4. Materials and manufacturing processes. Associated controls

The intended application brings with it constraints that need to be taken into account when choosing materials right from the design phase. The following examples of basic material properties illustrate the importance of choosing the right materials.

• Coefficient of thermal expansion (CTE) of the printed circuit board: choosing this parameter helps avoid thermal stresses due to the difference in CTE between the printed circuit board and surface-mounted assemblies, given that among base materials, the CTE value in the plane of the material (x and y axes) can vary by a factor of 10.

• PCB Maximum Operating Temperature (MOT): this is the temperature at which a laminate can be operated continuously over a long period without significant deterioration. This MOT is used to define the range of applications (under-hood...