Differences between Thermal tapes

Today I did a test run with a small led-strip that I adjusted to an aluminium strip with some tape that I got online for little money.

It's this tape: https://www.aliexpress.com/item/4000145 ... b201603_53



In the description it is said that the Thermal conductivity: 1.5W / m-K.
Now I know that those Chinese traders do not always take the truth very seriously.

There is also tape of 3M, type 8805.
I had read that this is actually the best tape that one could use.

https://www.3m.com/3M/en_US/company-us/ ... 801&rt=rud



In their description 3M says that the Thermal conductivity of this tape: 0.60 W / m-K.


It is my understanding the higher the W, the better the heat transfer is. Hope I am right there...

The 3M tape ($60-$80) is about 10 - 15 times as expensive as the Chinese tape ($4 - $ 7).

But what tape do the experienced members here think is better?

Are the Chinese not telling the truth? Is the Thermal Conductivity in reality not that heigh?

Or are they telling the truth and are we paying to much for the 3M Tape?

Who can shine some light on this?
Perhaps I am totaaly misunderstanding the numbers or even looking at the wrong numbers.

I know that there is also thermal paste and adhesive, but I want to know what the difference is between those 2 tapes.

I wanna know aswell.

Ive used standard 3M for low wattage operation with no probs.

@welight might be able to help answer this, his company are dealing with tapes constantly i would assume.

He sent me a few rolls when i built my lights.

Keesje said:

Today I did a test run with a small led-strip that I adjusted to an aluminium strip with some tape that I got online for little money.

It's this tape: https://www.aliexpress.com/item/4000145 ... b201603_53

In the description it is said that the Thermal conductivity: 1.5W / m-K.
Now I know that those Chinese traders do not always take the truth very seriously.

There is also tape of 3M, type 8805.
I had read that this is actually the best tape that one could use.

https://www.3m.com/3M/en_US/company-us/ ... 801&rt=rud

In their description 3M says that the Thermal conductivity of this tape: 0.60 W / m-K.


It is my understanding the higher the W, the better the heat transfer is. Hope I am right there...

The 3M tape ($60-$80) is about 10 - 15 times as expensive as the Chinese tape ($4 - $ 7).

But what tape do the experienced members here think is better?

Are the Chinese not telling the truth? Is the Thermal Conductivity in reality not that heigh?

Or are they telling the truth and are we paying to much for the 3M Tape?

Who can shine some light on this?
Perhaps I am totaaly misunderstanding the numbers or even looking at the wrong numbers.

I know that there is also thermal paste and adhesive, but I want to know what the difference is between those 2 tapes.

Click to expand...

Guy doing a similar test.


No idea how viable this guys test is or if its the same tape.

coreywebster said:

Guy doing a similar test.

No idea how viable this guys test is or if its the same tape.

Click to expand...

looks viable to me.
Thing is that you mostly need the high heat conductivity when you have to get away the heat from a very small surface.
Like a leds or cpu core.
For the leds there is a PCB underneath doing this job, spreading the heat, afterwards you have your surface area and it becomes less critical.

I'd like to see a strip light test using thermal tape vs thermal paste or glue. Maybe with nothing, just screwed down lightly but tite. Got me thinking my e3ay thermal tape was a waste of money.

What kind of interface material is used with the boards?

coreywebster said:

Guy doing a similar test.

No idea how viable this guys test is or if its the same tape.

Click to expand...

His test is nice, but he did not compare tapes.
He tested tape against other solutions.

I am curious if the 3M tape is so much better then the Chinese tape.

normally every paste is much better then a pad or tape.

Perhaps, but I am looking for the different performing of the tapes.

true, but it is a indication, if a in any case better perfoming paste do so little diff.

If you need an analogy, consider this. The base structure of DS Thermal tape is fundamentally fibreglass, as such it is not dramatically different from the structure of PCB dielectrics used as insulators between copper and base on PCB. Given that it means to some extent what you have are two insulators blocking thermal paths to the heatsink. This does not mean it is not a good solution in terms of convenience and assembly or even performance, however it is not the absolute best performing solution, thermal pastes are certainly better, but are messy
cheers

I say forget the spec on the cheap Chinese stuff, I'd be shocked if it's real.

I once did some very precise tests on paste, don't remember the numbers but the dirt cheap Chinese stuff was crap compared to Arctic MX-4. I used the cheap stuff on a strip build and it works very well in that application, strips have a lot of surface area per watt so they don't need great heat transfer.

GreenGenes said the 3M performed 2-3 degree better at higher currents than generic but at 1400mA and below the generic was just as good.

This is what I did with the Chinese tape:

I took an aluminium strip, size was about 65/70 cm x 4 cm and 3 mm thick
The led-strip was glued to it with tape. (2 strips of 2 cm wide)
TCI led 24 Watt (guess it is 45 cm x 4 cm)
They don't make them anymore, but here is a link of a fixture that used them: https://products.light4u.io/wp-content/uploads/2019/01/LIVAL_SCOPE_SPECIFICATION.pdf

On top of an aluminium strip I glued the sensor of a thermocouple thermometer.
In the middle of the strip, thus right above the led-strip.

The room temperature was around 50 Fahrenheit / 10 Celsius.
F***ing cold if you just have to stand there and do some (semi-scientific) test.
Before I turned the led-light on, the temperature of the aluminium strip was about 52-54 F / 11-12 C.
After 40 minutes the temperature of the strip was about 105 Fahrenheit / 40 Celsius and it stayed that way.

I also glued the sensor at a different spot: the end of the aluminium-strip. That strip was perhaps 3 or 4 inch longer (at each side) then the led-strip.
So I glued the sensor at the end, and then the temperature was 90 F / 32 C after 40 minutes.


In the future I will glue the sensor on top of the led-strip, and see what the temperature will be.

I did another test today.

This time I took just the led-strip (so no aluminium strip or heatsink)
The base of the TCI Led 24 W is made of plastic and bends a bit.
Room temperature was about the same 52 Fahrenheit / 11 Celsius.
Glued the sensor of the thermometer straight on top of the led-strip for this test.

Turned on the light and started measuring.
Fist thing I noticed was that the temperature was rising faster.
(I think because there was no cold aluminium to be heated up first)
After 5 minutes the temperature was already 106 Fahrenheit / 40.5 Celsius
After 30 minutes it was 112 Fahrenheit / 44.5 Celsius
Stopped testing at 40 minutes. The temperature stayed about the same. Sometimes a bit lower.

One thought I had was that maybe the temperature did not get higher, because of the cold room the test was done in.
So, perhaps some cold air above the sensor that cooled the sensor off.
That's why I took a piece of foam rubber.
Glued the sensor on top of the led strip, and with some tape I attached the foam rubber on top of the sensor.
Turned on the light again.
It all warmed up slightly slower, but after 25 minutes the temperature was about the same (110 Fahrenheit / 43 Celsius) as after 25 minutes with the test without a foam rubber piece.

Another thing I noticed that if I walked past the led strip and moved some air (just by walking by) you saw immediately the temperature go down. No big changes, but 0.2 degree or 0.4 degree. So I guess that even a tiny fan like the one's used in a car on 12 V or a computer fan, will bring the temperature down a few degrees easily.
Did not test it, but just a guess (and of course reading it on this and other forums)

Another method is to measure junction temperature my monitoring voltage and current. If driving with constant current, the voltage changes with temperature. If driving with constant voltage, the current changes with temperature.

Heat sink temperature can be held rock steady with water cooling and the temperature differential between heat sink and diode junction can be measured instantly, equilibrium is reached in a fraction of a second. Even with a 300W cob.

Rocket Soul said:

I wanna know aswell.

Ive used standard 3M for low wattage operation with no probs.

Click to expand...

The way I tested it, there was not a huge difference between the temperature with the led strip solo, and the led strip attached to the aluminium strip
Without the aluminium the the temperature was 112 Fahrenheit / 44.5 Celsius. With the aluminium strip I measured 105 Fahrenheit / 40 Celsius.
So a difference of 7 Fahrenheit / 4.5 Celsius.
Of course my test was not scientific, but I think it gives a close enough indication.
The Chinese tape is good enough for strips. It transfers the heat quite decent. For cobs I would not use it. And also not when you drive your strips really hot.

My guess is (but can't prove it) that the temperature of the aluminium strip would have been slightly higher with 3M tape or some fancy paste.
But I think it is pointless (with strips not driving to hot) and those extra 3 or 4 degrees that you might gain are not worth the money.

By the way: If anyone thinks I did my test in the wrong way, or the starting point was already wrong, please let me know.

Keesje said:

The way I tested it, there was not a huge difference between the temperature with the led strip solo, and the led strip attached to the aluminium strip
Without the aluminium the the temperature was 112 Fahrenheit / 44.5 Celsius. With the aluminium strip I measured 105 Fahrenheit / 40 Celsius.
So a difference of 7 Fahrenheit / 4.5 Celsius.

Click to expand...

I wonder, if one put the led on the aluminum both with and without the tape and compared the temperature of the aluminum to see how much hotter it gets with the tape. I would think aluminum getting hotter / quicker = better heat transfer from the LED strip to the heat sink.

Renfro said:

I wonder, if one put the led on the aluminum both with and without the tape and compared the temperature of the aluminum to see how much hotter it gets with the tape. I would think aluminum getting hotter / quicker = better heat transfer from the LED strip to the heat sink.

Click to expand...

The aluminium strip was meant as a heat sink.
Of course it would be better with fins, but for this test that was not important.
I did the test to see how well the Chinese tape would transfer heat from the led strip to the aluminium strip.

I am pretty sure the aluminium would get hotter.
But how would the led stay on the aluminium strip?
You will have to find a way to attach the led-strip to the aluminium strip.
Screws is a possibility. Paste. 3M Tape. Chinese Tape.

Or do you mean something else?