How to Become a PCB Designer?
If you're interested in becoming a PCB designer, one of the first things to consider is how much education you need. We've determined that 29.2% of PCB designers have a bachelor's degree. Choosing the right major is always an important step when researching how to become a PCB designer. If you are planning to be a PCB designer, come and read the content below to learn more information.If you want to order PCB product, please check and custom your order online. What are the requirements for becoming a PCB designer? Education Many engineers are laying out their own printed boards today. To become an electrical engineer or a mechanical engineer, you will need a BS in those related fields. Traditionally, PCB designers layout the board rather than "engineer" circuit boards or components of the board. As such, the educational background differs some. For those who are doing PCB layout specifically, there isn’t a degree dedicated to PCB design or printed circuit board creation. You will also find that there are still many positions that do not require the PCB designer to have a degree of any kind. However, you will have much better success as a PCB designer with experience or a degree that includes courses in drafting, computer-aided design, electronic design, hands-on printed circuit board work, or other related areas of study. As PCB designs become more complex, more companies will begin to require degrees for their PCB prototype designers. Lesson You need to work on real projects and get real experience. There are no shortcuts. Many people think, they can jump from Arduino to PC Motherboard design (would not be that fantastic? :). In reality, you need to practice. So, start with simple projects. This will help you to learn how to avoid all the beginners mistakes (e.g. connecting RX and TX the other way round ... yep, we all were there). When working with simple circuits, you will also start understanding how these simple circuits work … that is very important for more complex designs. This may be difficult for some people, but in many situations I found it very useful, that I went to University and we had all (for me quite difficult) subjects about electromagnetic fields, microwaves, semiconductors, … And I can tell you, there were times when I had no clue what they were talking about. However, having at least some understanding about electromagnetic fields can help you to imagine what is happening on your PCB. There may be times, when you may think, that you would like to explain others why you placed the component certain way or why you routed a track so complicated. But then you may think, that you may look weird, so at the end, you just keep it for yourself. What are the job contents of PCB designer? A PCB designer is responsible for taking a 2D schematic and creating the 3D CAD files used to manufacture the PCB. The first step is to create the component footprints, which show the size, shape, and orientation of each component. Second, the PCB designer creates a board outline with the dimensions and shape of the board as well as any keepout areas. Then the components with critical placement requirements are locked down, such as connectors that have to match up with another board. Once this is complete, the rest of the parts are placed onto the board. Routing is the process of running traces between components to connect them together. Critical routing happens first, where traces that must be the exact same length or traces that must be a specific distance away from another trace are routed first. Then the rest of the board is routed, with traces going up and down through multiple layers of the board. The final task a PCB designer does is to generate all of the manufacturing files. You can learn more about what PCB design is by reading our article. A good PCB is part electrical engineer, part manufacturing expert, and part computer guru with a bit of process engineer thrown in the mix as well. Mostly though, a PCB has to have the ability to see beyond the lines and shapes of components on their computer screen in order to visualize where the design is headed. A good PCB fabrication can create something from nothing while solving many different puzzles along the way. For example, a rats nest is when the netlist is loaded and all the traces are run from component to component without any regard. What is the future for PCB designer? With all of the new advancements in communications, computing, and IoT, the need for electronics design continues to grow. Simultaneously, the number of available PCB designers is becoming less as many are approaching retirement. As a result, the PCB design industry faces a shortage of new designers genuinely committed to the science and art of creating functional printed circuit board hardware. Therefore, this is the right time to pursue a career in PCB design. Does the idea of turning new ideas into working electronics hardware sound like something that you would like to do? PCB designers are used throughout the electronics industry, from original equipment design centers to printed circuit board manufacturers. Here at VSE, we have been manufacturing circuit boards for over 30 years and regularly work with PCB designers from companies representing a wide range of electronic technologies. So, if you are looking for a PCB contract manufacturer to build a circuit board or have questions about the role of PCB designers in today’s industry, give us a call.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/09/2021 10:18
Rigid-flex PCB Design Guidelines
A rigid flex PCB is a combination of both rigid and flexible substrates. One or more flexible circuits are used to connect subcircuits on rigid PCBs. Rigid flex PCBs are usually produced with flexible polyimide material on copper cladding substrate and connects to the rigid FR4 board. The flexible part of the rigid flex PCB usually features a multilayer built with padded through holes securing the interconnectivity between layers. If you are curious about the design process of rigid-flex PCB, please check and read the content below for more professional knowledge of it.If you want to order PCB product, please check and custom your order online. What are the benefits of rigid-flex PCB? Designing a rigid flex PCB is considerably more challenging than conventional rigid PCB. However, there are good reasons why rigid flex is used in some designs, particularly one that involves fitting the board in tight spaces. Increase reliabilityConnectors serve their purpose when there’s a need to remove the wire harness from the PCB routinely. For a design that involves multiple interlinking subcircuits in an enclosure, adding connectors to the PCB only increases the risk of failure. Space savingOften, the designs that call for a rigid flex PCB is one where space is a luxury. For example, handheld thermal scanners can benefit from a rigid flex PCB design as there isn’t much space to fit in wire harnesses and high profile connectors. Instead, with the interconnecting circuit built-in on the flexible substrate, you’ll have more space to route the traces around. Reduce costRigid flex PCBs are generally cheaper than their rigid counterparts, as the former is harder to produce. However, using rigid flex PCBs may reduce the overall cost of the product. As wired interconnects are replaced by the conductive layers of flexible material, you’ll save on the cost of assembly, which in some cases, involves manual labor. Ease of testingIt is also easy to automate testing of a rigid flex PCB as all the subcircuits are already interconnected when the PCB is manufactured. The ability to eliminate connectivity issues before the components are assembled, further, prevent unnecessary wastage and expenses. What are the guidelines of rigid-flex PCB design? Broadly speaking, a rigid flex design will closely resemble a hardboard design, with the flexible layers fully extending into the rigid areas of the board. Similarly to hardboard layouts, a rigid flex fabrication package will include Gerber layers, along with drill files, solder mask layers, nomenclature, perimeter/rout files, cover layer, etc. However, there are some key differences between the fabrication packages for rigid flex PCB’s and hardboard applications: · A rigid flex print generally has many more dimensions on it, and should carefully define the requirements, as these boards are generally used in 3D applications. It should also accurately define the rigid to flex transition areas, as these are not always apparent when viewing the Gerber layers alone. · The material layup in rigid flex boards is critical, and should be worked out in collaboration with your fabricator. Your fabricator can help you make the right choices in materials based your requirements such as UL flammability rating, minimum bend radii required, mechanical considerations, impedance control on both flex and rigid layers, RoHS certification, lead free assembly compatibility, and other considerations. · Rigid flex boards usually require additional layers in the Gerber files. Layers 1 and X will have solder mask layers, but you will also need artwork layers that define the coverlayer and bondply sections (if required) of the board, and how much each go into the hardboards. IPC 2223 recommends 0.100″ but your fabricator may be able to accommodate less than that. What is the future of rigid-flex PCB design? There are many new designs being manufactured with substantially higher flex layer counts. Some more prevalent designs include those with blind and buried via structures, integrated ZIF connections, and even designs with components mounted into both the flexible areas and the rigid sections. Some rigid-flex printed circuit board (PCB) designs may have flex areas that require shielding for Electromagnetic Interference (EMI) or Radio Frequency (RF) considerations. There are also designs that have varying thicknesses between the different rigid areas as well as asymmetrical constructions. This article covers some of the more common types of configurations and combinations that have been generating interest among OEMs. However, there are many additional configurations and combinations available for flex and rigid-flex circuit board stack-ups. The more advanced constructions covered here include odd layer count constructions, asymmetrical constructions, varying flex layer count designs, integrated ZIF connections, blind and buried vias, air gap flex layer constructions, multiple rigid area thicknesses, and shielded flex layers.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/09/2021 10:03
PCB Schematic Design and Layout 3 Tips for Designing PCB Schematic
Schematic is one of the important aspects of PCB design. A good schematic shows a well-structured circuit diagram clearly depicting the electrical connections between various electronic components. It should also be noted that a technically correct but crowded schematic is still a bad one as it might confuse designers. Schematics can be an extremely valuable troubleshooting tool as it traces out the connections in the circuit. In this passage, we will focus on the PCB schematic design. If you are curious about the topic please check and read the content we prepare to learn more information.If you want to order PCB product, please check and custom your order online. What are the considerations of PCB schematic design? Once you are working in your schematic capture system, there are some things that you can do to make sure that the design that you are creating will result in an easily assembled board: Start with your manufacturerThere are a lot of ways that a circuit board can be built, and manufacturing times and prices can vary greatly depending on the processes and materials that are required. Many designs have been canceled because once they reached the manufacturer, the fabrication and assembly costs were so high or lead times were so lengthy that the board wasn’t affordable. To avoid this problem, work upfront with your vendors to make sure that you are designing a board that can be built within your time and cost budgets. Use approved componentsAnother important consideration is the components that you will be using on the board. We’ve already talked about making sure that you are using approved parts in order to get the design right, but it goes further than that. You also need to make sure that the parts you are using are going to be available for the life cycle of the design, and their cost is within your budget. The last thing you need in the middle of building the board is to find out that a critical part is no longer available or is too expensive, requiring you to redesign the board. Make sure that the schematic and layout matchAll too often, the final layout of the board doesn’t match the schematic which leads to bad board builds. Problems like these can usually be traced back to a schematic change that was not incorporated into the board layout, or changes on the layout that weren’t back annotated into the schematic. Make sure that before you release the design for manufacturing that the schematic and layout are both finalized and updated, and then synchronized together. This way you will make sure that the schematic, bill of materials, and the layout all match together. What are the guidelines of PCB schematic design? To achieve a successful design, follow these standard schematic guidelines. Page size selectionMost of the design tools offer different page sizes. Generally, the tools would select the page size as A4. However, it should be noted that various other page sizes are also available. Designers should select the size based on the size of their circuit design. Page naming conventionThe logical blocks of the schematic should be separated by pages. By doing this, we can place the pages in alphabetical order. An example of such a naming convention is shown below. · Block Diagram· Power supply· MCU interface· Memory interface· Revision history Block diagrams and revision history are often ignored by most designers to save time. However, they can be very helpful for other designers trying to understand the schematic. Most of the product-based organizations mandate all such protocols and regulations. Grid settingThough it is not a direct requirement of the designer, the tool needs to have some references. Hence the grid system is followed. Having grids helps the designer to reference the parts properly and make their connection. Circuit components and connections must always be on the grid, this helps in probing the nets during analysis. What are the errors during PCB schematic design? It is very important to ensure that any schematic that has been captured is fully checked. While the simulation and other applications now available as part of an end-to-end design suite will trap and highlight many errors, some can still get through. Errors that creep through can be quite subtle. One that has been seen is where a particular node may be given slightly different names on different sheets. As the names are different they will not be connected by the computer. For example a node may be labelled "0v" on one sheet, but could appear as "gnd" on another. Accordingly it is very important to ensure that errors such as these do not creep through. Discipline in naming is essential. Computer based schematic capture has greatly simplified the process of drawing circuit diagrams. Circuit schematics can be drawn as the circuit is designed, and managed in such a way that there is little room for error. While errors can occur, the level of errors has fallen dramatically with the introduction of circuit schematic capture software.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/09/2021 09:05
PCB EMC Guidelines
Since PCB have strong performance to process in several products, it needs to have strong electromagnetic compatibility (EMC) built-in from the ground up. EMC is what keeps our devices from constantly interfering with each other. Now, EMC is more of an area of focus, and every PCB is expected to use these design practices to minimize unwanted emissions. If you are going to learn more information about it, we will provide you everything about PCB EMC. Please check and read the content below for more knowledge.If you want to order PCB product, please check and custom your order online. What is the importance of EMC test for PCB? There are a number of good reasons why your boards should undergo testing for EMC; including the following: Safety The prevailing motivation for EMC testing is to ensure the safety of users and operators of the electronic equipment and systems of which your boards are a part. Reliability In addition to safety, boards should be tested to find out whether they will function as designed and meet their operational objectives within their deployment environment. Regulations and Standards Just in case the two reasons listed above do not provide the necessary motivation to perform EMC testing, then the fact that most EMC testing is mandatory and defined by one of many standards. From a regulatory perspective, only applicable testing must be done to avoid sanction(s) for noncompliance. Applicability may be determined by manufacturer location, end-user geolocation or industry for which the board is made. How to design EMC for PCB? Obviously, EMC compliance can be a major development issue depending upon the type of board you are building. In fact, for the more restrictive industries (aerospace, automotive, medical devices) noncompliance is synonymous with non-usable. Therefore, we know what EMC testing is and why it should be done. The last remaining question is whether you can aid the testing process during design. The answer is yes; however, the level of assistance is dependent upon the design tool you use. Designing electronic systems for EMC can help you stay one step ahead by minimizing problems in the first place. Below are some EMC design techniques that you can implement to pass electromagnetic compatibility testing. Board LayoutIt is important to consider the signals that will be given off by your board. Some of these will be intentional, but 90% of electromagnetic interference (EMI) emissions from a PC board will be unintentional. Some of these unintentional signals are from common-mode currents, crosstalk coupling to I/O traces and power planes. Lower frequencies look for the path of least resistance. They can be harder to find because they spread out more. Outgoing and return paths may be distant from each other in this case. A few more general principles for controlling radiated emissions by design include the following. · Increase traces width where possible. A wider trace size is shown to effectively decrease radiated emissions.· One way to shield your inner layers from radiation is by filling your top and bottom layers with a solid ground plane and using ground-stitch vias throughout the PCB. Metalizing your PCB quote edges with copper plating may also help to decrease radiation from the inner layers and increase the cooling efficiency.· Add stitching vias between your layers and near high-speed signal vias to keep current loops as small as possible.· Avoid 90-degree angles if working with very high-speed applications. GroundingPoor grounding can be bad news for your EMC performance. It can lead to ground loops, resulting in radiated emissions or signals picked up from within the unit. Remember that a grounding system creates a path to return a current to its source. It needs to have low impedance and be as direct as possible. · One way to help this process is to place a ground plane directly below the plane with your signal traces. This plane can shield against EMI. It offers low inductance and low resistance common ground, creating a short lead length to the ground. For some areas, you may need to isolate the ground so ground currents can't flow across the section.· Never route signals over a split ground plane. Doing this can create large loops and high radiated emissions since the return current can't flow under or beside the forward current.· The length of a grounding system should be kept to a minimum, to prevent inductance from becoming a problem. At low frequencies, this impact can become quite significant. Thick wires can help, as well as using ground planes with critical tracks on your PCB. Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/08/2021 09:44
How to Properly Route a PCB？
There are several during the process of PCB manufacturing an every step of them is very important. Routing traces and vias on a PCB design is often thought of as a simple task. Routing copper traces is much easier when you can automate compliance with your PCB design rules using the best PCB layout tools. In this passage, we are going to provide you everything about PCB routing working principles methods. If you are curious about this topic, you can check and read the content below.If you want to order PCB product, please check and custom your order online. What are the technologies of PCB routing? When designing your PCB layout, there are many considerations that must be incorporated into your choices and decisions. A popular way to integrate these concerns is to adopt a design perspective that helps you organize your design choices. For example, if you design your based on board type, you may place a premium on signal integrity (SI) or power integrity (PI). Alternatively, if manufacturability is the most important consideration, then design for manufacturing (DFM) guidelines and tolerances may supercede other issues. Regardless of the perspective you choose, traces are typically viewed as a group and routing them is considered a collective exercise. A collective approach is good for specifying a general set of rules or guidelines for routing the traces on your board. However, it does not encourage you to make the best routing choice for individual traces. Conversely, by viewing each trace separately, we can define the best PCB routing techniques to follow when a given situation exists, as listed below. Trace width expansionTrace width expansion is always restricted. This may be to ensure adequate solder masking exists, to reduce crosstalk between traces, or other reasons. If the trace needs to be modified for current capacity reasons, the best course of action is to increase copper weight. Obstacles along traceThis is a common problem where either components or traces obstruct the desired path. Typically, changing component location is far too complex and it is easier to use vias and route under traces than move them. When routing around obstacles, it is best not to use sharp angles (≥ 45° is recommended). For routing under obstacles, you usually should choose the most direct or shortest route and least complex via type. Differential pairDifferential pairs are a special class of traces. As such, they should be routed as if they were a single trace. This means that their lengths and widths should be the same, and the distance between them should remain constant. Therefore, any changes to one should also be performed to the other, if at all possible. If not possible, then you use a meander, which is an arbitrary trace path used to match the other trace’s length. Adjacent layerYou should avoid running signals on adjacent layers, if possible. Instead, a ground plane should be placed between signal layers. However, if the signals must exist on adjacent layers, they should be routed orthogonal to each other to prevent coupling. This is true for adjacent layers in the stackup and for two-sided boards. How to route multilayer PCB? When designing PCB, most engineers would like to complete the high-signal routing by using multi-layer boards. Besides its role as the core of PCB, this type of multi-layer board is also capable of decreasing the circuit interference, which is a main method for engineers confronted with such a problem. When designing the high-speed signal circuit on PCB based on the utilization of multi-layer board, engineers need to shrink the board size by rationally determining the number of layer, to make the best use of the middle layer for shield setting to realize the nearby ground, all of which can effectively decrease the parasitic inductance, shrink the signal transmission length, reduce the cross interference between signals and so on. All of these methods are quite beneficial for the reliability of high-speed signal circuit. Apart from the methods above of increasing the reliability of PCB signal transmission with the help of multi-layer board, some authority data shows that when the same material is used, the noise generated by four-layer board is 20dB lower than that by 2-layer board. For the lead bending, the fewer the bending appears, the better it'll be. It's best to use the whole line and when bending is required, a 45 degree line or an Arc line can be used so that the emission towards outside will be cut down from high-speed signal and mutual coupling and both the radiation and reflection will be decreased as well. What are the considerations of PCB routing? Constraints and rules are used in PCB design for a number of reasons. They will help you to organize your design and communicate important information between the schematic and the layout. Primarily, though, they are used to prevent manufacturing problems and to ensure the electrical performance of the circuit board. Here are some issues that constraints are designed to address: Manufacturing Problems:Components that are placed too close to each other or oriented incorrectly may be difficult to assemble or solder correctly. Additionally, auto-insertion machinery may not be able to place the parts as needed, and technicians doing manual assembly may not be able to fit their tools and solder materials into the tight areas. Metal on the circuit board that is too close to other metal objects may also cause problems during the manufacturing process. Solder slivers can form, causing intermittent shorts, which are difficult to find and correct. Solder can also bridge between traces or pads causing direct shorts. Electrical Performance:Traces used to conduct power that aren’t wide enough may be inadequate for the amount of current that they are carrying. Some traces also must have exact widths to control their impedance. Other traces need to be routed to a specific length or to match the length of similar nets. Differential pairs must be perfectly routed side-by-side. It used to be that you could take a PCB design, throw it into the auto-router, and end up with a completely routed board that worked perfectly. That is no longer the case. Without the proper care in trace routing widths, spacing, lengths, and topologies, you may end up with a plethora of signal integrity problems.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/08/2021 09:15
PCB Design for Assembly Guidelines
After a PCB design is submitted and approved—be it flex, high density interconnect (HDI), or otherwise—it is fabricated. A PCB design may seem perfectly acceptable when viewed in isolation, but certain design decisions may make assembly difficult later on. In order for the PCB assembly process to flow smoothly—and, therefore, for the PCB production as a whole to progress effectively—the assembly vendor needs to have the requisite components on hand as soon as the boards arrive. In this passage, we will tell you everything about the considerations about PCB design for assembly. If you are looking for the topic please check and read the content we provide for more information.If you want to order PCB product, please check and custom your order online. What is the importance of PCB design for assembly? When it comes to anything you do—whether it’s cutting the grass or cooking a meal—we usually want the end result to turn out the way we planned. The same can be said when designing a PCB—we should worry first about getting it to work first, right? The answer here is both yes and no. Not only do we need our PCBs to work the way that we’ve designed them too, but those boards must be manufacturable for a reasonable price as well. There are several factors that can contribute to a board not being considered manufacturable. Here are the main categories of problems: ComponentsParts that are unique or not readily available will have higher costs attached to them. Also if the lead times on some parts cause delays in the board build, that will add to the expense as well. PlacementHow you place your parts can affect how the board is manufactured and drive up costs. Even simple things such as how a component is rotated can affect its solderability. LayoutYour PCB design will usually connect to other boards or interfaces. If these considerations haven’t been accounted for up front, it could add to the expense of manufacturing the entire system. What are the guidelines of PCB design for assembly? Working together with your CM before and during your design will give you both the best opportunity to be successful in building your PCBA. Your CM should review your design to help you to make the best component selections to avoid the cost and delay of EOL parts. They should also work with you on your component placement to enhance your design’s manufacturability. By helping you to design your board according to good design for assembly practices, your design will enjoy better yields, costs, and cycle times. The following guidelines are helpful during the design process in ensuring the efficient and easy assembly of the board and other components. Use standard and common componentsShould ensure that the components you plan to use are readily available. Also, you should validate their continued production to avoid having components whose end of life (EOL) is approaching as it will minimize delays in the future. Standard and readily available components result in reduced costs, higher quality, and lower inventories. Unique parts lead to increased costs and high chances of poor quality. Component Spacing RulesYou should design the board, ensuring that you carefully place the components in a way that they are not too close or too far from each other. No component should overlap with each other. A component placed too close to another cause issues that may require redesigning. To prevent spacing issues, you should ensure that you design your footprint in a way that allows enough gap between the boundaries of each component. The below table shows how much space should be left around each component for different types of IC packages. Updated BOMThe bill of materials (BOM) is crucial and it should not have any issues as it leads to project delays. You should review the BOM whenever there are changes in the design. Addition or change in the components should be updated with the correct component number, description, and values. Follow Datasheet Strictly for Footprint: The recommendations help in creating accurate footprints and identifications that prevent pad mismatches. Ignoring these recommendation lead to incorrect footprint, this may require full redesign and re-fabrication of the boards. What are the considerations of PCB design for assembly? The primary objective of DfA is ease-of-assembly. Moving towards that objective requires an emphasis on eliminating complexity and reducing uncertainty. An emphasis on eliminating complexity pushes design teams to think about reducing the number of components used for a PCB and to consider the type of components selected. For example, design teams may determine that selecting resistor or capacitor arrays—rather than groups of single passive components—saves board space and lowers costs. The “back-to-basics” approach to DfA also prompts design teams to consider—and perhaps reconsider—the use of fragile, heavy, or bulky components. Heavy and bulky transformers, power resistors, and mechanical assemblies drive shipping costs higher and require specific fabrication measures to ensure that the physical design of the board supports the components.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/07/2021 09:02
PCB Silkscreen Guidelines
Silkscreen is not only a type of printing process used to apply identification markings on a printed circuit board, but it is also the generic term used to describe the ink markings themselves. This is why the CAD tool layers devoted to these markings are referred to as the silkscreen layers. Printing the silkscreen onto the board is one of the last steps to be completed during printed circuit board fabrication. If you are going to know the guidelines of PCB silkscreen, welcome to check and read the content below for more professional knowledge about it. Let’s get it!If you want to order PCB product, please check and custom your order online. What is the importance of PCB silkscreen? Though the Silkscreen has nothing to do with the functionality of the Printed Circuit Board, the PCB Silkscreen provides information on · Warning Symbols – The warning symbols indicate the parameters on the high voltage points that you need to avoid or handle.· Polarity Indicators – It helps you to trace the polarized component’s orientation.· Locating the parts via reference designators· It helps in identifying the test points and unique numbers for each board.· Reference indicators – It helps in identifying the component types via BOM. The Pin 1 indicator helps you to connect the pins to the suitable pads in the footprint. The leading pattern of the component outline would show the placement of a component. The polarity indicators provide you with the polarized component’s orientation· Pin 1 indicator – It indicates the connection of pins on the correct pads of the footprints.· Component Online – It enables you to place the components on PCB through indications. The Component Online wouldn’t be essential for simpler components having a smaller number of pads. However, you would need them for general placement. But you can’t miss out on indicators, Pin 1, Polarity indicators. What is the process of PCB silkscreen? PCB silkscreen is a sub-process in the board tree of solder masking and baking, UV exposure, and development. However, due to its overall impact on the product’s grading and reliability, you can consider it the most sophisticated one among the four in its class. Preparation Once the CAD blueprint is finalized, it’s time to move towards hardware implementation. You need to perform some steps to finish the product with high quality. The material selected is then picked up for cleaning, followed by tape trolling and board handling. PCB board then gets ready for printing. At this point, the PCB Designs should be ready and printed (black) on transparent paper. The designs are placed on the dried silkscreen. In this case, the silkscreen PCB Design should be placed on the prepared silk fabric the way you would like the writings or the markings to appear on the PCB. Ensuring that the PCB Design paper does not move from where you have positioned it is essential. This can be done by fixing the designs firmly on the surface using TRANSPARENT tape. When this is done, the whole setup (silkscreen and the attached designs) is turned upside down such that the methods face downwards. The top side is then covered with dark cardboard. The UV light is shown below for about 15 minutes when the PCB silkscreen artwork is fully developed. To expose the developed silkscreen template, pressurized water is used to wash away the emulsion parts that were not exposed to the UV (not cured). What are the applications of PCB silkscreen? The silkscreen’s primary purpose is to mark the position of the components on the board with an outline, and the part’s unique reference designator. Silkscreen is also used for component polarity and pin 1 indicators. As the component density on printed circuit boards continues to increase, however, there is less space for silkscreen information to be printed. It is common therefore to see reference designators abbreviated as a sequence of numbers, and often the outlines themselves are completely omitted. This doesn’t lessen the need for component identification though, as these are still important for prototype, NPI, and limited-run boards that will require manual assembly. Component identification is also important for boards that are assembled using automated systems for test and debug purposes, as well as automated optical inspection (AOI), and manual inspection. Silkscreen markings are also used for marking non-component information as well. This can include the name, part number, and revision of the circuit board, as well as corporate contact information, copyrights, and manufacturing markings. The silkscreen conveys a lot of information about the circuit board, but it isn’t the only method of communicating board information. PCB design CAD systems have many layers built into them that can be used for board information other than the silkscreen, and we will take a look at that next. What are the methods of PCB silkscreen? In the past few years, the primary method of silkscreen referred to using a stencil to directly apply ink to the board surface. Nowadays, there are the two most common silkscreen PCB printing techniques, such as liquid photo imaging (LPI) and direct legend printing (DLP). Liquid photo imaging (LPI): This method is used when the line widths are greater than 4 mil. Liquid Photo Imaging is quite similar to the process used for the application of solder mask. In this a liquid photo-imageable epoxy is coated on to the laminate and then exposed with UV light. After this the board is developed and cured. It is much more accurate than manual screening. Direct legend printing (DLP):DLP is the most accurate of all these processes but is more expensive. In this process an inkjet projector is used with acrylic ink that is applied onto the raw PCB directly from the CAD data. The ink is cured with UV light as it is printed. It should be noted though that the acrylic ink does not cure on boards with silver finishes.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/06/2021 10:13
High Power PCB Design Guidelines
As a pretty important process of PCB manufacturing, PCB design is facing challenges and also necessary for engineers and manufacturers, especially when they are dealing with the high-power PCB. As the size of electronic devices is continuously and progressively reducing, design aspects such as power supply and thermal management must be taken into due consideration. In this article, we will tell you everything about the high-power PCB design, and if you are interested in the topic, welcome to check and read the content we prepare below for more professional knowledge.If you want to order PCB product, please check and custom your order online. What are the features of high-power PCB? In electronics, high-power PCBs usually conduct current that goes beyond a couple of Amps. An electrical motor driver, which could channel 30A of current within the circuit, is considered a high-power PCB. The same goes for an LED driver, which could be driving hundreds of LEDs configured in arrays. There isn’t a strict definition of what qualifies as a high-power PCB. Power can be defined by P=IV, and a high power design could mean a circuit that consists of elements of high voltage or current. Instead of placing a strict definition on the parameters, it is easier to categorize high-power PCBs by things that may arise if proper high-power PCB design practices are not followed: thermal generation and electrical shocks. What are the advantages of high-power PCB for environment? In 2009, the IPC-2152 Standard for Determining Current-carrying Capacity in Printed Board Design was released. This standard for relating trace width, copper weight and current carrying capacity replaced the long-standing and still often used the IPC-2221A standard. Based upon the guidelines of these standards, attempts to develop a reliable means of determining these parameters for high current PCBs have been made culminating in a number of on-line trace-width calculators. Most circuit boards process or transfer low power signals for digital, RF or power circuitry. For these applications, copper weights of 1oz or 2oz carrying currents in the mA to tens of amps range are typically sufficient. For some industries, such as military and aerospace, medical systems, automotive and industrial production, PCBs must have traces that are capable of carrying hundreds or thousands of amps. For these boards, trace widths must be much wider or copper weights must be higher. The typical approach to high current demands is to widen relatively thin (≤ 2oz) copper traces, which requires additional space on the surface and layers. However, the use of heavy or extreme copper routing has distinct advantages over that approach, including the following: · Greater trace current carry capacity· Greater via current carrying capacity· Accommodation of different circuit current levels on the same layer or PDN· Does not require increased trace widths· High reliability· Good mechanical strength at connectors· Utilization of high-temperature components without risk What are the considerations of high-power PCB design? Safety considerationAs with any circuit, the primary concern with a high current circuit is ensuring that it operates safely. There are a few potential issues that are unique with boards that drive such high powered loads. The main hazard is heat. No matter how well you design and lay out the board, more heat is produced than with a standard board. This must always be considered when the housing is made, and external vents/fans should be used. Something that I do on ALL designs that drive more than a few amps, is to have a dedicated temperature sensor on the PCB quote. This is a great firmware based failsafe. With the ability to monitor the temperature, you should always be able to react to any situation of overheating. To reduce the amount of heat produced on the board itself, it is best to choose components with low resistance. The next potential safety hazard is regarding short circuits. Since the board is designed to drive high power devices, when shorted, it will be able to source a considerable amount of current. It is crucial to consider this possibility in the design phase. The easiest way to deal with shorts is to have a fuse on ALL outputs that leave the board, and an input fuse. The fuses should always be rated for less current than the wires used can handle. Thermal managementThermal management techniques, or the lack of, can determine the fate of a high-power PCB design. A heatsink is preferable when you’re dealing with high-current components like a MOSFET. However, the decreasing size of a PCB may limit the space for a heatsink. In such cases, you’ll need to make use of techniques like pouring solid copper around the heat pad of a MOSFET and creating an array of thermal vias to spread out the heat. You may also want to consider active thermal dissipation techniques such as installing a cooling fan or liquid cooling system for high-power components. Component placementOften, a high-power PCB consists of components that generate excessive heat. Power MOSFETs, regulators, and associated passive components can produce a huge amount of heat as a high current passes through. As board size gets smaller, how and where you place components becomes more critical. In modern designs, where you place your components determines the effectiveness of heat dissipation. It is a good practice to place heat-generating components in a group and near the edge of the board. Avoid placing components like a power MOSFET near to temperature-sensitive components like amplifiers and converters.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/06/2021 09:50
IPC Component Spacing Guidelines
The IPC component spacing guidelines exist for two reasons: to prevent component overlap that could cause physical damage and to prevent electrical interference that could cause performance problems. Of the two, physical overlaps are a simpler problem to correct. If you are going to learn the professional knowledge about IPC component spacing, please follow us and read the content we prepare below for more information.If you want to order PCB product, please check and custom your order online. What is the importance of IPC component spacing? First, let’s review what some of the assembly problems are for PCB manufacturers when minimum spacing requirements aren’t met: · Component installation: Although automated placement equipment is extremely accurate, those systems still need enough room to operate in. Parts that aren’t candidates for machine placement, will need even more room for technicians to be able to work with them. · Soldering: For boards that are to be wave soldered, the spacing between parts is extremely important to prevent shadowing of smaller parts by larger. As with component installation, those that are to be manually soldered need enough room for the technician to be able to work with. · Test: There must be enough clearance between test points and components to allow access for the probes of the test fixture. There also needs to be proper clearance around the perimeter of the board for the test fixture outline. · Access: Printed circuit boards usually have connectors, switches, and other interfaces that require access for technicians. There needs to be enough clearance to fit fingers and tools in for a test, debug, rework, and normal operations. What is the purpose of IPC component spacing? The IPC component spacing guidelines are a third check on these potential physical problems. As long as designers follow the spacing guidelines, there should not be physical overlaps of components except in special circumstances that require additional engineering and development. Component spacing guidelines also manage negative space—the places where components are not present. Negative space on a PCB can be just as important as the regions where components exist, and this space is particularly important when preventing electrical interference. If conductive traces or circuits are too close together, unintentional connections may form between them as electrons jump between circuits. These unexpected connections reduce the strength of signals traveling through some regions of the PCB and can increase the amount of power flowing through other areas. Reductions in power can cause shorts or failures, while surges in power can cause physical damage or overloads. What are the considerations of IPC component spacing? There’s a common saying that goes something like this – PCB design is 90% placement and 10% routing. This is entirely accurate. Taking the time to precisely place your components will make your life a whole lot easier when it comes time to route everything, while also giving your board its best electrical performance. But what happen if you just slap your components down without care? IPC component spacing guidelines help designers create circuits that minimize interference while still making the best possible use of space. There is no minimum or maximum size for a circuit defined in the standard, so the guidelines are applicable to PCBs of any size. Instead, the guidelines recommend that designers decide upon the proper size for circuits and traces based on the amount of current they should carry, as well as their thermal tolerance. · Hours Wasted. You’ll likely create a nightmare for yourself when you find out that some of your parts don’t even have enough space to be routed because you packed them too close together. The worst component placement jobs can lead to an entire board that needs to be started again from scratch. · Busted Boards. Let’s say you do manage to place down some components and traces and ship your files off to your manufacturer. Next thing you know you might get a board back, that doesn’t work because your parts weren’t soldered correctly (more on this later). · Ugly Aesthetics. Let’s face it, as engineers we love symmetry and precision, and there’s nothing more unsettling than seeing a board that wasn’t given some proper love and care during its component placement. It’s just plain lazy. Many sizes of PCB boards are standardized, ranging from a few millimeters long to a third of a meter. In all PCBs, conductor leads should be as short as possible. Leads can be theoretically placed on a PCB at any angle and in any orientation, but unusual angles can make these leads more difficult to model computationally. The IPC recommends that leads be placed parallel to each other, perpendicular to each other, or at 45-degree angles to each other. It is common for a single PCB to have leads running in different directions, but leads should never overlap. Overlapping leads would be a violation of component spacing guidelines and could cause a lot of interference.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/04/2021 09:47
PCB Conformal Coating Types
Conformal coating is a thin film of protective insulating material applied to a fully assembled circuit board. It is made of a non-conductive material, and can cover the entire board depending on the needs of the PCB and what environment it will be operating in. It will cover and protect exposed areas of metal such as traces that aren’t already covered with solder mask, component leads, and solder joints. Conformal coatings will even increase the dielectric strength of a board allowing for reduced spacing between circuits in more compact and dense PCB layouts. In this passage, we are going to provide you everything about PCB conformal coating, please check and read the content below for more information.If you want to order PCB product, please check and custom your order online. What are the advantages of PCB conformal coating? · Insulating properties allow a reduction in PCB conductor spacing of over 80%· Can help eliminate the need for complex, sophisticated enclosures· Light weight· Completely protect the assembly against chemical and corrosive attack· Eliminate potential performance degradation due to environmental hazards· Minimize environmental stress on a PCB assembly What are the main applications of PCB conformal coating? When you have your circuit board coated, there are many different ways that the conformal coating can be applied: · Dipping: For boards that are in high volume production runs, dipping is the usual method of applying a conformal coat. Dipping will coat both sides of the board, so PCBs that have specific areas that either need or don’t need coating will have to use another method. · Automated spraying: This method is also used for production runs. The circuit boards are run through the process on a conveyor belt, and reciprocating spray heads will apply a consistent coating on the board. · Selective coating: This is a variation of the automated spraying, but programmable spray heads are used instead of reciprocating. This allows for boards with unique requirements to have specific areas programmed for applying the conformal coating. · Manual spraying: For technicians working on a board, manually spraying conformal coating with a spray gun or an aerosol can is the fastest approach. This is a labor intensive operation used in low production runs, although it lends itself well for boards that have unique requirements. Those areas can be masked off to prevent the conformal coating from applied there. · Brushed: This is the slowest method of applying conformal coating, and is usually done when a board is being reworked or repaired and the coating has been removed in specific areas. Brushing the coating on however could result in variations of the application as it is not as consistent as spraying the coating. What are the types of PCB conformal coating? There are different types of conformal coating materials or chemistries that are used depending on what the specific needs of your PCB QUOTE are. Here are the more common ones in use: Acrylic Resin (AR): These coatings are the most commonly used conformal coatings because they are economical and will protect against a broad range of contamination. They are not the highest level of protection, however, and do not protect against solvents or solvent vapors. They have a very high level of dielectric strength and can be easily removed, making PCB rework very practical. Silicone Resin (SR): Silicon coatings have a very wide temperature range of protection and are very chemical, moisture, and salt spray resistant. Due to its rubbery nature, it isn’t abrasion-resistant, but it does hold up very well against vibration stresses. These coatings are often used for environments with high humidity but are difficult to remove and require specialized solvents for PCB rework. Urethane Resin (UR): These coatings are excellent at resisting abrasion as well as being moisture and chemical resistant. Because of these qualities, urethane coatings are often used in aerospace applications due to their ability to resist fuel vapors. On the other hand, like silicone, this coating is very difficult to remove and requires specialized solvents for PCB rework. Epoxy Resin (ER): Epoxy is somewhat different from the other conformal coatings in that it used to completely encapsulate the electronics in a solid layer of material. This provides excellent protection against humidity, abrasion, and chemical contamination. The hard coating, however, is almost impossible to remove once it is cured.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/04/2021 09:31
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