(1) Pretreatment In the process of processing printed circuit boards, the copper foil substrate is first cut into a size suitable for processing and production, and then pretreatment is performed. Generally speaking, pretreatment has two functions: one is to use To clean the cut substrate, the daily purpose is to avoid the adverse effects of grease or dust on the subsequent lamination; the second is to use brushing, micro-etching and other methods to properly roughen the surface of the substrate, the purpose is to It is convenient for the combination of the substrate and the dry film. Usually, the cleaning solution and microetching solution used in the pre-treatment.
(2) Clean room In the transfer of circuit patterns, the processing of printed circuit boards has very high requirements for the cleanliness of the studio. Generally, laminating and exposure work should be performed in at least a 10,000-class clean room. In order to ensure the high quality of circuit pattern transfer, it is necessary to ensure indoor working conditions during processing. The indoor temperature is controlled at (2111) °C and the relative humidity is 55%-60%. The purpose is to ensure the dimensional stability of the substrate and film. Only when the whole production process is carried out under the same temperature and humidity, can it be ensured that the substrate and film will not expand or shrink. Therefore, the production areas in the current processing plants are equipped with central air conditioners to control the temperature and humidity.
Before substrate exposure, a layer of dry film needs to be pasted on the tomb board during processing. This work is usually done by a laminator, which automatically cuts the film according to the size and thickness of the substrate. The dry film generally has a 3-layer structure. The film laminating machine will stick the film on the substrate with appropriate temperature and pressure, and then it will automatically tear off the plastic film on the side that is combined with the board.
Because the photosensitive dry film has a certain shelf life. Therefore, the substrate after the lamination operation should be exposed as soon as possible during the processing, and the exposure is carried out by a light limiter. High-intensity TV rays (ultraviolet rays) are emitted inside the exposure machine. Used to irradiate substrates to be covered with film and film. With image transfer, the image on the negative after exposure is revers and transferred to the dry film. Thereby completing the corresponding exposure operation port.
(3) Etching line includes development section, etching section and film stripping section. The etching section is the core of this production line, and its function is to corrode the exposed copper that is not covered by dry film. (4) Automatic optical inspection is carried out After the inner layer is added, the substrate must be strictly inspected. Then the next processing step can be carried out, which can greatly reduce the risk. In this addition stage, the inspection of the board is carried out by the A0T machine for the bare board Appearance quality test. When working, the processing personnel first fix the board to be inspected on the machine, and AOT uses a laser positioner to precisely position the lens to scan the entire board. Then abstract the obtained pattern and compare it with the missing pattern to judge Whether there is a problem in the circuit production of eCE. At the same time, AOI can also point out the type of problem and the specific location of the problem on the substrate.
