Understanding the Importance of Quality Control in Electronic PCB Assembly

What is Electronic PCB Assembly?

In today’s modern technology, majority of the electronic devices we used in our daily activities has a Printed Circuit Board (PCB). One of its major functions is to serve as a substantial connection that will lead the path for the electric current flow towards the mounted electronic components like integrated circuits (ICs), resistors, and capacitors on the circuit board for it to function properly. The pathways which are patterned traces are made of copper and it connects the different component parts on the board to have a communication sharing within each other through signals and power. The process of soldering the electronic components with the PCB board are called electronic PCB assembly. 

The Importance of Quality Control in Electronic PCB Assembly

As quality control plays a vital role in PCB assembly process, the PCB assembly or production system should follow and maintain the set of defined quality control standards to ensure that the final product produced is aligned accordingly with the customer’s needs and requirements. These standards should excellently satisfy or better exceed customer’s expectations in terms of the final product overall performance.  Guaranteeing the quality control in the electronic PCB assembly process provides a safeguard to the final product branding by establishing a reputation for outstanding dynamic performance. 

Giving top priority to quality control in the PCB electronic assembly process can help the manufacturers lessen the risk of faulty or poor circuitry connections, open and short issues, or other electrical failures that could potentially lead to product deterioration and safety jeopardy. Enforcement of the quality control processes in the assembly of PCB provides a strong support in the identification and rectification of any PCB assembly defects. In addition to this, quality control methods that are implemented assists and guides in the prevention of potential issues that may arise during the lifecycle of PCB products such as components failure or system malfunction. 

Common Test Methods Used in the Electronic PCB Assembly

Catching-up issues and defects of a printed circuit board before shipping to customer is significantly a favorable aspect to electronic PCB assembly manufacturing than finding it once it is already utilized. In order to have a significant high-quality product, electronics PCB assembly process incorporates different PCB test methods at different stages in the production which makes the final product defect-free throughout the PCB assembly process. 

Common test methods used in the PCB assembly involves below quality control processes:

• Manual Visual Inspection – usually performed by a single operator using naked-eye, magnifying glass with lamp or a microscope to identify various PCB defects. This approach provides a good value for cost and efficient method to perform a quick evaluation of the product quality without demanding excessive effort and requiring any extensive resources or measures.
• Automated Optical Inspection (AOI) – a system that integrates high image acquisition which enables to identify defect patterns, image scanning and processing through a special software algorithm to identify defect patterns, and machine learning to inspect automatically various PCB defects. AOI increases the inspection quality in the PCB assembly ensuring that no defects are missed during the inspection process making this process incomparable to the accuracy eye’s capabilities. 
• X-Ray Inspection – X-ray uses technology that captures every angle of the PCB through proportionally absorbing of material’s atomic number, density and its thickness without manually rotating or destroying the PCB sample. As an X-ray tube generates radiation and passes through the material sample for isnspection, X-ray detector transform it to visual projections for us to be able to have defect analysis. This inspection method can specifically evaluate complicated defects in which are difficult to be visually inspected or cannot be visually inspected like solder void, solder quality, misalignments, etc.
• Flying Probe Testing (FPT) – is an electrical test method which uses power and test signals to test the continuity of the electronics PCB assembly wherein the probe is its core component. It is called flying probe because it does not use a fixture or testbeds and probes are mounted and is motioned controlled by a system that make contact swiftly at a high speed to specific test points to another to be able to detect electronic PCB assembly defects in the board. This method allows a fast validation of PCB electronic assembly quality.
• Burn-in Testing – is a test method that is also known as stress testing in which the components are mounted into a burn-in board and placed in a specialized burn-in chamber. The chamber system is controlled and operated beyond the normal working condition of the component. The operating conditions to be set can include various factors like temperature, voltage, current, frequency or other parameters that is set above the upper limit specification to induce failure into the device. Because of these harsh conditions, the PCB assembly manufacturers can identify which components will fail prematurely and discard the defective ones before reaching the next process or the customer.
• In-circuit Testing (ICT) – is a vital automated test method for PCB assembly process by detecting open or short circuits through probe contact in all the electronic component ensuring the quality of the electronic PCB assembly. The ICT uses test signals to components on a live circuit board and will perform a separate test on each component using specialized test probes to verify and assess PCB’s functionality and gain insight into how the units will operate collectively by using a testing equipment called In-circuit Testers. 
• Functional Testing (FCT) – is a test method used to perform to determine if the electronic PCB assembly is good or bad through the verification of the product’s functionality and connectivity. This test procedure is one of the attributes that needs to be performed for quality control as it is being done in the final assembly process. Test probe cards are used as a connection between the test equipment and the PCB test points and pads. By running a test software program from a computer, it can help to verify product’s possible issue on its functionality and reliability. As the FCT test method uses the PCB assembly’s normal operating condition for the simulation, it ensured that the process of. PCB process will be able to maintain the highest standards for prior delivery to next process or customer.

Furthermore, one of the essential aspects of PCB quality control is to ensure the integrity of the data all through out the electronics PCB assembly process. One factor to consider to be able to this, is to maintain and establish a proper system documentation and record-keeping procedure. Also, a fundamental item to contemplate for quality control is a robust training and development program for PCB assembly personnel. This program will help them gain knowledge as well as deep understanding of the quality controls and standards in order to empower them drive for product quality improvements and process stabilization.

Conclusion
In conclusion, the importance of quality control in the electronic PCB assembly process is beyond immeasurable because it provides a non-ending beneficial factors for the manufacturers. By implementation of these various quality control processes, it is ensured that high product standards are sustained with a sequential outcome of improved product quality, reduced liabilities, and a positive impact on profit and reputation. The most important thing is that the loyalty of the customer is assured because of the consistent sustenance of quality control in the PCB assembly process.