Active Brazing Filler Metals

Consumer Electronics Semiconductor Joining and Sealing (Packaging) Joining materials Sheets, Wires, and Tubes

Appearance of active metal brazing products and press sample of active metal brazing material / copper composite material

What is Active Brazing Filler Metal?
Active brazing filler metal is a specialized brazing material designed to bond non-metallic materials, such as ceramics and carbon, without prior metallization. It enables high-temperature bonding under vacuum conditions and is widely used in high-reliability applications, including power semiconductor modules, sensors, and aerospace components.

Bonding of various ceramics

Our active brazing filler metals enable brazing of various ceramics, regardless of whether they are oxides or nitrides, without metallization.
We also provide composite materials of copper and active brazing filler metals that are expected to be used for applications such as ceramic circuit boards, and heat dissipation parts such as heat sinks, for power devices.

Active Brazing Filler Metals

Features

Active brazing filler metals are brazing fillers with added titanium (Ti) to enable direct brazing of ceramics, which cannot be bonded using general brazing fillers.
They enable brazing of a range of materials, including alumina and other oxide ceramics, silicon nitride, and carbon.
A unique alloy composition with added tin (Sn) enables fine dispersion of titanium when added to brazing fillers. This enables provision in sheet thicknesses of 50 µm.

Cross-sectional structure of rolled material

Cross-sectional structure of conventional AgCuTi alloy used as active brazing filler metal (rolled material) — **AgCuTi Alloy**
Contains coarse CuTi compounds in within the AgCu matrix

Cross-sectional structure of active brazing filler metal (rolled material): TKC-661 - AgCuSnTi alloy — **AgCuSnTi Alloy**
Thin sheet manufacture and supply enabled by fine dispersion of SnTi compound

Types

Product name	Main component (wt%)
Product name	Ag	Cu	Ti	Sn
TKC-661	66	29.5	1.5	Remaining

Physical Properties

Product name	TKC-661	(comparable product) BAg-8
Specific gravity	9.7	10.0
Solidus (℃)	745	780
Liquidus (℃)	780	780
Hardness (HV)	113	90
Tensile Strength (MPa)	356	294
Young's modulus (GPa)	85.0	97.0
Coefficient of linear expansion (×10^-6/℃)	18.6	17.1
Thermal conductivity (W/mK)	102.0	311.0
Ceramic bonding	〇	×

Product format

Shape	Dimensions
Wire	Diameter: 0.2 mm or more
Sheet	Width: 120 mm or less Thickness: 0.05T or more

Forms of active brazing filler metal: rolled material and wire

Examples of Bonding

Examples of Joining Alumina — Alumina-to-alumina bond :
830℃ vacuum brazing

Four-Point Bending Test Results (Alumina)

Exterior of test piece

Fracture strength measurements

Comparison of Fracture Strength in Four-Point Bending Tests of BAg-8 and TKC-661 — Comparison of Fracture Strength in Four-Point Bending Test

Bond interface fractures were observed when using BAg-8 (metalized), whereas base material fractures were observed when using active brazing filler metals.
Testing confirmed sufficient strength was achieved for bonds that use active brazing filler metals.

Cross-sectional observation (SEM)

Results of EDX surface analysis of brazing bond interfaces： Al₂O₃

EDX surface analysis of soldering interface: Cross-sectional SEM of Al2O3

Titanium layers were formed at both the ceramic and brazing filler interfaces.
It is assumed that a compound layer consisting of Al-Ti-O is formed at the interface between the Ti layer and alumina.

Active Brazing Filler Metal/Copper Composite Material

Pressed pieces of active metal brazing material / copper composite material — Left: Composite (copper side)
Right: Composite (active brazing filler metal side)

New material will contribute to heat dissipation when used in next-generation heat sinks for power devices

This product is made by combining (cladding) active brazing filler metal on one side of copper (Cu) material. Since it can be joined directly to any material including ceramics (oxides, nitrides, and carbides) and carbon materials, it is expected that it will be used in ceramic substrates and next-generation heat sinks for power devices.

Features

Improved Performance
— The thick copper electrodes needed for high heat dissipation heat sinks can be formed directly on ceramics, and even finer wiring pitch is possible, which was difficult to do with existing etching processes.
— Since the material does not contain any solvents, there is no residue and bonding reliability is improved.
Cost reduction
— The brazing filler thickness can be 10 µm or less, which means that compared to earlier active brazing filler metal, silver bullion costs can be reduced by half or more and the brazing filler thermal resistance is halved.
— The copper material is compounded, which means that a pattern can be formed simply by setting the material, reducing processing costs.
Environmental impact reduction
- Since the material contains no solvents, volatile organic compounds (VOCs) are not released.
- The brazing time can be greatly reduced, which leads to energy savings and can be expected to reduce environmental impact.

～Enables both higher thermal conductivity and reduced processes～

Substrate model using the proposed method

Contributing to Power Device Market
Market for environmentally friendly vehicles such as electric vehicles (EVs) and hybrid vehices (HVs), etc.
High-Power Laser Diode Market
Contributing to the Next-Generation Heat Sink Market

Higher outputs and increased efficiency are demanded, and in conjunction with this, heat generation is rising. As a result, providing individual components with high heat dissipation, high thermal resistance, and high bonding reliability, and developing materials that are compatible with even further miniaturization, are urgent priorities for the industry.
Therefore, it is necessary to increase the thickness of the copper sheet
This product makes it possible to form electrodes on a thick copper material and enhances bonding reliability by not using etching, so it can be expected to contribute to higher heat dissipation.