Observation Eequirements For Printer Nozzle Under Microscope
1. Sample preparation requirements
1.1 Cleanliness: There is no residual ink, dust, or fibers on the surface and around the nozzle to avoid pollutants interfering with observation
1.2 Dry state: Before observation, it is necessary to ensure that the nozzle is completely dry, as residual ink may mask real defects
1.3 Fixing method: The nozzle should be stably fixed on the stage to avoid tilting or vibration affecting focusing
1.4 Protective measures: Avoid direct contact of fingers with the nozzle surface to prevent sweat stains and grease contamination
2. Microscope selection and setting requirements
2.1 Magnification factor: It is recommended to use a magnification of 100 ×~500 × to observe the overall nozzle array, which can be 50 ×~100 ×. Checking the details of a single nozzle requires a magnification of 400 × or more
2.2 Lighting method: Adopt coaxial falling beam lighting or circular LED lighting to avoid strong reflection affecting imaging
2.3 Working distance: Select a long working distance objective lens (≥ 8mm) based on the thickness of the nozzle to prevent collisions
2.4 Depth of field requirement: The nozzle surface may have slight undulations, and a microscope with sufficient depth of field or Z-axis stacking function should be selected
3. Key points of observation content
—Observe the specific requirements of the project
—The nozzle shape should have intact edges, no burrs, and no deformation. Circular nozzles should be perfectly round
—The deviation between the measured aperture size and the nominal value is ≤± 2 μ m, and the aperture consistency of each nozzle of the same nozzle is good
—The nozzle mouth is not blocked by dry ink or foreign objects, and the transparency is uniform
—Surface flatness: The nozzle surface has an overall flatness without scratches, dents, or protrusions
—Position accuracy: The spacing between the rows and columns of each nozzle is consistent and there is no deviation
4. Environmental and operational requirements
4.1 Temperature and humidity: Temperature 22 ± 2 ℃, relative humidity 45%~55%, to avoid changes in ink performance
4.2 Shock resistant: The microscope is placed on a shock resistant workbench to avoid external vibrations affecting high-power observation
4.3 Focusing accuracy: First, locate the target area at low magnification, and then gradually switch to high magnification fine focusing
4.4 Image recording: Retain ruler information, indicate magnification, date, and nozzle batch number
5. Common Defect Identification Standards
—Micro blockage: The nozzle mouth is covered with ink film but not completely closed
—Half blocked: The nozzle outlet area is partially unobstructed and partially blocked
—Wear and tear: nozzle edge rounding or asymmetric defects
—Residue: There are solidified ink droplets or foreign objects attached around the nozzle
The above requirements apply to the routine quality inspection and failure analysis of inkjet printer heads.