As an expert in the field of electronics and materials science, I can provide you with a comprehensive answer regarding the use of aluminum wire for soldering.

Soldering is a process used to join two or more metal parts together by melting and flowing a filler metal (solder) into the joint. Traditionally, soldering has been done using materials like copper, which has a high thermal conductivity and is easy to work with. However, when it comes to aluminum, the process becomes quite challenging due to several inherent properties of aluminum.

**Aluminum's Properties Affecting Soldering:**

1. Oxidation: Aluminum forms a thin, protective layer of aluminum oxide (Al2O3) on its surface almost instantly when exposed to air. This oxide layer is tenacious and has a high melting point, making it difficult for the solder to wet the aluminum surface effectively.

2. Thermal Conductivity: While aluminum is a good conductor of heat, its thermal conductivity is higher than that of most solders. This can lead to rapid heat dissipation, which might not allow the solder to reach its melting point uniformly across the joint.

3. Wetting: The process of solder wetting, where the molten solder spreads over the base metal, is not as effective with aluminum due to the aforementioned oxide layer and the metal's affinity for the solder.

Techniques for Soldering Aluminum:

1. Cleaning: Proper cleaning of the aluminum surface is crucial. Any contamination, including the natural oxide layer, must be removed to allow for better solder adhesion.

2. Flux: Using a special flux that is designed for aluminum is essential. This flux helps in breaking down the oxide layer and promoting the solder's flow onto the aluminum surface.

3. Solder Selection: A solder with a higher melting point than traditional solders is often used for aluminum. This is because the solder must remain molten long enough to penetrate the oxide layer and wet the aluminum properly.

4. Temperature Control: Controlling the temperature is vital. Too high a temperature can damage the aluminum or the components being soldered, while too low a temperature will not be effective in melting the solder or overcoming the oxide layer.

Post-Soldering Considerations:

1. Cleaning: After soldering, it is necessary to clean the joint thoroughly to remove any residual flux. This is important because the flux used for aluminum is very active and can cause corrosion if not removed.

2. Inspection: The solder joint should be inspected to ensure that it is mechanically and electrically sound. This includes checking for proper wetting and absence of voids or cold solder joints.

In conclusion, while it is possible to solder aluminum, it requires a different approach compared to soldering copper or other metals. The process is more complex and requires careful consideration of the materials and techniques used. Specialized equipment, materials, and a good understanding of the process are essential to achieve a successful solder joint with aluminum.

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Answer: Soldering to aluminum is very difficult and quite different than soldering to copper or solder coated surfaces. ... This flux is very active and cleaning is a must to removed the residual fluxes left behind after the solder joint is created, and in your case, after the shield is soldered.read more >>