There is a process called "exposure" in PCB production process. In general, CCD semi-automatic exposure machine is used in PCB Factory. In addition to CCD, there is also a LDI direct imaging exposure machine.
Compared with the traditional CCD semi-automatic exposure machine, LDI has many advantages, such as no need for direct imaging of film, reducing the cost of film production, shortening the sample delivery time, reducing the error of film production and alignment, and more accurate line exposure. In addition to the above advantages, the exposure speed of LDI is slower than that of CCD, so it is more suitable for making samples.

The bottleneck factors of LDI exposure speed include: data storage and transmission, laser energy, switching speed, multilateral production speed, photoresist sensitivity, laser head moving speed, circuit board transmission mode, etc.
In terms of basic influencing factors, there are three independent factors that affect the exposure rate:
1. Energy density
2. Speed of data adjustment
3. Mechanical speed
The switching speed of laser modulation determines the number of light points that can be drawn per second. The demand for resolution will certainly affect the production speed. When the resolution is increased to twice, the light spot to be made will be quadrupled. Therefore, the relationship between the resolution and the load of setting exposure equipment will produce geometric magnification.
The moving speed of the platform will be an influencing factor, especially the mechanism of acceleration and deceleration. When the circuit board has to move to a new scanning area, the time required for its movement will directly affect the production speed, which is similar to the concept of laser drilling machine
Although the speed of LDI exposure machine is slow, it is indispensable for making high-precision circuit. At the same time, it can shorten the time of making film and reduce the cost of making film for PCB samples.