Laser Manufacturing of Mechanical Structures in Flexible Substrates for Lifetime Increasing

Laser manufacturing has several advantages to traditional processes. It is non-contact manufacturing, flexible and controllable. Because of these advantages laser drilled microvias are commonly used in the microelectronics industry. However possibilities of laser ablation can be exploited in several other fields as well. These are: window opening for TAB IC, bending windows, ditches for microfluidics. The aforementioned applications require large processed area, controlled ablation depth and wall angle. The production of the so called bending window is a unique application of laser material processing. Bending windows can be used in flexible circuits to define the exact position of deformation. It is done by reducing the thickness of the flexible substrate in a well defined, narrow line. The effect of the material removal on the mechanical properties, such as tensile strength, flexibility, durability was investigated. Based on our experiences a new "multiple V" shaped bending window was developed from which longer lifetime and better mechanical properties are expected. Using the above mentioned procedure "bend and stay" substrates are likely to produce