Firstly, the copper foil substrate is cut into a size suitable for processing.
Note that before crimping the substrate, the copper foil on the copper surface needs to be roughened by bristling, micro etching and so on.
The dry film photoresist adheres to the copper core PCB board at an appropriate temperature and pressure. The photoresist polymerizes after the light transmission area of the film is irradiated by ultraviolet light (the dry film in this area will remain until the etching stops in the later steps of developing copper etching), and the line image on the film will be transferred to the dry film photoresist on the board.
On the film surface on which the protective film is torn off, use the post sodium carbonate solution to remove the unexposed area on the film surface on which the image is developed. Then, the exposed copper foil corrosion line is removed with a mixed solution of hydrochloric acid and hydrogen peroxide.
Finally, wash away the retreated dry film photoresist with sodium hydroxide aqueous solution. For inner circuit boards with six or more floors, use the automatic positioning punching machine to punch out the riveting reference hole for interlayer line alignment.
Connection between PCB components and substrate:
(1) Minimize the length of component leads;
(2) When selecting high-power components, the thermal conductivity of lead material shall be considered, and the lead with the largest section shall be selected as far as possible;
(3) Select components with a large number of pins.
PCB board device packaging selection:
(1) When considering thermal design, pay attention to the packaging description and thermal conductivity of components;
(2) It should be considered to provide a good heat conduction path between the substrate and the device package;
(3) Air barriers shall be avoided on the heat conduction path. If this is the case, a thermally conductive material can be used for filling.
