Reborn in 2012, building a new energy empire

Chapter 135 Cutting Test

On the seventeenth day of the twelfth lunar month, just after six o'clock in the morning, the courtyard was still shrouded in the deepest indigo blue before the winter dawn.

Jiang Haoran gently closed the door, picked up his laptop bag which he had packed the night before, and went downstairs.

The kitchen light was on, and Chen Fang, the mother, was already up, filling bowls with freshly cooked millet porridge and peeled tea eggs.

"Mom, why are you up so early?" He walked into the kitchen and lowered his voice.

"I'll make you something to eat." Chen Fang pulled out a chair, handed him a bowl, and said, "Drive carefully on the road, and call me when you arrive."

"Mm." Jiang Haoran took it and silently finished eating.

Jiang Jianguo, the father, also came out of the bedroom wearing a coat and silently patted his son on the shoulder.

Those hands were heavy and carried the unspoken entrustment of an elder.

Without another word, Jiang Haoran changed his shoes in the entryway, pushed open the door, and stepped into the chilly morning mist. A silver Panamera was parked outside, its roof covered in a thin layer of frost.

He fastened his seatbelt and turned on the navigation.

Destination: Suzhou-Hangzhou Industrial Park, Kylin Technology R&D Center.

It was seven o'clock in the morning, just as dawn was breaking.

When Jiang Haoran pushed open the heavy soundproof door of the laboratory, it was already brightly lit inside.

In the central open space, the diamond wire cutting prototype, which had been assembled and debugged over several months, stood quietly. Its silver-gray body gleamed with a cold metallic luster, and various pipelines were neatly arranged into the control cabinet.

Wang Qiming was squatting in front of the observation window on the side of the machine, shining a flashlight on the guide wheels of the wiring system inside.

Gu Qiushi stood in front of the control panel, repeatedly checking the densely packed parameters on the screen.

Two engineers were inspecting the cooling system; there was a faint smell of antifreeze and engine oil mixed in the air.

"Is everything ready?" Jiang Haoran took off his coat and hung it aside.

"Just finished the final power-on self-test." Zhao Haichuan looked up, his eyes bright despite noticeable dark circles under his eyes. "Vacuum level..."

Tension, temperature—all subsystems are functioning normally. We can begin the first full-process test.

Wang Qiming stood up and dusted off his hands: "The silicon ingots have been clamped in place. They are standard 156 mm square ingots, 400 mm long. We used our latest batch of diamond wire, numbered L-27, with a diameter of 70 micrometers."

Jiang Haoran walked to the control panel, where a 3D simulation of the cutting path was displayed on the screen. "As planned, start with the most conservative parameters. Slow down the speed, set the tension to the lower-middle limit, and provide sufficient cooling flow."

"Understood." Gu Qiushi took a deep breath, placing his finger above the start button. "Then—shall we begin?"

The laboratory fell silent, and everyone looked at the machine.

Gu Qiushi pressed the button.

A deep humming sound rang out, followed by the soft whine of the coolant pump starting up.

Through the observation window, you can see the crystal-clear coolant beginning to spray, and the silver diamond wire slowly starting up under the traction of the guide wheel, gradually accelerating, and finally gliding across the surface of the silicon block at a stable speed.

A subtle, high-frequency cutting sound came through the soundproofing layer, like the chanting of some kind of precision instrument.

The first cutting cycle takes four hours.

No one left the lab during the test; everyone was focused on waiting for the results.

The engineers took turns monitoring the parameters of their respective subsystems, and Wang Qiming recorded the tension and vibration data of the line every half hour.

Jiang Haoran spent most of his time standing behind the control panel, his gaze moving between multiple monitoring screens.

At 12:17 PM, the machine's operating indicator light turned from green to yellow, and then stopped. Cutting was complete.

Several people gathered around the material chute almost simultaneously.

The robotic arm removes the sliced ​​silicon wafers one by one and places them on a padded transfer tray. Under the light, the surface of the silicon wafers reflects a pale blue metallic luster.

Wang Qiming put on white gloves, picked up the first piece, and examined it closely under the light. His brows quickly furrowed.

"The surface roughness is wrong," he said in a low voice. "There are visible vertical lines."

Gu Qiushi took the silicon wafer and gently ran his fingertips along its edge: "It feels a bit rough, not as smooth as wafers cut from imported wire."

He quickly walked to the optical profilometer next to him and placed the silicon wafer on it. The screen soon displayed a three-dimensional topographic image, with clearly visible undulating ripples.

"Ra value 1.2 micrometers." The reading popped up, "Design target below 0.8."

The first test failed to meet the key performance indicators.

The atmosphere in the lab was heavy for a few seconds, but no one broke down in tears. This was expected. It would have been abnormal if it had succeeded on the first try.

"Where is the problem?" Jiang Haoran asked calmly.

Wang Qiming had already walked to the machine and pulled up the complete operation log from earlier.

"I suspect it's a mismatch between the coolant parameters and the routing speed." He pointed to a curve on the screen. "Look here, the coolant temperature fluctuated slightly during the cutting process, but the routing speed wasn't adjusted accordingly. The heat buildup caused localized micro-melting, affecting the surface quality."

"Should we continue the experiment or adjust the plan?" Jiang Haoran asked Gu Qiushi.

"We have two plans in mind," Gu Qiushi responded quickly. "One is to optimize the coolant flow control algorithm and add a temperature feedback closed loop; the other is to appropriately reduce the routing speed to leave sufficient margin for cooling. I suggest trying the second plan first, as it requires fewer modifications and is more effective."

"How long will it take?" Jiang Haoran asked.

"Modify the control parameters and recalibrate; it will take about two hours," Gu Qiushi replied.

"Let's begin then." Jiang Haoran glanced at his watch. "Three o'clock this afternoon, the second test."

After a quick lunch, the team immediately began making adjustments.

Modifying control parameters, recalibrating the sensor, replacing the diamond wire, and cleaning the silicon block clamping surface—all steps were carried out in an orderly manner.

At 2:50 PM, everything was ready.

The second test begins.

The fabrication speed was reduced by 15%. The dicing cycle was extended to nearly five hours. At 6 PM, the second batch of silicon wafers was produced.

Wang Qiming immediately measured the surface roughness. "Ra value 0.92 micrometers, close to the target!"

But a new problem arose. He picked up the used diamond wire fragments and examined them under a microscope: "The wire consumption was 2 percent higher than expected. The rate of diamond particle shedding from the wire surface was too high."

"It must be that the cutting load borne by a single particle per unit time increases after the speed decreases," Gu Qiushi analyzed. "We need to work on the particle adhesion strength."

"And then there's the coolant formula," a materials engineer added. "The current lubrication might not be enough, increasing wear on the production line."

Problems emerged one by one, and were then broken down, analyzed, and attributed to their causes. The lab lights stayed on all night.

The following week, the team entered a near-frantic debugging cycle.

Two to three cutting tests are conducted daily. After each test, the data is analyzed immediately, and parameters are adjusted. Sometimes this involves the coolant ratio, sometimes minor adjustments to the electroplating process, and sometimes optimization of the wiring path. If it fails, analyze the results and try again.

Jiang Haoran practically lived in the laboratory.

When I get tired, I take a two-hour nap on the folding bed next to me, and then continue when I wake up.

He doesn't directly participate in technical discussions; he mostly listens and observes, nodding or shaking his head at key decision points.

It's the 29th day of the twelfth lunar month, two days before the Spring Festival.

At 4 PM, the twelfth full-process test was completed.

When the last silicon wafer was removed, the laboratory was so quiet that the hum of the ventilation system could be heard.

Wang Qiming picked up the silicon wafer, but instead of measuring it immediately, he held it up to the light for a long time. Then he walked to the profilometer and placed the sample in it.