Pink colors on some SMD parts: what does it mean?

It’s me again. In KiCad 6, on the footprints for some SMD parts, there is a colored area that I don’t know what is. On LEDs, it’s around the cathode end, on caps, it along the sides at the midpart, on transistors, it’s on the sides, and on some of the IC’s, it’s at the ends of some of the pins. In my color scheme (the default) it’s a pinkish color. I know it means something, but I don’t know what. Thanks (again.)

It is the courtyard. The area required by the component for placement on the PCB
The line completely surrounds the part but may be hidden, in places, by another layer.

Check the “layers” in the “Appearance manager” on the right hand side of the screen.
Front Silk layer will be covering some of the Front Courtyard. If you turn off F.Silk you will see F. Courtyard surrounding the part.

I’d call the colour “hot pink” or fluro. pink. The other boss of the house has trained me to see more than a 16 colour pallet, but I’m still working on beige. :slightly_frowning_face:

You can select the object in question and look at the details at the bottom of the screen to see what layer it’s in.

It’s not clear to me what you are referring to exactly.
Can you post a screenshot to clarify what you see?

If it’s part of a footprint, you can also select the footprint, and then press [Ctrl + e] to load it in the footprint editor. This removes a lot of clutter and makes it easier to examine what it is.


The pink part on the RHS of this diode footprint is what I interpreted the OP to be discussing.

@retiredfeline the details at the bottom of the screen don’t mention “pink” :wink:

The goal is to discover what the object is, not to criticize his choice of nail polish colour. :rofl:

Sorry to be slow to answer. I was distracted. Here is a snip of the project I am working on. The caps, transistor, LEDs, and a couple of the IC pins have the pink trim. It’s not hot pink…maybe more of a flesh color. Does it mean anything?

That is what I’d call pink. The other thing is purple to me.

It is the Bottom.Silkscreen layer. Just click on the layer to toggle it and get more certainty.

Yep, you are correct; it is the bottom silk screen. But why is it not just an outline of the part? And why does only appear on a few of the pins of the LQFN48?
KiCad LQFN48 trimmed in pink

Ahhh, the back of the board.

@tracecom that is B.Silk.
You can test out which layer it is by clicking on the “eye” in the “layers” column on the RHS of the screen.

Looks more like pale brownish-pinkish to me. I’ve never been introduced to a name for a colour like that.

The author ran out of nail polish? :rofl:

Sorry, just couldn’t resist. my bad. :frowning_face:

@jmk Funny! Maybe it doesn’t mean anything. I guess maybe whoever created the footprints just wanted them to be different. I thought maybe it was indicative of something important, especially when I saw it on a few of the IC pads. I suppose I just think too much.

The (historically) “Silkscreen” (also called “Legend” in other programs) is intended as a guide for manufacturing and repair. PCB’s are often quite tightly stacked with parts, and often it’s a struggle to find decent places to put the Reference Designators on the Silkscreen layer. So there simply is not much room for more elaborate graphics.

The little squares on the silkscreen are near pins 10, 20, 30 and 40, and are intended to make it easier to count pins during repairs. However, I do not like these, because there are no tight tolerances for the silkscreen layer, and it can be misprinted so much that it indicates the wrong pin and become misleading. On top of that, there is no clear indication of pin 1 on that Footprint, and that is much more important. IC’s quite often are placed rotated during automated assembly mistakes, and for engineers and repairing, it’s not difficult to calculate what the pin numbers are in the corners of an LQFN48.

Where did you get that footprint, It’s not native to KiCad. It also has rectangular pads, while KiCad’s footprints have rounded corners, and this is better for the solder paste layer (which is derived from the copper pad dimensions).

Honestly don’t know.
Silkscreen is a printed layer on the PCB to identify components and their placement, so I suppose if too much printing is on the board it would hard to identify everything…just a guess though.

I am not sure, but it may have come from EasyEDA, but it might have been somewhere else. I drew my own in DipTrace, but I don’t know if KiCad can import it. The part is a CM108B, and the manufacturer doesn’t supply a symbol or a footprint. I just looked at it, and I can take those pink parts off. Thanks to everyone who posted. I have to go to bed now.

The footprint also does not look like a QFN. (Quad flat Non-Leaded) QFN packages have no leads and the pads must extend to under the IC.

The CM108B is a LQFP (Quad Flat Pack) and these do have pins, so your footprint looks like it could fit, but the naming is wrong. (I’m not sure what the L stands for in those abbreviations).

KiCad also has quite nice wizards scripts for custom footprints. Have you ever tried them?
Footprint Editor / File / Create Footprint / QFP and then fill in the data for number of pins, pitch, size etc.

apart from the pin markings the silkscreen actually looks quite standard for a SMD package nowadays. you usually don’t do an complete outline on silkscreen as it interferes with the pads which then can lead to problems in population (at least it will smell quite ugly). but this is also not a problem, as the minimal silk normally offers enough clues how to place the component for population.

On the pin markings: I think the autor of the footprint wanted to mark every 10th pin as an indication.

Okay, I guess the mystery is solved. And yes, the IC is an LQFP, and I don’t know what the L stands for either. As you might have noticed, I had planned to share some Gnd connections that would cross the ink around the cathodes of the LEDs, so I will change that. Thanks to all who replied.

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.