Rigid PCB (printed circuit board) inspection standards are an important quality control link that ensures the functionality, reliability and consistency of the circuit board.
The following is a detailed introduction to the rigid PCB inspection standards:
Dimensional inspection
Dimensional inspection is the first step in rigid PCB inspection. Its purpose is to confirm whether the actual size of the circuit board is consistent with the design drawing.
If the size deviation is too large, it may cause incorrect installation of components or connection problems. The specific contents of dimensional inspection include:
- Substrate size: Check whether the length, width and thickness of the circuit board meet the design requirements.
- Hole diameter and drilling position: Check whether the diameter and position of the drilling holes on the circuit board are accurate and consistent with the design drawings.
- Pad size: Check whether the size of the pad (connection point) meets the requirements to ensure that the component can be stably soldered to the circuit board.
Visual inspection
Appearance inspection is a link to quality control the surface and appearance of rigid PCBs, which mainly includes the following:
- Surface treatment inspection: Confirm whether the surface treatment of the circuit board meets the design requirements, such as gold plating, silver plating, tin spraying, etc. At the same time, check whether the surface treatment is uniform and whether there are defects such as peeling, scratches, etc.
- Contamination inspection: Observe whether the surface of the circuit board is clean and whether there are oil, dust and other contaminants. These contaminants can affect circuit performance and reliability.
- Color and texture inspection: Confirm whether the color and texture of the circuit board surface meet the requirements, especially for circuit boards with special appearance requirements.
Structural inspection
Structural inspection is an inspection of the internal structure and connection relationships of rigid PCBs, which mainly includes the following contents:
- Line inspection: Use a microscope to check whether the circuit board lines are complete and clear, and there are no breaks, short circuits, etc. At the same time, check whether parameters such as line width and spacing meet the design requirements.
- Pad inspection: Check whether the position, size and shape of the pads are accurate and match the circuits and components.
- Interlayer alignment check: For multi-layer rigid PCB, it is necessary to check the interlayer alignment to ensure that the positional relationship between each layer is correct.
Performance Testing
Performance testing is the evaluation process of the actual performance of rigid PCB, which mainly includes the following contents:
- Electrical performance test: Use test instruments to measure the voltage and current of key nodes on the circuit board to verify whether its electrical performance meets the design requirements.
- Reliability performance testing: Conduct environmental tests (such as temperature cycle, humidity cycle, etc.), mechanical tests (such as vibration test, impact test, etc.) to detect the reliability and durability of the circuit board.
- Functional test: Functionally test the circuit board by connecting relevant components and equipment to verify whether it can achieve the expected functions.
Logo and documentation checks
Marking and document inspection are important aspects of traceability and quality control of rigid PCBs, which mainly include the following:
- Marking inspection: Confirm whether there are clear and accurate markings on the circuit board, including product model, batch number, production date and other information for traceability and identification.
- Document inspection: Check whether relevant technical drawings, inspection records, production records and other documents are complete and accurate to ensure traceability of product quality.
To sum up, the rigid PCB inspection standard is a comprehensive quality control system covering many aspects from size, appearance to performance testing.
By strictly implementing these standards, the quality and reliability of rigid PCBs can be ensured, thereby ensuring the performance and stability of the entire electronic product.