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STIRRI RMA™ is a no-clean solder paste and tacky flux known for its excellent printability and suitability for stencil applications. It belongs to the rosin chemical family and complies with regulatory standards like REACH (Europe). Ideal for defense and aerospace applications, it offers reliability and precision in soldering tasks.

Product Type: Solder Paste

Application Area: Aerospace Applications, Defense, Stencil

Features: Excellent Printability

Chemical Family: Rosins

Technical Data Sheet

Knowde Enhanced TDS

Identification & Functionality

Chemical Family
Product Type

Features & Benefits

Ready-to-Use Product Features
Keynotes
  • Rosin-based low-activity ROL0 (No-clean)
  • World-class printability, instant activity response
  • Optimal tack/viscosity for Defense/Aerospace
  • Superior dispensing flow, stellar stencil printing, excellent pin transfer
  • Sharp definition at high-speeds
  • Low solder balling and graping
  • Long stencil life
  • REACH-complaint
  • Easy to clean using IPA, solvents, water-based saponifiers, vapor degreaser or ultrasonic devices

Applications & Uses

Properties

Typical Properties
ValueUnitsTest Method / Conditions
Stencil Life (at 30 - 70% R/H & 20 - 25°C)max. 12hours

Regulatory & Compliance

Certifications & Compliance

Technical Details & Test Data

Viscosity
PRINT jar/cartridge DISPENSE syringe Tacky flux Tack force (g/cm)
200-275 100-150 40-70 38-48

* Malcom @ 10 RPM @ 25°C x10³ g/cm/s

Printer Operations

Stencil printer does not require any specific optimization, should be fully adjustable based on standard in-house process requirements, including high-speed printers

Print Speed: 20-200 mm/sec (add pressure for speed)
Squeegee Pressure: 70-540 g/cm of blade (add for speed)
Stencil Vac/Wipe: Every 10-25 prints or as necessary

Automated and vacuum cleaning systems for both stencil and misprinted boards. Manual cleaning using Isopropyl alcohol (IPA), co-solvents and/or ultrasonic scrubbers, vapor degreaser.

Test Results
IPC-TM-650 Test Value Result
Corrosion 2.6.15 L: No corrosion PASS
Copper Mirror 2.3.32 L: No breakthrough PASS
ECM (No-clean) 2.6.14.1 <1 decade drop PASS
Quantitive Halides 2.3.28.1 L: <0.05% PASS
SIR Test (No-clean) 2.6.3.7 ≥100 MΩ PASS
Printing

Optimal print definition for fine pitch applications. Long stencil life of this product virtually eliminates waste of solder paste. For mesh/size determination refer to the Pitch Requirements chart below:

 

Size (micron) Type Value
75 - 45 μm T2 24 mil +
45 - 25 μm T3 16 - 24 mil
38 - 20 μm T4 12 - 16 mil
25 - 15 μm T5 < 12 mil
20 - 5 μm T6 < 8 mil
Sample Reflow Profile

STIRRI RMA™ (No-clean Solder Paste & Tacky Paste Flux) - Sample Reflow Profile - 1

Mt° Profile-A can be used as a starting point for the leaded process optimization with Sn60, Sn62, Sn63 alloys. A cooldown rate of 2-4°C/sec is ideal for the formation of fine grain structure without risking damage to thermally sensitive components.

STIRRI RMA™ (No-clean Solder Paste & Tacky Paste Flux) - Sample Reflow Profile - 2

Mt° Profile-B is an alternative approach to solder Sn60, Sn62, Sn63 utilizing a soak of up to two minutes at 155°C may help to minimize voiding in leaded BGA, LGA & QFN assembles. This will allow more time for solvent components of the solder paste to outgas prior to reflow.

Packaging & Availability

Availability

STIRRI-RMA™ available in many alloys including high reliability solder: Sn42Bi58, Sn42Bi57.6Ag0.4, Sn42Bi57Ag1, Sn43Pb43Bi14, Sn60Pb40, Sn62Pb36Ag2, Sn62.8Pb36.8Ag0.4, Sn63Pb37

Packaging Information

Options with various viscosity and metal load for stencil printing and dispensing applications:

  • Printing: Jars, 1/4 NPT nozzle cartridges
  • Dispensing: Syringes, ProFlow cassettes

Storage & Handling

Shelf Life, Storage, and Handling

Refrigerated storage at 5-7°C will prolong the solder paste shelf life to no less than 6 months. Solder Paste should be allowed to reach ambient temperature, normalize for about 6-8 hours before use. Tacky flux has 24 months shelf life stored in room temperature. Refrigeration won't extend shelf life. Normalize for 4-6 hours if stored refrigerated. Paste/flux in syringes and cartridges should be kept vertically, dispensing tip pointing down.

Note :NEVER FREEZE SOLDER PASTE / FLUX!