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- September 29, 2022
- PCB knowledge
- (0)
- 06 mins
A comprehensive look over PCB electronics
In the fast growing world of technology and it wonders printed circuit board (PCB) electronics play a vital role, although they are commonly unheard or unspoken in our tech talks, without them there will be no smartphones, satellites, LEDs, and countless other electronic devices which are making our lives easier and better. Made out of fiber glass, epoxy composite, these PCB electronics provide physical support and wiring area for through hole or surface mounted electronics component.
What is PCB electronics?
PCB electronics are simple electronic devices which have single layer PCBs, on the other hand our graphic card or motherboards have several layers sometimes up to twelve layers.
Common PCB electronics
Common PCB electronics that we use in our daily includes TV remotes, audio amplifiers, air conditioner control cards, etc. If you take a break and give a thought of the places mention below. How much these fields are dependent on electronic device?- Medical Devices
- Industrial Machinery
- Lighting
- Automobiles and aerospace industries
The role of PCB in electronic products
A printed circuit board (PCB) electronics provides a rigid structure which contains electrical circuitry which are interconnected by traces and large area of metal called planes. The FR-4, commonly used PCB are flame-resistant composite made up from fiberglass cloth and epoxy resin. Electrical and electronic components are soldered on metal pads of PCB to perform there desired task properly.
The advantage of PCB in electronics
It is necessary for electronic devices to work in all type of landscapes, be it mountains, plains, plateau, forest,desert, etc and all the weather which the planet Earth has to offer.
Since it is important for PCB (or PCBA; printed circuit board assembly) to function properly regardless of humidity in air, water from rain, temperature of its vicinity, moisture, dust, all these natural agents directly effects the performance of printed circuit boards,so the PCB in the electrical appliances can better face more stringent conditions.
How can PCB board of electronic products be waterproof, moisture-proof and corrosion resistant?
Protection of printed circuit board (PCB)
The need to protect PCB is crucial to function properly. For this purpose Ingress Protection (IP) ratings are specified to deal with different types of working environment for electronic devices to operate. In IP rating two numbers are used to express the level of protection. The first number indicates protection from solid materials and second number is use to indicate protection from liquid materials.
It does not require a downpour of water to ruin the PCB, only few drops of water or even moisture is enough to disturb functionality of PCBA (Printed Circuit Board Assembly) by shorting undesired electrical connection which can sometimes lead to flame, electrical spark or burnt electrical traces.
Waterproof printed circuit board
Waterproof PCB are special type of boards whose functionality is not effected if they become wet.
- Waterproof PCB can tolerate water and dust which prevent corrosion and oxidation.
- It provides comprehensive use of electronic devices e.g. smartphone can operate under water normally.
- Because of high level quality check these PCB tend to last longer than standard PCB.
- These are high precision boards with high baud rate.
Moisture protection of PCB
It is well-known that water is a good conductor of electricity but pure or distilled water behaves as an insulator because it is free of any type of impurities (chlorides, sulphate, dissolved salts and carbonates) this deionzed water has 1.8 x 10^7 Ω-m 25 ℃ resistivity which prevent the flow of electricity.
But tap water which contains inorganic materials is highly conductive and can easily cause short circuit, it provides alternative path for short and corrosion on PCB. Much higher threat which is often neglected is moisture. The moisture accumulates on PCB by the process of condensation which occur due to cold board surfaces. Following steps can be carried out during PCBA manufacturing for protection from moisture:
- A desiccant drying agent can used during lamination to absorb moisture from air.
- In case environment is not regulated during manufacturing process the baking the prepegs is appreciated.
- Meshed copper planes are used to prevent moisture motion between PCB layers.
- By choosing a right surface finishing can help in preventing from moisture and provide good surface for soldering of components on the PCB.
Corrosion resistant PCB
Copper and other base metal corrode easily so some manufacturer uses gold or gold nickel alloy for to lay PCB traces. Using precious metal like gold is expensive and only use for special or high performance PCB electronics.
Corrosion is an oxidation process occur due to humid air or water, so it can easily be minimized by blocking contact between PCB and air. For this purpose conformal coating is use for copper expose area. Epoxy coatings, aerosol spray coatings and solder mask effective against oxidation and corrosion
The process of PCB electronics manufacture
The PCB manufacturing is a complex procedure of different steps, usually the procedure changes after layer’s of production. The structure of the PCB may requires 20 steps which ensures mechanical and electrical support for the wafer and its connection between transistors.
The manufacturing process requires patience and dedication because the procedure require step by step working, if any step is skip this can lead to negative impact on PCB.
The process is taken under control environment. Initially electronic circuit designing software is required which decides what are the requirements of the device which is then further converted to PCB layout. Following steps are used for PCB manufacturing:
- Designing the PCB
- Design review and engineering questions
- Printing the PCB design
- Printing the copper for interior layers
- Etch the inner layers or core to remove copper
- Layer alignment
- Automated optical inspection
- Laminating the PCB layers
- Drilling
- PCB plating
- Outer layer imaging
- Outer layer etching
- Solder mask application
- Silkscreen application
- Electrical reliability test
- Profiling and route out
- Quality check and visual inspection
Hence, it is clear that although PCB looks simple but the process required for its manufacturing in extensive and detail which is needed in order for proper functioning of electronic circuit boards
Key points of PCB design for electronic products
The printed circuit boards (PCB) are the fundamental part of any electronic gadget or product which is used commercially and industrially. The PCB electronics design are made manually and automatically by hand and computer software. Computer software like Altium, Autodesk EAGLE, NI Multisim, Proteus, etc.
The PCB software is preferred because it provide efficient approach towards PCB designing and editing of single and multiple layers PCB. 3D rendering is used for inner and outer design of the board. PCB design reduces the possibilities of error and short circuit to prevent any hardware loss.
What are the features of PCB soldering in electronic product assembly?
Solder is a soft alloy used for electrical connection between the electronic components required on a PCB electronics. There are many types of solder available in market, selection of solder depend upon the type of soldering is needed. The solder also provide mechanical strength after solidification when required melting temperature is applied. Few common type of soldering are:
- Wave soldering is used for through hole components
- Reflow soldering is used for SMT (surface mount technology) in a reflow oven
- Selective soldering is used to remove damage components from PCB and where wave and reflow soldering is unsuitable.
What is circuit board copy board?
PCB copy board is also known as Circuit copy board, electronic products are operated by control parts of circuit board. The process of extracting the complete set of details, electrical connections and imitation of the product is called PCB copy board.
It make use of reverse engineering for making clone of desired PCB. Firstly, a PCB design tool is needed for making schematic of the circuit. Schematic make design process easier and predicts the working outcome of the hardware to be built. After schematic is completed, it is then transfer on PCB board for soldering of electronics component and testing.
The function of PCB copy board in upgrading PCB electronics
It is easier to upgrade PCB electronics when you have design the schematic. The electronic design software pace the upgrading and updating of the PCB and predicts the outcome before making it in hardware.
