Author Topic: Best way to connect pads with the same signal  (Read 3301 times)

0 Members and 1 Guest are viewing this topic.

Offline Twistx77Topic starter

  • Regular Contributor
  • *
  • Posts: 147
  • Country: 00
Best way to connect pads with the same signal
« on: February 18, 2013, 04:59:12 pm »
Hi,

I'm working in a new PCB and I wanted some advice in which is the best way to connect pads that have the same signal i.e. Ground or power signal in power IC's.

Here are three examples. Which of this is the best way to do it? Is there a better one?

Thank you.



 

Offline Kremmen

  • Super Contributor
  • ***
  • Posts: 1289
  • Country: fi
Re: Best way to connect pads with the same signal
« Reply #1 on: February 19, 2013, 07:42:21 am »
The chip pretty much dictates the way you have to connect. For solderability, you should make the connections cleanly; in that sense the bottom left is a bit messy as pads and traces get mixed.
Electrically, supply should be low impedance i.e. wide tracks, use planes, and above all put bypass caps right next to the supply entry pads. The cap should be already visible in the screengrab you attached.
The cross connections between adjacent pads probably don't do very much unless the pads draw significantly different currents. On the other hand they won't hurt much either.
Nothing sings like a kilovolt.
Dr W. Bishop
 

Offline Twistx77Topic starter

  • Regular Contributor
  • *
  • Posts: 147
  • Country: 00
Re: Best way to connect pads with the same signal
« Reply #2 on: February 20, 2013, 06:18:36 pm »
Hi,

Thanks for your tips. The bypass caps are not visible because I moved them away to clearly show my point. So by your comment I guess the one in the middle would be the best solution.
That's what I expected since the one in the left I only use it when I need to draw substantial current and I will solder by hand.

Thank you!
 

Offline David_AVD

  • Super Contributor
  • ***
  • Posts: 2879
  • Country: au
Re: Best way to connect pads with the same signal
« Reply #3 on: February 20, 2013, 08:26:44 pm »
I've moved away from connecting adjacent pads straight across as it makes it harder to visually inspect for shorts after manual soldering.
 

Offline Psi

  • Super Contributor
  • ***
  • Posts: 10452
  • Country: nz
Re: Best way to connect pads with the same signal
« Reply #4 on: February 20, 2013, 08:59:33 pm »
I've moved away from connecting adjacent pads straight across as it makes it harder to visually inspect for shorts after manual soldering.

+1 for this.
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline andersendr

  • Regular Contributor
  • *
  • Posts: 56
  • Country: us
Re: Best way to connect pads with the same signal
« Reply #5 on: February 20, 2013, 09:05:04 pm »
I agree with David_AVD.  I usually will make them look like your middle example so when you are hand soldering, you can see what is happening better. 
 

Offline Twistx77Topic starter

  • Regular Contributor
  • *
  • Posts: 147
  • Country: 00
Re: Best way to connect pads with the same signal
« Reply #6 on: February 20, 2013, 09:29:48 pm »
Thanks but usually that doesn't bother me since usually I solder right after I finish the design so I usually recognize the power leads of the IC's that are for power stuff.

Anyway good advice :) Thanks!
 

Offline Kremmen

  • Super Contributor
  • ***
  • Posts: 1289
  • Country: fi
Re: Best way to connect pads with the same signal
« Reply #7 on: February 21, 2013, 04:12:08 pm »
I've moved away from connecting adjacent pads straight across as it makes it harder to visually inspect for shorts after manual soldering.
A very good point. Didn't come to think of this because i don't usually connect adjacent pads.
Nothing sings like a kilovolt.
Dr W. Bishop
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf