Reborn America, this is my time

Chapter 9 Game Over
When Ethan stepped into Evelyn's experimental base again, what he saw was an empty table and a tidy space. The neatly packed tools and components piled up in the corner seemed to be It is telling the hard work of the owner, but the broom and dustpan lying casually are telling the carelessness of the user.

Ethan bent down to arrange these things, but Evelyn shook her head again and again because of the obsessive-compulsive behavior.

"I put it there on purpose, because it's more convenient to pick it up."

"But it's not beautiful." Ethan replied with a smile.

"Oh, all right, as long as you're happy."

This waste of time made Evelyn sneer, she was in a good mood and didn't bother to argue with her brother.

He patted the table and brought everything back to the point.

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

"Since you haven't studied this aspect systematically, I will omit this part of the explanation first. If you want to learn, I can teach you later. Now, I will use the circuit diagram designed last night to make the board. "

She shook the paper in her hand.

There are dense lines drawn on it.

"And after having the circuit diagram, the second step is to cut the copper-clad board so that its size matches the size of the circuit board you want."

Perhaps it was because she had come to her field of expertise. At this moment, Evelyn, who was standing in front of the operation desk, looked confident.

She picked up a copper-clad board that Ethan had just bought with her fingers, and said, "You'd better remember all the things I said below, because in the future, we will use all the circuit boards that involve such small-scale objects. It is the board of today. The board you see now is called phenolic paper-based copper-clad board, which uses phenolic resin as the adhesive, wood pulp fiber paper as the reinforcing material, and the surface is covered with a layer of copper foil."

While speaking, she also tapped the copper clad plate with her fingers.

That crisp voice sounded like it was saying——

'I'm a good board. '

"You'd better remember the specific size. The total thickness of this board is 63 mils, and the thickness of the copper foil layer is 1.4 mils. This data is a near-perfect small circuit board data measured by countless engineers through personal experience."

"Because the greater the total thickness of the copper-clad board, the harder it is, the harder it is to process, and the smaller the thickness, the softer it is, the easier it is to deform, and it is more fatal. At the same time, the heat resistance of the board will also change. Very bad."

"The thickness of the copper foil layer will affect the conductivity, heat resistance and anti-interference performance of the circuit board. The thicker it is, the better the conductivity is, and the thinner it is, the worse the conductivity is, and it is also easy to crack and break."

To be honest, Ethan knew that rubbing the circuit board by hand might be troublesome, but he didn't expect it to be so troublesome.

A small circuit board, just the board has exquisite material selection?

This is a field he never imagined.

However, the clearer Evelyn's description was, the safer he would feel.

Because, only those who have the goods in their stomachs dare to explain everything in detail, and the half bucket of water dangling is the most afraid of showing cowardice.

The fact is also the same. After Evelyn introduced the various materials for making circuit boards, she started to operate steadily.

First take out a piece of wax paper, spread it on the steel plate of the workbench, use a pen to engrave the pre-designed circuit diagram 1:1 on the wax paper, and then compare it to the wax paper, from a 41 inch × 49 inch Cut out a small board from the copper clad board and trim it to the size of the circuit diagram.

After finishing, stick the wax paper with the circuit diagram neatly on the cut copper clad board with double-sided tape.

Then, Evelyn asked Ethan to wear a mask for chemical work, opened the paint, took out the talcum powder, and mixed the two into a printing solution with a moderate viscosity, then dipped it with a brush, and applied it evenly in the same direction. on waxed paper.

Since there is no technical difficulty in this link, Ethan operates very quickly.

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

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

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

"It's simple, repeated brushing tends to wrinkle and break the stencil."

Although the question Ethan asked was idiotic, Evelyn didn't mean to laugh at the moment, but explained seriously: "If it's a plastic model in the factory, you can make it a little wilder, but you have to be careful when making it by hand. Because once the lines on the copper board overlap, the effect of the board will be worse, or even scrapped."

"learn."

Ethan felt that he had learned something.

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

What this process requires is to wait, so the two of them took advantage of this time to come to the kitchen and get some food.

Ethan made a fried egg sandwich, but it was a pity that he didn't control the heat properly and it was burnt.

But it doesn't matter, right?

At this moment, they were all focused on making circuit boards, and after eating their fill, they returned to the garage.

As the board dries, the next steps become very important, because they need to remove the non-circuit parts, and use an etching solution to etch away the unused copper surface, and this step is performed by Evelyn.

I saw that she carefully took out the potassium chlorate that Ethan bought, weighed out 1 dram with an ounce scale, and then prepared 8 teaspoons of 15% hydrochloric acid, and mixed them together.

Next, apply the circuit board very carefully.

Although the chemical protective mask was not comfortable to wear, but Evelyn's steady movements made Ethan feel at ease.

During this process, she also said: "Ethan, in fact, there is a wild way of operating this step. Some people like to mix ferric chloride solution, which is 40.00% ferric chloride plus 60.00% water , and then rinse the circuit board directly, it will be corroded quickly, but I don't like it, because I don't control it well, and I often splash the solution everywhere."

Hearing the honest words, Ethan laughed.

"It doesn't matter. I'm afraid of impatience when doing things, right? We're not in a competition, and we're not in a hurry."

Ethan closed his mouth after only replying, he didn't want to distract Evelyn.

Evelyn didn't speak any more, concentrating on her work.

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

After confirming that there was no residue, she bent over and worked for half a day and asked Ethan to open the banana water and wipe off the paint on the circuit.

Following Ethan's actions, a board with a green background and copper core also appeared.

At this point, the matter is not over yet.

Next, Evelyn punches the board while Ethan, with her guidance, mixes the rosin and acetone.

"The thing you are mixing now is called flux. Applying it on the circuit board can remove oxides, oil stains, prevent re-oxidation, and increase the welding area, which is very helpful for welding."

Meanwhile, Evelyn had already applied flux to the board.

And then, the entire garage was filled with green smoke.

Because the solder wire contains a certain amount of lead, Evelyn is still wearing the protective gear. In this case, Ethan couldn't see her face clearly, but he, who was sitting by the side, could feel the pain under the mask. seriously.

I don't know how long it took, but Ethan came back to his senses when the sound of good came out.

"Ready?" Ethan asked in surprise.

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

At twelve o'clock in the middle of the night, he quickly said, "Thanks for your hard work."

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

Evelyn took off the protective gear and said with a smile: "But I like the feeling now."

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

After teasing Ethan, Evelyn held up the circuit board again and said, "I don't do much of this kind of thing, and I don't know if there is a problem with solder joints, so let's try it out?"

This proposal made Ethan very happy, and he took the initiative to hold out the TV used for yesterday's demonstration.

The anxious look made Evelyn laugh without saying a word.

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

After a flash, countless snowflakes appeared on the TV screen.

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

There was a crisp sound of "clang", the steel plate on the table whined, and the TV set on the table vibrated suddenly. The next second, the snowflakes on the screen disappeared instantly, replaced by a black world.

This world is framed by white lines.

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

After it appeared, it stayed on the spot for three seconds, and then moved bravely to the right.

It took about five seconds to climb the horizontal path of the NTSC standard TV, and walked through about [-] pixels.

Then, he bumped into the white border.

Then, the screen vibrated.

Huge words appear in the center of the screen——

Game Over.

　Note: ①According to the memories of Apple founder Steve Wozniak, in the 70s, the process of making video games was almost like this, and the time was about 4 days to 1 week. What people lacked at that time was not technology, but inspiration. ②NTSC: American National Standards Committee.

　　
　
(End of this chapter)