KESTER EP256 Solder Paste

Harmonization Code : 3810.10.00 |   Soldering, brazing or welding powders and pastes consisting of metal and other materials
Main features
  • Stable wetting behavior
  • Excellent printing characteristics
  • High activity on all substrates

Product Description

KESTER EP256 is a no-clean, air or nitrogen reflowable solder paste specifically designed for  maximum robustness in reflow profiling and stencil  printing. EP256 has the widest possible reflow  processing window and it is also capable of  stencil printing downtimes of up to 90 minutes with an effective first print down to 20 mils. EP256 is a solder paste formula that maintains its activity and  printing characteristics for up to 8 hours without  any shear thinning.

Product Key Features

  • Stable wetting behavior over a wide range of profiles
  • Capable of 90-minute break times in printing
  • High print speeds to 200+ mm/sec (8+ in/sec)
  • Compatible with enclosed print head systems
  • Excellent printing characteristics to 0.4mm (16 mil) pitch with Type 3 powder.

Applications

  • Stencil printing and enclosed head printing (90% metal)
Product Family
AP-EP256  
Sn63Pb37 Sn62Pb36Ag2
T3
500g Jar 1kg Unit

Catalog Product

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TDS, SDS & Technical documents

Technical Specifications

Physical Properties
Viscosity
Viscosity
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
 1400000 mPa.s

Additional Information

Reflow Profile

The recommended reflow profile for EP256 made with either the Sn63Pb37 or Sn62Pb36Ag02 is shown here. This profile is simply a guideline. Since EP256 is a highly active solder paste, it can solder effectively over a wide range of profiles, including lead-free profiles in some cases.

EP256 is capable of reflowing at the 235 °C peak temperatures required for fully collapsing lead-free SAC BGAs for maximum reliability and remains easy to clean after these high temperature profiles. Your optimal profile may be different from the one shown based on your oven, board and mix of components.

Contact us if you need additional profiling advice.

Sn63Pb37 or Sn62Pb36Ag02 Alloys SnAgCu Alloys

Preheat Zone:

  • Ramp rate: ~1.0–1.5 °C/sec
  • Soak Zone: 150–180 °C
  • Duration: ~60–120 sec

Reflow Zone:

  • Peak Temperature: 210–230 °C
  • Time above liquidus (183 °C): ~60–90 sec

Cooling Zone:

  • Controlled cool down after peak

Preheat Zone:

  • Ramp rate: ~1.0–1.5 °C/sec
  • Soak Zone: 150–200 °C
  • Duration: ~60–120 sec

Reflow Zone:

  • Peak Temperature: 235–245 °C
  • Time above liquidus (217 °C): ~60–90 sec

Cooling Zone:

  • Controlled cool down after peak