INSPECTION & TESTING PROCEDURES FOR PCB ASSEMBLY

Inspection & Testing Procedures for PCB Assembly

Advanced Assembly employees at different stages of pcb assembly

Given mixed-performance requirements, today’s PCBs are amazingly complex. They also typically feature a diverse set of highly sensitive components, and they are quite literally crammed with capabilities on shrinking real estate. For these reasons, rigorous testing and inspection procedures are important for component compatibility and manufacturability, especially during the prototype stage when speed and flexibility are a must.

Testing Overview

Testing and inspecting PCBs throughout the PCB assembly process is crucial to ensure high quality products are delivered to customers. Emphasis should be on prevention rather the fixing mixing after the fact with rework. In this high-level article, read the most common types of testing and inspection performed by PCB assemblers.  

Read: PCB assembly testing & inspection overview

Common Defects

Statistical analysis of common defects in PCB assembly reveals nearly one-quarter of them are of the nature of open circuits, about one-fifth caused by insufficient solder, and nearly one-seventh due to solder shorts. Other less frequently occurring defects related to solder paste are misaligned components and excess solder making up about one-twelfth and one-thirtieth of defects respectively.

DEFECT RELATED TO RATE
Open Solder Paste 25%
Insufficient Solder Paste 20%
Shorts Solder Paste 14%
Excess Solder Solder Paste 8%
Misaligned Components Pick and Place 12%
Wrong Components Pick and Place 5%
Wrong Orientation Pick and Place 3%
Defective Components Various 8%

Tailoring of inspection and testing methods is necessary for varying levels of effectiveness with each type of defect.

DFM / DFA Checks

DID YOU KNOW … 94% OF ASSEMBLY DATA IS ACCIDENTALLY SUBMITTED WITH ERRORS.

Most PCB fabrication and assembly companies have some form of design rule checking functionality. But these tools are not all created equally. Only trust your designs to true comprehensive design for manufacturing or assembly checks. Here are two of the best: 

Advanced Assembly’s BOM Builder

This check catches design errors before they cause delays, saving up to a full week in assembly turn time.

Learn More

Royal Circuits’ DFM Check

Do a “spell check” of your design. Fifty-seven checks performed by this service in minutes.

Learn More

Debugging Your PCB

While working with reputable PCB fabrication and assembly partners greatly increases your chances of receiving PCBs that work straight out of the box, occasionally you will get a board that doesn’t work. When this happens, how do you start figuring out why? 

Read this article for useful tricks and steps that will help debug your PCB. 

read: debugging pcbs

Quality Testing

LEARN THE INS AND OUTS OF QUALITY TESTING

Today, PCBs are incredibly complex with tiny components and tight space restriction. For this reason, thoroughly testing completed boards for component compatibility and manufacturability is critical, especially during the prototype stage when speed and flexibility are a must.

Read this article for an overview of the types of testing methods used by PCB assemblers.

read: ins & outs of quality testing

3D X-Ray

3D X-Ray machines can detect a number of problems that can not be seen by the human eye including solder joint shorts, opens and voids. Watch this video to see Advanced Assembly’s X-Ray in action.