Industrial Flux

Soldering & Industrial Flux

Indium Corporation manufactures a broad range of fluxes for soldering and industrial use.

Industrial Flux

Indium Corporation offers a broad line of specialty materials and fluxes for soldering stainless steel, copper pretreatments, and more.

Industrial Fluxes
Formula Description
42-SS Industrial Flux for Stainless Steel

Industrial fluxes are available in 1-gallon and 5-gallon containers, and 55-gallon drums.

Liquid Soldering Fluxes

Flux #5R #5RMA #5RA
Description Heat Stabilized Resin-Based Flux Heat Stabilized Resin-Based Flux Heat Stabilized Resin-Based Flux
Soldering Temperature Range 125ºC - 350ºC 125ºC - 350ºC 125ºC - 350ºC
Metallization To Be Soldered Au, Ag, Pt, Pd, Clean Cu Au, Ag, Pt, Pd, Clean Cu, Sn, Solder Plate Ni, Rh, Cd, Brass, Bronze, BeCu, Pb, Oxidized Cu
Activation None Added Mildly Activated Fully Activated
Solids Content 47% 46% 44%
Water Resistivity Extract (ohm-cm) >100,000 >100,000 >50,000
Specific Gravity .90 .91 .88
Boiling Point 84ºC 84ºC 84ºC
Flash Point 11ºC 11ºC 11ºC
IPN 84072 84032 84039
Thinner #8300 (Part Number 84041) - all fluxes

Flux Removal

Since the post solder residues of types R and RMA fluxes are considered non-corrosive, non-conductive and non-hydroscopic, flux removal is not usually necessary. If cleaning is desired this is best accomplished with a commercially available flux residue remover.

Best practice is to always remove RA residues in electronics applications.

Standard Packaging

These liquid soldering fluxes are packaged in 2 different size plastic containers:

  • 1 U.S. pint (0.473 liter)
  • 1 U.S. gallon (3.785 liter)

NC-506 Flux

  • Suitable for Pin-Grid Array and standard Ball Grid Array applications
  • Excellent solderability to all common surface metallizations
  • No-clean residue
  • Can be used for printing, dipping, and pin transfer deposition
  • Offers high yields in BGA bumping process
  • Suitable for both Pb-Free or SnPb applications

Ball Attach Flux NC-506 is a low viscosity thixotropic no-clean flux designed for use in ball attachment to substrates (BGA manufacturing). It is especially useful in applications requiring soldering to surface finishes with tenacious oxides, such as nickel. It can also be used wherever a no-clean ball attach flux is needed, and is suitable for a variety of different deposition methods.

  Value Test Method
Flux type Classification: ROL1 J-STD-004 (IPC-TM-650: 2.3.32 and 2.3.33)
Typical Viscosity: 320kcps Brookfield HB DVII+ -CP (5rpm)
SIR (ohms, post cleaning): Pass (>109 after 7 days @ 85ºC & 85% RH) J-STD-004 (IPC-TM-650: IPC-B-24
Typical Acid Value: 103mg KOH/g Titration
Typical Tack Strength: 250g J-STD-005 (IPC-TM-650: 2.4.44)
Shelf Life: 6 months (-20°C to +5°C)* Viscosity change / microscope examination

All information is for reference only. Not to be used as incoming product specifications.

WS-366 Interconnect Flux

  • Excellent cleanability, residue can be removed with room temperature water
  • Can be used for printing, dipping, and pin transfer deposition
  • Offers high yields in BGA bumping process
  • Excellent solderability
  • Wide process window
  • Suitable for SnPb, Pb-Free, and high lead-containing applications
  • Designed for Flip-Chip applications

WS-366 Interconnect Flux is a high viscosity paste-type flux designed for use in BGA bumping and board level attachment. It can also be used wherever a water-soluble flux with excellent cleanability is desired.

Flux type Classification: H1
Color: Amber to brown
Stencil Life: >8 hours at room temperature
Shelf Life: 3 months at 0 to +30 °C
SIR (ohms, post cleaning): Pass (>109 after 7 days @ 85ºC & 85% RH)
Typical Viscosity:  
Brookfield: 425kcps at 5rpm
Halide Content: <3% Cl equivalent
Acid Value: 30-50
Tack Strength: 100-400g

All information is for reference only. Not to be used as incoming product specifications.

Fluxless Soldering

Some applications are very sensitive to the use of a flux due to the post reflow residue that may be present. Also, flux may be a problem in a vacuum environment or in an application in which it must be free of corrosive or volatile materials.

If gold is used for the outer metalization on the parts to be joined, acceptable wetting may be possible without the use of a flux. If this is not possible, a reducing atmosphere may be used to remove the oxides and result in sufficient wetting. Below are suggestions and helpful hints for choosing a reducing atmosphere that fits your application.

  • Common reducing atmospheres are:
    88% nitrogen, 12% hydrogen
    90% nitrogen, 10% hydrogen
    95% nitrogen, 5% hydrogen
    100% hydrogen
  • The higher the reflow temperature the more effective the oxidation removal using a reducing atmosphere. A reflow temperature that is 350°C and above is the best for oxide removal.
  • Nitrogen or argon is sometimes used in fluxless soldering because it prevents the formation of oxides during reflow. However, these gases do not remove preexisting oxides on the metalization, only the hydrogen can do that.

Fluxless soldering is also used when joining the two substrates together where flux residue would be detrimental to the operation of the final product. For example, voiding due to flux entrapment can result in poor performance because of reduced electrical or thermal conductivity.

In an application where a reducing atmosphere is not practical, two or more metalizations can be joined using flux in the initial pre-coating of the substrates. After precoating is complete, the flux residue can be removed using an appropriate solvent. The cleaned parts can then be assembled without a flux and reflowed a final time to join them. This method is especially effective when fairly large pieces need to be joined and flux entrapment can not be tolerated.

Liquid Tabbing Flux

Bringing decades of soldering expertise to the PV industry.
  • No-Clean, Clear Residue
  • Non-Conductive
  • Wider Process Window
  • Pb-Free and Sn/Pb
  • Non-Corrosive
  • Spray or Flux Bath Application
From One Engineer to Another®

Let the soldering experts at Indium Corporation solve your PV module assembly challenges.

Talk to an Indium PV Applications Engineer today.

Proven in PV module assembly processes, Indium Corporation's No-Clean Liquid Solar Tabbing Fluxes are non-corrosive, non-conductive, and provide excellent solderability on all types of silver metallizations. Formulated to provide a wide process window, Indium Corporation's Liquid Solar Photovoltaic Fluxes are compatible with Pb-Free and tin-lead alloys.

Liquid Tabbing Flux Product Specifications

Specifically developed for tabbing and stringing applications, Indium Corporation's Liquid Solar Fluxes work in popular module assembly processes utilizing conduction reflow, IR reflow, and convection reflow. Ideal for module assembly processes where high throughput is a necessity and minimum flux residue is a key requirement, Indium Corporation's line of Liquid Tabbing Flux provides excellent solderability on all type of metallizations.

Contact a PV Applications Engineer today to choose the right flux for your module.

Confirmed for use
with these alloys
Key Attributes
GS-5454 X - X - 62Sn / 36Pb / 2Ag
60Sn / 40Pb
96.5Sn / 3.5Ag
58Bi / 42Sn
57Bi / 42Sn / 1Ag
46Bi / 34Sn / 20Pb
Best for 'wet-reflow' applications

Quick activation at low temperatures allows use of alternate low temperature alloys

Excellent wetting to all types of metallizations
GS-3434 X - X - 62Sn / 36Pb / 2Ag
60Sn / 40Pb
96.5Sn / 3.5Ag
58Bi / 42Sn
57Bi / 42Sn / 1Ag
Invisible residue flux for Sn/Pb and Pb-free alloys
X X - X 62Sn / 36Pb / 2Ag
60Sn / 40Pb
96.5Sn / 3.5Ag
58Bi / 42Sn
57Bi / 42Sn / 1Ag
Non-flammable, non-hazardous

Quick drying

Specifically developed for pre-reflow evaporation applications
Liquid Tabbing Flux Packaging

Liquid Tabbing Flux is available in the following:

  • 1 gallon container (3400 grams)
  • 1 pint container (425 grams)
  • 1/2 pint container (212 grams)