ALPHA UP-78 Solder Paste
Harmonization Code : 3810.10.00 | Soldering, brazing or welding powders and pastes consisting of metal and other materials
Main features
- Stable Tack Across Production Shifts
- Clear, Colorless, Penetrable Post-Reflow Residue
- Standard and Fine-Pitch Stencil Printing
Product Description
ALPHA® UP-78 No-Clean Solder Paste is a stencil-printing solder paste developed for surface-mount assembly with air reflow and no required post-reflow cleaning. It produces a clear, colorless, soft, and non-tacky residue engineered for penetration during automated test equipment pin testing. The formulation maintains stable tack and printing performance during extended production shifts and is tolerant of varied reflow profiles across different board designs.
Key features
- Extended printing performance: Provides long stencil life and stable tack with minimal performance change over eight-hour shifts under varying humidity exposure.
- ATE-compatible residue: Produces a highly penetrable, soft, non-tacky residue designed to reduce false rejects during pin testing.
- Flexible reflow processing: Tolerates a variety of reflow profiles for use across different surface-mount board designs.
Applications / Suitable for
- Stencil printing for surface-mount assembly
- Air-reflow processes where post-reflow cleaning is not required
- Standard and fine-pitch printing
- Assemblies requiring automated pin-test compatibility
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Additional Information
As-supplied / before-processing properties
Published properties of ALPHA® UP-78 Paste Flux before reflow.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Color | Pale, off-white | — | Published chemical property |
| Specific gravity | 0.99 | g/cc | Published chemical property |
| Viscosity | 380–500 | poise | 5 RPM at 25°C |
| Tack strength | >6 | g/mm² | Published technical data |
| Stencil life | Approximately 8 | hours | 40–60% RH and 20–25°C |
| Halide content | 550 | ppm | Published technical data |
| Water content | 0.2 maximum | % | Published technical data |
| Flux classification | REL1 | — | IPC J-STD-004 |
| Shelf life | 6 | months | Unopened sealed container; avoid temperatures above 27°C (80°F) |
After-processing / final-state properties
Published residue and electrical test results after reflow without cleaning.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Reflowed residue | Tack-free | — | After reflow |
| Corrosivity | Pass | — | Copper mirror test |
| Surface insulation resistance | >2 × 109 | Ω | IPC J-STD-004; 7 days, uncleaned, comb down |
| Surface insulation resistance | >3 × 109 | Ω | IPC J-STD-004; 7 days, uncleaned, comb up |
| Surface insulation resistance | >1 × 1012 | Ω | Bellcore; 4 days, uncleaned, comb down |
| Surface insulation resistance | >3 × 1012 | Ω | Bellcore; 4 days, uncleaned, comb up |
| Electromigration | Pass | — | Bellcore; 500 hours |
