4900P-25G Lead Free No Clean Solder Paste 25g
MG Chemicals has developed a unique flux system designed specifically for high temperature lead free alloys. It provides the fluxing activity levels that promote thermal stability and prevents thermal degradation when reflowing under air atmosphere (normal). Since use of nitrogen is not required, MG 4900P Lead Free Solder paste will provide excellent cost savings.
In addition, MG 4900P Lead Free solder paste exhibits superior joint strength, excellent wettability, and extraordinary print definition and tack life. The post soldering residues of MG 4900P are non-conductive, non-corrosive and highly insulated.
Features & Benefits
- Low residues
- Easily dispensed
- Long tack-time
- Excellent wettability
- Hard non-conductive residues
| MG 4900P | Sn/Ag/CU | SN63/Pb37 |
|---|---|---|
| Melting Point, °C | 217-221 | 183 E |
| Hardness, Brinell | 15HB | 14HB |
| Coefficient of Thermal Expansion | Pure Sn=23.5 | 24.7 |
| Tensile Strength, psi | 4312 | 4442 |
| Density, g/cc | 7.39 | 8.42 |
| Electrical Resistivity, (µohm-cm) | 13.0 | 14.5 |
| Electrical Conductivity, %IACS | 16.6 | 11.9 |
| Yield Strength, psi | 3724 | 3950 |
| Total Elongation,% | 27 | 48 |
| Joint Shear Strength, at 0.1mm/min 20°C | 27 | 23 |
| Joint Shear Strength, at 0.1mm/min 100°C | 17 | 14 |
| Creep Strength, N/mm² at 0.1mm/min 20°C | 13.0 | 3.3 |
| Creep Strength, N/mm² at 0.1mm/min 100°C | 5 | 1 |
| Thermal Conductivity, W/m.K | 58.7 | 50.9 |
| Specification | Test Method | |
| Flux Classification | ROL0 | JST0-004 |
| Copper Mirror | No removal of copper film | IPC-TM-650 2.3.32 |
| Silver Chromate | Pass | IPC-TM-650 2.3.33 |
| Corrosion | Pass | IPC-TM-650 2.6.15 |
| SIR | ||
| JST0-004 | 6.55 x 1011 ohms | IPC-TM-650 2.6.3.3 |
| Bellcore (Telecordia) | 5.22 x 1011 ohms | Bellcore GR-78-CORE 13.1.3 |
| Electromigration | Pass | Bellcore GR-78-CORE 13.1.4 |
| Post Reflow Flux Residue | 45% | TGA Analysis |
| Acid Value | 110 | IPC-TM-650 2.3.13 |
| Metal Loading | 86% | IPC-TM-650 2.2.20 |
| Viscosity | ||
| Brookfield (1), kcps | 400+/-10% kcps | IPC-TM-650 2.4.34 modified |
| Malcom (2), poise | 85-125 | IPC-TM-650 2.4.34.3 modified |
| Thixotropic Index | 0.50-0.60 | |
| Slump Test | ||
| 25 C, 0.63 vertical/horizontal | No bridges all spacings | IPC-TM-650 2.4.35 |
| 150 C, 0.63 vertical/horizontal | No bridges all spacings | IPC-TM-650 2.4.35 |
| 25 C, 0.33 vertical/horizontal | 0.15 /0.15 | IPC-TM-650 2.4.35 |
| 150 C, 0.33 vertical/horizontal | 0.20/0.20 | IPC-TM-650 2.4.35 |
| Solder Ball Test | Pass | IPC-TM-650 2.4.43 |
| Tack | ||
| Initial | 85 gm | JIS Z 3284 |
| Tack retention @ 24 hr | 110 gm | JIS Z 3284 |
| Tack retention @ 72 hr | 127 gm | JIS Z 3284 |
Reflow
Best results have been achieved when MG 4900P is reflowed in a forced air convection oven with a minimum of 8 zones (top & bottom), however reflow is possible with a 4 zone oven (top & bottom).
The following is a recommended profile for a forced air convection reflow process. The melting temperature of the solder, the heat resistance of the components, and the characteristics of the PCB (i.e. density, thickness, etc.) determine the actual reflow profile.
Preheat Zone - The preheat zone, is also referred to as the ramp zone, and is used to elevate the temperature of the PCB to the desired soak temperature. In the preheat zone the temperature of the PCB is constantly rising, at a rate that should not exceed 2.5 C/sec. The oven’s preheat zone should normally occupy 25-33% of the total heated tunnel length.
The Soak Zone - normally occupies 33-50% of the total heated tunnel length exposes the PCB to a relatively steady temperature that will allow the components of different mass to be uniform in temperature. The soak zone also allows the flux to concentrate and the volatiles to escape from the paste.
The Reflow Zone - or spike zone is to elevate the temperature of the PCB assembly from the activation temperature to the recommended peak temperature. The activation temperature is always somewhat below the melting point of the alloy, while the peak temperature is always above the melting point.
WARNING
