Types of Solder Mask Material
Solder mask is a crucial layer in a printed circuit board. It protects the exposed area of the copper. Also, solder mask is usually green in color. However, there are other colors like white, red, yellow, and blue. There are different kinds of soldermask materials based on how they are applied to the copper.
Epoxy liquid
This is a thermosetting epoxy usually applied through the silk screening method. The epoxy liquid is not commonly used due to its low resolution and accuracy.
Dry film photoimageable
A dry film is ideal for flat PCBs having a uniform topography. You can use vacuum lamination to apply a dry film before development and exposure. Also, a dry film will always offer a uniform surface thickness. However, this type of soldermask is only suitable for flat boards.
Liquid photoimageable
The liquid photoimageable soldermask is ideal for circuit boards having unusual to pography. You can apply a UV curable ink with the use of different coating techniques. This soldermask doesn’t offer a consistent layer, but it offer better contact with the copper traces. Also, it offers a better coverage. It is ideal for circuit boards with very complex surface features.
Types of Materials Used in PCB Conductive Layers
The three main materials used as a conductive layer in PCBs are copper, iron, and aluminum. Copper is the most commonly used material for conductive layers. This is a major reason most printed circuit boards are copper clad.
Copper foil
Copper foil is a highly conductive material and as such, it is widely used as a conductive layer in a PCB. Also, copper has good electrical conductivity and ductility. Also, the copper layer as a conductive layer offers exceptional thermal properties and tensile strength. Copper layer thickness is usually measured in ounces.
This conductive material plays a crucial role in PCB manufacturing as it features great thermal and electrical properties required for heat dissipation and signal transmission. Also, this material is more resistant to corrosion compared to iron and aluminum.
Aluminum
Aluminum serves as a good conductive layer in a printed circuit board. This material features high durability. Also, aluminum is a sturdy material with great thermal and electrical characteristics. The use of aluminum as the conductive layer of a printed circuit board eliminates accidental breakage risk. Accidental breakage can occur during manufacturing or handling.
Aluminum is a very easy to solder material. The thickness of aluminum ranges between 1 ounce to 10 ounces. Also, aluminum offers a conductive path for electronic components.
Iron
Iron is also a type of metal used as a conductive layer of a circuit board. This material features a good shielding effect and is ideal for surface mounting. Also, iron offers good heat dissipation and stability.