Game Over

Chapter 9 Game Over

When Ethan stepped into Evelyn's experimental base again, he saw an empty table and a clean open space. The neatly arranged tools and components piled in the corner seemed to tell the story of the owner's hard work, but the casually lying broom and dustpan told the story of the user's carelessness.

Ethan bent down and arranged the things, but Evelyn shook her head repeatedly at his obsessive-compulsive behavior.

"I left it there for a reason, because it's easier to pick up."

"But it's not pretty," Ethan replied with a laugh.

"Oh, fine, whatever makes you happy."

Evelyn scoffed at this waste of time, but in a good mood, she didn't bother arguing with her brother.

He patted the table, bringing everything back to the main topic.

"Ethan, circuit boards are actually very simple to make. The first step is to draw the circuit diagram."

"Since you haven't systematically studied this topic, I'll skip this part 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 papers in her hand.

It was covered with dense lines.

"After obtaining the circuit diagram, the second step is to cut the copper-clad board to match the size of the circuit board you need."

Perhaps because she had come to her area of ​​expertise, Evelyn, standing in front of the control panel, exuded confidence.

She picked up a copper-clad board that Ethan had just bought with her finger and said, "You'd better remember everything I'm about to say, because from now on, whenever we're making circuit boards for small objects like this, we'll be using this kind of board. The board you see here is called a phenolic paper-based copper-clad board. It uses phenolic resin as a binder, wood pulp fiber paper as a reinforcing material, and a layer of copper foil on the surface."

As she spoke, she tapped the copper plate with her finger.

The crisp sound seemed to say—

"I'm a good board player."

"You'd better write down the specific dimensions as well. The total thickness of this board is 63 mils, and the copper foil layer thickness is 1.4 mils. These are near-perfect small circuit board dimensions measured by countless engineers through their own experience."

"Because the greater the total thickness of the copper-clad board, the harder it is and the more difficult it is to process; the smaller the thickness, the softer it is and the easier it is to deform. What's more fatal is that at the same time, the heat resistance of the board will also become very poor."

"The thickness of the copper foil layer affects the conductivity, heat resistance, and anti-interference performance of the circuit board. The thicker the copper foil layer, the better the conductivity; the thinner the copper foil layer, the worse the conductivity, and the more prone it is to cracking and breaking."

To be honest, Ethan knew that hand-making circuit boards could be troublesome, but he didn't expect it to be this troublesome.

Even a small circuit board requires careful selection of materials.

This was a field he had never even considered.

However, the clearer Evelyn's description was, the more at ease he felt.

Because only those who are truly knowledgeable dare to explain everything in detail, while those who are only half-baked are most afraid of revealing their ignorance.

And indeed, after Evelyn explained the various materials needed to make the circuit board, she began to operate it steadily.

First, take out a piece of wax paper and lay it flat on the steel plate of the worktable. Use a pen to engrave the pre-designed circuit diagram 1:1 onto the wax paper. Then, based on the wax paper, cut out a small board from a 41-inch × 49-inch copper-clad board and trim it to the size of the circuit diagram.

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

Next, Evelyn had Ethan put on a chemical work mask, opened the paint, took out the talcum powder, mixed the two into a printing liquid of suitable viscosity, and then used a brush to apply it evenly to the wax paper in the same direction.

Since this step didn't require much technical skill, Ethan completed it very quickly.

But at the same time, he also has a problem.

"Why does this thing have to be brushed in one direction?"

"Isn't it more convenient to brush repeatedly?"

"It's very simple. Repeated brushing will easily wrinkle and tear the wax paper."

Although Ethan's question was idiotic, Evelyn didn't mock him at this moment. Instead, she explained seriously, "If it's a plastic-sealed model in a factory, you can paint it wildly, but handmade ones must be done very carefully, because if the lines on the copper plate overlap, the effect of the plate will be worse, or even ruined."

"learn."

Ethan felt he had learned something.

After the circuit was printed, Evelyn asked Ethan to place it in a ventilated place to dry.

The process involved waiting, so the two took advantage of this time to go to the kitchen and prepare some food.

Ethan made a fried egg sandwich, but unfortunately he didn't control the heat well and one side burned.

But that's not important, right?

At this moment, their minds were focused on making the circuit boards. After a quick bite to eat, they returned to the garage.

Once the board is dry, the next step becomes crucial, as they need to remove the non-circuit parts and etch away the unused copper surfaces with an etchant. This step is performed by Evelyn.

She carefully took out the potassium chlorate that Ethan had bought, weighed out one dozen ounces using an ounce scale, and then prepared eight teaspoons of 15% hydrochloric acid, mixing them together.

Next, the circuit board was coated with a very fine coating.

Although the protective mask used for chemical work was not comfortable, Evelyn's steady movements reassured Ethan.

During this process, she also said, "Ethan, there's actually a wilder way to do this step. Some people like to prepare a ferric chloride solution, which is 40% ferric chloride and 60% water, and then directly rinse the circuit board. That way, it will corrode very quickly, but I don't like it because I don't control it well and often splash the solution everywhere."

Ethan laughed at the honest words.

"It's okay. The worst thing about doing things is being impatient, right? We're not in a competition, so there's no rush."

Ethan only replied once before shutting his mouth; he didn't want to distract Evelyn.

Evelyn didn't say anything more and focused on her work.

After she etched away the excess copper layer, she had Ethan bring over some clean water that had been prepared beforehand to rinse the plate.

After confirming there were no residues, she, who had been working bent over for half a day, asked Ethan to open the banana oil and wipe off the paint on the circuit.

As Ethan moved, the green-based copper core board also appeared.

Even at this point, the matter is not over yet.

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

"The stuff you're mixing now is called flux. Applying it to the circuit board can remove oxides and oil, prevent further oxidation, increase the soldering area, and greatly help with soldering."

As she spoke, Evelyn had already applied flux to the board.

Then, the entire garage was filled with wisps of smoke.

Because the solder wire contains a certain amount of lead, Evelyn was still wearing protective gear. Under these circumstances, Ethan couldn't see her face at all, but sitting next to her, he could sense the seriousness behind the mask.

After what seemed like an eternity, Ethan finally snapped out of his daze when a voice announced that everything was alright.

"Is it done?" Ethan asked in surprise.

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

The approaching midnight signal prompted him to quickly say, "Thank you for your hard work."

"Oh, Ethan, this is the first time I've heard you say that. You always used to say thank you, sister."

Evelyn removed her protective gear and said with a smile, "But I like how I feel now."

"When you said thank you before, it was just a perfunctory response."

After teasing Ethan, Evelyn picked up the circuit board again and said, "I don't make many of these things, so I don't know if there are any issues with cold solder joints. How about we run it and see?"

Ethan was delighted with the suggestion and brought out the television set that had been used for the demonstration the day before.

Evelyn smiled without saying a word at his impatient look.

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

After a flicker, countless static dots appeared on the television screen.

This sight made Evelyn frown slightly, and then she slammed her hand on the table.

With a sharp "clang," the steel plate on the table groaned, and the television set on the table shook violently. The next second, the static on the screen disappeared instantly, replaced by a black world.

This world is defined by white lines.

In the middle of the box, there is a pixel bar about half the length of a finger.

After it appeared, it paused in place for three seconds, and then bravely moved forward to the right.

It took about five seconds to climb the horizontal path of the NTSC standard television, covering approximately three hundred pixels.

Then, it crashed headfirst into the white boundary.

Then, the screen shook.

A huge word appeared in the center of the screen—

Game over.

Note: ① According to Apple founder Steve Wozniak's recollection, the process of making video games in the 70s was roughly like this, taking about 4 days to 1 week. At that time, people didn't lack technology, but inspiration. ② NTSC: National Standards Committee of the United States.

(End of this chapter)