Laser Sintering of Barium Titanate for On-Demand Manufacturing of Electronics in Space

Laser sintering is a method used in manufacturing printed electronics to cure the deposited ink composed of nanoparticles suspended in a combination of solvent and binders. The direct exposure of the laser on the printed ink causes the solvent to evaporate and the particles to meld together to form a continuous film. The connectivity achieved by the sintering process results in a film with the desired electrical properties for the printed circuit. This work investigates the laser sintering of La-doped barium titanate ink on rigid glass and flexible polyimide substrates. The laser parameters are varied to test the sintering capabilities of the laser on the La-doped barium titanate. Parameters such as the laser wavelength, pulse duration, power, and scanning speed are tested. The laser sintering capabilities of each laser on the La-doped barium titanate are characterized by its resulting morphology through scanning electron microscopy. On glass, melding of the particles is achieved to create a continuous film; however, on polyimide, the laser power required damages the substrate. This results in lower power used on the polyimide samples, and grain growth and melding of particles are not achieved - resulting in the particles detaching from the polyimide surface. Similarly, laser sintering trials of BTO on printed silver for MIM capacitor measurements result in the BTO peeling off and capacitance measurements being in the low pF range rather than the expected high pF or low mF range.