PCB chemicals- a comprehensive guide for beginners

Common PCB chemicals

Waste etchant and waste rinse water containing ammonia, copper, chromium, iron, and acids are used in PCB production. Suspended particles, metals, fluoride, phosphorus, cyanide, and chelators comprise most waste stream components.

PCB cleaning chemicals

PCB cleaning chemicals are used to remove impurities and contaminants from the surface of the circuit board before and after manufacturing. The cleaning process is an essential step in the manufacturing process, as it helps to ensure that the surface of the circuit board is free from dirt, oils, and other contaminants that can affect its performance.

There are several types of PCB cleaning chemicals that are commonly used in the manufacturing process, including:

1. Isopropyl alcohol: This is a common solvent used for cleaning PCBs. It effectively removes oils, dirt, and other contaminants from the surface of the circuit board.

2. Acetone: Acetone is a strong solvent often used to remove harsh residues and contaminants from the surface of the circuit board.

3. Sodium hydroxide is a robust alkaline solution often used to clean PCBs. It effectively removes oils and other contaminants from the surface of the circuit board.

4. Trichloroethylene: This is a powerful solvent that effectively removes harsh contaminants from the surface of the circuit board.

However, it is also a hazardous chemical and should be used cautiously.

PCB etching chemicals

1. 150 MG copper etchant: One of the most used PCB chemicals is a tried-and-true etchant made specifically for etching copper in the mass fabrication of printed circuit boards.

In carefully chosen ratios, ammoniac compounds serve as the foundation for etching chemicals. You can apply it through immersion or spray.

2. 1932 Nickel cleaner: It is a tried-and-true etching solution created especially for the etching metal in the production of PCB in large quantities.

Ammoniac compounds provide the basis for etching chemicals in precisely selected ratios. It can be used as a spray or by immersion.

3. 6401 Solder stripper: It is an acid-based stripper explicitly made for removing lead, tin, and lead/lead from PCBs. It is cost-effective and can hold more than 15 oz. each gal without replenishing.

It has a unique stabilizer, and copper inhibitor system minimizes base metal etching when stripping.

4. Wet Etching: In “wet etching,” etched materials are submerged in an etching solution—the most often used etching technique. Wet etching has the quality of being isotropic, and increasing the etching temperature and adding stirring can effectively enhance the etching rate.

Etching solution concentration, engraving column temperature, and stirring are the variables that impact how quickly object etchings are.

5. Dry Etching: Anisotropy is a property of dry etching, which uses plasma to directly bombard the top of the battered film or interact with surface film to create volatile chemicals.

The most crucial technology for etching sub-micron-sized devices is dry etching, which uses plasma to remove thin layers from surfaces.

Other PCB chemicals

Many other PCB chemicals are used as a primary solvent utilized in the circuit board industry are:

PCB plating chemicals

1. Copper sulfate:
This chemical is commonly used as a copper source in the electroplating process, where copper ions are deposited onto the surface of the circuit board to create a conductive layer.

2. Nickel sulfate:
It is utilized as a nickel source in the electroplating process. Nickel plating is often used as a barrier layer to protect the copper layer from oxidation and corrosion.

3. Gold chloride:
Gold chloride is naturally used to deposit a thin layer of gold onto the surface of the circuit board. Gold plating is often used in applications where high conductivity and resistance to corrosion are required.

4. Tin chloride:
It is used to deposit a tin layer onto the circuit board’s surface. Tin plating is often used as a protective layer to prevent oxidation and corrosion of the copper layer.

5. Silver nitrate:
This chemical is commonly used in depositing a thin layer of silver onto the surface of the circuit board. Silver plating is often used in high-frequency applications requiring low resistance and high conductivity.

PCB soldering chemicals

1. Flux:
Flux is used to clean the surface of the metal to be soldered and helps to remove oxidation, ensuring a solid bond between the metal and the solder. Flux also helps prevent new oxides from forming during the soldering process.

2. Solder paste:
Solder paste is a mixture of solder powder and flux used to apply solder to the circuit board. Solder paste is usually applied using a stencil and is then heated to melt the solder and create a strong bond between the components and the circuit board.

3. Solder wire:
Solder wire is used to make hand-soldering easier. The solder wire is made of tin and lead and is melted using a soldering iron to form a strong bond between the components and the circuit board.