PCB making and PCB designing are two different processes to consider. Yet, they are very much interconnected as these are the two major and unavoidable steps to be followed while we are developing electronic circuit boards. These two steps are very essential in the production of final, functional PCBs. PCBs are an inevitable factor for all of the electronic equipment nowadays ranging from smartphones to industrial devices. PCB designing is concerned with the conceptual and technical aspects of laying out a circuit whereas PCB making process just focuses on the physical fabrication of the board based on the design that we made. These two aspects must be strictly known by anybody who is dealing with electronic manufacturing and engineering. PCB making company would provide many services for the customers.
What is PCB Designing?
The initial phase of PCB development which involves designing the PCB layout according to the requirement of the consumer is known as PCB design. Before the PCB board making process, effective PCB designing is a must-be. In PCB design, the designers and engineers will create a schematic and layout which defines how the electrical components have to be arranged within the board and how the interconnections can be done within the components without any overlapping. The main aim of PCB designing is to ensure the circuit function as intended and also at the same time, consider factors like signal integrity, manufacturability and power distribution in the making of PCB board.
Key Features of PCB Designing
Schematic Capture: The initial process of designing a layout starts with the creation of a schematic diagram. The logical connection between each component can be seen from this schematic. The schematic also shows how the components like resistors, capacitors, ICs etc. are connected via electrical paths.
Component Placement: Right after the schematic is completed, we start with the component placement. It is generally called the assembly of the PCB, which could be with SMD (Surface Mount Devices), through-hole devices or even both. Designers design the layout accordingly so that each components have enough spacing in between them and they are placed in a way to reduce the signal path length as well as to prevent electromagnetic interference in the making of PCB board.
Routing: PCB routing consists of drawing the traces which will then connect the components according to the schematic provided. To maintain good signal integrity and to minimize noise after the entire making of PCB board, routing must be carefully done for High-speed signals, power lines ground planes etc.
Layer Stack-Up: Most of the PCBs will be multi-layered with internal layers dedicated to power distribution or signal routing. To avoid interference and to ensure proper grounding, the design phase will have the details specifying how many layers are needed for the action.
Design Rule Check: Designers will perform a design rule check specifically after routing to ensure that the PCB layout will meet the terms of the manufacturing protocols. These protocols include trace width, minimum hole size and clearance. Doing design rule checks will also avoid errors during the fabrication process.
File Formation: When the PCB design is completed, the design is produced into a set of manufacturing files. These files are generally known as Gerber files. They are used by the PCB making company to create the physical board from the PCB design.
PCB Designing Tools
PCB designing is carried out with specialized software and designing tools. Some of the commonly used software nowadays for designing PCBs are given below.
- Altium Designer
- Fusion
- EAGLE
- KiCAD
- OrCAD
PCB designing tools will help in creating schematics, placing components, routing signals, performing simulations etc.
What is PCB Making?
PCB board making process is the process of manufacturing the PCB board physically based on the design file created in the design phase. This process will transform the digital layout into a solid circuit board using several processes and machinery. The PCB board making process involves several stages. It starts from collecting the raw material to drilling, plating and applying solder masks. Reliable PCB manufacturers would provide a rational PCB making service. However, we need to learn about what is PCB fabrication.
Steps Involved in PCB board Making Process
- Material Selection: The first and foremost step for every PCB board making process. In the case of PCB, the selected material will be typically a composition of fibreglass and epoxy resin known as FR4. The PCB board material is then firstly laminated with a layer of copper foil. This copper foil will then form the conductive traces for the board.
- Photolithography: In photolithography, the traces and pads of the PCB design are transferred onto the copper-clad board using a photolithographic process. In this PCB board making process, a photosensitive layer is applied to the copper and then the board is exposed to UV light through a mask that is the same as the PCB layout. Then the copper traces are formed by itching away the exposed area.
- Etching: Etching is essential in the making of PCB board. The unexposed copper areas in the board are chemically itched away which will leave only the board with traces, pads and copper pours. This will exactly match the PCB design made. The electrical pathway of the board is created by this method.
- Drilling: Drilling in the board means putting holes for through-hole components. Drilling also helps in providing a connection between the layers by providing vias. In the PCB board making process, the size of the drill and the position to be drilled are determined by the design files of the PCB.
- Plating: Plating of the PCB is done right after the holes are drilled. After the drilling is done, the holes are plated with copper to create electrical contact between different layers. Plating is basically the process which will give conductive capabilities to the holes which are drilled.
- Solder Mask Application: A layer of solder mask which is generally green in colour is applied to the PCB board to protect the copper traces. This mask will also prevent the occurrence of the Solder Bridge during the time of component assembly. The solder mask will leave exposed areas and this is the area where the components will be soldered onto the board.
- Silkscreen Printing: The silkscreen layers are applied to the PCB to indicate component placement, number of pins, logos and other specific information. Silkscreen printing will help with component identification and they are very useful during assembly.
- Electrical Testing: As a final part after the PCB bard making process, the printed circuit boards undergo several electrical tests to make sure that all the connections are made properly and there is no presence of short circuits or open circuits in the circuitry of the board.
Difference Between PCB Making and PCB Designing
Focus and Goal
- PCB Making: The PCB board making process is clearly focused on the physical realization of the design. The main expertise needed for PCB making is the expertise in materials, fabrication process and machinery. The end goal of the PCB board making process is to provide a reliable physical board that accurately follows the design specifications.
- PCB Designing: The main focus of PCB designing is on the concept, logic and electrical aspects of the board. Designers, who are designing the board must be experts in electronics, circuit theory and CAD which are known as computer-aided design tools. The primary goal of PCB designing is to build efficient, functional and ready-to-make PCB designs.
Process
- PCB Making: The PCB board making process is completely a physical process it takes place inside a manufacturing unit or environment. This involves processing raw material, photolithography, etching, drilling, plating etc. The PCB board making process will be terminated after the production of the physical board is done.
- PCB Designing: This is not a physical process but more of a virtual process. This process is completed entirely using design software. The software side of PCB design involves schematic capture, component placement, routing, and simulation. The end product of the design process is a set of files which is known as Gerber files. This will delay the physical and electrical aspects of the board.
Time Taken
- PCB Making: The PCB board making process will typically take up to one or two days or some weeks in some critical cases. The time for fabrication of the physical board completely relies on the complexity of the board and the manufacturing capabilities. PCB making services can be done fast when the design gets finalized. Sometimes, delays might occur according to the production volume and because of used technologies.
- PCB Designing: The design phase can take a lot of time depending on the complexity of the circuit and the number of revisions required. To ensure proper functionality, the Design pathway may have simulation, testing and optimization on the timeline.
Final Output
- PCB Making: The final output that we get from the PCB board making process is a physical and intact printed circuit board. This board is then crowded with components in the assembly process making it a fully functional electronic circuitry which is good enough to be enclosed in any electronic devices that we have designed.
- PCB Designing: The output of the PCB design is a set of manufacturing files. This will include Gerber files, drill files, and a Bill of material (BOM file). These files are utilized for the PCB board making process and assembly process of PCB where we can place components according to the manufacturing part, component serial number and the silkscreen print on the PCB.
