How to compromise the tunable resolution requirement and mechanical design is a big issue for ink-jet fabrication. The conflict comes from the innate characteristics of loose pitch resolution between nozzles for the piezoelectricity inkjet print head. This article disclosed a mechanical design methodology for multiple print heads, to use for large size panel in high resolution by ink-jet printing without mechanical inaccuracy, and the white omission in pixel or drops mis-landing could be eliminated. Four heads consisted as a basic module, and could be continuous tuning the nozzle pitch by micro-driver and optical magnifier assistant up to 200 dpi ± 1um, and the surface alignment of ink-jet heads for different modules can be controlled with ± 50um above substrate. Besides, the mechanical designs for reduction of the ink temperature fluctuation, the isolation of temperature transfer into motion stages, as well as a trimming design of air bubble within ink flow path to avoid deterioration in printing quality were also presented. Several important concept included the ink supply, piping, temperature consideration, isolation of head module, degas function etc. were discussed. This design proved a good design in mechanical design and its alignment methodology, and can be transferring heat in uniform to keep the temperature variation along the direction of nozzle in order within ± 4°C, and by simulation results, multi-stage heating design is preferred to avoid the temperature drop from main chamber to print head.