Vias versus holes - a few short questions

[abaci]

hi there -

i’m still slowly learning kicad, so i apologize for what must be a redundant post.

i’d like to have some plated holes - similar to a standard prototyping board - in my design. 1mm holes with 2.54mm spacing - or whatever that standard is…

are these “mounting holes” or “vias”? i don’t know if there is a symbol for a “via” in the Schematic Editor.

is there a way to quickly add an array of them?

also, there doesn’t seem to be a preexisting footprint for this in the library, which seems strange since this would be an extremely ubiquitous design choice… is there one?

thank you!

[retiredfeline]

Sounds like you want PTH pads.

[abaci]

maybe so! can you tell me more about using them?

[retiredfeline]

They are found in footprints for connectors and such. I don’t know how to create one on the fly on the board. I think there are plugins to create vectors and arrays of them, but I haven’t used those. Except for the footprint wizard which can create DIP or SIP footprints.

[Piotr]

@abaci

if there is a symbol for a “via” in the Schematic Editor.

For wires at schematic you don’t show of how many track segments they are then made at PCB.
Via is like track segment but going in Z direction. There is no need to show at schematic how many times the wire when routed at PCB will switch layer.

[DelugeIA]

Hello,

I’m also still fairly new, so I welcome anyone to correct me here…

First, you typically won’t need vias, pads, or holes in the Schematic Editor. You can route connections directly over one another (or use net labels). If two lines cross, there will either be a dot indicating that they are connected networks, or no dot if they different nets. The Schematic Editor should be used to connect your components in a logical fashion, and not worry about the physical layout.

When it comes to physical layout, there are a few different types of “holes” that you can place on a PCB. The most commonly used ones are:

Plated Through-Hole (PTH) - These are your typical holes on a board where you connect components that have wires or pin connectors. They go “through” the board, have a copper “platting” inside of them, and an exposed pad where you can solder items. The thing that most new people don’t realize is that you have to create these in the Footprint Editor for the component. You (typically) do not create them in the PCB Editor.

Non-Plated Through-Hole (NPTH) - Also called a “Mechanical” hole, are like PTH except they do not have any copper platting or a pad. They are typically used for mounting your board where you do not want an electrical connection between the board and the case. These are also created in the footprint editor, though there are many pre-defined NPTH footprints in the “MountingHole” library.

Vias - These are effectively tiny plated through-holes that aren’t intended for soldering. Their typical use is for routing tracks, when tracks must cross each other. These are created in the PCB Editor. In short (pun intended), you draw part of the track on the front of the PCB, end it with a via, and continue the track on the back of the PCB.

In regard to creating an array, in any editor, you can right-click on an object and select “Create from Selection” > “Create Array…” (or more easily Ctrl+T). A dialog box will appear where you can create either a grid or circular array. Note that the counts include the starting object, so if you want a vertical column of 5 pads spaced 2.54 mm apart, you enter a horizontal count of 1, a vertical count of 5, a horizonal spacing of whatever (doesn’t matter since there’s just one), and a vertical spacing of 2.54mm.

For beginners (like myself), I also highly recommend following along with some of the many tutorials on YouTube, just search for “KiCad Tutorial”. There aren’t very many ones for version 7, but I found some of the old ones to still be helpful for getting started.

I am particularly fond of these:

• An Intro to KiCad
• KiCad 5 Tutorial
• KiCad (by Pcb Cupid)

Almost forgot to mention Contextual Electronics! Chris’ YouTube channel is a notable community leader (founder?). There a whole bunch of great getting started playlists.

I hope this helps a little!

– Jeff

[Piotr]

I write only because:

@DelugeIA

I welcome anyone to correct me here…

So

@DelugeIA

First, you typically won’t need vias, pads, or holes in the Schematic Editor.

I use symbols for holes (PTH and NPTH) at schematic. You can add holes during PCB design, but then when you update PCB from schematic your holes will disappear (unless you lock them). Because of this I just prefer to have at schematic symbols for all footprints at PCB (including holes).

@DelugeIA

Vias - These are effectively tiny plated through-holes that aren’t intended for soldering.

Not exactly. PTHs are not covered by solder mask and vias typically are.

@DelugeIA

you draw part of the track on the front of the PCB, end it with a via,

Not ‘end it’. You just ‘jump’ to another layer using V hotkey and continue routing (during that jump via is placed). But I have never done it as at my PCBs all signal tracks are at top - I don’t use bottom for signal tracks. So I have only GND vias and I place them by selecting ‘via’ from right hand tools. Such way of designing PCB is good from EMC point of view (each signal has return path just under it).
It looks like this:

Approaching PCB track routing for a newbie

Positioning for me is the main work in designing PCB. If each element is where it is needed than routing is simple. Till now all my PCBs are 2 layers and all of them have GND plane taking 100% of bottom layer. So except GND I design my PCBs as 1 layer. I use microcontrollers in QFP packages without thermal pad at bottom. This allows me to go with VCC under the microcontroller and go out through all corners and all VCC pins. That way GND and VCC don’t disturb my signal connections. At all digi…

@DelugeIA

Note that the counts include the starting object, so if you want a vertical column of 5 pads spaced 2.54 mm apart, you enter a horizontal count of 1, a vertical count of 5, a horizonal spacing of whatever (doesn’t matter since there’s just one), and a vertical spacing of 2.54mm.

Sounds for me as having sense when designing footprint, but KiCad library has so many footprints that I have never designed any from scratch but just copying and editing one of KiCads footprints.
When designing PCB I think making an array of selection is not very useful - I have never used it. Adding footprints by hand (making array have the same effect) you loose compatibility with schematic.

@DelugeIA

For beginners (like myself), I also highly recommend following along with some of the many tutorials

I prefer to read KiCad documentation at:

Documentation | KiCad

[BlackCoffee]

Example of VIA’s and PTH(BTM pad shows through PCB transparency, if you look closely. That PAD, can also be removed to just have a Plated Hole).

Via’s regardless of size will have an Top and Btm Pad, thus, I set Via ‘diam’ to less than the Via size.

Second image shows three vias and their Pads and the Via’s ‘Diam’ relationship

[abaci]

Thank you, @BlackCoffee, @DelugeIA, and @Piotr. This clarifies things tremendously for me.

Just to double-check before I go down the rabbit hole of Footprint Design… the standard 1mm PTH with BTM 2mm pad, etc… this doesn’t exist in the library already?

[BlackCoffee]

The smallest in the Library is 2mm but, you can edit/change it and save as your own
Footprint. Will need to hide/delete the Pads if not wanted… Or, edit it’s diameter/shape (all available in the tool panel)

Can also make a new Footprint (recommended for the experience of doing it)

[DelugeIA]

Piotr,

I’m sincere when I invite people to comment, correct, or share their option, so thank you!!!

@Piotr

I use symbols for holes (PTH and NPTH) at schematic. You can add holes during PCB design, but then when you update PCB from schematic your holes will disappear (unless you lock them).

That’s true, however instead of locking them I prefer to mark them as “Not in Schematic”. I find including them, especially for mount holes, clutters my schematic. I do include them if they’re for pin headers or some other logical connector. Locking them just makes it more difficult to move, adjust, or add as needed.

@Piotr

But I have never done it as at my PCBs all signal tracks are at top - I don’t use bottom for signal tracks.

I try to do the same but do occasionally need to use vias. For most projects, having a ground plane is good practice. The only exception for avoiding a ground plane, that I encounter, is when dealing with radio/WiFi signals.

@Piotr

When designing PCB I think making an array of selection is not very useful - I have never used it.

I would not use KiCad if it didn’t have an array function. Lol. But it is certainly project dependent. Most of my projects are working with addressable LEDs (WS2812B, aka “NeoPixel”). I use the create array function all the time, both in the schematic and pcb editors. I even use it for creating arrays of traces, vias, cuts, etc.

I also highly recommend the “Place Footprints” plugin for repetitive designs; it can be found in the Plugin and Content Manager. The only thing I don’t like is that the current version crashes if you try to do large arrays in mils.

@Piotr

I prefer to read KiCad documentation at:

Yup, the documentation is great, especially for those who are already familiar with PCB design. The “Getting Started in KiCad” is pretty good for beginners. But some people, like myself, learn better from more hand-held, guided tutorials.

@BlackCoffee

Can also make a new Footprint (recommended for the experience of doing it)

Absolutely! Taking the time learning to make your own symbols and footprints is crazy valuable in learning KiCad.

Thanks!

– Jeff

[Piotr]

@DelugeIA

I prefer to mark them as “Not in Schematic”.

I don’t investigate all new possibilities. My standrds were set when KiCad was 4.0.7. I suppose (but I’m not sure) there were not possible to mark something as “Not in Schematic”.
I will have to change how I do it.

@DelugeIA

for avoiding a ground plane, that I encounter, is when dealing with radio/WiFi signals.

I found that for RFID reader (even I have ferrite between antenna and PCB) gnd fill disturbs reading. It was not a problem when reading only Mifare card ID but it dramatically reduced the read distance for crypted cards (Desfire).

@DelugeIA

I also highly recommend the “Place Footprints” plugin

I didn’t reached the level of using any plugin. I just don’t know how to do it. I am working at PC disconnected from net so I suppose Plugin Manager can have some problems if plugins are not just in KiCad package (I don’t know where from they came and even where is Plugin Manager). Even I installed V6 and then V7 I didn’t looked around in new possibilities (so I am still at V5 level).

[abaci]

Alright - thanks to the help here, I am attempting to make a footprint now.
I am a little confused about how to make a plated through-hole with a pad on the bottom.

With “Pad Type” set to through-hole, none of the options for “Copper Layers” looks right. With “Pad Type” set to NPTH, Mechanical - there is an option for B. Cu only - but then the through-hole is no longer plated.

Any suggestions?

[retiredfeline]

I think you already have both F.Cu and B.Cu pads from the stack-up diagram at the top right. You can confirm it by using the 3D viewer and switching sides.

[abaci]

But if I don’t want to have the F. Cu layer, is that possible? I just un-click it in Technical Layers?

[retiredfeline]

No, I don’t think you can have PTH and one Cu layer only, at least not from the footprint editor. I’ve seen people asking for this, or alternately a SMD pad with a hole, and the experts in this forum have posted but I don’t understand (or need) any of that.

Why don’t you want both Cu layers for a PTH pad?

[abaci]

I’m mainly just trying to emulate standard prototyping PCB board for part of my circuit, of the attached variety.
I suppose I can have a F. Cu layer and it won’t cause any trouble. It is interesting that it’s not possible, though.

[retiredfeline]

These days 2 layer is the standard offering and no more expensive than 1 layer. So you might as well make a 2 layer prototype board. 2 pads and PTH will also be less likely to have the pad delaminate when heated.

[Piotr]

@abaci

With “Pad Type” set to through-hole, none of the options for “Copper Layers” looks right. With “Pad Type” set to NPTH, Mechanical - there is an option for B. Cu only - but then the through-hole is no longer plated.

I have never heard of plated holes having cu only at one side. I think plating grows from both sides and meets in the center of the PCB. Both sides must be connected during this process. I think that during plating also copper at both sides grows form 0.018mm to 0.035mm typically.

@abaci

I’m mainly just trying to emulate standard prototyping PCB board

Holes at your photo are not plated and I understood that you want them plated but with pad only at one side. I don’t know if it is possible (not in KiCad but in technology).

[abaci]

Isn’t the example that @BlackCoffee shows made in KiCad, though?