Gold-Tin Alloys for Brazing Overview

Features

• Gold-tin alloys of various compositions are available to suit each application.
• Improved gold-rich layer
• Excellent sealing reliability with fewer defects such as voids
• Sealed devices can be mounted on circuit boards using lead-free solder.

Types

Processed Products

Application

Semiconductor laser modules, optical devices, SAW filters, crystal oscillators, microwave radar components, lead frames, lead pins, ceramic packages, etc.

Gold-tin brazing lids for crystal oscillating devices (Window type)

Application Example – Fusion Products

Features

• The gold rich layer can be improved (bonding and sealing properties) by optimally adjusting gold and tin compositions according to the thickness of gold on the material surface.
• Can be fused not only to ceramics but also to metalized substrates and conductive surfaces.
• High dimensional accuracy with up-to-date equipment
• Shorter assembly process and improved product yields

Changes in the cross-sectional structure of the lid with different Au/Sn compositions

AuSn20

AuSn21.5

Examples of fused products

• Customer supplied materials
  • Conductive surfaces of ceramics
  • Heat sinks and lead frames
  • Semiconductor or compound devices
• Lead pins (Ni/Au plating) … Base materials: Kov, FeNi, Cu, Fe, etc.
• Lids (plates/stamped pieces) … Base materials: ceramic, Kov, FeNi, etc.
• Gold-tin brazing lids for package sealing (AuSn lid on the upper section and SKe-Lid on the lower section)
• Our developed lid for sealing small crystal oscillating devices (Window type) is designed so that gold-tin alloy does not flow into the lid when it is sealed, providing a highly reliable seal with a smaller amount of gold-tin alloy.

Quartz glass lid with AuSn for deep ultraviolet LEDs: SKe-Lid

Employed proprietary technologies that properly control the shape and dimensions when applying the AuSn sealant to the quartz glass. Possible to control cracking and metallization separation for obtaining higher yields to contribute to improved productivity and lower costs.

■Features

• By using quartz glass as a cover material (AR coating is also available), the transmissivity of high-output deep ultraviolet LEDs can be increased
• The AuSn solder is already applied to the glass, facilitating the positioning with the ceramic package during sealing
• AuSn airtight sealing raises reliability and durability
• The use of our proprietary technology controls the formation of cracks during application of AuSn to quartz glass with high transmissivity of deep ultraviolet wavelengths and ceramic package sealing

As the shift to SMD (Surface Mount Device) proceeds and advances are made in autonomous vehicles, AuSn sealing will likely be used in devices that require transparent covering materials, such as semiconductor lasers, which demand high reliability and durability, and automotive sensors.