Lead-Free (Pb-Free)

Lead-Free (Pb-Free)

Indium Corporation is proud to be your premier supplier of Pb-free solder paste.

No-Clean Pb-Free Solder Paste

As a leader in soldering technology, Indium Corporation offers a number of solder pastes for Pb-free assembly. We offer many different alloy choices and flux technologies to solve many of your process challenges.

Indium Corporation’s Pb-free solder pastes are ideal for miniaturized components and fine-pitch assembly. They provide first-class printing and robust reflow performance and are all designed to AVOID THE VOID®.

Pb-Free Water-Soluble Solder Pastes

Over the last decade, the electronics industry has shifted to no-clean fluxes for surface mount assembly. Despite this industry trend, Indium Corporation has not only maintained a variety of water-soluble solder pastes and fluxes, but has revolutionized the category with the release of several new and versatile solder pastes. These solder pastes allow current water-wash manufacturing processes to not only survive, but to thrive.

Indium6.6HF is a new water-soluble halogen-free solder paste that is complementary with both Sn/Pb and Pb-free alloys. It is designed to provide exceptional printing performance and minimize voiding in PCB assembly applications. Indium6.6HF exhibits superior wetting to a variety of surface finishes resulting in the fewest number of voids, a reduction in the size of the largest void, and minimized overall voiding. Other benefits include:

  • Halogen-free per IEC 61249-2-21 test method EN14582
  • Exceptional printing process window:
    • High transfer efficiency
    • Long stencil life (up to 12 hours)
    • Excellent response-to-pause
    • Prints consistently at a wide range of speeds
  • High tack value (>8 hours) ensures consistent component holding power, allowing high-speed component placement operation
  • Cleanable up to at least 72 hours after reflow
Other Water-Soluble Solder Pastes:
Product Value Proposition
Indium3.2 Industry-tested quality and reliability
Indium3.2HF Halogen-free solder paste with similar performance to Indium3.2
Indium6.6HF Versatile option for water-wash processes
Indium6.4R Superior wetting to a variety of surface finishes
Products complementary with Indium6.6HF Solder Paste:

Flux-Cored Wire:

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Residue Residue
CW-301 ORH1 ORH1 OR ~3.0% No Amber Water SnPb,
Electronics applications; water-soluble
RMA-155 - Fighter Jet

RMA-155 Solder Paste for Military, Aviation, and Medical Applications

RMA-155 Solder Paste was designed to offer a balanced performance, making it ideal for high-complexity boards with a variety of component sizes. Compatible with both SnPb and SAC alloys, RMA-155 delivers consistent transfer efficiencies, excellent response-to-pause, and a strong oxidation barrier, even for long and hot profiles. It is halogen-free, resists graping (even on small components and tiny deposits), prevents head-in-pillow, and minimizes voiding for BGAs and large thermal planes (QFNs).

RMA-155 solder paste conforms to the RMA classification for QQ-S0571F and offers proven performance similar to our best-in-class, award-winning Pb-free solder pastes.

Additionally, Indium Corporation offers a full suite of compatible RMA materials, including:


Die-attach is the term reserved for processes where the face of a die is attached to a substrate by a single joint. The joint may be of polymer (adhesive), metal-filled polymer, or in the form of solder derived from a preform, solder paste, or solder wire.