Visual Inspection Process
There are a variety of structural inspection techniques available in addition to VI (visual inspection) with varying costs, performance, and defect coverage. Automated inspection techniques include optical, laser triangulation, and X-ray lamination techniques. To accomplish the best process inspection, manufacturers should understand the advantages and disadvantages of each inspection method and specify the best performance of each type. Professionals divide PCB assembly inspection technology into VI and automatic process inspection. We will talk about the VI process.
1. What Is The Visual Inspection Process?
As the original inspection method for PCBA, manual VI (visual inspection) directly inspects digital circuits with a magnifying glass or the eye. The Items checked are the integrity of connection patterns in soldering, bridging of solder joints, missed soldering, and incomplete soldering.
In manual VI, magnifying glass and telescope are the essential tools of Manual VI, which makes the check more flexible. In addition, inspectors can check for incomplete soldering and bridging on the IC leads with the help of metal pins. The inspector can check whether the PCBA is qualified and decide how to make adjustments. Manual VI has a cost and operational advantages in the short term.
2. When Does The Visual Inspection Process?
Technicians do the VI after the SMD process. They can use VI after many steps in the PCB assembly process, and the equipment used for VI is selected based on the location of the inspection target. For example, after manufacturers print the solder paste and place the part, inspectors can spot apparent defects such as contaminated solder paste and missing components with the naked eye. The most common VI is the ability to check reflow joints by looking at light reflected from different angles by a standard prism.
Typically, this type of inspection can test up to five solder joints in one second. The effectiveness of the VI depends on the inspector’s ability, consistency, and the applicability of the inspection criteria. The inspector must fully understand the technical requirements for each type of solder joint, as each type may contain up to eight defect criteria, and there may be more than six types of solder joints on different assembly equipment.
3. Why Make The Visual Inspection Process?
The benefits of VI of PCB assembly include:
It helps pay attention to preventative measures rather than dealing with problems after production. Using preventive measures is helpful because fixing issues on the finished product are costly and time-consuming. Identify and resolve errors such as short circuits and functional problems. Reduces waste and cost, as PCB assembly testing requires small assemblies and prototypes rather than complete products.
VI is the most cost-effective method of PCB assembly testing for direct prototype PCB assembly projects, allowing for the most competitive pricing without sacrificing quality. We offer VI as a standard service for all PCB assembly orders at Venture.
4. How To Do The Visual Inspection Process?
Establish VI standards for PCBA appearance, confirm the smoothness of post-process assembly, and ensure product quality. Manual board inspection is a visual assessment of the PCBA using the naked eye or other optical devices. Standard tools are cameras and microscopes, providing higher resolution than natural observation. The advantage of this type of inspection is that it allows the technician or quality control personnel to target specific areas of the board or specific parts for inspection.
Venture’s experienced quality engineers perform thorough VI at every stage of the PCB assembly process, from solder paste screening to part placement and through each soldering procedure. Performing incremental inspections allows for early detection of any errors and ensures minimal impact on the overall project cycle if corrections are needed.