What Are the 5 Main Factors of Aerospace PCB Design Standards?

It’s no surprise that aerospace manufacturing and design must meet stringent standards. Electronics in aerospace often face harsh environments, and it may be impossible to repair them while they’re in use -- they’re thousands or millions of feet in the air, after all which means your aerospace PCB assembly better work as you intended. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } Do you know the details about aerospace PCB design? If you are searching for professional knowledge about aerospace PCB, please check and read the content below for more information. What are the rules of aerospace PCB design? Printed circuit boards designed for aerospace and military applications shall have a high degree of reliability and robustness, without offering any margin for error. Challenging applications, such as space missions, require an accurate understanding of how printed circuits must be designed and created to ensure a very long period of operation, in often very extreme operating conditions. Unlike most traditional PCBs, printed circuit boards used in aerospace applications are subjected to extreme environmental conditions, radiation, chemicals, contaminants, and more. It follows that these circuits must meet very strict standards, such as the IPC-A-610E Class 3, which refers to high-performance electronic devices whose operation must be guaranteed continuously, without any interruption, even in the most difficult and critical operating conditions. Some of the main applications falling within the scope of the IPC-A-610E Class 3 standard are the following: · Systems for satellite communication · Navigation systems, control systems and on-board avionic instrumentation · Applications for on-ground processing of data recorded during flights or missions (ground stations) · Passive detection systems · UAVs (Unmanned Aerial Vehicles) Circuits for aerospace applications are exposed to extreme temperatures and must be able to withstand and absorb shocks and vibrations of considerable intensity. In addition, they have many features in common with PCBs for RF high frequency applications, bearing in mind that radio communication in the HF (or higher) band is a fundamental requirement for these systems. Operating at high altitudes, the risk associated with radiation also increases and, as a result, PCBs (as well as the electronic components used) must be designed to withstand high levels of radiation for a long time without being damaged. What are the basic considerations of aerospace PCB design? With any military or aerospace electronics project, there are special boxes your design has to check off: · Can it last long before requiring maintenance? · Have you followed material specs down to the letter? · Can it hold up in a harsh environment? · What testing and inspection will be necessary? · Is it 100% compliant with AS9100 design standards? Have you fully assessed risk? Aerospace PCB design standards soar far above what you’d see in, say, a toddler’s LeapFrog tablet. Aerospace electronic components can be critical or noncritical. For example, there are PCB (printed circuit boards) in the autopilot system on an airplane -- obviously important to keeping people alive. If they fail, you have a big problem, Houston. In contrast, there are also circuit boards in the seat adjustment controls of a commercial airline. These are not considered critical; if they fail, lives aren’t at risk. Still, you’ve got to design electronics in a way that they can “fail safely” and not be a fire risk. When considering how you are going to design military & aerospace electronics, plan ahead to follow the appropriate protocols. The components and materials you use should reflect the requirements you must meet for your product’s final use. If your product is mission-critical, expect longer lead times. The approval process is going to be much longer.

PCB Knowledge ⋅ 02/19/2022 09:50

What is Crosstalk in PCB Design and What is the Function?

Crosstalk is generally specified as a percentage of the signal that appears on the victim line, relative to the aggressor line. It can also be expressed in terms of dB below the driven line level. NEXT varies with the frequency of the transmission since higher frequencies create more interference. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } Do you know the basic information of crosstalk in PCB design? If you are searching more information about crosstalk in PCB design, please check and read the content below for more professional knowledge. What are the causes of crosstalk? · Capacitive and inductive coupling: Capacitive coupling is due to parasitic capacitance and inductive coupling occurs due to mutual inductance. · Difference in propagation velocity: It can be avoided by trace length matching and propagation delay matching. · PCB vias: PCB vias with stubs create reflections, thus ringing which generates crosstalk. One way to avoid this is to back drill the vias. · Increased data rates: With increased data rate, the rise time increases as well. According to Faraday’s law, with an increase in rise time, the crosstalk will also increase. One way to reduce crosstalk between such signals is to increase the spacing between the traces. · Board size: As the PCB board size increases, the trace lengths also increase, and these traces behave as antennas. So, it is important to keep the trace lengths as minimum as possible. What are the issues of PCB crosstalk? Too much activity in a circuit board can make the transmission of a signal difficult. Think of two traces on a circuit board running together side-by-side. If the signal of one trace is “louder” with more amplitude than the signal of the other, it could over-power that other trace. And just as it can be difficult in a noisy room to keep your own thoughts straight when trying to speak, the “victim” trace on a PCB will be similarly influenced by the louder signal. The problem then is that the victim signal will start behaving like the aggressor signal instead of behaving the way that it is supposed to. Crosstalk is defined as the unintentional electromagnetic coupling between traces on a printed circuit board. The overpowering of one signal in a trace by another one is the result of this coupling even though the two traces are not in physical contact with each other. This can happen on a PCB that has acceptable trace spacing for manufacturing but where the spacing is not acceptable for crosstalk. In addition to the potential for crosstalk between two traces that are side-by-side on the same layer, there is an even greater risk for traces that are running parallel to each other vertically between two layers. This effect is known as broadside coupling and happens because the two signal layers are separated by only a very small thickness of core material. This distance is often less than the spacing between two traces on the same layer. How is PCB crosstalk minimized? · Make use of segregated transmission lines: Crosstalk is induced by the aggressor trace onto the victim trace, so it is obvious that a higher aggressor voltage will induce more crosstalk. Therefore, it is best to segregate groups of nets according to their signal amplitude. This strategy prevents larger voltage nets (3.3V) from affecting smaller voltage nets (1.5V). · Implement back drilled vias: Via stubs decrease signal integrity, hence an increase in crosstalk. This can be reduced by implementing back drilling. · Reduce parallel trace runs: Longer trace runs (more than 500mils) increase the mutual inductance hence crosstalk. · Maintain adequate separation between the traces: Provide adequate separation between traces (adopt 3W rule). If adequate separation is not maintained, then it will increase the mutual capacitance (Cm). The 3W rule reduces the crosstalk by 70%. To achieve 98% crosstalk reduction, go for 10W. · Use guard traces: Guard traces are used to control capacitive crosstalk between transmission lines. Such traces should be used wisely as they make routing difficult. · Adopt orthogonal routing: Route adjacent signal layers orthogonally to minimize capacitive coupling between them. · Do not decrease the signal rise time: Decreased signal rise time increases the crosstalk. · Opt for differential pair routing: Tightly coupled differential routing eliminates crosstalk because the noise from the aggressor is coupled equally into both branches of the differential pair, producing common-mode noise. Differential pairs reject the common mode noise that helps with crosstalk reduction. · Terminate even and odd mode transmission properly: A three resistor network (T termination) can be used to terminate the odd and even mode.

PCB Knowledge ⋅ 02/19/2022 09:47

How to Solder a Broken Wire on a Circuit Board?

Before we get started, let us understand a little more about soldering and what it actually is. Well, soldering is essentially the process where you establish a connection between electronic components, allowing for electric current to flow for one conductor to the other. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } Soldering works by heating metal wires with a soldering iron and then applying the solder to the joint. The solder acts as a glue, whereupon melting, it flows over the metals to be joined and then establishing a connection between the metals. If you are going to learn more information about solder wire on PCB, please check and read the content below in this passage. How to prepare solder broken wire on PCB? Before we get to the main point, eventually, we would like to suggest useful tips. The re-soldering of wires on the circuit board is similar to what we know about how to solder the electrical wire to the circuit board. So, you shouldn’t face many issues with the re-soldering process. However, if you have forgotten the soldering process, we will recap the process for re-soldering the damaged or cracked circuit board wires. Things you will need: Solder: This is pretty straightforward. You will need a solder for the re-soldering process. These are available in various thicknesses that usually start from 0.02mm. The thick solders are widely used for copper pipe or PCB. It is used with a butane torch. However, you will have to opt for the thin solders for detailing and repairing jobs. Soldering iron: You will need a quality soldering iron to generate the right amount of soldering temperature. You can opt from the low wattage (15-40W) or high wattage (60-140W) for the soldering process. The low wattage works on circuit boards, and high wattage helps work with braided speaker wire. How to process solder broken wire on PCB? Cut the exposed wire to length. Clean your soldering iron tip. Pre-tin your solder iron tip. On the underside of the board, place the soldering iron so that it touches the metal around the hole and the wire at the same time. Then touch the soldering iron to the pad and wire from the opposite side. The solder should flow around the pad and wire very quickly. Withdraw the soldering iron. Do not use the soldering iron to melt solder directly and then try to apply it to the pad and wire: solder flows towards heat, and it would rather stay on the soldering iron than transfer to the cooler pad and wire. Also, it’s not a good idea to clip the wire after soldering as a) you may shock the solder joint so it may fail later, and b) you will be leaving copper exposed on the cut end of the wire. Clean your soldering iron. Pre-tin your soldering iron. You are now ready for the next wire. If you don’t feel like cleaning or pre-tinning your iron, this means your solder joint will vary over time If you do this every time, they will all be the same. When you get into a rhythm, it can take you a second or so to accomplish each solder joint. Always, ALWAYS use the biggest soldering iron tip you can fit into the area to be soldered, rather than increasing temperature. As long as the soldering iron actually melts the solder, it’s the right temperature. By using a big soldering iron tip, you get the heat energy in there quick enough that the temperature in the board doesn’t rise too high, which can cause trace and pad delamination. A big mistake many people make is to assume that delicate electronics needs teeny-tiny soldering iron tips. Nope. Use the biggest honking tip that will fit. Unless you have really close pad spacing or close-together connections, you really don’t want to use those tiny little tips. They are a total pain. What are the different types of wires soldered on PCB? A wire is an electrical piece that consists of 2 or more metal strands coated with a winding of some non-metallic origin. Such a wire serves for transporting the energy from a power source to gadgets and devices. Any electric wire consists of 2 parts. The first one is the current-conducting part. The second part is the isolation that protects the core from external factors. As a core, copper and aluminum metals are used for wires. The insulation is made of paper, rubber, and varnish. There is a certain classification of wires: · Wires for winding · Copper wires · High resistance wires · Mounting connectors · Insulated for overhead lines · Uninsulated · Heat resistant wires · Wires for cars · Wires for aviation · Wires for installation

PCB Knowledge ⋅ 02/19/2022 09:40

How to Reduce Electromagnetic Interference in PCB for 7 Effective Tips?

In a PCB, the ground plane is there to provide a 0 volt reference line to the power supply ground terminal for the return path of a circuit. Unlike the basin, however, when “ripples” are made, noise is produced, dipoles can form and the entire board can become an antenna. This is why the ground plane, that copper foil layer in your PCB, takes up as much of the cross-sectional area of the board as possible. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } Do you know the methods of reducing electromagnetic interference in PCB? If you are searching more about reducing electromagnetic interference in PCB, please check and read the content below. What are EMI and EMC in a PCB? Electromagnetic compatibility (EMC) is the ability of an electronic system to operate within an electromagnetic environment satisfactorily without generating intolerable EMI (electromagnetic interference) in nearby devices/systems. EMC ensures that the system must perform as intended under the defined safety measures. EMI is an electromagnetic disturbance, where energy is transmitted through radiation/conduction from one electronic device to another and corrupts the signal quality causing malfunctioning. EMI focuses on the testing requirements and interference between the neighboring equipment. It can occur in any frequency range, say anything more than DC. Typically, it happens above 50MHz. Read understanding signal integrity in PCBs. Whenever a device deviates from the defined standards, EMC/EMI dominates the system performance. So, it is vital to control EMI during the initial phase of the PCB design. Controlling EMI in later production stages can be risky in cost terms. For EMC-friendly board designing, your primary concern should be on component selection, circuit design, and PCB layout design. To be market-ready, your product has to pass the prescribed EMI/EMC standards. Why to avoid electromagnetic interference? Sources of electromagnetic interference are all around us, and we can categorize them in several ways: Source Human-made EMI arises from electronic circuits. Naturally occurring EMI, on the other hand, can arise from environmental factors like cosmic noise and lightning. Duration Continuous interference is an EMI source that emits a constant signal, which most often appears as background noise. Impulse interference is intermittent, usually caused by switching systems, lightning and other non-constant sources. Bandwidth Narrowband signals like those used by radio can encounter interference from oscillators and transmitters, though these sources only affect certain parts of the spectrum intermittently. Broadband interference affects high-data signals like TV and can come from many sources, including arc welders and solar noise. Whether human-made or environmental, EMI can be both costly and dangerous. It can disrupt communication channels and sensitive devices. EMI is a notable concern in the medical field, where wirelesses device usage is on the rise. Unfortunately, EMI can affect the functionality of medical equipment like ventilators, ECG monitors, cardiac monitors and defibrillators. In other industries, EMI can disrupt sensors and navigational systems. The result in all cases is a disturbance of equipment that may be responsible for the health and safety of its users. How to reduce electromagnetic interference in PCB? PCB board design techniques for electromagnetic interference (EMI) There are many solutions to the EMI problem in today's PCB board design techniques, such as EMI suppression coatings, suitable EMI suppression parts, and EMI simulation designs. The above film describes how to reduce EMI. Now briefly explain these tips. · Common mode EMI interference sources (such as the voltage drop formed by the transient voltage formed in the power busbar across the inductor of the decoupling path) · With low-value inductors in the power plane, the transients synthesized by the inductors are reduced and common-mode EMI is reduced. · Reduce the length of the power layer to IC power pin connections. · Use 3-6 mil PCB layer spacing and FR4 dielectric material. Electromagnetic shielding · Try to place the signal traces on the same PCB layer and close to the power or ground plane. · The power plane should be as close as possible to the ground plane The layout of the parts (different layouts will affect the circuit's interference and anti-interference ability) · Block processing according to different functions in the circuit (such as demodulation circuit, high-frequency amplifier circuit and mixing circuit, etc.), in which the strong and weak electrical signals are separated, and the digital and analog signal circuits are separated. · The filter network of each part of the circuit must be connected nearby, which not only reduces the spokes, but also improves the anti-interference ability of the circuit and reduces the chance of interference. · Parts that are susceptible to interference should be avoided as much as possible in the layout, such as CPU interference on the data processing board.

PCB Knowledge ⋅ 02/18/2022 10:17

What is UL Certification for PCB and What Is the Function?

The Underwriters Laboratory (UL) was founded in 1894 by William Henry Merrill, an American electrical engineer. UL is an independent, international organization that tests products, certifies manufacturers and documents safety standards for a diverse range of industries and applications. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } Do you know the basic information of UL certification for PCB? If you are looking for more professional knowledge of UL certification for PCB, please check and read the content below. Why UL certification is important? UL is the only organization that publishes PCB safety standards. UL certification can demonstrate the PCB products have been passed the product safety benchmark. And the UL recognized PCBs could be used globally. It is well known that UL recognized PCB components and materials had passed the industry' s most stringent safety tests and follow-up program. With UL certification on the PCBs, PCB manufacturers can assure customers that the boards they get a match or exceed industry standards for preventing the electric shock or fire. It has been certified for safe use and follows specific standards and guidelines during development and construction. Why Should You Care About UL? Many end product standards now require their PCBs to be built with UL safety standards in mind. The following product categories are just a sample of the applications that UL standards cover: · IEC 60065: Audio and Video Equipment · IEC 60960: Information Technology Equipment · IEC 60601: Medical Equipment · IEC 61010: Equipment for Laboratory Use · UL 508: Industrial Control Equipment All of the applications above must be certified with a UL mark following three standards, UL 796, UL 746, and UL 94. These are broken down into specific sub-categories, which includes: PCB Standard UL 796: This covers printed wiring boards (PWBs) guidelines for standard rigid, metal-based, and high-density interconnect PCBs. PCB Standard UL 796F: This standard evolved to cover flexible material electronics including flex and rigid-flex PCBs. PCB Standard UL 746E: This covers all industrial laminates and materials used in the PCB manufacturing process. PCB Standard UL 746F: This covers all flexible dielectric film materials used in the PCB manufacturing process. UL 94: This covers all flammability requirements for plastics and PCBs. What is the function of UL certification for PCB? PCBs are key components of any electronic product. Any error in the design or assembly of the PCB can lead to product failure. Electrical engineers are under increasing pressure to design smaller, flexible and more efficient PCBs to meet consumer demand for wearables, smartphones, 5G and Internet of Things (IoT) devices. That type of pressure, coupled with stringent go-to-market deadlines, can lead to errors in design, easily damaging your product’s reputation. Fortunately, we can help you mitigate the risk of that happening. We have been advancing safety science in support of PCB conformance assessments for more than 50 years. We can help increase consumer confidence in your products by demonstrating that your PCB is compliant to regulatory safety requirements and has been tested to the highest set of reliability and performance standards. Our full range of PCB testing and certification services tests to UL Standards and many other international, national andregional requirements, including ASTM, IPC and International Electrotechnical Commission (IEC). Our testing services include: Getting Your PCB Certified The parameters for your PCB certification will be determined by the application of the board in the end product it is designed for. As we mentioned earlier, certain industries such as medical equipment have specific standards that must be met and certified in order for your board to be used. The parameters include the following: · Specific flame rating · Maximum operating temperature (MOT) · Direct support requirements (DSR) compliance · Minimum comparative tracking index (CTI) rating If this is information new to you or you’re having trouble deciphering the applicability of various standards, help is available. Underwriters Laboratory has an engineering staff that can help you to determine what parameters you need to design for in your PCB. Another source of assistance is your contract manufacturer (CM). They can help you determine which parameters you need certification for. They can also support you throughout the process of getting your boards set up and sent out for testing and certification.

PCB Knowledge ⋅ 02/18/2022 10:04

What is PCB Reverse Engineering with 7 Basic Information?

Reverse engineering circuit boards can be a long process, but it’s well worth the payout. There are a few primary stages of reverse engineering PCBs that anyone who attempts to do it should follow. These steps include creating initial drawings, scans or photographs of PCBs that are then uploaded to the appropriate reverse-engineering software and programs. Once uploaded, users have to build the PCB’s layout and use that layout to create schematics. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } Do you know the basic knowledge of PCB reverse engineering? If you are looking for more information about PCB reverse engineering, please check and read the passage for more professional knowledge. What is the definition of PCB reverse engineering? PCB reverse engineering is a multilayered process that includes targeted PCB research, reverse analysis and PCB design technology reproduction. The process is also used to identify and obtain the design of a product’s functional and structural characteristics, as well as the processing flow. With this information, a company can produce products with similar functions and abilities — though businesses will make sure they’re not reproducing an exact replica of a reverse-engineered PCB. Reverse engineering is primarily utilized to determine and analyze the design principles behind a product. It’s especially useful when a company can’t easily find design information on a specific product. The most common method of reverse engineering a PCB involves disassembling a sample PCB and then analyzing it. From this analysis, a company will create documentation about the sample PCB, which various team members can review. This documentation will often include information about how the product is designed and how it operates. A company can then use the information they gather from a sample PCB to manufacture similar PCBs that may function better than their competitors’ offerings. Alongside reverse engineering’s ability to help companies analyze and outdo competitors’ products, it can also help businesses improve their own PCB offerings. For example, reverse engineering can help them enhance their boards’ functionality by spotting obsolete parts, security issues or poor designs. What is process of Multilayer PCB reverse engineering? · Assign reference designations to unmarked components before starting PCB reverse engineering. · Create a Component level BOM. · Design -Identify the system’s components and their interrelationships. · Components Placement & Mechanical. · XY locations of Connectors, LED, Switches etc. · Board mechanical Mounting holes & any special cuts on Boards, Board size etc. · Download datasheets, application notes, and architecture information. · Create net list. · Make the Schematic Drawing and PCB Layout. Why reverse engineer a PCB? There are several advantages of reverse engineering PCBs — many companies use these devices for various purposes. Reverse engineering can also help you produce more effective or less costly versions of a competitor’s PCBs. Learn more about the advantages of reverse engineering PCBs below: · Maintain crucial PCBs · Get information on PCBs without documentation · Reduce your reliance on experts · Identify weaknesses in a competitor’s designs What are the considerations of PCB reverse engineering? Basically figuring out how the PCB works without the original engineering documentation. You start by creating a schematic by identifying all the components on the board and then finding all of the interconnections. This gives you a schematic which allows you to figure out how the board works. It sound easy but on complex boards in can be extremely time consuming and is frequently made more difficult by the use of complex custom chips. You can actually reverse engineer the actual chips as well, but this is even more specialized and requires a lot of specialized equipment. One of the common uses for reverse engineering is do determine if competitors are using your patents, hardware or Ontellectual property to make their competing products, but there are other malign reasons. Government security agencies do this kind of thing as well to gain insights into other countries weapons susystems, for example. There are specialist companies that perform this kind of work for a fee. If you are right and a competitor is illegally using your patents you may get a financial settlement that will cover your costs, but that is not guaranteed.

PCB Knowledge ⋅ 02/18/2022 09:49

How to Control Impedance of PCB with 7 Important Tips?

When a signal needs a specific impedance to operate properly, controlled impedance should be preferred. In high frequency applications, keeping impedance constant on the complete electronic board is essential to protect the transferred data from damage and to maintain the clarity of the signal. The longer the trace or the higher the frequency, the more adaptation is needed. Any lack of rigor at this stage can increase the switching time for an electronic device or circuit and cause unexpected errors. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } If you are looking for more professional knowledge about Impedance control of PCB, please check and read this passage for more information. What are the applications of PCB impedance control? Controlled Impedance should be considered for PCBs used in fast digital applications such as: · Telecommunications · Computing 100MHz and above · High Quality Analog Video · Signal Processing · RF Communication How to control dielectric of PCB impedance? The typical design considerations involved in the determination of the requirement for controlling the impedance are the strength of the signals involved, the susceptibility of the circuit to noise and signal distortion, the criticality of signal timing and the speed at which the signal’s source is attempting to force a change in voltage and/or current. Why control impedance on PCBs? When a signal needs a specific impedance to operate properly, controlled impedance should be preferred. In high frequency applications, keeping impedance constant on the complete electronic board is essential to protect the transferred data from damage and to maintain the clarity of the signal. The longer the trace or the higher the frequency, the more adaptation is needed. Any lack of rigor at this stage can increase the switching time for an electronic device or circuit and cause unexpected errors. Uncontrolled impedance is difficult to analyze once the components are mounted on the circuit. Components have different tolerance capacities depending on their batch. Furthermore, their specifications are impacted by temperature variations which can lead to malfunctions. In such cases, replacing the component may seem to be the solution at first when, as a matter of fact, it is the unsuitable trace impedance that is the cause of the problem. This is why trace impedances and their tolerances must be checked early on in the PCB design. Designers must work hand in hand with the manufacturer to guarantee the compliance of component values. What are the factors of PCB impedance control requirements? Many factors influence the stack-up design parameters and choices (such as impedance, physical structure, blind holes, and so on). The impedance of signal lines is affected by the stack-up structure characteristics. Change the stack-up parameters help attain target impedance. It is equally important to examine and balance other aspects in design that impact the stack-up. Consider the following: · The thicker the dielectric thickness, the higher the impedance · The smaller the dielectric constant, the greater the impedance · The thicker the copper weight, the lower the impedance · The impedance value will be higher if the dielectric constant is less · A greater inductance indicates a higher impedance · A higher capacitance indicates a lower impedance How to avoid the common problems of PCB impedance control? Here is a list of impedance-related notes we have seen that can also cause confusion or on-hold situations: Only one trace width can meet a particular impedance on any one layer. It is not sensible to expect, say, a 0.007” trace and a 0.005” trace to both solve for 50 Ohms on the same layer. Although this seems painfully obvious, we have seen instances where the requirements were called out in this manner. It does not work. Only one trace width or pair geometry can meet a particular target impedance per layer. If you have a dense 16-layer board, and your note reads: “All signal layers: 0.004” trace, 0.006” space to be 100 Ohms differential” please make sure that the specified geometry is present on ALL the signal layers. If it’s not, then clarify by specifying only the layers where the geometries exist. Searching through 8 or 10 dense signal layers with hundreds of seemingly parallel 0.004” traces in search of a few true differential pairs is tedious enough, but searching all those layers to discover that there are 0.004” / 0.006” pairs on just ONE of the internal layers wastes significant time. It is also necessary, once the weeding-through is completed, to document that impedance testing may be waived for layers not using those pairs. Otherwise an incoming inspector will reject the impedance report when the boards arrive, on the grounds that it is incomplete as defined by the drawing note. Therefore, it is important that you identify only those layers that actually use the specified trace geometries. If you supply a reference stack-up, it is good practice to also state clearly whether or not you permit adjustments to meet the impedance targets. Some drawings arrive with generic stack-ups included, which will not serve to meet the custom requirements of a controlled impedance PCB. If the notes do not make it clear that adjustments are permitted, then the fabricator has no choice but to stop the order and seek your permission to deviate from the supplied stack-up.

PCB Knowledge ⋅ 02/17/2022 10:23

How to Process Best PCB BOM Management during Manufacturing?

There are three questions you need to be asking yourself when creating a BOM for your next project: The "when," the "what," and the "how." After discussing these topics with your selected staff and the client who has assigned the project to your organization, you can then proceed with your project. PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } In this passage, we are going to provide you all the professional knowledge of PCB BOM. If you are curious about more information about PCB BOM, please check and read the content below. Why is BOM important? Anything that involves electronic products requires a lot of organization and operations when it comes to any materials. The purpose of a BOM is to make sure that everything involved in an electronic product project is operating smoothly. When this process is not organized correctly, a lot of unsavory things can happen. Costs The creation of a proper BOM can reduce the costs involved in a project. Because there are many materials necessary when it comes to a project, much money goes into them. If a BOM is accurate and organized correctly, it can save a lot of money. One of the worst things that any manufacturer can do is rush to create a BOM. If the logistics list is in a hurry, two things can happen. First, insufficient material is ordered, and it will cost more money to get more materials contained, especially if time is of the essence, and you need the materials delivered quickly. The second thing that can happen is that you can get too many materials, it also means spending too much money. While it is true that you will possibly have surplus materials for the next project, the amount paid exceeds the necessary amount. Staffing and Personnel One thing related to cost is employees and people. Having staff to work on a project is something that should be directly determined by what is contained in the BOM. If you don't take the BOM seriously, it can affect employees to hire too many people. The staff members will not be compensated the way they like or also employ a few people, and their production will suffer from being overwhelmed and overworked. What is the 4 parts of BOM? There can be many types of information in a PCB BOM, but the parts must have a core set of elements to start with. Here is a list of some of the more core elements that you will see in a PCB BOM: Comment: Each part type on the Printed Circuit Board needs to have a unique identifier, or part number, listed as a comment in the bill of materials. Typically a company designated part number is used as the comment, but this is not a requirement. Vendor component part numbers or other designations can be used as instead. An example of a comment could be the company part number “27-0477-03”. Description: This is a basic description of the part. In the case of the comment 27-0477-03 listed above, the description could be “CAP 10uF 20% 6.3V”. Designator: Each of the individual components on the board will have its own unique reference designator. In the case of the 10uF capacitor, it could be “C27”. Footprint: This is the name of the physical CAD footprint used by the part. For instance, C27 could be using a CAD footprint named “CAP-1206”. How to fill a BOM? Regardless of the particular tool used, the creation of a BOM is divided into the following common steps: Creation of the initial version of the document, indicating on top the project name and any other useful information that allows immediate identification; Document organization, which identifies the users who can access it and their access rights (reading, writing, creation, cancellation, etc.). It is also necessary to activate the change tracking system and set up the physical repository (with backup functionality) that will host the file; Columns definition: each column of the spreadsheet must show on top the name that identifies the category, such as: name of the part, quantity, manufacturer, code, description and more (see Figure 1); Rows filling: for each element belonging to the BOM, a row must be added and properly filled. Since this information is crucial for the success of the project, the information entered must be accurate and consistent with the Gerber files of the PCB; Keep the BOM updated: once created, the file must be kept up to date, tracking every revision produced.

PCB Knowledge ⋅ 02/17/2022 09:53

How to Check PCB Soldering during the Manufacturing?

High reliability assembled PCB prototypes as well as novel surface mounted devices (SMD) and mixed systems must be assessed according to well defined qualification test plans. Such high reliability verification programmes are not limited to just evaluate the robustness, reliability and performance of the product but they also address the verification of tools, fabrication procedures and involved materials, as well as the confirmation of product integrity. For instance, “European Cooperation for Space Standardization” (ECSS) standards used in space programs PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } In this passage, we are looking for more information about PCB soldering, if you are searching for more professional knowledge, please check and read the passage. What are the essential factors in PCB soldering? Solder Paste Printing technology primarily aims to solve problems concerning incompatibility of solder paste printing amount (filling amount and transferring amount of solder paste). Based on professional statistics, with PCBs correctly designed, 60% of PCBs for rework are caused as a result of bad solder paste printing. In solder paste printing, three important "S"s must be remembered: solder paste, stencil and scraper. If correct selections are made, excellent printing effect can be obtained. Quality of solder paste As a necessary material for reflow soldering, solder paste is a kind of paste solder evenly mixed by alloy powder and paste flux (rosin, diluents, stabilizer etc.) among which alloy powder is the key element to composition of solder joints. Flux is the critical material to eliminate surface oxidation, increase wettability and ensure quality of solder paste. In terms of quality, generally speaking, 80% to 90% of solder paste belongs to metal alloy while it accounts for 50% in terms of volume. Solder paste quality insurance comes primarily in two aspects: storage and application. Solder paste is usually stored between 0 and 10°C or stored according to requirement of manufacturers. Stencil design The key function of stencil lies in uniform solder paste coating on PCB pad. Stencil is a must-be in printing technology and its quality directly influences quality of solder paste printing. Up to now, there are three methods to manufacture stencils: chemical corrosion, laser cutting and galvanoformung. Stencil design won't be ensured until the following aspects are fully considered and suitably dealt with. What are the features of soldering finished PCB? Although it is possible for anyone to throw down solder onto PCBs, whether you get classy solder joints or downright caveman quality ones is a different matter altogether. With components becoming smaller and more compact, the chances of soldering issues occurring have become higher. When soldering the PCB, try to make the finished product have the following characteristics: · The soldering surface is kept clean; · The solder joints must have sufficient mechanical strength to prevent the soldered parts from falling off or loose under vibration or impact; · The soldering must be reliable and ensure electrical conductivity This is not only a guarantee for the product’s function but also to prevent the product from being burned out by a short circuit. What are the preparations before of PCB DIP soldering? First Article Inspection We will cross check and record all the supplied components’ quantity, item number, dimension, cathode direction, component silkscreen number, value, etc. Components outline processing Some components outline should be processed ahead of time because of their own design or for the PCB DIP soldering requirements and the whole PCB plan. Requests. The horizontal witch of the processed pins should be the same as the locating holes, the tolerance should be < 5%, the silkscreen upward. Components management Preparation before DIP soldering: Every operator should follow team leader’s arrangement, prepare their WI content in their own station and receive all the components which match the WI completely. Put the received components into the part box and mark them well, including the defect parts if there is. Check if there is any cathode components, and compare with the WI picture, should be familiar with the part appearance and find out the pin position.

PCB Knowledge ⋅ 02/16/2022 10:51

What is Solderability Test during Manufacturing to Guarantee the PCB Quality?

Solderability test on a printed circuit board is critical. If you fail to undertake some tests, then you are inviting trouble. There’s nothing riskier and expensive than rolling out faulty boards to the market. You can avoid such by only undertaking solderability tests. So what’s the importance of the PCB solderability test? PCB Instant Quote .my-button { display: inline-block; padding: 10px 50px; font-size: 16px; text-align: center; text-decoration: none; background-color: blue; color: #fffff0; border: none; border-radius: 5px; font-weight: bold; cursor: pointer; box-shadow: 0px 2px 5px rgba(0, 0, 0, 0.3); transition: background-color 0.3s ease, transform 0.3s ease; } .my-button:hover { background-color: #C23C30; transform: scale(1.05); } Do you know the importance of PCB solderability test and how to process it? In this passage we are providing all the information of PCB solderability test, if you are searching for more knowledge of PCB solderability test please check and read the content below. What are the types of PCB solderability test? Three of the most common solderability testing formats are: · “Dip and look” method · The surface mount simulation test · Wetting balance analysis 1. DIP AND LOOK Dip and look subjects the leads and terminations to up to 8 hours of steam conditioning, accelerating the aging process. (This is why skin doctors warn against saunas and hot showers!) Next, testers dip the components into solder using activated rosin flux. Finally, they’re inspected to ensure they meet requirements. 2. SURFACE MOUNT SIMULATION TEST The surface mount simulation test is available for all surface mount technology (SMT) components, including ones that can’t use other types of PCB testing methods like dip and look. A specific solder paste is screen-printed onto a ceramic plate. The component then goes into the paste and is subjected to a convection reflow profile. 3. WETTING BALANCE ANALYSIS Wetting balance analysis also ages the components to measure the wetting forces. The testers plot the wetting force, starting at negative (nonwet). Solderability is measured as the amount of time it takes for wetting to occur. What is the equipment of PCB solderability test? The right tools and equipment are one of those factors which will see you staying relevant in a competitive environment. Without a doubt, one of the essential tools that you must have is the soldering iron. A soldering iron provides the heat source to melt the solder. But again, the soldering iron doesn’t need to be expensive as such. If you look around, you’ll find some that go for as little as $10. Besides the soldering iron, other tools that you may need during soldering include the following: Solder Flux The Solder Flux acts as a purifying agent, and it purifies the components while closing out extra air to prevent rust. The Solder Flux is one of the essential tools to have at hand when soldering. Manufacturers love it as it goes further to better the dripping individuality of the solder itself. Solder Paste Solder Paste joins various leads of chip packages to connection ends of boards. The solder paste appears like a gray putty-like substance. During soldering, the paste joins the multiple charges of chip packages to the connection ends on a PCB. Solder suckers Solder suckers also go by the name solder pumps. These mechanical vacuum pumps suck solder away from solder joints. They enable the removal of solder from a joint for components desoldering for rework. Wire cutters Even though they tend to be small, wire cutters are convenient tools. You can use the wire cutter to cut off long component legs. Also, you can use these wire cutters to strip the end of the wires. Wire cutters again go by names such as diagonal cutters, flush-cutters, clippers, electronic snippers, and more. Soldering iron tip cleaner Soldering tip cleaners are necessary during soldering. They are for cleaning iron tips from any old solder or carbon accumulation. If you want your soldering iron to last for long, then you’ll need soldering iron tip cleaners. Desoldering Wick Manufacturers use this to clean the leftovers of solder that remained behind during soldering. A desoldering wick is a finely braided copper wire. The copper wire has a rosin coating flux that can finely remove excess copper. Circuit board holder It is the perfect equipment for holding the PCB into place during soldering. Some refer to this equipment as a soldering helping hand and comes in handy when soldering adequate equipment. The circuit board holder fixes the objects at the required angles for soldering.

PCB Knowledge ⋅ 02/16/2022 10:41