UL certification for PCB
Those seeking quality printed circuit boards may look for boards that are UL approved. UL is short for Underwriters Laboratories, a global independent safety science company with over 100 years of expertise innovating safety solutions. UL is an accepted leader worldwide in testing, certification and standards development, with a goal to use safety science and safety engineering to promote safe living and working environments. Having a UL logo on your board certifies that your PCB has been verified to have been designed according to UL standards for quality and safety. UL recognition addresses component safety concerns such as flammability and electric insulation. Those who buy UL-recognized PCB products can be confident that these boards comply with accepted component safety requirements. It will get lead time and quote for Your Board.If you want to order PCB product, please check and custom your order online. What is UL certification? The main standards of PCBs are UL 796, the specific PCB standard, and the UL 94 for flammability of plastics materials. These specify many performance tests to measure the long-term reliability and fire safety of the PCB. If a board is released in accordance with these standards, the board will be marked with the Underwriters Laboratories (UL) logo. The parameters used for PCB certification will be determined by the application of the circuit board in its final product. Some industries have some specific standards and vary parameters in UL certifications, such as specific flame rating, direct support requirements (DSR), maximum operating temperature (MOT), the relative thermal index (RTI), and minimum comparative tracking index (CTI) rating. The requirements of these parameters may be different for the PCBs based on different applications of the end-products. There are two levels of PCB recognition that manufacturers can apply for: full recognition and flammability-only recognition. The type of PCB identification required depends on the application of PCBs in the end-products. Materials, construction, parameters, and manufacturing process are the main elements controlled for a recognized PCB. Therefore, when customers indicate that the PCBs need to meet UL, customers need to specify the UL parameters required for the PCB applications of the end products. Or tell PCB manufacturers whose field is the PCBs applied in. 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. If PCB manufacturers produce PCBs for industries that do not have UL certifications, manufacturers may not need to certify the boards. But, many end products now also require PCBs to meet UL standards, such as audio and video equipment, medical equipment, and industrial control equipment, etc. In any case, if the boards are officially certified according to industry safety standards, PCB manufacturers will be more attractive than the competitors. Types of UL certification UL certifies PCBs under a PCB Recognition Program that comes in two flavors – Full Recognition and Flame-Only Recognition. Flame RatingsFlame ratings are typically specified by end product requirements and evaluate a sample burn time when a PCB is subjected to a horizontal and vertical flame. These flames are broken down into classes which includes V-0, V-1, V2, VTM-0, VTM-1, and VTM-2. Solder LimitsSolder limits test the kind of soldering processes that a PCB will be subjected to during the component assembly process. These tests simulate a thermal shock and maximum temperature to gauge how your PCB performs. Maximum Operating TemperatureMaximum Operating Temperature (MOT) defines a PCBs maximum continuous use at a specific temperature. This test simulates the exposure of a PCB to normal operating condition temperatures during a 10-56 day period, with temperatures based on your manufacturer’s guidelines. Direct Support RequestDirect Support Request (DSR) measures the performance of a PCB laminate when in contact with 120V or less. This test is only performed on laminates rather than the whole PCB, and each laminate receives a DSR compliant rating. During this testing, a laminate will undergo several performance tests, including: ·Dielectric strength·High current arc ignition·Hot wire ignition·Volume resistivity·Heat deflectionWanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/10/2021 17:45
Signal integrity in PCB
Signal Integrity (SI) signifies the signal’s ability to propagate without distortion. Signal integrity is nothing but the quality of the signal passing through a transmission line. It gives the measurement of the amount of signal degradation when the signal travels from the driver to the receiver. In the high-frequency regime, both digital and analog aspects of the signal need to be taken care of. When a signal propagates from the driver to the receiver, it doesn’t remain the same, whatever has been sent originally will be received with varying degrees of distortion. This signal distortion happens due to factors like impedance mismatch, reflections, ringing, crosstalk, jitter, and ground bounce. A designer’s primary aim should be minimizing such factors so that the original signal could make it to the destination with minimum distortion. Special care is also needed to maintain signal quality and to control their undesirable effects in electronic circuitry. If you want to order PCB product, please check and custom your order online. What are the signal integrity issues in PCB? FrequencyAt low frequencies, you should not experience any major problems with signal integrity. However, with increasing signal speeds, you get higher frequencies, which can affect both the analog and digital properties of the system. You may experience reflections, ground bounce, crosstalk and ringing at higher frequencies, which can seriously damage the integrity of your signal. If you anticipate higher frequencies, you need to consider transmission line effects on the I/O signaling in your board design. SpeedNaturally, the relationship between speed and frequency is one you need to keep in mind. Lower speeds mean lower frequencies and fewer signal transmission problems, while faster speeds mean higher frequencies and the attendant problems that can come with them. LengthAnother issue to consider when it comes to transmission and signal integrity is the length of the transmission medium. The longer the transmission medium, the greater the chance there’s some type of signal loss. Fortunately, these and most other signal integrity issues can be counteracted by a quality design and by keeping some basic layout guidelines in mind when designing your printed circuit boards. What are main signal integrity PCB considerations? Extensive research has been done on the best way to design transmission lines so high-speed signals can travel at maximum efficiency. To reduce potential problems with signal integrity and other transmission issues, it’s important to make sure your PCB supplier provides boards with a strong design. Below are some of the guidelines that have been published by many different sources, such as Texas Instruments, that address high-speed signals such as clock signals and their routing and give designers a review of the important coherences. Because many things can affect transmission lines, EMI problems can occur. In order to reduce these problems, good PCB design is important — and with some simple design rules, the PCB designer can minimize these problems. When approaching your PCBs, the designer should start by asking a few basic questions, including: ·Are there sensitive signals and will those sensitive signals require a stripline, or are a micro strip sufficient?·How high is the frequency and how fast can the system get?·What are the electrical specs at sinks and source inputs and outputs?·How many different supply voltages are there and do they each need their own power plane?·What are the minimum widths, separations and heights for the traces and what is the minimum distance between layers?·Are there interconnections between at least two independent functional groups?·What are the via requirements? Are blind and or buried vias possible? What are PCB Signal Integrity tips? Here are a few other tips to keep in mind when it comes to the design of efficient printed circuit boards: Right angles: Avoid right angles in your traces because they increase capacitance in that region, leading to impedance changes and reflections. 45-degree angles are better and round bends are ideal. Vias: Although vias can be vitally important to routings, they add inductance and capacitance and lead to reflections. They also increase trace length, so use them sparingly and avoid vias in differential traces. Signal Separation: Keep your high-speed and low-speed signals apart from each other. Separate your digital and analog signals as well. Route signals 90 degrees to each other to minimize crosstalk.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/09/2021 17:32
Fr4 material in PCB
FR4, also written as FR-4, is both a name and a rating. FR4 is the backbone material upon which most rigid circuit boards are built. The name also functions as a grade used to rate epoxy laminate sheets. The “FR” in the name stands for flame retardant, while the 4 differentiates the material from others of the same class. The designation essentially indicates the base quality of a laminate sheet, meaning a variety of sheet materials and designs fall under the FR4 rating. FR4 sheets are widely popular among electrical engineers and designers as a PCB base material. The low cost and versatility of the material, as well as its wealth of beneficial physical properties, accounts for that popularity. FR4 sheets are electrical insulators with high dielectric strength. They also feature a high strength-to-weight ratio and are lightweight and resistant to moisture. Add this to their relative temperature resistance, and FR4 can perform well in most environmental conditions. Let’s check the content below for more detailed knowledge of Fr4 material in PCB.If you want to order PCB product, please check and custom your order online. What is the connection of Fr4 in PCB? Within a PCB, FR4 forms the primary insulating backbone. This is the base upon which the manufacturing company builds the circuit. Once prepared, the FR4 board is laminated with one or more layers of copper foil using heat and adhesive. This copper forms the circuits in the finished product and may cover one or both sides, depending on the design of the board. Complex PCBs may use more than one side or even layer the circuit board to produce more sophisticated circuits. From here, the circuits are drawn and etched out before being covered with a solder mask layer, preparing the board for the final silkscreen layer and the subsequent soldering process. How to select Fr4 thickness? When ordering a laminate board for a PCB project, the designer or electrical engineer must specify the FR4 PCB thickness. This is measured in inch-based units, such as the thousandth of an inch, or thou, or millimeters, depending on which is most appropriate for the setting. The thickness of a sheet of FR4 ranges widely depending on the needs of the project, but it tends to range from ten thou to three inches. While board thickness may not seem like a significant factor in the design of a PCB, in reality, it is an essential feature. Board thickness affects several aspects of the board’s functionality, which is why several factors are considered in determining the thickness of a board for design. These include the following. Space: thinner may be betterIf space concerns the designer, a thinner FR4 board tends to be preferable. This is a predominant factor for the manufacture of smaller devices, like USB connectors and many Bluetooth accessories. Even for larger projects, smaller FR4 PCBs tend to be favored to save space within the device. Connections: the wrong one could result in damageA two-sided PCB design requires an edge connector to join the two sides. This can be a major limiting factor for the final size of the PCB since PCB edge connectors only fit a particular set of PCB thicknesses. The mating portion of a connector has to fit snugly on the side of the PCB, or else risk slippage or damage to the PCB. This is one of the primary reasons why circuit design comes before choosing materials for the circuit. Impedance matching: essential to maintaining board functionEvery multi-layered board acts as a capacitor on adjacent layers. This is why the thickness of this board is so important — the thickness of the PCB FR4 determines the thickness of the dielectric, which in turn affects the value of the capacitance. This is an especially key factor for some high-frequency PCBs, such as RF and microwave designs. High-frequency designs focus on impedance matching as an essential component to maintain optimal board function, so getting the right capacitance for each layer is crucial. Flexibility: depends on the applicationThinner boards can flex in some capacity. While an unusual trait, flexibility can be a positive or negative feature, depending on the application. More flexible boards tend to be preferable in some applications where the product is regularly stressed or flexed. For example, those using boards for medical and automotive applications often prefer flexible boards due to the constant stress and flexing to which these PCBs are often subjected. However, flexibility can be a detriment to the PCB manufacturing process, resulting in serious problems later in assembly. When handled by a machine, a more flexible board may flex when dealt with by a soldering machine, causing the component to be soldered at an angle. Additionally, this flexing has the potential to break freshly placed components and connections already on the board. Design requirements: intended use impacts Fr4 thicknessThin boards aren’t preferable in all cases, primarily due to the limitations thin boards put on PCB plans. Thin FR4 boards can’t feasibly feature grooves, and they can’t be too large without risking fracture. Thicker boards, however, can accomplish both. Always account for this when weighing options between FR4 thicknesses. Components compatibility: may work with a small rangeThe thickness of a board can also affect the compatibility of components with the board. Just like edge connectors, many components work with a small range of board thicknesses. This is especially true for some through-hole components, for example. Weight: lighter products may be more attractiveThe thickness of an FR4 board will, logically, affect the weight of the final PCB. While weight is less of an issue in some applications, it is often a consideration in consumer electronics. Lighter PCBs make for lighter products, which makes them cheaper to ship and, in some cases, more attractive to consumers. Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/09/2021 17:29
CAF in PCB
CAF formation is the term for the process by which CAF grows. CAF failure is a common and growing concern in the electronics industry. It will cause catastrophic failure mode and conductive salt remaining copper may from in PCBs. In this passage we will introduce all the details about CAF and follow us to read the content we provide.If you want to order PCB product, please check and custom your order online.What is CAF formation? CAF formation is described as a two-step process: First, the resin glass interface degrades, which is believed to be reversible. The second stage, the electrochemical migration, is not reversible. CAF failure refers to the electrical failure those results from CAF formation. The failure occurs when the CAF grows from the anode to the cathode. For CAF to form, you need several things present: ·Electrical-charge carriers, which enable the formation of an electrochemical cell.·Water, which occurs due to humidity and moisture build-up and dissolves the ionic material, sustaining them in their mobile ionic state.·An acid environment near conductors to enable corrosion at the anode.·A voltage bias, which is the force that drives the reaction.·A pathway for the ions to take as they move from the anode to the cathode. Many other factors are believed to accelerate the formation process including high temperatures, high humidity, repeated thermal cycles, high voltage gradient between anode and cathode, some soldering flux ingredients and more. Other problems, such as component failures and exceeding maximum operating temperatures might also contribute to a CAF-related failure. How to avoid CAF failure? There are many different measures you can take to minimize the risk of CAF failure. Researching into ways to avoid this problem is ongoing, but avoiding the conditions enabling CAF formation will help prevent it. Here are some of the factors to consider: Moisture and HumidityBecause it requires an electrolyte, higher water content increases the chance of CAF failure. Increased humidity leads to higher moisture content, which decreases CAF performance. Processes That Lead to Acid Contamination Processes used during fabrication can introduce acid contaminations, which increases the likelihood of CAF formation. The use of some soldering fluxes and the introduction of acid residues during the plating process are examples of this. Bias and Voltage Since bias voltage is the force that drives the reaction, a high-voltage bias will significantly lower the chances of CAF formation. Higher voltages decrease CAF performance as well. Pre-Existing DefectsPre-existing defects such as fracturing, voids, wicking, contamination and misregistration can also create pathways for problematic filaments. You need to be careful when drilling holes so as not to cause damage to the board. Such damage can create these pathways by causing cracks, wicking and other defects. Drill speed, feed rate and other factors influence how likely these issues are to occur. Partial defects such as incomplete bridging between features can contribute as well. High temperatures like those from environmental temperature, repetitive thermal cycling and reflow with a high peak temperature create more stress on a board and increase the likelihood of damage as well CAF formation. MaterialsAnother influential CAF-failure factor is the materials used to make the board. Using CAF-resistant materials, as Millennium Circuits Limited does, is one of the most effective ways to prevent CAF formation and failure. When it comes to laminate materials, various studies over the last 30 years have measured the susceptibility to CAF of various laminates. Laminates with high-thermal resistance tend to resist CAF formation better. Other material-related factors include finish type, such as HASL, ENIG, immersion silver or immersion tin, and solder-mask type. Design The design and fabrication of a PCB also plays a crucial role in determining its CAF resistance. Boards that have a smaller gap between voltage-biased features fail faster than those with larger gaps, although this is believed only to impact the second step of the CAF-formation process. In addition to hole-to-hole and line-to-line spacing, the size of the drilled holes and the thickness of copper in plated through-holes impact CAF resistance. Having more biased features also increases the number of opportunities CAF has to form. Anodic vias also fail faster than cathodic vias. Many different aspects of a PCB, including aspects of its design and fabrication, impact its resistance to CAF formation. These factors include: ·The materials used, including laminates, resign systems and glass coatings.·Design factors such as hole-to-hole distance and layout.·Processes such as soldering and reflow.·Voltage levels.·Bias voltage.·Pre-existing defects and other fabrication quality issues. Since so many factors influence CAF performance, you should consider CAF during every stage of the PCB-production process. Optimizing your board for CAF resistance will result in a more reliable end product.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/09/2021 17:26
A presensitized circuit board is a special board with a photosensitive surface coating. It enables you to create a customized design by shifting/burning the image with a UV light. In other words, a presensitized circuit board resembles a standard copper-clad board. The only difference between them is how you transfer the design into the boards. And in this passage, we will lead you to learn the detailed knowledge of presensitized PCB. Come and check the content below.If you want to order PCB product, please check and custom your order online. What are the advantages of presensitized PCB? Presensitized PCBs have numerous benefits, making them the number one choice of most manufacturers and engineers. Below are the main advantages of presensitized PCBs. ·The main advantage of presensitizing is that it is more accurate than other circuit board processing approaches, like the toner transfer technique. ·The process of presensitization is also very cost-effective. Presensitization excludes fabrication steps, lowering expenses. Therefore, you can experiment with your creative concepts without distressing about going beyond your budget limits. ·Presensitized circuit boards are dense, minimizing the use of several wires on a board. They use interconnections to link parts via copper tracks, unlike the use of multiple cables to conduct current in traditional circuit boards. With presensitized circuit boards, the interconnections are somewhat less immense. ·Presensitized circuit boards are easy to repair in case they break down. Additionally, they are easy to examine and consequently replace individual failure components. This is because manufacturers design and label the electronic parts and polarities present in presensitized boards accurately. ·Presensitized PCBs also save much time during assembling. You will take more time to connect components in traditional PCBs. On the other hand, you will take less time to connect components of presensitized PCBs. This is why many engineers love them. ·Most presensitized boards are resistant to movement. If you are a keen individual, you will realize that most presensitized circuit board components contain strong grips. They employ solders, which limit their movement regardless of the direction of the PCB to achieve stability. ·Presensitized PCBs are highly reliable compared to traditional PCBs. Talking about reliability and performance, presensitized boards provide desirable results. This is also another reason why most electrical engineers choose them over their traditional counterparts. How to make presensitized PCB? Here are the steps of making presensitized PCB: 1. PCB Artwork Remember to scrutinize your tracing paper before utilizing it. Light up one part of the paper with a shiny source of light, and examine it by viewing through the other side. The paper should be free from dark spots and stains. Dark spots cover the artwork portions, forming short circulating pathways around crowded sections of the board artwork. 2. PCB Printing You should use laser-made positive artwork in your PCB printing exercise as they form delicate, crisps, and compact black prints. Inkjet inks seam to stain with tracing paper, resulting in prints with draining and blurry edges. Consequently, this limits the feasible spacing between circuit board pads and traces. 3. PCB Preparation It is essential to realize that a presensitized board surface is shielded with a dense grey layer against unintended exposure and impurities. You will use the extended part later to attach your PCB standoff clip during the design and etching process. Burrs and uneven edges may limit your artwork from lying ideally uniform. 4. PCB Exposure First, clean your exposure box surface with a cloth containing a mild detergent. Then, rinse it with a clean, dry cloth. Take out the protective PCB layer. Thirdly, gently slide your board in between the upper and lower artwork. Fourthly, insert the board in the exposure box. Expose Your PCB for 8 Minutes then fit the Standoffs, finally drip the PCB in Developer Medium. 5. PCB Etching PCB etching is an important step in the chemical preparation of presensitized PCBs. It involves the removal of copper to obtain desirable patterns. Remember, you need to do away with every copper residue apart from the circuitry covered by the tin plating. PCB etching seems to be a complicated process for some people, but actually, it is not a challenging activity, as you may think. After collecting all the necessary materials, print your layout before printing the circuit layout. Sketch your design in transparent acetate material to achieve the desired results. Use a laser printer instead of an inkjet printer to print your acetate. We prefer printed ink on acetate because it does not stick; hence, you will not get undesired results. Alternatively, you can use a laser printer toner. But if you do not have a laser printer, you can make good use of an acetate photocopy. It would be best to dissolve a developer powder in warm water to form a universal circuit board developer. Most etching agents, like ferric chloride, come in powder or solution form. In the case of dust, apply the same approach with the developer powder.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/08/2021 17:57
Almost all electrical appliances that we use today have PCB. We also call it Printed Circuit Boards, which helps link PCB Connector Types between different parts on the board. Some devices require more than one PCB. Such a device will need a series of equipment to establish a connection on the board. PCB houses the PCB connectors. It helps transfer signals from one PCB to another. Manufacturers also use it to transfer power from one PCB within the unit. PCB board connectors exist in two broad categories: Wire-to-board and board-to-board. PCB connector types allow for flexibility in design as manufacturers can build smaller sub-systems. With this, users can connect various parts. That allows manufacturers to meet design needs and customer requirements. With this, future upgrades or repair will not pose any issue.If you want to order PCB product, please check and custom your order online. PCB connector types We have countless electronics that use PCB board connectors. As a result, the design must suit the type, size, and function. With this, there are numerous PCB connector types available. What is Wire-to-board Connector? It is a PCB connector type that connects a wire to a printed circuit board. The device makes it easy to have connections between circuits. What is Board-to-board Connector? Board-to-board Connectors allows manufacturers to connect PCB without a cable. This connection allows for a signal connection between two PCBs. It can be a permanent connection that will require a "fit and forget" approach. The device connects two PCBs using pins and receptacles. What is Male PCB Connectors / Pin header? Also known as pin headers, these are simply a row of pins with different spacing. The spacing could be 0.1, 0.2, 0.197 inches apart. What is Female PCB Connector? We also call this the socket or header receptacles. It accommodates the male connector tightly, which creates a through the passage for the signal (power or data) What is Backplane Connector? It is a particular type of PCB connector that can connect with other PCBs. It helps increase data rates and reduce signal rise. The backplane connector is a support structure that allows connection for other PCBs. It also serves as a plane to enable users to integrate other system components known as a daughterboard. What is USB PCB Connector? It is the most common type of PCB connector today. It is not surprising as the USB connector finds application in many devices we use. Examples are tablets, keyboards. Smartphones, digital camera, computer mice, and others All USB connectors come with at least four contact points. One receives power, and one is the ground. The remaining two transmit and receive the data. USB-A: Almost every computer and laptop device today have the female end of the USB type A version. Besides, the female end is the receptacle while the male part is present in various devices. Examples of such accessories are the mouse, keyboards, memory sticks., etc. USB-B: You will find type B USB in standard electronic devices like music players. In the USB family, they are tough, strong, and bulky. Type-B USB finds application in a device where size is not an issue. USB-Micro: this is a new release in the USB family. It is present in modern phones, external hard drives, tablets, digital cameras, etc. Like other USB types, the male part connects to the female part. USB-C: Type C USB connector is also one of the latest releases in the USB family. It stands out with a few advantages over other types. It features an upgraded strength that allows it to transmit data, video, and power simultaneously. Also, USB Type C stands out as a unique USB type with the absence of polarity. It makes connections possible in any orientation without having to flip and flop.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/08/2021 17:52
SMD in PCB
In simplest terms, a surface mount device (SMD) is an electronic device that you would use on your projects. Every electronics engineer eventually needs to use them. These devices are typically found on a printed circuit board. Day by day, electronic components are getting smaller in the printed circuit board market. It would help if you also evolved your projects with the need to ensure your survival in it. The new components revolving in the market are not only small but are also cheap and fast. They go by the name of surface mount devices (SMDs). Have you ever heard of them? This article will cover everything that you need to learn about them. Let's get started and read the content below.If you want to order PCB product, please check and custom your order online. What are the advantages of SMD products? Dependable ProcessingSome manufacturers are using high-performance plastic LCP for making surface mount devices. It makes sure precise grid alignment and maximum dimensional stability. The material has tremendous solder heat resistance. Therefore, a smooth, dependable SMD connection system is guaranteed. You will not need to pre-dry such SMDs as they have low moisture sensitivity (MSL 1). They also have a low thermal expansion coefficient, which prevents a PCB assembly from being dismantled during soldering. Therefore, you can rapidly perform the whole automatic PCB assembly process. Stable Solder ConnectionsThe PCB terminals of SMDs made using LSF make sure a firm grip on the board. It is because the manufacturers use two solder pads for each pole. You can even place large electronic components as the holding force/pin is more than 150 N. Manufacturers also perform endurance tests to make sure the shock resistance and high vibration are according to IEC 61373/10.2011. Thus, you will get a maintenance-free and smooth SMD process in the long run. Not just this, you will also get good results with composite PCBs made of aluminum, ceramics, or glass. Effective AssemblySMD with suction surfaces support and pick-and-place pads ensure accurate placement and safe mounting in the automatic PCB assembly process. You will also be maximizing the performance of the assembly due to the lightweight of the PCB terminals of SMD. Coming to the packaging of these components, you will get them in standard conveyor widths with tape-on-reel packing. Furthermore, they are made for automatic processes and thus contain many numbers of features for every roll. What does it mean? It just means that you are reducing your setup expenses. So, you already know the benefits of surface mount devices. In the coming section, we will tell you about what people think about these devices worldwide. What is the difference between SMT and SMD? Principally, SMT is a procedure, and SMD is a component. Surface mount technology (SMT) is the process of putting electronics components on the PCB. Moreover, these electronic components are surface-mount devices (SMDs). In the electronics market, you can use them together to add credibility to your project. Hopefully, now you will never get confused with the terms SMT and SMD. Now, we will briefly tell you about the alternatives to surface mount devices. What is SMD soldering？ Historically speaking, we soldered SMDs by hand until the advent of pick and place machines. Because of their nature, SMD components are conducive to soldering. They are perfect for first-time hobbyists who want to learn how to solder components to their PCBs. You can solder them traditionally, use solder paste, or flood with solder. If machines do the soldering, the first machine in the process will be the solder paste printer. It applies the solder to the pad. After solder is applied, we perform an inspection. Next, we surface to mount the components into the PCB pads. The PCB then goes through a pre-reflow automated optical inspection to ensure the integrity of the component placement process. The PCB will go through the reflow soldering machine, forming the connections between the components and PCB. Finally, the PCB will go through post-reflow automated optical inspection.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/05/2021 17:55
ICT in PCB
ICT, in the circuit board technology, is an abbreviation for In-Circuit Test. It's also known as the bed-of-nails In-circuit test. Structurally, it is an example of white box testing whereby an electrical probe tests a populated printed circuit board and checks for faultiness such as shorts, opens, etc. Ideally, you can perform this test with a bed of nails type test fixture or featureless in-circuit test alignment. This type of test method works by checking errors that may occur during fixing components onto the board. In doing so, you can easily replace any defective part. Moreover, they offer a fast and straightforward way of assessing the board’s manufacture and providing accurate results. ICTs can also utilize suction cups to check the soldiers’ sturdiness and the malleable strength of chips. ICT uses an electrical probe to evaluate how an assembled PCB will function. It uses an electrical current to check that each component is in place and working correctly. It tests for shorts and open circuits and assesses essential electrical qualities like capacitance and resistance.If you want to order PCB product, please check and custom your order online. What are the main types of ICT machines? There are several different types of ICT machines in the electronics manufacturing industries. The machine type usually is dependent on; -The manufacturing or testing process-The volume of purchased PCBs and-Types of PCB -The main types of ICT machines include Standard ICT machineIn normal circumstances, this is the general test in this form of testing. However, they're standard because they offer elemental resistance, capacitance, and some device functionality. Manufacturing defect analyzer, MDAMDA offers an essential ICT of resistance, continuity, and insulation. Manufacturers use it to detect defects such as shorts and open circuit connections on the board. It uses the printed circuit board CAD data to generate the fixture design and test programs while operating. Thus, you can automatically produce about 80% of the programs. Cableform testerAs the name suggests, you use its operation to test cables optimally. It works similarly to an MDA but differs in high voltage usage. The high voltage is for periodic testing for the insulation. Flying probe testerA roving or flying probe has a simple, inexpensive fixture that holds the board. A testing team then connects via a few inquiries that move around the board and make contact as needed. Often, software control monitors the movements of the probes. Therefore, any board updates will lead to a change in the software program. When choosing a type of ICT machine for your products, consider the following elements common in all ICT testers. They include; controller, software, interface, fixture, analog scanner, powered analog tests, and analog-digital opens. At all times, the mentioned elements steer the operation of ICT. What are the advantages of ICT? ICT has some significant advantages that have been the reason manufacturers opt for it for centuries. They include: -In contrast to the AOI and flying probe testers, it can test the ball grid array assemblies (BGAs). -Straightforward interpretation: the ICT system quickly locates the faultiness and presents it to you in a matter of minutes. You may not need professionally skilled personnel to proceed with the interpretation. -Fast/ Time-effective: it roughly takes 1 minute in comparison to a flying probe tester that may take about 25 minutes. Being short is in regards to contacting all the board’s test points at once. -Easy program generation: an ICT tester is effortlessly programmed. In that, you can take files from the PCB outline to make the essential program. -It can test functionality as well as assembly defects as ICT systems can handle complex testing methods. -Cost-effective: The high speed helps in quick recovering of the expense of setting up the fixture and program. It is especially true when considering boards that you assemble in large volumes. -ICT platforms: The testing platform for ICT is available in both Windows and UNIX OS, making it universal. -The testing can carry out several tests without applying power to the Device Under Test (DUT). It ensures a safe test and protects the board from any damage. -Coverage: For manufacturing defects, it has high failure coverage. A more straightforward explanation for the increased range is the board’s complexity.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/05/2021 17:48
HDI PCB, also known as high-density interconnect PCB, is a kind of PCB with a higher wiring density per unit area than traditional boards. HDI boards are more compact and have smaller vias, pads, copper traces and spaces. As a result, HDIs have denser wiring resulting in lighter weight, more compact, lower layer count PCBs. The lesser weight and size of the HDI circuitry means the PCBs fit into the little spaces and have a smaller amount of mass than conservative PCB designs. They have more functionality in a small area and a higher circuitry density per unit compared to other PCBs. They can come with a variety of features including but not limited to: -Through vias and buried vias-At least two layers with through vias-Coreless construction with layer pairs Please check the content below in this passage for more knowledge about HDI PCB.If you want to order PCB product, please check and custom your order online. What are the lamination & material of HDI PCB? Advanced multilayer technology allows for designers to sequentially add additional pairs of layers to form a multilayer PCB. The use of a laser drill to produce holes in the internal layers allows for plating, imaging and etching prior to pressing. This added process is known as sequential build up. SBU fabrication uses solid filled vias allowing for better thermal management, a stronger inter connect and increasing the board's reliability. Resin coated copper was developed specifically to aide with poor hole quality, longer drill times and to allow for thinner PCBs. RCC has an ultra-low profile and ultra-thin copper foil that is anchored with minuscule nodules to the surface. This material is chemically treated and primed for the thinnest and finest line and spacing technology. The application of dry resist to the laminate still uses heated roll method to apply the resist to core material. This older technology process, it is now recommended to preheat the material to a desired temperature prior to the lamination process for HDI printed circuit boards. The preheating of the material allows for better a steady application of the dry resist to the surface of the laminate, pulling less heat away from the hot rolls and allowing for consistent stable exit temperatures of the laminated product. Consistent entrance and exit temperatures lead to less air entrapment beneath the film; this is critical to the reproduction of fine lines and spacing. What are the advantages of HDI PCB? The primary benefit of HDI printed circuit boards is the capability to “do more with less”; with copper-etching technology continuously refined for better precision, it became possible to combine functionalities of multiple PCBs into one HDI PCB. Shortening the distance between devices and trace spaces, HDI PCBs allow for deployment of a large number of transistors for better performance in electronics while lowering power consumption. Signal integrity is also improved due to the shorter distance connections and lower power requirements. Other performance improvements over conventional PCBs include stable voltage rail, minimal stubs, lower RFI/EMI, and closer ground planes and distributed capacitance. Additionally, consider using a HDI printed circuit board for the following benefits: Cost-effectiveness: when properly planned out, overall costs are reduced due to the lower number of necessary layers and smaller sizes/fewer number of needed boards when compared to standard PCBs. Faster time-to-market: Design efficiencies in HDI PCB production mean faster time-to-market. Because of the easy placement of components and vias and electrical performance, it takes a shorter amount of time to go through the design and testing process for HDI PCBs. Better reliability: Microvias have much better reliability than typical through holes due to the use of a smaller aspect ratio; they are more dependable than through holes, granting HDIs outstanding performance with better materials and parts. What are uses of HDI PCB? A HDI PCB is usually found in complex electronic devices that demand excellent performance while conserving space. Applications include mobile /cellular phones, touch-screen devices, laptop computers, digital cameras, 4/5G network communications, and military applications such as avionics and smart munitions. Automotive and aerospace industries, where lower weight can mean more efficient operation, have been utilizing HDI PCBs at an increasing rate. Like almost everything else, cars are becoming more connected and computerized. Today’s cars have around 50 microprocessors on board that play a role in engine controls, diagnostics, safety features and other conveniences. Many advanced features such as onboard WiFi and GPS, rearview cameras and backup sensors rely on HDI PCBs. As automotive technology continues to advance, HDI tech will likely play an increasingly important role. HDI PCBs are also prominently featured in medical devices; advanced electronic medical devices such as equipment for monitoring, imaging, surgical procedures, laboratory analysis etc., and incorporate HDI boards. The high-density technology promotes improved performance and smaller, more cost-effective devices, potentially improving the accuracy of monitoring and medical testing. Industrial automation requires abundant computerization, and IoT devices are becoming more common in manufacturing, warehousing, and other industrial settings. Many of these advanced equipment employ HDI technology. Today, businesses use electronic tools to keep track of inventory and monitor equipment performance. Increasingly, machinery includes smart sensors that collect usage data and connect to the internet to communicate with other smart devices, as well as to relay information to management and help optimize operations.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/04/2021 17:21
OSP finish PCB
An OSP surface finish is an example of an organic PCB finish. There are no toxins involved in the process, making it environmentally friendly while still retaining its protective and anti-corrosive properties. Because of the absence of harmful chemicals, OSP boards are also RoHS compliant. This water-based finish provides a flat surface for attaching additional PCB components, and like the HASL process, it is cost-effective. OSP can be used as an effective replacement for lead-free HASL due to its co-planarity. When you need a PCB surface finish that will provide sufficient flatness while offering a simple manufacturing process, OSP is arguably the best choice. In s passage we will focus on the OSP finish and if you are curious about the detailed knowledge, check and read the content we provide below:If you want to order PCB product, please check and custom your order online. What is the OSP finish process? Applying an OSP surface finish to a PCB usually involves a conveyorized chemical method or a vertical dip tank. The process generally looks like this, with rinses between each step: Cleaning: The copper surface of the PCB is cleaned of oil, fingerprints and other contaminants that could affect the flatness of the applied finish. Topography enhancement: The exposed copper surface undergoes micro-etching to increase the bond between the board and the OSP. This process also reduces oxidation. To achieve adequate film thickness, the micro-etching must be kept at a consistent speed. Acid rinse: The PCB undergoes an acid rinse in a sulfuric acid solution. OSP application: At this point in the process, the OSP solution is applied to the PCB. Deionization rinse: The OSP solution is infused with ions to allow for easy elimination during soldering. This rinse should be used before preservatives build to avoid tarnishing from the presence of other ions in the OSP solution. Dry: After the OSP finish is applied, the PCB must be dried. OSP offers a simple and affordable process, but it’s also important to keep in mind that it’s extremely sensitive to handling and can easily retain scratches, which can degrade its solderability. Additionally, its shelf life is shorter than that of ENIG or HASL. Common uses for OSP include: Fine pitch devices: This finish is best to apply to fine pitch devices because of the lack of co-planar pads or uneven surfaces. Server boards: OSP’s uses range from low-end applications to high-frequency server boards. This wide variation in usability makes it suitable for numerous applications. It’s also often used for selective finishing. Surface mount technology (SMT): OSP works well for SMT assembly, for when you need to attach a component directly to a PCB’s surface. What are the advantages of OSP? Nowadays, OSP has been usually applied due to its advantages that are discussed below: • Simple manufacturing process and Reworkable: Circuit boards coated with OSP can be easily reworked by PCB fabricators so that PCB assemblers are allowed to have fresh coatings once its coating is found damaged. • Good wettability: OSP-coated boards perform better in terms of solder wetting when flux meets vias and pads. • Environment friendly: Since water-based compound is applied in the process of OSP generation, it does no harm to our environment, just falling into people's expectations for green world. As a result, OSP is an optimal selection for electronic products catering to green regulations such as RoHS. • Low cost: Due to the simple chemical compounds applied in OSP creation and its easy manufacturing process, OSP stands out in terms of cost among all types of surface finishes. It costs less, leading to a lower cost of circuit boards in the end. • Fit for reflow soldering in double-side SMT assembly: Along with the constant development and progress of OSP, it has been accepted from single-sided SMT assembly to double-sided SMT assembly, dramatically widening its application fields. • Low requirement for solder mask ink • Long storage time What is the storage requirement of OSP? OSP needs adequate care during transportation and operation because OSP technology’s generated preservatives can cut as thin. With the long exposure of PCBs with OSP as a surface finish to humidity and high temperature, there is a possible generation of oxidation on PCBs’ surface. As a result, it can result in low solderability. Thus, some of the principles of soldering technique to use include: Users must use a humidity display card and desiccant to utilize a vacuum package. They can also stop friction from destroying the PCB surface by placing release paper between PCBs.Users must not directly expose these PCBs to the sunlight. For an optimal storage environment, the requirements are storage time of fewer than 12 months, the temperature of about 15 to 300C, and relative humidity of about 30 to 70 percent RH.Wanna know PCB knowledge? Check and read for more.
PCB Glossary ⋅ 06/03/2021 18:08
PCB Instant Quote