Tag Archives: Printed Circuit Board Fabrication

Printed Circuit Board

Printed Circuit Board Heat Sink Features/Functions

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Heat management is essential for living on this earth as weather and devices affect buildings, vehicles, and equipment. Thermal management is also necessary for printed circuit boards, as they will get damaged if they can’t dissipate the heat their components generate. Besides, the board also gets hot due to soldering during manufacturing. Hence, heat dissipation methods become mandatory to increase the PCB speed.

Though FR4 is good at heat management, sometimes it is not enough when there is a high-speed circuit board. Likewise, the power supplies also generate heat and you have to install heat sinks and insulators. You must have experienced mechanical engineers to assess the heat flow to create a suitable heat dissipation system.

Printed circuit boards provide current to help devices function, but electronic devices get hot and heat sinks dissipate unnecessary heat. A PCB Manufacturer will use different heat sinks to prevent the overheating of PCB components and their damage, increasing the performance of the board.

Fourier’s law is an important law of heat that determines the heat sink function. When an element gets hot, heat travels from high-temperature areas to a low- temperature surface. The heat transfer occurs in three ways, such as:

  • Conduction
  • Radiation
  • Convention

When two components having different temperatures connect, it results in thermal conduction. In other words, fast molecules collide with slow molecules, resulting in heat transfer from hot components to cool components. PCB has high-temperature components like transistors, so you need to dissipate heat to cooling mediums, like water, air, or it can be oil, or some other element. This heat transfer occurs through conduction and convention.

Types of Heat Sinks

Heat sinks come up in different types as below:

Active Heat Sinks: There is a fan in an active heat sink to provide cooling. Such a heat sink provides great cooling, however, it needs regular maintenance as it is mostly running which affects its condition.

Passive Heat Sink: Passive heat sink is without a fan, so it remains still and needs less maintenance. You can consider it reliable and more effective than an active heat sink.

The shape and design also determine the type of heat sink, including swaged, stamped heat sinks, machining, folded and bonded fin, single fin sink, and forged heat sink.

Factors Affecting a Heat Sink

The main purpose of the heat sink is to exchange heat, so a large part of its surface area should be in contact with the cooling component like air. The quality of the heat sink depends on different factors, including its material, finishing, and certain physical features, like:

  • Air velocity
  • Attachment technique
  • Protrusion type

    Materials That Enhance Heat Sink Function

Manufacturers use specific materials to enhance the function of the heat sink in terms of heat transfer. These materials include:

  • Compounds
  • Conductive tape
  • Thermal paste

These materials are inserted between the surface of the heat sink and the surface of the component that generates heat. Metals having high thermal conductivity are ideal for heat sinks, including aluminum, copper, etc. But, aluminum is common as it is cheaper than others.

What To Consider Regarding Heat Sinks

Many factors affecting heat sink function include length, fin spacing and density, width, airflow, heat resistance, etc.

Which Devices Need Heat Sinks?

Electronic devices with components having poor heat dissipation ability need heat sinks. The devices in this case include multiple integrated circuits, diodes, transistors, switching devices, CPU and graphic processors, and LEDs.

Key Factors of Heat Sink Design

Heat sinks dissipate heat with the help of natural and forced convection, liquid, or radiation. The requirements of thermal management vary, depending upon the applications. Apart from a heat sink design, you have to consider several other factors while designing a thermal management system for a specific device. For like, you have to consider the standards of the component level, heat sink level standards, chassis levels, and requirements for a system level.

Let’s discuss essential factors that you have to consider during heat sink PCB design.

Heat Resistance: Thermal or heat resistance is the sum of multiple resistances occurring to heat flow between a cooling liquid and the die, thermal interference resistance, as well as the resistance between a moving fluid and a heat sink. Thermal resistance is bad for thermally unstable modeling systems.

The Value of Thermal Resistance: It is not precise, instead, it is approximate. It helps evaluate the thermal conductivity of the heat sinks and semiconductors. Heat dissipation depends on heat sink parameters that need proper analysis while designing the heat sink device. Heat sinks can be meshed through a 3D thermal resistance to have a complex system of thermal factors. Different platforms help design heat sink meshes.

Heat Sink Materials:  Generally, copper and aluminum are ideal heat sink materials as described above. These materials are good at conducting heat, especially copper as it also helps absorb heat, resists rust, and resist biofouling, moreover, it is also antimicrobial resistant. Though copper is better than aluminum, it is thick and costly compared to aluminum.

Another material is diamond and its thermal conductivity is also high due to the lattice vibrations it has. Some other materials for thermal applications include copper-tungsten pseudo-alloy, and AlSiC, Dymalloy.

Size and Shape of Heat Sink:  The shape and the size of the fins also help enhance heat dissipation. You can evaluate various fin shapes through modeling.

Fin Placement or Location: The arrangement of fins in a heat sink affects its cooling quality. Its configuration should be optimized to minimize the resistance of fluid movement, providing maximum air in the heat sink.

Cooling Quality: The cooling quality of the heat sinks has to be high. The aspect ratio of fins should be less to perform well. If the distance of the fin from the heat sink base is more, it will reduce the heat transfer to a cooling medium.

The function of the fins in a heat sink is to absorb heat from the electrical components of a device and sends it to the cooling medium. Besides, you should choose a cooling medium matching a PCB design and device requirements.

Heat Dissipation: Certain factors reduce the heat sink performance like a rough surface and gaps. They cause high resistance to thermal contact, thus affecting heat dissipation. You can reduce such thermal resistance by using thermal interface materials because most resistance-reduction techniques have limitations. You should consider specific things while selecting a thermal interface material, such as contact pressure, the material’s resistivity to current, and the dimensions of the surface gaps.

Attachment Methods: The attachment of the heat sink with PC Board components affects its thermal efficiency. So, you should choose the attachment technique carefully, considering the requirements of a thermal management system in terms of mechanical and thermal properties. Some popular attachment techniques include,

  • Thermal tape
  • Standoff spacers
  • Flat spring clamps

However, these attachment methods don’t end here as there are many others. You would also see m rein the future as engineers continuously update these methods according to new technologies.

By considering the above factors, engineers can design an effective heat dissipation system, including a heat sink.

Frequently Asked Questions

What Is Heat Sink?

The heat sink is a device and a way to manage heat in electronic products. Electronic components like transistors release heat, and you need heat sinks to dissipate heat to cooling mediums, like water, air, or it can be oil and other elements.

Do All Electronic Devices Need Heat Sinks?

Most devices need heat sinks to dissipate heat to cooling components. However, some electronic components have a built-in ability to dissipate heat. Generally, lasers or power transistors can’t transfer heat and need a solution to manage heat. MOSFETs and IGBTs are good examples in this case. So, here you need a heat sink device. 

Can PCB Survive Without Heat Sinks?

PCB components release heat which can damage them, making the electronic device slow. However, it also depends on the PCB materials as some have their heat dissipation property. Mostly you need a cooling system to enhance PCB performance. 

What Are The Types Of Heat Sinks?

The basic types in this case include the active heat sink system and the passive heat sink system. Some other types are also popular, like swaged heat sinks, stamped heat sinks, machining, folded and bonded fin, single-fin sinks, and forged heat sinks. 

Which Factors Influence The Heat Sink Design?

Many factors affect heat sink design, including its material, fin shape, and performance, fin size and location fin configuration, attachment technique of heat sink, and finally the thermal interface.

Final Thoughts

Devices having PCB also have heat sinks because they get hot due to high temperatures caused by different components. Heat sinks are either active or passive. You have to consider a few factors while designing the heat sinks, like its material, fin shape, and performance, fin size and location fin configuration, attachment technique of the heat sink, and finally the thermal interface. Various models help determine the heat sink parameters and geometry to provide a high-level heat transfer.

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Metal Core and Metal Black Printed Circuit Board

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Printed Circuit Boards are a crucial component of any electronic device, but the materials used to manufacture them can significantly affect the performance and durability of the device. Metal core and metal black PCBs are two types of PCBs that offer numerous benefits over standard FR-4 PCBs. Here, we will explore the advantages of using metal core and metal black PCBs in electronic projects. We will discuss how they can improve their performance and reliability,   as well as their suitability for a variety of applications.

When it comes to a circuit board design, the metal core and metal black printed circuit boards offer a number of advantages over traditional PCBs. These benefits include improved heat dissipation, increased strength, electrical isolation, and reduced electromagnetic interference (EMI).

The use of the metal core and metal black printed circuit boards is a great way to improve the performance of your electronic devices. This type of PC Board provides excellent electrical and thermal conductivity, making them ideal for applications that require more power, speed, and accuracy. Metal core and metal black PCBs are also more resistant to environmental factors, such as temperature changes and corrosion, making them a better option than traditional PCBs.

What Are The Benefits Of Metal Core PCB?

Metal core PCBs are gaining popularity in the electronics industry due to their many advantages over traditional FR-4 and other standard PCBs. Metal core PCBs feature a dielectric layer, which is made from metal instead of a traditional fiberglass-epoxy material used in other PCBs. Such a metal core serves as a heat spreader and helps have better heat dissipation and improved thermal performance. This makes them ideal for applications that require high-level dissipation, and large temperature ranges.

The metal core also allows for a much thinner board than can be achieved with standard PCBs, reducing the overall weight of the assembly and making it easier to integrate into the design. As the metal core increases the rigidity of the board, it reduces the possibility of warping or cracking due to vibration and mechanical shock.

The copper layer used on the MCPCBs is often thicker than on standard boards, providing increased electrical performance as well. The additional copper layer also adds greater protection against EMI (electromagnetic interference), making them ideal for high-frequency and wireless applications.

Another benefit of metal-core PCBs is that they are more reliable than standard PCBs. As the metal core has better thermal conductivity than traditional fiberglass epoxy, it reduces the risk of solder joint failure due to overheating. This means that components are less likely to fail due to excessive heat, resulting in greater reliability.

Overall, the metal core PCBs offer many advantages over traditional PCBs, making them ideal for applications that require high power dissipation, thin boards, or robust performance in harsh environments. While they may cost more upfront than other types of PCBs, the benefits that come with using the MCPCBs often outweigh the costs in terms of improved performance and reliability.

For anyone looking to upgrade an existing project, or build one from scratch, there is never been a better time to consider switching to the metal core. If you’re looking to improve your product’s efficiency and reduce downtime, switching to a metal core PCB, maybe the right move for your next project.

Metal core PCBs are a special type of printed circuit board that uses metal instead of the traditional epoxy resin-based substrate. Metal core PCBs provide many advantages over their traditional counterparts, such as increased heat dissipation and better performance in higher-power applications. However, metal black PCBs offer a slightly different approach.

Metal black PCBs are constructed using metal cores that are plated with a black finish. This black finish helps reduce the emission of electromagnetic interference or EMI that can interfere with sensitive electronic components and impair their performance. Besides, the black finish helps absorb heat, which is beneficial in high-power applications.

The black finish also helps to prevent corrosion in the PCB itself, which can cause premature failure of the PCB over time. Moreover, the black finish increases the electrical resistance of the PCB, which can help protect against the short circuits caused by sudden changes in the voltage.

Finally, the metal black PCB offers an aesthetically pleasing look and a more rugged construction than a traditional printed circuit board. This makes the board ideal for a variety of applications that require superior durability, such as outdoor or industrial environments.

Overall, both metal core and metal black PCBs offer distinct advantages when compared to traditional printed circuit boards. While metal core PCBs provide greater heat dissipation and performance in higher-power applications, metal black PCBs offer superior protection against EMI and corrosion, as well as a more robust design for difficult environments. Ultimately, the choice of which type of PCB to use will depend on the specific requirements of the application.

For instance, if the application requires a higher level of heat dissipation and power output, then metal core PCBs may be preferable. On the other hand, if low levels of EMI emissions and protection against corrosion are desired, then metal black PCBs may be more appropriate. The final decision will ultimately depend on the specific needs of your project.
Which Type Of PCB Is Right For My Project?

When it comes to selecting the right type of PCB for your project, there are a number of factors to consider. One important factor is the type of material used for the PCB. Metal core and metal black PCBs are two popular options for many projects. Each one offers its own unique benefits, so let’s take a closer look at what each has to offer.

Metal core PCBs are constructed with an insulated metal substrate layer sandwiched between two layers of copper. This metal substrate layer helps conduct heat away from the board more efficiently than other PCB types, making it ideal for applications that generate high levels of heat. MCPCBs are also more resistant to temperature fluctuations, which makes them well-suited for automotive and avionics systems that need to perform reliably in changing environments.

Metal black PCBs are a specialized type of MCPCB that offer additional protection against an electrostatic discharge. Such boards contain an integrated layer of insulating polymer that is laminated over the metal core and then coated with a black solder mask. This makes metal core PCBs well-suited for electronic equipment where electromagnetic interference or electrostatic discharge (ESD) could damage the components.

When it comes to choosing the right type of PCB for your project, both MCPCBs and MBPCBs have their advantages and disadvantages. If you need a PCB that can handle high temperatures, then an MCPCB is the right choice. If you need a PCB that provides additional protection against EMI/ESD, then an MBPCB is the better option. Ultimately, it’s important to carefully evaluate your project’s requirements before deciding on which type of PCB is best for your needs.
FAQs
Why DO Manufacturers Us Metal Core And Metal Black PCBs?
When it comes to the design and manufacture of printed circuit boards, there are several advantages to choosing a metal core or metal black PCB. From improved thermal dissipation and electrical conductivity to better environmental protection and durability, these types of boards offer an array of benefits that cannot be achieved with conventional FR4 boards. Not only can metal core and metal black PCBs help reduce costs in the long run, but they can also enable more efficient product designs.

Overall, it’s clear that the benefits of using a metal core or metal black PCB greatly outweigh the costs.

What Is A Metal Core PCB?

Metal core PCB is a special type of printed circuit board that uses metal instead of the traditional epoxy resin-based substrate. Metal core PCBs provide many advantages over their traditional counterparts, such as increased heat dissipation and better performance in higher-power applications. However, metal black PCBs offer a slightly different approach.

What Includes In A Metal Core PCB?

The structure of a metal core PCB has multiple layers, including the circuit, copper, metallic, and dielectric layer, as well as the solder mask.

Wrap Up

In conclusion, metal core and metal black PCBs offer a range of advantages for designers and manufacturers. They provide superior heat dissipation, improved mechanical strength, longer product lifecycles, and improved EMI shielding properties. These advantages can help reduce costs and increase the longevity of the products, leading to improved customer satisfaction and increased profits.

Whether you are looking for increased performance, durability, or functionality, the metal core and metal black PCBs offer an ideal solution. The exceptional benefits these materials provide make them an ideal choice for engineers designing high-end applications.

With their ability to improve product performance while reducing production costs, the metal core and metal black PCBs should be seriously considered when designing a printed circuit board. With so many different varieties available, the sky’s the limit.

Would like to know more about the metal core and metal black PCB or printed circuit board assembly? Email us at sales@pnconline.com

Drill, Lamination, and Plating of PCB Design

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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

Six Basic PCB Design Principles

Six Basic PCB Design Principles

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Printed circuit boards are vital parts of smart devices and several equipments as they provide current or electrical signals to run them. You need different elements to construct a PCB, such as:

  • Schematic design
  • Database login
  • Electronic component configuration
  • Design preparation
  • Wiring
  • Block division
  • Testing

If any issue happens during a process, you have to go back to the previous process to correct it. The layout of PCB components is a complex thin as it determines a board\s appearance and neatness. Moreover, it also affects the function of the end product or device. We will discuss below the six basic PCB design principles in terms of its components and other factors.

1-Components Layout and Clearance

You have to place the components evenly on the board, leaving some space on the edges. The components around the edge should be 3mm away from PCB edges. In general, designers leave 5 to 10 mm space around the edges.

The components should be only on a board’s one side. There should be a separate pad for each lead pin.

Don’t cross up and down the components’ layout and keep a certain distance between the nearby components on the board. However, this distance should not be too small as it can hinder PCB maintenance.

Components should be installed at a low height and its lead should not be more than 5mm away from the PCB, as it can affect its quality to bear vibration.

Printed Circuit Board components that reside on a pad’s both ends must be a bit larger than their axial dimensions. The pads should be located where the coordinate grid intersects. The central distance of the pad has to be more than the board thickness to have a neat layout.

According to IEC or International Electrotechnical Commission, the standard spacing of the coordinate grid should be 2.54mm, whereas the axillary spacing should be 1.27mm.

However, these standards practically impact a few processes, including automatic drilling, computer automated design, components welding, and automatic assembly. But, such a grid spacing is not restricted in the case of manual drilling.

2-Defined Solder Mask

Solder mask expansion should be well-defined as it can cause issues if you over-define or under-define it. Tombstoning may happen if you don’t define the solder mask properly. Like, one side cools down faster than another side, affecting the board. So, by following the right parameters, you won’t have to revise your design.

The solder mask opening should be larger than the pad. In general, it expands 4 mils or 0.1mm. However, both can also have the same size, depending on the Printed Circuit board Fabrication.

3- Via Type& Routing Width

You must use the right via for routing as it won’t work if its diameter or ratio is not precise. The current won’t pass correctly due to fused vias. So, via styles should be considered while routing the entire PCB.

The routs should have enough width to carry the current that your device requires. You must have an impedance-controlled routing that needs various impedance profiles. You have to apply these profiles to routing widths to ensure a functional layout. Don’t have routing at an acute angle even if the signals have a low speed as acute angle hinders manufacturing. Like, an acute angle can increase the corrosion, leading to an open circuit.

Whereas it is vital to avoid the acute angle in the case of high-frequency circuits because it fully changes the track width at the corners and results in poor signals and discontinued impedance.

Six Basic PCB Design Principles
Six Basic PCB Design Principles

4-Components Installation

Different PC Board components are installed either vertically or horizontally. The horizontal components are parallel to the surface of the circuit board. Whereas in vertical installation, components are perpendicular to the PCB surface.

Vertical components allow you to have more quantity on a board’s surface. It is ideal for hearing aids, semiconductor radios, portable instruments, or devices that need a dense placement of components. For vertical installation, components have to be lightweight. Don’t install heavy components in a vertical direction as it can affect a PCB’s mechanical strength. Moreover, it causes vibration, and components can collapse, making a circuit less reliable.

On the other hand, the horizontal installation provides mechanical stability, and the circuit board also looks neat. It also helps lay down the printed wires because it enhances the elements’ span.

You can use any installation method, depending on your needs but make sure to arrange components evenly and the circuit should be anti-vibration.

5-Considering The PCB Layout Type

PCB layout has either a regular arrangement of components or is irregular. In an irregular format, the axis of the components are not aligned with each other, so it seems messy. However, it helps lay down the printed wires easily as there is no restriction of direction. Such a layout is ideal for high-frequency circuits and involves a vertical installation.

Whereas in a regular format, the component axis is aligned and either parallel or perpendicular to the sides of a PCB. It provides a neat board and makes certain processes easier, like PCB assembly, debugging, welding, maintenance, and production.

Moreover, a regular format is ideal for low-frequency circuits where the board has a few component types and its surface is loose. However, the number of components is high and such an arrangement also suits electronic instruments. But, due to the direction restrictions, such a PCB has a complex layout of wires, increasing the overall length of the wires.

6-Factors That Affect the PCB Layout

You also have to consider the factors that affect a PCB layout, like the direction of the signals, device position electromagnetic interference, thermal interference, mechanical strength, etc.

  • Generally, the direction of the signal flow is from left to right of which left is the input and right is the output. It is also from top to bottom of which the top is the input and the bottom is the output. Connectors which are in direct connection to the input and output should be close to the input and output connectors. Integrated circuits or transistors should be the core components. Whereas other components should be located according to their electrodes’ location. You should also consider the size, a number of pins, shape, and polarity of components.
  • You should adopt certain ways to prevent electromagnetic interference that occurs due to different external factors, like spatial electromagnetic ways, poor wiring, poor installation of components, etc. You can avoid these issues during the layout design. But, interference will happen if the PCB design is not right
  • You should shield the components that interfere with each other. High-frequency components should have small wiring. Similarly, the components of weak and strong currents should be separated. Wires with high potential should be at a great distance to avoid 50Hz interference. Likewise, the metal components should not be adjacent or they should be well-insulated to avoid a short circuit.
  • While designing a PCB, you must know which components are temperature sensitive and which are heat components. The heating components like resistors should be located near the shell or near vent holes to dissipate heat. Don’t place many heating components near each other. Also, use fans or radiators to prevent the rise in temperature beyond its limit.
  • Whereas the temperature-sensitive components should be away from the heat source. In general, integrated circuits, transistors, electrolytic capacitors, and thermal components are temperature sensitive. These components get affected due to the rise in temperature, especially in a circuit’s long-term operation.
  • The board should also be mechanically strong and its center of gravity should be stable. Don’t install heavy or heating components directly on the board, instead, they should be under the chassis to have a stable board. If the board size is above 200mm it will cause mechanical stress, so it should be strengthened with a mechanical frame.

Finally, many PCB design software uses the power layer to have a fast design process. You can connect more wires to ensure the current has a minimum impedance or voltage drop down, thus giving enough ground return paths.

FAQs

1.How To Layout A Printed Circuit Board?
You have to follow certain steps to create a PCB layout. Such as making the schematic drawings, developing a blank PCB layout, creating a PCB stack-up, schematic capture, defining design principles, defining DFM, linking to PCB, placement of components, inserting drill holes, and the route traces.

2.Is It Hard To Design A PCB?
It is not hard to design your PCB if the electrical schematic is right. Besides, following the design parameters also makes the design process easy.

3.Why Is My PCB Green?
The color of the solder mask determines the PCB color. So, if the solder mask is green, you say that PCB is green. The solder mask shields a copper circuit to avoid shorts circuit or soldering issues.

4.What Is The Purpose Of Following PCB Design Rules?
PCB design rules or principles help you to develop a system to automate the testing of design requirements. You get an interface between the physical and logical sides to create a circuit board. So, you can automate the DFM tests by following the rules to ensure that you can build a PCB.
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Metal Core PCB Design & Manufacturing Concepts

Metal Core PCB Design & Manufacturing Concepts

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Metal core PCB consists of a layer of thermal insulation, copper foil, and metal plate, and you can also call it MCPCB. The basic benefits of metal core PCB include:

  • High magnetic conductivity
  • Great heat dissipation
  • Excellent mechanical strength
  • Easy processing

The base layer of the MCPCB is copper and aluminum, and you can choose to have any of them. Aluminum PCB is cheaper than copper, and you would find them in LED lights, mobile phones, and audio-frequency equipment. However, copper is better than aluminum in terms of performance. MCPCB was developed to overcome the heat dissipation issues occurring in high-power LED lights.

Things To Consider While Designing The Metal Core PCBs

The construction of the MCPCB stack-up depends on certain guidelines that we will discuss here. Such boards consist of a specific base layer, such as aluminum, copper, or even steel. You will have to determine the layer arrangement after selecting your desired metal and dielectric laminates. The type of the layer will determine other aspects, such as components and routing.
MCPCB has different types, depending on the number of layers as single-layer, double-layer, or multiple-layer metal core circuit board.

What Is A Metal-Backed PCB?

This Printed Circuit Board has a metal layer on its back, whereas the opposite layer has electric components. You can’t route traces on the back, however, through-holes are possible for routing between different dielectric layers, bringing ground to the metal substrate.

Metal Core PCB Routing

In the case of a double-side PCB, you can place through holes for routing between the metal core’s sides. You can use the multilayer dielectric stacks on the metal core’s sides to support different layers’ routing.You should ground the metal substrate for shielding, and to prevent it from acting as a monopoly antenna.

MCPCB Applications

Metal core circuit boards are ideal for aerospace and military industries that involve mechanical shocks, as well as high moisture and temperatures. So, MCPCB helps meet such requirements because they have a strong structure and a high thermal conductivity compared to PCB having an FR4. Such highly conductive circuit boards ensure an equal distribution of temperature when there is thermal cycling. So, it does not let the hot spots make closed components.
Metal core PCBs are also suitable for electric products which should work at high temperatures, such as high-current regulators, automotive electronics, and high-power LED lighting. The design of such applications depends on a precise stack up, and the board architecture should perform high at a low temperature.

Metal Core Printed Circuit board Fabrication Process

As there is a metal substrate in the stack up, such PCB involves a specific manufacturing process.You can use the FR4 dielectric in the case of a single-layer board by pressing the layer and bonding it to the metal plate.
If it’s a stack-up with a multilayer dielectric, you should first drill the metal core to have a layer transition independent of a short circuit. In the beginning, large holes are made and plugged with the insulating gels.Then, the gel has to be cured to make copper plating like a standard PCB. After that, you have to press and bond the remaining stack-up with the metal substrate. The stack-up needs through-holes followed by copper plating and residue cleaning.
The single-layer metal core circuit board has a metal base, copper layer, non-conducting or dielectric layer, solder mask, and IC components. Most thermoelectric separation applications consist of a COB or Chip-On-Board metal core circuit board,
It has two layers of copper conductor and both are on the metal core’s same side. Whereas the 2L MCPCB also has the metal core between two conductors, and designers call it a double-sided metal core circuit board.

Metal Core PCB Design & Manufacturing Concepts
Metal Core PCB Design

How to Select the MCPCB Components

It is essential to decide what components to choose when designing printed circuit boards as it can affect the final product. Such electronic components have different shapes and sizes, different power consumption specs, weights, and several other elements.
If you know how to choose PCB components efficiently, it can prevent big mistakes during design. We will help you in selecting the right components for your metal core PCB design.

You have to use certain design software tools to source the MCPCB components. These tools are necessary for all types of circuit boards, including a board with FR4, a rigid-flex circuit board, or a metal core board.
The surface mount technology is suitable for placing the components because it involves a minimum shorting to the metal substrate.You can also use the through-hole components,but you have to be careful to ensure that the solder mask does not get damaged on the back of the metal-backed PCB.
PCB fabrication involves multiple steps and the right design can enhance this process, preventing unnecessary design revisions.The manufacturer should have all documents having the fabrication details of the MCPCB.
Other than using metal cores, some passive techniques also help keep a circuit board cool through thermal management.

Designing MCPCB In A Closed Environment

The design of a multilayer PCB can become complex without compatible design software. You require the layout design tools for precise placement of the components, vias, routetraces, electrical, and thermal load crosscheck, etc.
You must have a good library of materials while designing the MCPCB. Likewise, the PCB layer-stack manager is required to handle your board’s structure. A suitable stack-up manager helps you to design a stack-up with an appropriate placement of the metal core, be it symmetric or asymmetric. Once the dielectric layers are defined, you need some groundwork for route traces and components’ placement.

Choosing The Design Software For PCB Layout

Different software help develop the PC Board layouts but make sure to choose the suitable one such as Altium. It helps you to have very precise CAD features to place the components. It also makes routing simple through special routing tools, whereas the layout engine helps ensure that the MCPCB is according to the design guidelines.
Remember that suitable software includes the 3-D design features to help you to design the complex mechanical parts of the MCPCB. You can also share your design with others through Altium 365, a cloud platform

Parameters of a Multi-Layer MCPCB

The design parameters of aluminum PCB sare described below.

  • Desired Aluminum thickness is 0.8-2.0mm
  • Solder resistance should be 288℃, >180 sec.
  • Breakdown voltage should be >3000v
  • The dielectric loss angle should be 0.03
  • Flammability should be UL 94V-0
  • Thermal conductivity should be 1.5W and 2.0W
  • Peeling strength should be >9lb/in

The minimum drilling diameter should be 1 mm in the case of an aluminum core, and the final diameter can be up to 0.3mm. There should be at least 1.2 mm spacing between the drill holes to avoid any damage.
Metal core PCB is also useful in several other areas having high mechanical loads where the dimensional stability should be high. Moreover, you can use it for electric vehicles, backlight units, automotive, audio systems, traffic lights, commercial buildings’ lighting, and solar panels.

Important Note

The digital devices depend on printed circuit boards for signals transmission to help them operate. These devices need a well-designed structure and manufacturing, but you have to encounter many issues in this case that we will discuss here. Circuit boards have different types and any issue in the design of a PCB would cause delays in its manufacturing, so you must know how to avoid them.

FAQs

What is A Metal Core Printed Circuit Board?
Metal core PCB has a metal base, such as aluminum, copper, or steel of which aluminum and copper are common.
Which One Is Cheaper, MCPCB with Aluminum or Copper?
MCPCB with aluminum is cheaper than copper. But, copper is better in terms of performance.
How Many Types of Metal Core Circuit Boards are there?
MCPCB has different types, depending on the number of layers, such as a single-layer, double-layer, or multiple-layer metal core circuit board.
Where Can I Use The Metal Core Circuit Board?
Metal core PCB is also useful for electric vehicles, backlight units, automotive, audio systems, traffic lights, commercial buildings’ lighting, and solar panels.

Wrap Up

There are several benefits of metal core PCBs, such as high magnetic conductivity great heat dissipation, excellent mechanical strength, and easy processing. The base surface of the MCPCB is copper and aluminum, and you can choose to have any of them. Aluminum PCB is cheaper than copper, and you would find them in LED lights, mobile phones, and audio-frequency equipment. But, copper is better than aluminum in terms of performance. Metal Core PCB was developed to overcome the heat dissipation issues occurring in high-power LED lights.
The design of a multilayer PCB can become complex without compatible design software. You require the layout design tools for precise placement of the components, vias, route traces, electrical, and thermal load crosscheck, etc.
Would like to know more about Metal Core PCB or pcb assembly services? Email us at sales@pnconline.com