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The Visitech technology glossary

DLP imaging, direct imaging lithography and additive manufacturing carry a vocabulary that is half acronym. This is what we mean by each of them — in plain terms, written by the engineers who build the hardware.

A to Z

Every term, defined

Search for a term, or narrow the list to a theme. Every entry links to itself, so you can send a colleague straight to the definition you meant.

22 terms

C

Cooling system
How the heat is taken away — air or liquid. Liquid cooling holds the optics at a steadier temperature, which matters because a warm optical train drifts and a drifting optical train moves the pattern.
Cost of ownership
What a machine costs to run over its life, not what it costs to buy: consumables, replacement parts, uptime, energy and the operator time it takes. LED sources with no lamp to replace are argued for on this basis.

D

Data format
Which artwork formats the head accepts directly — Gerber, ODB++, GDSII, OASIS and the bitmap formats — and therefore how much conversion sits between CAD and the machine.
Data throughput
How fast image data can be moved into the light engine. It is a real limit on scrolling exposure: the pattern has to arrive as fast as the stage travels, which is why 10 G links and streaming exist.

E

Ethernet
The network standard the light engines are controlled and fed data over. Industrial Ethernet means an integrator needs no proprietary interface card to talk to the head.

F

Firmware
The software running inside the light engine itself, as opposed to on the machine's controller.
Frame sync
The signal that ties each projected pattern to the motion system's position, so the right frame lands in the right place during a scrolling exposure.

L

LED driver
The electronics that power and regulate the LED source. Holding the flux constant rather than the current is what keeps the dose repeatable as the LED warms up.
LED safety switch
An interlock that cuts the light source when the enclosure it is built into is opened. A UV source at these powers is a hazard the integrator has to design around, and this is the hook to do it with.
Liquid cooling
Cooling by circulating fluid rather than moving air. Steadier optical temperature, no fan vibration, and the heat leaves the machine instead of the room.

M

Machine builder
The company that designs and sells the finished production machine, and integrates subsystems such as a photohead into it. Visitech's direct customer.
Motion stage
The moving platform that positions the substrate under the head.
Motion system
The stages and drives that move the substrate, the head, or both. In a scrolling system its accuracy and the exposure are one problem, not two.
Multihead
A configuration using several photoheads or light engines side by side to cover a larger area than one could, at the same resolution.

O

Operation mode
How the head exposes: scrolling past a moving substrate, or static over a stationary one. The choice drives throughput, accuracy and how the motion system has to be built around it.

P

Power consumption
What the unit draws from the supply. It is a cabinet and cooling number as much as an electrical one.
PSU
Power supply unit — the separate box that feeds a light engine. Its rating is part of what an integrator has to plan cabinet space and cooling around.

S

Scrolling
Exposing while the substrate moves continuously past the head, the pattern streaming to the DMD in step with the motion. It covers large areas without the start-stop of a stepper.
Stacking
Arranging several light engines over the same area so their fields combine — for more power, more coverage, or both.
Static / stacked
Exposing with the substrate held still, one field at a time — and, where more area or more power is needed, several heads stacked over the same region. Slower than scrolling, and where the ultimate precision is available.
Subsystem
A complete functional unit meant to be built into a larger machine rather than used on its own. Everything Visitech makes is a subsystem: the customer builds the machine.

T

Throughput
How much a machine gets through in a given time — panels an hour, parts a shift. The number an integrator is usually buying.

Still not clear?

Ask the people who built it

A definition only goes so far. Tell us the substrate, the line/space you are aiming at and the format, and we will come back with what it means for your machine — usually within two business days.