Tag Archives: printed circuit assembly

PCB Prototyping

PCB Prototyping- Best Practices for Fast and Accurate Results

When designing a printed circuit board the prototyping process is one of the most important steps. It’s essential to get it right the first time so that the end product meets all of your specifications. To ensure fast and accurate results in this case, you must follow certain best practices. From choosing the right design software to properly testing the boards, we’ll cover everything you need to know to get the most out of your PCB prototyping projects.

Use the Correct Board Material

When it comes to PCB prototyping, selecting the right board material is crucial. The type of material you choose can impact the board’s durability, and performance. Some materials are more prone to overheating or warping, while others may be more conductive or have better insulating properties.

One popular option for PCB prototyping is fiberglass. It is a relatively low-cost material and can provide good insulation properties. It is also ideal for single-sided boards. However, it may not be the best option for more complex designs.

For multi-layered boards, you may want to consider a material like FR4. This type of material is more expensive but provides better durability and stability, which is critical for high-performance circuit boards.

Before selecting your board material, you must consider the specifications of your design, including the application, environment, and electrical properties you require. Don’t be afraid to consult with PC Board experts to help determine which material is the best fit for your project.

Using the right board material is just one of the many best practices to consider when it comes to PCB prototyping. By following these tips, you can achieve faster, more accurate outcomes and set yourself up for success in your PCB design projects.

Invest in Quality Components

When it comes to circuit board prototyping, investing in high-quality components is crucial to achieving fast and accurate results. While it may be tempting to cut costs by using cheaper parts, this can lead to several issues down the line, from malfunctioning circuits to reduced durability.

Using quality components ensures that your circuit board will function properly and last longer, saving you time and money in the long run. You must find the components that have been tested and verified to meet industry standards and specifications.

Another benefit of using high-quality components is that they are less likely to fail during testing, reducing the need for repairs or replacements. This not only saves you time but also minimizes the risk of damaging other components or causing additional issues with the circuit board.

Make Sure Your Board Design is Complete and Accurate

Before starting your PCB prototyping project, you must ensure that your board design is complete and accurate. This step may seem obvious, but it is often overlooked, resulting in errors and the waste of time and money.

Start by double-checking your PCB design for errors, missing connections, or any other issues. Use reliable design software and go over your schematic and layout files thoroughly. Get a second pair of eyes to review your design before moving forward with prototyping.

Another best practice is to perform a Design Rule Check (DRC). This automated check ensures that your board meets the minimum manufacturing requirements. A DRC can identify potential errors, such as overlapping pads, inconsistent track widths, or drill holes that are too small or too close to each other.

If your board design has multiple layers, it is crucial to verify that your stack-up is correct and that the signal integrity is maintained. You can use a simulation tool to predict and optimize the electrical performance of your board.

Follow the Data Sheet

Following the datasheet is essential to achieving accurate and reliable results while PCB prototyping. The data sheet contains crucial information about the board’s electrical characteristics, material properties, and manufacturing specifications.

The data sheet typically contains the following information:

  • PCB layer stack-up and dimensions
  • Minimum and maximum board thickness
  • Trace and via size, spacing, and clearance
  • Impedance requirements
  • Material composition and properties
  • Surface finish options
  • Solder mask and silkscreen specifications
  • Thermal management guidelines

Such a practice can ensure that your PCB prototype meets the manufacturer’s specifications, as well as any relevant industry standards. Failure to follow the datasheet can result in design flaws, manufacturing errors, and functionality issues.

Moreover, you should communicate with your PCB manufacturer if you have any questions or concerns about the datasheet. A reputable manufacturer has a team of experts who can guide you throughout the prototyping process. So, following the datasheet is the best practice for fast and accurate PCB prototyping.

Make Test Points Accessible

Make sure that the test points are easily accessible. This helps have easy testing and debugging of the PCB during the prototype stage.

Test points are small metal points on the board where you can attach the testing equipment to measure the voltage. You can find them near components to be tested. By making them easily accessible, you can avoid having to take the board apart or maneuver equipment to access them. You should consider this factor during the design phase. Ideally, you should choose unobstructed areas. You should also consider adding extra test points to ensure thorough testing of the entire board.

Moreover, you should consider the size and type of test points to use. Small test points can be difficult to use, while larger test points can take up more space on the board. You should also consider the technology, such as surface mount or through-hole.

By making test points accessible during the prototyping phase, you can save time and ensure accurate results. It can also help to identify any issues with the board early on in the development process, helping in easier debugging and revisions.

Consider Your Assembly Options
After the PCB prototype process, comes the assembly. There are several assembly options available, and you should consider which one is best for your particular project.

One option is hand assembly, which involves soldering components to the board by hand. This method is cost-effective and works well for small-scale production runs, but it is time-consuming and may result in inconsistencies.

Another option is automated PCB assembly, which involves using machines to place components onto the board. This method is efficient and accurate, but it may be more expensive and more suitable for larger production runs.

You should also consider whether you want your board to be surface-mount or through-hole. Surface-mount components are smaller and lighter, making them ideal for compact designs. However, through-hole components can provide a stronger mechanical bond and are ideal for larger components or those that require high voltage.

Make sure to consider the assembly options before finalizing your PCB design and prototyping process. This will help ensure that the end product meets your expectations and requirements.

Don’t Forget the Silkscreen

When it comes to printed circuit board prototyping, people often overlook the importance of the silkscreen. The silkscreen is the layer of ink on top of the PCB that indicates component placement, orientation, and other important information. It may seem like a minor detail, but an accurate silkscreen can save a lot of time and confusion during the assembly process.

First and foremost, make sure your silkscreen is complete. This means double-checking that all component labels are correct and aligned properly with their respective pads. Make sure there are no overlapping labels or missing information.

Next, consider the size and color of the silkscreen. A too-small or too-light font may be difficult to read, especially for those with vision impairments. Conversely, a font that is too large or too dark can clutter the board.

Finally, be mindful of the placement of the silkscreen. It should not cover up any important traces or pads. Besides, it should not interfere with any assembly processes or inspection.

Final Thoughts

Prototyping printed circuit boards is a complex and time-consuming process, but with the right techniques, it doesn’t have to be. If you want to ensure fast and accurate results, you must follow best practices, in this case. Investing in quality components is an essential step in achieving fast and accurate PCB prototyping outcomes. Don’t compromise on quality to save a few bucks as it will end up costing you more in the long run. Also, make sure that your board design is complete and accurate, as it will save you time and money.

Before starting your PCB prototype, you should thoroughly review and understand the data sheet provided by the manufacturer. It ensures that your design meets the manufacturer’s specifications and industry standards, preventing errors and functionality issues. Also, don’t hesitate to consult with your prototype pcb manufacturer if you have any concerns about the datasheet.

Also, remember the importance of the silkscreen when prototyping your PCB. A well-designed silkscreen can improve the overall functionality and aesthetics of the PCB. Make sure to choose the right font and color, and be mindful of placement. A little attention to detail can go a long way in the success of your PCB prototyping project.

Would like to know more about PCB prototyping or printed circuit board assembly? Email us at sales@pnconline.com

PCB Assembly

The Impact of Miniaturization in Design and PCB Assembly

The miniaturization of technology is drastically changing the way we use electronics, and it’s affecting the design and assembly of printed circuit boards. The miniaturization of components helps engineers develop more powerful, sophisticated, and efficient products. You will see smaller, lighter, and easy-to-transport devices. Here, we will explore the impact of miniaturization on design and assembly and what this could mean for the future of electronic devices. Let’s discuss it further and also find out how it affects the end product, from manufacturing costs to product performance.

Higher Density

The miniaturization of printed circuit boards (PCBs) leads to a significant increase in density. As the size of electronic components decreases, PC Board designers can pack more functionality onto smaller boards, providing efficient use of space in devices. This higher density not only enables more functionality in a smaller space but also improves signal integrity and reduces power consumption.

However, with higher density comes a new set of challenges for PCB designers and manufacturers. You have to maintain tighter tolerances in the design process to ensure the proper functioning of the board. Moreover, the assembly must be precise to prevent shorts and other defects. This requires advanced equipment and techniques, including high-resolution imaging, precise soldering equipment, and inspection methods.

Despite the challenges, higher density has become essential in modern design and assembly, as electronic devices continue to get smaller and more powerful. The development of wearable technology, IoT devices, and more efficient computing is due to the developments in miniaturization, as they all rely on highly-dense PCBs.

Increased Reliability

Miniaturization makes printed circuit board design and assembly more reliable. This is because the smaller size and tighter component placement on the board minimize the risk of damage due to vibration, shock, or temperature fluctuations. The components and traces are closer together, making it easier for signals to travel between them. This also reduces the possibility of electrical noise and signal distortion, which can impact PCB performance.

Moreover, the advancement in surface mount technology enables assemblers to place components directly onto the PCB surface, rather than having to drill holes and attach the components to the board. This process is known as surface mount technology (SMT), and it has a few benefits. Firstly, it eliminates the need for holes, which can weaken the board and increase the risk of breakage. Secondly, it helps place smaller and lighter components, leading to a compact PCB. Lastly, SMT enables better quality control and accuracy during PCB assembly, as you can mount the components with precision machines.

The increased reliability of miniaturized PCBs is ideal for industries like aerospace, medical devices, and automotive, where reliability is highly important. Miniaturization helps develop smaller and more advanced electronics that can withstand harsh environments, vibrations, and other adverse conditions.

Greater Functionality

Miniaturization has opened up new avenues of greater functionality for Printed Circuit Boards With smaller, lighter, and more compact boards, designers and engineers can now cram more features, circuits, and components into a single PCB design. Hence, it helps to have highly functional products. For instance, a compact, Printed Circuit Board can now operate a variety of smart devices, wearables, and even miniature robots, enabling them to perform advanced functions with the least possible space requirements.

Miniaturization helps create more complex PCBs with multi-layered circuit designs, stacked components, and intricate traces. Hence such a board can handle more power, data, and complex signals.

The high functionality of compact PCBs also enables companies to meet the specific demands of different applications and end-users. With reduced space constraints and increased reliability, PCBs can now provide optimal solutions for various electronic systems. 

Smaller Size

One of the most obvious effects of miniaturization on printed circuit board design and assembly is the smaller size of the components. As technology continues to advance, electronic devices become increasingly compact, requiring the PCBs that power them to become smaller as well. Smaller size not only means that devices can be more portable, but it also enables more efficient use of space within a device.

However, the smaller size also brings some challenges for PCB designers and assemblers. It is hard to work with smaller components as it involves more precise placement and soldering techniques. The smaller the component, the more likely it is to be damaged during assembly, making quality control an essential part of the process.

Other than these challenges, the smaller size also brings many benefits to PCB design and assembly. It helps to have more user-friendly and portable devices. Besides, smaller components can also lead to a reduction in power consumption, since they require less energy to function.

Likewise, smaller PCBs are easier to manufacture since they require less material, and their production cost is also low. This ultimately leads to a more cost-effective product for consumers. Such PCBs also open up new opportunities for manufacturers to create innovative and low-cost products.

So, the effect of miniaturization on design and assembly is a mixed bag of benefits and challenges. However, the ability to create smaller and more powerful electronic devices is possible due to a compact PCB.

Lighter Weight

Miniaturization also reduces the weight of PCB components. It is ideal for applications where weight plays a crucial role, such as aerospace, automotive, and military industries. PCBs in these sectors must be lightweight to ensure efficient performance and lower costs.

With miniaturization, a PC Board manufacturer can replace large, and heavy components with smaller, and lightweight ones. So, it leads to the reduced weight of the entire board and the final product, resulting in improved fuel efficiency, increased payload capacity, and better handling of vehicles.

Moreover, the reduced weight of compact PCBs enables designers to create thinner and sleeker devices that are more portable and aesthetically appealing. Lighter PCBs are now common in portable devices such as smartphones, laptops, and tablets, making these gadgets easier to carry and use on the go.

The benefits of lightweight PCBs also extend to shipping and handling costs, which reduce as the overall weight of the products decreases. In turn, this helps manufacturers save on logistics costs and lower their prices to stay competitive.

In conclusion, miniaturization leads to lightweight and compact PCBs that are now crucial components in many industries. Their reduced weight and size help have improved performance, efficiency, portability, and cost savings. As technology continues to evolve, miniaturization will also continue to play an even bigger role in PCB design and assembly, resulting in more efficient and innovative products.

Reduced Cost

The miniaturization of electronic components has reduced the cost of printed circuit board design and assembly. Smaller and more densely packed components result in fewer materials for PCB manufacturing, ultimately lowering production costs.

Moreover, the surface mount technology helps have smaller components to be mounted directly onto the PCB which reduces the need for drilling and plating. This means that PCB designers and assemblers are spending less on the drilling process, which is traditionally the most expensive aspect of PCB production.

Besides, miniaturization helps manufacturers create more functional and smaller PCBs, needing less hardware to accomplish a task. This reduces the cost of not only PCB production but also the cost of the overall product as a whole.

Moreover, smaller PCBs result in lighter weight, which can further reduce transportation and handling costs. This means that end-users may benefit from a reduced overall cost for the product.

Overall, miniaturization has had a significant impact on design and assembly, not just in terms of increased functionality and reliability, but also in reducing costs. As technology continues to evolve, we can expect the miniaturization trend to continue, resulting in even smaller and more efficient PCBs in the future.

FAQs 

What Is The Benefit Of A Compact PCB?

PCB miniaturization helps develop smaller and more advanced electronics that can withstand harsh environments, vibrations, and other adverse conditions.

Which Industries Are Compatible with Smart and Lightweight PCBs?

Compact and lightweight PCB is ideal for applications where weight plays a crucial role, such as aerospace, automotive, and military industries

Which Technology Helps Assemble Compact Components On To PCBs?

The surface mount technology (SMT) is ideal for mounting smaller components onto the PCB surface.

Final Thoughts

Miniaturization has had a significant effect on modern technology and helps us make smaller, more powerful devices. From aerospace systems to medical devices, automotive to the Internet of Things (IoT) devices, miniaturized PCBs have revolutionized the electronics industry. The increased reliability of miniaturized PCBs is ideal for industries like aerospace, medical devices, and automotive, where reliability is highly important. 

Moreover, miniaturized PCBs have become a critical component in many consumer electronic products, providing better functionality and reducing the size of electronic devices. For instance, with smaller PCBs, mobile devices can now house more components, which ultimately translates into a better user experience, better performance, and increased portability.

Moreover, the advancement in surface mount technology enables assemblers to place components directly onto the PCB surface, rather than having to drill holes and attach the components to the board.

Would like to know more about the miniaturization impact on the printed circuit board? Email us at sales@pnconline.com

Printed Circuit Board

Printed Circuit Board Surface Finishes and Their Effects on Solderability and Reliability

When designing a printed circuit board, selecting the right PCB surface finish is essential to ensure the reliable soldering of components. Different types of PCB surface finishes have different effects on solderability and reliability. The PCB designer and manufacturer should understand the different finishes available and how to use them to maximize the performance of the PCB. We will discuss here the different types of PCB surface finishes available, their effects on solderability and reliability, and tips for selecting the best finish for your project.

Choosing the best surface finish for your application requires careful consideration of several factors. By understanding the properties and benefits of different surface finishes and how they align with your specific needs, you can make a good decision.

The Different Types of PCB Surface Finishes

There are several types of surface finishes to choose from, each with its unique characteristics and benefits.

  1. HASL (Hot Air Solder Leveling): This is one of the oldest and most commonly used surface finishes. It involves applying a layer of molten solder to the surface of the PCB and then flattening it using a hot air leveling process. HASL provides a durable and cost-effective surface finish, but it may not be suitable for fine-pitch components. It has some disadvantages such as the formation of solder balls and their thickness, which can cause issues with fine-pitch components.
  2. ENIG (Electroless Nickel Immersion Gold): ENIG is a popular surface finish for high-density PCBs with fine-pitch components. It involves depositing a thin layer of nickel on the surface of the PCB, followed by a layer of gold. ENIG offers excellent corrosion resistance and solderability, but it is more expensive than other surface finishes.
  1. OSP (Organic Solderability Preservatives): OSP is a thin organic coating applied to the surface of the PCB to protect it from oxidation and other environmental factors. OSP is a cost-effective option in this case, but it may not be as durable as other surface finishes.
  2. Immersion Tin: This surface finish involves depositing a thin layer of tin onto the surface of the PCB. Immersion tin offers good solderability and can be an affordable option for certain applications. However, it may not be suitable for PCBs with high-temperature requirements.
  3. Immersion Silver: This surface finish involves depositing a thin layer of silver onto the surface of the PCB. Immersion silver offers excellent solderability and is a popular option for high-speed PCB designs. However, it can be more expensive than other surface finishes and may not be as durable in harsh environments.

Each type of PCB surface finish has its unique advantages and disadvantages. When selecting a surface finish for your PCB design, consider factors such as the type of PCB components, the operating environment, and the cost.

The Effect of Surface Finish on Solderability

The surface finish of a PCB can have a significant impact on the solderability of the components and the overall reliability of the board. In this section, we will take a closer look at how different surface finishes can affect the solderability of PCBs.

First, you must understand that the surface finish of a PCB refers to the thin layer of material that is applied to the copper pads on the board’s surface. This layer is essential because it protects the copper from oxidation, corrosion, and other forms of damage.

You would see that HASL leaves behind a thick layer of solder on the surface, which can be difficult for small components to bond with and can also lead to uneven solder joints. Moreover, the excess solder can also create short circuits and reduce the board’s overall reliability.

In contrast, the electroless nickel immersion gold (ENIG) surface finish has become increasingly popular in recent years due to its ability to provide excellent solderability and reliability. ENIG provides a flat surface for components to bond with. The gold layer is also non-corrosive and has a high resistance to wear and tear.

On the other hand, immersion silver offers good solderability and a relatively low cost compared to ENIG. However, silver is more prone to tarnishing and can cause problems with the board’s reliability over time.

The Effect of Surface Finish on Reliability

The choice of surface finish can significantly impact the longevity and overall performance of the PCB. The surface finish of a PC Board can affect its ability to resist corrosion. Certain surface finishes, such as gold or silver, provide excellent corrosion resistance, ensuring that the PCB remains protected even in harsh environments. On the other hand, some finishes like HASL are prone to corrosion, which can lead to the failure of the circuit board.

The surface finish can impact the electrical performance of the PCB. Some surface finishes have low electrical resistance, which can help to minim ize signal loss. Conversely, finishes that have higher electrical resistance can lead to signal distortion and reduced performance. So, you should consider the electrical requirements of your PCB when selecting a surface finish.

The surface finish can also impact the mechanical durability of the PCB. Certain finishes, such as immersion gold, provide a thin and uniform layer that is less likely to crack or peel during thermal cycling. Other finishes, like OSP, are more susceptible to wear and tear, which can lead to damage to the circuit board.

Overall, the choice of surface finish for your PCB can have a significant impact on its reliability and performance. By understanding the strengths and weaknesses of each type of finish, you can choose the right finish for your specific application and maximize the longevity and reliability of your circuit board.

How to Choose the Best Surface Finish for Your Application

Now that we have covered the different types of surface finishes and their properties, it’s time to discuss how to choose the best surface finish for your specific PCB application. Here are some factors to consider:

  1. Environment: The first thing to consider is the environment in which the PCB will be operating. If it has to work in a harsh or high-temperature environment, you may want to choose a surface finish that is more durable and resistant to corrosion, such as ENIG or OSP.
  2. 2. Cost: Different surface finishes have different costs, so you need to consider your budget in this case. HASL is the most affordable option, while gold finishes tend to be more expensive.
  3. Solderability: As discussed earlier, you should consider the solderability of the surface finish. Some finishes, such as OSP, require a longer preheat time, while others may require the use of special solder pastes or fluxes. Make sure the surface finish you choose is compatible with your soldering process.
  4. Compatibility with other materials: If you have to assemble the PCB with other components or materials, make sure that the surface finish is compatible with them. For example, some finishes may react negatively with certain solders or coatings.
  5. Electrical properties: Finally, you need to consider the electrical properties of the surface finish. Some finishes, such as gold or silver, offer better conductivity, while others may cause increased resistance.

Ultimately, the choice of surface finish will depend on your specific requirements. If you are unsure which finish is best for your project, you can consult with a professional PCB manufacturer who can guide you through his expert advice.

FAQs

What are Common PCB Surface Finishes?

Some popular surface finishes of printed circuit boards include HSL (Hot Air Solder Leveling), OSP (Electroless Nickel Immersion Gold), ENIG (Organic Solderability Preservatives), immersion silver, and immersion tin.

What Is The Benefit Of HASL?

HASL is one of the most popular surface finishes due to its versatility. HASL provides good solderability and is suitable for most applications.

What Is The Benefit Of Using ENIG For PCB?

ENIG is corrosion-resistant and provides a flat surface that is perfect for fine-pitch components.

What Is The Benefit Of Using Immersion Silver For PCB?

Immersion silver offers excellent conductivity and is ideal for RF applications.

Which PCB Surface Finish Is Cost-Effective?

HASL is the most affordable surface finish for printed circuit boards.

Final Thoughts

When designing a printed circuit board, one of the most important factors to consider is the selection of the right surface finish. This is because different surface finishes can significantly affect the solderability and reliability of the finished PCB.

Choosing the right surface finish for your PCB can have a significant impact on its solderability and function.  Some finishes, like ENIG, provide excellent solderability and are preferred for applications that require a high degree of reliability. Other finishes, like OSP, can be more difficult to solder and may require extra steps to ensure proper adhesion.

While there are several options available, ENIG has become a popular choice due to its excellent performance and long-term durability. Ultimately, it’s essential to consider your application’s specific requirements and choose a surface finish that meets those needs.

Would like to know more about the PCB surface finishes or pcb assembly? Write us at sales@pnconline.com

Drill, Lamination, and Plating of PCB Design

Understanding Drilling

PC Board drilling involves different drilling machines which can make more than 30,000 holes in an hour. The machines have built-in systems for making precise holes and consist of spindles that can drill at a high speed of up to 110,000 RPM. An automated system and laser help manage drill bits to provide high-quality vias.

Drilling Of Through-Hole Vias

Standard PCBs have a through-hole where all PCB layers are drilled together under an NC machine. Then comes the plating of the holes’ inner and outer sides, and manufacturers use the same technique for all through holes, including the mounting holes.

Blind and Buried Via Drilling

The drilling of blind and buried vias occurs before lamination. The two-layered PCB goes through lamination after drilling. Whereas a multi-layer PCB is stacked and laminated after which it needs drilling and plating.

You can also make blind vias by drilling with a controlled depth where the drill machine works through the entire laminated board. Such a technique of making blind vias is cheaper than a sequential method, however, the hole size has some limitations. Besides, the routing of circuitry needs a specific technique.

Micro-vias Drilling

The drilling of micro-vias involves a laser machine because their size has to be small which is not easy to create through mechanical drilling. Micro-vias are ideal for thick PCBs, and you can connect them vertically by stacking them in layer pairs. Such as, in a traditional buried via, you can sequentially fabricate micro-vias whereas the buried vias need copper plating to connect the stacked vias.

When it comes to component holes, the through-hole technology works well. Such components are switches or standard connectors or mechanical components that need strong mounting that’s why the through hole suits them. Some common examples of devices having such holes include power regulators, resistors, op-amps, and capacitors, as they conduct heat and current.

How To Select A Drill

Though drilling is a basic function for a PCB Manufacturer, engineers use certain techniques to have precise drilling.

  • Sometimes a board needs lots of drills of the same size, which can cause changes in the bit during drilling. Such a change creates errors in terms of tolerance between hole diameters. So, engineers use drills of different sizes to avoid the quantity of the same-size drills.
  • Drilling diameter should be minimum, like in mechanical drilling, a six to eight mils drill is ideal for a 62-mils thick board. Whereas it is hard to use the small drill sizes in mechanical drilling, and its aspect ratio also makes plating difficult. So, engineers have to use laser drilling which is more expensive than normal drilling techniques. You have to use large drills for thick PCBs which are more than 62mils thick.
  • Use blind and buried vias when they are necessary otherwise avoid them. As their fabrication involves a sequential buildup method that increases the manufacturing cost of a raw board.

Different aspects affect the drilling methods and manufacturing cost of the PCB. Even the drill size affects the quality and cost of manufacturing. Too small holes highly increase a board’s cost, whereas too large holes can make assembly harder, increasing its cost. Engineers can avoid such issues by carefully designing a PCB, and having economical manufacturing.

PCB Plating or Metallization and Soldering

You need metal pads or lands to help components in mounting or soldering. You can’t solder the bare copper and have to plate it with an easy-to-solder material. In the past, lead-based tin was a common plating material. But, these days the environmental changes call for advanced materials like gold and nickel.

Unsoldered parts of the board need materials to resist soldering, such as polymer coating that prevents the bridging of traces. Moreover, it creates short circuits in the adjacent part leads.

Fabricating the External Layers

The above etching is ideal for circuits of external layers and the process includes drilling, metallization, and photoengraving. The final finishing happens after the external layers’ metallization. In general, the process includes soldering, silk screen application, testing, as well as packaging.

PCB Lamination

PCB lamination is crucial in terms of accuracy and creating a well-finished board. The process involves lots of stress, as you have to take care of the properties of PCB materials in terms of performance and production. PCB engineers and manufacturers have to work together to develop a functional product without sacrificing production.

Understanding the Lamination Process

The lamination of individual layers involves two main steps, such as:

Laying up:  It involves the stack-up of multiple layers. The manufacturer starts it from the bottom of the base substrate. Then comes the prepreg and internal etched layers. Then all layers are pinned together to make a final board without any disturbance. Laying up prepares the PCB before pressing.

Pressing of layers: Pressing involves heat and pressure that melts prepreg to finish the etched copper layer, making the insulation layers essential for electronic layers which can work closely. Prepreg bonds the layers, getting hard after curing, and makes a PCB mold.

You need to consider different factors during pressing. Like, many PCBs can be pressed together to save time and production costs. However, manufacturers have to place a separator between the individual layers to bear high pressure and heat without changing the PCB shape.

The laminating press also needs a vacuum to prevent the PCB voids to hinder the dielectric property, affecting its structural strength. The environment after pressing also needs consideration to prevent the STP quenching due to weather conditions. Manufacturers should store the pressed circuit boards in a press to cool them down. Cooling of the boards prevents the thermal contraction of the board.

Lamination Styles

Two styles are common in this case, such as:

  • Foil lamination
  • Cap lamination

PCB Lamination with A Foil: the foil lamination is simple and involves less hassle, as you have to foil the base and top layer. After lamination, the layers go through etching just like internal layers.  Foil lamination is more advanced than cap lamination, but you have to select the foil layer with care to remove them easily later on. The technician should work in alliance with the designer and material manufacturers to ensure precise production.

Copper Clad or Cap Lamination: It is an original method that PCB manufacturers have been using for years. There is a layer clad with copper between the base layer, top layer, and first and last inner layer. Such lamination is suitable for blind vias, however, you need a special laminate between the external and nearby layers to enhance a PCB function.

Purpose Of Sequential Lamination

You can use sequential lamination for advanced vias where drilling and plating come after lamination. However, vias other than through holes should be made before lamination, leading to sequential lamination. Such a technique involves many precautions in terms of materials and design to have a successful lamination. For like, you have to consider the z-axis CTE, Tg or glass transition temperature, and copper retention. A copper filling helps reduce copper accumulation to have a well-managed uniform CTE expansion.

The selection of the materials for PCB lamination involves great care. Besides, you should use the latest design software.

Testing a Final Product

Remember that PCB testing is very important to check damaged connectors and short circuits. Optical testing consists of layer scanning to find defects, whereas electrical tests involve a flying probe to verify different connections. It is easier to detect short circuits or breaks through electrical testing.  Whereas the optical inspection can better detect poor clearances between the conductors.

Final Thoughts

Drilling, plating, and lamination are important processes of PCB construction.  PCB drilling involves machines that can make more than 30,000 holes in an hour. The machines have built-in systems for making precise holes and consist of spindles that can drill at a high speed of up to 110,000 RPM.

An automated system and laser help manage drill bits to provide high-quality vias.  The two-layered PCB goes through lamination after drilling. Whereas a multi-layer PCB is stacked and laminated after which it needs drilling and plating.

The drilling of micro-vias involves a laser machine because their size has to be small which is not easy to create through mechanical drilling. Micro-vias are ideal for thick PCBs. Plating of the holes is also essential to provide electrical connections.

PCB laminating press needs a vacuum to prevent PCB voids to hinder the dielectric property, affecting its structural strength. The environment after pressing also needs to be considered to prevent any damage due to weather conditions.

Would like to know more about the Drilling, Lamination, & Plating or smt assembly? Email us at sales@pnconline.com

Why printed circuit board manufacturers use plated slots ?

Printed Circuit Board Plated Slots

Slots are holes, which are either plated or non- plated-through. So, plated slots are holes plated in copper. And we use them for electrical connections on the PCB. A through slot is the one that goes to the entire depth of the board, starting from one end to another. Whereas a PCB outline or edge also has plating called side plating.

printed circuit board manufacturers use plated slots for components packaging, however, non-plated slots are also in practice. But, PCB with multiple layers have only plated-through slots.

Why Prefer Plated Slots?

PCB assembly involves different designs and components, and you would often see round holes to accommodate the round components or square as well. A round hole suits a PCB with through-holes. However, certain components are compatible with the blade or rectangular leads, so the round or square holes are not ideal in that case, and this is where a plated slot works.

When the pin size becomes large, the rectangular connectors work with plated-through slots rather than round holes. Like, they are ideal for the DC Jacks. Though you can use the round holes for small connectors and rectangular pins, plated slots are better because they take less space on the PCB, unlike the round holes.

Difference between Plated And Non-Plated Slots

Plated slots have copper plating in the circuit layer, whereas it opens in the solder mask.
On the other hand, non-plated slots don’t have copper plating in the circuit layer, besides, it does not open in the solder mask.

Design of Plated Slots

There is a specific way to show plated holes on the Gerber, like:

    • You have to put the copper pads on the upper and lower solder mask.
    • Then you insert a milling slot in the mechanical layer.

Designers prefer a mechanical layer to put slots in the Gerber and it involves two possible options to do it.;

Use of Flashes Having the Right Size Slot

Drawing a slot with a 0.50 mm thick line, as it helps designers to check it visually to ensure that there is enough tolerance between copper and the PCB edge. Remember that a line’s center is considered the edge of the slot.

Then you have to join the slots with the PCB outline into the Gerber, and it should be parallel to the copper layer. However, the copper layer should also have a PC Board outline to stay on the safer side.
The mechanical layer in this case has different names, depending on the system. It also depends on milling as it should be there. However, you can use another layer in the absence of a mechanical layer. Use the README file to avoid any doubts regarding the right file.

Don’t always define slots in a legend or a copper layer because they could be misinterpreted. Show large slots in the legend or copper layer, however, the outline should be precise. Don’t forget to write the text SLOT in the center.

Creating a Drill File

You can also define the plated slots through drill files as it is a precise way, however not all CAD software allows this option. But, defining through the drill files involves the X and Y or the slot width and length, instead of a complete row of holes that overlap.

Understanding A Small Slot In The PCB

The size of the smallest slot varies, depending on the type of the PCB, like if it’s flex, rigid, or rigid-flex. The width of the smallest slot is 0.50 mm for a rigid and flex-rigid PCB, and the length is often 1.0 mm.

These sizes are so due to more thickness of the PCB, besides, the slots are created through the NC milling that is mechanical. As, the grooving cutter of NC is 0.50 mm and its length is twice the width, like 1.0 mm.

On the other hand, the thickness of the flex PCB is less, and you can make slots through a laser machine. Designers prefer the smallest slot because the bigger slot’s length becomes more which is twice its width.

Milling Of the Cutouts Or Slots

You have to use the round NC grooving bit for the milling of slots in the rigid PCB, and it’s just like the CNC machine. However, the inner corners of the slots are made round instead of sharp. Whereas the PCB edge is created to the center of the border.

Which Industries Can Use the Plated Slots?

Mostly the thick or multilayer PCBs have plated slots, and such boards are ideal for different industries, including aerospace, consumer electronics, computer, and telecommunications. As these slots don’t take much space, they are cost-effective in terms of making. A board with both plated slots and round slots is also ideal for multiple electrical connections.

Frequently Asked Questions

What Is A PCB?

PCB stands for a printed circuit board having different electrical components, holes, and other features. Various industries use PCB boards to provide the electrical signals to run different devices or electronics. A PCB board can be embedded, single or double-layered, or can have many layers like up to 60 plus.

What Is The Definition Of A Plated Slot?

A plated slot is a hole in the PCB with copper plating. It is not round, so it is ideal to accommodate the leads with rectangular pins. You can use such a slot for electrical connections and component packaging
The slot goes throughout the circuit board that’s why we call it a plated-through slot.

What Is Edge Plating?

If plating is done on the edges of a PCB, we call it edge plating. Besides, you can also call it the side plating of a circuit board. It goes from the upper layer to the lower layer of the PCB, extending to an edge of the perimeter.

Which Circuit Board Should Have Plated Slots?

Generally, the multilayered PCBs have slots with plating also known as plated-through slots. However, there are also non-plated slots, depending on the PCB design and its application.

Do I Need A Lot Of Space For Plated-Through Slots?

Plated slots are mostly rectangular, hence they don’t take much space on the PCB like the round slots. So, such slots are ideal when you run short of space on the PCB, and where you need to use the rectangular Jacks.

What is a Copper Layer?

PCB has different layers of which one is a lamination made of copper foil, and it is attached to the circuit board with some adhesive. The copper layer is essential for a two-sided PCB, including copper on both sides. But, PCB boards with more than 60 layers of copper are available by different companies.

What is Solder Mask Layer?

The green color on the circuit board is a solder mask and its surface is called the solder mask layer. The purpose of the solder mask is to cover the exposed copper to prevent users from the electric shock upon contact. Though it is mostly green, other colors are also available.

Final Thoughts

PCB manufacturers use plate slots for components packaging, however, the non-plated slots are also in practice. But, PCB with multiple layers has only the plated-through slots. Certain components are compatible with the blade or rectangular leads, so the round or square holes are not ideal in that case. This is where a plated slot works.

Plated slots have copper plating in the circuit layer, whereas it opens in the solder mask. Non-plated slots don’t have copper plating in the circuit layer, besides it does not open in the solder mask.

The size of the smallest slot varies, depending on the type of PCB, like if it’s flex, rigid, or rigid-flex. The width of the smallest slot is 0.50mm for rigid and rigid-flex PCB and the length is often 1.0 mm. Engineers use cad software to make Gerber files for different types of slots including plated through and non-plated through slots.

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