Fabricating chambers of inkjet printhead by bonding SU-8 nozzle plate with suitable crosslinked degree

The process of fabricating chambers is becoming increasingly important for inkjet printhead. However, the majority of present fabrication methods suffer from some problems, such as chamber collapsed, chamber blocked, and the deformation of nozzle plate. This paper develops a novel method for fabricating inkjet chambers by bonding the nozzle plate of SU-8 photoresist with suitable crosslinked degree onto the open microchamber. The softbake temperature of the nozzle plates was optimized for the high bonding strength and the low chamber deformation. The crosslinked degree of the SU-8 photoresist with different exposure dose and post exposure bake (PEB) parameters were calculated based on Fourier transform infrared spectroscopy experiments. The effects of exposure dose and PEB parameters on crosslinked degree of the SU-8 photoresist were analyzed. The influence of crosslinked degree of the SU-8 photoresist on the chamber deformation rate and bonding strength were investigated. The optimized bonding strength of 0.57 MPa and chamber deformation rate of 4.35% were obtained in the final inkjet printhead. Compared with most of the current processing methods, this fabrication technique has great potential due to the decreased chamber deformation rate and the increased bonding strength.