I drew a really nasty board today.

Nubility

I drew a really nasty board today. [Copy link]

 

Originally, I was supposed to spend a few days getting familiar with the company's products when I first joined the company, but I didn't expect that I would be asked to draw boards as soon as I arrived. To be more precise, it was a board that others couldn't handle, and there were a lot of boards with blocked signal lines for me to deal with. The board has more than a dozen layers, 6 DDRs, and 2 BGA chips, which together feel like there are thousands of pins. Add in other components, vias, and routing, and it feels like 80% of the PCB area has been occupied. I've been staring at the computer looking for routing space these past two days and I'm dizzy. I said that the routing couldn't be done, and I had to add layers or increase the area of the PCB, but he refused to do it. Then I looked at the routing that was originally a mess, and I thought it through. Since it was already a mess, and he refused to add layers or increase the area, I might as well go all out and just connect it directly. Now the routing is basically completed, but I feel sick at the sight of this board

Additional content (2023-6-29 08:56): To be precise, the board is 1835pin

littleshrimp

Those who can draw so many layers are masters.

Nubility

littleshrimp posted on 2023-6-20 21:23 Those who can draw so many layers are masters

It feels like it was squeezed out hard, and the actual crosstalk is very large

吾妻思萌

This is an obvious pitfall. If it is well drawn, the boss will take it to seek credit and reward, and bully you, the newcomer. If it is not well drawn, you will bear the blame for two years. , yes, it is so disgusting.

秦天qintian0303

Do you want to see what your level is?

damiaa

Good things come to those who wait

Nubility

Azuma Simeng posted on 2023-6-21 07:17 This is an obvious pitfall. If it is well drawn, the boss will take it to seek credit and reward, and bully you, the newcomer. If it is not well drawn, you will bear the blame for two years. , that's right...

horrible

wangerxian

damiaa posted on 2023-6-21 08:45 Good things take time

Did you change the color of the word "多磨" on purpose? . .

wangerxian

A board with more than ten layers? I have never come across one before.

qwqwqw2088

"Then I looked at the wiring that was originally a pile of shit, and I thought, since it's already a pile of shit, and they are unwilling to add layers or increase the area, I might as well go all out and just connect it directly."

What on earth is this "pile of shit"? I'm curious.

仙猫

If there are only slow signals on the board, it would be fine if the wiring is successful. However, if the design is really based on the requirements of DDR chip specifications, you need to look at a lot of restrictive information before laying out the board, and remember to follow them one by one when wiring, such as the bus distance, which lines need to be of equal length, where the terminal resistors should be placed, what the distance/ratio is, and so on and so forth. It's so annoying!

BTW, even if you are annoyed to death, the actual speed of the board may not reach 100% of the DDR chip specification. Good luck.

qwqwqw2088

This kind of multi-layer board, 6 DDR, 2 BGA chips add up to thousands of pins.

There should be a lot of external ports. These port devices and shells should be well matched and cannot be moved at will.

The difference in DDR local estimation, various grounds, and various timing signals are really annoying

It is really time-consuming to completely manually assemble the wires. It will probably take several days if the wires are not assembleable at all.

freebsder

It is enough to mention the risks and solutions, but you must send an email to make it clear that “they don’t want to”. . .

Nubility

freebsder posted on 2023-6-21 10:20 It’s enough to mention the risks and solutions. You must send an email to make it clear that “they don’t want to”. . .

The rules they set were particularly unreasonable. After the board was drawn, I checked and found more than 300 DRC errors. I asked if the rules could be optimized. The spacing rules were too large and would definitely not be met when the BGA was wired out. Then they said, "You just need to know. You can ignore it."

laker2008

The industry that LZ chose this time is quite impressive. Boards with more than ten layers are rare. I have worked for many years and have never come across boards with so many layers.

freebsder

Nubility posted on 2023-6-21 10:29 The rules are particularly unreasonable. After the board was drawn, I checked more than 300 DRC errors. I asked if the rules could be optimized. The spacing rules are too large. ...

Hahahaha, anyway, be careful of others passing the buck…

15874096935

Big Brother NB

Nubility

freebsder posted on 2023-6-21 15:23 Hahaha, anyway, be careful of others dumping the blame...

I said I had basically finished drawing the board, and he asked me to send it back to him.

Nubility

laker2008 Published on 2023-6-21 15:08 The industry that LZ chose this time is quite impressive. Boards with more than ten layers are rare. I have worked for many years and have never come across boards with so many layers.

The board is full of wiring and holes, it's very crowded

freebsder

Nubility posted on 2023-6-21 21:36 I said I had basically finished drawing the board, and he asked me to send the board back to him

Be more careful. People may say things in a nice way when they speak, but there are many times when they turn against you.