PCB design The problem of wiring line width on the pad, can it be different?

[jamesbulini]

As you can see, the thickness of the power line, blue line and red line on the circular pad is different. Is this feasible? The line to the left of the right square pad and the line above it are also different in thickness. Is this OK? I heard that this situation will reflect under high frequency signals? So what is the frequency of this high-frequency signal that can not be ignored? Is there 200kHz?

 

[ronsimpson]

I can not open your file.

 

[ronsimpson]

high-frequency signal that can not be ignored? Is there 200kHz?

I don't worry about reflection at 200khz. Maybe 200mhz. It is about wave length. I would not worry about reflections if your trace length is less than 1/10 wave length.

 

[jamesbulini]

Thanks for your hlep.Here is the file

 

[ronsimpson]

Looks good.

 

[eTech]

Hi

The track widths are not consistent but it will work. Although the track widths should be consistent. However, I would avoid connecting more than two tracks to a pad and avoid the sharp angles...

eT

 

[ronsimpson]

Although the track widths should be consistent.

In the old days, mechanical machines drew the traces and changing line widths was a process. Now days all that happens inside a computer and probably takes zero time.

I would avoid connecting more than two tracks to a pad

If you are hand soldering, it takes more heat to solder to a pad that has many traces connected. When hand soldering you can see if you applies the right amount of heat. I now use a oven to heat the entire board. My tests could not tell the difference between one small trace verses 4 large traces (using the oven).

and avoid the sharp angles

At first I thought there was a sharp angle. After some time I decided there is no sharp angles.

 

[eTech]

In the old days, mechanical machines drew the traces and changing line widths was a process. Now days all that happens inside a computer and probably takes zero time.

Back in the day...We didn’t have a machine...we hand taped the tracks to clear film at 4x the actual size...

Now it’s trivial with today’s PCB programs.

If you are hand soldering, it takes more heat to solder to a pad that has many traces connected. When hand soldering you can see if you applies the right amount of heat. I now use a oven to heat the entire board. My tests could not tell the difference between one small trace verses 4 large traces (using the oven).

Agreed.
The traces can act as a heat sink.. however..it has more to do with resistance thru the feed thru hole.

At first I thought there was a sharp angle. After some time I decided there is no sharp angles.

The trace on the left should be mitered away from the pad. While electrically it won’t hurt, the sharp angle could cause a solder bridge between the tracks.

 

[ronsimpson]

The trace on the left should be mitered away from the pad. While electrically it won’t hurt, the sharp angle could cause a solder bridge between the tracks.

The trace on the left is red and the pad is blue. They are on different sides of the board.

We didn’t have a machine

I remember coming home with black take all over my shoes. Later we moved up to red and blue tape.
Remember: "looks good, now move this area up a little." Thank the gods for computers.

 

[ronsimpson]

Many people don't know what we say "tape a PCB".
Start with clear film and flexible tape.

Boards look like this:

Making changes was a *****.

 

[eTech]

The trace on the left is red and the pad is blue. They are on different sides of the board.

oops...your right..

I remember coming home with black take all over my shoes. Later we moved up to red and blue tape.
Remember: "looks good, now move this area up a little." Thank the gods for computers.