Tag Archives: Printed Circuit Board

Physical and Electrical Partitioning In PCB Design

Physical and Electrical Partitioning In PCB Design

Partitioning your design into physical and electrical sections can significantly reduce the number of through-holes you need in your PCB, thereby increasing production speed and cutting down on manufacturing costs. Here, we will explain what physical and electrical partitioning are how they are used in PCB design, and how to create effective partitioning schemes in your PCB designs.
As you work on your next PCB design, you may be wondering how to implement physical and electrical partitioning in your design. These two factors are equally important to making the finished product successful, and both have a huge impact on the success of your design project as a whole. Stay with us if you’re looking to save time and money while producing high-quality products, read on!

Layout Considerations

When you’re laying out a Printed Circuit Board, you have two different considerations, such as physical, which is how your components are laid out on your printed circuit board; and electrical, which has to do with where you’re going to put all of your wires. These two can be grouped when it comes time for assembly.
For example, if you plan to use surface-mount parts that require soldering instead of wire-wrapping, then you will want to make sure that there is enough space between these parts so that they can be easily soldered onto your PCB. If you don’t leave enough space between them, then there won’t be room for solder paste. The solder paste is a sticky substance used to hold down SMT parts during pcb assembly.
This makes soldering difficult or impossible and the same logic applies to wiring. If you don’t leave enough space between components, then your wires may not fit without being bent too much or getting in each other’s way. This can cause problems when it comes time to solder everything together, as well as with heat dissipation, and too many wires crammed into one area might block airflow and cause overheating issues.
On top of that, you also need to consider things like trace width and spacing. Trace width refers to how wide your traces are (the lines connecting individual pads on your PCB), while trace spacing refers to how far apart they are from each other. Trace width should always be smaller than trace spacing because having wider traces means more copper is needed per unit length which means higher cost and greater weight.
Traces are usually made using either a single solid line or multiple lines connected by vias. Single solid lines tend to be faster but less reliable than multiple lines connected by vias, but they’re also easier to design and cheaper. Vias are holes drilled through layers of material that allow traces on different layers to connect.However, vias increase complexity and cost. There are several tools available to help designers create their circuits. Some free software options include EagleCAD, Kicad, Altium Designer, and CAD. However, regardless of what software you choose to use, remember that layout is only half of the process.

Physical and Electrical Partitioning In PCB Design-Content Image
Physical and Electrical Partitioning In PCB Design-Content Image

Overlapping Impedance Nets & Ghost Nets

To create a circuit board with electrical & physical separation, you must insert impedance nets into your design. There are three different ways you can do that, including overlapping impedances, creating ghosts, or through a virtual ground plane. In some designs, more than one method is used. So, let’s see how and when to use them.

An overlapping impedance net has part of it on one side of a barrier, and part of it on another side. A ghost net is used when you have two nets that need to be separated but you don’t want them physically separated because they are too close together or because they are too important for each other. A ghost net is just a virtual representation of an actual physical connection that exists between two parts of your circuit board.

A good example of why you might use a ghost PC board net instead of separating your nets with some physical method is if you have 2 power supplies that need to share ground. They can share ground by having their grounds tied together through some kind of wire.But, since they’re both supplying power independently, we don’t want them tied directly together at all times, but only when there is a current going through either one or both supplies. So what do we do? We create a ghost ground plane where we tie their grounds together. This way, when none ofthe supplies is active, there’s no connection between them, and when either supply is active, there isa connection between them.

An electrical partitioning net does exactly what it sounds like. It partitions electrical signals from each other. In a design where you want to physically separate your nets, you can do that by creating an impedance plane that separates them. But, then how do you keep them electrically isolated? That’s where a physical partitioning plane comes into play. This is just another name for a ghost ground plane, but instead of being used for sharing grounds between two supplies, it’s used for keeping two parts of your circuit board electrically isolated from each other while still allowing communication between them.

One last thing about these three methods is thatyou can’t use one without using at least one of the others. If you have a wall between two sections of your circuit board, there has to be some way for those sections to talk to each other. Otherwise, they wouldn’t be able to pass power or data. So, if you have a wall, you need ghosts or an impedance plane on both sides of it. And if you have ghosts, there needs to be a wall somewhere too.

Why Would You Ever Choose One Method Over Another?

Well, overlapping impedances are good when you don’t need high-frequency performance because they introduce more inductance than either of the other two methods. Ghosts are good when you don’t care as much about electromagnetic interference or EMI because they don’t create as much capacitance as either of the other two methods.

Whereas the physical partitioning nets are good when you want to keep your layout compact or if you have a design that’s already laid out and you can’t change it, as having a wall between two sections of your board is going to require some rework if it doesn’t already exist.
So, you need to decide if you want your partitions at a high frequency or low frequency. For a high-frequency circuit board, you’ll need to use overlapping impedances or ghosts; for a low-frequency circuit board, you can just go with physical partitioning nets.

Solving Unplanned Overlaps

It’s not uncommon for two different circuit boards or two different designs within a single board to overlap. Unplanned overlaps are hard to solve, but these tips will help you create better schematics so that you can avoid them.
Before you design your next PCB, make sure you follow all of these guidelines for PC Board Fabrication. By doing so, you’ll be able to identify overlaps before they occur and reduce your chances of creating any issues when manufacturing your product.
If you don’t have access to specialized tools or software, consider using some online tools like Google Sketch Up to help with your schematic design. These free programs allow you to build 3D models of your circuits, as well as export them into other applications like Eagle CAD or Altium Designer. This allows you to easily view how your components will fit together on a printed circuit board.
You should also use both software and hardware layout techniques to ensure that there aren’t any unplanned overlaps between your PCBs. While it may seem easier to just use one method, it’s important to understand how each technique works so that you can spot potential problems early on. For example, if you only use software-based layout techniques, then you might miss physical overlaps that would prevent a component from fitting onto your board.
Similarly, if you only rely on hardware-based methods, then you might overlook electrical conflicts that could lead to shorts or failures during testing. The best way to get around these kinds of issues is by using both types of layouts simultaneously. You can use a program like Altium Designer to lay out your circuit board, then print out an image of what you’ve created. Then take that printed image and place it over your actual PCB. This ensures that you catch any unplanned overlaps before they cause problems later on down the line.
Just remember, even though it takes more time upfront, double-checking everything twice is always worth it. With that said, there are still times when the overlap errors do slip through. When you find yourself in a situation where you need to resolve an issue like this, we recommend you double-check it. As it would become much easier to fix an error than it would be otherwise. You can also get professional help in this regard.
Would like to know more about physical and electrical partitioning in your designs or pcb assembly services? Write us at sales@pnconline.com

How Is PC Board Designed In KiCad

How Is PC Board Designed In KiCad

There are many free and open-source PC Board design software packages out there, but KiCad has become one of the more popular ones due to its combination of low cost and flexibility. As with most design software, it does take some practice to learn how to use it, which is why we created this guide on how to design PCBs in KiCad.
Whether you’re just getting started or want to review your skills, this guide will get you up and running quickly, allowing you to create your first PCB in no time.We’ll walk you through starting a new project, designing your circuit, creating the Gerber files to send off to your manufacturer, and much more.

Step 1: Open The File

To open up your chosen schematic file you need to double click on it. This will bring up your schematic editor, and also provide you with access to other tabs as well as additional views of your schematic. If you have more than one page in your project, they will appear separated by tabs that can be accessed at any time.

The first thing you should do is get rid of all unused components so that there is no clutter or confusion when designing your circuit board. You can do this by selecting each component individually and pressing delete or right-clicking on them to select Remove from Project from the menu.

Remember not to select any electrical connections you may have made during your design process because these are required for our circuit board to function correctly. When you are done removing everything that isn’t needed, save your project file under a new name so that you don’t lose what you’ve already done.

Step 2: Save Your Work

To save your work as you go, you must keep your progress handy. You can do so by clicking Save on KiCad’s main toolbar, or by using the CTRL+S on your keyboard.
As you work, you’ll want to save your work often. To do so, click File>Save Project (at the top left) or use the keyboard shortcut Control + S on Windows/Linux and Command + S on Mac.
Before saving, make sure that you haven’t included any hidden layers by clicking Layers>Show/Hide>Hidden Layers and making sure all layers are checked. It’s also helpful to set up a backup location for your project files.
If you choose to Save a project before compiling it when creating new projects, KiCad will automatically create backups of your files before compiling them into an output file. If something goes wrong during compilation, simply open one of these backups and continue working from there. The next time you compile, KiCad will overwrite your old backup with a new one.

Step 3: The Project Tree

You’ll notice that on your right-hand side, there’s a list of nodes. This is where you keep track of all your libraries, schematics,PCB designs and pcb fabrication files. The project tree will start with just one node called Unnamed; click on it and give it a name. That way you can return to it quickly and easily.

By default, designs are displayed as hierarchical project trees of symbols, footprints, and 3D models. Clicking on an object displays its properties in a panel at the left.

Right-clicking on any object opens a context menu for modifying it. It is also possible to create new project folders and objects from within KiCad using these menus.

There is no limit to how many objects or projects you can have in KiCad. When creating or editing the schematic sheets or PCBs, remember that the current sheet refers to either sheet 0, the top sheet, or sheet 1, the bottom sheet.

Step 4: Board Settings

The software is now configured for new designs. If you’re happy with all of your settings, click OK to save them and make sure that Configure Project for Manufacturing is unchecked. We want our design files to be suitable for creating prototype boards, but we don’t need any extra vias or silkscreen layers as those would just be an unnecessary drain on our budget.
The part of KiCad you’ll be focusing on is called Board, and it’s located under Preferences > Board. Click on that, then click Save as Default Project, then click OK. Now, any new projects you create will use these settings by default.
You’ve already got some elements selected in our schematic; now let’s check out how to add components from libraries. This is done using something called Footprints. For each component you want to add, different types of Footprintsdetermine their size and placement on your board.
To get started, find your library folder in Documents >KiCad Library> Components. There should be two folders inside here, such as footprints_1_0 and footprints_1_4. The former is used for older versions of KiCad while 1_4 has newer parts available.
Find one you like and double-click it to open up its details page. Here you can see a list of all the possible ways that components could be placed on your board, along with their respective sizes. Scroll down until you find one that matches your needs, and then right-click on it.
Once you have chosen a footprint, go back into your schematic editor and place your cursor where you want it on your board. It doesn’t matter where exactly, just somewhere near where you think it might fit nicely. Right-click again and select Add to Selection.
All instances of that component will now appear highlighted, allowing you to easily move them around without accidentally dragging another object instead. Move them around until they look good, and then press Ctrl+S to save your work.
Repeat steps 3–5 for each other component you want to add. When you’re finished adding everything, click File > Export Gerber Files… A window will pop up asking you where you want to export these files to.Choose your preferred file type before clicking Save.

Step 5: Trace Settings

To ensure your traces have sufficient space between them, you’ll need to change several settings in KiCad. If you’re working with 2 mils (0.002 inches) traces, choose Min trace width / Min clearance 0.2 mm and Min spacing 1 mm from under Advanced Tracing on the left side of the Project Properties dialog box.
If you’re using 5 mils (0.005 inches) traces, select Min trace width / Min clearance 0.5 mm and Min spacing 1 mm instead. For 10 mils (0.010 inches) or 20 mils (0.020 inches) traces, use 2mm/4mm as appropriate for those sizes.
Note that these values are set per layer, so if you want to use different values for top and bottom layers, simply click on the Top or Bottom layer in the Project Properties dialog box before changing these values. Once you’ve made your selections, click OK to save changes.
Now that you’ve got your trace size set up correctly, let’s move on to via size. Vias are used to connect one layer of copper to another through plated holes. These connections allow us to route signals through our board by allowing us to go from one layer to another without going all the way around (which would waste space).
The reason why we have two types of vias is that they serve different purposes depending on where they’re placed. Printed Circuit Board Blind vias are located inside a hole, which means they’re not visible from either side of our board. On the other hand, buried vias can be seen from both sides.

How Is PC Board Designed In KiCad
How Is PC Board Designed In KiCad

Step 6: Fabrication Output

You’ve created your schematic, laid out your board, and routed everything beautifully. Now it’s time to order those fab files. For now, let’s focus on getting these fab files ready for manufacturing.

  • Use DRC to ensure there aren’t any issues with trace width/spacing or via holes.
  • Add solder mask.
  • Add silkscreen.
  • Check for manufacturability (is your design feasible?).
    Export Gerber files.

Step 7. Exporting Gerber Files

Now that you have everything drawn up, save your schematic and board files. You will be using these files when it comes time to order your board. Start by going File > Save or hitting Ctrl+S.
To save Gerbers, you must create and name an output folder. Go ahead and do that now. After your boards are all laid out, you’ll be able to export them as Gerber files.
If you’re doing more than one layer of a board, like if you have an inner ground plane, then make sure that you select a Separate file per layer for Gerber, otherwise, they won’t work.
Also, make sure that you check every single box under File Options except Place component origin at the lower-left corner of pad/hole. This option puts components off-center on pads and is only useful if you plan to manually place components later.
Once you have checked those boxes, go to File > Export Gerber Files. A window will pop up asking where you want to save your Gerber. Name your project or whatever makes sense for what you’re making and click OK.
Then another window will pop up asking which layers you want to export. Select All Layers and click OK again. Finally, a third window will appear with progress bars telling you how long it will take to generate your Gerber. It can take anywhere from 10 seconds to over an hour, depending on how many layers you have selected and how complex they are.
Would like to know more about printed circuit board assembly? Email us at sales@pnconline.com

Tips for RF PCB Design

Tips for RF PCB Design

With so many things to consider when designing an RF PCB, it can be hard to know where to start. How do you choose the right layout? What tools should you use to get the job done? RF PCB design has its own set of challenges that need to be addressed to get the most out of your circuit. There are some best practices you can use to ensure that your design will function optimally and run smoothly.
The best PCB design solution can be the difference between success and failure for your product, so you want to make sure that you are getting it right the first time around. Our guide will walk you through all of the steps necessary to create an RF design that works and that makes your product even better than you envisioned.

Tips for RF PCB Design
Tips for RF PCB Design

Surface Mount Capacitors

Use surface mount capacitors when space is limited. You can incorporate them into your RF Printed Circuit Board design with no impact on performance. Try to keep track of how much space they’ll take and make sure there’s still enough room for other components on the board, like resistors and coils. The surface mount parts are more fragile than through-hole components and require an extra level of care when handling.
Consider using larger surface mount parts wherever possible, or incorporating test points into any sensitive areas if smaller parts are required. Remember that small surface-mount parts have very thin leads that could break off easily. Make sure you know what size of solder tip will be needed before moving forward with your design. If it’s too small, it could damage the delicate leads on these devices. It may also be difficult to attach them to boards after soldering as their leads are so small that they tend to slide around during assembly. When in doubt, use a slightly larger part.

Differential Pair Transformer Coupling

Choosing proper circuit components is an important part of designing and building circuits. When creating transmitter/receiver pairs, several factors influence how well each device will perform. The goal of any transmitter or receiver circuit is to accurately convert an input voltage into an output voltage with minimal noise and distortion.
These parameters are known as gain, linearity, bandwidth, noise figure, NF, return loss, RL, and intercept point, IP. A low NF results in more power being transferred from input to output. The IP value represents how much power can be handled by the front end of a given device before distorting or saturating it, all while maintaining its linearity characteristics.
In other words, if a device has high gain but poor linearity, then it may still have acceptable levels of IP. But if a device has high gain and poor linearity at lower power levels, then it won’t have good IP numbers. In general, devices with higher gains have lower bandwidths, however, there are exceptions to every rule. For example, some amplifiers have very high gains but also operate over wide frequency ranges.

Microstrip Transmission Lines

These are transmission lines in which all of their circuit elements, including those forming half-space planes, and terminations, such as capacitors and transformers, are fabricated on metal strip circuits. The strip circuit is usually etched onto an epoxy substrate using photo etching or electroplating techniques. The micro-strip designs have become very popular for many PC BOARD applications because they can be packaged in small cases with relative ease due to their thin profile. They also have good impedance matching properties over a wide frequency range.

Reference Planes, Power Planes & Ground Planes

Radio-frequency circuit boards or RF designs are often more sensitive to ground loops and signal integrity issues than regular designs because RF circuits and components are particularly susceptible to noise. One way that experienced designers combat these types of issues is by strategically adding power planes, reference planes, and ground planes to their board layouts.
Reference planes: The reference or signal planes can allow designers to focus on specific sections of a circuit without having to worry about interfering signals from other portions.
They also provide a convenient place for designers to add vias between layers of copper, which helps improve both signal quality and thermal performance. Reference planes can be especially useful when they’re directly connected to a component’s ground pin, which allows them to act as an extension of that component’s ground plane.
Power planes: they should always be connected directly to an external source of power, otherwise, they could cause voltage drops across adjacent traces and components.
Ground planes: They should always be connected directly to an external source of the earth, otherwise, they could cause the voltage rises across adjacent traces and components. It’s important to note that many high-speed applications use multiple ground planes at different potentials, so it may not be feasible to have just one global ground plane. However, it’s generally best practice to keep each section within a single board connected through at least one shared global ground plane.
By using separate grounds for different sections of a design, designers can avoid parasitic effects and increase the overall reliability by ensuring all parts of their designs have access to low impedance paths back to an external earth point.
In addition, it’s crucial to ensure that any ground or power planes are spaced far enough away from any active circuitry in order to minimize crosstalk. Generally speaking, there should be at least 1/10th of a millimeter between active circuitry and any nearby reference or power planes. The distance requirements become even more stringent with higher frequencies. When operating above 30 GHz, there should ideally be no less than 0.3 mm of separation between any ground or power plane and active circuitry.

Vias – Size, Shape & Placement

Vias are required in order for us to make electrical contact with traces on different layers. There are three types of vias, including plated through, blind, and buried. A plated through via connects one layer’s copper trace directly with another via’s copper trace or traces. A blind via creates electrical contact but no physical connection between two layers and a buried via provides both an electrical and physical connection.
Placement is generally determined by where it will be soldered or how many layers are involved. For example, if there are four or more layers involved then we recommend using plated through vias because they offer better conductivity than a blind via. If there are only two layers involved then we recommend using either type of visa, depending on its location relative to other components.
As far as shape goes, choose from square, round, or rectangular options that match your pcb fabrication layout requirements. Circular vias may also be available upon request, however, these have a higher cost associated with them due to their complexity and are not always necessary. We use wire-bondable vias wherever possible because they provide a faster assembly process. The above diagram illustrates each type of via along with its respective shape and size.

Isolating an RF trace

It is essential to isolate an RF trace from high-speed signals, including HDMI, USB differential pairs, or crystals’ clock traces. Experts do it through a method known as via stitching where vias are stitched around the RF traces to keep them away from other parts on the circuit board. But, there should be proper isolation as improper isolation can affect PCB function.

RF Circuit Board Insulation

Insulation is one of the most important factors for minimizing the signal loss in an RF transmission. If you want to ensure that your signal reaches its destination without any hiccups or interference, it’s crucial that you use good quality material for your board’s insulation, and choose one with at least 5-mil thickness.
One of our favorite options is Taconic TFEP as it offers superior heat resistance and can withstand temperatures as high as 350 degrees Celsius. It also has great mechanical properties and will last for years to come. Another great option is Rogers, which boasts similar properties but has a slightly higher temperature resistance.
You’ll also want to make sure that you’re using a good adhesive when attaching components to your board. This will ensure that everything stays intact even in tough conditions. If you want to ensure that your signal reaches its destination without any hiccups or interference, it’s crucial that you use a good, quality material for your board’s insulation.
You can create a flawless RF circuit board by considering all the above design guidelines.

Final Thoughts

RF PCB design has its own set of challenges that need to be addressed in order to get the most out of your circuit. There are some best practices you can use to ensure that your design will function optimally and run smoothly. You have to consider material, traces, surface mount capacitors, isolation, insulation, reference, ground, and power planes, vias size and shape, coupling, and micro-strip transmission line.
Would like to know more about RF design or pcb assembly services? Email us at sales@pnconline.com

Stencils for SMT Assembly

Stencils for SMT Assembly

A stencil mask is used in many manufacturing processes to make PCBs. This includes SMT stencils which are most commonly used in the process of making printed circuit boards. The use of these SMT assembly varies based on the size and complexity of the board that they will be used on and the type of assembly machine that will be using them.
For any SMT stencil application, solder paste should be used for paste dispensing. Advantages of using a stencil method are high yield rate, high accuracy, and repeatability, low labor cost, and good surface finish. The main disadvantage is that it is not suitable for mass production or high-mix low-volume assembly.

SMT Stencil Types

There are two types of stencils, including manual and automatic. Manual stencils are available in many materials, such as stainless steel, plastic, etc., while the automatic ones are made from silicon rubber material which has been pre-impregnated with the conductive paste by screen printing methods. Both manual and automatic stencils require cleaning after each use.

Cleaning Process

The cleaning of stencils can be either by hand washing with solvents or ultrasonic cleaning bath. If an ultrasonic cleaner is used, then the dry time must be taken into consideration before reusing a stencil again to avoid a short circuit caused by excess moisture on metalized pads.

When an ultrasonic cleaner is not available, the cleaning process should take place immediately after soldering to prevent a short circuit due to moisture trapped under soldered components. It is also important to ensure proper drying of a Printed Circuit Board before applying the stencil. This will help reduce contamination during the next round of the soldering process.

How To Choose The Right SMT Stencils For Your Project?

You have to consider many factors when choosing an SMT stencil, including material, thickness, complexity, size, durability, and cost. It’s important to do your research before ordering a stencil from a vendor.

Stencil Application In PCB Assembly Method

The solder paste should be applied to both sides of a printed circuit board with a stencil. After applying solder paste, components are placed on top of it. Soldering is done by passing an electric current through it. This will melt solder paste, allowing it to flow between pads on PCB and component leads. This process is known as reflow soldering.
There are two types of reflow soldering, including hot air reflow soldering, and infrared reflow soldering. The hot air reflow soldering uses heated air to heat a PCB and components, while infrared reflow soldering uses IR lamps or IR guns to heat a PCB and components.
Both methods can be used for stencil applications. However, the hot air reflow soldering can only be used if there is no need to change the position of components after they have been placed on PCB. If there is a need to change the position of components after they have been placed on a PCB, then infrared reflow soldering must be used instead.

Stencils for SMT Assembly
Stencils for SMT Assembly

What Types of Designs Work with SMT Stencils?

While most customers using stencil printers are familiar with traditional SMT stencils, it’s important to know that there are other types of SMT stencil designs. While each is suitable for certain circuit board and component types, not all of them work with on-demand printing, so there are other factors to consider.
Another consideration when choosing an SMT stencil printer is whether or not you plan to print a single part or multiple parts at once. Most on-demand printers allow users to print one part at a time, but if you need more than one per run, it’s important to find a machine that can handle high volume runs, as well as quick turnaround times. If speed is your top priority, look for a system that offers a fast setup and take-down times so you can get back to production quickly.
Finally, be sure to choose a printer that offers interchangeable nozzles so you have access to different tip sizes without having to buy new machines. For example, if you want to use larger components like QFP packages or BGA chips, you might want a larger nozzle size.
Similarly, smaller components will likely require a smaller nozzle size. This allows you to switch between jobs quickly and easily instead of waiting for replacement parts to arrive. Of course, you should also make sure that your printer supports all of these features before purchasing.

How to Avoid Overruns on a PCBA?

Overruns occur when you place too many components on a single layer of your PC BOARD. This problem can be easily avoided by using stencil masks to help guide where your components should go. While it’s possible to manually transfer the component placement onto a new layer, it’s much easier and more efficient to use stencil masks. These plastic sheets are placed over each hole and etched with a laser, creating an accurate pattern that allows for easy placement of components onto layers below. This process ensures that all your components are placed correctly, which will result in fewer problems once you begin assembling your PCBA.
When there is not enough space between components, they may short out or interfere with one another. Both scenarios will negatively impact performance and may even damage some parts entirely. To avoid these issues, make sure you always use stencil masks to ensure proper spacing.
Additionally, check any design files you received from your manufacturer before placing components; sometimes oversights occur during translation. If you find errors while working with stencil masks, don’t hesitate to reach out to a service provider who can offer additional assistance if needed.

What Are Some Common Mistakes Made When Using SMT Stencils?

A stencil is an important part of manufacturing printed circuit boards, and you should choose it with care. Here, we will discuss some common mistakes when using SMT stencils so you can avoid them on your next project.

Not Knowing How Your Stencil Is Manufactured: There are three ways that stencils are made, such as laser-cut, die-cut, and silkscreen. The first two are much more expensive than silk screening but they produce higher-quality results. Silk screening has been around for decades and allows people without special equipment to create professional-looking stencils that work well for mass production. However, they don’t last as long as other stencils.

Not Checking Your Board for Burrs before Using a Stencil: A burr is a small piece of metal leftover from cutting your board with a laser cutter or CNC machine. It can easily ruin your stencil and make it unusable. You should always check for burrs before using a stencil, and make sure you get rid of them by filing them down with an emery board or some other method if they are present.

Not Pressing the Stencil Firmly against PCB: If you don’t press firmly enough against your board when applying solder paste, there will be air pockets where components won’t be soldered properly. This may not seem like a big deal at a first glance, but it can cause issues later on that could cost you time and money. You should always make sure to press firmly against your stencil before starting to apply solder paste so you get high-quality results every time.

Using a Stencil That Is Too Small for Your Project: When using a stencil for SMT placement, it is important to choose one that is large enough for all of your components. If you try to use a stencil that is too small, you will end up with extra solder paste on your board and possibly even miss-placed components. You should always make sure you are using a stencil that has plenty of room for all of your parts so you don’t waste time or money trying to fix mistakes later on.

Not Cleaning the Board after Use: After you have finished soldering, you should clean off any excess solder paste from your board. If left on there too long, it can cause oxidation and other issues which could ruin both your board and stencil. You should always clean off your board after using a stencil to make sure you don’t run into problems later on.

Using A Stencil That Is Too Old: While they may seem like they last forever, SMT stencils do wear out over time. You should always make sure to replace them when they start showing signs of wear and tear. Signs that your stencil is worn out include warped edges or holes that are too large for your components. If you see these kinds of problems, it’s best to get a new one before continuing with your project so you don’t end up wasting money or having issues later on.
FAQs

Will My SMT Stencil Last Forever?

No matter which type of stencil you purchase, it won’t last forever. Eventually, all stencils will degrade and lose their effectiveness.

What Happens when an SMT Stencil Gets Damaged?

Damaged stencils pose a serious risk because they could cause solder paste to leak through and contaminate nearby components. This can result in costly repair work and even downtime for your production line.

How Do I Test My SMT Stencil to See If It’s Working Properly?

To test your stencil, you can use a device called a stencil tester. You can also get professional help in this case.
Would like to know more about SMT Stencils in PCB or PC Board assembly? Email us at sales@pnconline.com

PCB Design, Planning, and Components Selection in Printed Circuit Boards

PCB Design, Planning, and Components Selection in Printed Circuit Boards

Designing a printed circuit board or PCB can become challenging because there are many factors to consider, including environmental conditions the PCB will be exposed to and the desired electrical components that the PCB will use. The best design, planning, and component selection bring the best-printed circuit boards. All electronic products contain printed circuit boards so considering the above elements is essential that we will discuss these elements in this article.

Questions Regarding PCB Planning?

A few questions to keep in mind when designing and planning a PCB include:

  • How many layers do I want?
  • What thickness of copper foil/laminate do I want?
  • Do I want to use plated through holes or non-plated through holes?
  • Do I want my board to be double-sided, single-sided, or multilayer?
  • Are all of my components going to be surface mount or through-hole?
  • Are all of my connections going to be made using jumpers or solder pads?
  • Can I get away with using cheaper non-plated through holes instead of plated ones? Can I get away with not having a ground plane layer if all my signals are digital logic levels?
  • Does my design require low-noise analog filtering?
  • Will I need to isolate high-voltage circuitry from low-voltage circuitry, and high-speed circuitry from slow-speed circuitry?

You can start designing a PCB after getting answers to the above questions.

PCDesign: Basic Guidelines

Before you even begin to design your printed circuit board, make sure you understand some basics of PCB design. When designing a Printed Circuit Board several things should be considered. Keep in mind that most errors caused by circuit boards are usually associated with improper grounding and power distribution.
If you are trying to create a custom PCB or just update an existing board, it is important to consider whether it will be surface mounted or through-hole mounted.
Size: The size of your circuit board will also play a big role to see how much space you have for components. You can either choose to go with a larger board and have less room for components or vice versa.
Layers: The number of layers in your circuit board also plays an important role to see how many components you can fit into one area. There are three basic types of circuit boards, such as single-sided, double-sided, and multi-layer. Single-sided circuits only have traces on one side while double-sided circuits have traces on both sides of a sheet of material called laminate. Multi-layer circuits consist of multiple layers stacked together which increases current capacity.
It is important to know what type of circuit board you will need before starting any design work because it may require special tools or materials that aren’t available at home orin local electronics stores.

PCB Design, Planning, and Components Selection in Printed Circuit Boards
PCB Design, Planning, and Components Selection in Printed Circuit Boards

PCB Layout Techniques

While surface-mount technology dominates today’s electronics designs, you still may need to design or repair an older circuit that uses through-hole components. Whatever your reason is for dealing with through-hole components, there are several layout techniques you should be aware of to ensure reliable operation.
Many PCB layout problems stem from poor component placement rather than PCB material defects. By following these best practices when laying out a PC BOARD using through-hole components, you can help avoid these common mistakes If possible.

  • Place resistors before capacitors on each side of a power supply line. This way, if any capacitor fails, it will not causedamage to the resistors placed after it.
  • Place decoupling capacitors close to the chip they are used for decoupling. For example, if you have a microcontroller with two crystal oscillators, place one cap near each oscillator and connect them at opposite corners of their respective pads.
  • Placing both caps near only one oscillator would increase the parasitic inductance between those two connections, reducing efficiency.
  • Don’t place any other traces within 0.5mm of a signal trace running parallel to another signal trace on different layers. Signal traces running parallel are said to be coupled and can pick up noise from each other due to electromagnetic induction caused by nearby power or ground planes.
  • Try to keep traces spaced away from each other by 1mm or more if possible. If you must cross a signal trace over another signal trace, do so at right angles and use wide traces to reduce coupling.
  • When placing multiple closely-spaced power/ground pins on a single side of a DIP package, leave enough room between pins for solder mask relief cuts. Otherwise, you could end up with a solder mask bridging across adjacent pins when you remove your stencil during soldering operations.
  • Never put a hole in a signal trace and even small holes can cause shorts to the surrounding traces and components, especially if you don’t seal them off with liquid electrical tape or conformal coating. Similarly, don’t drill holes in the ground or power plane areas because those holes could become filled with solder during soldering operations.
  • Drill larger holes for mounting standoffs instead of smaller ones for mounting screws to save time and improve manufacturability.
  • Keep in mind that you may want to place components on a PCB around a standoff if you plan to solder wires or connectors directly to it. Always use solid core wire for power and ground traces. Stranded wire has too much resistance and tends to break easily under repeated flexing.
  • Keep track of your trace lengths to make sure none are longer than 2-3 times their widths. Longer traces can affect signal integrity and lead to intermittent failures in your final product.
  • When possible, use a ground plane layer to provide a return path for your power and ground traces. Power and ground planes also act as heat sinks, helping to dissipate heat from your components.
  • If you can’t use a separate ground plane layer for some reason, try to place as many of your signal traces on that layer as possible. That way, if one trace causes a problem with another trace or component, it won’t affect any other traces running on that layer.

Components Selection for Printed Circuit Boards

Deciding what components to choose when designing printed circuit boards is an important process that affects your final product. These electronic components come in many shapes and sizes, with different specifications for power consumption, weight, and other factors.

Knowing how to choose your components efficiently can prevent expensive mistakes down the line. This guide will help you understand how to select components for your PCB design effectively.

A printed circuit board contains conductive tracks made from metal foil and a conducting adhesive, typically etched into a thin layer of non-conductive material such as fiberglass or epoxy resin. Components are then placed on these tracks at specific points called pads, which are connected by copper traces forming circuits.
The PCB is usually used to connect electronic components like resistors, capacitors, transistors, and diodes with each other to form an electrical circuit. The most common materials used for PCBs are FR4 (fiberglass) and G10 (FR4 glass laminate). Other materials include CEM-1 (glass epoxy), Rogers 4003 (aluminum), Rogers 4350 (aluminum), and PTFE-based laminates.

The Purpose of Design

When designing printed circuit boards, many factors need to be considered and you can split them into two categories, such as functional requirements and design constraints.
The functional requirements describe what your printed circuit board needs to do, while design constraints determine how it will be designed. For example, if you want your product to have a battery life of more than five hours you need to consider things like battery size and power consumption when designing your product.
Functional Requirements
Four main functional requirements must be met when designing printed circuit boards, such as performance, reliability, serviceability, and cost.
Performance refers to how well your product performs its intended task.
Reliability means that your product should work correctly all of the time without fail.
Serviceability means that it should be easy to repair any problems with your product once they occur.
Cost refers to whether or not you can produce your final product for a reasonable price.
These requirements may change depending on who your target market is. If you are targeting high-end consumers, reliability and serviceability might take priority over cost. On the other hand, if you are targeting low-income customers in developing countries, affordability might take priority over everything else.

Connectors for Printed Circuit Boards

Solderless connectors are used to connect different electronic components on a printed circuit board. They’re available in two categories, such as through-hole and surface mount.
These connectors can also be classified by their location on a PCB, such as an edge-mounted or through-hole mounted. The primary difference between these two is the size.

Edge-mounted connectors are smaller than through-hole ones because they don’t have as much copper around them. This makes them better suited for smart devices having less space, such as cell phones and laptops. Whereas the through-hole mounted connectors are larger and easier to work with but require more space on a PCB.

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