Using Mirrors for Solder Joint Inspections? Here’s how to do it!

Abstract

This application note aims to discuss the use of mirrors to capture the side view of a PCB for solder joint inspections.

Problem Statement

If you are an engineer, you would know how essential solder joint inspections on a printed circuit board (PCB) is. Poor solder joints would go undetected if not done correctly or with your bare eyes, affecting your product or damaging your PCB. This is why many engineers would do a simple x-ray inspection on their PCBs, but if you do not have the materials, using an area scan camera should be sufficient for these inspections. 

However, area scan cameras can only produce a 2D image, or an image of the PCB from the front. This would be inefficient as it is unable to show the shape of the solder on the surface of the PCB. To combat this, many would attach additional cameras to capture the side view of the PCB. But is there a more efficient and cost-effective way to solve this problem? 

Solution

The SODA VISION Tech team has added two right-angle prism mirrors to both sides of the PCB to capture the side view of the solder joint, as seen in the figures below.

solder joint inspection with mirror set up
Figure 1: Solder joint inspection with mirrors set up
image of solder joint inspection with area scan camera
Figure 2: Side view of solder joints from mirrors

Along with a Basler camera acA4112-20uc, Basler lens C11-2520-12M, and a DCM Sistemes AMS2520A-W00i ring light, engineers are able to see and easily determine between good and bad solder joints through the mirrors. 

Using mirrors as a technique for solder joint inspections is also more cost-effective, as it helps engineers see the side view of the PCB without additional cameras. By using this technique, engineers are also able to measure the dimensions and thickness, and check the surface quality of the PCB during further inspections.

Reach out to us!

If you would like to know more about using mirrors in your applications, feel free to contact us!