Conformal coating is a dielectric layer of protective non conductive substance that is applied on the PCB or printed circuit board assembly. This layer protects the electronics assembly from contamination, moisture, dust, fungus, salt spray, and corrosion due to extreme environments. Additionally, the coating prevents harm during installation, rough handling and reduces thermal and mechanical stresses.
Conformal coating is generally applied in equipment that are used in external environments with extreme moisture and heat conditions. It prolongs the equipment’s life during its function. Simultaneously, it increases the dielectric power between conductors thereby allowing a smaller and more compact PCB design. It also protects the circuit and its components from solvents and abrasion.
Conformal coating is a simple measure to protect space electronic devices that needed additional security from external elements. The layer increased the capability of electronics assembly that were intended to perform complex tasks and target oriented elements further enhanced the need for conformal covering. It becomes imperative to check the quality of coating substance since the failure of space device could have dreadful consequences.
Significance of the thickness of conformal layer
The thickness of conformal layer is critical to the appropriate function of a space device. A thin coating cannot provide proper coverage whereas a thick coating may exert extreme pressure on components and solder joints. Therefore, it is significant to control the coating thickness with inflexible coating substances such as epoxies and urethane. This is because the residual pressure from an extremely thick coating of these substances is much better than with flexible layering materials like silicones and urethanes.
The conformal layer’s thickness is calculated on an even, empty, treated surface of a coupon or a printed electronic circuit assembly. The coupon could be of the same sort of substance as the printed circuit or of a nonporous substance like glass or metal.
Characteristics of the conformal coating thickness
Following are the characteristics of the conformal layer thickness that ensure specifications for coating thickness are sustained:
- Homogenous and completely treated
- Cover only the places specified on the assembly diagram/documents.
- Free of breaks and blisters that might affect the functions of the assembly or sealing of the conformal layer.
- Free of cracks, voids, bubbles, peeling, folds or substances which expose printed circuit conductors, component conductors, or other components and violate electrical design clearance.
The coatings are applied to the military, aerospace and medical equipments to prolong their operations. Recently, expansion of new processes and substances has enabled superior working of instruments of critical application.
Thus, it is necessary to choose the best company for space electronic manufacturing that produces electronics with all the above mentioned qualities. Additional