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Print Settings Overview
NOVA is able to measure the pressure of the ink while dispensing, giving it total control over the flow properties of the printing material. While NOVA’s calibrate procedure will dial in these settings for you, there may be cases where you would prefer to control some of these parameters on your own.
There are five dispensing parameters that are accessible to the user. Three of them are absolute values, and two are ratios.
The target max pressure for a dispense operation. The dispense pressure is an absolute value of pressure (converted through ADC units) that controls the peak flow rate of the ink. Together with the print height and print speed, this value will affect the final width and thickness of your printed trace or feature.
A ratio from 0 to 1 which tells NOVA when it should begin moving in the XY plane at the beginning of a dispense operation. Once NOVA is in position to dispense, the smart dispenser will rapidly apply pressure, which causes the pressure to ramp up from relief pressure (0) to the dispense pressure (1). This parameter will control the shape of the start of a printed trace or feature.
An absolute pressure value that indicates the target pressure to terminate a dispense operation. When NOVA has finished printing, the smart dispenser will retract the plunger and de-pressurize (or in some cases, create a negative pressure), until it reaches the relief pressure. This value prevents leakage from the nozzle tip between dispensed features.
Relief pressures can be negative, up to a point. The O-ring on the smart dispenser’s plunger allows it to create a negative pressure to prevent leaking, but it can only pull back so far. Going too far negative can introduce air bubbles into the ink, which will cause print defects.
An absolute value in mm, the distance from the end of a trace or printed feature at which the Smart Dispenser will start retracting the plunger and de-pressurizing. The relief offset will control the shape of the end of the printed trace or feature.
A ratio from 0 to 1 which tells NOVA when it should begin lifting (in Z-axis) at the end of a dispense operation. This value should usually not be changed from 0; it is included only for niche cases, and can increase the stringing of ink while lifting away from the substrate.
The target XY travel speed in mm/min during dispensing. Although this parameter does affect the total print time, it will have a large effect on the final width and thickness of your printed features. Increasing print speed can allow you to print faster, but will also begin to impact print quality, especially at corners or intersections. Print speed is also a convenient method to adjust trace width, without adjusting pressure.
The spacing between adjacent printed traces used when filling in a feature. This is automatically calculated during calibration, and set to 80% of the target width of the trace. It can be manually adjusted if necessary to either fill in more or less of a feature.
The target temperature for the smart dispenser module. Set to 35°C or higher for most consistent printing.
The standoff distance in um (1000th of a mm) between the tip of the nozzle and the surface of the substrate. Along with print speed and the dispensing settings, this will have a large effect on the final width and thickness of your printed features. Because of ink properties, print height is not equal to your final print thickness - this depends on the spreading of the ink and the solvent content. For example, a print height of 60um can often result in a print thickness of 10-20um after thermal curing.
NOVA generates a heightmap by interpolating between probed points, it does not have a full surface scan. For that reason, the lower your print height, or the more uneven your surface, the denser you want your probing data to be (see probe pitch). NOVA can only compensate for features it is aware of, so please adjust your minimum raise height if there are other features present that can't be accounted for in probing data.
This is the z-axis travel height for moving between features during printing. This value helps ensure that NOVA will avoid any raised features in your design. Both substrate and ink have minimum raise height values — by default, NOVA will choose the largest of the two to be safe.
The minimum distance between adjacent probe points. This parameter controls the measurement density for generating your height map. A lower probe pitch will take longer, but will compensate better for height variations, allowing you to print at a lower print height (within reason).