Laser Ablation of Thin Films on LTCC

Abstract

Direct Digital Manufacturing techniques such as laser ablation are proposed for the fabrication of lower cost, miniaturized, and lightweight integrated assemblies with high performance requirements. This paper investigates the laser ablation of a Ti/Cu/Pt/Au thin film metal stack on fired low temperature cofired ceramic (LTCC) surfaces using a 355 nm Nd:YAG diode pumped laser ablation system. It further investigates laser ablation applications using unfired, or ‘green’, LTCC materials: (1) through one layer of a laminated stack of unfired LTCC tape to a buried thick film conductor ground plane, and (2) in unfired Au thick films. The UV laser power profile and part fixturing were optimized to address defects such as LTCC microcracking, thin film adhesion failures, and redeposition of Cu and Pt. An alternate design approach to minimize ablation time was tested for efficiency in manufacture. Multichip Modules (MCM) were tested for solderability, solder leach resistance, and wire bondability. Scanning electron microscopy (SEM) as well as cross sections and microanalytical techniques were used in this study.

Fabrication of an Active PCB-MEMS Microfluidic Chip for CHO Cells Characterization by Electrochemical Impedance Spectroscopy

“…In this research, a combination of copper and FR-4 is presented but other combinations of metals like platinum, gold, silver, titanium, or even transparent conductive films can be patterned by laser ablation over flexible or ceramic substrates to improve biocompatibility and resistance to corrosion. 36 Additionally, the PCB-MEMS microfluidic chip was evaluated by using VNA for performed EIS measurements cells at previously Table IV. Characteristic times of the relaxation processes of conduction of current in the system as a function of the concentration of the CHO cells.…”

Experimental application of a laser‐based manufacturing process to develop a free customizable, scalable thermoelectric generator demonstrated on a hot shaft

“…The spot diameter was 120 μm. The parameters are based on the findings from preliminary work 47,48 and other studies on laser processing of LTCC 40–43,54–56 . In particular, when CO 2 lasers are used, a high amount of thermal energy is dissipated into the surrounding areas of the LTCC substrate due to the large wavelength and long pulse durations 40 .…”

“…The parameters are based on the findings from preliminary work 47,48 and other studies on laser processing of LTCC. [40][41][42][43][54][55][56] In particular, when CO 2 lasers are used, a high amount of thermal energy is dissipated into the surrounding areas of the LTCC substrate due to the large wavelength and long pulse durations. 40 When cutting the LTCC substrate, the binder matrix is thermally removed and ceramic particles are deposited.…”