In mid-July 2025, together with several leading creators from the embedded industry, we had the opportunity to visit the STMicroelectronics factory in Agrate, Italy. How did it happen? …well, I know 😅 This visit had been planned many months earlier as part of cooperation with Polish ST ambassadors. It was the first visit of this kind ever!

I was at the STMicroelectronics factory 😎 What did the visit look like?

Huge thanks to the Polish branch of STMicroelectronics, and especially to Karol, who strongly pushed the whole trip forward.

In today’s post, I will focus on what the meeting looked like, what we did, and what we saw on site — but not only that. The visit was also combined with some light sightseeing in the area, which I will also describe here.

“ST Ambassadors Event” — that’s how our visit was written on the board inside one of the factories we toured — was planned for Thursday and Friday. We started arriving in Milan, more precisely in Bergamo, on Wednesday evening. We arrived in two waves. Fortunately, I was in the first one, so while waiting for the second group we could drive to Bergamo for dinner.

I had already been to Bergamo once before, and it was very nice to return there. It’s a truly beautiful town, especially Città Alta (alta ≠ old, but high — in this case “Upper Town” 🥸). After picking up the second group, we went straight to the hotel near Agrate, stopping on the way to grab some food for the others. We got to our rooms around midnight, and the event started the next day at 9:00. For me, that’s rough, because I usually go to sleep at 22:00, but I managed 😅

Day 1 – Agrate

The first day was entirely spent at the largest STMicroelectronics factory in Europe, located in Agrate. Unfortunately, we were not allowed to take photos inside the entire complex. Therefore, the factory photos that appear in this post come from publicly available ST materials.

It is here in Agrate that the main Italian headquarters of ST is located. On a daily basis, over 5,000 people work there. It is one of the company’s key sites — MEMS devices and smart power solutions are produced here, including the famous BCD (Bipolar-CMOS-DMOS) technology.

It is also an important design and R&D center, and additionally EWS (Electrical Wafer Sort) testing is carried out here.

The factory is impressive already by its sheer scale — alongside the long-running 200 mm line, a modern 300 mm wafer production line was launched in 2023. The entire complex contains 35,000 m² of cleanrooms, where semiconductor production takes place.

A cleanroom is a specially designed space where an extremely low level of contamination is maintained — such as dust, pollen, bacteria, or microscopic particles.

For easy comparison, a standard football pitch is about 7,140 m², so here we have almost 5 pitches.

This is where ST is pushing its technology to a completely new level, and honestly — you can feel it in the air (even though it’s extremely clean 🥸).

Presentation of our activities

We went on the trip with a very strong lineup:

✅ Maciej Gajdzica – https://ucgosu.pl
✅ Mikołaj Andrzejewski – https://www.youtube.com/@embeddedGarage
✅ Mateusz Pluta – https://dmbp.pl/
✅ Piotr Czaplicki – https://www.stm32wrobotyce.pl/
… and me 😅

The first major part of our event was presenting our own activities. In the room, from the STMicroelectronics side, there were many people associated with marketing, EU programs, as well as people responsible for MEMS and production itself.

Each of us had about 20 minutes for a presentation. I started mine with a few sentences in Italian (I’ve been learning for a year) and got applause from our Italian colleagues. Apparently, I stole the whole show 😅

From my side, I talked a lot about the history of how my activity was created: how I started writing a blog, how readers convinced me to open a store and start producing online courses. I also showed how the “back office” is still developing — how the company evolves, for example in terms of office changes, hardware development, and the number of employees.

There were also numbers, of course — I shared the number and volume of my courses, the number of students, and the size of my social media and YouTube channels.

What was the coolest — the ST team took us incredibly seriously. They later remembered our presentations and what we do. For the next several hours, they kept referring to our activities and accurately pointed out who did what. One might think that some random guys who write things on the Internet came to bother them — but no! We really got to know each other well. This made a huge impression on us and made us feel really good being there.

How are semiconductors made? From sand to the final chip

Later it was time for a story about what the entire semiconductor manufacturing process looks like. Everything was explained to us by Krzysztof Smołko. You can find a similar presentation in the recordings from our meetup:
https://youtu.be/UnWOuzRiazk

This was a great introduction to what was about to come next — the factory tour. First, the cleanroom with semiconductor production on 200 mm wafers, i.e. the slightly older facility.

Of course, we could not enter the production area itself, but around the cleanrooms there are corridors with glass walls, through which we could see everything. We also had the opportunity to go through the basic procedure of moving from the “dirty” to the “clean” zone, including putting plastic covers over our own shoes 🙂

Inside the 200 mm line there were quite a lot of people. Silicon wafers are transported manually in special boxes holding 25 silicon discs. Wafers must not be touched directly by hand! You place such a box on a special station, and the machine itself takes and places the wafer.

Machine operators walk around in protective suits. They look a bit like astronauts. Fun fact: there is an absolute ban on running in the cleanroom — like in a school corridor 😉

Another interesting fact: since silicon wafers in this older factory have direct contact with the room’s “atmosphere,” the highest air cleanliness class, ISO 1, must be maintained.

✅ Cleanliness classes according to ISO 14644-1

The lower the number, the cleaner the room — fewer particles in the air.

ISO Class	Max. number of particles ≥0.5 μm per 1 m³ of air	Examples of usage
ISO 1	10	High-tech laboratories (optics, nanotechnology)
ISO 2	100	Lithography in state-of-the-art semiconductor production
ISO 3	1 000	Microprocessor production, photolithography
ISO 4	10 000	Advanced electronics manufacturing
ISO 5	100 000	Typical cleanrooms in semiconductors (often used in ST, Intel, TSMC fabs)
ISO 6	1 000 000	Pharmaceuticals, precision assembly
ISO 7	352 000 000	Pharmaceutical, medical industry
ISO 8	3 520 000 000	Assembly of optics, general-purpose electronics
ISO 9	~like office air	Offices, standard room

(For comparison: in a typical office there are tens of billions of particles per m³ of air!)

In this cleanroom, ALL THE AIR IS EXCHANGED EVERY 6 SECONDS. Can you even grasp that? Exchanged, meaning filtered and cleaned by powerful machinery.

Such a factory occupies 3 floors — not residential ones with 3-meter heights, but much higher. When we later went to the second factory on the 3rd floor, we were already over 30 meters above ground.

A typical multi-level structure of a semiconductor fab looks like this:

• Ground floor: logistics access to raw materials, warehouses, HVAC/filtering systems
• Upper floors: cleanroom, production lines, test areas, laboratories, server rooms
• Above the cleanroom: technical plenum with ventilation, filtration, pipelines, and cabling

ST does not show what this looks like internally (classified — which is why we couldn’t take photos), but I found something similar:

In the cleanroom, at first glance, you don’t see this filtration system. On the floor, you can find holes through which air is drawn out of the room.

You may also notice the distinctive yellow light. It is used in areas where lithography is performed. Lithography creates precise patterns on wafers using light, a mask, and photoresist.

Photoresists are light-sensitive — they react to blue and UV radiation. Yellow light does not trigger this reaction, allowing safe handling and precise processing.

In areas without lithography, standard cold white light is used.

300 mm wafer line

Later we moved to the building next door — the factory opened in 2023 for 300 mm wafers. And here we were shocked. Almost no one works here — around 5–6 people per shift, sitting at desks.

All transport between production stations is handled by automated carts moving on ceiling rails.

This eliminates manual wafer handling and maximizes machine uptime.

In this newer fab, ISO 6 cleanliness is sufficient. Why lower than before? Because inside the wafer cassettes transported by the carts, ISO 1 is maintained. These cassettes dock to machines like capsules to the ISS.

Thanks to such a sealed connection, the entire cleanroom can have much lower air cleanliness, which reduces fab operating costs.

In such a modern line, almost nothing can be seen from the outside. All machines are loaded from the top, so every process looks very similar. Each station is like a small building without doors. Only the maintenance team has access to them.

Production 24/7

The factory must operate without any interruption. Holidays and days off do not matter. They work in 3 shifts — 2 day shifts and 1 night shift. Stopping the line is very costly.

As we learned, there are two forms of emergency shutdown of such a line: yellow and red.

If I remember correctly, recovery from a yellow stop takes about 24 hours, while from a red one — up to 2 weeks! The point is that after a complete fab shutdown, the air must be cleaned, furnaces heated up, machines restarted, etc. These are losses likely counted in billions of euros.

How is a fab built?

The construction of such a fab is a complex and expensive process. They produce at the scale of nanometers, so precision is… quite important. ST has its factories, for example, near Mount Etna in Sicily, which is quite active. Here in Agrate, the busiest highway in Italy also runs nearby. This has a huge impact on production precision. How do they deal with it?

To ensure maximum ground stability and minimize vibrations and subsidence, fabs are usually built on deep pile foundations. This is a typical standard in the modern semiconductor industry.

What does a pile foundation under a fab involve?

Hundreds or thousands of concrete piles (reinforced concrete columns with circular or square cross-sections) are driven deep into the ground — to depths of several to even dozens of meters — until stable load-bearing soil layers are reached.

Above the piles, a so-called pile cap (foundation slab) is constructed, on which the entire building structure is erected. It distributes the building’s weight evenly across all piles.

Such a solution ensures stability even on heterogeneous soils or areas prone to earthquakes, and significantly reduces micro-vibrations that affect the precision of integrated circuit manufacturing.

Social media meeting and dinner

At the end of the day, we had meetings related to social media and marketing. ST showed us what they do, their reach, etc. We had the opportunity to discuss how we could cooperate and how ST could help us in our activities. Maybe something cool will come out of it. There are a few ideas 👌

We also learned that ST organizes a kind of idea accelerators — something very similar to hackerspaces, which we know, for example, from Gdańsk.

At the end of the day, we went to the town of Monza (where Formula 1 GPs take place) for a real Italian dinner. I visit Italy several times a year, but I had never been to dinner with Italians before 😅 An amazing experience. Delicious food, incredible atmosphere, and abundant conversations about everything.

The dinner lasted several hours, as is typical in Italy, and ended with sightseeing around the town of Monza. A very nice place, which we returned to on the evening of the second day.

Day 2 – Casteletto

On the second day, we went to the other side of Milan, to the town of Casteletto. It is a research and development center, i.e. R&D. Among other things, new generations of MEMS devices are developed here, and that was exactly what our visit focused on.

It is quite an old site and not very representative. The main building with the beautiful name Palazzo Quadrifoglio (a building shaped like a four-leaf clover) looks very old and resembles an abandoned psychiatric hospital more than an R&D center 😅 We, however, visited another building located several hundred meters away.

Here we had a very intense day with MEMS. We learned what current ST devices are capable of. I didn’t know things had advanced this far. In such tiny accelerometers, they even pack some simple AI (yes, I know… everything is AI now) to detect motion patterns without microcontroller intervention. Why? Because an MCU consumes currents in the order of mA, while such a MEMS can do the same for just a few μA.

MEMS have gone in the direction where signal processing happens inside them, and only the detection result is sent to the microcontroller. Sounds beautiful and works… probably also well, but in 3 hours of workshops you can’t do everything perfectly 😅

Training such a MEMS is a fairly complex process. A large amount of good data is required, as well as models for training embedded neural networks. There are also space limitations — how much of such a network can fit into a MEMS? Well, not much.

Fortunately, ST creates tools that make this easier — such as MEMS Studio or ST AIoT Craft. Plus development boards like SensorTile. Putting it all together, you can really focus on what matters most in such work — collecting data and training AI or a simple state machine.

Touring the MEMS testing line

After the workshops, we were taken to another machine hall. There were no cleanrooms here, so we could enter and walk among the devices. We were shown the final path of the chips — testing of the finished product. Trays with chips are loaded into subsequent machines. Among other things, sensor calibration is performed here.

One of the machines loads accelerometers and gyroscopes onto a special drum. It takes dozens of them at once using a Pick and Place system similar to those used in SMT soldering processes.

After loading, the drum spins with precisely known acceleration values along each axis. During rotation, values from all sensors are continuously read — the test tray contains a huge number of test pins contacting the MEMS.

At the end, the readings are compared with reference values, and differences are corrected by writing calibration data into the OTP registers of the sensor. Later, we programmers often read these calibration data and convert real values, or the MEMS itself does it for us if we have a newer one.

Temperature sensors are tested in a similar way — in small infrared heating chambers. For automotive devices, tests are doubled: at low and high temperatures.

Every MEMS must go through such a calibration and testing process. Otherwise, it would be useless. The line we toured was not a full-scale production line. It was more of an R&D test line for MEMS. The solutions prepared here are later replicated and built in so-called backend factories, where silicon is packaged.

Innovations and future trends

At the very end, we had the opportunity to meet one of the Vice Presidents of STMicroelectronics — Alessandro Cremonesi. He is responsible, among other things, for innovation and the vision of the direction ST should pursue. It must be said — he is a man with an enormous vision. It’s great to meet someone so inspiring.

We learned, for example, that ST received IEEE Milestone awards. This is an international recognition program run by IEEE (Institute of Electrical and Electronics Engineers), the world’s largest engineering organization related to technology and IT. The program was created to honor outstanding technological achievements in the broad fields represented by IEEE (engineering, computer science, physical sciences, and others).

For what?

• “Multiple Silicon Technologies on a Chip, 1985”: the award was granted for the development and implementation of the groundbreaking BCD (Bipolar–CMOS–DMOS) technology, allowing the integration of three types of transistors in a single integrated circuit: bipolar (for precise analog functions), CMOS (for complex digital operations), and DMOS (handling high power). This solution enabled engineers to build advanced, highly reliable, and efficient systems used in automotive, computing, industrial equipment, and consumer electronics. This technology has been widely deployed, and to date over 40 billion chips based on it have been sold.

• Integrated circuits for satellite digital radio: the latest IEEE Milestone (2025) was awarded to STMicroelectronics for inventing and implementing integrated circuits for satellite radio transmission, significantly contributing to global innovation in wireless audio and information transmission technologies.

The distinction is awarded for breakthrough innovations documented in products, technologies, patents, or publications that have brought clear societal benefits and whose impact has been visible for at least 25 years.

The award takes the form of unveiling a commemorative bronze plaque at a site associated with the achievement. It does not honor an individual or a company — the innovation itself and its impact on the world are recognized.

We also listened to a lot about AI on the Edge, i.e. small AI models and algorithms that run “on the edge,” on end devices. Hence AI solutions, for example, in MEMS. Whether we like it or not — there will be more and more of it.

Weekend in Milan

Most of us stayed for the whole weekend. It would be a shame to travel so far and not take advantage, right? Mateusz spent time in Bergamo, Piotr flew back to Poland on Saturday afternoon and toured Milan, and I went off into the distance with Mikołaj and Maciej 😅

Since I already know this region well, I acted as a guide for the guys (or maybe a semi-conductor? 🤔). I took them to Lake Como — considered one of the most beautiful in the world. Unfortunately, in recent years it has been heavily damaged by Instagram and posing influencers. And since ST calls us embedded influencers, why not go 🥸

We sailed along two branches — Lago di Como and Lago di Lecco — with a stop in Bellagio, one of the more popular towns on Lake Como. There I took the guys to a restaurant I know for very good pasta.

Mikołaj was poorly prepared for walking tours — he arrived with a large wheeled suitcase instead of just a backpack 😅 The result was that on the uneven stairs in Bellagio… he lost the wheels.

Write to Mikołaj to tell him to put together a vlog from the trip, because he recorded a lot 🙂 I, knowing that I couldn’t record the factory, skipped carrying a camera. I also didn’t record a travel vlog, because I wouldn’t have edited it later. I still have ones from 2022 waiting to be edited…

Sailing on Lake Como took us the whole day. Milan is actually close, but trains don’t run that often. We arrived late in the evening, strategically booking accommodation right next to the station.

Mikołaj had a flight early Sunday morning, so with the last metro services we went to the Duomo, the Milan cathedral. We walked through the Galleria Vittorio Emanuele II and returned to the room.

The next day we said goodbye to Mikołaj. Together with Maciej, we went up to the roof of the Duomo and walked around Castello Sforzesco and the adjacent park, where the Arco della Pace — the former city gate — is located.

In the park, we observed how scammers trick people into the three-cup game. Never play it — you can’t win! When I was explaining the scam to Maciej, one of the planted players heard the key word — “scam.” He approached us and told us to “move away quickly” 😅

In the evening, we went to the airport, and that’s how our journey ended.

Summary

The whole trip was great. The invitation from ST and the opportunity to tour the factories were something unique. Maybe we’ll manage to fly to another factory someday? Power and power-supply components are produced in Sicily. Who knows 🙂

It’s a pity we couldn’t document the trip even a little. At the time of writing this article, I’m still waiting for a group photo with the entire ST team in front of one of the factory buildings. These are not easy things to obtain 😀

Once again, thank you to the Polish branch of ST for the invitation, to the Italian side for the incredible hospitality, and to our embedded creators team for the great company! In my opinion, it’s great that we can all work together!