Solder paste
Solder paste is a crucial material in electronics manufacturing, used for attaching surface mount components to printed circuit boards (PCBs). This versatile material combines metal alloy particles with flux to create a reliable electrical and mechanical connection during the reflow soldering process.
Solder Paste Specifications
Our high-quality solder paste meets industry standards with the following specifications:
- Alloy Composition: SAC305 (96.5% Sn, 3% Ag, 0.5% Cu)
- Particle Size: Type 4 (20-38 μm)
- Flux Type: ROL0 (no-clean, low residue)
- Viscosity: 800-1200 kcps at 25°C
- Metal Content: 88.5% by weight
- Working Life: 8 hours at 25°C/60% RH
- Storage: 0-10°C in original container
- Shelf Life: 6 months from production date
Performance Characteristics
| Parameter | Value | Test Method |
|---|---|---|
| Slump Test | < 10% increase | IPC-TM-650 2.4.35 |
| Cold Solder Test | < 5% | IPC-J-STD-005 |
| Wetting Angle | < 30° | JIS Z 3197 |
| Solder Ball Test | No solder balls | IPC-J-STD-005 |
FAQ: Solder Paste Common Questions
Question: What is the proper storage condition for solder paste?
Answer: Solder paste should be stored refrigerated between 0-10°C (32-50°F) in its original, unopened container. Before use, allow the paste to reach room temperature (about 2-4 hours) while still sealed to prevent condensation. Never freeze solder paste as this can damage the flux properties.
Question: How long can solder paste remain on the stencil?
Answer: The working life of solder paste on the stencil typically ranges from 4-8 hours depending on environmental conditions. In controlled environments (25°C/60% RH), our solder paste maintains good printability for 8 hours. For extended production runs, consider using automatic solder paste dispensers or dividing the paste into smaller batches.
Application Guidelines
For optimal results with our solder paste:
- Maintain stencil temperature at 25±3°C
- Use stainless steel squeegee blades (60-70 durometer)
- Set print speed between 10-50 mm/sec
- Apply squeegee pressure of 0.2-0.5 kg/cm
- Maintain 0.1-0.3 mm snap-off distance
Reflow Profile Recommendations
| Zone | Temperature (°C) | Time (seconds) | Ramp Rate (°C/sec) |
|---|---|---|---|
| Preheat | 150-180 | 60-90 | 1.0-2.0 |
| Soak | 180-200 | 60-120 | 0.5-1.0 |
| Reflow | 230-250 | 40-60 | 1.5-2.5 |
| Cooling | To 100 | Max 4.0°C/sec | N/A |
FAQ: Solder Paste Handling
Question: Can I mix solder paste from different batches?
Answer: We strongly advise against mixing solder paste from different batches or different manufacturers. Each batch has unique rheological properties and mixing can compromise print performance and solder joint reliability. If you must combine pastes (for example, when changing batches), conduct thorough testing first to verify print quality, slump resistance, and reflow performance.
Quality Assurance
Our solder paste undergoes rigorous testing to ensure consistent performance:
- Viscosity testing with Brookfield viscometer
- Metal content verification by ignition loss method
- Printability tests with IPC standard test boards
- Reflow performance evaluation
- Solder ball test per IPC standards
- Wetting balance analysis
Technical Support
For technical assistance with our solder paste:
- Contact our technical support team for application troubleshooting
- Request customized reflow profiles for specific applications
- Ask about our solder paste evaluation program
- Inquire about training programs for your production staff
This high-performance solder paste delivers exceptional results for fine-pitch and standard SMT assembly applications. With its excellent printability, extended working life, and reliable solder joint formation, it's the ideal choice for demanding electronics manufacturing environments.