What Are the Importance of In-production Calibration of PCB Boards?
Historically, the design and manufacture of PCBs were seen as secondary to the circuit design, but increasing digital speeds and complexity have elevated the need for board quality. Optimal PCB performance can only be achieved with a board that is as uniquely engineered as the circuit itself. For designers new to electronic product development, this can be a heady task: on top of the design and simulation of the circuit, teams are also responsible for preparing a manufactured product that spans multiple disciplines, production practices, and industry guidelines. When time is of the essence – like meeting tight deadlines for an NPI – design teams do best when attending to their area of expertise. A contract manufacturer with extensive electrical engineering services will help keep teams focused on their strengths.If you want to order PCB product, please check and custom your order online. Engineering Consults As a Lead-in to Manufacturing The run-up to manufacturing is necessary to ascertain a design’s level of preparedness. Adjustments to manufacturing processes should be expected (but still minimized), and any changes at the design level will result in rework or revisions. Our engineering-focused production will systematically examine the common and uncommon elements of PCB manufacturing that detract from quality, yield, or development time: Schematic: At the heart of every PCB are the logic and connections between devices that define the functionality of the assembled board. A contract manufacturer can check land patterns for correct layout and associations as a library management system.Bill of Materials (BOM): The BOM itself is straightforward as a document output of the schematic listing all of the components in the design. However, sourcing and procuring components necessary for assembly is difficult, especially when device shortages are rampant and wait times remain stubbornly high.Stackup: The stackup is the starting point of the board. Designers must accommodate the different impedance profiles (single-ended transmissions, differential pairs, and other standard impedances) and signal/plane layer distribution to maximize layout efficiency and performance.Design rules: Design rules provide the framework for manufacturability during the layout stage. As PCB manufacturing is a multi-step process, design rules must cover all the points where a lack of adherence to equipment precision or capabilities will result in an unproducible or less-than-satisfactory board.Layout: The layout represents the digital master copy of the final product out of manufacturing. While design rules will cover many of the points for optimization, many best practices may not be covered by standard rulesets. Instead, a layout review allows engineers to analyze the board for any areas of DFM that would otherwise fall through the cracks.Documentation: Maintaining good documentation is critical not only for the current design iteration but also for any future revisions. As the primary method of communication between design and manufacturing, engineering will ensure clear intent and unambiguous directions to bolster quick turnaround times. Optimal Electronic Systems Need Electrical Engineering Services The best devices don’t just perform – they perform exemplary and for extended periods. Increasingly, devices have to do more with less: less space, power consumption, and time-to-market. Tradeoffs are certainly a cornerstone of engineering, but our customers have grown to expect quality and reliability for over forty years, no matter the design constraints. In-production calibration of boards is less flexible than pre-production, yet it remains a critical tool of agile manufacturing. Turning would-be scrap to rework or pushing designs back to layout to avoid secondary production minimizes turnaround times and maintains consistent quality. Even the most thoroughly-vetted design can benefit from engineering input to react and respond to board production. Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/06/2023 16:07
Is PCB Shielding Shield Necessary during Manufacturing?
Interconnections are a good thing for PCBs – even vital considering the density of modern packages and signals. But the requirements of through-hole sizes constrain already cramped layouts. However, through holes are tied to board thicknesses, and an HDI design that requires additional layers for routing and power/reference planes will continue to increase the size of the through holes. A more moderate approach to interconnections can be achieved with microvias formed through PCB laser drilling, which shrinks down drilled hole sizes with layer-by-layer drilling.If you want to order PCB product, please check and custom your order online. PCB Shielding Cans Shield Where Necessary PCB layouts are facing a crunch: on the one hand, electronics have grown to have extensive feature lists, while at the same time, portability and form factor are becoming more desired. Simply put, designers are often asked to do more with less; achieving complexity in cramped designs requires an evaluation of every board feature to maximize space savings. Traditional through-hole drilling methods tie the board’s width to the diameter of drilled holes through the aspect ratio. Typical aspect ratios for mechanically-drilled through-holes are in the range of 8~10:1 (that is, a minimum hole diameter of 6.3 mils for a standard 63 mil wide board). Exceeding the aspect ratio can cause multiple issues during fabrication. A board with an aspect ratio above recommended settings can experience plating issues. A via-hole plate outside-in from the openings slows the metal deposition rate at the vertical center of the through hole as the process progresses. A wide enough hole opening ensures good plating coverage along the length of the via barrel. In contrast, small openings can experience poor or incomplete plating at the via center. This poses continuity issues and affects the stress-strain profile, and CTE mismatches in the z-axis, undermining mechanical stability. PCB laser drilling affords additional design flexibility by creating microvias with maximum aspect ratios and depths of 1:1 and .25mm, respectively. While the aspect ratio is smaller than standard through holes, the controlled depth drilling through laser ablation means that the hole size can be shrunk significantly compared to drilled through holes. Because these microvias can only span one or two layers at a time, they must be combined to form a structure similar to a through hole in a stacked or staggered arrangement: Stacked microvias are aligned in the z-axis, one on top of another.Staggered microvias can be placed anywhere within the plane, provided a trace connects it to same-net microvias on adjacent layers.Microvias face additional fabrication costs and challenges compared to through-hole drilling, and designers must be cognizant of these requirements. Larger aspect ratio vias, wherever possible, are encouraged, and microvia “through holes” should limit stacked microvias to avoid reliability issues. Circumventing EMI During Layout As with standard drilling, the major considerations for laser drilling efficacy are accuracy and throughput. Positional accuracy arguably takes on an even greater importance in laser drilling due to the relative size of the via hole – via position that strays from its true center becomes more noticeable at this resolution. Additionally, HDI design necessitates greater fan out and routing density which translates to a greater number of vias overall. Laser drilling technology, therefore, requires advancements above and beyond standard techniques for feasibility. There are a few concepts necessary to successfully incorporate a laser process cycle into fabrication: High peak/short pulse: A higher powered laser pulse driven by a substantially faster rise time improves the ablation of the substrate material while also reducing the particular drilling time for each via.Scanning improvements: A significant amount of processing time is due to the jump from one via position to the next. Efficient servo motors quickly steer the scan head and reduce the time between drills.Motion-to-fire: Laser guiding systems must prepare for their next move before finishing their current drill job. A closed-loop system uses feedback response to search for its next target, while an open-loop method uses a pre-loaded look-up table for greater speed. A closed-loop system is more accurate between the two as it requires a positional check before firing the laser. At the same time, the open-loop method uses trial-and-error jump delays to sequence the travel time between drills and calibration of servo motors to account for mechanical aging. Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/05/2023 16:19
What Is Rice Cooker Pcb?
An electric rice cooker is a common household appliance that meets people's daily needs by automatically cooking and heating food. The PCB (Printed Circuit Board) in an electric rice cooker is one of its core components, responsible for controlling various functions such as heating, warming, and timing. This article will provide a detailed introduction to the PCB in electric rice cookers. Components of an Electric Rice CookerAn electric rice cooker is primarily composed of an outer shell, inner pot, heating plate, temperature control device, power switch, timer, and more. Among these components, the heating plate and temperature control device are the core components of an electric rice cooker. Common Structure of an Electric Rice Cooker:A typical electric rice cooker consists of components such as the heating plate, thermal limiter, keep-warm switch, lever switch, current limiting resistor, indicator lights, and socket. Heating Plate:The heating plate serves as the primary heating element in an electric rice cooker and is typically made of aluminum. It houses an electric heating tube, and the inner pot is placed on top of it. When removed, you can see the interior of the heating plate. Thermal Limiter:Also referred to as a magnetic limiter, it is a device that converts electrical energy into heat energy and maintains a constant temperature. There are two main types of thermal limiters: those made with permanent magnets and those utilizing magnetic materials. The former is suitable for lower-power appliances and consists of a permanent magnet and a spring that can press against the center of the heating plate. To order an electric rice cooker PCB online, please click here. Heating Principle of an Electric Rice Cooker The heating principle of an electric rice cooker primarily involves using electric current through the heating plate to generate heat, which in turn heats the food inside the inner pot. The heating plate is an electrical heating element capable of producing heat through the flow of electric current. The temperature control device is another core component of the electric rice cooker, responsible for controlling the on/off state of the heating plate by detecting the temperature inside the inner pot, thereby achieving temperature control within the inner pot. Keep-Warm Switch:Also known as a thermostat, this switch is commonly found in the control circuitry of household appliances. It features temperature display and control functions, allowing the appliance to operate at a constant temperature. Heating Element:Commonly referred to as an electric heater or heating coil, it consists of spring strips, a pair of normally closed contacts, a pair of normally open contacts, and a bimetallic strip. Lever Switch:The lever switch is a fully mechanical component with constant normally open contacts. When the temperature rises to a certain level (exceeding the set value), the lever switch automatically opens, connecting the heating element with the temperature limiter. When the temperature decreases to the predetermined value, the lever switch closes, cutting off the circuit. During cooking, pressing this switch connects the heating element to the power supply, and the heating indicator light illuminates. When the food is cooked, the temperature limiter will pop out, driving the lever switch to disconnect the contacts. Subsequently, the heating element is controlled only by the keep-warm switch. Current Limiting Resistor:Appearing in a golden or white color and typically with a size such as a 3W resistor, it is placed between the heating element and the power supply to protect the heating element. Common current limiting resistors are rated at 185°C and 5A or 10A (depending on the wattage of the electric rice cooker). Induction Coil:The induction coil consists of a metal outer shell and an insulating material. The outer shell is usually made of plastic, although some are made of copper, which is more expensive and susceptible to damage. The insulating material is primarily made from mica strips. The current limiting resistor is a crucial component for protecting the heating element and can be replaced with a conductor. These components collectively form the heating system of an electric rice cooker, ensuring precise control of temperature and safe operation during the cooking process. The PCB of an Electric Rice Cooker The PCB (Printed Circuit Board) of an electric rice cooker refers to the circuit board within the rice cooker. It encompasses multiple circuits, such as the temperature sensing signal section, temperature signal processing section, temperature control circuit, and display circuit. These circuits typically comprise components like thermistors or thermocouples. Temperature Signal Processing Section:The temperature signal processing section acts as the controller for the electric rice cooker. It is responsible for processing temperature sensing signals and converting them into control signals. This circuit usually consists of components such as microcontrollers and amplifiers. Temperature Control Circuit:The temperature control circuit is one of the central components of the electric rice cooker. It is responsible for controlling the on/off state of the heating plate. This circuit typically includes components like relays and silicon-controlled rectifiers (SCRs). Display Circuit:The display circuit serves as the visual interface of the electric rice cooker, responsible for displaying information about the cooker's operational status, timer settings, and other relevant information. This circuit typically comprises components like LED lights and LCD screens. These circuit sections collectively enable the electric rice cooker to accurately control temperature, provide user-friendly displays, and ensure efficient and convenient cooking. Functions of an Electric Rice Cooker PCB Control of Heating Plate On/Off:The PCB of an electric rice cooker controls the on/off state of the heating plate to regulate the temperature inside the inner pot. When the temperature inside the pot falls below the set value, the control circuit activates the heating plate, generating heat to raise the inner pot's temperature. Conversely, when the temperature inside the pot exceeds the set value, the control circuit deactivates the heating plate to prevent overheating. Display of Operational Status and Timer Settings:The PCB in an electric rice cooker can display information about the cooker's operational status and timer settings. This information can be presented to the user through components such as LED lights or LCD screens, allowing users to easily monitor the cooker's performance. Implementation of Automation Control:The PCB of an electric rice cooker can achieve automation control using microcontrollers and other chips. Users can set parameters like heating temperature and cooking time through buttons or other input methods. The microcontroller and related components then automatically control the heating plate's operation, display circuit, and other functions, enabling automated cooking. In SummaryThe PCB is a crucial component of an electric rice cooker, responsible for controlling various functions such as heating, warming, and timing. It comprises multiple circuits, including temperature sensing signal sections, temperature signal processing sections, temperature control circuits, and display circuits. These circuits work together to enable automation control, display operational status, and manage timer settings. When purchasing and using an electric rice cooker, it's important to consider its specifications and safety features. Additionally, proper cleaning and maintenance are essential to ensure its normal operation and longevity.
PCB Knowledge ⋅ 09/05/2023 11:02
Why Per-Board PCB Prototype Prices Are Higher Than Production Builds？
After spending time engineering and designing, your PCB is ready for its prototype build. Congratulations! The design is ready to jump from electronic files to physical boards, and a contract manufacturer (CM) is integral to overseeing this process for those without hardware production experience. There is much to consider here, and CMs possess varying strengths and weaknesses. Building a PCB prototype will involve many manufacturing processes and associated costs. The CM’s choice of PCB fabricator, the parts and materials used by the CM, and the manufacturing and test methods will heavily impact the PCB prototype price. Armed with an understanding of the processes that go into building a prototype will aid designers in making an informed decision for CM partnerships.If you want to order PCB product, please check and custom your order online. Why Per-Board PCB Prototype Prices Are Higher Than Production Builds As prototypes are more exploratory by nature than DFM boards, PCB prototype prices will typically exceed final production on a per-board basis. Some of the major factors contributing to this discrepancy include: Documentation: The amount and quality of the documentation that accompanies a prototype build may need to be completed, and the manufacturer has to update or create the necessary documents to proceed with the build.Component research: The parts in the design may require refining due to lack of availability or being of end–of–life (EOL) production status. As a result, the component engineers will need to spend time researching suitable replacements.Engineering: The design may be more conceptual than production-ready and require more engineering analysis to make sure that potential manufacturing errors have been corrected.Design for X: For a prototype, there often are more elements of design for assembly, design for testing, and design for debugging that will need to be included. DFA and DFT features will help when the board transitions to production, while a design for debugging is essential in a prototype. Options such as test probe points and component sockets should be added to make exploring the prototype’s performance or investigating alternative design strategies easier.Time to market: The CM will fast-track the project through the factory to get prototypes built as quickly as possible. While the manufacturing steps, such as component placement and soldering, will be the same as a regular production board, a prototype will be built in smaller numbers with dedicated team members to guide its progress. Why The Lowest Price Isn’t Always Best for Prototype Assembly The first criterion to consider when choosing a CM is what level of contract manufacturing is needed for your project. There are different levels of CM capabilities for building printed circuit boards, which affect how they approach prototyping designs. The lowest level of a contract manufacturer is the “garage shop” CM. They specialize in quick turns at a low price but may lack the infrastructure to fully support your prototype. Their engineering sophistication may struggle to translate designs to manufacturing or adequately evaluate component selection. On the other end of the spectrum are the “mega” CMs. These shops have the necessary resources for complete engineering and manufacturing support. Unfortunately, their business model is set up for high-volume production runs, and smaller prototype builds may not get the personalized attention they need to evolve the design toward its goals. Finding a low-volume, high-quality CM that is between these two aforementioned extremes has a greater upfront cost, yet it provides the best environment for building a prototype PCB. While PCB production is an iterative process, working with a CM that is ill-suited for prototype design may delay final manufacturing and incur unnecessary costs: Some CMs may not be able to provide a full documentation package that contains the list of modifications made during production. This pushes responsibility back to the design team, which is usually remedied with time and money to duplicate their work. Similarly, some CMs don’t identify and review DFA issues which can lead to yield issues in high-volume production. Engineering analysis of potential DFM issues, bill of materials (BOM) validation, and high-quality manufacturing standards may be substandard. CMs that don’t invest in these practices will be able to charge less, but correcting engineering and production problems later can prove costly when scheduling is more compact. CMs that do not have a vast network of vendors to use for bare-board materials or components will pay more per board. This may be acceptable during prototyping when the volume is low but becomes an issue with larger lot sizes.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/04/2023 16:20
What Are the PCB Quality Issues Can Cause Headaches During Production？
Testing is essential for ensuring high-quality PCBs. By employing well-established protocols, testers can effectively identify design flaws and malfunctions. Even the absence of testability can reveal errors, although this poses its own challenges. Inability to debug boards and understand design intent limits the extent to which PCB quality can be confirmed. At this stage, visual inspection becomes invaluable for process control engineers in troubleshooting manufacturing defects during production. Fabrication and assembly are complex multi-stage processes that offer numerous opportunities for deviations from acceptable board criteria. A contract manufacturer with extensive experience can leverage their expertise to identify and address poor outcomes in product development, thereby preventing such issues from occurring in the first place. An engineering-oriented CM will have robust systems and procedures to ensure the highest quality assembly for a design, while effectively mitigating common PCB quality issues.If you want to order PCB product, please check and custom your order online. PCB Quality Issues That Can Cause Headaches During Production The production of electronics involves multiple stages that are interconnected but can be treated as separate disciplines. Inadequate organizational structure or communication can result in substandard outcomes, leading to various issues: Unapproved part substitutions: Shortages or long lead times may necessitate part substitutions. However, it is crucial to pre-approve and document these engineering change orders (ECOs) in relevant documentation such as the bill of materials (BOM) and schematic. Failing to obtain proper notification can lead to two scenarios: either the substituted part works without detection of the change, or the substitution performs inadequately. Testers may observe discrepancies in device speed, timing, and value tolerances, which can have unpredictable effects on PCB performance. Correcting, revising, and documenting these substitutions at a later stage requires significant time and financial resources. Solder defects: The quality of solder joints on the finished printed circuit board assembly (PCBA) is vital for system continuity and long-term reliability. Solder issues often arise with complex component package types, but insufficient control and monitoring of solder processes can also contribute. Quality testing and inspection processes are fundamental for assembly performance in any contract manufacturer. Therefore, poor solder quality may only be the visible manifestation of underlying issues. PCBA system integration: Proper handling and protective equipment are essential when integrating the PCBA with mechanical enclosures or other system assemblies. Failure to follow guidelines during integration can introduce functional problems to the board. Since these errors are typically associated with the system assembly, they cannot be diagnosed by the contract manufacturer or detected during manufacturing. Identifying and resolving these issues may involve navigating through multiple shops, resulting in lengthy delays. Cables and connectors: Mechanical interconnects between boards and other system components are prone to intermittent failures. Cables must adhere to minimum bend radii requirements to avoid wire stress or issues with plug-receptacle interfaces. Mechanical assembly: Several mechanical components cannot be adequately examined using standard electrical test processes. These include heatsinks, faceplates, standoffs, and connectors that may be incorrectly installed and undetected during standard testing and inspection procedures. These oversights consume valuable time and budgets, potentially leading to production delays. However, contract manufacturers with established processes in place to mitigate PCB quality issues and implement thorough testing can offer higher levels of quality assurance. Best Practices for Manufacturing Processes and Standards Before entering into a production contract, design teams must have a comprehensive understanding of the capabilities and competencies of their chosen contract manufacturer (CM). The following list outlines the services that a high-quality PCB manufacturer should offer to avoid PCB quality issues: Component testing: A well-trained technical staff should be capable of validating component functionality through rigorous testing. Documented processes that outline the procedures for component substitutions, as well as guidelines for customer notifications and approvals, are essential to maintain design integrity. State-of-the-art soldering quality control (QC): Testing should be conducted both before and after the critical soldering step in PCB assembly. This includes utilizing automated optical testing and employing certified inspectors for electrical testing. Engineering expertise: A dedicated engineering staff should thoroughly review all design documents to create a specialized production plan. This expertise also extends to documenting work orders comprehenWanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/02/2023 16:20
What Are the Design Specifications of Gold Fingers in PCB?
Have you found out that the edges of PCB gold fingers are in slope forms? Well, the procedure of beveling allows sharp, square edges to turn into slopes. In the case of PCBs or printed circuit boards, the beveling process completes the surface finish. The beveling process of the gold fingers of a PCB gets initiated after completing the disposition of solder masks. The process of PCB gold finger beveling is unavoidable in terms of making insertions quicker and more effortless. Unless the gold finger beveling is completed, insertions will be more difficult than usual. If you are going to learn more knowledge of gold finger PCB, please check and read the content below.If you want to order PCB product, please check and custom your order online. How are gold fingers applied? Gold fingers can be used for many various things. And they use depending on the designer’s purpose. There are some common applications of gold fingers as the follows: 1. Provide an interconnection point for transferring network data;2. Connect external components to the PCB prototype;3. A place for attaching specialized adapters or daughter boards;4. Serve as an audio adapter How are gold fingers used in PCB? Gold fingers are used as connecting contacts between two adjoining PCBs. Aside from its conductivity, the purpose of the gold is to protect the connecting edges from wear over many uses. Due to the strength of hard gold at its specified thickness, gold fingers make it possible for a PCB to be connected, disconnected and reconnected up to 1,000 different times in a corresponding slot. The functions of gold fingers are multi-purpose. With any given computer setup, you will see a number of peripherals that connect with the computer itself thanks to PCB gold fingers. Some of the most widespread uses of gold fingers include the following: Interconnection points: When a secondary PCB connects to the main motherboard, it is done through one of several female slots, such as a PCI, ISA or AGP slot. Through these slots, the gold fingers conduct signals between a peripheral device or an internal card and the computer itself.Special adapters: Gold fingers make it possible to add numerous performance enhancements to a personal computer. Through secondary PCBs that slot perpendicular into the motherboard, a computer can deliver enhanced graphics and hi-fidelity sound. Since these cards are seldom unattached and reattached, the gold fingers generally outlast the card itself. External connections: The outer peripherals that have been added to a computer station are connected to the motherboard with PCB gold fingers. Devices such as speakers, subwoofers, scanners, printers and monitors are all plugged into specific slots behind the computer tower. These slots, in turn, attach to PCBs that connect to the motherboard. For the corresponding device to work, its own card must connect to a power source. The fingers and corresponding slots on the motherboard make it all possible. Gold fingers provide module PCBs the power to operate and deliver modern-day functionality to users of remote and stationary computing devices. The flexibility of the PCB system, whereby different slots connect different types of cards, makes it possible to upgrade the same computer periodically over five or ten years. Every time a sound or graphics card is updated, you can remove the pre-existing card from your motherboard and replace it with the new and improved model. Through each update, the PCB gold fingers remain the universal connecting contact. What Are the Design Specifications of Gold Fingers in PCB? 1. The internal PCB layer towards the edge of PCB must be free of copper to prevent exposure during chamfering. 2. It is not recommended to include PTH within 1mm of gold finger. 4. Keep a distance of at least 0.5mm between the gold finger and the circuit board outline. 5. Any compromise of the standard spacing values can lead to PCB weakness and failure. 6. Do not use anti welding or screen printing near the golden finger. 7. The gold finger shall be placed at the position with the PCB center facing outward. The IPC has set some standards for the production of PCB gold fingers. IPC standards are summarized as follows: · Chemical composition: in order to maximize the rigidity of the edge of PCB gold finger, the gold plating should contain 5% to 10% cobalt.· Thickness: coating thickness shall be in the range of 2 to 50 microinches.· Appearance test: the appearance inspection is carried out through a magnifying glass. The contact edge shall be smooth, the surface shall be clean and free of excessive coating such as nickel.· Tape test: carry out this test to check the adhesion of gold plating on the contact. In this test, a tape is fixed to the contact edge and removed. In the next step, check the tape for traces of plating. If any gold is visible on the tape, the coating is not considered adequate for continuous injection and ejection.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 09/01/2023 17:27
How Many PCB Manufacturing Defects Relate to Materials and Components？
Anyone who’s ever constructed or built a prototype on a breadboard knows how easy it is to make mistakes placing package legs that can take hours to troubleshoot later. One might think the easy part would simply be “combining the pieces as instructed,” while this is certainly more straightforward than circuit design, it is also fraught with difficulties. The need for considerable and pervasive attention to detail is critical for circuits, and this extends to the PCB itself for the best manufacturing outcomes. No matter how much a product has observed its design intent, it’s still necessary to closely monitor design details that could harm production. PCB manufacturing defects typically arise due to a failure to incorporate best practices or follow DFM best practices. However, an experienced engineering team can pore over a design to optimize areas needing refinement.If you want to order PCB product, please check and custom your order online. Many PCB Manufacturing Defects Relate to Materials and Components All designs are not inherently DFM. While general design best practices and DFM overlap heavily due to industry standards focusing on production, many boards are built to assuage the validity of testing, assembly, or other manufacturing sub-processes. For PCB designers that don’t have as deep manufacturing expertise as they do design, the issues discovered in manufacturing may seem entirely divorced from design best practices. Through no fault of their own, they may miss design and component issues that will cause manufacturing problems. Quality CMs, on the other hand, have years and years of experience working on PCBs from various industries and can partner with you to help mitigate these issues. Regarding PCB production, there are two key areas where manufacturing problems can arise: Materials: Certain materials that are optimal for specific circuits. If materials specified in the board layer stackups are ill-suited for a particular function – say high-speed design – the result will be suboptimal performance. There are also cases in which the materials requested for the design aren’t suitable for the operating environments of the board or cost-effective in its manufacturing. Components: Some components that designers choose for their designs may be legacy components enshrined in their libraries years ago, and they may not realize that the status of those components has changed over time. They may have longer lead times, or their end-of-life (EOL) status may render them unavailable. The CM will be able to verify the status of the components in the design and make recommendations on replacements, if necessary.Specific Design Defects That Impact Manufacturing Layer stackups and component issues are major design foci, but there are more subtle manufacturing defects that can be easy to overlook: Fiducials: These markers serve as targets for computer vision systems to align fine pitch parts, such as QFPs or BGAs. Fiducials need to be placed in any three corners of an assembly side of the board to enable targeting in the x- and y-axes.Proper clearance: For automated assembly and test equipment, components need enough clearance to features and board edges to prevent shorts, poor solderability, degraded signal integrity, and obstructions. Component-to-component placement: Components that are too close to each other or rotated incorrectly can cause problems during wave soldering: taller components preceding shorter components result in a shadowing effect that reduces the strength of their solder joints. Chip components rotated perpendicular to each other can result in the same issue. Tombstoning: This effect can happen when unequal heating is applied to a chip component during solder reflow, causing it to stand up on one end instead of both ends soldering down as expected. The unequal heating can be due to incorrect SMT land pattern sizes used for the part or different trace widths intersecting the pads. All of these issues can potentially cause problems for a PCB during manufacturing. The key is to use good design for manufacturability (DFM) practices during the PCB layout to avoid these common pitfalls. Here is where an experienced CM shines: helping designers understand DFM practices that apply to the particular needs of their design.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 08/31/2023 16:58
What Is Gas Stoves Pcb?
Circuit Board in Gas Stove Control System: Structure, Operation, and Importance for Gas Safety Structure of the Circuit Board The circuit board in a gas stove mainly consists of the following components: Power Interface: Used to connect to the power supply, usually through a power cord linked to an external power source.Microprocessor: Controls various operations of the gas stove, receives user input commands, and manages the gas valve's opening and closing.Gas Control Valve: Controls the flow of gas based on instructions from the microprocessor.Display Screen and Buttons: The display screen shows the gas stove's operational status, while buttons enable users to input commands.Other Electronic Components: Such as capacitors, resistors, diodes, etc., for auxiliary functions on the circuit board. Gas Stoves Pcb typesGas Circuit Board is an electronic device used for controlling and monitoring gas pipeline systems. Depending on different needs and application scenarios, there are various types of gas circuit boards to choose from. Among them, the double-sided circuit board is a common type, characterized by wiring on both sides of the board. It offers a higher circuit density and lower manufacturing costs, making it suitable for applications requiring a large number of wires. Single-sided circuit board, on the other hand, features wiring on only one side of the board, while the other side remains empty. It is suitable for applications that don't require a large number of wires. Substrate circuit board involves wiring on the surface of a thicker substrate, making it suitable for applications that demand high mechanical strength and temperature resistance. In addition, gas circuit boards offer multiple functionalities such as pressure sensors, temperature sensors, flow sensors, and alarm devices. These functionalities enable various monitoring and control measures for gas pipelines, ensuring the safe and stable delivery of gas to users' homes. If you wish to purchase a gas stove PCB, please click here.Gas Stoves Pcb used forThe specific usage of a gas circuit board should be referenced from the product manual or guided by professionals, as different models and brands of gas circuit boards may have varying operating methods. Generally, a gas circuit board is installed on control and monitoring equipment for gas pipelines, enabling various monitoring and control functions for the gas pipelines. The specific usage method may vary depending on the product model and application scenario. Therefore, it is recommended to carefully read the product manual before usage or consult professionals for guidance. When using a gas circuit board, safety precautions should be observed. These include avoiding contact with high-pressure gas pipelines, preventing mechanical damage or electromagnetic interference to the circuit board, and ensuring safe operation. Additionally, if there are any questions or anomalies during usage, the equipment should be promptly stopped and relevant personnel should be contacted for resolution.Operation Principle of the Circuit Board The operation process of the gas stove circuit board is as follows: Users input operational commands using buttons, such as ignition, flame adjustment, etc.The microprocessor receives and processes user input commands.Based on microprocessor instructions, the gas control valve regulates the gas flow.The display screen shows the gas stove's status, such as flame size, gas leakage, etc., as feedback from the microprocessor.Throughout this process, the circuit board acts as the central control unit, ensuring the proper functioning of the gas stove. Importance of the Circuit Board for Gas Safety The gas circuit board is a critical component of the gas stove, directly impacting the safety of the entire gas system. The following highlights the importance of the circuit board for gas safety: Fault Detection and Alarms: The circuit board continuously monitors the gas system. In case of faults or anomalies, it triggers immediate alarms and cuts off gas supply to prevent accidents from escalating.Safety Control: The circuit board features safety controls, such as automatically closing the gas valve in the event of unexpected extinguishing to ensure user safety.Smart Control: The circuit board can intelligently adjust flame size, offer timer functions, and other controls based on user input and stove status, enhancing the gas stove's efficiency. Hence, the design and manufacturing of the circuit board must adhere to relevant safety standards and undergo rigorous quality testing. Users should also maintain and upkeep the circuit board during regular usage to ensure its smooth operation.
PCB Knowledge ⋅ 08/31/2023 14:50
What Are the Main Effective Traceability Processes during PCB Manufacturing？
Being able to account for every possible variable is the key to traceability. This need is especially true in the medical equipment field, where every piece of the assembly must be able to be tracked back to its source. Implementing this traceability constraint is an enormous task, particularly when building a printed circuit board, as several components and materials go into manufacturing a PCB. To achieve traceability in medical devices, it is crucial to incorporate a traceability matrix specifically designed for medical devices. This traceability matrix, also known as the “traceability matrix medical device,” enables the comprehensive tracking and documentation of the origin and journey of the building blocks of the medical device through the supply chain. By utilizing this traceability matrix, manufacturers can ensure compliance with regulatory standards and maintain transparency throughout the manufacturing process.If you want to order PCB product, please check and custom your order online. Medical Devices and The Need for TransparencyA PCB contract manufacturer must be able to fulfill the traceability requirements for the medical device in production. The specifics of the board will determine which industry standard, such as ISO 13485, must be met. To fulfill these requirements, a CM should understand and be fully certified in the standards. Documentation is the cornerstone of traceability: if there is a problem with a part or product, it will be easy to identify any other parts or products that might be similarly affected. Accurately identifying parts and products is fundamental to tracking, saving time and money in the event of a supply chain investigation. Agencies strictly enforce precise product identification, and a CM must have a robust identification system (along with their tracking system) to quickly identify what parts are in use. This identification should include compliance certifications, test results, and other crucial electronic product data. Since many PCBA or subsystems appear similar but are configurable in either hardware or software, their performance can vary significantly and call for precise documentation. Thorough documentation can avoid numerous performance or reliability problems in the future. Traceability also aids design teams as they continue to develop and improve the product; the better the tracking of the parts, the richer the performance data will be for analysis. Traceability Processes During PCB ManufacturingAchieving traceability requires the work of a dedicated contract manufacturer with processes in place to accurately identify and track the information under consideration. A good CM will have a work order documentation system for building circuit boards; this serial number on the completed board can then trace back to the original work order. The documentation system in use should include the following work order information: Purchase order (PO) data: The work order should contain all of the POs used for procuring the parts and materials for the PCBA. The work order will include the unassembled PCB manufacturing from the fabricator, components, sheet metal, cables, and other manufacturing materials. This data should also include supplier data codes when possible. Manufacturing process steps: It is also helpful for traceability to know the manufacturing steps taken during assembly, including inspection and testing. Manufacturing technicians: Knowing which technicians performed specific operations also support traceability. The technician in question can then field any questions on a PCBA. An intricate tracking system relies on multiple sub-processes for effectiveness. Documentation must be in place, along with a method to assign and match up tracking numbers to products and parts the CM is using. Then, there must be the ability to identify those products and parts, usually with a barcode tracking system. The traceability matrix medical device plays a crucial role in this process, enabling the systematic identification and tracking of products and parts throughout the assembly of medical devices. Finally, there has to be a database that sorts all of this data, including the information captured by the traceability matrix medical device, and presents it in an organized and easy-to-understand format. An intricate tracking system relies on multiple sub-processes for effectiveness. Documentation must be in place, along with a method to assign and match up tracking numbers to products and parts the CM is using. Then, there must be the ability to identify those products and parts, usually with a barcode tracking system. Finally, there has to be a database that sorts all of this data and presents it in an organized and easy-to-understand format.Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 08/30/2023 15:57
How PCB Via Filling Affects Fabrication Process Workflow？
PCBs also encounter thermal mismatches that can ultimately undo the final product. Drilling evacuates material, and plating deposits only a thin layer that does not absorb heat and expands at the same rate as the substrate. This action can eventually cause early failure of the via (or other PTH), but via filling is a seemingly roundabout method that maintains structural integrity.If you want to order PCB product, please check and custom your order online. The Motivation for Via FillingThe via-filling process responds to reliability issues associated with standard via production. In terms of continuity, a via is simply a vertically-oriented trace. However, the long-term quality outcomes diverge because the fabrication method of drilling and plating is much more involved than etching on a plane. Primarily, the thermal cycling of the board develops a stress-strain matrix at the interface of the via barrel and surrounding substrate due to a difference in the z-axis coefficients of thermal expansion (CTE). CTEs are intrinsic material properties, and while design can opt for a CTE closer to the substrate material, the absence of material within the via barrel also contributes to an uneven heating profile. The solution is to deposit a material inside the via barrel and cap it shut to more closely align the z-axis expansion of the via with its surroundings, preventing intermittent connectivity and open circuits owing to thermal cracking. The fill material itself broadly fits into two categories: conductive and non-conductive. The material conductivity does not affect the electrical continuity of the via but impacts the thermal routing. Most designs settle on a non-conductive epoxy fill as the CTE better matches that of the board material, ensuring stable performance and high reliability over the device’s service life. The conductive fill option is less popular by a significant margin, but it can act as a thermal management solution as it improves the heat flow through the via barrel. Since thermal vias do not require any extra space in the layout (unlike copper pours or more robust heat sinks), they can be exceptionally vital in HDI designs looking to squeeze additional functionality out of a limited area. Two possible applications are a grid of thermal vias within the thermal pad of a flat-pin SMD package or BGA via-in-pad. Beyond thermal performance, via filling protects the long-term function of the via by serving as a physical barrier to contamination. Via filling offers two direct advantages to assembly: It serves as a barricade to solder capillary action wicking up the via and shorting connections between components on the other side of the board during wave soldering.It prevents solder paste from wicking into the via and undermining the quality of the joint; dogbone via arrays found in larger-pitch BGAs can be susceptible to this failure mode. How Via Filling Affects Design and Fabrication Workflow？ The process of material selection post-plating involves a careful balance of via design elements, namely the diameter, structure, and the drill’s depth versus the hole’s diameter (also known as the aspect ratio), further complicating the process. In general, designers should consult with manufacturers to optimize via characteristics: The finished diameter of the via is critical to the success of the filling process: too small and the filling material cannot easily flow into the opening, but too large and the filling material will run out of the opening. The exact values will differ by manufacturer equipment and expertise, but filled via hole diameters typically start near 8 mils/. 20 mm and max out around 18 mils/. 45 mm.Plated through-holes and blind vias are the only via structures compatible with filling. However, this process can iterate for microvias to form stacked and staggered via structures. Via filling can be universal to a design, but designers can also designate fill/no-fill styles individually. Designers have this option because the manufacturer must complete the via-fill process before further drilling on the bare board. Essentially, the additional processing steps amount to a secondary drill stage that finishes with the fill material pushed into the via before baking. Therefore, designers can create an extra layer in the board file (and associated artwork) that provides a quick reference of all the vias for filling. Wanna know PCB knowledge? Check and read for more.
PCB Knowledge ⋅ 08/29/2023 16:12
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