Chapter 9: Game Over

When Ethan Jones stepped into Evelyn's experimental base once again, all he saw was an empty table and a neatly organized workspace. The tools neatly arranged and the components piled in the corner seemed to tell the story of the owner's hard work, while the casually lying broom and dustpan spoke of the user's carelessness.

Ethan bent down and arranged these things, but Evelyn shook her head at his compulsive behavior.

"I left them there for a reason; it's more convenient that way."

"But it's not aesthetically pleasing," Ethan replied with a smile.

"Oh well, as long as you're happy," Evelyn said.

Evelyn chuckled at this time-wasting practice, and in her good mood, she didn't bother arguing with her brother.

She tapped the table, bringing everything back to the main topic.

"Ethan, making circuit boards like this is actually very simple. The first step is to draw the circuit diagram."

"Since you haven't systematically learned this, I'll skip the explanation for now. If you want to learn, I can teach you later. Now, I'll use the circuit diagram I designed last night to make the board."

She shook the paper in her hand.

It was covered in dense lines.

"After having the circuit diagram, the second step is to cut and lay the copper board, making its size match the size of the circuit board you want."

Perhaps because she was in her own area of expertise, Evelyn, standing confidently at the workstation, looked self-assured.

She picked up a copper board that Ethan had just bought and said, "You better remember everything I'm about to say because whenever we make small-scale circuit boards like this in the future, we'll be using this type of board. The one you see now is called a phenolic paper-based copper-clad board. It uses phenolic resin as the adhesive, wood pulp fiber paper as the reinforcing material, and is coated with a layer of copper foil on the surface."

As she spoke, she tapped the copper-clad board with her fingers.

The crisp sound seemed to say, "I am a good board."

"You should also note the specific dimensions. The total thickness of this board is 63 mils, and the copper foil layer is 1.4 mils thick. These dimensions have been measured by countless engineers and are close to perfect for small circuit boards."

"Because the greater the total thickness of the copper-clad board, the harder it becomes, making it more difficult to process. On the other hand, if it's too thin, it becomes flexible and easily deformed. What's even more critical is that at the same time, the board's heat resistance will become poor."

"The thickness of the copper foil layer affects the conductivity, heat resistance, and anti-interference performance of the circuit board. Thicker foil provides better conductivity, while thinner foil results in poorer conductivity and is prone to cracking and breaking."

To be honest, Ethan didn't expect making circuit boards to be so complicated. A small circuit board with such careful material selection?

This was a field he had never imagined.

However, the clearer Evelyn described it, the more confident he felt, because only someone with knowledge would dare to explain everything in detail.

Indeed, when Evelyn finished introducing the materials for making circuit boards, she confidently started working.

First, she took out a piece of wax paper, laid it flat on the workbench's steel plate, drew the pre-designed circuit diagram on the wax paper at a 1:1 scale, then compared it to the wax paper, and cut out a small board from a 41-inch by 49-inch copper-clad board, trimming it to the size of the circuit diagram.

After finishing, she neatly attached the wax paper with the circuit diagram to the cut copper-clad board using double-sided tape.

Then, Evelyn asked Ethan to put on a chemical work mask, open the paint, take out the talcum powder, mix them to create a moderately viscous printing ink, and then use a brush to evenly apply it to the wax paper in the same direction.

Since this step didn't require much technical difficulty, Ethan operated quickly.

But at the same time, he had a question.

"Why does it have to be brushed in one direction? Wouldn't it be more convenient to brush it repeatedly?"

"It's simple. Repeated brushing can easily wrinkle and break the wax paper."

Although Ethan's question was somewhat naive, Evelyn, at this moment, didn't mock him. Instead, she explained seriously, "If it were a plastic-sealed model in a factory, you could brush more wildly, but handmade production requires carefulness because if the lines on the copper board overlap, the performance of the board will deteriorate, and it might even become useless."

"Understood."

Ethan felt that he had learned something.

After printing the circuit, Evelyn asked Ethan to place it in a well-ventilated area to dry. This process required waiting, so they took the opportunity to go to the kitchen and prepare some food.

Ethan made a fried egg sandwich, but unfortunately, he didn't control the heat well, resulting in one side being burnt.

But that didn't matter, right?

At this moment, their minds were focused on making the circuit board. After a simple meal, they returned to the garage.

As the board dried, the next steps became crucial because they needed to remove the non-circuit parts, corrode the unused copper surface with etching solution, and Evelyn was in charge of this step.

She carefully took out the potassium chlorate Ethan had bought, measured out 1 ounce on the scale, and then mixed 8 teaspoons of hydrochloric acid, creating a 15% concentration solution. She then meticulously applied it to the circuit board.

Although the chemical protective mask wasn't comfortable, Ethan felt reassured by Evelyn's steady movements.

During this process, she also said, "Ethan, there's actually a wild way to do this step. Some people like to use ferric chloride solution, which is 40% ferric chloride mixed with 60% water, and directly rinse the circuit board. It corrodes quickly, but I don't like it because I can't control it well, and I often splash the solution everywhere."

Hearing her honest words, Ethan laughed.

"No problem. Isn't patience crucial in doing things? We're not in a race; there's no need to rush."

Ethan only said a sentence and then closed his mouth; he didn't want to distract Evelyn.

Evelyn didn't speak either, concentrating on her work.

After she corroded away the excess copper layer, she had Ethan bring over a pre-prepared water to rinse the board.

Once she confirmed there were no residues, after bending over for a long time, she had Ethan open a can of banana water and wipe off the paint on the circuit.

With Ethan's actions, the green-core copper-clad board appeared.

At this point, the task wasn't finished.

Next, Evelyn drilled holes in the board, and Ethan, under her guidance, mixed rosin with acetone.

"What you're adjusting now is called flux. Applying it to the circuit board can remove oxides, grease, prevent re-oxidation, and increase the soldering area. It's very helpful for soldering."

While speaking, Evelyn had already applied the flux to the board.

After that, the entire garage was filled with a wisp of smoke.

Because soldering wire contains a certain amount of lead, Evelyn still wore protective gear. In this situation, Ethan couldn't see her face clearly at all, but sitting on the side, he could feel her seriousness.

After an unknown amount of time, when a "done" sound appeared, Ethan finally snapped out of his daze.

"Is it done?" Ethan asked excitedly.

The next second, he also looked at the clock on the wall.

The pointing of the midnight twelve made him quickly say, "Hard work."

"Oh, Ethan, this is the first time I've heard these words from your mouth. Before, you always said 'thanks, sis,'" Evelyn teased.

Evelyn took off the protective gear, smiled, and said, "But I like the feeling now."

"Before, when you said thanks, it felt like you were just being perfunctory."

After teasing Ethan, Evelyn lifted the circuit board and said, "I don't make these things often, and I don't know if there are any soldering problems, so how about we give it a try?"

Ethan was very happy with this suggestion and actively brought out the TV used for the demonstration yesterday.

Eager to try, Evelyn laughed and said nothing.

She connected the finished circuit board to the TV and powered it on.

After a flicker, the TV screen was filled with countless snowflakes.

This scene made Evelyn frown slightly, and then she forcefully knocked on the table.

With a crisp sound, the steel plate under the TV emitted a mournful cry. The TV on the table shook for a moment, and the next second, the snowflakes on the screen disappeared instantly, replaced by a black world.

This world was framed by white lines.

In the center of the frame was a pixelated bar about half the length of a finger.

After appearing, it stayed in place for three seconds, then bravely moved to the right.

It took about five seconds to climb over the NTSC standard TV horizontal path, passing about three hundred pixels.

Then, it crashed into the white border.

The screen then shook.

A huge word appeared in the center of the screen—

Game Over.