PCB Assembly Inspection Guidelines and Procedures

In the past, manual inspections were the standard in the printed circuit board assembly (PCBA) industry. Today, machines help testers perform inspections. Learn more about this cost-effective and essential process:

Manual Inspections

During a manual visual inspection, a group of technicians will examine each board assembly individually. Then, they will compare the data to the proper design documents. Every board must meet the designer’s specifications.

AOI Inspection

An automatic  optical inspection (AOI) is faster, more reliable than a manual inspection, but it requires a state-of-the-art optical system. A typical AOI machine will take pictures of a board assembly, then it will compare duplicate images to find flaws.

X-Ray Inspection

BESTProto utilizes X-ray inspection on all lead-less devices such as BGAs, LGAs and QFNs.  In order to ensure there are no shorts between pads, we use an X-ray machine 100% of the time on lead-less devices.  X-ray inspection is also helpful to verify voiding on the solder joints and to quantify what percentage of the pad is covered with solder.

An AXI Inspection

To ensure a thorough inspection, a PCB technician must check every solder joint on a freshly assembled board. The problem is that some joints on a printed circuit board are hidden. In order to examine these joints, the PCB technician has to use an X-ray system. AXI stands for automated X-ray inspection. During this process, a machine produces an X-ray image that will display all solder joints that are nestled underneath the chips on a PCB.

Flying Probe Testing

This kind of test utilizes a machine that makes a quasi in-circuit test to the top and bottom of the PCB assembly. Flying probe testing can discover most manufacturing defects that most commonly occur during PCB manufacturing, such as:

  • Shorts
  • Opes
  • Resistant levels
  • Diode problems

Why PCB Assembly Inspections Are Important

A PCB assembly inspection is important because it helps manufacturers find defects before moving forward in the manufacturing process. By finding flaws early, manufacturers can ensure the reliability and quality of a PCB.

At BESTProto, we have experienced PCB inspection and testing technicians and engineers on our team. We can help you navigate the complex challenges of PCB inspection and testing. Contact us today to learn more about our PCB inspection and testing services.