Laser-induced surface activation of LTCC materials for chemical metallization

Low-temperature cofired ceramics (LTCCs) are mainly applied in hybrid microelectronics packaging technology, where the fabrication of metallic conductors on LTCC materials is done using various printing technologies. The conventional process is fast and cost-effective in the case of mass production, but too slow and difficult when repair and/or modifications of the circuitry are needed. Printing also fails when deposition of thin metal films on LTCC is required. Here, a simple laser-assisted process is presented, by which the surface of LTCCs can be activated for consecutive electroless chemical metal plating. The method enables the realization of thick high-conductance metallic Cu micropatterns and thin seed layers of Ag and Au, with a lateral resolution of a few tens of micrometers. The process is also suitable for 3-D-MEMS applications. A study of LTCC surfaces treated with Nd:YAG pulses is carried out using field emission scanning electron microscope (FESEM), SEM, x-ray diffraction (XRD) and Raman measurements.