Seiko Instruments Inc.


One second to enrich your life

Better life generated by solid technology

Our tuning fork quartz crystals were developed as the heart of quartz watches. If a one-second gap occurs, everything will go wrong.
We continue to provide high quality and high reliability in response to the strict demands and time accuracy required of such timepieces.
More convenient, easier to use, and more appealing… the desires of people never cease.
The challenge continues over time towards developing technology that can address these desires.


Addressing society’s needs through our technical philosophy of Craftsmanship, Miniaturization, and Efficiency.

Along with the miniaturization and increased high functionality of various electronic devices, there is increased demand for the miniaturization and high precision of quartz crystals that address high-density mounting. There are only a few companies around the world that have successfully made photolithography technology* a reality.

We have adopted this technology as early as possible to handle the thinning and mass production of quartz watches. This enabled the miniaturization and high productivity of quartz crystals. Furthermore, with our strengths though our technical philosophy of Craftsmanship, Miniaturization, and Efficiency, we offer high-quality, high-reliability quartz products that meet diverse needs by utilizing the latest technology such as FEM simulation and high-efficiency automation lines.

*Photolithography technology: A technology that creates a fine pattern on a quartz wafer by applying photo exposure technology.

  • Ceramic package type

    Ceramic package type

    The ceramic case package products were developed to address the market requirements for high density mounting. Recognized for their high precision and reliability and their continuous response to small products, they have been widely adopted in “internet of things” (IoT) products such as smartphones, smart watches, and healthcare devices.

  • Cylinder type

    Cylinder type

    This type has photolithographically processed tuning fork quartz crystals, which are characterized by high precision and reliability, built into a cylinder case. These products are recognized for their high precision and reliability and are used in products that require time management such as watches and clocks, industrial meters, and security devices.

  • Plastic mold type

    Plastic mold type

    This type has the tuning fork quartz crystal sealed in resin according to the surface mounting requirements of certain electronic components. These products are known for their high precision and reliability characteristic of photolithography and are used in products such as laptop PCs, home appliance, and security cameras.

  • Process chart

    SII Crystal Technology uses fully integrated manufacturing from the cutting process of quartz raw materials to application parts such as quartz crystals and oscillators.
    Our processing technology for fine-processing of hard and brittle material, photolithography, and precision assembly; circuit technology for reliable oscillation of processed products in a circuit; and technology to precisely measure these constitute our three core technologies cultivated through our watch production.

    Process technology

    Process chart

    Product details page

    Move to the site of Seiko Instruments Quartz Crystal Division.

    Our Vision

    Better life generated by solid technology

    We are surrounded by various types of electronic devices such as smartphones, tablets, TVs, and game consoles. These electronic devices are all standard with a quartz crystal that generates an electronic signal for their correct operation.

    SII Crystal Technology offers quartz crystals that meet the needs of society, taking advantage of the small size, high precision, and high reliability technologies cultivated over many years through the development and manufacture of quartz crystals for quartz watches.

    In our world today, IoT devices, which comprise various items connected to the internet, continue to increase. We will move forward providing high-precision, low-power consuming quartz crystals, and while supporting the realization of the IoT world, we will contribute to its future development.

    Realization of low-power consumption

    About Us

    Company Profile

    Company name SII Crystal Technology Inc.
    Head office 1110, Hirai-cho, Tochigi-shi, Tochigi 328-0054, Japan
    Tel: (+81) 282-24-1212 (Representative)
    Establishment April 2013
    Business description Development and manufacture of quartz-related products such as quartz crystals
    Capital 100 million yen
    Fiscal year-end March (once per year)
    Number of employees 223 (As of the end of February, 2024)
    Board of director President Tomitsuka Koji

    SII Group

    The Seiko Group is well-known throughout the world as a leading watch brand maker.

    SII Crystal Technology, a member of that Group, began its operations in Tochigi in April 1955 as a specialized factory for watch bearing stones and now the company manufactures products such as quartz crystals for quartz watches and has expanded its corporate activities globally by establishing a production base also outside of Japan.

  • Head office: Tochigi

    Head office: Tochigi

    SII Crystal Technology Inc.

  • Japan site: Makuhari

    Japan site: Makuhari

    Seiko Instruments Inc.

  • Overseas site: Singapore

    Overseas site: Singapore

    Asian Electronic Technology Pte. Ltd.

  • History

    Establishment of Tochigi Koseki Kojo in Hinode-cho,
    Tochigi City as a factory dealing with bearing stones for watches
    Construction of a new factory in Hirai-cho, Tochigi City
    Start of watch assembly work at the new factory
    Start of work on electronic circuits for quartz (crystal) watches
    Start of work related to quartz crystals
    Tochigi Koseki and Sendai Precision Materials Laboratory merge
    as equals establishing a company under the name Seiko Electronic Components Co., Ltd.
    Establishment of subsidiary in Singapore as production base for quartz crystal business
    Establishment of SII Quartz Techno Co., Ltd. to take over the quartz crystal business by dissolving Seiko Electronic Components Co., Ltd.
    Acquisition of ISO9001 certification
    Acquisition of ISO14001 certification
    Acquisition of QS9000 certification
    Merger with Seiko Instruments Inc. and change in company name
    Receiving the Kanto Bureau of Economy, Trade and Industry Director’s Award as a factory of excellence for energy management from the Kanto Region Electricity Use Rationalization Committee
    Completion of a new building (Building A)
    Acquisition of ISO/TS16949 certification
    Establishment of SII Crystal Technology Inc. as a spin-off of the crystal business of Seiko Instruments Inc.
    Receiving Award of Excellence from the National Total Health Promotion Plan Council
    Acquisition of IATF16949 certification

    Corporate Social Responsibility
    / Environment

    Environmental Activities

    In order to reduce raw materials such as crystals, chemicals, metals, water, energy, and wastes used in manufacturing processes, we manufacture many quartz crystals from a single wafer. Furthermore, we continue to promote a number of environment-friendly activities, including the use of LEDs for external lighting, the reduction of fuel oil and electricity consumption, and the installation of an emergency shutoff valves to reduce the risk in the event of a leakage emergency.

    Click here for company site report

    Community Relations

    We are always thinking of coexistence with nature at our factory located in the corner of Ohirasan Prefectural Natural Park, as our buildings use highly rated insulation materials as well as an inverter control for lighting and power systems including air conditioning, cutting the CO2 emissions to the utmost. In addition, we are actively working towards contributing to the community and improving employee health through actions such as accepting internships of students and participating in the Total Health Promotion Plan (THP) walking event as well as activities to clean the Nagano-gawa River, which flows through the city.