Standard 2 Layer PCB production process

The production process of a standard 2-layer PCB (printed circuit board) mainly includes the following key steps:

Cutting:

Cutting large-sized copper-clad boards into specific substrate sizes suitable for production needs. This process not only includes cutting, but also involves grinding the cut substrate to ensure that the material size is accurate and meets the requirements of subsequent processing.

Drilling:

Using a CNC drilling machine, holes are accurately drilled at predetermined locations on the copper-clad board based on engineering drilling data. These holes will be used for electrical connections between the two sides or for installing through-hole components. During the drilling process, it is necessary to ensure that the hole wall is smooth and burr-free to avoid affecting the subsequent copper deposition process.

Copper deposition:

After drilling, the hole wall of the PCB is bulked and chemically treated to increase the roughness of the hole wall and enhance the adhesion of copper. Then, the copper ions in the electrolyte are evenly deposited on the hole wall by electrochemical methods to form a thin and uniform copper foil layer. This layer of copper is essential to ensure the conductivity of the hole.

Circuit exposure and development:

The circuit diagram in the CAM data is accurately projected onto the copper clad layer of the PCB using LDI (laser direct imaging) technology. At this time, a layer of photosensitive dry film is pre-coated on the surface of the board. After being irradiated by strong ultraviolet light, the dry film undergoes polymerization and initial solidification. Subsequently, the unexposed dry film is removed through the development process, leaving the solidified dry film to protect the copper foil area that needs to be retained, thereby showing the prototype of the circuit diagram.

Electroplating:

Electroplating is an important step in PCB manufacturing. Its main purpose is to further increase the thickness of the copper layer on the developed circuit and hole wall to ensure its conductivity and mechanical strength. The PCB is installed on the electroplating production line and electroplated after surface pretreatment such as degreasing and pickling.

Etching and film stripping:

Use etching solution to corrode the copper foil exposed after film stripping, and retain the copper foil under the tinned layer. Then remove the tinned layer to obtain the circuit pattern required by the design. After that, the PCB is placed in the film stripping equipment, and the remaining dry film is removed by chemical reaction to reveal the final circuit pattern.

Detection:

Use machine vision technology (such as AOI equipment) to detect process defects of PCB circuit patterns, such as open circuits, short circuits, broken wires, burrs, etc., to ensure that product quality meets customer requirements.

Please note that although this is an overview of the production process of a standard 2-layer PCB, the specific steps may vary depending on different manufacturers, equipment, and technologies. In the actual production process, adjustments and optimizations need to be made according to specific circumstances.