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Re: Any significance to the shape of the solder pads on a PCB?
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William Sommerwerck
Aug 21, 2013, 7:02:05 PM8/21/13
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"Nelson" wrote in message
news:0001HW.CE3A82C6...@news.astraweb.com...
> I am trying to create a schematic from a PCB and I notice each
> component has one square solder pad hole and one circular one.
> Is there any significance to that?
Perhaps it indicates the polarity of diodes, LEDs, etc.
news:0001HW.CE3A82C6...@news.astraweb.com...
> I am trying to create a schematic from a PCB and I notice each
> component has one square solder pad hole and one circular one.
> Is there any significance to that?
Perhaps it indicates the polarity of diodes, LEDs, etc.
Paul Drahn
Aug 21, 2013, 7:54:13 PM8/21/13
to
Paul
David Platt
Aug 21, 2013, 7:26:01 PM8/21/13
to
>> I am trying to create a schematic from a PCB and I notice each
>> component has one square solder pad hole and one circular one.
>> Is there any significance to that?
>
>Perhaps it indicates the polarity of diodes, LEDs, etc.
Commonly a "pin 1" designation, entered as part of the "footprint"
>> component has one square solder pad hole and one circular one.
>> Is there any significance to that?
>
>Perhaps it indicates the polarity of diodes, LEDs, etc.
artwork for the part in whatever PCB-design package was used to do
the layout. You'll almost always see these used on IC footprint
patterns (the through-hole ones at least). I imagine that in
commercial PCB design packages, it's usually a convention to
identify Pin 1 in any footprint where it's practical, since these
footprints may be used both for polarized and non-polarized
components.
Message has been deleted
Paul Drahn
Aug 21, 2013, 11:04:02 PM8/21/13
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On 8/21/2013 2:27 PM, Nelson wrote:
> On Wed, 21 Aug 2013 15:54:13 -0400, Paul Drahn wrote
> (in article<kv35t8$98n$1...@dont-email.me>):
> But all the resistors are that way too :-) The board appears to have a
> plane sandwiched between the top and bottom. I'm guessing it is either
> a ground plane or a V+ plane. I thought maybe one or the other
> indicated a plated through hole that connected to the mid plane.
>
I thought you were referring to the silk screen art work. Are you saying
you took all the components off the board and sucked the solder out of
the holes so you can now see that some holes were drilled and some were
punched with a square punch?
A properly soldered board will not show any hole if they are
plated-through holes.
Paul
> On Wed, 21 Aug 2013 15:54:13 -0400, Paul Drahn wrote
> (in article<kv35t8$98n$1...@dont-email.me>):
> plane sandwiched between the top and bottom. I'm guessing it is either
> a ground plane or a V+ plane. I thought maybe one or the other
> indicated a plated through hole that connected to the mid plane.
>
I thought you were referring to the silk screen art work. Are you saying
you took all the components off the board and sucked the solder out of
the holes so you can now see that some holes were drilled and some were
punched with a square punch?
A properly soldered board will not show any hole if they are
plated-through holes.
Paul
stra...@yahoo.com
Aug 21, 2013, 11:15:23 PM8/21/13
to
Back when I worked with Tango (jurassic era) the pins had a name to match up with the pads in PCB. For non-polar components like resistors the pads were A and B. All the through hole footprints had 1 square terminal. The schematic component had the same name for the pins to match up with the pad name. Failing name matching would cause a net list error and you want NO net errors if you expect it to work.
G²
William Sommerwerck
Aug 21, 2013, 11:51:18 PM8/21/13
to
"Paul Drahn" wrote in message news:kv3h16$bab$1...@dont-email.me...
> I thought you were referring to the silk screen art work. Are you
> saying you took all the components off the board and sucked the
> solder out of the holes so you can now see that some holes were
> drilled and some were punched with a square punch?
He's referring to the shape of the metal pad, not the hole.
> I thought you were referring to the silk screen art work. Are you
> saying you took all the components off the board and sucked the
> solder out of the holes so you can now see that some holes were
> drilled and some were punched with a square punch?
Message has been deleted
John Robertson
Aug 22, 2013, 4:55:54 AM8/22/13
to
On 08/21/2013 5:46 PM, Nelson wrote:
> On Wed, 21 Aug 2013 17:27:10 -0400, Nelson wrote
> (in article <0001HW.CE3AA8EE...@news.astraweb.com>):
> photo:
>
> http://www.deejr.net/pbp/2013/08/21/PowerBoardFront.jpg
>
Those square holes are for the ground plane end of the resistor (and
other similar parts). This is so the solder will wet properly and thus
connect the leg of the device to the feedthrough hole. The feedthrough
hole is separated from the copper plane mass except for four corners
otherwise the copper plane will sink too much of the heat. More
important on boards that are hand soldered instead of wave-soldered...
John :-#)#
--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
> On Wed, 21 Aug 2013 17:27:10 -0400, Nelson wrote
> (in article <0001HW.CE3AA8EE...@news.astraweb.com>):
>
>> On Wed, 21 Aug 2013 15:54:13 -0400, Paul Drahn wrote
>> (in article <kv35t8$98n$1...@dont-email.me>):
>>
>> On Wed, 21 Aug 2013 15:54:13 -0400, Paul Drahn wrote
>> (in article <kv35t8$98n$1...@dont-email.me>):
>>
>> But all the resistors are that way too :-) The board appears to have a
>> plane sandwiched between the top and bottom. I'm guessing it is either
>> a ground plane or a V+ plane. I thought maybe one or the other
>> indicated a plated through hole that connected to the mid plane.
>>
>>
>
> Well, maybe not all the resistors, but quite a few of them. Here's a
>> plane sandwiched between the top and bottom. I'm guessing it is either
>> a ground plane or a V+ plane. I thought maybe one or the other
>> indicated a plated through hole that connected to the mid plane.
>>
>>
>
> photo:
>
> http://www.deejr.net/pbp/2013/08/21/PowerBoardFront.jpg
>
Those square holes are for the ground plane end of the resistor (and
other similar parts). This is so the solder will wet properly and thus
connect the leg of the device to the feedthrough hole. The feedthrough
hole is separated from the copper plane mass except for four corners
otherwise the copper plane will sink too much of the heat. More
important on boards that are hand soldered instead of wave-soldered...
John :-#)#
--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
Message has been deleted
John Robertson
Aug 22, 2013, 10:46:18 PM8/22/13
to
On 08/22/2013 4:48 AM, Nelson wrote:
> On Thu, 22 Aug 2013 00:55:54 -0400, John Robertson wrote
> (in article <JdOdnc5gOJ9HBIjP...@giganews.com>):
> Thanks! I'm having a hard time visualizing this, however. I have
> researched "thermal relief" which is what I think you are referring to
> but I can't find any discussion of square pads contacting only at the
> corners. In particular, in this case, the ground plane or "copper
> flow" appears to be an interior layer. I can't visualize how the
> through holes connect to this or pass through without connecting.
>
> Here is an image of the back of the board showing the embedded ground
> plane:
>
> http://www.deejr.net/pbp/2013/08/22/PowerBoardBack.jpg
>
> As you can see there are quite a few square pads which don't appear to
> connect to the ground plane.
>
>
It may then be an artifact of the PCB CAD software - the first pin of a
series (2 is a series in this case) is always square. I like the thermal
relief term (thanks!) and for some parts it is probably still valid.
> On Thu, 22 Aug 2013 00:55:54 -0400, John Robertson wrote
> (in article <JdOdnc5gOJ9HBIjP...@giganews.com>):
> researched "thermal relief" which is what I think you are referring to
> but I can't find any discussion of square pads contacting only at the
> corners. In particular, in this case, the ground plane or "copper
> flow" appears to be an interior layer. I can't visualize how the
> through holes connect to this or pass through without connecting.
>
> Here is an image of the back of the board showing the embedded ground
> plane:
>
> http://www.deejr.net/pbp/2013/08/22/PowerBoardBack.jpg
>
> As you can see there are quite a few square pads which don't appear to
> connect to the ground plane.
>
>
It may then be an artifact of the PCB CAD software - the first pin of a
series (2 is a series in this case) is always square. I like the thermal
relief term (thanks!) and for some parts it is probably still valid.
ss.c...@gmail.com
Sep 23, 2017, 1:16:52 PM9/23/17
to
SIL patterns invariably have one end with a square solder pad. This just helps you recognize which end is which when you turn your board over. I don't think it has a functional significance.
Foxs Mercantile
Sep 23, 2017, 1:24:59 PM9/23/17
to
On 9/23/2017 8:16 AM, ss.c...@gmail.com wrote:
> SIL patterns invariably have one end with a square solder pad.
The square pad is simply identification.
> SIL patterns invariably have one end with a square solder pad.
Pin-1, Cathode, (+) etc.
--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com
tabb...@gmail.com
Sep 23, 2017, 5:43:04 PM9/23/17
to
On Saturday, 23 September 2017 14:16:52 UTC+1, ss.c...@gmail.com wrote:
> SIL patterns invariably have one end with a square solder pad. This just helps you recognize which end is which when you turn your board over. I don't think it has a functional significance.
We never used that convention. They were either all square or all rounded.
> SIL patterns invariably have one end with a square solder pad. This just helps you recognize which end is which when you turn your board over. I don't think it has a functional significance.
NT
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