Modern Techniques for Improved PCB QC

June 9, 2019 by Web Admin

Modern Techniques for Improved PCB Quality Control

Inspection of printed circuit boards (PCBs) is essential for quality control. With the refinement in the production process, it’s critical now more than ever for manufacturers to utilize advanced inspection techniques. 

Advanced inspection techniques have greatly helped in improving the product quality. Here we will discuss three modern inspection tools that companies are using today for inspection and quality control of PCB.

1. Quality Inspection Using Machine Learning

Spending on AI techniques is on the rise among companies today. AI spending is expected to increase from $19.1 billion today to nearly $52.2 billion in 2021. Automatic Optical Inspection (AOI) is one such AI technique that is gaining prominence among electronics manufacturers. 

Traditional imaging techniques used for quality control have certain limitations. The imaging techniques cannot help in detecting all types of defects in circuit boards. AOI helps overcome the limitation by using machine learning code. 

AOI systems perform an optical inspection of PCBs using machine learning vision algorithms. The algorithms can assess 2D and 3D images captured using special cameras to find defects on the board. 

The AOI cameras are specially designed to look for defects in the board. The cameras consist of a telecentric lens that creates an orthographic 3D projection by ‘flattening’ it, which helps reduce distortion. It allows the machine learning code to precisely measure the board and identify defects. 

Some systems capture 3D images instead of creating a project using nine cameras. The algorithm can assess the 3D image of the board including top and bottom views for more precise inspection of the board. 

2. Golden Sample 

Companies are using a ‘golden sample’ to envision the perfect board. The ideal sample that is flawless in every way is used during the inspection phase as a standard to measure manufactured units. Using the golden sample ensures that the manufactured unit is completely free of any defects.

The golden sample can be used to ensure the quality of the board in every aspect, from the integrity of leads soldered on the QFN package to the skew of components of the circuit board. It helps in pinpointing errors resulting in a high-quality product with near-zero percent defect, or Six Sigma. 

3. Inspection Using High Powered Microscopes

IBM had revealed last year that it’s building the world’s smallest computer that measured just 1 mm by 1 mm, which is smaller than a grain of fancy salt. The company had crammed thousands of transistors, SRAM, and photo-voltaic cell into the tiny circuit board. 

IBM

More companies will develop microcircuit boards in the near future. To inspect the circuit boards, companies are using high powered microscopes for modern PCBs in which components are crammed into tiny spaces. 

Apps such as Tagarno are used to analyze images of a circuit board taken with a high power microscope. The apps allow comparison of images with a ‘golden’ sample to improve quality control. Using the app, you can also perform other functions such as create circular annotations, arrow, add text, or adjust color. 

All of the above methods result in a high-quality inspection of PCBs. These techniques will help in creating flawless devices that perform without any anomaly.

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