Modifying a mount hole

Beginner question.


The manufacturer says the “half hole” isn’t supported. How should I modify it?

My guess is I need to update the size X or hole size?

If you make it a CNC cutout, rather then a combination of slot and hole, your should be alright.
By cutout is meant an Edge.Cuts’ layer shape inside your board.

Do you have a datasheet for a component? Or other exact data which would help? Is the “half-hole” plated? If yes, and the manufacturer meant plated half-hole, then you have to change the manufacturer or find another solution.

I’m guessing this is a combination of a slot and a drilled hole. That is a bit difficult to manufacture.

Remove the drilled hole, but remember the location of the center. Mark it on the ECO1USER layer.

Select the EDGE CUTS layer.
At the center of the hole, ADD GRAPHIC ARC.
Do this placing an arc or the upper side and another separate arc on the lower side. If you haven’t done
this (arc) before, practice placing the center and then the radius and angle.
Be SURE to connect the ends of the slot lines to the ends of the arc.

This results in a pattern that is entirely milled rather than a combination of drill hole and milled slot.
Please post a reply if this works ok.

1 Like

Does he need a plated hole? A board vendor may not be able to plate a milled feature, and I doubt that ANY fabricator can plate the hole-portion of the milled feature, but not plate the slot. If a plated hole is required, this looks a lot like a “castellated edge”. If that’s the case, search the Forum for “castellated” or “castellation”.


Not identical, but…

1 Like

Yes, it comes down to the fact that some non-automated, person-to-person communication between designer and fabricator will be necessary. And, likely as not, a good picture may be worth 10^3 words.


P.S. - Out of curiosity . . . On the subject of good pictures . . . Are there any engineers here, under the age of 50, who were required to take a technical drawing class as part of their engineering education?

Can I change the drilled hole to a non plated hole at the footprint level, instead of the edge cuts layer?

In ‘Pad Properties | Pad type:’ select NPTH.
Set the shapes and masks to your needs.
That’s it.

I can see the hole is in the NPTH.drl file. Is it still edge plated or not?

To check your “hole’s” settings select it, and either press E, or right click ‘Properties…’.
The 3D view can show you what the ‘hole’ actually will be like. e.g. copper, mask etc.
After that you might want to double check in gerber view!

For a NPTH you also need to have the pad size equal to the hole size. (Some manufacturers use the fact of overlapping copper with the hole to determine if something is pth or npth so to be sure avoid having a copper ring like your screenshot shows)

You need to think about the PCB manufacturing process.

It may begin with holes being drilled in a blank, then plating which gives you a plated through hole.
Then the top and bottom are etched.
Finally they route the HUGE panel into individual boards.

At the time the routing is done, there is no opportunity get plate the resulting edges.

Q: what part of the hole and slot NEED to be plated?
If the answer is none, them do all the hole and slot on the Edge_Cuts layer. Remember you can place a large number of VIAs near the hole/slot to connect top-bottom.
If some part of it NEEDS to be plated, that is more difficult.

I do not really understand why you think the edge cuts layer is the only way here.

To be honest it all kind of depends on the software used by the manufacturer. If they can understand the slot command used by kicad then i see no real problem with the construction shown in the screenshot. It might look strange to them and merit asking for clarification but this should work in manufacturing. (This is my guess why they even asked. It is an unusual construction and could be the result of a mistake.)

Only assumption to be made is that the slot is done after all drilling is finished as you would have an increased risk of drills breaking when you drill into an existing slot. (But even if it is the other way round it should still work if the tooling used can handle it.)

It would even work if only the not slotted part is to be plated. Might however need extra communication as the speeds and feeds or tooling might be different for the slot to reduce the risk of damaging the copper plating.

I got my engineering degree a few years ago, and there was one class where we learned some Unigraphics, along with structure analysis in IDEAS.

Of course I was a bit older than the other students and had a few years of drafting in highscool and another drafting class at art school. Not CAD, drafting with pencils and vellum and powder to keep the graphite from smearing.

Hmm… the weird thing is, when I set the pad size = hole size, the manufacturer still shows the half edge plated ring.

Ignoring my own advice about wandering threads:

Here is the pcb STANDARD process. In particular, see item #12. My prior comment about the drill hole and the outline was in regard to this step. The outline is cut with a high speed rotary bit (think vertical milling machine). When that is going along, you don’t want the bit to go into the void of a hole and then hit the other side. This damages bits. Hence, some vendors charge more $ for this feature (castellated holes).

i graduated in 2013, had 2 class of technical drawing, first only by hand, second by hand and 2d CAD. I met 3d CAD in other disciplines that had projects involved, like heat exchanger design and pump design…

You folks are dis-proving my hypothesis. In my undergraduate course (1969 - '73) all the engineers had a year of technical drawing and communication. Most of it was traditional drafting (drawing board, t-square, compass, triangles, etc), and how to solve visualization problems using projections, rotations, etc. But we spent a significant amount of time talking about the broader scope of technical communication - the kinds of drawings, reports and other documents encountered by engineers; the information typically found in various documents; composition styles; presenting information in charts, graphs, tables, and sketches; the necessity and nature of document control systems; the roles of standards and standardizing organizations; etc.

Early in the first term my instructor emphasized that we would be making, using, or interpreting drawings as long as we worked in technical roles. I thought it was a rather arrogant claim. Perhaps true for a civil or mechanical engineer, but a very minor part of electrical or computer engineering. In the intervening decades I have come to recognize the truth and wisdom of his statement.

In the mid 1980’s I started to encounter both recent graduates and journeyman-level engineers who never had formal instruction in those topics, had difficulty understanding an assembly drawing, and struggled to sketch a legible schematic or mechanical detail. The posts from @Saulo and @Starbird are encouraging to me. They suggest that perhaps this trend has reversed.


1 Like