Tensile Testing of Copper Clad Laminates (CCL)

Laminates are basic materials used to mechanically support electronic components and to interconnect them electrically. Copper clad laminates (CCL) are comprised of multiple layers of copper foils and reinforcing materials that are used between the foils. In the printed circuit board (PCB) manufacturing process, CCLs are used as a base material for electrical conductivity and physical performance, such as dimensional stability, punching quality, peel strength, bending strength, heat resistance, etc. As new reinforced materials (i.e. fiber-glass cloth, asbestos sheet, and paper) and different types of resins (i.e. phenolic, epoxy, and polyimide) are used, it is critical to perform mechanical testing under various conditions in order to understand the total strength of particular laminates. Reinforced materials used in combination with resins are designed to have excellent heat resistance, which prevents thermal stress on the PCB during the assembly process. Therefore, manufacturers are particularly interested in understanding the mechanical performance of CCLs in high temperature conditions, with the expectation of a similar performance under ambient conditions.

Instron^® 6800 Series single column and dual column systems can perform tensile tests on CCL materials, and can be equipped with a set of grips to fit the dimensions of the CCL being tested. When performing strain measurements, contact and non-contact style strain devices are available. The 2630 Series and W-6820 Series axial clip-on extensometers are simple contact-style strain measurement devices. Non-contact video extensometers, such as the Advanced Video Extensometer 2 (AVE 2), are more advanced and offer higher accuracy for strain measurement.

To perform tensile tests at non-ambient temperatures, the 3119-600 Series environmental chambers are capable of achieving temperatures that can range from -150O C to +350O C. For high temperature conditions, corresponding grips and contact-style extensometers are also available.

Bluehill^® Universal software offers the ability to easily set up test methods and run tests at various environmental conditions. Results such as strain and tensile strength can be calculated from the software. The QuickTest feature allows the user to set up and quickly run a tensile test in order to understand preliminary results of CCL materials.