A printed circuit board(PCB) is used for mechanical support and electrical connection in electrical components by means of conductive pathways, signal traces or tracks from copper sheets laminated on a non conductive substrate. It was invented by Paul Eiser (Austria, 1941). PCB works as the foundational device of modern day electronic devices. It can be single layered board as in garage door opener, 6 layered in smart watch and as much as 60 layered in super computers. All the electrical components of a device are integrated by means of this board. Resistors, semi conductors, wheatstone bridge, diodes and capacitors are interconnected to one another and can communicate through PCB. These are widely useful in all of the modern day electronic devices ranging from smaller hearing aids to MRI, CT Scan machinaries, Aerospace monitoring tools, Super computers etc. PCB enables a single operating tool to regulate and manage all the electrical operations in a circuit.
PCB inspection is the necessary element in the manufacture of PCB. It evades all the possibilities of detected errors in default devices later on. To be used in smaller or larger electronic devices, PCB inspection facilitates the error reduction in modern day complex boards.
The various techniques used to undergo PCB inspection are:
-Manual Inspection: It is enabled by minute and detailed Inspection by engineering inspectors to survey any problem or error in the design of board. This method was used earlier in lack of automation devices and was very costly and time consuming. Repeated inspections were to be made that increased the chances of faluts after every inspection.
-Automated Optical PCB Inspection : This smart method involves a series of optical images where the image of a perfect assembly is compared to the image of the model to be inspected. It determines any faults with much accuracy.
-Automated X Ray Inspection: With the evolution of multi-layered boards as in super computers, the optical scanning of PCB has become very difficult. It is almost impossible to observe all the solder joints. The solder joints are must to be observed in new set ups to ensure proper joints. X Ray imaging has overcome this problem to inspect high density PCB. Automated X Ray Inspection detects the tracks, joints and signals from the hidden layers also. This method is little expensive but is the only option to find out defects in manufacture of high density PCB.
PCB inspection facilitates early detection of any manufacturing defects, directing the board for correction of defect before passing on to the next stage. This minimizes the wastage of time and cost required to remove the defect in next more complex stage of production. It enables the proper functioning of an electronic device managing all the assets of electronic components on an error free PCB.