Brazing & High-Temperature Soldering

Brazing & High-Temperature Soldering

Features & Benefits

Indium Corporation is the leading joining and bonding materials innovator for semiconductor packaging and assembly and PCB assembly applications. With over 200 alloys available, we have alloy solutions for temperatures up to 1,100°C.
Brazing & High-Temperature Soldering
High Temp Scale

Semiconductor Packaging and Assembly Applications:

Standard Semiconductor

Standard Semiconductor

For wafer and substrate-bumping applications, lead (Pb)-containing solders have been used for many years. Although 95Pb/5Sn and 90Pb/10Sn are the most common, the lower melting eutectic solder was prevalent for many years.

Most recently, these solders have been replaced by Sn-based Pb-free solders; however, the majority of cutting-edge applications, such as copper-pillar/microbump, have moved to a low-silver plated solder. Additionally, some very fine pitch temperature-sensitive applications now use pure indium or InAg-plated bumps.

Indium provides fine powder “eutectic” solder paste for both wafer and substrate solder deposition, including low and ultralow alpha solders. We also provide plating bath chemicals.

2.5D and 3D chip-stacking
  • Wafer bumping fluxes
  • Wafer bumping solder pastes
  • Copper pillar flip-chip fluxes
  • Standard flip-chip fluxes
  • Standard flip-chip fluxes
  • Wafer bumping and substrate-bumping solder pastes
Wafer level CSP ball mount
  • WL-CSP ball-attach fluxes
  • Specialty solder spheres
  • Ball-attach fluxes
  • Specialty solder spheres
Package-on-package and fine-pitch component attach
  • PoP pastes
  • PoP fluxes
Specialty component attach
  • Epoxy fluxes

Power Semiconductor

The selection of lead-based alloys for power semiconductor applications is very large, and their usage is likely to continue into the future; however, some long-standing Pb-free alloys and some novel high melting Pb-free solder paste technologies are used in specific applications.

  Standard Materials °C
Comments Sn Ag Sb Pb In Ge Solidus Liquidus
Commonly used in step soldering with higher Pb solders 5   10 85     240°C 256°C
Excellent thermal cycling and fatigue resistance       81 19   260°C 275°C
Excellent thermal cycling and fatigue resistance   2.5   92.5 5   300°C 310°C
Automotive and similar usage 5     95     308°C 312°C
Automotive and similar usage 10     90     275°C 302°C
Old standard alloy for die attach, but poor thermal cycling 10 2   88     268°C 290°C
Industry standard for silicon die-attach 5 2.5   92.5     287°C 296°C
Alternative alloy for silicon die-attach 2 2.5   95.5     299°C 304°C
  Standard Materials °C
Comments Sn Ag Sb Au Bi Ge Solidus Liquidus
Lower Tj IGBT usage 96.5 3.5         221°C Eutectic
Also known as "J-alloy" 65 25 10       233°C Eutectic
Commonly used in step-soldering processes 95   5       237°C 240°C
Highest Sb content possible in standard Sn/Sb wire 91.5   8.5       241°C 248°C
Commonly used in step-soldering processes 90   10       243°C 257°C
Highest melting standard Sn/Sb alloy 86   14          
Very poor solder-ability   11     89   262°C 360°C
Very high tensile strength and thermal / electrical conductivities 20     80     280°C Eutectic
Usable for very high Tj die-attach such as SiC       88   12 356°C Eutectic
  • Die-attach solder pastes
  • Die-attach (SSDA) wire

There are other specialty assembly materials that are used in a variety of different applications, such as solder spheres, as well as gold-tin and indium-containing solder pastes, wire, and preforms.

Au and Ag soldering and brazing applications

Indium Corporation is a leading joining and bonding materials innovator for medical, aerospace, optoelectronics, and automotive applications. When even 10 ppm of contamination can cause process and application failures – quality counts. Indium Corporation casts our alloys, which enables us to closely control the process from start to finish and ensure purity.

High-Temperature Solder and Braze Materials Deliver:

  • Highest tensile strength of any solder
  • High melting point is compatible with subsequent reflow processes
  • Pb-free and RoHS compliant
  • Superior thermal conductivity
  • Resistance to corrosion
  • Superior thermal fatigue resistance
  • Good joint strength
  • Excellent wetting properties
  • Resistance to oxidation
Laser Opt Packaging

Gold-tin (AuSn) Solders

  • Die-Attach: Thermal requirements often mandate a high-melting die-attach solder. With a melting point of 280°C, eutectic AuSn often satisfies these demands.
  • Hi-Reliability Applications: AuSn is compatible with gold metallizations. Coupled with its long-term reliability, AuSn is a good choice for high-reliability applications such as microwave systems, medical and aerospace applications, and more.
  • Lid Sealing: AuSn has excellent wetting properties. Its relatively low melting point (when compared to certain die-attach alloys) and its long-term reliability makes AuSn popular for lid sealing applications.
  • Braze Alternative: Eutectic AuSn, with a tensile strength of 275 MPa (40,000 pounds/square inch), provides a great alternative to brazes when high strength must be achieved at soldering temperatures.

Gold Preform Quick Turn Program

Need a gold preform right away? Contact us for our Quick Turn Program:
  • Designed to deliver parts quickly and affordably
  • New design, new tool, prototype quantities in 1-2 WEEKS
  • Engineering support from design to production
  • Gold and Gold-Based Solders in a Variety of Forms

Need a gold preform right away? Contact us for help choosing the right materials for your brazing and soldering applications.

Gold Preform Facility

Preforms and Ribbon

  • Thickness from 0.0127mm (0.0005”) and greater
  • Tight dimensional tolerances ensure repeatable solder volume
  • Flatness measurement capabilities to 0.00254mm (0.0001”)
  • Large die library with in-house tooling capabilities
  • Tiny solid shapes from 0.152mm (0.006”)
  • High aspect ratio and complex special shapes


  • Diameter starting at 0.025mm ± 0.0127mm (0.001” ± 0.0005”)
  • Tight dimensional tolerances
  • Packaging designed to minimize breakage of wire in soldering process
  • Maximum of 80% Au

Capillary Blocks®

  • New technology for brazing hermetic packages
  • Cost-efficient alternative to cut wire and frames
  • Doesn’t shift during movement and reflow
  • Increases yields and lowers cost of ownership


  • No-clean and water-soluble
  • Type 3-6 AuSn powder
  • Gold/Tin Paste with Type 7 powder size (2-11 microns)


  • Sizes starting at 0.254mm (0.010”)
  • Tight dimensional tolerances down to +/- 5 microns
Gold and Braze Materials for Hermetic Sealing
Auto LED Mod

Benefits of High-Temperature Alloys

  Attributes Alloys Temperature
Gold-Based Alloys Strong bond strength, excellent corrosion and oxidation resistance, and good thermal and electrial transfer at the braze joint. Indalloy®182 (80Au/20Sn)
Indalloy®183 (88Au/12Ge)
Indalloy®178 (82Au/18In)
Indalloy®195 (80Au/20Cu)
Braze Indalloy®B955 (50Au/50Cu)
Braze Indalloy®B9902 (65Cu/35Au)
Indalloy®200 (100Au)
96.8Au3.2Si used for die-attach
280°C Eutectic
356°C Eutectic
Solidus 451°C / Liquidus 485°C
891°C Eutectic
Solidus 955°C / Liquidus 970°C
Solidus 990°C / Liquidus 1010°C
1064°C Eutectic
363°C Eutectic
Silver-Based Alloys High thermal and electrical conductivity, capillaries very well into joints, and holds up well in applications with lots of stress and with CTE mismatches. Braze Indalloy®B625 (61.5Ag / 24Cu / 14.5In)
Braze Indalloy®B6851 (63Ag / 27Cu / 10In)
Indalloy®193 (72Ag / 28Cu)
Braze Indalloy®B962 (99.99Ag)
Solidus 625°C / Liquidus 705°C
Solidus 685°C / Liquidus 730°C
780°C Eutectic
962°C Eutectic

Precision Packaging

Indium Corporation’s packaging protects your solder preforms during shipping and handling, and is designed for ease of introduction into the manufacturing process.

  • Jar or bulk pack
  • Array tray pack
  • Waffle pack
  • Bulk tray pack
  • Tape & reel

We also can create customized packaging solutions to meet your needs and processes.