TANAKA is strengthening its business for semiconductors. Using the knowledge of precious metals developed over many years of experience as its strength, the company is also looking at expansion into emerging semiconductor markets such as India. Now, out of the products TANAKA exhibited at SEMICON India 2025, we will be introducing three products: silver adhesive pastes for die bonding, bonding wires, and probe pin materials.

Celebrating its 140th anniversary in 2025, TANAKA is strengthening its business for semiconductors at a faster pace. While TANAKA is well known for products such as asset bullion and coins as well as precious metals jewelry, its industrial business—including materials for semiconductors—makes up 70% of its total revenue base. Looking just at its products for semiconductors, TANAKA offers a wide-ranging product lineup, from front-end to back-end processes, covering everything from general-purpose chips to cutting-edge chips. While the company has been strengthening its globalization efforts for some time, it is also positive about entering emerging markets in the semiconductor industry, such as its inaugural participation at SEMICON India 2025, an international semiconductor exhibition held in Delhi, India from September 2 to 4, 2025.

Now, out of the products exhibited at SEMICON India 2025, we will be introducing three products used in semiconductor manufacturing. TANAKA stressed that many visitors came to its booth, and the company felt that all of its products were well received.

TANAKA’s booth at SEMICON India 2025 (source: TANAKA PRECIOUS METAL TECHNOLOGIES Co., Ltd.)

Hybrid silver adhesive pastes with both thermal cooling and reliability

TANAKA produces silver adhesive pastes for die bonding, which is used for bonding semiconductor chips to lead frames.

Silver adhesive pastes for die bonding mainly fall into resin-bonding types and sintering types. Sintering types, which adhere using metallic bonding, are made from silver (Ag) and a solvent. They have high thermal and electrical conductivity, but if there is a difference in the thermal expansion coefficient with the substrate, peeling or cracking can occur, reducing reliability. On the other hand, resin-bonding types, including epoxy resins, adhere using hydrogen bonding. They are low in stress and high in reliability, but their thermal conductivity is not as good as that of sintering types.

• TANAKA offers the TS-985 series of hybrid sintering silver adhesive pastes that bond using both metallic and hydrogen bonding. This series combines the best of both resin-bonding and sintering types. It is characterized by having both high thermal and electrical conductivity as well as reliability. “Today, adhesives for die bonding are required to have better thermal cooling ability due to the evolution of power semiconductors. We can meet such needs,” explained Yoshinori Fushimi, Product Manager for silver adhesive pastes at TANAKA.

  The TS-985 series can also be used as an alternative to lead (Pb) solder. Fushimi said, “Lead solder has been widely used because it is low in cost and hardens quickly. However, environmental regulations are currently being implemented, primarily in Europe. Therefore, many companies are refraining from using lead solder in anticipation of the future. Demand for the TS-985 series from such companies is steadily increasing.”

• 
  Yoshinori Fushimi,
  Product Manager for Silver Adhesive Paste,
  Product Sales,
  TANAKA PRECIOUS METAL TECHNOLOGIES Co., Ltd.

Another feature of the TS-985 series is its compatibility with copper (Cu) lead frames. The reliability of adhesives for die bonding varies depending on their compatibility with the lead frame material. Copper is the mainstream material for lead frames, while most adhesives for die bonding contain silver. However, as bonding compatibility is the highest between the same materials, there are times when lead frames are plated with silver. The TS-985 series is highly compatible with copper lead frames and can be used without plating even though it is a series of silver adhesive pastes, eliminating the plating process and resulting in cost reduction.

TANAKA has sites for research and development as well as manufacturing of silver adhesive pastes for die bonding in Kanagawa Prefecture’s Hiratsuka City and also in Singapore. Fushimi said, “Many of our customers are manufacturers of power semiconductors who have plants in Southeast Asia. TANAKA took the lead in setting up a site for research and development as well as manufacturing in Singapore, close to our customers, and has strengthened communication and support.”

Going forward, TANAKA will improve thermal cooling while maintaining its products’ strength of not requiring plating.

Bonding wires with a high market share and uninterrupted supply even during the COVID-19 pandemic

TANAKA has a long history of manufacturing bonding wires—which electrically connect the electrodes of semiconductor chips and printed circuit boards—for over 60 years, securing a large market share.

• TANAKA ELECTRONICS has seven manufacturing sites: one in Saga Prefecture’s Yoshinogari Town, which also serves as its research and development site, as well as one each in Singapore and Malaysia, and two each in China and Taiwan. This allows the company to reduce supply chain risk, serving as one of its strengths. Toshiteru Ogawa, who is in charge of bonding wires at TANAKA ELECTRONICS, said, “We have a system in place that allows us to produce all products at several sites, allowing us to continue supplying products without interruption even during the semiconductor shortage of the COVID-19 pandemic. Today, reducing supply chain risk is becoming increasingly important for semiconductor manufacturers due to changes in the global situation, and TANAKA is able to help through stable supply.”

• 
  Toshiteru Ogawa, Chief Manager,
  Product Management Department,
  TANAKA ELECTRONICS Co., Ltd.

The wire materials available include gold (Au), silver (Ag), copper (Cu), aluminum (Al), and palladium (Pd) coated copper (PCC). For wire types, besides the usual thin wires and thick wires for power devices, wide ribbon wires—which can increase the cross-sectional area without increasing the thickness compared to round wires—are also offered. Given the trend toward thinner bonding wires to reduce costs, TANAKA has also achieved an ultra-thin wire with a diameter of 10 μm in the research and development stage.

TANAKA customizes bonding wires to meet customer specifications, such as hardness and elongation. In addition, it uses its knowledge of precious metals to propose solutions, including bonding expertise such as compatibility between electrodes and wire materials.

Ogawa said, “We will continue to undertake development matching our customers’ directions. We hope to meet a wide range of customer requirements using our many years of experience in dealing with bonding wires.”

Probe pin materials that eliminate the trade-off between electrical resistance and hardness

• There are also products offered for test processes. These are probe pin materials, which are used in wafer testing, the final stage of pre-processing, and final testing, the last stage of post-processing.

  In wafer testing, high electrical resistance in probe pins generates heat and reduces test accuracy, such as causing good products to be judged as defective. Therefore, there is strong demand for probe pin materials to have low electrical resistance.

  In response to this demand, TANAKA launched the low-resistance Pd-alloy material TK-FS in 2023. It significantly reduces electrical resistance compared to conventional products while also maintaining high hardness. Takeshi Fuse, deputy product manager for probe pin materials at TANAKA, explained, “We eliminated the trade-off between electrical resistance and hardness using our unique composition and manufacturing methods.”

• 
  Takeshi Fuse, Section Manager,
  Materials Development Section, Isehara Plant,
  Manufacturing Management Department,
  TANAKA PRECIOUS METAL TECHNOLOGIES Co., Ltd.

TK-FS has both hardness and low electrical resistance (source: TANAKA PRECIOUS METAL TECHNOLOGIES)

Furthermore, a typical metal material is more likely to crack or break the harder it is. Meanwhile, TK-FS has high levels of bending durability and elongation. As cantilever probe pins with bent tips are widely used in wafer testing of logic ICs and such, TANAKA conducts its own repeated bending tests on TK-FS.

TK-FS is sold as a custom product, and its hardness can be freely customized with the range of 400 HV to 520 HV.

On the other hand, in final testing, test accuracy is determined by the entire system, not just the probe pin itself. Therefore, electrical resistance is not as high a priority as it is in wafer testing. Instead, hardness is extremely emphasized as the tip of the probe pin wears out when it comes into contact with the test subject.

In 2024, TANAKA launched the Pd-alloy material TK-SK to meet such requirements. Traditionally, the hardness of Pd alloys “has been considered to be around 560 HV at most,” said Fuse. TK-SK exceeds this limit, offering a maximum hardness of 640 HV. Commercialization was achieved by combining the wealth of development data that had been accumulated over the years with a new manufacturing method specialized for hardness.

TK-SK has hardness equivalent to non-precious metal high-hardness materials
(source: TANAKA PRECIOUS METAL TECHNOLOGIES)

Materials used as probe pin materials include non-precious metal high-hardness materials such as beryllium copper (BeCu) alloys. Non-precious metal high-hardness materials feature high hardness, but they also oxidize easily and require plating to prevent oxidation. However, Pd alloys can be used without plating. Fuse stated confidently, “TK-SK is a material that has hardness at least equivalent to non-precious metal high-hardness materials while having oxidation resistance that does not require plating. It is like a superior replacement for non-precious metal high-hardness materials.”

“There is also feedback to further reduce electrical resistance for power semiconductor wafer testing and such,” Fuse added. The company will continue to carry out development while confirming customer needs.

Becoming a reliable partner for semiconductor manufacturing with many years of knowledge and trust

TANAKA uses its deep knowledge of precious metals and many years of experience to provide a wide range of products that are essential to semiconductor manufacturing processes. Besides product quality, TANAKA also offers stable supply and has a solid support system in place, making it an increasingly reliable partner for semiconductor manufacturers and inspection equipment manufacturers who emphasize reliability.