Printed Circuit Board Design and Technologies PDF

University M’Hamed Bougara of Boumerdes, Institute of Electrical and Electronic Engineering, Department of Electronics Printed Circuit Board Design and Technologies...

University M’Hamed Bougara of Boumerdes, Institute of Electrical and Electronic Engineering, Department of Electronics Printed Circuit Board Design and Technologies Dr.F.MOUHOUCHE IGEE October 31, 2024 Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 1 / 68 Course Objectives This course provides the skills necessary to effectively design and implement a PCB. The course covers all the necessary aspects to design a PCB from an idea to a product by describing the steps involved in PCB Design and Fabrication process. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 2 / 68 Outline 1 Introduction 2 Introduction to PCB 3 PCB Fabrication Assembly 4 PCB design Software tools 5 PCB design: Practical examples + Projects for the students Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 3 / 68 Introduction The most vital element in electronic circuits and equipment’s is the Printed Circuit Board (PCB). It is also possible to build an electronic circuit with bread boards and zero boards, but the method is a low level and less efficient one wherein the designing circuit is prone to damage and the designing involves a complex process of placing the components of the circuit. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 4 / 68 Textbook(s) D. L. Jones, “PCB Design Tutorial”, June 29th 2004 M.I. Montrose, “Printed circuit board design techniques for EMC compliance (A handbook for designers)”, IEEE Press series on electronics technology, 2000 Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 5 / 68 What is PCB A printed circuit board (PCB) mechanically supports and electronically connects the electronic components using conductive tracks,pads and other features etched from copper sheets laminated onto a non conductive substrate. PCB is a non conductive material with conductive lines printed or etched. Printed circuit boards are the internal components that transmit electrical signals through electronic devices. A PCB allows signals and power to be routed between physical devices. Made up of one or more layers of electrical conductors that are separated by insulating material Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 6 / 68 The importance of PCB Saving Time and Energy They serve as the foundation for many computer components. A reliable option. PCBs not only helped in reducing the size of the electronic product but it also helped in making the product cost effective. Provides both the physical structure for mounting and holding electronic components They give input/output connections that make devices functional They provide electromagnetic shielding to guard the electronic components and cables against emissions of electromagnetic frequencies (EMF). Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 7 / 68 The history of PCB The first Printed Circuit Board can be traced all the back on early 1900 and a patent for Printed wire. In 1925 that Charles Ducas first submitted a patent that involved creating an electrical path directly on an insulated surface. It was a revolutionary idea because it could eliminate complex wiring and provide consistent results. Still , they did n’t really catch on until after WWII, when Dr. Paul Eisler in Austria began making the first real operational printed circuit boards in 1943. End of 20th century increased machine manufactured PCBs. Today 5G,Internet of things(IoT),artificial intelligence(AI) Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 8 / 68 PCB vs. Breadboard for PCB Stability and reliability More space efficient Better grounding Physical mounting is more stable(permanant) for breadboard Flexible Ease of debugging and isolating problems Fast! Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 9 / 68 PCB vs. Breadboard Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 10 / 68 PCB types There are several types of PCB S Single layer This type of printed circuit board contains just one layer of substrate, or base material. One side of the substrate is covered with a thin layer of metal,typically copper because it’s an excellent electrical conductor. Applications :Calculators, cameras, radio and stereo equipment, solid state drives, power supplies, printers and other consumer electronic products. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 11 / 68 PCB types Double layer are much more common than single- sided boards. Both sides of the substrate have metal conductive layers, and parts are attached to both sides as well. Holes in the board allow circuits on one side to connect to circuits on the other side. Applications Industrial controls, Power supply, Instrumentation, LED lighting, Vending machines, Automotive dashboards or Amplifiers. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 12 / 68 PCB types Multi layer Multi-layer PCB has multiple layers of PCB. So, we have to use a specialized glue for securing them together. We need to place the layer of boards by sandwiching them between insulation layers. Therefore, we can ensure that excess heat won’t damage the components. These types of PCBs are suitable for a wide range of advanced electronic applications. So, we often use multi-layer PCB in data storage, file servers, satellite systems, medical equipment, GPS technology, and weather analysis. Applications VLSI electronics, File servers, Data storage, GPS technology and Satellite systems, Weather analysis and Medical devices. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 13 / 68 PCB types Flexible PCBs are fexible and can be folded and are not hard as rigid pcb Rigid-Flex PCBs We manufacture rigid PCB from a solid substrate which prevents the twisting of the board. A computer motherboard is a common example of a rigid PCB. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 14 / 68 Parts of PCB PCBs consist of multiple layers that serve different functions: Conductive Layers: These layers are typically made of copper foil and form the electrical connections between the various components on the PCB. The copper is etched in specific patterns known as ”traces.” These traces are the electronic equivalent of wires in a traditional wiring harness and allow electrical signals and power to flow between the components. Insulating Layers: Between the conductive layers are insulating layers, also referred to as the dielectric. These layers prevent short circuits between the different conductive layers. They are mostly made from a material like FR4, a composite of fiberglass and epoxy resin. Components are the actual devices used in the circuit. This includes input/output connections. I/O ports, including power supply connections, are also important in the PCB design. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 15 / 68 Parts of PCB Pads are where the components are soldered to the PCB. Traces are the copper tracks that connect pads together.It is an Equivalent to wire for conducting signals Via are small holes through the board that link a bottom and top trace together electrically. Traces on the same layer cannot cross, so often, when you are laying out a PCB, you need to jump from one layer to another. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 16 / 68 Parts of PCB Silk-screen Print legend on PCB(line ,text or any art of the surface of PCB),usually for screen printing epoxy ink is used.Silk layer can be used in top and/or bottom layer of PCB. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 17 / 68 PCB characteristics Solder-mask is a layer of insulating layer that covers both sides of the board except where there are pads. This layer generally has green color.It is used to protect the copper foil from being directly exposed to the atmosphere, being oxidized and being accidentally touched by solder, which will affect the function of the circuit board. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 18 / 68 PCB characteristics In recent years,semiconductor packaging has evolved with an increased demand for greater functionality,smaller size and greater.A modern PCB design has two main methods for mounting components onto PCB:through hole mountingand surface mounting. Through hole mounting is the process of mounting electronic components by leads inserted through holes on one the board and soldered onto copper traces on the other side.Board may be single sided with an un planted component side, or more compact double sided boards with components soldered on the both sides. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 19 / 68 PCB characteristics Surface mount.technology is the process of the components were mechanically redesigned to have small metal tabs or end caps that could be soldered directly onto the PCB surface instead of wire leads to pass through the holes. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 20 / 68 Design process PCB design is the entire process of creating a Printed Circuit Board (PCB) through collaboration and integration between multiple disciplines and multiple domains which includes electrical, mechanical, software, system, test, and manufacturing. It’s a team effort that requires constant bi-directional communication Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 21 / 68 Step-by-Step PCB Design Guide 1 Understand the electrical parameters:Before starting a PCB design, you should know and understand the electrical parameters of the system, including: Current maximums Voltages Signal types Capacitance limitations Impedance characteristics Shielding considerations Type and location of circuit components and connectors Detailed net wire listing and schematic. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 22 / 68 Frame Title 1 Creating the schematic.One of the first steps is always creating a schematic, which refers to a circuit diagram. It uses agreed symbols to represent components and show how they area electrically connected. 2 Use a schematic capture tool to create your PCB layout which shows you exactly how your board will operate and where the components will be placed. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 23 / 68 Step-by-Step PCB Design Guide 1 Design your Board Layout PCB 2 Define design rules and requirements. Ensure that the logical (schematic) and physical (PCB) aspects of your design meet your design requirements. Proper design rule definition automates your design process ensuring quick, effortless, and error-free design manufacturing. 3 Place your components. 4 Insert drill holes. This step is driven by the components and a connection. About half of the flex circuits on the market are double-sided, which means they have connection to the drill hole on the bottom layer. 5 Route the traces by connecting segments of the path. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 24 / 68 Step-by-Step PCB Design Guide 1 Add labels and identifiers.Now is the time to add any labels, identifiers, markings, or reference designating to the layout. Reference designating are helpful in showing where specific components will go on the board. 2 Generate design/layout files.This is the final step in the layout process. These files contain all the information pertaining to your printed circuit board, and once they have been generated, your PCB is now ready for fabrication and manufacturing and assembly. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 25 / 68 PCB Designing process Steps Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 26 / 68 PCB design rules and constraints PCB constraints are used for defining the physical characteristics of a PCB to prevent manufacturing problems and to ensure the electrical performance of the board as well. There are four types of design rules: Electrical design rules Deal with electrical properties like impedance, voltage, and so on. Physical design rules Physical design rules: Related to factors such as trace width, via sizes, differential pairings, and so on. Spacing design rules: clearances between lines ;pads, vias and copper. Same net spacing design rules: clearances between lines ;pads, via and copper areas(shape) on the same net.These are differentiated from net to net rules. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 27 / 68 Design rules Keep enough space between traces:This avoids the occurrence of short circuits during the PCB manufacturing or assembly phases. As a general rule, it is recommended to leave a gap of 0.007 to 0.0010 inches between each adjacent trace and pad. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 28 / 68 Design rules Avoid 90° angles Trace width:there is no single standard PCB track width. Typical widths range from 0.2mm to 2mm. For signals, 0.25mm (10mil) is a common default, while power traces are often 0.5mm or wider. However, width should be based on current, impedance, and other requirements. Pad size :the standard size of a PCB pad can vary depending on the type of component and the design requirements. However, here are some general guidelines: For Surface-Mount Pads: These pads, which are used for components that are mounted directly on the surface of the PCB, usually range from about 0.8 mm to 2.5 mm in diameter. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 29 / 68 Design rules Types of PCB Pads Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 30 / 68 Design rules Pads to the edge of PCB:the minimum space from pad or plated holes to board edge is 3mm. Pad to Pad Spacingif the hole diameter of the pad is mechanically drilled, the minimum is not less than 0.2mm. If laser drilling is used, the minimum is not less than 4mil. Generally, the size of the hole in the pcb should not be greater than 0.5mm, Holes in PCBs are typically used to mount through-hole components (their main use), and to provide places to secure the board mechanically. Via is simply the name given to plated holes which are used to connect to tracks on different layers rather than to mount through-hole components Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 31 / 68 Component rules Separate the different areas from each other the separation of the different functional areas prevents dangerous interference between the mixed analog and digital signals, giving rise to cross-talk phenomena that compromise the integrity of the signal. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 32 / 68 Component rules Component orientation: All similar components should be placed in the same orientation.This will help in easy routing, faster soldering, and rapid placement by pick-and-place machines. Keep the components away from heat sources. The clearance between components in PCB is to keep a space of at least 40mil between the components, and at least 100mil between each component and the edge of the PCB. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 33 / 68 Designing of Multi-layer Boards A Multi-layer PCB is a printed circuit board that has more than 2 layers, unlike a double sided PCB or a 2 layer PCB board, which only has two conductive layers of material. All multi-layer PCB’s must have at least three layers of conductive material. layers in PCB design:PCB layers are the different conductive and insulating sheets that make up a circuit board, each serving a specific purpose in the overall design. These layers typically include copper for conducting electricity, insulating substrates, solder masks for protection, and silkscreen for labeling. Among all the multi-layered types, the 4-layer printed circuit board (PCB) is the most common. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 34 / 68 Designing of Multi-layer Boards Therefore, a 4-layer PCB means 2 signal layers + a positive voltage layer (VCC layer) + a ground layer (GND layer) or 3 signal layer + GND layer. In a 4-layer PCB design, more surface area is available for traces. Thus, this design structure offers excellent routing for low, as well as high-speed signals. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 35 / 68 How the multi layer board are constructed Multi-layer boards may be constructed using a double-sided sub-board at the center with single-sided sub-boards added to each side. There are many types of multi layer board construction. The different types are distinguished by the method used for making connections from one layer to another.There are three inter-connecting techniques which are newly used : Through viaPasses through all layers of the board. Blind viaConnects an outer layer to an inner layer but not all through. Buried viaConnect only to inner layers, which are not visible from the surface. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 36 / 68 Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 37 / 68 Structure of multi-layer When more routing space or signal integrity is required multi-layer PCBs are suited to meet these demands. Multi-layer PCBs stack multiple layers conductive and insulating materials to create a complex network of connections. The stack-up typically includes copper layers,cores,substrate and prep-reg Copper layers and substrate are familiar to the most designers. Prepreg and core are two types of insulating materials or dielectric materials in pcbs. prepreg is short or abbreviation of pre-impregnated.It refers to composite fibers that have already been impregnated with a matrix material, typically epoxy. In PCBs stack up prepreg serves as both insulating layer and adhesive layer. when constructing a PCB stack up the prepreg is placed between adjacent copper layers or between copper layer and a core material. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 38 / 68 Structure of multi-layer During manufacturing process ,high temperature and pressure cause the epoxy resin in the prepreg to flow and bond the layers together,resulting in a solid ,rigid board. Core:is the central layer of the board that provides mechanical support and rigidity.It typically consists of a laminate material made of thin layer of copper foil bounded to a rigid substrate material. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 39 / 68 Structure of multi-layer The lamination is the process of placing the stack-up under extreme temperature and pressure to bond prepreg and copper foil to the base PCB inner layers. The copper foil on the core serve multiple purposes, such as providing a ground plane or a signal plane. In multiple PCBs,there can be multiple core layers.with prepreg layers between each core layer and the outer core layer. The top layer is the outer layer of the multilayer PCB stackup. It’s where all the different components are placed, and it provides options for routing signals and traces. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 40 / 68 Frame Title Internal Signal Layers-Between the top and bottom layers, there are six internal signal layers. These layers give plenty of space to route signals, which is especially important for complex circuitry in designs with high density. Internal Power or Ground Planes Between the internal signal layers, two internal power or ground planes are placed. These layers are conductive and serve a couple of important purposes. They help distribute power and act as reference grounds, which helps reduce noise and electromagnetic interference. Bottom Layer-The bottom layer is the other layer for routing signals and traces, and it completes the circuit paths. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 41 / 68 Structure of multi-layer Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 42 / 68 Power and ground layers in PCB stack-up In multi-layered boards, if a component needs to draw power, then it is simply connected to the via that makes contact with the power plane.Similarly, the ground plane is a plane of flat copper connected to the common ground point in the PCB. Power and ground planes should be adjacent to each other to reduce EMI. The power and ground pins of the components can easily be connected to the power and ground planes. It provides a clear current return path, especially for high-speed signals. This in turn reduces the EMI (electromagnetic interference). Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 43 / 68 Advantages and disadvantages Advantages Smaller size: As electronics are becoming smaller and more sophisticated, PCBS are becoming smaller and smaller. Lighter weight: As PCBS get smaller, component sizes get smaller. flexibility. Higher durability: Multilayer PCBS tend to be durable due to their nature. Disadvantages Challenging Repairs and Modifications. Higher Costs. Increased Complexity. The design, manufacturing, and testing processes for multilayer PCBs are significantly more complex than for simpler single-layer or double-layer boards. Increased Design Time.. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 44 / 68 PCB Fabrication Steps Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 45 / 68 Step-1:Designing Electronic Circuit and layout Design the PCB Circuit With a Software Draw the schematic circuit diagram with the PCB layout software. Using KICAD software, Eagle and Multisim software PCB layout designing: Defining Trace Widths PCB layouts use traces to connect components, but how wide should these traces be? The required trace width for different nets depends on three possible factors: Manufacturability. Traces cannot be too thin, otherwise they can’t be reliably manufactured. Current. The current carried in a trace will determine the minimum required width to prevent the trace from overheating. When the current is higher, the trace will need to be wider. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 46 / 68 Step-1:Designing Electronic Circuit and layout Make important nodes accessible. Give space between components. Place components with the same orientation. Print the layout to see if components’ sizes match. Exchange wiring directions between layers. Do not mount the electronic components within 1.27mm around the non-mounting holes, such as tooling hole and standard holes. Avoid placing holes under the components such as the horizontally mounted resistors, inductors, (electrolytic capacitors, etc., so as to avoid short-circuiting the vias and component. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 47 / 68 Step-2:Layout Printing A special printer called a plotted printer is used to print the design of the PCB. It produces a film that shows the details and layers of the boards. When printed, there will be two ink colors used on the inside layer of the board: Clear Ink to show the non-conductive areas. Black Ink to show the conductive copper traces and circuits. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 48 / 68 Step-3:Preparing Substrate The selection of materials for a PCB is a critical aspect of the design and fabrication processes. The choice of materials can significantly affect the final product’s performance, reliability, and cost. The most common material used for the substrate in a PCB is fiberglass-reinforced epoxy resin (FR4). FR4 provides a good balance of performance, durability, and cost. It has excellent electrical insulation properties, good thermal stability, and high mechanical strength. Copper clad laminate, either single or double sided board is required. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 49 / 68 Step4: Etching The purpose of etching is to remove unnecessary copper traces from the substrate. During the PCB etching process, all copper is removed except for the circuitry that is protected by tin plating. Basic Ways of Etching Mechanical Etching :It involves the use of a machine tool and a special cutter to remove a narrow strip of copper from the boundary of each pad and trace this electrically isolates the circuit element from the rest of the foil. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 50 / 68 Step4: Etching Traditionally, PCB etching has been achieved using chemical methods. Chemical etching is the most widely used method in PCB manufacturing. It involves applying a chemical solution, typically an acid, to selectively remove the copper or unwanted copper from the substrate. The patterned areas are protected by a resist material, which prevents the etching solution from attacking the copper. The most commonly used technique is the Ferric Chloride etching process. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 51 / 68 Step-5: Preparing Drill Holes PCB drilling, or printed circuit board drilling, is the process of creating holes, slots, and other cavities into an electronic circuit board before soldering/mounting components onto it. It is typically done by using a PCB drill bit (an automated machine) that is slightly smaller than the components placed on it. Single-sided or double-sided PCB will be drilled directly after getting on the production line. Multi-layer board will be drilled after pressuring layers. By classification of the function, different drilling holes can be divided: through the hole, blind hole, Buried hole, etc.. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 52 / 68 Step-6:Electroless Copper Deposition Electroless copper deposition, also known as electroless copper plating, refers to the chemical process used to deposit a thin copper layer onto a substrate.The plating thickness is usually kept as 1 mil and sometimes it is set as half mil. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 53 / 68 Step-7: Soldermask Applications Applying soldermask is one of the most important process in board manufacturing. Coat the entire panel with a liquid soldermask.The board is then exposed to high intensity UV light.Soldermask is applied to achieve the following: 1 Protect copper circuitry from oxidation, damage, and corrosion. 2 Prevent solder shorting between components, and maintain isolation of the circuits during assembly Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 54 / 68 Step-8:Assemply Now, it is time to assemble all the electronic components onto the respective holes in the board. The components that are assembled in the board include: Terminals and Connectors Resistors. Switches. Capacitors. Network Components. Diodes. Transistors. Integrated Circuits (ICs) The following techniques are employed in assembling these electronic components: Surface mount assembly. Through-hole assembly. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 55 / 68 Step-8:Assemply Some of the key components of PCB assembly include: Solder: This is the material that is used to join the electronic components to the board. Flux: This is a chemical that is used to clean the surfaces of the board and the components before soldering. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 56 / 68 Step-8:Assemply PCB Assembly Process Solder Paste Application:The first step in the PCB assembly process is the application of solder paste to the board. Solder paste is a mixture of tiny solder particles and flux. The paste is applied to the board using a stencil, which ensures that the paste is applied only to the areas where components will be placed. The solder paste is then cured using a heat source. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 57 / 68 Step-8:Assembly Pick and Place:The next step is the pick and place of components onto the board. This is done using a pick and place machine, which picks up the components from a feeder and places them onto the board in the correct position. The machine uses a vision system to ensure that the components are placed accurately. Reflow Soldering:This process involves heating the board to a specific temperature to melt the solder paste and create a permanent bond between the components and the board. There are two types of reflow soldering: Convection reflow soldering uses hot air to heat the board. Vapor phase reflow soldering uses a vapor to heat the board. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 58 / 68 Step-8:Assembly Inspection and Quality Control The final step in the PCB assembly process is inspection and quality control. This step involves checking the board for defects and ensuring that it meets the required specifications. Inspection can be done manually or using automated optical inspection (AOI) machines. AOI machines use cameras to inspect the board and identify defects such as missing components, incorrect component placement, and solder defects. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 59 / 68 Step 9:Silk Screening Silk screening is where all the information is printed directly on the board with an ink-jet printer. It usually includes: Company ID Warning labels Logo or symbols Component numbers Pin locators and other marking Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 60 / 68 Step-10:PCB Testing The finished The finished boards are then sent for functional as well electrical testing to ensure optimum performance and quality. Electrical test is done using probe testers. Open and short circuit tests are performed. Electrical tests ensure functional reliability. Durability testing are also performed after functional test. Every PCB assembly is comprehensively tested against the original board data. At PCB Cart, we offer an advanced version of electrical testing called Flying Probe Testing, which depends on moving probes to test electrical performance of each net on a bare circuit board Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 61 / 68 Step-11:Cutting Individual PCBs The final manufacturing stage is cutting individual PCBs from the production panel. Generally, PCB manufacturers utilize computer-controlled milling machines or routers to cut individual PCBs without damaging other boards in the panel. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 62 / 68 Step-12:Final Inspection and Packaging In the final step of the process, the inspector should perform a final close inspection of each PCB. A rigorous inspection is conducted on individual boards to find out any obvious defects like scratches. In addition, they also check compliance of the board with the specifications provided by the customers. If all is well with the PCB,it will be packaged by securely boxed to keep out dirt, moisture, and other contaminants. The PCB is then delivered to the customer within a few days Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 63 / 68 Multilayer PCB Manufacturing Process 1. Design and Layout PCB Design Software:PCB design software, such as Altium, Eagle PCB, and KiCAD, is used to create the layout of the PCB Stackup Design:The stackup design is the process of determining the number of layers and the thickness of each layer in the PCB. The designer must consider factors such as the number of components, signal integrity, power distribution, and thermal management when deciding on the stackup design. Routing and Traces:Signal integrity analysis is a crucial step in the design and layout stage, as it helps to ensure that the signals on the PCB are transmitted correctly and without interference. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 64 / 68 Multilayer PCB Manufacturing Process 2. Pre-production:The pre-production stage is a critical step in the multilayer PCB manufacturing process. This stage involves selecting the materials and processes necessary for manufacturing the PCB and preparing them for production. Material Selection:The materials used for the PCB include copper foil, prepreg, and core materials. Process Selection:The selection of the manufacturing process for the multilayer PCB is also critical to ensure the quality and reliability of the final product. The manufacturing process involves several steps, including drilling, plating, lamination, and etching. 3. Inner Layers Production Inner Layer Imaging: Etchingto remove unwanted copper leaving behind traces Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 65 / 68 Multilayer PCB Manufacturing Process Stripping and Cleaning. Electrical testing of traces. Surface preparation for lamination. 4.Layer Lamination The inner layers have an oxide layer applied and then “stacked” together with pre-preg providing insulation between layers and copper foil is added to the top and bottom of the stack. The lamination process uses a combination of specific temperature, pressure for a specific time to allow the resin within the pre-preg to flow and bond the layers together to form a solid multilayer panel. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 66 / 68 Multilayer PCB Manufacturing Process Drilling :We now have to drill the holes that will subsequently create electrical connections within the multilayer PCB. This is a mechanical drilling process that must be optimised so that we can achieve registration to all of the the inner layer connections. The panels can be stacked at this process. The drilling can also be done by a laser drill Hole Plating Electroless copper plated as thin conductive layer Electrolytic copper plating to desired thickness Copper builds up on innerlayers and drilled holes 4. Outer Layers ProductionThe outer layer production process involves manufacturing the top and bottom copper layers of a multilayer PCB. The outer layers are bonded to the inner layers to create the multilayer PCB. Outer Layer Imaging: Etching Assembly Solder mask Application Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 67 / 68 Multilayer PCB Manufacturing Process 5.Final Production Routing This is the process of cutting the manufacturing panels into specific sizes and shapes based upon the customer design as defined within the gerber data. There are 3 main options available when providing the array or selling panel – scoring, routing or punching. Electrical Testing:Used for checking the integrity of the tracks and the through hole interconnections – checking to ensure there are no open circuits or no short circuits on the finished board. Quality ControlQuality control is the process of ensuring that the multilayer PCB meets the required quality standards. This involves inspecting the PCB for defects and ensuring it meets the design files’ specifications. Quality control can be performed manually or using automated inspection equipment. Dr.F.MOUHOUCHE (IGEE) EE341 October 31, 2024 68 / 68