Solder Connection

Solutions in Soldering Technology

OM-353 Ultra-Fine Solder Paste

ALPHA® OM-353 is a Low Silver & SAC305 capable paste designed for Type 5 (15–25μm) powder to meet market segments requiring ultra-fine features application.  It has been tested to give excellent printing performance down to 180μm pad size dimension with a 60° angled squeegee on stencil at 50 mm/s speed, 2 mm/s release speed and 0.18 N/m pressure printing parameters.

OM-353 is also available in Type 4 (20-38μm) powder size distribution.

Key Products Features & Benefits:

  • Long Stencil Life: engineered for consistent performance in warm/humid production climates, reducing variations in print performance and paste dry-out.
  • High Tack Force Life: ensures high pick-and-place yields, good self-alignment.
  • Wide Reflow Profile Window: enables quality soldering of complex, high density PWB assemblies in an N2 environment, using high ramp rates and soak profiles as high as 170°C to 180°C. 
  • Reduced Mid Chip Solder Balling, Head-in-Pillow: minimizes rework and increases first time yield. 
  • Excellent Solder Joint and Flux Residue Cosmetics: residue does not char or burn after reflow soldering, even when using long/high thermal soaking.
  • Excellent Voiding Performance: Pass IPC7095 Class III requirement for BGA.
  • Halogen Content: Zero Halogen, no halogen intentionally added.
  • Reliability: Pass JIS Copper Corrosion Test and all standard SIR Tests
  • Safe and Environmentally Friendly: Materials comply with ROHS, TSCA, EINECS and Halogen-free requirements.
  • Low-Silver alloy availability.
  • J-STD Classification: ROL0


Product Number : OM-353

Prod. No. 161874


Q - What is colophony and can it cause any health issues?
A - Colophony is a generic term for rosin, this is the sap or sticky substance that derives from pine and spruce trees. Its "stickiness" lends itself to being used in a wide range of products. We have traditionally used this product in fluxes due to these specific properties it can however lead to breathing difficulties and skin sensitivity. Always use fume filtration when soldering and change filters regularly.

Q - What is the difference between rosins and resins?
A - The terms are often used interchangeably, but rosin is a naturally occurring substance, and resin is either a modified rosin or completely synthetic material. Rosins are plant based products and are subject to more natural variation than resins, however resins are commonly used in newer flux formulations due to their more consistent performance.

Q - Do I need to change my printing process when I go to finer printing from size 3 to size 4 paste?
A - Generally when changing from T3 to T4 there is not much difference in printing setup. Depending upon the paste used you may have to make slight adjustments to print parameters such as release speed as aperture fill is greater with finer powders on small apertures but this is just to optimise the print as you would do when changing any paste. It’s by no means certain you will need to do this but it may give you further benefits.

Q - Do I need to change my printing process when I go to Ultra Fine printing from size 4 to size 5 paste?
A - The biggest change will be going to PS5 and its not so much the printing parameters changing but the stencils are invariably a lot thinner and so you need good support and setup such as making sure you have a release distance of 3 mm set (the distance over which release speed is controlled as the stencil acts more like a drum skin) I would also run with the minimum pressure to avoid stencil damage (coining) this is as most PS stencils are <100µm typically 75µm in thickness. It’s not as bad with PS4 as most stencils are in the 100µm or slightly above range and are more robust.

In all cases (can’t really think of an exception) smaller powder sizes go hand in hand with printing smaller features. Smaller features as we approach Area Ratio 0.66 and in some cases people try to/do operate in the region of AR 0.6-0.66 mean that the printing process has to be good, you have to “respect the fundamentals” i.e. board support, calibration of such things as print height, squeegee condition, decent PCB quality, registration etc.

Again more a feature of small apertures rather than the powder size of paste itself you may need to look at what is your maximum ‘abandon’ time with any paste if you run a start stop process and work to it i.e. don’t exceed and use automatic under screen cleaning where needed. Smaller apertures tend to ‘clog’ more readily and so may need a more frequent aperture clean regime.

Associated Products

Solder Paste Spatulas

More Info

Safewash SWA

More Info

OM-340 Lead-Free Solder Paste

More Info

Telecore HF-850 Flux Cored Solder Wire

More Info