Factors affecting the quality of exposure imaging by circuit board factories

　　Our staff strictly control every production detail of the circuit board factory. Today, we still share with us those factors that affect the exposure and imaging of the circuit board factory. Those who are interested must come and have a look. We have belonged to our circuit board factory (Shenzhen PCB circuit board manufacturer) own freestyle.

　　Factors affecting the quality of exposure and imaging by the circuit board factory:

　　One, the choice of light source

　　In the circuit board factory (Shenzhen PCB circuit board manufacturer), any kind of dry film has its own unique spectral absorption curve, and any kind of light source also has its own emission spectrum curve. If the main spectral absorption peak of a certain dry film overlaps or overlaps most of the main spectral emission peak of a certain light source, the two match well and the exposure effect is the best. The spectral absorption curve of domestic dry film shows that the spectral absorption region is 310~440nm. Dysprosium lamp, high pressure mercury lamp, and iodine gallium lamp have relatively large relative radiation intensity in the wavelength range of 310~440nml, which is an ideal light source for dry film exposure. .

　　Line exposure machine (PCB circuit board/circuit board)

　　Line exposure machine (PCB circuit board/circuit board)

　　2. Exposure time control

　　In the light-gathering process, the photopolymerization reaction of the dry film does not complete the reaction at the sight of light, but requires a certain exposure time

　　make an adequate response:

　　When the exposure is insufficient, due to the incomplete polymerization of the monomer, the film swells and becomes soft during the development process, and the lines are not clear.

　　The color is dim, or even stale. During the pre-treatment of electroplating or the process of electric quilting, the film is warped, infiltrated, or even peeled off;

　　In the circuit board factory (Shenzhen PCB circuit board manufacturer), it will be difficult to develop, the film will be brittle, and residual glue will be left when overexposure; incorrect exposure will cause deviation of the image line width, and excessive exposure will Make the lines of the pattern plating thinner, and make the printed and etched lines thicker. On the contrary, insufficient exposure makes the pattern plating lines thicker and the printed and etched lines thinner. In order to determine the exposure time, it is usually recommended to use a Riston 17-level or Sbuffer 21-level optical densitometer.

　　BGA circuit board (PCB circuit board)

　　BGA circuit board (PCB circuit board)

　　The circuit board factory (Shenzhen PCB circuit board manufacturer) also needs to pay attention to the visual positioning in the exposure positioning:

　　The visual positioning of the circuit board factory is usually suitable for the use of a diazo master. The diazo master is brown or orange in a semi-transparent state; but it is not transparent to ultraviolet light, and the pad of the master is overlapped with the hole of the printed board through the diazo image. Align and fix with tape to perform exposure.

　　The above is the freestyle of the small circuit board factory. I don't know if you already understand it. These are the factors that affect the quality of exposure and imaging of the circuit board factory.

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