PrecisionCore inkjet printheads are precision devices, and the complexity of their manufacture makes it extremely difficult for them to be reproduced. Epson is able to maximize printhead quality by combining inkjet technology that the company has fine-tuned over more than two decades with a microelectro-mechanical system (MEMS) microfabrication process that allows us to process parts on a submicron level. Moreover, Epson maximizes productivity with automated production lines outfitted with original robotics technology.
PrecisionCore printheads can eject 50,000 ink droplets per second from individually controlled nozzles. The ink droplets are extremely small, weighing about 7 nanograms each. These crucial core devices largely determine the image quality and speed of an inkjet printer, and their production requires highly advanced technology. PrecisionCore printheads are manufactured at Epson's Suwa Minami Plant and Hirooka Office in Japan as well as at subsidiaries Tohoku Epson and Akita Epson, also in Japan. Production is accomplished by using the inkjet technology Epson has refined over more than two decades in combination with MEMS technology that enables these sites to fabricate components to 0.001 mm accuracy.
PrecionCore printheads are fabricated using the same technology that is used to manufacture semiconductor integrated circuits.
The reason that PrecisionCore printheads are so difficult to manufacture is that the manufacture and assembly of MicroTFP print chips, the devices at the heart of these printheads, require three innovative technologies that only Epson possesses.
PrecisionCore printheads are made up of Micro TFP print chips. These chips are produced by bonding together three silicon chips-a TFP actuator, an ink channel, and a nozzle plate. Ink that enters the flow path in the ink channel is ejected from the nozzles by the pump-like action of the TFP actuator. Epson's innovative thin-film piezo technology is used to manufacture the TFP actuators, while its innovative MEMS technology is used to manufacture the chip components. Epson uses its ultra-precision assembly technology to assemble printheads from electronic components and components that form ink flow paths.
Epson currently manufacturers MicroTFP print chips at its Suwa Minami Plant and Hirooka Office, using the same photolithographic process that is used to fabricate semiconductor integrated circuits of extremely fine geometries. TFP actuators are produced by uniformly fabricating extremely thin piezoelectric elements on silicon wafers. The piezoelectric elements are a mere 1 micrometer (1/1000 mm) thick. Even the slightest variation in thickness will result in uneven ink coverage.
In addition, the nozzle plates are processed using MEMS technology to create a precisely ordered array of nearly perfectly spherical nozzle holes a mere 20 microns in diameter.
Head assembly process before automation
Head assembly process after automation
Completed MicroTFP print chips are transported to Tohoku Epson to be assembled in printheads.PrecisionCore printheads are assembled in four main processes that involve an ACT unit, holder unit, filter unit, and head unit. First, an ACT unit is assembled from print chips, a driver IC mounted on a film substrate (COF), and components that form an ink flow path structure. In the ACT unit assembly process, the parts are measured using image recognition so that they are aligned and automatically adjusted to an accuracy within ±0.001 mm. After assembly, the printheads are automatically inspected to ensure stable quality.
Six-axis robots and other Epson robotics and image recognition technologies are also used to maximize accuracy in all subsequent processes. By automating everything from workpiece transfers to inspections so that human intervention is not needed, we are also able to reduce the airborne particle count, which is important for maintaining printhead quality, as particles can cause clogging.
To ensure high quality and productivity, we not only automate the assembly and inspection processes, but we also manufacture 95% of the components that go into our printheads at injection molding and machine press workshops at Tohoku Epson. Moreover, the precision molds that are essential in the manufacture of PrecisionCore printheads are also manufactured on the Tohoku Epson premises. The number of manufacturers capable of making such molds is limited, so manufacturing them internally has helped guarantee excellent product quality.
In 2019, Epson began producing PrecisionCore print chips at Building 9 at its Hirooka Office. Launching print chip production at Hirooka will triple Epson's print chip production capacity in the future and will enable Epson to meet the expanding demand for printheads-demand that is being driven by growth in the commercial and industrial printing markets. Increasing production capacity has also enabled Epson to sell printheads to other printer manufacturers around the globe.
The Building 9 factory has a high production capacity yet mitigates environmental impacts in various ways. LED lights are used throughout the building and the latest LEDs are used for yellow lights in semiconductor fabrication equipment. The amount of construction materials was reduced and space efficiency was increased by using high-efficiency task and ambient air conditioning. Moreover, all the electricity needs of Building 9 can be met with renewable energy.
Epson is firmly committed to changing the world with inkjet and will provide PrecisionCore printheads that only Epson can produce.