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Electronic Components

Thermal management of semiconductors

Thermal management

Thermal management of semiconductors

Too hot to handle

Every electronic device or circuit will create heat when in use, and it’s important to manage this. If the thermal output isn’t carefully controlled it can end up damaging, or even destroying the circuit.

This is especially an issue in the area of power electronics, where circuits reaching high temperatures are inevitable.

Passive thermal dissipation can only do so much. Devices called heat sinks can be used in circuits to safely and efficiently dissipate the heat created. Fans or air and water-cooling devices can be used also.

Feelin’ hot, hot, hot!

Using thermistors can help reliably track the temperature limits of components. When used correctly, they can also trigger a cooling device at a designated temperature.

When it comes to choosing a thermistor, there is the choice between negative temperature coefficient (NTC) thermistors, and positive temperature coefficient (PTC) thermistors. PTCs are the most suitable, as their resistance will increase as the temperature does.

Thermistors can be connected in a series and can monitor several potential hotspots simultaneously. If a specified temperature is reached or exceeded, the circuit will switch into a high ohmic state.

I got the power!

Power electronics can suffer from mechanical damage and different components can have different coefficients of thermal expansion (CTE). If components like these are stacked and expand at different rates, the solder joints can get damaged.

After enough temperature changes, caused by thermal cycling, degradation will start to be visible.

If there are only short bursts of power applied, there will be more thermal damage in the wiring. The wire will expand and contract with the temperature, and since both ends of the wire are fixed in place this will eventually cause them to detach.

The heat is on

So we’ve established that temperature changes can cause some pretty severe damage, but how do we stop them? Well, you can’t really, but you can use components like heat sinks to dissipate the heat more efficiently.

Heat sinks work by effectively taking the heat away from critical components and spreading it across a larger surface area. They usually contain lots of strips of metal, called fins, which help to distribute heat. Some even utilise a fan or cooling fluid to cool the components at a quicker speed.

The disadvantage to using heat sinks is the amount of space they need. If you are trying to keep a circuit small, adding a heat sink will compromise this. To reduce the risk of this as much as possible,  identify the temperature limits of devices and choose the size of heat sink accordingly.

Most designers should provide the temperature limits of devices, so hopefully matching them to a heat sink will be easy.

Hot ‘n’ cold

When putting together a circuit or device, the temperature limits should be identified, and measures put in place to avoid unnecessary damage.

Heat sinks may not be the best choice for everyone, so make sure to examine your options carefully. There are also options like fan or liquid-based cooling systems.

Cyclops Electronics can supply both electronic components and the heat sinks to protect them. If you’re looking for everyday or obsolete components, contact Lantek today and see what we can do for you.

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Electronic Components

Superconductivity

Superconductivity

Superconductivity

Superconductivity is the absence of any electrical resistance of some materials at specific low temperatures. As a starting point this is pretty vague, so let’s define it a bit more clearly.

The benefits of a superconductor is that it can sustain a current indefinitely, without the drawback of resistance. This means it won’t lose any energy over time, as long as the material stays in a superconducting state.

Uses

Superconductors are used in some magnetic devices, like medical imaging devices and energy-storage systems. They can also be used in motors, generators and transformers, or devices for measuring magnetic fields, voltages, or currents.

The low power dissipation, high-speed operation and high sensitivity make superconductors an attractive prospect. However, due to the cool temperatures required to keep the material in a superconducting state, it’s not widely utilised.

Effect of temperature

The most common temperature that triggers the superconductor effect is -253⁰C (20 Kelvin). High-temperature superconductors also exist and have a transition temperature of around -193⁰C (80K).

This so-called transition temperature is not easily achieved under normal circumstances, hence why you don’t hear about superconductors that often. Currently superconductors are mostly used in industrial applications so they can be kept at low temperatures more efficiently.

Type I and Type II

You can sort superconductors into two types depending on their magnetic behaviour. Type I materials are only in their superconducting state until a threshold is reached, at which point they will no longer be superconducting.

Type II superconducting materials have two critical magnetic fields. After the first critical magnetic field the superconductor moves into a ‘mixed state’. In this state some of the superconductor reverts to normal conducting behaviour, which takes pressure off another part of the material and allows it to continue as a superconductor. At some point the material will hit its second critical magnetic field, and the entire material will revert to regular conducting behaviour.

This mixed state of type II superconductors has made it possible to develop magnets for use in high magnetic fields, like in particle accelerators.

The materials

There are 27 metal-based elements that are superconductors in their usual crystallographic forms at low temperatures and low atmospheric pressure. These include well-known materials such as aluminium, tin and lead.

Another 11 elements that are metals, semimetals or semiconductors can also be superconductors at low temperatures but high atmospheric pressure. There are also elements that are not usually superconducting, but can be made to be if prepared in a highly disordered form.

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Electronic Components

What is Raspberry Pi

Raspberry Pi

What is Raspberry Pi?

If you work in the electronics industry you might have heard of the Raspberry Pi circuit board. This device is a single-board computer, originally made by the UK-based Raspberry Pi Foundation.

Raspberry Pi boards use Linux and have a set of general purpose input/output (GPIO) pins. This means the user can attach electronic components and create different circuit boards.

History

The Raspberry Pi Foundation is a charity focused on teaching computing, and aims to make the subject simple and fun. To this end, The Raspberry Pi single-board computer was released to aid students and teachers in learning electronics affordably.

The original Pi was released in 2012 and quickly became popular, not only for education but in multiple industries. Since it uses a Linux-based OS it was also used by programmers and developers.

Raspberry Pi 1 Model B had a single-core 700MHz CPU, an ARM1176JZF-S processor, a VideoCore IV GPU, and had 512MB of RAM, and sold at lower than $35 on its release in April 2012.

Components

Since 2012 there have been several generations of Raspberry Pi. The latest model can have up to 8GB of RAM and a 64-Bit quad-core processor. Additionally, the Raspberry Pi 4 has two micro-HDMI ports that support 4K at 60GHz displays, a MIPI DSI (display serial interface) display port, MIPI CSI (camera serial interface) camera port, 4 pole stereo output and composite video port.

Potential Uses

One of the attractions of the Raspberry Pi device is the 40-pin GPIO header and four USB ports. This gives the opportunity for users to connect and build various types of circuits using external components.

Pi comes with an official operating system named Raspbian OS. The OS has a GUI that can be used for browsing, programming, games, and other applications.

Batteries or solar panels can be connected to power the circuit, which at peak would only require 7.6W of power. A power supply can also be connected via the USB port. One such power supply is provided by the Raspberry Pi Foundation itself at 5.1V.

Microphones and buzzers can be connected via the GPIO pins to create simple circuits. Motion sensors, servos and more, can also be attached in any combination.

There are numerous entertaining projects to undertake for those interested, and for the people who need it there is plenty of inspiration available online.

Pi’nally…

Cyclops Electronics can supply Raspberry Pi products, customers need only get in touch! For this, and all your other electronic component needs, contact Cyclops today.

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Electronic Components

RoHS, REACH, and dangerous substance legislation

RoHS, REACH, and dangerous substance legislation

RoHS, REACH, and dangerous substance legislation

RoHS and REACH are two pieces of legislation referring to the control of dangerous substances and chemicals. Companies manufacturing and distributing electronic equipment in Europe must comply to be able to trade.

RoHS

The Restriction of Hazardous Substances (RoHS) Directive came into force in 2004. With an aim to mitigate the effect of dangerous substances on customers, the Directive restricts the concentration of 10 substances used in Electrical and Electronic Equipment (EEE).

Acceptable levels of restricted substances in a single material are generally less than 0.1% or 1000 parts per million (ppm). For the chemical Cadmium, however, levels must be no more than 0.01% or 100ppm.

Companies must provide proof that they comply with the regulations by way of documentation. This includes a Declaration of Conformity, a record of the assessment procedure for conformity, and any other control documentation.

Since its release in ’04, there have been 3 iterations, with the latest being introduced in July of 2019. RoHS 3.0 introduces 11 new category products and four new substances.

The materials listed include products that could be harmful to not only human health, but the environment too. As such, non-compliance carries with it the potential for a heavy fine.

RoHS certification takes place in several steps:

  1. Extraction testing of the components takes place to determine the value of the RoHS substances contained.
  2. On-site manufacturing processes are inspected to ensure RoHS compliance at the facility.
  3. Review all relevant documentation, including the BOM (Bill of Materials), assembly drawings, and test reports from suppliers.
  4. Following this, if all is in order a RoHS Certificate of Compliance is issued.

REACH

REACH stands for the Registration, Evaluation, Authorisation and Restriction of Chemicals. It was introduced a few years on from RoHS, in 2006.

The scope of REACH is more inclusive than RoHS. It encompasses almost all products manufactured, imported, or sold in the EU or UK.

REACH revolves more around Substances of Very High Concern (SVCH), which includes those considered carcinogenic, mutagenic or toxic for reproduction.

Manufacturers and importers need to register the quantities of substances produced every year. Companies need to safely manage and publicise the risks associated with the substances. They’re also responsible for tracking and managing which substances are being used, and produce safety guidelines for each.

 

Recent changes

Due to events like Brexit in the UK, RoHS and REACH regulations became transplanted into UK law. Since many substances are imported between mainland Europe and the UK, the legislation in both remained very similar.

As part of the European Union (Withdrawal) Act 2018, REACH was copied into UK legislation, becoming UK REACH in 2021. Although the difference is seemingly in name alone, the two REACHs operate separately, and manufacturers need to comply with both.

REACH for the stars!

Cyclops can supply products that are RoHS and REACH compliant and can provide this information to our customers. This means Cyclops customers can guarantee if they want RoHS compliant parts, they will receive them. So contact Cyclops Electronics today!

This blog post is designed to be informative and is in no way offering advice or guidance on how to interpret legislation.

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Electronic Components

Resins and coatings for electronic components

Resins and coatings
Electronic technician holding tweezers and assemblin a circuit board.

Resins and coatings for electronic components

Coating components

Printed circuit boards (PCBs) are the core of many electronic devices and contain electronic components like capacitors, transistors and fuses. As such, keeping them safe and protecting them from damage is key to the continued working of electronic devices. Resins and conformal coatings can be used for this purpose.

Resins

Resins are the more sturdy, heavier option in terms of coatings. This is a great choice when protecting a PCB from adverse conditions and insulating it from potential physical damage.

Within the range of resins used, there are three main types that are used, with each suited to certain PCBs.

Epoxy resins

This compound is well-suited for potting electronics, and protects components against moisture and mechanical damage coming from vibrations or shocks.

Depending on if there are amines (curing agent) mixed with the resin the curing time of the PCB can differ. Something to watch out for is the exothermic reaction cause by the curing. Although this can be mitigated, there is a risk of damaging the component.

Polyurethane resins

The pricier cousin of epoxy resin, polyurethane can also protect PCBs against moisture, as well as high temperatures and UV. Most resins have a maximum temperature tolerance of 130⁰C.  However, polyurethane can cope with temperatures of up to 150⁰C if formulated well.

This maximum temperature is in part thanks to the resin having a lower exothermic rate compared to epoxy. Polyurethane is also more flexible, so is favoured when it comes to potting delicate components.

Silicon resins

Silicon also protects against UV light, and so is often used in LED applications where the change in the colour of the LED needs to be minimised.

Silicon is the most expensive of the three but is not as popular as its counterparts. The material thrives when it comes to high operating temperatures and heat-sensitive components, thanks to its low exothermic temperature.

Conformal coatings

While resins are thick, durable and designed for high levels of stress, conformal coatings are thinner, lighter and are transparent.

Thanks to the tiny layer of coating, usually applied with a paint brush or spray, this kind of coating is a lower-risk alternative than a heavy resin for fragile components.

The coating can be altered or removed more easily than the resin too, and the curing time is massively reduced. However, alongside this the component is more exposed and has a lower level of protection. This makes these coatings more useful for PCBs that will face shorter exposures.

Do your own research

Any coating of a PCB should be carefully considered depending on the purpose of the circuit board, the conditions and stresses it will face, and whether it already has a coating on it. If this is the case, chances are this original coating was meant as the PCB’s primary layer of protection.

Speaking of protection, Cyclops quality checks all of the electronic components it supplies. This protects its customers from damaged parts and counterfeits. For an extra layer of protection in your electronic component supply chain, contact Cyclops today.

This blog post is designed to be informative and is in no way offering advice or guidance on how to coat electronic components.

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Electronic Components

Electronic Components of a hearing aid

Hearing Aid

Electronic Components of a hearing aid

Hearing aids are an essential device that can help those with hearing loss to experience sound. The gadget comes in an analogue or digital format, with both using electronic components to amplify sound for the user.

Main components

Both types of hearing aid, analogue and digital, contain semiconductors for the conversion of sound waves to a different medium, and then back to amplified sound waves.

The main components of a hearing aid are the battery, microphone, amplifier, receiver, and digital signal processor or mini-chip.

The battery, unsurprisingly, is the power source of the device. Depending on the type of hearing aid it can be a disposable one or a rechargeable one.

The microphone can be directional, which means it can only pick up sound from a certain direction, which is in front of the hearing aid user. The alternative, omnidirectional microphones, can detect sound coming from all angles.

The amplifier receives signals from the microphone and amplifies it to different levels depending on the user’s hearing.

The receiver gets signals from the amplifier and converts them back into sound signals.

The digital signal processor, also called a mini-chip, is what’s responsible for all of the processes within the hearing aid. The heart of your hearing, if you will.

Chip shortages

As with all industries, hearing aids were affected by the chip shortages caused by the pandemic and increased demand for chips.

US manufacturers were also negatively impacted by Storm Ida in 2021, and other manufacturers globally reported that orders would take longer to fulfil than in previous years.

However, despite the obstacles the hearing aid industry faced thanks to covid, it has done a remarkable job of recovering compared to some industries, which are still struggling to meet demand even now.

Digital hearing aid advantages

As technology has improved over the years, traditional analogue hearing aids have slowly been replaced by digital versions. Analogue devices would convert the sound waves into electrical signals,  that would then be amplified and transmitted to the user. This type of hearing aid, while great for its time, was not the most authentic hearing experience for its users.

The newer digital hearing aid instead converts the signals into numerical codes before amplifying them to different levels and to different pitches depending on the information attached to the numerical signals.

Digital aids can be adjusted more closely to a user’s needs, too, because there is more flexibility within the components within. They often have Bluetooth capabilities too, being able to connect to phones and TVs. There will, however, be an additional cost that comes with the increased complexity and range of abilities.

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Electronic Components

Traditional fuses and eFuses

fuses

Traditional fuses and eFuses

Fuses are an essential electronic component in most circuits, and act as a safety feature to keep the other components within the circuit safe. Billions are used today to safeguard against circuit failures.

The purpose of fuses

If a circuit is overloaded, or there is a voltage surge, the fuse essentially self-destructs to protect the rest of the circuit. A traditional fuse contains a central fusible element that, when heated to excessive temperatures, melts and stops the flow of current through the circuit.

The speed that the thermal fuse melts depends on the how much heat is being caused by the current, and what temperature the fuse is designed to react to. The fuse can be designed with different melting elements that have varying melting points and resistance, so the currents they can cope with can differ.

eFuses

The new kid on the block is the newer electronic fuse, or eFuse. This component is an updated, re-usable version of the more traditional thermal, one-use fuse.

This component comprises of a field-effect transistor (FET) and a sense resistor. The resistor measures the voltage across it, and when it exceeds a certain limit, the current is cut off by the FET. Usually, the eFuse is placed in series with a thermal fuse rather than replacing it, giving the circuit a second layer of more localised protection for components.

Often eFuses are used as a protection when components are plugged into a computer while the power is still on, also called hot-swapping. In automotive applications, programmable logic controllers (PLCs) and battery management eFuses are a great tool to protect the circuits.

An offer you can’t reFuse.

As thermal fuses have been around for so long, it’s unsurprising that there are certain things the more recent eFuse can do slightly better.

The first and most straightforward advantage is the lifespan: once a thermal fuse is activated and the element inside it fuses, it will have to be replaced. The eFuse, however, can be reset and used multiple times without requiring replacement.

The eFuse is also able to respond to a circuit overload more quickly and works in circuits with a lower current and voltage. For some eFuses the current level it reacts at is set, but for some types it can be altered by an external resistor.

It’s possible to create a homemade eFuse too, just by putting together a few FETs, a resistor and an inductor, which filters the output and acts as your sense resistor.

Reaching melting point

Both fuses have their uses, and utilised together are even more effective as a circuit failsafe. However, each designer must consider their requirements and what will best suit their clients. There are scenarios where the thermal fuse just won’t do the job, and it’s better to be safe than sorry, right?

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Electronic Components

Could conductive ink replace conventional circuitry?

conductive ink

Could conductive ink replace conventional circuitry?

Intro

It seems like the stuff of dreams, having a pen or a paintbrush that could conduct electricity. Well, those dreams are very real, readily available to buy online, and at a relatively cheap rate, too.

Conductive ink pens and conductive paint that can be used with a pen, paintbrush, or a printer is a reality, and is already being put to work.

What is it?

Conductive ink and conductive paint are liquid materials mixed with nanoparticles of a conducting material like silver or graphite. The paint and ink are technically slightly different, in that the paint sits on the surface of a substrate, while the ink would sink into a substrate it was applied to, like regular ink on paper.

Although the metals are usually in a solid state at room temperature, if it’s in a nanoparticle form it can be mixed with a liquid. When the liquid is spread and begins to dry, the nanoparticles and electrons within them begin to form conductive chains that the current is then able to travel through.

The inks used normally work at 12V, and can be transparent which means it would be a good choice for companies to integrate it invisibly into their graphics.

Uses

One notable way silver-infused ink is currently used is to print Radio Frequency Identification (RFID) tags in tickets.

Another common place to find conductive paint or ink is in the rear windscreen of cars. The resistive traces applied to windscreens to help defrost them contain conductive paint. Traces printed on the window can also serve as a radio antenna in more recently manufactured cars.

Conductive inks and paints were originally intended to be used for e-textiles and wearables. The potential for clothes that could detect temperature and heart rate, among other features, is an area receiving considerable investment.

Problems

When compared to conventional circuity and conductors, conductive inks and paints will never be able to emulate the strength of conductivity. In a way, it would be unfair to pit the two against each other, like putting boxers from vastly different weight classes in a ring together.

The reliability and connectivity of traditional conductors is much higher so is preferred for regularly used products, however conductive inks and paints would be utilised in areas that traditional means could not. So, as much as these factors are disadvantages they would be irrelevant when it comes to the product.

Layers of the ink or paint may not always be thick enough to have any conductive strength at all, and it could take several layers of it to properly form a current-conducting pathway. Additionally, the user is relying on the nanoparticles in the liquid to align correctly for conduction. The material would work only for smaller direct voltages too, probably up to around 12V.

Silver is a material that has a higher cost than other conductors like graphite, and could make the price of some paints unreasonable for some customers. The low cost alternative is graphite, but this also has a higher resistivity than metals like silver.

The future

As far as development goes, nanoparticle paint is still in its infancy. Its uses are limited and occasionally unreliable, so although it has cornered a niche conductive market it’s unlikely we’ll see it permeating the sector for a while.

If you are looking for trustworthy day-to-day or obsolete electronic components, Lantek are here for you. Don’t paint yourself into a corner, contact Lantek today to find what you’re looking for, at sales@lantekcorp.com

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Chip shortage impact on electric car sales

electric car

Chip shortage impact on electric car sales

Many renowned car companies have, by this point, tested the waters of the electric vehicle (EV) market. However, thanks to the roaring success of electric car sales last year, and governmental and environmental incentives, the EV market is about to shift up a gear.

Global shortage

The vehicle market was not able to avoid the semiconductor shortage that has been prolific for the past few years. Safety features, connectivity and a car’s onboard touchscreen all require chips to function.

This, combined with the work-from-home evolution kick-started by the pandemic, meant that car sales decreased, and manufacturers slowed down production. New car sales were down 15% year-on-year in 2020, and the chips freed up by this ended up being redirected to other profiting sectors.

Even without the demand from the automotive industry, it has not been plain sailing for chipmakers, who not only had to contend with factory closures due to COVID-19, but also several natural disasters and factory fires, and a heightened demand from other sectors. Needless to say, the industry is still catching up two years later.

The automaker market

Despite new car sales having an overall decline in 2020, EV sales had about 40% growth, and in 2021 there were 6.6 million electric cars sold. This was more than triple of their market share from two years previously, going from 2.5% of all car sales in 2019 to 9% last year.

Part of the reason why EV sales were able to continue was due to the use of power electronics in the vehicles. While there is a dramatic shortage of semiconductors and microelectronics (MCUs), the shortage has not affected the power electronics market to the same extent. That is not to say that an EV doesn’t need chips. On the contrary, a single car needs around 2,000 of them.

It begs the question, how many EVs could have been sold if there weren’t any manufacturing constraints. Larger companies with more buying power would have been able to continue business, albeit at an elevated cost, while smaller companies may have been unable to sustain production.

Bestsellers

The growth of the EV business in China is far ahead of any other region, with more EVs being sold there in 2021 than in the entire world in 2020. The US also had a huge increase in sales in 2021, doubling their market share to 4.5% and selling more than 500,000 EVs.

In Europe last year 17% of car sales in 2021 were electric with Norway, Sweden, the Netherlands and Germany being the top customers. Between them, China, the US and Europe account for 90% of EV sales

Predictions and incentives

Several governments have set targets to incentivise the purchase of electric cars, and to cut down on CO² emissions caused by traditional combustion engines. Many of these authorities have given themselves ambitiously little time to achieve this, too.

Biden announced last year that the US would be aiming for half of all car sales to be electric by 2030, and half a million new EV charging points would be installed alongside this. The EU commission was similarly bold, proposing that the CO² emission standard for new cars should be zero by 2035, a 55% drop from the levels in 2021.

Companies are also setting EV targets and investing in new electronic models. Some manufacturers are setting targets as high as 50% of their production being electric within the next decade, while others have allotted $35 billion in investment in their pursuit of EV sales.

Possible pitfalls

Aside from the obvious issues there have been with semiconductor production and sourcing, there are also other factors that may make the future of EVs uncertain. One of the essential components of an electric car is its battery, and the materials that are used are increasing in price.

Lithium, used in the production of lithium-ion EV batteries, appears to be in short supply, while nickel, graphite and cobalt prices are also creeping up. However, research is underway for potential replacements for these, which may help for both supply times and the associated costs.

The shortages are affecting everyone, but thankfully Lantek is here to take some pressure off. No matter what electronic components you are looking for, the team at Lantek are ready to help. Contact us today at sales@lantekcorp.com Alternatively, you can use the rapid enquiry form on our website.

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Electronic Components

What are GaN and SiC?

What are GaN and SiC?

What are GaN and SiC?

Silicon will eventually go out of fashion, and companies are currently heavily investing in finding its protégé. Gallium Nitride (GaN) and Silicon Carbide (SiC) are two semiconductors that are marked as being possible replacements.

Compound semiconductors

Both materials contain more than one element, so they are given the name compound semiconductors. They are also both wide bandgap semiconductors, which means they are more durable and capable of higher performance than their predecessor Silicon (Si).

Could they replace Silicon?

SiC and GaN both have some properties that are superior to Si, and they’re more durable when it comes to higher voltages.

The bandgap of GaN is 3.2eV and SiC has a bandgap of 3.4eV, compared to Si which has a bandgap of only 1.1eV. This gives the two compounds an advantage but would be a downside when it comes to lower voltages.

Again, both GaN and SiC have a greater breakdown field strength than the current semiconductor staple, ten times better than Si. Electron mobility of the two materials, however, is drastically different from each other and from Silicon.

Main advantages of GaN

GaN can be grown by spraying a gaseous raw material onto a substrate, and one such substrate is silicon. This bypasses the need for any specialist manufacturing equipment being produced as the technology is already in place to produce Si.

The electron mobility of GaN is higher than both SiC and Si and can be manufactured at a lower cost than Si, and so produces transistors and integrated circuits with a faster switching speed and lower resistance.

There is always a downside, though, and GaN’s is the low thermal conductivity. GaN can only reach around 60% of SiC’s thermal conductivity which, although still excellent, could end up being a problem for designers.

Is SiC better?

As we’ve just mentioned, SiC has a higher thermal conductivity than its counterpart, which means it would outlast GaN at a higher heat.

SiC also has more versatility than GaN in what type of semiconductor it can become. The doping of SiC can be performed with phosphorous or nitrogen for an N-type semiconductor, or aluminium for a P-type semiconductor.

SiC is considered to be superior in terms of material quality progress, and the wafers have been produced to a bigger size than that of GaN. SiC on SiC wafers beat GaN on SiC wafers in terms of cost too.

SiC is mainly used for Schottky diodes and FET or MOSFET transistors to make converters, inverters, power supplies, battery chargers and motor control systems.