Author Topic: Through hole packages rectangular or oval pads  (Read 1623 times)

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Offline AlfBazTopic starter

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Through hole packages rectangular or oval pads
« on: July 08, 2018, 02:40:51 am »
I'm going through my libraries with the aim to standardize as much as possible.
I've noticed that I have a mix of rectangular and oval pads on through hole packages and want to stick with one or the other
I do tear drop all tracks onto component pins where possible but if you are connecting onto one side only that leaves the other with 90 degree corners

Pro's and cons anyone?

For example in high speed/frequency do the sharp corners radiate more into neighboring pins/tracks.
In the pcb etching phase are we more susceptible to acid traps?

Any thoughts?
 

Offline Dubbie

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Re: Through hole packages rectangular or oval pads
« Reply #1 on: July 08, 2018, 05:03:49 am »
Wouldn’t you be better served in high frequency stuff by making the switch to surface mount? It’s really not hard!
 

Offline tautech

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Re: Through hole packages rectangular or oval pads
« Reply #2 on: July 08, 2018, 05:53:57 am »
I'm going through my libraries with the aim to standardize as much as possible.
I've noticed that I have a mix of rectangular and oval pads on through hole packages and want to stick with one or the other
I do tear drop all tracks onto component pins where possible but if you are connecting onto one side only that leaves the other with 90 degree corners

Pro's and cons anyone?

For example in high speed/frequency do the sharp corners radiate more into neighboring pins/tracks.
In the pcb etching phase are we more susceptible to acid traps?

Any thoughts?
Keep some things uniform, like IC pin 1 always rectangular so when viewed from the underside there's no mistake !
Headers, similar.... positive and negative......always different ! Always indicate pin 1 with a different pad.
Polarised caps......just the same ^^^
Diode cathode.......always a different pad to anode !

Some general advice but with the above applied.
Passives = round.
IC's = oval.
Signal headers = oval
Power headers = square

You develop your own style based on your needs but give a thought to someone else picking up you work and trying to follow it.
While most of us rely on an overlay it's not on the underside of a TH PCB so anything that makes faultfinding/circuit tracing/reverse engineering easier is a win win.

When I do a home etched PCB and hence no overlay many symbols are added into the copper, a few: +, Gnd, . (a dot for pin 1), K and so on. Even I/O names are easily etched.
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Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Offline AlfBazTopic starter

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Re: Through hole packages rectangular or oval pads
« Reply #3 on: July 08, 2018, 11:07:14 am »
Thanks for the tips Tautech much appreciated :-+

@Dubbie... I don't always get to choose the parts. Available stock, price per unit, design certification, customer surplus stock, there are a plethora of reasons to use through hole

I just wanted to know if there were any electrical or manufacturability issues that may favor one over the other

 
 


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