Review: ALIENTEK T90B 140W Smart USB-C Soldering Iron

If you’re an electronics enthusiast or a maker, chances are, you’ve had to use a soldering iron at some point in your life, whether to build something new or to modify and repair something that already exists. Anyone serious about soldering will vouch for the necessity of a temperature-controlled soldering station, but they can be somewhat pricey as an initial investment, and their design mostly lends themselves to being on the bench.

But what if you’re the sort of person that gets called out into the field (e.g. a relative’s house) for a quick repair? Or perhaps you’ve got a wire to join or a connector to populate, but it’s in your car? Lugging around a soldering station isn’t ideal especially when power is not readily available. In those cases, a USB-C PD-based soldering iron is a good compromise. In the past few years, they’ve advanced quite a bit with the increasing popularity of higher-power EPR power supplies and power banks.

In this post, I’ll be reviewing the ALIENTEK T90B Smart Soldering Iron, which is powered via USB-C PD at up to 140W and uses JBC-style T245 compatible cartridge tips. As someone who’s soldered with the high-end (Metcal, Weller, Ersa) and the more reasonably-priced (Hakko, Atten) stations on a regular basis, will the ALIENTEK T90B be useful enough to find a spot in my tool bag?

Thanks to ALIENTEK for submitting this for review under the review challenge terms, via Platima (YouTube | GitHub).

Unboxing

The box arrived shrink-wrapped, with the front of the box showing a hero-photo of the soldering iron.

The rear provides a number of key specifications, along with a QR code for the user manual. The T90B that I am reviewing is part of a family of irons – the T90A which is a smaller fine-work oriented unit that uses T210 cartridges, the T90B that is more of a general purpose iron that uses T245 cartridges and the T90C that uses T65 tips.

The sides of the box provides some indications of the key features of the unit.

Rather than use disposable packaging, ALIENTEK have nicely decided to use a plastic box which can serve as a case for the unit throughout its life. I definitely appreciate this very thoughtful and consumer-friendly way to package their product.

The interior of the plastic box is well laid out, using foam to hold the included items in position.

The inclusions are an information card, a stand, a USB-C to USB-C cable and the T90B soldering iron.

The top half of the unit has an LCD with a protective cover. The ALIENTEK logo is printed above the screen and the model is on the cover. Below that is the two buttons (A and B) and a rubber grip.

On one end is the USB-C socket for power and data. The cap is secured using a bayonet (push and twist to lock) mechanism.

The body is made of a nice aluminium alloy. The metal cap is a nice touch, matching the rest of the body, safely covering up the warm tip after use. The tip cartridges, as with the JBC system it’s based on, is simply a pull-out and push-in affair, making it easy to change.

The pre-installed cartridge appears to be marked T245-KU BK with the ALIENTEK logo. This appears to be a knife-chisel style tip – I’m more of a conical tip user myself, but I can work with this too …

The included stand is made of silicone and has the ALIENTEK branding printed on one side. A small sponge is included for tip-cleaning, which I don’t mind, but will require water. Brass-wool users will have to supply their own.

The supplied USB-C to USB-C cable has a nice solid plug on both ends, with the ALIENTEK logo moulded into the ends. The cable is silicone-sheathed to avoid burning.

When placed on the stand, the iron stands with the tip safely raised above the bench surface with the iron at an angle. With the stand, there is no risk of the iron rolling away either.

User Experience

In this section, I focus on the user experience, looking at the user interface and how it handles a number of common tasks.

User Interface

The iron is relatively straightforward to operate – plug in USB-C power, watch the display and interact with the two buttons on the barrel – A and B. The buttons are placed high-enough that they are unlikely to be inadvertently pushed. Interactions are via short and long-presses of each button, which can be a bit tedious at first, but thankfully the menus are only really necessary for configuration. Once you’ve set up the T90B to your liking, you probably won’t need to worry about them.

While starting up, it displays the ALIENTEK logo. It starts up with the iron turned off, and a press of the A button closest to the tip is needed to start the iron.

The user interface has three presets – the currently active one is displayed in blue. The current temperature is displayed in large red font, while the bar underneath indicates the power status. The fine details about the available power is on the right, showing real-time voltage, current and power.

The menu can be invoked with both A and B pressed and is displayed two lines at a time.

Voltage information gives you information about your power source and the tip resistance. The unit will self-diagnose improper tip installation or heater failure.

Other settings can be configured such as the temperature step, preset, sleep temperature, sleep and standby timeouts.

The power mode can be manually set to a lower value if you’re experiencing issues with power supplies cutting out under load. The auto mode will use the highest power available – this is recommended in most circumstances and it makes good sense because the higher wattage means faster heat recovery and better soldering experience. Because of the temperature regulation, the power is cut back once the tip reaches temperature – old advice to stick to lower wattage irons for delicate work does not apply! Power trim allows for fine adjustments of the power.

Localisation is available to change the temperature unit and language. The unit can also be set to start up automatically rather than require a button press.

A temperature offset can be set to improve the calibration. My T90B came with firmware V1.1.1.

You can long-press the B button to put the iron to sleep which keeps it at a lower temperature to be ready to start-up quickly. This is also automatically invoked after the time-out, based on the inductive sensing to know if the iron is in the hand. If the unit is connected to a 5V-only supply, the screen will display “Vol low” – the soldering iron absolutely requires 9V at a minimum to operate.

If you’re really lost regarding the menus and features, the firmware download package also has the user manual which is quite comprehensive and readable.

Firmware Update

As it turns out, the firmware that was pre-loaded on the T90B that I received was not the latest. Firmware and the updater tool can be downloaded from ALIENTEK’s product page.

The tool loads in Chinese by default. It was only after I updated the firmware that I realised the language can be changed using the drop-down menu. You can choose to load the firmware and logo file at the same time, or just one at a time.

In my case, the firmware update went smoothly and I was able to load the English version of the boot-up logo. The new firmware improved the display rotation and added the option to disable the beeper, but otherwise remains unchanged.

Soldering Jobs

To fairly assess the soldering iron’s potential, I decided to use it as my primary soldering iron for a couple of weeks. That meant, despite having a Weller, Metcal and an Atten on the bench, I would use the ALIENTEK T90B – no excuses.

In my week, I was wiring up a few transfer switch boxes and needed to solder 2.5mm^2 copper wire to lugs on an IEC socket. This is probably a bit much for the knife-type tip to handle, but I managed to do it just fine with leaded solder. The tip could pass enough heat into the joint before the wire wicked it away, but the higher-temperature required for lead-free solder made this a bit tricky. Perhaps it would be better if I had a chisel or wider conical tip rather than a knife tip.

I came across an old Ktec-style plug-pack with bad capacitors that needed a quick swap. Squeezing off the top case, I managed to swap out three capacitors …

… with the main challenge being the tight confines due to not wanting to desolder the input lugs from the PCB. The thin general-purpose tip made it easy to sneak in and wiggle out the old caps, wick up the remaining solder and solder in new capacitors.

Speaking of wick, desoldering is one of those tasks that needs quite a bit of power to do effectively. But it was no challenge – the T90B managed this external drive power supply with ease, especially as a single-sided board.

Here’s a wider shot of the task on my workbench – this time it was replacing the primary high-voltage DC electrolytic capacitor.

Being less of a heat-sink, I managed to solder this with leaded solder …

… and lead-free (slightly less shiny) solder with no problems at all.

Final Thoughts

In all, I found the T90B to be exceptionally handy and good enough to replace my primary iron for a majority of tasks. Part of the reason it wasn’t quite able to cover every task is due to the knife-type tip that is included that has a limited amount of contact area and size. Perhaps a larger collection of tips would help.

In use, the heat-up is quite rapid at 140W, to the point that it feels practically as good as my Weller in terms of “pick-up and go” solderability, managing to heat up within three seconds. The “inductive” hand detection worked very reliably, with a “dot” on the display to indicate sensor status which accurately reflected whether the iron was “in-hand” or on the bench. While the T90B will work with lower-powered supplies, I found soldering at 18-20W with smaller power banks to be very frustrating for anything but joining thinner wires or doing smaller PCB tasks. Perhaps in an emergency, it’s better than nothing, but I’d recommend at least 60W for a usable soldering experience. The main downside at 60W is a slight wait of a few more seconds for it to come up to temperature, but it seems that once up-to-temperature, it handles quite well.

The supplied e-Marked cable that supports USB-C PD EPR has a silicone sheath, which is great for avoiding potentially burning the cord, and is connected-through for data so that firmware updates can be made using the included cable. But it is slightly thick and heavy, so compared to my higher end soldering stations, it’s not as easy to manoeuvre. But it’s far from the PVC “stiffness” of my older Atten station. The length is quite good at 1.2m, especially when used with a power bank which is my preferred configuration as that lets you easily reposition your work and reach awkward places that an ordinary soldering station would find hard.

The rubber grip feels nice and never seems to get beyond a comfortably warm at the front edge. It doesn’t seem to be conductive though and the finish on the soldering iron doesn’t seem to make good conduction. This means that the iron could be an ESD risk for sensitive chips – while the tip is connected directly to the shield of the USB-C connector, only some power supplies connect this to ground. Where you are using a power bank or many “two-prong” un-Earthed power supplies, the tip will “float” and may have a voltage on it that could be bad for ESD-sensitive devices. It would be nice if there is a way to connect an Earth to the iron itself to guarantee the tip is at a safe voltage, but until then, I’d recommend using an Earthed USB-C PD power supply (e.g. the ones supplied with laptops) if handling ESD-sensitive components.

The included silicone stand and sponge is basic, but better than some of the folded-metal style stands offered by other basic kits. It’s definitely more reusable and the sponge, while small, is enough for a small tip and occasional use. The inclusion of a plastic case to keep the kit together is also a nice bonus and the metal cover also means what you can sheath the hot tip and pack it away without risk of burns.

Unfortunately, there is no teardown in this review, as I did try but then I got stuck and discovered that it cannot be done easily or non-destructively. That being said, given the (likely) simplicity of the circuitry, short of bricking the firmware or wanting to modify/repair it, I don’t see myself wanting to take it apart. It feels so solidly built and elegantly simple as it’s just PWM-ing the USB-C PD power that I feel it should be quite reliable, but only time will tell.

Testing

This section has results measured using test equipment.

Weight

The soldering pencil, with tip, measured 39.77g on my set of scales. This excludes the cable and is roughly similar with many of the handpieces I have. The handpiece doesn’t feel specifically front or rear-weighted, which makes for comfortable handling.

e-Marked Cable

The FNB58 recognises the e-Mark chip in the cable as supporting 50V/5A, therefore supporting up to 250W. It is great the cable is included, as this means no worrying about finding EPR-capable cables that won’t be accidentally burnt.

Absolute Temperature Calibration

To test the temperature, I used a Weller WCU thermocouple-based temperature meter.

It seems that the temperature is a bit low at all settings – 350 degrees C measured 330.1 degrees C (~20 degrees C low)

At 450 degrees C, it measured 416 degrees C (~34 degrees C low) and at 200 degrees C, it measured 186.1 degrees C (~13 degrees C low). I could have used the temperature calibration setting to null-out the error in the middle, but because there’s a bit of a “curve” to the error, it would not result in accurate temperature across the scale.

However, even with the temperature offset, the fact that the unit regulates temperature just means that you need to set temperatures which work better for your purposes. I quickly changed the presets to more reasonable ones.

Thermal Image

Using the Thermal Master P3, I took a thermal image of the T90B handpiece without the tip to see what the temperature of the handle would be after some prolonged soldering.

Overall, the handle remains pretty cool – the middle of the handle was at 31 degrees C. The hottest part was 53.1 degrees C, which was the metallic collar near the tip cartridge itself, while the rubber grip was a slightly more comfortable temperature, feeling only slightly warm and not at all uncomfortable.

Power Input Behaviour

Initially, I tried to measure the power consumption directly using the Fnirsi FNB58 tester, but the rapid PWM made for a very messy graph even at the highest sample rate that the tester was capable of. The T90B seems to be switching the input hard, therefore, the meter is measuring 5A or near-zero, most of the time, with the duty changing depending on the load.

Using the Rohde and Schwarz MXO4 oscilloscope, watching the power supply voltage, I was able to determine the initial warm-up time of almost exactly three seconds, confirming the claimed specifications.

During heat-up, it seems there’s a short hiccup every 100ms (10Hz). Once fully warmed up, the PWM seems to be at 20ms intervals (50Hz).

Temperature Stability

High-rate temperature measurement was performed using a B&K Precision DAS240 multi-channel process recorder.

The warm-up curve doesn’t quite meet the three-second specification because the measuring thermocouple applies a load to the tip and wicks away some of the heat. There is also a slight lag in response of the thermocouple. Regardless, the warm-up curve is mostly smooth, with no signs of overshoot.

Once warmed up, I left it to run until it timed out, so over the space of around three minutes, the temperature seemed to creep up by almost four degrees Celsius. This isn’t particularly significant and can be considered relatively stable.

Upon expiry of the timeout, the unit goes into 200 degrees C standby for a bit before turning off and cooling naturally.

To more strenuously test the iron, I decided to get my Wolfbox MF100 to blow on the tip and create thermal load in a nearly step-load.

While the unit heated up to about 332 degrees C to start with, after it was blown on by the air duster several times in quick succession, the iron recovered quickly and did not overshoot, settling comfortably in the 324-326 degrees C range. This indicates a stable PID control algorithm.

Conclusion

The ALIENTEK T90B definitely impressed me. As a package, it was nicely finished with a handpiece that is well-balanced with a solid build quality with its aluminium alloy body. The kit includes a plastic case, silicone-based stand with cleaning sponge and a 1.2m silicone-sheathed USB-C to USB-C PD EPR e-Marked cable. The unit comes with a T245-KU knife-type tip, which may be a bit small for some work, but it is a common JBC style cartridge which can easily be replaced.

Having used the unit as my primary soldering iron for two weeks, it managed to handle most of the soldering and desoldering tasks with aplomb, leaded and lead-free, albeit slightly limited by the contact area of the included tip. With 140W support, when used with a power bank, it results in a portable soldering set-up that can reach places that traditional stations find difficult. Despite being portable, it is in no way compromised with three-second warm-up, accurate inductive sensing, configurable easy-to-use highly-informative user interface and tip-preserving sleep modes. Tip temperatures were consistent without overshoot and the rubber grip remained at a comfortable temperature even on longer soldering sessions.

The key drawbacks include a high temperature offset out-of-the-box which can be tuned out using the menus and the potential issue of ESD safety, depending on what power source you use, as there doesn’t seem to be an easy earthing point. Floating sources of power could develop some stray voltages. Finally, disassembly is a bit complicated, unlike earlier designs.

In the end, it’s hard to deny the T90B’s versatility and utility, especially considering its price. Whether it’s a first soldering-iron for someone starting out, or an iron for someone who’s a seasoned service technician, it’s exceptionally handy and will be in my tool bag for sure!

If you’re interested in a T90B for yourself, or its smaller (T90A) or bigger (T90C) cousins, you can find more information at ALIENTEK’s site and purchase from their official AliExpress and Amazon stores.

Thanks to ALIENTEK for providing this unit for review.