Post History
When using through-hole ("THR") connectors on a multi-layer PCB, I frequently notice problems with the ground pins, when these are connected to the ground plane(s) through various "thermal relief" ...
#4: Post edited
by
Nick Alexeev
·
2021-08-24T18:05:00Z (over 2 years ago)
#3: Post edited
by
Nick Alexeev
·
2021-08-24T18:04:39Z (over 2 years ago)
- When using through-hole ("THR") connectors on a multi-layer PCB, I frequently notice problems with the ground pins, when these are connected to the ground plane(s) through various "thermal relief" layouts. When this happens, the reflow soldering job becomes mediocre and hand soldering is nearly impossible.
- Example of a bad one I had problems with the other day when hand soldering:
- 
Red=ground plane. It didn't even need to handle this much current, the trace is 1.28mm [0.050inch]wide. This one was impossible to solder well even when we pre-heated the whole PCB.- Whenever I inspect the layouts in the CAD system, they never seem to follow a standard, but various designers seem to make these up as they go, on a case-to-case basis. Cross shapes, star shapes, varied amounts of traces on the stars...
- My question: are there any canonical reference designs for how to do thermal relief proper? Or at least some proven in use?
- And how do you calculate the maximum current, I'm assuming one just adds the width of all traces?
- When using through-hole ("THR") connectors on a multi-layer PCB, I frequently notice problems with the ground pins, when these are connected to the ground plane(s) through various "thermal relief" layouts. When this happens, the reflow soldering job becomes mediocre and hand soldering is nearly impossible.
- Example of a bad one I had problems with the other day when hand soldering:
- 
- Red=ground plane. It didn't even need to handle this much current, the trace is 1.28mm [0.050inch] wide. This one was impossible to solder well even when we pre-heated the whole PCB.
- Whenever I inspect the layouts in the CAD system, they never seem to follow a standard, but various designers seem to make these up as they go, on a case-to-case basis. Cross shapes, star shapes, varied amounts of traces on the stars...
- My question: are there any canonical reference designs for how to do thermal relief proper? Or at least some proven in use?
- And how do you calculate the maximum current, I'm assuming one just adds the width of all traces?
#2: Post edited
by
Nick Alexeev
·
2021-08-24T18:02:54Z (over 2 years ago)
- When using through-hole ("THR") connectors on a multi-layer PCB, I frequently notice problems with the ground pins, when these are connected to the ground plane(s) through various "thermal relief" layouts. When this happens, the reflow soldering job becomes mediocre and hand soldering is nearly impossible.
- Example of a bad one I had problems with the other day when hand soldering:
- 
Red=ground plane. It didn't even need to handle this much current, the trace is 1.28mm wide. This one was impossible to solder well even when we pre-heated the whole PCB.- Whenever I inspect the layouts in the CAD system, they never seem to follow a standard, but various designers seem to make these up as they go, on a case-to-case basis. Cross shapes, star shapes, varied amounts of traces on the stars...
- My question: are there any canonical reference designs for how to do thermal relief proper? Or at least some proven in use?
- And how do you calculate the maximum current, I'm assuming one just adds the width of all traces?
- When using through-hole ("THR") connectors on a multi-layer PCB, I frequently notice problems with the ground pins, when these are connected to the ground plane(s) through various "thermal relief" layouts. When this happens, the reflow soldering job becomes mediocre and hand soldering is nearly impossible.
- Example of a bad one I had problems with the other day when hand soldering:
- 
- Red=ground plane. It didn't even need to handle this much current, the trace is 1.28mm [0.050inch]wide. This one was impossible to solder well even when we pre-heated the whole PCB.
- Whenever I inspect the layouts in the CAD system, they never seem to follow a standard, but various designers seem to make these up as they go, on a case-to-case basis. Cross shapes, star shapes, varied amounts of traces on the stars...
- My question: are there any canonical reference designs for how to do thermal relief proper? Or at least some proven in use?
- And how do you calculate the maximum current, I'm assuming one just adds the width of all traces?
#1: Initial revision
by
Lundin
·
2021-08-24T06:47:59Z (over 2 years ago)
Thermal relief for through-hole on multi-layer PCB
When using through-hole ("THR") connectors on a multi-layer PCB, I frequently notice problems with the ground pins, when these are connected to the ground plane(s) through various "thermal relief" layouts. When this happens, the reflow soldering job becomes mediocre and hand soldering is nearly impossible.
Example of a bad one I had problems with the other day when hand soldering:
Red=ground plane. It didn't even need to handle this much current, the trace is 1.28mm wide. This one was impossible to solder well even when we pre-heated the whole PCB.
Whenever I inspect the layouts in the CAD system, they never seem to follow a standard, but various designers seem to make these up as they go, on a case-to-case basis. Cross shapes, star shapes, varied amounts of traces on the stars...
My question: are there any canonical reference designs for how to do thermal relief proper? Or at least some proven in use?
And how do you calculate the maximum current, I'm assuming one just adds the width of all traces?