LED exposure machine
UV curable ink (UVcurableink), also known as UV ink, refers to a certain wavelength of ultraviolet light, the ink component crosslinking reaction, from liquid to solid state to complete the curing ink. UV curable ink relative to the solvent based ink, is the main characteristics of quick drying, environmental friendly, energy saving.
A, PCB photosensitive ink photosensitive band
Wavelength range UV exposure lamp: UV exposure lamp spectral sensitivity range must match the UV ink. General requirements UV lamp wavelength range between l80-420nm.
Two, PCB board exposure required energy data
PCB board exposure ink types and energy requirements:
1, dry film thickness of 1.0-1.3mil to 45-60mj/C energy meters
2, wet film thickness 10-15 m 80-120mj/C energy meters
3, green solder film thickness 0.8mil 400-600mj/C energy meters
Three, we developed the light source for PCB exposure
With the advent of the LED light source, especially ultraviolet LED, we carried out the research and experiments were carried out in high power LED exposure machine field, and is tested in the light solid glue field, successful, on this basis, to process LED production of high-power planar light source and line light exposure machine.
I designed the LED exposure light source, using a single light source through LED, forming a rectangular arrangement.
From the source analysis in 5mm measure the intensity of light in the 2000mw/C square meters through the data.
Light energy = light intensity * time
Four, exposure mode
According to the energy required for the various types of solid materials, the light source can be used to finish the light in a short time.
Therefore, we design the LED exposure machine when scanning exposure.
The LED light source is parallel to the exposure frame from the exposure frame, and the exposure frame moves at a uniform speed for exposure. The speed of the exposure frame depends on how much light energy is needed for the solid ink. The exposure frame is driven by motor, and the speed is controlled by frequency converter.
The traditional exposure machine is used as the light source surface irradiation method, and exposure frame is stationary at the time of exposure.
Five, compared with the traditional exposure machine
Comparison between LED exposure machine and traditional exposure machine
1) analysis of the service life of the lamp source:
The traditional exposure machine with high pressure mercury lamp, high pressure mercury lamp life is about 800 hours, and the LED light source in the life of 30000-50000 hours.
2) the light emission rate:
The traditional metal halide lamp belongs to the thermal resistance luminous element, and has about 5 minutes in the opening process. The light source lighting, with the increase in heat current is reduced, the voltage at both ends of the lamp light source slowly rises, light, light power to make full play of each tube are equipped with a leakage transformer and a trigger circuit to maintain normal worklamp. Because of this feature, the exposure light is not exposed to the printed board (on standby). Exposure light is also in a state of light. On standby, just turn it to half power, while the light is on, in order to prevent ultraviolet radiation. The only way is to use a hood to cover the light, in the exposure of the hood when it opened, the light source power into full exposure. Standby time to light up 2/3. So the lamp life and energy wasted. In addition, we use the printed board as the light source is 7KW metal halide lamp, even in standby state can only be reduced to 5kW power, circuit board production are double-sided exposure, so the need for 2 7KW lamps. The LED light source is different, LED can light up instantly, and the optical power can be instantly released because of this characteristic, exposure by LED, but when the work to start light exposure, complete source is closed, the light source is not working when exposed to. This can save energy and prolong the service life of the lamp group. (energy conservation is also discussed in detail below)
3) environmental protection:
Traditional exposure machine light source is a metal halogen lamp, which is filled with a variety of elements in the lamp can shine. In order to achieve the peak wavelength, it is necessary to fill a part of the rare metal elements, when the lamp life is exhausted, the metal halogen lamp is abandoned. Most can not find a reasonable way to deal with, such as water and soil will cause serious pollution. The LED light source is different, it is the use of electronic components light-emitting, even after the scrap will not produce heavy metal pollution on the environment.
4) energy saving:
The traditional printed circuit board production using the exposure machine, metal halogen lamp with two 7KW, this source is a continuous spectrum, and the exposure is used the peak wavelength of 365nm-410nm light source, wavelength and other energy is being wasted. Circuit board exposure must be carried out at a lower temperature, usually controlled at 20 degrees Celsius, so as to ensure exposure accuracy. The exposure is a layer of film covering on board the PCB film on the graphics to be transferred to the printed circuit board, must ensure that the exposure area can make the film temperature is not easy deformation distortion, so as to ensure the accuracy of exposure, in order to ensure the exposure area must be equipped with a constant temperature cooling system. A large part of the energy consumed by the 7KW metal halide lamp is to produce heat energy, all of which must be matched with a chiller to cool the light source and the exposed area.
The existing double-sided high-power exposure machine, the total power of about 30kW, most of the energy generated by the lamp tube heat
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