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:

Rework Flux:

TACFlux®	Typical Tackiness (grams)	Typical Viscosity (kcps)	Max Temp (°C)	Reflow Residue (%)	Reliability J-STD 004	Flux Classification	Cleaning Method
TACFlux® 025-NP	550	850	370	47	Pass	ORMO	Water

Wave Flux:

Formula	pH	Solids %	S.G.	J-STD-004	J-STD-004B	Halogen	Apply	Thinner	Description
1095-NF	6.8-7.2	19.5	0.838	ORH1	ORH1	< 4.5%	Foam	16-1000	Water-wash; neutral pH
1081	Low	28.4	0.957	ORH0	ORH0	< 50 ppm	Foam	16-1081	Preferred product. Heat stable, water-wash, halide-free

Flux-Cored Wire:

Flux Number	J-STD- 004	J-STD- 004B	QQ-S- 571f	Halogen Content	JIETA ET-7304 Halogen Free	Residue	Residue Removal	Preferred Alloys	Application/ Comments
CW-301	ORH1	ORH1	OR	~3.0%	No	Amber	Water	SnPb, Pb-Free	Electronics applications; water-soluble

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:

• TACFlux^® RMA-155
• FP-2212 Flux Pen

Die-Attach

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.