In the PCBA production process, there is a link that cannot be ignored, namely the PCBA test link. This link is not only to check whether the PCBA is qualified and whether the subsequent work can be completed, but also to ensure the user experience and repair rate, and make the product more cost-effective. Therefore, PCBA testing is very important. So, what are the methods of PCBA testing? How to judge its specifications?

1. PCBA test method 1. 300X microscope

1) Use steps

① Place the observation object on the platform;

② Adjust the appropriate magnification and focal length to test until you see the clearest picture;

③ Use the 360-degree rotating lens to observe the state of the item.

2) Application scope

Including empty, cold welding judgment, foreign body identification, tin bead identification, parts damage inspection and parts eating tin surface height judgment.

3) Determine the specifications

First of all, the amount of tin noodles must be higher than 25%, the size of tin beads cannot be higher than 18um, and at the same time, there cannot be more than seven tin beads on the same board. Secondly, the parts must not be damaged, and there must be no foreign objects.

2. PCBA test two, red ink test

1) Use steps

① First use the flux residue on the 336A cleaner, and then add an appropriate amount of red ink to the object to be tested;

② After confirming that the red ink has penetrated completely, put the object to be tested in the oven and bake it, and then force it to be removed with pliers;

③ Use a 300X microscope to observe.

2) Application scope

Including cracks on the joint surfaces of parts and empty welding.

3) Determine the specifications

If the red ink penetrates into the corresponding pad, it means that there is crack or empty soldering at the joint.

3. PCBA test three, slice

1) Use steps

① Mix the acrylic powder and hardener in a ratio of one to one, and then put it into the box.

② Thirty minutes later, wait for the stirred object to solidify, take it out, and then grind it to a bad spot.

2) Application scope

Crack, empty welding, Cold Solder, observation of the joint surface of each part foot, etc., are all included.

3) Determine the specifications

When the operation of this tool is to determine the defect point, grind it to the defect point to assist other countermeasures to confirm the cause of the defect.

The above three are all PCBA test methods. In addition, there are PCBA test methods such as side microscope, X-RAY, solder paste printing inspection machine, ORT and so on.