Chapter 9: Game Over

As Ethan stepped into Evelyn's laboratory once more, he was greeted by an empty table and a neatly swept workspace. The tools were tidily arranged, and components were stacked in the corner, all of which seemed to tell of their owner's diligence. Yet, the carelessly discarded broom and dustpan painted a picture of a certain absentmindedness.

Ethan bent down, meticulously placing everything back where it belonged, his obsessive behavior causing Evelyn to shake her head in disapproval.

"I left them there for a reason—it's more convenient that way," she remarked.

"But it's unsightly," Ethan replied with a playful smile.

"Oh, fine. Whatever makes you happy," Evelyn sighed, her lighthearted mood preventing her from bickering with her brother over such trivialities.

With a sharp rap on the table, she brought the conversation back to the task at hand.

"Ethan, creating a circuit board is actually quite simple. The first step is to draft the circuit diagram."

"Since you haven't had formal training in this, I'll skip the detailed explanations for now. If you want to learn later, I can teach you. For now, let's focus on the circuit I designed last night."

She held up a sheet of paper covered in intricate, interwoven lines.

"After you've got the circuit diagram, the second step is cutting the copper-clad board to match the size of the circuit."

Standing at her workstation, Evelyn radiated confidence, fully in her element.

She picked up a piece of the copper-clad board Ethan had just brought back and said, "Pay close attention, because for any small-scale circuit board work, this type of board will be essential. This particular board is called a phenolic paper-based copper-clad laminate. It's made of phenolic resin bonded with wood pulp fiber paper, and its surface is coated with a layer of copper foil."

She tapped the board lightly, the crisp sound echoing like a declaration—"I'm a fine board."

"You might want to remember the specifics too. The total thickness of this board is 63 mils, with the copper foil layer being 1.4 mils thick. This measurement is the result of countless engineers perfecting the ideal dimensions for a small circuit board."

"The thicker the copper-clad board, the more rigid and difficult it is to work with. Too thin, and it becomes flexible and prone to deformation. Worse yet, it loses its heat resistance."

"As for the thickness of the copper foil, that affects the board's conductivity, heat resistance, and interference resistance. The thicker the foil, the better the conductivity. But if it's too thin, not only will conductivity suffer, but it's more likely to crack or break."

To be honest, Ethan had anticipated that making a circuit board by hand would be challenging, but he hadn't realized just how complicated it could be.

Such a small circuit board, and yet, even the choice of materials demanded so much precision?

It was an area entirely beyond his imagination.

However, the more thorough Evelyn's explanations became, the more reassured Ethan felt.

Only those who are truly knowledgeable are confident enough to explain things in such detail, after all. Those with shallow knowledge are the ones who fear being found out.

And as it turned out, Evelyn knew her craft well. After introducing all the materials, she smoothly transitioned into the process itself.

First, she took a sheet of wax paper and spread it evenly over the steel plate of the workbench. Using a pen, she carefully etched the circuit diagram onto the wax paper at a 1:1 scale. She then compared the wax paper to the copper-clad board and cut out a smaller piece, trimming it to match the dimensions of the diagram.

Once done, she neatly affixed the wax paper onto the copper-clad board with double-sided tape.

Next, Evelyn instructed Ethan to put on his safety mask. She opened a can of paint, mixed in some talc powder, and created a paste-like printing solution. Then, using a brush, she applied the mixture evenly over the wax paper in one direction.

This step wasn't particularly technical, so Ethan handled it quickly.

But he did have a question.

"Why do we have to brush it in one direction? Wouldn't brushing back and forth be faster?"

"It's simple. Brushing back and forth would wrinkle or tear the wax paper," Evelyn patiently explained. "In a factory, where models are sealed, you can be a bit more aggressive. But with handmade boards, you have to be delicate. If any lines on the copper get smudged or overlap, it will degrade the board's performance, or worse, ruin it entirely."

"Got it," Ethan nodded, feeling like he'd learned something valuable.

After printing the circuit, Evelyn had Ethan place it in a well-ventilated area to dry.

This stage required some waiting, so the two took the opportunity to head to the kitchen and grab a bite.

Ethan made an egg sandwich, though he slightly overcooked one side. But that hardly mattered, right?

At that moment, both their minds were fully occupied with the circuit board. After a quick meal, they returned to the garage.

Now that the board had dried, the next steps were crucial. They needed to peel away the excess areas and use an etching solution to remove the unwanted copper. Evelyn took charge of this step.

She carefully took out the potassium chlorate Ethan had bought, measured a precise drachm with the ounce scale, then prepared eight teaspoons of hydrochloric acid at a 15% concentration, blending them together meticulously.

With great care, she applied the mixture to the circuit board.

Though the chemical respirator wasn't exactly comfortable to wear, Evelyn's steady and confident movements reassured Ethan.

During the process, she remarked, "Ethan, there's actually a more reckless way to handle this step. Some people prefer to use ferric chloride solution—40% ferric chloride mixed with 60% water—and simply douse the circuit board. It corrodes much faster that way, but I'm not a fan of it. I always end up splashing the solution everywhere."

Her candid admission made Ethan chuckle.

"No worries. The last thing we need is impatience, right? We're not in a race here."

With that, Ethan fell silent, not wanting to distract her.

Evelyn, too, focused intently, not saying another word.

Once she had carefully etched away the excess copper, she asked Ethan to bring over the prepared clean water to rinse the board.

After ensuring no residue remained, Evelyn, who had been bent over the workstation for quite some time, had Ethan open the can of lacquer thinner to wipe away the paint on the circuit.

As Ethan worked, the green base and copper core of the board began to emerge.

Yet, even at this stage, the process wasn't complete.

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

"What you're preparing now is called flux," Evelyn explained. "By applying it to the circuit board, it clears away oxides and grease, prevents reoxidation, and increases the surface area for soldering, making the process much smoother."

As she spoke, Evelyn had already begun spreading the flux over the board.

Soon, wisps of blue smoke filled the garage.

Since the solder wire contained a degree of lead, Evelyn wore her protective gear. From his seat, Ethan couldn't see her face through the mask, but he could sense her focus and seriousness.

He had no idea how much time had passed when her voice finally cut through the silence: "It's done."

"Finished?" Ethan asked in surprise.

Glancing at the clock on the wall, he saw the hands pointing to midnight.

"Thank you for your hard work," he said quickly.

"Oh, Ethan, that's the first time I've ever heard you say that. You used to always say, 'Thanks, sis.'" Evelyn removed her protective gear, smiling. "But I like this new version of you."

"In the past, when you thanked me, it always felt so half-hearted."

Teasing him playfully, Evelyn held up the circuit board and said, "I haven't made too many of these, so I'm not sure if there's any cold soldering. Shall we give it a test?"

Her suggestion made Ethan light up with excitement, and he eagerly fetched the demonstration TV set from the previous day.

His impatient demeanor earned a silent smile from Evelyn.

She connected the circuit board to the TV and powered it up.

After a brief flicker, the screen displayed nothing but a flurry of static.

Evelyn frowned slightly before slamming the table with a forceful thud.

The steel plate under the table groaned in protest, and the television shook. In the next instant, the static vanished, replaced by a black screen.

On this dark backdrop, a world was defined by white lines.

At the center of the frame, a short pixel bar—about half a finger in length—appeared.

After lingering in place for three seconds, it began its determined march to the right.

In about five seconds, it had traversed the horizontal path of the NTSC standard television, covering roughly 300 pixels.

Then, it crashed headlong into the white border.

The screen shuddered.

A single, giant word appeared in the center of the screen—

Game Over.