PCB Base Material Features
The two main features of PCB base material are thermal-mechanical and electrical.
This test uses a technique in which a low current arc is placed at the top of the material surface. The arc resistance defines the time during which the material is resistant to tracking or forming the conductive path.
Copper Peel Strength
The peel strength is a measure of the bond strength between the conductor and the substrate.
The de-lamination time describes a specific test method for measuring how long the material is de-laminating or blister at a particular temperature. The method uses a thermal-mechanical analyzer (TMA) to heat the sample to a specific temperature. The common temperature is 260°C, and this is why it is also known as the T260 test.
This is a measure of the load that the base material does not break at both ends and is loaded at the center.
PCB Thermal-Mechanical Features
Thermal expansion can be calculated by thermal-mechanical analysis (TMA) which uses a device that can measure dimension of temperature versus sample. The z-axis CTE or x/y CTE can be measured based on the direction of the sample in the device. Here CTE refers to the coefficient of thermal expansion.
Thermal expansion of the z-axis can seriously affect the reliability of the printed circuit board. The electroplated through-hole passes through the z-axis of the printed circuit, shrinkage and thermal expansion in the substrate results in plastic and strain deformation in the plated through-hole, and also deforms the copper pad on the surface of printed circuit board.