It was Su Dingyu and Leng Lan, two laymen, who also had a general understanding of this picture during this time. After all, Jin Songyong only explained the mechanism of the single crystal furnace, and has not yet involved its principle and operation process.

As for Jiang Xinwei, he was a senior expert in telecommunications equipment in his previous years, because he had to understand the chip hardware used in telecommunications equipment, he naturally knew more or less about single crystal furnace technology and chip lithography technology, and he was in contact with a single crystal furnace that was far more advanced than the current single crystal furnace.

Next, Jin Songyong began to talk about the working principle of the structural diagram, only to listen to him talk eloquently: "The manufacture of monocrystalline silicon is very simple in terms of principle alone, the first thing is to electrify the heating equipment, increase the temperature of the charge, and when the temperature reaches the melting point of polysilicon, the polysilicon in the quartz crucible will melt." After that, we maintain a temperature slightly higher than the melting point of the silicon www.uuxs.cc, which is slightly higher than the melting point of the silicon, and use the seed crystal lifting mechanism to immerse the seed crystal into the melt of the polysilicon, and then pull the seed crystal upwards at a certain speed and rotate it at the same time, so that the crystal ...... can be drawn out."

After that, Professor Jin explained what are the processing steps such as neck reduction, shoulder release, cooling, and removal.

Just as Professor Jin's principle was about to finish, Leng Lan gently handed her notebook to Jiang Xinwei and motioned him to look at the question she wrote: "Jiang Xinwei, is what he said true or false." If monocrystalline silicon manufacturing is so simple, how can we bring in gringo equipment and technology?"

Jiang Xinwei read the question she wrote, and sighed in his heart that the ignorant are fearless: If you knew that this professor surnamed Jin was the first person in the semiconductor field in my country, and you knew that my country racked his brains but had nothing to do in order to improve the quality and output of monocrystalline silicon, it is estimated that you would not say such a thing.

He was about to pick up his pen to answer her, "It's complicated to answer this question, I'll talk about it after class," when Professor Kim happened to talk about it with a smile. Jiang Xinwei smiled and took the pen back.

Jin Songyong smiled and asked: "Comrades, after listening to my lecture, do you think that the principle of this single crystal furnace is really simple? Are you very confused, in the face of equipment and technology with such a simple principle, why do we still spend huge sums of money and do everything possible to attract foreign technology and equipment? Hehe, are you laughing at us guys who are engaged in scientific research in your hearts are so incompetent that we can't even master such a simple technology?"

Not to mention that Leng Lan, who had just written this question, quietly stuck out her tongue. Many technicians around them also disagreed with this problem, and they did feel a little strange in their hearts: how simple is this principle, why do we have to learn from gringos, why can't we make good monocrystalline silicon ourselves?

Professor Jin said with a smile: "Here, I have to admit that those of us who are engaged in scientific research are a little incompetent and have failed to live up to everyone's hopes. Then, after a moment's notice, he said, "But what I'm going to say is that a lot of high-tech things are very simple. For example, the atomic bomb. Everybody who has studied high school physics must be familiar with the principle of the atomic bomb, but you say it's simple? It's just too simple, just let the mass of two pieces of uranium metal together exceed their critical mass, and then let them touch together. However, in today's world, there are only a handful of countries that can build a qualified atomic bomb. ”

The audience smiled knowingly. Leng Lan also embarrassedly pulled her notebook back and gave Jiang Xinwei a rare shy smile. Seems to be a little embarrassed by the idiotic question he asked.

Jin Songyong continued to smile and said, "Simple principles contain countless problems beyond our imagination. First of all, the problem is the material, for example, the crucible used to hold the polysilicon melt is a very prominent problem. ”

Jin Songyong said in a low voice: "So far. Not only can we not manufacture crucibles with long life and low cost, but also crucibles that are produced at a huge cost, and their quality is not ideal, they will crack after a few times, and they contain too many impurities, which themselves have become a source of pollution. During the production process, the impurities it carries will seep into the monocrystalline silicon rods, causing the purity of the monocrystalline silicon to deteriorate. ”

Speaking of which, Kim Songyong used chalk to write a number on the blackboard: 99.9%. Then he said: "Everyone knows that the purity of monocrystalline silicon should not be lower than 99.9%, which is lower than this number. The semiconductor devices manufactured with it are not good in terms of service life and function, and the stability is very poor, and once there is a problem in the process of use, the entire semiconductor device will be scrapped, resulting in great losses. Monocrystalline silicon below this value can only make some diodes, transistors and other devices with low technical requirements, and cannot use integrated circuits, large-scale integrated circuits, let alone ultra-large-scale integrated circuits.

With our own production of crucibles, the average purity of the monocrystalline silicon rods we manufacture is only 97.45%, even if we choose and choose, the best of the best, but they still cannot be used by us to make microprocessors, can not be used to produce single-chip microcomputers. Not to mention that the silicon wafers needed for our scientific research need to be imported, even the silicon wafers needed by the factory cannot fully use them. ”

Jin Songyong added: "In addition to the material problems, we also have technical problems, especially some key numbers that we have not mastered. Because we have been engaged in this field for a short time, our country is now in economic difficulties, the investment funds are small, and many of the numbers required for the production of monocrystalline silicon are not from our own experiments, many of them are obtained from foreign technical literature and papers published by foreign experts.

In particular, some correlation numbers are very difficult to verify, must go through a long period of time, and must be observed by technical professionals for a long time. For example, the relationship between the growth rate of the crystal and the longitudinal temperature gradient in the crystal, and the relationship between the thermal conductivity of the crystal and the density of the crystal during the crystallization process, we do not have the corresponding instruments to test and verify. ”

Speaking of this, Jin Songyong sighed and said: "It's not that we are incompetent, it's not that we are lazy, it's really difficult for a clever woman to cook without rice." Well, I don't want to say anything about self-pity, and I'm not here to shirk the responsibility of our scientific researchers, I just hope that the technicians here can learn from their foreign counterparts with an open mind and take advantage of this opportunity to master technologies that we don't know.

Although the equipment and technology shipped from Italy this time may not be the most cutting-edge in the world at present, there are things that we have learned from in many aspects, especially some measuring instruments, which are very valuable to us, with them, our testing and production may be more smooth in the future, and in the future we can also produce monocrystalline silicon that meets the requirements of modern industry!"

……

Unconsciously, it was time to answer questions, Jin Songyong said with a smile: "That's all for today's lesson, now I invite you to ask questions, and we will discuss with each other." Don't have any worries, you can say whatever you think, ask whatever questions you want, as long as it's technical, I'm willing to answer, even if I don't know myself, can you brainstorm, you can also say your own understanding, maybe it can give us a new way of thinking. ”

Soon, quite a few people started asking questions.

It can be seen from their appearance and their respect for Jin Songyong's appearance that they are mostly technicians in the transistor factory. Obviously, monocrystalline furnaces were a completely new topic for them, and unlike the technical experts who had quietly moved into the plant, they had too many questions.

Because they were asking a group of rookies, none of their questions could stump Jin Songyong, and whenever their questions were asked, Jin Songyong answered the questions in a very orderly manner with a smile. After only ten minutes or so, no one asked any more questions, only one technician said, "Professor Jin, what if their single crystal furnace in Italy is very different from the one you introduced today?

Jin Songyong said with a smile: "Don't worry, their principle must be the same, but the appearance is definitely different from what we imagined, after all, they are all human beings, and there are also yellow, white, and black people...... , but no matter what kind of person they are, they have a head, a torso, and limbs. As long as we grasp the principle of monocrystalline furnace, it is easier to understand their monocrystalline furnace. ”

Seeing that no one else asked any more questions, Jin Songyong was about to end today's class, and said politely: "Thank you for your assistance today, so that this class can go very smoothly." If you don't have any other questions, then today's lesson is over, and I'll talk about parameters in the next class. ”

At this time, Jiang Xinxu raised his hand and asked, "Professor Jin, is there a heat reflector in our single crystal furnace?"

"Heat reflector?" Jin Songyong was stunned, he wanted to say that this question was inexplicable, how could there be that thing in the single crystal furnace, but seeing that it was Jiang Xinwei who asked the question, he had to refrain from asking a rhetorical question, but said politely, "What is the heat reflector that Mr. Jiang said? What is its function?"

Jiang Xinxu said: "It is a device suspended above the crucible that can re-reflect the heat emitted by the hot melt back into the molten liquid. ”

Jin Songyong was still thinking about what Jiang Xinwei said, as if he had thought of something, and his heart was as if someone had opened a bright window, and an expert listening to the lecture below said sarcastically: "Mr. Jiang, you shouldn't know about a single crystal furnace, right? Where did you know that a single crystal furnace will have such a superfluous thing, what are these heat reflections for? We use electric heating, is your purpose just to save energy? Hehe, how much electricity can be saved by this little bit of heat reflected back? The fact that it simply does not match the increased costs is simply redundant......"

(Ask for recommendation) (To be continued......) R1292