Leaded Sn63/Pb37 Solder Paste

Solder Paste Composition

The TS107E Leaded Sn63/Pb37 Solder Paste consists of Sn63/Pb37 alloy powder and solder flux. According to the technical datasheet, this Leaded solder paste has a composition of 63% tin (Sn) and 37% lead (Pb), forming a eutectic alloy with a melting point of 183°C. The flux content of this Leaded Sn63/Pb37 Solder Paste is approximately 5% (by weight), utilising an ROL0‑grade activator system (the highest reliability level per IPC J‑STD‑004). This Leaded solder paste formulation ensures minimal residue after reflow, full and reliable solder joints, and fully meets no‑clean process requirements.

Solder Paste Type – Customisable Powder Size Selection

TS107E Leaded Sn63/Pb37 Solder Paste offers the industry’s widest range of Solder Paste Type options, including:

Among these, Type 4.5 and Type 5 are exclusive options for this Leaded Sn63/Pb37 Solder Paste, particularly suited for ultra‑fine pitch applications down to 200μm (8mil) apertures. This advantage distinguishes TS107E from other Leaded solder paste products on the market.

SnPb Alloy Advantages

As a typical Leaded Sn63/Pb37 Solder Paste, TS107E utilises the Sn63/Pb37 eutectic alloy, offering the following core benefits:

• Eutectic characteristics – melting point of 183°C, no plastic zone, rapid solidification during soldering, reducing cold solder risks;
• Mature technology – Sn63/Pb37 is the most widely applied alloy system among Leaded solder paste products;
• Superior wettability – excellent performance across various PCB surface finishes, especially on CuOSP;
• Cost‑effectiveness – compared to lead‑free alloys, Leaded Sn63/Pb37 Solder Paste offers more competitive material costs.

This Leaded solder paste achieves complete alloy coalescence even on apertures as small as 200μm, producing uniform and full solder joints.

Flux and Electrical Reliability

The flux in TS107E employs an ROL0‑grade activator system (IPC J‑STD‑004 highest reliability level) and is halogen‑containing (confirmed by titration and silver halide tests). This flux system ensures that the Leaded Sn63/Pb37 Solder Paste passes all of the following tests:

This flux system leaves colourless, transparent, dry, and reliably insulating residue after reflow, meeting no‑clean requirements while delivering IPC Class III voiding performance (the highest IPC 7095 classification).

Printing Performance and Process Parameters

TS107E Leaded Sn63/Pb37 Solder Paste demonstrates outstanding printing consistency and high process capability index (Cpk) on the printer. The key printing parameters for this Leaded solder paste are:

• Printing speed: 25–150mm/s (1–6 in/s), supporting high‑speed printing for fast cycle times and high throughput;
• Squeegee pressure: 0.18–0.27kg/cm (1.0–1.5lbs/inch); higher speeds require increased pressure;
• Squeegee angle: 60° (standard);Squeegee material: metal or polyurethane rubber (hardness 80–90 Shore);
• Stencil thickness: 100–150μm (4–6mil);Stencil separation speed: 3–10mm/s;
• Stencil material: recommended Alpha series electroformed/laser‑cut stencils.

This Leaded Sn63/Pb37 Solder Paste exhibits minimal viscosity variation during continuous printing at 25°C/50%RH, significantly reducing cleaning frequency and improving production line efficiency – particularly well‑suited for high‑throughput applications.

Handling and Process Guidelines

TS107E Leaded Sn63/Pb37 Solder Paste must be stored refrigerated at 0–10°C (shelf life: 6 months). Prior to use, the Leaded solder paste should be allowed to warm to room temperature for approximately 4 hours (ensure temperature ≥19°C before opening), and then mixed:

• Manual mixing: can be stirred with a spatula until uniform;
• Centrifugal mixer (solder paste mixer): recommended speed below 300 RPM, with a pause after every 30–60 seconds of mixing;
• Important: Never mix solder paste recovered from the stencil with unused paste in the same container, as this will alter the rheological properties of the unused Leaded Sn63/Pb37 Solder Paste.

After printing, reflow should be completed as soon as possible. The reflow profile recommends a peak temperature of 210–220°C (above the 183°C melting point), and can be performed in air or nitrogen atmospheres.

Core Differentiating Advantages – Low Head‑in‑Pillow and High Probe Testability

TS107E Leaded Sn63/Pb37 Solder Paste offers two industry‑leading core advantages:

• Low head‑in‑pillow defect rate – This Leaded solder paste delivers outstanding resistance to head‑in‑pillow defects in BGA/CSP soldering, effectively reducing open defects caused by PCB warpage and component coplanarity issues, improving first‑pass yield.
• Excellent probe testability – TS107E provides best‑in‑class in‑circuit probe test yield. After reflow, the solder joint surface has minimal, colourless, transparent flux residue, resulting in low probe contact resistance and significantly reducing ICT (in‑circuit test) misjudgements. This Leaded Sn63/Pb37 Solder Paste is the preferred choice for leaded‑process ICT testing applications.
• Low voiding – Meets IPC 7095 Class III voiding performance (the highest level), ensuring long‑term reliability.

Application Scenarios and Supply Capacity

TS107E Leaded Sn63/Pb37 Solder Paste has been deployed in volume production across the following sectors:

This Leaded Sn63/Pb37 Solder Paste serves over 50 customers, with a monthly production capacity exceeding 3 tonnes and ample inventory, enabling delivery within 48 hours.