In today\u2019s post, I will focus on what the meeting looked like, what we did, and what we saw on site \u2014 but not only that. The visit was also combined with some light sightseeing in the area, which I will also describe here.<\/p>\n\n\n
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<\/figure>\n<\/div>\n\n\n\u201cST Ambassadors Event\u201d<\/strong> \u2014 that\u2019s how our visit was written on the board inside one of the factories we toured \u2014 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.<\/p>\n\n\n I had already been to Bergamo once before, and it was very nice to return there. It\u2019s a truly beautiful town, especially Citt\u00e0 Alta<\/strong> (alta \u2260 old, but high \u2014 in this case \u201cUpper Town\u201d \ud83e\udd78). 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\u2019s rough, because I usually go to sleep at 22:00, but I managed \ud83d\ude05<\/p>\n\n\n\n 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.<\/p>\n\n\n\n It is here in Agrate that the main Italian headquarters of ST is located. On a daily basis, over 5,000 people<\/strong> work there. It is one of the company\u2019s key sites \u2014 MEMS devices and smart power solutions are produced here, including the famous BCD (Bipolar-CMOS-DMOS)<\/strong> technology.<\/p>\n\n\n\n It is also an important design and R&D<\/strong> center, and additionally EWS (Electrical Wafer Sort)<\/strong> testing is carried out here.<\/p>\n\n\n\n The factory is impressive already by its sheer scale \u2014 alongside the long-running 200 mm<\/strong> line, a modern 300 mm<\/strong> wafer production line was launched in 2023<\/strong>. The entire complex contains 35,000 m\u00b2 of cleanrooms<\/strong>, where semiconductor production takes place.<\/p>\n\n\n\n A cleanroom<\/strong> is a specially designed space where an extremely low level of contamination is maintained \u2014 such as dust, pollen, bacteria, or microscopic particles.<\/p>\n\n\n\n For easy comparison, a standard football pitch is about 7,140 m\u00b2<\/strong>, so here we have almost 5 pitches<\/strong>.<\/p>\n\n\n\n This is where ST is pushing its technology to a completely new level, and honestly \u2014 you can feel it in the air (even though it\u2019s extremely clean \ud83e\udd78).<\/p>\n\n\n\n We went on the trip with a very strong lineup:<\/p>\n\n\n\n \u2705 Maciej Gajdzica<\/strong> \u2013 https:\/\/ucgosu.pl<\/a> 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.<\/p>\n\n\n\n Each of us had about 20 minutes<\/strong> for a presentation. I started mine with a few sentences in Italian (I\u2019ve been learning for a year) and got applause from our Italian colleagues. Apparently, I stole the whole show \ud83d\ude05<\/p>\n\n\n\n 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 \u201cback office\u201d<\/strong> is still developing \u2014 how the company evolves, for example in terms of office changes, hardware development, and the number of employees.<\/p>\n\n\n\n There were also numbers, of course \u2014 I shared the number and volume of my courses, the number of students, and the size of my social media and YouTube channels.<\/p>\n\n\n\n What was the coolest \u2014 the ST team took us incredibly seriously<\/strong>. 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 \u2014 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.<\/p>\n\n\n\n Later it was time for a story about what the entire semiconductor manufacturing process looks like. Everything was explained to us by Krzysztof Smo\u0142ko<\/a><\/strong>. You can find a similar presentation in the recordings from our meetup: This was a great introduction to what was about to come next \u2014 the factory tour. First, the cleanroom with semiconductor production on 200 mm wafers<\/strong>, i.e. the slightly older facility.<\/p>\n\n\n\n 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 \u201cdirty\u201d<\/strong> to the \u201cclean\u201d<\/strong> zone, including putting plastic covers over our own shoes \ud83d\ude42<\/p>\n\n\n\n Inside the 200 mm line there were quite a lot of people. Silicon wafers are transported manually in special boxes holding 25 silicon discs<\/strong>. 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.<\/p>\n\n\n 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 \u2014 like in a school corridor \ud83d\ude09<\/p>\n\n\n\n Another interesting fact: since silicon wafers in this older factory have direct contact with the room\u2019s \u201catmosphere,\u201d the highest air cleanliness class, ISO 1<\/strong>, must be maintained.<\/p>\n\n\n\n The lower the number, the cleaner the room \u2014 fewer particles in the air.<\/p>\n\n\n\n (For comparison: in a typical office there are tens of billions of particles per m\u00b3 of air!)<\/em><\/em><\/p>\n\n\n\n In this cleanroom, ALL THE AIR IS EXCHANGED EVERY 6 SECONDS<\/strong>. Can you even grasp that? Exchanged, meaning filtered and cleaned by powerful machinery.<\/p>\n\n\n\n Such a factory occupies 3 floors<\/strong> \u2014 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<\/strong>.<\/p>\n\n\n\n A typical multi-level structure of a semiconductor fab looks like this:<\/p>\n\n\n\n ST does not show what this looks like internally (classified \u2014 which is why we couldn\u2019t take photos), but I found something similar:<\/p>\n\n\n In the cleanroom, at first glance, you don\u2019t see this filtration system. On the floor, you can find holes through which air is drawn out of the room.<\/p>\n\n\n You may also notice the distinctive yellow light<\/strong>. It is used in areas where lithography<\/strong> is performed. Lithography creates precise patterns on wafers using light, a mask, and photoresist.<\/p>\n\n\n\n Photoresists are light-sensitive \u2014 they react to blue and UV radiation. Yellow light does not trigger this reaction, allowing safe handling and precise processing.<\/p>\n\n\n\n In areas without lithography, standard cold white light is used.<\/p>\n\n\n\n Later we moved to the building next door \u2014 the factory opened in 2023<\/strong> for 300 mm wafers<\/strong>. And here we were shocked. Almost no one works here \u2014 around 5\u20136 people per shift<\/strong>, sitting at desks.<\/p>\n\n\n\n All transport between production stations is handled by automated carts moving on ceiling rails.<\/p>\n\n\n This eliminates manual wafer handling and maximizes machine uptime.<\/p>\n\n\n\n In this newer fab, ISO 6<\/strong> cleanliness is sufficient. Why lower than before? Because inside the wafer cassettes transported by the carts, ISO 1<\/strong> is maintained. These cassettes dock to machines like capsules to the ISS.<\/p>\n\n\n Thanks to such a sealed connection, the entire cleanroom can have much lower air cleanliness, which reduces fab operating costs.<\/p>\n\n\n\n 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.<\/p>\n\n\n\n The factory must operate without any interruption. Holidays and days off do not matter. They work in 3 shifts \u2014 2 day shifts and 1 night shift. Stopping the line is very costly.<\/p>\n\n\n\n As we learned, there are two forms of emergency shutdown of such a line: yellow and red.<\/p>\n\n\n\n If I remember correctly, recovery from a yellow stop takes about 24 hours, while from a red one \u2014 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.<\/p>\n\n\n\n The construction of such a fab is a complex and expensive process. They produce at the scale of nanometers, so precision is\u2026 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?<\/p>\n\n\n\n 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.<\/p>\n\n\n\n Hundreds or thousands of concrete piles (reinforced concrete columns with circular or square cross-sections) are driven deep into the ground \u2014 to depths of several to even dozens of meters \u2014 until stable load-bearing soil layers are reached.<\/p>\n\n\n\n Above the piles, a so-called pile cap (foundation slab) is constructed, on which the entire building structure is erected. It distributes the building\u2019s weight evenly across all piles.<\/p>\n\n\n 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.<\/p>\n\n\n\n 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 \ud83d\udc4c<\/p>\n\n\n\n We also learned that ST organizes a kind of idea accelerators \u2014 something very similar to hackerspaces, which we know, for example, from Gda\u0144sk.<\/p>\n\n\n\n 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 \ud83d\ude05 An amazing experience. Delicious food, incredible atmosphere, and abundant conversations about everything.<\/p>\n\n\n 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.<\/p>\n\n\n 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.<\/p>\n\n\n\n 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 \ud83d\ude05 We, however, visited another building located several hundred meters away.<\/p>\n\n\n Here we had a very intense day with MEMS. We learned what current ST devices are capable of. I didn\u2019t know things had advanced this far. In such tiny accelerometers, they even pack some simple AI (yes, I know\u2026 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 \u03bcA.<\/p>\n\n\n\n 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\u2026 probably also well, but in 3 hours of workshops you can\u2019t do everything perfectly \ud83d\ude05<\/p>\n\n\n\n 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 \u2014 how much of such a network can fit into a MEMS? Well, not much.<\/p>\n\n\n\n Fortunately, ST creates tools that make this easier \u2014 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 \u2014 collecting data and training AI or a simple state machine.<\/p>\n\n\n\n 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 \u2014 testing of the finished product. Trays with chips are loaded into subsequent machines. Among other things, sensor calibration is performed here.<\/p>\n\n\n\n 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.<\/p>\n\n\n\n After loading, the drum spins with precisely known acceleration values along each axis. During rotation, values from all sensors are continuously read \u2014 the test tray contains a huge number of test pins contacting the MEMS.<\/p>\n\n\n\n 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.<\/p>\n\n\n\n Temperature sensors are tested in a similar way \u2014 in small infrared heating chambers. For automotive devices, tests are doubled: at low and high temperatures.<\/p>\n\n\n\n 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.<\/p>\n\n\n\n![\"\"](\"https:\/\/msalamon.pl\/wp-content\/uploads\/2025\/07\/20250716_201153.jpg\")
<\/figure>\n<\/div>\n\n\nDay 1 – Agrate<\/h2>\n\n\n
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<\/figure>\n<\/div>\n\n\nPresentation of our activities<\/strong><\/strong><\/h3>\n\n\n\n
\u2705 Miko\u0142aj Andrzejewski<\/strong> \u2013 https:\/\/www.youtube.com\/@embeddedGarage<\/a>
\u2705 Mateusz Pluta<\/strong> \u2013 https:\/\/dmbp.pl\/<\/a>
\u2705 Piotr Czaplicki<\/strong> \u2013 https:\/\/www.stm32wrobotyce.pl\/<\/a>
\u2026 and me \ud83d\ude05<\/p>\n\n\n\nHow are semiconductors made? From sand to the final chip<\/strong><\/h3>\n\n\n\n
https:\/\/youtu.be\/UnWOuzRiazk<\/a><\/p>\n\n\n![\"\"](\"https:\/\/msalamon.pl\/wp-content\/uploads\/2025\/07\/image-2-1024x819.png\")
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\u2705 Cleanliness classes according to ISO 14644-1<\/strong><\/h3>\n\n\n\n
ISO<\/strong> Class<\/strong><\/th> Max. number of particles \u22650.5 \u03bcm per 1 m\u00b3 of air<\/strong><\/strong><\/th> Examples of usage<\/th><\/tr><\/thead> ISO 1<\/strong><\/td> 10<\/td> High-tech laboratories (optics, nanotechnology)<\/td><\/tr> ISO 2<\/strong><\/td> 100<\/td> Lithography in state-of-the-art semiconductor production<\/td><\/tr> ISO 3<\/strong><\/td> 1 000<\/td> Microprocessor production, photolithography<\/td><\/tr> ISO 4<\/strong><\/td> 10 000<\/td> Advanced electronics manufacturing<\/td><\/tr> ISO 5<\/strong><\/td> 100 000<\/td> Typical cleanrooms in semiconductors (often used in ST, Intel, TSMC fabs)<\/td><\/tr> ISO 6<\/strong><\/td> 1 000 000<\/td> Pharmaceuticals, precision assembly<\/td><\/tr> ISO 7<\/strong><\/td> 352 000 000<\/td> Pharmaceutical, medical industry<\/td><\/tr> ISO 8<\/strong><\/td> 3 520 000 000<\/td> Assembly of optics, general-purpose electronics<\/td><\/tr> ISO 9<\/strong><\/td> ~like office air<\/td> Offices, standard room<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n \n
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![\"\"](\"https:\/\/msalamon.pl\/wp-content\/uploads\/2025\/07\/image-1-1024x916.png\")
300 mm wafer line<\/strong><\/h3>\n\n\n\n
![\"\"](\"https:\/\/msalamon.pl\/wp-content\/uploads\/2025\/07\/image-4.png\")
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Production 24\/7<\/h3>\n\n\n\n
How is a fab built?<\/h2>\n\n\n\n
What does a pile foundation under a fab involve?<\/h3>\n\n\n\n
![\"\"](\"https:\/\/msalamon.pl\/wp-content\/uploads\/2025\/07\/image-7.png\")
Social media meeting and dinner<\/h2>\n\n\n\n
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<\/figure>\n<\/div>\n\n\n![\"\"](\"https:\/\/msalamon.pl\/wp-content\/uploads\/2025\/07\/20250717_224028-830x1024.png\")
<\/figure>\n<\/div>\n\n\nDay 2 – Casteletto<\/h2>\n\n\n\n
![\"\"](\"https:\/\/msalamon.pl\/wp-content\/uploads\/2025\/07\/20250718_085412-1024x764.jpg\")
<\/figure>\n<\/div>\n\n\nTouring the MEMS testing line<\/h3>\n\n\n\n
Innovations and future trends<\/h3>\n\n\n\n
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