineers
Material sourcing Leveraged in-house chemical supply chains
Distribution: Built networks and support cadres from scratch
Impact & Legacy
- By 1975–1980, the HW-series thin‑film InSb Hall sensor was in production, enabling brushless electronic motors used in VTR, CD drives, PC floppies, and hard disks.
- Sales skyrocketed: production exceeded 1 billion units per year from 1997 to 2011, peaking in 2003 at 1.5 billion, and cumulative output reached over 21 billion by 2011.
- The sensors powered the Hall‐motor revolution, enabling no-contact, low-noise, energy-efficient precision drives—advancing the electronics, computing, and appliance industries.
- In 2013, IEEE “Denki no Ishizue” (Electric Foundations) recognized the technology for ushering in the electronic‑control motor era.
Closing Reflections on Obstacles and Innovation
Shibasaki’s team transformed a neglected academic concept into a global industrial ecosystem, i.e. by: developed, mass produced, thin film Hall elements HW-series at Nobeoka plant and then, by served them for Hall motor makers, .
- Defying domain boundaries: a chemical company entering semiconductor electronics.
- Solving five fundamental technical bottlenecks.
- Establishing rural manufacturing infrastructure for advanced devices.
- Achieving seamless industrial translation: from lab innovation to global distribution.
This journey embodies the IEEE Milestone spirit: technical creativity + determination + cross‑disciplinary fusion to overcome complex technical, political, and geographic barriers.
What features set this work apart from similar achievements?
What Features Set This Work Apart from Similar Achievements?
In the late 1970s and early 1980s, thin film Hall elements were being explored in laboratories around the world. However, while many remained in the experimental or prototype stage, Ichiro Shibasaki and his team at Asahi Kasei succeeded in achieving the world’s first practical and mass-producible thin film Hall element based on indium antimonide (InSb), launching it as a commercial product. Their achievement was not merely a technological advance—it was a pioneering integration of materials science, semiconductor process innovation, and magnetic sensor design that laid the foundation for an entirely new generation of electronic motion control systems.
What set Shibasaki’s Hall element apart was not just its high sensitivity, but the holistic approach taken to address the full spectrum of challenges that stood between laboratory feasibility and industrial viability. At the time, existing Hall sensors were typically built from mechanically polished single-crystal InSb and designed primarily for use in laboratory Gaussmeters. These devices suffered from several limitations: they were bulky, expensive (often costing thousands of yen per unit), poorly packaged, fragile, and highly susceptible to environmental conditions such as temperature and mechanical stress. Above all, they lacked the mass manufacturability required for integration into consumer electronic products.
Shibasaki’s work addressed these limitations with a novel thin-film-based solution that combined several key innovations:
First Large-Scale Production of Thin-Film InSb:
One of the most significant breakthroughs was the development of a scalable vacuum deposition process to fabricate high-quality InSb thin films. The challenge lay in controlling the deposition of two elements, indium and antimony, which differ in vapor pressure by five orders of magnitude. Shibasaki’s team developed the “two-temperature multi-boat evaporation method,” which enabled precise control of the composition and uniformity of the InSb thin film across large substrates. Using this method, they could simultaneously deposit uniform 0.8 μm thick films on up to 36 mica substrates on a single 2-inch wafer. This level of uniformity and throughput was unprecedented, establishing a viable production process for thin-film magnetic sensors.
Magnetic Amplification Structure Using Soft Ferrite:
Another key innovation was the introduction of a magnetic flux concentrator structure. By sandwiching the InSb thin film between two soft ferrite layers (Ni-Zn and Mn-Zn ferrite types, respectively), they achieved magnetic field amplification of 3 to 6 times at the sensing point. This structural enhancement allowed the Hall element to detect magnetic fields with 20 to 30 times higher sensitivity than conventional sensors at the time—something not possible by material improvements alone. This structure also significantly reduced output offset, improving signal-to-noise ratio and operational stability.
Temperature Stability Through Thin-Film Engineering:
One longstanding issue with InSb Hall sensors was their high temperature coefficient of sensitivity. Shibasaki’s thin-film approach, coupled with high input resistance design and constant-voltage drive methodology, reduced the temperature coefficient of the Hall voltage from −2%/°C (typical of conventional devices) to an unprecedented ±0.1–0.2%/°C—an improvement by a factor of 10 to 20. This performance was critical for applications in consumer electronics where temperature fluctuations are inevitable and tight control of motor speed and position is required.
Packaging and Integration with Modern Manufacturing Processes:
Recognizing that sensor performance alone was insufficient for adoption, the team designed the device in a compact, plastic-encapsulated form that was compatible with automatic mounting processes. This made it possible to integrate the Hall sensor into printed circuit boards in a fully automated fashion, reducing assembly costs and increasing reliability. This packaging strategy enabled the device to be used widely in high-volume manufacturing environments, including VTRs, CD players, floppy disk drives, and hard drives.
Industrial and Social Impact:
The introduction of this Hall sensor enabled the widespread adoption of brushless DC motors—commonly known as Hall motors—which offered precise speed and position control, low electrical noise, and high durability. This was especially crucial at a time when Japanese manufacturers were seeking noise-free, compact, and efficient motors to drive the emerging generation of consumer electronics. The sensor’s robustness, size, and cost-effectiveness made it a key component in the success of products like the Sony Walkman, VTRs, and personal computers, which defined the electronics boom of the 1980s and 1990s.
Long-Term Production and Market Leadership:
From the mid-1980s to the early 2000s, over 21 billion of these sensors were produced, with annual output exceeding 1 billion units for more than a decade. By the early 2000s, sensors using this magnetic amplification structure had achieved more than 70% global market share in certain applications. This is a testament not only to the technical excellence of the original design but also to its adaptability and relevance across multiple generations of electronics.
Paving the Way for Hybrid Hall ICs:
Shibasaki’s sensor technology also served as the basis for later innovations such as Hybrid Hall ICs—devices that combined high-sensitivity Hall sensors with integrated signal amplification. These hybrid devices offered digital outputs with low offset and high signal reliability, enabling a new class of smart sensors for switching and control in both consumer and industrial environments.
In summary, while many researchers in the 1970s and early 1980s explored thin film Hall technologies, Shibasaki’s work stands out for having crossed the crucial threshold from lab-scale experimentation to industrial production and widespread adoption. His work was not just about improving sensitivity; it was about delivering a solution that met the full demands of the electronics industry: high performance, mass manufacturability, environmental robustness, and seamless integration into emerging technologies. The InSb thin film Hall element developed under his leadership thus represents a landmark achievement in the history of semiconductor sensors, enabling the rise of intelligent motion control in modern electronics and leaving an enduring legacy in both technology and industry.
Why was the achievement successful and impactful?
Why was the achievement successful and impactful?
Breakthrough in Magnetic Sensor Technology
The development of thin-film InSb Hall elements by Ichiro Shibasaki and his team at Asahi Kasei in the early 1980s marked a major breakthrough in magnetic sensor technology. At the time, existing Hall sensors were based on bulk InSb crystals, which were expensive, unreliable, and too large for mass-market consumer electronics. Shibasaki’s innovation—using a thin-film vacuum deposition method to mass-produce high-sensitivity InSb Hall elements—was unprecedented and paved the way for practical, low-cost, high-performance magnetic sensors. His "two-temperature multi-boat evaporation" technique enabled uniform and large-area deposition of thin InSb films, achieving electron mobilities over 20,000 cm²/Vs and allowing mass production with high yield and reliability.
Enabling the Brushless DC Motor Revolution
The new thin-film Hall elements met an urgent industrial demand: compact, high-precision, non-contact angular velocity detection for brushless DC motors. These motors were critical for emerging devices like video cassette recorders (VCRs), CD players, and personal computers, which required precise motor control without the noise, size, and reliability issues of traditional brush-type motors. Shibasaki’s Hall elements, when combined with permanent magnet rotors and newly developed motor control ICs, enabled the commercialization of ultra-compact, low-noise brushless motors. These motors powered devices like Walkmans, floppy disk drives, and VCR capstan motors, becoming essential components of 1980s and 1990s consumer electronics.
Magnetic Amplification for Unprecedented Sensitivity
A key innovation in Shibasaki’s design was the use of soft ferrite magnetic materials to sandwich the InSb thin film. This structure amplified the magnetic flux density detected by the Hall element by a factor of 3–6, resulting in sensitivity levels 20–30 times greater than conventional sensors. Furthermore, the low offset voltage and high output signal made the device uniquely suitable for integration with bipolar IC-based motor drivers. The result was not only higher sensitivity but also enhanced signal stability and robustness against temperature variation—less than ±0.2%/°C in Hall voltage drift—addressing a longstanding problem of InSb sensors
.
Seamless Integration into Mass Production
Shibasaki’s Hall elements were designed for full compatibility with modern manufacturing and packaging. Their small resin-molded packages supported automated surface-mount assembly, enabling high-volume deployment in consumer electronics. This compatibility with both application circuits and production processes played a crucial role in their rapid adoption. By 1997, production surpassed 1 billion units per year, peaking at over 1.5 billion in 2003, with a cumulative production exceeding 21 billion units by 2011.
Widespread Industrial and Societal Impact
The success of Shibasaki’s thin-film Hall elements catalyzed the widespread use of brushless motors in a range of industries and supported the global expansion of consumer electronics. They became foundational components in devices that defined the late 20th century: VCRs, hard disk drives, CD-ROMs, and more. Furthermore, the hybrid integration of these sensors with ICs led to the development of digital magnetic switches and current sensors, extending their impact into industrial power control and home appliances. This achievement not only solved a key technical bottleneck but also exemplified the successful fusion of materials science, semiconductor engineering, and magnetics.
Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.
Bibliography
Reference
REferenceの表記方法は一般的な書き方にして下さい。論文の書き方を調べれば、Referenceの表記方法な載っています。
[1] Shibasaki I. 1984. Properties of Hall Elements by Vacuum Deposition, the Correction of Advanced Technology of
Semiconductor Devices (Multi-authors book, in Japanese).Keiei System Kennkyusyo, Shinjyuku, Tokyo [Chapter 3], Sec. 11,p. 373.
記事そのもののPDFを付ける。
日本語なら、関係する部分の英語訳を付けて下さい。
[2] Shibasaki, I., 1988. High sensitivity InSb Hall elements and their development for practical use. Monthly Report Jpn Soc. Chem Indus. 41
記事そのもののPDFを付ける。
日本語なら、関係する部分の英語訳を付けて下さい。
[3] Shibasaki,I High-Sensitivity InSb Thin-Film Hall Elements with Ferrite Sandwich Structure and Their Extensive Commercial Application （Invited paper）
記事そのもののPDFを付ける。
日本語なら、関係する部分の英語訳を付けて下さい。
[4] Shibasaki, I., 1997. Mass production of InAs Hall elements by MBE J. Cryst. Growth 175/176, 13.
記事そのもののPDFを付ける。
日本語なら、関係する部分の英語訳を付けて下さい。
[5] 電気の礎 平成26年3月 受賞資料
Referenceは5本以上欲しい。英文の論文はないか。
Patents
何の特許？デバイスの構造？製造方法？
[P1] I.Shibasaki, K.Nonaka, T.Shimizu, "Manufacturing method of Hall Element", April 28 ,1975. (JP)Tokko No.53-46675,
(US transrated)Media:US Trans 1978046675.pdf,
[P2] I.Shibasaki, T.Kajino, "magnetoelectric transducer”, May 10,1985. (JP)TokkoNo4-62474
Media:JPB 1992062474.pdf , ,br>
(US)Pat.4908685 Media:USA1004908685.pdf
[P3] I.Shibasaki, T.Kajino, "magnetoelectric transducer”, May 24,1985. (JP)TokkoNo4-71351
(US)Pat.4908685 Media:USA1004908685.pdf
Award
誰が（団体）、誰に、どんな業績に対して（Citation）、どんな種類？価値はどの程度。Website？ [A1] Ōkōchi Prize 1987, Media:Ōkōchi Prize.pdf
[A2] 紫綬褒章 ２００８
[A3］電機の礎 顕彰 2013
[A4] 発明奨励賞
[A5] The Yamazaki-Teiichi Prise 2018 , Media:Yamazaki_Teiichi_Prize_2.pdf
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