Precious Metal Wire and Precious Metal Coated Wire Materials (Bonding Wire)

  • * Source: SEMI Industry Research and Statistics/TECHCET, April 2020

Core Technologies

Technologies Created by Handling Precious Metals

Through the manufacturing of bonding wires, TANAKA Denshi Kogyo has developed advanced metal processing technologies, such as gold (Au), silver (Ag), copper (Cu), and aluminum (Al) ultra-fine wires, precious metal coatings, high-purity melting, and micro-rolling. TANAKA Denshi Kogyo will employ these technologies to contribute to fields such as jewelry, medical, automobile, next-generation communications, and energy saving.

Ultra-Fine Wire

TANAKA Denshi Kogyo’s area of specialization is drawing ultra-fine precious metal wire. Drawing is a processing technique in which a metal material is pull through a tool known as die and make it thinner into a wire shape. We use proprietary drawing technology accumulated over many years and uses dozens of dies to painstakingly reduce the diameter of wire, achieving precious metal wire drawing with diameters as small as 10 μm. In combination with original winding technology, we can product ultra-fine wire with a length in excess of 5,000 m.

High-Purity Melting

Proprietary melting technology enables us to manufacture high-purity alloys by introducing additive elements on the ppm level. In addition, we use original vacuum melting technology to provide high-purity materials. We control crystalline structures through optimization of drawing and heat treatment processes and can provide products with extremely high uniformity, even minute wires with diameters of tens of microns.


Rolling is a process in which a meal material is introduced to rotating rollers to manufacture a thin, flat ribbon material. By using proprietary technology for rolling wire ranging from 100 μm to 600 μm, we are able to produce ribbon materials with burr-less end faces that cannot be manufactured using slit processing. In addition, we provide products with semiconductor quality using mirror rolling that reduces surface irregularities to an average of 1 μm or less and surface cleanliness control equivalent to that used for bonding wires to order to meet the needs for high bondability for automotive devices.

Precious Metal Coatings

To respond to all semiconductor mounting needs, we use proprietary processes to manufacture pure wire with precious metal coatings applied to provide various functions. For example, recently we successfully achieved dramatic improvement in the oxidation and corrosion resistance of copper wiring by applying a coating of palladium, a precious metal.

Manufacturing Processes that Support the World’s Leading Market Share

Integrated Production in Clean Rooms

All processes from melting to drawing and winding are performed in clean rooms that are rigorously managed. This makes it possible to provide extremely clean products with little surface contamination.

Bonding Wire Manufacturing Flows

  1. 1. Melting

    In this process, high-purity metals and trace amounts of additive elements are melted and alloys with various functions are cast.

  2. 2. Drawing

    Tools known as dies are used to make the metal thinner and draw it into wire.

  3. 3. Annealing

    In this process, the wire is annealed to change its crystalline structure and adjust the hardness.

  4. 4. Coating

    A coating of precious metal is applied to the wire surface to provide anti-corrosion, anti-oxidation, and other functions.

  5. 5. Winding

    In this process, the manufactured wire is wound in a spool while taking care to minimize any damage.

TANAKA Denshi Kogyo’s New Challenges

TANAKA Denshi Kogyo is taking up the challenges of new fields using its accumulated technologies with the aim of create value in new areas.

For Medical

Wire Rods for Medical Applications

Soft gold wire is an optimal precious metal wire for use as a marker in minimally invasive procedures such as catheterization and with guide wires. To enhance the accuracy of radiation therapy, we provide high-purity, high-strength gold wire that X rays do not easily pass through, making it highly visible.


  • ○High purity (at least 99.99%)
  • ○High X ray impermeability
  • ○Low contamination
  • ○Wire diameters from 10 μ to 100 μm
  • ○High biological safety (unsafe elements are not used)

※The purity, diameter, and other parameters can be customized.
 Please inquire.

Ultra-Small Gold (Au) Pin (φ60 um×L55 um)

As gold wires of high purity are soft, it is difficult to make ultra-small pins through cutting. Our gold wires can be used to manufacture ultra-small pins with diameters down to φ60 um while having a purity of 99.99%. We can provide small samples for tests.


  • ○High purity (at least 99.99%)
  • ○Low contamination
  • 〇Small tolerance of cutting length

※ As this product is still being developed, please inquire about details such as other types of metals, including alloys, and dimensions.

The Future that TANAKA Denshi Kogyo Sees: Entering New Business Fields

About TANAKA Denshi Kogyo, Supporting the Semiconductor Industry

World’s Leading Provider What are Bonding Wires?

Solving Customer Problems Through Product Development: Examples of Solutions from TANAKA Denshi Kogyo

  1. 80% Reduction in Material Costs with Silver Bonding Wire

    With just a small capital investment, material costs can be reduced by 80%.Silver bonding wire exhibits excellent durability, conductivity and speed of production.
    Chipmaker;E Inc.

  2. Copper Bonding Wire With Better Performance than Gold

    Use of copper bonding wire reduces material costs by 90% to resolve the issue of steeply rising gold prices impacting profits.
    Chipmaker;M Inc.

Technical Data Download

Technical data can be downloaded from the banner below.

Download technical data

Contact TANAKA for more information on products and case studies. Online enquiries 24 hours a day!

Contact us for further information or materials (24 hours a day)