Tag Archives: PC Board

smt-assembly

SMT Assembly and Thru-Hole/Chip Functionality

Printed circuit boards are parts of various electronic devices, home appliances, and vehicles. The function of these green chips depends on their material and assembly technology. Each step of PCB assembly is important and needs careful processing considering essential features.
Two methods are popular in PCBA, including, MT and THT. Let’s study them in detail.

Through-Hole Technology (THT)

Traditional PCB has through whole technology, involving both automatic and manual processes. THT is PCB packaging technology that involves pins or leads, besides, you have to insert the chips in the PCB through holes, soldering from below. The technique gives it the name through-hole.
Through-hole technology was more in practice till 1980 and every PCB device had this technology. Then SMT emerged where chips are installed on the surface. However, some PCBs still need through-hole chips, like capacitors and resistors.
THT needs more drilling, however, the device with this technology has a durable bonding with the circuit board.
Let’s look at the important steps of THT.

Installation Of Components

Engineers place PCB components with their hands, however, it needs precision depending on the design.
PCB Inspection
PCB inspection is crucial because most devices need flawless PCBs to work well. Most of the through-hole process is manual, so you have to make sure that the assembly is without any mistakes.
Printed Circuit Board Soldering
Soldering of components is also important as you have to fix the components manually. This is the last part of assembly, and the manual work makes it more reliable than SMT.

Why Is THT Still In Use?

Though THT is an old PCBA technology, you still need it for certain reasons, such as:

  • Even a hobbyist can assemble a circuit board with THT by using a soldering iron. It involves less hassle because the holes are away from surface pads compared to SMT.
  • If you observe a hobbyist application of the THT circuit board, you will see the ICs with the 8 or 14-pin having centers up to 0.100”xp.300”. Sometimes even the DIP processors have such spacing between the holes that helps in manual soldering, making the PC Board assembly easier.
  • After assembly, the troubleshooting or revision reduces in THT because it does not involve bridges between the pins, be it single or multiple components.
  • THT has better professional assembly, especially when a project is at a prototype stage. You can apply the through holes in a prototype layout to assemble the board faster.
  • After evaluating the board function, you can swap in the SMT having the same value, revising the circuit board’s layout. The new layout has small footprints to be inspected before final production. Such techniques reduce the front cost of a project which can benefit a subcontractor.

Remember that small products demand more pricing from outside vendors as they prefer high-volume production for continuous machine work.

Benefits Of Through-Hole Technology

  • When it comes to PCB design revision, a through-hole technology doesn’t need to create an additional solder stencil. So, manufacturers can save a huge amount of money on a PCB design having 2 to 3 revisions before it is ready to use. Besides, you don’t have to arrange the equipment for the pick and place function.
  • The manual inspection of a small lot of printed circuit boards reduces the fixture expenses or any other cost regarding linked setups.
  • Soldering is also cheap in THT, such as the tin-lead solder. Besides the issue of HASL or hot air solder leveling does not occur in through-hole technology, unlike SMT where the HASL makes it hard to place the components having a precise pitch.
  • You can easily assess the mechanical faults, including twists, and warps, and can deal with them while redesigning without affecting the assembly as what happens in SMT. Issues like twist and warp are not as problematic in manual assembly as in SMT.
  • The hand assembly of a PCB helps fit hard components by changing the wrist angle. Whereas the automated assembly needs an extremely flat circuit board for proper functioning.
  • THT can help pinpoint mechanical faults before it gets hard to resolve them. Otherwise, the inspection becomes costly when it has to go into the hands of three persons, including you, the contract assembler, and the PCB Manufacturer.
  • The components for THT are easily accessible that keep the job going without interruption. Moreover, you don’t need a third-party assembly in the case of small production.
  • With THT, the project timeline is predictable and easy to manage with minimum issues without causing any production delays.
  • Even if you don’t want to prefer a through-hole assembly, you must consider it as a temporary solution at early stages like validation and development. So, it can benefit anyone, including a hobbyist, any established company, or a beginner in this industry.

Surface Mount Technology-Surface Mount Chip

Surface mount assembly and SMT is other popular PCB assembly technology. It is an advanced method involving automation. Besides, it is ideal for smart PCBs that today’s smart devices need.
As the name shows, PCB components are directly installed on its top surface, whereas the device having a surface mount technology is called SMD. You can say that traditional through-hole technology is being replaced by surface mount assembly.
However, through-hole technology is still in practice for big transformers or power semiconductors as their components are not compatible with SMT. Likewise, many other heavy electronic devices with heat sinks need through-hole PCBs.
Surface mount technology has more positive aspects than negative pros, so let’s discuss them in detail.

Positive Aspects Of Surface-Mount Technology

SMT Involves Minimal Surface: The component area, volume, and size in an SMT are 70% less than the component area in through-hole technology. Even the component area can become 90% less than its volume in a traditional PCB having a through-hole technology. Likewise, the overall weight of the PCB reduces, as the components’ weight reduces by 70 to 90%.
It Enhances The Signal Speed: a PCB assembled with SMT has a fast signal transmission due to a short circuit. The assembly density in such technology can go up to 5.5~20 solder joints in one square centimeter, like when there is paste on both sides of the PCB. Similarly, a PCB with SMT has a high impact and vibration resistance that helps create high-speed electronic devices.
Excellent Frequency: In SMT, the board has either no lead or it is very small which reduces its parameters, decreasing the interference in terms of RF. It means that the PCB gets high-frequency signals, and the device having it works faster.
Minimum Packaging Cost: when it comes to an SMT packaging price, you will see it much lower than THT. Since surface-mount technology involves effective production tools, the usage of packaging material reduces thus cutting down its cost. However, the decrease in the cost does not affect the quality of an SMT circuit board.
You don’t have to bend or cut the component leads in the SMT boards which reduce the assembly time, making production faster than THT. So, the production cost also reduces by 50% as the manufacturing process of SMT is quite simple.

Additional Info

In SMT, the solder paste is applied with a stencil printer that helps finish a raw board better and faster than a traditional method. In other words, you get fineness in an automated assembly.
The installation of the components becomes easier, as solder paste makes everything clear due to printing. Each SMT process is well-inspected that helps have accuracy.
In SMT, the process of reflow soldering also makes a circuit board highly durable. In reflow soldering, the technician places the circuit board under high temperature to melt and reshape the paste, making it permanent. You can use both reflow soldering and automation or can switch from one to another, depending on your needs.
The important thing is to design and assemble a PC Board considering all the dos and don’ts and have a flawless end product.

Some Negative Aspects Of SMT Assembly

Surface-mount technology is not full of benefits, instead, it has some drawbacks, such as:

  • It has less power
  • It is vulnerable to damage
  • SMT requires high-quality soldering because poor soldering can lead to leakage, tombstoning, bridging, and several other risks.
  • It involves delicate installation, resulting in dropped components.
  • Its inspection is hard, especially, the visual test as it has multiple types of solder joints.
  • The equipment cost is high.
  • It involves well-trained technicians that increase the learning expenses.
  • It needs consistent updates of assembly equipment due to fast development.

Final Thoughts

Printed circuit boards involve different assembly techniques, including a through-hole technology, and a surface-mount technology. The component area, volume, and size in an SMT are 70% less than the component area in through-hole technology.
When it comes to PCB design revision, a through-hole technology doesn’t need to create an additional solder stencil. So, manufacturers can save a huge amount of money on a PCB design having 2 to 3 revisions before it is ready to use.
Would like to know more about Surface Mount PCBs or PCB Assembly Services? Email us at sales@pnconline.com

printed circuit board

Differences Between IC and a PC Board

Before discussing the IC, you must know what PCB is. The PC Board or PCB has electronic components to help a device function. All digital and electronic devices have PCBs, like consumer products, smartphones, computers, laptops, tabs, etc. The purpose of the PCB is to eliminate assembly issues and have less wiring, enhancing automation and production.
The PCB has different types in terms of the number of layers. Like, it is either a single layer, double layer, four or six layers, or a multilayer circuit board. Now, we will discuss the difference between PCB and integrated circuits.

What Is IC Or Integrated Circuit Board?

The integration of chips makes an integrated circuit, like chips used in a CPU and motherboard are ICs or integrated circuits. Initially, IC was called an integrated block. You will see the IC soldered on a printed circuit board. In other words, a printed circuit board carries the integrated circuit.
The purpose of the integrated circuit or IC is to integrate an ordinary circuit into a chip. So, if the IC gets damaged, the chip won’t work. But, if the PCB gets damaged, you can replace the components.

Printed Circuit Board and Its Components

PCB has different types, however, today’s circuit board has specific components, such as:
Layout and Circuit: PCB circuit is a tool for conducting between different components. A copper surface becomes the base and power layer. Besides, it involves routing through drawing.
Dielectric Layer In The Board: it is also known as the substrate that contains insulation that lies between the layers and a circuit.
Through-Hole Via: vias are made for conducting and a through-hole via helps multiple layers conduct. The plug-in of a device is a large through-hole. There is also a non-through-hole that helps in surface mounting and fixes screws while PCB assembly.
Solder Mask: The copper surface is not always tinned. Epoxy resin is used to print the non-tinned area to separate the tinned copper to prevent a short circuit. Solder mask has different colors, including black, green, red blue, etc.
Silkscreen or Marking: Silkscreen is used to make legends or mark names and locations of different components. It helps maintain a PCB after assembly.
Finishing: the copper surface has to be tinned or it would get oxidized. The surface finish involves different processes, such as ENIG, HASL, immersion tin or silver, and OSP. You can use any method according to your needs as each finishing method has some pros and cons.

Features of Advanced PCB

High-Density PCB’s
PCB is becoming advanced due to new technology. You will see the HDI circuit boards in all small gadgets. Both installation and ICs are also improving with time.
More reliable
Now, PCB is more reliable than before because we have better testing tools. Moreover, its manufacturing and the end product are of high quality.
Up To Parameters
Each PCB material has certain mechanical, electrical, physical, and chemical properties. You will get a high-performing PCB if its design is according to the standards and design parameters.
Better PCB Production
PCB production has also increased with time due to better tools, design software, and advanced technology. Various standards ensure a high-quality device, such as automation, standardization, management, etc. You will see better equipment to test your PCB to have a high-quality end product.
PC Board Assembly
Assembly has also improved and helps you to have more production than the previous years. Similarly, you can develop complete equipment by assembling different components.
PCB Maintenance
PCB maintenance is also essential, especially, if the assembly gets issues. You can easily replace the damaged parts, restoring the system. Making lightweight, and mini or smart PCB is also easier than before. You can have a device with high-speed signals by maintaining your circuit board.

Features of Integrated Circuit

The integrated circuits were developed by Jack Kilby and Robert Noyce. The integrated circuit is very common in certain industries, such as military, civil electronics, television, communication, radio recorder, computer, etc. It provides the following benefits.

  • Lightweight structure
  • Less lead
  • Small volume
  • Solder joint
  • More reliability
  • Longer lifespan
  • High performance
  • Mass production
  • Low cost

IC is a microelectronic component or device in a PCB. IC technology involves the manufacturing of chips, design technology, processing technology, testing, packaging, design innovation, and mass production.
The integrated circuit is a key part of advanced electronic sand it is the heart of many circuits. You will see at least one chip or IC in every electronic device. IC is a combination of various electronic components, including capacitors, resistors, transistors, etc. These components together make a small chip and are linked to having a common goal. There are different types of ICs, such as

  • Single-circuit logic gates
  • Voltage regulators
  • Open amps
  • Motor controllers
  • 555 timers
  • Microprocessors
  • Microcontrollers
  • FPGAs
  • Many others

There is a complex process of making layers of copper, semiconductor wafers, and several other materials. These materials interconnect to make resistors, transistors, and other parts of a circuit.
Not only IC is too small, but it has very thin copper layers and semiconductor wafers. The layers have very delicate connections. Similarly, The IC die is a very small circuit that is too tiny to connect or solder, so you have to package the die that converts the delicate die into a black chip that you often see.
You can enhance the working life of equipment by using the IC to assemble different electronic tools. It helps you to increase the assembly density many times compared to transistors.
These days, you would see silicon ICs involving semiconductors. So, IC is a device that integrates capacitors, resistors, semiconductors, and other elements that make a circuit perform certain tasks. The device connects wires between these components on the silicon wafer through oxidation, diffusion, aluminum evaporation, epitaxy, and photolithography, and then it is welded in a casing or shell.

Differences Between IC and a PCBoard
Differences Between IC and a PCBoard

What Is IC Package?

IC package helps convert a die into a device to have a connection. Die’s outer connection has a small gold wire to a pad on the package that helps to connect it. The pad or pin is silver and it is an extruded terminal on the IC that continues to connect to a circuit’s outer parts. There are different types of IC packages having different dimensions, installation methods, and a number of pins.
Understanding Pin Numbering and Polarity Marking
You should know that every IC is polarized and each pin is different in its function and location. So, the package must show each pin’s nature and function. Mostly the ICs have DOT or Notch to differentiate the first pin. Like, sometimes only one pin is the first or sometimes both are.
Package Mounting
The mounting of a package on a PCB also varies, it can be SMT or surface mount, SMD, or a through-hole mounting. The through-hole package is often large and easy to manage, and it is created to get stuck through a board’s one side and soldering the other side.
The surface mount package has different sizes, small or minuscule. These packages are created to be soldered to the PCB surface and sit on one side. The SMD package has pins either perpendicular to the chip or extruded out the side, or set in a matrix on a chip’s lower part. Such ICs are hard to assemble with hands and need special tools for this purpose.
Dual In-Line Package or DIP
DIP is an ordinary through-hole IC package having two parallel lines of pins that extend perpendicularly from a black, and rectangular plastic casing.
SMT, SMD, or Surface Mount Package
There are many types of SMT packages and in the case of ICs, you must have a custom PCB having compatible copper patterns to be soldered. You need special automated tools to solder the SMD package.
SOP or Small Outline Package
The SOIC package is the SMT cousin of the DIP as this is what you see when you bend all the pins outward on a DIP, reducing the size. The SOP package is very easy to solder with hands. The spacing between the pins should be 1.27mm or 0.05”.
The shrink small-outline package or SSOP is a small type of SOIC package. Likewise, there are TSOP or thin-small outline packages and TSSOP or thin-shrink small-outline packages.
It is easy to understand the difference between IC and PCB if you know all their features as described above.

Final Thoughts

The integrated circuit is a key part of advanced electronics and it is the heart of many circuits. You will see at least one chip or IC in every electronic device. IC is a combination of various electronic components, including capacitors, resistors, transistors, etc.
The purpose of the integrated circuit or IC is to integrate an ordinary circuit into a chip. So, if the IC gets damaged, the chip won’t work. But, if the PCB gets damaged, you can replace the components. However, PCB and IC work together to help an electronic device function.
Would like to know more about the ICs, PCBs or pcb assembly? Email us at sales@pnconline.com

Printed Circuit Board FR4 Material

Printed Circuit Board FR4 Material

FR4 is a blend of fiberglass and epoxy resin, and manufacturers also call it a composite material. It resists flame and is highly used for PCBs as a substrate or base layer. FR4 circuit boards are now used instead of G10 boards due to their properties.

FR is also a great electrical insulator because it is completely water-resistant which means it does not absorb a little drop of water. Such qualities mechanically make it very strong and it maintains its qualities in all kinds of weather, including humid, hot, and dry weather.

Properties of FR4

FR4 is an inflammable material, and it is UL94V-0 compliant which means it does not spread fire, instead, it stops fire the moment the material starts burning. It has bromine that resists fire and does not absorb water as described above.
Moreover,the glass transition temperature is very high ranging from 115 to 2000 degrees Celsius, depending on the type of the resin and manufacturing method.Mostly such PCBs FR4 lies between the two layers of copper laminates.

Types of FR4 Material

FR4 material has different types, such as:
Standard FR4: Its heat resistance goes up to 140-a50 degrees Celsius.
High CTI FR4: The index of this type of FR4 goes beyond 600V.
High TG FR4: It has a high-glass transition value, such as 180 degrees Celsius.
FR4 without copper: This type of FR4 is suitable for insulating plates, and it can support the circuit board.

How To Choose The FR4 Thickness

FR4 thickness should be decided carefully as it contributes a lot to the applications of different PCBs. You should consider the following things in this case:

  • Design and flexibility
  • FR4 thickness should be compatible with components
  • It should not take much space on a PCB
  • Focus on the type of desired connections

Advantages of FR4

FR4 is cheaper than other substrates of circuit boards which makes it a standard material to develop small circuit boards. But, it is not good for high-frequency circuits or where the parts are suitable for flexible circuit boards.
FR4 is often suitable for RF applications with a frequency from 1GHz to 10 GHz. However, electric products having an FR4 have some disadvantages due to certain limitations.
FR4 material is one of the most popular choices for printed circuit boards because it offers a high degree of strength and rigidity. This means that your PCBoard will be less likely to warp or bend over time, which can lead to reliability issues. As already mentioned, FR4 material has excellent thermal stability, meaning it can withstand high temperatures without breaking down. This makes it ideal for use in harsh environments or in applications where heat dissipation is a concern.
As FR4 material is one of the most affordable materials on the market, which makes it is a great option for businesses on a budget. In addition to being cost-effective, FR4 material is also easy to work with, which can save time and money during the manufacturing process. It can be machined in a variety of ways, including deep draw and laser cutting, so customers are not limited in their design options
FR4 material is a great choice for PCBs because it offers good electromagnetic shielding. This means that it can help protect your circuit from outside interference. Additionally, FR4 is flame retardant, which makes it a safer option for use in electronic devices. It’s also strong and durable, so you can trust that your PCB will last for years to come.
It’s important to note that there are many different grades of FR4 material with different properties, so make sure you know what you need before ordering.

Some things worth considering when choosing an FR4 grade include: whether the PCB needs to support weight, how sensitive the device will be to temperature changes, how strong it needs to be, and how much flexibility is required.

Understanding PCB and Its Materials

Printed circuit boards manufacturers involve many steps, including design and finishing, leading to a huge production. Printed Circuit Board designers and engineers should consider the material in terms of its properties and applications. They should have it in Gerber files before sending the PCB design for manufacturing. In other words, PCB material determines the end product. Various PCB materials include the FR4, Teflon, PTFE, etc.
PCB substrates are made of phenolic and proxies, whereas PTFE is more costly than all others. Different PCB materials are available in the market, and you should choose them according to your needs.

Types of PCB Materials

Mostly PCB has four layers which are made one by laminating through a heating process. Each layer hasa specific PCB function and needs a specific material. PCB designersshould have full knowledge of materials in terms of their properties which should be suitable for specific applications.The end product with PCB is a specific device that needs a specific material, so it is a crucial factor.
PCB is composed of different materials from the base to the top, including copper, substrate or base layer, copper, solder mask, and silkscreen.
The subsequent layer of PCB is copper which is placed and bonded over a base material with heat and adhesive. The thickness of the copper layer is used according to the PCB and its application. Like, you can make it in one or two layers, depending on your needs. Mostly, cheap devices or gadgets have PCBs with a single layer of copper.
Like FR4, copper used in the circuit boards has different types in terms of resin, such as PF resin, epoxy resin, and polyester resin.
On the other hand, the silkscreen layer helps make marks or letters for programmers to read on a printed circuit board. The layer below a silkscreen is a solder mask and don’t forget to read our special post on solder masks.You can choose PCB materials by yourself or through an expert.

What is the FR4 Trace?

FR4 thickness is often 1oz,2oz, or 3oz, and the copper layer can be populated according to the design. It is also tested against the UV rays before removing the chemical solution to have correct copper traces which connect different parts on the FR4 PCB.
FR4 PCB trace can have signal issuesdue to mismatcheddriver’s and receiver’s impedance. Such an incompatibility results in bumps on the layer that reflects signals at a receiver’s end, sending them back to the copper trace.
The signal reflection that occurs due to mismatched impedance can affect the signal integrity. So, as a thumb rule, you should be careful, especially if the edge rate is lower than 1/6 of the propagation gap or delay in the copper trace’s length.
In the case of copper trace, signals occur 1 inch in 6 ns. You must take care of measurements to manage the impedance, especially if the edge rate is 1ns, whereas the copper trace is larger than one inch.

Printed Circuit Board FR4 Material
Printed Circuit Board FR4 Material

How To Manage The FR4 Trace Impedance

  • You can use resistive matching to make the driver and receiver’s impedance compatible. Such a technique involves a resistor having a value according to the source impedance. The resistive is set parallel with the receiver or in a series, depending on the requirements.
  • Some other techniques also help in this case, minimizing the signal reflection. A long PCB trace causes high-signal reflection. So, you can also reduce the trace length in a circuit board to overcome the signal reflection.
  • A signal’s return path is also important in this case because impedance can happen anywhere, including the signal trace or returning path.
  • If PCB has high-frequency signals, you should route the traces on the plane of a returning path. But, don’t route signals on a split plane because it would result in a discontinued impedance.
  • You must use advanced PCB design or analysis techniques to get precise results. The tools should possess advanced simulation.

Wrap Up

FR4 material is the standard fiberglass laminate that you’ll find in all PCBs (printed circuit boards). It has many uses, and each one will likely have its own set of requirements for using FR4 material. You’ll need to keep your specifications in mind when looking at FR4-based materials, but this will give you a good idea of what kind of FR4 laminates are available on the market today.
The FR4 board can be easily cut with a knife or saw and drilled through using a drill press or electric drill. You can even shape it using files or sandpaper if you need to, which makes it versatile as well as economical. So if you’re looking for high-quality circuitry in your next project, take a good look at what this particular type of PCB has to offer before making any decisions.
Would like to know more about the FR4 material or PC Board assembly? Email us at sales@pnconline.com

PC Board Color- Choosing Your Desired Color

PC Board Color- Choosing Your Desired Color

PC Board come up in different colors of which a green solder mask is the most common one. You will see most circuit boards with green solder masks. But, the industry is getting innovative due to changing technologies, so designers try new colors to make printed circuit boards.

PCB Solder Mask

Before getting into PCB colors, you should know what the solder mask is? The printed circuit board has different layers, and the top layer is the solder mask, whereas the bottom layer is the copper foil. The purpose of the solder mask is to cover the bottom layer from getting polluted or oxidized. The main material of solder masks is often the insulating resin which is printed on the circuit board’s unsoldered areas. The resin protects the board from heat, moisture, and any kind of damage.

Printed Circuit board Fabrication

You can customize a circuit board in terms of solder masks and other elements. According to research, 99% of solder masks are green. However, other colors are also emerging, such as red, black, white, yellow, blue, and purple. These colors are used for different applications. Such as RDs at the NPI stage are often made red. Whereas white is used for LED light circuit boards.
Each PCB color has some good and bad aspects that we will discuss here.We will also help you choose the right PCB color according to your application. Let’s start with the colorgreen.

Green Solder Mask In PCB

Though many colors are there, the green solder mask is still at the top as it helps to visually inspect the PCB to find any defects. Moreover, green makes a good contrast with the white silkscreen, helping you to remove the flux residue. If you don’t know how to select a color for the solder mask, go for green right away.

PC Board Color- Choosing Your Desired Color
PC Board Color

Red Solder Mask In PCB

Red is another color for PCB solder masks,and it adds brightness to the PCB. Red has a nice contrast with planes, areas without copper, and traces. However, the contrast is less than a green circuit board.
You may need a magnifier to find any defects in the traces. However, the red solder mask is compatible with screen printing and also helps remove residual flex like a green solder mask.Red also enhances a device if the circuit board is visible.

Blue Solder Mask In PCB

PCB with a dark blue solder mask is also popular. It hasless contrast with the planes, traces, and no-copper surfaces.Hence,you have to use a magnifying glass to inspect the construction defects. But, it has a high contrast with screen printing that makes blue suitable for a PCB with several components.
But, blue is less clear than green and red, and it highlights the dirt that makes it hard to remove the flux residue. A bluesolder mask is ideal for boards with hidden routes. It is also compatible with Arduino open-source tasks or products.

Black Solder Mask In PCB

A black solder mask is not so ideal in terms of inspection, as planes, traces, and no-copper surfaces have less contrast. Other than a strong magnifier, you also have to rotate the light to create a shadow to highlight the trace.
However, there is a good contrast of screen printing, and it’s visible on the board without any lights and so are the pads.But,the black solder mask has a high heat absorption during reflow. You have to place a temperature checker near the board while manufacturing. Moreover, the screen printing gets light brown during reflow due to the board’s high heat absorption.
The dirt also gets more prominent on the black surface, making it hard to clean. That’s why the manufacturing of a black PCB board involves more cost than other colors. On the other hand, black is ideal for LCD panels.
The black solder mask has two types, including matte and gloss of which matte black contrast is better than the glassy black.However, a black solder mask gets soiled and it becomes hard to repair it.

White Solder Mask in PCB

White solder masks have the lowest contrast than other colors, and placement of the marks becomeshard evenif they are under lighting. Whereas the cleaning of a white Printed Circuit Board is so difficult that you can’t imagine. You have to do so much effort to remove the stains from a white PCB.
However, it has some benefits as black printing on a white PCB creates a good contrast. You can use a white solder mask in LED applications where the front panel has to be white to increase the brightness.

Yellow Solder Mask in PCB

Yellow PCB is as good as green because there is a high contrast between theplanes, traces, and no-copper surfaces. You can use the dark yellow mask to enhance the routes, making them prominent.
There is one disadvantage of using a yellow solder maskand that is it’s less contrast with the white silkscreen. Many manufacturers prefer a black silkscreen with a yellow solder mask, even though it is less satisfactory.
It is easy to clean the residue from a yellow solder mask.So, yellow can be a great choice even though some people don’t like a lively color like this.

Purple Solder Mask in PCB

Purple PCBs are rare, however, advanced devices can have such boards. Purple has good contrast with the traces and planes. However, it does not go well with white silk printing. But, a purple solder mask would look great with an immersion gold surface, creating a good match.
So, you can choose any of the above colors to customize your PCB, depending on your requirements.
Why Should You Use Different PCB Colors?
It is not enough to know that PCB has different colors, because one should also know its reason. There are a few reasons behind using different PCB colors instead of just green, such as:

  • Different PCB colors help engineers indicate the revisions and changes to help users recognize them.
  • The application of other colors in PCBs can create better contrast. You have to understand the importance of the assembly tools in terms of transmission light, reflectance, and absorption.
  • Different PCB colors can reduce the errors caused by a mixed assembly. Moreover, the contrasting colors help decrease lead-free meetings.
  • The colors of the printed circuit boards are known as PCB codes. You would see modern PCBs in different colors compared to traditional boards. Even today, the PCmotherboard’s color is green epoxy because of its qualities
  • Though the colors of the PCB solder mask don’t influence a board’s performance, they can enhance its resolution. However, solder masks with clear transparency have a high resolution. The yellow and black PCB resolution is less than other colors like green, red, and purple.

Hope the above discussion helped you understand different PCB colors along with their advantages and disadvantages.

FAQs

What Is PCB Solder Mask?
The printed circuit board has different layers, and the top layer is the solder mask, whereas the bottom layer is the copper foil.
How Many PCB Colors Are There?
PCB comes up in several colors, such as green, red, black, white, yellow, blue, and purple.
What Is the Green Solder Mask?
The green solder mask makes a good contrast with the white silkscreen, helping you to remove the flux residue.
Is Red Solder Mask In PCB Effective?
Yes,the red solder mask has a nice contrast with planes, areas without copper, and traces.
What Is The Reason Behind Different PCB Colors?
Different PCB colors help engineers indicate the revisions and changes to help users recognize them. They reduce the errors caused by a mixed assembly. Moreover, the contrasting colors help decrease lead-free meetings.
Why Engineers Don’t Prefer Black Solder Mask?
A black solder mask is not so ideal in terms of inspection, as planes, traces, and no-copper surfaces have less contrast. Moreover, it gets dirty and is hard to clean.
Where Can I Use A Purple PCB?
The purple solder mask is compatible with an immersion gold surface, as both match very well.

Wrap Up

The green solder mask is the most common in circuit boards due to its high contrasting ability. The purpose of the solder mask is to cover the bottom layer from getting polluted or oxidized. The main material of solder masks is often the insulating resin which protects the board from heat, moisture, and any kind of damage.
Many users customize a circuit board in terms of solder masks and other elements. You will see various PCB colors in different applications, such as RDs, LEDs, PCs, etc.
Would like to know more about PCB Colors or smt assembly? Email us at sales@pnconline.com

Metal Core PCB Design & Manufacturing Concepts

Metal Core PCB Design & Manufacturing Concepts

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