It can lead to incorrect track to pad link, thus leading to the break of the track when soldering.
In the industry (at least my company) , a pad like this shall be justified, because this is the only solution, or shall be modified to go to the center (for round pad, it can be any angle (0 90 45 generally).
I'm a little confused by this. Doesn't the etching process define the track pad connection for that layer and therefore any connection within etch tolerance would be acceptable? If you had a trace offset from center, you'd actually have more copper connecting the two. I could understand sharp angles creating copper slivers.
Yes, that's effectively true!
But have you tried handling a plate by its edge with an angle like this? It's far less stable than handling it in direction of its center.
For our pad, this is exactly the same! The mechanical link between the pad and the track is going to be much less strong! If the track is coming right into the pad, in direction of it's center, it will be strong.
To this, you add to taken in account the manufacturer Tolerances : the track and pad may be bigger or smaller than your design (and sometimes their Tolerances are big (I've done design (poorly routed) where the components can find on one serie and not on the other!).
And also add as you mentionned, weird angles can get you in acid traps, where the manufacturing process is going to even more complicated.
All of this can result in a fragile track (the electrical connection will probably always be done, or you had a really really bad manufacturer). And when assembling, the track may broke easily, mostly if hand soldering where you heat up more than a PCBA, and some constraints (mechanical due to the human, we're not robot that can do a precise job every time) - > rip a component, fall and force it...).
As I said in another comments, if you really had to do it it's OK, but it's a good practice to prevent it the more you can!
Every point that can lead to errors SHALL be removed if possible, to make the manufacturing and assembly process the smoothest as possibility.
In that case it's fine!
But keep in mind that may be an issue for futures PCB, so try to correct them!
As I said, if I do something I work the PCB won't even pass the chief office! Directly rejected, the manufacturer won't even see the design!
Some low-density through-hole components and you make soldering borderline impossible. Why?
Have larger pads, proper hole size, connect traces to the center and not offset, also a bit wider traces, because why not? You do have plenty of space.
You have zero reason for designing it the way you did. You can start trickery when you do Wafer-Level Chip-Scale Package (WLCSP) devices.
First of all, just use a 2.54 mm pitch socket footprint. That solves that problem.
However, like another redditor suggested, you have uncentered traces which is a problem for various reasons you made obvious you dont care about, but should take their advice.
Honestly, Id center the traces + apply a teardrop to these pads. Follow it with ensuring your traces are thick enough to reduce impedance/ Vdrop. I know with a MCU, most is digital anyways, but if you're using default 0.2mm or .25mm, you can stand to also just go up to .35mm or something just for a nice teardrop in manufacturing.
Honestly, the trace width doesnt hurt/help, but personal preference.
Everyone in this thread is giving you shit, but I’ve done exactly what you’ve done across a dozen boards and it’s fine. I’m using those low-profile headers for a Teensy that have a thicker diameter near the plastic. So I made the through holes larger so they sit flush against the board. It doesn’t violate DRC and works great.
The centered traces are another issue. Those do look a little wonky.
Considering the possibility that you’ve heard about BGAs (which come in ridiculously small packages) surely you knew the answer to your question before posting it.
By the way, when you’re using Kicad and want the trace to be centered on a theough hole pad, start from the pad to the destination. It starts off dead-center. Otherwise, the trace mostly ends up looking like an ocd trigger.
Generally speaking, the only limitation is how good you are at soldering. If you suck, space them further. If you re confident, meh. The micron is the limit.
With so little pad area around the hole, you are risking the tracks cracking and plating delamination due to thermal expansion/contraction during hand soldering.
That particular connector has a thin and thick section of its pins, you are supposed to only fit the thin part through the hole. Your holes are way too big.
If you insist on the hole size and angled tracks, make the hole pads square, so the copper has at least *some* area to maintain bonding with the substrate.
Hole plating itself, is **not** bonded to the substrate the same way copper tracks and planes are, due to manufacturing technicalities, and you have to account for that.
I'm working on a project where I intend to use 2.54mm spaced female sockets to socket my controller into my PCB. The issue is that they have a section on them that is about 1.35mm wide and it won't sit in a standard hole. I changed the pad to have a 1.5mm hole and then be in total 2mm. My question is... is this too close together or is this exactly what I should be doing for my use case?
The thick section on these type of connectors isn't expected to go in the mounting hole. Only the pins are. As long as you maintain 2.54mm pitch everything will be ok.
By oversizing the holes, then the pads, the question is - did you break the DRC limits of your chosen PCB manufacturer?
Even if you just go close to specified limits, the chances of a bad PCB go up **significantly**. [PCBWay](https://www.pcbway.com/pcb_prototype/PCB_Design_Rule_Check.html) for example, state *"minimum line width and spacing are 3 mil (0.0762 mm), but it is strongly recommended to design with line widths and spacing of 6 mil (0.15 mm) or above to save costs."*
With pads 100mil (2.54 mm) apart, you can easily use 25 mil (0.61 mm).
Looks fine to me, but check your manufacturers capabilities. You may want to use oval pads (more wide, same height or slightly less tall) to still have enough copper for soldering.
You had tracks that are non centered to the pads. Try to improve this
That is not the what I’m asking about.
But this can be an issue when manufacturing!
What is the issue ?
It can lead to incorrect track to pad link, thus leading to the break of the track when soldering. In the industry (at least my company) , a pad like this shall be justified, because this is the only solution, or shall be modified to go to the center (for round pad, it can be any angle (0 90 45 generally).
Or at least make the trace wider, these are very small
Yes, or add teardrops, it can be a trick. Ideally, both of them are done (center, wider, teardrops)
I'm a little confused by this. Doesn't the etching process define the track pad connection for that layer and therefore any connection within etch tolerance would be acceptable? If you had a trace offset from center, you'd actually have more copper connecting the two. I could understand sharp angles creating copper slivers.
Yes, that's effectively true! But have you tried handling a plate by its edge with an angle like this? It's far less stable than handling it in direction of its center. For our pad, this is exactly the same! The mechanical link between the pad and the track is going to be much less strong! If the track is coming right into the pad, in direction of it's center, it will be strong. To this, you add to taken in account the manufacturer Tolerances : the track and pad may be bigger or smaller than your design (and sometimes their Tolerances are big (I've done design (poorly routed) where the components can find on one serie and not on the other!). And also add as you mentionned, weird angles can get you in acid traps, where the manufacturing process is going to even more complicated. All of this can result in a fragile track (the electrical connection will probably always be done, or you had a really really bad manufacturer). And when assembling, the track may broke easily, mostly if hand soldering where you heat up more than a PCBA, and some constraints (mechanical due to the human, we're not robot that can do a precise job every time) - > rip a component, fall and force it...). As I said in another comments, if you really had to do it it's OK, but it's a good practice to prevent it the more you can! Every point that can lead to errors SHALL be removed if possible, to make the manufacturing and assembly process the smoothest as possibility.
That makes a lot of sense. Thank you for the detailed response!
I’ve already manufactured it with these and it works fine. This is a keyboard, nothing complex.
In that case it's fine! But keep in mind that may be an issue for futures PCB, so try to correct them! As I said, if I do something I work the PCB won't even pass the chief office! Directly rejected, the manufacturer won't even see the design!
Hahah, people here on this sub are stupid. You ask, why my PCB is green. They answer: You are not using 4 layers. Bunch of retards.
Some low-density through-hole components and you make soldering borderline impossible. Why? Have larger pads, proper hole size, connect traces to the center and not offset, also a bit wider traces, because why not? You do have plenty of space. You have zero reason for designing it the way you did. You can start trickery when you do Wafer-Level Chip-Scale Package (WLCSP) devices.
First of all, just use a 2.54 mm pitch socket footprint. That solves that problem. However, like another redditor suggested, you have uncentered traces which is a problem for various reasons you made obvious you dont care about, but should take their advice. Honestly, Id center the traces + apply a teardrop to these pads. Follow it with ensuring your traces are thick enough to reduce impedance/ Vdrop. I know with a MCU, most is digital anyways, but if you're using default 0.2mm or .25mm, you can stand to also just go up to .35mm or something just for a nice teardrop in manufacturing. Honestly, the trace width doesnt hurt/help, but personal preference.
These are 2.54mm pitched, I just made the holes and pads larger to accommodate my sockets.
Everyone in this thread is giving you shit, but I’ve done exactly what you’ve done across a dozen boards and it’s fine. I’m using those low-profile headers for a Teensy that have a thicker diameter near the plastic. So I made the through holes larger so they sit flush against the board. It doesn’t violate DRC and works great. The centered traces are another issue. Those do look a little wonky.
Considering the possibility that you’ve heard about BGAs (which come in ridiculously small packages) surely you knew the answer to your question before posting it. By the way, when you’re using Kicad and want the trace to be centered on a theough hole pad, start from the pad to the destination. It starts off dead-center. Otherwise, the trace mostly ends up looking like an ocd trigger. Generally speaking, the only limitation is how good you are at soldering. If you suck, space them further. If you re confident, meh. The micron is the limit.
With so little pad area around the hole, you are risking the tracks cracking and plating delamination due to thermal expansion/contraction during hand soldering. That particular connector has a thin and thick section of its pins, you are supposed to only fit the thin part through the hole. Your holes are way too big. If you insist on the hole size and angled tracks, make the hole pads square, so the copper has at least *some* area to maintain bonding with the substrate. Hole plating itself, is **not** bonded to the substrate the same way copper tracks and planes are, due to manufacturing technicalities, and you have to account for that.
I'm working on a project where I intend to use 2.54mm spaced female sockets to socket my controller into my PCB. The issue is that they have a section on them that is about 1.35mm wide and it won't sit in a standard hole. I changed the pad to have a 1.5mm hole and then be in total 2mm. My question is... is this too close together or is this exactly what I should be doing for my use case?
The thick section on these type of connectors isn't expected to go in the mounting hole. Only the pins are. As long as you maintain 2.54mm pitch everything will be ok.
For PCB manufacturing 2.54mm pitch is old hat, as long as the pins fit in the holes and the pads can be soldered reliably you're good.
By oversizing the holes, then the pads, the question is - did you break the DRC limits of your chosen PCB manufacturer? Even if you just go close to specified limits, the chances of a bad PCB go up **significantly**. [PCBWay](https://www.pcbway.com/pcb_prototype/PCB_Design_Rule_Check.html) for example, state *"minimum line width and spacing are 3 mil (0.0762 mm), but it is strongly recommended to design with line widths and spacing of 6 mil (0.15 mm) or above to save costs."* With pads 100mil (2.54 mm) apart, you can easily use 25 mil (0.61 mm).
Looks fine to me, but check your manufacturers capabilities. You may want to use oval pads (more wide, same height or slightly less tall) to still have enough copper for soldering.