WHAT IS high temp PCB?
High Tg is another named for a high-temperature PCB, meaning is printed circuit boards designed to stand up to high-temperature extremes.
A circuit board is defined as high Tg if the glass transition temperature (Tg) is higher than 150 degrees Celsius.
WHEN DO YOU NEED A high temp PCB?
If you need a high temperature circuit board for your applications if your PCB will be experiencing a thermal load no greater than 25 degrees Celsius below the Tg. If your product will be operating in the 130-degree Celsius range or higher, you will want to use a high Tg PCB to be safe.
The main reason for the high Tg PCB is because of the movement to RoHS PCBs. It is causing most of the printed circuit board industry to move toward high Tg materials because of the higher temperatures needed for the lead-free solder to flow.
APPLICATIONS FOR high temp PCB
If you are working with high power density designs whose heat generation is likely to overwhelm your heat sinks or other heat management methods, a high Tg PCB is really the only answer.
Trying to reduce the heat generation of your PCB may affect the weight, cost, power requirements or size of your application, and it is usually much more cost-effective and practical to simply start with a high temperature heat resistant PCB.
Venture high temp PCB is another name for High-TG PCB.
So, it is designed to stand up to high-temperature extremes.
A PCB is defined as high temp if its glass transition temperature or TG is higher than 150 degrees Celsius.
Venture is a trusted supplier of high temp PCB or high-TG PCB for more than 10 years.
Whether you need high-quality high temp PCB for your project, Venture is the right place for you.
Your Leading High Temp PCB Supplier in China
Venture high temp PCBs or high-TG PCBs contain PCB material for high-temperature situations.
For that reason, you can count on them even under extreme temperature conditions.
As a leading manufacturer, our typical high temp PCB materials include:
- ISOLA 370HR,
- Shengyi S1000-2, etc.
If your PCB is experiencing a thermal load no greater than 25 degrees Celsius below the TG or operating 130-degree Celsius, then you must need high-temperature circuit board to be safe.
Venture high temp PCB is suitable for high power density whose heat generation is likely to overwhelm your heat sinks.
However, reducing the heat generation of your PCB may affect the following:
- power requirements
- size of your application
Venture high temp PCB is usually much more cost-effective and practical to simply start with a high-temperature heat-resistant PCB.
Just don’t forget to use high-temperature PCB or high-TG PCB if your applications are in any danger or required to be RoHS compliant.
Whether you are a distributor, retailer, or electronic engineer looking for a trusted manufacturer of high temp PCB, Venture is the right place to provide your needs.
As a professional manufacturer, we provide the best delivery options and flexible payment terms without minimum order required.
We will bring your project into the market and skyrocket your business.
We are aiming to work with you as your best partner in China.
For more information about our high temp PCB or high-TG PCB, please don’t hesitate to contact us now!
High Temp PCB: The Ultimate FAQ Guide
If you are looking for any information about high temp PCB, you will find it right here.
This guide has all information that will help you choose a perfect high temperature PCB for all your applications.
Keep reading to learn more.
- What Is High Temp PCB?
- Which Features Should You Consider In High Temp PCB?
- When Do You Need High Temp PCB?
- What Are The Benefits Of High Temperature Circuit Boards?
- Are There Limitations Of High Temperature PCBs?
- What Are The Applications Of High Temp PCB?
- Which Types Of High Temp PCB Do You Have?
- How Does High Temp PCB Compare To High Power PCB?
- In What Ways Does High Temp PCB Leverage Heat Management?
- What Causes High Temp PCB To Overheat?
- How Can You Prevent High Temp PCB From Over Heating?
- What Is The Maximum Operational Temperature For High Temp PCB?
- Which PCB Surface Finishes Can You Use On High Temp PCB?
- How Can You Make High Temp PCB Water Resistant?
- How Do You Eliminate Moisture In High Temp PCB?
- What Is High Temp PCB Thermal Resistance?
- Which PCB Materials Do You Use In High Temp PCB?
- Whys Should You Consider Power Density In High Temp PCB?
- Which New Thermal Management Technologies Do High Temp PCBs Use?
- What Is High TG PCB?
- How Can You Measure Temperature Of High Temp PCB?
- What Causes Failure In High Temp PCB?
- Is High TG PCB Same As High Temp PCB?
- Why Is TG Value Critical In High Temp PCB Design?
- Is There Relationship Between Coefficient Thermal Expansion And High Temp PCB?
What Is High Temp PCB?
A high temperature circuit board can be generally be defined as a PCB with a glass transition temperature (Tg) higher than 170 Degrees Celsius.
It is also known as a high Tg PCB.
High temperature PCBs need to follow a simple thumb rule for continuous thermal load with an operating temperature of 25 Degrees Celsius.
This is below the glass transition temperature.
High temp PCB
This implies that if your product ranges from 130 Degrees Celsius or higher, then you require a high Tg material.
Which Features Should You Consider In High Temp PCB?
- Flame resistance- a high temperature circuit should not burn at a certain temperature; only softened.
- Chemical resistance-high temperature PCBs have a high resistance to chemicals.
- High glass flow temperature value (Tg) of higher than 170 Degrees Celsius.
- High Tg PCBs have high temperature durability.
- Long delamination durability- high temperature PCBs take longer to delaminate even when subjected to extremely high temperatures.
- Low Z axis expansion (CTE)- high temperature PCBs undergo little to no dimension change at high temperatures.
This implies that when the temperature goes down, the risk of breakage is minimal.
When Do You Need High Temp PCB?
The major reason for high temperature PCBs due to the movement to RoHS PCBs.
This movement is causing most PCB industries to gear towards high temperature PCB materials.
This is as a result of the higher temperatures required for the flow of lead-free solder.
Instances when you need a high temp PCB include:
- In case your product will be operating within the temperature range of 130 Degrees Celsius and above.
- You will need a high temp PCB for your application in case your PCB will be undergoing a thermal load of a maximum of 25 Degrees Celsius.
This is below the glass transition temperature.
What Are The Benefits Of High Temperature Circuit Boards?
- Better stability- high Tg PCBs have higher moisture, chemical and heat resistance than standard PCBs.
This lengthens their lifespan by reducing the short circuit, overheating and other PCB failures.
- They are perfect for Multi-layer and HDI PCBs- multi-layer and HDI PCBs comprise of electronic circuits that are complex and dense.
The heat generation is way more for standard PCBs.
- Lower thermal expansion- high temperature PCBs undergo little dimensional change at high temperatures.
When the temperature lowers risk of cracking and breaking down is very minimal.
- Bear high density designs- high temperature PCBs provide heat management solutions to devices that have high power density with a high rate of heat generation.
- Thermal decomposition- High temperature PCBs are less likely to degrade or get damage caused by thermal degradation.
- High temperature PCBs have better water absorption capabilities.
- High temperature PCBs have high mechanical strength.
Are There Limitations Of High Temperature PCBs?
- Overheating- high temperature PCBs operate at extreme temperatures.
This poses the threat of overheating and this can result to failure or damage of the PCB.
What Are The Applications Of High Temp PCB?
High temperature PCBs are found in many electronic devices and can be used in a lot of industries. These include:
- Consumer electronics such as laptops and tablets.
- Medical devices
- Military and aerospace
- Wireless networks
- Wireless networks
- GPS tracking devices, etc.
Which Types Of High Temp PCB Do You Have?
- High Tg Flex PCBS– as the name suggest, flex PCBs are flexible. You can shape and design them to fit into different applications.
Flex have better ability to withstand harsh environments as well as high temperatures than rigid ones.
Flex PCBS are applied in the following fields and industries:
- Military and aerospace
- Medical field
- Industrial controls
- Auto world
- Consumer electronics
- Wireless networks etc.
- High Tg rigid PCBS– these are best suited for harsher environments.
They work best for
- applications and devices that have: lots of shock and vibration, extremely high temperatures and certain chemical components.
Examples are jet engines, car engine parts or the inside of missiles.
High Tg printed circuit boards are often used in the following environments:
- Military and equipment
- Auto applications
Rigid PCBs have the following advantages:
- They are lightweight
- They are cost effective
- Their design is compact
- They make low electronic noise
- They are easy to diagnose and repair.
- High Tg multilayer PCBs- these type of high temperature PCBs have more than two layers.
The design of multi-layer PCBs resembles a sandwich; with double sided layers being divided by an equal number of insulating sheets.
You can find multi-layer PCBs in complex circuits and devices such as:
- Mobile phones and tablets
- Medical equipment
- GPS tracking devices, etc.
Multi-layer PCBs are compact in size, they are highly flexible in terms of design, are more robust and are most suited for circuits that need high speed.
- High Tg rigid-flex PCBs – this is a hybrid combination of the rigid and flexible boards.
Rigid-flex PCBs are foldable and manufactures usually shape them into a flexible shape or curve during the manufacturing process.
The flexible part of the board serves as interconnections between rigid boards.
This removes the need for connectors which can be bulky resulting into smaller boards.
Rigid-flex boards are compact and flexible making them perfect for applications such as:
- Medical equipment
- Consumer electronics.
How Does High Temp PCB Compare To High Power PCB?
High power PCBs refer to PCBs that conduct current that goes above a couple of Amps.
high temp PCB
For instance, an electronic motor driver that channels 30 Amps within the circuit is regarded as high power PCB.
High temperature PCBs on the other hand are PCBs with a glass transition temperature of 170 Degrees Celsius and above.
High power PCB
In What Ways Does High Temp PCB Leverage Heat Management?
The design for high temperature PCBs require special measures to ensure smooth operation and functionality in harsh conditions.
A common strategy for this is the use of thermal conductivity optimized materials such as heavy copper boards.
The use of these heavy copper sheets help in boosting their current-carrying capacity, lowering electrical loss, improving heat dissipation and reducing heat generation.
By using heavy copper, the need for heat sinks drops significantly thus reducing the overall size of the PCB.
Using thermal adhesives can reduce the need for mechanical fasteners such as screws and clips.
This can in turn help lower the insulator or gap filler that keep a device away from a heat sink.
Other considerations should be materials with a good flame and chemical resistance as well as low smoke and ash formation.
These materials should provide electrical resistance and reduce heat dissipation.
What Causes High Temp PCB To Overheat?
Some of the main causes:
- Component malfunction– a common cause for overheating in a high temperature PCB, is when one of its component malfunctions causing dissipation.
It fails to generate the usual amount of power.
When this occurs, the other components have to compensate by producing more heat than normal which leads to overheating.
- Through- hole interference– through- hole and sink components make up the power supply of a PCB.
Their primary function being the generation of heat and dissipation. If you solder a heat sink wrongly, it causes overheating.
Also if another component of the high temperature PCB is interfering with the through hole, other components will produce more heat to compensate.
This causes overheating.
- Surface-mount device distance– SMDs connect to the high temperature PCB just as through-hole components do.
Their function is to allow for smooth flow of current through both the through-hole and heat sink components.
You should always position the SMDs and the through-hole components at the correct distance. Failure to this, the current will have a longer distance to travel.
The current will need extra time to travel causing the receiving components to remain cool for longer than they should.
Other components may produce excessive heat as compensation.
- High-frequency circuits– these circuits generate lots of power. Naturally, more power equals more heat.
How Can You Prevent High Temp PCB From Over Heating?
- Heat sinks– a high temperature PCB generates a lot of heat.
This heat needs dissipating in order to avoid overheating and therefore damage of the board.
A heat sink will dissipate the thermal energy safely to avoid build up which causes overheating.
- Fans- the function of fans in PCBs just like in other electronics is to cool them down.
Fans let in cool air in the PCB while dispersing the heat out.
This prevents overheating, enhances performance and prolongs the life span of the PCB.
- Choosing the right material and components- one of the most effective way of reducing heat in a high temperature PCB is choosing the right heat resistant materials.
For instance heavy copper is able to withstand extremely high temperatures.
- Increasing plate thickness and width- thicker plates seem to be poor in heat conduction than thinner ones.
They need more power in order to reach high temperature.
With the correct engineering they can significantly reduce the risk of overheating as well as disruption and warping.
- Lamination- application of lamination is another effective way to reduce overheating. Lamination prevents overheating by offering heat protection to the PCB components.
High temperature laminates need to have protective properties such as:
- Glass transition temperature (Tg)- this is the temperature range where polymers change from being rigid to soft.
Laminates with a high Tg offer excellent protection.
- Moisture absorption- laminates need to have a reliable and protective moisture absorption abilities.
This is especially if you intend to operate the PCB in an environment that is not air-controlled.
- Decomposition temperature- this is the temperature at which 5 percent of the laminates total mass is lost due to decomposition.
A laminate with a high decomposition temperature offers the best protection.
- Delamination time- high temperatures can cause delamination over time.
The best laminates are those that take a long while to delaminate under high heat.
- Maintain sufficient spacing- you should ensure adequate spacing between PCB components. When too close together, the components may interact with each other inappropriately.
These unnecessary interaction cause skin effect.
This effect in turn cause trace resistance to increase which leads to resistive losses and therefore causing the circuit to overheat.
Adequate and correct spacing prevents the board from overheating.
- Correct integration of heat pipes- heat pipes can as well help in the dispersion of heat.
The liquid found inside the pipes absorb the heat.
This protects the PCB and its components from the damage caused by overheating.
What Is The Maximum Operational Temperature For High Temp PCB?
The maximum operational temperature for high temperature PCBs is 170 Degrees Celsius.
Which PCB Surface Finishes Can You Use On High Temp PCB?
There are different types of PCB surface finishes available. It is best to compare them and select the most suitable one.
A good surface finish should have the following attributes:
- It should adhere to the ROHS regulations and be lead free.
- Should have a fairly long shelf life; at least six months.
- It should not be susceptible to contamination and breaking.
- You can use it for components with tight pitch.
- It should be able to form superior wire bounds.
Common types of PCB surface finishes are as follows:
- Hot Air Solder Level (HASL)
- Lead-Free HASL
- Organic Solderability Preservative (OSP)
- Immersion Silver (Au)
- Immersion Tin (Sn)
- Electro less Nickel Immersion Gold (ENIG)
- Electro less Nickel Electro less Palladium Immersion Gold (ENEPIG)
- Electrolytic Wire Bondable Gold
- Electrolytic Hard Gold
How Can You Make High Temp PCB Water Resistant?
You can use any of the following techniques:
- Using clear nail varnish- this is most probably the easiest and most popular way to waterproof a PCB.
However, this is just a temporary fix since the high temperatures of the board will scorch it and cause it to peel off.
Despite this disadvantage clear varnish is still widely used because of its affordability and availability.
- Using a special PCB varnish- this is essentially a coating in spray form, so this makes it easy for easy and even application throughout the entire board.
When it hardens, it remain clear and forms a hard layer of protection.
Despite the hardness, it maintains some flexibility that keeps it from cracking.
- Using clear silicone adhesive- ensure the silicone is transparent, nonconductive; has good adhesive properties and has a good temperature stability.
It might not be a long term solution but it does offer protection against water and dust.
- Using UV curable solder mask- solder masks have good temperature stability and adhesion.
This makes them ideal for protection against moisture. They come in a syringe form and is available in a variety of colors.
You will require a UV flashlight to dry the solder mask. After about 30 seconds under the UV light, it forms into a hard protection layer.
The limitation of using the solder mask is that it is only suitable for flat surfaces.
This limits it to small repairs and you can’t use it on the entire board.
How Do You Eliminate Moisture In High Temp PCB?
- Baking– this is the main method of moisture elimination in a PCB.
Baking involves applying high heat levels to dry out any traces of moisture. Baking is through and long lasting.
Manufacturers employ the baking process during the assembly stages before shipping the PCBs to customers.
One of the drawbacks of baking is it can cause delamination. This is in a case where the PCB contains large copper planes.
Certain concentrations of moisture might swell during the baking procedure. When this happens it becomes almost impossible to remove moisture.
- Dry enclosures-Another way to remove moisture from a PCB is to place them in drying enclosures.
This enclosure maintain the boards at ideal temperatures with air vapor below 0.05m/m3.
The dry environment provides a vacuum effect on PCBs that keeps the moisture from setting or even diffusing.
- Vertical positioning– another to deal with moisture in PCBs is to sit them in a vertical position. This is the reason why in many applications, PCBs are vertical. For moisture remove vertical is way better than horizontal.
What Is High Temp PCB Thermal Resistance?
Thermal resistance in high temperature PCBs is simply the measure of thermal conductivity.
You can easily calculate the thermal conductance from the thermal conductivity.
The thermal resistance is usually the inverse of thermal conductance.
There is a thermal analysis software that helps in easy and quick calculation of thermal resistance of your PCB.
Which PCB Materials Do You Use In High Temp PCB?
When choosing a material to use in high temperature PCB you should consider: flame resistance; chemical resistance; low smoke and ash formation.
Some of the most common PCB materials you may consider include:
- Isola Is410
- Isola Is420
- Isola G200
- Shengyi S1000-2
- Iteq It-180a
- Arlon 85n
Whys Should You Consider Power Density In High Temp PCB?
With power densities, high temperatures can cause destruction of conductors and dielectrics.
In recent times, high power density times overwhelm the older PCB heat management practices.
Which New Thermal Management Technologies Do High Temp PCBs Use?
PCB thermal management usually relies on the design and helper components such as heat sinks to handle the excessive heat.
To improve thermal management, you need to; select and distribute PCB components carefully. You can as well test for thermal shock.
What Is High TG PCB?
A high TG PCB is another name for high temperature PCBs; which are PCBs with a glass transition temperature of 170 and above Degree Celsius.
high TG PCB
How Can You Measure Temperature Of High Temp PCB?
Measuring the temperature of a high temperature PCB involves observing how the temperature increase and decrease.
You need to identify two things before measuring the PCB temperature; the temperature sensor and primary heat source.
This is where most current take place and where most of the heat is generated respectively.
The other thing to do is locate the GND pin of the heat source. Usually it is connected to the heat source’s substrate.
After doing the above, you can measure PCB temperature efficiently and accurately using the following tips:
- Use a common ground plane between the temperature sensor and the heat source.
- Keep the GND pins of all the temperature sensors connected to the ground plane of the heat source.
- Ensure to the distance between the temperature sensor and heat source is as minimal as possible on the PCB.
By following this tips, you will be able to track the accurate and consistent temperature of the PCB and the heat source.
What Causes Failure In High Temp PCB?
One of the common causes for high temperature PCB failure is manufacturing defects. These defects are as follows:
- Contamination- PCBs may get contamination during or before the assembly procedure.
Most boards get contaminated because of lack of surface finishing and the post assembly protective coat.
This usually leads to oxidation which causes abnormal PCB behavior and eventually failure.
To avoid contamination, ensure you specify that the manufacturer use and apply the surface finishing most appropriate for your design.
During operation, it is best to use conformal coating to prevent contamination of the surface.
- Material degradation- if a PCB is made with low CTE materials it’s likely to weaken resulting into premature failure.
In most cases this is due to excessive heat.
To avoid this, it is best to ensure that you follow the PCB thermal manufacturing guidelines. Also, use recommended materials or those are most suited for that specific manufacturing situation.
- Low quality solder joint connection-if you do not connect the solder joints correctly, component disconnection can occur during operation.
The solution to this is ensuring that you align both the pads and traces correctly.
You can also test the board for structural integrity during manufacturing.
Another reason for PCB failure is environmental factors.
This why it is essential to design the PCB and enclosure according to the environment they will operate in.
These factors are as follows:
- Moisture- moisture and humidity contribute to PCB failure.
Moisture can condense from the environment on to the circuits.
Ensure the manufacture incorporates moisture protective measures throughout the designing of your PCB.
This is especially if the PCB will be operating in a humid environment, where there is drastic change in temperatures.
- Dust- dust is the number one cause of failure in electronics.
To avoid the damage caused by dust ensure you select components that can handle dust. Alternatively, you can use a conformal coating.
- Heat- High temperature PCBs generate a lot of heat. This can cause cracks in solder joints, substrate materials and sometime enclosures.
To avoid overheating consider through hole components than can conduct more heat than SMTs.
Is High TG PCB Same As High Temp PCB?
High TG PCB is the same thing as high temperature. You can infact use the two terms interchangeably.
Why Is TG Value Critical In High Temp PCB Design?
You must determine the Tg prior in order to select the suitable material to design your PCB with.
You can use the Tg value of the base material as reference.
Is There Relationship Between Coefficient Thermal Expansion And High Temp PCB?
When components and materials of PCB experience high temperatures, thermal expansion takes place.
You can measure the thermal expansion using the CTE which stands for the coefficient for thermal expansion.
The CTE can determine the rate of thermal expansion for both PCB components and materials.
For all your high temperature PCB, Venture offers perfect solution for your electronics needs.
Contact us now for all your high temperature PCBs.